Microfluidic sample preparation for respiratory virus detection: A review

Techniques used to prepare clinical samples have been perfected for use in diagnostic testing in a variety of clinical situations, e.g., to extract, concentrate, and purify respiratory virus particles. These techniques offer a high level of purity and concentration of target samples but require significant equipment and highly trained personnel to conduct, which is difficult to achieve in resource-limited environments where rapid testing and diagnostics are crucial for proper handling of respiratory viruses. Microfluidics has popularly been utilized toward rapid virus detection in resource-limited environments, where most devices focused on detection rather than sample preparation. Initial microfluidic prototypes have been hindered by their reliance on several off-chip preprocessing steps and external laboratory equipment. Recently, sample preparation methods have also been incorporated into microfluidics to conduct the virus detection in an all-in-one, automated manner. Extraction, concentration, and purification of viruses have been demonstrated in smaller volumes of samples and reagents, with no need for specialized training or complex machinery. Recent devices show the ability to function independently and efficiently to provide rapid, automated sample preparation as well as the detection of viral samples with high efficiency. In this review, methods of microfluidic sample preparation for the isolation and purification of viral samples are discussed, limitations of current systems are summarized, and potential advances are identified.     

Learning to Value Mathematics and Reading: Relations to Mastery and Performance-Oriented Instructional Practices

Changes in students' achievement values in mathematics and reading were examined in a sample of children and early adolescents. Hierarchical linear modeling techniques were used to account for both classroom- and student-level effects. At the student level, positive changes in students' achievement values were associated positively with self-concept of ability and the previous year's achievement values in both reading and math. Measures of teachers' mastery- and performance-oriented instructional practices were included in the full HLM model. Students experienced decrements in achievement values, after controlling for other student and classroom-level variables, in classrooms where performance-oriented instructional practices were used. In the full model, self-concept of ability was related positively to increases in achievement values, whereas gender was unrelated to changes in achievement values. Copyright 2001 Academic Press.     

Communication apprehension in a first language and self‐perceived competence as predictors of communication apprehension in a second language: A study of speakers of English as a second language

This study addresses the communication apprehension of the non‐native English speaker in the U.S. Previous studies which have examined the implications of communication apprehension (CA) for bilingual, non‐native communicators have generated results which indicate that trait‐like CA is consistent across first and second language‐speaking situations. However, none of these studies have probed the cause of the cross‐linguistic consistency of CA. This research is designed to provide a scientific explanation for the etiology of CA by applying the communibiological paradigm to CA theory and research. By selecting the situational constraints of international students, this study tests a theory based on proposition 4 of the communibiological paradigm (Beatty & McCroskey w/Valencic, 2001, p. 128): “Environment or ‘situation’ has only a negligible effect on interpersonal behavior.” The results of this study replicate the strong relationship previously observed between CA in a first language and CA in a second language. It also found that the genetic markers employed (Eysenck's Big 3 temperament variables) predicted first and second language CA approximately equally. The results indicate that, although both first and second languages are learned, the CA associated with them most likely is not.     

Korean Students' Perceptions of Scientific Practices and Understanding of Nature of Science

Korean students have shown relatively little interest and confidence in learning science, despite being ranked in the top percentile in international evaluations of academic achievement in science such as the Trends in International Mathematics and Science Study. Although research indicates a positive relationship between student perceptions of science and their science learning, this area has not been sufficiently explored in Korea. Particularly, even though both students' perceptions of scientific practice and their understanding of the nature of science (NOS) are influenced by their science learning experiences at schools, little research examines how this perception, understanding, and experience are related to one another. This study aimed to uncover Korean students' perceptions of school scientific practice through exploring their drawings, writings, and responses to questionnaires. Participants were 500 Korean students in 3rd, 7th, and 10th grades who were asked to complete an open-ended questionnaire. The results indicated that Korean students typically viewed school scientific practices as experimental activities or listening to lecture; and that most participants held an insufficient understanding of the NOS. Overall, no significant relationship emerged between students' perceptions of school scientific practice and their understanding of the NOS. Our findings highlight the need to help both teachers and students understand the potential breadth of school scientific practices, beyond simple ‘activity mania.’ This study also suggests that teachers must balance implicit and explicit instructional approaches to teaching about the NOS through scientific practices in school science contexts.     

The Intellectual Demands of the Intended Primary Science Curriculum in Korea and Singapore: An analysis based on revised Bloom's taxonomy

While there has been a remarkable worldwide convergence in the emphases of primary science curricula over the last four decades, the cognitive and knowledge demands that they make on learners have not been well-researched. Without knowing what these intellectual or epistemic requirements are when learning science in school, issues concerning curricular alignment and access to abstract disciplinary knowledge are also likely to occur. To highlight the value of such forms of analyses, we examine the intended primary science curricula from Korea and Singapore using revised Bloom's taxonomy, as well as describe some of their general features for teaching. The results contribute insights into the complexities of the science curriculum among two similar yet different educational systems that have performed well in international science achievement tests at primary levels.     

‘Teaching What I Learned’: Exploring students’ Earth and Space Science learning experiences in secondary school with a particular focus on their comprehension of the concept of ‘geologic time’

According to the national survey of science education, science educators in the USA currently face many challenges such as lack of qualified secondary Earth and Space Science (ESS) teachers. Less qualified teachers may have difficulty teaching ESS because of a lack of conceptual understanding, which leads to diminished confidence in content knowledge. More importantly, teachers’ limited conceptual understanding of the core ideas automatically leads to a lack of pedagogical content knowledge. This mixed methods study aims to explore the ways in which current secondary schooling, especially the small numbers of highly qualified ESS teachers in the USA, might influence students’ learning of the discipline. To gain a better understanding of the current conditions of ESS education in secondary schools, in the first phase, we qualitatively examined a sample middle and high school ESS textbook to explore how the big ideas of ESS, particularly geological time, are represented. In the second phase, we quantitatively analyzed the participating college students’ conceptual understanding of geological time by comparing those who had said they had had secondary school ESS learning experience with those who did not. Additionally, college students’ perceptions on learning and teaching ESS are discussed. Findings from both the qualitative and quantitative phases indicate participating students’ ESS learning experience in their secondary schools seemed to have limited or little influence on their conceptual understandings of the discipline. We believe that these results reflect the current ESS education status, connected with the declining numbers of highly qualified ESS teachers in secondary schools.     

Two scalable algorithms for associative text classification

Associative classification methods have been recently applied to various categorization tasks due to its simplicity and high accuracy. To improve the coverage for test documents and to raise classification accuracy, some associative classifiers generate a huge number of association rules during the mining step. We present two algorithms to increase the computational efficiency of associative classification: one to store rules very efficiently, and the other to increase the speed of rule matching, using all of the generated rules. Empirical results using three large-scale text collections demonstrate that the proposed algorithms increase the feasibility of applying associative classification to large-scale problems.     

Multi-scale approach for the rheological characteristics of emulsions using molecular dynamics and lattice Boltzmann method

An emulsion system was simulated under simple shear rates to analyze its rheological characteristics using a hierarchical multi-scale approach. The molecular dynamics (MD) simulation was used to describe the interface of droplets in an emulsion. The equations derived from the MD simulation relative to interfacial tension, temperature, and surfactant concentration were applied as input parameters within lattice Boltzmann method (LBM) calculations. In the LBM simulation, we calculated the relative viscosity of an emulsion under a simple shear rate along with changes in temperature, shear rate, and surfactant concentration. The equations from the MD simulation showed that the interfacial tension of the droplets tended to decrease with an increase in temperature and surfactant concentration. The relative viscosity from the LBM simulation decreased with an increase in temperature. The shear thinning phenomena explaining the inverse proportion between shear rate and viscosity were observed. An increase in the surfactant concentration caused an increase in the relative viscosity for a decane-in-water emulsion, because the increased deformation caused by the decreased interfacial tension significantly influenced the wall shear stress.