Electroosmotic flow hysteresis for dissimilar ionic solutions

Electroosmotic flow (EOF) with two or more fluids is commonly encountered in various microfluidics applications. However, no investigation has hitherto been conducted to investigate the hysteretic or flow direction-dependent behavior during the displacement flow of solutions with dissimilar ionic species. In this investigation, electroosmotic displacement flow involving dissimilar ionic solutions was studied experimentally through a current monitoring method and numerically through finite element simulations. The flow hysteresis can be characterized by the turning and displacement times; turning time refers to the abrupt gradient change of current-time curve while displacement time is the time for one solution to completely displace the other solution. Both experimental and simulation results illustrate that the turning and displacement times for a particular solution pair can be directional-dependent, indicating that the flow conditions in the microchannel are not the same in the two different flow directions. The mechanics of EOF hysteresis was elucidated through the theoretical model which includes the ionic mobility of each species, a major governing parameter. Two distinct mechanics have been identified as the causes for the EOF hysteresis involving dissimilar ionic solutions: the widening/sharpening effect of interfacial region between the two solutions and the difference in ion concentration distributions (and thus average zeta potentials) in different flow directions. The outcome of this investigation contributes to the fundamental understanding of flow behavior in microfluidic systems involving solution pair with dissimilar ionic species.     

Hybrid capillary-inserted microfluidic device for sheathless particle focusing and separation in viscoelastic flow

A novel microfluidic device which consists of two stages for particle focusing and separation using a viscoelastic fluid has been developed. A circular capillary tube was used for three-dimensional particle pre-alignment before the separation process, which was inserted in a polydimethylsiloxane microchannel. Particles with diameters of 5 and 10 μm were focused at the centerline in the capillary tube, and the location of particles was initialized at the first bifurcation. Then, 5 and 10 μm particles were successfully separated in the expansion region based on size-dependent lateral migration, with ∼99% separation efficiency. The proposed device was further applied to separation of MCF-7 cells from leukocytes. Based on the cell size distribution, an approximate size cutoff for separation was determined to be 16 μm. At 200 μl/min, 94% of MCF-7 cells were separated with the purity of ∼97%. According to the trypan blue exclusion assay, high viability (∼90%) could be achieved for the separated MCF-7 cells. The use of a commercially available capillary tube enables the device to be highly versatile in dealing with particles in a wide size range by using capillary tubes with different inner diameters.     

Behavioral Intention to Adopt Digital Library by the Undergraduates

The purpose of this research is to investigate the factors that affect undergraduates' behavioral intention to use digital library among the private universities in Malaysia. The target respondents are undergraduates from Malaysian private universities. Questionnaires were distributed among 500 undergraduates through either online or face-to-face method. Reliability test, normality test, Pearson Correlation Coefficient analysis, and Multiple Linear Regression (MLR) were carried out for data analysis. Performance expectancy, social influence, facilitating conditions, hedonic motivation, habit, and information quality had a positive and significant association with behavioral intention to adopt a digital library except for effort expectancy. This research successfully reinforced that the inspiration to ameliorate Unified Theory of Acceptance and Use of Technology 2 (UTAUT 2) by synthesis of Information Systems Success Model (ISSM). This proposed framework with a combination of ISSM and UTAUT 2 has enhanced the fitness of UTAUT 2. Universities that have yet to implement digital library can comprehend undergraduates' needs better by considering all the significant factors to develop a digital library. The universities with the digital library may also notice the important features of the existing digital library that should be maintained and upgraded constantly so that they can fulfil undergraduates' requirements.     

Assessing the Efficacy of Contextualized Group Counseling Education in Asia: A Mixed Methods Study

International Journal for the Advancement of Counselling - Many experiential learning teaching models are developed in Western cultures, with their efficacy not tested in non-Western cultures,...     

Impact of combining data from multiple instruments on performance of patient-based real-time quality control

IntroductionIt is unclear what is the best strategy for applying patient-based real-time quality control (PBRTQC) algorithm in the presence of multiple instruments. This simulation study compared the error detection capability of applying PBRTQC algorithms for instruments individually and in combination using serum sodium as an example.Materials and methodsFour sets of random serum sodium measurements were generated with differing means and standard deviations to represent four simulated instruments. Moving median with winsorization was selected as the PBRTQC algorithm. The PBRTQC parameters (block size and control limits) were optimized and applied to the four simulated laboratory data sets individually and in combination.ResultsWhen the PBRTQC algorithm were individually optimized and applied to the data of the individual simulated instruments, it was able to detect bias several folds faster than when they were combined. Similarly, the individually applied algorithms had perfect error detection rates across different magnitudes of bias, whereas the error detection rates of the algorithm applied on the combined data missed smaller biases. The performance of the individually applied PBRTQC algorithm performed more consistently among the simulated instruments compared to when the data were combined.DiscussionWhile combining data from different instruments can increase the data stream and hence, increase the speed of error detection, it may widen the control limits and compromising the probability of error detection. The presence of multiple instruments in the data stream may dilute the effect of the error when it only affects a selected instrument.     

Cultural values and attitudes toward immigrants and multiculturalism: The case of the Eurobarometer survey on racism and xenophobia

The current paper uses archival data to examine variations in Schwartz's and Hofstede's cultural value orientations and their relationship to attitudes toward immigration and multiculturalism reported in the Eurobarometer Survey [Attitudes towards minority groups in the European Union: a special analysis of the Eurobarometer 2000 opinion poll on behalf of the European Monitoring Centre on Racism and Xenophobia. Eurobarometer Opinion Poll. Retrieved September 1, 2003, from http://europa.eu.int/comm/public_opinion/index_en.htm] on racism and xenophobia. The results demonstrated that mastery, masculinity, power distance, uncertainty avoidance, and collectivism were associated with weaker support for policies that promote social co-existence. Masculinity and mastery were also linked to more pessimistic attitudes towards multiculturalism, and increased harmony was correlated with less desire for cultural assimilation. The results largely converge with research undertaken at the individual-level of analysis, and the data suggest four clusters of cultural values related to immigration attitudes: humanitarianism-egalitarianism, conservation, collectivism, and instrumentality.     

Transformative Professional Learning Within Schools: Relationship to Teachers’ Beliefs, Expertise and Teaching

Although scholarship and research have demonstrated the positive impact of professional learning on academic teaching and learning, an inadequate amount of research has examined how professional learning is associated with transformative teaching for equity, diversity and social justice. This survey study explored the relationship between professional learning and teachers’ beliefs about diversity, transformative expertise, and transformative teaching by comparing two models of professional learning in 25 small urban elementary schools. Results indicated that factors in both the process and transformative content models predicted differences in teachers’ reported beliefs, expertise, or teaching. While some factors such as learning to teach for social justice consistently predicted increased transformative practices, other factors failed to predict or were associated with decreased transformative practices. After discussing the findings, implications for practice, theory and research are offered.     

How do congressional members appear on the web? Tracking the web visibility of South Korean politicians

The web visibility of politicians has substantial implications for the internet and politics. In this regard, the present paper examines the web visibility of South Korea's 18th National Assembly members. This study identifies those members with the highest web visibility and determines the factors affecting their web visibility by using a set of socio-demographic variables indicating web visibility. The concept of web visibility is operationally defined as the number of web mentions of each congressional member. Web mentions of the name of each congressional member were collected across many platforms, including blogs, images, news, and websites, by using a Naver search tool based on the API, and relationships between the web visibility of the members and their socio-demographic attributes (their gender, age, term, constituency, and party affiliation) were analyzed using Kruskal–Wallis, Median, and Mann–Whitney U tests. The most visible politicians in the Korean webosphere had highly qualified political careers and prominence, and the difference in politicians' web visibility depended on their political attributes (their term, constituency, and party), not on their demographic attributes (their gender and age). These findings suggest that politicians who build political power and influence through their political career in the offline world are likely to be more visible in the webosphere. Further, an integrated indicator based on politicians' web visibility status can reflect their “ubiquitous presence” in Korea's digitalized society.