Effect of a dual inlet channel on cell loading in microfluidics

Unwanted sedimentation and attachment of a number of cells onto the bottom channel often occur on relatively large-scale inlets of conventional microfluidic channels as a result of gravity and fluid shear. Phenomena such as sedimentation have become recognized problems that can be overcome by performing microfluidic experiments properly, such as by calculating a meaningful output efficiency with respect to real input. Here, we present a dual-inlet design method for reducing cell loss at the inlet of channels by adding a new “ upstream inlet ” to a single main inlet design. The simple addition of an upstream inlet can create a vertically layered sheath flow prior to the main inlet for cell loading. The bottom layer flow plays a critical role in preventing the cells from attaching to the bottom of the channel entrance, resulting in a low possibility of cell sedimentation at the main channel entrance. To provide proof-of-concept validation, we applied our design to a microfabricated flow cytometer system (μFCS) and compared the cell counting efficiency of the proposed μFCS with that of the previous single-inlet μFCS and conventional FCS. We used human white blood cells and fluorescent microspheres to quantitatively evaluate the rate of cell sedimentation in the main inlet and to measure fluorescence sensitivity at the detection zone of the flow cytometer microchip. Generating a sheath flow as the bottom layer was meaningfully used to reduce the depth of field as well as the relative deviation of targets in the z-direction (compared to the x-y flow plane), leading to an increased counting sensitivity of fluorescent detection signals. Counting results using fluorescent microspheres showed both a 40% reduction in the rate of sedimentation and a 2-fold higher sensitivity in comparison with the single-inlet μFCS. The results of CD4⁺ T-cell counting also showed that the proposed design results in a 25% decrease in the rate of cell sedimentation and a 28% increase in sensitivity when compared to the single-inlet μFCS. This method is simple and easy to use in design, yet requires no additional time or cost in fabrication. Furthermore, we expect that this approach could potentially be helpful for calculating exact cell loading and counting efficiency for a small input number of cells, such as primary cells and rare cells, in microfluidic channel applications.     

Reimagining Counselor Education with Diversity as a Core Value

To move diversity from the periphery of counselor preparation to its core requires effort beyond the 1 or 2 “special” courses that have been the mainstay of multicultural counselor education (T. E. Midgette & S. S. Meggert, 1991). The authors describe the processes and outcomes of a systemic reimagining of Auburn University's counselor education doctoral program, as well as community agency and school counseling master's‐degree programs that incorporate diversity as a core value. The development of diversity‐supportive department policies and procedures, curricular and cocurricular changes, and environmental considerations are discussed and evaluated.     

Does Dual Enrollment Influence High School Graduation,College Enrollment,Choice, and Persistence?

Research in Higher Education - This study examines relationships between dual enrollment and high school graduation, college enrollment, college choice (2-year or 4-year), and persistence in...     

Confidence Intervals for Weighted Composite Scores Under the Compound Binomial Error Model

Reporting confidence intervals with test scores helps test users make important decisions about examinees by providing information about the precision of test scores. Although a variety of estimation procedures based on the binomial error model are available for computing intervals for test scores, these procedures assume that items are randomly drawn from a undifferentiated universe of items, and therefore might not be suitable for tests developed according to a table of specifications. To address this issue, four interval estimation procedures that use category subscores for the computation of confidence intervals are presented in this article. All four estimation procedures assume that subscores instead of test scores follow a binomial distribution (i.e., compound binomial error model). The relative performance of the four compound binomial–based interval estimation procedures is compared to each other and to the better known normal approximation and Wilson score procedures based on the binomial error model.     

社会主义市场经济对大学生道德建设的影响及应对

大学生道德与社会经济的发展是紧密联系的。社会主义市场经济使社会主义生产关系更加适应生产力发展的同时，亦深深地影响着高校大学生的道德建设。一方面，它丰富学生道德建设的内容，为大学生道德建设提供了有利的物质条件，给社会主义道德建设带来良好的契机。另一方面，它不可避免的滋生繁衍了社会主义道德建格格不入的道德观念和行为，极大地冲击了大学生的道德观念，给大学生道德建设带来了复杂性的艰巨性。因此，高校要重点围绕社会主义道德教育、加大法制宣传教育、营造有利学生形成高尚道德的校园环境等方面加强大学生道德建设。     

Lord's Wald Test for Detecting DIF in Multidimensional IRT Models: A Comparison of Two Estimation Approaches

Lord's Wald test for differential item functioning (DIF) has not been studied extensively in the context of the multidimensional item response theory (MIRT) framework. In this article, Lord's Wald test was implemented using two estimation approaches, marginal maximum likelihood estimation and Bayesian Markov chain Monte Carlo estimation, to detect uniform and nonuniform DIF under MIRT models. The Type I error and power rates for Lord's Wald test were investigated under various simulation conditions, including different DIF types and magnitudes, different means and correlations of two ability parameters, and different sample sizes. Furthermore, English usage data were analyzed to illustrate the use of Lord's Wald test with the two estimation approaches.     

The effect of issue obtrusiveness,issue congruence,and response strategies on the acceptance of crisis communication messages

Based on issue ownership theory, this study identifies the effects of issue obtrusiveness, issue congruence, and crisis response strategies on the level of acceptance of crisis communication messages employing 2 × 2 × 3 (issue obtrusiveness × issue congruence × response strategies: scapegoat, justification, reminder) experimental research. Two large Korean business groups (Hyundai and SK) were selected. There was a main effect in crisis response strategies and a three-way interaction effect. A crisis communication message was effective when a corporation owns congruent and unobtrusive issues. Implications for public relations research and practices were discussed.     

Toward a Science of Learning Games

Reinforcement learning involves a tight coupling of reward‐associated behavior and a type of learning that is very different from that promoted by education. However, the emerging understanding of its underlying processes may help derive principles for effective learning games that have, until now, been elusive. This article first reviews findings from cognitive neuroscience and psychology to provide insight into the motivating role of uncertain reward in games, including educational games. Then, a short experiment is reported to illustrate the potential of reward‐based neurocomputational models of behavior in the understanding and development of effective learning games. In this study, a reward‐based model of behavior is shown to predict recall of newly learned information during a simple learning game.