Ripple structure-generated hybrid electrokinetics for on-chip mixing and separating of functionalized beads

We present an electrokinetics-based microfluidic platform that is capable of on-chip manipulating, mixing, and separating microparticles through adjusting the interrelated magnitudes of dielectrophoresis and AC electroosmosis. Hybrid electrokinetic phenomenon is generated from an electric field-induced micro-ripple structure made of ultraviolet-curable glue. Size-dependent particle separation and selective removal over the ripple structure is demonstrated successfully. Varying the waveform from sine-wave to square-wave allows generating a fluid convection at specific positions to mix the antibody-functionalized beads and antigen. Potential application in the bead-based immunoassay was also demonstrated for immuno-reaction and subsequently separating the bead-bead aggregate and non-binding beads on-chip.     

An economic valuation study of public libraries in Korea

The economic value of public libraries for local residents in Korea was measured. An economic-value measurement model that enables the estimation of diverse types of public library services was designed, using a conditional-value measurement method. Benefits were taken as the value of the main services provided by public libraries, such as accessibility to informational materials, facilities, and programs. Costs included the total amount of expenses at libraries such as personnel expenses, materials purchasing expenses, and other operational costs. Data were collected from 1220 users from 22 public libraries in the province of Seoul/Gyeonggi-do and the other seven Korean provinces. The return on investment (ROI) was calculated to be 3.66.     

Discrete-time nonlinear observer design with general criteria

A class of discrete-time nonlinear system and measurement equations having incrementally conic nonlinearities and finite energy disturbances is considered. A linear matrix inequality-based design approach is presented, which guarantees the satisfaction of a variety of performance criteria ranging from simple estimation error boundedness to dissipativity. Some simulation examples are included to illustrate and provide support to the proposed design methodology.     

Droplet based microfluidic fabrication of designer microparticles for encapsulation applications

Developing carriers of active ingredients with pre-determined release kinetics is a main challenge in the field of controlled release. In this work, we fabricate designer microparticles as carriers of active ingredients using droplet microfluidics. We show that monodisperse droplet templates do not necessarily produce monodisperse particles. Magnetic stirring, which is often used to enhance the droplet solidification rate, can promote breakup of the resultant microparticles into fragments; with an increase in the stirring time, microparticles become smaller in average size and more irregular in shape. Thus, the droplet solidification conditions affect the size, size distribution and morphology of the fabricated particles, and these attributes of the microparticles strongly influence their release kinetics. The smaller the average size of the microparticles is, the higher the initial release rate is. The release kinetics of drug carriers is strongly related to their characteristics. The understanding of this relationship enables the fabrication of tailor-designed carriers with a specified release rate, and even programmed release to meet the needs of applications that require a complex release profile of the active ingredients.     

Attributional beliefs of Singapore students: relations to self-construal,competence and achievement goals

This study investigates attributional beliefs of Singapore secondary students in their English study and how they can be predicted by self-construal, competence and achievement goals. A total of 1,496 students were administered surveys on seven attributions, independent and interdependent self-construals, previous achievement, self-efficacy, mastery approach and avoidance goals and performance approach and avoidance goals. We found that Singapore students attributed academic success mainly to internal regulation (effort, interest and study skills), followed by teachers’ help, ability, parents’ help and tuition classes. Hierarchical regression analyses showed that three predictors (self-construal, competence and achievement goals) explained 4.2–12.3% of the variances in students’ attributional beliefs. In particular, students with interdependent self-construal, high competence or mastery goals tended to attribute academic success to internal regulation (effort, interest and study skills) and support from teachers and parents. Students with low competence, high mastery avoidance goals or high performance goals were more likely to value tuition classes, and those with high performance avoidance goals also tended to ascribe academic success to ability and parent’s help. The findings are discussed in relation to the culture of Singapore.     

The intersection between perceived severity and frequency of being bullied: a Rasch measurement approach

School bullying has been investigated by looking at either the frequency of bullying or the perceived severity of being bullied. However, the relationship between these two constructs needs further clarification. The aim of this study was to clarify the connections between the frequency and the perceived severity of being bullied for bullying intervention and prevention, and examine gender differences in these two constructs. The participants consisted of 1423 secondary school students in southern Taiwan. The 21-item School Bullying Scales with Frequency and Severity were administered. Using Rasch analysis, the two subscales of frequency and severity were aligned on the interval logit scale to yield four quadrants. Results showed that the two latent traits derived from the two subscales had a weak correlation (r = ?.11). Some bullying behaviours, including ‘one’s friendship being ruined’, ‘belongings taken without permission’, ‘being hit and kicked’, ‘being spoken ill of in public’, and ‘being ostracised’, were perceived as the most severe and most frequent behaviours. Boys reported to be more frequently bullied than girls were, whereas girls perceived bullying to be more severe than boys did. It was suggested that bullying behaviours perceived as higher severity and frequency deserve greater attention.     

Reciprocal associations between family and peer conflict in adolescents' daily lives

Using a daily diary method, this study assessed daily episodes of family and peer conflict among 578 adolescents in the 9th grade to examine potential bidirectional associations between the family and peer domains. Adolescents completed a daily diary checklist at the end of each day over a 14-day period to report events of conflict and their emotional states for a given day. Overall, the within-person models provided evidence for the bidirectional nature of family peer linkages across gender and ethnicity. Adolescents experienced more peer conflict on days in which they argued with parents or other family members, and vice versa. Effect of family conflict further spilled over into peer relationships the next day and 2 days later, whereas peer conflict predicted only the following day family conflict. Adolescents' emotional distress partially explained these short-term spillovers between family and peer conflict.     

The core components of reading instruction in Chinese

The present study aimed at identifying core components of reading instruction in Chinese within the framework of the tiered intervention model. A curriculum with four teaching components of cognitive-linguistic skills was implemented in a Program school for 3 years since Grade 1. The findings showed that the Tier 1 intervention was effective in enhancing the literacy and cognitive-linguistic skills of children in the Program school. The positive effects were maintained at the end of Grade 2. Progress in both word-level and text-level cognitive-linguistic skills predicted significantly progress in reading comprehension. Based on the present findings, the four core reading components in Chinese were proposed—oral language, morphological awareness, orthographic skills, and syntactic skills. Comparing the Big Five in English and the four core components in Chinese reflects different cognitive demands for reading diverse orthographies.     

Developing and assessing beginning teacher effectiveness: the potential of performance assessments

The Performance Assessment for California Teachers (PACT) is an authentic tool for evaluating prospective teachers by examining their abilities to plan, teach, assess, and reflect on instruction in actual classroom practice. The PACT seeks both to measure and develop teacher effectiveness, and this study of its predictive and consequential validity provides information on how well it achieves these goals. The research finds that teacher candidates’ PACT scores are significant predictors of their later teaching effectiveness as measured by their students’ achievement gains in both English language arts (ELA) and mathematics. Several subscales of the PACT are also influential in predicting later effectiveness: These include planning, assessment, and academic language development in ELA, and assessment and reflection in mathematics. In addition, large majorities of PACT candidates report that they acquired additional knowledge and skills for teaching by virtue of completing the assessment. Candidates’ feelings that they learned from the assessment were the strongest when they also felt well-supported by their program in learning to teach and in completing the assessment process.     

Ethnic Differences in Career,Academic, and Social Self-Appraisals Among Incoming College Freshmen

Ethnic differences in self-appraisals among 2,743 incoming college freshmen were examined in this study. Results showed that (a) Asian and Black students reported lower academic and social self-appraisals than did White students, and (b) Asian students reported lower career and social self-appraisals than did Black students. Practical and research implications are discussed in the article.