Molecularly imprinted polymers as the extracted sorbents of clenbuterol ahead of liquid chromatographic determination

A pre-treatment methodology for clenbuterol hydrochloride (CLEN) isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers (MIPs). CLEN-imprinted polymers were synthesized by the combined use of ally-β-cyclodextrin (ally-β-CD) and methacrylic acid (MAA), allyl-β-CD and acrylonitrile (AN), and allyl-β-CD and methyl methacrylate (MMA) as the binary functional monomers. MAA-linked allyl-β-CD MIPs (M-MAA) were characterized by Fourier transform-infrared (FT-IR) spectroscopy and a scanning electron microscope (SEM). Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references: AN-linked allyl-β-CD MIPs (M-AN) and MMA-linked allyl-β-CD MIPs (M-MMA). M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction (MISPE) micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation (RSD) ≤4.45%.     

Do digital natives differ by computer self-efficacy and experience? An empirical study

This study serves to validate a Chinese translation of the Digital Native Assessment Scale (C-DNAS) and assess if significant differences exist between a sample of students and teachers from a culture different than the one used in the development of the DNAS. Participants were 402 university students from one province in Mainland China. Results of the confirmatory factor analysis revealed that the C-DNAS possessed a stable factorial structure and was a valid measure among Chinese-speaking participants in Mainland China. Tests of measurement invariance revealed score equivalence among the students for each of the four factors of the C-DNAS: grew up with technology; comfortable with multitasking; reliant on graphics for communication; and thrive on instant gratifications and rewards, by computer self-efficacy and experience. Finally, tests of latent mean differences revealed significant differences in each of the four factors by computer experience but not by computer self-efficacy. Implications for research are discussed.     

Elementary Teachers’ Perception of Language Issues in Science Classrooms

Although the importance of language in science learning has been widely recognized by researchers, there is limited research on how science teachers perceive the roles that language plays in science classrooms. As part of an intervention design project that aimed to enhance teachers’ capacity to address the language demands of science, interview data (N = 9) were collected to understand teachers’ perceptions and experiences with a wide range of issues related to language use in science classrooms. Adopting an interpretive approach to qualitative data, the analysis revealed that the teachers perceive a wide range of student difficulties related to language use in science classrooms, especially to the use of specialized terms and writing. Although the teachers are keenly aware of how language can be a barrier to learning science, they are less certain as to what students need to know about the language of science in order to master it. The findings suggested professional support that highlights the distinctive language demands of science and how these demands differ from other subject areas could be useful to these elementary school teachers.     

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.     

Minimax optimal control of linear system with input-dependent uncertainty

In this paper, the quadratic minimax optimal control of linear system with input-dependent uncertainty is studied. We show that it admits a unique solution and can be approximated by a sequence of finite-dimensional minimax optimal parameter selection problems. These finite-dimensional minimax optimal parameter selection problems are further reduced to scalar optimization problems which also admit unique solutions. Thus, the original minimax optimal control problem is solved via solving a sequence of simple scalar optimization problems. Numerical experiments are presented to illustrate the developed method.     

The Quality of Message Ideas,Thinking and Interaction in an Asynchronous CMC Environment

One of the major shifts in education today under the influence of information and communication technologies is that there is an increased tendency toward the use of computer-mediated communications (CMC). CMC has developed an assortment of methods from simple e-mail to wireless instant messages and synchronous and asynchronous discussions. A large portion of the research in this area focuses on the pedagogical aspects of CMC particularly on the use, strategies, effectiveness and the integration of the new technologies for teaching and learning. Some studies investigate different perspectives of interaction like keeping track of asynchronous discussion, quality of participation, interaction and collaborative or group learning. This paper reports findings from the study that examines the quality of message ideas, thinking and interaction in an asynchronous CMC environment in a teacher training institution. The authors suggest some practical strategies in the implementation of asynchronous discussions in CMC environment. La qualité des messages d’idées, de la pensée et de l’interaction dans un environnement CMC asynchrone. Un des changements majeurs dans l’éducation aujourd’hui sous l’influence de l’information et des technologies de la communication est une tendance accrue À l’usage des communications par ordinateur (Computer-mediated Communications CMC). CMC a permis le développement de tout un assortiment de méthodes depuis de simples e-mail jusqu’À des messages sans fil instantanés et des discussions synchrones et asynchrones. Une grande partie de la recherche en ce domaine est centrée sur les aspects pédagogiques des CMC en particulier sur l’emploi, les stratégies, l’efficacité et l’intégration des nouvelles technologies pour l’enseignement et l’apprentissage. Certains études examinent les perspectives différentes de l’interaction. Telles que garder la trace des discussions asynchrones, la qualité de la participation interaction et l’apprentissage en coopération ou en groupe. L’article rapporte les résultats de l’étude qui examine la qualité des messages d’idées, la pensée et l’interaction dans un environnement de CMC asynchrone dans un établissement de formation des enseignants. Les auteurs suggérent des stratégies pratiques dans l’introduction de discussions asynchrones dans un environnement CMC. Die Qualität der übermittlung von Ideen, Denken und Interaktion in einem asynchronen CMC Umfeld Eine der wichtigsten Umstellungen der heutigen Ausbildung ist die unter dem Einfluss von Informations- und Kommunikationstechnologien verstärkte Tendenz, rechnergestützte Kommunikation (computer-mediated communications:CMC)

zu benutzen. CMC hat ein ganzes Arsenal von Methoden entwickelt, von der einfachen E-Mail bis zu drahtlosen Nachrichten und synchron oder asynchron geführten Diskussionen. Die Forschung in diesem Bereich konzentriert sich hauptsächlich auf die pädagogischen Aspekte von CMC, besonders auf die Nutzung, die Strategien, den Wirkungsgrad und die Möglichkeiten der Einbindung der Neuen Technologien zum Lehren und Lernen. Einige Arbeiten erforschen die verschiedenen Perspektiven

der Interaktion wie das Verfolgen von asynchronen Diskussionen, die Qualität der Beteiligung, der Interaktion und Zusammenarbeit oder dem Lernen in Gruppen. In diesem Beitrag wird über Ergebnisse der Studie zur Untersuchung der Qualität der übermittlung von Ideen, Gedanken und Interaktionen in einem asynchron arbeitenden rechnergestützten

System (CMC) einer Lehrerfortbildungseinrichtung berichtet. Die Autoren erläutern praktische Strategien zur Einbindung asynchroner Diskussionen in eine CMC-Umgebung.     

Structuring professional dialogue through protocols: a study among elementary English teachers in Taiwan

This study focuses on the integration of protocols into elementary school English teacher’s professional dialogue and discusses the influence of protocols on teacher’s teaching and learning. Based on the analysis of documents, observations, and interviews, this study concludes that the introduction of protocols to elementary school English teachers led them to discuss their classroom practice and gain professional learning in instructional strategies and student learning during the professional dialogue. However, English teacher’s lack of experience in using protocols led to interruptions during the professional dialogue. Suggestions for effective protocol-based professional dialogue are provided.

     

Relooking Assessment: A Study on Assessing Developmental Learning Outcomes in Toddlers

In most countries the funding for early childhood education has increased and governments in some countries have taken serious steps to bring about positive change in the profession. However, the increase in funding by governments and other funding organisations around the world has, understandably, attracted increased accountability as these organisations need to know that their financial investments are achieving desired outcomes. To seek evidence that positive learning outcomes have indeed been achieved through these investments is a reasonable request, and there is a shared responsibility and accountability for professionals to provide appropriate evidence. The downside, however, can be the request for standardised test information, as if performance on such tests provides proof of all desired outcomes. More than ever before, it is important for early childhood educators to be able to provide accurate, objective information about children’s assessment in ways other than by standardised testing, which may not reflect the complex reality of children’s lives. This paper reports on a research study in Singapore that investigated curriculum effectiveness using developmental learning outcomes as a means of assessing children. The research was devised to examine if eight specified broad developmental learning outcomes could measure the effectiveness of the curriculum by assessing children’s learning as shown in qualitative data. Practical examples showed evidence of children’s learning and the role of the educator in facilitating and documenting developmental learning outcomes.