Reusable, polyethylene glycol-structured microfluidic channel for particle immunoassays

A microfluidic channel made entirely out of polyethylene glycol (PEG), not PEG coating to silicon or polydimethylsiloxane (PDMS) surface, was fabricated and tested for its reusability in particle immunoassays and passive protein fouling, at relatively high target concentrations (1 mg ml-1). The PEG devices were reusable up to ten times while the oxygen-plasma-treated polydimethyl siloxane (PDMS) device could be reused up to four times and plain PDMS were not reusable. Liquid was delivered spontaneously via capillary action and complicated bonding procedure was not necessary. The contact angle analysis revealed that the water contact angle on microchannel surface should be lower than ~60°, which are comparable to those on dried protein films, to be reusable for particle immunoassays and passive protein fouling

International students in teacher training : South Korean liberal studies students in Hong Kong

Since the globalization era, internationalization in higher education became inevitable. This allowed education students to partake in teacher training programs from all across the world, inducing an increase in teacher mobility. Although non-local education students are exposed to the same coursework as their local counterparts, progress in their teacher training differ from that of local students, as their learning experiences are significantly affected by cultural differences. This research implements a narrative inquiry approach, exploring the realities of teacher training experiences of South Korean Liberal Studies students in Hong Kong. Challenges faced by these non-local student teachers in their progress of understanding Liberal Studies are examined, in close relation to migrant teacher retention in Hong Kong. The findings of this study illustrate South Korean Liberal Studies students’ overall discontent with their learning, as differences in cultural and educational background, such as language and secondary education curriculum, hinder their fruitful teacher training experience in Hong Kong.published_or_final_versionEducationBachelorBachelor of Education in Liberal Studie

Time Dependent Gene Expression Changes in the Liver of Mice Treated with Benzene

Benzene is used as a general purpose solvent. Benzene metabolism starts from phenol and ends with p-benzoquinone and o-benzoquinone. Liver injury inducted by benzene still remains a toxicologic problem. Tumor related genes and immune responsive genes have been studied in patients suffering from benzene exposure. However, gene expression profiles and pathways related to its hepatotoxicity are not known. This study reports the results obtained in the liver of BALB/C mice (SLC, Inc., Japan) administered 0.05 ml/100 g body weight of 2% benzene for six days. Serum, ALT, AST and ALP were determined using automated analyzer (Fuji., Japan). Histopathological observations were made to support gene expression data. c-DNA microarray analyses were performed using Affymetrix Gene-chip system. After six days of benzene exposure, twenty five genes were down regulated whereas nineteen genes were up-regulated. These gene expression changes were found to be related to pathways of biotransformation, detoxification, apoptosis, oxidative stress and cell cycle. It has been shown for the first time that genes corresponding to circadian rhythms are affected by benzene. Results suggest that gene expression profile might serve as potential biomarkers of hepatotoxicity during benzene exposure

Estimating δ15N and δ13C in Barley and Pea Mixtures Using Near-Infrared Spectroscopy with Genetic Algorithm Based Partial Least Squares Regression

Stable isotope measurements have been increasingly used as a method to obtain information on relationships between plants and their environment (Dawson et al., 2002). Stable isotopes are seen as a powerful tool for advancing our knowledge on stock cycling and, nitrogen and carbon isotopic compositions have provided key insights into biogeochemical interactions between plants, soils and the atmosphere (Robinson, 2001). For the stable isotope measurements, the δ13C isotopic signature has been used successfully to disentangle physiological, ecological and biogeochemical processes and, δ15N studies have significantly improved our knowledge on nitrogen cycling pathways and nitrogen acquisition by plants (Vallano and Sparks, 2008). For the stable isotope measurements, traditional laboratory methods using isotope analysis are accurate and reliable, but usually time-consuming and expensive. Near-infrared spectroscopy (NIRS) analysis provides rapid, accurate and less expensive estimation. NIRS have been made to estimate herbage parameters using statistical methods such as multiple linear regression and partial least square regression (PLSR). PLSR uses all available wavebands in multivariate calibration for quantitative analysis of the spectral data. However, previous studies indicated that PLSR with waveband selection might improve their predictive accuracy in multivariate calibration at laboratory (Leardi, 2000) and the selection of appropriate wavelengths can refine the predictive accuracy of the PLS model by optimizing important spectral wavebands both in laboratory NIRS (Jiang et al., 2002). To optimize important spectral wavebands by wavelength selection, genetic algorithms (GA) is widely used, because GA has the ability to simulate the natural evolution of an individual and GA is well suited for solving variable subset selection problems (Ding et al., 1998). Barley and pea mixture is one of the most important forage species for livestock farming in Korea. To investigate nitrogen fixation and transfer in barley and pea mixture, stable isotope measurements was widely used. However, there was no research to estimate stable isotope in barley and pea mixture using NIRS in Korea. The aim of this study was to investigate performance of NIRS with PLSR using genetic algorithms based wavelength selection (GA-PLSR) and compare with PLSR without wavelength selection (FS-PLSR) for the estimation of δ15N and δ13C in barley and pea mixture

Integrative Literature Review on the Antecedents of Informal Learning in the Workplace: A Conceptual Framework for Future Research

Despite the explosion of interest in informal learning in the workplace, few attempts have been made to synthesize the current literature. This article provides an integrative and analytical review of prior empirical studies, particularly focusing on what factors have been identified as antecedents of informal learning in organizations and how informal learning has been conceptualized and measured. It then suggests future avenues for theory building, research, and practice. The authors propose a conceptual framework for understanding informal learning activities using three dimensions: learning competence, intentionality, and developmental relatedness. Implications for human resource development research and practice are also discussed