152 research outputs found

    Korean Pre-service Teachers\u27 Perception of Parent-Teacher Partnership: The Effects of Motivation and Teaching Beliefs

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    This chapter examined early childhood pre-service teachers’ perceptions of the parent-teacher partnership, especially for the interaction effect between motivation and teaching beliefs on the parent-teacher partnership among Korean early childhood pre-service teachers. The participants for this study included 265 pre-service teachers in two different types of childhood teacher education programs (early childhood education and elementary education) in Seoul, Kyunggi, and Busan in Korea. The results from t-tests and ANOVA showed that pre-service teachers’ perceptions of the parent-teacher partnership were differentiated by student status in the teacher education program with discrete differences depending on subfactors. Constructivist teaching beliefs were the most significant variable to predict the pre-service teachers’ perceptions of the parent-teacher partnership. Even though there were no statistically meaningful interaction effects between intrinsic motivation and constructivist teaching beliefs, two-way interaction plots implied interaction effects between these two predictors. Based on the results, we discussed the implications of the results in regard to curriculum development and educational policy for future endeavors to enhance teacher education quality and educational effectiveness

    Influence of bank geometry on the electrical characteristics of printed organic field-effect transistors

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    The electrical characteristics of organic field-effect transistors (OFETs) based on small-molecule organic semiconductors (OSCs) have been significantly improved by employing various fabrication techniques in solution processes to enhance the OSC crystallinity. However, complicated fabrication and inhomogeneity of OFETs remain as challenges before commercialization. In this work, we have efficiently controlled the size and orientation of 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) crystalline domains by tuning the Cytop bank dimension, in which OSC inks are printed, to improve the device performance. The optimized bank pattern forms uniform thin film morphology and well-aligned TIPS-pentacene crystalline domains along the charge transport direction, resulting in four-fold increase in field-effect mobility and one third reduction in relative standard deviation.11Ysciescopu

    A degree reduction method for an efficient QUBO formulation for the graph coloring problem

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    We introduce a new degree reduction method for homogeneous symmetric polynomials on binary variables that generalizes the conventional degree reduction methods on monomials introduced by Freedman and Ishikawa. We also design an degree reduction algorithm for general polynomials on binary variables, simulated on the graph coloring problem for random graphs, and compared the results with the conventional methods. The simulated results show that our new method produces reduced quadratic polynomials that contains less variables than the reduced quadratic polynomials produced by the conventional methods

    Robust Luttinger liquid state of 1D Dirac fermions in a van der Waals system Nb9_9Si4_4Te18_{18}

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    We report on the Tomonaga-Luttinger liquid (TLL) behavior in fully degenerate 1D Dirac fermions. A ternary van der Waals material Nb9_9Si4_4Te18_{18} incorporates in-plane NbTe2_2 chains, which produce a 1D Dirac band crossing Fermi energy. Tunneling conductance of electrons confined within NbTe2 chains is found to be substantially suppressed at Fermi energy, which follows a power law with a universal temperature scaling, hallmarking a TLL state. The obtained Luttinger parameter of ~0.15 indicates strong electron-electron interaction. The TLL behavior is found to be robust against atomic-scale defects, which might be related to the Dirac electron nature. These findings, as combined with the tunability of the compound and the merit of a van der Waals material, offer a robust, tunable, and integrable platform to exploit non-Fermi liquid physics

    The effects of improved sanitation on diarrheal prevalence, incidence, and duration in children under five in the SNNPR State, Ethiopia: study protocol for a randomized controlled trial.

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    BACKGROUND: Diarrhea is one of the leading causes of death, killing 1.3 million in 2013 across the globe, of whom, 0.59 million were children under 5 years of age. Globally, about 1 billion people practice open defecation, and an estimated 2.4 billion people were living without improved sanitation facilities in 2015. Much of the previous research investigating the effect of improved sanitation has been based on observational studies. Recent studies have executed a cluster-randomized controlled trial to investigate the effect of improved sanitation. However, none of these recent studies achieved a sufficient level of latrine coverage. Without universal or at least a sufficient level of latrine coverage, a determination of the effect of improved latrines on the prevention of diarrheal disease is difficult. This cluster-randomized trial aims to explore the net effect of improved latrines on diarrheal prevalence and incidence in children under five and to investigate the effect on the diarrheal duration. METHOD/DESIGN: A phase-in and factorial design will be used for the study. The intervention for improving latrines will be implemented in an intervention arm during the first phase, and the comparable intervention will be performed in the control arm during the second phase. During the second phase, a water pipe will be connected to the gotts (villages) in the intervention arm. After the second phase is completed, the control group will undergo the intervention of receiving a water pipe connection. For diarrheal prevalence, five rounds of surveying will be conducted at the household level. The first four rounds will be carried out in the first phase to explore the effect of improved latrines, and the last one, in the second phase to examine the combined effects of improved water and sanitation. For documentation of diarrheal incidence and duration, the mother or caregiver will record the diarrheal episodes of her youngest child on the "Sanitation Calendar" every day. Of 212 gotts in the project area, 48 gotts were selected for the trial, and 1200 households with a child under 5 will be registered for the intervention or control arm. Informed consent from 1200 households will be obtained from the mother or caregiver in written form. DISCUSSION: To our knowledge, this is the second study to assess the effects of improved latrines on child diarrheal reduction through the application of Community-Led Total Sanitation. TRIAL REGISTRATION: Current Controlled Trials, ISRCTN82492848

    Simultaneous determination of multi-class veterinary drugs in fishery products with liquid chromatography–tandem mass spectrometry

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    The objective of this study was to optimize the analytical method for multi-class veterinary drug residues of 64 compounds in fishery products. Several compounds from veterinary drugs are banned or unauthorized in fishery products according to the Korean Food Code. Samples were extracted using acetonitrile/water (4:1, v/v) and the clean-up step was carried out by adding octadecylsilane and acetonitrile-saturated hexane. The target compounds were confirmed and quantified using liquid chromatography–tandem mass spectrometry (LC–MS/MS). The proposed method was validated according to the CODEX guidelines (CAC/GL-71), and most target compounds were found to be in acceptable quantities under the requirements of the validation guidelines. The recovery of analytes was typically in the 60–120% range, and precision, expressed as the coefficient of variation was less than 31% at all levels of concentration. The limit of quantification ranged from 0.03 to 3 μg kg−1 in the fishery products. Moreover, the application of the proposed method to 96 real samples demonstrated that no drug residues exceeded the Korean maximum residue limits (MRLs). This evaluation method provides reliable identification and quantification of multi-class veterinary drugs in fishery products and can be an efficient means to inspect drugs currently banned or not approved for aquaculture in Korea.This study was funded by Grant No. 20161MFDS623 from the Ministry of Food and Drug Safety of South Korea in 2020

    Motility increase of adherent invasive Escherichia coli (AIEC) induced by a sub-inhibitory concentration of recombinant endolysin LysPA90

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    Endolysins are bacteriophage enzymes required for the eruption of phages from inside host bacteria via the degradation of the peptidoglycan cell wall. Recombinant endolysins are increasingly being seen as potential antibacterial candidates, with a number currently undergoing clinical trials. Bacteriophage PBPA90 infecting Pseudomonas aeruginosa harbors a gene encoding an endolysin, lysPA90. Herein, recombinant LysPA90 demonstrated an intrinsic antibacterial activity against Escherichia coli in vitro. It was observed that a sub-inhibitory concentration of the recombinant protein induced the upregulation of genes related to flagella biosynthesis in a commensal E. coli strain. Increases in the number of bacterial flagella, and in motility, were experimentally substantiated. The treatment caused membrane stress, leading to the upregulation of genes rpoE, rpoH, dnaK, dnaJ, and flhC, which are upstream regulators of flagella biosynthesis. When adherent invasive Escherichia coli (AIEC) strains were treated with subinhibitory concentrations of the endolysin, bacterial adhesion and invasion into intestinal epithelial Caco-2 cells was seen to visibly increase under microscopic examination. Bacterial counting further corroborated this adhesion and invasion of AIEC strains into Caco-2 cells, with a resultant slight decrease in the viability of Caco-2 cells then being observed. Additionally, genes related to flagella expression were also upregulated in the AIEC strains. Finally, the enhanced expression of the proinflammatory cytokine genes TNF-α, IL-6, IL-8, and MCP1 in Caco-2 cells was noted after the increased invasion of the AIEC strains. While novel treatments involving endolysins offer great promise, these results highlight the need for the further exploration of possible unanticipated and unintended effects
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