94 research outputs found
The Use of Blended Learning to Support Vocabulary Learning and Knowledge Retention in Thai Tertiary EFL Classrooms
The aim of the study was to investigate the feasibility of a blended learning approach to enhance students’ vocabulary knowledge and vocabulary knowledge retention in English as a foreign language (EFL) classrooms at the tertiary level in Thailand. This was to address challenges in relation to practice and use of English language, rote learning and memorisation, limited one-to-one interaction with peers and teacher, lack of learner-centredness, and low rate of knowledge retention. This study was conducted as a quasi-experimental design, employing the sample from four intact classes with a total of 146 students who registered in an English course at a university in Bangkok, Thailand. The sample was divided into experimental and control groups. The experimental group was exposed to the flipped classroom model, while the control group was taught in the traditional setting. Research tools consisted of an English language proficiency test, vocabulary pre-test, post-test, and delayed test, questionnaire, interviews and observations. The quantitative findings revealed a negative overall impact of the blended learning instruction on the experimental group, and on some particular classes and different academic majors. Gender differences and correlations occurred between language proficiency, vocabulary knowledge and knowledge retention. Qualitative results indicated that students and teachers had positive perceptions and attitudes towards feasibility of the approach. Although the blended learning method is perceived in a positive and feasible way, it may only be applicable for some particular groups or types of learners. Hence, different aspects regarding nature of learners and language learning should be taken into consideration, these include: language abilities, background knowledge, gender, academic majors, learners’ characteristics and capabilities, content and assessment, and selective types of technology
Molecular Structure and Electronic Properties of Porphyrin-Thiophene-Perylene Using Quantum Chemical Calculation
This study aimed to design a new series of compounds consisting of a porphyrin macrocycle linked to a perylene unit via a thiophenic bridge. The structural and electronic properties of the molecules, and the effects of mono- and di-substituents R on C3 and R′ on C4 of the thiophene ring were investigated using a quantum calculation approach. The results from the method validation revealed that using the density functional theory approach at B3LYP/6–31G(d) data set was the optimal one, considering the accuracy attained and maintaining the computer time required within tractable limits. The results from the B3LYP/6–31G(d) approach indicated that significant changes of the torsion angle between the molecular planes of the porphyrin and perylene rings, compared to that of the unsubstituted derivatives, were found in the di-substituted systems bearing R = R′ = −OCH3 and −NH2, and in a mono-substituted system having R = −H and R′=−NH2. The symmetric di-substitution does not provide a significantly lower HOMO-LUMO energy gap (ΔEg). Noticeable decreases in ΔEg were found only with the substitution patterns of: R, R′ = −OCH3, −H; −OH, −H; −N(CH3)2, −H; −H, −NH2. UV-visible spectra of all derivatives exhibited characteristic absorption maxima of the free bases of porphyrin and perylene
Structural model of a complex between the heterotrimeric G protein, Gsα, and tubulin
AbstractA number of studies have demonstrated interplay between the cytoskeleton and G protein signaling. Many of these studies have determined a specific interaction between tubulin, the building block of microtubules, and G proteins. The α subunits of some heterotrimeric G proteins, including Gsα, have been shown to interact strongly with tubulin. Binding of Gα to tubulin results in increased dynamicity of microtubules due to activation of GTPase of tubulin. Tubulin also activates Gsα via a direct transfer of GTP between these molecules. Structural insight into the interaction between tubulin and Gsα was required, and was determined, in this report, through biochemical and molecular docking techniques. Solid phase peptide arrays suggested that a portion of the amino terminus, α2–β4 (the region between switch II and switch III) and α3–β5 (just distal to the switch III region) domains of Gsα are important for interaction with tubulin. Molecular docking studies revealed the best-fit models based on the biochemical data, showing an interface between the two molecules that includes the adenylyl cyclase/Gβγ interaction regions of Gsα and the exchangeable nucleotide-binding site of tubulin. These structural models explain the ability of tubulin to facilitate GTP exchange on Gα and the ability of Gα to activate tubulin GTPase
Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia
© 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas
Association between praziquantel treatment and cholangiocarcinoma: a hospital-based matched case–control study
Molecular, cellular and physiological aspects of complexes between Gs alpha and tubulin.
Molecular, cellular and physiological aspects of complexes between Gs alpha and tubulin
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