Some solutions to respond climate change for the Mekong Delta, Viet Nam

In the recent decades, the Mekong River Delta has suffered quite significant impacts of climate change. Fluctuations of weather elements and sea level rises have caused adverse changes, namely: the appearance of unusual high and low levels of annual floods, more and more intense storms, more severe droughts, forest fires, river erosion, cyclones, and tidal surges appear increasingly more dangerous. Traditional adaptation measures to the environmental conditions may be unsuitable in the context of climate change in the Mekong River Delta. This paper summarizes some of the new adaptation measures that scientists and policy planners have proposed for the area to cope with the negative impacts of climate change

Adaptation and validation of a computer-assisted language learning attitude questionnaire in a Vietnamese EFL context: A comparison between online and paper modes of administration

The article reports on the validation of a computer-assisted language learning (CALL) attitude questionnaire and discusses differences between online and paper modes of administration, drawing on a sample of 1,769 Vietnamese undergraduates. Exploratory and confirmatory factor analyses were conducted to explore and assess the factor structure of the CALL instrument and specify the equivalence between the two versions of the questionnaire. Rasch model analysis was used to evaluate the overall fit and construct uni-dimensionality of the instrument. The findings of the study suggested a six-factor structure for the adapted questionnaire as well as both reliability and validity in the Vietnamese context. No significant difference was found between the two modes of administration as regards the construct and item levels of the questionnaire, although the paper-version was superior to the online version according to results from the Rasch model analysis. Hence, the instrument can be used in online and paper modes to measure Vietnamese tertiary students’ attitudes to the integration of technology into language learning. The study finds that further research is called for if the two modes of adminis- tration of the questionnaire are used in other contexts for teaching English as a foreign language (EFL)

Tools for assessing teacher digital literacy: a review

With the rapid advancement of technology, digital literacy has become a key component in educators’ professional development. A wide range of assessment tools has been developed to measure teacher digital literacy; however, there has been no previous attempt to systematically synthesize and scrutinize those tools to improve evaluation of this ability among educators. The current study reviews literature on instruments that assess teacher digital literacy with the purposes of ascertaining the main aspects of it that recent researchers focus on in their evaluation, instrument types used for assessment, and the reliability and validity report, as well as the frameworks or models used to design assessment tools. The review selected 33 English-language publications in the field of educational technology from peer-reviewed journals indexed in the Education Resources Information Center (ERIC), Web of Science, and Scopus. The study period spanned from 2011 to 2022 with the objective of reviewing the tools used to assess teacher digital competence. The major findings demonstrate that scholars focus on digital competence in teachers’ use of educational technology, teaching and learning, professional development, and support for learners through digital competence. Other researchers emphasize the ability of educators to apply technology to the assessment of learner outcomes or to empower students in using technology to enhance learning. Additionally, self-evaluation instruments are common, whereas a few studies promote subjective evaluation in combination with objective assessment to provide a comprehensive understanding of teacher digital competence. The results form the basis for several recommendations for future research for the further examination of teacher digital literacy

Bioaktive forbindelser i Syzygium guineense blad

Syzygium guineense er et tre som er utbredt i en rekke afrikanske land som Mali, Etiopia, Eritrea, Senegal og Uganda. Treet har et bredt bruksområde innen tradisjonell afrikansk medisin. Blader benyttes for eksempel mot diaré, magesmerter, kolikk, øyeinflammasjon og topikalt på sår, mens bark blant annet brukes for å behandle hoste og andre halsproblemer, i tillegg til behandling mot malaria, beinbrudd og sår. Med denne oppgaven var hensikten å isolere, strukturoppklare og identifisere biologisk aktive lavmolekylære substanser i planten. Undersøkelse av hvilke substanser som planten inneholder kan bidra til å forklare den tradisjonelle bruken. Blader fra S. guineense ble ekstrahert med diklormetan og metanol. Metanolråekstraktet utgjorde den største fraksjonen og ble fraksjonert ved kolonnekromatografi og preparativ HPLC for å isolere innholdsstoffene i bladene. Åtte forbindelser ble isolert, og de ble strukturoppklart ved hjelp av 1D (1H, 13C,APT) og 2D (COSY, HSQC og HMBC) NMR-spektroskopi. To gallotanniner; 1,2,3,4,6-penta-O-galloyl-b-D-glukose og 1,2,3,6-tetra-O-galloyl-b-D-glukose og seks flavonoider; gallokatekin, myricetin aglykon og glykosidene myricetin 3-O-rhamnosid,myricetin 3-O-glukosid, myricetin 3-O-glukuronid og 3-O-b-D-(6"-O-galloylgalaktopyranosyl)-myricetin ble isolert og identifisert. Råekstraktet, mellomfraksjoner og isolerte forbindelser ble testet for radikalscavenging aktivitet ovenfor radikalet difenylpikrylhydrazyl (DPPH). Det ble utført hemming av det prooksiderende enzymet xantin oksidase (XO) og det peroksiderende enzymet 15-lipoksygenase (15-LOX). Metanolråekstraktet viste en nokså god radikalscavenger aktivitet, IC50 9,8±1,0 ug/ml. Ekstraktet viste også noe hemming av15-LOX (IC50 69±8 ug/ml) og XO (IC50 73±6 ug/ml). Av de isolerte forbindelsene var det myricetin 3-O-glukosid, 1,2,3,4,6-penta-O-galloyl-b-D-glukose og 3-O-b-D-(6"-O-galloylgalaktopyranosyl)-myricetin som hadde høyest radikalscavenger aktivitet med henholdsvis IC50 10,8±1,6 uM, 4,9±1,1 uM og 10,6±3,2 uM. Myricetin og 1,2,3,4,6-penta-O-galloyl-b-D-glukose viste seg å være mest potent ved hemming av XO (8,1±0,7 uM og 8,0±1,4 uM), mens myricetin 3-O-glukosid og 1,2,3,4,6-penta-O-galloyl-b-D-glukose hadde sterkest 15-LOX hemming med henholdsvis IC50 42±4 uM og 25±4 uM. Myricetin 3-O-rhamnosid var en moderat DPPH-scavenger (IC50 27,6±2,6 uM) og 15-LOX hemmer (138,1±11 uM), men inaktivt som XO-hemmer, og myricetin 3-O-glukuronid var en svak DPPH-scavenger (IC50 85±33 uM) og var inaktiv som 15-LOX–og XO-hemmer. Gallokatekin viste god aktivitet som radikalscavenger, IC50 17,3±2,9 uM, moderat aktivitet som 15-LOX hemmer, IC50 112±4 uM, men var inaktivt som XO-hemmer. 1,2,3,6-tetra-O-galloyl-b-D-glukose kunne ikke testes på grunn av for liten mengde isolert. Ingen av de isolerte forbindelsene er tidligere rapportert i S. guineense, men de har derimot blitt rapportert i en rekke andre planter. Noen av disse substansene, som 3-O-b-D-(6"-O -galloylgalaktopyranosyl)-myricetin og 1,2,3,6-tetra-O-galloyl-b-D-glukose, er sjeldne naturstoffer. Flere av de observerte aktivitetene er ikke rapportert tidligere i litteraturen. Av de syv isolerte og testede substansene viste fire moderat til høy radikalscavenger aktivitet. Tre av dem ga moderat til god 15-LOX hemming, mens to substanser viste å være nokså gode XO-hemmere. Våre funn har vist at blader fra S. guineense inneholder forbindelser som kan bidra til biologiske aktiviteter, og dette kan kanskje forklare noe av den tradisjonelle bruken av medisinplanten

Essays on Business Cycles

The topic of my dissertation is to understand the sources of business cycles. In particular, using structural estimation, I quantitatively investigate different types of shocks that propagate within a country (Chapter One) and that cause business cycle comovement across countries (Chapter Two and Three). In the first chapter, Wataru Miyamoto and I propose the use of data on expectations to identify the role of news shocks in business cycles. News shocks are defined as information about future fundamentals that agents learn in advance. Our approach exploits the fact that news shocks cause agents to adjust their expectations about the future even when current fundamentals are not affected. Using data on expectations, we estimate a dynamic, stochastic, general equilibrium model that incorporates news shocks for the U.S. between 1955Q1 and 2006Q4 using Bayesian estimation. We find that the contribution of news shocks to output is about half of that estimated without data on expectations. The precision of the estimated role of news shocks also greatly improves when data on expectations are used. Although news shocks are important in explaining the 1980 recession and the 1993-94 boom, they do not explain much of other business cycles in our sample. Moreover, the contribution of news shocks to explaining short run fluctuations is negligible. These results arise because data on expectations show that changes in expectations are not large and do not resemble actual movements of output. Therefore, news shocks cannot be the main driver of business cycles. Chapters Two and Three focus on the driving forces of business cycles in open economies. We start Chapter Two with an observation that business cycles are strongly correlated across countries. We document that this pattern is also true for small open economies between 1900 and 2006 using a novel data set for 17 small developed and developing countries. Furthermore, we provide a new evidence about the role of common shocks in business cycles for small open economies in a structural estimation of a real small open economy model featuring a realistic debt adjustment cost and common shocks. We find that common shocks are a primary source of business cycles, explaining nearly 50\% of output fluctuations over the last 100 years in small open economies. The estimated common shocks capture important historical episodes such as the Great depression, the two World Wars and the two oil price shocks. Moreover, these common shocks are important for not only small developed countries but also developing countries. We point out the importance of our structural approach in identifying several types of common shocks and their sizable role in small open economies. The reduced form dynamic factor model approach in the previous literature, which often assumes one type of common component, would predict only a third of the contribution estimated in the structural model. Chapter Three further our understanding of the business cycle comovement across countries by investigating the transmission mechanism of shocks across countries. Our reading of the literature indicates that even though business cycles are correlated across countries, existing models are not able to generate substantial transmission through international trade. To the extent that business cycles are correlated across countries, it is because shocks are correlated across countries. We show that the nature of such transmission depends fundamentally on the features determining the responsiveness of labor supply and labor demand to international relative prices. We augment a standard international macroeconomic model to incorporate three key features: a weak short run wealth effect on labor supply, variable capital utilization, and imported intermediate inputs for production. This model can generate large and significant endogenous transmission of technology shocks through international trade. We demonstrate this by estimating the model using data for Canada and the United States. We find that this model can account for the substantial transmission of permanent U.S. technology shocks to Canadian aggregate variables such as output and hours documented in a structural vector autoregression. Transmission through international trade is found to explain the majority of the business cycle comovement between the United States and Canada while exogenous correlation of technology shocks is not important

Students’ Perceptions and Design Considerations of Flipped Interpreting Classroom

Digital technologies have become a driver of change that exerts tremendous impact across the disciplines, including education. The Flipped classroom model, carried out in a technology-enhanced environment, has been proven to bring educational innovations.  However, in the Vietnamese educational context, the adoption of the flipped model in interpreting courses for undergraduate students has been hardly touched upon in the existing literature. This current study is, therefore, an attempt to examine English-majored students’ perceptions about this teaching model on Moodle Learning Management Platform and put forward some proposals in the design and implementation of the Flipped Interpreting course. The data were collected using both quantitative and qualitative methods, including a Likert-scale questionnaire and individual interviews. The results revealed that students had positive perceptions toward the adoption of Flipped model and Moodle platform. Analyzing the interconnection of three domains in CoI framework and the additional domain of Technology Use, the authors then offer further recommendations for effective implementation of the model in the EFL classroom context

Synthesis, structural characterization, and application of N-doped TiO2 photocatalyst under visible-light irradiation

N-doped TiO2 nanomaterials were prepared with the sol-gel method. The structure and properties of the materials were characterized by using XRD, UV-Vis, SEM, EDX, and IR techniques. The optimal dose of ammonium chloride for doping is 600 mg. The optical absorption edge of N-TiO2 displays a redshift, and a long tail occurs in the presence of nitrogen in the material. Thereby, N-TiO2 may exhibit improved absorption properties under visible light and the solar irradiation. The photocatalytic activity was investigated on the degradation of rhodamine B. The optimal amount of the photocatalyst is 1.8 g/L under visible light

Understanding the Cross Country Effects of U.S. Technology Shocks

Abstract Business cycles are substantially correlated across countries. Yet, most existing models are not able to generate substantial transmission through international trade. We show that the nature of such transmission depends fundamentally on the features determining the responsiveness of labor supply and labor demand to international relative prices. We augment a standard international macroeconomic model to incorporate three key features: a weak short run wealth effect on labor supply, variable capital utilization, and imported intermediate inputs for production. This model can generate large and significant endogenous transmission of technology shocks through international trade. We demonstrate this by estimating the model using data for Canada and the United States with limited information Bayesian methods. We find that this model can account for the substantial transmission of permanent U.S. technology shocks to Canadian aggregate variables such as output and hours, documented in a structural vector autoregression. Transmission through international trade is found to explain the majority of the business cycle comovement between the United States and Canada

Understanding the Cross Country Effects of US Technology Shocks * †

Abstract Business cycles are substantially correlated across countries. Yet, most existing models are not able to generate substantial transmission through international trade. We show that the nature of such transmission depends fundamentally on the features determining the responsiveness of labor supply and labor demand to international relative prices. We augment a standard international macroeconomic model to incorporate three key features: a weak short run wealth effect on labor supply, variable capital utilization, and imported intermediate inputs for production. This model can generate large and significant endogenous transmission of technology shocks through international trade. We demonstrate this by estimating the model using data for Canada and the United States with quasi-Bayesian methods. We find that this model can account for the substantial transmission of permanent U.S. technology shocks to Canadian aggregate variables such as output and hours documented in a structural vector autoregression. Transmission through international trade is found to explain the majority of the business cycle comovement between the United States and Canada while exogenous correlation of technology shocks is not important. JEL classification: F41, F44, F62, E30