Variational Analysis In Parametric Optimization

The dissertation is devoted to the development of variational analysis and generalized differentiation in infinite dimensions. We derive new calculus rules for both first-order partial subdifferentials and second-order partial subdifferentials in the framework of general Banach spaces as well as more developed rules in the framework of Asplund spaces. This calculus is applied in the study of sensitivity analysis for solution maps to the parameterized generalized equations in Asplund spaces, where both bases and fields are parameter-dependent multifunctions. We analyze the parametric sensitivity of either stationary points or stationary point multiplier multifunctions associated with parameterized optimization problems under consideration. The dissertation also focus on a family of parameterized quasi-variational inequalities and conduct a sensitivity analysis for their solution maps

THE DIFFICULTIES IN ORAL PRESENTATION OF ENGLISH-MAJORED JUNIORS AT TAY DO UNIVERSITY, VIETNAM

It could be broadly accepted that oral presentations are becoming important for students. It is required in almost every field and in the university environment. To succeed in the university environment and in their future jobs, these students need to improve their oral presentation skills. However, one of the drawbacks of using oral presentations in the language classroom is that students often find oral presentations extremely challenging. Therefore, the researcher conducted this research with the main goal of finding out common problems when giving an oral presentation to English-majored juniors at Tay Do University. Ninety juniors majoring in English at Tay Do University were selected to take part in the study. Data are gathered through questionnaires and interviews. The researcher used quantitative and qualitative methods to do the research. From the collected data, when they give a presentation, students usually make some mistakes such as problems in vocabulary, grammar, pronunciation, psychological and background knowledge. Through this study, they would recognize their own problems when giving a presentation. Besides, understanding students' learning difficulties may also enable teachers to help students develop effective learning strategies and ultimately improve their presentation skills. It is hoped that this research can be helpful for not only students but also teachers in learning and teaching English.  Article visualizations

The Effects of Collaborative Learning on Young ESL Learners’ L2 Anxiety and Speaking Performance

Foreign Language Anxiety (FLA) is one of the issues of interest attracting researchers in recent decades. However, while collaborative learning introduced a prospective tool for FLA, it has not been much researched in the L2 classroom context, particularly in Vietnam. This paper focuses on using collaborative learning to reduce foreign language anxiety and enhance the L2 speaking performance of young learners at an English center in Ho Chi Minh City. A combination of tools, including Aydin et al.’s (2017) Children Foreign Language Anxiety Scale (CFLAS) for the pre-tests and post-tests, the teacher’s diary, and follow-up interviews, was used to measure the changes in learner’ FLA level and speaking performance. After five-week implementations, these learners’ FLA was slightly alleviated, and their speaking performance was improved using a collaborative learning approach. Moreover, learners were found to have positive attitudes and experience with learning in the new approach. These findings implied that collaborative learning could be a potential treatment to help L2 learners uncover their anxious selves and find more confidence in using the target languag

Vietnam's visa policy for tourists

States employ travel visa as an instrument to leverage on visitor arrivals for various reasons. In tourism, visa plays a crucial role in facilitating potential and last-minute tourists’ decision making process. This paper focuses on the Vietnamese government’s visa policy in the context of tourism development. Adopting an economic approach, this paper reviews key achievements in tourist immigration policies and examines the challenges that deter tourists from visiting the country. This study purports that a stronger national strategy pertaining to simplification of visa processing and streamlining common visa entry union with neighboring countries within the AEC 2015 framework will translate to gains for Vietnamese tourism. __________________________________________________ Key words: economic approach, national visa policy, tourism developmen

Effects of water scarcity awareness and climate change belief on recycled water usage willingness: Evidence from New Mexico, United States

The global water crisis is being exacerbated by climate change, even in the United States. Recycled water is a feasible alternative to alleviate the water shortage, but it is constrained by humans’ perceptions. The current study examines how residents’ water scarcity awareness and climate change belief influence their willingness to use recycled water directly and indirectly. Bayesian Mindsponge Framework (BMF) analytics was employed on a dataset of 1831 residents in Albuquerque, New Mexico, an arid inland region in the US. We discovered that residents’ willingness to use direct recycled potable water is positively affected by their awareness of water scarcity, but the effect is conditional on their belief in the impacts of climate change on the water cycle. Meanwhile, the willingness to use indirect recycled potable water is influenced by water scarcity awareness, and the belief in climate change further enhances this effect. These findings implicate that fighting climate change denialism and informing the public of the water scarcity situation in the region can contribute to the effectiveness and sustainability of long-term water conservation and climate change alleviation efforts

Cider Production from King Mandarin (Citrus nobilis Lour.) and Its Antioxidant Activity

With the necessity of diversifying alcoholic beverages, cider has become a kind of drink that can fulfill this demand. This is because the cider will be diversified depending on the kinds of fruit that are chosen to be used for the cider fermentation. Therefore, this study aims to investigate the effects of dilution ratio, Brix, pH, and yeast concentration on the production of cider from king mandarin (Citrus nobilis Lour.), and to evaluate the analytical characteristics and antioxidant activity of the product. After the investigation, it can be claimed that the dilution of the juice causes the ethanol content to decrease, whereas the increase of Brix, pH, and yeast concentration makes the ethanol content increase. However, the proportional increase in the ethanol content with Brix, pH, and yeast concentration has its limitations. Specifically, when the Brix and the yeast concentrations were, respectively, higher than 16°Brix and 0.04%, the ethanol content tended to maintain the same. This is also the same when the pH was lower than 4.5. In addition, by using the DPPH and ABTS●+ methods, the antioxidant activity of cider is estimated to be lower than the one of the juice before fermentation, which is smaller than 3.78 times for the DPPH method and 3.76 times for the ABTS●+ method

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Estimating Greenhouse Gas Emissions from a Seafood Processing Facility

At the end of COP26, Vietnam has developed many institutions and policies to fulfill its commitment to bring net emissions to “zero” by 2050 and reduce methane (CH4) to at least 30% by 2020 in 2030. In order to gradually achieve the above goal, an inventory of facilities with greenhouse gas emissions plays a very important role. This study was conducted to estimate greenhouse gas emissions at seafood export processing factory. The study was carried out based on the method of collecting data from different emission sources and calculating emissions based on activity data and emission factors from reliable sources. The research results show that, during the study period from March 2022 to March 2023, the total emissions at the facility were 19,144.14 tons of CO2eq, of which indirect emissions from waste and electricity accounted for the high rate is about 60.37% and 36.55% of the total CO2eq, respectively. Research results also show that CO2 is the most emitted gas into the environment and is present in most of the waste sources. In which, electricity consumption and CO2 emissions are the most significant, indirectly emitting 7,102.85 tons of CO2/year (accounting for 98.51% of total waste sources). For daily waste, landfilling indirectly release into the atmosphere an amount of methane (CH4) approximately 410 tons/year, accounting for more than 95% of the total emissions. In addition, in the process of using fuel (gasoline and DO) at the facility, a large amount of N2O gas enters the atmosphere (nearly 70% of emissions from DO and 30% from gasoline). Reduction of greenhouse gas emissions at the facility could be achieved by saving water, reducing wastewater and using clean energy

Comparative Study of the Silver Nanoparticle Synthesis Ability and Antibacterial Activity of the Piper Betle L. and Piper Sarmentosum Roxb. Extracts

Piper betle (P. betle) and Piper sarmentosum (P. sarmentosum) are the two members of the Piper genus, have been reported to be rich in phytochemicals and essential oils, which showed strong reducing power, antibacterial, and antifungal activities. P. betle recently has been studied and applied in several commercial products in the antimicrobial respect, meanwhile its relatives, P. sarmentosum has been lesser-known in this field. In this study, the two Piper species—P. betle and P. sarmentosum were studied to compare their ability in silver nanoparticle synthesis and efficacy in antibacterial activity. P. betle and P. sarmentosum were extracted by distilled water at different temperatures and times. Subsequently, their total reducing capacity was determined by DPPH scavenging and Folin-Ciocalteu assays to choose the appropriate extraction conditions. The silver nanoparticle solutions prepared by the extracts of P. betle (Pb.ext) and P. sarmentosum (Ps.ext) were characterized by Dynamic light scattering (DLS), Zeta potential, UV-vis, and Fourier-transform infrared (FTIR) measurements. Finally, the antibacterial activity of the synthesized silver nanoparticle solutions was tested against Escherichia coli using the agar diffusion well–variant method. The Pb.ext showed stronger reducing power with higher total polyphenol content (~125 mg GAE/mL extract) and better DPPH activity (IC50~1.45%). Both the green synthesized silver nanoparticle solutions (Pb.AgNP and Ps.AgNP) performed significantly stronger antibacterial activity on Escherichia coli compared to their initial extracts. Antibacterial tests revealed that Ps.AgNP showed remarkably better growth inhibition activity as compared to Pb.AgNP. This study would contribute useful and important information to the development of antibacterial products based on green synthesized silver nanoparticles fabricated by the extracts of P. betle and P. sarmentosum

Exploring English Major Students’ Self-Directed Technology Use for Language Learning

English, as a foreign language education, requires students to be taught in the classroom and participate in additional hands-on activities outside the classroom using technology resources or non-technology. However, language learners rarely use technology to learn outside the classroom, and types of technology have been limited. Therefore, it is crucial to provide language learners with various technology resources to enhance their learning experience and motivate them to continue practicing outside the classroom. The study aimed to provide insights into factors influencing students’ self-directed technology use for language learning. The study findings can help design effective language-learning programs integrating technology and enhancing self-directed learning. The study, which included 167 English major students, employed quantitative methods and an adapted questionnaire. Multiple Linear Regression, Pearson Correlation, and descriptive statistics helped quantitatively analyze the data. The findings show that the three factors—attitude toward an act or behavior, subjective norm, and perceived behavioral control—are highly correlated. Furthermore, the subjective norm was the most significant influence, and attitude toward action or behavior was the least. Teachers should focus on creating a positive social norm around self-directed technology use for language learning and encourage students to perceive it as socially desirable. Additionally, they can work on improving students’ attitudes toward technology by highlighting its benefits and providing opportunities for hands-on practice