Toward An IoT-based Expert System for Heart Disease Diagnosis

IoT technology has been recently adopted in the healthcare system to collect Electrocardiogram (ECG) signals for heart disease diagnosis and prediction. However, noises in collected ECG signals make the diagnosis and prediction system unreliable and imprecise. In this work, we have proposed a new lightweight approach to removing noises in collected ECG signals to perform precise diagnosis and prediction. First, we have used a revised Sequential Recursive (SR) algorithm to transform the signals into digital format. Then, the digital data is proceeded using a revised Discrete Wavelet Transform (DWT) algorithm to detect peaks in the data to remove noises. Finally, we extract some key features from the data to perform diagnosis and prediction based on a feature dataset. Redundant features are removed by using Fishers Linear Discriminant (FLD). We have used an ECG dataset from MIT-BIH (PhisioNet) to build a knowledge-base diagnosis features. We have implemented a proof-of concept system that collects and processes real ECG signals to perform heart disease diagnosis and prediction based on the built knowledge base

HMông Students’ Sources of Funds of Knowledge: A Case Study of Kinh Primary School Teachers’ Practices

Teachers working with ethnic minority students who have different language and cultural background from their own may have little knowledge of their students in out-of-school context. This lack of students’ knowledge and resources outside of the school may lead to deficit thinking regarding this non-dominated group as intellectually and academically deficient. Underachievement and low study engagement by HMông ethnic minority students in disadvantaged primary schools in Vietnam evidence a need for more effective teaching practices to support these minority students’ learning and reduce inequality within their educational environment. The funds of knowledge (FoK) approach attempts to overcome teachers’ perceptions of ethnic minority students and their knowledge through learning about these students’ FoK and incorporating these insights into the teaching practices. The purpose of this study is to explore how Kinh teachers identify HMông students’ sources of FoK in order to support their teaching/learning practices. This research employs qualitative educational research method together with case study method to examine the way Kinh primary teachers identify HMông students’ sources of FoK. The findings indicate that Kinh primary teachers identified HMông students’ different sources of FoK that the teachers could beneficially be drawing on to empowering HMông children’ participation, achievement and Kinh teachers’ teaching practices

SEASONAL VARIATION OF PHYTOPLANKTON FUNCTIONAL GROUPS IN TUYEN LAM RESERVOIR, CENTRAL HIGHLANDS, VIETNAM

Seasonal changes in freshwater phytoplankton assemblages at Tuyen Lam Reservoir in the Central Highlands of Vietnam were classified into 23 functional groups based on physiological, morphological, and ecological characteristics. A total of 168 species were recorded during 10 surveys from 2015 to 2019 at 7 sampling sites, with Chlorophyta dominating in number of species. Phytoplankton abundance varied from 0.18×105 to 21.2×105 cells/L during the study period, mainly due to cyanobacteria. Seven of the 23 functional groups were considered to be dominant (relative density > 5%).  The dominant functional groups were groups M and G in the dry season and groups M, G, P, and E in the rainy season. Group M (Microcystis aeruginosa) was the most common in both seasons, while group P (Closterium, Staurastrum, Aulacoseira), group E (Dinobryon, Synura), and group G (Sphaerocystis, Eudorina) were more common in the rainy season. The Shannon diversity index (H¢) showed that phytoplankton communities were relatively diverse and that most of the study sites were lightly polluted. However, the ecological status has deteriorated at some locations due to the overgrowth of group M, leading to eutrophication in this reservoir. This study highlights the usefulness of functional groups in the study of seasonal changes in phytoplankton dynamics. Functional groups are applied for the first time at Tuyen Lam Reservoir and can be used to predict early-stage cyanobacterial blooms in future studies

Evaluating household coal slag emissions in Binh Chanh District, Ho Chi Minh City, Viet Nam and recommended solutions

In Viet Nam, apart from coal-fired power plants, coal slag also emitted from households via coal burning activities. However, the quantity of slag emitted from households has been rarely determined, and most of it is not been well-treated. In addition, it is well-known that the untreated or mistreated coal slag can lead to severe impacts on both the environment and human health. Therefore, it is necessary to evaluate the emission of this slag, and thereafter to provide recommendations for improved management. In this study, the emission of household coal slag in Binh Chanh District of Ho Chi Minh City, Vietnam was investigated by undertaking a fact-finding survey coupled with GPS. Coal burning experiments were also performed for various fuels including large-sized honeycomb charcoal (3 kg/piece); small-sized honeycomb charcoal (1.7 kg/piece); charcoal (1 kg) and dried firewood with rice husk (1 kg) to estimate the quantity of household coal slag emissions slag, as well as to primarily examine the impact to the environment and human health. Results showed that the emissions of household coal slag in the study area was considerable, up to 146 tonnes per year,  almost 60% of which, was directly discharged into the environment. The burning coal for household purposes was found to dramatically change the quality of air with high concentration of pollutants including formaldehyde (HCHC), total volatile organic compound (TVOC), as well as particulate matters (PM2.5 and PM10) in exceedance of national standards which led to health effects. Finally, solutions for managing the slag were proposed

Peatmass Change and Water Level Influencing Regenerated Melaleuca Forest after a Fire in U Minh Thuong National Park, Vietnam

Following the largest forest fire in Vietnam in 2002, various activities were undertaken to sustain the mangrove forest on peat soil remnants in the Mekong Delta region. These activities included promoting natural regeneration, afforestation, and rapid forest restoration measures, in addition to other protective measures such as rainwater retention to maintain moisture levels for fire prevention. However, two critical challenges emerged: allowing the forest to naturally regenerate would lead to annual forest fires but maintaining a constant water level through year-round water retention would harm biodiversity. The study was conducted in U Minh Thuong National Park to address forest regeneration. After a major forest fire in Vietnam, various measures were taken to promote forest regeneration, including afforestation, silvicultural solutions, and hydrological techniques such as rainwater storage to maintain humidity and prevent future fires. A hand drill was used to collect samples, and a total of 15 plots were set up to survey the growth of the forest at three peat thickness levels. At each of the three collection sites, samples of one kg were collected and labeled according to the site as UTM1, UTM2, and UTM3. The samples were then sent to the laboratory of the Southern Institute of Forestry Science for analysis. There was a relationship between the chemical indicators of peat and the evolution of the Melaleuca forest. Peat thickness and flooding regime significantly influenced the growth of the Melaleuca forest, while another identified relationship was between peat chemical indicators and forest growth. The chemical composition of peat water changed significantly due to the rainy and dry seasons, with nutrient content and pH affecting forest growth. Peat thickness and flooding regime were essential in regulating forest growth. These studies highlight the importance of considering multiple factors, such as peat thickness and chemical properties, when developing effective forest restoration strategies. By understanding the relationship between peat thickness, chemical properties, and forest growth, forest managers can develop targeted strategies to promote regeneration while minimizing negative impacts on biodiversity

Income Diversification and Financial Performance: The Mediating Effect of Banks’ Size, Ownership Structure, and the Financial Crisis in Vietnam

Research aims: This study focuses on the correlation between income diversification and financial performance, taking into account banks’ size, type of ownership, and the financial crisis.Design/Methodology/Approach: This study uses financial data of 29 commercial banks in Vietnam during the period from 2005 to 2018. This research employs a Generalized Method of Moments (GMM) regression.Research findings: The results do not find statistical evidence of a direct effect of banks’ income diversification on their financial performance. However, when considering the classification factors, such as the bank’s size and ownership type, the findings show that big banks and state-owned banks could take advantage of diversification strategies to boost their profitability. Moreover, the study has proven that income diversification generates a significant positive effect on banks’ financial performance during the crisis time.Theoretical contribution/Originality: This study provides a theoretical evidence on the direct effect of income diversification on a bank’s financial performance concerning banks’ size, ownership type, and the financial crisis.Practitioner/Policy implication: Further, this research also offers the bank’s managers, policymakers, and investors an insight of good banks’ financial performance in the context of an unstable economy.Research limitation/Implication: The limitations still exist in this research, such as (1) the number of banks participating in the research sample was a predictable limitation; (2) this research mainly focused on financial variables but ignored the variables representing the managers’ behavior and the banks’ organizational structure; (3) the future studies can focus on these aspects to explore further the hidden picture of diversification strategy and banking performance

Multi-correlation between nematode communities and environmental variables in mangrove-shrimp ponds, Ca Mau Province, Southern Vietnam

Multi-correlation between bio-indices of nematode communities and ecological parameters in mangrove-shrimp farming ponds in Tam Giang commune, Nam Can District, Ca Mau Province, Vietnam were investigated. In which, diversities of nematode communities and several environmental variables in eight ponds were considered to process. Our findings underlined the high diversity of nematode communities in mangrove-shrimp farming ponds compared to other mangrove habitats. Nematode diversities provided more oppotunity in natural food for shrimp. Single correlation analyses showed that the species richness index correlated significantly to three variables (salinity, total organic carbon, and total nitrogen), the Margalef diversity index correlated to two variables (salinity, total organic carbon), and the expected number of species for 50 individuals index correlated with one variable (salinity). Results of multi-correlation analyses between the nematode bio-indices and the environmental variables were completely different from those of single-correlation analyses. In multi-correlation analyses, the species richness and the Margalef diversity index correlated to two variables (salinity, total organic carbon), Pielou’s evenness index and Hill indices correlated with dissolved oxygen, also the Hurlbert index correlated to total organic carbon. Hence, it is necessary to pay attention to the impact of complex interactions between the multi-environmental variables and nematode communities. This research aims to explain the differences between single- and multi-correlation for evaluation of the effects of environmental factors on nematodes as well as aquatic organisms.

Biocompatible chitosan-functionalized upconverting nanocomposites

Simultaneous integration of photon emission and biocompatibility into nanoparticles is an interesting strategy to develop applications of advanced optical materials. In this work, we present the synthesis of biocompatible optical nanocomposites from the combination of near-infrared luminescent lanthanide nanoparticles and water-soluble chitosan. NaYF4:Yb,Er upconverting nanocrystal guests and water-soluble chitosan hosts are prepared and integrated together into biofunctional optical composites. The control of aqueous dissolution, gelation, assembly, and drying of NaYF4:Yb,Er nanocolloids and chitosan liquids allowed us to design novel optical structures of spongelike aerogels and beadlike microspheres. Well-defined shape and near-infrared response lead upconverting nanocrystals to serve as photon converters to couple with plasmonic gold (Au) nanoparticles. Biocompatible chitosan-stabilized Au/NaYF4:Yb,Er nanocomposites are prepared to show their potential use in biomedicine as we find them exhibiting a half-maximal effective concentration (EC50) of 0.58 mg mL–1 for chitosan-stabilized Au/NaYF4:Yb,Er nanorods versus 0.24 mg mL–1 for chitosan-stabilized NaYF4:Yb,Er after 24 h. As a result of their low cytotoxicity and upconverting response, these novel materials hold promise to be interesting for biomedicine, analytical sensing, and other applications