A solution for synchronous incremental maintenance of materialized views based on SQL recursive query

Materialized views are excessively stored query execution results in the database. They can be used to partially or completely answer queries which will be further appeared instead of re-executing query from the scratch. There is a large number of published works that address the maintenance, especially incremental update, of materialized views and query rewriting for using those ones. Some of them support materialized views based on recursive query in datalog language. Although most of datalog queries can be transferred into SQL queries and vise versa but it is not the case for recursive queries. Recursive queries in the data log try to find all possible transitive closures. Recursive queries in SQL (Common Table Expression – CTE) return direct links but not transitive closures. In this paper, we propose efficient methods for incremental update of materialized views based on CTE; and then propose an algorithm for generating source codes in C language for any input SQL recursive queries. The synthesized source codes implement our proposed incremental update algorithms according to inserted/deleted/updated record set in the base tables. This paper focuses mainly on the recursive queries whose execution results are directed tree-structured data. The two cases of tree node are considered. In the first case, a child node has only one parent node and in the second case, a child node can have many parent nodes. Those two cases represent the two types of relationships between entities in real world, that are one–to–many and many–to–many, respectively. For the one–to–many relationships, the relationship data is accompanied with the records describing the child using some fields. Those fields are set as null in deleting a concrete relationship. For the many–to–many relationships, it is stored in a separate table and the concrete relationships are removed by deleting describing records from that table. Considering of enforcing referential integrity may help to reduce the searching space and therefore, help to improve the performance. However, the set of tree nodes or tree edges can be manipulated. All those combinations lead to different algorithms. The experimental results are provided and discussed to confirm the effectiveness of our proposed method

A solution for synchronous incremental maintenance of materialized views based on SQL recursive query

Materialized views are excessively stored query execution results in the database. They can be used to partially or completely answer queries which will be further appeared instead of re-executing query from the scratch. There is a large number of published works that address the maintenance, especially incremental update, of materialized views and query rewriting for using those ones. Some of them support materialized views based on recursive query in datalog language. Although most of datalog queries can be transferred into SQL queries and vise versa but it is not the case for recursive queries. Recursive queries in the data log try to find all possible transitive closures. Recursive queries in SQL (Common Table Expression – CTE) return direct links but not transitive closures. In this paper, we propose efficient methods for incremental update of materialized views based on CTE; and then propose an algorithm for generating source codes in C language for any input SQL recursive queries. The synthesized source codes implement our proposed incremental update algorithms according to inserted/deleted/updated record set in the base tables. This paper focuses mainly on the recursive queries whose execution results are directed tree-structured data. The two cases of tree node are considered. In the first case, a child node has only one parent node and in the second case, a child node can have many parent nodes. Those two cases represent the two types of relationships between entities in real world, that are one–to–many and many–to–many, respectively. For the one–to–many relationships, the relationship data is accompanied with the records describing the child using some fields. Those fields are set as null in deleting a concrete relationship. For the many–to–many relationships, it is stored in a separate table and the concrete relationships are removed by deleting describing records from that table. Considering of enforcing referential integrity may help to reduce the searching space and therefore, help to improve the performance. However, the set of tree nodes or tree edges can be manipulated. All those combinations lead to different algorithms. The experimental results are provided and discussed to confirm the effectiveness of our proposed method

HIGH PROTECTION PERFORMANCE OF COATING SYSTEMS BASED ON ZINC RICH PRIMER AND FLUOROPOLYMER COATING

Coating systems based on zinc rich primer and fluoropolymer top coat were exposed for 8 years at different atmospheric stations in Vietnam: Hanoi, Ha Long and Nha Trang. For comparison the coating system with zinc rich primer and polyurethane topcoat was also tested. The degradations of coating systems were evaluated by gloss measurement and electrochemical impedance spectroscopy. The obtained results show that coating systems with zinc rich primer and top coatings based on fluoropolymer  and polyurethane topcoats show very high weather resistance and corrosion protection performance, but the systems with fluoropolymer are better than coating system with polyurethane topcoat

The Epidemiology of Interpandemic and Pandemic Influenza in Vietnam, 2007–2010: The Ha Nam Household Cohort Study I

Prospective community-based studies have provided fundamental insights into the epidemiology of influenza in temperate regions, but few comparable studies have been undertaken in the tropics. The authors conducted prospective influenza surveillance and intermittent seroprevalence surveys in a household-based cohort in Vietnam between December 2007 and April 2010, resulting in 1,793 person-seasons of influenza surveillance. Age- and sex-standardized estimates of the risk of acquiring any influenza infection per season in persons 5 years of age or older were 21.1% (95% confidence interval: 17.4, 24.7) in season 1, 26.4% (95% confidence interval: 22.6, 30.2) in season 2, and 17.0% (95% confidence interval: 13.6, 20.4) in season 3. Some individuals experienced multiple episodes of infection with different influenza types/subtypes in the same season (n = 27) or reinfection with the same subtype in different seasons (n = 22). The highest risk of influenza infection was in persons 5–9 years old, in whom the risk of influenza infection per season was 41.8%. Although the highest infection risk was in school-aged children, there were important heterogeneities in the age of infection by subtype and season. These heterogeneities could influence the impact of school closure and childhood vaccination on influenza transmission in tropical areas, such as Vietnam

Polyphasic evaluation and cytotoxic investigation of isolated cyanobacteria with an emphasis on potent activities of a Scytonema strain

DATA AVAILABILITY STATEMENT : The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/supplementary material.Cyanobacteria are phototrophic organisms widely found in most types of natural habitats in the tropical regions of the world. In this study, we isolated and identified cyanobacterial strains from paddy soil in Hanoi (Vietnam) and investigated their cytotoxic activities. Five isolated cyanobacterial strains showed distinctive profiles of gene sequences (rRNA 16S and rbcL), phylogenetic placements, and morphological characteristics. Based on the polyphasic evaluation, they were classified as Scytonema bilaspurense NK13, Hapalosiphon welwitschii MD2411, Aulosira sp. XN1103, Desikacharya sp. NS2000, and Desmonostoc sp. NK1813. The cytotoxic screening revealed that the extract of strain Scytonema bilaspurense NK13 exhibited potent cytotoxic activities against four human cell lines of HeLa cells, OVCAR-8 cells, HaCaT cells, and HEK-293T cells, with IC50 values of 3.8, 34.2, 21.6, and 0.6μg/mL, respectively. This is the first time a well-classified Scytonema strain from tropical habitat in Southeast Asia has been recognized as a potential producer of cytotoxic compounds.The Vietnam National University, Hanoi (VNU).http://www.frontiersin.org/Microbiologyam2023BiochemistryGeneticsMicrobiology and Plant Patholog

Application of social media in supply chain 4.0 practices: a bibliometric analysis and research trends

In recent years, although scholars and practitioners in the supply chain (SC) field have become increasingly aware of the importance of social media for multipurpose applications, the subject remains unclarified about its functions and outcomes, especially in the 4.0 context. This review paper aims to visualize the big picture and structure of knowledge related to the application of social media in managing supply chains by adopting a bibliometric analysis on a sample of 354 research articles retrieved from the Web of Science during the period between 2008 and 2022 with two widely used bibliometric techniques: co-citation and co-word analysis. We discovered five major clusters of how social media is used in the supply chain context, including (1) in enhancing supply chain sustainability and business transformation, (2) social media analytics as an effective technique to extract business value, (3) in facilitating communication and coordination in the supply chain network, (4) in promoting social interaction and customer relationship management, and (5) in the development of supply chain relationship management. These will enable practitioners to adopt early changes in their SC, allowing them to become competitive and gain market leadership. Supply chain managers can connect with other SC stakeholders and share information through social media to improve operations, establish relationships, reduce risks, and altogether reach for sustainability. Potential research ideas are also offered for future investigation

A novel solution of enhanced loss function using deep learning in sleep stage classification : predict and diagnose patients with sleep disorders

Sleep stage classification is important to accurately predict and diagnose patients with sleep disorders. Though various deep learning approaches have been implemented to classify sleep classes, these consist limitations that impact the accuracy and processing time of the classification model. The aim of this research is to enhance the accuracy and minimize the training time of the deep learning classification model. The proposed system consists of One Dimensional Convolutional Neural Network (CNN) with enhanced loss function to improve the accuracy of scoring of five different sleep classes. Preprocessing, Feature Extraction and Classification are the main components of the proposed system. Initially, EEG signals are fed to an adaptive filter for preprocessing, in order to remove any noise in signal. Thereafter, feature is extracted through multiple convolutional and pooling layers, and finally the classification is done by fully connected layer using softmax activation with enhanced loss function. The proposed solution is tested on data samples from multiple datasets with five classes of Sleep classification. Based on the obtained results, the proposed solution has found to achieve an accuracy of 96.26% which is almost 4.2% higher than the state-of-the-art solution which is 92.76%. Furthermore, the processing time has been reduced by 11 milliseconds against the state-of-the-art solution. The proposed system focused on classifying sleep stages in five classes using EEG signals with deep learning approach. It enhances the loss function in order to minimize errors in the prediction of sleep classes and improves the accuracy of the model. Furthermore, the training speed of the model has also been reduced by applying batch normalization techniques inside the model. In the future, larger datasets of different sleep disorder patients with varying features can be used for training and implementing the proposed solution. The datasets can also be pre-processed using additional techniques to refine the data before feeding to the neural network model

Developmental Toxicity of Clerodendrum cyrtophyllum Turcz Ethanol Extract in Zebrafish Embryo

ETHNOPHARMACOLOGICAL RELEVANCE: Clerodendrum cyrtophyllum Turcz has been used in traditional medicine for the treatment of various diseases. In spite of its therapeutic applications, research on its toxicity and teratogenicity is still limited. AIM OF THE STUDY: The study aimed to investigate the developmental toxicity of the ethanol extract of C. cyrtophyllum (EE) in zebrafish embryo model. MATERIAL AND METHODS: Major compounds from crude ethanol extract of Clerodendron cyrtophyllum Turcz leaves were determined using HPLC-DAD-Orbitrap-MS analysis. The developmental toxicity of EE were investigated using zebrafish embryo model. Zebrafish embryos at 6 h post-fertilization (hpf) were treated with EE at different concentrations. Egg coagulation, mortality, hatching, yolk sac oedema, pericardial oedema and teratogenicity were recorded each day for during a 5-day exposure. At time point 120 hpf, body length, pericardial area, heartbeat and yolk sac area were assessed. In order to elucidate molecular mechanisms for the developmental toxicity of EE, we further evaluated the effects of the EE on the expression of genes involved on signaling pathways affecting fish embryo's development such as heart development (gata5, myl7, myh6, has2, hand2, nkx 2.5), oxidative stress (cat, sod1, gpx4, gstp2), wnt pathway (β-catenin, wnt3a, wnt5, wnt8a, wnt11), or cell apoptosis (p53, bax, bcl2, casp3, casp8, casp9, apaf-1, gadd45bb) using qRT-PCR analysis. RESULTS: Our results demonstrated that three major components including acteoside, cirsilineol and cirsilineol-4'-O-β-D-glucopyranoside were identified from EE. EE exposure during 6- 96 h post-fertilization (hpf) at doses ranging from 80 - 200 μg/ml increased embryo mortality and reduced hatching rate. EE exposure at 20 and 40 μg/ml until 72 - 120 hpf induced a series of malformations, including yolk sac oedema, pericardial oedema, spine deformation, shorter body length. Based on two prediction models using a teratogenic index (TI), a 25% lethality concentration (LD25) and the no observed-adverse-effect level (NOAEL), EE is considered as teratogenic for zebrafish embryos with TI (LC50/EC50) and LD25/NOAEC values at 96 hpf reaching 3.87 and 15.73 respectively. The mRNA expression levels of p53, casp8, bax/bcl2, gstp2, nkx2.5, wnt3a, wnt11, gadd45bb and gata5 were significantly upregulated by EE exposure at 20 and 40 μg/ml while the expression of wnt5, hand2 and bcl2 were downregulated. CONCLUSIONS: These results provide evidence for toxicity effects of EE to embryo stages and provide an insight into the potential toxicity mechanisms on embryonic development