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This study investigates the instructional strategies Vietnamese EFL lecturers prefer to employ to teach productive skills of general English in online and face-to-face teaching environments. Thirty-eight lecturers from 6 Vietnamese universities participated and responded to a questionnaire with 29 close-ended questions detailing instructional strategies. Four of the participants were invited to join the semi-interview about the reasons for their preference for instructional strategies. The collected data were analyzed with descriptive statistics for Quantitative data and content analysis for qualitative data. The findings indicate that the most favored strategy in both teaching environments is describing pictures while opinion sharing and group discussion are much more favorable in the face-to-face than in the online teaching environment. Additionally, certain strategies are preferred in the face-to-face setting over instruction in the online setting and vice versa. Some primary reasons for lecturers’ preference for instructional strategies were identified and participants gave some recommendations of choosing appropriate strategies for teaching productive skills via interviews. These findings highlight EFL lecturers' preferences in selecting instructional strategies to teach English productive skills in the two teaching contexts and underscore implications for choosing proper instructional strategies.

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Plant fibrous suspensions require electrostatically cationic polymers to provide proper and strong structures during papermaking. The charge bearing naturally and synthetically polymers (Polyelectrolytes), are considered as the most chemicals used in cellulosic products mills, due to improvement in the fibrous suspension and network properties. For this, cationic acrylamide polymer (CPAM) and anionic nano cellulose (ANC) were added individually and in combination forms into the fibrous suspension recycled from brown packaging papers. Compared to the blank sample without any the polymeric additive, the polymeric contained suspensions and networks revealed improvements in fibrous suspension properties; i.e., retention, freeness and the solid materials loss during the network formation; and in the fibrous dried network, include density, tensile and burst strengths. Individually application of each CPAM and ANC increased the suspension retention (productivity) as 8% and 2%, resp. Fibrous suspension freeness and loss materials content continuously increased and decreased up to 47%, respectively that could provide significant technologically and economically benefits. Paper density (+5%), tensile (+17%) and burst (+27%) properties improved drastically compared to the blank. But, tear strength of fibrous network decreased (-4%) which could be attributed to the network higher fines contents and retention, originated from the acrylamide polyelectrolyte flocculation effect. Individually application of ANC also enhanced suspension retention, network density, tensile and burst strengths and declined network tear strength with lesser suspension freeness and loss. Anionic nature, high specific surface area and huge hydrogen bonding potential of ANC are the main reasons of the obtained results. ANC post addition to CPAM contained suspension resulted in tear reduction, but higher suspension retention and freeness, together with higher density, tensile and burst strength of cellulosic network. 

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The combination of face-to-face and online teaching, also called Blended learning (BL) has practically become one of the prevalent models of teaching and learning all over the world. Particularly, it has been applied as a new trend of using technology to concurrently combine in-class and out-of-class learning to optimize the educational impacts on students. However, BL is still quite a new learning model and has not been applied widely in teaching English in Vietnam. The current study was conducted to explore students’ perceptions of BL, the difficulties students think they have, and the percentage of face-to-face and online learning they prefer when learning in the BL environment. Sixty civil engineering students participating in the survey filled out a questionnaire after the forms of BL and the Learning Management System (LMS) Moodle had been introduced to them. The findings indicated that more than half of the participants were stimulated by BL and willing to take on the challenges.  Nevertheless, some concerns about the lack of IT skills to fulfill the requirements of the BL course cannot be ignored.


 

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While cognitive and social-affective strategies have straightforward impacts on learners’ academic performance attached to specific tasks in a communicative and student-centered language classroom, metacognitive strategies, with their vigorous power, are arguably worth more attention. This group of strategies plays a vital role in making students become more self-directed and autonomous learners. This paper reported on a study investigating Vietnamese university students’ perception of using metacognitive strategies in their listening activities. Specifically, 140 English majors at the foreign language department of a university in Vietnam were involved in the study. Based on quantitative data from a questionnaire slightly adapted from Vandergrift et al. (2006), it was found that students in the study generally had a relatively high awareness of metacognitive strategies, with varying levels across the five subcategories of specific strategies. In addition, a comparison between the two groups (first-year and third-year students) showed minor differences regarding their listening strategy awareness. The findings suggested that metacognitive strategies should be encouraged, and listening strategies should be instructed early in English education programs.  

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 The objective of this study was to explore the microbial community diversities and the relationships between microbial community compositions and hydrochemical factors in nitrate contaminated groundwater of Hun River alluvial plain. The method of polymerase chain reaction (PCR)-denaturing, gradient gel electrophoresis (DGGE) gene fingerprints combined with canonical correspondence analysis（CCA） were applied. The Operational Taxonomic Units (OTUs) of all the sampling sites had a certain degree of heteroplasmy and 75% OTUs presented in less than half of the sampling sites. The un-weighted pair group mean average (UPGMA) cluster analysis showed that the microbial community similarity of all the sampling sites were not relatively high (0.6-0.8). The distribution of microbial community positively correlated with nitrate. The dominant bacteria of the nitrate contaminated groundwater mainly included Hyphomicrobium denitrifican sp., Halanaerobium praevalens sp., Desulfotomaculum reducens sp., Nitrosospira multiformis sp., among which the Nitrosospira multiformis sp.and Sulfurovum sp. existed in all the sampling sites. CCA results indicated that Mn²⁺and NO₃^- were the most relevant hydrochemical factors to regulate the microbial composition in nitrate contaminated groundwater of this area, and next were Fe²⁺ and SO₄^2- . The results could provide references for the bioremediation of the nitrate contaminated groundwater of Hun River alluvial plain

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The most important post harvesting factors that limiting grape berries after post harvesting are water losing and fungal decay. In this study, effect of titanium dioxide (TiO₂) and soy protein isolate edible coating against postharvest decay and increasing the storage life of table grape cultivar was investigated. Uniform clusters with no disease and physical damage were packed with coated and uncoated (control) TiO₂ nanoparticles. Then clusters were maintained for 31 days in cold storage at 0 ± 1 °C and RH 90 ± 5%. Grape berries abscission rate, total soluble solids (TSS), titratable acidity (TA), total phenolic content, color and clarity of grape berries, pH, antioxidant activity and total sugar characteristics were measured at intervals 6 days. The statistical analysis of results showed that the TiO₂ nanoparticles treatment had significant effects in cluster and grape berries weight losing, fungal infection, TA, total phenol content and coefficient of ripening. This treatment had best flavor, quality, appearance and marketability compared with the samples without TiO₂ nanoparticles treatment. In addition, the samples that treated with TiO₂ nanoparticles showed higher TSS, TA, antioxidant activity, total sugar and total phenolic content. In the present study, two varieties of grapes treated with TiO₂ nanoparticles in the comparison of control samples had higher quality at the end of the storage period.

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Today, consumption of milk and its products is one of the signs of development of human societies. Milk is a healthy, nutritious, delicious and thirsty drink that is consumed by a large group of people, especially children. Therefore, the aim of this study was using grape syrup as a flavoring in probiotic milk containing Bacillus coagulants and investigating effects of grape syrup on physicochemical and microbial properties of probiotic milk. For this purpose, two quantitative factors including grape syrup concentrations (0.17, 1, 3, 5 and 5.83 %) and storage time (0.96, 2, 4.5, 7 and 8.04 days) in five levels were evaluated by using a central composite design. The results showed that different concentrations of grape syrup and storage time on pH, acidity, dry matter, fat and viability of B. coagulation of probiotic flavored milk were significant (P<0.05). The optimum condition was obtained based on maximum pH and viability of B. coagulation and minimum acidity. The optimum condition was 1% grape syrup and 2 days’ storage time, which its total desirability was 95%.

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The aim of this study was to identify the lactic acid of the dominant bacteria in pickled garlic, using initial biochemical tests and PCR technique and to investigate their potential probiotic potential. For this purpose, to determine the probiotic potential of these isolates, some confirmatory tests including resistance to acid, resistance to simulated gastric conditions, resistance to bile salts, activity against pathogenic bacteria, susceptibility to some common antibiotics and hemolytic activity of isolates were performed. Based on BLAST results, five isolates of Lactobacillus plantarum, two isolates as Pediococcus ethanolidurans and one isolate as Lactobacillus brevis were identified. The lactic acid bacteria isolated in this study had the ability to survive at pH 2.5, grow in medium containing 0.3% bile salt, were sensitive to antibiotics and lacked hemolytic activity and therefore have probiotic properties. Supernatant of isolates of this study in high concentrations had the ability to inhibit growth of pathogenic bacteria and the lethal activity against them. Finally, the isolates of this study can be added to other products in the future as a strain with probiotic potential.

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Background and Aim:  According to the widespread epidemic of the COVID-19 around the world and the irreparable damage in all aspects of human life, surveying coping methods with this epidemic is one of the research priorities of societies. The aim of this study was to find the factors that predict the severity of the disease and the resulting death.
Methods: This descriptive-analytical study was performed on patients with COVID19 admitted to Bu-Ali Sina hospital in Qazvin in March 2020. Epidemiological, clinical, laboratory, and radiological characteristics of patients was collected. Data were analyzed by independent t-test and Mann-Whitney U test (for normally and non-normally distributed quantitative variables, respectively) and chi-squared (for qualitative variables) on SPSS version 22. P<0.05 was considered significant.
Results: The study population included 119 admitted COVID-19 patients. 94 patients recovered and 25 patients died. The deceased patients were significantly older than recovered patients (P=0.0007).  The frequency of smoking in our study was 5.4% of patients. The deceased patients had higher lymphopenia (P=0.015), neutrophil number (P=0.009), blood urea nitrogen (P=0.012) and creatinine (P=0.032) were significantly higher and blood oxygen saturation (P=0.001) was significantly lower in deceased patients than those who recovered.
Conclusion: Percentages of smokers in hospitalized patients with COVID-19 disease was significantly lower than general population. If COVID-19 patients are in the high-risk group, including older people having sever hypoxia, lymphopenia, neutrophilia, impaired renal function and sever lung involvement in CT scan should be examined with extra care due to the increased chance of death in these patients.