Biodiversity of ciliated protozoa in soil ecosystems and assessment of their potential as bio-indicators of soil quality.

The wide range of goods and services provided by terrestrial ecosystems are dependent on soil function. There is an increasing requirement for policy to monitor soils to improve agricultural productivity and protect soil quality. Soil biota, including protists, have fundamental roles in the services provided by soils, and have been considered as potential effective indicators to assess soil quality. Ciliated protozoa are abundant phagotrophic microorganisms in soil and play important roles in food webs by controlling smaller microorganisms and recycling organic matter. They can also be affected by soil properties, presenting a potential for their use as bio- indicators of soil quality. In the present study, a comparison of the abundance and species richness of soil ciliates and soil properties in the natural and agricultural soils was carried out in order to establish the relationships between soil ciliates and soil properties, and to investigate the potential of soil ciliates as bio-indicators of soil quality. Both field and pot based experiments were used and a wide range of methods was employed to determine soil properties. The abundance and species richness of soil ciliates were determined after 4 days and 10 days of incubation using the non-flooded petri dish method. The results showed that there were significant differences in soil properties amongst the soils investigated and there was a significantly higher abundance of soil ciliates in the natural soils. The seasonal variation in soil ciliate abundance was also clearly seen in the natural habitat. However, there were no significant differences in the total species richness of soil ciliates amongst the three ecosystems investigated. Three potential new species of ciliates were recorded, and one of them is fully described here at morphological and molecular levels. Soil ciliate abundance and total species richness of soil ciliates in the three ecosystems together had positive correlations with soil moisture, soil organic matter, available concentrations of phosphorus, ammonium, the available concentrations of Cu, Ni and Zn, total microbial activity and activity of β-glycosidase, but a negative correlation between ciliate abundance and soil pH was found. No correlations between the abundance of soil ciliates and the available concentrations of K and S and activity of acid-phosphomonoesterase in the three ecosystems together were found. Interestingly, strong negative correlations between ciliate species richness and available concentrations of measured trace metals were shown in the natural soil only. Copper at the highest treatment concentration (960 mg kg-1) decreased significantly the total microbial activity, but stimulated the abundance of soil ciliates after 4 days of incubation due to increased numbers of two species, Homalogastra setosa and Chilodonella uncinata. Similarly, insecticide cypermethrin increased the abundance of soil ciliates, but Homalogastra setosa started to be limited at concentration of 320 mg kg-1. This species was also affected by glyphosate concentrations of 16.82 and 33.6 mg kg-1. The structure of the soil ciliate community changed at the highest concentrations of all pollutants i.e., Cu, cypermethrin and glyphosate at 15 days after application. Overall, this research shows that the abundance and species richness of soil ciliates had strong correlations with soil properties. Hence, they have been shown to be potential bio-indicators for the presence of nutrients, soil pH, soil texture, and contamination from trace metals and pesticides

Factors affecting career turnover intention after graduation among nursing students: A cross-sectional study in Central Vietnam

Background & Aim: Turnover intention can predict the actual turnover behavior of nurses. Previous studies identified a variety of factors influencing nurses' turnover intention. However, few studies investigate nursing students' career turnover intention. This study aimed to examine turnover intention and associated factors among nursing students in Central Vietnam. Methods & Materials: A cross-sectional study was implemented among 425 nursing students recruited through a multistage sampling technique from April to May 2022. Data were collected using a questionnaire including demographic characteristics, fear of COVID-19, perceived academic stress, and turnover intention. Descriptive statistics were used to describe demographic characteristics and study variables. Independent t-test, one-way analysis of variance, and Pearson's correlation coefficients were computed to examine the association between variables. Results: Approximately one-third (32.5%) of the respondents will look for jobs without patient contact, 32.2% would not study nursing if given a choice, and 31.1% often think of not staying in the nursing profession. The sum scores of turnover intention ranged from 3 to 15 with a mean of 9.19 (SD= 2.49). The turnover intention was associated with the year of study, the reason to study nursing, and preparation for nursing school (p<.05). Perceived academic stress had a moderate correlation with turnover intention (r= -.325, p<.05). In contrast, the association between fear of COVID-19 and turnover intention was not significant. Conclusion: A considerable number of nursing students had turnover intention upon graduation. Factors affecting turnover intention should be considered to retain students in educational programs and avoid a future nursing shortage

POTENTIAL BENEFITS OF ARBUSCULAR MYCORRHIZA FUNGI IN SUSTAINABLE AGRICULTURAL CULTIVATION

The Arbuscular Mycorrhiza fungi have a mutualistic relationship with 80% of terrestrial plants. Arbuscular Mycorrhiza fungi are considered as a biofertilizer source because of their positive effects on plant growth and productivity They can help to reduce the amount of chemical fertilizers by up to 50% due to their ability in enhancing crops to uptake mineral nutrients efficently such as nitrogen, phosphorus, potassium, calcium, zinc. . . thereby increasing crop yield. Moreover, this endosymbiotic fungus also shows its potential as a biopesticide due to its ability to biologically antagonize a wide range of fungi, viruses, and nematodes, which cause diseases on plants. Besides, Arbuscular Mycorrhiza fungi also help plants to resist to abiotic streeses such as drought, salinity, and toxicity of heavy metals. The glomalin compound secreted by mycorrhizal fungi has the ability to bind tiny soil particles together to form a stable soil structure and aggregates, helping to improve soil qualitỵ Thus, Arbuscular Mycorrhiza fungi have a high use potential in sustainable agricultural development under the context of climate change such as drought, salinity intrusion

Isolation and characterization of a c-repeat binding factor gene from Tevang-1 maize cultivar

C-repeat binding factor (CBF) proteins are transcription factors involved in plant response to abiotic stresses, especially low-temperature condition. In this research, a CBF3-coding gene was isolated from a cold-acclimation maize variety, Zea mays var. Tevang-1 and denoted as ZmCBF3tv. The isolated gene shared 96.49% homology with the B73-reference gene and had no intron in the coding sequence. By using bioinformatic tools, a number of variations in the nucleotide and amino acid sequences were identified. An alignment between ZmCBF3tv and other CBF/DREB1 proteins from various species revealed functional regions and typical features, such as nuclear localization signal (NLS), the AP2 DNA-binding domain, and acidic-amino-acid-rich segments. Additionally, a phylogenetic analysis based on the AP2 domain showed that the maize CBF3 transcription factor had the highest similarity with that from rice and closely related to other DREB1/CBF protein of monocots. The function of the ZmCBF3tv product is suggested to be a CBF/DREB1 transcription factor.    

Intermetallic Bonding for High-Temperature Microelectronics and Microsystems: Solid-Liquid Interdiffusion Bonding

Solid-liquid interdiffusion (SLID) bonding for microelectronics and microsystems is a bonding technique relying on intermetallics. The high-melting temperature of intermetallics allows for system operation at far higher temperatures than what solder-bonded systems can do, while still using similar process temperatures as in common solder processes. Additional benefits of SLID bonding are possibilities of fine-pitch bonding, as well as thin-layer metallurgical bonding. Our group has worked on a number of SLID metal systems. We have optimized wafer-level Cu-Sn SLID bonding to become an industrially feasible process, and we have verified the reliability of Au-Sn SLID bonding in a thermally mismatched system, as well as determined the actual phases present in an Au-Sn SLID bond. We have demonstrated SLID bonding for very high temperatures (Ni-Sn, having intermetallics with melting points up to 1280°C), as well as SLID with low process temperatures (Au-In, processed at 180°C, and Au-In-Bi, processed at 90–115°C). We have verified experimentally the high-temperature stability for our systems, with quantified strength at temperatures up to 300°C for three of the systems: Cu-Sn, Au-Sn and Au-In

Effects of vermicompost on the growth and yield of spring onion (Allium fistulosum L.)

Spring onion (Allium fistulosum L.) is a popular salad vegetable produced widely over the world, including in Vietnam. Thanks to its flavor and aroma, it is an indispensable ingredient used to flavor soups and other dishes. Vermicompost is a natural and environmentally friendly fertilizer used widely to increase crop production and maintain the sustainability of agrosystems. Consequently, this study was conducted to investigate the efficiency of vermicompost at different application rates in promoting the growth and yield parameters of spring onion. The results show that adding vermicompost to spring onion production had significant positive effects on plant height, number of leaves, number of tillers, individual plant weight, and plot yield. Particularly, the application of vermicompost at 40 t ha-1 showed the highest performance in the observed parameters, increasing the number of leaves, number of tillers, individual plant weight, and plot yields to 64.78, 21.18, 302.96 g plant-1 , and 4.86 kg m-2 , respectively. The plot yields in the treatments of the highest and lowest vermicompost application increased by 49.1% and 3.9%, respectively, in comparison to the control. Consequently, there was a strongly positive relationship between the application rate of vermicompost and the plot yield

Effect of the Cultivation Technology on the Yield of Paddy Straw Mushroom (Volvariella volvacea)

The edible paddy straw mushroom Volvariella volvacea (Bull. ex F.) Singer has high nutritional and medicinal values. They are grown on a wide variety of agricultural byproducts using different several methods. The result of this present study showed that type of bed and cultivation condition (outdoor/indoor) had effects on the yield of paddy straw mushrooms grown on the spent oyster mushroom sawdust. The treatment of circular compact bed under indoor cultivation condition (CYIC) had the best yield and biological efficiency (B.E.) with 2,119.2 g/bed and 14.5%, respectively, followed by the treatment of conventional bed under outdoor cultivation condition (COOC) with the yield and B.E. of 1,935.5 g/bed and 13.2%, respectively, but the lowest yield and B.E. were observed in the treatment of conventional bed under indoor cultivation condition (COIC) with 1,226.1 g/bed and 8.4%, respectively. Paddy straw mushrooms cultivated on spent oyster mushroom sawdust should be proper in both outdoor and indoor conditions by conventional and circular compact methods as well. However, in indoor conditions, paddy straw mushrooms should be grown in a circular compact bed to ensure the temperature of the bed is suitable for the mushroom growth