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Differential effects of arsenite and arsenate on rice (Oryza sativa) plants differing in glutathione S-transferase gene expression Full text
2023
Pandey, Ambika | Wu, Lin-Bo | Murugaiyan, Varunseelan | Schaaf, Gabriel | Ali, Jauhar | Frei, Michael
Contamination of paddy soils with arsenic (As) can cause phytotoxicity in rice and increase the accumulation of arsenic in grains. The uptake and accumulation of As in rice depends on the different As species present in the soil. Plants detoxify As by conjugating and sequestering xenobiotic compounds into vacuoles using various enzymes. However, the severity of damage induced by arsenite (As(III)) and arsenate (As(V)), as well as the roles of glutathione S-transferase in detoxifying these As species in rice, are not fully understood. In this study, we developed plant materials overexpressing a glutathione S-transferase gene OsGSTU40 under the control of the maize UBIL promoter. Through systematic investigations of both wild-type Nipponbare (Oryza sativa L., ssp. japonica) and OsGSTU40 overexpression lines under chronic or acute stress of As, we aimed to understand the toxic effects of both As(III) and As(V) on rice plants at the vegetative growth stage. We hypothesized that (i) As(III) and As(V) have different toxic effects on rice plants and (ii) OsGSTU40 played positive roles in As toxicity tolerance. Our results showed that As(III) was more detrimental to plant growth than As(V) in terms of plant growth, biomass, and lipid peroxidation in both chronic and acute exposure. Furthermore, overexpression of OsGSTU40 led to better plant growth even though uptake of As(V), but not As(III), into shoots was enhanced in transgenic plants. In acute As(III) stress, transgenic plants exhibited a lower level of lipid peroxidation than wild-type plants. The element composition of plants was dominated by the different As stress treatments rather than by the genotype, while the As concentration was negatively correlated with phosphorus and silicon. Overall, our findings suggest that As(III) is more toxic to plants than As(V) and that glutathione S-transferase OsGSTU40 differentially affects plant reactions and tolerance to different species of arsenic.
Show more [+] Less [-]Concentration of Toxic Heavy Metals and Phytochemicals in a Medicinal Plant (Asclepias fruticosa) Collected Around Mining Areas in Brits, Pretoria Full text
2023
L. L. Mugivhisa, D. Mzimba and J. O. Olowoyo
The use of African traditional medicine in rural and peri-urban areas is common due to its affordability and accessibility. The study aimed to determine the levels of toxic heavy metals in the medicinal plant (Asclepias fruticosa) samples collected around three mining areas in Brits using ICP-OES. The phytochemical screening analysis was done to indicate the absence or presence of different phytochemicals in the medicinal plant. The results of the qualitative phytochemical analysis indicated the presence of flavonoids, alkaloids, proteins, and carbohydrates in Asclepias fruticosa collected from all the mining areas. The results of the heavy metals showed that the mean highest concentration for all the heavy metals was recorded for Mn from the leaves of the medicinal plants. The trend in the heavy metals accumulation was roots > leaves > stems from all the sites, and the differences were significant (p < 0.05). The range of heavy metals in the plant was in the range Mn (12.33 ± 2.31-85.33 ± 51.07 μg.g-1), Zn (10.67 ± 0.58-60.33 ± 0.56 μg.g-1), Cr (3.43 ± 0.06 -34.90 ± 0.10 μg.g-1), Cu (8.67 ± 0.12-18.8 ± 1.57 μg.g-1), Ni (5.67 ± 0.12-23.23 ± 1.7 μg.g-1) and Pb (0.53 ± 0.013-1.59 ± 0.15 μg.g-1). The values of the heavy metals Cr, Zn, and Ni in the plant exceeded the recommended limits set by WHO for human consumption. Heavy metals in the medicinal plant were accumulated in the roots and not translocated to the stems and leaves. It is therefore recommended that communities staying around the mines should be discouraged from picking and using medicinal plants growing around the mines and should be educated on the safety of medicinal plants growing around the mines.
Show more [+] Less [-]Radiation Risk Among Children due to Natural Radioactivity in Breakfast Cereals Full text
2023
H. H. Abbas, Shaymaa A. Kadhim, Shatha F. Alhous, H. H. Hussein, F. A. AL-Temimei and H. A. A. Mraity
Breakfast cereal is one of the common foods for children’s nutrition. It is made from sugar, barley, calcium carbonate, salt, maize, peanuts, molasses, and honey. Therefore, assessing the levels of radioactivity in breakfast cereal is essential for children’s health. Gamma-ray spectrometry NaI(Tl) was used to measure the radiation hazard in ten samples collected from the Iraqi market. The corresponding radiation dose quantities and hazard indices were also calculated. The average concentrations of 226Ra, 232Th, and 40K were found to be 18.195, 20.965, and 796.500 (Bq.kg-1). The annual effective dose equivalent (AEDEin), annual ingestion dose (AID), and the risk of cancer incidence (ELCR) were all seen to be within the accepted levels, except the annual gonadal equivalent dose (AGED). Radiation hazard index values (i.e., Iγ, Iα, and Hin) were noticed to be lower than unity, except Iγ was much higher than the internationally permissible limits for the samples of BGF5, BGF6, and BGF7 recommended by UNSCER2000. Therefore, the study findings reveal that this type of cereal can be considered a safe feeding material for children’s health.
Show more [+] Less [-]Statistical Model for Tube Settler Clarifier at Different Operational Conditions Full text
2023
Abdulmuhsin S. Shihab and Aladdin M. Ahmad
The present study aimed to find a relationship between turbidity removal percent in tube settler clarifier and independent variables (tube inclination, alum dosage, and surface loading rate) by constructing a statistical model and categorizing these explanatory variables according to their impact on turbidity removal percentage. A pilot scale of tube settlers was designed and fabricated to conduct the experiments. It consisted of a coagulation and flocculation basin, pre-tube settler chamber, and tube settler. Alum was used to coagulate the Tigris river raw water at different dosages. After flocculation, water is transferred to the pre-tube settler chamber and flows through the tube settler. It consists of four tubes of square section, 4 centimeters in diameter, with the flexibility of changing tube length and inclination angle to obtain different levels of surface loading rate. More than 120 experiments were conducted, and the results were analyzed statistically. A regression model was found with a coefficient of determination of 0.802 between turbidity removal percentage as a dependent variable and each tube inclination, alum dosage, and surface loading rate as independent variables. The model is considered good as the model’s relationship between actual and predicted values has a slope of one and a constant near zero. Surface loading rate has the highest effect on turbidity removal percentage with 4.44 times that of inclination angle and 2.5 times for the optimum alum dosage model. The study concluded that the linear model is suitable to represent the performance of tube settlers at optimum alum dosage.
Show more [+] Less [-]Modeling of Activated Sludge Process Using Multi-Layer Perceptron Neural Networks Full text
2023
Saurabh Sahadev , G. Madhu and M. Roy Thomas
Mathematical Modeling of the activated sludge process (ASP) enhances the understanding of the process and improves the quality of the effluent released. However, as the process is complex and nonlinear, mathematical modeling of the process has been a challenge. In this study, multi-layer perceptron neural networks (MLP-ANN) are investigated to predict water quality parameters for better control of wastewater treatment plants employing an activated sludge process. The study area selected was in a central district of the southern state of India. The parameters to be investigated are biochemical oxygen demand (BOD), suspended solids (SS), and pH. The model is evaluated based on statistical parameters of correlation coefficient R and mean square error (MSE). The neural network toolbox of MATLAB 2015b is used for modeling and simulation study. It has been found that effluent biochemical oxygen demand was predicted with a maximum correlation coefficient of 0.927 and minimum mean square error of 0.0022, effluent suspended solids were predicted with a maximum correlation coefficient value of 0.947 and minimum mean square value of 0.0058, effluent pH was predicted with a maximum correlation coefficient value of 0.8299 and minimum mean square value of 0.0132.
Show more [+] Less [-]Design and Development of Smart Irrigation System Using Internet of Things (IoT) - A Case Study Full text
2023
G. Sasi Kumar, G. Nagaraju, D. Rohith and A. Vasudevarao
With India’s population growing at a rapid pace, traditional agriculture will have a tough time meeting future food demands. Water availability and conservation are major concerns for farmers. This paper aims to discuss the aspects related to designing and fabricating an automatic irrigation system using the Internet of Things (IoT) which will save the farmer’s time and money significantly. Human intervention in fields will be reduced. Changes in soil moisture are detected by soil moisture sensors and irrigation is automated using IoT. The proposed system is most economical for underdeveloped places because it is very cost-effective. Based on the soil moisture content, the sensor detects and sends signals to the node MCU, which activates the motor. When the plants receive enough water, the motor automatically shuts off. The user will be alerted about the soil’s moisture content through his mobile phone. The proposed smart irrigation system is implemented at our campus which conserves energy and water.
Show more [+] Less [-]Susceptibility Evaluation of Debris Flow Disaster in Plateau Hydropower Cascade Development Reservoir Area Full text
2023
Feng Yang, Xudong Hu, Zhenyao Xia, Lei Cui and Qi Yang
The Rumei Hydropower Station is a typical cascade hydropower development project in a plateau area. The dam site is located in an area with complex topography, lithology, and geological structure. Geological disasters are developed in the area, mainly debris flow. Thus, taking the dam site and the surrounding areas as key evaluation objects, the engineering geological characteristics, geological environment characteristics, and the susceptibility and risk of geological disasters that may be caused are predicted and evaluated. The main methods used in this assessment are the binary logistic regression model and expert evaluation. The results show that the susceptibility to geological disasters is small and medium. The results of this study could provide a scientific basis for the rationality of the general layout and site selection of the project construction in the plateau water elevator level development reservoir area.
Show more [+] Less [-]Effect of Geographic Altitude on Carbon Stock in two Physiographic Units of the Reserved Forest of the Universidad Nacional Agraria de la Selva Full text
2023
M. Reategui, D. Reategui, E. Morales, R. Reategui and C. Aguirre
The objective of the research was to evaluate the effect of geographic altitude on the carbon stock in two physiographic units of the Reserved Forest of the Universidad Nacional Agraria de la Selva, Tingo Maria-Huanuco. The methodology used was the field manual for the remeasurement and establishment of plots of the Amazon Forest Inventory Network (RAINFOR), for which 2 hectares were permanently established (one hectare in low and high hills) in which the diameter (greater than or equal to 10 cm) and the height of the trees were measured. Finally, the density of the wood was obtained from previous studies. The pantropical model formula was used to estimate the carbon stock. The results show that geographic altitude significantly affects carbon stock (p < 0.05) in low and high-hill forests, concluding that this may be due to differences in meteorological variables such as precipitation, temperature, and humidity.
Show more [+] Less [-]Self-Healing and Thermomechanical Properties of Activated Carbon Pyrochar Derived from Municipal Mixed Plastic Waste Pyrolysis with Self-Healing Epoxy Vitrimer Composites Full text
2023
Krishna Moorthy Rajendran, Bhawna Yadav Lamba and Deepak Kumar
An ecological vitrimer is being developed using activated carbon pyrochar from municipal mixed plastic waste pyrolysis into an epoxy composite. Durable vitrimeric materials may be created by adding pyrochar to polymeric composites. Due to their ductility, reusability, and recyclability, vitrimeric materials have become popular and reliable materials. As a result, the self-healing temperature of composite vitrimers is lower via disulfide exchanges than that of virgin epoxy vitrimers. Additionally, compressive studies have been used to study self-healing capacities, and modulus variations have been used to highlight changes in the healing efficiency of the materials.
Show more [+] Less [-]Characterization of Wastewater and Evaluation of Recycling Technologies Using Analytical Hierarchical Process for a University Community Full text
2023
O. J. Oyebode and O. Waterway
Characterization and treatment of greywater are major environmental issues in most nations of the world. The research aims to characterize and evaluate recycling technologies using an analytical hierarchical process for Afe Babalola University Ado-Ekiti (ABUAD) community. A survey was conducted around ABUAD to determine the number of functioning boreholes and active water systems in the area, the total population of students was derived from the total head count of each room and student in each hostel, and a population projection for the next 3 years was conducted to determine the rate at which the student body will grow in terms of future water demands, and daily water volume and questionnaires were used to collect data. Before developing the small-scale model of the greywater filter system (consisting of activated carbon, shaft sand, pebbles, cotton fiber, and gravel), water grey samples were gathered from several ABUAD locations to evaluate the pollution level of each greywater source. A total of 88 students (43 males and 45 females) replied to the survey, revealing their high need for clean water and their dissatisfaction with the water supply in their respective hostels. The water quality tests conducted in the various locations of ABUAD reveal high levels of total dissolved solids (TDS) and turbidity, particularly in the girl’s hostels, and the water was discovered to be predominantly alkaline. After passing a sample of greywater through the small-scale greywater filtering device, it was determined to be effective, since it produced clear, reusable water and a greywater filtration system in ABUAD will yield favorable outcomes.
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