Twenty day-old seedling of Pokkali (salt-tolerant) and BRRI dhan 29 (salt-sensitive) rice genotypes were exposed to 0, 75 and 150 mM NaCl salinity levels for 7 days to investigate the efficacy of ...ascorbate-glutathione cycle for scavenging H2O2 during salinity stress. Results revealed that salinity caused a significant decrease in photosynthesis rate (A), stomatal conductance (gs), chlorophyll content and shoot dry matter yield, with a greater reduction in the sensitive genotype, BRRI dhan 29. The activity of SOD (super oxide dismutase), an H2O2 generating enzyme increased significantly due to salinity in both the rice genotypes. Pokkali exhibited increased activities of Fe-SOD and Cu/Zn-SOD while Mn-SOD was in BRRI dhan 29. With increasing salinity levels, H2O2 and Thiobarbituric acid reactive substances (TBARS) content were increased significantly in both the genotypes with a higher magnitude in BRRI dhan 29. Both rice genotypes exhibited an increased activity of Peroxidase (POD) and a decreased activity of Catalase (CAT). The salt-tolerant genotype, Pokkali exhibited increased activity of ASC-GSH cycle enzymes (APX, MDHAR, DHAR and GR) during salinity stress. But salt-sensitive, BRRI dhan 29 exhibited a significant decreased activity of APX, increased activity of DHAR and unchanged activity of Monodehydroascorbate reductase (MDHAR) and GR during salinity stress. The results clearly indicated that ASC-GSH cycle responded differentially in salt-tolerant and salt-sensitive rice genotypes during salinity stress.
Water is essential for economic, social, and environmental development. Global water resources are vulnerable due to increasing demand related to population growth, pollution potential, and climate ...change. Competition for water between different sectors is increasing. To meet the increasing demand, the use of groundwater is increasing worldwide. In this paper, the water-table dynamics of the north-eastern region of Bangladesh were studied using the MEKESENS software. This study reveals that the depth to water-table (WT) of almost all the wells is declining slowly. In many cases, the depth will approximately double by the year 2040, and almost all will double by 2060, if the present trend continues. If the decline of the water-table is allowed to continue in the long run, the result could be a serious threat to the ecology and to the sustainability of food production, which is vital for the nation’s food security. Therefore, necessary measures should be taken to sustain water resources and thereby agricultural production. Demand-side management of water and the development of alternative surface water sources seem to be viable strategies for the area. These strategies could be employed to reduce pressure on groundwater and thus maintain the sustainability of the resource.
Medicinal plants serve as important therapeutic agents as well as valuable raw materials for manufacturing numerous traditional and modern medicines. Aloe vera is a top ranked medicinal plant in ...Bangladesh. The objective of this study is to investigate the costs, returns and profitability of Aloe vera medicinal plant. The data were collected from the selected farmers of Bogura and Natore districts in Bangladesh during 2018. The total sample size is 123. The study applies the profitability analysis, break-even points and margin of safety percentage techniques. Surveyed farms are found at ranged from 0.01 to 0.41 hectares. Average cost of production per hectare is found at Tk. 876468.80, of which Tk. 647156.40 for operational cost and Tk. 229312.40 for fixed costs accounting for 73.84% and 26.16% of the total cost, respectively. The average yield of Aloe vera is stood at 41487.62 kg per hectare which is sold to two different markets: contract markets and local market. The mean price is estimated at Tk. 32.42 per kg in study area. The gross margin and net margin per hectare are found to be Tk. 698068.02 and Tk. 468755.61, respectively. The breakeven analysis showed that in the case of yield and price, the margin of safety percentage of Aloe vera is -53.48. It is also found at 42.01, 67.15 and 34.85 for variable cost, fixed cost and total cost of Aloe vera production. Therefore, the study noted that the Aloe vera medicinal plant production is profitable in the study area. Farmers have a great opportunity to allocate more land to Aloe vera production, which will make them more profit. Break-even analysis of Aloe vera production resists a large drop of yield and price before incurring a loss, which gives the farmers a comfortable margin of safety and a risk bearing ability.
Res. Agric., Livest. Fish.7(1): 75-81, April 2020
Reaction of heteroaromatic o-aminonitrile with ethyl N-bis(methylthio)methyleneamino acetate resulted in annelation of a thieno3,2-eimidazo1,2-cpyrimidine moiety in a one step process. ...1,2,4Triazolo4,3-cthieno- 3,2-epyrimidine derivatives were prepared by initial treatment of o-aminonitrile with carbon disulfide, followed by methylation with methyl iodide and subsequent reaction with benzhydrazide and thiosemicarbazide, respectively. Hydrazinothieno2,3-dpyrimidine was prepared by cyclization of heteroaromatic o-aminoester with formamide, followed by chlorination and subsequent displacement with hydrazine. Treatment of the hydrazino derivative with acetylacetone, benzaldehyde and acetic anhydride afforded pyrazolylpyrimidine, benzylidenehydrazonopyrimidine and triazolopyrimidine derivatives, respectively. Some of these derivatives exhibited pronounced antimicrobial activity.
Tungsten oxide (WOsub.x) thin films were synthesized through the RF magnetron sputtering method by varying the sputtering power from 30 W to 80 W. Different investigations have been conducted to ...evaluate the variation in different morphological, optical, and dielectric properties with the sputtering power and prove the possibility of using WOsub.x in optoelectronic applications. An Energy Dispersive X-ray (EDX), stylus profilometer, and atomic force microscope (AFM) have been used to investigate the dependency of morphological properties on sputtering power. Transmittance, absorbance, and reflectance of the films, investigated by Ultraviolet-Visible (UV-Vis) spectroscopy, have allowed for further determination of some necessary parameters, such as absorption coefficient, penetration depth, optical band energy gap, refractive index, extinction coefficient, dielectric parameters, a few types of loss parameters, etc. Variations in these parameters with the incident light spectrum have been closely analyzed. Some important parameters such as transmittance (above 80%), optical band energy gap (~3.7 eV), and refractive index (~2) ensure that as-grown WOsub.x films can be used in some optoelectronic applications, mainly in photovoltaic research. Furthermore, strong dependencies of all evaluated parameters on the sputtering power were found, which are to be of great use for developing the films with the required properties.
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•A simple method is applied for the direct iodination of substituted anilines.•DFT study is conducted understanding the structural features of iodinated products.•Most of the ...iodinated products are capable of forming a distinct “Halogen Bonding”.•Noncovalent interaction between the products may reduce the single product yield.
This study reports a simple and efficient method for the direct iodination of substituted anilines with molecular iodine and copper acetate in acetic acid producing 2-iodoacetanilies and 2-iodoanilines. Employing density functional theory (B3LYP) and MidiX basis set, computational study is performed to calculate equilibrium geometries, IR vibrational frequencies, and thermodynamic properties including change of energy, enthalpy and Gibbs free energies. The optimized geometries indicated longer C–I bond distance (2.133Å) which makes iodine slightly positive. The partial atomic charge profile and electrostatic potential further confirmed that most of the iodinated products are capable of forming a distinct “halogen bonding”. The thermodynamic properties disclosed that all iodination reactions are endothermic. Understanding the substituents’ effect, molecular frontier orbital (MO) calculations are conducted finding the HOMO, LUMO and HOMO–LUMO gaps for all compounds. The MO calculations revealed that two electron-withdrawing iodine groups have significant influence on lowering the HOMO–LUMO gap compared to one iodine group in the products.
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