Abstract A protocol for in vitro seed germination of Coelogyne asperata Lindl. has been established successfully. Immature seeds from 182 days old capsule were cultured on three different basal media; Murashige and Skoog (MS), Knudson C (KC), and Vacin and Went (VW) and maintained under continuous light at 25 ± 2 ˚C. After 30 days of culture (DAC), more than 90% of seeds were germinated on KC and VW media and about 84% of seeds germinated on MS medium. The incorporation of organic additives, including coconut water, potato homogenate and tomato juice each at 10% (v/v) in KC medium was tested to determine their effect on seed germination of C. asperata. The result revealed that KC basal medium alone without addition of organic additives promoted over 90% of seed germination at 30 DAC. Therefore, the protocol of using standard KC basal medium for C. asperata seeds germination could be suggested for mass propagation and conservation of this wild scented orchid.

Abstract Increasing the domestic production of Brassica vegetables is important to sustain the local food supply, maintain the healthy diets of the population, reduce the country's foreign exchange, and improve the local economy. In this study, a column hydroponic system (CHS) of 1.2 m L × 1.2 m W × 1.5 m H was built and tested to increase Brassica vegetable production per unit area. There were 16 rectangular polyvinyl chloride tubes (10.2 cm L × 5.1 cm W × 1.5 m H) positioned upright (PVC columns) at 30.0 cm apart in four rows. Each column had 36 planting cups (4 lines × 9 levels). The seeds of curly dwarf Pak-choy were germinated on mop yarns in the cups. The nutrient solution was supplied using a 0.5HP non-submersible pump. Data were recorded on day 37 by measuring the vegetable yield, development, growth, and quality. The data were analyzed using Microsoft Excel®2019 by performing one- and two-way ANOVAs, followed by post-hoc tests (α = 0.05). The vegetable yield/area of the CHS (12.7 kg/m2, or 400 plants/m2) was 60% higher than that of a raft hydroponic system (5.1 kg/m2, or 63 plants/m2), but the mean weight/plant was 62% lower than that of the latter system (31.3 g/plant vs. 82.1 g/plant). There were statistically significant (P < 0.05) effects of column horizontal position (CHP) or vegetable vertical location (VVL) on the parameters studied. However, the effects of CHP × VVL was statistically significant only on yield and leaf area. Pak-choy in outer columns facing the morning and afternoon sunlight directly or at the top were heavier (39.2 - 71.7 g/plant) than those in inner columns or at the bottom (8.8 - 20.3 g/plant). The CHS can be used effectively to increase Brassica vegetable production/area, but its full potential is yet to be achieved. Research is recommended to determine the ideal column spacing to achieve the best balance between plant/area and weight/plant to increase further the system's growth, yield, and quality of vegetables.

Abstract The objective of this study was to evaluate the effects of different drying methods on phytochemicals and in vitro antioxidant activity of brown seaweed, Sargassum polycystum. Six different drying methods employed in this study were freeze drying, oven drying at 40 °C, oven drying at 60 °C, sun drying, vacuum drying at 40 °C and vacuum drying at 60 °C. Five different polarity solvents, methanol, ethanol, acetone, ethyl acetate, cold water and hot water were used as extraction solvents to determinephytochemicals content for total phenolic content, total flavonoid content and total carotenoid content while that antioxidant activitywas assessed by employing ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) and beta carotene bleaching (BCB) assay. Ethyl acetate extracts vacuum dried at 40 °C showed highest total phenolic content (58.54 ± 1.30 mg PGE g^-1 dry extract), total flavonoid content (35.91 ± 1.54 mg RE g^-1 dry extract), FRAP value 379.41 ± 1.17 µmol TE g^-1 dry extract and DPPH EC50 values, 3.83 ± 0.18 mg mL^-1 among all drying methods. Sun dried extracts possessed lowest retention of phytochemicals content and antioxidant activity among other drying methods. As a conclusion, S. polycystum was best dried by vacuum drying methodat 40 °C which has the higher retention of phytochemicals and antioxidant content.

Abstract This study was carried out to understand the suitability of activated carbon (AC) which is modified with hydrochloric acid (HCl) and tested by its adsorption capacity of nitrogen containing compounds (NCC) from fuel with three variables such as different concentrations of model fuel, contact time, and amount of modified AC (MAC). Batch mode experiments were conducted to remove quinoline (QUI) and indole (IND) from the model fuel prepared from n-hexane. All the experimental data were analysed using ultraviolet-visible spectroscopy after adsorption experiment between adsorbent and model fuel. Modification of commercial AC involved impregnation with different ratios of HCl solution. The characterization of modified and unmodified AC was done by using fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The adsorption potential of the MAC was measured based on the two isotherms, which are Langmuir and Freundlich isotherms to determine the isotherm constants and two kinetic models which are pseudo-first order and pseudo-second order. The adsorption capacity for QUI and IND was found to be 0.4708 mg/g and 0.8094 mg/g, respectively. On the other hand, the rate of adsorption for QUI and IND was 6.3766 and 0.4992, respectively. The adsorption kinetic experiment for both QUI and IND was found to follow the pseudo first-order.

Abstract SARS-CoV-2, a member of the Betacoronavirus genera and causative agent of COVID-19 will go down in history as one of the most successful pathogens in recent times. COVID-19 was declared a pandemic on 11th of March 2020, and it is disturbing that only vaccines are available hitherto despite it being around for more than a year. Traditional virology attempts to explain events via host-pathogen interactions, yet it does not take into account of the multifarious factors that may alter odds for disease development. In line with this paucity, a literature review was performed to identify risk factors for developing severe COVID-19 from behavioural, demographical, environmental, genetic and physiological perspectives. Risk factors for disease are discussed by focusing on the receptors of SARS-CoV-2 which would be ACE2 and TMPRSS2 in addition to elaborating on multiple phenomena. An elaborate discourse is also performed to identify steps that can be taken to stymie or ideally break the chain of COVID-19 transmission in addition to discussing on what one should do after being confirmed or suspected as being COVID-19 positive.