Authors:Devendra Raj Upadhyay, Pramod Adhikari, Bal Vikram Khatri, Suffian Mohamad Tajudin, Himali Kalakhety, Raju Khanal Pages: 1 - 11 Abstract: Urban construction materials predominantly originate from mining sites, raising concerns about the associated natural radioactivity and its potential health impacts. This work focuses on assessing the distribution of three natural radionuclides and associated radiological indicators in the South Lalitpur mining area in Nepal. A portable gamma spectrometer information system (PGIS-2) was employed for in-situ measurement of natural radionuclide concentrations. The mean activity concentrations of 238U, 232Th, and 40K were found to be 85.82 ± 40.63 Bq kg−1, 104.87 ± 30.42 Bq kg−1, and 1257.47 ± 304.36 Bq kg−1, respectively. Radiological hazard parameters were computed and compared with global averages, revealing a radium equivalent activity (Raeq) mean of 332.62 ± 63.08 Bq kg−1, slightly below the global average. The average absorbed gamma radiation dose rate in the air was 155.94 ± 29.09 nSv hr-1, over twice the world average. Indoor and outdoor annual effective dose rates, excess lifetime cancer risks, and annual gonadal dose equivalents were slightly higher than world averages. Additional radiological indices were computed, indicating that most estimated parameters exceeded global averages. Multivariate statistical analysis was applied to the dataset. The study suggests that in-situ measurements of these radiological parameters in mining areas are essential, as most mean values were above global averages, emphasizing the need for environmental safety and awareness in mining regions. PubDate: 2024-07-12 DOI: 10.3126/jist.v29i1.60793 Issue No:Vol. 29, No. 1 (2024)
Authors:Ram Devi Tachamo-Shah, Deep Narayan Shah, Anusha Pandey, Junu Maharjan, Tanya M Doody, Susan Cuddy Pages: 13 - 24 Abstract: Macroinvertebrates have long been utilized in the ecological assessment of streams and rivers as they respond to multiple stressors present in aquatic environments. However, the application of macroinvertebrates as bioindicators in the assessment of hydro-morphologically degraded rivers in Nepal is limited. Therefore, we studied the macroinvertebrate diversity and community composition in 10 sites along the Kamala River and its tributaries, one of the hydro-morphologically degraded rivers in the Churia range of central Nepal, during the winter and spring seasons of 2019. The elevation of the sites ranges from 60 m asl to 636 m asl. Twelve water quality parameters and three hydrological parameters were measured for each site in addition to macroinvertebrates data. Water temperature (winter- 19.3 ± 2.2 ⁰ C; spring- 31.3 ± 2.3 ⁰ C), pH (winter- 8.7 ± 0.5, spring- 7.4 ± 0.5), turbidity (winter-3.0 ± 3.8 NTU, spring- 22.9 ± 22.8 NTU), total alkalinity (winter-156 ± 70.7 mg/L, spring- 33.8 ± 6.0 mg/L), phosphate (winter-3.0 ± 1.8 mg/L, spring- 0.4 ± 0.3 mg/L) and river discharge (winter- 2.01 ± 0.75 m3/s, spring- 0.77 ± 0.28 m3/s) differed significantly between seasons (p<0.05). In total 62 taxa representing 42 families and 13 orders for winter season and 69 taxa representing 49 families and 18 orders of macroinvertebrates were recorded for spring season. NMDS revealed two distinct clusters based on macroinvertebrates abundance data for the river. Ephemeroptera, in particular Baetis spp., Torleya coheri and Caenis sp., and Trichoptera- Chuematopsyche spp. were the major taxa contributing to dissimilarity across sites between seasons. PubDate: 2024-07-12 DOI: 10.3126/jist.v29i1.52941 Issue No:Vol. 29, No. 1 (2024)
Authors:Narayan Panthi, Indra Bahadur Bhandari, Ishwar Koirala Pages: 25 - 33 Abstract: Different modelled equations are used to analyze the variation of the thermodynamic, microscopic and surface characteristics between the Tl-Mg and Tl-Na liquid alloys at 1000 K by considering TlNa2 and TlMg2 complexes. The Thermodynamic properties are studied under Quasi-Chemical Approximation and the agreement between theoretical and experimental results of thermodynamic properties about their melting temperatures verifies the validity of model. The transport and surface properties of the alloys are studied by Kaptay and Butler models respectively. From the theoretical observations, it is shown that the Tl-Mg alloy is more interacting than that of the Tl-Na alloy and exhibits an ordering nature below 0.3 concentration of Tl, but above this concentration Tl-Na alloy shows more ordering tendency. The Tl-Mg has a higher viscosity than the Tl-Na alloy within whole concentration of Tl. On the basis of surface properties, Na segregates on the surface within entire concentration of Tl in Tl-Na alloy whereas Mg segregates on the surface below 0.35 concentration of Tl in Tl-Mg alloy. PubDate: 2024-07-12 DOI: 10.3126/jist.v29i1.53511 Issue No:Vol. 29, No. 1 (2024)
Authors:Bhogendra Kathayat, Arnico Kumar Panday, Binod Pokharel, Narayan Prasad Chapagain Pages: 35 - 45 Abstract: In winter, Tribhuvan International Airport (TIA) in Kathmandu, Nepal, is badly affected by poor visibility conditions due to the occurrence of thick haze and dense fog. In this study, we examined the microclimatic behaviors (e.g., consecutive duration and onset/dispersal) of the winter fog. Alongside, we analyzed the trend in the occurrence of fog, dense fog, and winter haze in TIA from a historic global hourly climatological dataset (1976–2022) from TIA. We found that radiation fog in the valley is mostly short spells having a consecutive duration of less than an hour (~86% of fog, ~95% of dense fog). The onset of fog starts most favorably in the early morning (05:45–09:00 am) and disperses mostly before noon. To ascertain the synergetic effect of enhanced natural and anthropogenic forcing, urbanization, and meteorological changes on winter haze and fog, we assessed their trend for the same period. There was a marked change in visibility around the year 2000 together with important changes in humidity and dew point depression. We observed an upward trend of winter haze frequency (2.36% day/year, at 0.001 level of significance (α)) and fog frequency (0.46% day/year, at α = 0.05) in regime-I (1976–2000). Whereas the trend of winter haze flattened to 0.36% day/year (at α = 0.05) and dense fog declined at the rate of 1.28% day per annum (at α = 0.01) in regime-II (2001–2022). By careful examination of all plausible climatological drivers of the change (relative humidity, temperature, wind speed, and dew point depression), we found strong evidence of decreasing humidity and increasing dew point depression after the year 2000. Effective air pollution and urbanization control measures are imminent to lessen the adverse impact of the increased frequency of haze and fog at the country’s major international airport, TIA. PubDate: 2024-07-12 DOI: 10.3126/jist.v29i1.56933 Issue No:Vol. 29, No. 1 (2024)
Authors:Keshav Bhattarai, Indira Pandey, Khaga Raj Sharma Pages: 47 - 58 Abstract: Boerhavia diffusa is a well-known plant for ethnomedical uses. The plant is well known for its antioxidant and antidiabetic properties. Therefore, in addition to the antioxidant and antidiabetic properties of this plant, the present study focuses on exploring antibacterial properties, and metabolites present in Boerhavia diffusa. The preliminary phytochemistry was studied by the colour differentiation method. The phenolic and flavonoid content of the plant extracts was calculated using the Folin-Ciocalteu phenol and aluminum chloride colorimetry methods. Similarly, to find out the radical scavenging capacity of the available samples, one of the reliable methods (DPPH assay) was conducted. To evaluate the antidiabetic property, α-amylase and α-glucosidase inhibition were conducted by colorimetry methods. Results of phytochemical screening indicate that the plant is rich in metabolites including alkaloids, flavonoids, and terpenoids. Along with this, root extracts were found to be rich in total phenolic and flavonoid content with calculated values of 40.84±1.90 mg GAE/g and 37.01±1.61 mg QE/g, respectively. Similarly, among three methanolic extracts of root, stem, and leaf; the root showed the highest antioxidant activity with IC50 value 152.83±4.85 µg/mL. Among different solvent fractions of the stem of the same plant, the most potential antioxidant activity was shown by ethyl acetate fractions with an IC50 value of 82.96 ± 2.23 µg/mL. Additionally, no extracts and fractions were significantly active against α-amylase and α-glucosidase inhibition except ethyl acetate fraction. This fraction exhibited the enzyme inhibition property with IC50 value of 493.91±2.53 µg/mL for α-amylase and 96.31±10.65 µg/mL for α-glucosidase. To identify the chemical composition, mass spectrometry-based isolation and molecular annotation were carried out and metabolites like 3,9,10-trimethoxy-13-methyl-5,6-dihydroisoquinoline[2,1-b]isoquinolin-7-ium-2-olate, (E)-3-(4-hydroxy-3-methoxyphenyl)-N-[2-(4-hydroxyphenyl)ethyl]prop-2-enamide, 11,12-dihydro-2,3-(methylenedioxy)-7,8-dimethoxybenzo[c]phenanthridine, and (E)-3-(4-hydroxy-3-methoxyphenyl)-N-[2-(4-hydroxy-3-methoxyphenyl)ethyl]prop-2-enamide were reported. These results provide strong support for the ethnomedical uses of Boerhavia diffusa since the ancient period against diabetes and to cure infections. However, the evaluation of biological activities from the active compounds is not performed in this study. PubDate: 2024-07-12 DOI: 10.3126/jist.v29i1.61075 Issue No:Vol. 29, No. 1 (2024)
Authors:Suwash Bhandari, Motilal Ghimire, Purusottam Mahat Pages: 59 - 73 Abstract: The landslide is a major and common natural hazard in the Nepalese Himalayas. This phenomenon is because of its active tectonic setting, extensively deformed rock formation, steep mountain terrain, frequent seismic events, high-intensity rainfall during monsoons, and high rate of weathering it occurs every year, especially during the monsoon season. The landslide susceptibility assessment using the Geographic Information System (GIS) and remote sensing tools helps to display the hazards, and vulnerable zones providing the required knowledge of the susceptibility of landslides in a specific region. Landslide susceptibility with vulnerability assessment covering the comprehensive parameters provides an important understanding of the areas that are more likely to the damaging effect of the landslide hazards and is useful for mitigation, management, and avoiding threats. A total of 339 landslides were identified in the Badigad watershed from the satellite images on Google Earth, out of which 20% were used for model validation. The study was carried out using the Weight of Evidence (WoE) model. Eleven factors were considered as possible causative factors for the hazard assessment. Based on the landslide susceptibility map, 11% to 29 % of the study area is found to be in the range of very high to shallow landslide susceptibility. From the final map prepared it is found that many areas of Satyawati Rural Municipality (RM), Ruru RM, Chandrakot RM, and Chhatrakot RM, along with Musikot Municipality in Gulmi and Badigad RM in Baglung district, exhibit a notable high hazard level. The Receiver Operating Characteristics (ROC) graph with the Area under the curve (AUC) value was used to check the performance of the WoE model which shows that the model has 80.4% prediction accuracy for future events which means, the model shows very good performance. The vulnerability within the study area is assessed by obtaining vulnerability scores. To obtain the vulnerability score, fourteen indicators were analyzed following the Local Disaster and Climate Resilience Planning (LDCRP) guideline. The result obtained from the vulnerability assessment showed that two wards, namely Thulolumpek in Satyawati RM of Gulmi and Bobang in Dhorpatan Municipality of Baglung are highly vulnerable. By analyzing and comparing the vulnerability obtained from susceptibility mapping (using GIS) and social methods (using LDCRP guideline), it is observed that they do not converge based on the factors studied. PubDate: 2024-07-12 DOI: 10.3126/jist.v29i1.66351 Issue No:Vol. 29, No. 1 (2024)
Authors:Surya Kant Kalauni, Gita Bhattarai, Lekha Nath Khanal Pages: 75 - 84 Abstract: The germination of dormant seeds triggers various metabolic reactions, resulting in the production of essential phytochemicals with diverse biological activities. This contributes to the inclination to consume sprout juices among individuals seeking to enhance their immune system, manage oxidative stress, and prevent complaints associated with metabolic disorders. In this study, we evaluated the antioxidant, toxicity, and antidiabetic activity of young sprout extracts of Hordium vulgare, Triticum aestivum, and Zea mays by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, brine shrimp lethality assay, and α-amylase inhibition methods, respectively. The ethanolic extracts showed the presence of alkaloids, flavonoids, tannins, and polyphenols. The extracts showed moderate antioxidant activity, with Z. mays having the highest capacity, followed by T. aestivum and H. vulgare. Their half-maximal concentration (IC50) values were 54.24±3.35, 95.94±3.29, and 129.26±5.97 μg/mL, respectively. The same trend of toxicity against brine shrimp nauplii was obtained with half-maximal lethal concentration (LC50) values of 326.41, 473.61, and 6768.75 mg/mL respectively. The antioxidant activity across various extracts displayed a positive correlation with the total phenolic and total flavonoid contents. The extracts demonstrated moderate activity in the α-amylase inhibition assay conducted through the starch-iodine method. The outcomes of this study underscore the presence of significant phytochemicals in the young sprouts of commonly consumed cereals, suggesting their potential use as immune boosters and in treating diseases associated with free radicals. PubDate: 2024-07-12 DOI: 10.3126/jist.v29i1.63637 Issue No:Vol. 29, No. 1 (2024)
Authors:Buddhi Ram Oli, Manoj Sharma, Pramod Shrestha, Meghnath Dhimal, Ishan Gautam Pages: 85 - 93 Abstract: Aedes aegypti and Aedes albopictus are vectors of many viral diseases including dengue. They prefer different types of wet containers for breeding which differ according to season and region. Hence, their distribution range and preferred breeding containers should be known for their control. To fulfill the information gap, an intensive survey of potential larval breeding sites was conducted in different altitudinal gradients of mid-western Nepal. A total of 2056 wet containers of 11 different types in 1540 household’s premises were inspected. Among them, 3.35% (n=69) containers of eight different types were positive for larvae and/or pupae of A. aegypti whereas 11 types of total 6.32 % (n=130) wet containers were positive for larvae and/or pupae of A. albopictus. Discarded tires and earthen pots were the most preferred breeding containers for A. aegypti and A. albopictus although the habitat preference was found to be different in different altitudinal gradients and seasons. The proportion of different types of available wet containers and the Aedes infested containers varied across the study sites and seasons. The dengue vectors show their presence up to 2438 m above sea level increasing the risk of Aedes borne diseases up to the high mountain region of mid-western Nepal. Hence, the extensive vector survey and change in breeding habitats either through public health education or by some form of law enforcement is essential. PubDate: 2024-07-12 DOI: 10.3126/jist.v29i1.64658 Issue No:Vol. 29, No. 1 (2024)
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