Journal of Institute of Science and Technology
Journal of Institute of Science and Technology (JIST) is a peer-reviewed multidisciplinary science journal published by the Institute of Science and Technology (IOST), Tribhuvan University (TU), Kathmandu, Nepal. Chief Editor: Prof. Anjana Singh, PhD Editors: Prof. Leela Pradhan Joshi, PhD Chitra Bahadur Baniya, PhD Hari Prasad Sharma, PhD Pramod Poudel, PhD Moti Lal Rijal, PhD Deval Prasad Bhattarai, PhD Bishnu Hari Subedi, PhD Managing Editor: Bishnu Prasad Bhattarai, PhD
Institute of Science and Technology, Tribhuvan University
The views and interpretations in this journal are those of the author(s). They are not attributable to the Institute of Science and Technology, T.U. and do not imply the expression of any opinion concerning the legal status of any country, territory, city, area of its authorities, or concerning the delimitation of its frontiers of boundaries. The copyright of the articles is held by the Institute of Science and Technology, T.U.
Journal of Institute of Science and Technology: A Strong Foundation in Basic Sciences
EDITORIAL Over the last four years, the Journal of Institute of Science and Technology (JIST) has seen remarkable growth in the diversity of its scientific contributions. A notable trend in this period has been the substantial presence of research rooted in the basic sciences—physics, chemistry, and biology—which have accounted for 52% of all published articles. This consistent emphasis reflects not only the vitality of foundational disciplines but also their indispensable role in shaping applied innovations. Basic sciences are the foundations upon which technological progress and interdisciplinary exploration are built. In an era increasingly driven by applications in artificial intelligence, climate resilience, biotechnology, and material sciences, it is essential to remember that each of these advances stands on decades of rigorous basic research. By publishing a majority of works from these core domains, JIST has reaffirmed its commitment to nurturing scientific inquiry at its most fundamental level. We commend our contributing authors, reviewers, and editorial team for maintaining high standards in these disciplines. The high proportion of basic science articles is also a reflection of the strong research culture in our associated institutions and the growing global recognition of JIST as a credible platform for theoretical and experimental research. As we look to the future, we aim to maintain this balance while encouraging interdisciplinary submissions that connect basic science with other disciplines. We believe that fostering such integration will not only advance knowledge but also address some of the most pressing challenges of our time. In conclusion, the past four years have underscored the journal’s role as a custodian of core scientific values. We are proud of this trajectory and look forward to further strengthening the scientific dialogue that begins in the laboratory but resonates far beyond it. Chief Editor: Prof. Chhatra Mani Sharma, PhD Editors: Madhav Prasad Ghimire, PhD Kishor Pandey, PhD Binod Pokharel, PhD Bhanu Bhakta Neupane, PhD Jeevan Kafle, PhD
Copyright (c) 2025 Institute of Science and Technology, T.U. https://creativecommons.org/licenses/by-nc/4.0
Weaker Forms of Commuting Mappings in Metric and Menger Probabilistic Metric Space
This paper aims to discuss the update of the comparative study of non-commuting mappings in metric space and probabilistic metric space. This interrelationship study in weaker commuting maps helps researchers understand, analyze, and reach their research goal.
Integration of Hypergeometric Supertrigonometric Functions Using Generalized Hypergeometric Functions and its Applications
This study explores the integration of hypergeometric supertrigonometric functions, with a particular focus on hypergeometric supersine and hypergeometric supercosine functions, by leveraging the properties and relationships of generalized hypergeometric functions. By expressing hypergeometric supertrigonometric functions in terms of hypergeometric functions, we derive integral representations that connect these functions to classical results in generalized hypergeometric theory. The work emphasizes the role of convergence conditions, parameters and highlighting special cases where the results can be expressed in simple form, providing a unified framework for evaluating integrals involving hypergeometric trigonometric functions.
Study of Potential in vitro Antidiabetic Activities of Methanolic Extracts of Memordica charantia, Nyctanthes arbor, and Tinospora cordifolia from Dang Nepal
A wide diversity of medicinal plants rich in phytochemicals are the potential source of drugs. The phytochemical composition of plants varies with the geographical location. These selected medicinal plants containing phytochemicals inhibit the catalytic action of α-amylase to ameliorate the complications of diabetes. The main goal of this work is to compare the phytochemical composition and biological activities such as antioxidant, toxicity, and α-amylase inhibitory activity of Memordica charantia, Nyctanthes arbor, and Tinospora cordifolia. The study employed qualitative analysis through phytochemical screening, followed by quantitative measurement of total phenolic and flavonoid content by using the Folin-Ciocalteu reagent and colorimetric method. Additionally, biological activities were assessed using the 2,2 diphenyl-1-picrylhydrazyl antioxidant assay, α-amylase starch iodine method, and brine shrimp lethal test. The study revealed that the total phenolic contents in T. cordifolia, M. charantia, and N. arbor were measured as 140.49, 101.69, and 98.76 mg GAE/g, respectively. Consequently, N. arbor, T. cordifolia, and M. charantia showed strong antioxidant properties, with IC50 values of 48.16, 45.07, and 69.34 μg/mL, respectively. Furthermore, in the brine shrimp lethal test, all the extracts exhibited low toxicity, with the LC50 value of M. charantia (316.22 μg/mL), N. arbor (275.42 μg/mL), and T. cordifolia (275.42 μg/mL), respectively. GC-MS analysis of hexane fraction of N. arbor methanol extract reveals the presence of compounds like Hexanoic acid, 6-amino-6-oxo-, and Benzo[b]thiophene-2- carboxamide,3-chloro-N-(2-bromophenyl). Therefore, in all the aspects of the study, the methanolic extract of M. charantia, N. arbor, and T. cordifolia were potent, which concludes that these extracts contain abundant phytochemicals and possess diverse biological activities.
Current Status of Small Indigenous Fish Species of Western Nepal
This study describes the diversity and current status of Small Indigenous Fish Species (SIS) in rivers and lakes of Western Nepal. Fish sampling was conducted between 2018 and 2022 across five major water bodies using cast nets and traditional fishing gear, with assistance from local fishermen. A total of 10,976 individual fish were recorded, representing 61 species from 9 orders, 21 families, and 43 genera, including six species apart from the SIS category. The identified species were grouped into nine categories: Barbs and Minnows, Catfishes, Eels, Featherbacks, Loaches, Minor carps, Perches, Snake heads, and Sucker heads. Among these, Barbs and Minnows were the most diverse, comprising 32.79% (20 species) of the total. Cypriniformes emerged as the dominant order, with Cyprinidae and Danionidae being the most represented families, highlighting their significant role in the region's fish diversity. The study classified species into three availability-based categories: commonly available (27 species), moderately available (25 species), and rare (9 species). The presence of rare species underscores the region's ecological richness and the urgent need for targeted conservation efforts. The study's findings emphasize the importance of abundance-based assessments in developing targeted conservation strategies. These strategies should include habitat restoration, sustainable fishing practices, policy reforms, and further research to fill existing knowledge gaps.
Green Synthesis of Zinc Oxide Nanoparticles Using Swertia chirayita for Photocatalytic and Antimicrobial Activity
This research work utilized an environmentally friendly and sustainable method to produce zinc oxide nanoparticles (ZnO NPs) using zinc nitrate as a precursor and the leaf extract of Swertia chirayita. The resulting nanoparticles were characterized using various analytical techniques, including UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and energy-dispersive spectroscopy (EDS). The ZnO nanoparticles were found to have a well-defined crystalline structure, with their average crystallite size measured at around 10.88 nm. Agar well diffusion was used to study the antimicrobial activity, revealing notable antibacterial and antifungal properties, indicating broad-spectrum antimicrobial potential. A degradation efficiency of 95.73 % was achieved for methylene blue (MB) dye by photocatalysis under sunlight within 210 minutes. These findings demonstrate that ZnO NPs synthesized using Swertia chirayita exhibit excellent antimicrobial and photocatalytic properties, making them promising candidates for environmental remediation and biomedicine. This study underscores the potential of green synthesis approaches for developing sustainable nanomaterials.
Pistachio Shell-derived Activated Carbon as an Efficient Bio-adsorbent for River Water Treatment
The remediation of river water using activated carbon is one of the economic solutions to overcome the water shortage problem. Nanoporous-activated carbons (ACs) were synthesized from pistachio shell powder using phosphoric acid as the activating agent. Various impregnation ratios of pistachio shell powder to phosphoric acid were used to activate the precursor and then carbonized at 400℃ for three hours in a nitrogen atmosphere. The activated carbons (ACs) were characterized using Scanning Electron Microscopy (SEM), Raman scattering, and Fourier Transform Infrared Spectroscopy (FTIR), semi-quantitative surface information was determined using Boehm titration, and iodine and methylene blue adsorption. The iodine adsorption was maximum (758.45 mg/g) at an impregnation ratio of 1:1.5 (precursor: phosphoric acid, PSC_1.5). Boehm titration and FTIR spectra showed oxygenated functional groups such as hydroxyl, carboxyl, and carbonyl are present in the pistachio shell-derived activated carbon (PSC_1.5). Langmuir and Freundlich models are best fitted for methylene blue adsorption. The coefficient of the determinant was comparatively higher for the Langmuir model than the Freundlich model with an adsorption capacity of 243 mg/g. The efficiency of PSC_1.5 for the treatment of Bagmati river water was studied. The physical and chemical properties reveal that the river water is excessively polluted and changes to clean and clear water after the treatment with PSC_1.5. It removed more than 80% of contaminants from the river water, and significantly improved water quality to the WHO limits. Therefore, it is considered that activated carbon from pistachio shells is useful as an efficient bio-adsorbent for the treatment of Bagmati River water.
First Principles Study of NaCl···A-B Type (A-B = Acceptor) Complexes
A first-principles study of NaCl•••A-B type (A-B =acceptor) complexes was performed using ab initio methods and the Atoms in Molecules (AIM) approach. We have considered ten different acceptors: C2H4, NH3, H2O, H2, HF, HNa, HLi, FNa, FLi, NaCl. This work reports whether these complexes form sodium bonds by examining sodium bond distances, bond angles, frequency shifts, binding energies, and topological parameters (electron density and Laplacian of electron density at sodium bond critical points). We calculated binding energies by correcting for both basis set superposition error and zero-point vibrational energies. Our findings reveal both red and blue shifts in the stretching frequency modes. The value of electron density and the value of the Laplacian of the electron density are consistent with earlier reports on sodium bonding. This study further shows that sodium bond distances are more closely related to ionic radii than to van der Waals radii, with notable differences compared to hydrogen bond radii. All these results provide the nature of sodium bonding, and its unique characteristics compared to other non-covalent interactions.
Water Adsorption on Pristine and Vacancy Defected h-BN Monolayer: First-principles Study
The adsorption of liquid or gas molecules on pristine or structurally defective systems exhibits unique properties. They have budding uses in the field of device applications. So, in this work, we have studied the structural, electronic, and magnetic properties of water adsorbed h-BN (w-hBN), and water adsorption on: 1B atom vacancy defect in h-BN (w-1B-hBN), 1N atom vacancy defect in h-BN (w-1N-hBN), nearest neighbours of 1B &1N atoms vacancies defect in h-BN (w-nBN-hBN), and alternate zone of 1B &1N atoms vacancies defect in h-BN (w-aBN-hBN), monolayer supercell structures using density functional theory (DFT) method by employing Quantum ESPRESSO computational tool. For the structural properties, we have estimated the bond length between B & N atoms, and ground state energy of materials. They are found to be compact form of stable two-dimensional materials. Material’s compactness is increased by decreasing number of vacancy defects 8in the material. Electronic properties of considered materials are studied by the analysis of their band structure and density of states (DOS) calculations. It is found that w-1B-hBN is a p-type semiconductor, and w-hBN, w-1B-hBN, w-1N-hBN, w-nBN-hBN, w-aBN-hBN are n-type semiconductors. Magnetic properties of considered materials are examined from their DOS and partial density of states (PDOS) plots, it is found that w-hBN is non-magnetic material, and w-1B-hBN, w-1N-hBN, w-nBN-hBN & w-aBN-hBN are magnetic materials. Magnetic properties are generated due to the arrangement of unpaired up or down spin states of electrons in the individual orbitals of atoms present in the materials.
Chromosomal Stability and its Effect on Morphology of Wheat-Thinopyrum elongatum Disomic Addition Lines
The introduction of chromosomes from wild relatives is of great importance as it helps in wheat improvement programs by introducing many useful traits like those related to stress tolerance that lead to increased yield, thereby contributing to food security and safety. In this regard, seven Chinese spring wheat addition lines disomic to different chromosomes from Thinopyrum elongatum were compared with the normal Chinese spring in order to study the chromosome stability and effect of disomic addition lines on spike characteristics. All the wheat lines were obtained from NBRP-Wheat Japan. Chromosome numbers were reconfirmed by counting from the mitotic metaphase spread of root tip cells, and spike and seed characteristics were measured from fully matured spikes. All the disomic addition lines showed a stable number of chromosomes (i.e., 44). The spike lengths of disomic addition lines were significantly different (P<0.05) from that of Chinese Spring (control). The seed set was higher in CS+2E’’ disomic addition lines, while the seed size and seed weight of 100 seeds were lower than that of Chinese Spring.
Landslide Susceptibility Assessment in the Marin Khola Watershed of the Sub Himalaya, Central Nepal
Nepal is facing the threat of landslides each year causing huge loss of lives and properties. Landslide prediction and susceptibility assessments help in identifying the potential zones of landslide occurrences and provide opportunities to treat them prior to their occurrence. Among different methods of landslide susceptibility mapping, the InfoVal method is one of the simple and useful methods. In this study, this method is used to study the landslide susceptibility in the Marin Khola Watershed within the Siwaliks of central Nepal as this area comprises of the weak geological formations that contribute to high potentialities of landslides, yet there are no studies for predicting landslides. A total of 217 landslides were taken for the study and they were divided into two groups: working landslides and validating landslides. 75% of these total landslides were selected as working landslides and the remaining 25% were selected for validating landslides. Spatial relationships of the landslide distribution with different causative factors including topographic factors, hydrologic factors, geological factors and landuse factors were employed and analyzed. The results depict that very high, high, moderate, low and very low susceptibility classes cover 1.15%, 49.93%, 30.17%, 11.48%, and 11.28% area, respectively. The Middle Siwaliks are most susceptible to landslides compared to the Upper Siwaliks and Lower Siwaliks. The accuracy values are found to be affected by the difference in the landslide characteristics and types occurring in the study area. The model accuracy remains at 66% and predictive accuracy at 75%.
Sesamum indicum Leaf Extract as Environmentally Benign Inhibitor to Mitigate Mild Steel Corrosion in Cement Pore Solution
Concrete is one of the most widely used building materials after water due to its exceptionally high compressive strength. However, mild steel-reinforced concrete (MSRC) structures often encounter the problem of premature corrosion of the reinforcement. This issue emphasizes the importance of developing effective strategies to mitigate corrosion using inhibitors and understanding corrosion-controlling mechanisms. This work evaluates the effectiveness of Sesamum indicum leaf extract (SILE) as an environmentally friendly corrosion inhibitor in a saturated lime water solution with a pH of approximately 12, which simulates a cement pore solution (CPS). For the aim, weight loss (WL) and polarization procedures were conducted over 4 months to assess the corrosion inhibitory ability of SILE at concentrations of 500, 1000, 2000, and 4000 ppm in CPS to mitigate embedded mild steel (EMS) corrosion at a laboratory temperature of 25°C. The maximum inhibition efficiency was observed at 4000 ppm SILE, achieving 93.9% and 81.7% inhibition rates as determined by WL and potentiodynamic polarization (PDP) techniques, respectively. Also, PDP studies revealed a decline in corrosion current density with increasing SILE concentrations, indicating its inhibitory action. By facilitating adsorption onto the EMS surface, secondary metabolites (SMs), like mostly the flavonoids, including polyphenols, alkaloids, and terpenoids in SILE, can impede cathodic, anodic, or both processes. White light interferometry (WLI) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX) images supported the results of corrosion-inhibiting effectiveness of SILE to improve the corrosion-resistant properties of concrete by the development of passive layer on EMS.
Phytochemical Properties, Antioxidant and Antimicrobial Activities, and Colorimetric pH Responsiveness of Rhododendron arboreum Sm. Flower Extract from Manma-Kalikot, Nepal
Rhododendron arboreum Sm. is widely found in the hilly regions of Asia and is recognized as the national flower of Nepal. This study examines the extracts of R. arboreum flowers for total phenolic and flavonoid contents, antioxidant and antimicrobial properties, and pH-responsive color sensing properties. The phenolic content of the extract was assessed using the Folin–Ciocalteu method, flavonoid levels were measured with the aluminum trichloride assay, and antioxidant activity was evaluated through the DPPH radical scavenging test. The antimicrobial properties of the flower extract were evaluated using the agar well diffusion method, while pH responsiveness was examined across the buffer solutions spanning pH 1 to 14. The extract contained total phenolic level of 11±0.15 mg gallic acid equivalent and flavonoid level of 13.36±0.11 mg quercetin equivalent per gram of dry extract. For antioxidant potential, IC50 value was determine which was found to be 20.6±1.18 μg/mL. A strong correlation was observed between phenolic level and antioxidant potential. The extracts showed bactericidal effects against Gram-positive and Gram-negative bacterial strains and moderate antifungal activity. Furthermore, anthocyanin pigments in the extracts displayed notable color variations in buffer solution under different pH conditions. These findings highlight the potential of R. arboreum flowers as a source of natural antioxidants, antimicrobials, and most importantly pH responsive color sensing anthocyanins, encouraging further exploration of their bioactive compounds. This study highlights the untapped potential of R. arboreum, promoting its broader application in scientific research and commercial development.
Landslide Susceptibility Mapping Using Remote Sensing and Bivariate Frequency Ratio Method in Bahrabise Municipality of Sindhupalchok District, Nepal
Sindhupalchok district, located in the northeastern region of Bagmati Province, Nepal, is highly susceptible to landslides. Every year during the monsoon season, many people lose their lives and properties due to landslides. Bahrabise municipality, in particular, has experienced repeated landslide events in recent years, yet remains under–researched in terms of localized susceptibility mapping. The area’s steep terrain, fragile geology, and proximity to settlements make it a critical zone for detailed landslide risk assessment. The present study focuses on mapping areas susceptible to landslides in Bahrabise Municipality, which lies in the Sindhupalchok district of Nepal. An integrated methodology was adopted in this study, incorporating Geographic Information System (GIS), Remote Sensing (RS), and the Frequency Ratio (FR) model. To prepare the landslide susceptibility map for the area, various spatial and environmental datasets were utilized, including precipitation, slope gradient, elevation, proximity to drainage networks, topographic wetness index, geological features, distance from roads, land use and land cover (LULC), terrain curvature, and slope orientation. These factors and thematic layers were derived from both remotely sensed data and ground – based information such as GPS field surveys, visual inspections, and household interviews, and analyzed using ArcGIS software. The Frequency Ratio (FR) model was applied to assign weights to each thematic layer, representing their influence on landslide occurrence. These weighted factors were then combined within the ArcGIS environment to generate the final landslide susceptibility map for the study area. The resulting landslide susceptibility map classified the study area into four zones, with 47.9% falling under high and very high susceptibility. The model achieved a prediction accuracy of 81.3%, indicating strong reliability in identifying landslide-prone areas. The study examines the feasibility of employing more comprehensive methodologies to identify the landslide susceptibility in the region.
Synthesis, Characterization, Anticancer Activity, and Computational Study of Umbelliferone Schiff’s Bases
4-Methylumbelliferrone derivatives (1a–1c) were synthesized by condensing 3-acetyl-4-methylumbelliferrone with hydroxyurea, urea, and thiourea. The synthesized new Schiff’s bases were characterized by elemental analysis, ESI-HR MS, NMR, FT-IR, UV-Vis, and evaluated for their anticancer activity against the human prostate cancer (DU145) cell line. The tested compounds 1a, 1b, and 1c exhibited good anticancer efficacy in a dose-dependent manner in the tested cell line with IC50; 122.78 μM, 109.65 μM, and 55.41μM, respectively in comparison to standard drug cisplatin. Furthermore, the ADMET profiling and Molecular Docking were carried with these synthesized compounds targeting protein Epidermal Growth Factor Receptor (EGFR) tyrosine Kinase (PDB ID 4HJO). Among these compounds, compound ‘1c’ showed better intestinal absorption, positive Caco-2 permeability and negative AMES toxicity and hepatotoxicity. Also, it exhibited better interaction with the catalytically active site, Methionine at position 769 (MET 769) along with Glutamine (GLN 767), with binding energy, –10.3 kcal/mol.
Prevalence of Blood Parasites of Dogs (Pet and Stray) in Bhaktapur Municipality
A cross-sectional study was conducted from September 2022 to February 2023 to investigate the prevalence of blood parasites in dogs (pet and stray) in Bhaktapur municipality. Altogether, 150 blood samples, 50 from pets and 100 from stray dogs, were collected with the help of a trained veterinary assistant from the saphenous or cephalic veins of dogs. Subsequently, the blood was examined microscopically by using a thin blood smear method staining with Giemsa’s stain. The overall prevalence of blood parasites was recorded at 27.33% in pet and stray dogs. On individual analysis, 21% of pet samples and 31% of stray dogs were found to be infected with various types of blood parasites. Altogether, there are 4 species of parasites observed in the study, Anaplasma spp. (18.67%), Babesia sp. (6.67%), Ehrlichia sp. (2.67%), and Hepatozoon sp. (1.33%). Younger dogs recorded higher infections (31.25%), followed by older dogs (27.2%) and puppies (22.22%). Females showed a higher prevalence (27.65%) than males (27.18%). Higher infection rates of parasites were recorded in the local breed (21.33%), followed by the Japanese breed (1.33%). In the study, the burden of parasites was slightly higher in dogs infested by ticks (52.30%) than in tick-free dogs. A single infection of blood parasites was higher (25.33%) than a double (2%). There was no significant association between factors such as age, sex, breed, and tick infestation and the prevalence of blood parasites (p > 0.05). However, significant relationships were found between species of parasites and the concurrency of parasites (p < 0.001).
Fishing Gears and Practices in the Aquatic Systems of Kanchanpur District, Nepal: Issue and Trends
Various types of fishing gears and fish catching methods have been used worldwide for harvesting fishes from natural water bodies since antiquity. The present work aims to elucidate the current fishing gears and practices and knowledge of indigenous people and others about the impact of overfishing on wild fisheries in the aquatic systems of Kanchanpur district, Nepal. Data and information on fishing gears, fishing methods and knowledge about the impact of overfishing were obtained through direct observation and interactions with the local fishers of all the municipalities and rural municipalities of the Kanchanpur district through structured questionnaires; annual reports and programs of governmental and non-governmental organizations from October 2022 to September 2023. Fifteen types of conventional fishing gears, four types of unconventional fishing practices and nine fishing techniques viz., netting, trapping, hand lining and long lining, fish barrier, dewatering and hand gathering, spearfishing, poisoning, electrofishing and blast fishing were found to be followed by the fishers in different seasons. Traditional fishing practices were used by 53% fishers while massive destructive fishing practices by remaining ones (47%). Statistically, there was significant difference in the use of fishing gears and devices by the fishers (p < 0.05). All the fishers were unaware about the impact of overfishing of wild fish resources. Use of indiscriminate massive destructive fishing techniques and small mesh sized nets, fish capturing during breeding seasons and lack of awareness on proper scientific fishing methods are the main challenges for the conservation of feral fishes in the aquatic bodies of district.
Eutrophication, Water Quality, and Ecosystem Services of Two Selected Urban Wetlands of Lalitpur District, Central Nepal
Eutrophication is a major cause of wetlands degradation worldwide. In Nepal, urban wetlands play a crucial role in delivering ecosystem services essential for maintaining biodiversity and supporting local livelihoods. Therefore, conservation, sustainable management, and wise use of wetlands are imperative. This study evaluates water quality, eutrophication status, and the ecosystem service of two urban wetlands- Nagdaha and Ankhidaha situated within the Kathmandu Valley, Nepal. Standard methodologies were followed to assess water quality parameters, while key informant interviews were conducted to evaluate ecosystem services. Temporal changes in Land use land cover (LUCC) for the years 2000, 2010, and 2020 were analyzed using Landsat-7 satellite imagery. The water quality index values of Nagdaha (50.15) and Ankhidaha (552.47) indicate poor water quality. Statistical analyses revealed a strong correlation between nitrate and dissolved oxygen levels in both wetlands- Nagdaha (t = 35.68, p<0.001) and Ankhidaha (t= 9.42, p<0.001). Dissolved oxygen levels in Ankhidaha for the years 2018, 2019, and 2021 were found to pose a substantial threat to aquatic life. The findings indicate that eutrophication is compromising wetlands quality, subsequently diminishing the provision of ecosystem services. Land use land cover analysis highlights rapid urbanization, leading to a decline in vegetated areas and a consequent deterioration in water quality. Nine ecosystem services were identified as relevant to both local and broader communities, with recreation and ecotourism, biodiversity conservation, and educational opportunities emerging as the most prioritized. These insights provide valuable guidance for urban wetlands management and ecological restoration efforts.
Analyzing Extreme Precipitation during the Prolonged Summer Monsoon of 2022 in Nepal: Insights from Hourly Observational Data
The South Asian Summer Monsoon is a vital part of the broader Asian monsoon system, heavily influencing atmospheric circulation, regional climate, and water resources across South Asia. Nepal, located on the southern slopes of the Himalayas, receives approximately 80% of its annual rainfall during the summer monsoon (June-September), which significantly impacts agriculture, water availability, and disaster risks. This study focuses on analyzing the diurnal variation, spatial distribution, and intensity of extreme precipitation events in Nepal during the 2022 monsoon season. Using hourly precipitation data from 63 meteorological stations across Nepal, the study investigates rainfall patterns from June to September 2022. The monsoon season of 2022 began earlier than usual on June 5th, extending for 134 days, the longest on record in Nepal. Despite its extended duration, the total rainfall was not significantly higher than average, with western Nepal experiencing below-normal precipitation and eastern regions receiving slightly above-normal rainfall. The analysis of spatial variation revealed considerable disparities in rainfall distribution, with the Lumle area recording the highest precipitation (3133 mm) and several western districts observing minimal rainfall. Diurnal analysis highlighted a consistent pattern of nighttime precipitation dominance, with the highest rainfall occurring around 9 PM and the lowest around 6 AM. Approximately 60% of the total monsoon rainfall occurred during nighttime hours. This diurnal cycle was consistent across Nepal’s major regions, suggesting large-scale atmospheric influences like monsoon troughs and southwesterly winds. The study also assessed extreme precipitation events, defined as rainfall exceeding 40 mm/h. These events were widespread across Nepal, with central and eastern regions experiencing a higher frequency of extreme rainfall compared to western areas. The findings emphasize significant spatial variability in precipitation intensity and duration, critical for understanding regional monsoon dynamics and improving disaster preparedness.
Water Quality and Fish Diversity of Bagmati River in Kathmandu Valley
This study assesses the water quality and aquatic habitat in various sites of the Bagmati River in Kathmandu Valley. This study was carried out between February and June across an urban gradient in the Bagmati River of Kathmandu Valley. We used a D-frame net of 90cm by dipping-net in the benthic zone maintaining a walking distance of 20 m and repeating the same process four times (two times at each bank of the river) on each site on each visit. Schizothorax labiatus (Snow Trout), Schistura beavani (Ring Loach), Esomus danrica (Flying barb), Glyptosternum maculatum (Torrent Catfish) and Channa orientalis (Asiatic snakehead) were various fish species found during our study. The maximum Biological oxygen demand (BOD) was observed from Teku and the lowest from Shivapuri. The minimum and maximum dissolved Oxygen recorded was at Sundarijal. The pH ranged from 7 to 7.4 in Sundarijal. The minimum conductivity was found in Sundarijal, whereas the maximum was found in Teku. The maximum turbidity was observed at Teku and the lowest at Sundarijal. Maximum alkalinity was observed at Teku and lowest at Shivapuri. The fish diversity and water quality were affected by urbanization. We recommend the study be conducted southwards to determine the impact urbanization has on the lotic ecosystem.
In-Silico Analysis of Secondary Metabolites that Inhibit Aldose Reductase Targeting Diabetic Retinopathy
Diabetic retinopathy (DR) is a harmful microvascular consequence of diabetes. Aldose reductase, an enzyme involved in the polyol pathway during hyperglycaemic conditions, is responsible for DR. Some commercially available enzyme inhibitors, such as epalrestat, zenarestat, etc., are recommended medications to control pathophysiology; nevertheless, most of them have been unable to satisfy the criteria to be considered a good drug choice. This study aims to explore a pool of secondary metabolites associated with their impressive anti-diabetic properties because they are related to undesirable side of the commercial medications currently on the market. We screened the most potent aldose reductase inhibitor via a thorough in silico study, which has been reported as good in vitro activity against human aldose reductase and rat lens aldose reductase. High-throughput computational techniques were applied to study the potency of 90 metabolites against target proteins. In silico pharmacokinetics and toxicity were evaluated for screened metabolites with binding energy less than -9.0 kcal/mol obtained through the molecular docking method. Among selected metabolites, myrciacitrin IV exhibited the best binding affinity (-9.1 kcal/mol and -11.8 kcal/mol) with both proteins and displayed the least band gap energy (3.379 eV), comparable with the standard drug. Further, molecular dynamics (MD) simulation and Molecular Mechanics Generalised-Born Surface Area (MM/GBSA) investigations confirm myrciacitrin IV as a potent drug candidate targeting aldose reductase.
Impact of Cold Atmospheric Plasma Jet Treatment on the Physicochemical Properties of Surface Water
Cold atmospheric plasma jet (CAPJ) is a rapidly emerging multidisciplinary research field that stands out for its chemical-free and eco-friendly characteristics. It has garnered notable interest in recent years owing to its vast potential applications across various domains. One of its intriguing applications is in the treatment of water. Plasma transforms water into an acidic environment, leading to alterations in several key properties, including redox potential, electrical conductivity, dissolved solids, pH, and turbidity. Water treated with plasma, due to its distinct chemical composition compared to regular water, offers a promising alternative for microbial disinfection. In this research, CAPJ is generated using high voltage power supply (5 kV, 20 kHz) at standard atmospheric conditions and room temperature in an argon environment. The discharge generated by this system is thoroughly characterized using electrical and optical methods. Water sample collected from tap and well are treated with cold plasma jet and their physiochemical properties have been characterized.
Probiotic Property of Lactobacillus spp Isolated from Different Food Samples
Lactic acid bacteria (LAB) are Gram-positive, non-sporing cocci or rod-shaped bacteria that produce lactic acid as a primary metabolic product and are recognized for their probiotic potential. This study aimed to isolate, screen, and identify LAB from 20 indigenous fermented food samples, including fermented leafy vegetable (Gundruk), yogurt (Dahi), bamboo shoot (Tama), pickle (Achar), and fresh cabbage. A total of 15 LAB isolates were identified based on Gram staining and biochemical tests. Their probiotic properties were evaluated through resistance to gastric pH 3.5 (9 isolates survived for 90 min), bile salt tolerance at 0.3% concentration (4 isolates exhibited strong growth), and NaCl tolerance at 2% and 4% concentrations (all isolates survived, but none at 6.5%). Antibiotic susceptibility testing revealed that all isolates were sensitive to ampicillin, gentamicin, erythromycin, ciprofloxacin, and oxacillin. Antibacterial activity assays demonstrated that LAB strains inhibited pathogenic bacteria, with inhibition zones ranging from 10 to 20 mm. Notably, two LAB isolates exhibited the strongest probiotic properties based on acid, bile, and NaCl tolerance, as well as antibacterial activity. These findings highlight the potential of indigenous fermented foods as a natural source of probiotic LAB strains.
Antifungal activity of Bacillus species Isolated from Soil Samples of Nepal against Aflatoxin Producing Aspergillus spp
In Nepal, improper storage of staple foods leads to contamination by aflatoxin-producing molds, posing serious health risks like liver cancer. Farmers, unaware of these dangers, often use unsafe chemicals for prevention, while biological control using Bacillus spp., a proven, safe, and multifunctional alternative, remains unexplored. This study aims to isolate native Bacillus species capable of inhibiting Aspergillus flavus growth and detoxifying aflatoxins, offering a sustainable solution. A total of 50 samples (40 soil samples, 5 compost and 5 food samples) were randomly collected from different places of Nepal. Bacillus. spp were selectively isolated by heating the samples at 80⁰C for 10 minutes. The isolates were identified by standard microbiological techniques. Growth inhibition of A. flavus by Bacillus. spp was done by dual-culture technique on potato dextrose agar. Isolates showing high inhibitory effect against A. flavus were further identified by 16S rRNA gene sequencing. Altogether 51 isolates were presumptively identified as Bacillus species. Five isolates, Bacillus subtilis, B. tequilensis, B. licheniformis, B. cereus, B. weidmannii effectively inhibited the growth of aflatoxigenic A. flavus. These potent Bacillus strains will have implication in the commercial production of bioactive anti-aflatoxigenic compound to minimize the postharvest contamination of the crops.
Compatible Mappings of Type (K) in Fuzzy Metric Space
This paper discusses common fixed-point theorem in fuzzy metric space for three self-mappings by using the conditions of compatible mappings of type (K). This theorem generalizes the results of K.B. Manandhar et al. (2014), and also the results of Cho (2006).
Maximum Flow Location (FlowLoc) Modeling without Size Restrictions on Facilities
There are situations when traffic flow is obstructed because of facility placement in the road segments. FlowLoc models deal with such a situation in which a set of facilities with given sizes (capacities) has to be allocated with a given set of arcs of a directed network. The existing models assume that the size of each facility does not exceed the capacity of each of the arc in the given set of arcs and that the number of given facilities does not exceed the total number of available locations on arcs. In this work, we extend the FlowLoc modeling in which facilities can have arbitrary sizes and can have arbitrary numbers. We construct mixed-integer programming models based on static and dynamic network flow modeling. Realizing NP-hardness of problems, we design polynomial time heuristic algorithms to solve the constructed models. The performance of the algorithms is tested in a road network of Bhaktapur city Nepal.
Hydrochemistry and Water Quality of Phoksundo Lake (Dolpa): Insights from the Higher Himalaya Ramsar Site of Nepal
Phoksundo Lake, a distinctive 'Y' shaped Ramsar site located in the arid alpine region of the Nepal Himalayas, is a critical freshwater resource with significant ecological and cultural value. This study presents the first comprehensive hydrochemical assessment of the lake to determine its baseline water quality and suitability for drinking and irrigation. Thirteen surface water samples were collected in June 2024 from the lake's inlets, outlet, and main body. Physicochemical analysis revealed that the lake water is of the Ca²⁺-HCO₃⁻ type, with ionic dominance orders of Ca²⁺ > Mg²⁺ > Na⁺ > K⁺ and HCO₃⁻ > SO₄²⁻ > Cl⁻. While most parameters, including electrical conductivity (EC), total dissolved solids (TDS), and major ions, were well within WHO guidelines, the pH (mean 8.88) exceeded the recommended range for potable water. Geochemical modeling using Gibbs and Piper plots confirmed that the lake's chemistry is overwhelmingly controlled by rock weathering, specifically the dissolution of carbonate minerals in the catchment, which explains its natural alkalinity. A weighted arithmetic water quality index (WQI) classified the water as "Excellent" for drinking, yet this was contradicted by the presence of E. coli in several samples, indicating localized anthropogenic contamination. Irrigation suitability indices (SAR, Na%) also rated the water as "Excellent," posing no risk to soil health. This study establishes a crucial hydrochemical baseline, concluding that while Phoksundo Lake remains a pristine, rock-dominated system, emerging microbial contamination necessitates targeted monitoring and management to preserve its ecological integrity. Further investigation across different seasons and depths is recommended for a holistic understanding of the lake's dynamics.
Modified Generalized Sequence of Functions
Uniform convergence is a more stringent type of convergence which preserves at least some shared properties of functions. In this sense, a unified method of generalized sequence of functions is more beneficial to study limiting operations. The purpose of this paper is to study the problem in a unifying approach using generalized sequence in order to obtain the basic result in general form and then indicate their application to concrete cases. It is quite observed that among various approaches, the abstract method is the simplest and most economical method for treating mathematical systems.