6 research outputs found
Elemental analysis and enzymes inhibitory potential of the soybean and soy products available in Nepal
No full textThe production and consumption of soybean and soy products, characterized by high nutritional values are augmenting. Particularly, Asians consume soy foods on daily basis in several forms. In this study, we evaluated the elemental contents, phenolics, antioxidants, and enzyme inhibitory potential of white soybean, black soybean, brown soybean, tofu, and soya chunks collected freshly from the agricultural field and Nepali market. Metal ions content was analyzed by the direct air-acetylene method. Antioxidant potential was evaluated by DPPH scavenging and Ferric Ion Reduction Assay. Enzymes; alpha-glucosidase, tyrosinase, acetylcholinesterase, and butyrylcholinesterase inhibition were evaluated by using specific substrates. Among the analyzed soybeans and soy products, soya chunks revealed the highest amount of sodium (Na), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), and chromium (Cr). Three principal components are defined by 97% variance with a major contribution of potassium (K), Mg, Fe, Cr, cadmium (Cd), and Cu. The methanol (80%) and ethanol (50%) extracts exhibited noteworthy flavonoids and phenolic content. Moreover, these crude extracts showed substantial antioxidant potential with a maximum of 62.17 ± 1.28% DPPH scavenging and 65.80 ± 0.24% ferric ions reduction. Further, the examined extracts revealed the noteworthy α-glucosidase, tyrosinase, acetylcholinesterase, and butyrylcholinesterase inhibition with highest of 71.54 ± 0.09, 78.85 ± 2.42, 73.04 ± 0.25, and 56.16 ± 0.06% inhibition correspondingly. Among the analyzed samples, tofu revealed essential elemental content and revealed good enzyme inhibitory potential. Among the analyzed soy sample, soy chunk extracts revealed relatively weak biological activities evident by least radical scavenging and enzyme inhibition. This study revealed the potential of soybeans and soy products in antioxidant and enzyme inhibition. Further study on the molecular mechanism underlying these activities is recommended
Impact on water sources due to land use and land cover change in Chitwan district, Nepal
No full textRapid urbanization and unplanned infrastructures are stressing the drinking water sources, primarily due to land use and land cover changes (LULCC). Rapid population increases water demand and is straining water resources. This study aims to analyze LULCC from 1991 to 2020 and explore its impact on 23 regular used drinking water sources in Ratnanagar and Kalika municipality in Chitwan district. ArcGIS 10.8 classified five different classes in the images compiled from Landsat 5 and 8. Supervised classification with Maximum Likelihood algorithm was used with 30 signatures for each class as training samples. After the calculation of producer's accuracy and user's accuracy, accuracy assessment of classified images based on the ground truth points in 2020 Google earth images shows that kappa coefficient was 0.892 and overall accuracy was 91.67%. Over a period of 30 years, tree cover, agricultural, and water body areas have decreased by 15.18 %, 2.94 %, and 0.08 %, respectively while built-up and barren land have increased by 7.09 % and 11.11 % correspondingly. Secondary data from 30 years shows the population growth in study area was about 400% and 337.12 mm per decade reduction of precipitation. Increased built-up area has reduced the surface area for percolation of water. Uncontrolled LULCC, urbanization, and local climatic phenomenon have threatened the drinking water sources. Implementing the principles of resilient and sustainable urbanization, sustainable land use practices, climate resilient water safety tools and adequate investment in water sources protection can be a sustainable approach to address LULCC
Greenhouse gas emissions from different containment system in Dhulikhel Municipality in Nepal
No full textOn-site sanitation systems (OSS), are commonly used in low and middle-income countries (LMICs) like Nepal because of their practicality and economic feasibility. These systems are vital for ensuring access to basic sanitation, which is essential for both human health and the environment. However, they can significantly contribute to greenhouse gas (GHG) emissions through the microbial breakdown of faecal sludge via anaerobic and aerobic processes. Onsite containments are responsible for the majority of the GHG emissions occurring in the whole sanitation value chain. Therefore, this study intends to estimate the GHG emissions from different onsite containments prevailing in Dhulikhel Municipality using updated 2019 Intergovernmental Panel on Climate Change (IPCC) Guidelines. It was observed that 2.33 Gg CO2 eq-per year is being emitted annually from Dhulikhel municipality from the containment systems and open defecation. A total of 2.32 Gg CO2 eq-per year is contributed by methane (CH4) emission from containment and rest of from nitrous oxide (N2O) emissions from the open defecation solely. Similarly, the annual per capita CH4 and N2O emissions (from OD) from the onsite containments prevailing in Dhulikhel were computed as 67.52 kg CO2-eq per person per year and 18.39 kg CO2-eq per person per year respectively. A comparison of the emission was made between the containments that were emptied once and those which were never emptied. Paired sample t-test showed that emptied containments are likely to emit lesser CH4 emissions compared to those which are never emptied (p-value<0.05). Similarly, a comparison of emissions was conducted between sealed and unsealed containment systems. Sealed containment systems were found to produce significantly lower GHG emissions compared to unsealed systems (p-value < 0.05). The design and typology of containment structures play a critical role in influencing emissions from different systems. However, our national statistics and other reports do not include precise and clear typological definition which have underestimated the emission originating from different kind of containment units
Bulk carbon and lignin fingerprinting of catchment sediments transported by mountain rivers in Nepal Himalayas
No full textThe Himalayan rivers yield the most significant flux of continental sediments into the ocean. Organic matter (OM) transported by these rivers provides a peek at the influence of diverse geological terrains, soil types, vegetation, and climate on carbon cycling within a narrow boundary. We analyzed suspended and bedload sediments from four Himalayan rivers to trace their sources, elucidate their fate during fluvial transport, and estimate the organic carbon (OC) flux. Hence, total OC (TOC), dissolved organic carbon (DOC), C:N ratios, and lignin phenols were measured. Consistent with the erosional intensity in the rivers, suspended sediment load input followed the order: Kaligandaki &gt; Myagdikhola &gt; Aadhikhola &gt; Tinahukhola. C:N values in rivers from the Lesser Himalayas and Siwalik indicate sediments from mixed biogenic sources. In contrast, high TOC and C/N values in the trans-Himalaya rivers flowing through barren landscapes reflect the erosion of catchment sediments yielding petrogenic carbon. The suspended matter in rivers from the Lesser Himalayas and Siwalik has higher lignin phenol concentrations than the trans-Himalaya and Higher Himalaya rivers. The lignin phenol ratios indicate higher degradation in rivers from the trans and Higher Himalaya sections. This implies that only a small fraction of the terrestrial OM transported by these rivers deposits in the ocean sink. In contrast, rivers from the Lesser Himalayas and Siwaliks sequester a significant amount of OM bound to their bedload. As a result, these rivers transferred lower particulate OC (POC) but higher DOC than similar rivers worldwide. Rivers from Lesser Himalayas and Siwaliks transfer &gt; 90 % of annual POC flux during monsoons. Finally, although Himalayan rivers transport less OC than other global rivers traversing densely vegetated landscapes, the sheer number of these rivers has significant implications on the fate and transport of total OC from catchments sediments.Funding Agencies|Vetenskapsr?det [2016-05642]</p
Groundwater implications on methane emission from non-sewered sanitation systems in Nepal
No full textNon-sewered sanitation systems (NSSS) are identified as significant contributors of greenhouse gases (GHGs), primarily due to biological processes occurring within the containment systems. In unsealed or unlined containment systems like pit latrines, the emissions are influenced by moisture. This work quantified the GHG emission from unlined or unsealed containments prevalent in Nepal and compared it with sealed containment-like septic tanks, where the chances of groundwater (GW) inundation are low. The modeled GW data extracted from the secondary sources were validated with available national data. The emissions were quantified using the Intergovernmental Panel for Climate Change (IPCC) model for different ecological and provincial divisions of Nepal. Spatial representation for the results was done using the Geographical Information System (GIS) tool. The total methane (CH4) emission occurring from the various NSSS was determined to be 2618 Gg CO2 e per year which is almost twice the emission from the waste sector in 2011, as reported by the recent national communication submitted to the United Nations Framework Convention on Climate Change (UNFCC). Variation of the CH4 emission was found to be prominent in lowlands (Terai region) with total national emissions of 1329.37 Gg CO2e per year. The lowland has a shallow GW table that can easily inundate the unlined containments like pit latrines thus contributing to more anaerobic conditions which may lead to higher CH4 emissions compared to containments in mid and highlands. This study concludes that the GHG emissions occurring from NSSS are substantial and addressing these emissions can help fulfil the Nationally Determined Contributions (NDCs) in the waste sector
Himalayan watersheds in Nepal record high soil erosion rates estimated using the RUSLE model and experimental erosion plots
No full textThe rising unpredictability in the food supply chain in many parts of the world is related to soil loss and poor agricultural output. The Revised Universal Soil Loss Equation (RUSLE), widely used for estimating soil loss, was applied in the western mid-hills in Nepal, with steep slopes and fragile geology. This region is at high risk for rapid soil erosion and mass wasting. To estimate soil loss, this study utilized the RUSLE model with experimental erosion plots in the Aadhikhola and Tinahukhola watersheds, capturing real-time erosion in the field. The annual soil loss for the Aadhikhola watershed is estimated at ∼41.4 tons ha−1 yr−1. In contrast, in the Tinahukhola watershed, soil loss is low (∼24.1 tons ha−1 yr−1). Although annual rainfall showed an increasing trend in both watersheds, the change in soil loss was statistically insignificant. The high erosion rates from the experimental plots in both watersheds support the model outputs. Results from the experimental plots recorded the rate of soil erosion for different land use as: irrigated agricultural land > rainfed agricultural land > forests. The trends highlight the role of human activities in enhancing soil erosion in these mountainous terrains in terms of medium to long-term perspectives. Therefore, sustainable agriculture practices in these terrains must investigate alternate ways to decrease soil erosion to support people's livelihoods
