15 research outputs found

    Study of aerosol optical properties in Lumbini, Nepal

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    The mixture of different sized particles (fine and coarse) with air composition forms aerosols. Increased economic activities, vehicles, and rapid urbanization made Lumbini one of the heavily polluted regions in Nepal. Data are extracted from AERONET websites between 2013 to 2019 with standard deviation. We are mainly focused on understanding variations in aerosol optical properties: aerosol optical depth (AOD), angstrom parameter (α and β), visibility, single-scattering albedo (SSA), refractive index (real and imaginary), and asymmetry parameter (AP) in the Lumbini region. The maximum value of AOD (675nm) in Lumbini occurred mostly during post-monsoon season (0.61 ± 0.38) whereas, the values of AOD were found to be lower during the monsoon season (0.18 ± 0.12). Most of the AOD values  are found to be greater than 0.4, indicating the higher level of pollution in the study area. There is a positive correlation between perceptible water and AOD, maximum correlation (0.4) occurs at the lowest AOD (440nm) while the minimum (0.1) at the highest AOD (1020nm). The turbidity coefficient (β) has an adverse effect on visibility. The Visibility over Lumbini was found to be highest (20 km) during monsoon. Single-scattering albedo (SSA) accretions occur at wavelengths between 440 and 675 nm, but the pattern changes from 675 to 1020 nm. All parameters were found to be distinct and seasonal fluctuations among this station are mainly due to the different aerosols availability such as biomass burning, mixed aerosols, and anthropogenic aerosols over the Lumbini site

    Study of aerosol optical properties in Lumbini, Nepal

    Get PDF
    The mixture of different sized particles (fine and coarse) with air composition forms aerosols. Increased economic activities, vehicles, and rapid urbanization made Lumbini one of the heavily polluted regions in Nepal. Data are extracted from AERONET websites between 2013 to 2019 with standard deviation. We are mainly focused on understanding variations in aerosol optical properties: aerosol optical depth (AOD), angstrom parameter (α and β), visibility, single-scattering albedo (SSA), refractive index (real and imaginary), and asymmetry parameter (AP) in the Lumbini region. The maximum value of AOD (675nm) in Lumbini occurred mostly during post-monsoon season (0.61 ± 0.38) whereas, the values of AOD were found to be lower during the monsoon season (0.18 ± 0.12). Most of the AOD values  are found to be greater than 0.4, indicating the higher level of pollution in the study area. There is a positive correlation between perceptible water and AOD, maximum correlation (0.4) occurs at the lowest AOD (440nm) while the minimum (0.1) at the highest AOD (1020nm). The turbidity coefficient (β) has an adverse effect on visibility. The Visibility over Lumbini was found to be highest (20 km) during monsoon. Single-scattering albedo (SSA) accretions occur at wavelengths between 440 and 675 nm, but the pattern changes from 675 to 1020 nm. All parameters were found to be distinct and seasonal fluctuations among this station are mainly due to the different aerosols availability such as biomass burning, mixed aerosols, and anthropogenic aerosols over the Lumbini site

    Regenerative callus induction and biochemical analysis of Stevia rebaudiana Bertoni

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    Stevia Leaves are the principal source of stevioside, which is estimated to be 100-300 times sweeter than table sugar. Stevioside has clinical significance as they are reported to maintain glucose levels in human blood. Owing to the difficulties in propagation of stevia through seeds and vegetative methods, callus culture has been an efficient alternative for generation of stevioside. The aim of this study is to develop an efficient and standardized protocol for maximum induction and multiplication of callus from a leaf. Callus culture was established from leaves in MS basal media fortified with various combinations (BAP, NAA, 2,4-D, KN, IBA) and concentrations of phytohormones. The best callusing (100%) was recorded in MS media supplemented with (2,4-D 1.0mg/l + NAA 1.0mg/l). The callus was harvested after 4 weeks and screened for the presence of various bioactive compounds. The qualitative results showed that the extracts of callus contained bioactive compounds like flavonoids, glycosides, phenol, tannins, sterols and saponins thereby making callus one of the sources for extraction of various secondary metabolites

    The Correlative study of Aerosol Optical Depth with Precipitable water over five AERONET station across the world

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    Ground-based measurements were taken at various locations, including Kathmandu Bode, Beijing, Gandhi College (located in South Asian zone, highly polluted area), Canberra, and UNC Gaitan (located in South Eastern zone, low polluted area), from January to December 2016. The study investigated the seasonal and inter-annual AOD that were obtained using CIMEL Sunphotometer, as a part of the Aerosol Robotic Network (AERONET). The data showed that Kathmandu (0.45±0.01), Gandhi College (0.45±0.02 and Beijing (0.85±0.03) had higher AOD values compared to other stations, with Kathmandu being a high-altitude site. The analysis found that pre-monsoon AOD were higher over Kathmandu (0.45±0.01), Gandhi College (0.45±0.02), UNC Gaitan (0.28±0.001), and Canberra (0.06±0.002). On the other hand, the monsoon AOD was higher over Beijing (0.85±0.03). The study identified various factors contributing to the higher AOD values in specific regions. Beijing, Gandhi College, and Kathmandu, located in Asian monsoon regions, experienced high aerosol loading due to economic activities, vehicles, urbanization, vegetation fire, land clearing for crop cultivation, as well as winter biomass burning, heating needs, and pollution from bricks kilns, factories, and vehicles. Canberra and UNC Gaitan had higher AOD values primarily due to biomass burning and dust. AOD values are higher for shorter wavelength and vice-versa. We conducted a correlation analysis between AOD and perceptible water at different wavelengths and observed one to one correspondence. The columnar water vapor (CWV) exhibited a high correlation with AOD in Canberra (Coefficient of determination, R2 = 0.61) at 1640 nm but had no relationship with AOD in Gandhi College (Coefficient of determination, R2 = 0) at 1640nm. There is weak negative correlation between AOD and preceptable water over Kathmandu and UNC Gaitan, but have positive correlation in Canberra, Beijing and Gandhi Colleg

    Correlative study of Aerosol Optical Depth with Precipitable water over five AERONET station across the world

    No full text
    Ground-based measurements were taken at various locations, including Kathmandu Bode, Beijing, Gandhi College (located in South Asian zone, highly polluted area), Canberra, and UNC Gaitan (located in South Eastern zone, low polluted area), from January to December 2016. The study investigated the seasonal and inter-annual AOD that were obtained using CIMEL Sunphotometer, as a part of the Aerosol Robotic Network (AERONET). The data showed that Kathmandu (0.45±0.01), Gandhi College (0.45±0.02 and Beijing (0.85±0.03) had higher AOD values compared to other stations, with Kathmandu being a high-altitude site. The analysis found that pre-monsoon AOD were higher over Kathmandu (0.45±0.01), Gandhi College (0.45±0.02), UNC Gaitan (0.28±0.001), and Canberra (0.06±0.002). On the other hand, the monsoon AOD was higher over Beijing (0.85±0.03). The study identified various factors contributing to the higher AOD values in specific regions. Beijing, Gandhi College, and Kathmandu, located in Asian monsoon regions, experienced high aerosol loading due to economic activities, vehicles, urbanization, vegetation fire, land clearing for crop cultivation, as well as winter biomass burning, heating needs, and pollution from bricks kilns, factories, and vehicles. Canberra and UNC Gaitan had higher AOD values primarily due to biomass burning and dust. AOD values are higher for shorter wavelength and vice-versa. We conducted a correlation analysis between AOD and perceptible water at different wavelengths and observed one to one correspondence. The columnar water vapor (CWV) exhibited a high correlation with AOD in Canberra (Coefficient of determination, R2 = 0.61) at 1640 nm but had no relationship with AOD in Gandhi College (Coefficient of determination, R2 = 0) at 1640nm. There is weak negative correlation between AOD and preceptable water over Kathmandu and UNC Gaitan, but have positive correlation in Canberra, Beijing and Gandhi Colleg

    Dolutegravir‐induced acquired sideroblastic anemia in a HIV positive patient: A challenging hematologic complication

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    Key Clinical Message Dolutegravir, the most recent antiretroviral drug with high efficacy, good tolerability, infrequent drug–drug interactions, and a favorable safety profile has not been reported in current literature as a cause of acquired sideroblastic anemia. Here, we present a 35‐year‐old male patient who was diagnosed with acquired sideroblastic anemia to Dolutegravir therapy
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