Production of polyclonal antibodies against leek yellow stripe virus (LYSV) coat protein expressed in Escherichia coli and its application in serological diagnostics.

Leek yellow stripe virus (LYSV) is one of the most important potyviruses, associated with garlic throughout the world, including India. LYSV causes stunting and yellow streaks in garlic and leek leaves and with other coinfecting viruses leading to severe symptom expression and yield reduction. In this study, we have made the first reported attempt to produce specific polyclonal antibodies to LYSV using expressed recombinant coat protein (CP), which would be useful for screening and routine indexing of the garlic germplasm. The CP gene was cloned, sequenced, and further subcloned in pET-28a(+) expression vector, which yielded ∼35 kDa fusion protein. The fusion protein was obtained in insoluble fraction after purification and its identity was confirmed by SDS-PAGE and western blotting. The purified protein was used as immunogen for production of polyclonal antisera in New Zealand white rabbit. Antisera raised, was able to recognize the corresponding recombinant proteins in western blotting, immunosorbent electron microscopy and dot immunobinding assay (DIBA). Developed antisera to LYSV (titer 1:2000) was used for screening of 21 garlic accessions in antigen coated plate enzyme-linked immunosorbent assay (ACP-ELISA) and 16 accessions were found positive for LYSV, indicating its widespread presence within the collection tested. To the best of our knowledge, this is the first report of a polyclonal antiserum against the in-vitro expressed CP of LYSV and its successful application in diagnosis of LYSV in garlic accessions in India.

Female gender is associated with increased late luminal narrowing within the stent graft after thoracic endovascular aortic repair.

BACKGROUND: Luminal narrowing, suspected secondary to thrombus, occurs within stent grafts at an unclear incidence after thoracic endovascular aortic repair (TEVAR). The significance of this phenomenon has not been determined, nor have the risk factors for development of intragraft luminal narrowing. Small graft diameter is hypothesized to be a risk factor for the development of ingraft stenosis. METHODS: A retrospective analysis was performed of a multicenter healthcare system including all patients who underwent TEVAR between July 2011 and July 2019 with at least 1 year of subsequently available surveillance contrast-enhanced computed tomography imaging. Standard demographic, preoperative, intraoperative, and postoperative variables were collected. Measurements were obtained via direct off-line images from computed tomography scans. Patent intragraft diameters were compared with baseline and interval change values were normalized to time to follow-up. The primary outcome measure was annual rate of intragraft luminal narrowing. RESULTS: There were 208 patients who met the inclusion criteria (94 women, 114 men) with a median follow-up of 822 days. The mean annual rate of percent intragraft diameter reduction was 10.5 ± 7.7% for women and 7.6 ± 5.6% for men (P = .0026). Multivariate analysis demonstrated female gender (P = .0283), preoperative diagnosis of hypertension (P = .0449), and need for coverage of the left subclavian artery (P = .0328) were all significant predictors of intragraft luminal narrowing. Small aortic diameters were not found to be associated independently with ingraft luminal narrowing nor was the concomitant use of antiplatelet or anticoagulation medications. Significant amounts of ingraft luminal narrowing, defined as a greater than 20% intragraft diameter decrease, were associated with an increased need for any reintervention, including for malperfusion, endoleak, and symptomatic aneurysm (P = .0249). Kaplan-Meier estimates demonstrated a significant gender-associated difference in high rates of intragraft luminal narrowing (P = .00189). CONCLUSIONS: In this analysis, female gender is shown to be a significant nonmodifiable risk factor for intragraft luminal narrowing after TEVAR. The development of this phenomenon is not benign; as such, these findings were associated with an increased need for reintervention. This finding may be attributable to differences in aortic compliance or gender-associated differences in coagulation pathways and merits further investigation. Surveillance after thoracic stent grafting must account for patient-specific variations in complication risk.

Challenges and opportunities in productivity and sustainability of rice cultivation system: a critical review in Indian perspective.

Abstract: Rice-wheat cropping system, intensively followed in Indo-Gangetic plains (IGP), played a prominent role in fulfilling the food grains demand of the increasing population of South Asia. In northern Indian plains, some practices such as intensive rice cultivation with traditional method for long-term have been associated with severe deterioration of natural resources, declining factor productivity, multiple nutrients deficiencies, depleting groundwater, labour scarcity and higher cost of cultivation, putting the agricultural sustainability in question. Varietal development, soil and water management, and adoption of resource conservation technologies in rice cultivation are the key interventions areas to address these challenges. The cultivation of lesser water requiring crops, replacing rice in light-textured soil and rainfed condition, should be encouraged through policy interventions. Direct seeding of short duration, high-yielding and stress tolerant rice varieties with water conservation technologies can be a successful approach to improve the input use efficiency in rice cultivation under medium-heavy-textured soils. Moreover, integrated approach of suitable cultivars for conservation agriculture, mechanized transplanting on zero-tilled/unpuddled field and need-based application of water, fertilizer and chemicals might be a successful approach for sustainable rice production system in the current scenario. In this review study, various challenges in productivity and sustainability of rice cultivation system and possible alternatives and solutions to overcome such challenges are discussed in details.

Development and characterization of genic SSR-FDM for stem gall disease resistance in coriander (Coriandrum sativum L.) and its cross species transferability.

Coriander (Coriandrum sativum L.) is well known vegetable and spice crop grown globally for its leaves and seeds. Stem gall (Protomyces macrosporus L.) is a fungal disease affecting its quality and yield. However, no information is available on SSR markers linked to disease resistance in coriander. Hence, development of co-dominant genetic markers is prerequisite for disease investigations in coriander. In-house stem gall resistance and susceptible cultivars transcriptome data were utilized. Totally, 59,933 and 56,861 transcripts were examined, 9141 and 8346 Simple Sequence Repeats (SSR) were identified and the most abundant type was the tri, followed by di, tetra, penta and hexa nucleotide repeats. A total of ten selected SSR-Functional Domain Markers (FDM) were developed based on functional annotation terms associated with pathogen response and validated among ten coriander cultivars and their transferability was examined in five fennel (Foeniculum vulgare L.) cultivars. Nine primer pairs resulted from amplified bands. Marker ACorSGD-1 shown monomorphic bands among coriander genotypes except Acr-1 showed heterologouse and multiple bands in fennel cultivars. Markers ACorSGD-4, 5, 7 and 9 shown presence in resistant cultivars and absence of bands among susceptible cultivars of coriander and thus, considered to be the candidate markers for disease screening. Marker ACorSGD-6 shown monomorphic bands among coriander. Markers ACorSGD-1, 2, 3, and 5 shown transferability among fennel cultivars. A total of 136 alleles in coriander and fennel were produced. Using UPGMA clustering method a dendrogram was generated and cultivars were grouped into two separate clusters with coriander and fennel. Identified and developed SSR-FDM markers are useful for linkage mapping for disease resistant in coriander.

Stent Graft Oversizing is Associated with an Increased Risk of Long-Term Left Ventricular Wall Thickening in Young Patients Following Thoracic Endovascular Aortic Repair.

BACKGROUND: Left ventricular (LV) wall thickening occurs in patients following thoracic endovascular aortic repair (TEVAR). Clinical consequences of cardiovascular (CV) remodeling may be more significant younger patients with longer anticipated life spans. Risk factors for CV remodeling following TEVAR are unknown but may be related to graft size. METHODS: A retrospective analysis was performed of a multicenter healthcare system including patients aged ≤60 who underwent TEVAR between 2011 and 2019 with at least 1 year follow-up computed tomography angiography imaging available. Standard perioperative variables, native aortic diameter, and stent graft specifications were collected. Graft oversizing was calculated by dividing proximal graft diameter by proximal aortic diameter on preoperative imaging. Posterior LV wall thickness was measured at baseline and interval increases were normalized to time-to-follow-up. Primary outcome was annual rate of posterior LV wall thickening. RESULTS: One hundred one patients met inclusion criteria with a mean (SD) follow-up time of 1270 (693) days. Overall mean (SD) rate of LV wall thickness change was 0.534 (0.750) mm per year. Mean (SD) absolute LV wall thickness at most recent follow-up was 10.97 (2.85) mm for men, 9.69 (2.03) mm for women. Multivariate analysis demonstrated that higher rates of LV wall thickening were associated with narrower graft diameters (P = 0.0311). Greater absolute LV wall thickness at follow-up was associated with narrower grafts (P= 0.0155) and greater graft oversizing (P= 0.0376). Logistic regression demonstrated individuals who met criteria for LV hypertrophy were more likely to have narrower stent-grafts (P= 0.00798) and greater graft oversizing (P= 0.0315). CONCLUSIONS: LV wall thickening occurred to a greater degree in individuals with narrower stent-grafts and higher rates of graft oversizing. This has significant implications for long-term cardiovascular health in younger patients may undergo TEVAR for atypical indications. Particular attention should be paid to long-term effects of stent-graft oversizing when selecting grafts in such populations.

Functional characterization of Candida glabrata ORF, CAGL0M02233g for its role in stress tolerance and virulence.

Present investigation is aimed to analyze the role of an uncharacterized ORF of Candida glabrata (CBS138), CAGL0M02233g (an ortholog of RAD53, a key DNA checkpoint effector in Saccharomyces cerevisiae) in tolerance of various stresses and in biofilm formation. The CAGL0M02233g was cloned in p416TEF shuttle vector for constitutive expression under TEF1 promoter in BG14 strain (ura3 auxotrophic C. glabrata), and upregulated expression of the cloned ORF was confirmed by immunoblotting. The constitutive expression of CAGL0M02233g rendered cells resistant to the DNA damage stressor (MMS), replication stressor (HU) and hypoxia mimetic (CoCl2) in plate spot and growth curve assays. Hypoxia (a low oxygen condition) is an imperative host factor that influences Candida pathogenesis. Biofilm formation by the BG14 cells transformed with p416TEF-CAGL0M02233g (REX cell) was reduced to approximately 50% under hypoxia. It is notable that biofilm formation by the REX cells was significantly lower than that of BG14 cells transformed with p416TEF vector (VC cell) under hypoxia. The biofilm of the REX cells has shown higher susceptibility to fluconazole than that of VC cells under hypoxia and REX cells at normoxia. This is the first report on the function of CAGL0M02233g in tolerance of various stressors and in modulation of the biofilm under hypoxia.

Identification and expression analysis of candidate genes associated with stem gall disease in Coriander (Coriandrum sativum L.) cultivars.

Coriander (Coriandrum sativum L.) is a well-known spice and aromatic crop cultivated globally. Stem gall disease is one of the major constraints for its leaf and seed quality used for consumption and also affecting the yield. The identification of resistance genes and further characterization of such genes could help to understand the molecular basis of resistance and lay a solid ground for cloning of stem gall resistance genes in coriander. To evaluate the genetic expression of disease resistance-relevant genes in popularly grown coriander cultivars in India such as Pant Haritma, Hisar Sugandh, Hisar Surabhi, Hisar Anand, Rajendra Swathi, ACr-1, ACr-2, AgCr-1, CO-2 and CS-6 were used for LRR, GDSL, USP, ANK and PDR gene expression using Real Time PCR along with 18S housekeeping gene as internal control for the normalization. Result revealed the different expression pattern of genes among the cultivars tested. Highest expression was shown in cultivar AgCr-1 followed by Pant Haritma, Hisar Sugandh and ACr-1, and least expression in Hisar Anand, ACr-2, CO-2, Rajendra Swathi and CS-6. Domain analysis revealed the conserved domain relevance of the genes. This is the first report on stem gall resistance gene expression in coriander. The identified genes have a potential role in coriander and further utilize in crop improvement program. We hypothesize that contrasting cultivars can be a good source for candidate gene evaluation and further to use them as potential markers and used in hybridization program focus on incorporating and develop durable disease-resistance into the adapted cultivars of the region.

Recent updates on drug resistance in Mycobacterium tuberculosis.

Tuberculosis (TB) along with acquired immune deficiency syndrome and malaria rank among the top three fatal infectious diseases which pose threat to global public health, especially in middle and low income countries. TB caused by Mycobacterium tuberculosis (Mtb) is an airborne infectious disease and one-third of the world's population gets infected with TB leading to nearly 1·6 million deaths annually. TB drugs are administered in different combinations of four first-line drugs (rifampicin, isoniazid, pyrazinamide and ethambutol) which form the core of treatment regimens in the initial treatment phase of 6-9 months. Several reasons account for the failure of TB therapy such as (i) late diagnosis, (ii) lack of timely and proper administration of effective drugs, (iii) lower availability of less toxic, inexpensive and effective drugs, (iv) long treatment duration, (v) nonadherence to drug regimen and (vi) evolution of drug-resistant TB strains. Drug-resistant TB poses a significant challenge to TB therapy and control programs. In the background of worldwide emergence of 558 000 new TB cases with resistance to rifampicin in the year 2017 and of them, 82% becoming multidrug-resistant TB (MDR-TB), it is essential to continuously update the knowledge on the mechanisms and molecular basis for evolution of Mtb drug resistance. This narrative and traditional review summarizes the progress on the anti-tubercular agents, their mode of action and drug resistance mechanisms in Mtb. The aim of this review is to provide recent updates on drug resistance mechanisms, newly developed/repurposed anti-TB agents in pipeline and international recommendations to manage MDR-TB. It is based on recent literature and WHO guidelines and aims to facilitate better understanding of drug resistance for effective TB therapy and clinical management.

Molecular Diversity Analysis of Plant Growth Promoting Rhizobium Isolated from Groundnut and Evaluation of Their Field Efficacy.

Rhizobium are nitrogen-fixing bacteria which possess the nif gene that codes for the nitrogenase enzyme involved in the reduction of atmospheric dinitrogen (N2) to ammonia. Thirty rhizobial strains were identified from ten groundnut plant root nodules collected from semi-arid regions of Rajasthan, India. The isolates were initially identified on the basis of morphological, biochemical, and molecular characteristics. These rhizobium strains were further screened for plant growth promoting activities. Twenty-eight strains were able to produce indole acetic acid, nine strains could solubilize phosphate, and twenty-nine strains exhibited positive results for siderophore and ammonia production. All the bacterial strains were able to efficiently nodulate the groundnut under pot conditions and based on multiple PGP activities six strains were selected for field evaluation. Field experiments confirmed the effectiveness of these selected rhizobium strains resulted in significantly higher nodule number, nodule dry weight, grain yield, and yield components of inoculated plants. Inoculation of the rhizobium strain GN223 followed by GN221 resulted in high yield and field efficiency. Isolation of effective microbial strains is the prerequisite to increase the yield which is evident from the field data of the present study. Hence, these strains might serve as proficient inoculants.

Carbapenemase and ESBL genes with class 1 integron among fermenting and nonfermenting bacteria isolated from water sources from India.

The present study was aimed to detect the carbapenemase, extended-spectrum ß-lactamase (ESBL), and intI1 gene of class 1 integron among fermenting (n = 61) and nonfermenting (n = 10) bacterial isolates recovered from water samples (n = 128). Isolates were identified by 16S rRNA sequencing. These isolates showed reduced-susceptibility to third-generation cephalosporins and carbapenems. The isolates varied in number and size of plasmids (2 kb to >20 kb). Plasmid DNA screening showed 5·6, 7, 11·2 and 26·7% prevalence of blaKPC , blaNDM , blaSHV and blaTEM genes respectively. Diverse blaNDM (blaNDM-1 and blaNDM-4 ) and blaSHV subtypes (blaSHV-2 and blaSHV-11 ) were recorded, unlike the single allelic blaKPC (blaKPC-2 ) and blaTEM (blaTEM-1 ) gene. Of the total 27 bla-gene-producing bacterial isolates, seven isolates co-harboured the carbapenemase genes (blaNDM or blaKPC or the both) along with the ESBL genes (blaSHV or blaTEM ). The intI1 gene of class 1 integron was detected among 12 (44·4%) of ESBL- and/or carbapenemase-harbouring isolates. Gene transferability was seen among four of the 10 Enterobacteriaceae donors. Carbapenemases and ESBLs with class 1 integron among aquatic environmental isolates raise the serious issue of the biosecurity and health of the ecosystem. SIGNIFICANCE AND IMPACT OF THE STUDY: Anthropologically affected and polluted environment harbours the resistance threats, where a diverse bacterial species maintain, develop and exchange genetic determinants that constitute a risk to human and ecological health. The antimicrobial resistance (AMR) in Enterobacteriaceae and non-Enterobacteriaceae bacteria caused the failure of the therapy of last resort (carbapenems) and thus lead to life-threatening infections affecting public health. Surveillance and monitoring of AMR could be important for epidemiological, diagnostic testing and control of pathogens. This is a point-prevalence study reporting the comparative occurrence and co-occurrence of carbapenemase and extended-spectrum ß-lactamase genes among fermenting and nonfermenting bacteria isolated from the aquatic environment in India.

Utilization of byproducts of sheep farming as organic fertilizer for improving soil health and productivity of barley forage.

Wool is a biodegradable fiber, rich in nutrients and can be recycled in soil as a fertilizer for maximum benefits. The present study was planned with the hypothesis that waste wool could be used as a nutrient source or manure to forage crops and aim of this study was to identify practicable recycling options of sheep based wastes in agriculture. In our study, we have compared the effect of different sheep based organic wastes on soil health, crop productivity and water use. Application of waste wool in soil significantly improved the fertility status of soil, and considerable improvement was also observed in organic carbon and nitrogen, i.e. around 30.8 and 32.6% higher over control. The activities of soil enzymes were 10-30% and 3-20% higher in waste wool treatment as compared to control and sheep based manures, respectively. Application of waste wool not only improved soil health but produced 50% higher grain and dry fodder yield of barley over control. The improvement in physical properties of soil with waste wool resulted in higher water use efficiency of the system. Our study will help in distinguishing choices for safe use of organic wastes along with up gradation of soil health and crop water utilization, particularly in nutrient poor soils of arid and semi-arid region of India.

Effect of Radiotherapy on Cariogenic Organism Streptococcus sobrinus in Saliva in Head and Neck Cancer: A Clinical Study.

AIM: Aim of the study was to assess salivary Streptococcus sobrinus in head and neck cancer using quantitative polymerase chain reaction (PCR). MATERIALS AND METHODS: Unstimulated saliva samples were collected from head and neck cancer patient preradiotherapy. Unstimulated saliva samples were collected from oral and laryngeal cancer patients after 6 weeks of radiotherapy (dose 60 Gy). The subjects were explained not to consume solids or liquids or carry out any dental hygiene activity 1 hour prior to saliva collection. Accumulated unstimulated saliva was collected in cylindrical tube through funnel. The collected saliva was then transferred to Eppendorf tube containing Tris-ethylenediamine-tetraacetic acid (EDTA) (TE) buffer and was transported to lab for real-time PCR analysis. RESULTS: Streptococcus sobrinus significantly increased post-radiotherapy as compared with preradiotherapy in head and neck cancer patients. CONCLUSION: Within the limitation of this study, we conclude that amount of S. sobrinus increases postradiotherapy in head and neck cancer patients. CLINICAL SIGNIFICANCE: As radiation therapy has harmful effects on hard and soft tissues of oral cavity, dentists should provide motivation for oral health care to the patients.

Isolated Myocysticercosis.

Cysticercosis, a parasitic disease caused by larval form of Taenia solium, is a major health concern in the developing world. The encysted larval stage can affect any part of the body, but are most frequently detected in brain, eye, skeletal muscle and subcutaneous tissue. Most muscular cysticercosis are almost always associated with central nervous system involvement or with multiple intramuscular cysts or both. Here we report an unusual case of cysticercosis in right rectus muscle which was an isolated muscle involvement without any other systemic manifestation.

Fundamental studies on the feasibility of deep eutectic solvents for the selective partition of glaucarubinone present in the roots of Simarouba glauca.

Several deep eutectic solvents prepared by the complexation of choline chloride as the hydrogen bond acceptor and hydrogen bond donors such as urea, thiourea, ethylene glycol, and glycerol were employed to partition glaucarubinone, an antimalarial compound present in roots of the plant, Simarouba glauca. Among all the solvents, the deep eutectic solvent consisting of the mixture of choline chloride and urea the most suitable to partition the antimalarial compound from the extract selectively. Analytical tools such as high-performance liquid chromatography and electrospray ionization mass spectrometry were used for characterizations, and glaucarubinone extracted from the roots of the plant by conventional solvent extraction method was used as a reference for comparison. The hydrogen and noncovalent bonds formed between glaucarubinone and the deep eutectic solvents could be responsible for the selective partition of the drug molecule.

Full-length cloning and phylogenetic analyses of translationally controlled tumour protein and ferritin genes from the Indian white prawn, Fenneropenaeus indicus (H. Milne Edwards).

Elucidation, through molecular analyses, of bacterial afflictions in commercially important aquaculture-reared shrimps is pivotal for the prevention and/or control of disease outbreaks. In this study, we examined the phylogenetic relatedness and compared the possible immune-related functional roles of both translationally controlled tumour protein (TCTP) and ferritin genes with previous studies. Both TCTP and ferritin genes were substantially upregulated in the Indian white prawn, Fenneropenaeus indicus (H. Milne Edwards), post-larvae following bath challenge with the virulent strain of bacteria, Vibrio harveyi D3. Full-length cloning of these genes by rapid amplification of complementary DNA ends -polymerase chain reaction (RACE-PCR) yielded 727-base pair (bp)-long TCTP and 1212-bp-long ferritin gene sequences. Their open reading frames (ORFs) were 507 and 510 bp, respectively. The TCTP-ORF coded for 168 amino acids with three substitutions at positions 37, 141, 155, and the ferritin ORF coded for 170 amino acids with no species-specific substitutions. Phylogenetic analysis suggested the closest relatedness of both TCTP and ferritin from F. indicus to Chinese white prawn, Fenneropenaeus chinensis (Osbeck). In addition to reporting the full-length sequences of these immune-relevant genes, this study highlighted their conserved natures, which perhaps make them important defence-related proteins in the innate immune system of F. indicus.

Characterization of polycyclic aromatic hydrocarbons in emissions of different mosquito coils.

Emission rates and emission factors of particulate matter and polycyclic aromatic hydrocarbons (PAHs) were determined in the emissions of three prevalent mosquito coil brands available in the market in India, under controlled conditions in an environmental chamber. The emission rates varied between the brands and ranged between 2.0 ± 1.9 to 27.1 ± 1.5 µg h(-1) for brand A, 3.4 ± 1.1 to 32.3 ± 1.2 µg h(-1) for brand B and 3.1 ± 1.0 to 72.2 ± 1.1 µg h(-1) for brand C for different compounds. Five and six ring PAHs were not detected, however four and three ring PAHs dominated. Three ring PAHs contributed 24 %, 42 % and 29 %, while four ring compounds contributed 53 %, 35 % and 61 % to total PAHs in the three brands. Carcinogenic PAH compounds were also present in the emissions, indicating the potential risks associated with the inhalation of coil smoke.

Summertime oxidative potential of atmospheric PM2.5 over New Delhi: Effect of aerosol ageing.

Exposure to elevated particulate matter (PM) concentrations in ambient air has become a major health concern over urban areas worldwide. Reactive oxygen species (ROS) generation due to ambient PM (termed as their oxidative potential, OP) is shown to play a major role in PM-induced health effects. In the present study, the OP of the ambient PM2.5 samples, collected during summer 2019 from New Delhi, were measured using the dithiothreitol (DTT) assay. Average volume-normalized OP (OPV) was 2.9 ± 1.1 nmol DTT min-1 m-3, and mass-normalized OP (OPm) was 61 ± 29 pmol DTT min-1 µg-1. The regression statistics of OPv vs chemical species show the maximum slope of OPV with the elemental carbon (EC, r2 = 0.72) followed by water-soluble organic carbon (WSOC, r2 = 0.72), and organic carbon (OC, r2 = 0.64). A strong positive correlation between OPm and secondary inorganic aerosols (SIA, such as NH4+ and NO3- mass fractions) was also observed, indicating that the sources emitting NO2 and NH3, precursors of NO3- and NH4+, also emit DTT-active species. Interestingly, the slope value of OPv vs OC for aged aerosols (OM/OC > 1.7, f44 > 0.12 and f43 < 0.04) was 1.7 times higher than relatively fresh organic aerosols (OA, OM/OC < 1.7, f44 < 0.12, f43 > 0.04). An increase in OPv and OPoc with f44 indicates the formation of more DTT active species with the ageing of OA. A linear increase in OPoc with increasing Nitrogen/Carbon (N/C) ratio suggests that nitrogenous OA have higher OP.

Dual carbon isotope-based brown carbon aerosol characteristics at a high-altitude site in the northeastern Himalayas: Role of biomass burning.

PM2.5 samples (n = 34) were collected from January to April 2017 over Shillong (25.7°N, 91.9°E; 1064 m amsl), a high-altitude site situated in the northeastern Himalaya. The main aim was to understand the sources, characteristics, and optical properties of local vs long-range transported carbonaceous aerosols (CA) using chemical species and dual carbon isotopes (13C and 14C). Percentage biomass burning (BB)/biogenic fraction (fbio, calculated from 14C) varied from 67 to 92 % (78 ± 7) and correlated well with primary BB tracers like f60, and K+, suggesting BB as a considerable source. Rain events are shown to reduce the fbio fraction, indicating majority of BB-derived CA are transported. Further, δ13C (-26.6 ± 0.4) variability was very low over Shillong, suggesting it's limitations in source apportionment over the study region, if used alone. Average ratio of absorption coefficient of methanol-soluble BrC (BrCMS) to water-soluble BrC (BrCWS) at 365 nm was 1.8, indicating a significant part of BrC was water-insoluble. A good positive correlation between fbio and mass absorption efficiency of BrCWS and BrCMS at 365 nm with the higher slope for BrCMS suggests BB derived water-insoluble BrC was more absorbing. Relative radiative forcing (RRF, 300 to 2500 nm) of BrCWS and BrCMS with respect to EC were 11 ± 5 % and 23 ± 16 %, respectively. Further, the RRF of BrCMS was up to 60 %, and that of BrCWS was up to 22 % with respect to EC for the samples with fbio ≥ 0.85 (i.e., dominated by BB), reflecting the importance of BB in BrC RRF estimation.