43 research outputs found

    DNA barcoding and evolutionary lineage of 15 insect pests of horticultural crops in South India

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    Abstract Pest management tools should rely to proper identification of arthropod species, which are usually classified relying on morphological keys. However, the shortcomings and limitations of the conventional taxonomical identification methods highlighted need for new and simple methods of pest identification. In this research, DNA barcoding was used to identify 15 insect pests attacking horticultural crops in South India. Accurate phylogenetic information and evolutionary divergence data were supported and evidenced by various parameters, including the rates of substitution, nucleotide composition, genetic divergence, test of selection and saturation analysis. The null hypothesis of neutral selection was rejected in favour of the alternate hypothesis of purifying selection. NJ and ML trees were calculated and the individuals of the same species clustered together based on the CO1 sequence similarity, regardless of their collection site and geographic location. Overall, this study adds basic knowledge to molecular ecology of important insect pests attacking horticultural crops in South India

    A Study on Management of Non Performing Assets in Priority Sector reference to Indian Bank and Public Sector Banks (PSBs)

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    The problem of NPA is not limited to only Indian public sector banks, but it prevails in the entire banking industry.  Major portion of bad debts in Indian Banks arose out of lending to the priority sector at the dictates of politicians and bureaucrats.  If only banks had monitored their loans effectively, the bad debt problem could have been contained if not eliminated. The present study has been designed to illustrate the necessity and the nature of the non-performing assets in Indian Bank, Tamil Nadu. Finding out Non Performing Assets –NPA- under the Priority sector lending in Indian Bank and Compare with Public Sector Banks and making appropriate suggestions to avoid future NPAs and to manage existing NPAs in Indian Bank are the other major objectives of this study. The scope of this study covers on the basis: (i)  measuring for the banks to avoid future NPAs & to reduce existing NPAs, (ii) guiding for the government in creating & implementing new strategies to control NPAs, (iii) selecting appropriate techniques suited to manage the NPAs and develop a time bound action plan to arrest the growth of NPAs

    Exosomal mediated signal transduction through artificial microRNA (amiRNA):A potential target for inhibition of SARS-CoV-2

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    Exosome trans-membrane signals provide cellular communication between the cells through transport and/or receiving the signal by molecule, change the functional metabolism, and stimulate and/or inhibit receptor signal complexes. COVID19 genetic transformations are varied in different geographic positions, and single nucleotide polymorphic lineages were reported in the second waves due to the fast mutational rate and adaptation. Several vaccines were developed and in treatment practice, but effective control has yet to reach in cent presence. It was initially a narrow immune-modulating protein target. Controlling these diverse viral strains may inhibit their transuding mechanisms primarily to target RNA genes responsible for COVID19 transcription. Exosomal miRNAs are the main sources of transmembrane signals, and trans-located miRNAs can directly target COVID19 mRNA transcription. This review discussed targeted viral transcription by delivering the artificial miRNA (amiRNA) mediated exosomes in the infected cells and significant resources of exosome and their efficacy

    Earthworm-mediated synthesis of silver nanoparticles: a potent tool against hepatocellular carcinoma, Plasmodium falciparum parasites and malaria mosquitoes

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    The development of parasites and pathogens resistant to synthetic drugs highlighted the needing of novel, eco-friendly and effective control approaches. Recently, metal nanoparticles have been proposed as highly effective tools towards cancer cells and Plasmodium parasites. In this study, we synthesized silver nanoparticles (EW–AgNP) using Eudrilus eugeniae earthworms as reducing and stabilizing agents. EW–AgNP showed plasmon resonance reduction in UV–vis spectrophotometry, the functional groups involved in the reduction were studied by FTIR spectroscopy, while particle size and shape was analyzed by FESEM. The effect of EW–AgNP on in vitro HepG2 cell proliferation was measured using MTT assays. Apoptosis assessed by flow cytometry showed diminished endurance of HepG2 cells and cytotoxicity in a dose-dependent manner. EW–AgNP were toxic to Anopheles stephensi larvae and pupae, LC50 were 4.8 ppm (I), 5.8 ppm (II), 6.9 ppm (III), 8.5 ppm (IV), and 15.5 ppm (pupae). The antiplasmodial activity of EW–AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. EW–AgNP IC50 were 49.3 μg/ml (CQ-s) and 55.5 μg/ml (CQ-r), while chloroquine IC50 were 81.5 μg/ml (CQ-s) and 86.5 μg/ml (CQ-r). EW–AgNP showed a valuable antibiotic potential against important pathogenic bacteria and fungi. Concerning non-target effects of EW–AgNP against mosquito natural enemies, the predation efficiency of the mosquitofish Gambusia affinis towards the II and II instar larvae of A. stephensi was 68.50% (II) and 47.00% (III), respectively. In EW–AgNP-contaminated environments, predation was boosted to 89.25% (II) and 70.75% (III), respectively. Overall, this research highlighted the EW–AgNP potential against hepatocellular carcinoma, Plasmodium parasites and mosquito vectors, with little detrimental effects on mosquito natural enemies

    Fabrication of nano-mosquitocides using chitosan from crab shells: impact on non-target organisms in the aquatic environment

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    Mosquitoes are arthropods of huge medical and veterinary relevance, since they vector pathogens and parasites of public health importance, including malaria, dengue and Zika virus. Currently, nanotechnology is considered a potential eco-friendly approach in mosquito control research. We proposed a novel method of biofabrication of silver nanoparticles (AgNP) using chitosan (Ch) from crab shells. Ch-AgNP nanocomposite was characterized by UV–vis spectroscopy, FTIR, SEM, EDX and XRD. Ch-AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi obtaining LC50 ranging from 3.18 ppm (I) to 6.54 ppm (pupae). The antibacterial properties of Ch-AgNP were proved against Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi, while no growth inhibition was reported in assays conducted on Proteus vulgaris. Concerning non-target effects, in standard laboratory considtions the predation efficiency of Danio rerio zebrafishes was 68.8% and 61.6% against I and II instar larvae of A. stephensi, respectively. In a Ch-AgNP-contaminated environment, fish predation was boosted to 89.5% and 77.3%, respectively. Quantitative analysis of antioxidant enzymes SOD, CAT and LPO from hepatopancreas of fresh water crabs Paratelphusa hydrodromous exposed for 16 days to a Ch-AgNP-contaminated aquatic environment were conducted. Notably, deleterious effects of Ch-AgNP contaminating aquatic enviroment on the non-target crab P. hydrodromous were observed, particularly when doses higher than 8–10 ppm are tested. Overall, this research highlights the potential of Ch-AGNP for the development of newer control tools against young instar populations of malaria mosquitoes, also highlighting some risks concerned the employ of nanoparticles in aquatic environments

    A novel nano therapeutic using convalescent plasma derived exosomal (CPExo) for Covid-19: A combined hyperactive immune modulation and diagnostics

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    Extracellular vesicles like exosomes are important therapeutic tactics for treating COVID -19. By utilizing convalescent plasma derived exosomes (CPExo) from COVID-19 recovered persistence could accelerate the treatment strategies in the current state of affairs. Adequate literature has shown that administering the exosome to the in vivo system could be beneficial and could target the pathogens in an effective and precise manner. In this hypothesis we highlight the CPExo instead of convalescent plasma (CP), perhaps to dispense of exosomes are gratified and it’s more effectively acquired immune response conferral through antibodies. COVID-19 convalescent plasma has billions of exosomes and it has aptitudes to carry molecular constituents like proteins, lipids, RNA and DNA, etc. Moreover, exosomes are capable of recognizing antigens with adequate sensitivity and specificity. Many of these derivatives could trigger an immune modulation into the cells and act as an epigenetic inheritor response to target pathogens through RNAs. COIVID-19 resistance activated plasma-derived exosomes are either responsible for the effects of plasma beyond the contained immune antibodies or could be inhibitory

    Toxicity on Dengue Mosquito Vectors Through Myristica fragrans-Synthesized Zinc Oxide Nanorods, and Their Cytotoxic Effects on Liver Cancer Cells (HepG2)

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    Dengue is an arbovirus mainly vectored by Aedes mosquitoes. Its prevention and control depends to effective vector control measures. Cancer causes millions of death every year. Most of the anticancer drugs have high toxicity and low specificity of action, leading to systemic toxicity and severe side effects. Thus, the development of effective tools is a priority. We fabricated zinc oxide nanoparticles using the Myristica fragrans extract as a reducing and stabilizing agent. Nanoparticles were studied using UV–vis spectrophotometry, Fourier transform infrared spectroscopy, X-ray diffraction, zeta potential, dynamic light scattering, energy dispersive X-ray analysis, field emission scanning electron microscopy and transmission electron microscopy. ZnO nanorods were highly effective against A. aegypti young instars, with LC50 ranging from 3.44 (larva I) to 14.63 ppm (pupa). Nanorods showed adult LC50 of 15.004 ppm. ZnO nanorods exhibited dose-dependent cytotoxicity against human hepato-cancer cells (HepG2). After 48 and 24 h of incubation, the IC50 were 20 and 22 μg/ml, respectively. Nanorods triggered the induction of apoptosis. Overall, this study highlights that the possibility to employ M. fragrans-synthesized ZnO nanorods in mosquito control, as well as in the development of novel chemotherapeutic agents with reduced systemic toxicity

    Exploring genetic variation in haplotypes of the filariasis vector Culex quinquefasciatus (Diptera: Culicidae) through DNA barcoding

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    Culex quinquefasciatus (Diptera: Culicidae) is a vector of many pathogens and parasites of humans, as well as domestic and wild animals. In urban and semi-urban Asian countries, Cx. quinquefasciatus is a main vector of nematodes causing lymphatic filariasis. In the African region, it vectors the Rift Valley fever virus, while in the USA it transmits West Nile, St. Louis encephalitis and Western equine encephalitis virus. In this study, DNA barcoding was used to explore the genetic variation of Cx. quinquefasciatus populations from 88 geographical regions. We presented a comprehensive approach analyzing the effectiveness of two gene markers, i.e. CO1 and 16S rRNA. The high threshold genetic divergence of CO1 (0.47%) gene was reported as an ideal marker for molecular identification of this mosquito vector. Furthermore, null substitutions were lower in CO1 if compared to 16S rRNA, which influenced its differentiating potential among Indian haplotypes. NJ tree was well supported with high branch values for CO1 gene than 16S rRNA, indicating ideal genetic differentiation among haplotypes. TCS haplotype network revealed 14 distinct clusters. The intra- and inter-population polymorphism were calculated among the global and Indian Cx. quinquefasciatus lineages. The genetic diversity index Tajima' D showed negative values for all the 4 intra-population clusters (G2-4, G10). Fu's FS showed negative value for G10 cluster, which was significant and indicated recent population expansion. However, the G2-G4 (i.e. Indian lineages) had positive values, suggesting a bottleneck effect. Overall, our research firstly shed light on the genetic differences among the haplotypes of Cx. quinquefasciatus species complex, adding basic knowledge to the molecular ecology of this important mosquito vector

    Contrasting genetic diversity and intra-population polymorphism of the invasive pest Henosepilachna vigintioctopunctata (Coleoptera, Coccinellidae): A DNA barcoding approach

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    Henosepilachna vigintioctopunctata (Coleoptera: Coccinellidae) is one of the most important pests attacking Solanaceae crops in Asian countries. Despite its agricultural importance, little information is available on the molecular ecology and evolution. In this study, we used DNA barcoding to explore the genetic diversity and intrapopulation polymorphisms of H. vigintioctopunctata. Haplotype analysis of the partial COI gene sequences of H. vigintioctopunctata fromfour localities in South India and other globally available haplotypes revealed two genetically distinctive lineages. The TCS haplotype network with the main clusters G1, G2, G4 and G6 represented intra-population polymorphismamong the Indian lineages,while other clusterswere differentiatedwith unique mutational steps. High substitutions in the 1st and 3rd codon suggested the dominance of synonymous substitutionswith significant p-values b 0.05, that inferred for purifying selection. The genetic diversity indices Fu's Fs and neutrality index Tajima-D had negative values that implied for recent population expansion and lowfrequency of polymorphism. Further, high genetic divergences among certain haplotype comparisons evidenced the influence of micro-evolutionary pressures. The threshold value was 1.26%, which was supported by the postulates of 10× rule. Overall, the study firstly reported the genetic diversity and intra-population polymorphism of H. vigintioctopunctata populations attacking Solanaceae species in Asian countries
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