Tilka Manjhi Bhagalpur University
Recent publications
This paper contained some notations connected with algebraic number theory and indicates some of its applications in the Gaussian field namely K(i) = (−1)..
Globally, substantial research into endophytic microbes is being conducted to increase agricultural and environmental sustainability. Endophytic microbes such as bacteria, actinomycetes, and fungi inhabit ubiquitously within the tissues of all plant species without causing any harm or disease. Endophytes form symbiotic relationships with diverse plant species and can regulate numerous host functions, including resistance to abiotic and biotic stresses, growth and development, and stimulating immune systems. Moreover, plant endophytes play a dominant role in nutrient cycling, biodegradation, and bioremediation, and are widely used in many industries. Endophytes have a stronger predisposition for enhancing mineral and metal solubility by cells through the secretion of organic acids with low molecular weight and metal-specific ligands (such as siderophores) that alter soil pH and boost binding activity. Finally, endophytes synthesize various bioactive compounds with high competence that are promising candidates for new drugs, antibiotics, and medicines. Bioprospecting of endophytic novel secondary metabolites has given momentum to sustainable agriculture for combating environmental stresses. Biotechnological interventions with the aid of endophytes played a pivotal role in crop improvement to mitigate biotic and abiotic stress conditions like drought, salinity, xenobiotic compounds, and heavy metals. Identification of putative genes from endophytes conferring resistance and tolerance to crop diseases, apart from those involved in the accumulation and degradation of contaminants, could open new avenues in agricultural research and development. Furthermore, a detailed molecular and biochemical understanding of endophyte entry and colonization strategy in the host would better help in manipulating crop productivity under changing climatic conditions. Therefore, the present review highlights current research trends based on the SCOPUS database, potential biotechnological interventions of endophytic microorganisms in combating environmental stresses influencing crop productivity, future opportunities of endophytes in improving plant stress tolerance, and their contribution to sustainable remediation of hazardous environmental contaminants. Graphical Abstract
Breast cancer (BC) is the most frequent cancer affecting women worldwide. High-throughput genomic platforms and microarray-based gene expression profiling have emerged as one of the best strategies for understanding and interpreting BC at the genetic level. BRCA1/2 are the main target gene while several other genes also play crucial role in BC. In the present study, we evaluated the expression, diagnostic and survival/prognostic role of the KIAA0101 gene in BC. We applied the student t test (equal or unequal sample sizes, unequal variances/Welch’s t test) and the Kaplan–Meier estimator to validate dependability of the KIAA0101 (PCLAF, PCNA clamp associated factor) gene in BC. Microarray data (GSE10810) were retrieved from “Gene Expression Omnibus”, “National Center for Biotechnology Information (NCBI)”. KIAA0101 gene was one of the significantly expressed genes while comparing 31 breast tumor samples with 27 normal breast samples (control) at the threshold (fold change of ± 2 and p value < 0.001) using the Welch t test. The Kaplan–Meier Plotter tool was used to verify the overall survival and the relapse free survival of the KIAA0101 gene on bigger and 50 independent GEO datasets; 20 BC, 13 ovarian cancer, 11 lung cancer, and 6 gastric cancer cohorts. Hazard ratio and log rank p value of the KIAA0101 gene were determined under different restrictions of estrogen receptors, progesterone receptors and lymph node status (positive and negative). Finally, the wFisher, Lancaster, and weighted Z-method robust meta-analysis and statistical approaches were used to combine p-values for collective statistical significance of KIAA0101 gene. Score of log rank p value (< 0.05) indicated the therapeutic and prognostic importance of gene. Furthermore, to improve the precision of the analysis, qPCR was done to validate microarray expression result of KIAA0101 gene. In conclusion, KIAA0101 was one of the most over-expressed genes in BC which can be considered as a potential prognostic and diagnostic biomarker.
Magnetic nanobiochar (MNBC) is a sort of nanobiochar that has been enhanced with magnetic qualities. MNBC is made from a variety of feedstocks, including wood chips, agricultural waste, municipal sludge, animal manure, and other organic waste. These feedstocks are pyrolyzed at various temperatures to produce biochar, which is then mixed with magnetic precursors to create MNBC. Crystallinity, high porosity, specific surface area, and great catalytic activity are a few of the dynamic properties of MNBC. The major purpose of this review paper is to characterize MNBC, using the various biochar synthesis methods and how bulk biochar is converted into MNBC with their high-value applications discussed here.
Biosurfactants are bio-origin surfactants synthesized by microorganisms, plants, and higher organism such as vertebrates. Due to its diverse range of profitable and beneficial properties as well as eco-friendly nature, it is gaining its popularity as a potential nature-based alternative for synthetic surfactants, which the latter is found to be problematic to the society and environment due to its nonbiodegradability and high toxicity. Following its high emulsification potential, antimicrobial action, and antibiofilm formation properties, rhamnolipids are the most studied and widely applied biosurfactant molecules in the present scenario. They are almost entirely employed in food industries as an additives or surface-modifying agents. Biosurfactant has exceptionally satisfactory properties, which include surface interface activity, extreme condition tolerance, biodegradability, and low toxicity. Large-scale production of biosurfactant is unfeasible due to its huge production cost, low availability of raw materials, toxic-related issues. The present article highlights some of the concerning issues with special reference to application, important parameters for commercialization, biochemical properties, and socioeconomic impact on environment of biosurfactants to have uses as next-generation surfactant in food industry in particular.
The present study discusses the fabrication of non-lead ceramic/polymer composites employing (Na 1/2 Bi 1/2 )TiO 3 (NBT) ceramic powder as a filler and poly(vinylidene fluoride); PVDF as a polymer matrix. The NBT (volume fraction, ϕ = 1) ceramics were synthesized using the conventional mixed-oxide method followed by the high-energy ball milling method whereas (1- ϕ )PVDF/ ϕ (Na 1/2 Bi 1/2 )TiO 3 ; 0 ≤ ϕ ≤ 0.3 composites were prepared from a melt-mixing process. It was observed that the real and imaginary parts of dielectric permittivity, ac conductivity, and longitudinal piezoelectric charge coefficient increase with the increase in NBT-content. Different dielectric mixing models were presented to determine the effective complex permittivity of the composites. Five dielectric mixture equations have been chosen to test the acceptability of experimental data. It was revealed that theoretical models as given by Bruggman, Rother-Lichtenecker, and modified Rother-Lichtenecker show good agreement with the experimental results of filler-concentration dependent alteration of effective relative permittivity and loss factor of the PVDF/NBT composite. A mathematical model of first-order exponential growth has also been proposed, which fitted excellently the experimental data ( r ² > 0.998).
The X-ray diffraction, microstructure, impedance, electric modulus, and ac-conductivity of Ba(Fe 1/2 Ta 1/2 )O 3 –(Na 1/2 Bi 1/2 )TiO 3 solid-solutions were studied utilising a traditional high-temperature mixed-oxide technique. The phase-formations of the solid-solutions were determined utilising X-ray data, while SEM micrographs revealed a non-uniform dispersion of grains in the sample of unequal size (~1 – 20 mm). In all of the developed solid-solutions, the frequency (1Hz - 1MHz) dependence of imaginary and real parts of electric impedance in the temperature region of 50 and 500°C showed the NTCR character and hopping type of electrical conduction. The modulus spectrum variation was intrigued by the hopping mechanism for charge transport (temperature-dependent) in the samples with non-Debye type of behaviour. Besides, the low electrical conductivity of these solid-state solutions makes them ideal for industrial applications, particularly as capacitors.
The first objective is to examine the trends, patterns and socio-demographic factors associated with the under-five mortality in Bihar and Bhagalpur district. The second objective is to study the geographical differences in under-five mortality in Bihar. The study uses both secondary and primary data. The information of under-five mortality drawn from the secondary sources i.e. Sample Registration System (SRS) for 1981-2013 and the National Family Health Survey for 2015-16. The primary data was collected in 2019 from Bhagalpur district of Bihar. Trends of under-five mortality rates in Bihar are presented in line graphs. The spatial distribution of under-five mortality rates is presented in maps. Cox-proportional hazard model and logistic regression models are applied to assess the socioeconomic and demographic correlates of under-five mortality in Bihar and in Bhagalpur district respectively. Under-five mortality rate has decreased significantly since 2006 in Bihar, still it remains higher than the national average. Geographical patterns show the under-five deaths were disproportionately high in north-eastern regions of Bihar. This pattern of under-five mortality rates is considerably varied across the selected socioeconomic and demographic characteristics. The findings confirm that the mother’s nutritional status (BMI) and level of education, wealth status, and caste were significant factors of under-five mortality. The regression analysis show that the likelihood of under-five mortality was 1.2 times higher among the women who are underweight, who belong to the scheduled caste compared to their counterparts. Besides, the female children are more likely to die during their childhood than their male counterparts. Similar patterns also found in Bhagalpur district. The study reveals that under-five mortality is a serious public health concern in Bihar and Bhagalpur. The high under-five mortality in the study area is associated to poverty, maternal illiteracy and malnutrition, and geographical regions of Bihar. The flood prone north-eastern parts of Bihar experiencing higher under-five mortality compared to other parts. To reduce under-five mortality in Bihar as well as Bhagalpur, women's education, work involvement, and empowerment need to be prioritised to achieve the sustainable development goal-3 by 2030.
The structure, microstructure, Fourier transformed infrared spectra, dielectric, and impact generated energy harvesting characteristics of x (Ba 0.7 Ca 0. 3 )TiO 3 –(1- x )Ba (Zr 0.2 Ti 0.8 )O 3 ; x = 0, 0.5, and 1.0 synthesized using solid-state reaction method are discussed in this work. The X-ray diffraction (XRD) process was used to examine the forming of a single-phase compound. The Rietveld refinements of XRD data were used in FullProf software to determine crystal symmetry, lattice parameters, and space groups. A scanning electron microscope was taken into use to examine the surface morphology of all of the samples. The samples' phase transition temperature was observed to lie between-10°C and 87°C, shifting toward the higher temperature side as x increased. In the case of x = 0.5, two-phase transitions were discovered at 22°C and 70°C. The value of impact generated output voltage and electrical energy increases as applied mechanical energy increases. The findings of this study point to the possibility of using 0.5(Ba 0.7 Ca 0. 3 )TiO 3 –0.5Ba (Zr 0.2 Ti 0.8 )O 3 ceramic for energy harvesting and sensing purposes.
The thermodynamic, structural, surface and transport properties of PbSn eutectic alloys at 1050 K have been analyzed employing self association model. The model parameters have been evaluated on utilizing the experimental data of free energy of mixing of PbSn liquid alloys at 1050 K. For the validation of the model parameters, the calculated values of the excess free energy of mixing and activity of the components of PbSn liquid alloys have been compared with the experimentally measured data. Further, the estimated model parameters have been used to determine the thermodynamic functions i.e. the free energy of mixing, thermodynamic activity, entropy of mixing and heat (or enthalpy) of mixing, and the structural properties such as the concentration fluctuations and shortrange order parameter. The theoretical and experimental values are compared. A good agreement is observed. Again, the surface properties of PbSn liquid alloys at 1050 K have been investigated using the Butler model in the framework of self association model. The calculated values of surface tension of PbSn liquid alloys at 1050 K are in reasonable agreement with the data available in the literature. The transport properties like the diffusivity and viscosity of PbSn liquid alloys at 1050 K have been theoretically analyzed. For the computation of viscosity, the simple formula developed by Moelwin- Hughes has been used in conjunction with self association model. The present study reveals that PbSn eutectic liquid alloys at 1050 K are segregating in nature. Further, the model parameters are found to depend on temperature. Keywords : Gibbsfree energy; concentration fluctuations; short-range order parameter; surface tension; diffusivity; viscosity
The mechanical impact-based energy harvesting behavior of a 0-3 Bi 0.5 Na 0.5 TiO 3 /PVDF(25/75) composite prepared using the melt-mixing method have been demonstrated. X-ray diffraction analyses revealed the formation of a composite sample, while AFM image analyses revealed that BNT-particle sizes ranged between 0.6 and 1.4 μm and were evenly distributed throughout the polymer matrix, and surface roughness was found to be between 0.2 and 1.8 μm. With increasing impact height (applied mechanical energy), a remarkable increase in generated electric voltage and energy was observed. As a result, the present composite is a better lead-free alternative for piezo-sensing/detection and energy harvesting applications.
The microstructure, energy dispersive X-ray spectra, and field dependent polarization and electrostrictive strain characteristics of x (Ba 0.7 Ca 0. 3 )TiO 3 –(1- x )Ba (Zr 0.2 Ti 0.8 )O 3 ; x = 0, 0.5, and 1.0 synthesised using solid-state reaction process are discussed in this work. The X-ray diffraction process and scanning electron microscope were, respectively taken into use to examine the forming of single-phase compound and the surface morphology as well as elemental analyses of all of the samples. The grains sizes were found to lie between 3–12 μm and was largest for x = 0.5. The value of piezoelectric coefficient, converse piezoelectric effect (strain maximum to peak electric field), and electrostrictive coefficient were found to be the highest for x = 0.5 sample. Ba 0.85 Ca 0.15 Zr 0.10 Ti 0.90 O 3 was shown to be a potential lead-free electrostriction material for industrial applications, particularly in positioning actuators, based on field-dependent polarisation and strain experiments at ambient temperature.
The vaccination drive against COVID-19 worldwide was quite successful. However, the second wave of infections was even more disastrous. There was a rapid increase in reinfections and human deaths due to the appearance of new SARS-CoV-2 variants. The viral genome mutations in the variants were acquired while passing through different human hosts that could escape antibodies in convalescent or vaccinated individuals. The treatment was based on oxygen supplements and supportive protocols due to the lack of a specific drug. In this study, we identified three lead inhibitors of arylated coumarin derivatives 4,6,8-tri(naphthalen-2-yl)-2H-chromen-2-one (NF1), 8-(4-hydroxyphenyl)-4,6-di(naphthalen-2-yl)-2H-chromen-2-one (NF12) and 8-(4-hydroxyphenyl)-3,6-di(naphthalen-2-yl)-2H-chromen-2-one (NF-13) that showed higher binding affinity towards the junction of SARS-CoV-2 spike glycoprotein (S-protein) and human angiotensin-converting enzyme 2 (ACE2) receptor. Using molecular docking analysis, we identified the putative binding sites of these potent inhibitors. Notably, molecular dynamics (MD) simulation and MM-PBSA studies confirmed that these inhibitors have the potential ability to bind Spike-protein/ACE2 protein complex with minimal energy. Further, the two major concerns are an adaptive mutation of spike proteins- N501Y and D614G which displayed strong affinity towards NF-13 in docking analysis. Additionally, in vitro and in vivo studies are required to confirm the above findings and develop the inhibitors as potential drugs against SARS-CoV-2.
Metabolic alteration is an important hallmark in cancer progression. Cancer cell redirects the different metabolic pathways such as glycolysis, glutaminolysis, nucleotide biosynthesis, etc to ensure the continuous supply required for the uncontrolled cell proliferation and growth of cancer cells. Similarly, autophagy which is an inevitable and multistep recycling process and helps in the degradation of unfolded proteins and damaged organelles to restore energy and homeostasis has been implicated in cancer cell regulatory mechanism. Recent understandings of the correlation between autophagy and cancer metabolism result in therapeutic evolution for researchers and medicinal professionals. Dysregulation of autophagy is known to be responsible for various types of carcinomas and neurological disorders. Several studies revealed that autophagy plays a dual role in cancer by suppressing tumor growth and proliferation of tumors depending upon cancer genotype. Hence different strategies for the modulation of autophagy via inducers and inhibitors would be a novel therapeutic tool for the inhibition of cancer. Considering the metabolic dysregulation and alteration in autophagy, these have been explored as very attractive therapeutic targets. This chapter discusses the different inhibitors including drugs and phytochemicals which targets different proteins and metabolites involved in the various metabolic pathways and autophagy to display anticancerous effect in different types of cancer cells. Furthermore, various preclinical and clinical trials of drug candidates and their combinatorial role have been discussed with their participation in autophagy modulation which might be possible for future clinical therapeutics.
Microorganisms are an important component of the ecosystem and have an enormous impact on human lives. Moreover, microorganisms are considered to have desirable effects on other co-existing species in a variety of habitats, such as agriculture and industries. In this way, they also have enormous environmental applications. Hence, collections of microorganisms with specific traits are a crucial step in developing new technologies to harness the microbial potential. Microbial culture collections (MCCs) are a repository for the preservation of a large variety of microbial species distributed throughout the world. In this context, culture collections (CCs) and microbial biological resource centres (mBRCs) are vital for the safeguarding and circulation of biological resources, as well as for the progress of the life sciences. Ex situ conservation of microorganisms tagged with specific traits in the collections is the crucial step in developing new technologies to harness their potential. Type strains are mainly used in taxonomic study, whereas reference strains are used for agricultural, biotechnological, pharmaceutical research and commercial work. Despite the tremendous potential in microbiological research, little effort has been made in the true sense to harness the potential of conserved microorganisms. This review highlights (1) the importance of available global microbial collections for man and (2) the use of these resources in different research and applications in agriculture, biotechnology, and industry. In addition, an extensive literature survey was carried out on preserved microorganisms from different collection centres using the Web of Science (WoS) and SCOPUS. This review also emphasizes knowledge gaps and future perspectives. Finally, this study provides a critical analysis of the current and future roles of microorganisms available in culture collections for different sustainable agricultural and industrial applications. This work highlights target-specific potential microbial strains that have multiple important metabolic and genetic traits for future research and use.
At present, enzyme immobilization is a big issue. It improves enzyme stability, activity, specificity, or selectivity, particularly the enantioselectivity compared to the native enzymes, and by solving the separation problem, it helps in recovering the catalyst with good reusability as desired in vitro. Motivated by these facts, in this work, Jack bean urease (JBU) is immobilized on three-dimensional (3D)-network silica gel (SG) via multipoint covalent bonding employing dimethyldichlorosilane (DMDCS) and p-nitrophenol, respectively, as the second-generation silane-coupling reagent and spacer. The homofunctional diazo group appearing at the functionalized SG unit cell makes a diazo linkage at the inert center, the ortho position of the phenolic-OH of the tyrosine moiety, where all of the amino, thiol, phenol, imidazole, carboxy, etc., groups of the enzyme residues, including those that belong to the active site, remain intact. The coupling process, analyzed using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible spectroscopy (UV-vis), and fluorescence spectroscopy, occurs without molecular aggregation in borate buffer at pH 8.8 ± 0.4, which is much higher than the iso-electric point (pH 5.1) of the macromolecule where it becomes soluble. Eventually, the immobilization is maximize and also the native-enzyme activities are restored remarkably. The immobilized catalyst converts urea (0.0625-0.15 mmol L-1) to ammonia appreciably (94.50 ± 1.5%) at 27 °C, and the efficiency is well comparable to that of the native enzyme (93.0 ± 0.4%). The efficiency gradually diminishes, coming down to 50% at the 40th cycle, and the enzyme returns to its native conformation within 72 h in tris-EDTA borate buffer at 27 °C for the next 40 cycles of reuse and so on. The efficiency becomes hindered by 8-10% in every 5th subsequent reuse to reach 50% on the 30th reuse, resulting in room-temperature catalytic sustainability of 90 days. The catalytic performances are well restored in rice extract and coconut water.
Arsenic and chromium have affected wider area in the world including Gangetic plains of India due to its toxicity and carcinogenic characteristics. Entry of As(III) into food chain has also escalated problem. A novel approach has been adopted to develop remediation technique using bacteria and herbs. The bioremediation study showed Bixa orellana as an accumulator of As(III) of Cr(VI) which was validated by SEM-EDX, FTIR and other kinetic analyses. Maximum percentage removal of Cr(VI) with fixed bio mass of B. orellana is 82.8% for an initial concentration of 3 ppm Cr(VI) concentration whereas maximum percentage removal of As(III) is 40.42 for an initial concentration of 6 ppm As(III). The R² values and graphs showed that Freundlich as well as Elovich model best fitted to the experimental data. Three bacteria isolated from the coal mines of Rajmahal hills showed As(III) resistance and bioremediation potentials (up to 150 ppm). The 16S rRNA genotyping of these isolates was done (GenBank accession no: MK231250, MK231251 and MK231252) which showed similarity with Stenotrophomonas maltophilia, Uncultured gamma proteobacteria clone and Bacterium E1. Further, the presence of genes involved in arsenic biotransformation like aox, acr and ars was also confirmed in these bacterial isolates. Maximum percentage removal od As(III) in 50 ppm concentration by ASBBRJM16, ASBBRJM85 and ASBBRJM87 bacteria are 60.66%, 28.36% and 10.30% respectively for an initial concentration of 50 ppm As(III). Our results suggest that bacterial isolates may be adopted as an effective tool to remove As(III) from aqueous medium in spite of different cell structures and composition.
Background Demand for family planning is predominantly for birth limiting rather than birth spacing in India. Despite several family planning programmes in India, the use of reversible contraception for limiting family planning has been stagnant and largely depends on female sterilization. Though many researchers have examined patterns and determinants of using modern contraception for total family planning, studies on patterns and determinants of contraceptive use for birth limiting are limited in India. This paper examines the patterns of contraceptive use for liming demand and its determinants in India. Methods The National Family Health Survey-4, 2015–16 data was used. Bivariate chi-square significant test and multivariate binary logistic regression model used to accomplish the study objectives. Results Majority of women (86.5%) satisfied limiting demand (SLD) in India; the SLD was found significantly low among the women’s age 15–19 years (53.1%) and parity 0 (42%). The satisfied limiting demand by modern reversible contraception (mrSLD) was found significantly high in age group 15–19 years (49.1%), Muslims (30.6%) and North-east region (45.4%). The satisfied limiting demand by traditional contraception (tSLD) was almost three times higher in North-east region (26.1%) than national average of India (8.7%). The women’s years of schooling, wealth status, religion and presence of son child found to be significant determinants of mrSLD. The likelihood of tSLD was found significantly high among the women who had no son child (AOR = 1.41; 95% CI:1.34, 1.48), Muslim (AOR = 1.78; 95% CI:1.70, 1.87). A considerable regional variability in levels of SLD, mrSLD and tSLD was found in India. Conclusion Public investment in family planning is required to promote and provide subsidized modern reversible contraception (MRC) services, especially to women from North-east region, Muslim, Scheduled tribe, poor household and who had no son child. Improving the quality and availability of MRC services in public health centre will be helpful to increase SLD among the above mentioned women. Besides, the promotion of MRC will be supportive to overcome the issues of sterilization regrets in India.
Since healthy parents are more likely to provide a fulfilling childhood to their children, it seems crucial to examine those aspects of parenthood that add to parental well-being. The present article discusses the theoretical relationship between well-being and parenting within the contemporary social and relational context by underlining how society and children play significant roles in determining parental well-being.
Potato leafroll virus (PLRV) uses powerful molecular machines to package its genome into a viral capsid employing ATP as fuel. Although, recent bioinformatics and structural studies have revealed detailed mechanism of DNA packaging, little is known about the mechanochemistry of genome packaging in small plant viruses such as PLRV. We have identified a novel P-loop-containing ATPase domain with two Walker A-like motifs, two arginine fingers, and two sensor motifs distributed throughout the polypeptide chain of PLRV capsid protein (CP). The composition and arrangement of the ATP binding and hydrolysis domain of PLRV CP is unique and rarely reported. The discovery of the system sheds new light on the mechanism of viral genome packaging, regulation of viral assembly process, and evolution of plant viruses. Here, we used the RNAi approach to suppress CP gene expression, which in turn prevented PLRV genome packaging and assembly in Solanum tuberosum cv. Khufri Ashoka. Potato plants agroinfiltrated with siRNA constructs against the CP with ATPase domain exhibited no rolling symptoms upon PLRV infection, indicating that the silencing of CP gene expression is an efficient method for generating PLRV-resistant potato plants. In addition, molecular docking study reveals that the PLRV CP protein has ATP-binding pocket at the interface of each monomer. This further confirms that knockdown of the CP harboring ATP-binding domain could hamper the process of viral genome packaging and assembly. Moreover, our findings provide a robust approach to generate PLRV-resistant potato plants, which can be further extended to other species. Finally, we propose a new mechanism of genome packaging and assembly in plant viruses.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
87 members
Sunil Choudhary
  • University Department of Botany
K. Prasad
  • Department of Physics
S. N. Choudhary
  • Department of Physics
Dipo Mahto
  • Department of Physics
Md Equbal Ahmad
  • P.G.Dept. of zoology
Bhāgalpur, India