Browsing by Author "V.K. Singh"

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A Family of Estimators for Population Mean Under Model Approach in Presence of Non-Response
(River Publishers, 2022) Ajeet Kumar Singh; V.K. Singh
We have defined a class of estimators for population mean under nonresponse error based upon the concept of sub-sampling of non-respondents utilizing an auxiliary variable. The class is a one-parameter class of estimators which is based on the idea of exponential type estimators (ETE). The model biasness and model-mean square error of the class and some of its important members have been derived under polynomial regression model (PRM). The effect of variations in PRM specifications on the efficiency of the estimators has been discussed based upon the empirical results. © 2022 River Publishers.
A generalised stochastic model for the most recent inter-arrival time
(Marcel Dekker Inc., 1997) V.K. Singh
The analysis of intervals between successive arrivals is an important component in any study of point processes. In this context, the most recent inter-arrival time (MRIAT), that is, the interval between last and second-last arrivals has a prominent place in the characterization of such a process if the study is made only for a limited period of time. In this paper, a general probability model for MRIAT is derived under some realistic assumptions. Some particular cases of the model have also been obtained which might be applicable in real data sets.
A generalized stochastic model for number of events in equilibrium renewal process (ERP)
(2011) V.K. Singh; B.P. Singh
If a system, producing point events has been running for a long time before it is first observed, one obtains an equilibrium renewal process (ERP). Such renewal processes are common in real life experiments where the experimenter enters the system abruptly at a fixed point, a long time after the start of the process and counts the number of events of his interest upto the time point.The present paper is aimed at to develop a generalized model for number of point events in ERP with point state space of the process. Some special cases of the model have been dealt with. Expressions for mean and variance of the model have been obtained for estimating parameters of the model.
A hybrid technique for onboard image data compression
(1998) M.L. Mittal; V.K. Singh; R. Krishnan
This paper presents a hybrid compression technique in which lossless and lossy techniques have been combined. This technique can be used to compress 10 bit data. The 8 LSBS are compressed using the Joint Photographic Expert Group (JPEG) compression technique and the 2 MSBS are coded using run length encoding. This compressed data is merged in the JPEG specified format and transmitted to the receiver. The decoder process splits the compressed data into two data sets and decodes them accordingly, using the associated technique. The software has been developed for this scheme in 'C' under UNIX OS on SGI O2 machine. Future Remote Sensing Missions are planned to carry payloads with higher spectral and spatial resolutions (1m/2m). This hybrid technique can be used to compress this data onboard with reduced onboard hardware and better performance. This technique can also be used for storage and transmission of data on ground.
A modification of a continuous time model for first conception
(1976) S.N. Singh; K.C. Chakrabarty; V.K. Singh
The interval between marriage and the first conception leading to a live birth plays an important role in the determination of fertility components. Several probability models (Potter and Parker, 1964; Singh, 1961, 1964, 1967) based on varying sets of assumptions relating to this interval have been propounded in the recent past. All of them are based on the assumption that the females under study are susceptible to conception at the time of marriage. However, in certain situations, where some of the females already pregnant at the time of marriage report to have conceived within a short interval following marriage, this condition is not satisfied and these models become unsuitable. A probability distribution which is an inflated form of the continuous model proposed by Singh, for the time of the first conception leading to a live birth, is presented in this paper. It describes reasonably well the data on first conception times in the context of premarital conceptions. Simple expressions for the maximum likelihood estimators of the parameters involved in the model are obtained and a method for finding the asymptotic covariance matrix of the estimators is outlined. The model is applied to four sets of data. © 1976 Population Association of America.
A new arsenate reductase involved in arsenic detoxification in Anabaena sp. PCC7120
(2013) Sarita Pandey; A.K. Shrivastava; V.K. Singh; R. Rai; P.K. Singh; S. Rai; L.C. Rai
In silico analysis followed by experimental validation leads us to propose that the predicted protein All0195 of Anabaena sp. PCC7120 showing enhanced expression under sodium arsenate (Na2HAsO4) stress belongs to the thioredoxin superfamily with structural similarity to bacterial arsenate reductase. The All0195 protein demonstrated C-X-TC-X-K, NTSG-X2-YR, and D-X2-L-X-KRP as functional motifs that show similarity to seven known bacterial arsenate reductase family protein homologs with Cys, Arg, and Pro as conserved residues. In view of physicochemical properties, such as aliphatic index, ratio of Glu + Lys to Gln + His, and secondary structure, it was evident that All0195 was also a thermostable protein. The predicted three-dimensional structure on molecular docking with arsenate oxyanion (HAsO4-2) revealed its interaction with conserved Cys residue as also known for other bacterial arsenate reductase. In silico derived properties were experimentally attested by cloning and heterologous expression of all0195. Furthermore, this protein functionally complemented the arsenate reductase-deficient sodium arsenate-hypersensitive phenotype of Escherichia coli strainWC3110 (ΔarsC) and depicted arsenate reductase activity on purification. In view of the above properties, All0195 appears to be a new arsenate reductase involved in arsenic detoxification in Anabaena sp. PCC7120. © 2012 Springer-Verlag Berlin Heidelberg.
A newton-like method for solving generalized operator equations and variational inequalities
(Yokohama Publications, 2015) D.R. Sahu; K.K. Singh; V.K. Singh; Y.J. Cho
Intlris paper, we present a semilocal convergence analysis of a Newton- like method for solving the generalized operator equations in Hilbert spaces and also discuss the convergence analysis of the proposed algorithm under weak con- ditions. We establish sharp generalizations of Kantorovich theory for operator equations when the derivative is not necessarily invertible. As a simple con- sequence of our result, we discuss the existence and uniqueness of solutions of mixed variational inequality problems. Finally, we give numerical examples for the equations involving single valued as well as multi-valued mappings. © 2015.
A probability model for the number of births in an equilibrium birth process
(Springer India, 1981) S.N. Singh; V.K. Singh
A probability model for the number of complete conceptions (that is, live births) taking into account foetal wastages, occurring in a couple during a specified period of time (T0, T0+T) is developed assuming that the data was collected starting a long time after marriage. A method of estimating some of the underlying parameters is given. The model is applied to data obtained in a Varanasi Survey in 1969-70. © 1981 Indian Academy of Sciences.
A study on assessment of hydrocarbon potential of the lignite deposits of Saurashtra basin, Gujarat (Western India)
(Springer International Publishing, 2017) Prakash K. Singh; V.K. Singh; P.K. Rajak; Neeraj Mathur
In the present investigation, Bhavnagar lignites of the Saurashtra basin (Gujarat) have been studied to assess their hydrocarbon generating potential. The samples of upper as well as lower lignite seams have been studied through microscopy and subjected to various chemical analyses viz. proximate analysis, ultimate analysis and Rock-Eval Pyrolysis. These lignites have high moisture and low to moderate ash yield but are characterized by high volatile matter. Petrographically they comprise predominantly of huminite group maceral while liptinite and inertinite groups occur in subordinated amount. Huminite is chiefly composed of detrohuminite and telohuminite. The Tmax (av. 416.23 °C) and huminite reflectivity (0.28%–0.30%) indicate a low degree of maturity for these lignites which is also substantiated by the Tmax versus hydrogen index plot. The organic matter is subjugated by kerogen Type-III with a potential to expel hydrocarbon on liquefaction. Study further reveals that the fixed hydrocarbon is several folds higher than the free hydrocarbons. Being high in reactive maceral content, a high ‘conversion’ and good ‘oil yield’ values for these lignites were observed. Thus, the empirically derived values match well with those obtained through the experimental values of Rock-Eval Pyrolysis and validate their hydrocarbon generating potential. © 2017, The Author(s).
An automated course feedback system using opinion mining
(2011) V.K. Singh; P. Kumari; A. Singh; J. Thapa
This paper presents our experimental work on designing an automated web-based course feedback system that uses opinion mining to compute the overall feedback score. The system collects user responses through an online form. The online feedback form consists of a set of binary and graded response questions as well as a free-form input text box where a student can write about his overall experiences with the course. Every student is encouraged to write in detail about his experience. The text entered by the student in free form input text box is then used for opinion mining to label the feedback as 'positive' or 'negative'. We have used an unsupervised SO-PMI-IR based approach for opinion mining. The final feedback of a course is thus a combination of an overall score (computed on various binary and graded questions) and a 'positive' or 'negative' label to mark the student's overall evaluation. We evaluated the system for more than 20 courses with a total of about 1000 reviews. © 2011 IEEE.
Analytical mapping of opinion mining and sentiment analysis research during 2000–2015
(Elsevier Ltd, 2017) R. Piryani; D. Madhavi; V.K. Singh
The new transformed read-write Web has resulted in a rapid growth of user generated content on the Web resulting into a huge volume of unstructured data. A substantial part of this data is unstructured text such as reviews and blogs. Opinion mining and sentiment analysis (OMSA) as a research discipline has emerged during last 15 years and provides a methodology to computationally process the unstructured data mainly to extract opinions and identify their sentiments. The relatively new but fast growing research discipline has changed a lot during these years. This paper presents a scientometric analysis of research work done on OMSA during 2000–2016. For the scientometric mapping, research publications indexed in Web of Science (WoS) database are used as input data. The publication data is analyzed computationally to identify year-wise publication pattern, rate of growth of publications, types of authorship of papers on OMSA, collaboration patterns in publications on OMSA, most productive countries, institutions, journals and authors, citation patterns and an year-wise citation reference network, and theme density plots and keyword bursts in OMSA publications during the period. A somewhat detailed manual analysis of the data is also performed to identify popular approaches (machine learning and lexicon-based) used in these publications, levels (document, sentence or aspect-level) of sentiment analysis work done and major application areas of OMSA. The paper presents a detailed analytical mapping of OMSA research work and charts the progress of discipline on various useful parameters. © 2016 Elsevier Ltd
Antimicrobial assay and genetic screening of selected freshwater Cyanobacteria and identification of a biomolecule dihydro-2H-pyran-2-one derivative
(2017) A. Srivastava; V.K. Singh; S. Patnaik; J. Tripathi; P. Singh; G. Nath; R.K. Asthana
Aims: Explorations of freshwater Cyanobacteria as antimicrobial (bacteria, fungi and methicillin-resistant Staphylococcus aureus (MRSA) strains) drug resource using bioassay, NRPS (non-ribosomal polypeptide synthetase) and PKS (polyketide synthase) genes, as well as in silico approach. Methods and Results: We have bioassayed the extracts of Phormidium CCC727, Geitlerinema CCC728, Arthrospira CCC729, Leptolyngbya CCC732, Phormidium CCC730, Phormidium CCC731 against six pathogenic bacteria comprising Gram (+ve): S. aureus including seven clinical MRSA and Enterococcus faecalis, Gram (−ve): Escherichia coli, Salmonella Typhimurium, Klebsiella pneumoniae and Shigella boydii along with non-pathogenic Enterobacter aerogenes as well as fungal strains (Cryptococcus neoformans and Candida albicans, C. krusei, C. tropicalis and Aspergillus niger) exhibiting antimicrobial potential. The NRPS and PKS genes of the target strains were also amplified and sequenced. The putative protein structures were predicted using bioinformatics approach. Conclusion: PKS gene expression indicated β keto-acyl synthase as one of the important active domains in the biomolecules related to antitumour and antifungal group. The simultaneous identification of the biomolecule (dihydro-2H-pyran-2-one derivative) was also inferred spectroscopically. Significance and Impact of the Study: Freshwater Cyanobacteria are prolific producers of secondary metabolite(s) that may act as the antimicrobial drug resource in addition to their much explored marine counterpart. © 2016 The Society for Applied Microbiology
Arsenic and cadmium are inhibitors of cyanobacterial dinitrogenase reductase (nifH1) gene
(Springer Verlag, 2014) Shilpi Singh; A.K. Shrivastava; V.K. Singh
The enzyme nitrogenase complex is a key component conferring nitrogen fixation in all known diazotrophs. This study for the first time examines the impact of As, Na, Cd, Cu and butachlor on component II (dinitrogenase reductase, nifH1) of nitrogenase from diazotrophic cyanobacterium Anabaena sp. PCC7120 using in silico and wet lab approaches. The nifH1 of Anabaena is a glycine-rich stable protein having DNA-binding properties and shows close similarity with free living compared with symbiotic diazotrophs. Phylogenetic tree revealed an adverse effect of the selected stresses on close homologs across the diazotroph community. The protein interaction network demonstrated the presence of nirA, glnA, glnB, alr4255 and alr2485 proteins besides nif proteins, suggesting their involvement in nitrogen fixation along with nifH1. Homology modelling and docking under As, Na, Cd, Cu and butachlor revealed an interaction between stressors and nifH1 protein which was further validated by a transcript of the gene through quantitative real-time PCR (qRT-PCR). Presence of binding sites for As, Na, Cd and Cu on oxyR promoter attested their adverse affects on nifH1. Maximum down-regulation of nifH1 in Cd and As followed by salt, copper and butachlor revealed that arsenic and cadmium were most potential inhibitors of nitrogenase of diazotrophic community, which might negatively affect crop yield. © 2014 Springer-Verlag.
Biochemical and spectroscopic characterization of morning glory peroxidase from an invasive and hallucinogenic plant weed Ipomoea carnea
(2008) Ashok Kumar Patel; V.K. Singh; A.J. Moir; Medicherla V. Jagannadham
A novel heme peroxidase MGP from the latex of Ipomoea carnea subsp. fistulosa (morning glory) belonging to the Convolvulaceae family was purified to homogeneity using ammonium sulfate precipitation, anion exchange, hydrophobic interaction, and gel filtration chromatography. The enzyme is glycosylated and has a molecular mass of 42.06 kDa (MALDI-TOF) and an isoelectric point of pH 4.3. The enzyme has high yield, broad substrate specificity, and a high stability toward pH, temperature, chaotrophs, and organic solvents. The extinction coefficient (ε2801% of the enzyme was estimated as 20.56 and it consists of 13 tryptophan, 9 tyrosine, and 8 cysteine residues forming 4 disulfide bridges. There is significant effect of inhibitors targeting S-S bridges (mercaptoethanol, L-cysteine, glutathione), as well as of inhibitors targeting heme (sodium azide and hydroxylamine) on peroxidase activity, whereas inhibition was not observed with ethylmaleinimide due to the absence of reduced cysteine in the enzyme. Polyclonal antibodies against the enzyme have been raised in rabbit, and immunodiffusion suggests that the antigenic determinants of MGP are unique. The N-terminal sequence of MGP (D-E-A-C-I-F-S-A-V-K-E-V-V-D-A) exhibited considerable similarity to the sequence of other known plant peroxidases. Spectroscopic studies (absorbance, fluorescence, and circular dichroism) reveal that MGP has secondary structural features with α/β type with approximately 20% α-helicity. © 2008 American Chemical Society.
Biodegradation of vegetable and agrowastes by Pleurotus sapidus: A novel strategy to produce mushroom with enhanced yield and nutrition
(2012) M.P. Singh; V.K. Singh
Edible oyster mushroom Pleurotus sapidus was cultivated, on pea pod shell, cauliflower leaves, radish leaves, brassica straw in various combinations of paddy straw. The mushroom failed to grow on these vegetable wastes separately. However, it grew very well on these vegetable wastes when mixed with various combinations of paddy straw as substrate. Total yield and biological efficiency of the mushroom cultivated on substrate containing 20% and 30% vegetable wastes mixed with 70% and 80% (w/w) of paddy straw was found to be better, when compared with yield and efficiency obtained with paddy straw alone (100%). The protein content in the fruit bodies was found to be higher in the mushroom grown on paddy straw mixed with vegetable wastes than that obtained with paddy straw alone. Similarly, six amino acids (Leu, Ile, Val, Thr, Met and Phe) showed a significant increase when the mushroom was grown on a mixed substrate containing both vegetable wastes and paddy straw. On the contrary, the total sugar and reducing sugar content declined in the mushroom grown on the mixture of paddy straw and other wastes, when compared with the results obtained with paddy straw alone. © 2012.
Bioremediation of vegetable and agrowastes by Pleurotus ostreatus: A novel strategy to produce edible mushroom with enhanced yield and nutrition
(Cellular and Molecular Biology Association, 2014) V.K. Singh; M.P. Singh
Pleurotus ostreatus was grown on paddy straw as well as other vegetable and agricultural wastes i.e. pea pod shell, cauliflower leaves, radish leaves and brassica straw in various combinations with paddy straw. The mushroom did not grow on the vegetable wastes separately. The cumulative yield and biological efficiency of the edible oyster mushroom P. ostreatus grown on substrate containing paddy straw in various combinations with different vegetable wastes i.e. 20% and 30 % vegetable wastes mixed with 80% and 70% (w/w) of paddy straw was found to be better, when compared with yield and biological efficiency obtained on paddy straw (100%) alone. The protein content and six essential amino acid contents (Leu, Ile, Val, Thr, Met, Phe) showed a significant increase and total sugar and reducing sugar contents showed decrease in the mushroom fruit bodies grown at different combinations of vegetable wastes with paddy straw as compared to paddy straw alone. However, there was not any significant change in moisture content of mushroom cultivated on different groups of wastes. Hence, results of this investigation suggest that the vegetable wastes which are generally left to rot in situ in many cities and villages causing outbreak of diseases can be bioremediated by edible mushroom P. ostreatus. The added advantage is that we get edible mushroom fruit body with improved nutrition. © 2014.
Blog text analysis using topic modeling, named entity recognition and sentiment classifier combine
(2013) Pranav Waila; V.K. Singh; M.K. Singh
This paper describes our experimental work on computational analysis of socio-political blog data through a novel combine of sophisticated language processing and visualization techniques. We have designed an integrated framework by utilizing Topic Modeling, Entity Extraction and Sentiment Analysis; to draw sociologically relevant inferences from unstructured free form blogosphere data. The dataset comprised of more than 9290 blog posts on social-political events related to the Arab spring. We have tried to extract important inferences from the dataset; such as key themes, persons, places, organizations and overall sentiment orientation of the content around different entities in the texts. We have tried to validate the inferences obtained through manual and Google search trends statistics. The results obtained are quite relevant and demonstrate the usefulness of our approach for computational analysis of social media data. © 2013 IEEE.
Collective intelligence based computational approach to web intelligence
(2009) V.K. Singh; R. Jalan; S.K. Chaturvedi; A.K. Gupta
The World Wide Web has undergone major transformation during last few years, primarily due to its newly discovered ability to harness collective intelligence of the millions of users across the world. Users are no longer only passive consumers; they are actively participating to create new and useful content and more rich & personalized web applications. Techniques to leverage user contributions are on one hand making the Web a collective knowledge system (applications like Wikipedia), and on the other hand provide a new approach to mine the unstructured web-content for useful inferences & new knowledge. In this paper, we have discussed how the collective intelligence phenomenon is bringing about the paradigm shift in the Web; and presented our experimental work on a social-inference oriented approach for opinion analysis on the Blogosphere. © 2009 IEEE.
Comparative analysis of genome-wide Mlo gene family in Cajanus cajan and Phaseolus vulgaris
(Springer International Publishing, 2016) Reena Deshmukh; V.K. Singh; B.D. Singh
The Mlo gene was discovered in barley because the mutant ‘mlo’ allele conferred broad-spectrum, non-race-specific resistance to powdery mildew caused by Blumeria graminis f. sp. hordei. The Mlo genes also play important roles in growth and development of plants, and in responses to biotic and abiotic stresses. The Mlo gene family has been characterized in several crop species, but only a single legume species, soybean (Glycine max L.), has been investigated so far. The present report describes in silico identification of 18 CcMlo and 20 PvMlo genes in the important legume crops Cajanus cajan (L.) Millsp. and Phaseolus vulgaris L., respectively. In silico analysis of gene organization, protein properties and conserved domains revealed that the C. cajan and P. vulgarisMlo gene paralogs are more divergent from each other than from their orthologous pairs. The comparative phylogenetic analysis classified CcMlo and PvMlo genes into three major clades. A comparative analysis of CcMlo and PvMlo proteins with the G. max Mlo proteins indicated close association of one CcMlo, one PvMlo with two GmMlo genes, indicating that there was no further expansion of the Mlo gene family after the separation of these species. Thus, most of the diploid species of eudicots might be expected to contain 15–20 Mlo genes. The genes CcMlo12 and 14, and PvMlo11 and 12 are predicted to participate in powdery mildew resistance. If this prediction were verified, these genes could be targeted by TILLING or CRISPR to isolate powdery mildew resistant mutants. © 2016, Springer International Publishing Switzerland.
Comparative phylogenetic analysis of genome-wide Mlo gene family members from Glycine max and Arabidopsis thaliana
(Springer Verlag, 2014) Reena Deshmukh; V.K. Singh; B.D. Singh
Powdery mildew locus O (Mlo) gene family is one of the largest seven transmembrane protein-encoding gene families. The Mlo proteins act as negative regulators of powdery mildew resistance and a loss-of-function mutation in Mlo is known to confer broad-spectrum resistance to powdery mildew. In addition, the Mlo gene family members are known to participate in various developmental and biotic and abiotic stress response-related pathways. Therefore, a genome-wide similarity search using the characterized Mlo protein sequences of Arabidopsis thaliana was carried out to identify putative Mlo genes in soybean (Glycine max) genome. This search identified 39 Mlo domain containing protein-encoding genes that were distributed on 15 of the 20 G. max chromosomes. The putative promoter regions of these Mlo genes contained response elements for different external stimuli, including different hormones and abiotic stresses. Of the 39 GmMlo proteins, 35 were rich (8.7-13.1 %) in leucine, while five were serine-rich (9.2-11.9 %). Furthermore, all the GmMlo members were localized in the plasma membrane. Phylogenetic analysis of the GmMlo and the AtMlo proteins classified them into three main clusters, and the cluster I comprised two sub-clusters. Multiple sequence alignment visualized the location of seven transmembrane domains, and a conserved CaM-binding domain. Some of the GmMlo proteins (GmMlo10, 20, 22, 23, 32, 36, 37) contained less than seven transmembrane domains. The motif analysis yielded 27 motifs; out of these, motif 2, the only motif present in all the GmMlos, was highly conserved and three amino acid residues were essentially invariant. Five of the GmMlo members were much smaller in size; presumably they originated through deletion following a gene duplication event. The presence of a large number of GmMlo members in the G. max genome may be due to its paleopolyploid nature and the large genome size as compared to that of Arabidopsis. The findings of this study may further help in characterization and isolation of individual GmMlo members. © 2014 Springer-Verlag.