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Gaurav Sharma

Publications and source records attributed to Gaurav Sharma.

15 recordsLinked to original sources
PubMed2026

A Pilot Study on the Utility of Whole Genome Sequencing for Detecting Drug Resistance in Mycobacterium tuberculosis in the Current Scenario.

PURPOSE: Whole Genome Sequencing (WGS) comprehensively detects all drug-resistant mutants, which can help in the early initiation of specific treatment for the patient. But there is a need to evaluate the performance of WGS in comparison with Line Probe Assays (LPA) and Phenotypic Drug Susceptibility Tests (pDST). METHODS: Consecutive sputum samples (58) found positive for Mycobacterium tuberculosis (MTB) by GeneXpert were tested for first-and second-line LPA, pDST and WGS for anti-tubercular drugs. RESULTS: Of 58, 34 (58.6%) culture isolates were resistant to one or more drugs. Resistance detected by WGS was as follows: Isoniazid 23(39.6%), Rifampicin 21(36.2%), FQs 21(36.2%), Ethambutol 18(31%), Linezolid 12(20.6%), Streptomycin 8(13.8%), Kanamycin 6(10.3%), Amikacin and Capreomycin 5(8.6%), Para-amino salicylic acid 1(1.7%) and Ethionamide 1(1.7%). No resistance was detected to Pyrazinamide, Bedaquiline, Clofazimine, Delamanid and Pretomanid. Lineage 3(EAI) was the most predominant 23(39.6%) followed by Lineage 2: 13(22.4%). Intermediate Resistance (IR) and potential novel mutations were observed in a few cases, CONCLUSION: Overall accuracy for first-line drugs between pDST vs WGS was >98% &pDST vs LPA >95%, while for second-line drugs accuracy was >96% and >90% respectively. IR and potential novel mutations should be followed up closely to understand their clinical significance.

IR↗
PubMed2026

Molecular dissection and functional characterization of the liguleless1 gene for manipulation of leaf angle in maize.

Recessive liguleless1 (lg1) gene significantly reduces leaf angle in maize and has become the choice in breeding for high plant density. Here, we sequenced the entire lg1 gene (5560 bp) among seven wild-type (Lg1) and one mutant (lg1) inbreds. The analysis revealed a total of 229 SNPs and 155 InDels within the Lg1 gene. The study also revealed the existence of three exons, with lg1-mutant having two exons. The lg1-mutant harboured an insertion of 130 bp Tourist MITE transposable element in exon-2 at 1663rd base, which deleted 157 amino acids of C-terminal region of the mutant LG1 protein. The mutant LG1 protein was 247 amino acids in length, in contrast to 399-404 amino acids in wild-type protein. The analysis with 26 paralogues and 66 orthologues of Lg1 revealed conservation of the squamosa promoter-binding (SBP) domain. A PCR-based co-dominant InDel marker (MGU-lg1-Tourist) specific to insertion of 130 bp was developed that differentiated the mutant allele (lg1) from the wild-type allele (Lg1). The marker was validated in two F2 populations, which showed a 1:2:1 ratio. F2 plants showed a 3 (wide angle: 41.58°) :1 (narrow angle: 5.88°) segregation for leaf angle. A set of 11 gene-based InDel markers (MGU-InDel1 to MGU-InDel11) specific to Lg1 was also developed, and along with MGU-lg1-Tourist, they classified a diverse set of 48 inbreds into 35 distinct haplotypes (hap1 to hap35) with lg1-based inbreds possessing hap1. This is the first report of the development and validation of a co-dominant gene-based marker specific to lg1, and information generated assumes great significance in maize breeding aimed to tailor the plant architecture suitable for high plant density..

Zea mays↗
PubMed2025

A decentralized future for the open-science databases.

The continuous and reliable open access to curated biological data repositories is indispensable for accelerating rigorous scientific inquiry and fostering reproducible research outcomes. However, the current paradigm, which relies heavily on centralized infrastructure for the storage and distribution of foundational biomedical datasets, inherently introduces significant vulnerabilities. This centralized model is susceptible to single points of failure, including cyberattacks, technical malfunctions, natural disasters, and even political or funding uncertainties. Such disruptions can lead to widespread data unavailability, data loss, integrity compromises, and substantial delays in critical research, ultimately impeding scientific progress. The downstream effect of such interruptions can be the widespread paralysis of diverse research activities, including computational, clinical, molecular, and climate studies. This scenario vividly illustrates the inherent dangers of consolidating essential scientific resources within a single geopolitical or institutional locus. As data generation is accelerating and the global landscape continues to fluctuate, the sustainability of centralized models must be critically re-evaluated. A shift toward federated and decentralized architectures may offer a robust and forward-looking approach to enhancing the resilience of scientific data infrastructures by reducing exposure to governance instability, infrastructural fragility, and funding volatility, while also promoting equity and global accessibility. Inspired by established models such as ELIXIR's federated infrastructure and the policy and funding frameworks developed by CODATA and the Global Biodata Coalition (GBC), emerging Decentralized Science (DeSci) initiatives can contribute to building more resilient, fair, and incentive-aligned data ecosystems. The future of open science depends on integrating these complementary approaches to establish a globally distributed, economically sustainable, and institutionally robust infrastructure that safeguards scientific data as a public good, further ensuring continued accessibility, interoperability, and preservation for generations to come. Here, we examine the structural limitations of centralized repositories, evaluate federated and decentralized models, and propose a hybrid framework for resilient, fair, and sustainable scientific data stewardship.

data accessibility↗
PubMed2024

Putative evolution of Myxococcus fulvus 124B02 plasmid pMF1 from a chromosomal segment in another Myxococcus species.

Myxobacteria or order Myxococcales (old nomenclature) or phylum Myxococcota (new terminology) are fascinating organisms well known for their diverse peculiar physiological, taxonomic, and genomic properties. Researchers have long sought to identify plasmids within these organisms, yet thus far, only two organisms from different families have been found to harbor a plasmid. This study delves into the putative evolution of one of these plasmids, i.e., pMF1 present in Myxococcus fulvus 124B02 in the suborder Cystobacterineae and family Myxococcaceae. Here, we first reannotated the pMF1 plasmid genome sequence and identified two additional open reading frames or putative genes which were not annotated until now. We further reported that all pMF1 plasmid genes depict homology with Myxococcus stipitatus CYD1 draft genome (contig 28) and a chromosomal segment of M. stipitatus DSM14675 in a syntenic manner, implying the presence of plasmid-like structure in M. stipitatus CYD1, integrated into its chromosome. To comprehend the relationship among these three species, we conducted phylogenetic analyses using 16S and concatenated housekeeping genes and genome-to-genome distance calculator (GGDC) analysis, which confirmed that M. stipitatus CYD1 is a distinct and novel species within the genus Myxococcus. Overall, this comparative genomic study sheds light on the putative emergence of the pMF1 plasmid from a common ancestor of closely related yet distinct species, M. stipitatus CYD1, possibly through the partition from its chromosome as a segment.IMPORTANCEMyxobacteria are not well known to have plasmids. Until now, only two organisms have been shown to have plasmids, raising a pertinent question about how these plasmids evolved randomly within the phylum Myxococcota. The study presented in this manuscript delves into the emergence of the pMF1 plasmid found in Myxococcus fulvus 124B02, a member of the suborder Cystobacterineae and family Myxococcaceae. Our research addresses this intriguing topic of plasmid identification and evolution within myxobacteria, which are a group of fascinating organisms that have garnered significant interest due to their diverse physiological, taxonomic, and genomic properties.

Plasmids↗
PubMed2006

Lossless watermarking for image authentication: a new framework and an implementation.

We present a novel framework for lossless (invertible) authentication watermarking, which enables zero-distortion reconstruction of the un-watermarked images upon verification. As opposed to earlier lossless authentication methods that required reconstruction of the original image prior to validation, the new framework allows validation of the watermarked images before recovery of the original image. This reduces computational requirements in situations when either the verification step fails or the zero-distortion reconstruction is not needed. For verified images, integrity of the reconstructed image is ensured by the uniqueness of the reconstruction procedure. The framework also enables public(-key) authentication without granting access to the perfect original and allows for efficient tamper localization. Effectiveness of the framework is demonstrated by implementing the framework using hierarchical image authentication along with lossless generalized-least significant bit data embedding.

Algorithms↗
PubMed2006

Local image registration by adaptive filtering.

We propose a new adaptive filtering framework for local image registration, which compensates for the effect of local distortions/displacements without explicitly estimating a distortion/displacement field. To this effect, we formulate local image registration as a two-dimensional (2-D) system identification problem with spatially varying system parameters. We utilize a 2-D adaptive filtering framework to identify the locally varying system parameters, where a new block adaptive filtering scheme is introduced. We discuss the conditions under which the adaptive filter coefficients conform to a local displacement vector at each pixel. Experimental results demonstrate that the proposed 2-D adaptive filtering framework is very successful in modeling and compensation of both local distortions, such as Stirmark attacks, and local motion, such as in the presence of a parallax field. In particular, we show that the proposed method can provide image registration to: a) enable reliable detection of watermarks following a Stirmark attack in nonblind detection scenarios, b) compensate for lens distortions, and c) align multiview images with nonparametric local motion.

Algorithms↗
PubMed2006

Current trend of poisoning--a hospital profile.

A one-year study was carried out among the poisoning cases admitted in the emergency wing of Guru Nanak Dev Hospital attached to Government Medical College, Amritsar during the period from 10-5-1997 to 9-5-1998. Out of 10,664 admitt emergencies, 3.19% were poisoning cases. Male to female ratio was nearly 3:1. Majority (45.59%) of the victims were in the age group of 21-30 years, 69.12% were married and 51.47% belonged to urban area. At the time of admission 61.47% cases were conscious, 26.17% were partially conscious and 12.36% were unconscious. Majority (76.47%) of the victims committed suicide, in 20.88% cases manner of death was accident and homicide was reported in 1.76% cases. Commones poison was aluminium phosphide (38.23%) followed by organophosphorus compounds (17.64%). The study observed increasing trend of suicide by aluminium phosphide and organophosphorus compounds, whereas other poisons for committing suicide were less commonly used.

Accidents↗
PubMed2005

Attenuation of protein adsorption on static and oscillating magnetostrictive nanowires.

The research described here investigates the hypothesis that nanoarchitecture contained in a nanowire array is capable of attenuating the adverse host response generated when medical devices are implanted in the body. This adverse host response, or biofouling, generates an avascular fibrous mass transfer barrier between the device and the analyte of interest, disabling the implant if it is a sensor. Numerous studies have indicated that surface chemistry and architecture modulate the host response. These findings led us to hypothesize that nanostructured surfaces will inhibit the formation of an avascular fibrous capsule significantly. We are investigating whether arrays of oscillating magnetostrictive nanowires can prevent protein adsorption. Magnetostrictive nanowires were fabricated by electroplating a ferromagnetic metal alloy into the pores of a nanoporous alumina template. The ferromagnetic nanowires are made to oscillate by oscillating the magnetic field surrounding the wires. Radiolabeled bovine serum albumin, enzyme-linked immunosorbent assay (ELISA), and other protein assays were used to study protein adhesion on the nanowire arrays. These results display a reduced protein adsorption per surface area of static nanowires. Comparing the surfaces, 14-30% of the protein that absorbed on the flat surface adsorbed on the nanowires. Our contact angle measurements indicate that the attenuation of protein on the nanowire surface might be due to the increased hydrophilicity of the nanostructured surface compared to a flat surface of the same material. We oscillated the magnetostrictive wires by placing them in a 38 G 10 Hz oscillating magnetic field. The oscillating nanowires show a further reduction in protein adhesion where only 7-67% of the protein on the static wires was measured on the oscillating nanowires. By varying the viscosity of the fluid the nanowires are oscillated in, we determined that protein detachment is shear-stress modulated. We created a high shearing fluid with dextran, which reduced protein adsorption on the oscillating nanowires by 70% over nanowires oscillating in baseline viscosity fluid. Our preliminary studies strongly suggest that the architecture in the static nanowire arrays and the shear created by oscillating the nanowire arrays would attenuate the biofouling response in vivo.

Adsorption↗
PubMed2005

Lossless generalized-lSB data embedding.

We present a novel lossless (reversible) data-embedding technique, which enables the exact recovery of the original host signal upon extraction of the embedded information. A generalization of the well-known least significant bit (LSB) modification is proposed as the data-embedding method, which introduces additional operating points on the capacity-distortion curve. Lossless recovery of the original is achieved by compressing portions of the signal that are susceptible to embedding distortion and transmitting these compressed descriptions as a part of the embedded payload. A prediction-based conditional entropy coder which utilizes unaltered portions of the host signal as side-information improves the compression efficiency and, thus, the lossless data-embedding capacity.

Algorithms↗
PubMed2005

Two-dimensional transforms for device color correction and calibration.

Color device calibration is traditionally performed using one-dimensional (1-D) per-channel tone-response corrections (TRCs). While 1-D TRCs are attractive in view of their low implementation complexity and efficient real-time processing of color images, their use severely restricts the degree of control that can be exercised along various device axes. A typical example is that per separation (or per-channel), TRCs in a printer can be used to either ensure gray balance along the C = M = Y axis or to provide a linear response in delta-E units along each of the individual (C, M, and Y) axis, but not both. This paper proposes a novel two-dimensional color correction architecture that enables much greater control over the device color gamut with a modest increase in implementation cost. Results show significant improvement in calibration accuracy and stability when compared to traditional 1-D calibration. Superior cost quality tradeoffs (over 1-D methods) are also achieved for emulation of one color device on another.

Algorithms↗
PubMed2004

Synthesis and characterization of extremely uniform Fe-Co-Ni ternary alloy nanowire arrays.

We have fabricated extremely uniform arrays of polycrystalline Fe-Co-Ni ternary alloy nanowires having composition Fe 12.3 wt.%, Co 43.9 wt.% and Ni 43.8 wt.%. The wires are made by electrodeposition into nanoporous alumina templates, using an electrodeposition voltage of 15 V at 1000 Hz. Nanowires have been fabricated having diameters ranging from 43 nm to 120 nm, and lengths of 3 microm to 7 microm, as dependent upon template topology. The magnetization easy axis lies along the nanowire length, with an easy axis coercivity of 72 kA/m.

Alloys↗