TANMOY SARKAR - Academia.edu (original) (raw)

Papers by TANMOY SARKAR

Biotechnological Approaches for Medicinal and Aromatic Plants, 2018

Mulberry (Morus spp.) is a woody, perennial, highly heterozygous, fast-growing plant and grown ma... more Mulberry (Morus spp.) is a woody, perennial, highly heterozygous, fast-growing plant and grown mainly for its foliage worldwide under various agroclimatic zones (tropical, subtropical and temperate) of Asia, Africa and the Americas. Mulberry leaves are the sole food source for monophagous and domesticated mulberry silkworm, Bombyx mori L. Moreover, mulberry fruits are fleshy, succulent and delicious berries. The fruits are low in calories and contain health-promoting phytonutrients such as polyphenols, minerals and vitamins having medicinal importance for its antioxidant, antitumor, neuroprotective activities and hypo-lipidemic/macrophage activating effects. Genetic improvement of mulberry is mainly aimed for improving productivity and quality of leaf for silk production. Conventional plant breeding techniques including tissue culture and molecular biology methods are employed in mulberry genetic improvement programmes to develop varieties for improved leaf productivity and biotic/abiotic stress tolerance. This review focuses on various tissue culture approaches such as in vitro regeneration, micropropagation, genetic transformation, somaclonal variation, in vitro selection, suspension culture, and much more which often supplement the traditional breeding methods. Further, characterization and production of secondary metabolites from mulberry tissues through suspension culture which are becoming a blooming option for commercial exploration of bioactive compounds have been discussed.

Congenital tooth agenesis (CTA) is one of the most common craniofacial anomalies. Its frequency v... more Congenital tooth agenesis (CTA) is one of the most common craniofacial anomalies. Its frequency varies among different population depending upon the genetic heterogeneity. CTA could be of familial or sporadic and syndromic or non-syndromic. Five major genes are found to be associated with non-syndromic CTA namely, PAX9, MSX1, EDA1, AXIN2 and WNT10A. In this study, an India family with CTA was investigated and a novel c.336C>G variation was identified in the exon 3 of PAX9, leading to substitution of evolutionary conserved Cys with Trp at 112 amino acid position located at the functionally significant DNA binding paired domain region. Functional analysis revealed that p.Cys112Trp mutation did not prevent the nuclear localization although mutant protein had higher cytoplasmic retention. EMSA using e5 probe revealed that mutant protein was unable to bind with the paired-domain binding site. Subsequently, GST pull-down assay revealed lower binding activity of the mutant protein with ...

ENSEMBLE, 2021

Soil erosion (by water) is a major land degradation process that may threat the Sustainable Devel... more Soil erosion (by water) is a major land degradation process that may threat the Sustainable Development Goals (SDG) by its negative impact on environment and human well-being. Soil erosion research demands scientific methods, tools and techniques to assess soil erosion with more accuracy and reliability. Soil erosion research has had experienced crude field-based techniques in early twentieth century to model-based approaches since the 1970s and very recent machine learning and artificial intelligence models to predict soil erosion susceptibility and risk. The paper aims to review the trend in methodological development in soil erosion by water through time. The brief background of different approaches, their relative advantages and disadvantages are reviewed. Depending on the time of establishment and wide application the approaches are classified and represented as erosion plot/runoff approach, erosion pin technique followed by environmental tracer method and model approach in com...

Niva Das Kellton Tech Solutions Limited, Hyderabad, India Email: niva.cu@gmail.com --------------... more Niva Das Kellton Tech Solutions Limited, Hyderabad, India Email: niva.cu@gmail.com ---------------------------------------------------------------------ABSTRACT-----------------------------------------------------------In recent years IoT (Internet of Things) is gaining interest among researchers and many IoT development platforms, SDK’s have been proposed. There are lots of low powered, efficient devices available in market which can be used to create IoT solutions. The main drawbacks of IoT is that every manufacture proposed it owns protocol and provide their own API’s to work with it. You need to be an avid programmer to implement, understand, customized and use this API’s. Since lots of these libraries are open source not much information can be gathered online. To solve this protocol agnostic problem in IoT many researchers are now focusing on WoT i.e. Web of Things. The main advantage of implementing WoT is that we can use familiar Web protocols to build up our solutions. In t...

Journal of Sedimentary Environments, 2020

The term ‘laterite’ and the process ‘laterization’—both have raised perpetual scientific debates.... more The term ‘laterite’ and the process ‘laterization’—both have raised perpetual scientific debates. The present study reviews the relevant scientific pieces of literature associated with tropical red lateritic and ferralitic soils and tries to justify them with the observations in the Paschim Medinipur Lateritic Upland. This particular area is practically the natural laboratory for observing the laterization process. The area exhibits a distinctive geomorphologic, hydrological, and climatic characteristic over an evolutionary geological setting. The favorable tropical climate, intense weathering, groundwater movement with seasons, and neo-tectonic upliftment exerts complex influences on the pedo-geomorphological distinctiveness of this area. Presence of planation surfaces, typical scarp development along the surface margins and exposure of deep lateritic profiles by basal sapping, accelerated erosion of the margin, and formation of rills and gullies with waxing slope development are worthy of being synced with available scientific understandings. The study is based on extensive field observations, profile studies, and soil sample analysis from different geomorphic units. The study reveals that the role of tectono-climatic evolution has had a massive influence on characteristics and development of the present lateritic formations. Transportation and deposition of Neogene ferruginous sediments over basin shelf region as paradeltaic formation, alternating wet (June–October), and dry (November–May) monsoonal climate with adequate rainfall and iron segregation and relative accumulation along with neo-tectonic modification are the important considerations regarding ferrugination process in the area under study. The justifications of the observed attributes of this particular tropical lateritic landscape may be used as a reference work for future scientific studies and model building processes on the same in this area as well as the other parts of the world.

Indian Journal of Otolaryngology and Head & Neck Surgery, 2021

Neck masses can be defined as any abnormal swelling or growth from the level of base of skull to ... more Neck masses can be defined as any abnormal swelling or growth from the level of base of skull to clavicle. They can be benign or malignant so a thorough investigation is necessary to reach to a final diagnosis. Here we report a case series of three unusual neck masses presenting to the Out patient Department of Otorhinolaryngology and Head and Neck Surgery in R. G. Kar Medical College, a tertiary care hospital of Kolkata in a span of 1.5 years. The rarity of the etiology behind the neck masses makes this case series unique.

2021 International Conference on Automation, Control and Mechatronics for Industry 4.0 (ACMI), 2021

In this paper, a new excitation controller for a synchronous generator (SG) is presented. The pro... more In this paper, a new excitation controller for a synchronous generator (SG) is presented. The proposed controller is designed by combining the theory of integral-backstepping control and feedback linearizing control to augment the transient stability. At first the partial feedback linearization strategy is employed in order to linearize the model to a reduce order and then the nonlinear backstepping scheme is employed to get the control signal. Therefore, the proposed excitation controller not only overcomes the rotor angle’s measurement but also ensures the faster transient stability. The power system’s stability by means of the designed controller is ensured with the help of a Lyapunov function. Finally, the designed controller’s usefulness is assessed on a test power system. The result is also compared to an excitation controller developed only using the partial feedback linearizing technique.

Physical Review Letters, Apr 17, 2020

Polycrystals are partially ordered solids where crystalline order extends over mesoscopic length ... more Polycrystals are partially ordered solids where crystalline order extends over mesoscopic length scales, namely, the grain size. We study the Poisuielle flow of such materials in a rough channel. In general, similar to yield stress fluids, three distinct dynamical states, namely, flowing, stick-slip and jammed can be observed, with a yield threshold dependent on channel width. Importantly, the interplay between the finite channel width, and the intrinsic ordering scale (the grain size) leads to new type of spatiotemporal heterogeneity. In wide channels, although the average flow profile remains plug like, at the underlying granular level, there is vigorous grain remodelling activity resulting from the velocity heterogeneity among the grains. As the channel width approaches typical grain size, the flowing polycrystalline state breaks up into a spatially heterogeneous mixture of flowing liquid like patches and chunks of nearly static grains. Despite these static grains, the average velocity still shows a parabolic profile, dominated by the moving liquid like patches. However, the solid-liquid front moves at nearly constant speed in the opposite direction of the external drive.

I would like to dedicate this thesis to my parents Tapas Sarkar, Sikha Sarkar and my girlfriend B... more I would like to dedicate this thesis to my parents Tapas Sarkar, Sikha Sarkar and my girlfriend Beas Roy, who were always there to support me to move forward. I would also like to thank my friends and family in USA and in India for their loving guidance and all sorts of assistance during the writing of this work.

Materials Research Express, 2018

IEEE Access, 2019

In this paper, a quasi-planar composite microstrip antenna consisting of a single layer rectangul... more In this paper, a quasi-planar composite microstrip antenna consisting of a single layer rectangular microstrip antenna along with two metallic posts (monopoles) has been studied theoretically and experimentally. The proposed antenna exhibits wide, symmetrical radiation (around 145 •) in both principle planes, along with flat-top radiation in the entire bore sight region (72 • along with bore sight) with high gain (8.5 dBi) and significantly low cross polarized radiation. More than 26 dB co-cross polarization isolation over an entire broadside direction is obtained. The present structure is very simple and easy to manufacture. The present investigation provides an insightful, visualization-based understanding of concurrent improvement of the radiation characteristics. INDEX TERMS Cross polarization, flat-top radiation, microstrip antenna.

Advanced materials (Deerfield Beach, Fla.), Jan 10, 2018

The fundamental structure of all organic electronic devices is a stack of thin layers sandwiched ... more The fundamental structure of all organic electronic devices is a stack of thin layers sandwiched between electrodes, with precise intralayer morphology and interlayer interactions. Solution processing multilayers with little to no intermixing is, however, technically challenging and often incompatible with continuous roll-to-roll, high-speed manufacturing. Here, an overview of a recently developed methodology for self-generation of interlayers positioned between the active layer and metal contact is presented. The interlayer material is blended as an additive in the active layer and migrates to the organic/metal interface during metal deposition. The driving force for this migration is additive-metal interactions. The generated interlayer positions an interfacial dipole that reduces barriers for charge transfer across the organic/metal interface. This methodology is generic and, as reported here, the self-generated interlayers significantly improve the performance of many devices. I...

Nature communications, Oct 27, 2017

Buckling and wrinkling instabilities are failure modes of elastic sheets that are avoided in the ... more Buckling and wrinkling instabilities are failure modes of elastic sheets that are avoided in the traditional material design. Recently, a new paradigm has appeared where these instabilities are instead being utilized for high-performance applications. Multiple approaches such as heterogeneous gelation, capillary stresses, and confinement have been used to shape thin macroscopic elastic sheets. However, it remains a challenge to shape two-dimensional self-assembled monolayers at colloidal or molecular length scales. Here, we show the existence of a curvature instability that arises during the crystallization of finite-sized monolayer membranes of chiral colloidal rods. While the bulk of the membrane crystallizes, its edge remains fluid like and exhibits chiral ordering. The resulting internal stresses cause the flat membrane to buckle macroscopically and wrinkle locally. Our results demonstrate an alternate pathway based on intrinsic stresses instead of the usual external ones to ass...

International Journal of Cast Metals Research, 2017

In this investigation the characteristics of thin wall (3 mm thickness) castings of copper alloye... more In this investigation the characteristics of thin wall (3 mm thickness) castings of copper alloyed gray cast iron have been examined. The samples of the thin wall castings have been austempered isothermally thus the thin wall austempered gray iron (TWAGI) produced. The samples austenitizing at 927 °C (1700 °F), the samples have been austempered at 260 °C (500 °F), 285 °C (545 °F), 310 °C (590 °F), 335 °C (635 °F), 360 °C (680 °F) and 385 °C (725 °F) respectively for 1 h. As a result, these samples developed an ausferrite matrix and excellent mechanical properties. The microstructures of these samples TWAGI have been characterized through optical microscopy, scanning electron microscopy and X-ray diffraction analysis. The mechanical properties may be correlated with the volume fraction of austenite and ferrite and ferrite cell size in the ausferrite microstructure.

Gene, Jan 25, 2017

Several studies on experimental animals indicate that the process of organogenesis crucially depe... more Several studies on experimental animals indicate that the process of organogenesis crucially depends upon the spatiotemporal dose of certain critical bio-molecules. Tooth development is also not an exception. While most of the knowledge regarding the molecular mechanism of tooth development comes from mouse, pathogenic variations identified in human tooth agenesis also provide valuable information on mammalian tooth development. Until now five major candidate genes have been identified for tooth agenesis in human. Among them PAX9 plays the crucial role in tooth development and in non-syndromic congenital tooth agenesis. In this study, microsatellite and SNP based genotyping identifies a disease specific haplotype group, which includes PAX9 gene, segregates with autosomal dominant tooth agenesis phenotype. Direct sequencing of PAX9 identifies a novel heterozygous G to A transition at the third base (c.3G>A) of initiation codon leading to ATG to ATA shift in all affected individual...

2014 11th International Conference on Information Technology: New Generations, 2014

ABSTRACT

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Proceedings of the 2015 Third International Conference on Computer, Communication, Control and Information Technology (C3IT), 2015

In this paper, the broad banding of microstrip antenna by using fractal slot structure is discuss... more In this paper, the broad banding of microstrip antenna by using fractal slot structure is discussed. The investigation has been carried out by modifying a basic microstrip slot antenna by three possible fractal shaped slot structures namely Giuseppe Peano, Koch and Apollonian type. The simulation results show that the impedance bandwidth of 60% for S11 ≤ - 10 dB can be obtained. Maximum realized gain is 5.2 dB.

ABSTRACT AtDREB1A transgenic groundnut shows tolerance to drought and salinity stresses Tanmoy Sa... more ABSTRACT AtDREB1A transgenic groundnut shows tolerance to drought and salinity stresses Tanmoy Sarkar, Radhakrishnan T, A. Kumar, Gyan Mishra and JR Dobaraia Directorate of Groundnut Research, PB No. 05, Junagadh-362 001, Gujarat. E-mail:radhakrishnan.nrcg@gmail.com Introduction: Groundnut (Arachis hypogaea L.) is an important leguminous cash crop for farmers particularly in the semi-arid tropics and its productivity is adversely affected by various abiotic stresses. Abiotic stress tolerance is a polygenic character making use of regulated expression of large number of genes in response to a particular stress. So, genetic transformation using transcription factor controlling signal transduction pathway and expression of various stress inducible genes offers a viable option to address the problems in groundnut cultivation. DREB1A/CBF3 transcription factor recognizes dehydration responsive elements (DRE/CRT) of promoter region of stress-inducible downstream genes under abiotic stress; subsequently regulates their expression in Arabidopsis thaliana and conferred stress tolerance (Pellegrineschi et al. 2004, Bhatnagar-Mathur et al. 2007).This research work is aimed to develop transgenic groundnut tolerant to abiotic stress by incorporating the transgene AtDREB1A under the control of stress-inducible rd29A promoter in groundnut cv. GG20.