Bhaskar Chanda - Academia.edu (original) (raw)

Papers by Bhaskar Chanda

2018 IEEE MTT-S International Microwave and RF Conference (IMaRC), 2018

The test and evaluation method to evaluate Radio Proximity Fuze (RPF) performance for its role in... more The test and evaluation method to evaluate Radio Proximity Fuze (RPF) performance for its role in air target weapon systemhas been presented in this paper. The effectiveness of weapon system depends on RPF performance also; hence evaluation of RPF performance is crucial before integrating into the weapon.In this paper Dynamic Test plan, Instrumentation support and test results are discussed. With Antenna patterns RPF coverage diagrams are plotted, measured results are compared with the antenna patterns.

In this paper a suitable digital modulation technique for the detection of fast moving object wil... more In this paper a suitable digital modulation technique for the detection of fast moving object will be studied and one of the suitable modulation techniques is implemented. The modulated signal is produced by modulating a carrier according to the binary code. The binary code taken here is the Gold code sequence. Such modulated signal of interest is transmitted through AWGN channel. The resulting noisy modulated signal is demodulated using the suitable demodulation technique. The demodulated signal is the Gold code sequence that is given at the transmitter. Both the input and output sequences are compared and the results are plotted. This paper highlights the modulation technique that is best suited for detecting the fast moving object and that modulation scheme is implemented.

This paper presents the theoretical background of digital modulation and evaluate the performance... more This paper presents the theoretical background of digital modulation and evaluate the performance of BPSK system with respect to Bit error Rate and finally implement Binary Phase shift Keying modulation technique in MATLAB. The main objective of any communication system is to receive the transmitted data accurately. There are lot digital modulation techniques that are well flourished in the communications field, selection of a suitable modulation technique for an application depends on many factors like Bit error rate, data rate, design complexity etc., one of the modulation techniques that is used in many areas of applications is the BPSK modulation. It is widely used due to its low BER and simplicity in design when compared to other modulation techniques. The BER for BPSK is performed using Matlab Graphical User Interface tool i.e., BERTool. The modulated signal is produced by modulating a carrier according to the binary code. The binary code taken here is the Gold code sequence. ...

Wave Motion, 2010

Wave propagation and its frequency bandgaps in a parametrically modulated composite laminate are ... more Wave propagation and its frequency bandgaps in a parametrically modulated composite laminate are reported in this paper. The modulated properties under considerations are due to periodic microstructure, for example honeycomb core sandwich composite, which can be parameterized and homogenized in a suitable scale. Wave equations are derived by assuming a third-order shear deformation theory. Homogenization of the wave equations is carried out in the scale of wavelength. In-plane wave and flexural-shear wave dispersions are obtained for a range of values of a stiffness modulation coefficient ðaÞ. A clear pattern of stop-bands is observed for a P 4. To validate the band-gap phenomena, we take recourse to time domain response obtained from finite element simulation. As predicted by the proposed analytical technique, a distinct correlation between the chosen frequency band and the simulated wave arrival time and amplitude reduction is found. This promises practical applications of the proposed analytical technique to designing parametrically modulated composite laminate for wave suppression.

PurposeTo identify the cause(s) of chromosome 6p25 segmental duplication and deletion, which resu... more PurposeTo identify the cause(s) of chromosome 6p25 segmental duplication and deletion, which result in a spectrum of Axenfeld Rieger phenotypes. MethodsArray Comparative Genome Hybridization (CGH) was undertaken to refine the location of breakpoints in segmental deletion (n=1) and duplication (n=5) pedigrees. Subsequently, long range PCR was performed to amplify breakpoint-spanning junctional fragments with sequencing and in silico analysis used to determine the genomic architecture of the junctional fragment and the region flanking the breakpoints. ResultsCGH accurately defined the extent of 6p25 segmental anomalies [deletion 1216 kb; duplications 474, 477.5 and 492kb]. A 1.2kb junctional fragment amplified in the deletion pedigree (n=5 affected) segregated with the clinical phenotype. The breakpoints lie within simple repeats with 368bp of novel sequence, comprising two 100% homologous motifs in head to tail orientation, inserted between them separated by a 13bp insert. Analyses of the segmental duplications are commencing. ConclusionsArray CGH represents a powerful technique to define the extent of chromosomal anomalies and facilitate analysis of the mechanism(s) that cause glaucoma-associated segmental duplications and deletions. The segmental deletion exhibits features of both homologous recombination and non-homologous end joining with an unusually large insert of DNA at the breakpoint. The variation in segmental duplication size indicates existence of a common causative mechanism and elucidation of this will clarify the etiology of a proportion of Axenfeld Rieger syndrome cases

2011 Annual IEEE India Conference, 2011

Detection of moving target/object is a challenging task as far as any radar system is concerned. ... more Detection of moving target/object is a challenging task as far as any radar system is concerned. This paper describes one of the techniques which can be used for detection of a very low range high speed target using a small coherent active CW radar System. This system is a combination of dedicated hardware like transmitter, receiver, antennas and software subsystem

TENCON 2008 - 2008 IEEE Region 10 Conference, 2008

Abstract—Proximity sensing is required for a wide range of military applications, especially for ... more Abstract—Proximity sensing is required for a wide range of military applications, especially for weapon fuzing. In this paper, wavelet video processing is discussed which is used for proximity sensing of objects through their time dependent Doppler shift. A continuous wavelet ...

Human Molecular Genetics, 2009

Proteins of the bone morphogenetic protein (BMP) family are known to have a role in ocular and sk... more Proteins of the bone morphogenetic protein (BMP) family are known to have a role in ocular and skeletal development; however, because of their widespread expression and functional redundancy, less progress has been made identifying the roles of individual BMPs in human disease. We identified seven heterozygous mutations in growth differentiation factor 6 (GDF6), a member of the BMP family, in patients with both ocular and vertebral anomalies, characterized their effects with a SOX9-reporter assay and western analysis, and demonstrated comparable phenotypes in model organisms with reduced Gdf6 function. We observed a spectrum of ocular and skeletal anomalies in morphant zebrafish, the latter encompassing defective tail formation and altered expression of somite markers noggin1 and noggin2. Gdf6 1/ 2 mice exhibited variable ocular phenotypes compatible with phenotypes observed in patients and zebrafish. Key differences evident between patients and animal models included pleiotropic effects, variable expressivity and incomplete penetrance. These data establish the important role of this determinant in ocular and vertebral development, demonstrate the complex genetic inheritance of these phenotypes, and further understanding of BMP function and its contributions to human disease.

Human Molecular Genetics, 2008

The factors that mediate chromosomal rearrangement remain incompletely defined. Among regions pro... more The factors that mediate chromosomal rearrangement remain incompletely defined. Among regions prone to structural variant formation, chromosome 6p25 is one of the few in which disease-associated segmental duplications and segmental deletions have been identified, primarily through gene dosage attributable ocular phenotypes. Using array comparative genome hybridization, we studied ten 6p25 duplication and deletion pedigrees and amplified junction fragments from each. Analysis of the breakpoint architecture revealed that all the rearrangements were non-recurrent, and in contrast to most previous examples the majority of the segmental duplications and deletions utilized coupled homologous and non-homologous recombination mechanisms. One junction fragment exhibited an unprecedented 367 bp insert derived from tandemly arranged breakpoint elements. While this accorded with a recently described replication-based mechanism, it differed from the previous example in being unassociated with template switching, and occurring in a segmental deletion. These results extend the mechanisms involved in structural variant formation, provide strong evidence that a spectrum of recombination, DNA repair and replication underlie 6p25 rearrangements, and have implications for genesis of copy number variations in other genomic regions. These findings highlight the benefits of undertaking the extensive studies necessary to characterize structural variants at the base pair level.

Environmental Geochemistry and Health, 1996

Irrigation is one of the important inputs for enhancing the level of productivity of crops. West ... more Irrigation is one of the important inputs for enhancing the level of productivity of crops. West Bengal is well endowed with ground water. Historically, groundwater and surface water irrigation have played an important role in West Bengal's agriculture. The study has been conducted in respect of some districts selected on the basis of percentage increase in irrigated land in various districts of West Bengal. The study is based mainly on secondary data. Data used in the study are mostly taken from secondary sources such as Economic Review, Statistical Abstract of Bureau of Applied Economics and Statistics, Government of West Bengal. Data pertain to agricultural years during the period from 1990-91 to 2010-11. The study has been carried out with the objectives of finding growth of area under groundwater irrigation in the districts under study and comparing it with irrigated area under surface water. The results of the study indicate a positive compound growth rate of area irrigated by ground water during the period from 1990-91 to 2010-11. Negative growth rate has been observed in case of area under surface irrigation during the same period of time. These mostly attribute to increase in areas under boro paddy, vegetables and other irrigated crops.

Cell, 2013

Hematopoietic stem cells (HSCs) develop from a specialized subpopulation of endothelial cells kno... more Hematopoietic stem cells (HSCs) develop from a specialized subpopulation of endothelial cells known as hemogenic endothelium (HE). Although the HE origin of HSCs is now well established in different species, the signaling pathways that control this transition remain poorly understood. Here, we show that activation of retinoic acid (RA) signaling in aorta-gonad-mesonephros-derived HE ex vivo dramatically enhanced its HSC potential, whereas conditional inactivation of the RA metabolizing enzyme retinal dehydrogenase 2 in VE-cadherin expressing endothelial cells in vivo abrogated HSC development. Wnt signaling completely blocked the HSC inductive effects of RA modulators, whereas inhibition of the pathway promoted the development of HSCs in the absence of RA signaling. Collectively, these findings position RA and Wnt signaling as key regulators of HSC development and in doing so provide molecular insights that will aid in developing strategies for their generation from pluripotent stem cells.

Biotechnology Letters, 1989

SummaryA method for the quantitative enantioselective bioreduction of ethyl acetoacetate [1] to o... more SummaryA method for the quantitative enantioselective bioreduction of ethyl acetoacetate [1] to optically pure (+)-S-ethyl-3 hydroxybutyrate [II] usingSclerotiumrolfsii mycelium is described. In a synthetic medium 1 g mycelium (dry weight) could convert 1 g of I to II within 2–3 days of fermentation (pH 5.8, 30°C). This is the first report demonstrating use ofS.rolfsii biomass for asymmetric reduction to get chiral building blocks.

2018 IEEE MTT-S International Microwave and RF Conference (IMaRC), 2018

The test and evaluation method to evaluate Radio Proximity Fuze (RPF) performance for its role in... more The test and evaluation method to evaluate Radio Proximity Fuze (RPF) performance for its role in air target weapon systemhas been presented in this paper. The effectiveness of weapon system depends on RPF performance also; hence evaluation of RPF performance is crucial before integrating into the weapon.In this paper Dynamic Test plan, Instrumentation support and test results are discussed. With Antenna patterns RPF coverage diagrams are plotted, measured results are compared with the antenna patterns.

In this paper a suitable digital modulation technique for the detection of fast moving object wil... more In this paper a suitable digital modulation technique for the detection of fast moving object will be studied and one of the suitable modulation techniques is implemented. The modulated signal is produced by modulating a carrier according to the binary code. The binary code taken here is the Gold code sequence. Such modulated signal of interest is transmitted through AWGN channel. The resulting noisy modulated signal is demodulated using the suitable demodulation technique. The demodulated signal is the Gold code sequence that is given at the transmitter. Both the input and output sequences are compared and the results are plotted. This paper highlights the modulation technique that is best suited for detecting the fast moving object and that modulation scheme is implemented.

This paper presents the theoretical background of digital modulation and evaluate the performance... more This paper presents the theoretical background of digital modulation and evaluate the performance of BPSK system with respect to Bit error Rate and finally implement Binary Phase shift Keying modulation technique in MATLAB. The main objective of any communication system is to receive the transmitted data accurately. There are lot digital modulation techniques that are well flourished in the communications field, selection of a suitable modulation technique for an application depends on many factors like Bit error rate, data rate, design complexity etc., one of the modulation techniques that is used in many areas of applications is the BPSK modulation. It is widely used due to its low BER and simplicity in design when compared to other modulation techniques. The BER for BPSK is performed using Matlab Graphical User Interface tool i.e., BERTool. The modulated signal is produced by modulating a carrier according to the binary code. The binary code taken here is the Gold code sequence. ...

Wave Motion, 2010

Wave propagation and its frequency bandgaps in a parametrically modulated composite laminate are ... more Wave propagation and its frequency bandgaps in a parametrically modulated composite laminate are reported in this paper. The modulated properties under considerations are due to periodic microstructure, for example honeycomb core sandwich composite, which can be parameterized and homogenized in a suitable scale. Wave equations are derived by assuming a third-order shear deformation theory. Homogenization of the wave equations is carried out in the scale of wavelength. In-plane wave and flexural-shear wave dispersions are obtained for a range of values of a stiffness modulation coefficient ðaÞ. A clear pattern of stop-bands is observed for a P 4. To validate the band-gap phenomena, we take recourse to time domain response obtained from finite element simulation. As predicted by the proposed analytical technique, a distinct correlation between the chosen frequency band and the simulated wave arrival time and amplitude reduction is found. This promises practical applications of the proposed analytical technique to designing parametrically modulated composite laminate for wave suppression.

PurposeTo identify the cause(s) of chromosome 6p25 segmental duplication and deletion, which resu... more PurposeTo identify the cause(s) of chromosome 6p25 segmental duplication and deletion, which result in a spectrum of Axenfeld Rieger phenotypes. MethodsArray Comparative Genome Hybridization (CGH) was undertaken to refine the location of breakpoints in segmental deletion (n=1) and duplication (n=5) pedigrees. Subsequently, long range PCR was performed to amplify breakpoint-spanning junctional fragments with sequencing and in silico analysis used to determine the genomic architecture of the junctional fragment and the region flanking the breakpoints. ResultsCGH accurately defined the extent of 6p25 segmental anomalies [deletion 1216 kb; duplications 474, 477.5 and 492kb]. A 1.2kb junctional fragment amplified in the deletion pedigree (n=5 affected) segregated with the clinical phenotype. The breakpoints lie within simple repeats with 368bp of novel sequence, comprising two 100% homologous motifs in head to tail orientation, inserted between them separated by a 13bp insert. Analyses of the segmental duplications are commencing. ConclusionsArray CGH represents a powerful technique to define the extent of chromosomal anomalies and facilitate analysis of the mechanism(s) that cause glaucoma-associated segmental duplications and deletions. The segmental deletion exhibits features of both homologous recombination and non-homologous end joining with an unusually large insert of DNA at the breakpoint. The variation in segmental duplication size indicates existence of a common causative mechanism and elucidation of this will clarify the etiology of a proportion of Axenfeld Rieger syndrome cases

2011 Annual IEEE India Conference, 2011

Detection of moving target/object is a challenging task as far as any radar system is concerned. ... more Detection of moving target/object is a challenging task as far as any radar system is concerned. This paper describes one of the techniques which can be used for detection of a very low range high speed target using a small coherent active CW radar System. This system is a combination of dedicated hardware like transmitter, receiver, antennas and software subsystem

TENCON 2008 - 2008 IEEE Region 10 Conference, 2008

Abstract—Proximity sensing is required for a wide range of military applications, especially for ... more Abstract—Proximity sensing is required for a wide range of military applications, especially for weapon fuzing. In this paper, wavelet video processing is discussed which is used for proximity sensing of objects through their time dependent Doppler shift. A continuous wavelet ...

Human Molecular Genetics, 2009

Proteins of the bone morphogenetic protein (BMP) family are known to have a role in ocular and sk... more Proteins of the bone morphogenetic protein (BMP) family are known to have a role in ocular and skeletal development; however, because of their widespread expression and functional redundancy, less progress has been made identifying the roles of individual BMPs in human disease. We identified seven heterozygous mutations in growth differentiation factor 6 (GDF6), a member of the BMP family, in patients with both ocular and vertebral anomalies, characterized their effects with a SOX9-reporter assay and western analysis, and demonstrated comparable phenotypes in model organisms with reduced Gdf6 function. We observed a spectrum of ocular and skeletal anomalies in morphant zebrafish, the latter encompassing defective tail formation and altered expression of somite markers noggin1 and noggin2. Gdf6 1/ 2 mice exhibited variable ocular phenotypes compatible with phenotypes observed in patients and zebrafish. Key differences evident between patients and animal models included pleiotropic effects, variable expressivity and incomplete penetrance. These data establish the important role of this determinant in ocular and vertebral development, demonstrate the complex genetic inheritance of these phenotypes, and further understanding of BMP function and its contributions to human disease.

Human Molecular Genetics, 2008

The factors that mediate chromosomal rearrangement remain incompletely defined. Among regions pro... more The factors that mediate chromosomal rearrangement remain incompletely defined. Among regions prone to structural variant formation, chromosome 6p25 is one of the few in which disease-associated segmental duplications and segmental deletions have been identified, primarily through gene dosage attributable ocular phenotypes. Using array comparative genome hybridization, we studied ten 6p25 duplication and deletion pedigrees and amplified junction fragments from each. Analysis of the breakpoint architecture revealed that all the rearrangements were non-recurrent, and in contrast to most previous examples the majority of the segmental duplications and deletions utilized coupled homologous and non-homologous recombination mechanisms. One junction fragment exhibited an unprecedented 367 bp insert derived from tandemly arranged breakpoint elements. While this accorded with a recently described replication-based mechanism, it differed from the previous example in being unassociated with template switching, and occurring in a segmental deletion. These results extend the mechanisms involved in structural variant formation, provide strong evidence that a spectrum of recombination, DNA repair and replication underlie 6p25 rearrangements, and have implications for genesis of copy number variations in other genomic regions. These findings highlight the benefits of undertaking the extensive studies necessary to characterize structural variants at the base pair level.

Environmental Geochemistry and Health, 1996

Irrigation is one of the important inputs for enhancing the level of productivity of crops. West ... more Irrigation is one of the important inputs for enhancing the level of productivity of crops. West Bengal is well endowed with ground water. Historically, groundwater and surface water irrigation have played an important role in West Bengal's agriculture. The study has been conducted in respect of some districts selected on the basis of percentage increase in irrigated land in various districts of West Bengal. The study is based mainly on secondary data. Data used in the study are mostly taken from secondary sources such as Economic Review, Statistical Abstract of Bureau of Applied Economics and Statistics, Government of West Bengal. Data pertain to agricultural years during the period from 1990-91 to 2010-11. The study has been carried out with the objectives of finding growth of area under groundwater irrigation in the districts under study and comparing it with irrigated area under surface water. The results of the study indicate a positive compound growth rate of area irrigated by ground water during the period from 1990-91 to 2010-11. Negative growth rate has been observed in case of area under surface irrigation during the same period of time. These mostly attribute to increase in areas under boro paddy, vegetables and other irrigated crops.

Cell, 2013

Hematopoietic stem cells (HSCs) develop from a specialized subpopulation of endothelial cells kno... more Hematopoietic stem cells (HSCs) develop from a specialized subpopulation of endothelial cells known as hemogenic endothelium (HE). Although the HE origin of HSCs is now well established in different species, the signaling pathways that control this transition remain poorly understood. Here, we show that activation of retinoic acid (RA) signaling in aorta-gonad-mesonephros-derived HE ex vivo dramatically enhanced its HSC potential, whereas conditional inactivation of the RA metabolizing enzyme retinal dehydrogenase 2 in VE-cadherin expressing endothelial cells in vivo abrogated HSC development. Wnt signaling completely blocked the HSC inductive effects of RA modulators, whereas inhibition of the pathway promoted the development of HSCs in the absence of RA signaling. Collectively, these findings position RA and Wnt signaling as key regulators of HSC development and in doing so provide molecular insights that will aid in developing strategies for their generation from pluripotent stem cells.

Biotechnology Letters, 1989

SummaryA method for the quantitative enantioselective bioreduction of ethyl acetoacetate [1] to o... more SummaryA method for the quantitative enantioselective bioreduction of ethyl acetoacetate [1] to optically pure (+)-S-ethyl-3 hydroxybutyrate [II] usingSclerotiumrolfsii mycelium is described. In a synthetic medium 1 g mycelium (dry weight) could convert 1 g of I to II within 2–3 days of fermentation (pH 5.8, 30°C). This is the first report demonstrating use ofS.rolfsii biomass for asymmetric reduction to get chiral building blocks.