ARUN KUMAR - Academia.edu (original) (raw)
Papers by ARUN KUMAR
Purpose: Mutations in IDH3B, an enzyme participating in the Krebs cycle, have recently been found... more Purpose: Mutations in IDH3B, an enzyme participating in the Krebs cycle, have recently been found to cause autosomal recessive retinitis pigmentosa (arRP). The MDH1 gene maps within the RP28 arRP linkage interval and encodes cytoplasmic malate dehydrogenase, an enzyme functionally related to IDH3B. As a proof of concept for candidate gene screening to be routinely performed by ultra high throughput sequencing (UHTs), we analyzed MDH1 in a patient from each of the two families described so far to show linkage between arRP and RP28. Methods: With genomic long-range PCR, we amplified all introns and exons of the MDH1 gene (23.4 kb). PCR products were then sequenced by short-read UHTs with no further processing. Computer-based mapping of the reads and mutation detection were performed by three independent software packages. Results: Despite the intrinsic complexity of human genome sequences, reads were easily mapped and analyzed, and all algorithms used provided the same results. The two patients were homozygous for all DNA variants identified in the region, which confirms previous linkage and homozygosity mapping results, but had different haplotypes, indicating genetic or allelic heterogeneity. None of the DNA changes detected could be associated with the disease. Conclusions: The MDH1 gene is not the cause of RP28-linked arRP. Our experimental strategy shows that long-range genomic PCR followed by UHTs provides an excellent system to perform a thorough screening of candidate genes for hereditary retinal degeneration.
Journal of Evolution of medical and Dental Sciences, 2014
BACKGROUND: The involvement of liver in dengue fever is not uncommon as reported in literature si... more BACKGROUND: The involvement of liver in dengue fever is not uncommon as reported in literature since 1970. Liver and nervous system involvement simultaneously predicts poor outcome in dengue fever. Atypical manifestations include liver involvement with elevation of enzymes, central nervous involvement (encephalopathy) and cardiac alterations (myocarditis). Liver involvement in dengue fever is manifested by the elevation of transaminases representing reactive hepatitis, due to direct attack of virus itself or the use of hepatotoxic drugs. OBJECTIVE OF THE STUDY: Study of serum aminotransferase levels in dengue fever. METHODOLOGY: In this descriptive, cross sectional study, all patients who presented to the Department of medicine with dengue IgM positive were included. Study period of 24 months from July 2010-June 2012, patients attending to M.S. Ramaiah medical college were included (n=166). RESULTS: 166 patients reactive for dengue virus specific IgM antibody were studied. As per WH...
Darvyadi Raskriya is a combination of herbal drugs mentioned in Ayurvedic classic Sharangdhar Sam... more Darvyadi Raskriya is a combination of herbal drugs mentioned in Ayurvedic classic Sharangdhar Samhita. The formulation is believed to cure ocular complaints like Netra Daha, Ashru, raag and Ruja if prepared following appropriate methods. Material and Methods: For making the application of drug more convenient present study has been undertaken with the aim to modify Darvyadi Raskriya into ointment form and to develop the physicochemical profile of the final product. This form was designed in two steps viz. preparation of Ghana Satva from decoction of herbal drugs and mixing powdered Satva with Goghrit and paraffin wax used as a base for attaining the final product. The prepared drug was evaluated for organoleptic study, physicochemical study, pH value and also the product was subjected for microbial contamination test. It was tested in analytical laboratory and results were documented. Result and Discussion: The result shows the organoleptic character and sterility of the product. Co...
Optics Communications, 1981
In this paper, we have given a perturbation analysis of a directional coupler formed by two parab... more In this paper, we have given a perturbation analysis of a directional coupler formed by two parabolic index media, and have shown by comparison with the exact solutions obtained earlier, that perturbation theory is indeed quite accurate for small or large separations while the accuracy decreases slightly for separations of the order of the fundamental mode size. This gives us confidence in applying perturbation analysis to coupling between parallel cylindrical structures where exact solutions cannot be found.
Indian Journal of Genetics and Plant Breeding (The), 2014
Inheritance of siliquae bearing pattern was studied in Indian mustard using F1, back cross (BC1, ... more Inheritance of siliquae bearing pattern was studied in Indian mustard using F1, back cross (BC1, BC2) and F2 generations derived from a cross NIF-V (clustered siliquae type) and NRCHB 101 (dispersed siliquae type). Individual plants from segregating generations were grouped into two phenotypic classes viz. dispersed and clustered siliquae bearing pattern. The dispersed pattern was dominant over clustered siliquae bearing pattern. The estimated ratio of F2 plants fitted to an assumed phenotypic ratio of 15 dispersed: 1 clustered. A two gene model, each with two alleles and having duplicate gene action, is proposed to explain the inheritance of siliquae bearing pattern in Indian mustard. The information generated in this study will help in developing breeding strategy for utilizing this trait to redesign the mustard ideotype for high siliqua density.
International Journal of Scientific Research, 2012
Journal of Experimental Zoology, 2000
The ovulation induction property of clomiphene citrate (CC) and human chorionic gonadotropin (hCG... more The ovulation induction property of clomiphene citrate (CC) and human chorionic gonadotropin (hCG) was studied in Scotophilius heathi, an Indian tropical vespertilionid bat, during the period of delayed ovulation between December to early January. The results of the study showed that 10 µg of CC alone was ineffective to induce ovulation, whereas 100 µg CC and 10 IU hCG alone induced ovulation. A significant (P < 0.01) increase in the ovulation rate was observed when 10 µg CC followed by 10 IU hCG, compared to 10 IU hCG and 100 µg CC alone groups. Finally, CC at a 100 µg dose, followed by 10 IU hCG, produced superovulation (14.00 ± 0.70), which is significantly different in comparison to all other groups. This is the first report of ovulation induced by CC in the Indian tropical bat as well as in any animal model that exhibits temporary anovulation similar to polycystic ovary syndrome (PCOD) during the normal physiology of reproduction.
Proceedings of the 14th international conference on World Wide Web - WWW '05, 2005
The demand for quickly delivering new applications is increasingly becoming a business imperative... more The demand for quickly delivering new applications is increasingly becoming a business imperative today. Application development is often done in an ad hoc manner, without standard frameworks or libraries, thus resulting in poor reuse of software assets. Web services have received much interest in industry due to their potential in facilitating seamless business-to-business or enterprise application integration. A web services composition tool can help automate the process, from creating business process functionality, to developing executable workflows, to deploying them on an execution environment. However, we find that the main approaches taken thus far to standardize and compose web services are piecemeal and insufficient. The business world has adopted a (distributed) programming approach in which web service instances are described using WSDL, composed into flows with a language like BPEL and invoked with the SOAP protocol. Academia has propounded the AI approach of formally representing web service capabilities in ontologies, and reasoning about their composition using goal-oriented inferencing techniques from planning. We present the first integrated work in composing web services end to end from specification to deployment by synergistically combining the strengths of the above approaches. We describe a prototype service creation environment along with a use-case scenario, and demonstrate how it can significantly speed up the time-tomarket for new services.
Polyhedron, 2006
Reactions of [(4-MeOC 6 H 4 COCH 2)Ph 3 P]Br (1c) with (4-XC 6 H 4 COCH 2) 2 TeBr 2 (X = H, 2a; M... more Reactions of [(4-MeOC 6 H 4 COCH 2)Ph 3 P]Br (1c) with (4-XC 6 H 4 COCH 2) 2 TeBr 2 (X = H, 2a; Me, 2b; OMe, 2c) lead to Te-C bond cleavage to afford [(4-MeOC 6 H 4 COCH 2)Ph 3 P] 2 [TeBr 6 ] (3c). The analogous complexes [(4-MeC 6 H 4 COCH 2)Ph 3 P] 2 [TeBr 6 ] (3b) and [(C 6 H 5 COCH 2)Ph 3 P] 2 [TeBr 6 ] (3a) are obtained from the reaction of the corresponding phosphonium bromide with 2c. The 1:1 adducts [(4-XC 6 H 4 COCH 2)Ph 3 P] + [(4-XC 6 H 4 COCH 2) 2 TeBr 3 ] À , formed as intermediates, could be isolated only in case of X = H or Me. The crystal structure of 3b, which crystallizes with one molecule of dichloromethane, shows the presence of close C-HÁ Á ÁBr/Cl contacts among the ions and solvated molecules. These weak interactions distort, though marginally, the otherwise ideal octahedral shape of the [TeBr 6 ] À anion adopted as a consequence of stereochemical inertness of the lone pair on the central tellurium atom. The supramolecular extended arrays of ionic molecular units formed by means of solvated head-to-tail linkers are identified.
Plant Systematics and Evolution, 2010
Abstract Realizing the inconsistencies that exist in the extent and nature of differentiation in ... more Abstract Realizing the inconsistencies that exist in the extent and nature of differentiation in the Withania somni-fera genetic resources in India, the 21 cultivated and wild accessions, and the two hybrids (cultivated 9 wild acces-sions and vice versa) were investigated for ...
Phytochemistry, 2006
The main active components and genetic profile of 15 selected accessions of Withania somnifera Du... more The main active components and genetic profile of 15 selected accessions of Withania somnifera Dunal. were analysed. Ethanolic extract of the dried roots/leaves of the plant was concentrated under pressure at 50 ± 5°C and was analysed for main compounds (withanolides and withaferin A) by HPLC. All the main components were found to be present in accessions (AGB 002, AGB 009, RSS 009, RSS 033). Correlation of these main components with their genetic factors, was undertaken using AFLP (amplified fragment length polymorphism) markers. Among 64 primers 7 yielded optimum polymorphism. A total of 913 polymorphic peaks were generated using these primers. Jaccard's similarity coefficient indicated that accessions having almost the same active compounds clustered together. The present study demonstrates that AFLP can be successfully used to resolve the correlation of AFLP data with the presence of secondary metabolites.
Physical Review D, 2012
Results are presented on the production of jets of particles in association with a Z= Ã boson, in... more Results are presented on the production of jets of particles in association with a Z= Ã boson, in protonproton collisions at ffiffi ffi s p ¼ 7 TeV with the ATLAS detector. The analysis includes the full 2010 data set, collected with a low rate of multiple proton-proton collisions in the accelerator, corresponding to an integrated luminosity of 36 pb À1. Inclusive jet cross sections in Z= Ã events, with Z= Ã decaying into electron or muon pairs, are measured for jets with transverse momentum p T > 30 GeV and jet rapidity jyj < 4:4. The measurements are compared to next-to-leading-order perturbative QCD calculations, and to predictions from different Monte Carlo generators implementing leading-order matrix elements supplemented by parton showers.
Oxidation of Metals, 1974
The effect of quaternary additions of 0.5%Y, 0.5 and 1.0%Th to a base alloy of Ni-10Cr-5A& on the... more The effect of quaternary additions of 0.5%Y, 0.5 and 1.0%Th to a base alloy of Ni-10Cr-5A& on the oxidation behavior and mechanism was studied during oxidation in air over the range of 1000 to 1200°C. The presence of yttrium decreased the oxidation kinetics slightly, whereas, the addition of thorium caused a slight increase. Oxide scale adherence was markedly improved by the addition of the quaternary elements. Although a number of oxides formed on yttrium-containing alloys, quantitative X-ray diffraction clearly showed that the rate-controlling step was the diffusion of aluminum through short-circuit paths in a thin layer of alumina that formed parabolically with time. Mixed oxides containing both aluminum and yttrium formed by the reaction of Y£0 3 to form YA&0 3 initially, and ^^5^]2 ^^ after longer times. Although the scale adherence of the yttrium-containing alloy was considerably better than the base alloys, spelling did occur that was attributed to the formation of the voluminous YAG particles which grew in a "mushroom"-like manner, lifting the protective scale off the substrate locally. The YAG particles formed primarily at grain boundaries in the substrate in which the yttrium originally existed as YNig. This intermetallic compound reacted to form YpOo, liberating metallic nickel that subsequently reacted to form NiO and/or NiA&pO* spinel. The Yo0 3 reacted with aluminum to ultimately form the YAG "mushrooms." Thorium did not form any mixed oxides; the only oxide involving thorium was Th0 2 > which existed as small particles at the oxide-metal interface. A highly beneficial effect of the thoria particles in reducing film spall ing was observed. Scale spall ing in the base alloy was attributed to void formation at the oxide-metal interface, the voids forming by condensation of excess vacancies from the Kirkendall effect associated with slow back-diffusion of nickel into the substrate as aluminum was preferentially oxidized and diffused rapidly outward. The mechanism of improved scale adherence in the quaternary alloys was the elimination of voids by annihilation of the Kirkendall vacancies at vacancy sinks introduced by the non-coherent interfaces between yttrium and thorium-containing intermetallics and/or oxides.
Optics Letters, 1988
It is shown that use of the effective-index method for a rectangular-core waveguide is equivalent... more It is shown that use of the effective-index method for a rectangular-core waveguide is equivalent to analysis of a pseudorectangular-core waveguide, the dielectric constant of which is higher in some of the cladding regions than that of the actual waveguide. This explains why the effective-index method gives higher values for the propagation constants for the various guided modes than other methods and different results depending on whether one starts with the longer dimension or the shorter dimension to construct the effective-index waveguide.
Optical and Quantum Electronics, 1984
1. Introduction Highly elliptical core fibres are used as single polarization single mode (SPSM) ... more 1. Introduction Highly elliptical core fibres are used as single polarization single mode (SPSM) fibres. These fibres have a large number of applications such as in coherent optical communication systems [ 1 ], fibre optic sensors [2] and in coupling with polarization-sensitive integrated ...
Journal of Nuclear Materials, 2009
The co-precipitation technique renders an excellent route to obtain a homogeneous mixture of ThO ... more The co-precipitation technique renders an excellent route to obtain a homogeneous mixture of ThO 2 and UO 2 powders. In this process, after the nitrate solutions of Th and U are mixed in the intended ratio, oxalic acid is added for co-precipitation. The precipitate is then dried and calcined to get a solid solution of ThO 2 and UO 2. In this study, ThO 2-30%UO 2 and ThO 2-50%UO 2 (% in weight) powders were characterized in terms of particle size, particle shape, surface area, phase content, O/M ratio etc. The pellets obtained by sintering these powders were characterized with the help of optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The XRD data for ThO 2-30%UO 2 and ThO 2-50%UO 2 pellets showed the presence of a small amount of U 3 O 8 phase besides fluorite phase. The grain size of ThO 2-30%UO 2 and ThO 2-50%UO 2 was found to be 5.7 and 4.5 lm, respectively.
Journal of Neurosurgical Anesthesiology, 2005
UK PubMed Central (UKPMC) is an archive of life sciences journal literature.
Journal of Medical Systems, 2006
Timely and accurate delivery of surgical instruments to operating rooms is critical for success i... more Timely and accurate delivery of surgical instruments to operating rooms is critical for success in surgical operations in hospitals. The National Hospital of Singapore was facing several problems in the process of surgical instrument distribution on ad hoc orders from operating rooms. To solve the problems, the Hospital management considered adopting a new process of surgical instrument distribution on ad hoc orders that involves staffing new healthcare assistants for delivery of surgical instruments to operating rooms. Using computer simulation, this study assessed the efficiency of the new process and recommended the optimal number of healthcare assistants needed for delivery of surgical instruments on ad hoc orders, at which healthcare assistants as well as surgical instruments could be most efficiently utilized. The results show that computer simulation is an effective tool supporting decisions on staffing needs for surgical instrument distribution in hospitals.
Journal of Infrastructure Systems, 1998
Two discussions of a paper with the aforementioned title by W.H.K. Lam and M.L. Tam, published in... more Two discussions of a paper with the aforementioned title by W.H.K. Lam and M.L. Tam, published in this journal (Volume 4, Number 1, March 1998), are presented. The first discusser maintains that the tolerance of convergence should be indicated and questions the breakdown of vehicle types in the paper's analysis. The remaining four discussers are of the opinion that a simple regression model could be formulated where the internal rate of return (IRR) is given in terms of critical random variables such as traffic volume at commencement, traffic growth rate, estimated project cost, and toll growth rate. They maintain that the random variables could then be defined in terms of their expected value and their ranges and that the probabilistic analysis of the IRR could be performed analytically.
Journal of Exposure Science & Environmental Epidemiology, 2009
Although approximately 35 million people in the US obtain drinking water from domestic wells, few... more Although approximately 35 million people in the US obtain drinking water from domestic wells, few studies have investigated the risk of arsenic exposure from this source. In this paper arsenic concentrations were modeled for public and domestic wells using a dataset from the US Geological Survey (USGS). Excess lifetime and annual risks for lung and bladder cancer were calculated based on the carcinogenic potency and average arsenic concentrations in public and domestic water supplies. Monte Carlo uncertainty analysis was used to estimate the degree of confidence in these estimations. Results indicated that domestic well users accounted for 12% of the US population, but 23% of overall arsenic exposure from drinking water. Assuming that the new and more restrictive arsenic maximum contaminant limit (MCL) is implemented for public water supplies, it is anticipated that the proportion of people experiencing excess annual fatalities from drinking water from domestic wells will increase to 29% unless corresponding efforts are made to reduce exposures among domestic well users. Differences between public and domestic wells were not consistent across the nation. Public wells tend to tap deeper aquifers than domestic wells, and as a result local arsenic-depth trends can contribute to differences between public and domestic wells. Domestic wells and public wells in the western US have the highest arsenic levels with excess fatality risks estimated to be in the range of 1 per 9300 to 1 per 6600 in these regions. Uncertainty distributions of excess fatalities were developed and resultant uncertainties were propagated in arsenic exposure and potency factor. Uncertainty in the carcinogenic potency of arsenic was the dominant source of uncertainty in most regions, but for domestic wells in the New England and Southeast regions uncertainty in arsenic exposure was dominant, indicating that additional data on arsenic concentrations in these areas would substantially improve regional risk estimates.
Purpose: Mutations in IDH3B, an enzyme participating in the Krebs cycle, have recently been found... more Purpose: Mutations in IDH3B, an enzyme participating in the Krebs cycle, have recently been found to cause autosomal recessive retinitis pigmentosa (arRP). The MDH1 gene maps within the RP28 arRP linkage interval and encodes cytoplasmic malate dehydrogenase, an enzyme functionally related to IDH3B. As a proof of concept for candidate gene screening to be routinely performed by ultra high throughput sequencing (UHTs), we analyzed MDH1 in a patient from each of the two families described so far to show linkage between arRP and RP28. Methods: With genomic long-range PCR, we amplified all introns and exons of the MDH1 gene (23.4 kb). PCR products were then sequenced by short-read UHTs with no further processing. Computer-based mapping of the reads and mutation detection were performed by three independent software packages. Results: Despite the intrinsic complexity of human genome sequences, reads were easily mapped and analyzed, and all algorithms used provided the same results. The two patients were homozygous for all DNA variants identified in the region, which confirms previous linkage and homozygosity mapping results, but had different haplotypes, indicating genetic or allelic heterogeneity. None of the DNA changes detected could be associated with the disease. Conclusions: The MDH1 gene is not the cause of RP28-linked arRP. Our experimental strategy shows that long-range genomic PCR followed by UHTs provides an excellent system to perform a thorough screening of candidate genes for hereditary retinal degeneration.
Journal of Evolution of medical and Dental Sciences, 2014
BACKGROUND: The involvement of liver in dengue fever is not uncommon as reported in literature si... more BACKGROUND: The involvement of liver in dengue fever is not uncommon as reported in literature since 1970. Liver and nervous system involvement simultaneously predicts poor outcome in dengue fever. Atypical manifestations include liver involvement with elevation of enzymes, central nervous involvement (encephalopathy) and cardiac alterations (myocarditis). Liver involvement in dengue fever is manifested by the elevation of transaminases representing reactive hepatitis, due to direct attack of virus itself or the use of hepatotoxic drugs. OBJECTIVE OF THE STUDY: Study of serum aminotransferase levels in dengue fever. METHODOLOGY: In this descriptive, cross sectional study, all patients who presented to the Department of medicine with dengue IgM positive were included. Study period of 24 months from July 2010-June 2012, patients attending to M.S. Ramaiah medical college were included (n=166). RESULTS: 166 patients reactive for dengue virus specific IgM antibody were studied. As per WH...
Darvyadi Raskriya is a combination of herbal drugs mentioned in Ayurvedic classic Sharangdhar Sam... more Darvyadi Raskriya is a combination of herbal drugs mentioned in Ayurvedic classic Sharangdhar Samhita. The formulation is believed to cure ocular complaints like Netra Daha, Ashru, raag and Ruja if prepared following appropriate methods. Material and Methods: For making the application of drug more convenient present study has been undertaken with the aim to modify Darvyadi Raskriya into ointment form and to develop the physicochemical profile of the final product. This form was designed in two steps viz. preparation of Ghana Satva from decoction of herbal drugs and mixing powdered Satva with Goghrit and paraffin wax used as a base for attaining the final product. The prepared drug was evaluated for organoleptic study, physicochemical study, pH value and also the product was subjected for microbial contamination test. It was tested in analytical laboratory and results were documented. Result and Discussion: The result shows the organoleptic character and sterility of the product. Co...
Optics Communications, 1981
In this paper, we have given a perturbation analysis of a directional coupler formed by two parab... more In this paper, we have given a perturbation analysis of a directional coupler formed by two parabolic index media, and have shown by comparison with the exact solutions obtained earlier, that perturbation theory is indeed quite accurate for small or large separations while the accuracy decreases slightly for separations of the order of the fundamental mode size. This gives us confidence in applying perturbation analysis to coupling between parallel cylindrical structures where exact solutions cannot be found.
Indian Journal of Genetics and Plant Breeding (The), 2014
Inheritance of siliquae bearing pattern was studied in Indian mustard using F1, back cross (BC1, ... more Inheritance of siliquae bearing pattern was studied in Indian mustard using F1, back cross (BC1, BC2) and F2 generations derived from a cross NIF-V (clustered siliquae type) and NRCHB 101 (dispersed siliquae type). Individual plants from segregating generations were grouped into two phenotypic classes viz. dispersed and clustered siliquae bearing pattern. The dispersed pattern was dominant over clustered siliquae bearing pattern. The estimated ratio of F2 plants fitted to an assumed phenotypic ratio of 15 dispersed: 1 clustered. A two gene model, each with two alleles and having duplicate gene action, is proposed to explain the inheritance of siliquae bearing pattern in Indian mustard. The information generated in this study will help in developing breeding strategy for utilizing this trait to redesign the mustard ideotype for high siliqua density.
International Journal of Scientific Research, 2012
Journal of Experimental Zoology, 2000
The ovulation induction property of clomiphene citrate (CC) and human chorionic gonadotropin (hCG... more The ovulation induction property of clomiphene citrate (CC) and human chorionic gonadotropin (hCG) was studied in Scotophilius heathi, an Indian tropical vespertilionid bat, during the period of delayed ovulation between December to early January. The results of the study showed that 10 µg of CC alone was ineffective to induce ovulation, whereas 100 µg CC and 10 IU hCG alone induced ovulation. A significant (P < 0.01) increase in the ovulation rate was observed when 10 µg CC followed by 10 IU hCG, compared to 10 IU hCG and 100 µg CC alone groups. Finally, CC at a 100 µg dose, followed by 10 IU hCG, produced superovulation (14.00 ± 0.70), which is significantly different in comparison to all other groups. This is the first report of ovulation induced by CC in the Indian tropical bat as well as in any animal model that exhibits temporary anovulation similar to polycystic ovary syndrome (PCOD) during the normal physiology of reproduction.
Proceedings of the 14th international conference on World Wide Web - WWW '05, 2005
The demand for quickly delivering new applications is increasingly becoming a business imperative... more The demand for quickly delivering new applications is increasingly becoming a business imperative today. Application development is often done in an ad hoc manner, without standard frameworks or libraries, thus resulting in poor reuse of software assets. Web services have received much interest in industry due to their potential in facilitating seamless business-to-business or enterprise application integration. A web services composition tool can help automate the process, from creating business process functionality, to developing executable workflows, to deploying them on an execution environment. However, we find that the main approaches taken thus far to standardize and compose web services are piecemeal and insufficient. The business world has adopted a (distributed) programming approach in which web service instances are described using WSDL, composed into flows with a language like BPEL and invoked with the SOAP protocol. Academia has propounded the AI approach of formally representing web service capabilities in ontologies, and reasoning about their composition using goal-oriented inferencing techniques from planning. We present the first integrated work in composing web services end to end from specification to deployment by synergistically combining the strengths of the above approaches. We describe a prototype service creation environment along with a use-case scenario, and demonstrate how it can significantly speed up the time-tomarket for new services.
Polyhedron, 2006
Reactions of [(4-MeOC 6 H 4 COCH 2)Ph 3 P]Br (1c) with (4-XC 6 H 4 COCH 2) 2 TeBr 2 (X = H, 2a; M... more Reactions of [(4-MeOC 6 H 4 COCH 2)Ph 3 P]Br (1c) with (4-XC 6 H 4 COCH 2) 2 TeBr 2 (X = H, 2a; Me, 2b; OMe, 2c) lead to Te-C bond cleavage to afford [(4-MeOC 6 H 4 COCH 2)Ph 3 P] 2 [TeBr 6 ] (3c). The analogous complexes [(4-MeC 6 H 4 COCH 2)Ph 3 P] 2 [TeBr 6 ] (3b) and [(C 6 H 5 COCH 2)Ph 3 P] 2 [TeBr 6 ] (3a) are obtained from the reaction of the corresponding phosphonium bromide with 2c. The 1:1 adducts [(4-XC 6 H 4 COCH 2)Ph 3 P] + [(4-XC 6 H 4 COCH 2) 2 TeBr 3 ] À , formed as intermediates, could be isolated only in case of X = H or Me. The crystal structure of 3b, which crystallizes with one molecule of dichloromethane, shows the presence of close C-HÁ Á ÁBr/Cl contacts among the ions and solvated molecules. These weak interactions distort, though marginally, the otherwise ideal octahedral shape of the [TeBr 6 ] À anion adopted as a consequence of stereochemical inertness of the lone pair on the central tellurium atom. The supramolecular extended arrays of ionic molecular units formed by means of solvated head-to-tail linkers are identified.
Plant Systematics and Evolution, 2010
Abstract Realizing the inconsistencies that exist in the extent and nature of differentiation in ... more Abstract Realizing the inconsistencies that exist in the extent and nature of differentiation in the Withania somni-fera genetic resources in India, the 21 cultivated and wild accessions, and the two hybrids (cultivated 9 wild acces-sions and vice versa) were investigated for ...
Phytochemistry, 2006
The main active components and genetic profile of 15 selected accessions of Withania somnifera Du... more The main active components and genetic profile of 15 selected accessions of Withania somnifera Dunal. were analysed. Ethanolic extract of the dried roots/leaves of the plant was concentrated under pressure at 50 ± 5°C and was analysed for main compounds (withanolides and withaferin A) by HPLC. All the main components were found to be present in accessions (AGB 002, AGB 009, RSS 009, RSS 033). Correlation of these main components with their genetic factors, was undertaken using AFLP (amplified fragment length polymorphism) markers. Among 64 primers 7 yielded optimum polymorphism. A total of 913 polymorphic peaks were generated using these primers. Jaccard's similarity coefficient indicated that accessions having almost the same active compounds clustered together. The present study demonstrates that AFLP can be successfully used to resolve the correlation of AFLP data with the presence of secondary metabolites.
Physical Review D, 2012
Results are presented on the production of jets of particles in association with a Z= Ã boson, in... more Results are presented on the production of jets of particles in association with a Z= Ã boson, in protonproton collisions at ffiffi ffi s p ¼ 7 TeV with the ATLAS detector. The analysis includes the full 2010 data set, collected with a low rate of multiple proton-proton collisions in the accelerator, corresponding to an integrated luminosity of 36 pb À1. Inclusive jet cross sections in Z= Ã events, with Z= Ã decaying into electron or muon pairs, are measured for jets with transverse momentum p T > 30 GeV and jet rapidity jyj < 4:4. The measurements are compared to next-to-leading-order perturbative QCD calculations, and to predictions from different Monte Carlo generators implementing leading-order matrix elements supplemented by parton showers.
Oxidation of Metals, 1974
The effect of quaternary additions of 0.5%Y, 0.5 and 1.0%Th to a base alloy of Ni-10Cr-5A& on the... more The effect of quaternary additions of 0.5%Y, 0.5 and 1.0%Th to a base alloy of Ni-10Cr-5A& on the oxidation behavior and mechanism was studied during oxidation in air over the range of 1000 to 1200°C. The presence of yttrium decreased the oxidation kinetics slightly, whereas, the addition of thorium caused a slight increase. Oxide scale adherence was markedly improved by the addition of the quaternary elements. Although a number of oxides formed on yttrium-containing alloys, quantitative X-ray diffraction clearly showed that the rate-controlling step was the diffusion of aluminum through short-circuit paths in a thin layer of alumina that formed parabolically with time. Mixed oxides containing both aluminum and yttrium formed by the reaction of Y£0 3 to form YA&0 3 initially, and ^^5^]2 ^^ after longer times. Although the scale adherence of the yttrium-containing alloy was considerably better than the base alloys, spelling did occur that was attributed to the formation of the voluminous YAG particles which grew in a "mushroom"-like manner, lifting the protective scale off the substrate locally. The YAG particles formed primarily at grain boundaries in the substrate in which the yttrium originally existed as YNig. This intermetallic compound reacted to form YpOo, liberating metallic nickel that subsequently reacted to form NiO and/or NiA&pO* spinel. The Yo0 3 reacted with aluminum to ultimately form the YAG "mushrooms." Thorium did not form any mixed oxides; the only oxide involving thorium was Th0 2 > which existed as small particles at the oxide-metal interface. A highly beneficial effect of the thoria particles in reducing film spall ing was observed. Scale spall ing in the base alloy was attributed to void formation at the oxide-metal interface, the voids forming by condensation of excess vacancies from the Kirkendall effect associated with slow back-diffusion of nickel into the substrate as aluminum was preferentially oxidized and diffused rapidly outward. The mechanism of improved scale adherence in the quaternary alloys was the elimination of voids by annihilation of the Kirkendall vacancies at vacancy sinks introduced by the non-coherent interfaces between yttrium and thorium-containing intermetallics and/or oxides.
Optics Letters, 1988
It is shown that use of the effective-index method for a rectangular-core waveguide is equivalent... more It is shown that use of the effective-index method for a rectangular-core waveguide is equivalent to analysis of a pseudorectangular-core waveguide, the dielectric constant of which is higher in some of the cladding regions than that of the actual waveguide. This explains why the effective-index method gives higher values for the propagation constants for the various guided modes than other methods and different results depending on whether one starts with the longer dimension or the shorter dimension to construct the effective-index waveguide.
Optical and Quantum Electronics, 1984
1. Introduction Highly elliptical core fibres are used as single polarization single mode (SPSM) ... more 1. Introduction Highly elliptical core fibres are used as single polarization single mode (SPSM) fibres. These fibres have a large number of applications such as in coherent optical communication systems [ 1 ], fibre optic sensors [2] and in coupling with polarization-sensitive integrated ...
Journal of Nuclear Materials, 2009
The co-precipitation technique renders an excellent route to obtain a homogeneous mixture of ThO ... more The co-precipitation technique renders an excellent route to obtain a homogeneous mixture of ThO 2 and UO 2 powders. In this process, after the nitrate solutions of Th and U are mixed in the intended ratio, oxalic acid is added for co-precipitation. The precipitate is then dried and calcined to get a solid solution of ThO 2 and UO 2. In this study, ThO 2-30%UO 2 and ThO 2-50%UO 2 (% in weight) powders were characterized in terms of particle size, particle shape, surface area, phase content, O/M ratio etc. The pellets obtained by sintering these powders were characterized with the help of optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The XRD data for ThO 2-30%UO 2 and ThO 2-50%UO 2 pellets showed the presence of a small amount of U 3 O 8 phase besides fluorite phase. The grain size of ThO 2-30%UO 2 and ThO 2-50%UO 2 was found to be 5.7 and 4.5 lm, respectively.
Journal of Neurosurgical Anesthesiology, 2005
UK PubMed Central (UKPMC) is an archive of life sciences journal literature.
Journal of Medical Systems, 2006
Timely and accurate delivery of surgical instruments to operating rooms is critical for success i... more Timely and accurate delivery of surgical instruments to operating rooms is critical for success in surgical operations in hospitals. The National Hospital of Singapore was facing several problems in the process of surgical instrument distribution on ad hoc orders from operating rooms. To solve the problems, the Hospital management considered adopting a new process of surgical instrument distribution on ad hoc orders that involves staffing new healthcare assistants for delivery of surgical instruments to operating rooms. Using computer simulation, this study assessed the efficiency of the new process and recommended the optimal number of healthcare assistants needed for delivery of surgical instruments on ad hoc orders, at which healthcare assistants as well as surgical instruments could be most efficiently utilized. The results show that computer simulation is an effective tool supporting decisions on staffing needs for surgical instrument distribution in hospitals.
Journal of Infrastructure Systems, 1998
Two discussions of a paper with the aforementioned title by W.H.K. Lam and M.L. Tam, published in... more Two discussions of a paper with the aforementioned title by W.H.K. Lam and M.L. Tam, published in this journal (Volume 4, Number 1, March 1998), are presented. The first discusser maintains that the tolerance of convergence should be indicated and questions the breakdown of vehicle types in the paper's analysis. The remaining four discussers are of the opinion that a simple regression model could be formulated where the internal rate of return (IRR) is given in terms of critical random variables such as traffic volume at commencement, traffic growth rate, estimated project cost, and toll growth rate. They maintain that the random variables could then be defined in terms of their expected value and their ranges and that the probabilistic analysis of the IRR could be performed analytically.
Journal of Exposure Science & Environmental Epidemiology, 2009
Although approximately 35 million people in the US obtain drinking water from domestic wells, few... more Although approximately 35 million people in the US obtain drinking water from domestic wells, few studies have investigated the risk of arsenic exposure from this source. In this paper arsenic concentrations were modeled for public and domestic wells using a dataset from the US Geological Survey (USGS). Excess lifetime and annual risks for lung and bladder cancer were calculated based on the carcinogenic potency and average arsenic concentrations in public and domestic water supplies. Monte Carlo uncertainty analysis was used to estimate the degree of confidence in these estimations. Results indicated that domestic well users accounted for 12% of the US population, but 23% of overall arsenic exposure from drinking water. Assuming that the new and more restrictive arsenic maximum contaminant limit (MCL) is implemented for public water supplies, it is anticipated that the proportion of people experiencing excess annual fatalities from drinking water from domestic wells will increase to 29% unless corresponding efforts are made to reduce exposures among domestic well users. Differences between public and domestic wells were not consistent across the nation. Public wells tend to tap deeper aquifers than domestic wells, and as a result local arsenic-depth trends can contribute to differences between public and domestic wells. Domestic wells and public wells in the western US have the highest arsenic levels with excess fatality risks estimated to be in the range of 1 per 9300 to 1 per 6600 in these regions. Uncertainty distributions of excess fatalities were developed and resultant uncertainties were propagated in arsenic exposure and potency factor. Uncertainty in the carcinogenic potency of arsenic was the dominant source of uncertainty in most regions, but for domestic wells in the New England and Southeast regions uncertainty in arsenic exposure was dominant, indicating that additional data on arsenic concentrations in these areas would substantially improve regional risk estimates.