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Long-term optical flux and colour variability in quasars

Research in Astronomy and Astrophysics 2016年第2期16卷 63-68页

作者： N.sukanya C.s.stalin s.jeyakumar D.Praveen Amab Dhani R.Damle Department of Physics Bangalore UniversityBangalore 560 056India Indian Institute of Astrophysics Bangalore 560 034India Departmento de Astronomia Universidad de GuanajuatoMexico Department of Physics Amrita School of EngineeringBangalore 560 035India Indian Institute of Technology Roorkee 247 667India

We have used optical V and R band observations from the Massive Compact Halo Object （MACHO） project on a sample of 59 quasars behind the Magellanic clouds to study their long term optical flux and colour variations. These quasars, lying in the redshift range of 0.2 〈 z 〈 2.8 and having apparent V band magnitudes between 16.6 and 20.1 mag, have observations ranging from 49 to 1353 epochs span- ning over 7.5 yr with frequency of sampling between 2 to 10 days. All the quasars show variability during the observing period. The normalised excess variance （Fvar） in V and R bands are in the range 0.2% 〈 F^r 〈 1.6% and 0.1% 〈 Fnr 〈 1.5% respectively. In a large fraction of the sources, Fvar is larger in the V band compared to the R band. From the z-transformed discrete cross-correlation function analysis, we find that there is no lag between the V and R band variations. Adopting the Markov Chain Monte Carlo （MCMC） approach, and properly taking into account the correlation between the errors in colours and mag- nitudes, it is found that the majority of sources show a bluer when brighter trend, while a minor fraction of quasars show the opposite behaviour. This is similar to the results obtained from another two independent algorithms, namely the weighted linear least squares fit （FITEXY） and the bivariate correlated errors and intrinsic scatter regression （BCEs）. However, the ordinary least squares （OLs） fit, normally used in the colour variability studies of quasars, indicates that all the quasars studied here show a bluer when brighter trend. It is therefore very clear that the OLs algorithm cannot be used for the study of colour variability in quasars.

关键词： time lag -- periodicity -- active galaxies -- quasars

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Antimicrobial and cytotoxic activities of endophytic fungus Colletotrichum gloeosporioides isolated from endemic tree Cinnamomum malabatrum

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studies in Fungi 2016年第1期1卷 104-113页

作者： Packiaraj R jeyakumar s Ayyappan N Adhirajan N Premkumar G Rajarathinam K Muthuramkumar s Department of Botany Virudhunagar Hindu Nadar Senthikumara Nadar College(Autonomous)Virudhunagar-626001Tamil NaduIndia Department of Ecology French Institute of PondicherryPuducherry-605001 Department of Pharmaceutical Biotechnology/Pharmacognosy KMCH College of PharmacyCoimbatore-641048Tamil NaduIndia.

In a survey of endophytic fungi associated with endemic plant Cinnamomum malabatrum leaves harbored a bioactive endophytic isolate CMs 3 was identified as Colletotrichum gloeosporioides through morphological and phylogenetic analysis based on *** ethyl acetate extract of fermentation broth of Colletotrichum gloeosporioides CMs 3 displayed antimicrobial activity against gram positive and gram negative bacteria as well as the fungal pathogen,Candida *** ethyl acetate crude extract showed in vitro cytotoxicity against the HeLa,MCF-7 and MG63 cancer cell lines with the IC50 values of 94.2μg/ml,84.3μg/ml and 162μg/ml *** chromatography and Mass spectrophotometry(GC-Ms)analysis of crude extract confirmed that CMs 3 was a prolific producer of secondary metabolites,in which nearly 74%of the metabolites not listed in the NIsT *** compounds were phenol 3,5-dimethoxy acetate(11.82%),4'-isopropylidene-bis-(2-cyclohexyl)phenol,N-Didehydrohexacarboxyl-2,4,5-trimethylpiperazine and 1,2,4-Triazolium *** metabolites may be responsible for its antimicrobial and cytotoxic activities.

关键词： Antimicrobial potential Colletotrichum gloeosporioides Cytotoxic activity,Endemic tree Endophytic fungus GC-Ms

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separation Behavior of U(VI) and Th(IV) on a Mixed Ion Exchange Column Using 2,6-Pyridine Dicarboxylic Acid as a Complexing Agent and Determination of Trace Level Thorium in Uranium Matrix Employing High Performance Ion Chromatography

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International Journal of Analytical Mass spectrometry and Chromatography 2013年第1期1卷 61-71页

作者： Vaibhavi V. Raut s. P. Roy M. K. Das s. jeyakumar K. L. Ramakumar Product Development Division Bhabha Atomic Research Centre Mumbai India Radioanalytical Chemistry Division Bhabha Atomic Research Centre Mumbai India Radiochemistry and Isotope Group Bhabha Atomic Research Centre Mumbai India

Retention behavior of U(VI) and Th(IV) as their 2, 6-pyridine dicarboxylic acid (PDCA) complexes on reversed phase and ion exchange (cation, anion and mixed ion exchange) columns was studied and based on the results, a simple ion chromatography method for the determination of trace level thorium in uranium oxide using 0.075mM 2, 6-pyridine dicarboxylic acid (PDCA) and 1M KNO3 in 1.2M HNO3 as eluent (flow rate 1 mL/min)was proposed. The advantage of the developed method is that the separation of uranium matrix is not required prior to the ion chromatographic determination of trace Th. separation was carried out on a mixed ion exchange stationary phase and a 10?4 M arsenazo (III) solution was used as post column reagent for detecting the separated metal ions. The separation of Th from uranium using PDCA in the present investigation is attributed through cation exchange mechanism. A calibration plot was constructed by following the standard addition method over the concentration range of 0.25 to 10 ppm of Th in the presence of uranium matrix, which resulted in a linear regression coefficient of 0.9978. The precision of the method was better than 5% and the LOD for Th was found to be 0.1ppm (s/N=3). The method has been validated by comparing the results with the results obtained from ICP-Ms analysis where the This separated from the uranium matrix. The proposed method is simple, rapid, accurate and cost effective compared to techniques like ICP-Ms or ICP-AEs and is suitable for the routine kind of analysis.

关键词： Ion Chromatography Uranium Thorium 2 6-Pyridine Dicarboxylic Acid

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Computational identification and analysis of neurodegenerative disease associated protein kinases in hominid genomes

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Genes & Diseases 2016年第3期3卷 228-237页

作者： saranya Jayapalan Devika subramanian jeyakumar Natarajan Data Mining and Text Mining Lab Department of BioinformaticsBharathiar UniversityCoimbatoreIndia

Protein kinases play an important role in the incidence of neurodegenerative *** their incidence in non-human primates is found to be very *** differences among the genomes might influence the disease *** present study deals with finding the genetic differences of protein kinases in humans and their three closest evolutionary partners chimpanzee,gorilla and orangutan for three neurodegenerative diseases namely,Alzheimer’s,Parkinson’s and Huntington’s *** total 47 human protein kinases associated with three neurodegenerative diseases and their orthologs from other three nonhuman primates were identified and analyzed for any possible susceptibility factors in *** sequence alignment and pairwise sequence alignment revealed that,18 human protein kinases including DYRK1A,RPs6KB1,and GRK6 contained significant indels and *** phosphorylation site analysis revealed that eight kinases including MARK2 and LTK contained sites of phosphorylation exclusive to human genomes which could be particular candidates in determining disease susceptibility between human and non-human *** pathway analysis of these eight kinases and their targets revealed that these kinases could have long range consequences in important signaling pathways which are associated with neurodegenerative diseases.

关键词： Hominids Interaction analysis Neurodegenerative diseases Phosphorylation sites Protein kinases

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The effect of leaves extracts of Clitoria ternatea Linn against the fish pathogens

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Asian Pacific Journal of Tropical Medicine 2010年第9期3卷 723-726页

作者： selvamaleeswaran Ponnusamy Wesely Ebenezer Gnanaraj Johnson Marimuthu Antonisamy Velusamy selvakumar jeyakumar Nelson Research and Development centre Bharathiar UniversityCoimbatoreTamil NaduIndia Department of Botany Arignar Anna Government Arts CollegeNamakkalTamil NaduIndia Department of Plant Biology and Plant Biotechnology St.Xavier's College(Autonomous)PalayamkottaiIndia - 627 002 Unit of Microbiology Faculty of MedicineAIMST UniversityMalaysia

Objective:To investigate the antimicrobial activity of Clitoria ternatea(***) against the fish pathogens viz.,Pseudomonas aeruginosa(***),Escherichia coli(***),Klebsiella pneumonia(***),Bacillus subtilis(***),Aeromonas formican(***)s, Aeromonas hydrophila(***) and streptococcus agalactiae(*** )isolated from diseased Tilapia(Oreochromis niloticus).Methods:The extracts of *** was tested against ***,***,***,***,***,*** and *** by the agar well diffusion ***:Different extracts of *** showed inhibitory effects against ***,***,***,***,***,*** and s. *** acetate extracts of *** showed maximum of zone of inhibition against A. formicans(18 mm),***(19 mm),***(19 mm) and ***(21 mm) next to that ethanol extract of *** showed ***(18 mm) and ***(14 mm) followed by Acetone extract showed maximum zone of inhibition ***(19 mm) and ***(17 mm).Conclusions:The antimicrobial activities of all the four plant extracts are comparable and their potential as alternative in the treatment of infectious by these microorganisms was present in the *** testing is conducted on isolates using drugs selected on the basis of their importance to human medicine and use in fish production.

关键词： Anti-bacterial Fish Pathogens Well diffusion Clitoria tematea

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Defect assessment of welded specimen considering weld induced residual stresses using sINTAP procedure and FEA

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Transactions of Nonferrous Metals society of China 2013年第5期23卷 1452-1458页

作者： M.jeyakumar T.CHRIsTOPHER Faculty of Mechanical Engineering Sardar Raja College of Engineering Faculty of Mechanical Engineering Government College of Engineering

The defect assessment in butt-welded joint of AsTM A36 steel plates and 7075-T7351 aluminum alloy plates containing transverse through thickness crack was analyzed using sINTAP procedure and FEA incorporating weld induced residual stresses. Weld induced longitudinal residual stress profile can be obtained through sINTAP procedure, FEA or experimental analysis. This residual stress profile can be fitted with the trapezoidal residual stress profile available in sINTAP. For three different cases, crack length and residual stress intensity factor （sIF） are calculated and its comparison with the results obtained through FEA is plotted with respect to crack length. The stress intensity factor for mechanical loading is also plotted in the same graph. Using this graphical plot, the total sIF, including residual stress and mechanical loading, can be calculated for any particular crack size. The total sIF can be compared with the fracture toughness of the material for damage tolerance analysis. Also a failure assessment diagram is drawn for welded 7075-T7351 aluminum alloy plates with different crack sizes for as-welded （only residual stress） and mechanical loading along with the existing weld induced residual stresses to show the safety level for a particular crack size and mechanical loading.

关键词： failure assessment diagram fracture toughness stress intensity factor through thickness crack welding residual stress

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Antifouling Effect of Bioactive Compounds from selected Marine Organisms in the Obhur Creek,Red sea

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Journal of Ocean University of China 2016年第3期15卷 465-470页

作者： Abdulmohsin Al-sofyani N.Marimuthu J.Jerald Wilson Arulazhagan Pugazhendi jeyakumar Dhavamani Department of Marine Biology Faculty of Marine SciencesKing Abdulaziz UniversityP.O.Box.80207Jeddah 21589Kingdom of Saudi Arabia Wildlife Institute of lndia P.O.Box.18ChandrabaniDehradun 248001India Centre of Excellence in Environmental studies King Abdulaziz UniversityJeddah 21589Saudi Arabia

Three species of sponges and a tunicate were collected from Obhur creek of Jeddah coast for this bioactivity study. In order to assess the antifouling efficacy of selected marine organisms, methanolic extracts of these organisms were tested against different fouling bacterial forms and II-instar stage of the barnacle, Balanus amphitrite. Antibiosis, bioactivity and followed by multivariate analyses were carried out to check the efficacy of antifouling effect of the selected marine organisms. Principal component analysis revealed the exemplary antifouling efficacy of the sponge extracts of stylissa sp. observed followed by Hyrtios sp. against bacterial forms in the laboratory study. De-trended correspondence analysis confirmed that the contribution of antifouling efficacy of the selected sponge extracts was observed to be more towards Bacillus sp., Vibrio sp. and Alteromonas sp. Moreover, the efficacy of Hyrtios sp. extract(20.430 μg m L^(-1)) followed by stylissa sp.(30.945 μg m L^(-1)) showed higher against barnacle instar compared with other extracts in the bioactivity assay. Bray-Curtis cluster analysis under paired linkage categorized all the sponge extracts into one major cluster with 75% similarity, and one outlier tunicate. More than 80% similarity observed between Hyrtios sp. and stylissa sp. Fourier transform infrared spectroscopy(FTIR) showed that the contribution of major peaks found in the marine organisms were towards sulfones, sulfoxides, cyanates and ketones.

关键词： antifouling extract bioactivity Balanus amphitrite Hyrtios sp. stylissa sp. Haliclona sp.

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Investigating Additional Cochlear Parameters: A follow-up systematic review and meta-analysis

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Journal of Otology 2024年第3期19卷 178-183页

作者： Deven P.Curtis Anthony N.Baumann Natasha salmen Anita jeyakumar Northeast Ohio Medical University RootstownOHUSA Bon secours Mercy Health YoungstownOHUSA

Objectives:The movement towards personalization of cochlear implantation has continued to generate interest about variabilities in cochlear *** a recent metaanalysis,Atalay et al.(2022)examined organ of corti length,cochlear lateral wall,and“A”value and found that most covariates,other than congenital sensorineural hearing loss,did not impact cochlear size via these ***,no meta-analysis exists on how patient-specific variables could impact other cochlear size measurements,such as cochlear height(CH),and“B”value(defined as the distance between opposite lateral walls and perpendicular to“A”value).The purpose of this systematic review and meta-analysis is to examine how patient-specific variables impact additional cochlear size measurements to assist clinical *** reviewed:A systematic review for cochlear size measurements using PRIsMA methodology was performed using PubMed,CINAHL,and MEDLINE from database inception to October 1st,***:search terms used included English,cochlea,size,histology,anatomy,and *** criteria were measurements for human cochlea,full-text articles,and articles in *** measurements were“B”value and CH,as these measurements differ from the recent meta-analysis on this *** duct length(CDL)was also included.A random-effects continuous model for meta-analysis was *** were stratified by gender(male/female)and disease type(sensorineural hearing loss(sNHL)/conductive hearing loss(CHL)).Results:A total of 7 articles met final inclusion criteria from a total of 674 articles received on initial search,resulting in 2263 total human *** was a statistical difference between male CDL(n=681 cochlea)compared to female CDL(n=657)from four articles(ps d effect size(Es):0.421;95%confidence intervals(CI):0.171,0.671).The frequency weighted mean for male CDL was 33.5 mm±1.8 mm and the frequency weighted mean for female CDL was 32.4 mm±1.5 mm w

关键词： anatomy analysis walls

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The effect of extracts of selaginella involvens and selaginella inaequalifolia leaves on poultry pathogens

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Asian Pacific Journal of Tropical Medicine 2010年第9期3卷 678-681页

作者： Haripriya Duraiswamy selvan Nallaiyan jeyakumar Nelson Periasamy Rathina samy Marimuthu Johnson Irudayaraj Varaprasadam Department of Biochemistry Muthayammal College of Arts and ScienceRasipuramTamil NaduIndia Centre for Biotechnology Muthayammal College of Arts and ScienceRasipuramTamil NaduIndia Unit of Microbiology Faculty of MedicineAIMST UniversityMalaysia Department of Plant Biology & Plant Biotechnology St.Xaveirs College(Autonomous)TirunelveliTamil NaduIndia

Objective:To investigate the antimicrobial activity of some commonly available herbs against poultry pathogens such as Escherichia coli(***) and Pseudomonas species isolated from poultry ***:The extracts of selaginella involvens and selaginella inaequalifolia were tested against *** and Pseudomonas isolated from poultry litter by the agar diffusion ***:Results indicated that different plant extracts showed inhibitory effects against ***(8-13 mm ) and Pseudomonas(6.5-13 mm).The four different extracts of selaginella involvens and selaginella inaequalifolia showed similar levels of antimicrobial activity on ***. Conclusions:The antimicrobial activities of all the four plant extracts are comparable and their potential as alternatives in the treatment of infections by these microorganisms were present in the poultry *** testing is conduced on isolates using drugs selected on the basis of their importance to human medicine and use in poultry production.

关键词： Poultry litter Medicinal plants Crude extracts Escherichia coli Pseudomonas species Antimicrobial activity

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Production and application of recombinant haemagglutinin neuraminidase of Newcastle disease virus

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Asian Pacific Journal of Tropical Medicine 2010年第8期3卷 629-632页

作者： selvan Nallaiyan Ranjit singh Amirtha Jacob Abbadorai sukumar sundaramoorthy jeyakumar Nelson suryanarayana Veluvarthy Venkata sanyasi Centre for Biotechnology Muthayammal College of Arts & ScienceRasipuram -637 408Tamil NaduIndia Department of Advanced Zoology Sri Paramakalyani CollegeAlwarkuruchi - 627412Tamil NaduIndia Centralized Instrumentation Laboratory Madras Veterinary CollegeChennai - 600 007Tamil NaduIndia Unit of Microbiology Faculty of MedicineAIMST UniversityMalaysia Molecular Virology Laboratory Indian Veterinary Research Institute CampusHebbalBangalore-560024KamatakaIndia

Objective:To discuss the possibility of expressing the haemagglutinin-neuraminidase（HN） protein in prokaryotic system such as Escherichia coli（***） cells by cloning the full length HN ***:The full length HN gene of Newcastle Disease Virus（NDV） of size 1 734 bp was preciously isolated by *** sequence was assessed and submitted to Nucleic Acid Databank（NCBI） and the gene ID was EU215390.1 after cloning and *** the assessed HN gene was subcloned into pET 32 a+ expression vector for production the HN protein in ***, BL21（DE3） Psup>LYssup>s cells following standard *** crude lysate protein from the induced positive clone was size assessed by sodium dodecyl sulfale-polyacrylamide gel electrophoresis （sDs-PAGE） and their haemagglutination（HA） property against chicken RBC was assessed by standard micro HA ***:The molecular size of the full HN gene of NDV as assessed by cloning and digesting the positive clone to release the insert was 1.7 *** expressed protein in both crude and pure form was assessed to be 63 kDa and 81 kDa,*** HA activity of the crude protein of the positive clone was 1 in ***:This finding indicates that the fusion protein retains the biological activity of native protein in the crude form and therefore could be used as a diagnostic reagent for antibody detection and for routine assessment of immune status in commercial layer forms.

关键词： Newcastle disease virus Haemagglutinin Neuraminidase surface glycoprotein Diagnostic reagent

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