Genotypic Susceptibility Testing of <i>Mycobacterium tuberculosis</i> Isolates for Amikacin and Kanamycin Resistance by Use of a Rapid Sloppy Molecular Beacon-Based Assay Identifies More Cases of Low-Level Drug Resistance than Phenotypic Lowenstein-Jense

Chakravorty, Soumitesh,Lee, Jong Seok,Cho, Eun Jin,Roh, Sandy S.,Smith, Laura E.,Lee, Jiim,Kim, Cheon Tae,Via, Laura E.,Cho, Sang-Nae,Barry III, Clifton E.,Alland, David American Society for Microbiology 2015 Journal of clinical microbiology Vol.53 No.1

<P>Resistance to amikacin (AMK) and kanamycin (KAN) in clinical <I>Mycobacterium tuberculosis</I> strains is largely determined by specific mutations in the <I>rrs</I> gene and <I>eis</I> gene promoter. We developed a rapid, multiplexed sloppy molecular beacon (SMB) assay to identify these mutations and then evaluated assay performance on 603 clinical <I>M. tuberculosis</I> DNA samples collected in South Korea. Assay performance was compared to gold-standard phenotypic drug susceptibility tests, including Lowenstein-Jensen (LJ) absolute concentration, mycobacterial growth indicator tubes (MGIT), and TREK Sensititre MycoTB MIC plate (MycoTB) methods. Target amplicons were also tested for mutations by Sanger sequencing. The SMB assay correctly detected 115/116 mutant and mixed sequences and 487/487 wild-type sequences (sensitivity and specificity of 99.1 and 100%, respectively). Using the LJ method as the reference, sensitivity and specificity for AMK resistance were 92.2% and 100%, respectively, and sensitivity and specificity for KAN resistance were 87.7% and 95.6%, respectively. Mutations in the <I>rrs</I> gene were unequivocally associated with high-level cross-resistance to AMK and KAN in all three conventional drug susceptibility testing methods. However, <I>eis</I> promoter mutations were associated with KAN resistance using the MGIT or MycoTB methods but not the LJ method. No testing method associated <I>eis</I> promoter mutations with AMK resistance. Among the discordant samples with AMK and/or KAN resistance but wild-type sequence at the target genes, we discovered four new mutations in the <I>whiB7</I> 5′ untranslated region (UTR) in 6/22 samples. All six samples were resistant only to KAN, suggesting the possible role of these <I>whiB7</I> 5′ UTR mutations in KAN resistance.</P>

Performance Issues with General Packet Radio Service

Chakravorty, Rajiv,Pratt, Ian The Korea Institute of Information and Commucation 2002 Journal of communications and networks Vol.4 No.4

The General Packet Radio Service (GPRS) is being deployed by GSM network operators world-wide, and promises to provide users with “always-on” data access at bandwidths comparable to that of conventional fixed-wire telephone modems. However, many users have found the reality to be rather different, experiencing very disappointing performance when, for example, browsing the web over GPRS. In this paper, we examine the causes, and show how unfortunate interactions between the GPRS link characteristics and TCP/IP protocols lead to poor performance. A performance characterization of the GPRS link-layer is presented, determined through extensive measurements taken over production networks. We present measurements of packet loss rates, bandwidth availability, link stability, and round-trip time. The effect these characteristics have on TCP behavior are examined, demonstrating how they can result in poor link utilization, excessive packet queueing, and slow recovery from packet losses. Further, we show that the HTTP protocol can compound these issues, leading to dire WWW performance. We go on to show how the use of a transparent proxy interposed near the wired-wireless border can be used to alleviate many of these performance issues without requiring changes to either client or server end systems.

Nutritional and anti-nutritional composition of Oecophylla smaragdina (Hymenoptera: Formicidae) and Odontotermes sp. (Isoptera: Termitidae): Two preferred edible insects of Arunachal Pradesh, India

Jharna Chakravorty,ghosh sampat,Karsing Megu,Chuleui Jung,V.Benno Meyer-Rochow 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.3

The nutritional potential of Oecophylla smaragdina and Odontotermes sp., two common species of insects used as food by tribal people of Arunachal Pradesh and elsewhere in Indiawas assessed. O. smaragdina and Odontotermes sp. contained 55.28 and 33.67% protein, 14.99 and 50.93% fat, 19.84 and 6.30% fibre, 2.59 and 3.01% ash and 7.30 and 6.09% carbohydrates, respectively. The protein of both species involved 18 amino acids, including all of the essential ones with the exception of methionine, which satisfies the recommended level (score N 100). In O. smaragdina, the MUFA fraction (51.55%) dominated the lipids and was followed by SFA (40.26%) and PUFA (8.19%). In Odontotermes sp. SFAs (52.89%) were dominant, followed by MUFAs (44.52%) and PUFAs (2.59%). In both species iron, zinc and copper were themost abundant minerals and calcium, magnesium, sodiumand potassium were present in substantial amounts. Respective values for anti-nutrients like phytic acid and tannin (mg/100 g) were 171.0 and 496.67 for O. smaragdina and 141.23 and 615.0 for Odontotermes sp., values much lower than corresponding ones fromsome common foods of plant origin. The two insects, once under controlled cultivation, could be a good choice as a replacement for some vertebrate animal food products.

Nutritional composition of Chondacris rosea and Brachytrupes orientalis: Two common insects used as food by tribes of Arunachal Pradesh, India

Jharna Chakravorty,ghosh sampat,정철의,V.B. Meyer-Rochowc 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3

The nutritional potential of short-horned grasshopper, Chondacris rosea (Acrididae) and mole cricket,Brachytrupes orientalis (Gryllidae), two common species of Orthoptera used as food by tribal people of ArunachalPradesh (NE India), was assessed. C rosea and B. orientalis contain 68.88 and 65.74% crude protein, 7.88 and 6.33%fat, 12.38 and 8.75% crude fiber, 4.16 and 4.33% ash, and 6.69% and 15.18% carbohydrate, respectively. The proteinin both species is composed of 18 amino acids, including all of the essential ones, which except for methionine,satisfy (scores N 100) the recommended dose suggested by FAO/WHO/UNU. The predominant fatty acids inC. rosea were: palmitic, stearic, oleic, linolenic and linoleic acid viz. 17.2, 12.4, 21, 24.5 and 16.4%, respectively. In B. orientalis palmitic (50.3%) and stearic acids (32%) were dominating. Mineral content was generally higherthan that of conventional meat types. B. orientalis fulfilled the RDA (88–109%) for Fe and both species fulfilledthe RDA for Zn (70 to 108%) and Cu (N100%). Based on 100 g of fresh insects the calorific values of C. rosea andB. orientaliswere 373.24 and 380.65% kcal.Weconclude that these insects can be recommended as a replacementof vertebrate animal food items as and when required.

Cloning and Characterization of a Gene Encoding 22 kDa Functional Protein of Bacteriophage MB78

Gupta, Lalita,Chakravorty, Maharani Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.2

Functional protein of MB78 bacteriophage having apparent molecular weight of 22 kDa is expressed from 1.7 kb HindIII G fragment. The nucleotide sequence of this fragment showed two open reading frames of 222 and 196 codons in tail-to-tail orientation separated by a 62-nucleotide intercistronic region. The ORF of 22 kDa protein is present in opposite orientation, i.e. in the complementary strand, preceded by a strong ribosomal binding site and a promoter sequence. Another ORF started from the beginning of the fragment whose promoter region and translational start site lies in the 0.45 kb HincII U fragment which is located next to the HindIII G fragment, that has the sequence for DNA bending. 3' end of the fragment has high sequence homology to the EaA and EaI proteins of bacteriophage P22, a close relative of MB78 phage.

Nonlinear first ply failure analysis of composite skewed hypar shells using FEM

Ghosh, Arghya,Chakravorty, Dipankar Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.1

This paper uses the finite element method (FEM) considering geometrically nonlinear strains to study the first ply failure of laminated composite skewed hypar shell roofs through well-established failure criteria along with the serviceability criterion of deflection. Apart from validating the approach through solution of benchmark problems, skewed hypars with different practical parametric variations are studied for failure loads and tendencies. First ply failure zones are also identified to suggest design and non-destructive monitoring guidelines to the practising engineers. Recommendation tables regarding the design approaches to be adopted in specific cases and factor of safety values needed to be imposed on first ply failure load values for varying shell curvatures are also suggested in this paper. Providing practical inputs to design engineers is the main achievement of the present study.

Application of FEM on first ply failure of composite hypar shells with various edge conditions

Arghya Ghosh,Dipankar Chakravorty 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.32 No.4

This study aims to accurately predict the first ply failure loads of laminated composite hypar shell roofs with different boundary conditions. The geometrically nonlinear finite element method (FEM) is used to analyse different symmetric and anti-symmetric, cross and angle ply shells. The first ply failure loads are obtained through different well-established failure criteria including Puck’s criterion along with the serviceability criterion of deflection. The close agreement of the published and present results for different validation problems proves the correctness of the finite element model used in the present study. The effects of edge conditions on first ply failure behavior are discussed critically from practical engineering point of view. Factor of safety values and failure zones are also reported to suggest design and non-destructive monitoring guidelines to practicing engineers. Apart from these, the present study indicates the rank wise relative performances of different shell options. The study establishes that the angle ply laminates in general perform better than the cross ply ones. Among the stacking sequences considered here, three layered symmetric angle ply laminates offer the highest first ply failure load. The probable failure zones on the different shell surfaces, identified in this paper, are the areas where non-destructive health monitoring may be restricted to. The contributions made through this paper are expected to serve as important design aids to engineers engaged in composite hypar shell design and construction.

Relative static and dynamic performances of composite conoidal shell roofs

Kaustav Bakshi,Dipankar Chakravorty 국제구조공학회 2013 Steel and Composite Structures, An International J Vol.15 No.4

Conoidal shells are doubly curved stiff surfaces which are easy to cast and fabricate due to their singly ruled property. Application of laminated composites in fabrication of conoidal shells reduces gravity forces and mass induced forces compared to the isotropic constructions due to the high strength to weight ratio of the material. These light weight shells are preferred in the industry to cover large column free open spaces. To ensure design reliability under service conditions, detailed knowledge about different behavioral aspects of conoidal shell is necessary. Hence, in this paper, static bending, free and forced vibration responses of composite conoidal shells are studied. Lagrange's equation of motion is used in conjunction with Hamilton's principle to derive governing equations of the shell. A finite element code using eight noded curved quadratic isoparametric elements is developed to get the solutions. Uniformly distributed load for static bending analysis and three different load time histories for solution of forced vibration problems are considered. Eight different stacking sequences of graphite-epoxy composite and two different boundary conditions are taken up in the present study. The study shows that relative performances of different shell combinations in terms of static behaviour cannot provide an idea about how they will relatively behave under dynamic loads and also the fact that the points of occurrence of maximum static and dynamic displacement may not be same on a shell surface.

Grey Wolf Optimization for Active Power Dispatch Planning Problem Considering Generator Constraints and Valve Point Effect

Navpreet Singh Tung,Sandeep Chakravorty 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.12

This research proposed an application of swarm inspired new meta heuristic algorithm Grey Wolf Optimization to solve active power dispatch problem imposing valve point effect and generator constraints. Grey Wolf optimization is based on mathematical approach whose solution convergence inspired by the leadership hierarchy and hunting mechanism of grey wolves. It explores search space as a multi-level decision mechanism and does not require gradient for search path. This approach converged to global optimal solution in spite of the non linearity added by valve point effect while solving the fitness function. Optimal scheduling of generators to minimize the total operating cost coupled with generator constraints and valve point effect to match load demand is implemented with proposed method and. Exploration, Computation and Convergence power are evaluated to track the computational efficiency of the proposed technique. The presented technique is tested on different test cases comprises three, six and thirteen test systems incorporating valve point effect. Test results are compared with other nature and bio inspired algorithms presented in literature .Analysis shows cut throat results as total operating cost turns out to be minimum as compared to other techniques which infers the effectiveness of proposed method and encourage to further explore the potential of proposed method to solve complex optimization problems in active power dispatch planning area.

Water Cycle Algorithm for Small Scale Electrical Economic Power Dispatch Problem

Navpreet Singh Tung,Sandeep Chakravorty 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.8

Efficient and optimal planning of economic electrical power dispatch problem is an integral part of economic electrical energy generation planning and it is the need of time for the electrical engineers to browse this area in multi-scale planning scenarios. Intelligent and Optimization techniques based on evolutionary computing, metaheuristic,biological base,nature inspired, search method establish their applications in the area of electrical economic power dispatch planning(EEPDP) to reach global optimal solution for this multi scale, multi-decision, multi-objective combinatorial problem subjected to different constraints. In this paper, water cycle algorithm (WCA) has been proposed to solve electrical economic power dispatch problem for three and six unit system.This is based on how the streams and rivers flow downhill towards the sea and recycle in nature The suggested technique is tested on small scale system of three and six unit system of EEPDP considering various equality and inequality constraints . Test results are compared with other techniques grey wolf optimization(GWO),cuckoo search(CS),artificial bee colony(ABC),firefly algorithm(FA),particle swarm optimization(PSO),shuffled frog leap (SFL) ,bacteria foraging algorithm(BFO),harmony search(HS) applied in literature.Convergence of solution with iteration is presented for both cases.Simulation results proved that the WCA technique is better as compared to other nature inspired,heuristic,metaheuristic techniques to find global minima and maintain the solution quality in terms of low fuel cost.