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Sample records for a32 modular polyketide

  1. Engineering modular polyketide synthases for production of biofuels and industrial chemicals.

    Science.gov (United States)

    Cai, Wenlong; Zhang, Wenjun

    2018-04-01

    Polyketide synthases (PKSs) are one of the most profound biosynthetic factories for producing polyketides with diverse structures and biological activities. These enzymes have been historically studied and engineered to make un-natural polyketides for drug discovery, and have also recently been explored for synthesizing biofuels and industrial chemicals due to their versatility and customizability. Here, we review recent advances in the mechanistic understanding and engineering of modular PKSs for producing polyketide-derived chemicals, and provide perspectives on this relatively new application of PKSs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Bio-based production of fuels and industrial chemicals by repurposing antibiotic-producing type I modular polyketide synthases: opportunities and challenges.

    Science.gov (United States)

    Yuzawa, Satoshi; Keasling, Jay D; Katz, Leonard

    2017-04-01

    Complex polyketides comprise a large number of natural products that have broad application in medicine and agriculture. They are produced in bacteria and fungi from large enzyme complexes named type I modular polyketide synthases (PKSs) that are composed of multifunctional polypeptides containing discrete enzymatic domains organized into modules. The modular nature of PKSs has enabled a multitude of efforts to engineer the PKS genes to produce novel polyketides of predicted structure. We have repurposed PKSs to produce a number of short-chain mono- and di-carboxylic acids and ketones that could have applications as fuels or industrial chemicals.

  3. Bio-based production of fuels and industrial chemicals by repurposing antibiotic-producing type I modular polyketide synthases: opportunities and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Yuzawa, Satoshi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Biological Systems and Engineering Division; Keasling, Jay D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Biological Systems and Engineering Division; Univ. of California, Berkeley, CA (United States). QB3 Inst.; Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States). Dept. of Bioengineering; Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engineering; Technical Univ. of Denmark, Horsholm (Denmark). Novo Nordisk Foundation Center for Biosustainability; Katz, Leonard [Univ. of California, Berkeley, CA (United States). QB3 Inst.

    2016-11-16

    Complex polyketides comprise a large number of natural products that have broad application in medicine and agriculture. They are produced in bacteria and fungi from large enzyme complexes named type I modular polyketide synthases (PKSs) that are composed of multifunctional polypeptides containing discrete enzymatic domains organized into modules. The modular nature of PKSs has enabled a multitude of efforts to engineer the PKS genes to produce novel polyketides of predicted structure. Finally, we have repurposed PKSs to produce a number of short-chain mono- and di-carboxylic acids and ketones that could have applications as fuels or industrial chemicals.

  4. Bio-based production of fuels and industrial chemicals by repurposing antibiotic-producing type I modular polyketide synthases: opportunities and challenges

    DEFF Research Database (Denmark)

    Yuzawa, Satoshi; Keasling, Jay D.; Katz, Leonard

    2017-01-01

    Complex polyketides comprise a large number of natural products that have broad application in medicine and agriculture. They are produced in bacteria and fungi from large enzyme complexes named type I modular polyketide synthases (PKSs) that are composed of multifunctional polypeptides containin...... have applications as fuels or industrial chemicals....

  5. Heterologous Gene Expression of N-Terminally Truncated Variants of LipPks1 Suggests a Functionally Critical Structural Motif in the N-terminus of Modular Polyketide Synthase

    DEFF Research Database (Denmark)

    Yuzawa, Satoshi; Bailey, Constance B.; Fujii, Tatsu A.

    2017-01-01

    Streptomyces-derived, Well-characterized modular, polyketide synthase (PKS). Using this enzyme as a model, we experimentally investigated the effects of alternative TSSs using a heterologous host, Streptomyces venezuelae. One of the TSSs employed boosted the protein level by 59-fold and the product yield by 23...

  6. Aromatic Polyketide GTRI-02 is a Previously Unidentified Product of the act Gene Cluster in Streptomyces coelicolor A3(2).

    Science.gov (United States)

    Wu, Changsheng; Ichinose, Koji; Choi, Young Hae; van Wezel, Gilles P

    2017-07-18

    The biosynthesis of aromatic polyketides derived from type II polyketide synthases (PKSs) is complex, and it is not uncommon that highly similar gene clusters give rise to diverse structural architectures. The act biosynthetic gene cluster (BGC) of the model actinomycete Streptomyces coelicolor A3(2) is an archetypal type II PKS. Here we show that the act BGC also specifies the aromatic polyketide GTRI-02 (1) and propose a mechanism for the biogenesis of its 3,4-dihydronaphthalen-1(2H)-one backbone. Polyketide 1 was also produced by Streptomyces sp. MBT76 after activation of the act-like qin gene cluster by overexpression of the pathway-specific activator. Mining of this strain also identified dehydroxy-GTRI-02 (2), which most likely originated from dehydration of 1 during the isolation process. This work shows that even extensively studied model gene clusters such as act of S. coelicolor can still produce new chemistry, offering new perspectives for drug discovery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Towards prediction of metabolic products of polyketide synthases: an in silico analysis.

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    Gitanjali Yadav

    2009-04-01

    Full Text Available Sequence data arising from an increasing number of partial and complete genome projects is revealing the presence of the polyketide synthase (PKS family of genes not only in microbes and fungi but also in plants and other eukaryotes. PKSs are huge multifunctional megasynthases that use a variety of biosynthetic paradigms to generate enormously diverse arrays of polyketide products that posses several pharmaceutically important properties. The remarkable conservation of these gene clusters across organisms offers abundant scope for obtaining novel insights into PKS biosynthetic code by computational analysis. We have carried out a comprehensive in silico analysis of modular and iterative gene clusters to test whether chemical structures of the secondary metabolites can be predicted from PKS protein sequences. Here, we report the success of our method and demonstrate the feasibility of deciphering the putative metabolic products of uncharacterized PKS clusters found in newly sequenced genomes. Profile Hidden Markov Model analysis has revealed distinct sequence features that can distinguish modular PKS proteins from their iterative counterparts. For iterative PKS proteins, structural models of iterative ketosynthase (KS domains have revealed novel correlations between the size of the polyketide products and volume of the active site pocket. Furthermore, we have identified key residues in the substrate binding pocket that control the number of chain extensions in iterative PKSs. For modular PKS proteins, we describe for the first time an automated method based on crucial intermolecular contacts that can distinguish the correct biosynthetic order of substrate channeling from a large number of non-cognate combinatorial possibilities. Taken together, our in silico analysis provides valuable clues for formulating rules for predicting polyketide products of iterative as well as modular PKS clusters. These results have promising potential for discovery of

  8. Toblerols: Cyclopropanol-Containing Polyketide Modulators of Antibiosis in Methylobacteria.

    Science.gov (United States)

    Ueoka, Reiko; Bortfeld-Miller, Miriam; Morinaka, Brandon I; Vorholt, Julia A; Piel, Jörn

    2018-01-22

    Trans-AT polyketide synthases (PKSs) are a family of biosynthetically versatile modular type I PKSs that generate bioactive polyketides of impressive structural diversity. In this study, we detected, in the genome of several bacteria a cryptic, architecturally unusual trans-AT PKS gene cluster which eluded automated PKS prediction. Genomic mining of one of these strains, the model methylotroph Methylobacterium extorquens AM1, revealed unique epoxide- and cyclopropanol-containing polyketides named toblerols. Relative and absolute stereochemistry were determined by NMR experiments, chemical derivatization, and the comparison of CD data between the derivatized natural product and a synthesized model compound. Biosynthetic data suggest that the cyclopropanol moiety is generated by carbon-carbon shortening of a more extended precursor. Surprisingly, a knock-out strain impaired in polyketide production showed strong inhibitory activity against other methylobacteria in contrast to the wild-type producer. The activity was inhibited by complementation with toblerols, thus suggesting that these compounds modulate an as-yet unknown methylobacterial antibiotic. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Comprehensive in Vitro Analysis of Acyltransferase Domain Exchanges in Modular Polyketide Synthases and Its Application for Short-Chain Ketone Production

    Energy Technology Data Exchange (ETDEWEB)

    Yuzawa, Satoshi [Univ. of California, Berkeley, CA (United States); Deng, Kai [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Wang, George [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Baidoo, Edward E. K. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Northen, Trent R. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Adams, Paul D. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Katz, Leonard [Univ. of California, Berkeley, CA (United States); Synthetic Biology Research Center, Emeryville, CA (United States); Keasling, Jay D. [Univ. of California, Berkeley, CA (United States); Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Synthetic Biology Research Center, Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-08-22

    Type I modular polyketide synthases (PKSs) are polymerases that utilize acyl-CoAs as substrates. Each polyketide elongation reaction is catalyzed by a set of protein domains called a module. Each module usually contains an acyltransferase (AT) domain, which determines the specific acyl-CoA incorporated into each condensation reaction. Although a successful exchange of individual AT domains can lead to the biosynthesis of a large variety of novel compounds, hybrid PKS modules often show significantly decreased activities. Using monomodular PKSs as models, we have systematically analyzed in this paper the segments of AT domains and associated linkers in AT exchanges in vitro and have identified the boundaries within a module that can be used to exchange AT domains while maintaining protein stability and enzyme activity. Importantly, the optimized domain boundary is highly conserved, which facilitates AT domain replacements in most type I PKS modules. To further demonstrate the utility of the optimized AT domain boundary, we have constructed hybrid PKSs to produce industrially important short-chain ketones. Our in vitro and in vivo analysis demonstrated production of predicted ketones without significant loss of activities of the hybrid enzymes. Finally, these results greatly enhance the mechanistic understanding of PKS modules and prove the benefit of using engineered PKSs as a synthetic biology tool for chemical production.

  10. Engineered biosynthesis of regioselectively modified aromatic polyketides using bimodular polyketide synthases.

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    Yi Tang

    2004-02-01

    Full Text Available Bacterial aromatic polyketides such as tetracycline and doxorubicin are a medicinally important class of natural products produced as secondary metabolites by actinomyces bacteria. Their backbones are derived from malonyl-CoA units by polyketide synthases (PKSs. The nascent polyketide chain is synthesized by the minimal PKS, a module consisting of four dissociated enzymes. Although the biosynthesis of most aromatic polyketide backbones is initiated through decarboxylation of a malonyl building block (which results in an acetate group, some polyketides, such as the estrogen receptor antagonist R1128, are derived from nonacetate primers. Understanding the mechanism of nonacetate priming can lead to biosynthesis of novel polyketides that have improved pharmacological properties. Recent biochemical analysis has shown that nonacetate priming is the result of stepwise activity of two dissociated PKS modules with orthogonal molecular recognition features. In these PKSs, an initiation module that synthesizes a starter unit is present in addition to the minimal PKS module. Here we describe a general method for the engineered biosynthesis of regioselectively modified aromatic polyketides. When coexpressed with the R1128 initiation module, the actinorhodin minimal PKS produced novel hexaketides with propionyl and isobutyryl primer units. Analogous octaketides could be synthesized by combining the tetracenomycin minimal PKS with the R1128 initiation module. Tailoring enzymes such as ketoreductases and cyclases were able to process the unnatural polyketides efficiently. Based upon these findings, hybrid PKSs were engineered to synthesize new anthraquinone antibiotics with predictable functional group modifications. Our results demonstrate that (i bimodular aromatic PKSs present a general mechanism for priming aromatic polyketide backbones with nonacetate precursors; (ii the minimal PKS controls polyketide chain length by counting the number of atoms

  11. Towards Precision Engineering of Canonical Polyketide Synthase Domains: Recent Advances and Future Prospects

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    Carmen L. Bayly

    2017-02-01

    Full Text Available Modular polyketide synthases (mPKSs build functionalized polymeric chains, some of which have become blockbuster therapeutics. Organized into repeating clusters (modules of independently-folding domains, these assembly-line-like megasynthases can be engineered by introducing non-native components. However, poor introduction points and incompatible domain combinations can cause both unintended products and dramatically reduced activity. This limits the engineering and combinatorial potential of mPKSs, precluding access to further potential therapeutics. Different regions on a given mPKS domain determine how it interacts both with its substrate and with other domains. Within the assembly line, these interactions are crucial to the proper ordering of reactions and efficient polyketide construction. Achieving control over these domain functions, through precision engineering at key regions, would greatly expand our catalogue of accessible polyketide products. Canonical mPKS domains, given that they are among the most well-characterized, are excellent candidates for such fine-tuning. The current minireview summarizes recent advances in the mechanistic understanding and subsequent precision engineering of canonical mPKS domains, focusing largely on developments in the past year.

  12. Engineering the Polyketide Cell Factory

    DEFF Research Database (Denmark)

    Mølgaard, Louise

    sufficient titers. To improve the production of polyketides biological engineering principles have been applied for the development and engineering of microbial polyketide cell factories. The two biological hosts used for heterologous polyketide production were Aspergillus nidulans and Saccharomyces...... phosphopantetheinylase (PPTase). This versatile vector system can easily be used for expression of other polyketides of interest as well as extended to express whole gene clusters. After achieving proof of principle in terms of expression, the polyketide cell factory must be optimized. The optimization can be achieved...... characterization in bioreactors revealed that the yields of 6-MSA on biomass increased albeit not significantly. As a result of this it may be argued that there is still more work to be done in terms of model building in A. nidulans. Utilizing another well-established cell factory S. cerevisiae the capabilities...

  13. Engineered fungal polyketide biosynthesis in Pichia pastoris: a potential excellent host for polyketide production.

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    Gao, Limei; Cai, Menghao; Shen, Wei; Xiao, Siwei; Zhou, Xiangshan; Zhang, Yuanxing

    2013-09-08

    Polyketides are one of the most important classes of secondary metabolites and usually make good drugs. Currently, heterologous production of fungal polyketides for developing a high potential industrial application system with high production capacity and pharmaceutical feasibility was still at its infancy. Pichia pastoris is a highly successful system for the high production of a variety of heterologous proteins. In this work, we aim to develop a P. pastoris based in vivo fungal polyketide production system for first time and evaluate its feasibility for future industrial application. A recombinant P. pastoris GS115-NpgA-ATX with Aspergillus nidulans phosphopantetheinyl transferase (PPtase) gene npgA and Aspergillus terrus 6-methylsalicylic acid (6-MSA) synthase (6-MSAS) gene atX was constructed. A specific compound was isolated and identified as 6-MSA by HPLC, LC-MS and NMR. Transcription of both genes were detected. In 5-L bioreactor, the GS115-NpgA-ATX grew well and produced 6-MSA quickly until reached a high value of 2.2 g/L by methanol induction for 20 hours. Thereafter, the cells turned to death ascribing to high concentration of antimicrobial 6-MSA. The distribution of 6-MSA changed that during early and late induction phase it existed more in supernatant while during intermediate stage it mainly located intracellular. Different from 6-MSA production strain, recombinant M. purpureus pksCT expression strains for citrinin intermediate production, no matter PksCT located in cytoplasm or in peroxisomes, did not produce any specific compound. However, both npgA and pksCT transcripted effectively in cells and western blot analysis proved the expression of PPtase. Then the PPTase was expressed and purified, marked by fluorescent probes, and reacted with purified ACP domain and its mutant ACPm of PksCT. Fluoresence was only observed in ACP but not ACPm, indicating that the PPTase worked well with ACP to make it bioactive holo-ACP. Thus, some other factors may

  14. Sampling Terrestrial Environments for Bacterial Polyketides

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    Patrick Hill

    2017-04-01

    Full Text Available Bacterial polyketides are highly biologically active molecules that are frequently used as drugs, particularly as antibiotics and anticancer agents, thus the discovery of new polyketides is of major interest. Since the 1980s discovery of polyketides has slowed dramatically due in large part to the repeated rediscovery of known compounds. While recent scientific and technical advances have improved our ability to discover new polyketides, one key area has been under addressed, namely the distribution of polyketide-producing bacteria in the environment. Identifying environments where producing bacteria are abundant and diverse should improve our ability to discover (bioprospect new polyketides. This review summarizes for the bioprospector the state-of-the-field in terrestrial microbial ecology. It provides insight into the scientific and technical challenges limiting the application of microbial ecology discoveries for bioprospecting and summarizes key developments in the field that will enable more effective bioprospecting. The major recent efforts by researchers to sample new environments for polyketide discovery is also reviewed and key emerging environments such as insect associated bacteria, desert soils, disease suppressive soils, and caves are highlighted. Finally strategies for taking and characterizing terrestrial samples to help maximize discovery efforts are proposed and the inclusion of non-actinomycetal bacteria in any terrestrial discovery strategy is recommended.

  15. Modeling holo-ACP:DH and holo-ACP:KR complexes of modular polyketide synthases: a docking and molecular dynamics study

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    Anand Swadha

    2012-05-01

    Full Text Available Abstract Background Modular polyketide synthases are multifunctional megasynthases which biosynthesize a variety of secondary metabolites using various combinations of dehydratase (DH, ketoreductase (KR and enoyl-reductase (ER domains. During the catalysis of various reductive steps these domains act on a substrate moiety which is covalently attached to the phosphopantetheine (P-pant group of the holo-Acyl Carrier Protein (holo-ACP domain, thus necessitating the formation of holo-ACP:DH and holo-ACP:KR complexes. Even though three dimensional structures are available for DH, KR and ACP domains, no structures are available for DH or KR domains in complex with ACP or substrate moieties. Since Ser of holo-ACP is covalently attached to a large phosphopantetheine group, obtaining complexes involving holo-ACP by standard protein-protein docking has been a difficult task. Results We have modeled the holo-ACP:DH and holo-ACP:KR complexes for identifying specific residues on DH and KR domains which are involved in interaction with ACP, phosphopantetheine and substrate moiety. A novel combination of protein-protein and protein-ligand docking has been used to first model complexes involving apo-ACP and then dock the phosphopantetheine and substrate moieties using covalent connectivity between ACP, phosphopantetheine and substrate moiety as constraints. The holo-ACP:DH and holo-ACP:KR complexes obtained from docking have been further refined by restraint free explicit solvent MD simulations to incorporate effects of ligand and receptor flexibilities. The results from 50 ns MD simulations reveal that substrate enters into a deep tunnel in DH domain while in case of KR domain the substrate binds a shallow surface exposed cavity. Interestingly, in case of DH domain the predicted binding site overlapped with the binding site in the inhibitor bound crystal structure of FabZ, the DH domain from E.Coli FAS. In case of KR domain, the substrate binding site

  16. Structural basis for olivetolic acid formation by a polyketide cyclase from Cannabis sativa.

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    Yang, Xinmei; Matsui, Takashi; Kodama, Takeshi; Mori, Takahiro; Zhou, Xiaoxi; Taura, Futoshi; Noguchi, Hiroshi; Abe, Ikuro; Morita, Hiroyuki

    2016-03-01

    In polyketide biosynthesis, ring formation is one of the key diversification steps. Olivetolic acid cyclase (OAC) from Cannabis sativa, involved in cannabinoid biosynthesis, is the only known plant polyketide cyclase. In addition, it is the only functionally characterized plant α+β barrel (DABB) protein that catalyzes the C2-C7 aldol cyclization of the linear pentyl tetra-β-ketide CoA as the substrate, to generate olivetolic acid (OA). Herein, we solved the OAC apo and OAC-OA complex binary crystal structures at 1.32 and 1.70 Å resolutions, respectively. The crystal structures revealed that the enzyme indeed belongs to the DABB superfamily, as previously proposed, and possesses a unique active-site cavity containing the pentyl-binding hydrophobic pocket and the polyketide binding site, which have never been observed among the functionally and structurally characterized bacterial polyketide cyclases. Furthermore, site-directed mutagenesis studies indicated that Tyr72 and His78 function as acid/base catalysts at the catalytic center. Structural and/or functional studies of OAC suggested that the enzyme lacks thioesterase and aromatase activities. These observations demonstrated that OAC employs unique catalytic machinery utilizing acid/base catalytic chemistry for the formation of the precursor of OA. The structural and functional insights obtained in this work thus provide the foundation for analyses of the plant polyketide cyclases that will be discovered in the future. Structural data reported in this paper are available in the Protein Data Bank under the accession numbers 5B08 for the OAC apo, 5B09 for the OAC-OA binary complex and 5B0A, 5B0B, 5B0C, 5B0D, 5B0E, 5B0F and 5B0G for the OAC His5Q, Ile7F, Tyr27F, Tyr27W, Val59M, Tyr72F and His78S mutant enzymes, respectively. © 2016 Federation of European Biochemical Societies.

  17. Antimicrobial polyketide furanoterpenoids from seaweed-associated heterotrophic bacterium Bacillus subtilis MTCC 10403.

    Science.gov (United States)

    Chakraborty, Kajal; Thilakan, Bini; Raola, Vamshi Krishna

    2017-10-01

    Brown seaweed Anthophycus longifolius (Turner) Kützing (family Sargassaceae) associated heterotrophic bacterium Bacillus subtilis MTCC 10403 was found to be a potent isolate with broad range of antibacterial activity against important perceptive food pathogens Vibrio parahaemolyticus, V. vulnificus, and Aeromonas hydrophila. This bacterium was positive for polyketide synthetase gene (KC589397), and therefore, was selected to bioprospect specialized metabolites bearing polyketide backbone. Bioactivity-guided chromatographic fractionation of the ethyl acetate extract of the seaweed-associated bacterium segregated four homologous polyketide furanoterpenoids with potential antibacterial activities against clinically important pathogens. The minimum inhibitory concentration (MIC) assay showed that the referral antibiotics tetracycline and ampicillin were active at 25 μg/mL against the test pathogens, whereas the previously undescribed (4E)-methyl 13-((16-(furan-2-yl) ethyl)-octahydro-7-hydroxy-4-((E)-23-methylbut-21-enyl)-2H-chromen-6-yl)-4-methylpent-4-enoate (compound 1) and methyl 3-(hexahydro-9-((E)-3-methylpent-1-enyl)-4H-furo[3,2-g]isochromen-6-yl) propanoate (compound 3) displayed antibacterial activities against the test pathogens at a lesser concentration (MIC subtilis MTCC 10403 demonstrated to represent a potential source of antimicrobial polyketides for pharmaceutical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Quantification of N-acetylcysteamine activated methylmalonate incorporation into polyketide biosynthesis

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    Stephan Klopries

    2013-04-01

    Full Text Available Polyketides are biosynthesized through consecutive decarboxylative Claisen condensations between a carboxylic acid and differently substituted malonic acid thioesters, both tethered to the giant polyketide synthase enzymes. Individual malonic acid derivatives are typically required to be activated as coenzyme A-thioesters prior to their enzyme-catalyzed transfer onto the polyketide synthase. Control over the selection of malonic acid building blocks promises great potential for the experimental alteration of polyketide structure and bioactivity. One requirement for this endeavor is the supplementation of the bacterial polyketide fermentation system with tailored synthetic thioester-activated malonates. The membrane permeable N-acetylcysteamine has been proposed as a coenzyme A-mimic for this purpose. Here, the incorporation efficiency into different polyketides of N-acetylcysteamine activated methylmalonate is studied and quantified, showing a surprisingly high and transferable activity of these polyketide synthase substrate analogues in vivo.

  19. Genetics of Polyketide Metabolism in Aspergillus nidulans

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    Marie L. Klejnstrup

    2012-01-01

    Full Text Available Secondary metabolites are small molecules that show large structural diversity and a broad range of bioactivities. Some metabolites are attractive as drugs or pigments while others act as harmful mycotoxins. Filamentous fungi have the capacity to produce a wide array of secondary metabolites including polyketides. The majority of genes required for production of these metabolites are mostly organized in gene clusters, which often are silent or barely expressed under laboratory conditions, making discovery and analysis difficult. Fortunately, the genome sequences of several filamentous fungi are publicly available, greatly facilitating the establishment of links between genes and metabolites. This review covers the attempts being made to trigger the activation of polyketide metabolism in the fungal model organism Aspergillus nidulans. Moreover, it will provide an overview of the pathways where ten polyketide synthase genes have been coupled to polyketide products. Therefore, the proposed biosynthesis of the following metabolites will be presented; naphthopyrone, sterigmatocystin, aspyridones, emericellamides, asperthecin, asperfuranone, monodictyphenone/emodin, orsellinic acid, and the austinols.

  20. The LINKS motif zippers trans-acyltransferase polyketide synthase assembly lines into a biosynthetic megacomplex.

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    Gay, Darren C; Wagner, Drew T; Meinke, Jessica L; Zogzas, Charles E; Gay, Glen R; Keatinge-Clay, Adrian T

    2016-03-01

    Polyketides such as the clinically-valuable antibacterial agent mupirocin are constructed by architecturally-sophisticated assembly lines known as trans-acyltransferase polyketide synthases. Organelle-sized megacomplexes composed of several copies of trans-acyltransferase polyketide synthase assembly lines have been observed by others through transmission electron microscopy to be located at the Bacillus subtilis plasma membrane, where the synthesis and export of the antibacterial polyketide bacillaene takes place. In this work we analyze ten crystal structures of trans-acyltransferase polyketide synthases ketosynthase domains, seven of which are reported here for the first time, to characterize a motif capable of zippering assembly lines into a megacomplex. While each of the three-helix LINKS (Laterally-INteracting Ketosynthase Sequence) motifs is observed to similarly dock with a spatially-reversed copy of itself through hydrophobic and ionic interactions, the amino acid sequences of this motif are not conserved. Such a code is appropriate for mediating homotypic contacts between assembly lines to ensure the ordered self-assembly of a noncovalent, yet tightly-knit, enzymatic network. LINKS-mediated lateral interactions would also have the effect of bolstering the vertical association of the polypeptides that comprise a polyketide synthase assembly line. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. KirCII- promising tool for polyketide diversification

    DEFF Research Database (Denmark)

    Musiol-Kroll, Ewa Maria; Härtner, Thomas; Kulik, Andreas

    2014-01-01

    Kirromycin is produced by Streptomyces collinus Tü 365. This compound is synthesized by a large assembly line of type I polyketide synthases and non-ribosomal peptide synthetases (PKS I/NRPS), encoded by the genes kirAI-kirAVI and kirB. The PKSs KirAI-KirAV have no acyltransferase domains integra...... introducing the non-native substrates in an in vivo context. Thus, KirCII represents a promising tool for polyketide diversification....

  2. Expression, purification and crystallization of a plant polyketide cyclase from Cannabis sativa.

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    Yang, Xinmei; Matsui, Takashi; Mori, Takahiro; Taura, Futoshi; Noguchi, Hiroshi; Abe, Ikuro; Morita, Hiroyuki

    2015-12-01

    Plant polyketides are a structurally diverse family of natural products. In the biosynthesis of plant polyketides, the construction of the carbocyclic scaffold is a key step in diversifying the polyketide structure. Olivetolic acid cyclase (OAC) from Cannabis sativa L. is the only known plant polyketide cyclase that catalyzes the C2-C7 intramolecular aldol cyclization of linear pentyl tetra-β-ketide-CoA to generate olivetolic acid in the biosynthesis of cannabinoids. The enzyme is also thought to belong to the dimeric α+β barrel (DABB) protein family. However, because of a lack of functional analysis of other plant DABB proteins and low sequence identity with the functionally distinct bacterial DABB proteins, the catalytic mechanism of OAC has remained unclear. To clarify the intimate catalytic mechanism of OAC, the enzyme was overexpressed in Escherichia coli and crystallized using the vapour-diffusion method. The crystals diffracted X-rays to 1.40 Å resolution and belonged to space group P3121 or P3221, with unit-cell parameters a = b = 47.3, c = 176.0 Å. Further crystallographic analysis will provide valuable insights into the structure-function relationship and catalytic mechanism of OAC.

  3. Algal carbohydrates affect polyketide synthesis of the lichen-forming fungus Cladonia rangiferina.

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    Elshobary, Mostafa E; Osman, Mohamed E; Abo-Shady, Atef M; Komatsu, Emy; Perreault, Hélène; Sorensen, John; Piercey-Normore, Michele D

    2016-01-01

    Lichen secondary metabolites (polyketides) are produced by the fungal partner, but the role of algal carbohydrates in polyketide biosynthesis is not clear. This study examined whether the type and concentration of algal carbohydrate explained differences in polyketide production and gene transcription by a lichen fungus (Cladonia rangiferina). The carbohydrates identified from a free-living cyanobacterium (Spirulina platensis; glucose), a lichen-forming alga (Diplosphaera chodatii; sorbitol) and the lichen alga that associates with C. rangiferina (Asterochloris sp.; ribitol) were used in each of 1%, 5% and 10% concentrations to enrich malt yeast extract media for culturing the mycobiont. Polyketides were determined by high performance liquid chromatography (HPLC), and polyketide synthase (PKS) gene transcription was measured by quantitative PCR of the ketosynthase domain of four PKS genes. The lower concentrations of carbohydrates induced the PKS gene expression where ribitol up-regulated CrPKS1 and CrPKS16 gene transcription and sorbitol up-regulated CrPKS3 and CrPKS7 gene transcription. The HPLC results revealed that lower concentrations of carbon sources increased polyketide production for three carbohydrates. One polyketide from the natural lichen thallus (fumarprotocetraric acid) also was produced by the fungal culture in ribitol supplemented media only. This study provides a better understanding of the role of the type and concentration of the carbon source in fungal polyketide biosynthesis in the lichen Cladonia rangiferina. © 2016 by The Mycological Society of America.

  4. Identification of olivetolic acid cyclase from Cannabis sativa reveals a unique catalytic route to plant polyketides.

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    Gagne, Steve J; Stout, Jake M; Liu, Enwu; Boubakir, Zakia; Clark, Shawn M; Page, Jonathan E

    2012-07-31

    Δ(9)-Tetrahydrocannabinol (THC) and other cannabinoids are responsible for the psychoactive and medicinal properties of Cannabis sativa L. (marijuana). The first intermediate in the cannabinoid biosynthetic pathway is proposed to be olivetolic acid (OA), an alkylresorcinolic acid that forms the polyketide nucleus of the cannabinoids. OA has been postulated to be synthesized by a type III polyketide synthase (PKS) enzyme, but so far type III PKSs from cannabis have been shown to produce catalytic byproducts instead of OA. We analyzed the transcriptome of glandular trichomes from female cannabis flowers, which are the primary site of cannabinoid biosynthesis, and searched for polyketide cyclase-like enzymes that could assist in OA cyclization. Here, we show that a type III PKS (tetraketide synthase) from cannabis trichomes requires the presence of a polyketide cyclase enzyme, olivetolic acid cyclase (OAC), which catalyzes a C2-C7 intramolecular aldol condensation with carboxylate retention to form OA. OAC is a dimeric α+β barrel (DABB) protein that is structurally similar to polyketide cyclases from Streptomyces species. OAC transcript is present at high levels in glandular trichomes, an expression profile that parallels other cannabinoid pathway enzymes. Our identification of OAC both clarifies the cannabinoid pathway and demonstrates unexpected evolutionary parallels between polyketide biosynthesis in plants and bacteria. In addition, the widespread occurrence of DABB proteins in plants suggests that polyketide cyclases may play an overlooked role in generating plant chemical diversity.

  5. Polyketide Synthases in the Microbiome of the Marine Sponge Plakortis halichondrioides: A Metagenomic Update

    Directory of Open Access Journals (Sweden)

    Gerardo Della Sala

    2014-11-01

    Full Text Available Sponge-associated microorganisms are able to assemble the complex machinery for the production of secondary metabolites such as polyketides, the most important class of marine natural products from a drug discovery perspective. A comprehensive overview of polyketide biosynthetic genes of the sponge Plakortis halichondrioides and its symbionts was obtained in the present study by massively parallel 454 pyrosequencing of complex and heterogeneous PCR (Polymerase Chain Reaction products amplified from the metagenomic DNA of a specimen of P. halichondrioides collected in the Caribbean Sea. This was accompanied by a survey of the bacterial diversity within the sponge. In line with previous studies, sequences belonging to supA and swfA, two widespread sponge-specific groups of polyketide synthase (PKS genes were dominant. While they have been previously reported as belonging to Poribacteria (a novel bacterial phylum found exclusively in sponges, re-examination of current genomic sequencing data showed supA and swfA not to be present in the poribacterial genome. Several non-supA, non-swfA type-I PKS fragments were also identified. A significant portion of these fragments resembled type-I PKSs from protists, suggesting that bacteria may not be the only source of polyketides from P. halichondrioides, and that protistan PKSs should receive further investigation as a source of novel polyketides.

  6. Fungal polyketide azaphilone pigments as future natural food colorants?

    DEFF Research Database (Denmark)

    Mapari, Sameer Shamsuddin; Thrane, Ulf; Meyer, Anne S.

    2010-01-01

    The recent approval of fungal carotenoids as food colorants by the European Union has strengthened the prospects for fungal cell factories for the production of polyketide pigments. Fungal production of colorants has the main advantage of making the manufacturer independent of the seasonal supply...... functionality and to expand the color palette of contemporary natural food colorants.......The recent approval of fungal carotenoids as food colorants by the European Union has strengthened the prospects for fungal cell factories for the production of polyketide pigments. Fungal production of colorants has the main advantage of making the manufacturer independent of the seasonal supply...... of raw materials, thus minimizing batch-to-batch variations. Here, we review the potential of polyketide pigments produced from chemotaxonomically selected non-toxigenic fungal strains (e.g. Penicillium and Epicoccum spp.) to serve as food colorants. We argue that the production of polyketide azaphilone...

  7. Hybrid polyketide synthases

    Energy Technology Data Exchange (ETDEWEB)

    Fortman, Jeffrey L.; Hagen, Andrew; Katz, Leonard; Keasling, Jay D.; Poust, Sean; Zhang, Jingwei; Zotchev, Sergey

    2016-05-10

    The present invention provides for a polyketide synthase (PKS) capable of synthesizing an even-chain or odd-chain diacid or lactam or diamine. The present invention also provides for a host cell comprising the PKS and when cultured produces the even-chain diacid, odd-chain diacid, or KAPA. The present invention also provides for a host cell comprising the PKS capable of synthesizing a pimelic acid or KAPA, and when cultured produces biotin.

  8. Antibacterial polyketides from Bacillus amyloliquefaciens associated with edible red seaweed Laurenciae papillosa.

    Science.gov (United States)

    Chakraborty, Kajal; Thilakan, Bini; Raola, Vamshi Krishna; Joy, Minju

    2017-03-01

    Heterotrophic Bacillus amyloliquefaciens associated with edible red seaweed, Laurenciae papillosa was used to isolate antibacterial polyketide compounds. Antibacterial activity studies integrated with the outcome obtained by polyketide synthetase (pks) coding genes established that seaweed-affiliated bacterial flora had a wide-ranging antibacterial activities and potential natural product diversity, which proved that the bacterium is valuable reservoir of novel bioactive metabolites. Bioactivity-guided isolation of 3-(octahydro-9-isopropyl-2H-benzo[h]chromen-4-yl)-2-methylpropyl benzoate and methyl 8-(2-(benzoyloxy)-ethyl)-hexahydro-4-((E)-pent-2-enyl)-2H-chromene-6-carboxylate of polyketide origin, with activity against human opportunistic food pathogenic microbes, have been isolated from the ethyl acetate extract of B. amyloliquefaciens. Structure-activity relationship analysis revealed that hydrophobic descriptor of the polyketide compounds significantly contribute towards its antibacterial activity. Seaweed-associated microorganisms were shown to represent a potential source of antimicrobial compounds for food and health benefits. The antibacterial polyketide compounds described in the present study may find potential applications in the food industry to reduce food-borne pathogens. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Role of Modular Polyketide Synthases in the Production of Polyether Ladder Compounds in Ciguatoxin-Producing Gambierdiscus polynesiensis and G. excentricus (Dinophyceae).

    Science.gov (United States)

    Kohli, Gurjeet S; Campbell, Katrina; John, Uwe; Smith, Kirsty F; Fraga, Santiago; Rhodes, Lesley L; Murray, Shauna A

    2017-09-01

    Gambierdiscus, a benthic dinoflagellate, produces ciguatoxins that cause the human illness Ciguatera. Ciguatoxins are polyether ladder compounds that have a polyketide origin, indicating that polyketide synthases (PKS) are involved in their production. We sequenced transcriptomes of Gambierdiscus excentricus and Gambierdiscus polynesiensis and found 264 contigs encoding single domain ketoacyl synthases (KS; G. excentricus: 106, G. polynesiensis: 143) and ketoreductases (KR; G. excentricus: 7, G. polynesiensis: 8) with sequence similarity to type I PKSs, as reported in other dinoflagellates. In addition, 24 contigs (G. excentricus: 3, G. polynesiensis: 21) encoding multiple PKS domains (forming typical type I PKSs modules) were found. The proposed structure produced by one of these megasynthases resembles a partial carbon backbone of a polyether ladder compound. Seventeen contigs encoding single domain KS, KR, s-malonyltransacylase, dehydratase and enoyl reductase with sequence similarity to type II fatty acid synthases (FAS) in plants were found. Type I PKS and type II FAS genes were distinguished based on the arrangement of domains on the contigs and their sequence similarity and phylogenetic clustering with known PKS/FAS genes in other organisms. This differentiation of PKS and FAS pathways in Gambierdiscus is important, as it will facilitate approaches to investigating toxin biosynthesis pathways in dinoflagellates. © 2017 The Author(s) Journal of Eukaryotic Microbiology © 2017 International Society of Protistologists.

  10. Antibacterial polyketides from the jellyfish-derived fungus Paecilomyces variotii.

    Science.gov (United States)

    Liu, Juan; Li, Famei; Kim, Eun La; Li, Jian Lin; Hong, Jongki; Bae, Kyung Sook; Chung, Hae Young; Kim, Hyung Sik; Jung, Jee H

    2011-08-26

    Four new polyketides (1-4) were isolated from the fungus Paecilomyces variotii, which was derived from the jellyfish Nemopilema nomurai. The planar structures and relative configurations of these polyketides were elucidated on the basis of spectroscopic analyses, including 2D NMR experiments. The compounds showed inhibitory activity against pathogenic bacteria including methicillin-resistant Staphylococcus aureus 3089 and multi-drug-resistant Vibrio parahemolyticus 7001 with MIC values in the range 5-40 μg/mL.

  11. Probing the Selectivity and Protein•Protein Interactions of a Non-Reducing Fungal Polyketide Synthase Using Mechanism-Based Crosslinkers

    Science.gov (United States)

    Bruegger, Joel; Haushalter, Bob; Vagstad, Anna; Shakya, Gaurav; Mih, Nathan; Townsend, Craig A.; Burkart, Michael D.; Tsai, Shiou-Chuan

    2013-01-01

    SUMMARY Protein•protein interactions, which often involve interactions between an acyl carrier protein (ACP) and its partner enzymes, are important for coordinating polyketide biosynthesis. However, the nature of such interactions is not well understood, especially in the fungal non-reducing polyketide synthases (NR-PKSs) that biosynthesize toxic and pharmaceutically important polyketides. Here, we employ a mechanism-based crosslinker to successfully probe ACP and ketosynthase (KS) domain interactions in NR-PKSs. We found that crosslinking efficiency is closely correlated with the strength of ACP•KS interactions, and that KS demonstrates strong starter unit selectivity. We further identified positively charged surface residues by KS mutagenesis, which mediate key interactions with the negatively-charged ACP surface. Such complementary/matching contact pairs can serve as “adapter surfaces” for future efforts to generate new polyketides using NR-PKSs. PMID:23993461

  12. In vitro biosynthesis of unnatural enterocin and wailupemycin polyketides.

    Science.gov (United States)

    Kalaitzis, John A; Cheng, Qian; Thomas, Paul M; Kelleher, Neil L; Moore, Bradley S

    2009-03-27

    Nature has evolved finely tuned strategies to synthesize rare and complex natural products such as the enterocin family of polyketides from the marine bacterium Streptomyces maritimus. Herein we report the directed ex vivo multienzyme syntheses of 24 unnatural 5-deoxyenterocin and wailupemycin F and G analogues, 18 of which are new. We have generated molecular diversity by priming the enterocin biosynthesis enzymes with unnatural substrates and have illustrated further the uniqueness of this type II polyketide synthase by way of exploiting its unusual starter unit biosynthesis pathways.

  13. Structure and Absolute Configuration of Jurassic Polyketide-Derived Spiroborate Pigments Obtained from Microgram Quantities.

    Science.gov (United States)

    Wolkenstein, Klaus; Sun, Han; Falk, Heinz; Griesinger, Christian

    2015-10-28

    Complete structural elucidation of natural products is often challenging due to structural complexity and limited availability. This is true for present-day secondary metabolites, but even more for exceptionally preserved secondary metabolites of ancient organisms that potentially provide insights into the evolutionary history of natural products. Here, we report the full structure and absolute configuration of the borolithochromes, enigmatic boron-containing pigments from a Jurassic putative red alga, from samples of less than 50 μg using microcryoprobe NMR, circular dichroism spectroscopy, and density functional theory calculations and reveal their polyketide origin. The pigments are identified as spiroborates with two pentacyclic sec-butyl-trihydroxy-methyl-benzo[gh]tetraphen-one ligands and less-substituted derivatives. The configuration of the sec-butyl group is found to be (S). Because the exceptional benzo[gh]tetraphene scaffold is otherwise only observed in the recently discovered polyketide clostrubin from a present-day Clostridium bacterium, the Jurassic borolithochromes now can be unambiguously linked to the modern polyketide, providing evidence that the fossil pigments are almost originally preserved secondary metabolites and suggesting that the pigments in fact may have been produced by an ancient bacterium. The borolithochromes differ fundamentally from previously described boronated polyketides and represent the first boronated aromatic polyketides found so far. Our results demonstrate the potential of microcryoprobe NMR in the analysis of previously little-explored secondary metabolites from ancient organisms and reveal the evolutionary significance of clostrubin-type polyketides.

  14. Polyketides isolated from Penicillium herquei

    International Nuclear Information System (INIS)

    Marinho, Andrey Moacir do Rosario; Marinho, Patricia Santana Barbosa; Rodrigues Filho, Edson; Ferreira, Izabel Cristina Piloto

    2011-01-01

    In this work we are reporting the isolation of polyketides citreoserine (1), emodin (2), janthinone (3), dihydrocitrinone (4) and citrinin H-1 (5). The compounds were isolated by chromatographic procedures and identified by spectral methods of NMR 1D and 2D and MS. The compounds 1, 2 and 3 were tested against promastigotes of Leishmania brasiliensis. (author)

  15. Protoplasting impact on polyketide activity and characterization of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-03

    Sep 3, 2008 ... Key words: Streptomyces, polyketide antibiotic, gene transfer, .... bacterial and fungal. In fact .... as a ring of pigmented mycelial growth surrounding SCB1 .... hybridization between Aspergillus niger and Trichoderma viride by.

  16. Allergens/Antigens, toxins and polyketides of important Aspergillus species.

    Science.gov (United States)

    Bhetariya, Preetida J; Madan, Taruna; Basir, Seemi Farhat; Varma, Anupam; Usha, Sarma P

    2011-04-01

    The medical, agricultural and biotechnological importance of the primitive eukaryotic microorganisms, the Fungi was recognized way back in 1920. Among various groups of fungi, the Aspergillus species are studied in great detail using advances in genomics and proteomics to unravel biological and molecular mechanisms in these fungi. Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus nidulans and Aspergillus terreus are some of the important species relevant to human, agricultural and biotechnological applications. The potential of Aspergillus species to produce highly diversified complex biomolecules such as multifunctional proteins (allergens, antigens, enzymes) and polyketides is fascinating and demands greater insight into the understanding of these fungal species for application to human health. Recently a regulator gene for secondary metabolites, LaeA has been identified. Gene mining based on LaeA has facilitated new metabolites with antimicrobial activity such as emericellamides and antitumor activity such as terrequinone A from A. nidulans. Immunoproteomic approach was reported for identification of few novel allergens for A. fumigatus. In this context, the review is focused on recent developments in allergens, antigens, structural and functional diversity of the polyketide synthases that produce polyketides of pharmaceutical and biological importance. Possible antifungal drug targets for development of effective antifungal drugs and new strategies for development of molecular diagnostics are considered.

  17. The Catalytic Diversity of Multimodular Polyketide Synthases: Natural Product Biosynthesis Beyond Textbook Assembly Rules.

    Science.gov (United States)

    Gulder, Tobias A M; Freeman, Michael F; Piel, Jörn

    2011-03-01

    Bacterial multimodular polyketide synthases (PKSs) are responsible for the biosynthesis of a wide range of pharmacologically active natural products. These megaenzymes contain numerous catalytic and structural domains and act as biochemical templates to generate complex polyketides in an assembly line-like fashion. While the prototypical PKS is composed of only a few different domain types that are fused together in a combinatorial fashion, an increasing number of enzymes is being found that contain additional components. These domains can introduce remarkably diverse modifications into polyketides. This review discusses our current understanding of such noncanonical domains and their role in expanding the biosynthetic versatility of bacterial PKSs.

  18. Deletion of a regulatory gene within the cpk gene cluster reveals novel antibacterial activity in Streptomyces coelicolor A3(2)

    NARCIS (Netherlands)

    Gottelt, Marco; Kol, Stefan; Gomez-Escribano, Juan Pablo; Bibb, Mervyn; Takano, Eriko

    Genome sequencing of Streptomyces coelicolor A3(2) revealed an uncharacterized type I polyketide synthase gene cluster (cpk) Here we describe the discovery of a novel antibacterial activity (abCPK) and a yellow-pigmented secondary metabolite (yCPK) after deleting a presumed pathway-specific

  19. A dual role for a polyketide synthase in dynemicin enediyne and anthraquinone biosynthesis

    Science.gov (United States)

    Cohen, Douglas R.; Townsend, Craig A.

    2018-02-01

    Dynemicin A is a member of a subfamily of enediyne antitumour antibiotics characterized by a 10-membered carbocycle fused to an anthraquinone, both of polyketide origin. Sequencing of the dynemicin biosynthetic gene cluster in Micromonospora chersina previously identified an enediyne polyketide synthase (PKS), but no anthraquinone PKS, suggesting gene(s) for biosynthesis of the latter were distant from the core dynemicin cluster. To identify these gene(s), we sequenced and analysed the genome of M. chersina. Sequencing produced a short list of putative PKS candidates, yet CRISPR-Cas9 mutants of each locus retained dynemicin production. Subsequently, deletion of two cytochromes P450 in the dynemicin cluster suggested that the dynemicin enediyne PKS, DynE8, may biosynthesize the anthraquinone. Together with 18O-labelling studies, we now present evidence that DynE8 produces the core scaffolds of both the enediyne and anthraquinone, and provide a working model to account for their formation from the programmed octaketide of the enediyne PKS.

  20. A proteomic survey of nonribosomal peptide and polyketide biosynthesis in actinobacteria

    Science.gov (United States)

    Actinobacteria such as streptomycetes are renowned for their ability to produce bioactive natural products including nonribosomal peptides (NRPs) and polyketides (PKs). The advent of genome sequencing has revealed an even larger genetic repertoire for secondary metabolism with most of the small mole...

  1. Discovery, biosynthesis, and rational engineering of novel enterocin and wailupemycin polyketide analogues.

    Science.gov (United States)

    Kalaitzis, John A

    2013-01-01

    The marine actinomycete Streptomyces maritimus produces a structurally diverse set of unusual polyketide natural products including the major metabolite enterocin. Investigations of enterocin biosynthesis revealed that the unique carbon skeleton is derived from an aromatic polyketide pathway which is genetically coded by the 21.3 kb enc gene cluster in S. maritimus. Characterization of the enc biosynthesis gene cluster and subsequent manipulation of it via heterologous expression and/or mutagenesis enabled the discovery of other enc-based metabolites that were produced in only very minor amounts in the wild type. Also described are techniques used to harness the enterocin biosynthetic machinery in order to generate unnatural enc-derived polyketide analogues. This review focuses upon the molecular methods used in combination with classical natural products detection and isolation techniques to access minor metabolites of the S. maritimus secondary metabolome.

  2. In Vitro Biosynthesis of Unnatural Enterocin and Wailupemycin Polyketides¥

    Science.gov (United States)

    Kalaitzis, John A.; Cheng, Qian; Thomas, Paul M.; Kelleher, Neil L.; Moore, Bradley S.

    2009-01-01

    Nature has evolved finely tuned strategies to synthesize rare and complex natural products such as the enterocin family of polyketides from the marine bacterium Streptomyces maritimus. Herein we report the directed ex vivo multienzyme syntheses of 24 unnatural 5-deoxyenterocin and wailupemycin F and G analogues, 18 of which are new. We have generated molecular diversity by priming the enterocin biosynthesis enzymes with unnatural substrates and have illustrated further the uniqueness of this type II polyketide synthase by way of exploiting its unusual starter unit biosynthesis pathways. PMID:19215142

  3. A novel polyketide biosynthesis gene cluster is involved in fruiting body morphogenesis in the filamentous fungi Sordaria macrospora and Neurospora crassa.

    Science.gov (United States)

    Nowrousian, Minou

    2009-04-01

    During fungal fruiting body development, hyphae aggregate to form multicellular structures that protect and disperse the sexual spores. Analysis of microarray data revealed a gene cluster strongly upregulated during fruiting body development in the ascomycete Sordaria macrospora. Real time PCR analysis showed that the genes from the orthologous cluster in Neurospora crassa are also upregulated during development. The cluster encodes putative polyketide biosynthesis enzymes, including a reducing polyketide synthase. Analysis of knockout strains of a predicted dehydrogenase gene from the cluster showed that mutants in N. crassa and S. macrospora are delayed in fruiting body formation. In addition to the upregulated cluster, the N. crassa genome comprises another cluster containing a polyketide synthase gene, and five additional reducing polyketide synthase (rpks) genes that are not part of clusters. To study the role of these genes in sexual development, expression of the predicted rpks genes in S. macrospora (five genes) and N. crassa (six genes) was analyzed; all but one are upregulated during sexual development. Analysis of knockout strains for the N. crassa rpks genes showed that one of them is essential for fruiting body formation. These data indicate that polyketides produced by RPKSs are involved in sexual development in filamentous ascomycetes.

  4. Plant pathogenic anaerobic bacteria use aromatic polyketides to access aerobic territory.

    Science.gov (United States)

    Shabuer, Gulimila; Ishida, Keishi; Pidot, Sacha J; Roth, Martin; Dahse, Hans-Martin; Hertweck, Christian

    2015-11-06

    Around 25% of vegetable food is lost worldwide because of infectious plant diseases, including microbe-induced decay of harvested crops. In wet seasons and under humid storage conditions, potato tubers are readily infected and decomposed by anaerobic bacteria (Clostridium puniceum). We found that these anaerobic plant pathogens harbor a gene locus (type II polyketide synthase) to produce unusual polyketide metabolites (clostrubins) with dual functions. The clostrubins, which act as antibiotics against other microbial plant pathogens, enable the anaerobic bacteria to survive an oxygen-rich plant environment. Copyright © 2015, American Association for the Advancement of Science.

  5. Producing biofuels using polyketide synthases

    Science.gov (United States)

    Katz, Leonard; Fortman, Jeffrey L; Keasling, Jay D

    2013-04-16

    The present invention provides for a non-naturally occurring polyketide synthase (PKS) capable of synthesizing a carboxylic acid or a lactone, and a composition such that a carboxylic acid or lactone is included. The carboxylic acid or lactone, or derivative thereof, is useful as a biofuel. The present invention also provides for a recombinant nucleic acid or vector that encodes such a PKS, and host cells which also have such a recombinant nucleic acid or vector. The present invention also provides for a method of producing such carboxylic acids or lactones using such a PKS.

  6. Defining Modules, Modularity and Modularization

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth; Pedersen, Per Erik Elgård

    The paper describes the evolution of the concept of modularity in a historical perspective. The main reasons for modularity are: create variety, utilize similarities, and reduce complexity. The paper defines the terms: Module, modularity, and modularization.......The paper describes the evolution of the concept of modularity in a historical perspective. The main reasons for modularity are: create variety, utilize similarities, and reduce complexity. The paper defines the terms: Module, modularity, and modularization....

  7. Identification of a polyketide synthase required for alternariol (AOH and alternariol-9-methyl ether (AME formation in Alternaria alternata.

    Directory of Open Access Journals (Sweden)

    Debjani Saha

    Full Text Available Alternaria alternata produces more than 60 secondary metabolites, among which alternariol (AOH and alternariol-9-methyl ether (AME are important mycotoxins. Whereas the toxicology of these two polyketide-based compounds has been studied, nothing is known about the genetics of their biosynthesis. One of the postulated core enzymes in the biosynthesis of AOH and AME is polyketide synthase (PKS. In a draft genome sequence of A. alternata we identified 10 putative PKS-encoding genes. The timing of the expression of two PKS genes, pksJ and pksH, correlated with the production of AOH and AME. The PksJ and PksH proteins are predicted to be 2222 and 2821 amino acids in length, respectively. They are both iterative type I reducing polyketide synthases. PksJ harbors a peroxisomal targeting sequence at the C-terminus, suggesting that the biosynthesis occurs at least partly in these organelles. In the vicinity of pksJ we found a transcriptional regulator, altR, involved in pksJ induction and a putative methyl transferase, possibly responsible for AME formation. Downregulation of pksJ and altR caused a large decrease of alternariol formation, suggesting that PksJ is the polyketide synthase required for the postulated Claisen condensations during the biosynthesis. No other enzymes appeared to be required. PksH downregulation affected pksJ expression and thus caused an indirect effect on AOH production.

  8. Diversity of polyketides produced by Penicillium species isolated from Melia azedarach and Murraya paniculata

    International Nuclear Information System (INIS)

    Pastre, Renata; Marinho, Andrey M.R.; Rodrigues-Filho, Edson; Souza, Antonia Q.L.; Pereira, Jose Odair

    2007-01-01

    Eight compounds comprising four groups of polyketides, the xanthone fusarindin, the mixed peptide alkaloid-polyketide GKK1032, the anthraquinones crysophanol, citreoveridin and janthinone, and the azaphylones dihydrocitrinone, citrinin and citrinin H-1, were identified in Penicillium species isolated as endophytic fungi from Melia azedarach and Murraya paniculata. The antibacterial activity of the azaphylones was tested and showed that citrinin H-1 is more active than citrinin. (author)

  9. Use of heterologous expressed polyketide synthase and small molecule foldases to make aromatic and cyclic compounds

    DEFF Research Database (Denmark)

    2016-01-01

    A method for producing individual or libraries of tri- to pentadecaketide-derived aromatic compounds of interest by heterologous expression of polyketide synthase and aromatase/cyclase in a recombinant host cell.......A method for producing individual or libraries of tri- to pentadecaketide-derived aromatic compounds of interest by heterologous expression of polyketide synthase and aromatase/cyclase in a recombinant host cell....

  10. Insights into natural products biosynthesis from analysis of 490 polyketide synthases from Fusarium.

    Science.gov (United States)

    Brown, Daren W; Proctor, Robert H

    2016-04-01

    Species of the fungus Fusarium collectively cause disease on almost all crop plants and produce numerous natural products (NPs), including some of the mycotoxins of greatest concern to agriculture. Many Fusarium NPs are derived from polyketide synthases (PKSs), large multi-domain enzymes that catalyze sequential condensation of simple carboxylic acids to form polyketides. To gain insight into the biosynthesis of polyketide-derived NPs in Fusarium, we retrieved 488 PKS gene sequences from genome sequences of 31 species of the fungus. In addition to these apparently functional PKS genes, the genomes collectively included 81 pseudogenized PKS genes. Phylogenetic analysis resolved the PKS genes into 67 clades, and based on multiple lines of evidence, we propose that homologs in each clade are responsible for synthesis of a polyketide that is distinct from those synthesized by PKSs in other clades. The presence and absence of PKS genes among the species examined indicated marked differences in distribution of PKS homologs. Comparisons of Fusarium PKS genes and genes flanking them to those from other Ascomycetes provided evidence that Fusarium has the genetic potential to synthesize multiple NPs that are the same or similar to those reported in other fungi, but that have not yet been reported in Fusarium. The results also highlight ways in which such analyses can help guide identification of novel Fusarium NPs and differences in NP biosynthetic capabilities that exist among fungi. Published by Elsevier Inc.

  11. The polyketide components of waxes and the Cer-cqu gene cluster encoding a novel polyketide synthase, the β-diketone synthase, DKS

    DEFF Research Database (Denmark)

    von Wettstein, Penny

    2017-01-01

    The primary function of the outermost, lipophilic layer of plant aerial surfaces, called the cuticle, is preventing non-stomatal water loss. Its exterior surface is often decorated with wax crystals, imparting a blue-grey color. Identification of the barley Cer-c, -q and -u genes forming the 101 kb...... Cer-cqu gene cluster encoding a novel polyketide synthase-the β-diketone synthase (DKS), a lipase/carboxyl transferase, and a P450 hydroxylase, respectively, establishes a new, major pathway for the synthesis of plant waxes. The major product is a β-diketone (14,16-hentriacontane) aliphatic that forms...

  12. Polyketide synthases from poison hemlock (Conium maculatum L.).

    Science.gov (United States)

    Hotti, Hannu; Seppänen-Laakso, Tuulikki; Arvas, Mikko; Teeri, Teemu H; Rischer, Heiko

    2015-11-01

    Coniine is a toxic alkaloid, the biosynthesis of which is not well understood. A possible route, supported by evidence from labelling experiments, involves a polyketide formed by the condensation of one acetyl-CoA and three malonyl-CoAs catalysed by a polyketide synthase (PKS). We isolated PKS genes or their fragments from poison hemlock (Conium maculatum L.) by using random amplification of cDNA ends (RACE) and transcriptome analysis, and characterized three full-length enzymes by feeding different starter-CoAs in vitro. On the basis of our in vitro experiments, two of the three characterized PKS genes in poison hemlock encode chalcone synthases (CPKS1 and CPKS2), and one encodes a novel type of PKS (CPKS5). We show that CPKS5 kinetically favours butyryl-CoA as a starter-CoA in vitro. Our results suggest that CPKS5 is responsible for the initiation of coniine biosynthesis by catalysing the synthesis of the carbon backbone from one butyryl-CoA and two malonyl-CoAs. © 2015 FEBS.

  13. Interaction between Polyketide Synthase and Transporter Suggests Coupled Synthesis and Export of Virulence Lipid in M. tuberculosis.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available Virulent mycobacteria utilize surface-exposed polyketides to interact with host cells, but the mechanism by which these hydrophobic molecules are transported across the cell envelope to the surface of the bacteria is poorly understood. Phthiocerol dimycocerosate (PDIM, a surface-exposed polyketide lipid necessary for Mycobacterium tuberculosis virulence, is the product of several polyketide synthases including PpsE. Transport of PDIM requires MmpL7, a member of the MmpL family of RND permeases. Here we show that a domain of MmpL7 biochemically interacts with PpsE, the first report of an interaction between a biosynthetic enzyme and its cognate transporter. Overexpression of the interaction domain of MmpL7 acts as a dominant negative to PDIM synthesis by poisoning the interaction between synthase and transporter. This suggests that MmpL7 acts in complex with the synthesis machinery to efficiently transport PDIM across the cell membrane. Coordination of synthesis and transport may not only be a feature of MmpL-mediated transport in M. tuberculosis, but may also represent a general mechanism of polyketide export in many different microorganisms.

  14. Broad Substrate Specificity of the Loading Didomain of the Lipomycin Polyketide Synthase

    Energy Technology Data Exchange (ETDEWEB)

    Yuzawa, S; Eng, CH; Katz, L; Keasling, JD

    2013-06-04

    LipPks1, a polyketide synthase subunit of the lipomycin synthase, is believed to catalyze the polyketide chain initiation reaction using isobutyryl-CoA as a substrate, followed by an elongation reaction with methylmalonyl-CoA to start the biosynthesis of antibiotic alpha-lipomycin in Streptomyces aureofaciens Tu117. Recombinant LipPks1, containing the thioesterase domain from the 6-deoxyerythronolide B synthase, was produced in Escherichia coli, and its substrate specificity was investigated in vitro. Surprisingly, several different acyl-CoAs, including isobutyryl-CoA, were accepted as the starter substrates, while no product was observed with acetyl-CoA. These results demonstrate the broad substrate specificity of LipPks1 and may be applied to producing new antibiotics.

  15. The enzymology of polyether biosynthesis.

    Science.gov (United States)

    Liu, Tiangang; Cane, David E; Deng, Zixin

    2009-01-01

    Polyether ionophore antibiotics are a special class of polyketides widely used in veterinary medicine, and as food additives in animal husbandry. In this article, we review current knowledge about the mechanism of polyether biosynthesis, and the genetic and biochemical strategies used for its study. Several clear differences distinguish it from traditional type I modular polyketide biosynthesis: polyether backbones are assembled by modular polyketide synthases but are modified by two key enzymes, epoxidase and epoxide hydrolase, to generate the product. All double bonds involved in the oxidative cyclization in the polyketide backbone are of E geometry. Chain release in the polyether biosynthetic pathway requires a special type II thioesterase which specifically hydrolyzes the polyether thioester. All these discoveries should be very helpful for a deep understanding of the biosynthetic mechanism of this class of important natural compounds, and for the targeted engineering of polyether derivatives.

  16. HSQC-TOCSY Fingerprinting-Directed Discovery of Antiplasmodial Polyketides from the Marine Ascidian-Derived Streptomyces sp. (USC-16018).

    Science.gov (United States)

    Buedenbender, Larissa; Robertson, Luke P; Lucantoni, Leonardo; Avery, Vicky M; Kurtböke, D İpek; Carroll, Anthony R

    2018-05-30

    Chemical investigations on the fermentation extract obtained from an ascidian-derived Streptomyces sp. (USC-16018) yielded a new ansamycin polyketide, herbimycin G ( 1 ), as well as a known macrocyclic polyketide, elaiophylin ( 2 ), and four known diketopiperazines ( 3 ⁻ 6 ). The structures of the compounds were elucidated based on 1D/2D NMR and MS data. The absolute configuration of 1 was established by comparison of experimental and predicted electronic circular dichroism (ECD) data. Antiplasmodial activities were tested for the natural products against chloroquine sensitive (3D7) and chloroquine resistant (Dd2) Plasmodium falciparum strains; the two polyketides ( 1 ⁻ 2 ) demonstrated an inhibition of >75% against both parasite strains and while 2 was highly cytotoxic, herbimycin G ( 1 ) showed no cytotoxicity and good predicted water solubility.

  17. The Polyketide Components of Waxes and the Cer-cqu Gene Cluster Encoding a Novel Polyketide Synthase, the β-Diketone Synthase, DKS.

    Science.gov (United States)

    von Wettstein-Knowles, Penny

    2017-07-10

    The primary function of the outermost, lipophilic layer of plant aerial surfaces, called the cuticle, is preventing non-stomatal water loss. Its exterior surface is often decorated with wax crystals, imparting a blue-grey color. Identification of the barley Cer-c , -q and -u genes forming the 101 kb Cer-cqu gene cluster encoding a novel polyketide synthase-the β-diketone synthase (DKS), a lipase/carboxyl transferase, and a P450 hydroxylase, respectively, establishes a new, major pathway for the synthesis of plant waxes. The major product is a β-diketone (14,16-hentriacontane) aliphatic that forms long, thin crystalline tubes. A pathway branch leads to the formation of esterified alkan-2-ols.

  18. Genetics of Polyketide Metabolism in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Klejnstrup, Marie L.; Frandsen, Rasmus John Normand; Holm, Dorte Koefoed

    2012-01-01

    Secondary metabolites are small molecules that show large structural diversity and a broad range of bioactivities. Some metabolites are attractive as drugs or pigments while others act as harmful mycotoxins. Filamentous fungi have the capacity to produce a wide array of secondary metabolites...... including polyketides. The majority of genes required for production of these metabolites are mostly organized in gene clusters, which often are silent or barely expressed under laboratory conditions, making discovery and analysis difficult. Fortunately, the genome sequences of several filamentous fungi...

  19. A modular optical sensor

    Science.gov (United States)

    Conklin, John Albert

    This dissertation presents the design of a modular, fiber-optic sensor and the results obtained from testing the modular sensor. The modular fiber-optic sensor is constructed in such manner that the sensor diaphragm can be replaced with different configurations to detect numerous physical phenomena. Additionally, different fiber-optic detection systems can be attached to the sensor. Initially, the modular sensor was developed to be used by university of students to investigate realistic optical sensors and detection systems to prepare for advance studies of micro-optical mechanical systems (MOMS). The design accomplishes this by doing two things. First, the design significantly lowers the costs associated with studying optical sensors by modularizing the sensor design. Second, the sensor broadens the number of physical phenomena that students can apply optical sensing techniques to in a fiber optics sensor course. The dissertation is divided into seven chapters covering the historical development of fiber-optic sensors, a theoretical overview of fiber-optic sensors, the design, fabrication, and the testing of the modular sensor developed in the course of this work. Chapter 1 discusses, in detail, how this dissertation is organized and states the purpose of the dissertation. Chapter 2 presents an historical overview of the development of optical fibers, optical pressure sensors, and fibers, optical pressure sensors, and optical microphones. Chapter 3 reviews the theory of multi-fiber optic detection systems, optical microphones, and pressure sensors. Chapter 4 presents the design details of the modular, optical sensor. Chapter 5 delves into how the modular sensor is fabricated and how the detection systems are constructed. Chapter 6 presents the data collected from the microphone and pressure sensor configurations of the modular sensor. Finally, Chapter 7 discusses the data collected and draws conclusions about the design based on the data collected. Chapter 7 also

  20. Engineering a Polyketide Synthase for In Vitro Production of Adipic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, A; Poust, S; De Rond, T; Fortman, JL; Katz, L; Petzold, CJ; Keasling, JD

    2015-10-26

    Polyketides have enormous structural diversity, yet polyketide synthases (PKSs) have thus far been engineered to produce only drug candidates or derivatives thereof. Thousands of other molecules, including commodity and specialty chemicals, could be synthesized using PKSs if composing hybrid PKSs from well-characterized parts derived from natural PKSs was more efficient. Here, using modern mass spectrometry techniques as an essential part of the design–build–test cycle, we engineered a chimeric PKS to enable production one of the most widely used commodity chemicals, adipic acid. To accomplish this, we introduced heterologous reductive domains from various PKS clusters into the borrelidin PKS’ first extension module, which we previously showed produces a 3-hydroxy-adipoyl intermediate when coincubated with the loading module and a succinyl-CoA starter unit. Acyl-ACP intermediate analysis revealed an unexpected bottleneck at the dehydration step, which was overcome by introduction of a carboxyacyl-processing dehydratase domain. Appending a thioesterase to the hybrid PKS enabled the production of free adipic acid. Using acyl-intermediate based techniques to “debug” PKSs as described here, it should one day be possible to engineer chimeric PKSs to produce a variety of existing commodity and specialty chemicals, as well as thousands of chemicals that are difficult to produce from petroleum feedstocks using traditional synthetic chemistry.

  1. HSQC-TOCSY Fingerprinting for Prioritization of Polyketide- and Peptide-Producing Microbial Isolates.

    Science.gov (United States)

    Buedenbender, Larissa; Habener, Leesa J; Grkovic, Tanja; Kurtböke, D İpek; Duffy, Sandra; Avery, Vicky M; Carroll, Anthony R

    2018-04-27

    Microbial products are a promising source for drug leads as a result of their unique structural diversity. However, reisolation of already known natural products significantly hampers the discovery process, and it is therefore important to incorporate effective microbial isolate selection and dereplication protocols early in microbial natural product studies. We have developed a systematic approach for prioritization of microbial isolates for natural product discovery based on heteronuclear single-quantum correlation-total correlation spectroscopy (HSQC-TOCSY) nuclear magnetic resonance profiles in combination with antiplasmodial activity of extracts. The HSQC-TOCSY experiments allowed for unfractionated microbial extracts containing polyketide and peptidic natural products to be rapidly identified. Here, we highlight how this approach was used to prioritize extracts derived from a library of 119 ascidian-associated actinomycetes that possess a higher potential to produce bioactive polyketides and peptides.

  2. Bioinformatics Prediction of Polyketide Synthase Gene Clusters from Mycosphaerella fijiensis.

    Science.gov (United States)

    Noar, Roslyn D; Daub, Margaret E

    2016-01-01

    Mycosphaerella fijiensis, causal agent of black Sigatoka disease of banana, is a Dothideomycete fungus closely related to fungi that produce polyketides important for plant pathogenicity. We utilized the M. fijiensis genome sequence to predict PKS genes and their gene clusters and make bioinformatics predictions about the types of compounds produced by these clusters. Eight PKS gene clusters were identified in the M. fijiensis genome, placing M. fijiensis into the 23rd percentile for the number of PKS genes compared to other Dothideomycetes. Analysis of the PKS domains identified three of the PKS enzymes as non-reducing and two as highly reducing. Gene clusters contained types of genes frequently found in PKS clusters including genes encoding transporters, oxidoreductases, methyltransferases, and non-ribosomal peptide synthases. Phylogenetic analysis identified a putative PKS cluster encoding melanin biosynthesis. None of the other clusters were closely aligned with genes encoding known polyketides, however three of the PKS genes fell into clades with clusters encoding alternapyrone, fumonisin, and solanapyrone produced by Alternaria and Fusarium species. A search for homologs among available genomic sequences from 103 Dothideomycetes identified close homologs (>80% similarity) for six of the PKS sequences. One of the PKS sequences was not similar (< 60% similarity) to sequences in any of the 103 genomes, suggesting that it encodes a unique compound. Comparison of the M. fijiensis PKS sequences with those of two other banana pathogens, M. musicola and M. eumusae, showed that these two species have close homologs to five of the M. fijiensis PKS sequences, but three others were not found in either species. RT-PCR and RNA-Seq analysis showed that the melanin PKS cluster was down-regulated in infected banana as compared to growth in culture. Three other clusters, however were strongly upregulated during disease development in banana, suggesting that they may encode

  3. Bioinformatics Prediction of Polyketide Synthase Gene Clusters from Mycosphaerella fijiensis.

    Directory of Open Access Journals (Sweden)

    Roslyn D Noar

    Full Text Available Mycosphaerella fijiensis, causal agent of black Sigatoka disease of banana, is a Dothideomycete fungus closely related to fungi that produce polyketides important for plant pathogenicity. We utilized the M. fijiensis genome sequence to predict PKS genes and their gene clusters and make bioinformatics predictions about the types of compounds produced by these clusters. Eight PKS gene clusters were identified in the M. fijiensis genome, placing M. fijiensis into the 23rd percentile for the number of PKS genes compared to other Dothideomycetes. Analysis of the PKS domains identified three of the PKS enzymes as non-reducing and two as highly reducing. Gene clusters contained types of genes frequently found in PKS clusters including genes encoding transporters, oxidoreductases, methyltransferases, and non-ribosomal peptide synthases. Phylogenetic analysis identified a putative PKS cluster encoding melanin biosynthesis. None of the other clusters were closely aligned with genes encoding known polyketides, however three of the PKS genes fell into clades with clusters encoding alternapyrone, fumonisin, and solanapyrone produced by Alternaria and Fusarium species. A search for homologs among available genomic sequences from 103 Dothideomycetes identified close homologs (>80% similarity for six of the PKS sequences. One of the PKS sequences was not similar (< 60% similarity to sequences in any of the 103 genomes, suggesting that it encodes a unique compound. Comparison of the M. fijiensis PKS sequences with those of two other banana pathogens, M. musicola and M. eumusae, showed that these two species have close homologs to five of the M. fijiensis PKS sequences, but three others were not found in either species. RT-PCR and RNA-Seq analysis showed that the melanin PKS cluster was down-regulated in infected banana as compared to growth in culture. Three other clusters, however were strongly upregulated during disease development in banana, suggesting that

  4. Biosynthesis of Akaeolide and Lorneic Acids and Annotation of Type I Polyketide Synthase Gene Clusters in the Genome of Streptomyces sp. NPS554

    Directory of Open Access Journals (Sweden)

    Tao Zhou

    2015-01-01

    Full Text Available The incorporation pattern of biosynthetic precursors into two structurally unique polyketides, akaeolide and lorneic acid A, was elucidated by feeding experiments with 13C-labeled precursors. In addition, the draft genome sequence of the producer, Streptomyces sp. NPS554, was performed and the biosynthetic gene clusters for these polyketides were identified. The putative gene clusters contain all the polyketide synthase (PKS domains necessary for assembly of the carbon skeletons. Combined with the 13C-labeling results, gene function prediction enabled us to propose biosynthetic pathways involving unusual carbon-carbon bond formation reactions. Genome analysis also indicated the presence of at least ten orphan type I PKS gene clusters that might be responsible for the production of new polyketides.

  5. Genomic and transcriptomic analyses reveal differential regulation of diverse terpenoid and polyketides secondary metabolites in Hericium erinaceus.

    Science.gov (United States)

    Chen, Juan; Zeng, Xu; Yang, Yan Long; Xing, Yong Mei; Zhang, Qi; Li, Jia Mei; Ma, Ke; Liu, Hong Wei; Guo, Shun Xing

    2017-08-31

    The lion's mane mushroom Hericium erinaceus is a famous traditional medicinal fungus credited with anti-dementia activity and a producer of cyathane diterpenoid natural products (erinacines) useful against nervous system diseases. To date, few studies have explored the biosynthesis of these compounds, although their chemical synthesis is known. Here, we report the first genome and tanscriptome sequence of the medicinal fungus H. erinaceus. The size of the genome is 39.35 Mb, containing 9895 gene models. The genome of H. erinaceus reveals diverse enzymes and a large family of cytochrome P450 (CYP) proteins involved in the biosynthesis of terpenoid backbones, diterpenoids, sesquiterpenes and polyketides. Three gene clusters related to terpene biosynthesis and one gene cluster for polyketides biosynthesis (PKS) were predicted. Genes involved in terpenoid biosynthesis were generally upregulated in mycelia, while the PKS gene was upregulated in the fruiting body. Comparative genome analysis of 42 fungal species of Basidiomycota revealed that most edible and medicinal mushroom show many more gene clusters involved in terpenoid and polyketide biosynthesis compared to the pathogenic fungi. None of the gene clusters for terpenoid or polyketide biosynthesis were predicted in the poisonous mushroom Amanita muscaria. Our findings may facilitate future discovery and biosynthesis of bioactive secondary metabolites from H. erinaceus and provide fundamental information for exploring the secondary metabolites in other Basidiomycetes.

  6. Kernel based machine learning algorithm for the efficient prediction of type III polyketide synthase family of proteins

    Directory of Open Access Journals (Sweden)

    Mallika V

    2010-03-01

    Full Text Available Type III Polyketide synthases (PKS are family of proteins considered to have significant role in the biosynthesis of various polyketides in plants, fungi and bacteria. As these proteins show positive effects to human health, more researches are going on regarding this particular protein. Developing a tool to identify the probability of sequence, being a type III polyketide synthase will minimize the time consumption and manpower efforts. In this approach, we have designed and implemented PKSIIIpred, a high performance prediction server for type III PKS where the classifier is Support Vector Machine (SVM. Based on the limited training dataset, the tool efficiently predicts the type III PKS superfamily of proteins with high sensitivity and specificity. PKSIIIpred is available at http://type3pks.in/prediction/. We expect that this tool may serve as a useful resource for type III PKS researchers. Currently work is being progressed for further betterment of prediction accuracy by including more sequence features in the training dataset.

  7. Crystallization and preliminary crystallographic analysis of an acridone-producing novel multifunctional type III polyketide synthase from Huperzia serrata

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Hiroyuki [Mitsubishi Kagaku Institute of Life Sciences (MITILS), 11 Minamiooya, Machida, Tokyo 194-8511 (Japan); Kondo, Shin; Kato, Ryohei [Innovation Center Yokohama, Mitsubishi Chemical Corporation, 1000 Kamoshida, Aoba, Yokohama, Kanagawa 227-8502 (Japan); Wanibuchi, Kiyofumi; Noguchi, Hiroshi [School of Pharmaceutical Sciences, University of Shizuoka and the COE21 Program, Shizuoka 422-8526 (Japan); Sugio, Shigetoshi [Innovation Center Yokohama, Mitsubishi Chemical Corporation, 1000 Kamoshida, Aoba, Yokohama, Kanagawa 227-8502 (Japan); Abe, Ikuro [School of Pharmaceutical Sciences, University of Shizuoka and the COE21 Program, Shizuoka 422-8526 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kohno, Toshiyuki [Mitsubishi Kagaku Institute of Life Sciences (MITILS), 11 Minamiooya, Machida, Tokyo 194-8511 (Japan)

    2007-07-01

    An acridone-producing novel type III polyketide synthase from H. serrata has been overexpressed in E. coli, purified and crystallized. Diffraction data have been collected to 2.0 Å. Polyketide synthase 1 (PKS1) from Huperzia serrata is a plant-specific type III polyketide synthase that shows an unusually versatile catalytic potential, producing various aromatic tetraketides, including chalcones, benzophenones, phlorogulucinols and acridones. Recombinant H. serrata PKS1 expressed in Escherichia coli was crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group I222 or I2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 73.3, b = 85.0, c = 137.7 Å, α = β = γ = 90.0°. Diffraction data were collected to 2.0 Å resolution using synchrotron radiation at BL24XU of SPring-8.

  8. Design of modular coils for a quasi-axisymmetric stellarator with a flexible control of the magnetic field configuration

    International Nuclear Information System (INIS)

    Shimizu, A.; Okamura, S.; Isobe, M.; Suzuki, C.; Nishimura, S.; Watari, T.; Matsuoka, K.

    2002-08-01

    A design of the modular coil system for CHS-qa has been made for the plasma configuration '2b32' with the aspect ratio 3.2. The magnetic field strength and the major radius are 1.5 T and 1.5 m, respectively. The normal component of magnetic field produced by the modular coils is minimized on the plasma boundary to obtain the optimum coil design. We put engineering constraint on the distance between adjacent modular coils and the radius of coil curvature. The dependence of the residual normal component of the field on these conditions is examined, and the realistic values for them are selected. Additional coils to control various properties of the magnetic field configuration (the rotational transform, the magnetic well depth, etc.) have been designed and a flexibility of the magnetic field configuration is realized. For the case that the rotational transform crosses the low-order rational value resulting in magnetic islands, the residues of islands are evaluated with which a further improvement of coil design can be made to eliminate magnetic islands. (author)

  9. Nine New and Five Known Polyketides Derived from a Deep Sea-Sourced Aspergillus sp. 16-02-1

    Directory of Open Access Journals (Sweden)

    Xiu-Wen Chen

    2014-05-01

    Full Text Available Nine new C9 polyketides, named aspiketolactonol (1, aspilactonols A–F (2–7, aspyronol (9 and epiaspinonediol (11, were isolated together with five known polyketides, (S-2-(2′-hydroxyethyl-4-methyl-γ-butyrolactone (8, dihydroaspyrone (10, aspinotriol A (12, aspinotriol B (13 and chaetoquadrin F (14, from the secondary metabolites of an Aspergillus sp. 16-02-1 that was isolated from a deep-sea sediment sample. Structures of the new compounds, including their absolute configurations, were determined by spectroscopic methods, especially the 2D NMR, circular dichroism (CD, Mo2-induced CD and Mosher’s 1H NMR analyses. Compound 8 was isolated from natural sources for the first time, and the possible biosynthetic pathways for 1–14 were also proposed and discussed. Compounds 1–14 inhibited human cancer cell lines, K562, HL-60, HeLa and BGC-823, to varying extents.

  10. Biologically active polyketides produced by Penicillium janthinellum isolated as an endophytic fungus from fruits of Melia azedarach

    International Nuclear Information System (INIS)

    Marinho, Andrey M. do Rosario; Rodrigues-Filho, Edson; Moitinho, Maria da Luz R.; Santos, Lourivaldo S.

    2005-01-01

    Penicillium janthinellum, isolated as an endophytic fungus from fruits of Melia azedarach, was cultivated over 20 days on ground and autoclaved white corn, where the known polyketides citrinin, emodin, 1,6,8-trihydroxy-3-hydroxymethylanthraquinone, and a new modified anthraquinone, named janthinone, were produced and isolated by classical chromatographic procedures and identified by MS and 1D and 2D NMR spectroscopic data. The antibacterial properties of these polyketides were investigated. Citrinin inhibited 100% of Leishmania growth after 48h at a concentration of 40 μg mL -1 . (author)

  11. Biologically active polyketides produced by Penicillium janthinellum isolated as an endophytic fungus from fruits of Melia azedarach

    Energy Technology Data Exchange (ETDEWEB)

    Marinho, Andrey M. do Rosario; Rodrigues-Filho, Edson [Sao Carlos Univ., SP (Brazil). Dept. de Quimica; Moitinho, Maria da Luz R. [Universidade Estadual de Maringa, PR (Brazil). Dept. de Analises Clinicas; Santos, Lourivaldo S. [Para Univ., Belem, PA (Brazil). Dept. de Quimica]. E-mail: edson@dq.ufscar.br

    2005-04-01

    Penicillium janthinellum, isolated as an endophytic fungus from fruits of Melia azedarach, was cultivated over 20 days on ground and autoclaved white corn, where the known polyketides citrinin, emodin, 1,6,8-trihydroxy-3-hydroxymethylanthraquinone, and a new modified anthraquinone, named janthinone, were produced and isolated by classical chromatographic procedures and identified by MS and 1D and 2D NMR spectroscopic data. The antibacterial properties of these polyketides were investigated. Citrinin inhibited 100% of Leishmania growth after 48h at a concentration of 40 {mu}g mL{sup -1}. (author)

  12. A Modularized Counselor-Education Program.

    Science.gov (United States)

    Miller, Thomas V.; Dimattia, Dominic J.

    1978-01-01

    Counselor-education programs may be enriched through the use of modularized learning experiences. This article notes several recent articles on competency-based counselor education, the concepts of simulation and modularization, and describes the process of developing a modularized master's program at the University of Bridgeport in Connecticut.…

  13. Polyketides isolated from Penicillium herquei; Policetideos isolados de Penicillium herquei

    Energy Technology Data Exchange (ETDEWEB)

    Marinho, Andrey Moacir do Rosario; Marinho, Patricia Santana Barbosa, E-mail: andrey@ufpa.br [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Faculdade de Quimica; Rodrigues Filho, Edson [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica; Ferreira, Izabel Cristina Piloto [Universidade Estadual de Maringa (UEM), PR (Brazil). Departamento de Analises Clinicas

    2011-07-01

    In this work we are reporting the isolation of polyketides citreoserine (1), emodin (2), janthinone (3), dihydrocitrinone (4) and citrinin H-1 (5). The compounds were isolated by chromatographic procedures and identified by spectral methods of NMR 1D and 2D and MS. The compounds 1, 2 and 3 were tested against promastigotes of Leishmania brasiliensis. (author)

  14. Metric modular spaces

    CERN Document Server

    Chistyakov, Vyacheslav

    2015-01-01

    Aimed toward researchers and graduate students familiar with elements of functional analysis, linear algebra, and general topology; this book contains a general study of modulars, modular spaces, and metric modular spaces. Modulars may be thought of as generalized velocity fields and serve two important purposes: generate metric spaces in a unified manner and provide a weaker convergence, the modular convergence, whose topology is non-metrizable in general. Metric modular spaces are extensions of metric spaces, metric linear spaces, and classical modular linear spaces. The topics covered include the classification of modulars, metrizability of modular spaces, modular transforms and duality between modular spaces, metric  and modular topologies. Applications illustrated in this book include: the description of superposition operators acting in modular spaces, the existence of regular selections of set-valued mappings, new interpretations of spaces of Lipschitzian and absolutely continuous mappings, the existe...

  15. Mapping of polyketide biosynthesis pathways in Aspergillus nidulans using a genome wide PKS gene deletion library

    DEFF Research Database (Denmark)

    Larsen, Thomas Ostenfeld; Rank, Christian; Klejnstrup, Marie Louise

    In order to map new links between PKS genes and their products in Aspergillus nidulans we have systematically deleted all thirty-two individual genes predicted to encode polyketide synthases in this model organism. This number greatly exceeds the number of currently known PKs calling for new appr...

  16. Uncovering the formation and selection of benzylmalonyl-CoA from the biosynthesis of splenocin and enterocin reveals a versatile way to introduce amino acids into polyketide carbon scaffolds.

    Science.gov (United States)

    Chang, Chenchen; Huang, Rong; Yan, Yan; Ma, Hongmin; Dai, Zheng; Zhang, Benying; Deng, Zixin; Liu, Wen; Qu, Xudong

    2015-04-01

    Selective modification of carbon scaffolds via biosynthetic engineering is important for polyketide structural diversification. Yet, this scope is currently restricted to simple aliphatic groups due to (1) limited variety of CoA-linked extender units, which lack aromatic structures and chemical reactivity, and (2) narrow acyltransferase (AT) specificity, which is limited to aliphatic CoA-linked extender units. In this report, we uncovered and characterized the first aromatic CoA-linked extender unit benzylmalonyl-CoA from the biosynthetic pathways of splenocin and enterocin in Streptomyces sp. CNQ431. Its synthesis employs a deamination/reductive carboxylation strategy to convert phenylalanine into benzylmalonyl-CoA, providing a link between amino acid and CoA-linked extender unit synthesis. By characterization of its selection, we further validated that AT domains of splenocin, and antimycin polyketide synthases are able to select this extender unit to introduce the phenyl group into their dilactone scaffolds. The biosynthetic machinery involved in the formation of this extender unit is highly versatile and can be potentially tailored for tyrosine, histidine and aspartic acid. The disclosed aromatic extender unit, amino acid-oriented synthetic pathway, and aromatic-selective AT domains provides a systematic breakthrough toward current knowledge of polyketide extender unit formation and selection, and also opens a route for further engineering of polyketide carbon scaffolds using amino acids.

  17. Crystallization and preliminary X-ray diffraction studies of polyketide synthase-1 (PKS-1) from Cannabis sativa

    International Nuclear Information System (INIS)

    Taguchi, Chiho; Taura, Futoshi; Tamada, Taro; Shoyama, Yoshinari; Shoyama, Yukihiro; Tanaka, Hiroyuki; Kuroki, Ryota; Morimoto, Satoshi

    2008-01-01

    Polyketide synthase-1 from C. sativa has been crystallized. The crystal diffracted to 1.55 Å resolution with sufficient quality for further structure determination. Polyketide synthase-1 (PKS-1) is a novel type III polyketide synthase that catalyzes the biosynthesis of hexanoyl triacetic acid lactone in Cannabis sativa (Mexican strain). PKS-1 was overproduced in Escherichia coli, purified and finally crystallized in two different space groups. The crystal obtained in 0.1 M HEPES buffer pH 7.5 containing 0.2 M calcium acetate and 20%(w/v) polyethylene glycol 3350 diffracted to 1.65 Å resolution and belonged to space group P1, with unit-cell parameters a = 54.3, b = 59.3, c = 62.6 Å, α = 69, β = 81, γ = 80°. Another crystal obtained in 0.1 M HEPES buffer pH 7.5 containing 0.2 M sodium chloride and 20%(w/v) polyethylene glycol 3350 diffracted to 1.55 Å resolution and belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 54.3, b = 110, c = 130 Å. These data will enable us to determine the crystal structure of PKS-1

  18. Crystallization and preliminary X-ray diffraction studies of polyketide synthase-1 (PKS-1) from Cannabis sativa

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, Chiho [Faculty of Pharmaceutical Sciences, Kyushu University (Japan); Quantum Beam Science Directorate, Japan Atomic Energy Agency (Japan); Taura, Futoshi [Faculty of Pharmaceutical Sciences, Kyushu University (Japan); Tamada, Taro; Shoyama, Yoshinari [Quantum Beam Science Directorate, Japan Atomic Energy Agency (Japan); Shoyama, Yukihiro; Tanaka, Hiroyuki [Faculty of Pharmaceutical Sciences, Kyushu University (Japan); Kuroki, Ryota [Quantum Beam Science Directorate, Japan Atomic Energy Agency (Japan); Morimoto, Satoshi [Faculty of Pharmaceutical Sciences, Kyushu University (Japan)

    2008-03-01

    Polyketide synthase-1 from C. sativa has been crystallized. The crystal diffracted to 1.55 Å resolution with sufficient quality for further structure determination. Polyketide synthase-1 (PKS-1) is a novel type III polyketide synthase that catalyzes the biosynthesis of hexanoyl triacetic acid lactone in Cannabis sativa (Mexican strain). PKS-1 was overproduced in Escherichia coli, purified and finally crystallized in two different space groups. The crystal obtained in 0.1 M HEPES buffer pH 7.5 containing 0.2 M calcium acetate and 20%(w/v) polyethylene glycol 3350 diffracted to 1.65 Å resolution and belonged to space group P1, with unit-cell parameters a = 54.3, b = 59.3, c = 62.6 Å, α = 69, β = 81, γ = 80°. Another crystal obtained in 0.1 M HEPES buffer pH 7.5 containing 0.2 M sodium chloride and 20%(w/v) polyethylene glycol 3350 diffracted to 1.55 Å resolution and belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 54.3, b = 110, c = 130 Å. These data will enable us to determine the crystal structure of PKS-1.

  19. Implementing Modular A Levels.

    Science.gov (United States)

    Holding, Gordon

    This document, which is designed for curriculum managers at British further education (FE) colleges, presents basic information on the implementation and perceived benefits of the General Certificate of Education (GCE) modular A (Advanced) levels. The information was synthesized from a survey of 12 FE colleges that introduced the modular A levels…

  20. Identification and regulation of fusA, the polyketide synthase gene responsible for fusarin production in Fusarium fujikuroi.

    Science.gov (United States)

    Díaz-Sánchez, Violeta; Avalos, Javier; Limón, M Carmen

    2012-10-01

    Fusarins are a class of mycotoxins of the polyketide family produced by different Fusarium species, including the gibberellin-producing fungus Fusarium fujikuroi. Based on sequence comparisons between polyketide synthase (PKS) enzymes for fusarin production in other Fusarium strains, we have identified the F. fujikuroi orthologue, called fusA. The participation of fusA in fusarin biosynthesis was demonstrated by targeted mutagenesis. Fusarin production is transiently stimulated by nitrogen availability in this fungus, a regulation paralleled by the fusA mRNA levels in the cell. Illumination of the cultures results in a reduction of the fusarin content, an effect partially explained by a high sensitivity of these compounds to light. Mutants of the fusA gene exhibit no external phenotypic alterations, including morphology and conidiation, except for a lack of the characteristic yellow and/or orange pigmentation of fusarins. Moreover, the fusA mutants are less efficient than the wild type at degrading cellophane on agar cultures, a trait associated with pathogenesis functions in Fusarium oxysporum. The fusA mutants, however, are not affected in their capacities to grow on plant tissues.

  1. Constructing a small modular stellarator in Latin America

    International Nuclear Information System (INIS)

    Vargas, V I; Mora, J; Asenjo, J; Zamora, E; Otárola, C; Barillas, L; Carvajal-Godínez, J; González-Gómez, J; Soto-Soto, C; Piedras, C

    2015-01-01

    This paper aims at briefly describing the design and construction issues of the stellarator of Costa Rica 1 (SCR-1). The SCR-1 is a small modular stellarator for magnetic confinement of plasma developed by the Plasma Laboratory for Fusion Energy and Applications of the Instituto Tecnológico de Costa Rica (ITCR). SCR-1 will be a 2-field period small modular stellarator with an aspect ratio > 4.4; low shear configuration with core and edge rotational transform equal to 0.32 and 0.28; it will hold plasma in a 6061-T6 aluminum torus shaped vacuum vessel with an minor plasma radius 54.11 mm, a volume of 13.76 liters (0.01 m3), and major radius R = 238 mm. Plasma will be confined in the volume by on axis magnetic field 43.8 mT generated by 12 modular coils with 6 turns each, carrying a current of 767.8 A per turn providing a total toroidal field (TF) current of 4.6 kA-turn per coil. The coils will be supplied by a bank of cell batteries of 120 V. Typical length of the plasma pulse will be between 4 s to 10 s. The SCR-1 plasmas will be heated by ECH second harmonic at 2.45 GHz with a plasma density cut-off value of 7.45 × 10 16 m -3 . Two magnetrons with a maximum output power of 2 kW and 3 kW will be used. (paper)

  2. Synergistic Cytotoxicity Effect by Combination Treatment of Polyketide Derivatives from Annona muricata Linn Leaves and Doxorubicin as Potential Anticancer Material on Raji Cell Line

    Science.gov (United States)

    Artanti, A. N.; Astirin, O. P.; Prayito, A.; Fisma, R.; Prihapsara, F.

    2018-03-01

    Nasopharynx cancer is one of the most deadly cancer. The main priority of nasopharynx cancer treatment is the use of chemotherapeutic agents, especially doxorubicin. However, doxorubicin might also lead to diverse side effect. An approach recently develop to overcome side effect of doxorubicin is to used of combined chemotherapeutic agent. One of the compounds found effication as an anticancer agent on nasopharynx cancer is acetogenin, a polyketide compound that is abundant in Annona muricata L. leaves. This study has been done to examine polyketide derivatives was isolated from Annona muricata L. which has potency to induce apoptosis by p53 expression on raji cell line. The determination of cytotoxic combination activity from polyketide derivative and doxorubicin was evaluated using MTT assay to obtain the value of CI (combination index). Data analysis showed that combination of polyketide derivative from Annona muricata L. (14,4 µg/ml) and doxorubicin with all of concentration performed synergistic effect on raji cell line with CI value from 0.13 – 0.65.

  3. On sub-modularization and morphological heterogeneity in modular robotics

    DEFF Research Database (Denmark)

    Lyder, A. H.; Stoy, K.; Garciá, R. F. M.

    2012-01-01

    Modular robots are a kind of robots built from mechatronic modules, which can be assembled in many different ways allowing the modular robot to assume a wide range of morphologies and functions. An important question in modular robotics is to which degree modules should be heterogeneous....... In this paper we introduce two contributing factors to heterogeneity namely morphological heterogeneity and sub-functional modularization. Respectively, the ideas are to create modules with significantly different morphologies and to spread sub-functionality across modules. Based on these principles we design...... and implement the Thor robot and evaluate it by participating in the ICRA Planetary Robotic Contingency Challenge. The Thor robot demonstrates that sub-functional modularity and morphological heterogeneity may increase the versatility of modular robots while reducing the complexity of individual modules, which...

  4. Plant polyketide synthases: a chalcone synthase-type enzyme which performs a condensation reaction with methylmalonyl-CoA in the biosynthesis of C-methylated chalcones.

    Science.gov (United States)

    Schröder, J; Raiber, S; Berger, T; Schmidt, A; Schmidt, J; Soares-Sello, A M; Bardshiri, E; Strack, D; Simpson, T J; Veit, M; Schröder, G

    1998-06-09

    Heterologous screening of a cDNA library from Pinusstrobus seedlings identified clones for two chalcone synthase (CHS) related proteins (PStrCHS1 and PStrCHS2, 87.6% identity). Heterologous expression in Escherichia coli showed that PStrCHS1 performed the typical CHS reaction, that it used starter CoA-esters from the phenylpropanoid pathway, and that it performed three condensation reactions with malonyl-CoA, followed by the ring closure to the chalcone. PstrCHS2 was completely inactive with these starters and also with linear CoA-esters. Activity was detected only with a diketide derivative (N-acetylcysteamine thioester of 3-oxo-5-phenylpent-4-enoic acid) that corresponded to the CHS reaction intermediate postulated after the first condensation reaction. PstrCHS2 performed only one condensation, with 6-styryl-4-hydroxy-2-pyrone derivatives as release products. The enzyme preferred methylmalonyl-CoA against malonyl-CoA, if only methylmalonyl-CoA was available. These properties and a comparison with the CHS from Pinus sylvestris suggested for PstrCHS2 a special function in the biosynthesis of secondary products. In contrast to P. sylvestris, P. strobus contains C-methylated chalcone derivatives, and the methyl group is at the position predicted from a chain extension with methylmalonyl-CoA in the second condensation of the biosynthetic reaction sequence. We propose that PstrCHS2 specifically contributes the condensing reaction with methylmalonyl-CoA to yield a methylated triketide intermediate. We discuss a model that the biosynthesis of C-methylated chalcones represents the simplest example of a modular polyketide synthase.

  5. Service Modularity

    DEFF Research Database (Denmark)

    Avlonitis, Viktor; Hsuan, Juliana

    2015-01-01

    The purpose of this research is to investigate the studies on service modularity with a goal of informing service science and advancing contemporary service systems research. Modularity, a general systems property, can add theoretical underpinnings to the conceptual development of service science...... in general and service systems in particular. Our research is guided by the following question: how can modularity theory inform service system design? We present a review of the modularity literature and associated concepts. We then introduce the contemporary service science and service system discourse...

  6. Heterologous gene expression and functional analysis of a type III polyketide synthase from Aspergillus niger NRRL 328

    Energy Technology Data Exchange (ETDEWEB)

    Kirimura, Kohtaro, E-mail: kkohtaro@waseda.jp; Watanabe, Shotaro; Kobayashi, Keiichi

    2016-05-13

    Type III polyketide synthases (PKSs) catalyze the formation of pyrone- and resorcinol-types aromatic polyketides. The genomic analysis of the filamentous fungus Aspergillus niger NRRL 328 revealed that this strain has a putative gene (chr-8-2: 2978617–2979847) encoding a type III PKS, although its functions are unknown. In this study, for functional analysis of this putative type III PKS designated as An-CsyA, cloning and heterologous expression of the An-CsyA gene (An-csyA) in Escherichia coli were performed. Recombinant His-tagged An-CsyA was successfully expressed in E. coli BL21 (DE3), purified by Ni{sup 2+}-affinity chromatography, and used for in vitro assay. Tests on the substrate specificity of the His-tagged An-CsyA with myriad acyl-CoAs as starter substrates and malonyl-CoA as extender substrate showed that His-tagged An-CsyA accepted fatty acyl-CoAs (C2-C14) and produced triketide pyrones (C2-C14), tetraketide pyrones (C2-C10), and pentaketide resorcinols (C10-C14). Furthermore, acetoacetyl-CoA, malonyl-CoA, isobutyryl-CoA, and benzoyl-CoA were also accepted as starter substrates, and both of triketide pyrones and tetraketide pyrones were produced. It is noteworthy that the His-tagged An-CsyA produced polyketides from malonyl-CoA as starter and extender substrates and produced tetraketide pyrones from short-chain fatty acyl-CoAs as starter substrates. Therefore, this is the first report showing the functional properties of An-CsyA different from those of other fungal type III PKSs. -- Highlights: •Type III PKS from Aspergillus niger NRRL 328, An-CsyA, was cloned and characterized. •An-CsyA produced triketide pyrones, tetraketide pyrones and pentaketide resorcinols. •Functional properties of An-CsyA differs from those of other fungal type III PKSs.

  7. Heterologous gene expression and functional analysis of a type III polyketide synthase from Aspergillus niger NRRL 328

    International Nuclear Information System (INIS)

    Kirimura, Kohtaro; Watanabe, Shotaro; Kobayashi, Keiichi

    2016-01-01

    Type III polyketide synthases (PKSs) catalyze the formation of pyrone- and resorcinol-types aromatic polyketides. The genomic analysis of the filamentous fungus Aspergillus niger NRRL 328 revealed that this strain has a putative gene (chr-8-2: 2978617–2979847) encoding a type III PKS, although its functions are unknown. In this study, for functional analysis of this putative type III PKS designated as An-CsyA, cloning and heterologous expression of the An-CsyA gene (An-csyA) in Escherichia coli were performed. Recombinant His-tagged An-CsyA was successfully expressed in E. coli BL21 (DE3), purified by Ni"2"+-affinity chromatography, and used for in vitro assay. Tests on the substrate specificity of the His-tagged An-CsyA with myriad acyl-CoAs as starter substrates and malonyl-CoA as extender substrate showed that His-tagged An-CsyA accepted fatty acyl-CoAs (C2-C14) and produced triketide pyrones (C2-C14), tetraketide pyrones (C2-C10), and pentaketide resorcinols (C10-C14). Furthermore, acetoacetyl-CoA, malonyl-CoA, isobutyryl-CoA, and benzoyl-CoA were also accepted as starter substrates, and both of triketide pyrones and tetraketide pyrones were produced. It is noteworthy that the His-tagged An-CsyA produced polyketides from malonyl-CoA as starter and extender substrates and produced tetraketide pyrones from short-chain fatty acyl-CoAs as starter substrates. Therefore, this is the first report showing the functional properties of An-CsyA different from those of other fungal type III PKSs. -- Highlights: •Type III PKS from Aspergillus niger NRRL 328, An-CsyA, was cloned and characterized. •An-CsyA produced triketide pyrones, tetraketide pyrones and pentaketide resorcinols. •Functional properties of An-CsyA differs from those of other fungal type III PKSs.

  8. Modular forms a classical approach

    CERN Document Server

    Cohen, Henri

    2017-01-01

    The theory of modular forms is a fundamental tool used in many areas of mathematics and physics. It is also a very concrete and "fun" subject in itself and abounds with an amazing number of surprising identities. This comprehensive textbook, which includes numerous exercises, aims to give a complete picture of the classical aspects of the subject, with an emphasis on explicit formulas. After a number of motivating examples such as elliptic functions and theta functions, the modular group, its subgroups, and general aspects of holomorphic and nonholomorphic modular forms are explained, with an emphasis on explicit examples. The heart of the book is the classical theory developed by Hecke and continued up to the Atkin-Lehner-Li theory of newforms and including the theory of Eisenstein series, Rankin-Selberg theory, and a more general theory of theta series including the Weil representation. The final chapter explores in some detail more general types of modular forms such as half-integral weight, Hilbert, Jacob...

  9. A Polyketide Synthase Encoded by the Gene An15g07920 Is Involved in the Biosynthesis of Ochratoxin A in Aspergillus niger.

    Science.gov (United States)

    Zhang, Jian; Zhu, Liuyang; Chen, Haoyu; Li, Min; Zhu, Xiaojuan; Gao, Qiang; Wang, Depei; Zhang, Ying

    2016-12-28

    The polyketide synthase gene An15g07920 was known in Aspergillus niger CBS 513.88 as putatively involved in the production of ochratoxin A (OTA). Genome resequencing analysis revealed that the gene An15g07920 is also present in the ochratoxin-producing A. niger strain 1062. Disruption of An15g07920 in A. niger 1062 removed its capacity to biosynthesize ochratoxin β (OTβ), ochratoxin α (OTα), and OTA. These results indicate that the polyketide synthase encoded by An15g07920 is a crucial player in the biosynthesis of OTA, in the pathway prior to the phenylalanine ligation step. The gene An15g07920 reached its maximum transcription level before OTA accumulation reached its highest level, confirming that gene transcription precedes OTA production. These findings will not only help explain the mechanism of OTA production in A. niger but also provide necessary information for the development of effective diagnostic, preventive, and control strategies to reduce the risk of OTA contamination in foods.

  10. Reconstruction of the biosynthetic pathway for the core fungal polyketide scaffold rubrofusarin in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Rugbjerg, Peter; Naesby, Michael; Mortensen, Uffe Hasbro

    2013-01-01

    production in easily fermentable and genetically engineerable organisms, such as Saccharomyces cerevisiae and Escherichia coli are desirable. Rubrofusarin is an orange polyketide pigment that is a common intermediate in many different fungal biosynthetic pathways. RESULTS: In this study, we established...

  11. Modular cryogenic interconnects for multi-qubit devices

    Energy Technology Data Exchange (ETDEWEB)

    Colless, J. I.; Reilly, D. J., E-mail: david.reilly@sydney.edu.au [ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia)

    2014-11-15

    We have developed a modular interconnect platform for the control and readout of multiple solid-state qubits at cryogenic temperatures. The setup provides 74 filtered dc-bias connections, 32 control and readout connections with −3 dB frequency above 5 GHz, and 4 microwave feed lines that allow low loss (less than 3 dB) transmission 10 GHz. The incorporation of a radio-frequency interposer enables the platform to be separated into two printed circuit boards, decoupling the simple board that is bonded to the qubit chip from the multilayer board that incorporates expensive connectors and components. This modular approach lifts the burden of duplicating complex interconnect circuits for every prototype device. We report the performance of this platform at milli-Kelvin temperatures, including signal transmission and crosstalk measurements.

  12. Habitat-specific type I polyketide synthases in soils and street sediments

    Czech Academy of Sciences Publication Activity Database

    Hill, P.; Piel, J.; Aris-Brosou, S.; Krištůfek, Václav; Boddy, Ch.N.; Dijkhuizen, L.

    2014-01-01

    Roč. 41, č. 1 (2014), s. 75-85 ISSN 1367-5435 R&D Projects: GA MŠk LC06066; GA MŠk 2B06154 Grant - others:NATO(NL) ESP.EAP.CLG 981785 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : natural product discovery * polyketides * urban microbiology * bioprospecting * mycobactin Subject RIV: EE - Microbiology, Virology Impact factor: 2.439, year: 2014

  13. Marine myxobacteria as a source of antibiotics--comparison of physiology, polyketide-type genes and antibiotic production of three new isolates of Enhygromyxa salina.

    Science.gov (United States)

    Schäberle, Till F; Goralski, Emilie; Neu, Edith; Erol, Ozlem; Hölzl, Georg; Dörmann, Peter; Bierbaum, Gabriele; König, Gabriele M

    2010-09-03

    Three myxobacterial strains, designated SWB004, SWB005 and SWB006, were obtained from beach sand samples from the Pacific Ocean and the North Sea. The strains were cultivated in salt water containing media and subjected to studies to determine their taxonomic status, the presence of genes for the biosynthesis of polyketides and antibiotic production. 16S rDNA sequence analysis revealed the type strain Enhygromyxa salina SHK-1(T) as their closest homolog, displaying between 98% (SWB005) and 99% (SWB004 and SWB006) sequence similarity. All isolates were rod-shaped cells showing gliding motility and fruiting body formation as is known for myxobacteria. They required NaCl for growth, with an optimum concentration of around 2% [w/v]. The G + C-content of genomic DNA ranged from 63.0 to 67.3 mol%. Further, the strains were analyzed for their potential to produce polyketide-type structures. PCR amplified ketosynthase-like gene fragments from all three isolates enhances the assumption that these bacteria produce polyketides. SWB005 was shown to produce metabolites with prominent antibacterial activity, including activity towards methicillin resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE).

  14. Marine Myxobacteria as a Source of Antibiotics—Comparison of Physiology, Polyketide-Type Genes and Antibiotic Production of Three New Isolates of Enhygromyxa salina

    Directory of Open Access Journals (Sweden)

    Gabriele Bierbaum

    2010-09-01

    Full Text Available Three myxobacterial strains, designated SWB004, SWB005 and SWB006, were obtained from beach sand samples from the Pacific Ocean and the North Sea. The strains were cultivated in salt water containing media and subjected to studies to determine their taxonomic status, the presence of genes for the biosynthesis of polyketides and antibiotic production. 16S rDNA sequence analysis revealed the type strain Enhygromyxa salina SHK-1T as their closest homolog, displaying between 98% (SWB005 and 99% (SWB004 and SWB006 sequence similarity. All isolates were rod-shaped cells showing gliding motility and fruiting body formation as is known for myxobacteria. They required NaCl for growth, with an optimum concentration of around 2% [w/v]. The G + C-content of genomic DNA ranged from 63.0 to 67.3 mol%. Further, the strains were analyzed for their potential to produce polyketide-type structures. PCR amplified ketosynthase-like gene fragments from all three isolates enhances the assumption that these bacteria produce polyketides. SWB005 was shown to produce metabolites with prominent antibacterial activity, including activity towards methicillin resistant Staphylococcus aureus (MRSA and Staphylococcus epidermidis (MRSE.

  15. Modularity and Economic Organization

    DEFF Research Database (Denmark)

    Sanchez, Ron; Mahoney, Joseph T.

    This paper addresses modularity as a basis for organizing economic activity. We first define the key concepts of architecture and of modularity as a special form of architecture. We then suggest how modular systems of all types may exhibit several properties of fundamental importance to the organ......This paper addresses modularity as a basis for organizing economic activity. We first define the key concepts of architecture and of modularity as a special form of architecture. We then suggest how modular systems of all types may exhibit several properties of fundamental importance...... to the organization of economic activities, including greater adaptability and evolvability than systems that lack modular properties. We draw extensively on our original 1996 paper on modularity and subsequent research to suggest broad theoretical implications of modularity for (i) firms' product strategies...... markets. We also discuss an evolutionary perspective on modularity as an emergent phenomenon in firms and industries. We explain how modularity as a relatively new field of strategy and economic research may provide a new theoretical perspective on economic organizing that has significant potential...

  16. Understanding Socio Technical Modularity

    DEFF Research Database (Denmark)

    Thuesen, Christian Langhoff; Kudsk, Anders; Hvam, Lars

    2011-01-01

    Modularity has gained an increasing popularity as a central concept for exploring product structure, process structure, organization structure and supply chain structure. With the offset in system theory the predominant understanding of modularity however faces difficulties in explaining the social...... dimension of modularity like irrational behaviors, cultural differences, learning processes, social organization and institutional influences on modularity. The paper addresses this gab offering a reinterpretation of the modularity concept from a socio-technical perspective in general and Actor Network...... Theory in particular. By formulating modularity from an ANT perspective covering social, material and process aspects, the modularity of a socio-technical system can be understood as an entanglement of product, process, organizational and institutional modularity. The theoretical framework is illustrated...

  17. A Formal Theory for Modular ERDF Ontologies

    Science.gov (United States)

    Analyti, Anastasia; Antoniou, Grigoris; Damásio, Carlos Viegas

    The success of the Semantic Web is impossible without any form of modularity, encapsulation, and access control. In an earlier paper, we extended RDF graphs with weak and strong negation, as well as derivation rules. The ERDF #n-stable model semantics of the extended RDF framework (ERDF) is defined, extending RDF(S) semantics. In this paper, we propose a framework for modular ERDF ontologies, called modular ERDF framework, which enables collaborative reasoning over a set of ERDF ontologies, while support for hidden knowledge is also provided. In particular, the modular ERDF stable model semantics of modular ERDF ontologies is defined, extending the ERDF #n-stable model semantics. Our proposed framework supports local semantics and different points of view, local closed-world and open-world assumptions, and scoped negation-as-failure. Several complexity results are provided.

  18. Polyketide synthases of Diaporthe helianthi and involvement of DhPKS1 in virulence on sunflower.

    Science.gov (United States)

    Ruocco, Michelina; Baroncelli, Riccardo; Cacciola, Santa Olga; Pane, Catello; Monti, Maurilia Maria; Firrao, Giuseppe; Vergara, Mariarosaria; Magnano di San Lio, Gaetano; Vannacci, Giovanni; Scala, Felice

    2018-01-06

    The early phases of Diaporthe helianthi pathogenesis on sunflower are characterized by the production of phytotoxins that may play a role in host colonisation. In previous studies, phytotoxins of a polyketidic nature were isolated and purified from culture filtrates of virulent strains of D. helianthi isolated from sunflower. A highly aggressive isolate (7/96) from France contained a gene fragment of a putative nonaketide synthase (lovB) which was conserved in a virulent D. helianthi population. In order to investigate the role of polyketide synthases in D. helianthi 7/96, a draft genome of this isolate was examined. We were able to find and phylogenetically analyse 40 genes putatively coding for polyketide synthases (PKSs). Analysis of their domains revealed that most PKS genes of D. helianthi are reducing PKSs, whereas only eight lacked reducing domains. Most of the identified PKSs have orthologs shown to be virulence factors or genetic determinants for toxin production in other pathogenic fungi. One of the genes (DhPKS1) corresponded to the previously cloned D. helianthi lovB gene fragment and clustered with a nonribosomal peptide synthetase (NRPS) -PKS hybrid/lovastatin nonaketide like A. nidulans LovB. We used DhPKS1 as a case study and carried out its disruption through Agrobacterium-mediated transformation in the isolate 7/96. D. helianthi DhPKS1 deleted mutants were less virulent to sunflower compared to the wild type, indicating a role for this gene in the pathogenesis of the fungus. The PKS sequences analysed and reported here constitute a new genomic resource that will be useful for further research on the biology, ecology and evolution of D. helianthi and generally of fungal plant pathogens.

  19. A Modular SOS for Action Notation - Revisited

    DEFF Research Database (Denmark)

    Mosses, Peter David

    A draft modular SOS for the new version of AN, referred to as AN-2, has been available since 2000. It is written in CASL and has been checked for well-formedness using CATS (CASL Tool Set). It appears to be significantly more accessible than the original SOS of AN-1. However, it now appears......-notation for the modular SOS rules. After discussing the issues, we look at some illustrative examples taken from an improved modular SOS of AN-2 (in preparation). We also look at the possibility of empirical testing of the modular SOS by a straightforward translation to Prolog....

  20. Lectures on Hilbert modular varieties and modular forms

    CERN Document Server

    Goren, Eyal Z

    2001-01-01

    This book is devoted to certain aspects of the theory of p-adic Hilbert modular forms and moduli spaces of abelian varieties with real multiplication. The theory of p-adic modular forms is presented first in the elliptic case, introducing the reader to key ideas of N. M. Katz and J.-P. Serre. It is re-interpreted from a geometric point of view, which is developed to present the rudiments of a similar theory for Hilbert modular forms. The theory of moduli spaces of abelian varieties with real multiplication is presented first very explicitly over the complex numbers. Aspects of the general theory are then exposed, in particular, local deformation theory of abelian varieties in positive characteristic. The arithmetic of p-adic Hilbert modular forms and the geometry of moduli spaces of abelian varieties are related. This relation is used to study q-expansions of Hilbert modular forms, on the one hand, and stratifications of moduli spaces on the other hand. The book is addressed to graduate students and non-exper...

  1. A Comprehensive View On Benefits From Product Modularization

    DEFF Research Database (Denmark)

    Hansen, Poul H. Kyvsgård; Sun, Hongyi

    2010-01-01

    In many cases the phenomenon of product modularization is presented in an inherently positive way. Based on the frequency of these positive cases it might be expected that product modularization is a universal cure for any competitive weaknesses experienced by manufacturing or service companies....... Definitely, the many various aspects of product modularization have demonstrated substantial potentials regarding improved and enhanced competitiveness, but our empirical studies illustrate that the efforts in regards to realizing specific product modularization benefits need to be managed carefully. Our...... studies illustrates that the expected and the realized benefits from a product modularization effort rarely match. In most cases the companies have only weak estimations about both the type and the magnitude of the potential benefits when planning the modularization project. This indicates a serious need...

  2. Towards a Standard for Modular Petri Nets

    DEFF Research Database (Denmark)

    Kindler, Ekkart; Petrucci, Laure

    2009-01-01

    concepts could or should be subject to import and export in high-level Petri nets. In this paper, we formalise a minimal version of modular high-level Petri nets, which is based on the concepts of modular PNML. This shows that modular PNML can be formalised once a specific version of Petri net is fixed....... Moreover, we present and discuss some more advanced features of modular Petri nets that could be included in the standard. This way, we provide a formal foundation and a basis for a discussion of features to be included in the upcoming standard of a module concept for Petri nets in general and for high-level...

  3. Model engineering in a modular PSA

    International Nuclear Information System (INIS)

    Friedlhuber, Thomas

    2014-01-01

    For the purpose of PSA (Probabilistic Safety Analysis) for complex industrial systems, often PSA models in the form of fault and event trees are developed to model the risk of unwanted situations (hazards). While the recent decades, PSA models have gained high acceptance and have been developed massively. This lead to an increase in model sizes and complexity. Today, PSA models are often difficult to understand and maintain. This manuscript presents the concept of a modular PSA. A modular PSA tries to cope with the increased complexity by the techniques of modularization and instantiation. Modularization targets to treat a model by smaller pieces (the 'modules') to regain control over models. Instantiation aims to configure a generic model to different contexts. Both try to reduce model complexity. A modular PSA proposes new functionality to manage PSA models. Current model management is rather limited and not efficient. This manuscript shows new methods to manage the evolutions (versions) and deviations (variants) of PSA models in a modular PSA. The concepts of version and variant management are presented in this thesis. In this context, a model comparison and fusion of PSA models is precised. Model comparison provides important feedback to model engineers and model fusion kind of combines the work from different model engineers (concurrent model engineering). Apart from model management, methods to understand the content of PSA models are presented. The methods focus to highlight the dependencies between modules rather than their contents. Dependencies are automatically derived from a model structure. They express relations between model objects (for example a fault tree may have dependencies to basic events). To visualize those dependencies (for example in form of a model cartography) can constitute a crucial aid to model engineers for understanding complex interrelations in PSA models. Within the scope of this thesis, a software named 'Andromeda' has been

  4. Analysis of the Sequences, Structures, and Functions of Product-Releasing Enzyme Domains in Fungal Polyketide Synthases

    Directory of Open Access Journals (Sweden)

    Lu Liu

    2017-09-01

    Full Text Available Product-releasing enzyme (PRE domains in fungal non-reducing polyketide synthases (NR-PKSs play a crucial role in catalysis and editing during polyketide biosynthesis, especially accelerating final biosynthetic reactions accompanied with product offloading. However, up to date, the systematic knowledge about PRE domains is deficient. In the present study, the relationships between sequences, structures, and functions of PRE domains were analyzed with 574 NR-PKSs of eight groups (I–VIII. It was found that the PRE domains in NR-PKSs could be mainly classified into three types, thioesterase (TE, reductase (R, and metallo-β-lactamase-type TE (MβL-TE. The widely distributed TE or TE-like domains were involved in NR-PKSs of groups I–IV, VI, and VIII. The R domains appeared in NR-PKSs of groups IV and VII, while the physically discrete MβL-TE domains were employed by most NR-PKSs of group V. The changes of catalytic sites and structural characteristics resulted in PRE functional differentiations. The phylogeny revealed that the evolution of TE domains was accompanied by complex functional divergence. The diverse sequence lengths of TE lid-loops affected substrate specificity with different chain lengths. The volume diversification of TE catalytic pockets contributed to catalytic mechanisms with functional differentiations. The above findings may help to understand the crucial catalysis of fungal aromatic polyketide biosyntheses and govern recombination of NR-PKSs to obtain unnatural target products.

  5. Product Architecture Modularity Strategies

    DEFF Research Database (Denmark)

    Mikkola, Juliana Hsuan

    2003-01-01

    The focus of this paper is to integrate various perspectives on product architecture modularity into a general framework, and also to propose a way to measure the degree of modularization embedded in product architectures. Various trade-offs between modular and integral product architectures...... and how components and interfaces influence the degree of modularization are considered. In order to gain a better understanding of product architecture modularity as a strategy, a theoretical framework and propositions are drawn from various academic literature sources. Based on the literature review......, the following key elements of product architecture are identified: components (standard and new-to-the-firm), interfaces (standardization and specification), degree of coupling, and substitutability. A mathematical function, termed modularization function, is introduced to measure the degree of modularization...

  6. Identification of potentially safe promising fungal cell factories for the production of polyketide natural food colorants using chemotaxonomic rationale

    Directory of Open Access Journals (Sweden)

    Frisvad Jens C

    2009-04-01

    Full Text Available Abstract Background Colorants derived from natural sources look set to overtake synthetic colorants in market value as manufacturers continue to meet the rising demand for clean label ingredients – particularly in food applications. Many ascomycetous fungi naturally synthesize and secrete pigments and thus provide readily available additional and/or alternative sources of natural colorants that are independent of agro-climatic conditions. With an appropriately selected fungus; using in particular chemotaxonomy as a guide, the fungal natural colorants could be produced in high yields by using the optimized cultivation technology. This approach could secure efficient production of pigments avoiding use of genetic manipulation. Results Polyketide pigment producing ascomycetous fungi were evaluated for their potential as production organisms based on a priori knowledge on species-specific pigment and potential mycotoxin production and BioSafety level (BSL classification. Based on taxonomic knowledge, we pre-selected ascomycetous fungi belonging to Penicillium subgenus Biverticillium that produced yellow, orange or red pigments while deselecting Penicillium marneffei; a well known human pathogen in addition to other mycotoxigenic fungi belonging to the same group. We identified 10 strains belonging to 4 species; viz. P. purpurogenum, P. aculeatum, P. funiculosum, and P. pinophilum as potential pigment producers that produced Monascus-like pigments but no known mycotoxins. The selection/deselection protocol was illustrated in the pigment extracts of P. aculeatum IBT 14259 and P. crateriforme IBT 5015 analysed by HPLC-DAD-MS. In addition, extracellular pigment producing ability of some of the potential pigment producers was evaluated in liquid media with a solid support and N-glutarylmonascorubramine was discovered in the partially purified pigment extract of P. purpurogenum IBT 11181 and IBT 3645. Conclusion The present work brought out that the use

  7. Modular implicits

    Directory of Open Access Journals (Sweden)

    Leo White

    2015-12-01

    Full Text Available We present modular implicits, an extension to the OCaml language for ad-hoc polymorphism inspired by Scala implicits and modular type classes. Modular implicits are based on type-directed implicit module parameters, and elaborate straightforwardly into OCaml's first-class functors. Basing the design on OCaml's modules leads to a system that naturally supports many features from other languages with systematic ad-hoc overloading, including inheritance, instance constraints, constructor classes and associated types.

  8. Towards a Formal Basis for Modular Safety Cases

    Science.gov (United States)

    Denney, Ewen; Pai, Ganesh

    2015-01-01

    Safety assurance using argument-based safety cases is an accepted best-practice in many safety-critical sectors. Goal Structuring Notation (GSN), which is widely used for presenting safety arguments graphically, provides a notion of modular arguments to support the goal of incremental certification. Despite the efforts at standardization, GSN remains an informal notation whereas the GSN standard contains appreciable ambiguity especially concerning modular extensions. This, in turn, presents challenges when developing tools and methods to intelligently manipulate modular GSN arguments. This paper develops the elements of a theory of modular safety cases, leveraging our previous work on formalizing GSN arguments. Using example argument structures we highlight some ambiguities arising through the existing guidance, present the intuition underlying the theory, clarify syntax, and address modular arguments, contracts, well-formedness and well-scopedness of modules. Based on this theory, we have a preliminary implementation of modular arguments in our toolset, AdvoCATE.

  9. Quick guide to polyketide synthase and nonribosomal synthetase genes in Fusarium

    DEFF Research Database (Denmark)

    Hansen, Jørgen T.; Sørensen, Jens L.; Giese, Henriette

    2012-01-01

    Fusarium species produce a plethora of bioactive polyketides and nonribosomal peptides that give rise to health problems in animals and may have drug development potential. Using the genome sequences for Fusarium graminearum, F. oxysporum, F. solani and F. verticillioides we developed a framework...... and NRPS genes in sequenced Fusarium species and their known products. With the rapid increase in the number of sequenced fungal genomes a systematic classification will greatly aid the scientific community in obtaining an overview of the number of different NRPS and PKS genes and their potential...

  10. Exploring Modularity in Services

    DEFF Research Database (Denmark)

    Avlonitis, Viktor; Hsuan, Juliana

    2017-01-01

    the effects of modularity and integrality on a range of different analytical levels in service architectures. Taking a holistic approach, the authors synthesize and empirically deploy a framework comprised of the three most prevalent themes in modularity and service design literature: Offering (service...... insights on the mirroring hypothesis of modularity theory to services. Originality/value The paper provides a conceptualization of service architectures drawing on service design, modularity, and market relationships. The study enriches service design literature with elements from modularity theory...

  11. Nonthmicin, a Polyether Polyketide Bearing a Halogen-Modified Tetronate with Neuroprotective and Antiinvasive Activity from Actinomadura sp.

    Science.gov (United States)

    Igarashi, Yasuhiro; Matsuoka, Noriaki; In, Yasuko; Kataura, Tetsushi; Tashiro, Etsu; Saiki, Ikuo; Sudoh, Yuri; Duangmal, Kannika; Thamchaipenet, Arinthip

    2017-03-17

    Nonthmicin (1), a new polyether polyketide bearing a chlorinated tetronic acid, was isolated from the culture extract of a soil-derived Actinomadura strain. The structure of 1 was elucidated by interpretation of NMR and MS spectroscopic data, and the absolute configuration of 1 was proposed on the basis of the crystal structure of its dechloro congener ecteinamycin (2) also isolated from the same strain. Tetronic acids modified by halogenation have never been reported from natural products. Compounds 1 and 2 were found to have neuroprotective activity and antimetastatic properties at submicromolar concentrations in addition to antibacterial activity.

  12. Complexity in Managing Modularization

    DEFF Research Database (Denmark)

    Hansen, Poul H. Kyvsgård; Sun, Hongyi

    2011-01-01

    In general, the phenomenon of managing modularization is not well known. The cause-effect relationships between modularization and realized benefits are complex and comprehensive. Though a number of research works have contributed to the study of the phenomenon of efficient and effective...... modularization management it is far from clarified. Recognizing the need for further empirical research, we have studied 40 modularity cases in various companies. The studies have been designed as long-term studies leaving time for various types of modularization benefits to emerge. Based on these studies we...... have developed a framework to support the heuristic and iterative process of planning and realizing modularization benefits....

  13. Tanzawaic acids I–L: Four new polyketides from Penicillium sp. IBWF104-06

    Directory of Open Access Journals (Sweden)

    Louis P. Sandjo

    2014-01-01

    Full Text Available Four new polyketides have been identified in culture filtrates of the fungal strain Penicillium sp. IBWF104-06 isolated from a soil sample. They are structurally based on the same trans-decalinpentanoic acid skeleton as tanzawaic acids A–H. One of the new compounds was found to inhibit the conidial germination in the rice blast fungus Magnaporthe oryzae at concentrations of 25 μg/mL.

  14. Characterization of a polyketide synthase in Aspergillus niger whose product is a precursor for both dihydroxynaphthalene (DHN) melanin and naphtho-γ-pyrone.

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yi Ming; Meyer, Kristen M; Praseuth, Michael; Baker, Scott E; Bruno, Kenneth S; Wang, Clay C

    2010-12-06

    The genome sequencing of the fungus Aspergillus niger, an industrial workhorse, uncovered a large cache of genes encoding enzymes thought to be involved in the production of secondary metabolites yet to be identified. Identification and structural characterization of many of these predicted secondary metabolites are hampered by their low concentration relative to the known A. niger metabolites such as the naphtho-γ-pyrone family of polyketides. We deleted a nonreducing PKS gene in A. niger strain ATCC 11414, a daughter strain of A. niger ATCC strain 1015 whose genome was sequenced by the DOE Joint Genome Institute. This PKS encoding gene is a predicted ortholog of alb1 from Aspergillus fumigatus which is responsible for production of YWA1, a precursor of fungal DHN melanin. Our results show that the A. niger alb1 PKS is responsible for the production of the polyketide precursor for DHN melanin biosynthesis. Deletion of alb1 elimnates the production of major metabolites, naphtho-γ-pyrones. The generation of an A. niger strain devoid of naphtho-γ-pyrones will greatly facilitate the elucidation of cryptic biosynthetic pathways in this organism.

  15. Policing starter unit selection of the enterocin type II polyketide synthase by the type II thioesterase EncL.

    Science.gov (United States)

    Kalaitzis, John A; Cheng, Qian; Meluzzi, Dario; Xiang, Longkuan; Izumikawa, Miho; Dorrestein, Pieter C; Moore, Bradley S

    2011-11-15

    Enterocin is an atypical type II polyketide synthase (PKS) product from the marine actinomycete 'Streptomyces maritimus'. The enterocin biosynthesis gene cluster (enc) codes for proteins involved in the assembly and attachment of the rare benzoate primer that initiates polyketide assembly with the addition of seven malonate molecules and culminates in a Favorskii-like rearrangement of the linear poly-β-ketone to give its distinctive non-aromatic, caged core structure. Fundamental to enterocin biosynthesis, which utilizes a single acyl carrier protein (ACP), EncC, for both priming with benzoate and elongating with malonate, involves maintaining the correct balance of acyl-EncC substrates for efficient polyketide assembly. Here, we report the characterization of EncL as a type II thioesterase that functions to edit starter unit (mis)priming of EncC. We performed a series of in vivo mutational studies, heterologous expression experiments, in vitro reconstitution studies, and Fourier-transform mass spectrometry-monitored competitive enzyme assays that together support the proposed selective hydrolase activity of EncL toward misprimed acetyl-ACP over benzoyl-ACP to facilitate benzoyl priming of the enterocin PKS complex. While this system resembles the R1128 PKS that also utilizes an editing thioesterase (ZhuC) to purge acetate molecules from its initiation module ACP in favor of alkylacyl groups, the enterocin system is distinct in its usage of a single ACP for both priming and elongating reactions with different substrates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. A modular interpretation of various cubic towers

    DEFF Research Database (Denmark)

    Anbar Meidl, Nurdagül; Bassa, Alp; Beelen, Peter

    2017-01-01

    In this article we give a Drinfeld modular interpretation for various towers of function fields meeting Zink's bound.......In this article we give a Drinfeld modular interpretation for various towers of function fields meeting Zink's bound....

  17. Arithmetical Fourier and Limit values of elliptic modular functions

    Indian Academy of Sciences (India)

    2

    In order to remove singularities, Riemann used a well-known device of taking the odd part (3.2) or an alternate sum (3.3) to be stated in §3. In §2 of this note we shall reveal that the limit values of elliptic modular functions in Riemann's fragment II evaluated by the differences of polyloga- rithm function l1(x) of order 1 (cf.

  18. Service Modularity and Architecture

    DEFF Research Database (Denmark)

    Brax, Saara A.; Bask, Anu; Hsuan, Juliana

    2017-01-01

    , platform-based and mass-customized service business models, comparative research designs, customer perspectives and service experience, performance in context of modular services, empirical evidence of benefits and challenges, architectural innovation in services, modularization in multi-provider contexts......Purpose: Services are highly important in a world economy which has increasingly become service driven. There is a growing need to better understand the possibilities for, and requirements of, designing modular service architectures. The purpose of this paper is to elaborate on the roots...... of the emerging research stream on service modularity, provide a concise overview of existing work on the subject, and outline an agenda for future research on service modularity and architecture. The articles in the special issue offer four diverse sets of research on service modularity and architecture. Design...

  19. The marine sponge-derived polyketide endoperoxide plakortide F acid mediates its antifungal activity by interfering with calcium homeostasis

    Science.gov (United States)

    Plakortide F acid (PFA) is a marine-derived polyketide endoperoxide exhibiting strong inhibitory activity against several clinically important fungal pathogens. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Sacch...

  20. Modular nuclear fuel element, modular capsule for a such element and fabrication process for a modular capsule

    International Nuclear Information System (INIS)

    Chotard, A.

    1988-01-01

    The nuclear fuel rod is made by a tubular casing closed at both ends and containing a series of modular capsules with little play with the casing and made by a jacket closed by porous plugs at both ends and containing a stack of fuel pellets [fr

  1. A Modular Approach to Redundant Robot Control

    International Nuclear Information System (INIS)

    Anderson, R.J.

    1997-12-01

    This paper describes a modular approach for computing redundant robot kinematics. First some conventional redundant control methods are presented and shown to be 'passive control laws', i.e. they can be represented by a network consisting of passive elements. These networks are then put into modular form by applying scattering operator techniques. Additional subnetwork modules can then be added to further shape the motion. Modules for obstacle detection, joint limit avoidance, proximity sensing, and for imposing nonlinear velocity constraints are presented. The resulting redundant robot control system is modular, flexible and robust

  2. Modular forms

    NARCIS (Netherlands)

    Edixhoven, B.; van der Geer, G.; Moonen, B.; Edixhoven, B.; van der Geer, G.; Moonen, B.

    2008-01-01

    Modular forms are functions with an enormous amount of symmetry that play a central role in number theory, connecting it with analysis and geometry. They have played a prominent role in mathematics since the 19th century and their study continues to flourish today. Modular forms formed the

  3. [Modular enteral nutrition in pediatrics].

    Science.gov (United States)

    Murillo Sanchís, S; Prenafeta Ferré, M T; Sempere Luque, M D

    1991-01-01

    Modular Enteral Nutrition may be a substitute for Parenteral Nutrition in children with different pathologies. Study of 4 children with different pathologies selected from a group of 40 admitted to the Maternal-Childrens Hospital "Valle de Hebrón" in Barcelona, who received modular enteral nutrition. They were monitored on a daily basis by the Dietician Service. Modular enteral nutrition consists of modules of proteins, peptides, lipids, glucids and mineral salts-vitamins. 1.--Craneo-encephalic traumatisms with loss of consciousness, Feeding with a combination of parenteral nutrition and modular enteral nutrition for 7 days. In view of the tolerance and good results of the modular enteral nutrition, the parenteral nutrition was suspended and modular enteral nutrition alone used up to a total of 43 days. 2.--55% burns with 36 days of hyperproteic modular enteral nutrition together with normal feeding. A more rapid recovery was achieved with an increase in total proteins and albumin. 3.--Persistent diarrhoea with 31 days of modular enteral nutrition, 5 days on parenteral nutrition alone and 8 days on combined parenteral nutrition and modular enteral nutrition. In view of the tolerance and good results of the modular enteral nutrition, the parenteral nutrition was suspended. 4.--Mucoviscidosis with a total of 19 days on modular enteral nutrition, 12 of which were exclusively on modular enteral nutrition and 7 as a night supplement to normal feeding. We administered proteic intakes of up to 20% of the total calorific intake and in concentrations of up to 1.2 calories/ml of the final preparation, always with a good tolerance. Modular enteral nutrition can and should be used as a substitute for parenteral nutrition in children with different pathologies, thus preventing the complications inherent in parenteral nutrition.

  4. The polyketide synthase gene pks4 is essential for sexual development and regulates fruiting body morphology in Sordaria macrospora.

    Science.gov (United States)

    Schindler, Daniel; Nowrousian, Minou

    2014-07-01

    Filamentous ascomycetes have long been known as producers of a variety of secondary metabolites, many of which have toxic effects on other organisms. However, the role of these metabolites in the biology of the fungi that produce them remains in most cases enigmatic. A major group of fungal secondary metabolites are polyketides. They are chemically diverse, but have in common that their chemical scaffolds are synthesized by polyketide synthases (PKSs). In a previous study, we analyzed development-dependent expression of pks genes in the filamentous ascomycete Sordaria macrospora. Here, we show that a deletion mutant of the pks4 gene is sterile, producing only protoperithecia but no mature perithecia, whereas overexpression of pks4 leads to enlarged, malformed fruiting bodies. Thus, correct expression levels of pks4 are essential for wild type-like perithecia formation. The predicted PKS4 protein has a domain structure that is similar to homologs in other fungi, but conserved residues of a methyl transferase domain present in other fungi are mutated in PKS4. Expression of several developmental genes is misregulated in the pks4 mutant. Surprisingly, the development-associated app gene is not downregulated in the mutant, in contrast to all other previously studied mutants with a block at the protoperithecial stage. Our data show that the polyketide synthase gene pks4 is essential for sexual development and plays a role in regulating fruiting body morphology. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Polyketides with Immunosuppressive Activities from Mangrove Endophytic Fungus Penicillium sp. ZJ-SY₂.

    Science.gov (United States)

    Liu, Hongju; Chen, Senhua; Liu, Weiyang; Liu, Yayue; Huang, Xishan; She, Zhigang

    2016-11-25

    Nine polyketides, including two new benzophenone derivatives, peniphenone ( 1 ) and methyl peniphenone ( 2 ), along with seven known xanthones ( 3 - 9 ) were obtained from mangrove endophytic fungus Penicillium sp. ZJ-SY₂ isolated from the leaves of Sonneratia apetala . Their structures were elucidated on the basis of MS, 1D, and 2D NMR data. Compounds 1 , 3 , 5 , and 7 showed potent immunosuppressive activity with IC 50 values ranging from 5.9 to 9.3 μg/mL.

  6. Modular entanglement.

    Science.gov (United States)

    Gualdi, Giulia; Giampaolo, Salvatore M; Illuminati, Fabrizio

    2011-02-04

    We introduce and discuss the concept of modular entanglement. This is the entanglement that is established between the end points of modular systems composed by sets of interacting moduli of arbitrarily fixed size. We show that end-to-end modular entanglement scales in the thermodynamic limit and rapidly saturates with the number of constituent moduli. We clarify the mechanisms underlying the onset of entanglement between distant and noninteracting quantum systems and its optimization for applications to quantum repeaters and entanglement distribution and sharing.

  7. Modular design in fahion industry

    Directory of Open Access Journals (Sweden)

    Ying Chen

    2018-03-01

    Full Text Available "Modular design" is a kind of design mode that not only can made clothing more interesting, makes the wearer can participate in choices, increase the possibility of clothing style .but also can extend the service cycle of clothing. In this "fast fashion" run market, the design idea of modular design can be a breakthrough point, help us find the way to balance the low-carbon and environmentally-friendly need and fashion. The article will combine the existing examples put the modular design summarized into three categories: component modular design and geometric modular design and compounded modular design.

  8. Inhibition of Grape Crown Gall by Agrobacterium vitis F2/5 Requires Two Nonribosomal Peptide Synthetases and One Polyketide Synthase.

    Science.gov (United States)

    Zheng, Desen; Burr, Thomas J

    2016-02-01

    Agrobacterium vitis nontumorigenic strain F2/5 is able to inhibit crown gall disease on grapevines. The mechanism of grape tumor inhibition (GTI) by F2/5 has not been fully determined. In this study, we demonstrate that two nonribosomal peptide synthetase (NRPS) genes (F-avi3342 and F-avi5730) and one polyketide synthase gene (F-avi4330) are required for GTI. Knockout of any one of them resulted in F/25 losing GTI capacity. We previously reported that F-avi3342 and F-avi4330 but not F-avi5730 are required for induction of grape tissue necrosis and tobacco hypersensitive response. F-avi5730 is predicted to encode a single modular NRPS. It is located in a cluster that is homologous to the siderophore vicibactin biosynthesis locus in Rhizobium species. Individual disruption of F-avi5730 and two immediate downstream genes, F-avi5731 and F-avi5732, all resulted in reduced siderophore production; however, only F-avi5730 was found to be required for GTI. Complemented F-avi5730 mutant (ΔF-avi5730(+)) restored a wild-type level of GTI activity. It was determined that, over time, populations of ΔF-avi4330, ΔF-avi3342, and ΔF-avi5730 at inoculated wound sites on grapevine did not differ from those of ΔF-avi5730(+) indicating that loss of GTI was not due to reduced colonization of wound sites by mutants.

  9. From modular invariants to graphs: the modular splitting method

    International Nuclear Information System (INIS)

    Isasi, E; Schieber, G

    2007-01-01

    We start with a given modular invariant M of a two-dimensional su-hat(n) k conformal field theory (CFT) and present a general method for solving the Ocneanu modular splitting equation and then determine, in a step-by-step explicit construction (1) the generalized partition functions corresponding to the introduction of boundary conditions and defect lines; (2) the quantum symmetries of the higher ADE graph G associated with the initial modular invariant M. Note that one does not suppose here that the graph G is already known, since it appears as a by-product of the calculations. We analyse several su-hat(3) k exceptional cases at levels 5 and 9

  10. Production of 17-O-demethyl-geldanamycin, a cytotoxic ansamycin polyketide, by Streptomyces hygroscopicus DEM20745.

    Science.gov (United States)

    Baksh, Aron; Kepplinger, Bernhard; Isah, Hadiza A; Probert, Michael R; Clegg, William; Wills, Corinne; Goodfellow, Michael; Errington, Jeff; Allenby, Nick; Hall, Michael J

    2017-08-01

    The actinomycete DEM20745, collected from non-rhizosphere soil adjacent to Paraserianthes falactaria trees (Cangkringan, Indonesia), is an efficient producer of the anticancer ansamycin polyketide 17-O-demethyl-geldanamycin (17-O-DMG), a biosynthetic precursor of the Hsp90 inhibitor geldanamycin (GDM). In DEM20745, 17-O-DMG is the major ansamycin product observed reaching a maximum titre of 17 mg/L in the fermentation broth. 17-O-DMG has the potential to be a key starting material for the semi-synthesis of GDM analogues for use in anticancer therapy. Thus, this preferential biosynthesis of 17-O-DMG facilitates easy access to this important molecule and provides further insight in the biosynthesis of the geldanamycins.

  11. Modular Robotic Wearable

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Pagliarini, Luigi

    2009-01-01

    In this concept paper we trace the contours and define a new approach to robotic systems, composed of interactive robotic modules which are somehow worn on the body. We label such a field as Modular Robotic Wearable (MRW). We describe how, by using modular robotics for creating wearable....... Finally, by focusing on the intersection of the combination modular robotic systems, wearability, and bodymind we attempt to explore the theoretical characteristics of such approach and exploit the possible playware application fields....

  12. United States Department of Agriculture-Agricultural Research Service studies on polyketide toxins of Fusarium oxysporum f sp vasinfectum: potential targets for disease control.

    Science.gov (United States)

    Bell, Alois A; Wheeler, Michael H; Liu, Jinggao; Stipanovic, Robert D; Puckhaber, Lorraine S; Orta, Heather

    2003-01-01

    A group of 133 isolates of the cotton wilt pathogen Fusarium oxysporum Schlecht f sp vasinfectum (Atk) Sny & Hans, representing five races and 20 vegetative compatibility groups within race 1 were used to determine the identity, biosynthetic regulation and taxonomic distribution of polyketide toxins produced by this pathogen. All isolates of F oxysporum f sp vasinfectum produced and secreted the nonaketide naphthazarin quinones, bikaverin and norbikaverin. Most isolates of race 1 (previously denoted as races 1, 2 and 6; and also called race A) also synthesized the heptaketide naphthoquinones, nectriafurone, anhydrofusarubin lactol and 5-O-methyljavanicin. Nine avirulent isolates of F oxysporum from Upland cotton roots, three isolates of race 3 of F oxysporum f sp vasinfectum, and four isolates of F oxysporum f sp vasinfectum from Australia, all of which previously failed to cause disease of Upland cotton (Gossypium hirsutum L) in stem-puncture assays, also failed to synthesize or secrete more than trace amounts of the heptaketide compounds. These results indicate that the heptaketides may have a unique role in the virulence of race 1 to Upland cotton. The synthesis of all polyketide toxins by ATCC isolate 24908 of F oxysporum f sp vasinfectum was regulated by pH, carbon/nitrogen ratios, and availability of calcium in media. Synthesis was greatest below pH 7.0 and increased progressively as carbon/nitrogen ratios were increased by decreasing the amounts of nitrogen added to media. The nonaketides were the major polyketides accumulated in synthetic media at pH 4.5 and below, whereas the heptaketides were predominant at pH 5.0 and above. The heptaketides were the major polyketides formed when 10 F oxysporum f sp vasinfectum race 1 isolates were grown on sterilized stems of Fusarium wilt-susceptible cotton cultivars, but these compounds were not produced on sorghum grain cultures. Both groups of polyketide toxins were apparently secreted by F oxysporum f sp vasinfectum

  13. Modular beam diagnostics instrument design for Cyclotrons

    International Nuclear Information System (INIS)

    Chaddha, N.; Bhole, R.B.; Sahoo, S.; Nandy, P.P.; Pal, S.

    2012-01-01

    The Cyclotrons at VECC, Kolkata i.e. Room Temperature Cyclotron (RTC) and Superconducting Cyclotron (SCC) comprise of internal and external Beam Diagnostic systems. These systems provide the beam developer with position, intensity, beam profile, a visual impression of the size and shape of ion beam, and operational control over diagnostic components like 3-finger probe, Beam Viewer probe, Deflector probe, Faraday cup, X-Y slit, Beam viewer etc. Automation of these components was initially done using customised modules for individual sub-system. An expansion of this facility and various levels of complexity demand modular design to cater easy modification and upgradation. The overall requirements are analysed and modular cards are developed based on basic functionalities like valve operation, probe/slit/viewer control, position read-out, Interlock, aperture control of beam line and communication. A 32-bit Advanced RISC Machine (ARM) based card with embedded EPICS is chosen as the master controller and FPGA/microcontroller is used for functional modules. The paper gives a comprehensive description of all modules and their integration with the control system. (author)

  14. Evolution of Modularity Literature

    DEFF Research Database (Denmark)

    Frandsen, Thomas

    2017-01-01

    Purpose The purpose of this paper is to review and analyze the modularity literature to identify the established and emerging perspectives. Design/methodology/approach A systematic literature search and review was conducted through the use of bibliometrics and network analysis. The analysis...... identified structure within the literature, which revealed how the research area evolved between 1990 and 2015. Based on this search, the paper establishes the basis for analyzing the structure of modularity literature. Findings Factors were identified within the literature, demonstrating how it has evolved...... from a primary focus on the modularity of products to a broader view of the applicability of modularity. Within the last decade, numerous research areas have emerged within the broader area of modularity. Through core-periphery analysis, eight emerging sub-research areas are identified, of which one...

  15. Modularization of Industrial Service Processes

    DEFF Research Database (Denmark)

    Frandsen, Thomas; Hsuan, Juliana

    In this paper we examine how complex service processes can be dealt with through the lenses of modularization strategies. Through an illustrative case study of a manufacturer of industrial equipment for process industries we propose the use of the service modularity function to conceptualize...... and assess the service modularity of service offerings. The measured degree of modularity would allow us to sharpen our understanding of modularity in the context of industrial services, such as the role of standardization and component reuse on architecture flexibility. It would also provide a foundation...

  16. Journal of Biosciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Non-ribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) present in bacteria and fungi are themajor multi-modular enzyme complexes which synthesize secondary metabolites like the pharmacologically importantantibiotics and siderophores. Each of the multiple modules of an NRPS activates a ...

  17. Designing Modular Robotic Playware

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Marti, Patrizia

    2009-01-01

    In this paper, we explore the design of modular robotic objects that may enhance playful experiences. The approach builds upon the development of modular robotics to create a kind of playware, which is flexible in both set-up and activity building for the end-user to allow easy creation of games....... Key features of this design approach are modularity, flexibility, and construction, immediate feedback to stimulate engagement, activity design by end-users, and creative exploration of play activities. These features permit the use of such modular playware by a vast array of users, including disabled...... children who often could be prevented from using and taking benefits from modern technologies. The objective is to get any children moving, exchanging, experimenting and having fun, regardless of their cognitive or physical ability levels. The paper describes two prototype systems developed as modular...

  18. RoboMusic with modular playware

    DEFF Research Database (Denmark)

    Falkenberg, Kasper; Bærendsen, Niels Kristian; Nielsen, Jacob

    2011-01-01

    Based on the concepts of RoboMusic and modular playware, we developed a system composed of modular playware devices which allow any user to perform music in a simple, interactive manner. The key features exploited in the modular playware approach are modularity, fl exibility, construction......, immediate feedback to stimulate engagement, creative exploration of play activities, and in some cases activity design by end-users (e.g., DJs). We exemplify the approach with the development of 11 rock genres and 6 pop music pieces for modular I-BLOCKS, which are exhibited and in daily use at the Rock Me...

  19. RoboMusic with Modular Playware

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Bærendsen, Niels Kristian; Nielsen, Jacob

    2010-01-01

    Based on the concepts of RoboMusic and Modular Playware, we developed a system composed of modular playware devices, which allow any user to perform music in a simple, interactive manner. The key features exploited from the Modular Playware approach are modularity, flexibility, and construction......, immediate feedback to stimulate engagement, creative exploration of play activities, and in some cases activity design by end-users (e.g. DJ’s). We exemplify the approach with the development of 11 rock genres and 6 pop music pieces for modular I-BLOCKS, which are exhibited and in daily use at the Rock Me...

  20. Exploring Protein Interactions on a Minimal Type II Polyketide Synthase Using a Yeast Two-Hybrid System

    Directory of Open Access Journals (Sweden)

    Gaetano Castaldo

    2005-01-01

    Full Text Available Interactions between proteins that form the ’minimal’ type II polyketide synthase in the doxorubicin producing biosynthetic pathway from Streptomyces peucetius were investigated using a yeast two-hybrid system (Y2H. Proteins that function as the so called ’chain length factor’ (DpsB and putative transacylase (DpsD were found to interact with the ketosynthase subunit (DpsA, which can also interact with itself. On the basis of these results we propose a head-to-tail homodimeric structure, which is consistent with previously published in vivo mutagenesis studies. No interactions were found between the acyl-carrier protein (DpsG and any of the other constituents of the complex, however, transient interactions, not detectable using the Y2H system, cannot be discounted and warrant further investigation.

  1. MOBS - A modular on-board switching system

    Science.gov (United States)

    Berner, W.; Grassmann, W.; Piontek, M.

    The authors describe a multibeam satellite system that is designed for business services and for communications at a high bit rate. The repeater is regenerative with a modular onboard switching system. It acts not only as baseband switch but also as the central node of the network, performing network control and protocol evaluation. The hardware is based on a modular bus/memory architecture with associated processors.

  2. Self-organized modularization in evolutionary algorithms.

    Science.gov (United States)

    Dauscher, Peter; Uthmann, Thomas

    2005-01-01

    The principle of modularization has proven to be extremely successful in the field of technical applications and particularly for Software Engineering purposes. The question to be answered within the present article is whether mechanisms can also be identified within the framework of Evolutionary Computation that cause a modularization of solutions. We will concentrate on processes, where modularization results only from the typical evolutionary operators, i.e. selection and variation by recombination and mutation (and not, e.g., from special modularization operators). This is what we call Self-Organized Modularization. Based on a combination of two formalizations by Radcliffe and Altenberg, some quantitative measures of modularity are introduced. Particularly, we distinguish Built-in Modularity as an inherent property of a genotype and Effective Modularity, which depends on the rest of the population. These measures can easily be applied to a wide range of present Evolutionary Computation models. It will be shown, both theoretically and by simulation, that under certain conditions, Effective Modularity (as defined within this paper) can be a selection factor. This causes Self-Organized Modularization to take place. The experimental observations emphasize the importance of Effective Modularity in comparison with Built-in Modularity. Although the experimental results have been obtained using a minimalist toy model, they can lead to a number of consequences for existing models as well as for future approaches. Furthermore, the results suggest a complex self-amplification of highly modular equivalence classes in the case of respected relations. Since the well-known Holland schemata are just the equivalence classes of respected relations in most Simple Genetic Algorithms, this observation emphasizes the role of schemata as Building Blocks (in comparison with arbitrary subsets of the search space).

  3. Modular products: Smartphone design from a circular economy perspective

    OpenAIRE

    Schischke, Karsten; Proske, Marina; Nissen, Nils F.; Lang, Klaus-Dieter

    2016-01-01

    Currently a range of modular smartphones is emerging, including the Fairphone 2, Puzzlephone, Google's Project ARA, RePhone, LG's G5 and others. In an industry of perceived short product cycles a modular design concept might become crucial for longer product lifetimes. The paper provides an overview on latest product developments and assesses these against environmental criteria, including longevity, durability, upgradeability, repairability and Design for Recycling and Reuse. Modular product...

  4. Diversity of polyketides produced by Penicillium species isolated from Melia azedarach and Murraya paniculata; Diversidade de policetideos produzidos por especies de penicillium isolados de Melia azedarach e Murraya paniculata

    Energy Technology Data Exchange (ETDEWEB)

    Pastre, Renata; Marinho, Andrey M.R.; Rodrigues-Filho, Edson [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Quimica]. E-mail: edson@dq.ufscar.br; Souza, Antonia Q.L.; Pereira, Jose Odair [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Genetica e Evolucao

    2007-07-01

    Eight compounds comprising four groups of polyketides, the xanthone fusarindin, the mixed peptide alkaloid-polyketide GKK1032, the anthraquinones crysophanol, citreoveridin and janthinone, and the azaphylones dihydrocitrinone, citrinin and citrinin H-1, were identified in Penicillium species isolated as endophytic fungi from Melia azedarach and Murraya paniculata. The antibacterial activity of the azaphylones was tested and showed that citrinin H-1 is more active than citrinin. (author)

  5. Modular coils: a promising toroidal-reactor-coil system

    International Nuclear Information System (INIS)

    Chu, T.K.; Furth, H.P.; Johnson, J.L.; Ludescher, C.; Weimer, K.E.

    1981-04-01

    The concept of modular coils originated from a need to find reactor-relevant stellarator windings, but its usefulness can be extended to provide an externally applied, additional rotational transform in tokamaks. Considerations of (1) basic principles of modular coils, (2) types of coils, (3) types of configurations (general, helically symmetric, helically asymmetric, with magnetic well, with magnetic hill), (4) types of rotational transform profile, and (5) structure and origin of ripples are given. These results show that modular coils can offer a wide range of vacuum magnetic field configurations, some of which cannot be obtained with the classical stellarator or torsatron coil configuration

  6. Robotic hand with modular extensions

    Science.gov (United States)

    Salisbury, Curt Michael; Quigley, Morgan

    2015-01-20

    A robotic device is described herein. The robotic device includes a frame that comprises a plurality of receiving regions that are configured to receive a respective plurality of modular robotic extensions. The modular robotic extensions are removably attachable to the frame at the respective receiving regions by way of respective mechanical fuses. Each mechanical fuse is configured to trip when a respective modular robotic extension experiences a predefined load condition, such that the respective modular robotic extension detaches from the frame when the load condition is met.

  7. Modularization and Flexibilization.

    Science.gov (United States)

    Van Meel, R. M.

    Publications in the fields of educational science, organization theory, and project management were analyzed to identify the possibilities that modularization offers to institutions of higher professional education and to obtain background information for use in developing a method for modularization in higher professional education. It was…

  8. Identification and characterization of the polyketide synthase involved in ochratoxin A biosynthesis in Aspergillus carbonarius

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Antonia; Knox, Benjamin P.; Bruno, Kenneth S.; Solfrizzo, Michele; Baker, Scott E.; Perrone, Giancarlo

    2014-06-02

    Ochratoxin A (OTA) is a potent mycotoxin produced by Aspergillus and Penicillium species and is a common contaminant of a wide variety of food commodities, with Aspergillus carbonarius being the main producer of OTA contamination in grapes and wine. The molecular structure of OTA is composed of a dihydroisocoumarin ring linked to phenylalanine and, as shown in different producing fungal species, a polyketide synthase (PKS) is a component of the OTA biosynthetic pathway. Similar to observations in other filamentous ascomycetes, the genome sequence of A. carbonarius contains a large number of genes predicted to encode PKSs. In this work a pks gene identified within the putative OTA cluster of A. carbonarius, designated as AcOTApks, was inactivated and the resulting mutant strain was unable to produce OTA, confirming the role of AcOTApks in this biosynthetic pathway. AcOTApks protein is characteristic of the highly reduced (HR)-PKS family, and also contains a putative methyltransferase domain likely responsible for the addition of the methyl group to the OTA polyketide structure. AcOTApks is different from the ACpks protein that we previously described which showed an expression profile compatible with OTA production. We performed phylogenetic analyses of the β-ketosynthase and acyl-transferase domains of the OTA PKSs which had been identified and characterized in different OTA producing fungal species. The phylogenetic results were similar for both the two domains analyzed and showed that OTA PKS of A. carbonarius, Aspergillus niger, and Aspergillus ochraceus clustered in a monophyletic group with 100% bootstrap support suggesting a common origin, while the other OTA PKSs analyzed were phylogenetically distant. A qRT-PCR assay monitored AcOTApks expression during fungal growth and concomitant production of OTA by A. carbonarius in synthetic grape medium. A clear correlation between the expression profile of AcOTApks and kinetics of OTA production was observed with

  9. Proposal of 'modular heliotron'

    International Nuclear Information System (INIS)

    Yamazaki, Kozo.

    1993-11-01

    A new modular helical configuration named 'Modular Heliotron' with clean and efficient helical magnetic divertor is proposed as an extension of the present conventional design of the continuous helical coil system. The sectored helical coils on one plane of the torus and the sectored returning vertical field coils on the other plane are combined. This coil system produces magnetic surfaces nearly equivalent to those of the l=2 helical system with one-pair poloidal coils, and overcomes the defects of construction and maintenance difficulties of the continuous coil systems. This concept satisfies the compatibility between the coil modularity and the sufficient divertor-space utilization, different from previous modular coil designs. The allowable length of the gap between each modular coil is clarified to keep good magnetic surfaces. Typical examples of the reactor coil configuration are described as an extension of the LHD (Large Helical Device) configuration. (author)

  10. Proposal of 'Modular Heliotron'

    International Nuclear Information System (INIS)

    Yamazaki, Kozo

    1994-01-01

    A new modular helical system named 'Modular Heliotron' with clean and efficient helical magnetic divertor is proposed as an extension of the present conventional design of the continuous helical coil system. The sectored helical coils on one plane of the torus and the sectored returning vertical field coils on the other plane are combined. This coil system produces magnetic surfaces nearly equivalent to those of the l=2 helical system with one-pair poloidal coils, and overcomes the defects of construction and maintenance difficulties of the continuous coil systems. This concept satisfies the compatibility between the coil modularity and the sufficient divertor-space utilization, different from previous modular coil designs. The allowable length of the gap between each modular coil is clarified to keep good magnetic surfaces. Typical examples of the reactor coil configuration are described as an extension of the LHD (Large Helical Device) configuration. (author)

  11. Ripple transport in a modular Helias

    International Nuclear Information System (INIS)

    Beidler, C.D.

    1989-01-01

    Neoclassical transport rates are determined for Helical-Axis Advanced Stellarators (Helias). Special emphasis is given to Wendelstein VII-X candidates, for which the magnetic field is produced by a large number of discrete non-planar coils. The investigation is concentrated on the long-mean-free-path regime where particles trapped in local ripple wells of the magnetic field make the dominant contribution to transport. For Wendelstein VII-X, such particles fall into two classes; those localized in the helical ripple common to all stellarator-type devices and those very-localized particles which are trapped in the modular ripples existing between the individual coils. Using analytical techniques it is shown that helical-ripple transport rates are substantially reduced for all Wendelstein VII-X candidates relative to classical stellarator/torsatron configurations. This reduction is most pronounced in the 1/ν regime - equivalent helical ripples of less than 1% lead to reduction factors of more than an order of magnitude - but is significant throughout the entire long-mean-free-path regime. Modular ripple transport in Wendelstein VII-X is calculated by analytically solving the appropriate bounce-averaged kinetic equation. This solution assumes a general magnetic field model and fully accounts for the deformation of modular ripples due to the presence of the other magnetic-field harmonics. Results indicate that 12 coils per field period are necessary if modular-ripple losses are to remain smaller than helical-ripple losses over the entire plasma cross section. (orig.)

  12. Report of study group 3.2 ''small scale LNG projects and modular systems''; Rapport du groupe d'etude 3.2 ''projets de GNL a petite echelle et systemes modulaires''

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, B.

    2000-07-01

    This report details the work undertaken by Study Group 3.2 during the triennium 1997-2000. The Study Group has held three meetings in Stavanger (Norway) in Dubai (UAE) and in London (UK) between March 1998 and October 1999. The study group membership is listed in appendix 1. The subject treated by the Study Group is 'Small Scale LNG Projects and Modular Systems' The study report undertakes a general survey of: 1) the state of the art of the technology; 2) the potential market applications; 3) prospects for gas development and marginal fields. The study addresses three main items: a) Adapting regulation to compact LNG production systems (e.g. distances between equipment in fixed installations); b) LNG production in a marine environment; c) The need for substantial cost reductions. The questions that are addressed in this study report are: Will small scale LNG projects be economically viable? When an onshore industry moves offshore - which standards are to be applied? (author)

  13. Modular organization and hospital performance.

    Science.gov (United States)

    Kuntz, Ludwig; Vera, Antonio

    2007-02-01

    The concept of modularization represents a modern form of organization, which contains the vertical disaggregation of the firm and the use of market mechanisms within hierarchies. The objective of this paper is to examine whether the use of modular structures has a positive effect on hospital performance. The empirical section makes use of multiple regression analyses and leads to the main result that modularization does not have a positive effect on hospital performance. However, the analysis also finds out positive efficiency effects of two central ideas of modularization, namely process orientation and internal market mechanisms.

  14. HexaMob—A Hybrid Modular Robotic Design for Implementing Biomimetic Structures

    Directory of Open Access Journals (Sweden)

    Sasanka Sankhar Reddy CH.

    2017-10-01

    Full Text Available Modular robots are capable of forming primitive shapes such as lattice and chain structures with the additional flexibility of distributed sensing. The biomimetic structures developed using such modular units provides ease of replacement and reconfiguration in co-ordinated structures, transportation etc. in real life scenarios. Though the research in the employment of modular robotic units in formation of biological organisms is in the nascent stage, modular robotic units are already capable of forming such sophisticated structures. The modular robotic designs proposed so far in modular robotics research vary significantly in external structures, sensor-actuator mechanisms interfaces for docking and undocking, techniques for providing mobility, coordinated structures, locomotions etc. and each robotic design attempted to address various challenges faced in the domain of modular robotics by employing different strategies. This paper presents a novel modular wheeled robotic design - HexaMob facilitating four degrees of freedom (2 degrees for mobility and 2 degrees for structural reconfiguration on a single module with minimal usage of sensor-actuator assemblies. The crucial features of modular robotics such as back-driving restriction, docking, and navigation are addressed in the process of HexaMob design. The proposed docking mechanism is enabled using vision sensor, enhancing the capabilities in docking as well as navigation in co-ordinated structures such as humanoid robots.

  15. Modular interdependency in complex dynamical systems.

    Science.gov (United States)

    Watson, Richard A; Pollack, Jordan B

    2005-01-01

    Herbert A. Simon's characterization of modularity in dynamical systems describes subsystems as having dynamics that are approximately independent of those of other subsystems (in the short term). This fits with the general intuition that modules must, by definition, be approximately independent. In the evolution of complex systems, such modularity may enable subsystems to be modified and adapted independently of other subsystems, whereas in a nonmodular system, modifications to one part of the system may result in deleterious side effects elsewhere in the system. But this notion of modularity and its effect on evolvability is not well quantified and is rather simplistic. In particular, modularity need not imply that intermodule dependences are weak or unimportant. In dynamical systems this is acknowledged by Simon's suggestion that, in the long term, the dynamical behaviors of subsystems do interact with one another, albeit in an "aggregate" manner--but this kind of intermodule interaction is omitted in models of modularity for evolvability. In this brief discussion we seek to unify notions of modularity in dynamical systems with notions of how modularity affects evolvability. This leads to a quantifiable measure of modularity and a different understanding of its effect on evolvability.

  16. Modular Design in Treaty Verification Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Macarthur, Duncan Whittemore [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Benz, Jacob [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tolk, Keith [Milagro Consulting, Albuquerque, NM (United States); Weber, Tom [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-27

    It is widely believed that modular design is a good thing. However, there are often few explicit arguments, or even an agreed range of definitions, to back up this belief. In this paper, we examine the potential range of design modularity, the implications of various amounts of modularity, and the advantages and disadvantages of each level of modular construction. We conclude with a comparison of the advantages and disadvantages of each type, as well as discuss many caveats that should be observed to take advantage of the positive features of modularity and minimize the effects of the negative. The tradeoffs described in this paper will be evaluated during the conceptual design to determine what amount of modularity should be included.

  17. Modular Robotics in an African Context

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop

    2011-01-01

    In this paper, we review the concept, development and use of modular robotic devices for education, health improvements, and business in Africa. The modular robotics inspired technology has the advantage of allowing any user easy access to a physical construction of new and advanced technology. We...... conceptualized several educational tools inspired by modular robotics for contextualized IT education in Tanzania, leading to a novel IT degree program and the development of East Africa’s first science and business park in Iringa, Tanzania. The prototypes inspired by modular robotics were developed in the local......, rural context and tested by local users in hospitals and rehabilitation centres. In this paper, we review the development of both modular building blocks for education and modular robotic tiles for rehabilitation in Tanzania....

  18. Theoretical Analysis of the Relationships Between Modularity in Design and Modularity in Production

    DEFF Research Database (Denmark)

    Kubota, Flávio Issao; Hsuan, Juliana; Cauchick-Miguel, Paulo Augusto

    2017-01-01

    This paper investigates the relationships between modularity in design (MID) and modularity in production (MIP) in the automotive industry in terms of how automotive companies obtain benefits and/or drawbacks through MID/MIP relationships. A literature analysis was conducted in order to identify...... the possible relationships between MID and MIP as well as the concepts behind these connections. Sixty-one papers were identified to portray relationships between modular product architecture and modular production systems. Results show a representation of MID and MIP relationships by illustrating that many...... propositions are offered for future field research. Finally, relationships between MID and MIP might be connected with modularity’s maturity level in companies. This is a literature review paper; therefore, empirical evidence is needed to further support current findings. Future studies could analyze...

  19. Identification and reconstitution of the polyketide synthases responsible for biosynthesis of the anti-malarial agent, cladosporin

    OpenAIRE

    Cochrane, Rachel V. K.; Sanichar, Randy; Lambkin, Gareth R.; Reiz, Béla; Xu, Wei; Tang, Yi; Vederas, John C.

    2015-01-01

    The anti-malarial agent cladosporin is a nanomolar inhibitor of Plasmodium falciparum lysyl-tRNA synthetase, and exhibits activity against both blood and liver stage infection. Cladosporin can be isolated from the fungus Cladosporium cladosporioides, where it was believed to be biosynthesized by a highly reducing (HR) and non-reducing (NR) iterative type I polyketide synthase (PKS) pair. Genome sequencing of the host organism, and subsequent heterologous expression of these enzymes in Sacchar...

  20. Portable modular detection system

    Science.gov (United States)

    Brennan, James S [Rodeo, CA; Singh, Anup [Danville, CA; Throckmorton, Daniel J [Tracy, CA; Stamps, James F [Livermore, CA

    2009-10-13

    Disclosed herein are portable and modular detection devices and systems for detecting electromagnetic radiation, such as fluorescence, from an analyte which comprises at least one optical element removably attached to at least one alignment rail. Also disclosed are modular detection devices and systems having an integrated lock-in amplifier and spatial filter and assay methods using the portable and modular detection devices.

  1. A modular control system

    International Nuclear Information System (INIS)

    Cruz, B.; Drexler, J.; Olcese, G.; Santome, D.

    1990-01-01

    The main objective of the modular control system is to provide the requirements to most of the processes supervision and control applications within the industrial automatization area. The design is based on distribution, modulation and expansion concepts. (Author) [es

  2. (Automated) software modularization using community detection

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius; Manikas, Konstantinos

    2015-01-01

    The modularity of a software system is known to have an effect on, among other, development effort, change impact, and technical debt. Modularizing a specific system and evaluating this modularization is, however, challenging. In this paper, we apply community detection methods to the graph...... of class dependencies in software systems to find optimal modularizations through communities. We evaluate this approach through a study of 111 Java systems contained in the Qualitas Corpus. We found that using the modularity function of Newman with an Erdős-Rényi null-model and using the community...... detection algorithm of Reichardt and Bornholdt improved community quality for all systems, that coupling decreased for 99 of the systems, and that coherence increased for 102 of the systems. Furthermore, the modularity function correlates with existing metrics for coupling and coherence....

  3. What professionals consider when designing a modular service architecture

    NARCIS (Netherlands)

    Broekhuis, Manda; van Offenbeek, Marjolein; van der Laan, Monique

    2017-01-01

    Abstract Purpose: The paper explores how functional and appropriateness arguments influence the adoption of modularity principles during the design of a professional service architecture. Design: Action design research was conducted to examine the design process of a modular service architecture for

  4. Supply Chain Management of a Modular Product with Returns

    DEFF Research Database (Denmark)

    Ulku, M. Ali; Hsuan, Juliana; Yu, Dennis

    Modularity and returns relate to sustainability. In a retailer-manufacturer setting and when the demand for a returnable product depends on both price and modularity level, we develop a profit-maximizing stochastic model. The solution includes optimal expressions for the price, and the order...

  5. Modular tree automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Tree automata are traditionally used to study properties of tree languages and tree transformations. In this paper, we consider tree automata as the basis for modular and extensible recursion schemes. We show, using well-known techniques, how to derive from standard tree automata highly modular...

  6. The 16-Year Evolution of Proximal Modular Stem Design – Eliminating Failure of Modular Junction

    Directory of Open Access Journals (Sweden)

    Thomas Tkach

    2017-10-01

    Full Text Available Background: The complexity of hip reconstruction has been and continues to be a perplexing problem with restoring leg length, femoral offset, joint stability and overall hip implant fixation. These were contributing factors that lead to the development of a novel proximal femoral component design “Apex Modular Stem” (Omni, Raynham, MA. The basic stem geometry features a straight stem with a metaphyseal fit and fill cone, a medial triangle and a modular neck junction that allows for version and offset adjustment. In recent years, there has been great concern with the use of modularity in total hip arthroplasty. The goals of this study are (1 to identify complications with the use of a proximal modular design and (2 demonstrated factors that have eliminated those complications. Methods: This is a retrospective study of a single surgeon series (Design A and Design B of using the same cementless stem and proximal modular neck body (Apex Modular Stem and Omni Mod Hip Stem from 2000 to 2016 totaling 2,125 stems. 483 stems were the Design A and 1,642 stems, were of the Design B style. Results: Design A, 483 stems were implanted between 2000 and 2004. 31 alignment pins sheared resulting in a revision rate of 6.4%. Design B, 1,642 stems have been implanted between 2004 and 2016 all by the same surgeon, with no failures of the modular junction. Conclusion: All implant devices entail a multitude of risks and benefits. The Apex Modular Stem (Design A, provided excellent fixation, minimal risk of modular junction  corrosion, and simple control of anteversion and femoral offset. The limitation was found to be the risk of the alignment pin shearing (6.4%. The pin was enlarged to make it 225% stronger in torsional resistance, and in a subsequent series of over 1,600 femoral stems in a single surgeon series, there were no pin failures over a 12 year duration.

  7. Modular analysis of biological networks.

    Science.gov (United States)

    Kaltenbach, Hans-Michael; Stelling, Jörg

    2012-01-01

    The analysis of complex biological networks has traditionally relied on decomposition into smaller, semi-autonomous units such as individual signaling pathways. With the increased scope of systems biology (models), rational approaches to modularization have become an important topic. With increasing acceptance of de facto modularity in biology, widely different definitions of what constitutes a module have sparked controversies. Here, we therefore review prominent classes of modular approaches based on formal network representations. Despite some promising research directions, several important theoretical challenges remain open on the way to formal, function-centered modular decompositions for dynamic biological networks.

  8. PL-MOD: a computer code for modular fault tree analysis and evaluation

    International Nuclear Information System (INIS)

    Olmos, J.; Wolf, L.

    1978-01-01

    The computer code PL-MOD has been developed to implement the modular methodology to fault tree analysis. In the modular approach, fault tree structures are characterized by recursively relating the top tree event to all basic event inputs through a set of equations, each defining an independent modular event for the tree. The advantages of tree modularization lie in that it is a more compact representation than the minimal cut-set description and in that it is well suited for fault tree quantification because of its recursive form. In its present version, PL-MOD modularizes fault trees and evaluates top and intermediate event failure probabilities, as well as basic component and modular event importance measures, in a very efficient way. Thus, its execution time for the modularization and quantification of a PWR High Pressure Injection System reduced fault tree was 25 times faster than that necessary to generate its equivalent minimal cut-set description using the computer code MOCUS

  9. Adaptability of competitive electricity reforms a modular analysis

    International Nuclear Information System (INIS)

    Dubois, Ute

    2009-01-01

    Among the competitive electricity reforms that have been implemented in Europe and the US for the last 18 years, none has 'survived' over several years without major changes. Their changing nature raises the question of their adaptability. Two characteristics of reforms play a key role on their adaptation properties. Firstly, they are 'modular' objects in the sense of [Baldwin, C., 2008. Where do transactions come from? Modularity, transactions, and the boundaries of firms. Industrial and Corporate Change 17 (1), 155-195]. Secondly, they are produced in an institutional process which leads to 'incomplete' rules and designs [Pistor, K., Xu, C., 2003. Incomplete law. International Law and Politics 35, 931-1013]. We propose a typology of adaptations based on the framework proposed by [Williamson, O.E., 1991. Comparative economic organization: the analysis of discrete structural alternatives. Administrative Science Quarterly 36 (2), 269-296] for contracts: (1) in case of small disturbances, adaptations are realized quasi-automatically, by autonomous decisions of the institutions governing the implementation of reforms; (2) in case of middle-range disturbances, adaption is made by Coasian bargaining; (3) finally, in case of strong disturbances, or when bargaining is not feasible, the adaptation of reforms is in the hands of legislative and executive institutions [North, D.C., 2005. Le processus du developpement economique. Editions d'Organisation]. These institutions can reform the reforms [Joskow, P.L., 2006. Introduction to electricity sector liberalization: lessons learned from cross-country studies. In: Sioshansi, F.P. (Ed.), Electricity Market Reform: An International Perspective. Elsevier, Amsterdam, pp. 1-32; Hogan, W.W., 2002. Electricity market restructuring: reforms of reforms. Journal of Regulatory Economics 21, 103-132]. The role of these types of adaptations in each electricity reform is a consequence of the allocation of rights to the regulator, to

  10. Modular Power Standard for Space Explorations Missions

    Science.gov (United States)

    Oeftering, Richard C.; Gardner, Brent G.

    2016-01-01

    Future human space exploration will most likely be composed of assemblies of multiple modular spacecraft elements with interconnected electrical power systems. An electrical system composed of a standardized set modular building blocks provides significant development, integration, and operational cost advantages. The modular approach can also provide the flexibility to configure power systems to meet the mission needs. A primary goal of the Advanced Exploration Systems (AES) Modular Power System (AMPS) project is to establish a Modular Power Standard that is needed to realize these benefits. This paper is intended to give the space exploration community a "first look" at the evolving Modular Power Standard and invite their comments and technical contributions.

  11. Synthesizing Modular Invariants for Synchronous Code

    Directory of Open Access Journals (Sweden)

    Pierre-Loic Garoche

    2014-12-01

    Full Text Available In this paper, we explore different techniques to synthesize modular invariants for synchronous code encoded as Horn clauses. Modular invariants are a set of formulas that characterizes the validity of predicates. They are very useful for different aspects of analysis, synthesis, testing and program transformation. We describe two techniques to generate modular invariants for code written in the synchronous dataflow language Lustre. The first technique directly encodes the synchronous code in a modular fashion. While in the second technique, we synthesize modular invariants starting from a monolithic invariant. Both techniques, take advantage of analysis techniques based on property-directed reachability. We also describe a technique to minimize the synthesized invariants.

  12. The R-operator for a modular double

    International Nuclear Information System (INIS)

    Chicherin, D; Derkachov, S

    2014-01-01

    We construct the R-operator—the solution of the Yang–Baxter equation acting in the tensor product π s 1 ⊗π s 2 of two infinite-dimensional representations of Faddeev’s modular double. This R-operator intertwines the product of two L-operators associated with the modular double and it is built from three basic operators generating the permutation group of four parameters S 4 . (paper)

  13. The modularity of pollination networks

    DEFF Research Database (Denmark)

    Olesen, Jens Mogens; Bascompte, J.; Dupont, Yoko

    2007-01-01

    In natural communities, species and their interactions are often organized as nonrandom networks, showing distinct and repeated complex patterns. A prevalent, but poorly explored pattern is ecological modularity, with weakly interlinked subsets of species (modules), which, however, internally...... consist of strongly connected species. The importance of modularity has been discussed for a long time, but no consensus on its prevalence in ecological networks has yet been reached. Progress is hampered by inadequate methods and a lack of large datasets. We analyzed 51 pollination networks including...... almost 10,000 species and 20,000 links and tested for modularity by using a recently developed simulated annealing algorithm. All networks with >150 plant and pollinator species were modular, whereas networks with

  14. A truly Lego®-like modular microfluidics platform

    Science.gov (United States)

    Vittayarukskul, Kevin; Lee, Abraham Phillip

    2017-03-01

    Ideally, a modular microfluidics platform should be simple to assemble and support 3D configurations for increased versatility. The modular building blocks should also be mass producible like electrical components. These are fundamental features of world-renowned Legos® and why Legos® inspire many existing modular microfluidics platforms. In this paper, a truly Lego®-like microfluidics platform is introduced, and its basic feasibility is demonstrated. Here, PDMS building blocks resembling 2  ×  2 Lego® bricks are cast from 3D-printed master molds. The blocks are pegged and stacked on a traditional Lego® plate to create simple, 3D microfluidic networks, such as a single basket weave. Characteristics of the platform, including reversible sealing and automatic alignment of channels, are also analyzed and discussed in detail.

  15. A truly Lego®-like modular microfluidics platform

    International Nuclear Information System (INIS)

    Vittayarukskul, Kevin; Lee, Abraham Phillip

    2017-01-01

    Ideally, a modular microfluidics platform should be simple to assemble and support 3D configurations for increased versatility. The modular building blocks should also be mass producible like electrical components. These are fundamental features of world-renowned Legos ® and why Legos ® inspire many existing modular microfluidics platforms. In this paper, a truly Lego ® -like microfluidics platform is introduced, and its basic feasibility is demonstrated. Here, PDMS building blocks resembling 2  ×  2 Lego ® bricks are cast from 3D-printed master molds. The blocks are pegged and stacked on a traditional Lego ® plate to create simple, 3D microfluidic networks, such as a single basket weave. Characteristics of the platform, including reversible sealing and automatic alignment of channels, are also analyzed and discussed in detail. (paper)

  16. Theory for the Emergence of Modularity in Complex Systems

    Science.gov (United States)

    Deem, Michael; Park, Jeong-Man

    2013-03-01

    Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a theory for the dynamics of modularity in these systems. We find a principle of least action for the evolved modularity at long times. In addition, we find a fluctuation dissipation relation for the rate of change of modularity at short times. We discuss a number of biological and social systems that can be understood with this framework. The modularity of the protein-protein interaction network increases when yeast are exposed to heat shock, and the modularity of the protein-protein networks in both yeast and E. coli appears to have increased over evolutionary time. Food webs in low-energy, stressful environments are more modular than those in plentiful environments, arid ecologies are more modular during droughts, and foraging of sea otters is more modular when food is limiting. The modularity of social networks changes over time: stock brokers instant messaging networks are more modular under stressful market conditions, criminal networks are more modular under increased police pressure, and world trade network modularity has decreased

  17. AES Modular Power Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The AES Modular Power Systems (AMPS) project will demonstrate and infuse modular power electronics, batteries, fuel cells, and autonomous control for exploration...

  18. Mapping Modular SOS to Rewriting Logic

    DEFF Research Database (Denmark)

    Braga, Christiano de Oliveira; Haeusler, Erik Hermann; Meseguer, José

    Modular SOS (MSOS) is a framework created to improve the modularity of structural operational semantics specifications, a formalism frequently used in the fields of programming languages semantics and process algebras. With the objective of defining formal tools to support the execution and verif......Modular SOS (MSOS) is a framework created to improve the modularity of structural operational semantics specifications, a formalism frequently used in the fields of programming languages semantics and process algebras. With the objective of defining formal tools to support the execution...

  19. Mapping Modular SOS to Rewriting Logic

    DEFF Research Database (Denmark)

    Braga, Christiano de Oliveira; Haeusler, Edward Hermann; Meseguer, José

    2003-01-01

    Modular SOS (MSOS) is a framework created to improve the modularity of structural operational semantics specifications, a formalism frequently used in the fields of programming languages semantics and process algebras. With the objective of defining formal tools to support the execution and verif......Modular SOS (MSOS) is a framework created to improve the modularity of structural operational semantics specifications, a formalism frequently used in the fields of programming languages semantics and process algebras. With the objective of defining formal tools to support the execution...

  20. Analysis Of Power Characteristics Of Model Thermoelectric Generator TEG Small Modular

    Directory of Open Access Journals (Sweden)

    Kisman H. Mahmud

    2017-04-01

    Full Text Available Thermoelectrically Generator TEG can generate electricity from the temperature difference between hot and cold at the junction thermoelectric module with two different semiconductor materials there will be a flow of current through the junction so as to produce a voltage. This principle uses the Seebeck effect thermoelectric generator as a base. By using these principles this research was conducted to determine the potential of the electric energy of the two peltier modules which would be an alternative source for mobile charger using heat from source of methylated. The focus in this research is the testing of the model TEG Thermoelectric Generator Small Modular to generate power with a variety of different materials of 4 namely Bi2Te3 Bismuth Telluride PbTe-Bite CMO and CMO Cascade-32-62S-32-62S Calcium Mangan oxide to use the cold side heat sink and a fan to simulate heat aluminum plate attached to the hot side of the TEG modules with heat source of methylated. Test results on the TEG Small Modular Model for mobile charger output voltage obtained from 2 pieces Bi2Te3 module Bismuth Telluride Peltier strung together a series of 3.01 Volt with amp916T of 22.7 C which produce power of 0.091 Watt.

  1. A Modularity Degree Based Heuristic Community Detection Algorithm

    Directory of Open Access Journals (Sweden)

    Dongming Chen

    2014-01-01

    Full Text Available A community in a complex network can be seen as a subgroup of nodes that are densely connected. Discovery of community structures is a basic problem of research and can be used in various areas, such as biology, computer science, and sociology. Existing community detection methods usually try to expand or collapse the nodes partitions in order to optimize a given quality function. These optimization function based methods share the same drawback of inefficiency. Here we propose a heuristic algorithm (MDBH algorithm based on network structure which employs modularity degree as a measure function. Experiments on both synthetic benchmarks and real-world networks show that our algorithm gives competitive accuracy with previous modularity optimization methods, even though it has less computational complexity. Furthermore, due to the use of modularity degree, our algorithm naturally improves the resolution limit in community detection.

  2. Symmetric modular torsatron

    Science.gov (United States)

    Rome, J.A.; Harris, J.H.

    1984-01-01

    A fusion reactor device is provided in which the magnetic fields for plasma confinement in a toroidal configuration is produced by a plurality of symmetrical modular coils arranged to form a symmetric modular torsatron referred to as a symmotron. Each of the identical modular coils is helically deformed and comprise one field period of the torsatron. Helical segments of each coil are connected by means of toroidally directed windbacks which may also provide part of the vertical field required for positioning the plasma. The stray fields of the windback segments may be compensated by toroidal coils. A variety of magnetic confinement flux surface configurations may be produced by proper modulation of the winding pitch of the helical segments of the coils, as in a conventional torsatron, winding the helix on a noncircular cross section and varying the poloidal and radial location of the windbacks and the compensating toroidal ring coils.

  3. Crystallization and preliminary crystallographic analysis of a novel plant type III polyketide synthase that produces pentaketide chromone

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Hiroyuki [Mitsubishi Kagaku Institute of Life Sciences (MITILS), 11 Minamiooya, Machida, Tokyo 194-8511 (Japan); Kondo, Shin [ZOEGENE Corporation, 1000 Kamoshida, Aoba, Yokohama, Kanagawa 227-8502 (Japan); Abe, Tsuyoshi; Noguchi, Hiroshi [School of Pharmaceutical Sciences and the COE21 Program, University of Shizuoka, Shizuoka 422-8526 (Japan); Sugio, Shigetoshi, E-mail: ssugio@rc.m-kagaku.co.jp [ZOEGENE Corporation, 1000 Kamoshida, Aoba, Yokohama, Kanagawa 227-8502 (Japan); Abe, Ikuro, E-mail: ssugio@rc.m-kagaku.co.jp [School of Pharmaceutical Sciences and the COE21 Program, University of Shizuoka, Shizuoka 422-8526 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kohno, Toshiyuki, E-mail: ssugio@rc.m-kagaku.co.jp [Mitsubishi Kagaku Institute of Life Sciences (MITILS), 11 Minamiooya, Machida, Tokyo 194-8511 (Japan)

    2006-09-01

    Pentaketide chromone synthase from A. arborescens has been overexpressed in E. coli, purified and crystallized. Diffraction data have been collected to 1.6 Å. Pentaketide chromone synthase (PCS) from Aloe arborescens is a novel plant-specific type III polyketide synthase that catalyzes the formation of 5,7-dihydroxy-2-methylchromone from five molecules of malonyl-CoA. Recombinant PCS expressed in Escherichia coli was crystallized by the hanging-drop vapour-diffusion method. The crystals belonged to space group P2{sub 1}, with unit-cell parameters a = 73.2, b = 88.4, c = 70.0 Å, α = γ = 90.0, β = 95.6°. Diffraction data were collected to 1.6 Å resolution using synchrotron radiation at BL24XU of SPring-8.

  4. Synthetic biology approaches to fluorinated polyketides.

    Science.gov (United States)

    Thuronyi, Benjamin W; Chang, Michelle C Y

    2015-03-17

    The catalytic diversity of living systems offers a broad range of opportunities for developing new methods to produce small molecule targets such as fuels, materials, and pharmaceuticals. In addition to providing cost-effective and renewable methods for large-scale commercial processes, the exploration of the unusual chemical phenotypes found in living organisms can also enable the expansion of chemical space for discovery of novel function by combining orthogonal attributes from both synthetic and biological chemistry. In this context, we have focused on the development of new fluorine chemistry using synthetic biology approaches. While fluorine has become an important feature in compounds of synthetic origin, the scope of biological fluorine chemistry in living systems is limited, with fewer than 20 organofluorine natural products identified to date. In order to expand the diversity of biosynthetically accessible organofluorines, we have begun to develop methods for the site-selective introduction of fluorine into complex natural products by engineering biosynthetic machinery to incorporate fluorinated building blocks. To gain insight into how both enzyme active sites and metabolic pathways can be evolved to manage and select for fluorinated compounds, we have studied one of the only characterized natural hosts for organofluorine biosynthesis, the soil microbe Streptomyces cattleya. This information provides a template for designing engineered organofluorine enzymes, pathways, and hosts and has allowed us to initiate construction of enzymatic and cellular pathways for the production of fluorinated polyketides.

  5. Interfaces in service modularity : A typology developed in modular health care provision

    NARCIS (Netherlands)

    de Blok, C.; Meijboom, B.R.; Luijkx, K.G.; Schols, J.M.G.A.; Schroeder, R.G.

    2014-01-01

    We conduct case research in a particular service context, i.e. the sector for elderly care, in order to explore characteristics of interfaces and the role they play in service customization. Even though the study of modularity in areas other than goods production is increasing, little is known about

  6. Size reduction of complex networks preserving modularity

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, A.; Duch, J.; Fernandez, A.; Gomez, S.

    2008-12-24

    The ubiquity of modular structure in real-world complex networks is being the focus of attention in many trials to understand the interplay between network topology and functionality. The best approaches to the identification of modular structure are based on the optimization of a quality function known as modularity. However this optimization is a hard task provided that the computational complexity of the problem is in the NP-hard class. Here we propose an exact method for reducing the size of weighted (directed and undirected) complex networks while maintaining invariant its modularity. This size reduction allows the heuristic algorithms that optimize modularity for a better exploration of the modularity landscape. We compare the modularity obtained in several real complex-networks by using the Extremal Optimization algorithm, before and after the size reduction, showing the improvement obtained. We speculate that the proposed analytical size reduction could be extended to an exact coarse graining of the network in the scope of real-space renormalization.

  7. Enablers & Barriers for Realizing Modularity Benefits

    DEFF Research Database (Denmark)

    Storbjerg, Simon Haahr; Brunø, Thomas Ditlev; Thyssen, Jesper

    2012-01-01

    far less attention compared to the theories and methods concerning modularization of technical systems. Harvesting the full potential of modularization, particularly in relation to product development agility, depends on more than an optimal architecture. Key enablers in this context......Although modularization is becoming both a well-described domain in academia and a broadly applied concept in business, many of today’s firm still struggle to realize the promised benefits of this approach. Managing modularization is a complex matter, and in spite of this, a topic that has received...... are the organizational and systems related aspects. Recognizing the need for guidance to realize the benefits of modularity, the purpose of this study is through a literature study and a case study to improve the insight into the organizational and systems related enablers and barriers with regard to obtaining the full...

  8. Modular Product Families and Assembly Systems

    DEFF Research Database (Denmark)

    Thyssen, Jesper

    2005-01-01

    This research centres on assembly systems designed for utilizing product modularization. Altogether, the task for companies has become an issue of managing the overall trade-off between the external market’s desire for variety and the internal efficiency and effectiveness. Product modularization...... a number of theoretical and managerial implications are identified. From a management point of view, the most im-portant finding is that modularization needs to be configured for the two competitive situations, i.e. 1) the volume flexible configuration focusing on generational product variety and 2......) the mix flexible con-figuration focusing on the simultaneous product variety. These two views are in particular different in respect to the understanding of product modularization. All in all, modularization needs to be, and can be, configured in regard to the specific task, which is believed constituting...

  9. Development of SC structure modularization in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Mun, Taeyoup

    2008-01-01

    New Focus on NPP are Rising Concerns on Global Warming, Potential energy crisis (geo-political), Improved reliability and safety of nuclear power plant, Advent of Generation 3+ NPP technology and Economical Energy Resource. New NPPs are 6 units in Korea and 23 in Asia being built, 32 units being planned in China by 2020 (150 by 2050), 10 units being planned in US by 2020 and IAEA expects $200 billions on NPP construction next 25 years (up to 30% of total world energy). □ SC(Steel Plate Concrete) structure · Steel Plate is used as a Structural Element instead of Reinforcing Bars in RC · SC structure consists of Steel Plate with Headed Studs. Connected by Tie-bars - The Primary Purpose of Tie-bars is to Stiffen and Hold Together the Plates during Construction Process - Headed Studs are Welded to the Inside of Steel Plate for composite action □ Benefits of SC Structure · Shorten Construction Duration for Re bar, Forming and Scaffolding Works · Minimize Site Labors · Improve the Construction Quality · Enable Construction Sites to be kept Clean □ SC Modularization · Fit for Modular Construction for Structural Features · Fit for Modular Construction for Structural Features · Inattentively Effective for Integrated Modules · Pre-fabrication, Pre-assembly and Modularization □ Project Overview · Project Name: Development of SC structure for Modularization in NPP · Project Type: Electric Power Industry R and D (Ministry of Knowledge Economy) · Duration: Sep. 2005 ∼ Aug. 2008 (36 Months) · Research Team and Scopes - Project Management: Korea Hydro and Nuclear Power Company (KHNP) - Development of Code and Standards for SC Structure: Korea Society of Steel Construction (KSSC) Korea Electric Power Research Institute (KEPRI) - Development of SC Structural Analysis and Design: Korea Power Engineering Company (KOPEC) - Development of Construction Techniques for SC Modularization: KHNP, Korea Institute of Nuclear Safety(KINS), KOPEC □ Performance

  10. Bundling Products and Services Through Modularization Strategies

    DEFF Research Database (Denmark)

    Bask, Anu; Hsuan, Juliana; Rajahonka, Mervi

    2012-01-01

    Modularity has been recognized as a powerful tool in improving the efficiency and management of product design and manufacturing. However, the integrated view on covering both, product and service modularity for product-service systems (PSS), is under researched. Therefore, in this paper our...... objective is to contribute to the PSS modularity. Thus, we describe configurations of PSSs and the bundling of products and services through modularization strategies. So far there have not been tools to analyze and determine the correct combinations of degrees of product and service modularities....

  11. Modular High Voltage Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    Newell, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-18

    The goal of this project is to develop a modular high voltage power supply that will meet the needs of safeguards applications and provide a modular plug and play supply for use with standard electronic racks.

  12. System Design of a Supercritical CO_2 cooled Micro Modular Reactor

    International Nuclear Information System (INIS)

    Kim, Seong Gu; Cho, Seongkuk; Yu, Hwanyeal; Kim, Yonghee; Jeong, Yong Hoon; Lee, Jeong Ik

    2014-01-01

    Small modular reactor (SMR) systems that have advantages of little initial capital cost and small restriction on construction site are being developed by many research organizations around the world. Existing SMR concepts have the same objective: to achieve compact size and a long life core. Most of small modular reactors have much smaller size than the large nuclear power plant. However, existing SMR concepts are not fully modularized. This paper suggests a complete modular reactor with an innovative concept for reactor cooling by using a supercritical carbon dioxide. The authors propose the supercritical CO_2 Brayton cycle (S-CO_2 cycle) as a power conversion system to achieve small volume of power conversion unit (PCU) and to contain the reactor core and PCU in one vessel. A conceptual design of the proposed small modular reactor was developed, which is named as KAIST Micro Modular Reactor (MMR). The supercritical CO_2 Brayton cycle for the S-CO_2 cooled reactor core was optimized and the size of turbomachinery and heat exchanger were estimated preliminary. The nuclear fuel composed with UN was proposed and the core lifetime was obtained from a burnup versus reactivity calculation. Furthermore, a system layout with fully passive safety systems for both normal operation and emergency operation was proposed. (author)

  13. Modular representation and analysis of fault trees

    Energy Technology Data Exchange (ETDEWEB)

    Olmos, J; Wolf, L [Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Nuclear Engineering

    1978-08-01

    An analytical method to describe fault tree diagrams in terms of their modular compositions is developed. Fault tree structures are characterized by recursively relating the top tree event to all its basic component inputs through a set of equations defining each of the modulus for the fault tree. It is shown that such a modular description is an extremely valuable tool for making a quantitative analysis of fault trees. The modularization methodology has been implemented into the PL-MOD computer code, written in PL/1 language, which is capable of modularizing fault trees containing replicated components and replicated modular gates. PL-MOD in addition can handle mutually exclusive inputs and explicit higher order symmetric (k-out-of-n) gates. The step-by-step modularization of fault trees performed by PL-MOD is demonstrated and it is shown how this procedure is only made possible through an extensive use of the list processing tools available in PL/1. A number of nuclear reactor safety system fault trees were analyzed. PL-MOD performed the modularization and evaluation of the modular occurrence probabilities and Vesely-Fussell importance measures for these systems very efficiently. In particular its execution time for the modularization of a PWR High Pressure Injection System reduced fault tree was 25 times faster than that necessary to generate its equivalent minimal cut-set description using MOCUS, a code considered to be fast by present standards.

  14. Modularization of fault trees: a method to reduce the cost of analysis

    International Nuclear Information System (INIS)

    Chatterjee, P.

    1975-01-01

    The problem of analyzing large fault trees is considered. The concept of the finest modular representation of a fault tree is introduced and an algorithm is presented for finding this representation. The algorithm will also identify trees which cannot be modularized. Applications of such modularizations are discussed

  15. Modularization and nuclear power. Report by the Technology Transfer Modularization Task Team

    International Nuclear Information System (INIS)

    1985-06-01

    This report describes the results of the work performed by the Technology Transfer Task Team on Modularization. This work was performed as part of the Technology Transfer work being performed under Department of Energy Contract 54-7WM-335406, between December, 1984 and February, 1985. The purpose of this task team effort was to briefly survey the current use of modularization in the nuclear and non-nuclear industries and to assess and evaluate the techniques available for potential application to nuclear power. A key conclusion of the evaluation was that there was a need for a study to establish guidelines for the future development of Light Water Reactor, High Temperature Gas Reactor and Liquid Metal Reactor plants. The guidelines should identify how modularization can improve construction, maintenance, life extension and decommissioning

  16. Model Thermoelectric Generator TEG Small Modular As Micro Electricity Plant At Indonesia Part 1 Design And Material

    Directory of Open Access Journals (Sweden)

    Kisman M. Mahmud

    2015-08-01

    Full Text Available Thermoelectrically Generator TEG can generate electricity from the temperature difference between hot and cold at the junction thermoelectric module with two different semiconductor materials there will be a flow of current through the junction so as to produce a voltage. This principle uses the Seebeck effect thermoelectric generator as a base. By using these principles this study was conducted to determine the potential of the electric energy of the two Peltier modules which would be an alternative source for micro electricity plant using heat from methylated. The focus of this research is to design a model TEG Thermoelectric Generator Small Modular to produce the kind of material that is optimum for a TEG on the simulation Computer Aided Design CAD with a variety of four different materials that Bi2Te3 Bismuth Telluride PbTe-BiTe CMO-32 -62S Cascade and CMO-32-62S Calcium Manganese Oxide to its cold side using the heat sink fan and simulating heat aluminum plate attached to the hot side of the TEG modules with heat source of methylated. Model simulation results on TEG Small Modular micro electrical plant material obtained CMO-32-62S Cascade thermal material that has a value greater than 3 other material.

  17. A New Modular Multilevel Converter with Integrated Energy Storage

    DEFF Research Database (Denmark)

    Trintis, Ionut; Munk-Nielsen, Stig; Teodorescu, Remus

    2011-01-01

    applications. Furthermore, this solution can interconnect a DC and AC grid with bidirectional power flow, where both of them can receive or generate excess power to the third source integrated in each converter sub-module. This particularity enables the converter usage as a high voltage UPS system......This paper introduces a new modular converter with integrated energy storage based on the cascaded half-bridge modular multilevel converter with common DC bus. It represents a complete modular solution with power electronics and energy storage building blocks, for medium and high voltage...... in the future HVDC meshed grids. Its functionality and flexibility makes the converter independent on the energy storage unit characteristic. The converter concept with its basic functions and control schemes are described and evaluated in this paper....

  18. Evolution of Chemical Diversity in a Group of Non-Reduced Polyketide Gene Clusters: Using Phylogenetics to Inform the Search for Novel Fungal Natural Products

    Directory of Open Access Journals (Sweden)

    Kurt Throckmorton

    2015-09-01

    Full Text Available Fungal polyketides are a diverse class of natural products, or secondary metabolites (SMs, with a wide range of bioactivities often associated with toxicity. Here, we focus on a group of non-reducing polyketide synthases (NR-PKSs in the fungal phylum Ascomycota that lack a thioesterase domain for product release, group V. Although widespread in ascomycete taxa, this group of NR-PKSs is notably absent in the mycotoxigenic genus Fusarium and, surprisingly, found in genera not known for their secondary metabolite production (e.g., the mycorrhizal genus Oidiodendron, the powdery mildew genus Blumeria, and the causative agent of white-nose syndrome in bats, Pseudogymnoascus destructans. This group of NR-PKSs, in association with the other enzymes encoded by their gene clusters, produces a variety of different chemical classes including naphthacenediones, anthraquinones, benzophenones, grisandienes, and diphenyl ethers. We discuss the modification of and transitions between these chemical classes, the requisite enzymes, and the evolution of the SM gene clusters that encode them. Integrating this information, we predict the likely products of related but uncharacterized SM clusters, and we speculate upon the utility of these classes of SMs as virulence factors or chemical defenses to various plant, animal, and insect pathogens, as well as mutualistic fungi.

  19. Modular properties of 6d (DELL) systems

    Science.gov (United States)

    Aminov, G.; Mironov, A.; Morozov, A.

    2017-11-01

    If super-Yang-Mills theory possesses the exact conformal invariance, there is an additional modular invariance under the change of the complex bare charge [InlineMediaObject not available: see fulltext.]. The low-energy Seiberg-Witten prepotential ℱ( a), however, is not explicitly invariant, because the flat moduli also change a - → a D = ∂ℱ/∂ a. In result, the prepotential is not a modular form and depends also on the anomalous Eisenstein series E 2. This dependence is usually described by the universal MNW modular anomaly equation. We demonstrate that, in the 6 d SU( N) theory with two independent modular parameters τ and \\widehat{τ} , the modular anomaly equation changes, because the modular transform of τ is accompanied by an ( N -dependent!) shift of \\widehat{τ} and vice versa. This is a new peculiarity of double-elliptic systems, which deserves further investigation.

  20. Stratway: A Modular Approach to Strategic Conflict Resolution

    Science.gov (United States)

    Hagen, George E.; Butler, Ricky W.; Maddalon, Jeffrey M.

    2011-01-01

    In this paper we introduce Stratway, a modular approach to finding long-term strategic resolutions to conflicts between aircraft. The modular approach provides both advantages and disadvantages. Our primary concern is to investigate the implications on the verification of safety-critical properties of a strategic resolution algorithm. By partitioning the problem into verifiable modules much stronger verification claims can be established. Since strategic resolution involves searching for solutions over an enormous state space, Stratway, like most similar algorithms, searches these spaces by applying heuristics, which present especially difficult verification challenges. An advantage of a modular approach is that it makes a clear distinction between the resolution function and the trajectory generation function. This allows the resolution computation to be independent of any particular vehicle. The Stratway algorithm was developed in both Java and C++ and is available through a open source license. Additionally there is a visualization application that is helpful when analyzing and quickly creating conflict scenarios.

  1. Decentralizing decision making in modularization strategies

    DEFF Research Database (Denmark)

    Israelsen, Poul; Jørgensen, Brian

    2011-01-01

    which distorts the economic effects of modularization at the level of the individual product. This has the implication that decisions on modularization can only be made by top management if decision authority and relevant information are to be aligned. To overcome this problem, we suggest a solution...... that aligns the descriptions of the economic consequences of modularization at the project and portfolio level which makes it possible to decentralize decision making while making sure that local goals are congruent with the global ones in order to avoid suboptimal behaviour. Keywords: Modularization......; Accounting; Cost allocation; Decision rule; Decentralization...

  2. Specialization can drive the evolution of modularity.

    Directory of Open Access Journals (Sweden)

    Carlos Espinosa-Soto

    2010-03-01

    Full Text Available Organismal development and many cell biological processes are organized in a modular fashion, where regulatory molecules form groups with many interactions within a group and few interactions between groups. Thus, the activity of elements within a module depends little on elements outside of it. Modularity facilitates the production of heritable variation and of evolutionary innovations. There is no consensus on how modularity might evolve, especially for modules in development. We show that modularity can increase in gene regulatory networks as a byproduct of specialization in gene activity. Such specialization occurs after gene regulatory networks are selected to produce new gene activity patterns that appear in a specific body structure or under a specific environmental condition. Modules that arise after specialization in gene activity comprise genes that show concerted changes in gene activities. This and other observations suggest that modularity evolves because it decreases interference between different groups of genes. Our work can explain the appearance and maintenance of modularity through a mechanism that is not contingent on environmental change. We also show how modularity can facilitate co-option, the utilization of existing gene activity to build new gene activity patterns, a frequent feature of evolutionary innovations.

  3. Modularization--A Road to Relevance?

    Science.gov (United States)

    Palow, William P.

    This paper describes a modular program at a community college for instructing non-science majors in college algebra. The two-course sequence is comprised of four modules each and successful completion of a module is required before a student proceeds to the next. Placement, grading policies, and scheduling are all discussed. A formative evaluation…

  4. Integrity and change in modular ontologies

    NARCIS (Netherlands)

    Stuckenschmidt, Heiner; Klein, Michel

    2003-01-01

    The benefits of modular representations arc well known from many areas of computer science. In this paper, we concentrate on the benefits of modular ontologies with respect to local containment of terminological reasoning. We define an architecture for modular ontologies that supports local

  5. Justification of the technical requirements of a fully functional modular robot

    Directory of Open Access Journals (Sweden)

    Shlyakhov Nikita

    2017-01-01

    Full Text Available Modular robots are characterized by limited built-in resources necessary for communication, connection and movement of modules, when performing reconfiguration tasks at rigidly interconnected elements. In developing the technological fundamentals of designing modular robots with pairwise connection mechanisms, we analysed modern hardware and model algorithms typical of a fully functional robot, which provide independent locomotion, communication, navigation, decentralized power and control. A survey of actuators, batteries, sensors, communication means, suitable for modular robotics is presented.

  6. A Modular Architecture for Developing Robots for Industrial Applications

    DEFF Research Database (Denmark)

    Faina, Andres; Orjales, Felix; Souto, Daniel

    2015-01-01

    addresses the problem the other way around. In this line, we start by defining the industrial settings the architecture is aimed at and then extract the main features that would be required from a modular robotic architecture to operate successfully in this context. Finally, a particular heterogeneous......This chapter is concerned with proposing ways to make feasible the use of robots in many sectors characterized by dynamic and unstructured environments. In particular, we are interested in addressing the problem through a new approach, based on modular robotics, to allow the fast deployment...... modular robotic architecture is designed from these requirements and a laboratory implementation of it is built in order to test its capabilities and show its versatility using a set of different configurations including manipulators, climbers and walkers....

  7. Adaptive multi-resolution Modularity for detecting communities in networks

    Science.gov (United States)

    Chen, Shi; Wang, Zhi-Zhong; Bao, Mei-Hua; Tang, Liang; Zhou, Ji; Xiang, Ju; Li, Jian-Ming; Yi, Chen-He

    2018-02-01

    Community structure is a common topological property of complex networks, which attracted much attention from various fields. Optimizing quality functions for community structures is a kind of popular strategy for community detection, such as Modularity optimization. Here, we introduce a general definition of Modularity, by which several classical (multi-resolution) Modularity can be derived, and then propose a kind of adaptive (multi-resolution) Modularity that can combine the advantages of different Modularity. By applying the Modularity to various synthetic and real-world networks, we study the behaviors of the methods, showing the validity and advantages of the multi-resolution Modularity in community detection. The adaptive Modularity, as a kind of multi-resolution method, can naturally solve the first-type limit of Modularity and detect communities at different scales; it can quicken the disconnecting of communities and delay the breakup of communities in heterogeneous networks; and thus it is expected to generate the stable community structures in networks more effectively and have stronger tolerance against the second-type limit of Modularity.

  8. Identification of PaPKS1, a polyketide synthase involved in melanin formation and its use as a genetic tool in Podospora anserina.

    Science.gov (United States)

    Coppin, Evelyne; Silar, Philippe

    2007-08-01

    In the filamentous fungus Podospora anserina, many pigmentation mutations map to the median region of the complex locus '14', called segment '29'. The data presented in this paper show that segment 29 corresponds to a gene encoding a polyketide synthase, designated PaPKS1, and identifies two mutations that completely or partially abolish the activity of the PaPKS1 polypeptide. We present evidence that the P. anserina green pigment is a (DHN)-melanin. Using the powerful genetic system of PaPKS1 cloning, we demonstrate that in P. anserina trans-duplicated sequences are subject to the RIP process as previously demonstrated for the cis-duplicated regions.

  9. Reasoning and change management in modular ontologies

    NARCIS (Netherlands)

    Stuckenschmidt, Heiner; Klein, Michel

    2007-01-01

    The benefits of modular representations are well known from many areas of computer science. While in software engineering modularization is mainly a vehicle for supporting distributed development and re-use, in knowledge representation, the main goal of modularization is efficiency of reasoning. In

  10. MODULAR ANALYTICS: A New Approach to Automation in the Clinical Laboratory.

    Science.gov (United States)

    Horowitz, Gary L; Zaman, Zahur; Blanckaert, Norbert J C; Chan, Daniel W; Dubois, Jeffrey A; Golaz, Olivier; Mensi, Noury; Keller, Franz; Stolz, Herbert; Klingler, Karl; Marocchi, Alessandro; Prencipe, Lorenzo; McLawhon, Ronald W; Nilsen, Olaug L; Oellerich, Michael; Luthe, Hilmar; Orsonneau, Jean-Luc; Richeux, Gérard; Recio, Fernando; Roldan, Esther; Rymo, Lars; Wicktorsson, Anne-Charlotte; Welch, Shirley L; Wieland, Heinrich; Grawitz, Andrea Busse; Mitsumaki, Hiroshi; McGovern, Margaret; Ng, Katherine; Stockmann, Wolfgang

    2005-01-01

    MODULAR ANALYTICS (Roche Diagnostics) (MODULAR ANALYTICS, Elecsys and Cobas Integra are trademarks of a member of the Roche Group) represents a new approach to automation for the clinical chemistry laboratory. It consists of a control unit, a core unit with a bidirectional multitrack rack transportation system, and three distinct kinds of analytical modules: an ISE module, a P800 module (44 photometric tests, throughput of up to 800 tests/h), and a D2400 module (16 photometric tests, throughput up to 2400 tests/h). MODULAR ANALYTICS allows customised configurations for various laboratory workloads. The performance and practicability of MODULAR ANALYTICS were evaluated in an international multicentre study at 16 sites. Studies included precision, accuracy, analytical range, carry-over, and workflow assessment. More than 700 000 results were obtained during the course of the study. Median between-day CVs were typically less than 3% for clinical chemistries and less than 6% for homogeneous immunoassays. Median recoveries for nearly all standardised reference materials were within 5% of assigned values. Method comparisons versus current existing routine instrumentation were clinically acceptable in all cases. During the workflow studies, the work from three to four single workstations was transferred to MODULAR ANALYTICS, which offered over 100 possible methods, with reduction in sample splitting, handling errors, and turnaround time. Typical sample processing time on MODULAR ANALYTICS was less than 30 minutes, an improvement from the current laboratory systems. By combining multiple analytic units in flexible ways, MODULAR ANALYTICS met diverse laboratory needs and offered improvement in workflow over current laboratory situations. It increased overall efficiency while maintaining (or improving) quality.

  11. Modular Engineering of Production Plants

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth

    1998-01-01

    Based on a case-study on design of pharmaceutical production plants, this paper suggests that modularity may support business efficiency for companies with one-of-a-kind production and without in-house manufacturing. Modularity may support efficient management of design knowledge and may facilitate...

  12. Modular robotics for playful physiotherapy

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop

    2009-01-01

    We developed modular robotic tiles to be used for playful physiotherapy, which is supposed to motivate patients to engage in and perform physical rehabilitation exercises. We tested the modular robotic tiles for an extensive period of time (3 years) in daily use in a hospital rehabilitation unit e.......g. for cardiac patients. Also, the tiles were tested for performing physical rehabilitation of stroke patients in their private home. In all pilot test cases qualitative feedback indicate that the patients find the playful use of modular robotic tiles engaging and motivating for them to perform...

  13. KWU's modular approach to HTR commercialization

    International Nuclear Information System (INIS)

    Frewer, H.; Weisbrodt, I.

    1983-01-01

    As a way of avoiding the uncertainties, delays and unacceptable commercial risks which have plagued advanced reactor projects in Germany, KWU is advocating a modular approach to commercialization of the high-temperature reactor (HTR), using small size standard reactor units. KWU has received a contract for the study of a co-generation plant based on this modular system. Features of the KWU modular HTR, process heat, gasification, costs and future development are discussed. (UK)

  14. Modular reconfigurable machines incorporating modular open architecture control

    CSIR Research Space (South Africa)

    Padayachee, J

    2008-01-01

    Full Text Available degrees of freedom on a single platform. A corresponding modular Open Architecture Control (OAC) system is presented. OAC overcomes the inflexibility of fixed proprietary automation, ensuring that MRMs provide the reconfigurability and extensibility...

  15. A Comparison of Modular Verification Techniques

    DEFF Research Database (Denmark)

    Andersen, Henrik Reif; Staunstrup, Jørgen; Maretti, Niels

    1997-01-01

    This paper presents and compares three techniques for mechanized verification of state oriented design descriptions. One is a traditional forwardgeneration of a fixed point characterizing the reachable states. The two others can utilize a modular structure provided by the designer. Onerequires...

  16. Isolation and Assessment of the in Vitro Anti-Tumor Activity of Smenothiazole A and B, Chlorinated Thiazole-Containing Peptide/Polyketides from the Caribbean Sponge, Smenospongia aurea

    Directory of Open Access Journals (Sweden)

    Germana Esposito

    2015-01-01

    Full Text Available The study of the secondary metabolites contained in the organic extract of Caribbean sponge Smenospongia aurea led to the isolation of smenothiazole A (3 and B (4, hybrid peptide/polyketide compounds. Assays performed using four solid tumor cell lines showed that smenothiazoles exert a potent cytotoxic activity at nanomolar levels, with selectivity over ovarian cancer cells and a pro-apoptotic mechanism.

  17. Episodic Memory Retrieval Benefits from a Less Modular Brain Network Organization.

    Science.gov (United States)

    Westphal, Andrew J; Wang, Siliang; Rissman, Jesse

    2017-03-29

    Most complex cognitive tasks require the coordinated interplay of multiple brain networks, but the act of retrieving an episodic memory may place especially heavy demands for communication between the frontoparietal control network (FPCN) and the default mode network (DMN), two networks that do not strongly interact with one another in many task contexts. We applied graph theoretical analysis to task-related fMRI functional connectivity data from 20 human participants and found that global brain modularity-a measure of network segregation-is markedly reduced during episodic memory retrieval relative to closely matched analogical reasoning and visuospatial perception tasks. Individual differences in modularity were correlated with memory task performance, such that lower modularity levels were associated with a lower false alarm rate. Moreover, the FPCN and DMN showed significantly elevated coupling with each other during the memory task, which correlated with the global reduction in brain modularity. Both networks also strengthened their functional connectivity with the hippocampus during the memory task. Together, these results provide a novel demonstration that reduced modularity is conducive to effective episodic retrieval, which requires close collaboration between goal-directed control processes supported by the FPCN and internally oriented self-referential processing supported by the DMN. SIGNIFICANCE STATEMENT Modularity, an index of the degree to which nodes of a complex system are organized into discrete communities, has emerged as an important construct in the characterization of brain connectivity dynamics. We provide novel evidence that the modularity of the human brain is reduced when individuals engage in episodic memory retrieval, relative to other cognitive tasks, and that this state of lower modularity is associated with improved memory performance. We propose a neural systems mechanism for this finding where the nodes of the frontoparietal control

  18. Fable: Socially Interactive Modular Robot

    DEFF Research Database (Denmark)

    Magnússon, Arnþór; Pacheco, Moises; Moghadam, Mikael

    2013-01-01

    Modular robots have a significant potential as user-reconfigurable robotic playware, but often lack sufficient sensing for social interaction. We address this issue with the Fable modular robotic system by exploring the use of smart sensor modules that has a better ability to sense the behavior...

  19. Shortened OR time and decreased patient risk through use of a modular surgical instrument with artificial intelligence.

    Science.gov (United States)

    Miller, David J; Nelson, Carl A; Oleynikov, Dmitry

    2009-05-01

    With a limited number of access ports, minimally invasive surgery (MIS) often requires the complete removal of one tool and reinsertion of another. Modular or multifunctional tools can be used to avoid this step. In this study, soft computing techniques are used to optimally arrange a modular tool's functional tips, allowing surgeons to deliver treatment of improved quality in less time, decreasing overall cost. The investigators watched University Medical Center surgeons perform MIS procedures (e.g., cholecystectomy and Nissen fundoplication) and recorded the procedures to digital video. The video was then used to analyze the types of instruments used, the duration of each use, and the function of each instrument. These data were aggregated with fuzzy logic techniques using four membership functions to quantify the overall usefulness of each tool. This allowed subsequent optimization of the arrangement of functional tips within the modular tool to decrease overall time spent changing instruments during simulated surgical procedures based on the video recordings. Based on a prototype and a virtual model of a multifunction laparoscopic tool designed by the investigators that can interchange six different instrument tips through the tool's shaft, the range of tool change times is approximately 11-13 s. Using this figure, estimated time savings for the procedures analyzed ranged from 2.5 to over 32 min, and on average, total surgery time can be reduced by almost 17% by using the multifunction tool.

  20. Prospect of small modular reactor development

    International Nuclear Information System (INIS)

    Li Huailin; Zhu Qingyuan; Wang Suli; Xia Haihong

    2014-01-01

    Small modular reactor has the advantages of modular construction, enhanced safety/robustness from simplified designs, better ecomonic, clean and carbon free, compatible with the needs of smaller utilities and diversified application. In this paper, the prospect of small modular reactor is discussed from technology development status, constraints, economic. (authors)

  1. Modularity-like objective function in annotated networks

    Science.gov (United States)

    Xie, Jia-Rong; Wang, Bing-Hong

    2017-12-01

    We ascertain the modularity-like objective function whose optimization is equivalent to the maximum likelihood in annotated networks. We demonstrate that the modularity-like objective function is a linear combination of modularity and conditional entropy. In contrast with statistical inference methods, in our method, the influence of the metadata is adjustable; when its influence is strong enough, the metadata can be recovered. Conversely, when it is weak, the detection may correspond to another partition. Between the two, there is a transition. This paper provides a concept for expanding the scope of modularity methods.

  2. Analysis of enabling factors in realizing modularization benefits

    DEFF Research Database (Denmark)

    Storbjerg, Simon Haahr; Brunø, Thomas Ditlev

    2012-01-01

    Although modularization is becoming a welldescribed and broadly applied concept, many of today’s firms still struggle to realize the promised benefits of this approach. Managing modularization is a complex matter, and in spite of this, a topic that has received far less attention compared...... to theories and methods concerning modularization of technical systems.Recognizing the need for guidance to realize the benefits of modularity, the purpose of this study is through a literature study and a case study to improve the insight into the organizational and systems related enablers and barriers...... with regard to obtaining the full potential of modularization....

  3. Modular Algorithm Testbed Suite (MATS): A Software Framework for Automatic Target Recognition

    Science.gov (United States)

    2017-01-01

    NAVAL SURFACE WARFARE CENTER PANAMA CITY DIVISION PANAMA CITY, FL 32407-7001 TECHNICAL REPORT NSWC PCD TR-2017-004 MODULAR ...31-01-2017 Technical Modular Algorithm Testbed Suite (MATS): A Software Framework for Automatic Target Recognition DR...flexible platform to facilitate the development and testing of ATR algorithms. To that end, NSWC PCD has created the Modular Algorithm Testbed Suite

  4. Understanding Complex Construction Systems Through Modularity

    DEFF Research Database (Denmark)

    Jensen, Tor Clarke; Bekdik, Baris; Thuesen, Christian

    2014-01-01

    This paper develops a framework for understanding complexity in construction projects by combining theories of complexity management and modularization. The framework incorporates three dimensions of product, process, and organizational modularity with the case of gypsum wall elements. The analysis...... system, rather than a modular, although the industry forces modular organizational structures. This creates a high complexity degree caused by the non-alignment of building parts and organizations and the frequent swapping of modules....... finds that the main driver of complexity is the fragmentation of the design and production, which causes the production modules to construct and install new product types and variants for each project as the designers are swapped for every project. The many interfaces are characteristics of an integral...

  5. Endomorphisms on half-sided modular inclusions

    International Nuclear Information System (INIS)

    Svegstrup, Rolf Dyre

    2006-01-01

    In algebraic quantum field theory we consider nets of von Neumann algebras indexed over regions of the space time. Wiesbrock [''Conformal quantum field theory and half-sided modular inclusions of von Neumann algebras,'' Commun. Math. Phys. 158, 537-543 (1993)] has shown that strongly additive nets of von Neumann algebras on the circle are in correspondence with standard half-sided modular inclusions. We show that a finite index endomorphism on a half-sided modular inclusion extends to a finite index endomorphism on the corresponding net of von Neumann algebras on the circle. Moreover, we present another approach to encoding endomorphisms on nets of von Neumann algebras on the circle into half-sided modular inclusions. There is a natural way to associate a weight to a Moebius covariant endomorphism. The properties of this weight have been studied by Bertozzini et al. [''Covariant sectors with infinite dimension and positivity of the energy,'' Commun. Math. Phys. 193, 471-492 (1998)]. In this paper we show the converse, namely, how to associate a Moebius covariant endomorphism to a given weight under certain assumptions, thus obtaining a correspondence between a class of weights on a half-sided modular inclusion and a subclass of the Moebius covariant endomorphisms on the associated net of von Neumann algebras. This allows us to treat Moebius covariant endomorphisms in terms of weights on half-sided modular inclusions. As our aim is to provide a framework for treating endomorphisms on nets of von Neumann algebras in terms of the apparently simpler objects of weights on half-sided modular inclusions, we lastly give some basic results for manipulations with such weights

  6. Synchronization in complex networks with a modular structure.

    Science.gov (United States)

    Park, Kwangho; Lai, Ying-Cheng; Gupte, Saurabh; Kim, Jong-Won

    2006-03-01

    Networks with a community (or modular) structure arise in social and biological sciences. In such a network individuals tend to form local communities, each having dense internal connections. The linkage among the communities is, however, much more sparse. The dynamics on modular networks, for instance synchronization, may be of great social or biological interest. (Here by synchronization we mean some synchronous behavior among the nodes in the network, not, for example, partially synchronous behavior in the network or the synchronizability of the network with some external dynamics.) By using a recent theoretical framework, the master-stability approach originally introduced by Pecora and Carroll in the context of synchronization in coupled nonlinear oscillators, we address synchronization in complex modular networks. We use a prototype model and develop scaling relations for the network synchronizability with respect to variations of some key network structural parameters. Our results indicate that random, long-range links among distant modules is the key to synchronization. As an application we suggest a viable strategy to achieve synchronous behavior in social networks.

  7. BetaWB - A language for modular representation of biological systems

    DEFF Research Database (Denmark)

    Ihekwaba, Adoha; Larcher, Roberto; Mardare, Radu Iulian

    2007-01-01

    A. Ihekwaba, R. Larcher, R. Mardare, C. Priami. BetaWB - A language for modular representation of biological systems. In Proc. of International Conference on Systems Biology (ICSB), 2007......A. Ihekwaba, R. Larcher, R. Mardare, C. Priami. BetaWB - A language for modular representation of biological systems. In Proc. of International Conference on Systems Biology (ICSB), 2007...

  8. Crystallization and preliminary crystallographic analysis of an octaketide-producing plant type III polyketide synthase

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Hiroyuki [Mitsubishi Kagaku Institute of Life Sciences (MITILS), 11 Minamiooya, Machida, Tokyo 194-8511 (Japan); Kondo, Shin; Kato, Ryohei [Innovation Center Yokohama, Mitsubishi Chemical Corporation, 1000 Kamoshida, Aoba, Yokohama, Kanagawa 227-8502 (Japan); Wanibuchi, Kiyofumi; Noguchi, Hiroshi [School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526 (Japan); Sugio, Shigetoshi, E-mail: sugio.shigetoshi@mw.m-kagaku.co.jp [Innovation Center Yokohama, Mitsubishi Chemical Corporation, 1000 Kamoshida, Aoba, Yokohama, Kanagawa 227-8502 (Japan); Abe, Ikuro, E-mail: sugio.shigetoshi@mw.m-kagaku.co.jp [School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kohno, Toshiyuki, E-mail: sugio.shigetoshi@mw.m-kagaku.co.jp [Mitsubishi Kagaku Institute of Life Sciences (MITILS), 11 Minamiooya, Machida, Tokyo 194-8511 (Japan)

    2007-11-01

    Octaketide synthase from A. arborescens has been overexpressed in E. coli, purified and crystallized. Diffraction data have been collected to 2.6 Å. Octaketide synthase (OKS) from Aloe arborescens is a plant-specific type III polyketide synthase that produces SEK4 and SEK4b from eight molecules of malonyl-CoA. Recombinant OKS expressed in Escherichia coli was crystallized by the hanging-drop vapour-diffusion method. The crystals belonged to space group I422, with unit-cell parameters a = b = 110.2, c = 281.4 Å, α = β = γ = 90.0°. Diffraction data were collected to 2.6 Å resolution using synchrotron radiation at BL24XU of SPring-8.

  9. Modular thought in the circuit analysis

    Science.gov (United States)

    Wang, Feng

    2018-04-01

    Applied to solve the problem of modular thought, provides a whole for simplification's method, the complex problems have become of, and the study of circuit is similar to the above problems: the complex connection between components, make the whole circuit topic solution seems to be more complex, and actually components the connection between the have rules to follow, this article mainly tells the story of study on the application of the circuit modular thought. First of all, this paper introduces the definition of two-terminal network and the concept of two-terminal network equivalent conversion, then summarizes the common source resistance hybrid network modular approach, containing controlled source network modular processing method, lists the common module, typical examples analysis.

  10. Identification of drivers for modular production

    DEFF Research Database (Denmark)

    Brunoe, Thomas Ditlev; Bossen, Jacob; Nielsen, Kjeld

    2015-01-01

    Todays competitive environment in industry creates a need for companies to enhance their ability to introduce new products faster. To increase rampup speed reconfigurable manufacturing systems is a promising concept, however to implement this production platforms and modular manufacturing...... is required. This paper presents an analysis whether and which module drivers from general product development can be applied to the development process of a modular manufacturing system. The result is a compiled list of modular drivers for manufacturing and examples of their use....

  11. Activity-based costing as a method for assessing the economics of modularization

    DEFF Research Database (Denmark)

    Thyssen, Jesper; Israelsen, Poul; Jørgensen, Brian

    2006-01-01

    The paper accounts for an Activity-Based Costing (ABC) analysis supporting decision-making concerning product modularity. The ABC analysis carried out is communicated to decision-makers by telling how much higher the variable cost of the multi-purpose module can be compared to the average variable...... cost for the product-unique modules that it substitutes to break even in total cost. The analysis provides the platform for stating three general rules of cost efficiency of modularization, which in combination identify the highest profit potential of product modularization. Finally the analysis points...... to problems of using ABC in costing modularity, i.e. handling of R&D costs and identification of product profitability upon an enhanced modularization....

  12. Modular Structures in a Multinational Force Headquarters

    National Research Council Canada - National Science Library

    Stewart, K; Christie, M

    2004-01-01

    .... It is proposed that future Multinational Force (MNF) military headquarters (HQ) can achieve this flexibility through a modular organizational structure enabled by networked information management and communication technologies...

  13. A novel infrastructure modularity index for the segmentation of water distribution networks

    Science.gov (United States)

    Giustolisi, O.; Ridolfi, L.

    2014-10-01

    The search for suitable segmentations is a challenging and urgent issue for the analysis, planning and management of complex water distribution networks (WDNs). In fact, complex and large size hydraulic systems require the division into modules in order to simplify the analysis and the management tasks. In the complex network theory, modularity index has been proposed as a measure of the strength of the network division into modules and its maximization is used in order to identify community of nodes (i.e., modules) which are characterized by strong interconnections. Nevertheless, modularity index needs to be revised considering the specificity of the hydraulic systems as infrastructure systems. To this aim, the classic modularity index has been recently modified and tailored for WDNs. Nevertheless, the WDN-oriented modularity is affected by the resolution limit stemming from classic modularity index. Such a limit hampers the identification/design of small modules and this is a major drawback for technical tasks requiring a detailed resolution of the network segmentation. In order to get over this problem, we propose a novel infrastructure modularity index that is not affected by the resolution limit of the classic one. The rationale and good features of the proposed index are theoretically demonstrated and discussed using two real hydraulic networks.

  14. A Modular, Reconfigurable Mold for a Soft Robotic Gripper Design Activity

    Directory of Open Access Journals (Sweden)

    Jiawei Zhang

    2017-09-01

    Full Text Available Soft robotics is an emerging field with strong potential to serve as an educational tool due to its advantages such as low costs and shallow learning curves. In this paper, we introduce a modular and reconfigurable mold for flexible design of pneumatic soft robotic grippers. By using simple assembly kits, students at all levels are able to design and construct soft robotic grippers that vary in function and performance. The process of constructing the modular mold enables students to understand how design choices impact system performance. Our unique modular mold allows students to select the number and length of fingers in a gripper, as well as to adjust the internal geometry of the pneumatic actuator cavity, which dictates how and where bending of a finger occurs. In addition, the mold may be deconstructed and reconfigured, which allows for fast iterative design and lowers material costs (since a new mold does not need to be made to implement a design change. We further demonstrate the feasibility of the modular mold by implementing it in a soft robot design activity in classrooms and showing a sufficiently high rate of student success in designing and constructing a functional soft robotic gripper.

  15. A proposal of optimal sampling design using a modularity strategy

    Science.gov (United States)

    Simone, A.; Giustolisi, O.; Laucelli, D. B.

    2016-08-01

    In real water distribution networks (WDNs) are present thousands nodes and optimal placement of pressure and flow observations is a relevant issue for different management tasks. The planning of pressure observations in terms of spatial distribution and number is named sampling design and it was faced considering model calibration. Nowadays, the design of system monitoring is a relevant issue for water utilities e.g., in order to manage background leakages, to detect anomalies and bursts, to guarantee service quality, etc. In recent years, the optimal location of flow observations related to design of optimal district metering areas (DMAs) and leakage management purposes has been faced considering optimal network segmentation and the modularity index using a multiobjective strategy. Optimal network segmentation is the basis to identify network modules by means of optimal conceptual cuts, which are the candidate locations of closed gates or flow meters creating the DMAs. Starting from the WDN-oriented modularity index, as a metric for WDN segmentation, this paper proposes a new way to perform the sampling design, i.e., the optimal location of pressure meters, using newly developed sampling-oriented modularity index. The strategy optimizes the pressure monitoring system mainly based on network topology and weights assigned to pipes according to the specific technical tasks. A multiobjective optimization minimizes the cost of pressure meters while maximizing the sampling-oriented modularity index. The methodology is presented and discussed using the Apulian and Exnet networks.

  16. Modular robotic tiles: experiments for children with autism

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Dam Pedersen, Martin; Beck, Richard

    2009-01-01

    rehabilitation), and with the proper radio communication mechanism they may give unique possibilities for documentation of the physical activity (e.g., therapeutic treatment). A major point of concern in modular robotics is the connection mechanism, so we investigated different solutions for the connection......We developed a modular robotic tile and a system composed of a number of these modular robotic tiles. The system composed of the modular robotic tiles engages the user in physical activities, e.g., physiotherapy, sports, fitness, and entertainment. The modular robotic tiles motivate the user...... to perform physical activities by providing immediate feedback based upon their physical interaction with the system. With the modular robotic tiles, the user is able to make new physical set-ups within less than a minute. The tiles are applicable for different forms of physical activities (e.g., therapeutic...

  17. Contrasting platform thinking and product modularization

    DEFF Research Database (Denmark)

    Boer, Henrike Engele Elisabeth; Persson, Magnus

    2015-01-01

    Product modularization and platform thinking are both practices that seek to alleviate the negative impact of product customization and variety on internal operations by relying on economies of substitution. Through the use of a standardized pool of components and interfaces, these practices aim...... to create a broad spectrum of product choices. At first sight, product modularization and platform thinking are very similar. The difference between these practices can, however, be found in the manner in which they employ standardization. Where product modularization focuses on creating standardized...... variants. There is a general lack of research addressing the contingency factors that dictate the appropriateness of the use of product modularization and platform thinking in different contexts. To our knowledge, no large-scale empirical research has been reported in which the two concepts, contextual...

  18. Modular low-voltage electron emitters

    International Nuclear Information System (INIS)

    Berejka, Anthony J.

    2005-01-01

    Modular, low-voltage electron emitters simplify electron beam (EB) technology for many industrial uses and for research and development. Modular electron emitters are produced in quantity as sealed systems that are evacuated at the factory, eliminating the need for vacuum pumps at the point of use. A plug-out-plug-in method of replacement facilitates servicing. By using an ultra-thin 6-7 μm titanium foil window, solid-state power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, these modular units combine ease of use and electrical transfer efficiency at voltages that can be varied between 80 kV and 150 kV with beam currents up to 40 mA per 25 cm across the beam window. These new devices have been made in three widths: 5 cm, 25 cm, and 40 cm. Details of the beam construction and illustrations of industrial uses will be presented. Traditional uses in the graphic arts and coatings areas have welcomed this modular technology as well as uses for surface sterilization. Being compact and lightweight (∼15 kg/emitter), these modular beams have been configured around complex shapes to achieve three-dimensional surface curing at high production rates

  19. Modular low-voltage electron emitters

    Science.gov (United States)

    Berejka, Anthony J.

    2005-12-01

    Modular, low-voltage electron emitters simplify electron beam (EB) technology for many industrial uses and for research and development. Modular electron emitters are produced in quantity as sealed systems that are evacuated at the factory, eliminating the need for vacuum pumps at the point of use. A plug-out-plug-in method of replacement facilitates servicing. By using an ultra-thin 6-7 μm titanium foil window, solid-state power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, these modular units combine ease of use and electrical transfer efficiency at voltages that can be varied between 80 kV and 150 kV with beam currents up to 40 mA per 25 cm across the beam window. These new devices have been made in three widths: 5 cm, 25 cm, and 40 cm. Details of the beam construction and illustrations of industrial uses will be presented. Traditional uses in the graphic arts and coatings areas have welcomed this modular technology as well as uses for surface sterilization. Being compact and lightweight (∼15 kg/emitter), these modular beams have been configured around complex shapes to achieve three-dimensional surface curing at high production rates.

  20. Problems in the theory of modular forms

    CERN Document Server

    Murty, M Ram; Graves, Hester

    2016-01-01

    This book introduces the reader to the fascinating world of modular forms through a problem-solving approach. As such, besides researchers, the book can be used by the undergraduate and graduate students for self-instruction. The topics covered include q-series, the modular group, the upper half-plane, modular forms of level one and higher level, the Ramanujan τ-function, the Petersson inner product, Hecke operators, Dirichlet series attached to modular forms and further special topics. It can be viewed as a gentle introduction for a deeper study of the subject. Thus, it is ideal for non-experts seeking an entry into the field. .

  1. ClusterCAD: a computational platform for type I modular polyketide synthase design

    DEFF Research Database (Denmark)

    Eng, Clara H.; Backman, Tyler W. H.; Bailey, Constance B.

    2018-01-01

    barrier to the design of active variants, and identifying strategies to reliably construct functional PKS chimeras remains an active area of research. In this work, we formalize a paradigm for the design of PKS chimeras and introduce ClusterCAD as a computational platform to streamline and simplify...

  2. Modular Chemical Process Intensification: A Review.

    Science.gov (United States)

    Kim, Yong-Ha; Park, Lydia K; Yiacoumi, Sotira; Tsouris, Costas

    2017-06-07

    Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. These dramatic improvements lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. This article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.

  3. Summer School and Conference : Computations with Modular Forms

    CERN Document Server

    Wiese, Gabor

    2014-01-01

    This volume contains original research articles, survey articles and lecture notes related to the Computations with Modular Forms 2011 Summer School and Conference, held at the University of Heidelberg. A key theme of the Conference and Summer School was the interplay between theory, algorithms and experiment. The 14 papers offer readers both, instructional courses on the latest algorithms for computing modular and automorphic forms, as well as original research articles reporting on the latest developments in the field. The three Summer School lectures provide an introduction to modern algorithms together with some theoretical background for computations of and with modular forms, including computing cohomology of arithmetic groups, algebraic automorphic forms, and overconvergent modular symbols. The 11 Conference papers cover a wide range of themes related to computations with modular forms, including lattice methods for algebraic modular forms on classical groups, a generalization of the Maeda conjecture, ...

  4. A Modular Set of Mixed Reality Simulators for Blind and Guided Procedures

    Science.gov (United States)

    2017-08-01

    AWARD NUMBER: W81XWH-14-1-0113 TITLE: A modular set of mixed reality simulators for blind and guided procedures PRINCIPAL INVESTIGATOR...2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER A modular set of mixed reality simulators for blind and guided procedures 5b. GRANT NUMBER W81XWH...A Modular Set of Mixed Reality Simulators for “Blind” and Guided Procedures Award W81XWH-14-1-0113 Reporting Period: 8/1/2016 – 7/31/2017 (Year 3

  5. Modular Software-Defined Radio

    Directory of Open Access Journals (Sweden)

    Rhiemeier Arnd-Ragnar

    2005-01-01

    Full Text Available In view of the technical and commercial boundary conditions for software-defined radio (SDR, it is suggestive to reconsider the concept anew from an unconventional point of view. The organizational principles of signal processing (rather than the signal processing algorithms themselves are the main focus of this work on modular software-defined radio. Modularity and flexibility are just two key characteristics of the SDR environment which extend smoothly into the modeling of hardware and software. In particular, the proposed model of signal processing software includes irregular, connected, directed, acyclic graphs with random node weights and random edges. Several approaches for mapping such software to a given hardware are discussed. Taking into account previous findings as well as new results from system simulations presented here, the paper finally concludes with the utility of pipelining as a general design guideline for modular software-defined radio.

  6. Higher-order (non-)modularity

    DEFF Research Database (Denmark)

    Appel, Claus; van Oostrom, Vincent; Simonsen, Jakob Grue

    2010-01-01

    We show that, contrary to the situation in first-order term rewriting, almost none of the usual properties of rewriting are modular for higher-order rewriting, irrespective of the higher-order rewriting format. We show that for the particular format of simply typed applicative term rewriting...... systems modularity of confluence, normalization, and termination can be recovered by imposing suitable linearity constraints....

  7. A Case Study in Modular Programming

    DEFF Research Database (Denmark)

    Christensen, Aske Simon; Midtgaard, Jan; Winther, Johnni

    We report our experience in using two different languages to build the same software project. Specifically, we have converted an entire undergraduate compiler course from using AspectJ, an aspect-oriented language, to using OCaml, a functional language. The course has evolved over a period of eig...... in a modular way....

  8. Amplification and diversity analysis of keto synthase domains of putative polyketide synthase genes in Aspergillus ochraceus and Aspergillus carbonarius producers of ochratoxin A

    International Nuclear Information System (INIS)

    Atoui, A.; Phong Dao, H.; Mathieu, F.; Lebrihi, A.

    2006-01-01

    The diversity of polyketide synthase (PKS) genes in Aspergillus ochraceus NRRL 3174 and Aspergil- lus carbonarius 2Mu134 has been investigated using different primer pairs previously developed for the ketosynthase (KS) domain of fungal PKSs. Nine different KS domain sequences in A. ochraceus NRRL 3174 as well as five different KS domain sequences in A. carbonarius 2Mu134 have been identified. The identified KS fragments were distributed in five different clusters on the phylogenetic tree, indicating that they most probably represent PKSs responsible for different functions. (author)

  9. Duality ensures modular covariance

    International Nuclear Information System (INIS)

    Li Miao; Yu Ming

    1989-11-01

    We show that the modular transformations for one point functions on the torus, S(n), satisfy the polynomial equations derived by Moore and Seiberg, provided the duality property of the model is ensured. The formula for S(n) is derived by us previously and should be valid for any conformal field theory. As a consequence, the full consistency conditions for modular invariance at higher genus are completely guaranteed by duality of the theory on the sphere. (orig.)

  10. Episodic Memory Retrieval Benefits from a Less Modular Brain Network Organization

    Science.gov (United States)

    2017-01-01

    Most complex cognitive tasks require the coordinated interplay of multiple brain networks, but the act of retrieving an episodic memory may place especially heavy demands for communication between the frontoparietal control network (FPCN) and the default mode network (DMN), two networks that do not strongly interact with one another in many task contexts. We applied graph theoretical analysis to task-related fMRI functional connectivity data from 20 human participants and found that global brain modularity—a measure of network segregation—is markedly reduced during episodic memory retrieval relative to closely matched analogical reasoning and visuospatial perception tasks. Individual differences in modularity were correlated with memory task performance, such that lower modularity levels were associated with a lower false alarm rate. Moreover, the FPCN and DMN showed significantly elevated coupling with each other during the memory task, which correlated with the global reduction in brain modularity. Both networks also strengthened their functional connectivity with the hippocampus during the memory task. Together, these results provide a novel demonstration that reduced modularity is conducive to effective episodic retrieval, which requires close collaboration between goal-directed control processes supported by the FPCN and internally oriented self-referential processing supported by the DMN. SIGNIFICANCE STATEMENT Modularity, an index of the degree to which nodes of a complex system are organized into discrete communities, has emerged as an important construct in the characterization of brain connectivity dynamics. We provide novel evidence that the modularity of the human brain is reduced when individuals engage in episodic memory retrieval, relative to other cognitive tasks, and that this state of lower modularity is associated with improved memory performance. We propose a neural systems mechanism for this finding where the nodes of the frontoparietal

  11. Anomalies and modular invariance in string theory

    International Nuclear Information System (INIS)

    Schellekens, A.N.; Warner, N.P.

    1986-01-01

    All known anomaly cancellations of heterotic string theories are derived directly from one-loop modular invariance, and are shown to be related to a property of modular functions of weight 2. Using modular invariance infinite classes of anomaly free field theories are constructed in (8m+2) dimensions for any m. A generating function is obtained for the anomalies of string-related field theories in (8m+2) dimensions. (orig.)

  12. Individualization and Modularization of Vocational Education Instructional Materials. An Annotated Bibliography of Publications and Projects. Bibliography Series No. 32.

    Science.gov (United States)

    Magisos, Joel H., Comp.; Stakelon, Anne E., Comp.

    This annotated bibliography is designed to assist applicants for research grants under part C (section 131a) of the amendments to the Vocational Education Act of 1963 by providing access to documents, journal articles, and current projects related to the individualization and modularization of vocational education instructional materials. The…

  13. The cost of customising: assessing the performance of a modular product programme

    DEFF Research Database (Denmark)

    Ulrikkeholm, Jeppe Bjerrum; Hvam, Lars

    2014-01-01

    Introducing modularity in product development as a mean for dealing with increasing levels of variance within product portfolios has been widely and successfully applied by many companies. It is however important to acknowledge that challenges related to product portfolio variance...... will not disappear after introducing modularity. A new type of variance on modular level is likely to develop over time. Empirical work carried out in a large international engineering company designing customer specific products confirms that increasing levels of variance within module portfolios can lead...

  14. Modularity for Modulating Exercises and Levels

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Nielsen, Camilla Balslev

    2011-01-01

    The modular interactive tiles aim at engaging anybody (elderly, carer, hospital personnel, children) in performing playful and motivating physical activities. Inspired by modular robotics, each tile is a self-contained module with processing power and communication to neighbouring modules....... In this paper, we investigate the therapeutic use. We show how the tiles are tested extensively with cardiac patients, COLD patients and stroke patients in hospitals and in the private homes of patients and elderly. We find that therapists are using the modular aspect of the tiles for personalized training...

  15. Modular high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Shepherd, L.R.

    1988-01-01

    The high financial risk involved in building large nuclear power reactors has been a major factor in halting investment in new plant and in bringing further technical development to a standstill. Increased public concern about the safety of nuclear plant, particularly after Chernobyl, has contributed to this stagnation. Financial and technical risk could be reduced considerably by going to small modular units, which would make it possible to build up power station capacity in small steps. Such modular plant, based on the helium-cooled high temperature reactor (HTR), offers remarkable advantages in terms of inherent safety characteristics, partly because of the relatively small size of the individual modules but more on account of the enormous thermal capacity and high temperature margins of the graphitic reactor assemblies. Assessments indicate that, in the USA, the cost of power from the modular systems would be less than that from conventional single reactor plant, up to about 600 MW(e), and only marginally greater above that level, a margin that should be offset by the shorter time required in bringing the modular units on line to earn revenue. The modular HTR would be particularly appropriate in the UK, because of the considerable British industrial background in gas-cooled reactors, and could be a suitable replacement for Magnox. The modular reactor would be particularly suited to combined heat and power schemes and would offer great potential for the eventual development of gas turbine power conversion and the production of high-temperature process heat. (author)

  16. The TOTEM modular trigger system

    Energy Technology Data Exchange (ETDEWEB)

    Bagliesi, M.G., E-mail: mg.bagliesi@pi.infn.i [University of Siena and INFN Pisa (Italy); Berretti, M.; Cecchi, R.; Greco, V.; Lami, S.; Latino, G.; Oliveri, E.; Pedreschi, E.; Scribano, A.; Spinella, F.; Turini, N. [University of Siena and INFN Pisa (Italy)

    2010-05-21

    The TOTEM experiment will measure the total cross-section with the luminosity independent method and study elastic and diffractive scattering at the LHC. We are developing a modular trigger system, based on programmable logic, that will select meaningful events within 2.5{mu}s. The trigger algorithm is based on a tree structure in order to obtain information compression. The trigger primitive is generated directly on the readout chip, VFAT, that has a specific fast output that gives low resolution hits information. In two of the TOTEM detectors, Roman Pots and T2, a coincidence chip will perform track recognition directly on the detector readout boards, while for T1 the hits are transferred from the VFATs to the trigger hardware. Starting from more than 2000 bits delivered by the detector electronics, we extract, in a first step, six trigger patterns of 32 LVDS signals each; we build, then, on a dedicated board, a 1-bit (L1) trigger signal for the TOTEM experiment and 16 trigger bits to the CMS experiment global trigger system for future common data taking.

  17. The TOTEM modular trigger system

    International Nuclear Information System (INIS)

    Bagliesi, M.G.; Berretti, M.; Cecchi, R.; Greco, V.; Lami, S.; Latino, G.; Oliveri, E.; Pedreschi, E.; Scribano, A.; Spinella, F.; Turini, N.

    2010-01-01

    The TOTEM experiment will measure the total cross-section with the luminosity independent method and study elastic and diffractive scattering at the LHC. We are developing a modular trigger system, based on programmable logic, that will select meaningful events within 2.5μs. The trigger algorithm is based on a tree structure in order to obtain information compression. The trigger primitive is generated directly on the readout chip, VFAT, that has a specific fast output that gives low resolution hits information. In two of the TOTEM detectors, Roman Pots and T2, a coincidence chip will perform track recognition directly on the detector readout boards, while for T1 the hits are transferred from the VFATs to the trigger hardware. Starting from more than 2000 bits delivered by the detector electronics, we extract, in a first step, six trigger patterns of 32 LVDS signals each; we build, then, on a dedicated board, a 1-bit (L1) trigger signal for the TOTEM experiment and 16 trigger bits to the CMS experiment global trigger system for future common data taking.

  18. A Modular Instant Messaging System

    OpenAIRE

    Mohamad Raad; Zouhair Bazzal; Majd Ghareeb; Hanan Farhat; Semar Bahmad

    2017-01-01

    Instant Messaging (IM) Android applications are a trend nowadays. These applications are categorized according to their features: usability, flexibility, privacy and security. However, IM applications tend to be inflexible in terms of functionality offered. The “Dble-U” system was developed as a solution to this inflexibility, with a focus on privacy as an example use case. “Dble-U” is a configurable modular system consisting of an Android chatting application, a privacy controller applicatio...

  19. Modular co-evolution of metabolic networks

    Directory of Open Access Journals (Sweden)

    Yu Zhong-Hao

    2007-08-01

    Full Text Available Abstract Background The architecture of biological networks has been reported to exhibit high level of modularity, and to some extent, topological modules of networks overlap with known functional modules. However, how the modular topology of the molecular network affects the evolution of its member proteins remains unclear. Results In this work, the functional and evolutionary modularity of Homo sapiens (H. sapiens metabolic network were investigated from a topological point of view. Network decomposition shows that the metabolic network is organized in a highly modular core-periphery way, in which the core modules are tightly linked together and perform basic metabolism functions, whereas the periphery modules only interact with few modules and accomplish relatively independent and specialized functions. Moreover, over half of the modules exhibit co-evolutionary feature and belong to specific evolutionary ages. Peripheral modules tend to evolve more cohesively and faster than core modules do. Conclusion The correlation between functional, evolutionary and topological modularity suggests that the evolutionary history and functional requirements of metabolic systems have been imprinted in the architecture of metabolic networks. Such systems level analysis could demonstrate how the evolution of genes may be placed in a genome-scale network context, giving a novel perspective on molecular evolution.

  20. Does habitat variability really promote metabolic network modularity?

    Science.gov (United States)

    Takemoto, Kazuhiro

    2013-01-01

    The hypothesis that variability in natural habitats promotes modular organization is widely accepted for cellular networks. However, results of some data analyses and theoretical studies have begun to cast doubt on the impact of habitat variability on modularity in metabolic networks. Therefore, we re-evaluated this hypothesis using statistical data analysis and current metabolic information. We were unable to conclude that an increase in modularity was the result of habitat variability. Although horizontal gene transfer was also considered because it may contribute for survival in a variety of environments, closely related to habitat variability, and is known to be positively correlated with network modularity, such a positive correlation was not concluded in the latest version of metabolic networks. Furthermore, we demonstrated that the previously observed increase in network modularity due to habitat variability and horizontal gene transfer was probably due to a lack of available data on metabolic reactions. Instead, we determined that modularity in metabolic networks is dependent on species growth conditions. These results may not entirely discount the impact of habitat variability and horizontal gene transfer. Rather, they highlight the need for a more suitable definition of habitat variability and a more careful examination of relationships of the network modularity with horizontal gene transfer, habitats, and environments.

  1. Criteria for software modularization

    Science.gov (United States)

    Card, David N.; Page, Gerald T.; Mcgarry, Frank E.

    1985-01-01

    A central issue in programming practice involves determining the appropriate size and information content of a software module. This study attempted to determine the effectiveness of two widely used criteria for software modularization, strength and size, in reducing fault rate and development cost. Data from 453 FORTRAN modules developed by professional programmers were analyzed. The results indicated that module strength is a good criterion with respect to fault rate, whereas arbitrary module size limitations inhibit programmer productivity. This analysis is a first step toward defining empirically based standards for software modularization.

  2. Generalized epidemic process on modular networks.

    Science.gov (United States)

    Chung, Kihong; Baek, Yongjoo; Kim, Daniel; Ha, Meesoon; Jeong, Hawoong

    2014-05-01

    Social reinforcement and modular structure are two salient features observed in the spreading of behavior through social contacts. In order to investigate the interplay between these two features, we study the generalized epidemic process on modular networks with equal-sized finite communities and adjustable modularity. Using the analytical approach originally applied to clique-based random networks, we show that the system exhibits a bond-percolation type continuous phase transition for weak social reinforcement, whereas a discontinuous phase transition occurs for sufficiently strong social reinforcement. Our findings are numerically verified using the finite-size scaling analysis and the crossings of the bimodality coefficient.

  3. Modular Universal Scalable Ion-trap Quantum Computer

    Science.gov (United States)

    2016-06-02

    SECURITY CLASSIFICATION OF: The main goal of the original MUSIQC proposal was to construct and demonstrate a modular and universally- expandable ion...Distribution Unlimited UU UU UU UU 02-06-2016 1-Aug-2010 31-Jan-2016 Final Report: Modular Universal Scalable Ion-trap Quantum Computer The views...P.O. Box 12211 Research Triangle Park, NC 27709-2211 Ion trap quantum computation, scalable modular architectures REPORT DOCUMENTATION PAGE 11

  4. Development of SC structure modularization in Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Mun, Taeyoup [Korea Hydro and Nuclear Power Co., Ltd., Seoul (Korea, Republic of)

    2008-04-15

    New Focus on NPP are Rising Concerns on Global Warming, Potential energy crisis (geo-political), Improved reliability and safety of nuclear power plant, Advent of Generation 3+ NPP technology and Economical Energy Resource. New NPPs are 6 units in Korea and 23 in Asia being built, 32 units being planned in China by 2020 (150 by 2050), 10 units being planned in US by 2020 and IAEA expects $200 billions on NPP construction next 25 years (up to 30% of total world energy). {open_square} SC(Steel Plate Concrete) structure {center_dot} Steel Plate is used as a Structural Element instead of Reinforcing Bars in RC {center_dot} SC structure consists of Steel Plate with Headed Studs. Connected by Tie-bars - The Primary Purpose of Tie-bars is to Stiffen and Hold Together the Plates during Construction Process - Headed Studs are Welded to the Inside of Steel Plate for composite action {open_square} Benefits of SC Structure {center_dot} Shorten Construction Duration for Re bar, Forming and Scaffolding Works {center_dot} Minimize Site Labors {center_dot} Improve the Construction Quality {center_dot} Enable Construction Sites to be kept Clean {open_square} SC Modularization {center_dot} Fit for Modular Construction for Structural Features {center_dot} Fit for Modular Construction for Structural Features {center_dot} Inattentively Effective for Integrated Modules {center_dot} Pre-fabrication, Pre-assembly and Modularization {open_square} Project Overview {center_dot} Project Name: Development of SC structure for Modularization in NPP {center_dot} Project Type: Electric Power Industry R and D (Ministry of Knowledge Economy) {center_dot} Duration: Sep. 2005 {approx} Aug. 2008 (36 Months) {center_dot} Research Team and Scopes - Project Management: Korea Hydro and Nuclear Power Company (KHNP) - Development of Code and Standards for SC Structure: Korea Society of Steel Construction (KSSC) Korea Electric Power Research Institute (KEPRI) - Development of SC Structural Analysis and Design

  5. Modularity in automakers: a research under the strategy point of view

    Directory of Open Access Journals (Sweden)

    José Antonio Carnevalli

    2015-06-01

    Full Text Available The relationships between the application of modularity in the car industry and the organizational strategies are a study field which needs to be better understood. This study is intended to research the organizational strategies and competencies inherent to the modularity process in the car-making enterprises. Case-based research was conducted in two car-makers. The study shows that the modularity process has been used to transfer fixed costs to the suppliers generating dependence among the enterprises and making the change of supplier difficult whenever necessary. There is concern of the car-makers in creating strategies capable of preventing the loss of know how. For this reason, not all the projects of the modules are outsourced. It was found that the enterprises studied reached partially the essential competencies and operate at the level of the distinctive competencies, but enough to give support to modular strategy. The set of organizational strategies and competencies conquered held in the construction of competitive advantage in those enterprises.

  6. Advantages of a Modular Mars Surface Habitat Approach

    Science.gov (United States)

    Rucker, Michelle A.; Hoffman, Stephan J.; Andrews, Alida; Watts, Kevin

    2018-01-01

    Early crewed Mars mission concepts developed by the National Aeronautics and Space Administration (NASA) assumed a single, large habitat would house six crew members for a 500-day Mars surface stay. At the end of the first mission, all surface equipment, including the habitat, -would be abandoned and the process would be repeated at a different Martian landing site. This work was documented in a series of NASA publications culminating with the Mars Design Reference Mission 5.0 (NASA-SP-2009-566). The Evolvable Mars Campaign (EMC) explored whether re-using surface equipment at a single landing site could be more affordable than the Apollo-style explore-abandon-repeat mission cadence. Initial EMC assumptions preserved the single, monolithic habitat, the only difference being a new requirement to reuse the surface habitat for multiple expedition crews. A trade study comparing a single large habitat versus smaller, modular habitats leaned towards the monolithic approach as more mass-efficient. More recent work has focused on the operational aspects of building up Mars surface infrastructure over multiple missions, and has identified compelling advantages of the modular approach that should be considered before making a final decision. This paper explores Mars surface mission operational concepts and integrated system analysis, and presents an argument for the modular habitat approach.

  7. Sambot II: A self-assembly modular swarm robot

    Science.gov (United States)

    Zhang, Yuchao; Wei, Hongxing; Yang, Bo; Jiang, Cancan

    2018-04-01

    The new generation of self-assembly modular swarm robot Sambot II, based on the original generation of self-assembly modular swarm robot Sambot, adopting laser and camera module for information collecting, is introduced in this manuscript. The visual control algorithm of Sambot II is detailed and feasibility of the algorithm is verified by the laser and camera experiments. At the end of this manuscript, autonomous docking experiments of two Sambot II robots are presented. The results of experiments are showed and analyzed to verify the feasibility of whole scheme of Sambot II.

  8. When modularization fails to occur: a developmental perspective.

    Science.gov (United States)

    D'Souza, Dean; Karmiloff-Smith, Annette

    2011-05-01

    We argue that models of adult cognition defined in terms of independently functioning modules cannot be applied to development, whether typical or atypical. The infant brain starts out highly interconnected, and it is only over developmental time that neural networks become increasingly specialized-that is, relatively modularized. In the case of atypical development, even when behavioural scores fall within the normal range, they are frequently underpinned by different cognitive and neural processes. In other words, in neurodevelopmental disorders the gradual process of relative modularization may fail to occur.

  9. Targeting a polyketide synthase gene for Aspergillus carbonarius quantification and ochratoxin A assessment in grapes using real-time PCR

    International Nuclear Information System (INIS)

    Atoui, A.; Mathieu, F.; Lebrihi, A.

    2007-01-01

    Aspergillus carbonarius is an ochratoxin producing fungus that has been considered to be responsible of the ochratoxin A (OTA) contamination in grapes and wine. In order to monitor and quantify A. carbonarius, a specific primer pair Ac12RL O TAF/Ac12RL O TAR has been designed from the acyltransferase (AT) domain of the polyketide synthase sequence Ac12RL3 to amplify 141 bp PCR product. Among the mycotoxigenic fungi tested, only A. carbonarius gave a positive result. This specific primer pair was also successfully employed in real-time PCR conjugated with SYBR Green I dye for the direct quantification of this fungus in grape samples. A positive correlation (R2 = 0.81) was found between A. carbonarius DNA content and OTA concentration in 72 grape samples, allowing for the estimation of the potential risk from OTA contamination. Consequently, this work offers a quick alternative to conventional methods of OTA quantification and mycological detection and quantification of A. carbonarius in grapes. (author)

  10. A modular projection autostereoscopic system for stereo cinema

    Science.gov (United States)

    Elkhov, Victor A.; Kondratiev, Nikolai V.; Ovechkis, Yuri N.; Pautova, Larisa V.

    2009-02-01

    The lenticular raster system for 3D movies non-glasses show designed by NIKFI demonstrated commercially in Moscow in the 40'st of the last century. Essential lack of this method was narrow individual viewing zone as only two images on the film used. To solve this problem, we propose to use digital video projective system with modular principle of its design. Increase of the general number of the pixels forming the stereo image is reached by using of more than one projector. The modular projection autostereoscopic system for demonstration of the 3D movies includes diffuser screen; lenticular plate located in front of the screen; projective system consisted from several projectors and the block of parallax panoramogram fragments creator. By means of this block the parallax panoramogram is broken into fragments which quantity corresponds to number of projectors. For the large dimension lenticular screen making rectangular fragments of inclined raster were joined in a uniform leaf. To obtain the needed focal distance of the screen lenses we used immersion - aqueous solution of glycerin. The immersion also let essentially decrease visibility of fragments joints. An experimental prototype of the modular projection autostereoscopic system was created to validate proposed system.

  11. The modular high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Lutz, D.E.; Lipps, A.J.

    1984-01-01

    Due to relatively high operating temperatures, the gas-cooled reactor has the potential to serve a wide variety of energy applications. This paper discusses the energy applications which can be served by the modular HTGR, the magnitude of the potential markets, and the HTGR product cost incentives relative to fossil fuel competition. Advantages of the HTGR modular systems are presented along with a description of the design features and performance characteristics of the current reference HTGR modular systems

  12. Algebra and Arithmetic of Modular Forms

    DEFF Research Database (Denmark)

    Rustom, Nadim

    In [Rus14b] and [Rus14a], we study graded rings of modular forms over congruence subgroups, with coefficients in subrings A of C, and determine bounds of the weights of modular forms constituting a minimal set of generators, as well as on the degree of the generators of the ideal of relations...... between them. We give an algorithm that computes the structures of these rings, and formulate conjectures on the minimal generating weight for modular forms with coefficients in Z. We discuss questions of finiteness of systems of Hecke eigenvalues modulo pm, for a prime p and an integer m ≥ 2, in analogy...

  13. Modularization, inter-functional integration and operational performance

    DEFF Research Database (Denmark)

    Boer, Henrike Engele Elisabeth; Boer, Harry

    2014-01-01

    for firms to indeed use product modularity beneficially, in particular inter-functional integration between manufacturing and purchasing, design and sales, respectively. The purpose of the paper is to investigate the direct performance effects of modularization, as well as the mediating effects of the three...... forms of integration in the modularization-performance relationship....

  14. Configurable double-sided modular jet impingement assemblies for electronics cooling

    Science.gov (United States)

    Zhou, Feng; Dede, Ercan Mehmet

    2018-05-22

    A modular jet impingement assembly includes an inlet tube fluidly coupled to a fluid inlet, an outlet tube fluidly coupled to a fluid outlet, and a modular manifold having a first distribution recess extending into a first side of the modular manifold, a second distribution recess extending into a second side of the modular manifold, a plurality of inlet connection tubes positioned at an inlet end of the modular manifold, and a plurality of outlet connection tubes positioned at an outlet end of the modular manifold. A first manifold insert is removably positioned within the first distribution recess, a second manifold insert is removably positioned within the second distribution recess, and a first and second heat transfer plate each removably coupled to the modular manifold. The first and second heat transfer plates each comprise an impingement surface.

  15. Hierarchical modularity in human brain functional networks

    Directory of Open Access Journals (Sweden)

    David Meunier

    2009-10-01

    Full Text Available The idea that complex systems have a hierarchical modular organization originates in the early 1960s and has recently attracted fresh support from quantitative studies of large scale, real-life networks. Here we investigate the hierarchical modular (or “modules-within-modules” decomposition of human brain functional networks, measured using functional magnetic resonance imaging (fMRI in 18 healthy volunteers under no-task or resting conditions. We used a customized template to extract networks with more than 1800 regional nodes, and we applied a fast algorithm to identify nested modular structure at several hierarchical levels. We used mutual information, 0 < I < 1, to estimate the similarity of community structure of networks in different subjects, and to identify the individual network that is most representative of the group. Results show that human brain functional networks have a hierarchical modular organization with a fair degree of similarity between subjects, I=0.63. The largest 5 modules at the highest level of the hierarchy were medial occipital, lateral occipital, central, parieto-frontal and fronto-temporal systems; occipital modules demonstrated less sub-modular organization than modules comprising regions of multimodal association cortex. Connector nodes and hubs, with a key role in inter-modular connectivity, were also concentrated in association cortical areas. We conclude that methods are available for hierarchical modular decomposition of large numbers of high resolution brain functional networks using computationally expedient algorithms. This could enable future investigations of Simon's original hypothesis that hierarchy or near-decomposability of physical symbol systems is a critical design feature for their fast adaptivity to changing environmental conditions.

  16. Automatic Modeling and Simulation of Modular Robots

    Science.gov (United States)

    Jiang, C.; Wei, H.; Zhang, Y.

    2018-03-01

    The ability of reconfiguration makes modular robots have the ability of adaptable, low-cost, self-healing and fault-tolerant. It can also be applied to a variety of mission situations. In this manuscript, a robot platform which relied on the module library was designed, based on the screw theory and module theory. Then, the configuration design method of the modular robot was proposed. And the different configurations of modular robot system have been built, including industrial mechanical arms, the mobile platform, six-legged robot and 3D exoskeleton manipulator. Finally, the simulation and verification of one system among them have been made, using the analyses of screw kinematics and polynomial planning. The results of experiments demonstrate the feasibility and superiority of this modular system.

  17. SMARBot: a modular miniature mobile robot platform

    Science.gov (United States)

    Meng, Yan; Johnson, Kerry; Simms, Brian; Conforth, Matthew

    2008-04-01

    Miniature robots have many advantages over their larger counterparts, such as low cost, low power, and easy to build a large scale team for complex tasks. Heterogeneous multi miniature robots could provide powerful situation awareness capability due to different locomotion capabilities and sensor information. However, it would be expensive and time consuming to develop specific embedded system for different type of robots. In this paper, we propose a generic modular embedded system architecture called SMARbot (Stevens Modular Autonomous Robot), which consists of a set of hardware and software modules that can be configured to construct various types of robot systems. These modules include a high performance microprocessor, a reconfigurable hardware component, wireless communication, and diverse sensor and actuator interfaces. The design of all the modules in electrical subsystem, the selection criteria for module components, and the real-time operating system are described. Some proofs of concept experimental results are also presented.

  18. Performance Evaluation of a Small Scale Modular Solar Trigeneration System

    Directory of Open Access Journals (Sweden)

    Handong Wang

    2014-01-01

    Full Text Available In order to improve the efficiency of solar thermal power (STP system, a novel modular system combining cooling, heating, and power generation (CCHP is proposed and introduced in this work. This modular CCHP system can simultaneously provide 10 kW electricity, −15~5°C coolant, and 60°C hot water to meet the requirements of cooling, heating, and electricity in a general family or other fields. The flow chart and working process of the modular system are introduced, based on which the energy and exergy efficiencies at the CCHP and STP operation modes are primarily evaluated and discussed. The results show that when the output electricity is constant, the overall efficiencies of energy and exergy of the system operating at the CCHP mode are 9.37 times and 2.62 times as big as those of the system operating at the STP mode, respectively. Thus, the modular solar thermal CCHP system can improve the energy and exergy efficiencies. Furthermore, calculation shows that both the overall energy and exergy efficiencies decrease with increase of inlet vapor temperature at given inlet vapor pressure, but both the efficiencies increase with increase of inlet vapor pressure at given inlet temperature.

  19. Towards Versatile Robots Through Open Heterogeneous Modular Robots

    DEFF Research Database (Denmark)

    Lyder, Andreas

    arises, a new robot can be assembled rapidly from the existing modules, in contrast to conventional robots, which require a time consuming and expensive development process. In this thesis we define a modular robot to be a robot consisting of dynamically reconfigurable modules. The goal of this thesis......Robots are important tools in our everyday life. Both in industry and at the consumer level they serve the purpose of increasing our scope and extending our capabilities. Modular robots take the next step, allowing us to easily create and build various robots from a set of modules. If a problem...... is to increase the versatility and practical usability of modular robots by introducing new conceptual designs. Until now modular robots have been based on a pre-specified set of modules, and thus, their functionality is limited. We propose an open heterogeneous design concept, which allows a modular robot...

  20. HAIFA: A modular, fiber-optic coupled, spectroscopic diagnostic for plasmas

    International Nuclear Information System (INIS)

    Ramsey, A.T.; Turner, S.L.

    1987-01-01

    HAIFA is a modular, multichannel, fiber optically coupled spectroscopy diagnostic for tokamak plasmas. It operates in the visible, measuring H/sub α/ radiation, the visible continuum from thermal bremsstrahlung, and selected impurity lines. HAIFA is characterized by high modularity and flexibility, good radiation resistance, high noise immunity, and low cost. Details of design, construction, and calibration are given. The analysis of visible bremsstrahlung radiation measurements to deduce the effective ionic charge in a plasma is discussed

  1. Failure of Emperion modular femoral stem with implant analysis

    Directory of Open Access Journals (Sweden)

    Benjamin M. Stronach, MD, MS

    2016-03-01

    Full Text Available Modularity in total hip arthroplasty provides multiple benefits to the surgeon in restoring the appropriate alignment and position to a previously damaged hip joint. The vast majority of modern implants incorporate modularity into their design with some implants having multiple modular interfaces. There is the potential for failure at modular junctions because of fretting and crevice corrosion in combination with mechanical loading. This case report details the failure of an Emperion (Smith and Nephew, Memphis, TN femoral stem in a 67-year-old male patient 6 years after total hip replacement. Analysis of the implant revealed mechanically assisted crevice corrosion that likely accelerated fatigue crack initiation in the hip stem. The benefits of modularity come with the potential drawback of a combination of fretting and crevice corrosion at the modular junction, which may accelerate fatigue, crack initiation and ultimately reduce the hip longevity.

  2. Modular invariance and stochastic quantization

    International Nuclear Information System (INIS)

    Ordonez, C.R.; Rubin, M.A.; Zwanziger, D.

    1989-01-01

    In Polyakov path integrals and covariant closed-string field theory, integration over Teichmueller parameters must be restricted by hand to a single modular region. This problem has an analog in Yang-Mills gauge theory---namely, the Gribov problem, which can be resolved by the method of stochastic gauge fixing. This method is here employed to quantize a simple modular-invariant system: the Polyakov point particle. In the limit of a large gauge-fixing force, it is shown that suitable choices for the functional form of the gauge-fixing force can lead to a restriction of Teichmueller integration to a single modular region. Modifications which arise when applying stochastic quantization to a system in which the volume of the orbits of the gauge group depends on a dynamical variable, such as a Teichmueller parameter, are pointed out, and the extension to Polyakov strings and covariant closed-string field theory is discussed

  3. Expanding the chemical diversity of natural esters by engineering a polyketide-derived pathway into Escherichia coli.

    Science.gov (United States)

    Menendez-Bravo, Simón; Comba, Santiago; Sabatini, Martín; Arabolaza, Ana; Gramajo, Hugo

    2014-07-01

    Microbial fatty acid (FA)-derived molecules have emerged as promising alternatives to petroleum-based chemicals for reducing dependence on fossil hydrocarbons. However, native FA biosynthetic pathways often yield limited structural diversity, and therefore restricted physicochemical properties, of the end products by providing only a limited variety of usually linear hydrocarbons. Here we have engineered into Escherichia coli a mycocerosic polyketide synthase-based biosynthetic pathway from Mycobacterium tuberculosis and redefined its biological role towards the production of multi-methyl-branched-esters (MBEs) with novel chemical structures. Expression of FadD28, Mas and PapA5 enzymes enabled the biosynthesis of multi-methyl-branched-FA and their further esterification to an alcohol. The high substrate tolerance of these enzymes towards different FA and alcohol moieties resulted in the biosynthesis of a broad range of MBE. Further metabolic engineering of the MBE producer strain coupled this system to long-chain-alcohol biosynthetic pathways resulting in de novo production of branched wax esters following addition of only propionate. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  4. Brain modularity controls the critical behavior of spontaneous activity.

    Science.gov (United States)

    Russo, R; Herrmann, H J; de Arcangelis, L

    2014-03-13

    The human brain exhibits a complex structure made of scale-free highly connected modules loosely interconnected by weaker links to form a small-world network. These features appear in healthy patients whereas neurological diseases often modify this structure. An important open question concerns the role of brain modularity in sustaining the critical behaviour of spontaneous activity. Here we analyse the neuronal activity of a model, successful in reproducing on non-modular networks the scaling behaviour observed in experimental data, on a modular network implementing the main statistical features measured in human brain. We show that on a modular network, regardless the strength of the synaptic connections or the modular size and number, activity is never fully scale-free. Neuronal avalanches can invade different modules which results in an activity depression, hindering further avalanche propagation. Critical behaviour is solely recovered if inter-module connections are added, modifying the modular into a more random structure.

  5. Modular invariance of N=2 minimal models

    International Nuclear Information System (INIS)

    Sidenius, J.

    1991-01-01

    We prove modular covariance of one-point functions at one loop in the diagonal N=2 minimal superconformal models. We use the recently derived general formalism for computing arbitrary conformal blocks in these models. Our result should be sufficient to guarantee modular covariance at arbitrary genus. It is thus an important check on the general formalism which is not manifestly modular covariant. (orig.)

  6. The Post-polyketide Synthase Steps in iso-Migrastatin Biosynthesis Featuring Tailoring Enzymes with Broad Substrate Specificity

    Science.gov (United States)

    Ma, Ming; Kwong, Thomas; Lim, Si-Kyu; Ju, Jianhua; Lohman, Jeremy R.; Shen, Ben

    2013-01-01

    The iso-migrastatin (iso-MGS) biosynthetic gene cluster from Streptomyces platensis NRRL 18993 consists of 11 genes, featuring an acyltransferase (AT)-less type I polyketide synthase (PKS) and three tailoring enzymes MgsIJK. Systematic inactivation of mgsIJK in S. platensis enabled us to (i) identify two nascent products (10 and 13) of the iso-MGS AT-less type I PKS, establishing an unprecedented novel feature for AT-less type I PKSs, and (ii) account for the formation of all known post-PKS biosynthetic intermediates (10-17) generated by the three tailoring enzymes MgsIJK, which possessed significant substrate promiscuities. PMID:23394593

  7. Hierarchy of modular graph identities

    Energy Technology Data Exchange (ETDEWEB)

    D’Hoker, Eric; Kaidi, Justin [Mani L. Bhaumik Institute for Theoretical Physics, Department of Physics and Astronomy,University of California,Los Angeles, CA 90095 (United States)

    2016-11-09

    The low energy expansion of Type II superstring amplitudes at genus one is organized in terms of modular graph functions associated with Feynman graphs of a conformal scalar field on the torus. In earlier work, surprising identities between two-loop graphs at all weights, and between higher-loop graphs of weights four and five were constructed. In the present paper, these results are generalized in two complementary directions. First, all identities at weight six and all dihedral identities at weight seven are obtained and proven. Whenever the Laurent polynomial at the cusp is available, the form of these identities confirms the pattern by which the vanishing of the Laurent polynomial governs the full modular identity. Second, the family of modular graph functions is extended to include all graphs with derivative couplings and worldsheet fermions. These extended families of modular graph functions are shown to obey a hierarchy of inhomogeneous Laplace eigenvalue equations. The eigenvalues are calculated analytically for the simplest infinite sub-families and obtained by Maple for successively more complicated sub-families. The spectrum is shown to consist solely of eigenvalues s(s−1) for positive integers s bounded by the weight, with multiplicities which exhibit rich representation-theoretic patterns.

  8. Hierarchy of modular graph identities

    International Nuclear Information System (INIS)

    D’Hoker, Eric; Kaidi, Justin

    2016-01-01

    The low energy expansion of Type II superstring amplitudes at genus one is organized in terms of modular graph functions associated with Feynman graphs of a conformal scalar field on the torus. In earlier work, surprising identities between two-loop graphs at all weights, and between higher-loop graphs of weights four and five were constructed. In the present paper, these results are generalized in two complementary directions. First, all identities at weight six and all dihedral identities at weight seven are obtained and proven. Whenever the Laurent polynomial at the cusp is available, the form of these identities confirms the pattern by which the vanishing of the Laurent polynomial governs the full modular identity. Second, the family of modular graph functions is extended to include all graphs with derivative couplings and worldsheet fermions. These extended families of modular graph functions are shown to obey a hierarchy of inhomogeneous Laplace eigenvalue equations. The eigenvalues are calculated analytically for the simplest infinite sub-families and obtained by Maple for successively more complicated sub-families. The spectrum is shown to consist solely of eigenvalues s(s−1) for positive integers s bounded by the weight, with multiplicities which exhibit rich representation-theoretic patterns.

  9. Measuring Modularity in Open Source Code Bases

    Directory of Open Access Journals (Sweden)

    Roberto Milev

    2009-03-01

    Full Text Available Modularity of an open source software code base has been associated with growth of the software development community, the incentives for voluntary code contribution, and a reduction in the number of users who take code without contributing back to the community. As a theoretical construct, modularity links OSS to other domains of research, including organization theory, the economics of industry structure, and new product development. However, measuring the modularity of an OSS design has proven difficult, especially for large and complex systems. In this article, we describe some preliminary results of recent research at Carleton University that examines the evolving modularity of large-scale software systems. We describe a measurement method and a new modularity metric for comparing code bases of different size, introduce an open source toolkit that implements this method and metric, and provide an analysis of the evolution of the Apache Tomcat application server as an illustrative example of the insights gained from this approach. Although these results are preliminary, they open the door to further cross-discipline research that quantitatively links the concerns of business managers, entrepreneurs, policy-makers, and open source software developers.

  10. Modularity in supply chains: a multiple case study in the construction industry

    NARCIS (Netherlands)

    Voordijk, Johannes T.; Meijboom, Bert; de Haan, Job

    2006-01-01

    Purpose – The objective of this study is to assess the applicability of Fine's three-dimensional modularity concept as a tool to describe and to analyze the alignment of product, process, and supply chain architectures. Fine claims that the degree of modularity in the final output product has a

  11. Modular supervisory controller for hybrid power systems

    Energy Technology Data Exchange (ETDEWEB)

    Lemos Pereira, A. de

    2000-06-01

    The power supply of remote places has been commonly provided by thermal power plants, usually diesel generators. Although hybrid power systems may constitute the most economical solution in many applications their widespread application to the electrification schemes of remote areas still depends on improvements in the issues of design and operation control. The main limitations of the present hybrid power systems technology, which are identified in this work, are related to the control and supervision of the power system. Therefore this thesis focuses on the modularity of supervisory controllers in order to design cost-competitive and reliable hybrid power systems. The modular supervisory controller created in this project is considered an important part of a system design approach that aims to overcome the technical difficulties of the current engineering practice and contribute to open the market of hybrid power systems. The term modular refers to a set of design characteristics that allows the use of basically the same supervisory controller in different projects. The modularization and standardisation of the controller include several issues such as interfacing components, communication protocols, modelling, programming and control strategies. The modularity can reduce the highly specialised system engineering related to the integration of components, operation and control. It can also avoid the high costs for installation, service and maintenance. A modular algorithm for supervisory controllers has been developed (a Matlab program called SuperCon) using an object-oriented design and it has been tested through several simulations using different hybrid system configurations and different control strategies. This thesis presents a complete control system design process which can be used as the basis for the development and implementation of intelligent and autonomous supervisory controllers for hybrid power systems with modular characteristics. (au)

  12. A Semantics for Modular General Logic Programs

    NARCIS (Netherlands)

    Etalle, Sandro

    1998-01-01

    Modular programs are built as a combination of separate modules, which may be developed and verified separately. Therefore, in order to reason over such programs, compositionality plays a crucial role: the semantics of the whole program must be obtainable as a simple function from the semantics of

  13. A semantics for modular general logic programs

    NARCIS (Netherlands)

    Etalle, S.

    1998-01-01

    Modular programs are built as a combination of separate modules, which may be developed and verified separately. Therefore, in order to reason over such programs, compositionality plays a crucial role: the semantics of the whole program must be obtainable as a simple function from the semantics of

  14. Modularizing development

    DEFF Research Database (Denmark)

    Müller, Anders Riel; Doucette, Jamie

    a deeper and wider understanding of Korea’s development experience with the hope that Korea’s past can offer lessons for developing countries in search of sustainable and broad‐based development" (KSP 2011). To do so, the KSP provides users with a modularized set of policy narratives that represent Korea...

  15. Modularity, Working Memory, and Second Language Acquisition: A Research Program

    Science.gov (United States)

    Truscott, John

    2017-01-01

    Considerable reason exists to view the mind, and language within it, as modular, and this view has an important place in research and theory in second language acquisition (SLA) and beyond. But it has had very little impact on the study of working memory and its role in SLA. This article considers the need for modular study of working memory,…

  16. Advantages of going modular in HTRs

    International Nuclear Information System (INIS)

    Reutler, H.; Lohnert, G.H.

    1984-01-01

    A multitude of problems that are encountered in large HTR power plans, constructively as well as concerning plant safety, can be related to the mere physical size of a large reactor core. In limiting the thermal power of an HTR-module to approximately 200 MW an inherent limitation of the fuel element temperature below critical values can be guaranteed for all possible core heat up accidents. Consequently, a significant failure rate of coated particles can be excluded and, hence, out of physical reasons, no intolerable fission product release from the core will ever have to be considered. The HTR-module is so qualified and very well suited for all possible plant sides which have to be taken into consideration for medium sized plants for the production of process steam and electricity. The cost investigations show considerable cost advantages for modular HTRs. For German conditions it was found that even a four-modular plant (800 MW/thermal) is competitive with a fossile-fueled plant of the same size, the specific plant costs were evaluated to be DM 4700/kW (electric). Moreover the investigations show that the increase of the power of the modular unit yields only small cost advantages, therefore in a modularized power plant it even would be possible to reduce the power of a modular unit below 200 MW without having to cope with severe economic penalties, if the distance from technological or safety limits is felt to be too small. (orig.)

  17. AMPX: a modular system for multigroup cross-section generation and manipulation

    International Nuclear Information System (INIS)

    Greene, N.M.; Ford, W.E. III; Petrie, L.M.; Diggs, B.R.; Webster, C.C.; Lucius, J.L.; White, J.E.; Wright, R.Q.; Westfall, R.M.

    1978-01-01

    The AMPX system, developed at the Oak Ridge National Laboratory over the past seven years, is a collection of computer programs in a modular arrangement. Starting with ENDF-formatted nuclear data files, the system includes a full range of features needed to produce and use multigroup neutron, gamma-ray production, and gamma-ray interaction cross-section data. The balance between production and analysis is roughly even; thus, the system serves a wide variety of needs. The modularity is particularly attractive, since it allows the user to choose an arbitrary execution sequence from the approximately 40 to 50 modules available in the system. The modularity also allows selection from different treatments; e.g., the Nordheim method, a full-blown integral transport calculation, the Bondarenko method, or other alternative can be selected for resonance shielding. 2 figures

  18. Modular co-culture engineering, a new approach for metabolic engineering.

    Science.gov (United States)

    Zhang, Haoran; Wang, Xiaonan

    2016-09-01

    With the development of metabolic engineering, employment of a selected microbial host for accommodation of a designed biosynthetic pathway to produce a target compound has achieved tremendous success in the past several decades. Yet, increasing requirements for sophisticated microbial biosynthesis call for establishment and application of more advanced metabolic engineering methodologies. Recently, important progress has been made towards employing more than one engineered microbial strains to constitute synthetic co-cultures and modularizing the biosynthetic labor between the co-culture members in order to improve bioproduction performance. This emerging approach, referred to as modular co-culture engineering in this review, presents a valuable opportunity for expanding the scope of the broad field of metabolic engineering. We highlight representative research accomplishments using this approach, especially those utilizing metabolic engineering tools for microbial co-culture manipulation. Key benefits and major challenges associated with modular co-culture engineering are also presented and discussed. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  19. An Incremental Approach to Support Realization of Modularization Benefits

    DEFF Research Database (Denmark)

    Hansen, Poul H. Kyvsgård; Sun, Hongyi

    2010-01-01

    In general, the phenomenon of managing modularization is not well known. The cause-effect relationships between modularization and realized benefits are complex and comprehensive. Though a number of research works have contributed to the study of the phenomenon of efficient and effective...... modularization management it is far from clarified. Recognizing the need for further empirical research, we studied 40 modularity cases. Then we develop a research framework with the purpose of uncovering the current state. Furthermore, we formulate a tentative model aiming at guiding the platform management...

  20. Modular assembly of optical nanocircuits

    Science.gov (United States)

    Shi, Jinwei; Monticone, Francesco; Elias, Sarah; Wu, Yanwen; Ratchford, Daniel; Li, Xiaoqin; Alù, Andrea

    2014-05-01

    A key element enabling the microelectronic technology advances of the past decades has been the conceptualization of complex circuits with versatile functionalities as being composed of the proper combination of basic ‘lumped’ circuit elements (for example, inductors and capacitors). In contrast, modern nanophotonic systems are still far from a similar level of sophistication, partially because of the lack of modularization of their response in terms of basic building blocks. Here we demonstrate the design, assembly and characterization of relatively complex photonic nanocircuits by accurately positioning a number of metallic and dielectric nanoparticles acting as modular lumped elements. The nanoparticle clusters produce the desired spectral response described by simple circuit rules and are shown to be dynamically reconfigurable by modifying the direction or polarization of impinging signals. Our work represents an important step towards extending the powerful modular design tools of electronic circuits into nanophotonic systems.

  1. BEETLE - A modular electronics family for robotics

    CSIR Research Space (South Africa)

    Dickens, J

    2015-11-01

    Full Text Available of applications. A family of modular electronic elements is proposed to address this need. The Beautiful Embedded Electronic Logic Element (BEETLE) family of boards is designed to be compact, low cost, robust, reusable and easy to program. This allows the boards...

  2. A mircocontroller MC68HC908GP32 based intelligent scalar

    International Nuclear Information System (INIS)

    Liu Huiying

    2001-01-01

    A Mircocontroller MC68HC908GP32 based intelligent scalar is presented. By replacing traditional IC modular with Mircocontroller, the new type scalar can provide new functions, such as countering rate measurement, control signal output, LCD display, PC control, etc., in addition to traditional functions of normal scalar. This intelligent scalar achieved comprehensive technical innovation to the traditional nuclear electronic instrument, with regard to the design methodology, structure and functions. In this way, the overall technical performance of the new type scalar, such as counting rate, accuracy, volume, cost and operation, etc., has been improved obviously, with bright prospects for application and dissemination

  3. Modularity in developmental biology and artificial organs: a missing concept in tissue engineering.

    Science.gov (United States)

    Lenas, Petros; Luyten, Frank P; Doblare, Manuel; Nicodemou-Lena, Eleni; Lanzara, Andreina Elena

    2011-06-01

    Tissue engineering is reviving itself, adopting the concept of biomimetics of in vivo tissue development. A basic concept of developmental biology is the modularity of the tissue architecture according to which intermediates in tissue development constitute semiautonomous entities. Both engineering and nature have chosen the modular architecture to optimize the product or organism development and evolution. Bioartificial tissues do not have a modular architecture. On the contrary, artificial organs of modular architecture have been already developed in the field of artificial organs. Therefore the conceptual support of tissue engineering by the field of artificial organs becomes critical in its new endeavor of recapitulating in vitro the in vivo tissue development. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  4. Fractal gene regulatory networks for robust locomotion control of modular robots

    DEFF Research Database (Denmark)

    Zahadat, Payam; Christensen, David Johan; Schultz, Ulrik Pagh

    2010-01-01

    Designing controllers for modular robots is difficult due to the distributed and dynamic nature of the robots. In this paper fractal gene regulatory networks are evolved to control modular robots in a distributed way. Experiments with different morphologies of modular robot are performed and the ......Designing controllers for modular robots is difficult due to the distributed and dynamic nature of the robots. In this paper fractal gene regulatory networks are evolved to control modular robots in a distributed way. Experiments with different morphologies of modular robot are performed...

  5. Modular system design and evaluation

    CERN Document Server

    Levin, Mark Sh

    2015-01-01

    This book examines seven key combinatorial engineering frameworks (composite schemes consisting of algorithms and/or interactive procedures) for hierarchical modular (composite) systems. These frameworks are based on combinatorial optimization problems (e.g., knapsack problem, multiple choice problem, assignment problem, morphological clique problem), with the author’s version of morphological design approach – Hierarchical Morphological Multicritieria Design (HMMD) – providing a conceptual lens with which to elucidate the examples discussed. This approach is based on ordinal estimates of design alternatives for systems parts/components, however, the book also puts forward an original version of HMMD that is based on new interval multiset estimates for the design alternatives with special attention paid to the aggregation of modular solutions (system versions). The second part of ‘Modular System Design and Evaluation’ provides ten information technology case studies that enriches understanding of th...

  6. Complex modular structure of large-scale brain networks

    Science.gov (United States)

    Valencia, M.; Pastor, M. A.; Fernández-Seara, M. A.; Artieda, J.; Martinerie, J.; Chavez, M.

    2009-06-01

    Modular structure is ubiquitous among real-world networks from related proteins to social groups. Here we analyze the modular organization of brain networks at a large scale (voxel level) extracted from functional magnetic resonance imaging signals. By using a random-walk-based method, we unveil the modularity of brain webs and show modules with a spatial distribution that matches anatomical structures with functional significance. The functional role of each node in the network is studied by analyzing its patterns of inter- and intramodular connections. Results suggest that the modular architecture constitutes the structural basis for the coexistence of functional integration of distant and specialized brain areas during normal brain activities at rest.

  7. Implementing a modular system of computer codes

    International Nuclear Information System (INIS)

    Vondy, D.R.; Fowler, T.B.

    1983-07-01

    A modular computation system has been developed for nuclear reactor core analysis. The codes can be applied repeatedly in blocks without extensive user input data, as needed for reactor history calculations. The primary control options over the calculational paths and task assignments within the codes are blocked separately from other instructions, admitting ready access by user input instruction or directions from automated procedures and promoting flexible and diverse applications at minimum application cost. Data interfacing is done under formal specifications with data files manipulated by an informed manager. This report emphasizes the system aspects and the development of useful capability, hopefully informative and useful to anyone developing a modular code system of much sophistication. Overall, this report in a general way summarizes the many factors and difficulties that are faced in making reactor core calculations, based on the experience of the authors. It provides the background on which work on HTGR reactor physics is being carried out

  8. Evolution and Morphogenesis of Simulated Modular Robots: A Comparison Between a Direct and Generative Encoding

    DEFF Research Database (Denmark)

    Veenstra, Frank; Faina, Andres; Risi, Sebastian

    2017-01-01

    Modular robots oer an important benet in evolutionary robotics, which is to quickly evaluate evolved morphologies and control systems in reality. However, articial evolution of simulated modular robotics is a dicult and time consuming task requiring signicant computational power. While articial...... evolution in virtual creatures has made use of powerful generative encodings, here we investigate how a generative encoding and direct encoding compare for the evolution of locomotion in modular robots when the number of robotic modules changes. Simulating less modules would decrease the size of the genome...

  9. Equacions de corbes modulars biel.líptiques

    OpenAIRE

    Ribes González, Jordi

    2013-01-01

    This thesis deals primarily with the question of finding equations for bielliptic modular curves of the type $X_{0}(N)$. After introducing the reader to some of the fundamental aspects on the theory modular curves, we discuss four different techniques for finding such models and give examples of their implementation in Sage.. Es tracta d'estudiar les corbes modulars biel.líptiques, determinades per F. Bars en l'article Bielliptic Modular curves [1999], amb l'objectiu de trobar equacions i, en...

  10. Sequential Modular Position and Momentum Measurements of a Trapped Ion Mechanical Oscillator

    Science.gov (United States)

    Flühmann, C.; Negnevitsky, V.; Marinelli, M.; Home, J. P.

    2018-04-01

    The noncommutativity of position and momentum observables is a hallmark feature of quantum physics. However, this incompatibility does not extend to observables that are periodic in these base variables. Such modular-variable observables have been suggested as tools for fault-tolerant quantum computing and enhanced quantum sensing. Here, we implement sequential measurements of modular variables in the oscillatory motion of a single trapped ion, using state-dependent displacements and a heralded nondestructive readout. We investigate the commutative nature of modular variable observables by demonstrating no-signaling in time between successive measurements, using a variety of input states. Employing a different periodicity, we observe signaling in time. This also requires wave-packet overlap, resulting in quantum interference that we enhance using squeezed input states. The sequential measurements allow us to extract two-time correlators for modular variables, which we use to violate a Leggett-Garg inequality. Signaling in time and Leggett-Garg inequalities serve as efficient quantum witnesses, which we probe here with a mechanical oscillator, a system that has a natural crossover from the quantum to the classical regime.

  11. Modularized substrate culture:a new method for green leafy vegetable planting

    Directory of Open Access Journals (Sweden)

    WANG Quanxi

    2015-10-01

    Full Text Available On the basis of analyzing general situation of green leafy vegetable production and main difficulty,we introduce the characteristics of modularized substrate culture for green leafy vegetable,and point out the important issues of modularized substrate culture which urgently need be solved in the coming future.

  12. Buying Modular Systems in Technology-Intensive Markets

    NARCIS (Netherlands)

    Frambach, R.T.; Stremersch, S.; Weiss, Allen M.; Dellaert, B.

    2003-01-01

    Technology-intensive markets consist of products that are often interdependent and operate together as a modular system. Although prior research has extensively addressed standardization and network externalities in such markets, it has not addressed the buying of modular systems. The authors

  13. Economics of the modular reactor as new-generation nuclear power

    International Nuclear Information System (INIS)

    Hattori, Sadao

    1987-01-01

    This paper lists thirteen advantages which could be effectuated by modular reactors. These advantages are derived basically from the general attributes of modularization, i.e., continuity of production, smallness of size/capacity, ease of standardization, and built-in passive safety. This paper also suggests a general direction in which the development of modular reactors evolve, and a possible nuclear application where modular reactors be effectively utilized. (author)

  14. Modular categories and 3-manifold invariants

    International Nuclear Information System (INIS)

    Tureav, V.G.

    1992-01-01

    The aim of this paper is to give a concise introduction to the theory of knot invariants and 3-manifold invariants which generalize the Jones polynomial and which may be considered as a mathematical version of the Witten invariants. Such a theory was introduced by N. Reshetikhin and the author on the ground of the theory of quantum groups. here we use more general algebraic objects, specifically, ribbon and modular categories. Such categories in particular arise as the categories of representations of quantum groups. The notion of modular category, interesting in itself, is closely related to the notion of modular tensor category in the sense of G. Moore and N. Seiberg. For simplicity we restrict ourselves in this paper to the case of closed 3-manifolds

  15. Modular Lego-Electronics

    KAUST Repository

    Shaikh, Sohail F.; Ghoneim, Mohamed T.; Bahabry, Rabab R.; Khan, Sherjeel M.; Hussain, Muhammad Mustafa

    2017-01-01

    . Here, a generic manufacturable method of converting state-of-the-art complementary metal oxide semiconductor-based ICs into modular Lego-electronics is shown with unique geometry that is physically identifiable to ease manufacturing and enhance

  16. Robustness and modular structure in networks

    DEFF Research Database (Denmark)

    Bagrow, James P.; Lehmann, Sune; Ahn, Yong-Yeol

    2015-01-01

    -12]. Many complex systems, from power grids and the Internet to the brain and society [13-15], can be modeled using modular networks comprised of small, densely connected groups of nodes [16, 17]. These modules often overlap, with network elements belonging to multiple modules [18, 19]. Yet existing work...... on robustness has not considered the role of overlapping, modular structure. Here we study the robustness of these systems to the failure of elements. We show analytically and empirically that it is possible for the modules themselves to become uncoupled or non-overlapping well before the network disintegrates....... If overlapping modular organization plays a role in overall functionality, networks may be far more vulnerable than predicted by conventional percolation theory....

  17. Modular invariants from simple currents. An explicit proof

    International Nuclear Information System (INIS)

    Schellekens, A.N.; Yankielowicz, S.

    1989-01-01

    In a previous paper an orbifold construction was used to demonstrate that the existence of primary fields with simple fusion rules in a conformal field theory implies the existence of non-diagonal modular invariant partition functions. Here we present a direct and explicit proof of modular invariance, which also covers a few cases that could not be obtained with the orbifold method. We also give a very simple general formula for the modular matrix M. (orig.)

  18. Curriculum Development through YTS Modular Credit Accumulation.

    Science.gov (United States)

    Further Education Unit, London (England).

    This document reports the evaluation of the collaborately developed Modular Training Framework (MainFrame), a British curriculum development project, built around a commitment to a competency-based, modular credit accumulation program. The collaborators were three local education authorities (LEAs), those of Bedfordshire, Haringey, and Sheffield,…

  19. On Modularity in (V)Shorad Air Defense

    NARCIS (Netherlands)

    Veen, E.M. van der

    2001-01-01

    This paper addresses the concept of modularity in the context of (V)Shorads Air Defence. Modularity is a technical concept that provides improved operational flexibility to (V)Shorad systems. Such improved flexibility is specifically relevant to mobile crisis reaction forces. The discussion is

  20. Performance Evaluation of a Modular Design of Wind Tower with Wetted Surfaces

    Directory of Open Access Journals (Sweden)

    Sajad M.R. Khani

    2017-06-01

    Full Text Available Wind towers or wind catchers, as passive cooling systems, can provide natural ventilation in buildings located in hot, arid regions. These natural cooling systems can provide thermal comfort for the building inhabitants throughout the warm months. In this paper, a modular design of a wind tower is introduced. The design, called a modular wind tower with wetted surfaces, was investigated experimentally and analytically. To determine the performance of the wind tower, air temperature, relative humidity (RH and air velocity were measured at different points. Measurements were carried out when the wind speed was zero. The experimental results were compared with the analytical ones. The results illustrated that the modular wind tower can decrease the air temperature significantly and increase the relative humidity of airflow into the building. The average differences for air temperature and air relative humidity between ambient air and air exiting from the wind tower were approximately 10 °C and 40%, respectively. The main advantage of the proposed wind tower is that it is a modular design that can reduce the cost of wind tower construction.

  1. Calculation and modular properties of multi-loop superstring amplitudes

    International Nuclear Information System (INIS)

    Danilov, G S

    2012-01-01

    Multi-loop superstring amplitude is calculated in the conventional gauge where Grassmann moduli are carried by the 2D gravitino field. Generally, instead of the modular symmetry, the amplitudes hold the symmetry under modular transformations added by relevant transformations of the 2D local supersymmetry. If a number of loops are larger than 3, the integration measures are not modular forms. In this case the expression for the amplitude contains an integral over the bound of the fundamental region of the modular group. (paper)

  2. Modular Knowledge Representation and Reasoning in the Semantic Web

    Science.gov (United States)

    Serafini, Luciano; Homola, Martin

    Construction of modular ontologies by combining different modules is becoming a necessity in ontology engineering in order to cope with the increasing complexity of the ontologies and the domains they represent. The modular ontology approach takes inspiration from software engineering, where modularization is a widely acknowledged feature. Distributed reasoning is the other side of the coin of modular ontologies: given an ontology comprising of a set of modules, it is desired to perform reasoning by combination of multiple reasoning processes performed locally on each of the modules. In the last ten years, a number of approaches for combining logics has been developed in order to formalize modular ontologies. In this chapter, we survey and compare the main formalisms for modular ontologies and distributed reasoning in the Semantic Web. We select four formalisms build on formal logical grounds of Description Logics: Distributed Description Logics, ℰ-connections, Package-based Description Logics and Integrated Distributed Description Logics. We concentrate on expressivity and distinctive modeling features of each framework. We also discuss reasoning capabilities of each framework.

  3. Development of a two-level modular simulation tool for dysim

    International Nuclear Information System (INIS)

    Kofoed, J.E.

    1987-07-01

    A simulation tool to assist the user when constructing continuous simulation models is described. The simulation tool can be used for constructing simulation programmes that are executed with the rutime executive DYSIM86 which applied a modular approach. This approach makes it possible to split a model into several modules. The simulation tool introduces one more level of modularity. In this level a module is constructed from submodules taken from a library. A submodule consists of a submodel for a component in the complete model. The simulation tool consists of two precompilers working on the two different levels of modularity. The library is completely open to the user so that it is possible to extend it. This is done by a routine which is also part of the simulation tool. The simulation tool is demonstrated by simulating a part of a power plant and a part of a sugar factory. This illustrates that the precompilers can be used for simulating different types of process plants. 69 ill., 13 tabs., 41 refs. (author)

  4. Modularity and its effects on innovation

    DEFF Research Database (Denmark)

    Boer, Henrike Engele Elisabeth; Hansen, Poul H. Kyvsgård

    systematic work and management type of tasks, although it conflicts with the typical characteristics associated with the entrepreneur. If not managed properly, modularization can foster the modularity trap over time. At this stage intrapreneurial activities can help the organization stay ahead of the game...

  5. A Framework for Determining Product Modularity Levels

    DEFF Research Database (Denmark)

    Hvam, Lars; Herbert-Hansen, Zaza Nadja Lee; Haug, Anders

    2017-01-01

    products have been implemented in specific types companies (mostly mass producers), but little guidance exists on how to identify the right level of modularity for other types of companies (such as engineer-to-order companies). In this article, we address this gap by suggesting a framework that categorizes...

  6. Development of modularity in the neural activity of children's brains

    International Nuclear Information System (INIS)

    Chen, Man; Deem, Michael W

    2015-01-01

    We study how modularity of the human brain changes as children develop into adults. Theory suggests that modularity can enhance the response function of a networked system subject to changing external stimuli. Thus, greater cognitive performance might be achieved for more modular neural activity, and modularity might likely increase as children develop. The value of modularity calculated from functional magnetic resonance imaging (fMRI) data is observed to increase during childhood development and peak in young adulthood. Head motion is deconvolved from the fMRI data, and it is shown that the dependence of modularity on age is independent of the magnitude of head motion. A model is presented to illustrate how modularity can provide greater cognitive performance at short times, i.e. task switching. A fitness function is extracted from the model. Quasispecies theory is used to predict how the average modularity evolves with age, illustrating the increase of modularity during development from children to adults that arises from selection for rapid cognitive function in young adults. Experiments exploring the effect of modularity on cognitive performance are suggested. Modularity may be a potential biomarker for injury, rehabilitation, or disease. (paper)

  7. Manufacturing Development of the NCSX Modular Coil Windings

    International Nuclear Information System (INIS)

    Chrzanowski, JH; Fogarty, PJ; Heitzenroeder, PJ; Meighan, T.; Nelson, B.; Raftopoulos, S.; Williamson, D.

    2005-01-01

    The modular coils on the National Compact Stellarator Experiment (NCSX) present a number of significant engineering challenges due to their complex shapes, requirements for high dimensional accuracy and the high current density required in the modular coils due to space constraints. In order to address these challenges, an R and D program was established to develop the conductor, insulation scheme, manufacturing techniques, and procedures. A prototype winding named Twisted Racetrack Coil (TRC) was of particular importance in dealing with these challenges. The TRC included a complex shaped winding form, conductor, insulation scheme, leads and termination, cooling system and coil clamps typical of the modular coil design. Even though the TRC is smaller in size than a modular coil, its similar complex geometry provided invaluable information in developing the final design, metrology techniques and development of manufacturing procedures. In addition a discussion of the development of the copper rope conductor including ''Keystoning'' concerns; the epoxy impregnation system (VPI) plus the tooling and equipment required to manufacture the modular coils will be presented

  8. A software architecture for adaptive modular sensing systems.

    Science.gov (United States)

    Lyle, Andrew C; Naish, Michael D

    2010-01-01

    By combining a number of simple transducer modules, an arbitrarily complex sensing system may be produced to accommodate a wide range of applications. This work outlines a novel software architecture and knowledge representation scheme that has been developed to support this type of flexible and reconfigurable modular sensing system. Template algorithms are used to embed intelligence within each module. As modules are added or removed, the composite sensor is able to automatically determine its overall geometry and assume an appropriate collective identity. A virtual machine-based middleware layer runs on top of a real-time operating system with a pre-emptive kernel, enabling platform-independent template algorithms to be written once and run on any module, irrespective of its underlying hardware architecture. Applications that may benefit from easily reconfigurable modular sensing systems include flexible inspection, mobile robotics, surveillance, and space exploration.

  9. A Modular Toolkit for Distributed Interactions

    Directory of Open Access Journals (Sweden)

    Julien Lange

    2011-10-01

    Full Text Available We discuss the design, architecture, and implementation of a toolkit which supports some theories for distributed interactions. The main design principles of our architecture are flexibility and modularity. Our main goal is to provide an easily extensible workbench to encompass current algorithms and incorporate future developments of the theories. With the help of some examples, we illustrate the main features of our toolkit.

  10. Emergent interfaces for feature modularization

    CERN Document Server

    Ribeiro, Márcio; Brabrand, Claus

    2014-01-01

    Developers frequently introduce errors into software systems when they fail to recognise module dependencies. Using forty-three software families and Software Product Lines (SPLs), where the majority are commonly used in industrial practice, the authors reports on the feature modularization problem and provides a study of how often it may occur in practice. To solve the problem they present the concept of emergent feature modularization which aims to establish contracts between features to prevent developers from breaking other features when performing a maintenance task.

  11. Hierarchical functional modularity in the resting-state human brain.

    Science.gov (United States)

    Ferrarini, Luca; Veer, Ilya M; Baerends, Evelinda; van Tol, Marie-José; Renken, Remco J; van der Wee, Nic J A; Veltman, Dirk J; Aleman, André; Zitman, Frans G; Penninx, Brenda W J H; van Buchem, Mark A; Reiber, Johan H C; Rombouts, Serge A R B; Milles, Julien

    2009-07-01

    Functional magnetic resonance imaging (fMRI) studies have shown that anatomically distinct brain regions are functionally connected during the resting state. Basic topological properties in the brain functional connectivity (BFC) map have highlighted the BFC's small-world topology. Modularity, a more advanced topological property, has been hypothesized to be evolutionary advantageous, contributing to adaptive aspects of anatomical and functional brain connectivity. However, current definitions of modularity for complex networks focus on nonoverlapping clusters, and are seriously limited by disregarding inclusive relationships. Therefore, BFC's modularity has been mainly qualitatively investigated. Here, we introduce a new definition of modularity, based on a recently improved clustering measurement, which overcomes limitations of previous definitions, and apply it to the study of BFC in resting state fMRI of 53 healthy subjects. Results show hierarchical functional modularity in the brain. Copyright 2009 Wiley-Liss, Inc

  12. Modular chemiresistive sensor

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Maksudul M.; Sampathkumaran, Uma

    2018-02-20

    The present invention relates to a modular chemiresistive sensor. In particular, a modular chemiresistive sensor for hypergolic fuel and oxidizer leak detection, carbon dioxide monitoring and detection of disease biomarkers. The sensor preferably has two gold or platinum electrodes mounted on a silicon substrate where the electrodes are connected to a power source and are separated by a gap of 0.5 to 4.0 .mu.M. A polymer nanowire or carbon nanotube spans the gap between the electrodes and connects the electrodes electrically. The electrodes are further connected to a circuit board having a processor and data storage, where the processor can measure current and voltage values between the electrodes and compare the current and voltage values with current and voltage values stored in the data storage and assigned to particular concentrations of a pre-determined substance such as those listed above or a variety of other substances.

  13. Modular remote radiation monitor

    International Nuclear Information System (INIS)

    Lacerda, Fabio; Farias, Marcos S.; Aghina, Mauricio A.C.; Oliveira, Mauro V.

    2013-01-01

    The Modular Remote Radiation Monitor (MRRM) is a novel radiation monitor suitable for monitoring environmental exposure to ionizing radiation. It is a portable compact-size low-power microprocessor-based electronic device which provides its monitoring data to other electronic systems, physically distant from it, by means of an electronic communication channel, which can be wired or wireless according to the requirements of each application. Besides its low-power highly-integrated circuit design, the Modular Remote Radiation Monitor is presented in a modular architecture, which promotes full compliance to the technical requirements of different applications while minimizing cost, size and power consumption. Its communication capability also supports the implementation of a network of multiple radiation monitors connected to a supervisory system, capable of remotely controlling each monitor independently as well as visualizing the radiation levels from all monitors. A prototype of the MRRM, functionally equivalent to the MRA-7027 radiation monitor, was implemented and connected to a wired MODBUS network of MRA-7027 monitors, responsible for monitoring ionizing radiation inside Argonauta reactor room at Instituto de Engenharia Nuclear. Based on the highly positive experimental results obtained, further design is currently underway in order to produce a consumer version of the MRRM. (author)

  14. Phenotypic plasticity and morphological integration in a marine modular invertebrate

    Directory of Open Access Journals (Sweden)

    Manrique Nelson

    2007-07-01

    Full Text Available Abstract Background Colonial invertebrates such as corals exhibit nested levels of modularity, imposing a challenge to the depiction of their morphological evolution. Comparisons among diverse Caribbean gorgonian corals suggest decoupling of evolution at the polyp vs. branch/internode levels. Thus, evolutionary change in polyp form or size (the colonial module sensu stricto does not imply a change in colony form (constructed of modular branches and other emergent features. This study examined the patterns of morphological integration at the intraspecific level. Pseudopterogorgia bipinnata (Verrill (Octocorallia: Gorgoniidae is a Caribbean shallow water gorgonian that can colonize most reef habitats (shallow/exposed vs. deep/protected; 1–45 m and shows great morphological variation. Results To characterize the genotype/environment relationship and phenotypic plasticity in P. bipinnata, two microsatellite loci, mitochondrial (MSH1 and nuclear (ITS DNA sequences, and (ITS2 DGGE banding patterns were initially compared among the populations present in the coral reefs of Belize (Carrie Bow Cay, Panama (Bocas del Toro, Colombia (Cartagena and the Bahamas (San Salvador. Despite the large and discrete differentiation of morphotypes, there was no concordant genetic variation (DGGE banding patterns in the ITS2 genotypes from Belize, Panama and Colombia. ITS1–5.8S-ITS2 phylogenetic analysis afforded evidence for considering the species P. kallos (Bielschowsky as the shallow-most morphotype of P. bipinnata from exposed environments. The population from Carrie Bow Cay, Belize (1–45 m was examined to determine the phenotypic integration of modular features such as branch thickness, polyp aperture, inter-polyp distance, internode length and branch length. Third-order partial correlation coefficients suggested significant integration between polypar and colonial traits. Some features did not change at all despite 10-fold differences in other integrated

  15. Design Requirements for Designing Responsive Modular Manufacturing Systems

    DEFF Research Database (Denmark)

    Jørgensen, Steffen; Madsen, Ole; Nielsen, Kjeld

    2011-01-01

    Customers demand the newest technologies, newest designs, the ability to customise, high quality, and all this at a low cost. These are trends which challenge the traditional way of operating manufacturing companies, especially in regard to product development and manufacturing. Research...... the needed flexibility and responsiveness, but such systems are not yet fully achieved. From related theory it is known that achieving modular benefits depend on the modular architecture; a modular architecture which must be developed according to the customer needs. This makes production needs a design...... requirement in order to achieve responsiveness and other benefits of modular manufacturing systems (MMS). Due to the complex and interrelated nature of a production system and its surroundings these production needs are complex to identify. This paper presents an analysis framework for identification...

  16. Evaluation of modular robot system for maintenance tasks in hot cell

    Energy Technology Data Exchange (ETDEWEB)

    Pagala, Prithvi Sekhar, E-mail: ps.pagala@upm.es [Centre for Automation and Robotics UPM-CSIC (Spain); Ferre, Manuel, E-mail: m.ferre@upm.es [Centre for Automation and Robotics UPM-CSIC (Spain); Orona, Luis, E-mail: l.orona@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung (Germany)

    2014-10-15

    Highlights: •Modular robot deployment inside hot cell for remote manipulation evaluated. •Flexible and adaptable system for variety of tasks presented. •Uses in large workspaces and evolving requirements shown. -- Abstract: This work assesses the use of a modular robot system to perform maintenance and inspection tasks such as, remote flexible inspection, manipulation and cooperation with deployed systems inside the hot cell. A flexible modular solution for the inclusion in maintenance operations is presented. The proposed heterogeneous modular robotic system is evaluated using simulations of the prototype across selected robot configuration to perform tasks. Results obtained show the advantages and ability of the modular robot to perform the necessary tasks as well as its ability to adapt and evolve depending on the need. The simulation test case inside hot cell shows modular robot configuration, a two modular arm to perform tele-operation tasks in the workspace and a wheeled platform for inspection collaborating to perform tasks. The advantage of using re-configurable modular robot over conventional robot platforms is shown.

  17. Modular bootstrap in Liouville field theory

    International Nuclear Information System (INIS)

    Hadasz, Leszek; Jaskolski, Zbigniew; Suchanek, Paulina

    2010-01-01

    The modular matrix for the generic 1-point conformal blocks on the torus is expressed in terms of the fusion matrix for the 4-point blocks on the sphere. The modular invariance of the toric 1-point functions in the Liouville field theory with DOZZ structure constants is proved.

  18. Modular bootstrap in Liouville field theory

    Energy Technology Data Exchange (ETDEWEB)

    Hadasz, Leszek, E-mail: hadasz@th.if.uj.edu.p [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Jaskolski, Zbigniew, E-mail: jask@ift.uni.wroc.p [Institute of Theoretical Physics, University of Wroclaw, pl. M. Borna, 50-204 Wroclaw (Poland); Suchanek, Paulina, E-mail: paulina@ift.uni.wroc.p [Institute of Theoretical Physics, University of Wroclaw, pl. M. Borna, 50-204 Wroclaw (Poland)

    2010-02-22

    The modular matrix for the generic 1-point conformal blocks on the torus is expressed in terms of the fusion matrix for the 4-point blocks on the sphere. The modular invariance of the toric 1-point functions in the Liouville field theory with DOZZ structure constants is proved.

  19. Modular bootstrap in Liouville field theory

    Science.gov (United States)

    Hadasz, Leszek; Jaskólski, Zbigniew; Suchanek, Paulina

    2010-02-01

    The modular matrix for the generic 1-point conformal blocks on the torus is expressed in terms of the fusion matrix for the 4-point blocks on the sphere. The modular invariance of the toric 1-point functions in the Liouville field theory with DOZZ structure constants is proved.

  20. A “4-cell” modular passive DMFC (direct methanol fuel cell) stack for portable applications

    International Nuclear Information System (INIS)

    Wang, Luwen; He, Mingyan; Hu, Yue; Zhang, Yufeng; Liu, Xiaowei; Wang, Gaofeng

    2015-01-01

    A “4-cell” modular passive DMFC (direct methanol fuel cell) stack, which can be freely combined and applied to various electronic devices, is designed, fabricated and tested. Two PCB (printed circuit board) based accessories are designed and fabricated for electrically connecting and mechanically assembling the “4-cell” modules. The maximum power density of the “4-cell” module is 27 mW cm −2 at 5 M methanol concentration. The steady-state performances of the modular stacks with different numbers of modules are tested. The extra power loss of the multiple module stacks due to inter-module electrical connections is predicted by mathematical fitting method. The fitting results indicate that the efficiencies of the multiple module stacks are all above 90% up to 10 modules. The dynamic performances of the modular stacks are also investigated for portable applications. The results show that the modular stacks exhibit good responsiveness and reproducibility at high loading current (>100 mA). Finally, the modular stacks are successfully applied to drive the experimental fan and charge the mobile phone. - Highlights: • A “4-cell” modular passive DMFC (direct methanol fuel cell) stack is designed, fabricated and tested. • This modular DMFC stack can assemble more single cells with high efficiency. • The modular stack exhibit good responsiveness and reproducibility for portable application

  1. Smartfactory, a modular, low cost productivity monitoring system

    CSIR Research Space (South Africa)

    Bosscha, PA

    2010-07-01

    Full Text Available lack of objectivity and plain incorrect data entries. In aid of the SMMEs the Smartfactory system offers a low-cost modular monitoring solution capable of implementation in a step by step fashion with little training required in installation...

  2. Capital costs of modular HTR reactors

    International Nuclear Information System (INIS)

    Kugeler, K.; Froehling, W.

    1993-01-01

    A decisive factor in the introduction of a reactor line, in addition of its safety, which should exclude releases of radioactivity into the environment, is its economic development and, consequently, its competitiveness. The costs of the pressurized water reactor are used for comparison with the modular HTR reactor. If the measures proposed for evolutionary increases in safety of the PWR are taken, cost increases will have to be expected for that line. The modular HTR can now attain specific construction costs of 3000 deutschmarks per electric kilowatt. Mass production and the introduction of cost-reducing innovations can improve the economy of this line even further. In this way, the modular HTR concept offers the possibility to vendors and operators to set up new economic yardsticks in safety technology. (orig.) [de

  3. A novel Bayesian learning method for information aggregation in modular neural networks

    DEFF Research Database (Denmark)

    Wang, Pan; Xu, Lida; Zhou, Shang-Ming

    2010-01-01

    Modular neural network is a popular neural network model which has many successful applications. In this paper, a sequential Bayesian learning (SBL) is proposed for modular neural networks aiming at efficiently aggregating the outputs of members of the ensemble. The experimental results on eight...... benchmark problems have demonstrated that the proposed method can perform information aggregation efficiently in data modeling....

  4. An analytically solvable model for rapid evolution of modular structure.

    Directory of Open Access Journals (Sweden)

    Nadav Kashtan

    2009-04-01

    Full Text Available Biological systems often display modularity, in the sense that they can be decomposed into nearly independent subsystems. Recent studies have suggested that modular structure can spontaneously emerge if goals (environments change over time, such that each new goal shares the same set of sub-problems with previous goals. Such modularly varying goals can also dramatically speed up evolution, relative to evolution under a constant goal. These studies were based on simulations of model systems, such as logic circuits and RNA structure, which are generally not easy to treat analytically. We present, here, a simple model for evolution under modularly varying goals that can be solved analytically. This model helps to understand some of the fundamental mechanisms that lead to rapid emergence of modular structure under modularly varying goals. In particular, the model suggests a mechanism for the dramatic speedup in evolution observed under such temporally varying goals.

  5. A Grey Wolf Optimizer for Modular Granular Neural Networks for Human Recognition

    Directory of Open Access Journals (Sweden)

    Daniela Sánchez

    2017-01-01

    Full Text Available A grey wolf optimizer for modular neural network (MNN with a granular approach is proposed. The proposed method performs optimal granulation of data and design of modular neural networks architectures to perform human recognition, and to prove its effectiveness benchmark databases of ear, iris, and face biometric measures are used to perform tests and comparisons against other works. The design of a modular granular neural network (MGNN consists in finding optimal parameters of its architecture; these parameters are the number of subgranules, percentage of data for the training phase, learning algorithm, goal error, number of hidden layers, and their number of neurons. Nowadays, there is a great variety of approaches and new techniques within the evolutionary computing area, and these approaches and techniques have emerged to help find optimal solutions to problems or models and bioinspired algorithms are part of this area. In this work a grey wolf optimizer is proposed for the design of modular granular neural networks, and the results are compared against a genetic algorithm and a firefly algorithm in order to know which of these techniques provides better results when applied to human recognition.

  6. Investigation of small and modular-sized fast reactor

    International Nuclear Information System (INIS)

    Kubota, Kenichi; Kawasaki, Nobuchika; Umetsu, Yoichiro; Akatsu, Minoru; Kasai, Shigeo; Konomura, Mamoru; Ichimiya, Masakazu

    2000-06-01

    In this paper, feasibility of the multipurpose small fast reactor, which could be used for requirements concerned with various utilization of electricity and energy and flexibility of power supply site, is discussed on the basis of examination of literatures of various small reactors. And also, a possibility of economic improvement by learning effect of fabrication cost is discussed for the modular-sized reactor which is expected to be a base load power supply system with lower initial investment. (1) Multipurpose small reactor (a) The small reactor with 10MWe-150MWe has a potential as a power source for large co-generation, a large island, a middle city, desalination and marine use. (b) Highly passive mechanism, long fuel exchange interval, and minimized maintenance activities are required for the multipurpose small reactor design. The reactor has a high potential for the long fuel exchange interval, since it is relatively easy for FR to obtain a long life core. (c) Current designs of small FRs in Japan and USA (NERI Project) are reviewed to obtain design requirements for the multipurpose small reactor. (2) Modular-sized reactor (a) In order that modular-sized reactor could be competitive to 3200MWe twin plant (two large monolithic reactor) with 200kyenWe, the target capital cost of FOAK is estimated to be 260kyen/yenWe for 800MWe modular, 280kyen/yenWe for 400MWe modular and 290kyen/yenWe for 200MWe by taking account of the leaning effect. (b) As the result of the review on the current designs of modular-sized FRs in Japan and USA (S-PRISM) from the viewpoint of economic improvement, since it only be necessary to make further effort for the target capital cost of FOAK, since the modular-sized FRs requires a large amount of material for shielding, vessels and heat exchangers essentially. (author)

  7. The effects of predictor method factors on selection outcomes: A modular approach to personnel selection procedures.

    Science.gov (United States)

    Lievens, Filip; Sackett, Paul R

    2017-01-01

    Past reviews and meta-analyses typically conceptualized and examined selection procedures as holistic entities. We draw on the product design literature to propose a modular approach as a complementary perspective to conceptualizing selection procedures. A modular approach means that a product is broken down into its key underlying components. Therefore, we start by presenting a modular framework that identifies the important measurement components of selection procedures. Next, we adopt this modular lens for reviewing the available evidence regarding each of these components in terms of affecting validity, subgroup differences, and applicant perceptions, as well as for identifying new research directions. As a complement to the historical focus on holistic selection procedures, we posit that the theoretical contributions of a modular approach include improved insight into the isolated workings of the different components underlying selection procedures and greater theoretical connectivity among different selection procedures and their literatures. We also outline how organizations can put a modular approach into operation to increase the variety in selection procedures and to enhance the flexibility in designing them. Overall, we believe that a modular perspective on selection procedures will provide the impetus for programmatic and theory-driven research on the different measurement components of selection procedures. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. Modular control system for embedded applications

    Directory of Open Access Journals (Sweden)

    Dostálek Petr

    2016-01-01

    Full Text Available This paper deals with hardware design of a modular control system intended for embedded applications demanding high computational power while maintaining low cost. The control system central unit is based on 32bit microcontroller MK60DN512 with ARM Cortex-M4 core manufactured by NXP Semiconductor. Module provides all the necessary signals on the two 2-row 40 pin headers and Ethernet communication interface in the form of a small daughter board. It is connected to the mainboard which must always contain 5 V stabilized power supply; other circuits are application specific. In our application the mainboard is equipped with SD card slot, RS232 and RS485 interface which is used for high speed interconnection with up to 15 expansion peripheral modules. This concept enables high flexibility to specific application demands without necessity of redesigning the control system. Controller is freely programmable in C language using any compatible integrated development environment – NXP Kinetis Design Studio, for example. Software development and debugging is simplified by our support program libraries including necessary routines for control and monitoring tasks.

  9. Modular invariance, chiral anomalies and contact terms

    International Nuclear Information System (INIS)

    Kutasov, D.

    1988-03-01

    The chiral anomaly in heterotic strings with full and partial modular invariance in D=2n+2 dimensions is calculated. The boundary terms which were present in previous calculations are shown to be cancelled in the modular invariant case by contact terms, which can be obtained by an appropriate analytic continuation. The relation to the low energy field theory is explained. In theories with partial modular invariance, an expression for the anomaly is obtained and shown to be non zero in general. (author)

  10. A Software Architecture for Adaptive Modular Sensing Systems

    Directory of Open Access Journals (Sweden)

    Andrew C. Lyle

    2010-08-01

    Full Text Available By combining a number of simple transducer modules, an arbitrarily complex sensing system may be produced to accommodate a wide range of applications. This work outlines a novel software architecture and knowledge representation scheme that has been developed to support this type of flexible and reconfigurable modular sensing system. Template algorithms are used to embed intelligence within each module. As modules are added or removed, the composite sensor is able to automatically determine its overall geometry and assume an appropriate collective identity. A virtual machine-based middleware layer runs on top of a real-time operating system with a pre-emptive kernel, enabling platform-independent template algorithms to be written once and run on any module, irrespective of its underlying hardware architecture. Applications that may benefit from easily reconfigurable modular sensing systems include flexible inspection, mobile robotics, surveillance, and space exploration.

  11. A Modular Telerobot Control System for Accident Response

    International Nuclear Information System (INIS)

    Anderson, Robert J.; Shirey, David L.

    1999-01-01

    The Accident Response Mobile Manipulator System (ARMMS) is a teleoperated emergency response vehicle that deploys two hydraulic manipulators, five cameras, and an array of sensors to the scene of an incident. It is operated from a remote base station that can be situated up to four kilometers away from the site. Recently, a modular telerobot control architecture called SMART (Sandia's Modular Architecture for Robotic and Teleoperation) was applied to ARMMS to improve the precision, safety, and operability of the manipulators on board. Using SMART, a prototype manipulator control system was developed in a couple of days, and an integrated working system was demonstrated within a couple of months. New capabilities such as camera teleoperation, autonomous tool changeout and dual manipulator control have been incorporated. The final system incorporates twenty-two separate modules and implements eight different behavior modes. This paper describes the integration of SMART into the ARMMS system

  12. Modularity in New Market Formation

    DEFF Research Database (Denmark)

    Sanchez, Ron; Hang, Chang Chieh

    2017-01-01

    In this paper we appraise the ways in which use of closed-system proprietary product architectures versus open-system modular product architectures is likely to influence the dynamics and trajectory of new product market formation. We compare the evolutions of new markets in China for gas......-powered two-wheeled vehicles (G2WVs) based (initially) on closed-system proprietary architectures and for electric-powered two-wheeled vehicles (E2WVs) based on open-system modular architectures. We draw on this comparison to suggest ways in which the use of the two different kinds of architectures...... as the basis for new kinds of products may result in very different patterns and speeds of new market formation. We then suggest some key implications of the different dynamics of market formation associated with open-system modular architectures for both the competence-based strategic management (CBSM...

  13. Modular pulse sequencing in a tokamak system

    International Nuclear Information System (INIS)

    Chew, A.C.; Lee, S.; Saw, S.H.

    1992-01-01

    Pulse technique applied in the timing and sequencing of the various part of the MUT tokamak system are discussed. The modular architecture of the pulse generating device highlights the versatile application of the simple physical concepts in precise and complicated research experiment. (author)

  14. Convergent evolution of modularity in metabolic networks through different community structures

    Directory of Open Access Journals (Sweden)

    Zhou Wanding

    2012-09-01

    Full Text Available Abstract Background It has been reported that the modularity of metabolic networks of bacteria is closely related to the variability of their living habitats. However, given the dependency of the modularity score on the community structure, it remains unknown whether organisms achieve certain modularity via similar or different community structures. Results In this work, we studied the relationship between similarities in modularity scores and similarities in community structures of the metabolic networks of 1021 species. Both similarities are then compared against the genetic distances. We revisited the association between modularity and variability of the microbial living environments and extended the analysis to other aspects of their life style such as temperature and oxygen requirements. We also tested both topological and biological intuition of the community structures identified and investigated the extent of their conservation with respect to the taxomony. Conclusions We find that similar modularities are realized by different community structures. We find that such convergent evolution of modularity is closely associated with the number of (distinct enzymes in the organism’s metabolome, a consequence of different life styles of the species. We find that the order of modularity is the same as the order of the number of the enzymes under the classification based on the temperature preference but not on the oxygen requirement. Besides, inspection of modularity-based communities reveals that these communities are graph-theoretically meaningful yet not reflective of specific biological functions. From an evolutionary perspective, we find that the community structures are conserved only at the level of kingdoms. Our results call for more investigation into the interplay between evolution and modularity: how evolution shapes modularity, and how modularity affects evolution (mainly in terms of fitness and evolvability. Further, our results

  15. Convergent evolution of modularity in metabolic networks through different community structures.

    Science.gov (United States)

    Zhou, Wanding; Nakhleh, Luay

    2012-09-14

    It has been reported that the modularity of metabolic networks of bacteria is closely related to the variability of their living habitats. However, given the dependency of the modularity score on the community structure, it remains unknown whether organisms achieve certain modularity via similar or different community structures. In this work, we studied the relationship between similarities in modularity scores and similarities in community structures of the metabolic networks of 1021 species. Both similarities are then compared against the genetic distances. We revisited the association between modularity and variability of the microbial living environments and extended the analysis to other aspects of their life style such as temperature and oxygen requirements. We also tested both topological and biological intuition of the community structures identified and investigated the extent of their conservation with respect to the taxonomy. We find that similar modularities are realized by different community structures. We find that such convergent evolution of modularity is closely associated with the number of (distinct) enzymes in the organism's metabolome, a consequence of different life styles of the species. We find that the order of modularity is the same as the order of the number of the enzymes under the classification based on the temperature preference but not on the oxygen requirement. Besides, inspection of modularity-based communities reveals that these communities are graph-theoretically meaningful yet not reflective of specific biological functions. From an evolutionary perspective, we find that the community structures are conserved only at the level of kingdoms. Our results call for more investigation into the interplay between evolution and modularity: how evolution shapes modularity, and how modularity affects evolution (mainly in terms of fitness and evolvability). Further, our results call for exploring new measures of modularity and network

  16. Modular Robotic Vehicle

    Science.gov (United States)

    Borroni-Bird, Christopher E. (Inventor); Vitale, Robert L. (Inventor); Lee, Chunhao J. (Inventor); Ambrose, Robert O. (Inventor); Bluethmann, William J. (Inventor); Junkin, Lucien Q. (Inventor); Lutz, Jonathan J. (Inventor); Guo, Raymond (Inventor); Lapp, Anthony Joseph (Inventor); Ridley, Justin S. (Inventor)

    2015-01-01

    A modular robotic vehicle includes a chassis, driver input devices, an energy storage system (ESS), a power electronics module (PEM), modular electronic assemblies (eModules) connected to the ESS via the PEM, one or more master controllers, and various embedded controllers. Each eModule includes a drive wheel containing a propulsion-braking module, and a housing containing propulsion and braking control assemblies with respective embedded propulsion and brake controllers, and a mounting bracket covering a steering control assembly with embedded steering controllers. The master controller, which is in communication with each eModule and with the driver input devices, communicates with and independently controls each eModule, by-wire, via the embedded controllers to establish a desired operating mode. Modes may include a two-wheel, four-wheel, diamond, and omni-directional steering modes as well as a park mode. A bumper may enable docking with another vehicle, with shared control over the eModules of the vehicles.

  17. Modular, Reconfigurable, High-Energy Technology Development

    Science.gov (United States)

    Carrington, Connie; Howell, Joe

    2006-01-01

    The Modular, Reconfigurable High-Energy (MRHE) Technology Demonstrator project was to have been a series of ground-based demonstrations to mature critical technologies needed for in-space assembly of a highpower high-voltage modular spacecraft in low Earth orbit, enabling the development of future modular solar-powered exploration cargo-transport vehicles and infrastructure. MRHE was a project in the High Energy Space Systems (HESS) Program, within NASA's Exploration Systems Research and Technology (ESR&T) Program. NASA participants included Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), and Glenn Research Center (GRC). Contractor participants were the Boeing Phantom Works in Huntsville, AL, Lockheed Martin Advanced Technology Center in Palo Alto, CA, ENTECH, Inc. in Keller, TX, and the University of AL Huntsville (UAH). MRHE's technical objectives were to mature: (a) lightweight, efficient, high-voltage, radiation-resistant solar power generation (SPG) technologies; (b) innovative, lightweight, efficient thermal management systems; (c) efficient, 100kW-class, high-voltage power delivery systems from an SPG to an electric thruster system; (d) autonomous rendezvous and docking technology for in-space assembly of modular, reconfigurable spacecraft; (e) robotic assembly of modular space systems; and (f) modular, reconfigurable distributed avionics technologies. Maturation of these technologies was to be implemented through a series of increasingly-inclusive laboratory demonstrations that would have integrated and demonstrated two systems-of-systems: (a) the autonomous rendezvous and docking of modular spacecraft with deployable structures, robotic assembly, reconfiguration both during assembly and (b) the development and integration of an advanced thermal heat pipe and a high-voltage power delivery system with a representative lightweight high-voltage SPG array. In addition, an integrated simulation testbed would have been developed

  18. Modular biometric system

    Science.gov (United States)

    Hsu, Charles; Viazanko, Michael; O'Looney, Jimmy; Szu, Harold

    2009-04-01

    Modularity Biometric System (MBS) is an approach to support AiTR of the cooperated and/or non-cooperated standoff biometric in an area persistent surveillance. Advanced active and passive EOIR and RF sensor suite is not considered here. Neither will we consider the ROC, PD vs. FAR, versus the standoff POT in this paper. Our goal is to catch the "most wanted (MW)" two dozens, separately furthermore ad hoc woman MW class from man MW class, given their archrivals sparse front face data basis, by means of various new instantaneous input called probing faces. We present an advanced algorithm: mini-Max classifier, a sparse sample realization of Cramer-Rao Fisher bound of the Maximum Likelihood classifier that minimize the dispersions among the same woman classes and maximize the separation among different man-woman classes, based on the simple feature space of MIT Petland eigen-faces. The original aspect consists of a modular structured design approach at the system-level with multi-level architectures, multiple computing paradigms, and adaptable/evolvable techniques to allow for achieving a scalable structure in terms of biometric algorithms, identification quality, sensors, database complexity, database integration, and component heterogenity. MBS consist of a number of biometric technologies including fingerprints, vein maps, voice and face recognitions with innovative DSP algorithm, and their hardware implementations such as using Field Programmable Gate arrays (FPGAs). Biometric technologies and the composed modularity biometric system are significant for governmental agencies, enterprises, banks and all other organizations to protect people or control access to critical resources.

  19. Advanced Modular Power Approach to Affordable, Supportable Space Systems

    Science.gov (United States)

    Oeftering, Richard C.; Kimnach, Greg L.; Fincannon, James; Mckissock,, Barbara I.; Loyselle, Patricia L.; Wong, Edmond

    2013-01-01

    Recent studies of missions to the Moon, Mars and Near Earth Asteroids (NEA) indicate that these missions often involve several distinct separately launched vehicles that must ultimately be integrated together in-flight and operate as one unit. Therefore, it is important to see these vehicles as elements of a larger segmented spacecraft rather than separate spacecraft flying in formation. The evolution of large multi-vehicle exploration architecture creates the need (and opportunity) to establish a global power architecture that is common across all vehicles. The Advanced Exploration Systems (AES) Modular Power System (AMPS) project managed by NASA Glenn Research Center (GRC) is aimed at establishing the modular power system architecture that will enable power systems to be built from a common set of modular building blocks. The project is developing, demonstrating and evaluating key modular power technologies that are expected to minimize non-recurring development costs, reduce recurring integration costs, as well as, mission operational and support costs. Further, modular power is expected to enhance mission flexibility, vehicle reliability, scalability and overall mission supportability. The AMPS project not only supports multi-vehicle architectures but should enable multi-mission capability as well. The AMPS technology development involves near term demonstrations involving developmental prototype vehicles and field demonstrations. These operational demonstrations not only serve as a means of evaluating modular technology but also provide feedback to developers that assure that they progress toward truly flexible and operationally supportable modular power architecture.

  20. Non-Archimedean L-functions and arithmetical Siegel modular forms

    CERN Document Server

    1991-01-01

    This book is devoted to the arithmetical theory of Siegel modular forms and their L-functions. The central object are L-functions of classical Siegel modular forms whose special values are studied using the Rankin-Selberg method and the action of certain differential operators on modular forms which have nice arithmetical properties. A new method of p-adic interpolation of these critical values is presented. An important class of p-adic L-functions treated in the present book are p-adic L-functions of Siegel modular forms having logarithmic growth (which were first introduced by Amice, Velu and Vishik in the elliptic modular case when they come from a good supersingular reduction of ellptic curves and abelian varieties). The given construction of these p-adic L-functions uses precise algebraic properties of the arihmetical Shimura differential operator. The book could be very useful for postgraduate students and for non-experts giving a quick access to a rapidly developping domain of algebraic number theory: ...

  1. Local modular Hamiltonians from the quantum null energy condition

    Science.gov (United States)

    Koeller, Jason; Leichenauer, Stefan; Levine, Adam; Shahbazi-Moghaddam, Arvin

    2018-03-01

    The vacuum modular Hamiltonian K of the Rindler wedge in any relativistic quantum field theory is given by the boost generator. Here we investigate the modular Hamiltonian for more general half-spaces which are bounded by an arbitrary smooth cut of a null plane. We derive a formula for the second derivative of the modular Hamiltonian with respect to the coordinates of the cut which schematically reads K''=Tv v . This formula can be integrated twice to obtain a simple expression for the modular Hamiltonian. The result naturally generalizes the standard expression for the Rindler modular Hamiltonian to this larger class of regions. Our primary assumptions are the quantum null energy condition—an inequality between the second derivative of the von Neumann entropy of a region and the stress tensor—and its saturation in the vacuum for these regions. We discuss the validity of these assumptions in free theories and holographic theories to all orders in 1 /N .

  2. Number theory and modular forms papers in memory of Robert A Rankin

    CERN Document Server

    Ono, Ken

    2003-01-01

    Robert A. Rankin, one of the world's foremost authorities on modular forms and a founding editor of The Ramanujan Journal, died on January 27, 2001, at the age of 85. Rankin had broad interests and contributed fundamental papers in a wide variety of areas within number theory, geometry, analysis, and algebra. To commemorate Rankin's life and work, the editors have collected together 25 papers by several eminent mathematicians reflecting Rankin's extensive range of interests within number theory. Many of these papers reflect Rankin's primary focus in modular forms. It is the editors' fervent hope that mathematicians will be stimulated by these papers and gain a greater appreciation for Rankin's contributions to mathematics. This volume would be an inspiration to students and researchers in the areas of number theory and modular forms.

  3. Identification and functional characterization of three type III polyketide synthases from Aquilaria sinensis calli

    International Nuclear Information System (INIS)

    Wang, Xiaohui; Zhang, Zhongxiu; Dong, Xianjuan; Feng, Yingying; Liu, Xiao; Gao, Bowen; Wang, Jinling; Zhang, Le; Wang, Juan; Shi, Shepo; Tu, Pengfei

    2017-01-01

    Type III polyketide synthases (PKSs) play an important role in biosynthesis of various plant secondary metabolites and plant adaptation to environmental stresses. Aquilaria sinensis (A. sinensis) is the main plant species for production of agarwood, little is known about its PKS family. In this study, AsCHS1 and two new type III PKSs, AsPKS1 and AsPKS2, were isolated and characterized in A. sinensis calli. The comparative sequence and phylogenetic analysis indicated that AsPKS1 and AsPKS2 belonged to non-CHS group different from AsCHS1. The recombinant AsPKS1 and AsPKS2 produced the lactone-type products, suggesting their different enzyme activities from AsCHS1. Three PKS genes had a tissues-specific pattern in A. sinensis. Moreover, we examined the expression profiles of three PKS genes in calli under different abiotic stresses and hormone treatments. AsCHS1 transcript was most significantly induced by salt stress, AsPKS1 abundance was most remarkably enhanced by CdCl 2 treatment, while AsPKS2 expression was most significantly induced by mannitol treatment. Furthermore, AsCHS1, AsPKS1 and AsPKS2 expression was enhanced upon gibberellins (GA3), methyl jasmonate (MeJA), or salicylic acid (SA) treatment, while three PKS genes displayed low transcript levels at the early stage under abscisic acid (ABA) treatment. In addition, three GFP:PKSs fusion proteins were localized in the cytoplasm and cell wall in Nicotiana benthamiana cells. These results indicated the multifunctional role of three type III PKSs in polyketide biosynthesis, plant resistance to abiotic stresses and signal transduction. - Highlights: • Two new PKS genes (AsPKS1 and AsPKS2) were isolated and characterized from A. sinensis. • The recombinant AsPKS1 and AsPKS2 catalyzed lactone-type products in vitro. • AsCHS1, AsPKS1 and AsPKS2 were involved in plant responses to abiotic stresses and hormone stimuli. • Our results also indicated that AsCHS1, AsPKS1 and AsPKS2 were predominantly localized

  4. Modular robotics overview of the 'state of the art'

    International Nuclear Information System (INIS)

    Kress, R.L.; Jansen, J.F.; Hamel, W.R.

    1996-08-01

    The design of a robotic arm processing modular components and reconfigurable links is the general goal of a modular robotics development program. The impetus behind the pursuit of modular design is the remote engineering paradigm of improved reliability and availability provided by the ability to remotely maintain and repair a manipulator operating in a hazardous environment by removing and replacing worn or failed modules. Failed components can service off- line and away from hazardous conditions. The desire to reconfigure an arm to perform different tasks is also an important driver for the development of a modular robotic manipulator. In order to bring to fruition a truly modular manipulator, an array of technical challenges must be overcome. These range from basic mechanical and electrical design considerations such as desired kinematics, actuator types, and signal and transmission types and routings, through controls issues such as the need for control algorithms capable of stable free space and contact control, to computer and sensor design issues like consideration of the use of embedded processors and redundant sensors. This report presents a brief overview of the state of the art of technical issues relevant of modular robotic arm design. The focus is on breadth of coverage, rather than depth, in order to provide a reference frame for future development

  5. The Impact of Product and Service Modularity on Business Performance

    DEFF Research Database (Denmark)

    Hsuan, Juliana; Frandsen, Thomas; Raja, Jawwad

    Modularity has been proposed as a powerful way of managing complexity. The emerging literature points to the importance of modularity of service architecture, with case based studies in logistics and healthcare. Little is known about the relationship between product and service modularity...... and their effects on business performance, both empirically and theoretically. This paper explores the relationship between product and service modularity and their effects on business performance based on a survey of Danish manufacturers. We provide empirical and theoretical insights into the emerging fields...

  6. Functional modularity in lake-dwelling characin fishes of Mexico

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Ornelas-García

    2017-09-01

    Full Text Available Modular evolution promotes evolutionary change, allowing independent variation across morphological units. Recent studies have shown that under contrasting ecological pressures, patterns of modularity could be related to divergent evolution. The main goal of the present study was to evaluate the presence of modular evolution in two sister lacustrine species, Astyanax aeneus and A. caballeroi, which are differentiated by their trophic habits. Two different datasets were analyzed: (1 skull X-rays from 73 specimens (35 A. aeneus and 38 A. caballeroi to characterize skull variation patterns, considering both species and sex effects. For this dataset, three different modularity hypotheses were tested, previously supported in other lacustrine divergent species; (2 a complete body shape dataset was also tested for four modularity hypotheses, which included a total of 196 individuals (110 Astyanax aeneus and 86 A. caballeroi. Skull shape showed significant differences among species and sex (P < 0.001, where Astyanax caballeroi species showed an upwardly projected mandible and larger preorbital region. For the skull dataset, the modularity hypothesis ranked first included three partitioning modules. While for the complete body dataset the best ranked hypothesis included two modules (head vs the rest of the body, being significant only for A. caballeroi.

  7. Analysis of Advanced Modular Power Systems (AMPS) for Deep Space Exploration

    Science.gov (United States)

    Oeftering, Richard; Soeder, James F.; Beach, Ray

    2014-01-01

    The Advanced Modular Power Systems (AMPS) project is developing a modular approach to spacecraft power systems for exploration beyond Earth orbit. AMPS is intended to meet the need of reducing the cost of design development, test and integration and also reducing the operational logistics cost of supporting exploration missions. AMPS seeks to establish modular power building blocks with standardized electrical, mechanical, thermal and data interfaces that can be applied across multiple exploration vehicles. The presentation discusses the results of a cost analysis that compares the cost of the modular approach against a traditional non-modular approach.

  8. Application and development analysis of nuclear power plant modular construction

    International Nuclear Information System (INIS)

    Fang Xiaopeng

    2015-01-01

    Modular Construction is currently one of the major development trends for the nuclear power plant construction technology worldwide. In the first-of-a-kind AP1000 Nuclear Power Project practiced in China, the large-scale structural modules and mechanical modules have been successfully fabricated, assembled and installed. However, in the construction practice of the project, some quality issues are identified with the assembly and installation process of large-scale structural modules in addition to the issue of incomplete supply of mechanical modules, which has failed to fully demonstrate the features and merits of modular construction. This paper collects and consolidates the issues of modular construction of AP1000 first of a kind reactor, providing root cause analysis in the aspects of process design, quality control, site construction logic, interface management in the process of module fabrication, assembly and installation; modular construction feasibility assessment index is proved based on the quantification and qualitative analysis of the impact element. Based on the modular construction feasibility, NPP modular construction improvement suggestions are provided in the aspect of modular assembly optimization definition, tolerance control during the fitting process and the construction logic adjustment. (author)

  9. Music, Language and Modularity Framed in Action

    Directory of Open Access Journals (Sweden)

    Isabelle Peretz

    2009-06-01

    Full Text Available Here, I examine to what extend music and speech share processing components by focusing on vocal production, that is, singing and speaking. In shaping my review, the modularity concept has been and continues to play a determinant role. Thus, I will first provide a brief background on the contemporary notion of modularity. Next, I will present evidence that musical abilities depend, in part, on modular processes. The evidence is coming mainly from neuropsychological dissociations. The relevance of findings of overlap in neuroimaging, of interference and domain-transfer effects between music and speech will also be addressed and discussed. Finally, I will contrast the modularity position with the resource-sharing framework proposed by Patel (2003, 2008a. This critical review should be viewed as an invitation to undertake future comparative research between music and language by focusing on the details of the functions that these mechanisms carry out, not only their specificity. Such comparative research is very important not only theoretically but also in practice because of their obvious clinical and educational implications.

  10. Modularization Technology in Power Plant Construction

    International Nuclear Information System (INIS)

    Kenji Akagi; Kouichi Murayama; Miki Yoshida; Junichi Kawahata

    2002-01-01

    Since the early 1980's, Hitachi has been developing and applying modularization technology to domestic nuclear power plant construction, and has achieved great rationalization. Modularization is one of the plant construction techniques which enables us to reduce site labor by pre-assembling components like equipment, pipes, valves and platforms in congested areas and installing them using large capacity cranes for cost reduction, better quality, safety improvement and shortening of construction time. In this paper, Hitachi's modularization technologies are described especially from with respect to their sophisticated design capabilities. The application of 3D-CAD at the detailed layout design stage, concurrent design environment achieved by the computer network, module design quantity control and the management system are described. (authors)

  11. A modular approach to numerical human body modeling

    NARCIS (Netherlands)

    Forbes, P.A.; Griotto, G.; Rooij, L. van

    2007-01-01

    The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body

  12. Harmonic Maass forms and mock modular forms

    CERN Document Server

    Bringmann, Kathrin; Ono, Ken

    2017-01-01

    Modular forms and Jacobi forms play a central role in many areas of mathematics. Over the last 10-15 years, this theory has been extended to certain non-holomorphic functions, the so-called "harmonic Maass forms". The first glimpses of this theory appeared in Ramanujan's enigmatic last letter to G. H. Hardy written from his deathbed. Ramanujan discovered functions he called "mock theta functions" which over eighty years later were recognized as pieces of harmonic Maass forms. This book contains the essential features of the theory of harmonic Maass forms and mock modular forms, together with a wide variety of applications to algebraic number theory, combinatorics, elliptic curves, mathematical physics, quantum modular forms, and representation theory.

  13. Understanding the Modularity of Socio-technical Production Systems

    DEFF Research Database (Denmark)

    Thuesen, Christian Langhoff

    This paper seeks to contribute to the development of Configurational Theory by offering a reinterpretation of the modularity concept from a socio-technical perspective in general and Actor Network Theory (ANT) in particular. By formulating modularity from an ANT perspective covering social...

  14. In Silico Investigation of a Surgical Interface for Remote Control of Modular Miniature Robots in Minimally Invasive Surgery

    Directory of Open Access Journals (Sweden)

    Apollon Zygomalas

    2014-01-01

    Full Text Available Aim. Modular mini-robots can be used in novel minimally invasive surgery techniques like natural orifice transluminal endoscopic surgery (NOTES and laparoendoscopic single site (LESS surgery. The control of these miniature assistants is complicated. The aim of this study is the in silico investigation of a remote controlling interface for modular miniature robots which can be used in minimally invasive surgery. Methods. The conceptual controlling system was developed, programmed, and simulated using professional robotics simulation software. Three different modes of control were programmed. The remote controlling surgical interface was virtually designed as a high scale representation of the respective modular mini-robot, therefore a modular controlling system itself. Results. With the proposed modular controlling system the user could easily identify the conformation of the modular mini-robot and adequately modify it as needed. The arrangement of each module was always known. The in silico investigation gave useful information regarding the controlling mode, the adequate speed of rearrangements, and the number of modules needed for efficient working tasks. Conclusions. The proposed conceptual model may promote the research and development of more sophisticated modular controlling systems. Modular surgical interfaces may improve the handling and the dexterity of modular miniature robots during minimally invasive procedures.

  15. Modular cathode assemblies and methods of using the same for electrochemical reduction

    Science.gov (United States)

    Wiedmeyer, Stanley G.; Barnes, Laurel A.; Williamson, Mark A.; Willit, James L.

    2018-03-20

    Modular cathode assemblies are useable in electrolytic reduction systems and include a basket through which fluid electrolyte may pass and exchange charge with a material to be reduced in the basket. The basket can be divided into upper and lower sections to provide entry for the material. Example embodiment cathode assemblies may have any shape to permit modular placement at any position in reduction systems. Modular cathode assemblies include a cathode plate in the basket, to which unique and opposite electrical power may be supplied. Example embodiment modular cathode assemblies may have standardized electrical connectors. Modular cathode assemblies may be supported by a top plate of an electrolytic reduction system. Electrolytic oxide reduction systems are operated by positioning modular cathode and anode assemblies at desired positions, placing a material in the basket, and charging the modular assemblies to reduce the metal oxide.

  16. Phylogenomic and functional domain analysis of polyketide synthases in Fusarium

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Daren W.; Butchko, Robert A.; Baker, Scott E.; Proctor, Robert H.

    2012-02-01

    Fusarium species are ubiquitous in nature, cause a range of plant diseases, and produce a variety of chemicals often referred to as secondary metabolites. Although some fungal secondary metabolites affect plant growth or protect plants from other fungi and bacteria, their presence in grain based food and feed is more often associated with a variety of diseases in plants and in animals. Many of these structurally diverse metabolites are derived from a family of related enzymes called polyketide synthases (PKSs). A search of genomic sequence of Fusarium verticillioides, F. graminearum, F. oxysporum and Nectria haematococca (anamorph F. solani) identified a total of 58 PKS genes. To gain insight into how this gene family evolved and to guide future studies, we conducted a phylogenomic and functional domain analysis. The resulting genealogy suggested that Fusarium PKSs represent 34 different groups responsible for synthesis of different core metabolites. The analyses indicate that variation in the Fusarium PKS gene family is due to gene duplication and loss events as well as enzyme gain-of-function due to the acquisition of new domains or of loss-of-function due to nucleotide mutations. Transcriptional analysis indicate that the 16 F. verticillioides PKS genes are expressed under a range of conditions, further evidence that they are functional genes that confer the ability to produce secondary metabolites.

  17. A Modular Set of Mixed Reality Simulators for Blind and Guided Procedures

    Science.gov (United States)

    2016-08-01

    presented the mixed reality simulator among other technologies at a lecture at the University of Southern California Institute of Creative Technologies (ICT...AWARD NUMBER: W81XWH-14-1-0113 TITLE: A Modular Set of Mixed Reality Simulators for “blind” and Guided Procedures PRINCIPAL INVESTIGATOR...2015 – 07/31/2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER A Modular Set of Mixed Reality Simulators for “Blind” and Guided Procedures 5b

  18. Modularization of Courses.

    Science.gov (United States)

    Eastern Arizona Coll., Thatcher.

    Eastern Arizona College has developed a modularized system of instruction for five vocational and vocationally related courses--Introduction to Business, Business Mathematics, English, Drafting, and Electronics. Each course is divided into independent segments of instruction and students have open-entry and exit options. This document reviews the…

  19. Multi-kilowatt modularized spacecraft power processing system development

    International Nuclear Information System (INIS)

    Andrews, R.E.; Hayden, J.H.; Hedges, R.T.; Rehmann, D.W.

    1975-07-01

    A review of existing information pertaining to spacecraft power processing systems and equipment was accomplished with a view towards applicability to the modularization of multi-kilowatt power processors. Power requirements for future spacecraft were determined from the NASA mission model-shuttle systems payload data study which provided the limits for modular power equipment capabilities. Three power processing systems were compared to evaluation criteria to select the system best suited for modularity. The shunt regulated direct energy transfer system was selected by this analysis for a conceptual design effort which produced equipment specifications, schematics, envelope drawings, and power module configurations

  20. Multiple D3-Instantons and Mock Modular Forms II

    Science.gov (United States)

    Alexandrov, Sergei; Banerjee, Sibasish; Manschot, Jan; Pioline, Boris

    2018-03-01

    We analyze the modular properties of D3-brane instanton corrections to the hypermultiplet moduli space in type IIB string theory compactified on a Calabi-Yau threefold. In Part I, we found a necessary condition for the existence of an isometric action of S-duality on this moduli space: the generating function of DT invariants in the large volume attractor chamber must be a vector-valued mock modular form with specified modular properties. In this work, we prove that this condition is also sufficient at two-instanton order. This is achieved by producing a holomorphic action of {SL(2,Z)} on the twistor space which preserves the holomorphic contact structure. The key step is to cancel the anomalous modular variation of the Darboux coordinates by a local holomorphic contact transformation, which is generated by a suitable indefinite theta series. For this purpose we introduce a new family of theta series of signature (2, n - 2), find their modular completion, and conjecture sufficient conditions for their convergence, which may be of independent mathematical interest.

  1. Modular nuclear fuel assembly rack

    International Nuclear Information System (INIS)

    Davis, C.J.

    1982-01-01

    A modular nuclear fuel assembly rack constructed of an array of identical cells, each cell constructed of a plurality of identical flanged plates. The unique assembly of the plates into a rigid rack provides a cellular compartment for nuclear fuel assemblies and a cavity between the cells for accepting neutron absorbing materials thus allowing a closely spaced array. The modular rack size can be easily adapted to conform with available storage space. U-shaped flanges at the edges of the plates are nested together at the intersection of four cells in the array. A bar is placed at the intersection to lock the cells together

  2. Multiple D3-Instantons and Mock Modular Forms I

    Science.gov (United States)

    Alexandrov, Sergei; Banerjee, Sibasish; Manschot, Jan; Pioline, Boris

    2017-07-01

    We study D3-instanton corrections to the hypermultiplet moduli space in type IIB string theory compactified on a Calabi-Yau threefold. In a previous work, consistency of D3-instantons with S-duality was established at first order in the instanton expansion, using the modular properties of the M5-brane elliptic genus. We extend this analysis to the two-instanton level, where wall-crossing phenomena start playing a role. We focus on the contact potential, an analogue of the Kähler potential which must transform as a modular form under S-duality. We show that it can be expressed in terms of a suitable modification of the partition function of D4-D2-D0 BPS black holes, constructed out of the generating function of MSW invariants (the latter coincide with Donaldson-Thomas invariants in a particular chamber). Modular invariance of the contact potential then requires that, in the case where the D3-brane wraps a reducible divisor, the generating function of MSW invariants must transform as a vector-valued mock modular form, with a specific modular completion built from the MSW invariants of the constituents. Physically, this gives a powerful constraint on the degeneracies of BPS black holes. Mathematically, our result gives a universal prediction for the modular properties of Donaldson-Thomas invariants of pure two-dimensional sheaves.

  3. Modular envelopes, OSFT and nonsymmetric (non-$\\sum$) modular operads

    Czech Academy of Sciences Publication Activity Database

    Markl, Martin

    2016-01-01

    Roč. 10, č. 2 (2016), s. 775-809 ISSN 1661-6952 Institutional support: RVO:67985840 Keywords : open string * surface * modular completion Subject RIV: BA - General Mathematics Impact factor: 0.625, year: 2016 http://www.ems-ph.org/journals/show_abstract.php?issn=1661-6952&vol=10&iss=2&rank=12

  4. Emergency systems and protection equipment of modular steam generators for fast reactors

    International Nuclear Information System (INIS)

    Matal, O.

    The requirements are discussed for accident protection of modular steam generators for fast reactors. Accident protection is assessed for a modular through-flow steam generator and for a natural circulation modular steam generator. Benefits and constraints are shown and possible improvements are outlined for accident protection of liquid sodium fired modular steam generators. (Kr)

  5. Balancing Modularity and Solution Space Freedom

    DEFF Research Database (Denmark)

    Vos, Maren A.; Raassens, Néomie; Van der Borgh, Michel

    2018-01-01

    that modularity reflects knowledge specialisation and solution space freedom reflects knowledge variety. Both of these dimensions affect organisational learning and, in turn, sustainable innovation. Second, we argue that the relationship between customisation and organisational learning is affected by supplier...... theory to provide insights into how TI firms can achieve ‘win-win’ situations where sustainable innovation is increased through customisation. First, we argue that customisation should be viewed two-dimensionally and identify both modularity and solution space freedom as important dimensions. We argue...... characteristics, specifically supplier sophistication. Survey data from 166 managers were used to empirically test the conceptual model and hypotheses. Polynomial response surface analysis confirms that customising by balancing high degrees of both modularity and solution space freedom results in superior...

  6. Fast quantum modular exponentiation

    International Nuclear Information System (INIS)

    Meter, Rodney van; Itoh, Kohei M.

    2005-01-01

    We present a detailed analysis of the impact on quantum modular exponentiation of architectural features and possible concurrent gate execution. Various arithmetic algorithms are evaluated for execution time, potential concurrency, and space trade-offs. We find that to exponentiate an n-bit number, for storage space 100n (20 times the minimum 5n), we can execute modular exponentiation 200-700 times faster than optimized versions of the basic algorithms, depending on architecture, for n=128. Addition on a neighbor-only architecture is limited to O(n) time, whereas non-neighbor architectures can reach O(log n), demonstrating that physical characteristics of a computing device have an important impact on both real-world running time and asymptotic behavior. Our results will help guide experimental implementations of quantum algorithms and devices

  7. Altas Habilidades/Superdotação e a psicopedagogia modular: avaliando potencialidades

    Directory of Open Access Journals (Sweden)

    Elizabeth Carvalho da Veiga

    2014-09-01

    Full Text Available http://dx.doi.org/10.5902/1984686X14283A psicopedagogia modular é uma proposta que apresenta um modelo de avaliação  dinâmica, um processo interativo, flexível e individualizado, buscando compreender a funcionalidade dos sistemas inteligentes. A presente investigação foi realizada com crianças que buscaram avaliação psicopedagógica no Núcleo de Pratica em Psicologia da PUCPR  e teve por objetivos apontar a funcionalidade dos sistemas inteligentes, reconhecendo a existência ou não , de altas habilidades e identificar a predominância  entre os sistemas analítico , prático ou criativo , utilizados pela clientela  em questão. A metodologia de avaliação  contou com os seguintes instrumentos : entrevista evolutiva modular; questionário para os pais; brasão familiar; E.M.C.A ; WISC III;  provas multimodais e provas cognitivas modulares. Este processo levou aproximadamente 25 encontros de  cinquenta minutos .Participaram da pesquisa 28 alunos de 8 a 17 anos  de diferentes escolas de Curitiba-Pr/ Brasil. Por meio dos dados obtidos, ainda que apurados a partir de uma amostra pequena, pode-se concluir que a proposta da Psicopedagogia Modular  com seu  modelo dinâmico de avaliação, favoreceu a identificação das altas habilidades/superdotação, na sua especificidade, ou seja ,  considerando  a multiplicidade dos sistemas inteligentes  e as habilidades envolvidas nos processos mentais que sustentam  as inteligências analítica, prática e criativa. A visão modular no processo de identificação traz uma identidade ao superdotado, tirando-o  da concepção generalista.

  8. Application of Network Analysis for Characterizing Service Modularity

    DEFF Research Database (Denmark)

    Frandsen, Thomas

    2012-01-01

    The purpose of this paper is to explore the potential of the application of network analytical techniques to identify and characterize modularity of service processes. Services can be conceptualized as systems of interrelated components which can be decomposed in order to achieve a modular design...

  9. Summary description of the scale modular code system

    International Nuclear Information System (INIS)

    Parks, C.V.

    1987-12-01

    SCALE - a modular code system for Standardized Computer Analyses for Licensing Evaluation - has been developed at Oak Ridge National Laboratory at the request of the US Nuclear Regulatory Commission staff. The SCALE system utilizes well-established computer codes and methods within standard analytic sequences that allow simplified free-form input, automate the data processing and coupling between codes, and provide accurate and reliable results. System development has been directed at criticality safety, shielding, and heat transfer analysis of spent fuel transport and/or storage casks. However, only a few of the sequences (and none of the individual functional modules) are restricted to cask applications. This report will provide a background on the history of the SCALE development and review the components and their function within the system. The available data libraries are also discussed, together with the automated features that standardize the data processing and systems analysis. 83 refs., 32 figs., 11 tabs

  10. Environmental versatility promotes modularity in large scale metabolic networks

    OpenAIRE

    Samal A.; Wagner Andreas; Martin O.C.

    2011-01-01

    Abstract Background The ubiquity of modules in biological networks may result from an evolutionary benefit of a modular organization. For instance, modularity may increase the rate of adaptive evolution, because modules can be easily combined into new arrangements that may benefit their carrier. Conversely, modularity may emerge as a by-product of some trait. We here ask whether this last scenario may play a role in genome-scale metabolic networks that need to sustain life in one or more chem...

  11. Modular structure of functional networks in olfactory memory.

    Science.gov (United States)

    Meunier, David; Fonlupt, Pierre; Saive, Anne-Lise; Plailly, Jane; Ravel, Nadine; Royet, Jean-Pierre

    2014-07-15

    Graph theory enables the study of systems by describing those systems as a set of nodes and edges. Graph theory has been widely applied to characterize the overall structure of data sets in the social, technological, and biological sciences, including neuroscience. Modular structure decomposition enables the definition of sub-networks whose components are gathered in the same module and work together closely, while working weakly with components from other modules. This processing is of interest for studying memory, a cognitive process that is widely distributed. We propose a new method to identify modular structure in task-related functional magnetic resonance imaging (fMRI) networks. The modular structure was obtained directly from correlation coefficients and thus retained information about both signs and weights. The method was applied to functional data acquired during a yes-no odor recognition memory task performed by young and elderly adults. Four response categories were explored: correct (Hit) and incorrect (False alarm, FA) recognition and correct and incorrect rejection. We extracted time series data for 36 areas as a function of response categories and age groups and calculated condition-based weighted correlation matrices. Overall, condition-based modular partitions were more homogeneous in young than elderly subjects. Using partition similarity-based statistics and a posteriori statistical analyses, we demonstrated that several areas, including the hippocampus, caudate nucleus, and anterior cingulate gyrus, belonged to the same module more frequently during Hit than during all other conditions. Modularity values were negatively correlated with memory scores in the Hit condition and positively correlated with bias scores (liberal/conservative attitude) in the Hit and FA conditions. We further demonstrated that the proportion of positive and negative links between areas of different modules (i.e., the proportion of correlated and anti-correlated areas

  12. Analytic properties of the Virasoro modular kernel

    Energy Technology Data Exchange (ETDEWEB)

    Nemkov, Nikita [Moscow Institute of Physics and Technology (MIPT), Dolgoprudny (Russian Federation); Institute for Theoretical and Experimental Physics (ITEP), Moscow (Russian Federation); National University of Science and Technology MISIS, The Laboratory of Superconducting metamaterials, Moscow (Russian Federation)

    2017-06-15

    On the space of generic conformal blocks the modular transformation of the underlying surface is realized as a linear integral transformation. We show that the analytic properties of conformal block implied by Zamolodchikov's formula are shared by the kernel of the modular transformation and illustrate this by explicit computation in the case of the one-point toric conformal block. (orig.)

  13. Plant systems/components modularization study. Final report

    International Nuclear Information System (INIS)

    1977-07-01

    The final results are summarized of a Plant Systems/Components Modularization Study based on Stone and Webster's Pressurized Water Reactor Reference Design. The program has been modified to include evaluation of the most promising areas for modular consideration based on the level of the Sundesert Project engineering design completion and the feasibility of their incorporation into the plant construction effort

  14. Cranial modularity and sequence heterochrony in mammals.

    Science.gov (United States)

    Goswami, Anjali

    2007-01-01

    Heterochrony, the temporal shifting of developmental events relative to each other, requires a degree of autonomy among those processes or structures. Modularity, the division of larger structures or processes into autonomous sets of internally integrated units, is often discussed in relation to the concept of heterochrony. However, the relationship between the developmental modules derived from studies of heterochrony and evolutionary modules, which should be of adaptive importance and relate to the genotype-phenotype map, has not been explicitly studied. I analyzed a series of sectioned and whole cleared-and-stained embryological and neonatal specimens, supplemented with published ontogenetic data, to test the hypothesis that bones within the same phenotypic modules, as determined by morphometric analysis, are developmentally integrated and will display coordinated heterochronic shifts across taxa. Modularity was analyzed in cranial bone ossification sequences of 12 therian mammals. A dataset of 12-18 developmental events was used to assess if modularity in developmental sequences corresponds to six phenotypic modules, derived from a recent morphometric analysis of cranial modularity in mammals. Kendall's tau was used to measure rank correlations, with randomization tests for significance. If modularity in developmental sequences corresponds to observed phenotypic modules, bones within a single phenotypic module should show integration of developmental timing, maintaining the same timing of ossification relative to each other, despite differences in overall ossification sequences across taxa. Analyses did not find any significant conservation of developmental timing within the six phenotypic modules, meaning that bones that are highly integrated in adult morphology are not significantly integrated in developmental timing.

  15. CAMAC: a standardized modular instrumentation system

    International Nuclear Information System (INIS)

    Michot, Felicia

    1978-01-01

    In view of its modular aspect and its standardization at the international level, the CAMAC system appears as a very interesting system every time that there is a need for fastly constructing an experiment or a mounting in the laboratory or industry. As it can be connected to a computer interface CAMAC may be used for data acquisition, with machine-tools or for industrial process control. The operation mode of said system is discussed in the paper, together with its constituting elements and performance [fr

  16. PLM system support for modular product development

    DEFF Research Database (Denmark)

    Bruun, Hans Peter Lomholt; Mortensen, Niels Henrik; Harlou, Ulf

    2015-01-01

    A modular design strategy both enables, but also demands, parallelism in design activities and collaboration between a diversity of disciplines in companies, which often involves supporting computer-based tools for enhancing interaction, design management, and communication. Product data management...... (PDM) and product lifecycle management (PLM) systems offer support by automating and managing some of the operational complexity of modular design activities. PLM system tools are used for handling a variety of product definitions, to manage workflow of development activities, and to measure relational...... properties such as cost and performance. Companies often use a PLM tool for management of CAD files, documents, and drawings, but they do not take advantage of the full potential of the PLM system to support the development activities of modular product designs. The key result of this paper...

  17. Ecological, historical and evolutionary determinants of modularity in weighted seed-dispersal networks

    DEFF Research Database (Denmark)

    Schleuning, Matthias; Ingmann, Lili; Strauß, Rouven

    2014-01-01

    Modularity is a recurrent and important property of bipartite ecological networks. Although well-resolved ecological networks describe interaction frequencies between species pairs, modularity of bipartite networks has been analysed only on the basis of binary presence-absence data. We employ a new...... algorithm to detect modularity in weighted bipartite networks in a global analysis of avian seed-dispersal networks. We define roles of species, such as connector values, for weighted and binary networks and associate them with avian species traits and phylogeny. The weighted, but not binary, analysis...... identified a positive relationship between climatic seasonality and modularity, whereas past climate stability and phylogenetic signal were only weakly related to modularity. Connector values were associated with foraging behaviour and were phylogenetically conserved. The weighted modularity analysis...

  18. Modularity and the spread of perturbations in complex dynamical systems.

    Science.gov (United States)

    Kolchinsky, Artemy; Gates, Alexander J; Rocha, Luis M

    2015-12-01

    We propose a method to decompose dynamical systems based on the idea that modules constrain the spread of perturbations. We find partitions of system variables that maximize "perturbation modularity," defined as the autocovariance of coarse-grained perturbed trajectories. The measure effectively separates the fast intramodular from the slow intermodular dynamics of perturbation spreading (in this respect, it is a generalization of the "Markov stability" method of network community detection). Our approach captures variation of modular organization across different system states, time scales, and in response to different kinds of perturbations: aspects of modularity which are all relevant to real-world dynamical systems. It offers a principled alternative to detecting communities in networks of statistical dependencies between system variables (e.g., "relevance networks" or "functional networks"). Using coupled logistic maps, we demonstrate that the method uncovers hierarchical modular organization planted in a system's coupling matrix. Additionally, in homogeneously coupled map lattices, it identifies the presence of self-organized modularity that depends on the initial state, dynamical parameters, and type of perturbations. Our approach offers a powerful tool for exploring the modular organization of complex dynamical systems.

  19. Dissociation of modular total hip arthroplasty at the neck-stem interface without dislocation.

    Science.gov (United States)

    Kouzelis, A; Georgiou, C S; Megas, P

    2012-12-01

    Modular femoral and acetabular components are now widely used, but only a few complications related to the modularity itself have been reported. We describe a case of dissociation of the modular total hip arthroplasty (THA) at the femoral neck-stem interface during walking. The possible causes of this dissociation are discussed. Successful treatment was provided with surgical revision and replacement of the modular neck components. Surgeons who use modular components in hip arthroplasties should be aware of possible early complications in which the modularity of the prostheses is the major factor of failure.

  20. Mapping Modular SOS to Rewriting Logic

    DEFF Research Database (Denmark)

    Braga, Christiano de Oliveira; Haeusler, Edward Hermann; Meseguer, José

    2003-01-01

    and verification of MSOS specifications, we have defined a mapping, named , from MSOS to rewriting logic (RWL), a logic which has been proposed as a logical and semantic framework. We have proven the correctness of and implemented it as a prototype, the MSOS-SL Interpreter, in the Maude system, a high......Modular SOS (MSOS) is a framework created to improve the modularity of structural operational semantics specifications, a formalism frequently used in the fields of programming languages semantics and process algebras. With the objective of defining formal tools to support the execution...

  1. Calculation and modular properties of multiloop superstring amplitudes

    International Nuclear Information System (INIS)

    Danilov, G. S.

    2013-01-01

    Multiloop superstring amplitudes are calculated within an extensively used gauge where the two-dimensional gravitino field carries Grassmann moduli. In general, the amplitudes possess, instead of modular symmetry, symmetry with respect to modular transformation supplemented with appropriate transformations of two-dimensional local supersymmetry. If the number of loops is larger than three, the integrationmeasures are notmodular forms, while the expression for the amplitude contains integrals along the boundary of the fundamental region of the modular group.

  2. A Systematic study of modular coil characteristics for 2-field periods quasi-axisymmetric stellarator QAS-LA

    International Nuclear Information System (INIS)

    Zheng, Jinxing; Song, Yuntao; Breslau, Joshua; Neilson, George Hutch

    2014-01-01

    Highlights: • Systematic studies of modular coils characteristics for quasi-axisymmetric stellarator were carried out for the key design parameters. • We systematically analyzed the relationships between design parameters of modular coils and electromagnetic properties such as the maximum field. • The approximate formulae relating modular coil parameters to the maximum magnetic field were derived by the use of simple two coil systems. - Abstract: Modular coil characteristics of a 2-field periods quasi-axisymmetric stellarator QAS-LA configuration with an aspect ratio A p = 3, magnetic pressure ∼4% and rotational transform ι ∼ 0.15 per field period supplied by its own shaping have been detailed studied. In addition, the characteristics of modular coils for QAS-LA were compared with those of an intermediate QA configuration QAS-LAx and a tokamak based on the same center magnet field B 0 , aspect ratio and number of coils. As expected, the B max /B 0 , force F and overturning moment M, increase with the increased complexity of the coil shape. The relationships between the modular coils’ parameters (such as radius curvature ρ, distance from coil to coil Δ c–c and the cross-section of coils) and the electromagnetic characteristics have been systematically summarized. The approximate formula for the maximum magnetic field in the coil body as functions of modular coil parameters (Δ c–c , ρ) was derived for a simple two wire system which will be useful when optimizations of coil properties are called for

  3. Modular robotic applications in nuclear power plant maintenance

    International Nuclear Information System (INIS)

    Glass, S.W.; Ranson, C.C.; Reinholtz, C.F.; Calkins, J.M.

    1996-01-01

    General-purpose factory automation robots have experienced limited use in nuclear maintenance and hazardous-environment work spaces due to demanding requirements on size, weight, mobility and adaptability. Robotic systems in nuclear power plants are frequently custom designed to meet specific space and performance requirements. Examples of these custom configurations include Framatome Technologies COBRA trademark Steam Generator Manipulator and URSULA trademark Reactor Vessel Inspection Manipulator. The use of custom robots in nuclear plants has been limited because of the lead time and expense associated with custom design. Developments in modular robotics and advanced robot control software coupled with more powerful low-cost computers, however, are helping to reduce the cost and schedule for deploying custom robots. A modular robotic system allows custom robot configurations to be implemented using standard (modular) joints and adaptable controllers. This paper discusses Framatome Technologies (FTI) current and planned developments in the area of modular robot system design

  4. MUSIC, MODULARITY AND SYNTAX

    Directory of Open Access Journals (Sweden)

    Javier Valenzuela

    2007-06-01

    Full Text Available First generation cognitive science has always maintained that the mind/brain is a modular system. This has been especially apparent in linguistics, where the modularity thesis goes largely unquestioned by the linguistic mainstream. Cognitive linguists have long disputed the reality of modular architectures of grammar. Instead of conceiving syntax as a computational system of a relatively small set of formal principles and parameters, cognitive linguists take the notion of grammatical construction to be the basic unit of syntax: syntax is simply our repertoire of form-meaning pairings. On such a view, there is no a-priori reason to believe that semantics and phonology cannot affect syntax. In the present paper, we want to take things a step further and suggest, more generally, that language is not a module of cognition in any strict sense. We present preliminary results from research in progress concerning the effect of music on grammatical constructions. More specifically, our experiment compares reaction times between two grammatical constructions that differ in semantics and intonational curves but share lexical material. Our data so far suggests that subjects take less time reading the construction when the semantic bias and intonation match than in non-matching cases. This, we argue, suggests not only that semantics, phonology and syntax form an information bundle (i.e. a construction in the cognitive linguistic sense, but that perceived similarity of music can influence linguistic cognition.

  5. Reliability and diagnostic of modular systems

    Directory of Open Access Journals (Sweden)

    J. Kohlas

    2014-01-01

    Full Text Available Reliability and diagnostic are in general two problems discussed separately. Yet the two problems are in fact closely related to each other. Here, this relation is considered in the simple case of modular systems. We show, how the computation of reliability and diagnostic can efficiently be done within the same Bayesian network induced by the modularity of the structure function of the system.

  6. The Cer-cqu gene cluster determines three key players in a β-diketone synthase polyketide pathway synthesizing aliphatics in epicuticular waxes

    DEFF Research Database (Denmark)

    Schneider, Lizette Marais; Adamski, Nikolai M.; Christensen, Caspar Elo

    2016-01-01

    identification of mutants in their synthesis or transport. The present study discloses three such Eceriferum (cer) genes in barley - Cer-c, Cer-q and Cer-u - known to be tightly linked and functioning in a biochemical pathway forming dominating amounts of β-diketone and hydroxy-β-diketones plus some esterified...... alkan-2-ols. These aliphatics are present in many Triticeae as well as dicotyledons such as Eucalyptus and Dianthus. Recently developed genomic resources and mapping populations in barley defined these genes to a small region on chromosome arm 2HS. Exploiting Cer-c and -u potential functions pinpointed...... five candidates, of which three were missing in apparent cer-cqu triple mutants. Sequencing more than 50 independent mutants for each gene confirmed their identification. Cer-c is a chalcone synthase-like polyketide synthase, designated diketone synthase (DKS), Cer-q is a lipase/carboxyl transferase...

  7. Reliability modeling and analysis for a novel design of modular converter system of wind turbines

    International Nuclear Information System (INIS)

    Zhang, Cai Wen; Zhang, Tieling; Chen, Nan; Jin, Tongdan

    2013-01-01

    Converters play a vital role in wind turbines. The concept of modularity is gaining in popularity in converter design for modern wind turbines in order to achieve high reliability as well as cost-effectiveness. In this study, we are concerned with a novel topology of modular converter invented by Hjort, Modular converter system with interchangeable converter modules. World Intellectual Property Organization, Pub. No. WO29027520 A2; 5 March 2009, in this architecture, the converter comprises a number of identical and interchangeable basic modules. Each module can operate in either AC/DC or DC/AC mode, depending on whether it functions on the generator or the grid side. Moreover, each module can be reconfigured from one side to the other, depending on the system’s operational requirements. This is a shining example of full-modular design. This paper aims to model and analyze the reliability of such a modular converter. A Markov modeling approach is applied to the system reliability analysis. In particular, six feasible converter system models based on Hjort’s architecture are investigated. Through numerical analyses and comparison, we provide insights and guidance for converter designers in their decision-making.

  8. A modular approach to creating large engineered cartilage surfaces.

    Science.gov (United States)

    Ford, Audrey C; Chui, Wan Fung; Zeng, Anne Y; Nandy, Aditya; Liebenberg, Ellen; Carraro, Carlo; Kazakia, Galateia; Alliston, Tamara; O'Connell, Grace D

    2018-01-23

    Native articular cartilage has limited capacity to repair itself from focal defects or osteoarthritis. Tissue engineering has provided a promising biological treatment strategy that is currently being evaluated in clinical trials. However, current approaches in translating these techniques to developing large engineered tissues remains a significant challenge. In this study, we present a method for developing large-scale engineered cartilage surfaces through modular fabrication. Modular Engineered Tissue Surfaces (METS) uses the well-known, but largely under-utilized self-adhesion properties of de novo tissue to create large scaffolds with nutrient channels. Compressive mechanical properties were evaluated throughout METS specimens, and the tensile mechanical strength of the bonds between attached constructs was evaluated over time. Raman spectroscopy, biochemical assays, and histology were performed to investigate matrix distribution. Results showed that by Day 14, stable connections had formed between the constructs in the METS samples. By Day 21, bonds were robust enough to form a rigid sheet and continued to increase in size and strength over time. Compressive mechanical properties and glycosaminoglycan (GAG) content of METS and individual constructs increased significantly over time. The METS technique builds on established tissue engineering accomplishments of developing constructs with GAG composition and compressive properties approaching native cartilage. This study demonstrated that modular fabrication is a viable technique for creating large-scale engineered cartilage, which can be broadly applied to many tissue engineering applications and construct geometries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Discovery Strategies of Bioactive Compounds Synthesized by Nonribosomal Peptide Synthetases and Type-I Polyketide Synthases Derived from Marine Microbiomes

    Science.gov (United States)

    Amoutzias, Grigoris D.; Chaliotis, Anargyros; Mossialos, Dimitris

    2016-01-01

    Considering that 70% of our planet’s surface is covered by oceans, it is likely that undiscovered biodiversity is still enormous. A large portion of marine biodiversity consists of microbiomes. They are very attractive targets of bioprospecting because they are able to produce a vast repertoire of secondary metabolites in order to adapt in diverse environments. In many cases secondary metabolites of pharmaceutical and biotechnological interest such as nonribosomal peptides (NRPs) and polyketides (PKs) are synthesized by multimodular enzymes named nonribosomal peptide synthetases (NRPSes) and type-I polyketide synthases (PKSes-I), respectively. Novel findings regarding the mechanisms underlying NRPS and PKS evolution demonstrate how microorganisms could leverage their metabolic potential. Moreover, these findings could facilitate synthetic biology approaches leading to novel bioactive compounds. Ongoing advances in bioinformatics and next-generation sequencing (NGS) technologies are driving the discovery of NRPs and PKs derived from marine microbiomes mainly through two strategies: genome-mining and metagenomics. Microbial genomes are now sequenced at an unprecedented rate and this vast quantity of biological information can be analyzed through genome mining in order to identify gene clusters encoding NRPSes and PKSes of interest. On the other hand, metagenomics is a fast-growing research field which directly studies microbial genomes and their products present in marine environments using culture-independent approaches. The aim of this review is to examine recent developments regarding discovery strategies of bioactive compounds synthesized by NRPS and type-I PKS derived from marine microbiomes and to highlight the vast diversity of NRPSes and PKSes present in marine environments by giving examples of recently discovered bioactive compounds. PMID:27092515

  10. Discovery Strategies of Bioactive Compounds Synthesized by Nonribosomal Peptide Synthetases and Type-I Polyketide Synthases Derived from Marine Microbiomes

    Directory of Open Access Journals (Sweden)

    Grigoris D. Amoutzias

    2016-04-01

    Full Text Available Considering that 70% of our planet’s surface is covered by oceans, it is likely that undiscovered biodiversity is still enormous. A large portion of marine biodiversity consists of microbiomes. They are very attractive targets of bioprospecting because they are able to produce a vast repertoire of secondary metabolites in order to adapt in diverse environments. In many cases secondary metabolites of pharmaceutical and biotechnological interest such as nonribosomal peptides (NRPs and polyketides (PKs are synthesized by multimodular enzymes named nonribosomal peptide synthetases (NRPSes and type-I polyketide synthases (PKSes-I, respectively. Novel findings regarding the mechanisms underlying NRPS and PKS evolution demonstrate how microorganisms could leverage their metabolic potential. Moreover, these findings could facilitate synthetic biology approaches leading to novel bioactive compounds. Ongoing advances in bioinformatics and next-generation sequencing (NGS technologies are driving the discovery of NRPs and PKs derived from marine microbiomes mainly through two strategies: genome-mining and metagenomics. Microbial genomes are now sequenced at an unprecedented rate and this vast quantity of biological information can be analyzed through genome mining in order to identify gene clusters encoding NRPSes and PKSes of interest. On the other hand, metagenomics is a fast-growing research field which directly studies microbial genomes and their products present in marine environments using culture-independent approaches. The aim of this review is to examine recent developments regarding discovery strategies of bioactive compounds synthesized by NRPS and type-I PKS derived from marine microbiomes and to highlight the vast diversity of NRPSes and PKSes present in marine environments by giving examples of recently discovered bioactive compounds.

  11. Theta function identities associated with Ramanujan's modular ...

    Indian Academy of Sciences (India)

    In Chapter 20 of his second notebook [6], Ramanujan recorded several theta function identities associated with modular equations of composite degree 15. These identities have previously been proved by Berndt in [3]. But he proved most of these theta function identities using modular equations. These identities can also ...

  12. Novel relationships between superoscillations, weak values, and modular variables

    International Nuclear Information System (INIS)

    Tollaksen, Jeff

    2007-01-01

    We present several novel, unexpected relationships between superoscillations, weak values and modular variables. For example, we show how an uncertain phase, which characterizes the process of projecting a particle onto a superoscillatory region, can create the high-momentum associated with the super-oscillation. If an uncertain phase can localize the particle, then a definite phase can also localize it. This introduction of a relative phase corresponds to a nonlocal exchange of modular variables. We also present a new way to measure the nonlocality in the equation of motion for modular variables by using weak measurements

  13. The modularization construction of piping system installation in AP1000 plant

    International Nuclear Information System (INIS)

    Lu Song; Wang Yuan; Wei Junming

    2012-01-01

    Modularization construction is the main technique used in AP1000 plants, the piping Modularization installation will impact directly to the module construction as the important part of the Modularization construction. After the piping system has took the modularization design in AP1000 plants, some installation works of piping system has moved from the site to fabrication shop. With improving the construction quality and minimizing the time frame of project, the critical paths can be optimized. This paper has analyzed the risk and challenge that met during the modularization construction period of piping systems though introducing the characteristic of modularization construction for AP1000 piping systems, and get construction experiences from the First AP1000 plants in the world, then it will be the firmly basics for the wide application of modularization construction in the future. (authors)

  14. Antifouling and antibacterial polyketides from marine gorgonian coral-associated fungus Penicillium sp. SCSGAF 0023.

    Science.gov (United States)

    Bao, Jie; Sun, Yu-Lin; Zhang, Xiao-Yong; Han, Zhuang; Gao, Hai-Chun; He, Fei; Qian, Pei-Yuan; Qi, Shu-Hua

    2013-04-01

    Two new polyketides, 6,8,5'6'-tetrahydroxy-3'-methylflavone (1) and paecilin C (2), together with six known analogs secalonic acid D (3), secalonic acid B (4) penicillixanthone A (5), emodin (6), citreorosein (7) and isorhodoptilometrin (8) were obtained from a broth of gorgonian coral-associated fungus Penicillium sp. SCSGAF 0023. Compounds 1 and 6-8 had significant antifouling activity against Balanus amphitrite larvae settlement with EC50 values of 6.7, 6.1, 17.9 and 13.7 μg ml(-1), respectively, and 3-5 showed medium antibacterial activity against four tested bacterial strains. This was the first report of antibacterial activity of 3-5 against marine bacteria and antifouling activity of 6-8 against marine biofouling organism's larvae. The results indicated that gorgonian coral-associated fungus Penicillium sp. SCSGAF 0023 strain could produce antifouling and antibacterial compounds that might aid the host gorgonian coral in protection against marine pathogen bacteria, biofouling organisms and other intruders.

  15. Safety concerns related to modular/prefabricated building construction.

    Science.gov (United States)

    Fard, Maryam Mirhadi; Terouhid, Seyyed Amin; Kibert, Charles J; Hakim, Hamed

    2017-03-01

    The US construction industry annually experiences a relatively high rate of fatalities and injuries; therefore, improving safety practices should be considered a top priority for this industry. Modular/prefabricated building construction is a construction strategy that involves manufacturing of the whole building or some of its components off-site. This research focuses on the safety performance of the modular/prefabricated building construction sector during both manufacturing and on-site processes. This safety evaluation can serve as the starting point for improving the safety performance of this sector. Research was conducted based on Occupational Safety and Health Administration investigated accidents. The study found 125 accidents related to modular/prefabricated building construction. The details of each accident were closely examined to identify the types of injury and underlying causes. Out of 125 accidents, there were 48 fatalities (38.4%), 63 hospitalized injuries (50.4%), and 14 non-hospitalized injuries (11.2%). It was found that, the most common type of injury in modular/prefabricated construction was 'fracture', and the most common cause of accidents was 'fall'. The most frequent cause of cause (underlying and root cause) was 'unstable structure'. In this research, the accidents were also examined in terms of corresponding location, occupation, equipment as well as activities during which the accidents occurred. For improving safety records of the modular/prefabricated construction sector, this study recommends that future research be conducted on stabilizing structures during their lifting, storing, and permanent installation, securing fall protection systems during on-site assembly of components while working from heights, and developing training programmes and standards focused on modular/prefabricated construction.

  16. Domain organizations of modular extracellular matrix proteins and their evolution.

    Science.gov (United States)

    Engel, J

    1996-11-01

    Multidomain proteins which are composed of modular units are a rather recent invention of evolution. Domains are defined as autonomously folding regions of a protein, and many of them are similar in sequence and structure, indicating common ancestry. Their modular nature is emphasized by frequent repetitions in identical or in different proteins and by a large number of different combinations with other domains. The extracellular matrix is perhaps the largest biological system composed of modular mosaic proteins, and its astonishing complexity and diversity are based on them. A cluster of minireviews on modular proteins is being published in Matrix Biology. These deal with the evolution of modular proteins, the three-dimensional structure of domains and the ways in which these interact in a multidomain protein. They discuss structure-function relationships in calcium binding domains, collagen helices, alpha-helical coiled-coil domains and C-lectins. The present minireview is focused on some general aspects and serves as an introduction to the cluster.

  17. Modular action on the massive algebra

    International Nuclear Information System (INIS)

    Saffary, T.

    2005-12-01

    The subject of this thesis is the modular group of automorphisms (σ m t ) t element of R , m>0, acting on the massive algebra of local observables M m (O) having their support in O is contained in R 4 . After a compact introduction to micro-local analysis and the theory of one-parameter groups of automorphisms, which are used extensively throughout the investigation, we are concerned with modular theory and its consequences in mathematics, e.g., Connes' cocycle theorem and classification of type III factors and Jones' index theory, as well as in physics, e.g., the determination of local von Neumann algebras to be hyperfinite factors of type III 1 , the formulation of thermodynamic equilibrium states for infinite-dimensional quantum systems (KMS states) and the discovery of modular action as geometric transformations. However, our main focus are its applications in physics, in particular the modular action as Lorentz boosts on the Rindler wedge, as dilations on the forward light cone and as conformal mappings on the double cone. Subsequently, their most important implications in local quantum physics are discussed. The purpose of this thesis is to shed more light on the transition from the known massless modular action to the wanted massive one in the case of double cones. First of all the infinitesimal generatore δ m of the group (σ m t ) t element of R is investigated, especially some assumptions on its structure are verified explicitly for the first time for two concrete examples. Then, two strategies for the calculation of σ m t itself are discussed. Some formalisms and results from operator theory and the method of second quantisation used in this thesis are made available in the appendix. (orig.)

  18. Modular Firewalls for Storage Areas

    Science.gov (United States)

    Fedor, O. H.; Owens, L. J.

    1986-01-01

    Giant honeycomb structures assembled in modular units. Flammable materials stored in cells. Walls insulated with firebrick to prevent spread of fire among cells. Portable, modular barrier withstands heat of combustion for limited time and confines combustion products horizontally to prevent fire from spreading. Barrier absorbs heat energy by ablation and not meant to be reused. Designed to keep fires from spreading among segments of solid rocket propellant in storage, barrier erected between storage units of other flammable or explosive materials; tanks of petroleum or liquid natural gas. Barrier adequate for most industrial purposes.

  19. Activity Based Costing as a method for assessing the economics of modularization - a case study and beyond

    DEFF Research Database (Denmark)

    Thyssen, Peter; Israelsen, Poul; Jørgensen, Brian

    The paper accounts for an Activity Based Costing (ABC) analysis supporting decision-making concerning product modularity. The ABC analysis carried out is communicated to decision-makers by telling how much higher the variable cost of the multi-purpose module can be compared to the average variable...... cost for the product-unique modules that it substitutes to break even in total cost. The analysis provides the platform for stating three general rules of cost efficiency of modularization, which in combination identify the highest profit potential of product modularisation. Finally the analysis points...... to problems of using ABC in costing modularity, i.e. handling of R&D costs and identification of product-profitability upon an enhanced modularization....

  20. Directional selection can drive the evolution of modularity in complex traits.

    Science.gov (United States)

    Melo, Diogo; Marroig, Gabriel

    2015-01-13

    Modularity is a central concept in modern biology, providing a powerful framework for the study of living organisms on many organizational levels. Two central and related questions can be posed in regard to modularity: How does modularity appear in the first place, and what forces are responsible for keeping and/or changing modular patterns? We approached these questions using a quantitative genetics simulation framework, building on previous results obtained with bivariate systems and extending them to multivariate systems. We developed an individual-based model capable of simulating many traits controlled by many loci with variable pleiotropic relations between them, expressed in populations subject to mutation, recombination, drift, and selection. We used this model to study the problem of the emergence of modularity, and hereby show that drift and stabilizing selection are inefficient at creating modular variational structures. We also demonstrate that directional selection can have marked effects on the modular structure between traits, actively promoting a restructuring of genetic variation in the selected population and potentially facilitating the response to selection. Furthermore, we give examples of complex covariation created by simple regimes of combined directional and stabilizing selection and show that stabilizing selection is important in the maintenance of established covariation patterns. Our results are in full agreement with previous results for two-trait systems and further extend them to include scenarios of greater complexity. Finally, we discuss the evolutionary consequences of modular patterns being molded by directional selection.

  1. Modular Cure Provision

    DEFF Research Database (Denmark)

    Winther-Hansen, Casper; Frandsen, Thomas

    facilitate co-creation through open platforms and service modularity. Based on data from two pharmaceuticals we explore issues of governance related to the relative openness of platforms and their completeness. Whereas some pharmaceuticals should cater to sophisticated needs of competent users through open...

  2. Implications of an arithmetical symmetry of the commutant for modular invariants

    International Nuclear Information System (INIS)

    Ruelle, P.; Thiran, E.; Weyers, J.

    1993-01-01

    We point out the existence of an arithmetical symmetry for the commutant of the modular matrices S and T. This symmetry holds for all affine simple Lie algebras at all levels and implies the equality of certain coefficients in any modular invariant. Particularizing to SU(3) k , we classify the modular invariant partition functions when k+3 is an integer coprime with 6 and when it is a power of either 2 or 3. Our results imply that no detailed knowledge of the commutant is needed to undertake a classification of all modular invariants. (orig.)

  3. Expanding to teleoperation of a tight modular workshop for dismantling radioactive components

    International Nuclear Information System (INIS)

    Gasc, B.

    1990-01-01

    The CEA (French Nuclear Energy Commission) in connection with TECHNICATOME developed a tight modular workshop for the dismantling of AT1 plant facilities in LA HAGUE. This workshop constructed of reusable stainless steel panels assembled by bolting provides a tight and decontaminable working zone compatible with any building configuration. This being the case, the operators bearing ventilated suits may work under the best safety conditions on alpha-contaminated materials. For the purpose of expanding the working capacities of this workshop it was decided to develop special components for teleoperation from the outside as in a conventional cell. To meet this objective which is within the scope of the contract signed with the CEC, the following components were developed and constructed: - manipulator holder panel, - swivelling hatch panel, - wall equipment sealed transfer device and, - modular biological protection. The design, construction and tests of these new components led to their qualification and further incorporation in the list of components of the modular workshop liable to be used for teleoperation procedures

  4. Hybrid green permeable pave with hexagonal modular pavement systems

    International Nuclear Information System (INIS)

    Rashid, M A; Abustan, I; Hamzah, M O

    2013-01-01

    Modular permeable pavements are alternatives to the traditional impervious asphalt and concrete pavements. Pervious pore spaces in the surface allow for water to infiltrate into the pavement during rainfall events. As of their ability to allow water to quickly infiltrate through the surface, modular permeable pavements allow for reductions in runoff quantity and peak runoff rates. Even in areas where the underlying soil is not ideal for modular permeable pavements, the installation of under drains has still been shown to reflect these reductions. Modular permeable pavements have been regarded as an effective tool in helping with stormwater control. It also affects the water quality of stormwater runoff. Places using modular permeable pavement has been shown to cause a significant decrease in several heavy metal concentrations as well as suspended solids. Removal rates are dependent upon the material used for the pavers and sub-base material, as well as the surface void space. Most heavy metals are captured in the top layers of the void space fill media. Permeable pavements are now considered an effective BMP for reducing stormwater runoff volume and peak flow. This study examines the extent to which such combined pavement systems are capable of handling load from the vehicles. Experimental investigation were undertaken to quantify the compressive characteristics of the modular. Results shows impressive results of achieving high safety factor for daily life vehicles.

  5. A modularized operator interface framework for Tokamak based on MVC design pattern

    International Nuclear Information System (INIS)

    Yin, Xuan; Zheng, Wei; Zhang, Ming; Zhang, Jing; Zhuang, G.; Ding, T.

    2014-01-01

    Highlights: • Our framework is based on MVC design pattern. • XML is used to cope with minor difference between different applications. • Functions dealing with EPICS and MDSplus have been modularized into reusable modules. • The modularized framework will shorten J-TEXT's software development cycle. - Abstract: Facing various and continually changing experimental needs, the J-TEXT Tokamak experiment requires home-made software applications developed for different sub-systems. Though dealing with different specific problems, these software applications usually share a lot of functionalities in common. With the goal of improving the productivity of research groups, J-TEXT has designed a C# desktop application framework which is mainly focused on operator interface development. Following the Model–View–Controller (MVC) design pattern, the main functionality dealing with Experimental Physics and Industrial Control System (EPICS) or MDSplus has been modularized into reusable modules. Minor difference among applications can be coped with XML configuration files. In this case, developers are able to implement various kinds of operator interface without knowing the implementation details of the bottom functions in Models, mainly focusing on Views and Controllers. This paper presents J-TEXT C# desktop application framework, introducing the technology of fast development of the modularized operator interface. Some experimental applications designed in this framework have been already deployed in J-TEXT, and will be introduced in this paper

  6. Adopting Product Modularity in House Building to Support Mass Customisation

    Directory of Open Access Journals (Sweden)

    Cecília G. da Rocha

    2015-04-01

    Full Text Available Product modularity is a concept that can contribute to the improvement of product quality and production efficiency in house-building. However, there is a lack of consensus in the literature on the concepts that define product modularity. Furthermore, little attention has been given to the differences between building construction and manufacturing, for which product modularity was originally developed. This research aims to address that gap by adapting the conceptualization of product modularity so that it can effectively be used in the house-building industry. The methodological approach adopted in this study was Design Science Research, and two empirical studies were carried out on construction companies based in Brazil and in the U.K. Those studies are used to illustrate the applicability and utility of the proposed concepts and tools. Research findings indicate that the adoption of product modularity concepts results in benefits to both traditional construction technologies and pre-fabricated building systems.

  7. DomPep--a general method for predicting modular domain-mediated protein-protein interactions.

    Directory of Open Access Journals (Sweden)

    Lei Li

    Full Text Available Protein-protein interactions (PPIs are frequently mediated by the binding of a modular domain in one protein to a short, linear peptide motif in its partner. The advent of proteomic methods such as peptide and protein arrays has led to the accumulation of a wealth of interaction data for modular interaction domains. Although several computational programs have been developed to predict modular domain-mediated PPI events, they are often restricted to a given domain type. We describe DomPep, a method that can potentially be used to predict PPIs mediated by any modular domains. DomPep combines proteomic data with sequence information to achieve high accuracy and high coverage in PPI prediction. Proteomic binding data were employed to determine a simple yet novel parameter Ligand-Binding Similarity which, in turn, is used to calibrate Domain Sequence Identity and Position-Weighted-Matrix distance, two parameters that are used in constructing prediction models. Moreover, DomPep can be used to predict PPIs for both domains with experimental binding data and those without. Using the PDZ and SH2 domain families as test cases, we show that DomPep can predict PPIs with accuracies superior to existing methods. To evaluate DomPep as a discovery tool, we deployed DomPep to identify interactions mediated by three human PDZ domains. Subsequent in-solution binding assays validated the high accuracy of DomPep in predicting authentic PPIs at the proteome scale. Because DomPep makes use of only interaction data and the primary sequence of a domain, it can be readily expanded to include other types of modular domains.

  8. An a posteriori measure of network modularity [v3; ref status: indexed, http://f1000r.es/2ju

    Directory of Open Access Journals (Sweden)

    Timothée Poisot

    2013-12-01

    Full Text Available Measuring the modularity of networks, and how it deviates from random expectations, important to understand their structure and emerging properties. Several measures exist to assess modularity, which when applied to the same network, can return both different modularity values (i.e. different estimates of how modular the network is and different module compositions (i.e. different groups of species forming said modules. More importantly, as each optimization method uses a different optimization criterion, there is a need to have an a posteriori measure serving as an equivalent of a goodness-of-fit. In this article, I propose such a measure of modularity, which is simply defined as the ratio of interactions established between members of the same modules vs. members of different modules. I apply this measure to a large dataset of 290 ecological networks representing host–parasite (bipartite and predator–prey (unipartite interactions, to show how the results are easy to interpret and present especially to a broad audience not familiar with modularity analyses, but still can reveal new features about modularity and the ways to measure it.

  9. On modular properties of the AdS3 CFT

    International Nuclear Information System (INIS)

    Baron, Walter H.; Nunez, Carmen A.

    2011-01-01

    We study modular properties of the AdS 3 Wess-Zumino-Novikov-Witten model. Although the Euclidean partition function is modular invariant, the characters on the Euclidean torus diverge and the regularization proposed in the literature removes information on the spectrum and the usual one to one map between characters and representations of rational models is lost. Reconsidering the characters defined on the Lorentzian torus and focusing on their structure as distributions, we obtain expressions that recover those properties. We study their modular transformations and find a generalized S matrix, depending on the sign of the real modular parameters, which has two diagonal blocks and one off-diagonal block, mixing discrete and continuous representations, that we fully determine. We then explore the relations among the modular transformations, the fusion algebra and the boundary states. We explicitly construct Ishibashi states for the maximally symmetric D-branes and show that the generalized S matrix defines the one-point functions associated to pointlike and H 2 -branes as well as the fusion rules of the degenerate representations of sl(2,R) appearing in the open string spectrum of the pointlike D-branes, through a generalized Verlinde theorem.

  10. Adaptive Modular Playware

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Þorsteinsson, Arnar Tumi

    2011-01-01

    In this paper, we describe the concept of adaptive modular playware, where the playware adapts to the interaction of the individual user. We hypothesize that there are individual differences in user interaction capabilities and styles, and that adaptive playware may adapt to the individual user...

  11. Facile "modular assembly" for fast construction of a highly oriented crystalline MOF nanofilm.

    Science.gov (United States)

    Xu, Gang; Yamada, Teppei; Otsubo, Kazuya; Sakaida, Shun; Kitagawa, Hiroshi

    2012-10-10

    The preparation of crystalline, ordered thin films of metal-organic frameworks (MOFs) will be a critical process for MOF-based nanodevices in the future. MOF thin films with perfect orientation and excellent crystallinity were formed with novel nanosheet-structured components, Cu-TCPP [TCPP = 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin], by a new "modular assembly" strategy. The modular assembly process involves two steps: a "modularization" step is used to synthesize highly crystalline "modules" with a nanosized structure that can be conveniently assembled into a thin film in the following "assembly" step. With this method, MOF thin films can easily be set up on different substrates at very high speed with controllable thickness. This new approach also enabled us to prepare highly oriented crystalline thin films of MOFs that cannot be prepared in thin-film form by traditional techniques.

  12. New Modular Heliotron system compatible with closed helical divertor and good plasma confinement

    International Nuclear Information System (INIS)

    Yamazaki, K.; Watanabe, K.Y.

    1994-04-01

    A new helical system ('Modular Heliotron') with improved modular coils compatible with efficient closed helical divertor and good plasma confinement property is proposed based on a Heliotron system with continuous helical coils and one pair of poloidal coils. The physics optimization of this system as a function of the gap angle between adjacent modular coils has been carried out by means of vacuum magnetic surface calculations and finite-beta plasma analyses, and a new improved coil system is invented by combining sectored helical field coils with sectored returning poloidal field coils. The Modular Heliotron with standard coil winding law (reference Modular Heliotron) was previously proposed, but it is found that this is not appropriate to keep clean helical divertor and high beta configuration when the coil gap becomes large. By modulating the modular coil winding with outside-plus and inside-minus pitch modulation, almost the same good magnetic configuration as that of a conventional Heliotron can be produced. The optimal gap angle is determined as a function of the modulation parameter. This improved Modular Heliotron permits larger gap angle between adjacent modules and produces more clean helical divertor configuration than the reference Modular Heliotron. All these helical system are created by only modular coils without poloidal coils. (author)

  13. Modular jet impingement assemblies with passive and active flow control for electronics cooling

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Feng; Dede, Ercan Mehmet; Joshi, Shailesh

    2016-09-13

    Power electronics modules having modular jet impingement assembly utilized to cool heat generating devices are disclosed. The modular jet impingement assemblies include a modular manifold having a distribution recess, one or more angled inlet connection tubes positioned at an inlet end of the modular manifold that fluidly couple the inlet tube to the distribution recess and one or more outlet connection tubes positioned at an outlet end of the modular manifold that fluidly coupling the outlet tube to the distribution recess. The modular jet impingement assemblies include a manifold insert removably positioned within the distribution recess and include one or more inlet branch channels each including an impinging slot and one or more outlet branch channels each including a collecting slot. Further a heat transfer plate coupled to the modular manifold, the heat transfer plate comprising an impingement surface including an array of fins that extend toward the manifold insert.

  14. Deficits and Solutions in the Development of Modular Factory Systems

    OpenAIRE

    Achim Kampker; Peter Burggräf; Moritz Krunke; Hanno Voet

    2017-01-01

    As a reaction to current challenges in factory planning, many companies think about introducing factory standards to lower planning times and decrease planning costs. If these factory standards are set-up with a high level of modularity, they are defined as modular factory systems. This paper deals with the main current problems in the application of modular factory systems in practice and presents a solution approach with its basic models. The methodology is based on methods from factory pla...

  15. Crystallization and preliminary X-ray analysis of the bacillaene synthase trans-acting acyltransferase PksC

    International Nuclear Information System (INIS)

    Cuskin, Fiona; Solovyova, Alexandra S.; Lewis, Richard J.; Race, Paul R.

    2011-01-01

    The expression, purification and crystallization of the trans-acting acyltransferase PksC from the bacillaene hybrid polyketide synthase/nonribosomal peptide synthetase is described. The crystals belonged to the orthorhombic space group P2 1 2 1 2 1 and diffracted to 1.44 Å resolution. The antibiotic bacillaene is biosynthesized in Bacillus subtilis by a hybrid type 1 modular polyketide synthase/nonribosomal peptide synthetase of the trans-acyltransferase (trans-AT) class. Within this system, the essential acyl-group loading activity is provided by the action of three free-standing trans-acting acyltransferases. Here, the recombinant expression, purification and crystallization of the bacillaene synthase trans-acting acyltransferase PksC are reported. A diffraction data set has been collected from a single PksC crystal to 1.44 Å resolution and the crystal was found to belong to the orthorhombic space group P2 1 2 1 2 1

  16. Game Analysis of Determinants of Stability of Semiconductor Modular Production Networks

    Directory of Open Access Journals (Sweden)

    Wei He

    2014-07-01

    Full Text Available In today’s rapidly changing environment, semiconductor manufacturers compete more in the area of modular production networks. However, the instability of semiconductor modular production networks can to a large extent lead to the failure of these networks. The aim of this paper is to discuss the significance and explore the maintenance of the stability of these semiconductor modular production networks. Firstly, this paper qualitatively and quantitatively defines the stability of semiconductor modular production networks. Based on this, by establishing game models, this paper analyzes the influence mechanism of the main factors: external market fluctuation, the internal benefit allocation mechanism, and opportunism, which can jeopardize the stability of these networks. We find that: the greater the benefits a member enterprise derives from the common benefits, the more likely it is the member enterprise will not exit the modular production network; the adaptive ability of the networks to the external environment is closely related to the stability of the modular production networks; the supervision and punishment in networks can be substituted for each other and the level of supervision, punishment and trust can exert great influence on the stability of semiconductor modular production networks. Lastly, we propose some specific suggestions.

  17. INFORMATION SECURITY IN MOBILE MODULAR MEASURING SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. N. Tkhishev

    2017-01-01

    Full Text Available A special aspect of aircraft test is carrying out both flight evaluation and ground operation evaluation in a structure of flying aids and special tools equipment. The specific of flight and sea tests involve metering in offshore zone, which excludes the possibility of fixed geodetically related measuring tools. In this regard, the specific role is acquired by shipbased measurement systems, in particular the mobile modular measuring systems. Information processed in the mobile modular measurement systems is a critical resource having a high level of confidentiality. When carrying out their functions, it should be implemented a proper information control of the mobile modular measurement systems to ensure their protection from the risk of data leakage, modification or loss, i.e. to ensure a certain level of information security. Due to the specific of their application it is difficult to solve the problems of information security in such complexes. The intruder model, the threat model, the security requirements generated for fixed informatization objects are not applicable to mobile systems. It was concluded that the advanced mobile modular measuring systems designed for flight experiments monitoring and control should be created due to necessary information protection measures and means. The article contains a diagram of security requirements formation, starting with the data envelopment analysis and ending with the practical implementation. The information security probabilistic model applied to mobile modular measurement systems is developed. The list of current security threats based on the environment and specific of the mobile measurement system functioning is examined. The probabilistic model of the information security evaluation is given. The problems of vulnerabilities transformation of designed information system into the security targets with the subsequent formation of the functional and trust requirements list are examined.

  18. Modular construction approach for advanced nuclear plants

    International Nuclear Information System (INIS)

    Johnson, F.T.; Orr, R.S.; Boudreaux, C.P.

    1988-01-01

    Modular construction has been designated as one of the major features of the AP600 program, a small innovative 600-MW (electric) advanced light water reactor (ALWR) that is currently being developed by Westinghouse and its subcontractors. This program is sponsored by the US Department of Energy (DOE) in conjunction with several other DOE and Electric Power Research Institute ALWR programs. Two major objectives of the AP600 program are as follows: (1) to provide a cost of power competitive with other power generation alternatives; and (2) to provide a short construction schedule that can be met with a high degree of certainty. The AP600 plant addresses these objectives by providing a simplified plant design and an optimized plant arrangement that result in a significant reduction in the number and size of systems and components, minimizes the overall building volumes, and consequently reduces the required bulk quantities. However, only by adopting a modular construction approach for the AP600 can the full cost and schedule benefits be realized from the advances made in the plant systems design and plant arrangement. Modularization is instrumental in achieving both of the above objectives, but most of all, a total modularization approach is considered absolutely essential to ensure that an aggressive construction schedule can be met with a high degree of certainty

  19. DYSIM - A Modular Simulation System for Continuous Dynamic Processes

    DEFF Research Database (Denmark)

    Christensen, P. la Cour; Kofoed, J. E.; Larsen, N.

    1986-01-01

    The report describes a revised version of a simulation system for continuous processes, DYSIM. In relation to the previous version, which was developed in 1981, the main changes are conversion to Fortran 77 and introduction of a modular structure. The latter feature gives the user a possibility...

  20. Modular low-voltage electron beams

    Science.gov (United States)

    Berejka, Anthony J.; Avnery, Tovi; Carlson, Carl

    2004-09-01

    Modular, low-voltage systems have simplified electron beam (EB) technology for industrial uses and for research and development. Modular EB units are produced in quantity as sealed systems that are evacuated at the factory eliminating the need for vacuum pumps at the point of use. A simple plug-out—plug-in method of replacement eliminates downtime for servicing. Use of ultra-thin beam windows (innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, combine for ease of use and electrical transfer efficiency at voltages that can be varied between 80 and 150 kV and with high beam currents (up to 40 mA across the 25 cm window). These electron systems are available in three widths, the standard 25 cm and new 5 and 40 cm beams. Traditional uses in the graphic arts and coatings areas as well as uses in surface sterilization have found these compact, lightweight (approximately 15 kg) modular beams of interest. Units have been configured around complex shapes to enable three-dimensional surface curing (as for coatings on aluminum tubing) to be achieved at high production rates. Details of the beam construction and some industrial uses are discussed.

  1. Modular assembly of a photovoltaic solar energy receiver

    Science.gov (United States)

    Graven, Robert M.; Gorski, Anthony J.; Schertz, William W.; Graae, Johan E. A.

    1978-01-01

    There is provided a modular assembly of a solar energy concentrator having a photovoltaic energy receiver with passive cooling. Solar cell means are fixedly coupled to a radiant energy concentrator. Tension means bias a large area heat sink against the cell thereby allowing the cell to expand or contract with respect to the heat sink due to differential heat expansion.

  2. Lean transformation in a modular building company: a case for implementation

    NARCIS (Netherlands)

    Yu, H.; Al-Hussein, M.; Al-Jibouri, Saad H.S.; Telyas, A.

    2013-01-01

    Encouraged by the remarkable productivity improvements in the manufacturing sector, the construction industry has a long history of trying to garner the benefits of manufacturing technologies. Whereas industrialized construction methods, such as modular and manufactured buildings, have evolved over

  3. New modular heliotron system compatible with closed helical divertor and good plasma confinement

    International Nuclear Information System (INIS)

    Yamazaki, K.; Watanabe, K.Y.

    1995-01-01

    A new helical system ('modular heliotron') with improved modular coils compatible with an efficient closed helical divertor and a good plasma confinement property is proposed, based on a heliotron system with continuous helical coils and one pair of poloidal coils. The physics optimization of this system as a function of the gap angle between adjacent modular coils has been carried out by means of vacuum magnetic surface calculations and finite-beta plasma analyses, and a new improved coil system is invented by combining sectored helical field coils with sectored returning poloidal field coils. A modular heliotron with standard coil winding law (the reference modular heliotron) was previously proposed, but it is found that this was not appropriate to keep a clean helical divertor and high beta configuration when the coil gap becomes large. By modulating the modular coil winding with outside-plus and inside-minus pitch modulation, almost the same good magnetic configuration as that of a conventional heliotron can be produced. The optimal gap angle is determined as a function of the modulation parameter. This improved modular heliotron permits a larger gap angle between adjacent modules and produces a cleaner helical divertor configuration than the reference modular heliotron. All these helical systems are created by only modular coils without poloidal coils. (author). Letter-to-the-editor. 11 refs, 7 figs

  4. Breaching the Phalanx: Developing a More Engineer-Centric Modular BCT

    National Research Council Canada - National Science Library

    Schultze, James M

    2007-01-01

    ... to OIF and OEF for SSTR operations. These new modular combat units are based on predominantly infantry and armor capabilities and have resulted in a large divestiture of engineering units and capabilities...

  5. A Distributed Control Strategy Based on DC Bus Signaling for Modular Photovoltaic Generation Systems With Battery Energy Storage

    DEFF Research Database (Denmark)

    Sun, Kai; Zhang, Li; Xing, Yan

    2011-01-01

    on improved dc bus signaling is proposed for a modular photovoltaic (PV) generation system with battery energy storage elements. In this paper, the modular PV generation system is composed of three modular dc/dc converters for PV arrays, two grid-connected dc/ac converters, and one dc/dc converter for battery......, grid-connected inversion, and islanding with constant voltage (CV) generation.The power balance of the system under extreme conditions such as the islanding operation with a full-charged battery is taken into account in this control strategy. The dc bus voltage level is employed as an information......Modular generation system, which consists of modular power conditioning converters, is an effective solution to integrate renewable energy sources with conventional utility grid to improve reliability and efficiency, especially for photovoltaic generation. A distributed control strategy based...

  6. Mutation rules and the evolution of sparseness and modularity in biological systems.

    Directory of Open Access Journals (Sweden)

    Tamar Friedlander

    Full Text Available Biological systems exhibit two structural features on many levels of organization: sparseness, in which only a small fraction of possible interactions between components actually occur; and modularity--the near decomposability of the system into modules with distinct functionality. Recent work suggests that modularity can evolve in a variety of circumstances, including goals that vary in time such that they share the same subgoals (modularly varying goals, or when connections are costly. Here, we studied the origin of modularity and sparseness focusing on the nature of the mutation process, rather than on connection cost or variations in the goal. We use simulations of evolution with different mutation rules. We found that commonly used sum-rule mutations, in which interactions are mutated by adding random numbers, do not lead to modularity or sparseness except for in special situations. In contrast, product-rule mutations in which interactions are mutated by multiplying by random numbers--a better model for the effects of biological mutations--led to sparseness naturally. When the goals of evolution are modular, in the sense that specific groups of inputs affect specific groups of outputs, product-rule mutations also lead to modular structure; sum-rule mutations do not. Product-rule mutations generate sparseness and modularity because they tend to reduce interactions, and to keep small interaction terms small.

  7. Modular load flow for restructured power systems

    CERN Document Server

    Hariharan, M V; Gupta, Pragati P

    2016-01-01

    In the subject of power systems, authors felt that a re-look is necessary at some conventional methods of analysis. In this book, the authors have subjected the time-honoured load flow to a close scrutiny. Authors have discovered and discussed a new load flow procedure – Modular Load Flow. Modular Load Flow explores use of power – a scalar – as source for electrical circuits which are conventionally analysed by means of phasors – the ac voltages or currents. The method embeds Kirchhoff’s circuit laws as topological property into its scalar equations and results in a unique wonderland where phase angles do not exist! Generators are shown to have their own worlds which can be superimposed to obtain the state of the composite power system. The treatment is useful in restructured power systems where stakeholders and the system operators may desire to know individual generator contributions in line flows and line losses for commercial reasons. Solution in Modular Load Flow consists of explicit expression...

  8. Hydraulic Modular Dosaging Systems for Machine Drives

    Directory of Open Access Journals (Sweden)

    A. J. Kotlobai

    2005-01-01

    Full Text Available The justified principle of making modular dosaging systems for positive-displacement multimotor hydraulic drives used in running gear and technological equipment of mobile construction, road and agricultural machines makes it possible to synchronize motion of running parts. The examples of the realization of modular dosaging systems and an algorithm of their operation are given in the paper.

  9. Toward modular biological models: defining analog modules based on referent physiological mechanisms.

    Science.gov (United States)

    Petersen, Brenden K; Ropella, Glen E P; Hunt, C Anthony

    2014-08-16

    Currently, most biomedical models exist in isolation. It is often difficult to reuse or integrate models or their components, in part because they are not modular. Modular components allow the modeler to think more deeply about the role of the model and to more completely address a modeling project's requirements. In particular, modularity facilitates component reuse and model integration for models with different use cases, including the ability to exchange modules during or between simulations. The heterogeneous nature of biology and vast range of wet-lab experimental platforms call for modular models designed to satisfy a variety of use cases. We argue that software analogs of biological mechanisms are reasonable candidates for modularization. Biomimetic software mechanisms comprised of physiomimetic mechanism modules offer benefits that are unique or especially important to multi-scale, biomedical modeling and simulation. We present a general, scientific method of modularizing mechanisms into reusable software components that we call physiomimetic mechanism modules (PMMs). PMMs utilize parametric containers that partition and expose state information into physiologically meaningful groupings. To demonstrate, we modularize four pharmacodynamic response mechanisms adapted from an in silico liver (ISL). We verified the modularization process by showing that drug clearance results from in silico experiments are identical before and after modularization. The modularized ISL achieves validation targets drawn from propranolol outflow profile data. In addition, an in silico hepatocyte culture (ISHC) is created. The ISHC uses the same PMMs and required no refactoring. The ISHC achieves validation targets drawn from propranolol intrinsic clearance data exhibiting considerable between-lab variability. The data used as validation targets for PMMs originate from both in vitro to in vivo experiments exhibiting large fold differences in time scale. This report demonstrates

  10. Functional annotation of hierarchical modularity.

    Directory of Open Access Journals (Sweden)

    Kanchana Padmanabhan

    Full Text Available In biological networks of molecular interactions in a cell, network motifs that are biologically relevant are also functionally coherent, or form functional modules. These functionally coherent modules combine in a hierarchical manner into larger, less cohesive subsystems, thus revealing one of the essential design principles of system-level cellular organization and function-hierarchical modularity. Arguably, hierarchical modularity has not been explicitly taken into consideration by most, if not all, functional annotation systems. As a result, the existing methods would often fail to assign a statistically significant functional coherence score to biologically relevant molecular machines. We developed a methodology for hierarchical functional annotation. Given the hierarchical taxonomy of functional concepts (e.g., Gene Ontology and the association of individual genes or proteins with these concepts (e.g., GO terms, our method will assign a Hierarchical Modularity Score (HMS to each node in the hierarchy of functional modules; the HMS score and its p-value measure functional coherence of each module in the hierarchy. While existing methods annotate each module with a set of "enriched" functional terms in a bag of genes, our complementary method provides the hierarchical functional annotation of the modules and their hierarchically organized components. A hierarchical organization of functional modules often comes as a bi-product of cluster analysis of gene expression data or protein interaction data. Otherwise, our method will automatically build such a hierarchy by directly incorporating the functional taxonomy information into the hierarchy search process and by allowing multi-functional genes to be part of more than one component in the hierarchy. In addition, its underlying HMS scoring metric ensures that functional specificity of the terms across different levels of the hierarchical taxonomy is properly treated. We have evaluated our

  11. Rational design of modular circuits for gene transcription: A test of the bottom-up approach

    Directory of Open Access Journals (Sweden)

    Giordano Emanuele

    2010-11-01

    Full Text Available Abstract Background Most of synthetic circuits developed so far have been designed by an ad hoc approach, using a small number of components (i.e. LacI, TetR and a trial and error strategy. We are at the point where an increasing number of modular, inter-changeable and well-characterized components is needed to expand the construction of synthetic devices and to allow a rational approach to the design. Results We used interchangeable modular biological parts to create a set of novel synthetic devices for controlling gene transcription, and we developed a mathematical model of the modular circuits. Model parameters were identified by experimental measurements from a subset of modular combinations. The model revealed an unexpected feature of the lactose repressor system, i.e. a residual binding affinity for the operator site by induced lactose repressor molecules. Once this residual affinity was taken into account, the model properly reproduced the experimental data from the training set. The parameters identified in the training set allowed the prediction of the behavior of networks not included in the identification procedure. Conclusions This study provides new quantitative evidences that the use of independent and well-characterized biological parts and mathematical modeling, what is called a bottom-up approach to the construction of gene networks, can allow the design of new and different devices re-using the same modular parts.

  12. Aspects and modular reasoning in nonmonotonic logic

    DEFF Research Database (Denmark)

    Ostermann, Klaus

    2008-01-01

    Nonmonotonic logic is a branch of logic that has been developed to model situations with incomplete information. We argue that there is a connection between AOP and nonmonotonic logic which deserves further study. As a concrete technical contribution and "appetizer", we outline an AO semantics de...... defined in default logic (a form of nonmonotonic logic), propose a definition of modular reasoning, and show that the default logic version of the language semantics admits modular reasoning whereas a conventional language semantics based on weaving does not....

  13. Building Real Modularity Competence in Automotive Design, Development, Production, and After-service

    DEFF Research Database (Denmark)

    Sanchez, Ron

    2013-01-01

    the essential principles on which effective implementation of modular strategies depends in any industry. We illustrate these principles with examples of both effective and faulty modularity practice from the automotive and other industries. We then propose a modularity maturity model for assessing the degree...

  14. Plant systems/components modularization study. Final report. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-01

    The final results are summarized of a Plant Systems/Components Modularization Study based on Stone and Webster's Pressurized Water Reactor Reference Design. The program has been modified to include evaluation of the most promising areas for modular consideration based on the level of the Sundesert Project engineering design completion and the feasibility of their incorporation into the plant construction effort.

  15. A new modular procedure for industrial plant simulations and its reliable implementation

    International Nuclear Information System (INIS)

    Carcasci, C.; Marini, L.; Morini, B.; Porcelli, M.

    2016-01-01

    Modeling of industrial plants, and especially energy systems, has become increasingly important in industrial engineering and the need for accurate information on their behavior has grown along with the complexity of the industrial processes. Consequently, accurate and flexible simulation tools became essential yielding the development of modular codes. The aim of this work is to propose a new modular mathematical modeling for industrial plant simulation and its reliable numerical implementation. Regardless of their layout, a large class of plant's configurations is modeled by a library of elementary parts; then the physical properties, compositions of the working fluid, and plant's performance are estimated. Each plant component is represented by equations modeling fundamental mechanical and thermodynamic laws and giving rise to a system of algebraic nonlinear equations; remarkably, suitable restrictions on the variables of such nonlinear equations are imposed to guarantee solutions of physical meaning. The proposed numerical procedure combines an outer iterative process which refines plants characteristic parameters and an inner one which solves the arising nonlinear systems and consists of a trust-region solver for bound-constrained nonlinear equalities. The new procedure has been validated performing simulations against an existing modular tool on two compression train arrangements with both series and parallel-mounted compressors. - Highlights: • A numerical modular tool for industrial plants simulation is presented. • Mathematical modeling is thoroughly described. • Solution of the nonlinear system is performed by a trust-region Gauss–Newton solver. • A detailed explanation of the optimization solver named TRESNEI is provided. • Code flexibility and robustness are investigated through numerical simulations.

  16. The universal modular platform

    International Nuclear Information System (INIS)

    North, R.B.

    1995-01-01

    A new and patented design for offshore wellhead platforms has been developed to meet a 'fast track' requirement for increased offshore production, from field locations not yet identified. The new design uses modular construction to allow for radical changes in the water depth of the final location and assembly line efficiency in fabrication. By utilizing high strength steels and structural support from the well conductors the new design accommodates all planned production requirements on a support structure significantly lighter and less expensive than the conventional design it replaces. Twenty two platforms based on the new design were ready for installation within 18 months of the project start. Installation of the new platforms began in 1992 for drilling support and 1993 for production support. The new design has become the Company standard for all future production platforms. Large saving and construction costs have been realized through its light weight, flexibility in both positioning and water depth, and its modular construction

  17. Hydraulic design and optimization of a modular pump-turbine runner

    International Nuclear Information System (INIS)

    Schleicher, W.C.; Oztekin, A.

    2015-01-01

    Highlights: • A modular pumped-storage scheme using elevated water storage towers is investigated. • The pumped-storage scheme also aides in the wastewater treatment process. • A preliminary hydraulic pump-turbine runner design is created based on existing literature. • The preliminary design is optimized using a response surface optimization methodology. • The performance and flow fields between preliminary and optimized designs are compared. - Abstract: A novel modular pumped-storage scheme is investigated that uses elevated water storage towers and cement pools as the upper and lower reservoirs. The scheme serves a second purpose as part of the wastewater treatment process, providing multiple benefits besides energy storage. A small pumped-storage scheme has been shown to be a competitive energy storage solution for micro renewable energy grids; however, pumped-storage schemes have not been implemented on scales smaller than megawatts. Off-the-shelf runner designs are not available for modular pumped-storage schemes, so a custom runner design is sought. A preliminary hydraulic design for a pump-turbine runner is examined and optimized for increased pumping hydraulic efficiency using a response surface optimization methodology. The hydraulic pumping efficiency was found to have improved by 1.06% at the best efficiency point, while turbine hydraulic efficiency decreased by 0.70% at the turbine best efficiency point. The round-trip efficiency for the system was estimated to be about 78%, which is comparable to larger pumped-storage schemes currently in operation

  18. Fast estimation of space-robots inertia parameters: A modular mathematical formulation

    Science.gov (United States)

    Nabavi Chashmi, Seyed Yaser; Malaek, Seyed Mohammad-Bagher

    2016-10-01

    This work aims to propose a new technique that considerably helps enhance time and precision needed to identify ;Inertia Parameters (IPs); of a typical Autonomous Space-Robot (ASR). Operations might include, capturing an unknown Target Space-Object (TSO), ;active space-debris removal; or ;automated in-orbit assemblies;. In these operations generating precise successive commands are essential to the success of the mission. We show how a generalized, repeatable estimation-process could play an effective role to manage the operation. With the help of the well-known Force-Based approach, a new ;modular formulation; has been developed to simultaneously identify IPs of an ASR while it captures a TSO. The idea is to reorganize the equations with associated IPs with a ;Modular Set; of matrices instead of a single matrix representing the overall system dynamics. The devised Modular Matrix Set will then facilitate the estimation process. It provides a conjugate linear model in mass and inertia terms. The new formulation is, therefore, well-suited for ;simultaneous estimation processes; using recursive algorithms like RLS. Further enhancements would be needed for cases the effect of center of mass location becomes important. Extensive case studies reveal that estimation time is drastically reduced which in-turn paves the way to acquire better results.

  19. Design and development of a new modular bathroom system = Diseño y desarrollo de un novedoso sistema de baños modulares

    Directory of Open Access Journals (Sweden)

    Sandra Llorente Monleón

    2017-04-01

    Full Text Available Abstract The techniques of production and in particular of construction tend to be technified, improving its precision, optimizing costs and times of production. This is the strategy to follows for those companies who need to increase its competitiveness. This is the way how modular or prefabrication systems have been introduced in the new construction processes. The modular construction no longer only applies to the structure of a building, but has also specialized in other parts, such as wet rooms; bathrooms and kitchens. Being those stays of the house more reproducible. Modular bathrooms are more common in buildings where houses have the same dimensions and /or distributions, and where therefore their construction is repetitive. The basis of this work is the development of a series production system of modular bathrooms that can be customized, maintaining the specifications and the lines indicated in the project. Also the development of a lifting and assembly tool that allows to minimize the transfer of the modules and facilitate the speed of its installation in its definitive location. The result is an industrialized bath module of high quality, with traceability of the materials and components used, tested and guaranteed, in a assembly line of fast manufacture. The bathroom is delivered completely finished and installed, minimizing the construction deadlines and improving its quality and safety. Resumen Las técnicas de producción y en particular de construcción tienden a tecnificarse, mejorando su precisión, optimizando costes y tiempos de producción. La construcción modular ya no solo se aplica a la estructura de una edificación, sino que también se ha especializado en otras estancias de la casa menos personales y con una composición de elementos más reproducible y por tanto industrializable. Los baños modulares cada vez son más comunes en aquellas edificaciones donde las viviendas tienen las mismas dimensiones y

  20. Proving relations between modular graph functions

    International Nuclear Information System (INIS)

    Basu, Anirban

    2016-01-01

    We consider modular graph functions that arise in the low energy expansion of the four graviton amplitude in type II string theory. The vertices of these graphs are the positions of insertions of vertex operators on the toroidal worldsheet, while the links are the scalar Green functions connecting the vertices. Graphs with four and five links satisfy several non-trivial relations, which have been proved recently. We prove these relations by using elementary properties of Green functions and the details of the graphs. We also prove a relation between modular graph functions with six links. (paper)

  1. Geometric modular action and transformation groups

    International Nuclear Information System (INIS)

    Summers, S.J.

    1996-01-01

    We study a weak form of geometric modular action, which is naturally associated with transformation groups of partially ordered sets and which provides these groups with projective representations. Under suitable conditions it is shown that these groups are implemented by point transformations of topological spaces serving as models for space-times, leading to groups which may be interpreted as symmetry groups of the space-times. As concrete examples, it is shown that the Poincare group and the de Sitter group can be derived from this condition of geometric modular action. Further consequences and examples are discussed. (orig.)

  2. Modular arrangement of regulatory RNA elements.

    Science.gov (United States)

    Roßmanith, Johanna; Narberhaus, Franz

    2017-03-04

    Due to their simple architecture and control mechanism, regulatory RNA modules are attractive building blocks in synthetic biology. This is especially true for riboswitches, which are natural ligand-binding regulators of gene expression. The discovery of various tandem riboswitches inspired the design of combined RNA modules with activities not yet found in nature. Riboswitches were placed in tandem or in combination with a ribozyme or temperature-responsive RNA thermometer resulting in new functionalities. Here, we compare natural examples of tandem riboswitches with recently designed artificial RNA regulators suggesting substantial modularity of regulatory RNA elements. Challenges associated with modular RNA design are discussed.

  3. Reduced modular symmetries of threshold corrections and gauge coupling unification

    Energy Technology Data Exchange (ETDEWEB)

    Bailin, David; Love, Alex [Department of Physics & Astronomy, University of Sussex,Brighton, BN1 9QH (United Kingdom)

    2015-04-01

    We revisit the question of gauge coupling unification at the string scale in orbifold compactifications of the heterotic string for the supersymmetric Standard Model. In the presence of discrete Wilson lines threshold corrections with modular symmetry that is a subgroup of the full modular group arise. We find that reduced modular symmetries not previously reported are possible. We conjecture that the effects of such threshold corrections can be simulated using sums of terms built from Dedekind eta functions to obtain the appropriate modular symmetry. For the cases of the ℤ{sub 8}-I orbifold and the ℤ{sub 3}×ℤ{sub 6} orbifold it is easily possible to obtain gauge coupling unification at the “observed” scale with Kähler moduli T of approximately one.

  4. Classical and modular methods applied to Diophantine equations

    NARCIS (Netherlands)

    Dahmen, S.R.

    2008-01-01

    Deep methods from the theory of elliptic curves and modular forms have been used to prove Fermat's last theorem and solve other Diophantine equations. These so-called modular methods can often benefit from information obtained by other, classical, methods from number theory; and vice versa. In our

  5. Modular Zero Energy. BrightBuilt Home

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States). Steven Winters Associates, Inc.; Butterfield, Karla [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States). Steven Winters Associates, Inc.

    2016-03-01

    Kaplan Thompson Architects (KTA) has specialized in sustainable, energy-efficient buildings, and they have designed several custom, zero-energy homes in New England. These zero-energy projects have generally been high-end, custom homes with budgets that could accommodate advanced energy systems. In an attempt to make zero energy homes more affordable and accessible to a larger demographic, KTA explored modular construction as way to provide high-quality homes at lower costs. In the mid-2013, KTA formalized this concept when they launched BrightBuilt Home (BBH). The BBH mission is to offer a line of architect-designed, high-performance homes that are priced to offer substantial savings off the lifetime cost of a typical home and can be delivered in less time. For the past two years, CARB has worked with BBH and Keiser Homes (the primary modular manufacturer for BBH) to discuss challenges related to wall systems, HVAC, and quality control. In Spring of 2014, CARB and BBH began looking in detail on a home to be built in Lincolnville, ME by Black Bros. Builders. This report details the solution package specified for this modular plan and the challenges that arose during the project.

  6. RAMS (Risk Analysis - Modular System) methodology

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, R.D.; Strenge, D.L.; Buck, J.W. [and others

    1996-10-01

    The Risk Analysis - Modular System (RAMS) was developed to serve as a broad scope risk analysis tool for the Risk Assessment of the Hanford Mission (RAHM) studies. The RAHM element provides risk analysis support for Hanford Strategic Analysis and Mission Planning activities. The RAHM also provides risk analysis support for the Hanford 10-Year Plan development activities. The RAMS tool draws from a collection of specifically designed databases and modular risk analysis methodologies and models. RAMS is a flexible modular system that can be focused on targeted risk analysis needs. It is specifically designed to address risks associated with overall strategy, technical alternative, and `what if` questions regarding the Hanford cleanup mission. RAMS is set up to address both near-term and long-term risk issues. Consistency is very important for any comparative risk analysis, and RAMS is designed to efficiently and consistently compare risks and produce risk reduction estimates. There is a wide range of output information that can be generated by RAMS. These outputs can be detailed by individual contaminants, waste forms, transport pathways, exposure scenarios, individuals, populations, etc. However, they can also be in rolled-up form to support high-level strategy decisions.

  7. Study on modular technology based on the reference nuclear power plant

    International Nuclear Information System (INIS)

    Lu Qinwu; Zhao Shuyu; Li Yi; Han Xiaoping; Chai Weidong; Zhang Shuxia

    2014-01-01

    As an important technology for shortening the construction period and reducing the cost of nuclear power project, modular technology has become one of the development orientations of the third generation nuclear power plant. Taking CPR1000 nuclear power reactor as reference plant and drawing on advanced foreign technology of modularization, the overall concept design has been completed with the help of the self-developed 3D modular design system. On this basis, a typical detailed design work has been carried out so as to verify the feasibility of technology. Besides, an analysis on implementation of modular technology has been made from two aspects (procurement and construction), and the feasibility of research results in actual project has been evaluated. It provides references for the promotion of self-reliant modular technology in nuclear power project in China. (authors)

  8. Inherent controllability in modular ALMRs

    International Nuclear Information System (INIS)

    Sackett, J.I.; Sevy, R.H.; Wei, T.Y.C.

    1989-01-01

    As part of recent development efforts on advanced reactor designs ANL has proposed the IFR (Integral Fast Reactor) concept. The IFR concept is currently being applied to modular sized reactors which would be built in multiple power paks together with an integrated fuel cycle facility. It has been amply demonstrated that the concept as applied to the modular designs has significant advantages in regard to ATWS transients. Attention is now being focussed on determining whether or not those advantages deriving from the traits of the IFR can be translated to the operational/DBA (design basis accident) class of transients. 5 refs., 3 figs., 3 tabs

  9. Application of Engineered Cementitious Composites (ECC) in modular floor panels

    DEFF Research Database (Denmark)

    Lárusson, Lárus Helgi; Fischer, Gregor; Jönsson, Jeppe

    2008-01-01

    This paper describes the design, manufacturing, and structural behavior of a prefabricated floor panel consisting of a modular assembly of a thin-walled ECC slab and steel truss girders. The features of this composite structure include light weight, the modular manufacturing process...... concept introduced in this paper aims at improvements in the manufacturing process of the panels by casting the ECC slab separately and subsequently joining it with the steel trusses. The focus of this paper is on design and manufacturing of a prototype modular panel and on its structural behavior under...

  10. IT PROJECT PORTFOLIO MANAGEMENT: MODULARITY PROBLEMS IN A PUBLIC ORGANIZATION

    DEFF Research Database (Denmark)

    Hansen, Lars Kristian; Mengiste, Shegaw Anagaw

    2012-01-01

    As today’s public and private sector organizations heavily rely on Information Technology (IT) to provide faster cycle times and better services, IT Project Portfolio Management (IT PPM) has become a high priority issue. This research adopts engaged scholarship to investigate IT PPM practices...... within a large local government. The investigation applies Modularity theory to analyze rich data from the local government covering several units with quite diverse functions to address the following two questions (1) which modularity problems does a public organization have in its IT PPM practices...... suggest a model addressing the identified problems by organizing IT PPM in three modules connected by three gateways. These results may be used to inform further research into IT PPM and to help managers improve IT PPM practices in public organizations. Keywords: IT Project Portfolio Management (IT PPM...

  11. Multiple D3-instantons and mock modular forms I

    CERN Document Server

    Alexandrov, Sergei; Manschot, Jan; Pioline, Boris

    2017-01-01

    We study D3-instanton corrections to the hypermultiplet moduli space in type IIB string theory compactified on a Calabi-Yau threefold. In a previous work, consistency of D3-instantons with S-duality was established at first order in the instanton expansion, using the modular properties of the M5-brane elliptic genus. We extend this analysis to the two-instanton level, where wall-crossing phenomena start playing a role. We focus on the contact potential, an analogue of the Kahler potential which must transform as a modular form under S-duality. We show that it can be expressed in terms of a suitable modification of the partition function of D4-D2-D0 BPS black holes, constructed out of the generating function of MSW invariants (the latter coincide with Donaldson-Thomas invariants in a particular chamber). Modular invariance of the contact potential then requires that, in case where the D3-brane wraps a reducible divisor, the generating function of MSW invariants must transform as a vector-valued mock modular fo...

  12. Unraveling the disease consequences and mechanisms of modular structure in animal social networks

    Science.gov (United States)

    Sah, Pratha; Leu, Stephan T.; Cross, Paul C.; Hudson, Peter J.; Bansal, Shweta

    2017-01-01

    Disease risk is a potential cost of group living. Although modular organization is thought to reduce this cost in animal societies, empirical evidence toward this hypothesis has been conflicting. We analyzed empirical social networks from 43 animal species to motivate our study of the epidemiological consequences of modular structure in animal societies. From these empirical studies, we identified the features of interaction patterns associated with network modularity and developed a theoretical network model to investigate when and how subdivisions in social networks influence disease dynamics. Contrary to prior work, we found that disease risk is largely unaffected by modular structure, although social networks beyond a modular threshold experience smaller disease burden and longer disease duration. Our results illustrate that the lowering of disease burden in highly modular social networks is driven by two mechanisms of modular organization: network fragmentation and subgroup cohesion. Highly fragmented social networks with cohesive subgroups are able to structurally trap infections within a few subgroups and also cause a structural delay to the spread of disease outbreaks. Finally, we show that network models incorporating modular structure are necessary only when prior knowledge suggests that interactions within the population are highly subdivided. Otherwise, null networks based on basic knowledge about group size and local contact heterogeneity may be sufficient when data-limited estimates of epidemic consequences are necessary. Overall, our work does not support the hypothesis that modular structure universally mitigates the disease impact of group living.

  13. Modular industrial robots as the tool of process automation in robotized manufacturing cells

    Science.gov (United States)

    Gwiazda, A.; Banas, W.; Sekala, A.; Foit, K.; Hryniewicz, P.; Kost, G.

    2015-11-01

    Recently the number of designed modular machine was increased. The term modular machine is used to denote different types of machinery, equipment and production lines, which are created using modular elements. Modular could be both mechanic elements, and drives, as well as control systems. This method of machine design is more and more popular because it allows obtaining flexible and relatively cheap solutions. So it is worth to develop the concept of modularity in next areas of application. The advantages of modular solutions are: simplification of the structure, standardization of components, and faster assembly process of the complete machine Additional advantages, which is particularly important for manufacturers, are shorter manufacturing times, longer production series and reduced manufacturing costs. Modular designing is also the challenge for designers and the need for a new approach to the design process, to the starting process and to the exploitation process. The purpose for many manufacturers is the standardization of the components used for creating the finished products. This purpose could be realized by the application of standard modules which could be combined together in different ways to create the desired particular construction as much as possible in accordance with the order. This solution is for the producer more favorable than the construction of a large machine whose configuration must be matched to each individual order. In the ideal case each module has its own control system and the full functionality of the modular machine is obtained due to the mutual cooperation of all modules. Such a solution also requires the modular components which create the modular machine are equipped with interfaces compatible one with another to facilitate their communication. The individual components of the machine could be designed, manufactured and used independently and production management task could be divided into subtasks. They could be also

  14. Modular low-voltage electron beams

    International Nuclear Information System (INIS)

    Berejka, A.J.; Avnery, Tovi; Carlson, Carl

    2004-01-01

    Modular, low-voltage systems have simplified electron beam (EB) technology for industrial uses and for research and development. Modular EB units are produced in quantity as sealed systems that are evacuated at the factory eliminating the need for vacuum pumps at the point of use. A simple plug-out--plug-in method of replacement eliminates downtime for servicing. Use of ultra-thin beam windows (<10 μm of titanium foil), solid-state 19 in. (48 cm) rack-mounted power supplies, an innovative design to extract and spread the beam (enabling systems to be placed adjacent to each other to extend beam width) and touch-screen computer controls, combine for ease of use and electrical transfer efficiency at voltages that can be varied between 80 and 150 kV and with high beam currents (up to 40 mA across the 25 cm window). These electron systems are available in three widths, the standard 25 cm and new 5 and 40 cm beams. Traditional uses in the graphic arts and coatings areas as well as uses in surface sterilization have found these compact, lightweight (approximately 15 kg) modular beams of interest. Units have been configured around complex shapes to enable three-dimensional surface curing (as for coatings on aluminum tubing) to be achieved at high production rates. Details of the beam construction and some industrial uses are discussed

  15. Model-based Kinematics Generation for Modular Mechatronic Toolkits

    DEFF Research Database (Denmark)

    Bordignon, Mirko; Schultz, Ulrik Pagh; Støy, Kasper

    2011-01-01

    Modular robots are mechatronic devices that enable the construction of highly versatile and flexible robotic systems whose mechanical structure can be dynamically modified. The key feature that enables this dynamic modification is the capability of the individual modules to connect to each other...... in multiple ways and thus generate a number of different mechanical systems, in contrast with the monolithic, fixed structure of conventional robots. The mechatronic flexibility, however, complicates the development of models and programming abstractions for modular robots, since manually describing...... the Modular Mechatronics Modelling Language (M3L). M3L is a domain-specific language, which can model the kinematic structure of individual robot modules and declaratively describe their possible interconnections, rather than requiring the user to enumerate them in their entirety. From this description, the M...

  16. Modular co-ordination

    DEFF Research Database (Denmark)

    Blach, K.

    Notatet er på engelsk, idet det er lavet som et oplæg til den internationale standardiseringsorganisations (ISO) arbejde med målkoordinering i byggeriet. Materialet har også været forelagt ekspertgrupperne i CIB W24 og i International Modular Group. Det i notatet præsenterede materiale er blevet...

  17. The Gas Turbine - Modular Helium Reactor: A Promising Option for Near Term Deployment

    International Nuclear Information System (INIS)

    LaBar, Malcolm P.

    2002-01-01

    The Gas Turbine - Modular Helium Reactor (GT-MHR) is an advanced nuclear power system that offers unparalleled safety, high thermal efficiency, environmental advantages, and competitive electricity generation costs. The GT-MHR module couples a gas-cooled modular helium reactor (MHR) with a high efficiency modular Brayton cycle gas turbine (GT) energy conversion system. The reactor and power conversion systems are located in a below grade concrete silo that provides protection against sabotage. The GT-MHR safety is achieved through a combination of inherent safety characteristics and design selections that take maximum advantage of the gas-cooled reactor coated particle fuel, helium coolant and graphite moderator. The GT-MHR is projected to be economically competitive with alternative electricity generation technologies due to the high operating temperature of the gas-cooled reactor, high thermal efficiency of the Brayton cycle power conversion system, high fuel burnup (>100,000 MWd/MT), and low operation and maintenance requirements. (author)

  18. Modular nuclear reactor for a land-based power plant and method for the fabrication installation and operation thereof

    International Nuclear Information System (INIS)

    Craig, E. R.; Blumberg, B. Jr.

    1985-01-01

    A self-contained modular nuclear reactor which can be prefabricated at a factory location, nuclear-certified at the factory, transported to a field location for final assembly and connection to a large-scale electric-power generating facility. The modular reactor includes a prefabricated nuclear heat supply module and a plurality of shell segments which can be assembled about the heat supply module and which provide a form for the pouring and curing of a cementatious biological shield about the heat supply module. The modular reactor includes passive shutdown heat removal systems sufficient to render the reactor safe in an emergency. A large-scale power plant arrangement is disclosed which incorporates a plurality of the modular reactors

  19. Split green fluorescent protein as a modular binding partner for protein crystallization

    International Nuclear Information System (INIS)

    Nguyen, Hau B.; Hung, Li-Wei; Yeates, Todd O.; Terwilliger, Thomas C.; Waldo, Geoffrey S.

    2013-01-01

    A strategy using a new split green fluorescent protein (GFP) as a modular binding partner to form stable protein complexes with a target protein is presented. The modular split GFP may open the way to rapidly creating crystallization variants. A modular strategy for protein crystallization using split green fluorescent protein (GFP) as a crystallization partner is demonstrated. Insertion of a hairpin containing GFP β-strands 10 and 11 into a surface loop of a target protein provides two chain crossings between the target and the reconstituted GFP compared with the single connection afforded by terminal GFP fusions. This strategy was tested by inserting this hairpin into a loop of another fluorescent protein, sfCherry. The crystal structure of the sfCherry-GFP(10–11) hairpin in complex with GFP(1–9) was determined at a resolution of 2.6 Å. Analysis of the complex shows that the reconstituted GFP is attached to the target protein (sfCherry) in a structurally ordered way. This work opens the way to rapidly creating crystallization variants by reconstituting a target protein bearing the GFP(10–11) hairpin with a variety of GFP(1–9) mutants engineered for favorable crystallization

  20. Environmental versatility promotes modularity in genome-scale metabolic networks.

    Science.gov (United States)

    Samal, Areejit; Wagner, Andreas; Martin, Olivier C

    2011-08-24

    The ubiquity of modules in biological networks may result from an evolutionary benefit of a modular organization. For instance, modularity may increase the rate of adaptive evolution, because modules can be easily combined into new arrangements that may benefit their carrier. Conversely, modularity may emerge as a by-product of some trait. We here ask whether this last scenario may play a role in genome-scale metabolic networks that need to sustain life in one or more chemical environments. For such networks, we define a network module as a maximal set of reactions that are fully coupled, i.e., whose fluxes can only vary in fixed proportions. This definition overcomes limitations of purely graph based analyses of metabolism by exploiting the functional links between reactions. We call a metabolic network viable in a given chemical environment if it can synthesize all of an organism's biomass compounds from nutrients in this environment. An organism's metabolism is highly versatile if it can sustain life in many different chemical environments. We here ask whether versatility affects the modularity of metabolic networks. Using recently developed techniques to randomly sample large numbers of viable metabolic networks from a vast space of metabolic networks, we use flux balance analysis to study in silico metabolic networks that differ in their versatility. We find that highly versatile networks are also highly modular. They contain more modules and more reactions that are organized into modules. Most or all reactions in a module are associated with the same biochemical pathways. Modules that arise in highly versatile networks generally involve reactions that process nutrients or closely related chemicals. We also observe that the metabolism of E. coli is significantly more modular than even our most versatile networks. Our work shows that modularity in metabolic networks can be a by-product of functional constraints, e.g., the need to sustain life in multiple

  1. Environmental versatility promotes modularity in genome-scale metabolic networks

    Directory of Open Access Journals (Sweden)

    Wagner Andreas

    2011-08-01

    Full Text Available Abstract Background The ubiquity of modules in biological networks may result from an evolutionary benefit of a modular organization. For instance, modularity may increase the rate of adaptive evolution, because modules can be easily combined into new arrangements that may benefit their carrier. Conversely, modularity may emerge as a by-product of some trait. We here ask whether this last scenario may play a role in genome-scale metabolic networks that need to sustain life in one or more chemical environments. For such networks, we define a network module as a maximal set of reactions that are fully coupled, i.e., whose fluxes can only vary in fixed proportions. This definition overcomes limitations of purely graph based analyses of metabolism by exploiting the functional links between reactions. We call a metabolic network viable in a given chemical environment if it can synthesize all of an organism's biomass compounds from nutrients in this environment. An organism's metabolism is highly versatile if it can sustain life in many different chemical environments. We here ask whether versatility affects the modularity of metabolic networks. Results Using recently developed techniques to randomly sample large numbers of viable metabolic networks from a vast space of metabolic networks, we use flux balance analysis to study in silico metabolic networks that differ in their versatility. We find that highly versatile networks are also highly modular. They contain more modules and more reactions that are organized into modules. Most or all reactions in a module are associated with the same biochemical pathways. Modules that arise in highly versatile networks generally involve reactions that process nutrients or closely related chemicals. We also observe that the metabolism of E. coli is significantly more modular than even our most versatile networks. Conclusions Our work shows that modularity in metabolic networks can be a by-product of functional

  2. Modular development mat reinforcing and liners containment/annulus building. Final report supplement. Volume I

    International Nuclear Information System (INIS)

    Wainrib, J.

    1978-06-01

    The feasibility of developing a modular system approach for the construction of containment mats has been established. The investigative results obtained from a plant used for the modular study has determined that (1) modularization results in a 10-week reduction in the construction schedule critical path over that for the conventional approach, and (2) modularization is cost effective and could result in a savings of approximately $10,700,000. Accordingly, it is recommended that the modular system approach be adopted as standard practice for the construction of containment mats

  3. Modular Stellarator Fusion Reactor concept

    International Nuclear Information System (INIS)

    Miller, R.L.; Krakowski, R.A.

    1981-08-01

    A preliminary conceptual study is made of the Modular Stellarator Reactor (MSR). A steady-state ignited, DT-fueled, magnetic fusion reactor is proposed for use as a central electric-power station. The MSR concept combines the physics of the classic stellarator confinement topology with an innovative, modular-coil design. Parametric tradeoff calculations are described, leading to the selection of an interim design point for a 4-GWt plant based on Alcator transport scaling and an average beta value of 0.04 in an l = 2 system with a plasma aspect ratio of 11. The physics basis of the design point is described together with supporting magnetics, coil-force, and stress computations. The approach and results presented herein will be modified in the course of ongoing work to form a firmer basis for a detailed conceptual design of the MSR

  4. A Framework for Modular Modeling of the Diesel Engine Exhaust Gas Cleaning System

    DEFF Research Database (Denmark)

    Åberg, Andreas; Hansen, Thomas Klint; Linde, Kasper

    2015-01-01

    Pollutants from diesel engines have a negative effect on urban air quality. Because of this and new legislation restricting the emission level, it is necessary to develop exhaust gas treatment systems for diesel engines that can reduce the amount of pollutants. A modular model capable of simulating...... model. Four different models in the automotive diesel exhaust gas cleaning system are presented briefly. Based on the presented methodology, it is discussed which changes are needed to the models to create a modular model of the whole catalytic system....

  5. The impact of module morphologies on modular robots

    DEFF Research Database (Denmark)

    Liu, Ceyue; Liu, Jiangong; Moreno Garcia, Rodrigo

    2017-01-01

    RGE, and defined the number of connection faces and their relative positions as morphological parameters. Afterwards, we evolved the morphology and control of robots composed of EMeRGE modules in a robotic simulation platform. Simulation results indicate that robots containing modules with only two available......Many different types of modular robots have been designed in the last two decades. However, limited research has been done on analyzing which module morphology is able to create better robots for a given task. To address this issue, this paper investigates how the number and position of available...... connection faces in a module influence the evolvability of the modular robot. In contrast to previous research on modular robots, an analysis of the morphology of the module is done in order to improve and simplify its mechanical design. To this end, we designed a homogeneous module called EMe...

  6. AP1000{sup TM} plant modularization

    Energy Technology Data Exchange (ETDEWEB)

    Cantarero L, C.; Demetri, K. J. [Westinghouse Electric Co., 1000 Westinghouse Drive, Cranberry Township, PA 16066 (United States); Quintero C, F. P., E-mail: cantarc@westinghouse.com [Westinghouse Electric Spain, Padilla 17, 28006 Madrid (Spain)

    2016-09-15

    The AP1000{sup TM} plant is an 1100 M We pressurized water reactor (PWR) with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. Modules are used extensively in the design of the AP1000 plant nuclear island. The AP1000 plant uses modern, modular-construction techniques for plant construction. The design incorporates vendor-designed skids and equipment packages, as well as large, multi-ton structural modules and special equipment modules. Modularization allows traditionally sequential construction tasks to be completed simultaneously. Factory-built modules can be installed at the site in a planned construction schedule. The modularized AP1000 plant allows many more construction activities to proceed in parallel. This reduces plant construction calendar time, thus lowering the costs of plant financing. Furthermore, performing less work onsite significantly reduces the amount of skilled field-craft labor, which costs more than shop labor. In addition to labor cost savings, doing more welding and fabrication in a factory environment raises the quality of work, allowing more scheduling flexibility and reducing the amount of specialized tools required onsite. The site layout for the AP1000 plant has been established to support modular construction and efficient operations during construction. The plant layout is compact, using less space than previous conventional plant layouts. This paper provides and overview of the AP1000 plant modules with an emphasis on structural modules. Currently the Westinghouse AP1000 plant has four units under construction in China and four units under construction in the United States. All have shown successful fabrication and installation of various AP1000 plant modules. (Author)

  7. AP1000"T"M plant modularization

    International Nuclear Information System (INIS)

    Cantarero L, C.; Demetri, K. J.; Quintero C, F. P.

    2016-09-01

    The AP1000"T"M plant is an 1100 M We pressurized water reactor (PWR) with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. Modules are used extensively in the design of the AP1000 plant nuclear island. The AP1000 plant uses modern, modular-construction techniques for plant construction. The design incorporates vendor-designed skids and equipment packages, as well as large, multi-ton structural modules and special equipment modules. Modularization allows traditionally sequential construction tasks to be completed simultaneously. Factory-built modules can be installed at the site in a planned construction schedule. The modularized AP1000 plant allows many more construction activities to proceed in parallel. This reduces plant construction calendar time, thus lowering the costs of plant financing. Furthermore, performing less work onsite significantly reduces the amount of skilled field-craft labor, which costs more than shop labor. In addition to labor cost savings, doing more welding and fabrication in a factory environment raises the quality of work, allowing more scheduling flexibility and reducing the amount of specialized tools required onsite. The site layout for the AP1000 plant has been established to support modular construction and efficient operations during construction. The plant layout is compact, using less space than previous conventional plant layouts. This paper provides and overview of the AP1000 plant modules with an emphasis on structural modules. Currently the Westinghouse AP1000 plant has four units under construction in China and four units under construction in the United States. All have shown successful fabrication and installation of various AP1000 plant modules. (Author)

  8. Evaluation of a Prototype Low-Cost, Modular, Wireless Electroencephalography (EEG) Headset Design for Widespread Application

    Science.gov (United States)

    2016-06-01

    therefore did not implement or test actual sensors or electronic components (analog-to-digital conversion, power , and the wireless transmission ...ARL-TR-7703 ● JUNE 2016 US Army Research Laboratory Evaluation of a Prototype Low-Cost, Modular, Wireless Electroencephalography...originator. ARL-TR-7703 ● JUNE 2016 US Army Research Laboratory Evaluation of a Prototype Low-Cost, Modular, Wireless

  9. Systems analysis for modular versus multi-beam HIF drivers

    International Nuclear Information System (INIS)

    Meier, W.R.; Logan, B.G.

    2004-01-01

    Previous modeling for HIF drivers concentrated on designs in which 100 or more beams are grouped in an array and accelerated through a common set of induction cores. The total beam energy required by the target is achieved by the combination of final ion energy, current per beam and number of beams. Economic scaling favors a large number of small (∼1 cm dia.) beams. An alternative architecture has now been investigated, which we refer to as a modular driver. In this case, the driver is subdivided into many (>10) independent accelerators with one or many beams each. A key objective of the modular driver approach is to be able to demonstrate all aspects of the driver (source-to-target) by building a single, lower cost module compared to a full-scale, multi-beam driver. We consider and compare several design options for the modular driver including single-beam designs with solenoid instead of quadrupole magnets in order to transport the required current per module in a single beam, solenoid/quad combinations, and multi-beam, all-quad designs. The drivers are designed to meet the requirements of the hybrid target, which can accommodate a larger spot size than the distributed radiator target that was used for the Robust Point Design. We compare the multi-beam and modular driver configuration for a variety and assumptions and identify key technology advances needed for the modular design

  10. Duality and modular class of a Nambu-Poisson structure

    International Nuclear Information System (INIS)

    Ibanez, R.; Leon, M. de; Lopez, B.; Marrero, J.C.; Padron, E.

    2001-01-01

    In this paper we introduce cohomology and homology theories for Nambu-Poisson manifolds. Also we study the relation between the existence of a duality for these theories and the vanishing of a particular Nambu-Poisson cohomology class, the modular class. The case of a regular Nambu-Poisson structure and some singular examples are discussed. (author)

  11. Modular and Spatially Explicit: A Novel Approach to System Dynamics

    Science.gov (United States)

    The Open Modeling Environment (OME) is an open-source System Dynamics (SD) simulation engine which has been created as a joint project between Oregon State University and the US Environmental Protection Agency. It is designed around a modular implementation, and provides a standa...

  12. A Modular Approach To Developing A Large Deployable Reflector

    Science.gov (United States)

    Pittman, R.; Leidich, C.; Mascy, F.; Swenson, B.

    1984-01-01

    NASA is currently studying the feasibility of developing a Large Deployable Reflector (LDR) astronomical facility to perform astrophysical studies of the infrared and submillimeter portion of the spectrum in the mid 1990's. The LDR concept was recommended by the Astronomy Survey Committee of the National Academy of Sciences as one of two space based projects to be started this decade. The current baseline calls for a 20 m (65.6 ft) aperture telescope diffraction limited at 30 μm and automatically deployed from a single Shuttle launch. The volume, performance, and single launch constraints place great demands on the technology and place LDR beyond the state-of-the-art in certain areas such as lightweight reflector segments. The advent of the Shuttle is opening up many new options and capabilities for producing large space systems. Until now, LDR has always been conceived as an integrated system, deployed autonomously in a single launch. This paper will look at a combination of automatic deployment and on-orbit assembly that may reduce the technological complexity and cost of the LDR system. Many technological tools are now in use or under study that will greatly enhance our capabilities to do assembly in space. Two Shuttle volume budget scenarios will be examined to assess the potential of these tools to reduce the LDR system complexity. Further study will be required to reach the full optimal combination of deployment and assembly, since in most cases the capabilities of these new tools have not been demonstrated. In order to take maximum advantage of these concepts, the design of LDR must be flexible and allow one subsystem to be modified without adversely affecting the entire system. One method of achieving this flexibility is to use a modular design approach in which the major subsystems are physically separated during launch and assembled on orbit. A modular design approach facilitates this flexibility but requires that the subsystems be interfaced in a simple

  13. Modular helium reactor for non-electric applications

    International Nuclear Information System (INIS)

    Shenoy, A.

    1997-01-01

    The high temperature gas-cooled Modular Helium Reactor (MHR) is an advanced, high efficiency reactor system which can play a vital role in meeting the future energy needs of the world by contributing not only to the generation of electric power, but also the non-electric energy traditionally served by fossil fuels. This paper summarizes work done over 20 years, by several people at General Atomics, how the Modular Helium Reactor can be integrated to provide different non-electric applications during Process Steam/Cogeneration for industrial application, Process Heat for transportation fuel development and Hydrogen Production for various energy applications. The MHR integrates favorably into present petrochemical and primary metal process industries, heavy oil recovery, and future shale oil recovery and synfuel processes. The technical fit of the Process Steam/Cogeneration Modular Helium Reactor (PS/C-MHR) into these processes is excellent, since it can supply the required quantity and high quality of steam without fossil superheating. 12 refs, 25 figs, 2 tabs

  14. Nunamycin and Nunapeptin: Two novel cyclic peptides are key components of the antimicrobial activity of the Greenlandic isolate Pseudomonas fluorescens In5

    DEFF Research Database (Denmark)

    Hennessy, Rosanna Catherine; Phippen, Christopher; Nielsen, Kristian F.

    Pseudomonas spp. are a rich source of secondary metabolites including bioactive non-ribosomal peptides (NRPs) and polyketides. NRPs are synthesised in large assembly lines by multi-domain modular enzymes known as NRP-synthetases (NRPS). Nunamycin and nunapeptin are two cyclic NRPs synthesised...... by the Greenlandic isolate P. fluorescens In5. Nunamycin shows antifungal activity against the basidiomycete Rhizoctonia solani whereas the only partially structure elucidated nunapeptin appears most active against the ascomycete Fusarium graminearum and the oomycete Pythium aphanidermatum. Originally isolated from...

  15. Applications of modularized circuit designs in a new hyper-chaotic system circuit implementation

    International Nuclear Information System (INIS)

    Wang Rui; Sun Hui; Wang Jie-Zhi; Wang Lu; Wang Yan-Chao

    2015-01-01

    Modularized circuit designs for chaotic systems are introduced in this paper. Especially, a typical improved modularized design strategy is proposed and applied to a new hyper-chaotic system circuit implementation. In this paper, the detailed design procedures are described. Multisim simulations and physical experiments are conducted, and the simulation results are compared with Matlab simulation results for different system parameter pairs. These results are consistent with each other and they verify the existence of the hyper-chaotic attractor for this new hyper-chaotic system. (paper)

  16. Reduced modeling of signal transduction – a modular approach

    Directory of Open Access Journals (Sweden)

    Ederer Michael

    2007-09-01

    Full Text Available Abstract Background Combinatorial complexity is a challenging problem in detailed and mechanistic mathematical modeling of signal transduction. This subject has been discussed intensively and a lot of progress has been made within the last few years. A software tool (BioNetGen was developed which allows an automatic rule-based set-up of mechanistic model equations. In many cases these models can be reduced by an exact domain-oriented lumping technique. However, the resulting models can still consist of a very large number of differential equations. Results We introduce a new reduction technique, which allows building modularized and highly reduced models. Compared to existing approaches further reduction of signal transduction networks is possible. The method also provides a new modularization criterion, which allows to dissect the model into smaller modules that are called layers and can be modeled independently. Hallmarks of the approach are conservation relations within each layer and connection of layers by signal flows instead of mass flows. The reduced model can be formulated directly without previous generation of detailed model equations. It can be understood and interpreted intuitively, as model variables are macroscopic quantities that are converted by rates following simple kinetics. The proposed technique is applicable without using complex mathematical tools and even without detailed knowledge of the mathematical background. However, we provide a detailed mathematical analysis to show performance and limitations of the method. For physiologically relevant parameter domains the transient as well as the stationary errors caused by the reduction are negligible. Conclusion The new layer based reduced modeling method allows building modularized and strongly reduced models of signal transduction networks. Reduced model equations can be directly formulated and are intuitively interpretable. Additionally, the method provides very good

  17. Theoretical Interpretation of Modular Artistic Forms Based on the Example of Contemporarylithuanian Architecture

    Directory of Open Access Journals (Sweden)

    Aušra Černauskienė

    2015-05-01

    Full Text Available The article analyses modular artistic forms that emerge in all scale structures of contemporary architecture. Module, as a standard unit of measure has been in use since antiquity. It gained even more significance amid innovative building and computing technologies of the 20th and 21st centuries. Static and fixed perceptions of a module were supplemented with concepts of dynamic and adaptable modular units, such as fractals, parameters and algorithms. Various expressions and trends of modular design appear in contemporary architecture of Lithuania, where modular forms consist of repetitive spatial and planar elements. Spatial modules as blocks or flats and planar modular wall elements are a characteristic expression of the contemporary architecture in Lithuania.

  18. Modularization of genetic elements promotes synthetic metabolic engineering.

    Science.gov (United States)

    Qi, Hao; Li, Bing-Zhi; Zhang, Wen-Qian; Liu, Duo; Yuan, Ying-Jin

    2015-11-15

    In the context of emerging synthetic biology, metabolic engineering is moving to the next stage powered by new technologies. Systematical modularization of genetic elements makes it more convenient to engineer biological systems for chemical production or other desired purposes. In the past few years, progresses were made in engineering metabolic pathway using synthetic biology tools. Here, we spotlighted the topic of implementation of modularized genetic elements in metabolic engineering. First, we overviewed the principle developed for modularizing genetic elements and then discussed how the genetic modules advanced metabolic engineering studies. Next, we picked up some milestones of engineered metabolic pathway achieved in the past few years. Last, we discussed the rapid raised synthetic biology field of "building a genome" and the potential in metabolic engineering. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. An Approach for a National eHealth Implementation – the Case of Modular Interactive Tiles for Rehabilitation

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Jensen, Line Steiness Dejnbjerg; Ssessanga, Yusuf

    2015-01-01

    By the development of a mHealth tablet app together with modular interactive tiles for rehabilitation, we intend to facilitate the co-design, adaptation, demonstration and validation of modular ICT solutions for rehabilitation in deep rural sub-Saharan Africa. This results in highly mobile, modular...... community-based rehabilitation. Thereby, we investigate the adaptation, contextualisation and implementation in different rehabilitation methods and centres, including hospitals both in a city centres and in a rural area, NGO’s performing community based rehabilitation, and rehabilitation centres. Together...

  20. A modular positive feedback-based gene amplifier

    Directory of Open Access Journals (Sweden)

    Bhalerao Kaustubh D

    2010-02-01

    Full Text Available Abstract Background Positive feedback is a common mechanism used in the regulation of many gene circuits as it can amplify the response to inducers and also generate binary outputs and hysteresis. In the context of electrical circuit design, positive feedback is often considered in the design of amplifiers. Similar approaches, therefore, may be used for the design of amplifiers in synthetic gene circuits with applications, for example, in cell-based sensors. Results We developed a modular positive feedback circuit that can function as a genetic signal amplifier, heightening the sensitivity to inducer signals as well as increasing maximum expression levels without the need for an external cofactor. The design utilizes a constitutively active, autoinducer-independent variant of the quorum-sensing regulator LuxR. We experimentally tested the ability of the positive feedback module to separately amplify the output of a one-component tetracycline sensor and a two-component aspartate sensor. In each case, the positive feedback module amplified the response to the respective inducers, both with regards to the dynamic range and sensitivity. Conclusions The advantage of our design is that the actual feedback mechanism depends only on a single gene and does not require any other modulation. Furthermore, this circuit can amplify any transcriptional signal, not just one encoded within the circuit or tuned by an external inducer. As our design is modular, it can potentially be used as a component in the design of more complex synthetic gene circuits.