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Sample records for exhibit functional redundancy

  1. Bax and Bak Do Not Exhibit Functional Redundancy in Mediating Radiation-Induced Endothelial Apoptosis in the Intestinal Mucosa

    International Nuclear Information System (INIS)

    Rotolo, Jimmy A.; Maj, Jerzy G.; Feldman, Regina; Ren, Decheng; Haimovitz-Friedman, Adriana; Cordon-Cardo, Carlos; Cheng, Emily H.-Y.; Kolesnick, Richard; Fuks, Zvi

    2008-01-01

    Purpose: To address in vivo the issue of whether Bax and Bak are functionally redundant in signaling apoptosis, capable of substituting for each other. Methods and Materials: Mice were exposed to whole-body radiation, and endothelial cell apoptosis was quantified using double immunostaining with TUNEL and anti-CD31 antibody. Crypt survival was determined at 3.5 days after whole-body radiation by the microcolony survival assay. Actuarial animal survival was calculated by the product-limit Kaplan-Meier method, and autopsies were performed to establish cause of death. Results: Radiation exposure of Bax- and Bak-deficient mice, both expressing a wild-type acid sphingomyelinase (ASMase) phenotype, indicated that Bax and Bak are both mandatory, though mutually independent, for the intestinal endothelial apoptotic response. However, neither affected epithelial apoptosis at crypt positions 4-5, indicating specificity toward endothelium. Furthermore, Bax deficiency and Bak deficiency each individually mimicked ASMase deficiency in inhibiting crypt lethality in the microcolony assay and in rescuing mice from the lethal gastrointestinal syndrome. Conclusions: The data indicate that Bax and Bak have nonredundant functional roles in the apoptotic response of the irradiated intestinal endothelium. The observation that Bax deficiency and Bak deficiency also protect crypts in the microcolony assay provides strong evidence that the microvascular apoptotic component is germane to the mechanism of radiation-induced damage to mouse intestines, regulating reproductive cell death of crypt stem cell clonogens

  2. The 3-hydroxyacyl-CoA dehydratases HACD1 and HACD2 exhibit functional redundancy and are active in a wide range of fatty acid elongation pathways.

    Science.gov (United States)

    Sawai, Megumi; Uchida, Yukiko; Ohno, Yusuke; Miyamoto, Masatoshi; Nishioka, Chieko; Itohara, Shigeyoshi; Sassa, Takayuki; Kihara, Akio

    2017-09-15

    Differences among fatty acids (FAs) in chain length and number of double bonds create lipid diversity. FA elongation proceeds via a four-step reaction cycle, in which the 3-hydroxyacyl-CoA dehydratases (HACDs) HACD1-4 catalyze the third step. However, the contribution of each HACD to 3-hydroxyacyl-CoA dehydratase activity in certain tissues or in different FA elongation pathways remains unclear. HACD1 is specifically expressed in muscles and is a myopathy-causative gene. Here, we generated Hacd1 KO mice and observed that these mice had reduced body and skeletal muscle weights. In skeletal muscle, HACD1 mRNA expression was by far the highest among the HACDs However, we observed only an ∼40% reduction in HACD activity and no changes in membrane lipid composition in Hacd1 -KO skeletal muscle, suggesting that some HACD activities are redundant. Moreover, when expressed in yeast, both HACD1 and HACD2 participated in saturated and monounsaturated FA elongation pathways. Disruption of HACD2 in the haploid human cell line HAP1 significantly reduced FA elongation activities toward both saturated and unsaturated FAs, and HACD1 HACD2 double disruption resulted in a further reduction. Overexpressed HACD3 exhibited weak activity in saturated and monounsaturated FA elongation pathways, and no activity was detected for HACD4. We therefore conclude that HACD1 and HACD2 exhibit redundant activities in a wide range of FA elongation pathways, including those for saturated to polyunsaturated FAs, with HACD2 being the major 3-hydroxyacyl-CoA dehydratase. Our findings are important for furthering the understanding of the molecular mechanisms in FA elongation and diversity. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Manic fringe is not required for embryonic development, and fringe family members do not exhibit redundant functions in the axial skeleton, limb, or hindbrain

    Science.gov (United States)

    Moran, Jennifer L.; Shifley, Emily T.; Levorse, John M.; Mani, Shyamala; Ostmann, Kristin; Perez-Balaguer, Ariadna; Walker, Dawn M.; Vogt, Thomas F.; Cole, Susan E.

    2009-01-01

    Tight regulation of Notch pathway signaling is important in many aspects of embryonic development. Notch signaling can be modulated by expression of fringe genes, encoding glycosyltransferases that modify EGF repeats in the Notch receptor. Although Lunatic fringe (Lfng) has been shown to play important roles in vertebrate segmentation, comparatively little is known regarding the developmental functions of the other vertebrate fringe genes, Radical fringe (Rfng) and Manic fringe (Mfng). Here we report that Mfng expression is not required for embryonic development. Further, we find that despite significant overlap in expression patterns, we detect no obvious synergistic defects in mice in the absence of two, or all three, fringe genes during development of the axial skeleton, limbs, hindbrain and cranial nerves. PMID:19479951

  4. Does functional redundancy stabilize fish communities?

    DEFF Research Database (Denmark)

    Rice, Jake; Daan, Niels; Gislason, Henrik

    2012-01-01

    Functional redundancy is a community property thought to contribute to ecosystem resilience. It is argued that trophic (or other) functional groups with more species have more linkages and opportunities to buffer variation in abundance of individual species. We explored this concept with a 30‐year...... time‐series of data on 83 species sampled in the International Bottom Trawl Survey. Our results were consistent with the hypothesis that functional redundancy leads to more stable (and by inference more resilient) communities. Over the time‐series trophic groups (assigned by diet, size (Lmax) group......, or both factors) with more species had lower coefficients of variation (CVs) in abundance and biomass than did trophic groups with fewer species. These findings are also consistent with Bernoulli’s Law of Large Numbers, a rule that does not require complex ecological and evolutionary processes to produce...

  5. Does functional redundancy stabilize fish communities?

    DEFF Research Database (Denmark)

    Rice, Jake; Daan, Niels; Gislason, Henrik

    2013-01-01

    in abundance or biomass could be accounted for by the Law of Large Numbers, providing no evidence that specific ecological processes or co-adaptations are necessary to produce this effect. This implies that successful conservation policies to maintain the resilience of a marine fish community could be based......Functional redundancy of species sharing a feeding strategy and/or maximum size has been hypothesized to contribute to increased resilience of marine fish communities (the “portfolio effect”). A consistent time-series of survey data of fish in the North Sea was used to examine if trophic functional...... groups or maximum length of species (Lmax) groups with larger numbers of species had lower coefficients of variation in abundance and biomass over time than did groupings with fewer species. Results supported this hypothesis. However, the stabilizing effect of numbers of species in a group on variation...

  6. The Evolution of Functionally Redundant Species; Evidence from Beetles

    NARCIS (Netherlands)

    Scheffer, M.; Vergnon, R.O.H.; Nes, van E.H.; Cuppen, J.G.M.; Peeters, E.T.H.M.; Leijs, R.; Nilsson, A.N.

    2015-01-01

    While species fulfill many different roles in ecosystems, it has been suggested that numerous species might actually share the same function in a near neutral way. So-far, however, it is unclear whether such functional redundancy really exists. We scrutinize this question using extensive data on the

  7. Biogeographical disparity in the functional diversity and redundancy of corals.

    Science.gov (United States)

    McWilliam, Mike; Hoogenboom, Mia O; Baird, Andrew H; Kuo, Chao-Yang; Madin, Joshua S; Hughes, Terry P

    2018-03-20

    Corals are major contributors to a range of key ecosystem functions on tropical reefs, including calcification, photosynthesis, nutrient cycling, and the provision of habitat structure. The abundance of corals is declining at multiple scales, and the species composition of assemblages is responding to escalating human pressures, including anthropogenic global warming. An urgent challenge is to understand the functional consequences of these shifts in abundance and composition in different biogeographical contexts. While global patterns of coral species richness are well known, the biogeography of coral functions in provinces and domains with high and low redundancy is poorly understood. Here, we quantify the functional traits of all currently recognized zooxanthellate coral species ( n = 821) in both the Indo-Pacific and Atlantic domains to examine the relationships between species richness and the diversity and redundancy of functional trait space. We find that trait diversity is remarkably conserved (>75% of the global total) along latitudinal and longitudinal gradients in species richness, falling away only in species-poor provinces ( n < 200), such as the Persian Gulf (52% of the global total), Hawaii (37%), the Caribbean (26%), and the East-Pacific (20%), where redundancy is also diminished. In the more species-poor provinces, large and ecologically important areas of trait space are empty, or occupied by just a few, highly distinctive species. These striking biogeographical differences in redundancy could affect the resilience of critical reef functions and highlight the vulnerability of relatively depauperate, peripheral locations, which are often a low priority for targeted conservation efforts.

  8. The Evolution of Functionally Redundant Species; Evidence from Beetles.

    Directory of Open Access Journals (Sweden)

    Marten Scheffer

    Full Text Available While species fulfill many different roles in ecosystems, it has been suggested that numerous species might actually share the same function in a near neutral way. So-far, however, it is unclear whether such functional redundancy really exists. We scrutinize this question using extensive data on the world's 4168 species of diving beetles. We show that across the globe these animals have evolved towards a small number of regularly-spaced body sizes, and that locally co-existing species are either very similar in size or differ by at least 35%. Surprisingly, intermediate size differences (10-20% are rare. As body-size strongly reflects functional aspects such as the food that these generalist predators can eat, these beetles thus form relatively distinct groups of functional look-a-likes. The striking global regularity of these patterns support the idea that a self-organizing process drives such species-rich groups to self-organize evolutionary into clusters where functional redundancy ensures resilience through an insurance effect.

  9. Functional diversity and redundancy across fish gut, sediment and water bacterial communities.

    Science.gov (United States)

    Escalas, Arthur; Troussellier, Marc; Yuan, Tong; Bouvier, Thierry; Bouvier, Corinne; Mouchet, Maud A; Flores Hernandez, Domingo; Ramos Miranda, Julia; Zhou, Jizhong; Mouillot, David

    2017-08-01

    This article explores the functional diversity and redundancy in a bacterial metacommunity constituted of three habitats (sediment, water column and fish gut) in a coastal lagoon under anthropogenic pressure. Comprehensive functional gene arrays covering a wide range of ecological processes and stress resistance genes to estimate the functional potential of bacterial communities were used. Then, diversity partitioning was used to characterize functional diversity and redundancy within (α), between (β) and across (γ) habitats. It was showed that all local communities exhibit a highly diversified potential for the realization of key ecological processes and resistance to various environmental conditions, supporting the growing evidence that macro-organisms microbiomes harbour a high functional potential and are integral components of functional gene dynamics in aquatic bacterial metacommunities. Several levels of functional redundancy at different scales of the bacterial metacommunity were observed (within local communities, within habitats and at the metacommunity level). The results suggested a high potential for the realization of spatial ecological insurance within this ecosystem, that is, the functional compensation among microorganisms for the realization and maintenance of key ecological processes, within and across habitats. Finally, the role of macro-organisms as dispersal vectors of microbes and their potential influence on marine metacommunity dynamics were discussed. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Analysis of functional redundancies within the Arabidopsis TCP transcription factor family

    NARCIS (Netherlands)

    Danisman, S.; Dijk, van A.D.J.; Bimbo, A.; Wal, van der F.; Hennig, L.; Folter, de S.; Angenent, G.C.; Immink, R.G.H.

    2013-01-01

    Analyses of the functions of TEOSINTE-LIKE1, CYCLOIDEA, and ROLIFERATING CELL FACTOR1 (TCP) transcription factors have been hampered by functional redundancy between its individual members. In general, putative functionally redundant genes are predicted based on sequence similarity and confirmed by

  11. The Development of Synchronization Function for Triple Redundancy System Based on SCADE

    Directory of Open Access Journals (Sweden)

    Moupeng

    2015-07-01

    Full Text Available Redundancy technique is an effective approach to improve the reliability and security of flight control system, synchronization function of redundancy system is the key technology of redundancy management. The flight control computer synchronization model is developed by graphical modeling method in the SCADE development environment, the automatic code generation technology is used to generate high level reliable embedded real-time code for synchronization function, omitting the code test process, shorten the development cycle. In the practical application, the program can accomplish the functional synchronization, and lay a well foundation for the redundancy system.

  12. Functional over-redundancy and high functional vulnerability in global fish faunas on tropical reefs.

    Science.gov (United States)

    Mouillot, David; Villéger, Sébastien; Parravicini, Valeriano; Kulbicki, Michel; Arias-González, Jesus Ernesto; Bender, Mariana; Chabanet, Pascale; Floeter, Sergio R; Friedlander, Alan; Vigliola, Laurent; Bellwood, David R

    2014-09-23

    When tropical systems lose species, they are often assumed to be buffered against declines in functional diversity by the ability of the species-rich biota to display high functional redundancy: i.e., a high number of species performing similar functions. We tested this hypothesis using a ninefold richness gradient in global fish faunas on tropical reefs encompassing 6,316 species distributed among 646 functional entities (FEs): i.e., unique combinations of functional traits. We found that the highest functional redundancy is located in the Central Indo-Pacific with a mean of 7.9 species per FE. However, this overall level of redundancy is disproportionately packed into few FEs, a pattern termed functional over-redundancy (FOR). For instance, the most speciose FE in the Central Indo-Pacific contains 222 species (out of 3,689) whereas 38% of FEs (180 out of 468) have no functional insurance with only one species. Surprisingly, the level of FOR is consistent across the six fish faunas, meaning that, whatever the richness, over a third of the species may still be in overrepresented FEs whereas more than one third of the FEs are left without insurance, these levels all being significantly higher than expected by chance. Thus, our study shows that, even in high-diversity systems, such as tropical reefs, functional diversity remains highly vulnerable to species loss. Although further investigations are needed to specifically address the influence of redundant vs. vulnerable FEs on ecosystem functioning, our results suggest that the promised benefits from tropical biodiversity may not be as strong as previously thought.

  13. Functional redundancy patterns reveal non-random assembly rules in a species-rich marine assemblage.

    Directory of Open Access Journals (Sweden)

    Nicolas Guillemot

    Full Text Available The relationship between species and the functional diversity of assemblages is fundamental in ecology because it contains key information on functional redundancy, and functionally redundant ecosystems are thought to be more resilient, resistant and stable. However, this relationship is poorly understood and undocumented for species-rich coastal marine ecosystems. Here, we used underwater visual censuses to examine the patterns of functional redundancy for one of the most diverse vertebrate assemblages, the coral reef fishes of New Caledonia, South Pacific. First, we found that the relationship between functional and species diversity displayed a non-asymptotic power-shaped curve, implying that rare functions and species mainly occur in highly diverse assemblages. Second, we showed that the distribution of species amongst possible functions was significantly different from a random distribution up to a threshold of ∼90 species/transect. Redundancy patterns for each function further revealed that some functions displayed fast rates of increase in redundancy at low species diversity, whereas others were only becoming redundant past a certain threshold. This suggested non-random assembly rules and the existence of some primordial functions that would need to be fulfilled in priority so that coral reef fish assemblages can gain a basic ecological structure. Last, we found little effect of habitat on the shape of the functional-species diversity relationship and on the redundancy of functions, although habitat is known to largely determine assemblage characteristics such as species composition, biomass, and abundance. Our study shows that low functional redundancy is characteristic of this highly diverse fish assemblage, and, therefore, that even species-rich ecosystems such as coral reefs may be vulnerable to the removal of a few keystone species.

  14. About the complete loss of functions assumed by redundant systems

    International Nuclear Information System (INIS)

    Boaretto, Y.; Cayol, A.; Fourest, M.; Guimbail, H.

    1980-04-01

    Are to be taken into account situations resulting from loss of redundant safety systems. Two ways of approach were to be probed: evaluation of the failure probability and analysis of the consequences of those situations. The first way leads to improve reliability of concerned systems, the second way to set up mitigating means. Before TMI-2 occured, safety advices had already been issued about three kinds of situations: anticipated transients without scram, loss of ultimate heat sink, simultaneous loss of out-and inside power supplies. That, in some cases, something had to be done to improve safety showed the rightness of the concern. Next step is the study of the loss of both normal and emergency feedwater: The regulatory request has been issued on September 1979

  15. Functional redundancy and food web functioning in linuron-exposed ecosystems

    International Nuclear Information System (INIS)

    De Laender, F.; Van den Brink, P.J.; Janssen, C.R.

    2011-01-01

    An extensive data set describing effects of the herbicide linuron on macrophyte-dominated microcosms was analysed with a food web model to assess effects on ecosystem functioning. We showed that sensitive phytoplankton and periphyton groups in the diets of heterotrophs were gradually replaced by more tolerant phytoplankton species as linuron concentrations increased. This diet shift - showing redundancy among phytoplankton species - allowed heterotrophs to maintain their functions in the contaminated microcosms. On an ecosystem level, total gross primary production was up to hundred times lower in the treated microcosms but the uptake of dissolved organic carbon by bacteria and mixotrophs was less sensitive. Food web efficiency was not consistently lower in the treated microcosms. We conclude that linuron predominantly affected the macrophytes but did not alter the overall functioning of the surrounding planktonic food web. Therefore, a risk assessment that protects macrophyte growth also protects the functioning of macrophyte-dominated microcosms. - Highlights: → Food web modelling reveals the functional response of species and ecosystem to linuron. → Primary production was more sensitive to linuron than bacterial production. → Linuron replaced sensitive phytoplankton by tolerant phytoplankton in heterotrophs' diets. → Linuron did not change the functioning of heterotrophs. - Food web modelling reveals functional redundancy of the planktonic community in microcosms treated with linuron.

  16. Functional redundancy and food web functioning in linuron-exposed ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    De Laender, F., E-mail: frederik.delaender@ugent.be [Laboratory of Environmental Toxicity and Aquatic Ecology, Ghent University, Plateaustraat 22, 9000 Ghent (Belgium); Van den Brink, P.J., E-mail: Paul.vandenBrink@wur.nl [Department of Aquatic Ecology and Water Quality Management, Wageningen University, PO Box 47, 6700 AA Wageningen (Netherlands); Janssen, C.R., E-mail: colin.janssen@ugent.be [Laboratory of Environmental Toxicity and Aquatic Ecology, Ghent University, Plateaustraat 22, 9000 Ghent (Belgium)

    2011-10-15

    An extensive data set describing effects of the herbicide linuron on macrophyte-dominated microcosms was analysed with a food web model to assess effects on ecosystem functioning. We showed that sensitive phytoplankton and periphyton groups in the diets of heterotrophs were gradually replaced by more tolerant phytoplankton species as linuron concentrations increased. This diet shift - showing redundancy among phytoplankton species - allowed heterotrophs to maintain their functions in the contaminated microcosms. On an ecosystem level, total gross primary production was up to hundred times lower in the treated microcosms but the uptake of dissolved organic carbon by bacteria and mixotrophs was less sensitive. Food web efficiency was not consistently lower in the treated microcosms. We conclude that linuron predominantly affected the macrophytes but did not alter the overall functioning of the surrounding planktonic food web. Therefore, a risk assessment that protects macrophyte growth also protects the functioning of macrophyte-dominated microcosms. - Highlights: > Food web modelling reveals the functional response of species and ecosystem to linuron. > Primary production was more sensitive to linuron than bacterial production. > Linuron replaced sensitive phytoplankton by tolerant phytoplankton in heterotrophs' diets. > Linuron did not change the functioning of heterotrophs. - Food web modelling reveals functional redundancy of the planktonic community in microcosms treated with linuron.

  17. Functional redundancy and sensitivity of fish assemblages in European rivers, lakes and estuarine ecosystems.

    Science.gov (United States)

    Teichert, Nils; Lepage, Mario; Sagouis, Alban; Borja, Angel; Chust, Guillem; Ferreira, Maria Teresa; Pasquaud, Stéphanie; Schinegger, Rafaela; Segurado, Pedro; Argillier, Christine

    2017-12-14

    The impact of species loss on ecosystems functioning depends on the amount of trait similarity between species, i.e. functional redundancy, but it is also influenced by the order in which species are lost. Here we investigated redundancy and sensitivity patterns across fish assemblages in lakes, rivers and estuaries. Several scenarios of species extinction were simulated to determine whether the loss of vulnerable species (with high propensity of extinction when facing threats) causes a greater functional alteration than random extinction. Our results indicate that the functional redundancy tended to increase with species richness in lakes and rivers, but not in estuaries. We demonstrated that i) in the three systems, some combinations of functional traits are supported by non-redundant species, ii) rare species in rivers and estuaries support singular functions not shared by dominant species, iii) the loss of vulnerable species can induce greater functional alteration in rivers than in lakes and estuaries. Overall, the functional structure of fish assemblages in rivers is weakly buffered against species extinction because vulnerable species support singular functions. More specifically, a hotspot of functional sensitivity was highlighted in the Iberian Peninsula, which emphasizes the usefulness of quantitative criteria to determine conservation priorities.

  18. The world's richest tadpole communities show functional redundancy and low functional diversity: ecological data on Madagascar's stream-dwelling amphibian larvae

    Directory of Open Access Journals (Sweden)

    Randrianiaina Roger-Daniel

    2010-05-01

    Full Text Available Abstract Background Functional diversity illustrates the range of ecological functions in a community. It allows revealing the appearance of functional redundancy in communities and processes of community assembly. Functional redundancy illustrates the overlap in ecological functions of community members which may be an indicator of community resilience. We evaluated patterns of species richness, functional diversity and functional redundancy on tadpole communities in rainforest streams in Madagascar. This habitat harbours the world's most species-rich stream tadpole communities which are due to their occurrence in primary habitat of particular interest for functional diversity studies. Results Species richness of tadpole communities is largely determined by characteristics of the larval habitat (stream structure, not by adult habitat (forest structure. Species richness is positively correlated with a size-velocity gradient of the streams, i.e. communities follow a classical species-area relationship. While widely observed for other taxa, this is an unusual pattern for anuran larvae which usually is expected to be hump-shaped. Along the species richness gradient, we quantified functional diversity of all communities considering the similarity and dissimilarity of species in 18 traits related to habitat use and foraging. Especially species-rich communities were characterised by an overlap of species function, i.e. by functional redundancy. By comparing the functional diversity of the observed communities with functional diversity of random assemblages, we found no differences at low species richness level, whereas observed species-rich communities have lower functional diversity than respective random assemblages. Conclusions We found functional redundancy being a feature of communities also in primary habitat, what has not been shown before using such a continuous measure. The observed species richness dependent pattern of low functional

  19. Real-time instrument-failure detection in the LOFT pressurizer using functional redundancy

    International Nuclear Information System (INIS)

    Tylee, J.L.

    1982-07-01

    The functional redundancy approach to detecting instrument failures in a pressurized water reactor (PWR) pressurizer is described and evaluated. This real-time method uses a bank of Kalman filters (one for each instrument) to generate optimal estimates of the pressurizer state. By performing consistency checks between the output of each filter, failed instruments can be identified. Simulation results and actual pressurizer data are used to demonstrate the capabilities of the technique

  20. Hybrid online sensor error detection and functional redundancy for systems with time-varying parameters.

    Science.gov (United States)

    Feng, Jianyuan; Turksoy, Kamuran; Samadi, Sediqeh; Hajizadeh, Iman; Littlejohn, Elizabeth; Cinar, Ali

    2017-12-01

    Supervision and control systems rely on signals from sensors to receive information to monitor the operation of a system and adjust manipulated variables to achieve the control objective. However, sensor performance is often limited by their working conditions and sensors may also be subjected to interference by other devices. Many different types of sensor errors such as outliers, missing values, drifts and corruption with noise may occur during process operation. A hybrid online sensor error detection and functional redundancy system is developed to detect errors in online signals, and replace erroneous or missing values detected with model-based estimates. The proposed hybrid system relies on two techniques, an outlier-robust Kalman filter (ORKF) and a locally-weighted partial least squares (LW-PLS) regression model, which leverage the advantages of automatic measurement error elimination with ORKF and data-driven prediction with LW-PLS. The system includes a nominal angle analysis (NAA) method to distinguish between signal faults and large changes in sensor values caused by real dynamic changes in process operation. The performance of the system is illustrated with clinical data continuous glucose monitoring (CGM) sensors from people with type 1 diabetes. More than 50,000 CGM sensor errors were added to original CGM signals from 25 clinical experiments, then the performance of error detection and functional redundancy algorithms were analyzed. The results indicate that the proposed system can successfully detect most of the erroneous signals and substitute them with reasonable estimated values computed by functional redundancy system.

  1. IPD3 and IPD3L Function Redundantly in Rhizobial and Mycorrhizal Symbioses

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    Yue Jin

    2018-03-01

    Full Text Available Legume plants form symbiotic associations with either nitrogen-fixing bacteria or arbuscular mycorrhizal (AM fungi, which are regulated by a set of common symbiotic signaling pathway genes. Central to the signaling pathway is the activation of the DMI3/IPD3 protein complex by Ca2+ oscillations, and the initiation of nodule organogenesis and mycorrhizal symbiosis. DMI3 is essential for rhizobial infection and nodule organogenesis; however, ipd3 mutants have been shown to be impaired only in infection thread formation but not in root nodule organogenesis in Medicago truncatula. We identified an IPD3-like (IPD3L gene in the M. truncatula genome. A single ipd3l mutant exhibits a normal root nodule phenotype. The ipd3l/ipd3-2 double mutant is completely unable to initiate infection threads and nodule primordia. IPD3L can functionally replace IPD3 when expressed under the control of the IPD3 promoter, indicating functional redundancy between these two transcriptional regulators. We constructed a version of IPD3 that was phosphomimetic with respect to two conserved serine residues (IPD3-2D. This was sufficient to trigger root nodule organogenesis, but the increased multisite phosphorylation of IPD3 (IPD3-8D led to low transcriptional activity, suggesting that the phosphorylation levels of IPD3 fine-tune its transcriptional activity in the root nodule symbiosis. Intriguingly, the phosphomimetic version of IPD3 triggers spontaneous root-like nodules on the roots of dmi3-1 and dmi2-1 (DMI2 is an LRR-containing receptor-like kinase gene which is required for Ca2+ spiking, but not on the roots of wild-type or ipd3l ipd3-2 plants. In addition, fully developed arbuscules were formed in the ipd3l ipd3-2 mutants but not the ccamk/dmi3-1 mutants. Collectively, our data indicate that, in addition to IPD3 and IPD3L, another new genetic component or other new phosphorylation sites of IPD3 function downstream of DMI3 in rhizobial and mycorrhizal symbioses.

  2. Exhibition

    CERN Document Server

    Staff Association

    2017-01-01

    A Look of Hope Islam Mahmoud Sweity From 19 to 30 June 2017 CERN Meyrin, Main Building Islam Mahmoud Sweity Islam Mahmoud Sweity was born in 1997 at Beit Awwa, Palestine. She is currently following a course to get an Art diploma of Painting at the college of Fine Arts at An-Najah National University under the supervision of Esmat Al As'aad. Her portraits, landscapes and still life paintings are full of life and shining colours. Charged of emotional empathy they catch the attention of the viewer and are reminding us that life is beautiful and worth living in spite of all difficulties we have to go through. She participated in many exhibitions and has exposed her drawings in 2015 at CERN and in France in the framework of the exhibition "The Origin“, and in 2017 in the Former Yugoslav Republic of Macedonia, Palestina and Jordan. In this exhibition the oil paintings made in the past year will be presented. For more information : staff.association@cern.ch | T&eacu...

  3. Functional redundancy and complementarities of seed dispersal by the last neotropical megafrugivores.

    Science.gov (United States)

    Bueno, Rafael S; Guevara, Roger; Ribeiro, Milton C; Culot, Laurence; Bufalo, Felipe S; Galetti, Mauro

    2013-01-01

    Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest. We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest. Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers.

  4. Functional Redundancy and Complementarities of Seed Dispersal by the Last Neotropical Megafrugivores

    Science.gov (United States)

    Bueno, Rafael S.; Guevara, Roger; Ribeiro, Milton C.; Culot, Laurence; Bufalo, Felipe S.; Galetti, Mauro

    2013-01-01

    Background Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest. Methodology/Principal Findings We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest. Conclusions/Significance Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers. PMID

  5. Functional redundancy and complementarities of seed dispersal by the last neotropical megafrugivores.

    Directory of Open Access Journals (Sweden)

    Rafael S Bueno

    Full Text Available Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris and muriquis (Brachyteles arachnoides are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest.We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest.Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers.

  6. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    Encounters Hanne Blitz From February 1st to 12th 2016 CERN Meyrin, Main Building What is our reaction to a first encounter with a tourist attraction? Contemporary Dutch painter Hanne Blitz captures visitors' responses to art and architecture, sweeping vistas and symbolic memorials. Encounters, a series of oil paintings curated specially for this CERN exhibition, depicts tourists visiting cultural highlights around the world. A thought-provoking journey not to be missed, and a tip of the hat to CERN's large Hadron Collider.

  7. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Sintropie Flavio Pellegrini From 13 to 24 March 2017 CERN Meyrin, Main Building Energia imprigionata - Flavio Pellegrini. The exhibition is composed by eleven wood artworks with the expression of movement as theme. The artworks are the result of harmonics math applied to sculpture. The powerful black colour is dominated by the light source, generating reflexes and modulations. The result is a continuous variation of perspective visions. The works generate, at a first approach, an emotion of mystery and incomprehension, only a deeper contemplation lets one discover entangling and mutative details, evidencing the elegance of the lines and letting the meaning emerge. For more information : staff.association@cern.ch | Tél: 022 766 37 38

  8. Functional Redundancy of ERK1 and ERK2 MAP Kinases during Development

    Directory of Open Access Journals (Sweden)

    Christophe Frémin

    2015-08-01

    Full Text Available ERK1 and ERK2 are the effector kinases of the ERK1/2 MAP-kinase signaling pathway, which plays a central role in transducing signals controlling cell proliferation, differentiation, and survival. Deregulated activity of the ERK1/2 pathway is linked to a group of developmental syndromes and contributes to the pathogenesis of various human diseases. One fundamental question that remains unaddressed is whether ERK1 and ERK2 have evolved unique physiological functions or whether they are used redundantly to reach a threshold of global ERK activity. Here, we show that the extent of development of the mouse placenta and embryo bearing different combinations of Erk1 and Erk2 alleles is strictly correlated with total ERK1/2 activity. We further demonstrate that transgenic expression of ERK1 fully rescues the embryonic and placental developmental defects associated with the loss of ERK2. We conclude that ERK1 and ERK2 exert redundant functions in mouse development.

  9. Response diversity, functional redundancy, and post-logging productivity in northern temperate and boreal forests.

    Science.gov (United States)

    Correia, David Laginha Pinto; Raulier, Frédéric; Bouchard, Mathieu; Filotas, Élise

    2018-04-19

    The development of efficient ecosystem resilience indicators was identified as one of the key research priorities in the improvement of existing sustainable forest management frameworks. Two indicators of tree diversity associated with ecosystem functioning have recently received particular attention in the literature: functional redundancy (FR) and response diversity (RD). We examined how these indicators could be used to predict post-logging productivity in forests of Québec, Canada. We analysed the relationships between pre-logging FR and RD, as measured with sample plots, and post-logging productivity, measured as seasonal variation in enhanced vegetation index obtained from MODIS satellite imagery. The effects of the deciduous and coniferous tree components in our pre-disturbance diversity assessments were isolated in order to examine the hypothesis that they have different impacts on post-disturbance productivity. We also examined the role of tree species richness and species identity effects. Our analysis revealed the complementary nature of traditional biodiversity indicators and trait-based approaches in the study of biodiversity-ecosystem-functioning relationships in dynamic ecosystems. We report a significant and positive relationship between pre-disturbance deciduous RD and post-disturbance productivity, as well as an unexpected significant negative effect of coniferous RD on productivity. This negative relationship with post-logging productivity likely results from slower coniferous regeneration speeds and from the relatively short temporal scale examined. Negative black-spruce-mediated identity effects were likely associated with increased stand vulnerability to paludification and invasion by ericaceous shrubs that slow down forest regeneration. Response diversity outperformed functional redundancy as a measure of post-disturbance productivity most likely due to the stand-replacing nature of the disturbance considered. To the best of our knowledge

  10. Functional Redundancy Between Canonical Endocannabinoid Signaling Systems in the Modulation of Anxiety.

    Science.gov (United States)

    Bedse, Gaurav; Hartley, Nolan D; Neale, Emily; Gaulden, Andrew D; Patrick, Toni A; Kingsley, Philip J; Uddin, Md Jashim; Plath, Niels; Marnett, Lawrence J; Patel, Sachin

    2017-10-01

    Increasing the available repertoire of effective treatments for mood and anxiety disorders represents a critical unmet need. Pharmacological augmentation of endogenous cannabinoid (eCB) signaling has been suggested to represent a novel approach to the treatment of anxiety disorders; however, the functional interactions between two canonical eCB pathways mediated via anandamide (N-arachidonylethanolamine [AEA]) and 2-arachidonoylglycerol (2-AG) in the regulation of anxiety are not well understood. We utilized pharmacological augmentation and depletion combined with behavioral and electrophysiological approaches to probe the role of 2-AG signaling in the modulation of stress-induced anxiety and the functional redundancy between AEA and 2-AG signaling in the modulation of anxiety-like behaviors in mice. Selective 2-AG augmentation reduced anxiety in the light/dark box assay and prevented stress-induced increases in anxiety associated with limbic AEA deficiency. In contrast, acute 2-AG depletion increased anxiety-like behaviors, which was normalized by selective pharmacological augmentation of AEA signaling and via direct cannabinoid receptor 1 stimulation with Δ 9 -tetrahydrocannabinol. Electrophysiological studies revealed 2-AG modulation of amygdala glutamatergic transmission as a key synaptic correlate of the anxiolytic effects of 2-AG augmentation. Although AEA and 2-AG likely subserve distinct physiological roles, a pharmacological and functional redundancy between these canonical eCB signaling pathways exists in the modulation of anxiety-like behaviors. These data support development of eCB-based treatment approaches for mood and anxiety disorders and suggest a potentially wider therapeutic overlap between AEA and 2-AG augmentation approaches than was previously appreciated. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  11. Finding an acceleration function for calculating the reliability of redundant systems - Application to common mode failures

    International Nuclear Information System (INIS)

    Gonnot, R.

    1975-01-01

    While it may be reasonable to assume that the reliability of a system - the design of which is perfectly known - can be evaluated, it seems less easy to be sure that overall reliability is correctly estimated in the case of multiple redundancies arranged in sequence. Framatome is trying to develop a method of evaluating overall reliability correctly for its installations. For example, the protection systems in its power stations considered as a whole are such that several scram signals may be relayed in sequence when an incident occurs. These signals all involve the same components for a given type of action, but the components themselves are in fact subject to different stresses and constraints, which tend to reduce their reliability. Whatever the sequence in which these signals are transmitted (in a fast-developing accident, for example), it is possible to evaluate the actual reliability of a given system (or component) for different constraints, as the latter are generally obtained via the transient codes. By applying the so-called ''equal probability'' hypothesis one can estimate a reliability acceleration function taking into account the constraints imposed. This function is linear for the principal failure probability distribution laws. By generalizing such a method one can: (1) Perform failure calculations for redundant systems (or components) in a more general way than is possible with event trees, since one of the main parameters is the constraint exercised on that system (or component); (2) Determine failure rates of components on the basis of accelerated tests (up to complete failure of the component) which are quicker than the normal long-term tests (statistical results of operation); (3) Evaluate the multiplication factor for the reliability of a system or component in the case of common mode failures. The author presents the mathematical tools required for such a method and described their application in the cases mentioned above

  12. The Msi Family of RNA-Binding Proteins Function Redundantly as Intestinal Oncoproteins

    Directory of Open Access Journals (Sweden)

    Ning Li

    2015-12-01

    Full Text Available Members of the Msi family of RNA-binding proteins have recently emerged as potent oncoproteins in a range of malignancies. MSI2 is highly expressed in hematopoietic cancers, where it is required for disease maintenance. In contrast to the hematopoietic system, colorectal cancers can express both Msi family members, MSI1 and MSI2. Here, we demonstrate that, in the intestinal epithelium, Msi1 and Msi2 have analogous oncogenic effects. Further, comparison of Msi1/2-induced gene expression programs and transcriptome-wide analyses of Msi1/2-RNA-binding targets reveal significant functional overlap, including induction of the PDK-Akt-mTORC1 axis. Ultimately, we demonstrate that concomitant loss of function of both MSI family members is sufficient to abrogate the growth of human colorectal cancer cells, and Msi gene deletion inhibits tumorigenesis in several mouse models of intestinal cancer. Our findings demonstrate that MSI1 and MSI2 act as functionally redundant oncoproteins required for the ontogeny of intestinal cancers.

  13. Synthesis of atmospheric turbulence point spread functions by sparse and redundant representations

    Science.gov (United States)

    Hunt, Bobby R.; Iler, Amber L.; Bailey, Christopher A.; Rucci, Michael A.

    2018-02-01

    Atmospheric turbulence is a fundamental problem in imaging through long slant ranges, horizontal-range paths, or uplooking astronomical cases through the atmosphere. An essential characterization of atmospheric turbulence is the point spread function (PSF). Turbulence images can be simulated to study basic questions, such as image quality and image restoration, by synthesizing PSFs of desired properties. In this paper, we report on a method to synthesize PSFs of atmospheric turbulence. The method uses recent developments in sparse and redundant representations. From a training set of measured atmospheric PSFs, we construct a dictionary of "basis functions" that characterize the atmospheric turbulence PSFs. A PSF can be synthesized from this dictionary by a properly weighted combination of dictionary elements. We disclose an algorithm to synthesize PSFs from the dictionary. The algorithm can synthesize PSFs in three orders of magnitude less computing time than conventional wave optics propagation methods. The resulting PSFs are also shown to be statistically representative of the turbulence conditions that were used to construct the dictionary.

  14. Phyllosphere Metaproteomes of Trees from the Brazilian Atlantic Forest Show High Levels of Functional Redundancy.

    Science.gov (United States)

    Lambais, M R; Barrera, S E; Santos, E C; Crowley, D E; Jumpponen, A

    2017-01-01

    The phyllosphere of the Brazilian Atlantic Forest has been estimated to contain several million bacterial species that are associated with approximately 20000 plant species. Despite the high bacterial diversity in the phyllosphere, the function of these microorganisms and the mechanisms driving their community assembly are largely unknown. In this study, we characterized the bacterial communities in the phyllospheres of four tree species of the Atlantic Forest (Mollinedia schottiana, Ocotea dispersa, Ocotea teleiandra, and Tabebuia serratifolia) and their metaproteomes to examine the basic protein functional groups expressed in the phyllosphere. Bacterial community analyses using 16S rRNA gene sequencing confirmed prior observations that plant species harbor distinct bacterial communities and that plants of the same taxon have more similar communities than more distantly related taxa. Using LC-ESI-Q-TOF, we identified 216 nonredundant proteins, based on 3503 peptide mass spectra. Most protein families were shared among the phyllosphere communities, suggesting functional redundancy despite differences in the species compositions of the bacterial communities. Proteins involved in glycolysis and anaerobic carbohydrate metabolism, solute transport, protein metabolism, cell motility, stress and antioxidant responses, nitrogen metabolism, and iron homeostasis were among the most frequently detected. In contrast to prior studies on crop plants and Arabidopsis, a low abundance of OTUs related to Methylobacterium and no proteins associated with the metabolism of one-carbon molecules were detected in the phyllospheres of the tree species studied here. Our data suggest that even though the phyllosphere bacterial communities of different tree species are phylogenetically diverse, their metaproteomes are functionally convergent with respect to traits required for survival on leaf surfaces.

  15. Coded aperture imaging: the modulation transfer function for uniformly redundant arrays

    International Nuclear Information System (INIS)

    Fenimore, E.E.

    1980-01-01

    Coded aperture imaging uses many pinholes to increase the SNR for intrinsically weak sources when the radiation can be neither reflected nor refracted. Effectively, the signal is multiplexed onto an image and then decoded, often by a computer, to form a reconstructed image. We derive the modulation transfer function (MTF) of such a system employing uniformly redundant arrays (URA). We show that the MTF of a URA system is virtually the same as the MTF of an individual pinhole regardless of the shape or size of the pinhole. Thus, only the location of the pinholes is important for optimum multiplexing and decoding. The shape and size of the pinholes can then be selected based on other criteria. For example, one can generate self-supporting patterns, useful for energies typically encountered in the imaging of laser-driven compressions or in soft x-ray astronomy. Such patterns contain holes that are all the same size, easing the etching or plating fabrication efforts for the apertures. A new reconstruction method is introduced called delta decoding. It improves the resolution capabilities of a coded aperture system by mitigating a blur often introduced during the reconstruction step

  16. Overexpressed HDAC8 in cervical cancer cells shows functional redundancy of tubulin deacetylation with HDAC6.

    Science.gov (United States)

    Vanaja, G R; Ramulu, Hemalatha Golaconda; Kalle, Arunasree M

    2018-05-02

    Histone deacetylases (HDACs) are involved in epigenetic gene regulation via deacetylation of acetylated lysine residues of both histone and non-histone proteins. Among the 18 HDACs identified in humans, HDAC8, a class I HDAC, is best understood structurally and enzymatically. However, its precise subcellular location, function in normal cellular physiology, its protein partners and substrates still remain elusive. The subcellular localization of HDAC8 was studied using immunofluorescence and confocal imaging. The binding parterns were identified employing immunoprecipitation (IP) followed by MALDI-TOF analysis and confirmed using in-silico protein-protein interaction studies, HPLC-based in vitro deacetylation assay, intrinsic fluorescence spectrophotometric analysis, Circular dichroism (CD) and Surface Plasmon Resonance (SPR). Functional characterization of the binding was carried out using immunoblot and knockdown by siRNA. Using one way ANOVA statistical significance (n = 3) was determined. Here, we show that HDAC8 and its phosphorylated form (pHDAC8) localized predominantly in the cytoplasm in cancerous, HeLa, and non-cancerous (normal), HEK293T, cells, although nucleolar localization was observed in HeLa cells. The study identified Alpha tubulin as a novel interacting partner of HDAC8. Further, the results indicated binding and deacetylation of tubulin at ac-lys40 by HDAC8. Knockdown of HDAC8 by siRNA, inhibition of HDAC8 and/or HDAC6 by PCI-34051 and tubastatin respectively, cell-migration, cell morphology and cell cycle analysis clearly explained HDAC8 as tubulin deacetylase in HeLa cells and HDAC6 in HEK 293 T cells. HDAC8 shows functional redundancy with HDAC6 when overexpressed in cervical cancer cells, HeLa, and deacetylaes ac-lys40 of alpha tubulin leading to cervical cancer proliferation and progression.

  17. Investigating functional redundancy versus complementarity in Hawaiian herbivorous coral reef fishes.

    Science.gov (United States)

    Kelly, Emily L A; Eynaud, Yoan; Clements, Samantha M; Gleason, Molly; Sparks, Russell T; Williams, Ivor D; Smith, Jennifer E

    2016-12-01

    Patterns of species resource use provide insight into the functional roles of species and thus their ecological significance within a community. The functional role of herbivorous fishes on coral reefs has been defined through a variety of methods, but from a grazing perspective, less is known about the species-specific preferences of herbivores on different groups of reef algae and the extent of dietary overlap across an herbivore community. Here, we quantified patterns of redundancy and complementarity in a highly diverse community of herbivores at a reef on Maui, Hawaii, USA. First, we tracked fish foraging behavior in situ to record bite rate and type of substrate bitten. Second, we examined gut contents of select herbivorous fishes to determine consumption at a finer scale. Finally, we placed foraging behavior in the context of resource availability to determine how fish selected substrate type. All species predominantly (73-100 %) foraged on turf algae, though there were differences among the types of macroalgae and other substrates bitten. Increased resolution via gut content analysis showed the composition of turf algae consumed by fishes differed across herbivore species. Consideration of foraging behavior by substrate availability revealed 50 % of herbivores selected for turf as opposed to other substrate types, but overall, there were variable foraging portfolios across all species. Through these three methods of investigation, we found higher complementarity among herbivorous fishes than would be revealed using a single metric. These results suggest differences across species in the herbivore "rain of bites" that graze and shape benthic community composition.

  18. Handling data redundancy in helical cone beam reconstruction with a cone-angle-based window function and its asymptotic approximation

    International Nuclear Information System (INIS)

    Tang Xiangyang; Hsieh Jiang

    2007-01-01

    A cone-angle-based window function is defined in this manuscript for image reconstruction using helical cone beam filtered backprojection (CB-FBP) algorithms. Rather than defining the window boundaries in a two-dimensional detector acquiring projection data for computed tomographic imaging, the cone-angle-based window function deals with data redundancy by selecting rays with the smallest cone angle relative to the reconstruction plane. To be computationally efficient, an asymptotic approximation of the cone-angle-based window function is also given and analyzed in this paper. The benefit of using such an asymptotic approximation also includes the avoidance of functional discontinuities that cause artifacts in reconstructed tomographic images. The cone-angle-based window function and its asymptotic approximation provide a way, equivalent to the Tam-Danielsson-window, for helical CB-FBP reconstruction algorithms to deal with data redundancy, regardless of where the helical pitch is constant or dynamically variable during a scan. By taking the cone-parallel geometry as an example, a computer simulation study is conducted to evaluate the proposed window function and its asymptotic approximation for helical CB-FBP reconstruction algorithm to handle data redundancy. The computer simulated Forbild head and thorax phantoms are utilized in the performance evaluation, showing that the proposed cone-angle-based window function and its asymptotic approximation can deal with data redundancy very well in cone beam image reconstruction from projection data acquired along helical source trajectories. Moreover, a numerical study carried out in this paper reveals that the proposed cone-angle-based window function is actually equivalent to the Tam-Danielsson-window, and rigorous mathematical proofs are being investigated

  19. Ethernet redundancy

    Energy Technology Data Exchange (ETDEWEB)

    Burak, K. [Invensys Process Systems, M/S C42-2B, 33 Commercial Street, Foxboro, MA 02035 (United States)

    2006-07-01

    We describe the Ethernet systems and their evolution: LAN Segmentation, DUAL networks, network loops, network redundancy and redundant network access. Ethernet (IEEE 802.3) is an open standard with no licensing fees and its specifications are freely available. As a result, it is the most popular data link protocol in use. It is important that the network be redundant and standard Ethernet protocols like RSTP (IEEE 802.1w) provide the fast network fault detection and recovery times that is required today. As Ethernet does continue to evolve, network redundancy is and will be a mixture of technology standards. So it is very important that both end-stations and networking devices be Ethernet (IEEE 802.3) compliant. Then when new technologies, such as the IEEE 802.1aq Shortest Path Bridging protocol, come to market they can be easily deployed in the network without worry.

  20. Ethernet redundancy

    International Nuclear Information System (INIS)

    Burak, K.

    2006-01-01

    We describe the Ethernet systems and their evolution: LAN Segmentation, DUAL networks, network loops, network redundancy and redundant network access. Ethernet (IEEE 802.3) is an open standard with no licensing fees and its specifications are freely available. As a result, it is the most popular data link protocol in use. It is important that the network be redundant and standard Ethernet protocols like RSTP (IEEE 802.1w) provide the fast network fault detection and recovery times that is required today. As Ethernet does continue to evolve, network redundancy is and will be a mixture of technology standards. So it is very important that both end-stations and networking devices be Ethernet (IEEE 802.3) compliant. Then when new technologies, such as the IEEE 802.1aq Shortest Path Bridging protocol, come to market they can be easily deployed in the network without worry

  1. Predicting genome-wide redundancy using machine learning

    Directory of Open Access Journals (Sweden)

    Shasha Dennis E

    2010-11-01

    Full Text Available Abstract Background Gene duplication can lead to genetic redundancy, which masks the function of mutated genes in genetic analyses. Methods to increase sensitivity in identifying genetic redundancy can improve the efficiency of reverse genetics and lend insights into the evolutionary outcomes of gene duplication. Machine learning techniques are well suited to classifying gene family members into redundant and non-redundant gene pairs in model species where sufficient genetic and genomic data is available, such as Arabidopsis thaliana, the test case used here. Results Machine learning techniques that combine multiple attributes led to a dramatic improvement in predicting genetic redundancy over single trait classifiers alone, such as BLAST E-values or expression correlation. In withholding analysis, one of the methods used here, Support Vector Machines, was two-fold more precise than single attribute classifiers, reaching a level where the majority of redundant calls were correctly labeled. Using this higher confidence in identifying redundancy, machine learning predicts that about half of all genes in Arabidopsis showed the signature of predicted redundancy with at least one but typically less than three other family members. Interestingly, a large proportion of predicted redundant gene pairs were relatively old duplications (e.g., Ks > 1, suggesting that redundancy is stable over long evolutionary periods. Conclusions Machine learning predicts that most genes will have a functionally redundant paralog but will exhibit redundancy with relatively few genes within a family. The predictions and gene pair attributes for Arabidopsis provide a new resource for research in genetics and genome evolution. These techniques can now be applied to other organisms.

  2. Low functional richness and redundancy of a predator assemblage in native forest fragments of Chiloe island, Chile.

    Science.gov (United States)

    Farias, Ariel A; Jaksic, Fabian M

    2011-07-01

    1. Changes in land use and habitat fragmentation are major drivers of global change, and studying their effects on biodiversity constitutes a major research programme. However, biodiversity is a multifaceted concept, with a functional component linking species richness to ecosystem function. Currently, the interaction between functional and taxonomic components of biodiversity under realistic scenarios of habitat degradation is poorly understood. 2. The expected functional richness (FR)-species richness relationship (FRSR) is positive, and attenuated for functional redundancy in species-rich assemblages. Further, environmental filters are expected to flatten that association by sorting species with similar traits. Thus, analysing FRSR can inform about the response of biodiversity to environmental gradients and habitat fragmentation, and its expected functional consequences. 3. Top predators affect ecosystem functioning through prey consumption and are particularly vulnerable to changes in land use and habitat fragmentation, being good indicators of ecosystem health and suitable models for assessing the effects of habitat fragmentation on their FR. 4. Thus, this study analyses the functional redundancy of a vertebrate predator assemblage at temperate forest fragments in a rural landscape of Chiloe island (Chile), testing the existence of environmental filters by contrasting an empirically derived FRSR against those predicted from null models, and testing the association between biodiversity components and the structure of forest fragments. 5. Overall, contrasts against null models indicate that regional factors determine low levels of FR and redundancy for the vertebrate predator assemblage studied, while recorded linear FRSR indicates proportional responses of the two biodiversity components to the structure of forest fragments. Further, most species were positively associated with either fragment size or shape complexity, which are highly correlated. This, and the

  3. Functional redundancy and/or ongoing pseudogenization among F-box protein genes expressed in Arabidopsis male gametophyte.

    Science.gov (United States)

    Ikram, Sobia; Durandet, Monique; Vesa, Simona; Pereira, Serge; Guerche, Philippe; Bonhomme, Sandrine

    2014-06-01

    F-box protein genes family is one of the largest gene families in plants, with almost 700 predicted genes in the model plant Arabidopsis. F-box proteins are key components of the ubiquitin proteasome system that allows targeted protein degradation. Transcriptome analyses indicate that half of these F-box protein genes are found expressed in microspore and/or pollen, i.e., during male gametogenesis. To assess the role of F-box protein genes during this crucial developmental step, we selected 34 F-box protein genes recorded as highly and specifically expressed in pollen and isolated corresponding insertion mutants. We checked the expression level of each selected gene by RT-PCR and confirmed pollen expression for 25 genes, but specific expression for only 10 of the 34 F-box protein genes. In addition, we tested the expression level of selected F-box protein genes in 24 mutant lines and showed that 11 of them were null mutants. Transmission analysis of the mutations to the progeny showed that none of the single mutations was gametophytic lethal. These unaffected transmission efficiencies suggested leaky mutations or functional redundancy among F-box protein genes. Cytological observation of the gametophytes in the mutants confirmed these results. Combinations of mutations in F-box protein genes from the same subfamily did not lead to transmission defect either, further highlighting functional redundancy and/or a high proportion of pseudogenes among these F-box protein genes.

  4. Palpebral redundancy from hypothyroidism.

    Science.gov (United States)

    Wortsman, J; Wavak, P

    1980-01-01

    A patient is described with disabling palpebral edema. Primary hypothyroidism had been previously diagnosed and treated. Testing of thyroid function revealed persistence of the hypothyroidism. Treatment with L-thyroxine produced normalization of the biochemical parameters and resolution of palpebral edema. The search for hypothyrodism in patients with palpebral redundancy is emphasized.

  5. Zebrafish Lacking Circadian Gene per2 Exhibit Visual Function Deficiency

    Directory of Open Access Journals (Sweden)

    Deng-feng Huang

    2018-03-01

    Full Text Available The retina has an intrinsic circadian clock, but the importance of this clock for vision is unknown. Zebrafish offer many advantages for studying vertebrate vision and circadian rhythm. Here, we explored the role of zebrafish per2, a light-regulated gene, in visual behavior and the underlying mechanisms. We observed that per2 mutant zebrafish larvae showed decreased contrast sensitivity and visual acuity using optokinetic response (OKR assays. Using a visual motor response (VMR assay, we observed normal OFF responses but abnormal ON responses in mutant zebrafish larvae. Immunofluorescence showed that mutants had a normal morphology of cone photoreceptor cells and retinal organization. However, electron microscopy showed that per2 mutants displayed abnormal and decreased photoreceptor ribbon synapses with arciform density, which resulted in retinal ON pathway defect. We also examined the expression of three cone opsins by quantitative real-time PCR (qRT-PCR, and the expression of long-wave-sensitive opsin (opn1lw and short-wave-sensitive opsin (opn1sw was reduced in mutant zebrafish larvae. qRT-PCR analyses also showed a down-regulation of the clock genes cry1ba and bmal1b in the adult eye of per2 mutant zebrafish. This study identified a mechanism by which a clock gene affects visual function and defined important roles of per2 in retinal information processing.

  6. The Drosophila melanogaster DmCK2beta transcription unit encodes for functionally non-redundant protein isoforms.

    Science.gov (United States)

    Jauch, Eike; Wecklein, Heike; Stark, Felix; Jauch, Mandy; Raabe, Thomas

    2006-06-07

    Genes encoding for the two evolutionary highly conserved subunits of a heterotetrameric protein kinase CK2 holoenzyme are present in all examined eukaryotic genomes. Depending on the organism, multiple transcription units encoding for a catalytically active CK2alpha subunit and/or a regulatory CK2beta subunit may exist. The phosphotransferase activity of members of the protein kinase CK2alpha family is thought to be independent of second messengers but is modulated by interaction with CK2beta-like proteins. In the genome of Drosophila melanogaster, one gene encoding for a CK2alpha subunit and three genes encoding for CK2beta-like proteins are present. The X-linked DmCK2beta transcription unit encodes for several CK2beta protein isoforms due to alternative splicing of its primary transcript. We addressed the question whether CK2beta-like proteins are redundant in function. Our in vivo experiments show that variations of the very C-terminal tail of CK2beta isoforms encoded by the X-linked DmCK2beta transcription unit influence their functional properties. In addition, we find that CK2beta-like proteins encoded by the autosomal D. melanogaster genes CK2betates and CK2beta' cannot fully substitute for a loss of CK2beta isoforms encoded by DmCK2beta.

  7. Zebrafish neurofibromatosis type 1 genes have redundant functions in tumorigenesis and embryonic development

    Directory of Open Access Journals (Sweden)

    Jimann Shin

    2012-11-01

    Neurofibromatosis type 1 (NF1 is a common, dominantly inherited genetic disorder that results from mutations in the neurofibromin 1 (NF1 gene. Affected individuals demonstrate abnormalities in neural-crest-derived tissues that include hyperpigmented skin lesions and benign peripheral nerve sheath tumors. NF1 patients also have a predisposition to malignancies including juvenile myelomonocytic leukemia (JMML, optic glioma, glioblastoma, schwannoma and malignant peripheral nerve sheath tumors (MPNSTs. In an effort to better define the molecular and cellular determinants of NF1 disease pathogenesis in vivo, we employed targeted mutagenesis strategies to generate zebrafish harboring stable germline mutations in nf1a and nf1b, orthologues of NF1. Animals homozygous for loss-of-function alleles of nf1a or nf1b alone are phenotypically normal and viable. Homozygous loss of both alleles in combination generates larval phenotypes that resemble aspects of the human disease and results in larval lethality between 7 and 10 days post fertilization. nf1-null larvae demonstrate significant central and peripheral nervous system defects. These include aberrant proliferation and differentiation of oligodendrocyte progenitor cells (OPCs, dysmorphic myelin sheaths and hyperplasia of Schwann cells. Loss of nf1 contributes to tumorigenesis as demonstrated by an accelerated onset and increased penetrance of high-grade gliomas and MPNSTs in adult nf1a+/−; nf1b−/−; p53e7/e7 animals. nf1-null larvae also demonstrate significant motor and learning defects. Importantly, we identify and quantitatively analyze a novel melanophore phenotype in nf1-null larvae, providing the first animal model of the pathognomonic pigmentation lesions of NF1. Together, these findings support a role for nf1a and nf1b as potent tumor suppressor genes that also function in the development of both central and peripheral glial cells as well as melanophores in zebrafish.

  8. Functional redundancy ensures performance robustness in 3-stage PHA-producing mixed cultures under variable feed operation.

    Science.gov (United States)

    Carvalho, Gilda; Pedras, Inês; Karst, Soren M; Oliveira, Catarina S S; Duque, Anouk F; Nielsen, Per H; Reis, Maria A M

    2018-01-25

    Polyhydroxyalkanoates (PHA) are biopolymers that can be produced by mixed microbial cultures using wastes or industrial by-products, which represent an economical and environmental advantage over pure culture processes. The use of alternate feedstocks enables using seasonal by-products, providing that the process is resilient to transient conditions. The mixed microbial communities of a 3-stage PHA producing system fed initially with molasses and then cheese whey were investigated through amplicon sequencing of the 16S rRNA gene. The transition in feedstock resulted in an adaptation of the acidogenic community, where Actinobacteria dominated with sugarcane molasses (up to 93% of the operational taxonomic units) and Firmicutes, with cheese whey (up to 97%). The resulting fermentation products profile also changed, with a higher fraction of HV precursors obtained with molasses than cheese whey (7.1±0.5 and 1.7±0.7 gCOD/L, respectively). As for the PHA storing culture, the genera Azoarcus, Thauera and Paracoccus were enriched with fermented molasses (average 89% of Bacteria). Later, fermented cheese whey fostered a higher diversity, including some less characterised PHA-storers such as the genera Paenibacillus and Lysinibacillus. Although the microbial community structure was significantly affected by the feedstock shift, the acidogenic and PHA storing performance of the 3-stage system was very similar once a pseudo steady state was attained, showing that a reliable level of functional redundancy was attained in both mixed cultures. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Functionally redundant but dissimilar microbial communities within biogas reactors treating maize silage in co-fermentation with sugar beet silage

    Science.gov (United States)

    Langer, Susanne G; Ahmed, Sharif; Einfalt, Daniel; Bengelsdorf, Frank R; Kazda, Marian

    2015-01-01

    Numerous observations indicate a high flexibility of microbial communities in different biogas reactors during anaerobic digestion. Here, we describe the functional redundancy and structural changes of involved microbial communities in four lab-scale continuously stirred tank reactors (CSTRs, 39°C, 12 L volume) supplied with different mixtures of maize silage (MS) and sugar beet silage (SBS) over 80 days. Continuously stirred tank reactors were fed with mixtures of MS and SBS in volatile solid ratios of 1:0 (Continuous Fermenter (CF) 1), 6:1 (CF2), 3:1 (CF3), 1:3 (CF4) with equal organic loading rates (OLR 1.25 kgVS m−3 d−1) and showed similar biogas production rates in all reactors. The compositions of bacterial and archaeal communities were analysed by 454 amplicon sequencing approach based on 16S rRNA genes. Both bacterial and archaeal communities shifted with increasing amounts of SBS. Especially pronounced were changes in the archaeal composition towards Methanosarcina with increasing proportion of SBS, while Methanosaeta declined simultaneously. Compositional shifts within the microbial communities did not influence the respective biogas production rates indicating that these communities adapted to environmental conditions induced by different feedstock mixtures. The diverse microbial communities optimized their metabolism in a way that ensured efficient biogas production. PMID:26200922

  10. Redundant function of DNA ligase 1 and 3 in alternative end-joining during immunoglobulin class switch recombination.

    Science.gov (United States)

    Masani, Shahnaz; Han, Li; Meek, Katheryn; Yu, Kefei

    2016-02-02

    Nonhomologous end-joining (NHEJ) is the major DNA double-strand break (DSB) repair pathway in mammals and resolves the DSBs generated during both V(D)J recombination in developing lymphocytes and class switch recombination (CSR) in antigen-stimulated B cells. In contrast to the absolute requirement for NHEJ to resolve DSBs associated with V(D)J recombination, DSBs associated with CSR can be resolved in NHEJ-deficient cells (albeit at a reduced level) by a poorly defined alternative end-joining (A-EJ) pathway. Deletion of DNA ligase IV (Lig4), a core component of the NHEJ pathway, reduces CSR efficiency in a mouse B-cell line capable of robust cytokine-stimulated CSR in cell culture. Here, we report that CSR levels are not further reduced by deletion of either of the two remaining DNA ligases (Lig1 and nuclear Lig3) in Lig4(-/-) cells. We conclude that in the absence of Lig4, Lig1, and Lig3 function in a redundant manner in resolving switch region DSBs during CSR.

  11. CISH has no non-redundant functions in glucose homeostasis or beta cell proliferation during pregnancy in mice.

    Science.gov (United States)

    Jiao, Yang; Rieck, Sebastian; Le Lay, John; Kaestner, Klaus H

    2013-11-01

    Increased beta cell proliferation during pregnancy is mediated by the Janus kinase 2/signal transducer and activator of transcription 5 (JAK2/STAT5) signalling pathway in response to increased lactogen levels. Activation of the pathway leads to transcriptional upregulation of Cish (encoding cytokine-inducible SH2 domain-containing protein), a member of the suppressor of cytokine signalling (SOCS) family of genes, forming a negative-feedback loop. Here, we examined whether conditional gene ablation of Cish in the pancreas improves beta cell proliferation and beta cell function during pregnancy in mice. We derived mice with a novel, conditional loxP allele for Cish. Pancreas-specific ablation of Cish was achieved by crossing Cish (loxP/loxP) mice with Pdx1-Cre (Early) mice. Beta cell proliferation was quantified by BrdU labelling. Glucose homeostasis was examined with glucose tolerance tests and determination of plasma insulin levels. The expression of other Socs genes and target genes of p-STAT5 related to beta cell function and beta cell proliferation was determined by quantitative PCR. There was no difference in beta cell proliferation or glucose homeostasis between the Cish mutant group and the control group. The p-STAT5 protein level was the same in Cish mutant and control mice. Socs2 gene expression was higher in Cish mutant than control mice at pregnancy day 9.5. The expression of other Socs genes was the same between control and mutant mice. Our results show that CISH has no non-redundant functions in beta cell proliferation or glucose homeostasis during pregnancy in mice. Socs2 might compensate for the loss of Cish during pregnancy.

  12. Post-surgical functional recovery, lumbar lordosis, and range of motion associated with MR-detectable redundant nerve roots in lumbar spinal stenosis.

    Science.gov (United States)

    Chen, Jinshui; Wang, Juying; Wang, Benhai; Xu, Hao; Lin, Songqing; Zhang, Huihao

    2016-01-01

    T1- and T2-weighted magnetic resonance images (MRI) can reveal lumbar redundant nerve roots (RNRs), a result of chronic compression and nerve elongation associated with pathogenesis of cauda equina claudication (CEC) in degenerative lumbar canal stenosis (DLCS). The study investigated effects of lumbar lordosis angle and range of motion on functional recovery in lumbar stenosis patents with and without RNRs. A retrospective study was conducted of 93 lumbar spinal stenosis patients who underwent decompressive surgery. Eligible records were assessed by 3 independent blinded radiologists for presence or absence of RNRs on sagittal T2-weighted MR (RNR and non-RNR groups), pre- and post-operative JOA score, lumbar lordosis angle, and range of motion. Of 93 total patients, the RNR group (n=37, 21/37 female) and non-RNR group (n=56; 31/56 female) had similar preoperative conditions (JOA score) and were not significantly different in age (mean 64.19 ± 8.25 vs. 62.8 ± 9.41 years), symptom duration (30.92 ± 22.43 vs. 28.64 ± 17.40 months), or follow-up periods (17.35 ± 4.02 vs. 17.75 ± 4.29 mo) (all p>0.4). The non-RNR group exhibited significantly better final JOA score (p=0.015) and recovery rate (p=0.002). RNR group patients exhibited larger lumbar lordosis angles in the neutral position (p=0.009) and extension (p=0.021) and larger range of motion (p=0.008). Poorer surgical outcomes in patients with RNRs indicated that elevated lumbar lordosis angle and range of motion increased risks of RNR formation, which in turn may cause poorer post-surgical recovery, this information is possibly useful in prognostic assessment of lumbar stenosis complicated by RNRs. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. A GA based penalty function technique for solving constrained redundancy allocation problem of series system with interval valued reliability of components

    Science.gov (United States)

    Gupta, R. K.; Bhunia, A. K.; Roy, D.

    2009-10-01

    In this paper, we have considered the problem of constrained redundancy allocation of series system with interval valued reliability of components. For maximizing the overall system reliability under limited resource constraints, the problem is formulated as an unconstrained integer programming problem with interval coefficients by penalty function technique and solved by an advanced GA for integer variables with interval fitness function, tournament selection, uniform crossover, uniform mutation and elitism. As a special case, considering the lower and upper bounds of the interval valued reliabilities of the components to be the same, the corresponding problem has been solved. The model has been illustrated with some numerical examples and the results of the series redundancy allocation problem with fixed value of reliability of the components have been compared with the existing results available in the literature. Finally, sensitivity analyses have been shown graphically to study the stability of our developed GA with respect to the different GA parameters.

  14. Redundant and distinct functions of the ABA response loci ABA-INSENSITIVE(ABI)5 and ABRE-BINDING FACTOR (ABF)3.

    Science.gov (United States)

    Finkelstein, Ruth; Gampala, Srinivas S L; Lynch, Tim J; Thomas, Terry L; Rock, Christopher D

    2005-09-01

    Abscisic acid-responsive gene expression is regulated by numerous transcription factors, including a subgroup of basic leucine zipper factors that bind to the conserved cis-acting sequences known as ABA-responsive elements. Although one of these factors, ABA-insensitive 5 (ABI5), was identified genetically, the paucity of genetic data for the other family members has left it unclear whether they perform unique functions or act redundantly to ABI5 or each other. To test for potential redundancy with ABI5, we identified the family members with most similar effects and interactions in transient expression systems (ABF3 and ABF1), then characterized loss-of-function lines for those loci. The abf1 and abf3 monogenic mutant lines had at most minimal effects on germination or seed-specific gene expression, but the enhanced ABA- and stress-resistance of abf3 abi5 double mutants revealed redundant action of these genes in multiple stress responses of seeds and seedlings. Although ABI5, ABF3, and ABF1 have some overlapping effects, they appear to antagonistically regulate each other's expression at specific stages. Consequently, loss of any one factor may be partially compensated by increased expression of other family members.

  15. Functional Analysis and Treatment of Human-Directed Undesirable Behavior Exhibited by a Captive Chimpanzee

    Science.gov (United States)

    Martin, Allison L.; Bloomsmith, Mollie A.; Kelley, Michael E.; Marr, M. Jackson; Maple, Terry L.

    2011-01-01

    A functional analysis identified the reinforcer maintaining feces throwing and spitting exhibited by a captive adult chimpanzee ("Pan troglodytes"). The implementation of a function-based treatment combining extinction with differential reinforcement of an alternate behavior decreased levels of inappropriate behavior. These findings further…

  16. Reliability–redundancy allocation problem considering optimal redundancy strategy using parallel genetic algorithm

    International Nuclear Information System (INIS)

    Kim, Heungseob; Kim, Pansoo

    2017-01-01

    To maximize the reliability of a system, the traditional reliability–redundancy allocation problem (RRAP) determines the component reliability and level of redundancy for each subsystem. This paper proposes an advanced RRAP that also considers the optimal redundancy strategy, either active or cold standby. In addition, new examples are presented for it. Furthermore, the exact reliability function for a cold standby redundant subsystem with an imperfect detector/switch is suggested, and is expected to replace the previous approximating model that has been used in most related studies. A parallel genetic algorithm for solving the RRAP as a mixed-integer nonlinear programming model is presented, and its performance is compared with those of previous studies by using numerical examples on three benchmark problems. - Highlights: • Optimal strategy is proposed to solve reliability redundancy allocation problem. • The redundancy strategy uses parallel genetic algorithm. • Improved reliability function for a cold standby subsystem is suggested. • Proposed redundancy strategy enhances the system reliability.

  17. Murine dishevelled 3 functions in redundant pathways with dishevelled 1 and 2 in normal cardiac outflow tract, cochlea, and neural tube development.

    Science.gov (United States)

    Etheridge, S Leah; Ray, Saugata; Li, Shuangding; Hamblet, Natasha S; Lijam, Nardos; Tsang, Michael; Greer, Joy; Kardos, Natalie; Wang, Jianbo; Sussman, Daniel J; Chen, Ping; Wynshaw-Boris, Anthony

    2008-11-01

    Dishevelled (Dvl) proteins are important signaling components of both the canonical beta-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP) pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE) movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3(-/-) mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+). Although neurulation appeared normal in both Dvl3(-/-) and LtapLp/+ mutants, Dvl3(+/-);LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant.

  18. Murine dishevelled 3 functions in redundant pathways with dishevelled 1 and 2 in normal cardiac outflow tract, cochlea, and neural tube development.

    Directory of Open Access Journals (Sweden)

    S Leah Etheridge

    2008-11-01

    Full Text Available Dishevelled (Dvl proteins are important signaling components of both the canonical beta-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3(-/- mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+. Although neurulation appeared normal in both Dvl3(-/- and LtapLp/+ mutants, Dvl3(+/-;LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant.

  19. Oxytocin Neurons Exhibit Extensive Functional Plasticity Due To Offspring Age in Mothers and Fathers.

    Science.gov (United States)

    Kelly, Aubrey M; Hiura, Lisa C; Saunders, Alexander G; Ophir, Alexander G

    2017-09-01

    The needs of offspring change as they develop. Thus, parents should concomitantly change their investment based on the age-related needs of the offspring as they mature. Due to the high costs of parental care, it is optimal for parents to exhibit a shift from intense caregiving of young offspring to promoting independence in older offspring. Yet, the neural mechanisms that underlie shifts in parental behavior are poorly understood, and little is known about how the parental brain responds to offspring of different ages. To elucidate mechanisms that relate to shifts in parental behavior as offspring develop, we examined behavioral and neural responses of male and female prairie voles (Microtus ochrogaster), a biparental rodent, to interactions with offspring at different stages of development (ranging from neonatal to weaning age). Importantly, in biparental species, males and females may adjust their behavior differentially as offspring develop. Because the nonapeptides, vasopressin (VP) and oxytocin (OT), are well known for modulating aspects of parental care, we focused on functional activity of distinct VP and OT cell groups within the maternal and paternal brain in response to separation from, reunion (after a brief period of separation) with, or no separation from offspring of different ages. We found several differences in the neural responses of individual VP and OT cell groups that varied based on the age of pups and sex of the parent. Hypothalamic VP neurons exhibit similar functional responses in both mothers and fathers. However, hypothalamic and amygdalar OT neurons exhibit differential functional responses to being separated from pups based on the sex of the parent. Our results also reveal that the developmental stage of offspring significantly impacts neural function within OT, but not VP, cell groups of both mothers and fathers. These findings provide insight into the functional plastic capabilities of the nonapeptide system, specifically in relation

  20. Bio-inspired composites with functionally graded platelets exhibit enhanced stiffness.

    Science.gov (United States)

    Tapse, Sanjay; S, Anup

    2017-11-09

    Unidirectional composites inspired from biological materials such as nacre, are composed of stiff platelets arranged in a staggered manner within a soft matrix. Elaborate analyses have been conducted on the aforementioned composites and they are found to have excellent mechanical properties like stiffness, strength and fracture toughness. The superior properties exhibited by these composites have been proved to be the result of its unique structure. An emerging development in the field of composite structures is Functionally Graded Composites(FGC), whose properties vary spatially and possess enhanced thermo-mechanical properties. In this paper, the platelets are functionally graded with its Young's Modulus varying parabolically along the length. Two different models - namely, Tension Shear Chain Model and Minimisation of Complementary Energy Model have been employed to obtain the stiffness of the overall composite analytically. The effect of various parameters that define the composite model such as overlapping length between any two neighbouring platelets, different gradation parameters and platelet aspect ratio on the overall mechanical properties have been studied. Composites with functionally graded platelets are found to possess enhanced stiffness (upto 14% higher) for certain values of these parameters. The obtained solutions have been validated using Finite Element Analysis. Bio-inspired composites with functionally graded platelets can be engineered for structural applications, such as in automobile, aerospace and aircraft industry, where stiffness plays a crucial role. © 2017 IOP Publishing Ltd.

  1. The conserved WW-domain binding sites in Dystroglycan C-terminus are essential but partially redundant for Dystroglycan function

    Directory of Open Access Journals (Sweden)

    Deng W-M

    2009-02-01

    Full Text Available Abstract Background Dystroglycan (Dg is a transmembrane protein that is a part of the Dystrophin Glycoprotein Complex (DGC which connects the extracellular matrix to the actin cytoskeleton. The C-terminal end of Dg contains a number of putative SH3, SH2 and WW domain binding sites. The most C-terminal PPXY motif has been established as a binding site for Dystrophin (Dys WW-domain. However, our previous studies indicate that both Dystroglycan PPXY motives, WWbsI and WWbsII can bind Dystrophin protein in vitro. Results We now find that both WW binding sites are important for maintaining full Dg function in the establishment of oocyte polarity in Drosophila. If either WW binding site is mutated, the Dg protein can still be active. However, simultaneous mutations in both WW binding sites abolish the Dg activities in both overexpression and loss-of-function oocyte polarity assays in vivo. Additionally, sequence comparisons of WW binding sites in 12 species of Drosophila, as well as in humans, reveal a high level of conservation. This preservation throughout evolution supports the idea that both WW binding sites are functionally required. Conclusion Based on the obtained results we propose that the presence of the two WW binding sites in Dystroglycan secures the essential interaction between Dg and Dys and might further provide additional regulation for the cytoskeletal interactions of this complex.

  2. Two ABREs, two redundant root-specific and one W-box cis-acting elements are functional in the sunflower HAHB4 promoter.

    Science.gov (United States)

    Manavella, Pablo A; Dezar, Carlos A; Ariel, Federico D; Chan, Raquel L

    2008-10-01

    HAHB4 is a sunflower gene encoding a homeodomain-leucine zipper (HD-Zip) transcription factor. It was previously demonstrated that this gene is regulated at the transcriptional level by several abiotic factors and hormones. A previous analysis in the PLACE database revealed the presence of four putative ABREs. In this work these four elements and also one W-box and two root-specific expression elements were characterized as functional. Site-directed mutagenesis on the promoter, stable transformation of Arabidopis plants as well as transient transformation of sunflower leaves, were performed. The analysis of the transformants was carried out by histochemistry and real time RT-PCR. The results indicate that just one ABRE out of the four is responsible for ABA, NaCl and drought regulation. However, NaCl induction occurs also by an additional ABA-independent way involving another two overlapped ABREs. On the other hand, it was determined that the W-box located 5' upstream is responsive to ethylene and only two root-specific expression elements, among the several detected, are functional but redundant. Conservation of molecular mechanisms between sunflower and Arabidopsis is strongly supported by this experimental work.

  3. Pivotal advance: CTLA-4+ T cells exhibit normal antiviral functions during acute viral infection.

    Science.gov (United States)

    Raué, Hans-Peter; Slifka, Mark K

    2007-05-01

    Previous studies have shown that T cells, which are genetically deficient in CTLA-4/CD152 expression, will proliferate uncontrollably, resulting in lethal autoimmune disease. This and other evidence indicate that CTLA-4 plays a critical role in the negative regulation of effector T cell function. In contrast to expectations, BrdU incorporation experiments demonstrated that CTLA-4 expression was associated with normal or even enhanced in vivo proliferation of virus-specific CD4+ and CD8+ T cells following acute lymphocytic choriomeningitis virus or vaccinia virus infection. When compared with CTLA-4- T cells directly ex vivo, CTLA-4+ T cells also exhibited normal antiviral effector functions following stimulation with peptide-coated cells, virus-infected cells, plate-bound anti-CD3/anti-CTLA-4, or the cytokines IL-12 and IL-18. Together, this indicates that CTLA-4 does not directly inhibit antiviral T cell expansion or T cell effector functions, at least not under the normal physiological conditions associated with either of these two acute viral infections.

  4. Functionally redundant RXLR effectors from Phytophthora infestans act at different steps to suppress early flg22-triggered immunity.

    Directory of Open Access Journals (Sweden)

    Xiangzi Zheng

    2014-04-01

    Full Text Available Genome sequences of several economically important phytopathogenic oomycetes have revealed the presence of large families of so-called RXLR effectors. Functional screens have identified RXLR effector repertoires that either compromise or induce plant defense responses. However, limited information is available about the molecular mechanisms underlying the modes of action of these effectors in planta. The perception of highly conserved pathogen- or microbe-associated molecular patterns (PAMPs/MAMPs, such as flg22, triggers converging signaling pathways recruiting MAP kinase cascades and inducing transcriptional re-programming, yielding a generic anti-microbial response. We used a highly synchronizable, pathogen-free protoplast-based assay to identify a set of RXLR effectors from Phytophthora infestans (PiRXLRs, the causal agent of potato and tomato light blight that manipulate early stages of flg22-triggered signaling. Of thirty-three tested PiRXLR effector candidates, eight, called Suppressor of early Flg22-induced Immune response (SFI, significantly suppressed flg22-dependent activation of a reporter gene under control of a typical MAMP-inducible promoter (pFRK1-Luc in tomato protoplasts. We extended our analysis to Arabidopsis thaliana, a non-host plant species of P. infestans. From the aforementioned eight SFI effectors, three appeared to share similar functions in both Arabidopsis and tomato by suppressing transcriptional activation of flg22-induced marker genes downstream of post-translational MAP kinase activation. A further three effectors interfere with MAMP signaling at, or upstream of, the MAP kinase cascade in tomato, but not in Arabidopsis. Transient expression of the SFI effectors in Nicotiana benthamiana enhances susceptibility to P. infestans and, for the most potent effector, SFI1, nuclear localization is required for both suppression of MAMP signaling and virulence function. The present study provides a framework to decipher the

  5. Knock-down of transcript abundance of a family of Kunitz proteinase inhibitor genes in white clover (Trifolium repens) reveals a redundancy and diversity of gene function.

    Science.gov (United States)

    Islam, Afsana; Leung, Susanna; Burgess, Elisabeth P J; Laing, William A; Richardson, Kim A; Hofmann, Rainer W; Dijkwel, Paul P; McManus, Michael T

    2015-12-01

    The transcriptional regulation of four phylogenetically distinct members of a family of Kunitz proteinase inhibitor (KPI) genes isolated from white clover (Trifolium repens; designated Tr-KPI1, Tr-KPI2, Tr-KPI4 and Tr-KPI5) has been investigated to determine their wider functional role. The four genes displayed differential transcription during seed germination, and in different tissues of the mature plant, and transcription was also ontogenetically regulated. Heterologous over-expression of Tr-KPI1, Tr-KPI2, Tr-KPI4 and Tr-KPI5 in Nicotiana tabacum retarded larval growth of the herbivore Spodoptera litura, and an increase in the transcription of the pathogenesis-related genes PR1 and PR4 was observed in the Tr-KPI1 and Tr-KPI4 over-expressing lines. RNA interference (RNAi) knock-down lines in white clover displayed significantly altered vegetative growth phenotypes with inhibition of shoot growth and a stimulation of root growth, while knock-down of Tr-KPI1, Tr-KPI2 and Tr-KPI5 transcript abundance also retarded larval growth of S. litura. Examination of these RNAi lines revealed constitutive stress-associated phenotypes as well as altered transcription of cellular signalling genes. These results reveal a functional redundancy across members of the KPI gene family. Further, the regulation of transcription of at least one member of the family, Tr-KPI2, may occupy a central role in the maintenance of a cellular homeostasis. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  6. Optimal redundant systems for works with random processing time

    International Nuclear Information System (INIS)

    Chen, M.; Nakagawa, T.

    2013-01-01

    This paper studies the optimal redundant policies for a manufacturing system processing jobs with random working times. The redundant units of the parallel systems and standby systems are subject to stochastic failures during the continuous production process. First, a job consisting of only one work is considered for both redundant systems and the expected cost functions are obtained. Next, each redundant system with a random number of units is assumed for a single work. The expected cost functions and the optimal expected numbers of units are derived for redundant systems. Subsequently, the production processes of N tandem works are introduced for parallel and standby systems, and the expected cost functions are also summarized. Finally, the number of works is estimated by a Poisson distribution for the parallel and standby systems. Numerical examples are given to demonstrate the optimization problems of redundant systems

  7. Specific substrate-driven changes in human faecal microbiota composition contrast with functional redundancy in short-chain fatty acid production.

    Science.gov (United States)

    Reichardt, Nicole; Vollmer, Maren; Holtrop, Grietje; Farquharson, Freda M; Wefers, Daniel; Bunzel, Mirko; Duncan, Sylvia H; Drew, Janice E; Williams, Lynda M; Milligan, Graeme; Preston, Thomas; Morrison, Douglas; Flint, Harry J; Louis, Petra

    2018-02-01

    The diet provides carbohydrates that are non-digestible in the upper gut and are major carbon and energy sources for the microbial community in the lower intestine, supporting a complex metabolic network. Fermentation produces the short-chain fatty acids (SCFAs) acetate, propionate and butyrate, which have health-promoting effects for the human host. Here we investigated microbial community changes and SCFA production during in vitro batch incubations of 15 different non-digestible carbohydrates, at two initial pH values with faecal microbiota from three different human donors. To investigate temporal stability and reproducibility, a further experiment was performed 1 year later with four of the carbohydrates. The lower pH (5.5) led to higher butyrate and the higher pH (6.5) to more propionate production. The strongest propionigenic effect was found with rhamnose, followed by galactomannans, whereas fructans and several α- and β-glucans led to higher butyrate production. 16S ribosomal RNA gene-based quantitative PCR analysis of 22 different microbial groups together with 454 sequencing revealed significant stimulation of specific bacteria in response to particular carbohydrates. Some changes were ascribed to metabolite cross-feeding, for example, utilisation by Eubacterium hallii of 1,2-propanediol produced from fermentation of rhamnose by Blautia spp. Despite marked inter-individual differences in microbiota composition, SCFA production was surprisingly reproducible for different carbohydrates, indicating a level of functional redundancy. Interestingly, butyrate formation was influenced not only by the overall % butyrate-producing bacteria in the community but also by the initial pH, consistent with a pH-dependent shift in the stoichiometry of butyrate production.

  8. Hydrodynamic Drag Force Measurement Of A Functionalized Surface Exhibiting Superhydrophobic Properties

    Science.gov (United States)

    2016-12-01

    hydrodynamic skin friction is greatly reduced and the water is said to slip over the air layer [12]. A number of direct numerical simulations ( DNS ) [13...practical means of reducing drag. It is therefore important to investigate materials where in the passive state exhibit the desired qualities of

  9. Detection of sensor failures in nuclear plants using analytic redundancy

    International Nuclear Information System (INIS)

    Kitamura, M.

    1980-01-01

    A method for on-line, nonperturbative detection and identification of sensor failures in nuclear power plants was studied to determine its feasibility. This method is called analytic redundancy, or functional redundancy. Sensor failure has traditionally been detected by comparing multiple signals from redundant sensors, such as in two-out-of-three logic. In analytic redundancy, with the help of an assumed model of the physical system, the signals from a set of sensors are processed to reproduce the signals from all system sensors

  10. The Arabidopsis NF-YA3 and NF-YA8 genes are functionally redundant and are required in early embryogenesis.

    Directory of Open Access Journals (Sweden)

    Monica Fornari

    Full Text Available Nuclear factor Y (NF-Y is a trimeric transcription factor composed of three distinct subunits called NF-YA, NF-YB and NF-YC. In Arabidopsis thaliana, NF-Y subunits are known to play roles in many processes, such as gametogenesis, embryogenesis, seed development, drought resistance, ABA signaling, flowering time, primary root elongation, Endoplasmic Reticulum (ER stress response and blue light responses. Here, we report that the closely related NF-YA3 and NF-YA8 genes control early embryogenesis. Detailed GUS and in situ analyses showed that NF-YA3 and NF-YA8 are expressed in vegetative and reproductive tissues with the highest expression being during embryo development from the globular to the torpedo embryo stage. Plants from the nf-ya3 and nf-ya8 single mutants do not display any obvious phenotypic alteration, whereas nf-ya3 nf-ya8 double mutants are embryo lethal. Morphological analyses showed that the nf-ya3 nf-ya8 embryos fail to undergo to the heart stage and develop into abnormal globular embryos with both proembryo and suspensor characterized by a disordered cell cluster with an irregular shape, suggesting defects in embryo development. The suppression of both NF-YA3 and NF-YA8 gene expression by RNAi experiments resulted in defective embryos that phenocopied the nf-ya3 nf-ya8 double mutants, whereas complementation experiments partially rescued the abnormal globular nf-ya3 nf-ya8 embryos, confirming that NF-YA3 and NF-YA8 are required in early embryogenesis. Finally, the lack of GFP expression of the auxin responsive DR5rev::GFP marker line in double mutant embryos suggested that mutations in both NF-YA3 and NF-YA8 affect auxin response in early developing embryos. Our findings indicate that NF-YA3 and NF-YA8 are functionally redundant genes required in early embryogenesis of Arabidopsis thaliana.

  11. Structural redundance of NPPs and diagnostics

    International Nuclear Information System (INIS)

    Znyshev, V.V.; Sabaev, E.F.

    1988-01-01

    A new approach to functional diagnosis of NPP state based on structural redundance, owing to which in major of the facilities there are elements identical as to the structure and operational conditions, is suggested. The difference from zero by the given value for one parameter measured for various identical elements is an indicator of a failed element and a signal for diagnostic analysis

  12. Functional diversity exhibits a diverse relationship with area, even a decreasing one

    Science.gov (United States)

    Karadimou, Elpida K.; Kallimanis, Athanasios S.; Tsiripidis, Ioannis; Dimopoulos, Panayotis

    2016-01-01

    The relationship between species richness and area is one of the few well-established laws in ecology, and one might expect a similar relationship with functional diversity (FD). However, only a few studies investigate the relationship between trait-based FD and area, the Functional Diversity - Area Relationship (FDAR). To examine FDAR, we constructed the species accumulation curve and the corresponding FD curve. We used plant diversity data from nested plots (1–128 m2), recorded on the Volcanic islands of Santorini Archipelagos, Greece. Six multidimensional FD indices were calculated using 26 traits. We identified a typology of FDARs depending on the facet of FD analyzed: (A) strongly positive for indices quantifying the range of functional traits in the community, (B) negative correlation for indices quantifying the evenness in the distribution of abundance in the trait space, (C) no clear pattern for indices reflecting the functional similarity of species and (D) idiosyncratic patterns with area for functional divergence. As area increases, the range of traits observed in the community increases, but the abundance of traits does not increase proportionally and some traits become dominant, implying a reliance on some functions that may be located in either the center or the periphery of the trait space. PMID:27752086

  13. Software engineering : redundancy is key

    NARCIS (Netherlands)

    Brand, van den M.G.J.; Groote, J.F.

    2015-01-01

    Software engineers are humans and so they make lots of mistakes. Typically 1 out of 10 to 100 tasks go wrong. The only way to avoid these mistakes is to introduce redundancy in the software engineering process. This article is a plea to consciously introduce several levels of redundancy for each

  14. The Birth and Death of Redundancy in Decoherence and Quantum Darwinism

    Science.gov (United States)

    Riedel, Charles; Zurek, Wojciech; Zwolak, Michael

    2012-02-01

    Understanding the quantum-classical transition and the identification of a preferred classical domain through quantum Darwinism is based on recognizing high-redundancy states as both ubiquitous and exceptional. They are produced ubiquitously during decoherence, as has been demonstrated by the recent identification of very general conditions under which high-redundancy states develop. They are exceptional in that high-redundancy states occupy a very narrow corner of the global Hilbert space; states selected at random are overwelming likely to exhibit zero redundancy. In this letter, we examine the conditions and time scales for the transition from high-redundancy states to zero-redundancy states in many-body dynamics. We identify sufficient condition for the development of redundancy from product states and show that the destruction of redundancy can be accomplished even with highly constrained interactions.

  15. Two Arabidopsis cytochrome P450 monooxygenases, CYP714A1 and CYP714A2, function redundantly in plant development through gibberellin deactivation.

    Science.gov (United States)

    Zhang, Yingying; Zhang, Baichen; Yan, Dawei; Dong, Weixin; Yang, Weibing; Li, Qun; Zeng, Longjun; Wang, Jianjun; Wang, Linyou; Hicks, Leslie M; He, Zuhua

    2011-07-01

    The rice gene ELONGATED UPPERMOST INTERNODE1 (EUI1) encodes a P450 monooxygenase that epoxidizes gibberellins (GAs) in a deactivation reaction. The Arabidopsis genome contains a tandemly duplicated gene pair ELA1 (CYP714A1) and ELA2 (CYP714A2) that encode EUI homologs. In this work, we dissected the functions of the two proteins. ELA1 and ELA2 exhibited overlapping yet distinct gene expression patterns. We showed that while single mutants of ELA1 or ELA2 exhibited no obvious morphological phenotype, simultaneous elimination of ELA1 and ELA2 expression in ELA1-RNAi/ela2 resulted in increased biomass and enlarged organs. By contrast, transgenic plants constitutively expressing either ELA1 or ELA2 were dwarfed, similar to those overexpressing the rice EUI gene. We also discovered that overexpression of ELA1 resulted in a severe dwarf phenotype, while overexpression of ELA2 gave rise to a breeding-favored semi-dwarf phenotype in rice. Consistent with the phenotypes, we found that the ELA1-RNAi/ela2 plants increased amounts of biologically active GAs that were decreased in the internodes of transgenic rice with ELA1 and ELA2 overexpression. In contrast, the precursor GA(12) slightly accumulated in the transgenic rice, and GA(19) highly accumulated in the ELA2 overexpression rice. Taken together, our study strongly suggests that the two Arabidopsis EUI homologs subtly regulate plant growth most likely through catalyzing deactivation of bioactive GAs similar to rice EUI. The two P450s may also function in early stages of the GA biosynthetic pathway. Our results also suggest that ELA2 could be an excellent tool for molecular breeding for high yield potential in cereal crops. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  16. Distribution of mammalian-like melanopsin in cyclostome retinas exhibiting a different extent of visual functions.

    Directory of Open Access Journals (Sweden)

    Lanfang Sun

    Full Text Available Mammals contain 1 melanopsin (Opn4 gene that is expressed in a subset of retinal ganglion cells to serve as a photopigment involved in non-image-forming vision such as photoentrainment of circadian rhythms. In contrast, most nonmammalian vertebrates possess multiple melanopsins that are distributed in various types of retinal cells; however, their functions remain unclear. We previously found that the lamprey has only 1 type of mammalian-like melanopsin gene, which is similar to that observed in mammals. Here we investigated the molecular properties and localization of melanopsin in the lamprey and other cyclostome hagfish retinas, which contribute to visual functions including image-forming vision and mainly to non-image-forming vision, respectively. We isolated 1 type of mammalian-like melanopsin cDNA from the eyes of each species. We showed that the recombinant lamprey melanopsin was a blue light-sensitive pigment and that both the lamprey and hagfish melanopsins caused light-dependent increases in calcium ion concentration in cultured cells in a manner that was similar to that observed for mammalian melanopsins. We observed that melanopsin was distributed in several types of retinal cells, including horizontal cells and ganglion cells, in the lamprey retina, despite the existence of only 1 melanopsin gene in the lamprey. In contrast, melanopsin was almost specifically distributed to retinal ganglion cells in the hagfish retina. Furthermore, we found that the melanopsin-expressing horizontal cells connected to the rhodopsin-containing short photoreceptor cells in the lamprey. Taken together, our findings suggest that in cyclostomes, the global distribution of melanopsin in retinal cells might not be related to the melanopsin gene number but to the extent of retinal contribution to visual function.

  17. OFD1, as a Ciliary Protein, Exhibits Neuroprotective Function in Photoreceptor Degeneration Models.

    Directory of Open Access Journals (Sweden)

    Juan Wang

    Full Text Available Ofd1 is a newly identified causative gene for Retinitis pigmentosa (RP, a photoreceptor degenerative disease. This study aimed to examine Ofd1 localization in retina and further to investigate its function in photoreceptor degeneration models. Ofd1 localization in rat retina was examined using immunofluorescence. N-methyl-N-nitrosourea (MNU-induced rats and Royal College of Surgeons (RCS rats were used as photoreceptor degeneration models. The expression pattern of Ofd1, other ciliary associated genes and Wnt signaling pathway genes were examined in rat models. Furthermore, pEGFP-Ofd1-CDS and pSUPER-Ofd1-shRNA were constructed to overexpress and knockdown the expression level in 661W and R28 cells. MNU was also used to induce cell death. Cilia formation was observed using immunocytochemistry (ICC. Reactive oxygen species (ROS were detected using the 2', 7'-Dichlorofluorescin diacetate (DCFH-DA assay. Apoptosis genes expression was examined using qRT-PCR, Western blotting and fluorescence-activated cell sorting (FACS. Ofd1 localized to outer segments of rat retina photoreceptors. Ofd1 and other ciliary proteins expression levels increased from the 1st and 4th postnatal weeks and decreased until the 6th week in the RCS rats, while their expression consistently decreased from the 1st and 7th day in the MNU rats. Moreover, Wnt signaling pathway proteins expression was significantly up-regulated in both rat models. Knockdown of Ofd1 expression resulted in a smaller population, shorter length of cell cilia, and lower cell viability. Ofd1 overexpression partially attenuated MNU toxic effects by reducing ROS levels and mitigating apoptosis. To the best of our knowledge, this is the first study demonstrating Ofd1 localization and its function in rat retina and in retinal degeneration rat models. Ofd1 plays a role in controlling photoreceptor cilium length and number. Importantly, it demonstrates a neuroprotective function by protecting the photoreceptor

  18. Motion control of musculoskeletal systems with redundancy.

    Science.gov (United States)

    Park, Hyunjoo; Durand, Dominique M

    2008-12-01

    Motion control of musculoskeletal systems for functional electrical stimulation (FES) is a challenging problem due to the inherent complexity of the systems. These include being highly nonlinear, strongly coupled, time-varying, time-delayed, and redundant. The redundancy in particular makes it difficult to find an inverse model of the system for control purposes. We have developed a control system for multiple input multiple output (MIMO) redundant musculoskeletal systems with little prior information. The proposed method separates the steady-state properties from the dynamic properties. The dynamic control uses a steady-state inverse model and is implemented with both a PID controller for disturbance rejection and an artificial neural network (ANN) feedforward controller for fast trajectory tracking. A mechanism to control the sum of the muscle excitation levels is also included. To test the performance of the proposed control system, a two degree of freedom ankle-subtalar joint model with eight muscles was used. The simulation results show that separation of steady-state and dynamic control allow small output tracking errors for different reference trajectories such as pseudo-step, sinusoidal and filtered random signals. The proposed control method also demonstrated robustness against system parameter and controller parameter variations. A possible application of this control algorithm is FES control using multiple contact cuff electrodes where mathematical modeling is not feasible and the redundancy makes the control of dynamic movement difficult.

  19. Distinct ubiquitin binding modes exhibited by SH3 domains: molecular determinants and functional implications.

    Directory of Open Access Journals (Sweden)

    Jose L Ortega Roldan

    Full Text Available SH3 domains constitute a new type of ubiquitin-binding domains. We previously showed that the third SH3 domain (SH3-C of CD2AP binds ubiquitin in an alternative orientation. We have determined the structure of the complex between first CD2AP SH3 domain and ubiquitin and performed a structural and mutational analysis to decipher the determinants of the SH3-C binding mode to ubiquitin. We found that the Phe-to-Tyr mutation in CD2AP and in the homologous CIN85 SH3-C domain does not abrogate ubiquitin binding, in contrast to previous hypothesis and our findings for the first two CD2AP SH3 domains. The similar alternative binding mode of the SH3-C domains of these related adaptor proteins is characterised by a higher affinity to C-terminal extended ubiquitin molecules. We conclude that CD2AP/CIN85 SH3-C domain interaction with ubiquitin constitutes a new ubiquitin-binding mode involved in a different cellular function and thus changes the previously established mechanism of EGF-dependent CD2AP/CIN85 mono-ubiquitination.

  20. Trophic redundancy reduces vulnerability to extinction cascades.

    Science.gov (United States)

    Sanders, Dirk; Thébault, Elisa; Kehoe, Rachel; Frank van Veen, F J

    2018-03-06

    Current species extinction rates are at unprecedentedly high levels. While human activities can be the direct cause of some extinctions, it is becoming increasingly clear that species extinctions themselves can be the cause of further extinctions, since species affect each other through the network of ecological interactions among them. There is concern that the simplification of ecosystems, due to the loss of species and ecological interactions, increases their vulnerability to such secondary extinctions. It is predicted that more complex food webs will be less vulnerable to secondary extinctions due to greater trophic redundancy that can buffer against the effects of species loss. Here, we demonstrate in a field experiment with replicated plant-insect communities, that the probability of secondary extinctions is indeed smaller in food webs that include trophic redundancy. Harvesting one species of parasitoid wasp led to secondary extinctions of other, indirectly linked, species at the same trophic level. This effect was markedly stronger in simple communities than for the same species within a more complex food web. We show that this is due to functional redundancy in the more complex food webs and confirm this mechanism with a food web simulation model by highlighting the importance of the presence and strength of trophic links providing redundancy to those links that were lost. Our results demonstrate that biodiversity loss, leading to a reduction in redundant interactions, can increase the vulnerability of ecosystems to secondary extinctions, which, when they occur, can then lead to further simplification and run-away extinction cascades. Copyright © 2018 the Author(s). Published by PNAS.

  1. Quantum redundancies and local realism

    International Nuclear Information System (INIS)

    Horodecki, R.; Horodecki, P.

    1994-01-01

    The basic properties of quantum redundancies are presented. The previous definitions of the informationally coherent quantum (ICQ) system are generalized in terms of the redundancies. The ICQ systems are also considered in the context of local realism in terms of the information integrity factor η. The classical region η≤qslant[1]/[2] for the two classes of mixed, nonfactorizable states admitting the local hidden variable model is found. ((orig.))

  2. Selective Redundancy Removal: A Framework for Data Hiding

    Directory of Open Access Journals (Sweden)

    Ugo Fiore

    2010-02-01

    Full Text Available Data hiding techniques have so far concentrated on adding or modifying irrelevant information in order to hide a message. However, files in widespread use, such as HTML documents, usually exhibit high redundancy levels, caused by code-generation programs. Such redundancy may be removed by means of optimization software. Redundancy removal, if applied selectively, enables information hiding. This work introduces Selective Redundancy Removal (SRR as a framework for hiding data. An example application of the framework is given in terms of hiding information in HTML documents. Non-uniformity across documents may raise alarms. Nevertheless, selective application of optimization techniques might be due to the legitimate use of optimization software not supporting all the optimization methods, or configured to not use all of them.

  3. Akita spontaneously type 1 diabetic mice exhibit elevated vascular arginase and impaired vascular endothelial and nitrergic function.

    Science.gov (United States)

    Toque, Haroldo A; Nunes, Kenia P; Yao, Lin; Xu, Zhimin; Kondrikov, Dmitry; Su, Yunchao; Webb, R Clinton; Caldwell, Ruth B; Caldwell, R William

    2013-01-01

    Elevated arginase (Arg) activity is reported to be involved in diabetes-induced vascular endothelial dysfunction. It can reduce L-arginine availability to nitric oxide (NO) synthase (NOS) and NO production. Akita mice, a genetic non-obese type 1 diabetes model, recapitulate human diabetes. We determined the role of Arg in a time-course of diabetes-associated endothelial dysfunction in aorta and corpora cavernosa (CC) from Akita mice. Endothelium-dependent relaxation, Arg and NOS activity, and protein expression levels of Arg and constitutive NOS were assessed in aortas and CC from Akita and non-diabetic wild type (WT) mice at 4, 12 and 24 wks of age. Systolic blood pressure (SBP) was assessed by tail cuff. In aorta and CC, Akita mice exhibited a progressive impairment of vascular endothelial and nitrergic function increased Arg activity and expression (Arg1 in aorta and both Arg1 and Arg2 in CC) compared with that of age-matched WT mice. Treatment of aorta and CC from Akita mice with an Arg inhibitor (BEC or ABH) reduced diabetes-induced elevation of Arg activity and restored endothelial and nitrergic function. Reduced levels of phospho-eNOS at Ser(1177) (in aorta and CC) and nNOS expression (in CC) were observed in Akita mice at 12 and 24 wks. Akita mice also had decreased NOS activity in aorta and CC at 12 and 24 wks that was restored by BEC treatment. Further, Akita mice exhibited moderately increased SBP at 24 wks and increased sensitivity to PE-induced contractions in aorta and sympathetic nerve stimulation in CC at 12 and 24 wks. Over 24 wks of diabetes in Akita mice, both aortic and cavernosal tissues exhibited increased Arg activity/expression, contributing to impaired endothelial and nitrergic function and reduced NO production. Our findings demonstrate involvement of Arg activity in diabetes-induced impairment of vascular function in Akita mouse.

  4. Akita spontaneously type 1 diabetic mice exhibit elevated vascular arginase and impaired vascular endothelial and nitrergic function.

    Directory of Open Access Journals (Sweden)

    Haroldo A Toque

    Full Text Available Elevated arginase (Arg activity is reported to be involved in diabetes-induced vascular endothelial dysfunction. It can reduce L-arginine availability to nitric oxide (NO synthase (NOS and NO production. Akita mice, a genetic non-obese type 1 diabetes model, recapitulate human diabetes. We determined the role of Arg in a time-course of diabetes-associated endothelial dysfunction in aorta and corpora cavernosa (CC from Akita mice.Endothelium-dependent relaxation, Arg and NOS activity, and protein expression levels of Arg and constitutive NOS were assessed in aortas and CC from Akita and non-diabetic wild type (WT mice at 4, 12 and 24 wks of age. Systolic blood pressure (SBP was assessed by tail cuff. In aorta and CC, Akita mice exhibited a progressive impairment of vascular endothelial and nitrergic function increased Arg activity and expression (Arg1 in aorta and both Arg1 and Arg2 in CC compared with that of age-matched WT mice. Treatment of aorta and CC from Akita mice with an Arg inhibitor (BEC or ABH reduced diabetes-induced elevation of Arg activity and restored endothelial and nitrergic function. Reduced levels of phospho-eNOS at Ser(1177 (in aorta and CC and nNOS expression (in CC were observed in Akita mice at 12 and 24 wks. Akita mice also had decreased NOS activity in aorta and CC at 12 and 24 wks that was restored by BEC treatment. Further, Akita mice exhibited moderately increased SBP at 24 wks and increased sensitivity to PE-induced contractions in aorta and sympathetic nerve stimulation in CC at 12 and 24 wks.Over 24 wks of diabetes in Akita mice, both aortic and cavernosal tissues exhibited increased Arg activity/expression, contributing to impaired endothelial and nitrergic function and reduced NO production. Our findings demonstrate involvement of Arg activity in diabetes-induced impairment of vascular function in Akita mouse.

  5. Technology Exhibition

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1979-09-15

    Linked to the 25th Anniversary celebrations, an exhibition of some of CERN's technological achievements was opened on 22 June. Set up in a new 600 m{sup 2} Exhibition Hall on the CERN site, the exhibition is divided into eight technology areas — magnets, vacuum, computers and data handling, survey and alignment, radiation protection, beam monitoring and handling, detectors, and workshop techniques.

  6. Analysis of the robustness of network-based disease-gene prioritization methods reveals redundancy in the human interactome and functional diversity of disease-genes.

    Directory of Open Access Journals (Sweden)

    Emre Guney

    Full Text Available Complex biological systems usually pose a trade-off between robustness and fragility where a small number of perturbations can substantially disrupt the system. Although biological systems are robust against changes in many external and internal conditions, even a single mutation can perturb the system substantially, giving rise to a pathophenotype. Recent advances in identifying and analyzing the sequential variations beneath human disorders help to comprehend a systemic view of the mechanisms underlying various disease phenotypes. Network-based disease-gene prioritization methods rank the relevance of genes in a disease under the hypothesis that genes whose proteins interact with each other tend to exhibit similar phenotypes. In this study, we have tested the robustness of several network-based disease-gene prioritization methods with respect to the perturbations of the system using various disease phenotypes from the Online Mendelian Inheritance in Man database. These perturbations have been introduced either in the protein-protein interaction network or in the set of known disease-gene associations. As the network-based disease-gene prioritization methods are based on the connectivity between known disease-gene associations, we have further used these methods to categorize the pathophenotypes with respect to the recoverability of hidden disease-genes. Our results have suggested that, in general, disease-genes are connected through multiple paths in the human interactome. Moreover, even when these paths are disturbed, network-based prioritization can reveal hidden disease-gene associations in some pathophenotypes such as breast cancer, cardiomyopathy, diabetes, leukemia, parkinson disease and obesity to a greater extend compared to the rest of the pathophenotypes tested in this study. Gene Ontology (GO analysis highlighted the role of functional diversity for such diseases.

  7. Partial functional redundancy of MreB isoforms, MreB, Mbl and MreBH, in cell morphogenesis of Bacillus subtilis.

    Science.gov (United States)

    Kawai, Yoshikazu; Asai, Kei; Errington, Jeffery

    2009-08-01

    MreB proteins are bacterial actin homologues thought to have a role in cell shape determination by positioning the cell wall synthetic machinery. Many bacteria, particularly Gram-positives, have more than one MreB isoform. Bacillus subtilis has three, MreB, Mbl and MreBH, which colocalize in a single helical structure. We now show that the helical pattern of peptidoglycan (PG) synthesis in the cylindrical part of the rod-shaped cell is governed by the redundant action of the three MreB isoforms. Single mutants for any one of mreB isoforms can still incorporate PG in a helical pattern and generate a rod shape. However, after depletion of MreB in an mbl mutant (or depletion of all three isoforms) lateral wall PG synthesis was impaired and the cells became spherical and lytic. Overexpression of any one of the MreB isoforms overcame the lethality as well as the defects in lateral PG synthesis and cell shape. Furthermore, MreB and Mbl can associate with the peptidoglycan biosynthetic machinery independently. However, no single MreB isoform was able to support normal growth under various stress conditions, suggesting that the multiple isoforms are used to allow cells to maintain proper growth and morphogenesis under changing and sometimes adverse conditions.

  8. Immersive Exhibitions

    DEFF Research Database (Denmark)

    Achiam, Marianne

    2015-01-01

    The immersive exhibition is a specialized exhibition genre in museums, which creates the illusion of time and place by representing key characteristics of a reference world and by integrating the visitor in this three-dimensionally reconstructed world (Mortensen 2010). A successful representation...... of the reference world depends on three criteria: whether the exhibition is staged as a coherent whole with all the displayed objects supporting the representation, whether the visitor is integrated as a component of the exhibition, and whether the content and message of the exhibition become dramatized...

  9. Development of a super-redundant multijoint manipulator for maintenance of nuclear reactors

    International Nuclear Information System (INIS)

    Ma, Shugen; Hirose, Shigeo.

    1994-01-01

    A tendon-driven manipulator, the CT Arm, has a specific tendon traction transmission mechanism, in which a pair of tendons for driving a joint is pulled from base actuators via pulleys mounted on the based-side joints. The mechanism makes the most of the coupled drive function of the tendon tractions and thus enables the lightweight manipulator to exhibit enormous payload capability. By this tendon-driven mechanism, a multijoint manipulator with super-redundant degrees of freedom could be realized, which is suitable to the maintenance of nuclear reactors. In this article, we introduce the CT Arm and discuss the possibility to generate a multijoint maintenance manipulator which has a super-redundant degrees of freedom. (author)

  10. The p110beta isoform of phosphoinositide 3-kinase signals downstream of G protein-coupled receptors and is functionally redundant with p110gamma.

    Science.gov (United States)

    Guillermet-Guibert, Julie; Bjorklof, Katja; Salpekar, Ashreena; Gonella, Cristiano; Ramadani, Faruk; Bilancio, Antonio; Meek, Stephen; Smith, Andrew J H; Okkenhaug, Klaus; Vanhaesebroeck, Bart

    2008-06-17

    The p110 isoforms of phosphoinositide 3-kinase (PI3K) are acutely regulated by extracellular stimuli. The class IA PI3K catalytic subunits (p110alpha, p110beta, and p110delta) occur in complex with a Src homology 2 (SH2) domain-containing p85 regulatory subunit, which has been shown to link p110alpha and p110delta to Tyr kinase signaling pathways. The p84/p101 regulatory subunits of the p110gamma class IB PI3K lack SH2 domains and instead couple p110gamma to G protein-coupled receptors (GPCRs). Here, we show, using small-molecule inhibitors with selectivity for p110beta and cells derived from a p110beta-deficient mouse line, that p110beta is not a major effector of Tyr kinase signaling but couples to GPCRs. In macrophages, both p110beta and p110gamma contributed to Akt activation induced by the GPCR agonist complement 5a, but not by the Tyr kinase ligand colony-stimulating factor-1. In fibroblasts, which express p110beta but not p110gamma, p110beta mediated Akt activation by the GPCR ligands stromal cell-derived factor, sphingosine-1-phosphate, and lysophosphatidic acid but not by the Tyr kinase ligands PDGF, insulin, and insulin-like growth factor 1. Introduction of p110gamma in these cells reduced the contribution of p110beta to GPCR signaling. Taken together, these data show that p110beta and p110gamma can couple redundantly to the same GPCR agonists. p110beta, which shows a much broader tissue distribution than the leukocyte-restricted p110gamma, could thus provide a conduit for GPCR-linked PI3K signaling in the many cell types where p110gamma expression is low or absent.

  11. The p110β isoform of phosphoinositide 3-kinase signals downstream of G protein-coupled receptors and is functionally redundant with p110γ

    Science.gov (United States)

    Guillermet-Guibert, Julie; Bjorklof, Katja; Salpekar, Ashreena; Gonella, Cristiano; Ramadani, Faruk; Bilancio, Antonio; Meek, Stephen; Smith, Andrew J. H.; Okkenhaug, Klaus; Vanhaesebroeck, Bart

    2008-01-01

    The p110 isoforms of phosphoinositide 3-kinase (PI3K) are acutely regulated by extracellular stimuli. The class IA PI3K catalytic subunits (p110α, p110β, and p110δ) occur in complex with a Src homology 2 (SH2) domain-containing p85 regulatory subunit, which has been shown to link p110α and p110δ to Tyr kinase signaling pathways. The p84/p101 regulatory subunits of the p110γ class IB PI3K lack SH2 domains and instead couple p110γ to G protein-coupled receptors (GPCRs). Here, we show, using small-molecule inhibitors with selectivity for p110β and cells derived from a p110β-deficient mouse line, that p110β is not a major effector of Tyr kinase signaling but couples to GPCRs. In macrophages, both p110β and p110γ contributed to Akt activation induced by the GPCR agonist complement 5a, but not by the Tyr kinase ligand colony-stimulating factor-1. In fibroblasts, which express p110β but not p110γ, p110β mediated Akt activation by the GPCR ligands stromal cell-derived factor, sphingosine-1-phosphate, and lysophosphatidic acid but not by the Tyr kinase ligands PDGF, insulin, and insulin-like growth factor 1. Introduction of p110γ in these cells reduced the contribution of p110β to GPCR signaling. Taken together, these data show that p110β and p110γ can couple redundantly to the same GPCR agonists. p110β, which shows a much broader tissue distribution than the leukocyte-restricted p110γ, could thus provide a conduit for GPCR-linked PI3K signaling in the many cell types where p110γ expression is low or absent. PMID:18544649

  12. The Dutch-Flemish PROMIS Physical Function item bank exhibited strong psychometric properties in patients with chronic pain.

    Science.gov (United States)

    Crins, Martine H P; Terwee, Caroline B; Klausch, Thomas; Smits, Niels; de Vet, Henrica C W; Westhovens, Rene; Cella, David; Cook, Karon F; Revicki, Dennis A; van Leeuwen, Jaap; Boers, Maarten; Dekker, Joost; Roorda, Leo D

    2017-07-01

    The objective of this study was to assess the psychometric properties of the Dutch-Flemish Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function item bank in Dutch patients with chronic pain. A bank of 121 items was administered to 1,247 Dutch patients with chronic pain. Unidimensionality was assessed by fitting a one-factor confirmatory factor analysis and evaluating resulting fit statistics. Items were calibrated with the graded response model and its fit was evaluated. Cross-cultural validity was assessed by testing items for differential item functioning (DIF) based on language (Dutch vs. English). Construct validity was evaluated by calculation correlations between scores on the Dutch-Flemish PROMIS Physical Function measure and scores on generic and disease-specific measures. Results supported the Dutch-Flemish PROMIS Physical Function item bank's unidimensionality (Comparative Fit Index = 0.976, Tucker Lewis Index = 0.976) and model fit. Item thresholds targeted a wide range of physical function construct (threshold-parameters range: -4.2 to 5.6). Cross-cultural validity was good as four items only showed DIF for language and their impact on item scores was minimal. Physical Function scores were strongly associated with scores on all other measures (all correlations ≤ -0.60 as expected). The Dutch-Flemish PROMIS Physical Function item bank exhibited good psychometric properties. Development of a computer adaptive test based on the large bank is warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Distributed redundancy and robustness in complex systems

    KAUST Repository

    Randles, Martin

    2011-03-01

    The uptake and increasing prevalence of Web 2.0 applications, promoting new large-scale and complex systems such as Cloud computing and the emerging Internet of Services/Things, requires tools and techniques to analyse and model methods to ensure the robustness of these new systems. This paper reports on assessing and improving complex system resilience using distributed redundancy, termed degeneracy in biological systems, to endow large-scale complicated computer systems with the same robustness that emerges in complex biological and natural systems. However, in order to promote an evolutionary approach, through emergent self-organisation, it is necessary to specify the systems in an \\'open-ended\\' manner where not all states of the system are prescribed at design-time. In particular an observer system is used to select robust topologies, within system components, based on a measurement of the first non-zero Eigen value in the Laplacian spectrum of the components\\' network graphs; also known as the algebraic connectivity. It is shown, through experimentation on a simulation, that increasing the average algebraic connectivity across the components, in a network, leads to an increase in the variety of individual components termed distributed redundancy; the capacity for structurally distinct components to perform an identical function in a particular context. The results are applied to a specific application where active clustering of like services is used to aid load balancing in a highly distributed network. Using the described procedure is shown to improve performance and distribute redundancy. © 2010 Elsevier Inc.

  14. Exhibit Engineering

    DEFF Research Database (Denmark)

    Mortensen, Marianne Foss

    Science museums define the objectives of their exhibitions in terms of visitor learning outcomes. Yet, exhibit designers lack theoretical and empirical research findings on which to base the creation of such educational environments. Here, this shortcoming is addressed through the development...... of tools and processes to guide the design of educational science exhibits. The guiding paradigm for this development is design-based research, which is characterised by an iterative cycle of design, enactment, and analysis. In the design phase, an educational intervention is planned and carried out based...... on the generation of theoretical ideas for exhibit design is offered in a fourth and parallel research undertaking, namely the application of the notion of cultural border-crossing to a hypothetical case of exhibit design....

  15. The cellular robustness by genetic redundancy in budding yeast.

    Directory of Open Access Journals (Sweden)

    Jingjing Li

    2010-11-01

    Full Text Available The frequent dispensability of duplicated genes in budding yeast is heralded as a hallmark of genetic robustness contributed by genetic redundancy. However, theoretical predictions suggest such backup by redundancy is evolutionarily unstable, and the extent of genetic robustness contributed from redundancy remains controversial. It is anticipated that, to achieve mutual buffering, the duplicated paralogs must at least share some functional overlap. However, counter-intuitively, several recent studies reported little functional redundancy between these buffering duplicates. The large yeast genetic interactions released recently allowed us to address these issues on a genome-wide scale. We herein characterized the synthetic genetic interactions for ∼500 pairs of yeast duplicated genes originated from either whole-genome duplication (WGD or small-scale duplication (SSD events. We established that functional redundancy between duplicates is a pre-requisite and thus is highly predictive of their backup capacity. This observation was particularly pronounced with the use of a newly introduced metric in scoring functional overlap between paralogs on the basis of gene ontology annotations. Even though mutual buffering was observed to be prevalent among duplicated genes, we showed that the observed backup capacity is largely an evolutionarily transient state. The loss of backup capacity generally follows a neutral mode, with the buffering strength decreasing in proportion to divergence time, and the vast majority of the paralogs have already lost their backup capacity. These observations validated previous theoretic predictions about instability of genetic redundancy. However, departing from the general neutral mode, intriguingly, our analysis revealed the presence of natural selection in stabilizing functional overlap between SSD pairs. These selected pairs, both WGD and SSD, tend to have decelerated functional evolution, have higher propensities of co

  16. Variance of measurements from a calibration function derived from data which exhibit run-to-run differences

    International Nuclear Information System (INIS)

    Liebetrau, A.M.

    1985-01-01

    The volume of liquid in a nuclear process tank is determined from a calibration equation which expresses volume as a function of liquid level. Successive calibration runs are made to obtain data from which to estimate either the calibration function or its inverse. For tanks equipped with high-precision measurement systems to determine liquid level, it frequently happens that run-to-run differences due to uncontrolled or uncontrollable ambient conditions are large relative to within-run measurement errors. In the strict sense, a calibration function cannot be developed from data which exhibit significant run-to-run differences. In practice, run-to-run differences are ignored when they are small relative to the accuracy required for measurements of the tank's contents. The use of standard statistical techniques in this situation can result in variance estimates which severely underestimate the actual uncertainty in volume measurements. This paper gives a method whereby reasonable estimates of the calibration uncertainty in volume determinations can be obtained in the presence of statistically significant run-to-run variability. 4 references, 3 figures, 1 table

  17. Linezolid-Dependent Function and Structure Adaptation of Ribosomes in a Staphylococcus epidermidis Strain Exhibiting Linezolid Dependence

    Science.gov (United States)

    Kokkori, Sofia; Apostolidi, Maria; Tsakris, Athanassios; Pournaras, Spyros

    2014-01-01

    Linezolid-dependent growth was recently reported in Staphylococcus epidermidis clinical strains carrying mutations associated with linezolid resistance. To investigate this unexpected behavior at the molecular level, we isolated active ribosomes from one of the linezolid-dependent strains and we compared them with ribosomes isolated from a wild-type strain. Both strains were grown in the absence and presence of linezolid. Detailed biochemical and structural analyses revealed essential differences in the function and structure of isolated ribosomes which were assembled in the presence of linezolid. The catalytic activity of peptidyltransferase was found to be significantly higher in the ribosomes derived from the linezolid-dependent strain. Interestingly, the same ribosomes exhibited an abnormal ribosomal subunit dissociation profile on a sucrose gradient in the absence of linezolid, but the profile was restored after treatment of the ribosomes with an excess of the antibiotic. Our study suggests that linezolid most likely modified the ribosomal assembly procedure, leading to a new functional ribosomal population active only in the presence of linezolid. Therefore, the higher growth rate of the partially linezolid-dependent strains could be attributed to the functional and structural adaptations of ribosomes to linezolid. PMID:24890589

  18. Reliability optimization of a redundant system with failure dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Yu Haiyang [Institute Charles Delaunay (ICD, FRE CNRS 2848), Troyes University of Technology, Rue Marie Curie, BP 2060, 10010 Troyes (France)]. E-mail: Haiyang.YU@utt.fr; Chu Chengbin [Institute Charles Delaunay (ICD, FRE CNRS 2848), Troyes University of Technology, Rue Marie Curie, BP 2060, 10010 Troyes (France); Management School, Hefei University of Technology, 193 Tunxi Road, Hefei (China); Chatelet, Eric [Institute Charles Delaunay (ICD, FRE CNRS 2848), Troyes University of Technology, Rue Marie Curie, BP 2060, 10010 Troyes (France); Yalaoui, Farouk [Institute Charles Delaunay (ICD, FRE CNRS 2848), Troyes University of Technology, Rue Marie Curie, BP 2060, 10010 Troyes (France)

    2007-12-15

    In a multi-component system, the failure of one component can reduce the system reliability in two aspects: loss of the reliability contribution of this failed component, and the reconfiguration of the system, e.g., the redistribution of the system loading. The system reconfiguration can be triggered by the component failures as well as by adding redundancies. Hence, dependency is essential for the design of a multi-component system. In this paper, we study the design of a redundant system with the consideration of a specific kind of failure dependency, i.e., the redundant dependency. The dependence function is introduced to quantify the redundant dependency. With the dependence function, the redundant dependencies are further classified as independence, weak, linear, and strong dependencies. In addition, this classification is useful in that it facilitates the optimization resolution of the system design. Finally, an example is presented to illustrate the concept of redundant dependency and its application in system design. This paper thus conveys the significance of failure dependencies in the reliability optimization of systems.

  19. Reliability optimization of a redundant system with failure dependencies

    International Nuclear Information System (INIS)

    Yu Haiyang; Chu Chengbin; Chatelet, Eric; Yalaoui, Farouk

    2007-01-01

    In a multi-component system, the failure of one component can reduce the system reliability in two aspects: loss of the reliability contribution of this failed component, and the reconfiguration of the system, e.g., the redistribution of the system loading. The system reconfiguration can be triggered by the component failures as well as by adding redundancies. Hence, dependency is essential for the design of a multi-component system. In this paper, we study the design of a redundant system with the consideration of a specific kind of failure dependency, i.e., the redundant dependency. The dependence function is introduced to quantify the redundant dependency. With the dependence function, the redundant dependencies are further classified as independence, weak, linear, and strong dependencies. In addition, this classification is useful in that it facilitates the optimization resolution of the system design. Finally, an example is presented to illustrate the concept of redundant dependency and its application in system design. This paper thus conveys the significance of failure dependencies in the reliability optimization of systems

  20. Flat H Redundant Frangible Joint Development

    Science.gov (United States)

    Brown, Chris

    2016-01-01

    Orion and Commercial Crew Program (CCP) Partners have chosen to use frangible joints for certain separation events. The joints currently available are zero failure tolerant and will be used in mission safety applications. The goal is to further develop a NASA designed redundant frangible joint that will lower flight risk and increase reliability. FY16 testing revealed a successful design in subscale straight test specimens that gained efficiency and supports Orion load requirements. Approach / Innovation A design constraint is that the redundant joint must fit within the current Orion architecture, without the need for additional vehicle modification. This limitation required a design that changed the orientation of the expanding tube assemblies (XTAs), by rotating them 90deg from the standard joint configuration. The change is not trivial and affects the fracture mechanism and structural load paths. To address these changes, the design incorporates cantilevered arms on the break plate. The shock transmission and expansion of the XTA applies force to these arms and creates a prying motion to push the plate walls outward to the point of structural failure at the notched section. The 2014 test design revealed that parts could slip during functioning wasting valuable energy needed to separate the structure with only a single XTA functioning. Dual XTA functioning fully separated the assembly showing a discrepancy can be backed up with redundancy. Work on other fully redundant systems outside NASA is limited to a few patents that have not been subjected to functionality testing Design changes to prevent unwanted slippage (with ICA funding in 2015) showed success with a single XTA. The main goal for FY 2016 was to send the new Flat H RFJ to WSTF where single XTA test failures occurred back in 2014. The plan was to gain efficiency in this design by separating the Flat H RFJ with thicker ligaments with dimensions baselined in 2014. Other modifications included geometry

  1. Redundancy in Nigerian Business Organizations: Alternatives (Pp ...

    African Journals Online (AJOL)

    FIRST LADY

    Redundancy in Nigerian Business Organizations: Alternatives (Pp. ... When business downturns ... The galloping pace of information technologies is a harbinger of profound ... Redundant staff in public departments can also be retained as.

  2. Redundant measurements for controlling errors

    International Nuclear Information System (INIS)

    Ehinger, M.H.; Crawford, J.M.; Madeen, M.L.

    1979-07-01

    Current federal regulations for nuclear materials control require consideration of operating data as part of the quality control program and limits of error propagation. Recent work at the BNFP has revealed that operating data are subject to a number of measurement problems which are very difficult to detect and even more difficult to correct in a timely manner. Thus error estimates based on operational data reflect those problems. During the FY 1978 and FY 1979 R and D demonstration runs at the BNFP, redundant measurement techniques were shown to be effective in detecting these problems to allow corrective action. The net effect is a reduction in measurement errors and a significant increase in measurement sensitivity. Results show that normal operation process control measurements, in conjunction with routine accountability measurements, are sensitive problem indicators when incorporated in a redundant measurement program

  3. Exhibiting Epistemic Objects

    DEFF Research Database (Denmark)

    Tybjerg, Karin

    2017-01-01

    of exhibiting epistemic objects that utilize their knowledge-generating potential and allow them to continue to stimulate curiosity and generate knowledge in the exhibition. The epistemic potential of the objects can then be made to work together with the function of the exhibition as a knowledge-generating set...

  4. Redundancy in Kiss1 Expression Safeguards Reproduction in the Mouse

    Science.gov (United States)

    Popa, Simina M.; Moriyama, Ryutaro M.; Caligioni, Claudia S.; Yang, Jasmine J.; Cho, Caroline M.; Concepcion, Tessa L.; Oakley, Amy E.; Lee, In Hae; Sanz, Elisenda; Amieux, Paul S.; Caraty, Alain; Palmiter, Richard D.; Navarro, Victor M.; Chan, Yee-Ming; Seminara, Stephanie B.; Clifton, Donald K.

    2013-01-01

    Kisspeptin (Kiss1) signaling to GnRH neurons is widely acknowledged to be a prerequisite for puberty and reproduction. Animals lacking functional genes for either kisspeptin or its receptor exhibit low gonadotropin secretion and infertility. Paradoxically, a recent study reported that genetic ablation of nearly all Kiss1-expressing neurons (Kiss1 neurons) does not impair reproduction, arguing that neither Kiss1 neurons nor their products are essential for sexual maturation. We posited that only minute quantities of kisspeptin are sufficient to support reproduction. If this were the case, animals having dramatically reduced Kiss1 expression might retain fertility, testifying to the redundancy of Kiss1 neurons and their products. To test this hypothesis and to determine whether males and females differ in the required amount of kisspeptin needed for reproduction, we used a mouse (Kiss1-CreGFP) that has a severe reduction in Kiss1 expression. Mice that are heterozygous and homozygous for this allele (Kiss1Cre/+ and Kiss1Cre/Cre) have ∼50% and 95% reductions in Kiss1 transcript, respectively. We found that although male Kiss1Cre/Cre mice sire normal-sized litters, female Kiss1Cre/Cre mice exhibit significantly impaired fertility and ovulation. These observations suggest that males require only 5% of normal Kiss1 expression to be reproductively competent, whereas females require higher levels for reproductive success. PMID:23736293

  5. A functional (E)-4-hydroxy-3-methylbut-2-enyl diphosphate reductase exhibits diurnal regulation of expression in Stevia rebaudiana (Bertoni).

    Science.gov (United States)

    Kumar, Hitesh; Kumar, Sanjay

    2013-09-15

    The leaves of stevia [Stevia rebaudiana (Bertoni)] are a rich source of steviol glycosides that are used as non-calorific sweetener in many countries around the world. Steviol moiety of steviol glycosides is synthesized via plastidial 2C-methyl-D-erythritol 4-phosphate pathway, where (E)-4-hydroxy-3-methylbut-2-enyl diphosphate reductase (HDR) is the key enzyme. HDR catalyzes the simultaneous conversion of (E)-4-hydroxy-3-methylbut-2-enyl diphosphate into five carbon isoprenoid units, isopentenyl diphosphate and dimethylallyl diphosphate. Stevia HDR (SrHDR) successfully rescued HDR lethal mutant strain MG1655 araispH upon genetic complementation, suggesting SrHDR to encode a functional protein. The gene exhibited diurnal variation in expression. To identify the possible regulatory elements, upstream region of the gene was cloned and putative cis-acting elements were detected by in silico analysis. Electrophoretic mobility shift assay, using a putative light responsive element GATA showed the binding of nuclear proteins (NP) isolated from leaves during light period of the day, but not with the NP from leaves during the dark period. Data suggested the involvement of GATA box in light mediated gene regulation of SrHDR in stevia. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. A heuristic for solving the redundancy allocation problem for multi-state series-parallel systems

    International Nuclear Information System (INIS)

    Ramirez-Marquez, Jose E.; Coit, David W.

    2004-01-01

    The redundancy allocation problem is formulated with the objective of minimizing design cost, when the system exhibits a multi-state reliability behavior, given system-level performance constraints. When the multi-state nature of the system is considered, traditional solution methodologies are no longer valid. This study considers a multi-state series-parallel system (MSPS) with capacitated binary components that can provide different multi-state system performance levels. The different demand levels, which must be supplied during the system-operating period, result in the multi-state nature of the system. The new solution methodology offers several distinct benefits compared to traditional formulations of the MSPS redundancy allocation problem. For some systems, recognizing that different component versions yield different system performance is critical so that the overall system reliability estimation and associated design models the true system reliability behavior more realistically. The MSPS design problem, solved in this study, has been previously analyzed using genetic algorithms (GAs) and the universal generating function. The specific problem being addressed is one where there are multiple component choices, but once a component selection is made, only the same component type can be used to provide redundancy. This is the first time that the MSPS design problem has been addressed without using GAs. The heuristic offers more efficient and straightforward analyses. Solutions to three different problem types are obtained illustrating the simplicity and ease of application of the heuristic without compromising the intended optimization needs

  7. Human Exhibitions

    DEFF Research Database (Denmark)

    Andreassen, Rikke

    light on the staging of exhibitions, the daily life of the exhibitees, the wider connections between shows across Europe and the thinking of the time on matters of race, science, gender and sexuality. A window onto contemporary racial understandings, the book presents interviews with the descendants...... of displayed people, connecting the attitudes and science of the past with both our (continued) modern fascination with ‘the exotic’, and contemporary language and popular culture. As such, it will be of interest to scholars of sociology, anthropology and history working in the areas of gender and sexuality...

  8. Gene Expression Responses to FUS, EWS, and TAF15 Reduction and Stress Granule Sequestration Analyses Identifies FET-Protein Non-Redundant Functions

    DEFF Research Database (Denmark)

    Blechingberg, Jenny; Luo, Yonglun; Bolund, Lars

    2012-01-01

    The FET family of proteins is composed of FUS/TLS, EWS/EWSR1, and TAF15 and possesses RNA- and DNA-binding capacities. The FET-proteins are involved in transcriptional regulation and RNA processing, and FET-gene deregulation is associated with development of cancer and protein granule formations...... in amyotrophic lateral sclerosis, frontotemporal lobar degeneration, and trinucleotide repeat expansion diseases. We here describe a comparative characterization of FET-protein localization and gene regulatory functions. We show that FUS and TAF15 locate to cellular stress granules to a larger extend than EWS....... FET-proteins have no major importance for stress granule formation and cellular stress responses, indicating that FET-protein stress granule association most likely is a downstream response to cellular stress. Gene expression analyses showed that the cellular response towards FUS and TAF15 reduction...

  9. High precision redundant robotic manipulator

    International Nuclear Information System (INIS)

    Young, K.K.D.

    1998-01-01

    A high precision redundant robotic manipulator for overcoming contents imposed by obstacles or imposed by a highly congested work space is disclosed. One embodiment of the manipulator has four degrees of freedom and another embodiment has seven degrees of freedom. Each of the embodiments utilize a first selective compliant assembly robot arm (SCARA) configuration to provide high stiffness in the vertical plane, a second SCARA configuration to provide high stiffness in the horizontal plane. The seven degree of freedom embodiment also utilizes kinematic redundancy to provide the capability of avoiding obstacles that lie between the base of the manipulator and the end effector or link of the manipulator. These additional three degrees of freedom are added at the wrist link of the manipulator to provide pitch, yaw and roll. The seven degrees of freedom embodiment uses one revolute point per degree of freedom. For each of the revolute joints, a harmonic gear coupled to an electric motor is introduced, and together with properly designed based servo controllers provide an end point repeatability of less than 10 microns. 3 figs

  10. Maximization of learning speed in the motor cortex due to neuronal redundancy.

    Directory of Open Access Journals (Sweden)

    Ken Takiyama

    2012-01-01

    Full Text Available Many redundancies play functional roles in motor control and motor learning. For example, kinematic and muscle redundancies contribute to stabilizing posture and impedance control, respectively. Another redundancy is the number of neurons themselves; there are overwhelmingly more neurons than muscles, and many combinations of neural activation can generate identical muscle activity. The functional roles of this neuronal redundancy remains unknown. Analysis of a redundant neural network model makes it possible to investigate these functional roles while varying the number of model neurons and holding constant the number of output units. Our analysis reveals that learning speed reaches its maximum value if and only if the model includes sufficient neuronal redundancy. This analytical result does not depend on whether the distribution of the preferred direction is uniform or a skewed bimodal, both of which have been reported in neurophysiological studies. Neuronal redundancy maximizes learning speed, even if the neural network model includes recurrent connections, a nonlinear activation function, or nonlinear muscle units. Furthermore, our results do not rely on the shape of the generalization function. The results of this study suggest that one of the functional roles of neuronal redundancy is to maximize learning speed.

  11. Sexual selection, redundancy and survival of the most beautiful

    Indian Academy of Sciences (India)

    A model is described of a highly redundant complex organism that has overlapping banks of genes such that each vital function is specified by several different genetic systems. This generates a synergistic profile linking probability of survival to the number of deleterious mutations in the genome. Computer models show ...

  12. The conservation of redundancy in genetic systems: effects of sexual ...

    Indian Academy of Sciences (India)

    Unknown

    probability of a fatal error is reduced by a redundant sampling system, but the chance of error rises as the sys- .... Thus every function is covered three times and every component covers a ... ples reduce the variance of the distributions in figure 3a and thereby ..... cases p = 0⋅1, q = 1000 and the value of b is adjusted to.

  13. A Comparison of Routing Protocol for WSNs: Redundancy Based Approach A Comparison of Routing Protocol for WSNs: Redundancy Based Approach

    Directory of Open Access Journals (Sweden)

    Anand Prakash

    2014-03-01

    Full Text Available Wireless Sensor Networks (WSNs with their dynamic applications gained a tremendous attention of researchers. Constant monitoring of critical situations attracted researchers to utilize WSNs at vast platforms. The main focus in WSNs is to enhance network localization as much as one could, for efficient and optimal utilization of resources. Different approaches based upon redundancy are proposed for optimum functionality. Localization is always related with redundancy of sensor nodes deployed at remote areas for constant and fault tolerant monitoring. In this work, we propose a comparison of classic flooding and the gossip protocol for homogenous networks which enhances stability and throughput quiet significantly.  

  14. Timing control by redundant inhibitory neuronal circuits

    Energy Technology Data Exchange (ETDEWEB)

    Tristan, I., E-mail: itristan@ucsd.edu; Rulkov, N. F.; Huerta, R.; Rabinovich, M. [BioCircuits Institute, University of California, San Diego, La Jolla, California 92093-0402 (United States)

    2014-03-15

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model.

  15. Timing control by redundant inhibitory neuronal circuits

    International Nuclear Information System (INIS)

    Tristan, I.; Rulkov, N. F.; Huerta, R.; Rabinovich, M.

    2014-01-01

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model

  16. Mutual information and redundancy in spontaneous communication between cortical neurons.

    Science.gov (United States)

    Szczepanski, J; Arnold, M; Wajnryb, E; Amigó, J M; Sanchez-Vives, M V

    2011-03-01

    An important question in neural information processing is how neurons cooperate to transmit information. To study this question, we resort to the concept of redundancy in the information transmitted by a group of neurons and, at the same time, we introduce a novel concept for measuring cooperation between pairs of neurons called relative mutual information (RMI). Specifically, we studied these two parameters for spike trains generated by neighboring neurons from the primary visual cortex in the awake, freely moving rat. The spike trains studied here were spontaneously generated in the cortical network, in the absence of visual stimulation. Under these conditions, our analysis revealed that while the value of RMI oscillated slightly around an average value, the redundancy exhibited a behavior characterized by a higher variability. We conjecture that this combination of approximately constant RMI and greater variable redundancy makes information transmission more resistant to noise disturbances. Furthermore, the redundancy values suggest that neurons can cooperate in a flexible way during information transmission. This mostly occurs via a leading neuron with higher transmission rate or, less frequently, through the information rate of the whole group being higher than the sum of the individual information rates-in other words in a synergetic manner. The proposed method applies not only to the stationary, but also to locally stationary neural signals.

  17. Redundancy in electronic health record corpora: analysis, impact on text mining performance and mitigation strategies.

    Science.gov (United States)

    Cohen, Raphael; Elhadad, Michael; Elhadad, Noémie

    2013-01-16

    The increasing availability of Electronic Health Record (EHR) data and specifically free-text patient notes presents opportunities for phenotype extraction. Text-mining methods in particular can help disease modeling by mapping named-entities mentions to terminologies and clustering semantically related terms. EHR corpora, however, exhibit specific statistical and linguistic characteristics when compared with corpora in the biomedical literature domain. We focus on copy-and-paste redundancy: clinicians typically copy and paste information from previous notes when documenting a current patient encounter. Thus, within a longitudinal patient record, one expects to observe heavy redundancy. In this paper, we ask three research questions: (i) How can redundancy be quantified in large-scale text corpora? (ii) Conventional wisdom is that larger corpora yield better results in text mining. But how does the observed EHR redundancy affect text mining? Does such redundancy introduce a bias that distorts learned models? Or does the redundancy introduce benefits by highlighting stable and important subsets of the corpus? (iii) How can one mitigate the impact of redundancy on text mining? We analyze a large-scale EHR corpus and quantify redundancy both in terms of word and semantic concept repetition. We observe redundancy levels of about 30% and non-standard distribution of both words and concepts. We measure the impact of redundancy on two standard text-mining applications: collocation identification and topic modeling. We compare the results of these methods on synthetic data with controlled levels of redundancy and observe significant performance variation. Finally, we compare two mitigation strategies to avoid redundancy-induced bias: (i) a baseline strategy, keeping only the last note for each patient in the corpus; (ii) removing redundant notes with an efficient fingerprinting-based algorithm. (a)For text mining, preprocessing the EHR corpus with fingerprinting yields

  18. Redundancy in Nigerian Business Organizations: Alternatives ...

    African Journals Online (AJOL)

    This theoretical discourse examined the incidence of work redundancy in Nigerian organizations as to offer alternative options. Certainly, some redundancy exercises may be necessary for the survival of the organizations but certain variables may influence employees' reactions to the exercises and thus influence the ...

  19. Increasing The Dexterity Of Redundant Robots

    Science.gov (United States)

    Seraji, Homayoun

    1990-01-01

    Redundant coordinates used to define additional tasks. Configuration control emerging as effective way to control motions of robot having more degrees of freedom than necessary to define trajectory of end effector and/or of object to be manipulated. Extra or redundant degrees of freedom used to give robot humanlike dexterity and versatility.

  20. Redundancy Optimization for Error Recovery in Digital Microfluidic Biochips

    DEFF Research Database (Denmark)

    Alistar, Mirela; Pop, Paul; Madsen, Jan

    2015-01-01

    Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate all the necessary functions for biochemical analysis. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow, but as discrete droplets. Research......Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate all the necessary functions for biochemical analysis. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow, but as discrete droplets....... Researchers have proposed approaches for the synthesis of digital microfluidic biochips, which, starting from a biochemical application and a given biochip architecture, determine the allocation, resource binding, scheduling, placement and routing of the operations in the application. During the execution...... propose an online recovery strategy, which decides during the execution of the biochemical application the introduction of the redundancy required for fault-tolerance. We consider both time redundancy, i.e., re-executing erroneous operations, and space redundancy, i.e., creating redundant droplets...

  1. Sibling rivalry: related bacterial small RNAs and their redundant and non-redundant roles.

    Science.gov (United States)

    Caswell, Clayton C; Oglesby-Sherrouse, Amanda G; Murphy, Erin R

    2014-01-01

    Small RNA molecules (sRNAs) are now recognized as key regulators controlling bacterial gene expression, as sRNAs provide a quick and efficient means of positively or negatively altering the expression of specific genes. To date, numerous sRNAs have been identified and characterized in a myriad of bacterial species, but more recently, a theme in bacterial sRNAs has emerged: the presence of more than one highly related sRNAs produced by a given bacterium, here termed sibling sRNAs. Sibling sRNAs are those that are highly similar at the nucleotide level, and while it might be expected that sibling sRNAs exert identical regulatory functions on the expression of target genes based on their high degree of relatedness, emerging evidence is demonstrating that this is not always the case. Indeed, there are several examples of bacterial sibling sRNAs with non-redundant regulatory functions, but there are also instances of apparent regulatory redundancy between sibling sRNAs. This review provides a comprehensive overview of the current knowledge of bacterial sibling sRNAs, and also discusses important questions about the significance and evolutionary implications of this emerging class of regulators.

  2. Sibling rivalry: Related bacterial small RNAs and their redundant and non-redundant roles

    Directory of Open Access Journals (Sweden)

    Clayton eCaswell

    2014-10-01

    Full Text Available Small RNA molecules (sRNAs are now recognized as key regulators controlling bacterial gene expression, as sRNAs provide a quick and efficient means of positively or negatively altering the expression of specific genes. To date, numerous sRNAs have been identified and characterized in a myriad of bacterial species, but more recently, a theme in bacterial sRNAs has emerged: the presence of more than one highly related sRNAs produced by a given bacterium, here termed sibling sRNAs. Sibling sRNAs are those that are highly similar at the nucleotide level, and while it might be expected that sibling sRNAs exert identical regulatory functions on the expression of target genes based on their high degree of relatedness, emerging evidence is demonstrating that this is not always the case. Indeed, there are several examples of bacterial sibling sRNAs with non-redundant regulatory functions, but there are also instances of apparent regulatory redundancy between sibling sRNAs. This review provides a comprehensive overview of the current knowledge of bacterial sibling sRNAs, and also discusses important questions about the significance and evolutionary implications of this emerging class of regulators.

  3. Few items in the thyroid-related quality of life instrument ThyPRO exhibited differential item functioning

    DEFF Research Database (Denmark)

    Watt, Torquil; Grønvold, Mogens; Hegedüs, Laszlo

    2014-01-01

    To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis.......To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis....

  4. Pentameric ligand-gated ion channels exhibit distinct transmembrane domain archetypes for folding/expression and function.

    Science.gov (United States)

    Therien, J P Daniel; Baenziger, John E

    2017-03-27

    Although transmembrane helix-helix interactions must be strong enough to drive folding, they must still permit the inter-helix movements associated with conformational change. Interactions between the outermost M4 and adjacent M1 and M3 α-helices of pentameric ligand-gated ion channels have been implicated in folding and function. Here, we evaluate the role of different physical interactions at this interface in the function of two prokaryotic homologs, GLIC and ELIC. Strikingly, disruption of most interactions in GLIC lead to either a reduction or a complete loss of expression and/or function, while analogous disruptions in ELIC often lead to gains in function. Structural comparisons suggest that GLIC and ELIC represent distinct transmembrane domain archetypes. One archetype, exemplified by GLIC, the glycine and GABA receptors and the glutamate activated chloride channel, has extensive aromatic contacts that govern M4-M1/M3 interactions and that are essential for expression and function. The other archetype, exemplified by ELIC and both the nicotinic acetylcholine and serotonin receptors, has relatively few aromatic contacts that are detrimental to function. These archetypes likely have evolved different mechanisms to balance the need for strong M4 "binding" to M1/M3 to promote folding/expression, and the need for weaker interactions that allow for greater conformational flexibility.

  5. Redundant arrays of IDE drives

    Energy Technology Data Exchange (ETDEWEB)

    D.A. Sanders et al.

    2002-01-02

    The authors report tests of redundant arrays of IDE disk drives for use in offline high energy physics data analysis. Parts costs of total systems using commodity EIDE disks are now at the $4000 per Terabyte level. Disk storage prices have now decreased to the point where they equal the cost per Terabyte of Storage Technology tape silos. The disks, however, offer far better granularity; even small institutions can afford to deploy systems. The tests include reports on software RAID-5 systems running under Linux 2.4 using Promise Ultra 100{trademark} disk controllers. RAID-5 protects data in case of a single disk failure by providing parity bits. Tape backup is not required. Journaling file systems are used to allow rapid recovery from crashes. The data analysis strategy is to encapsulate data and CPU processing power. Analysis for a particular part of a data set takes place on the PC where the data resides. The network is only used to put results together. They explore three methods of moving data between sites; internet transfers, not pluggable IDE disks in FireWire cases, and DVD-R disks.

  6. Redundant arrays of IDE drives

    International Nuclear Information System (INIS)

    Sanders, D.A.

    2002-01-01

    The authors report tests of redundant arrays of IDE disk drives for use in offline high energy physics data analysis. Parts costs of total systems using commodity EIDE disks are now at the $4000 per Terabyte level. Disk storage prices have now decreased to the point where they equal the cost per Terabyte of Storage Technology tape silos. The disks, however, offer far better granularity; even small institutions can afford to deploy systems. The tests include reports on software RAID-5 systems running under Linux 2.4 using Promise Ultra 100trademark disk controllers. RAID-5 protects data in case of a single disk failure by providing parity bits. Tape backup is not required. Journaling file systems are used to allow rapid recovery from crashes. The data analysis strategy is to encapsulate data and CPU processing power. Analysis for a particular part of a data set takes place on the PC where the data resides. The network is only used to put results together. They explore three methods of moving data between sites; internet transfers, not pluggable IDE disks in FireWire cases, and DVD-R disks

  7. The Interface Between Redundant Processor Modules Of Safety Grade PLC Using Mass Storage DPRAM

    International Nuclear Information System (INIS)

    Hwang, Sung Jae; Song, Seong Hwan; No, Young Hun; Yun, Dong Hwa; Park, Gang Min; Kim, Min Gyu; Choi, Kyung Chul; Lee, Ui Taek

    2010-01-01

    Processor module of safety grade PLC (hereinafter called as POSAFE-Q) developed by POSCO ICT provides high reliability and safety. However, POSAFEQ would have suffered a malfunction when we think taking place of abnormal operation by exceptional environmental. POSAFE-Q would not able to conduct its function normally in such case. To prevent these situations, the necessity of redundant processor module has been raised. Therefore, redundant processor module, NCPU-2Q, has been developed which has not only functions of single processor module with high reliability and safety but also functions of redundant processor

  8. The EORTC computer-adaptive tests measuring physical functioning and fatigue exhibited high levels of measurement precision and efficiency

    DEFF Research Database (Denmark)

    Petersen, Morten Aa; Aaronson, Neil K; Arraras, Juan I

    2013-01-01

    The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is developing a computer-adaptive test (CAT) version of the EORTC Quality of Life Questionnaire (QLQ-C30). We evaluated the measurement properties of the CAT versions of physical functioning (PF...

  9. The EORTC computer-adaptive tests measuring physical functioning and fatigue exhibited high levels of measurement precision and efficiency

    NARCIS (Netherlands)

    Petersen, M.A.; Aaronson, N.K.; Arraras, J.I.; Chie, W.C.; Conroy, T.; Constantini, A.; Giesinger, J.M.; Holzner, B.; King, M.T.; Singer, S.; Velikova, G.; Verdonck-de Leeuw, I.M.; Young, T.; Groenvold, M.

    2013-01-01

    Objectives The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is developing a computer-adaptive test (CAT) version of the EORTC Quality of Life Questionnaire (QLQ-C30). We evaluated the measurement properties of the CAT versions of physical functioning (PF)

  10. The EORTC computer-adaptive tests measuring physical functioning and fatigue exhibited high levels of measurement precision and efficiency

    NARCIS (Netherlands)

    Petersen, M.A.; Aaronson, N.K.; Arraras, J.I.; Chie, W.C.; Conroy, T.; Costantini, A.; Giesinger, J.M.; Holzner, B.; King, M.T.; Singer, S.; Velikova, G.; de Leeuw, I.M.; Young, T.; Groenvold, M.

    2013-01-01

    Objectives: The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is developing a computer-adaptive test (CAT) version of the EORTC Quality of Life Questionnaire (QLQ-C30). We evaluated the measurement properties of the CAT versions of physical functioning (PF)

  11. Murine epidermal Langerhans cells and langerin-expressing dermal dendritic cells are unrelated and exhibit distinct functions

    NARCIS (Netherlands)

    Nagao, Keisuke; Ginhoux, Florent; Leitner, Wolfgang W.; Motegi, Sei-Ichiro; Bennett, Clare L.; Clausen, Björn E.; Merad, Miriam; Udey, Mark C.

    2009-01-01

    A new langerin(+) DC subset has recently been identified in murine dermis (langerin(+) dDC), but the lineage and functional relationships between these cells and langerin(+) epidermal Langerhans cells (LC) are incompletely characterized. Selective expression of the cell adhesion molecule EpCAM by LC

  12. The bliss (not the problem) of motor abundance (not redundancy).

    Science.gov (United States)

    Latash, Mark L

    2012-03-01

    Motor control is an area of natural science exploring how the nervous system interacts with other body parts and the environment to produce purposeful, coordinated actions. A central problem of motor control-the problem of motor redundancy-was formulated by Nikolai Bernstein as the problem of elimination of redundant degrees-of-freedom. Traditionally, this problem has been addressed using optimization methods based on a variety of cost functions. This review draws attention to a body of recent findings suggesting that the problem has been formulated incorrectly. An alternative view has been suggested as the principle of abundance, which considers the apparently redundant degrees-of-freedom as useful and even vital for many aspects of motor behavior. Over the past 10 years, dozens of publications have provided support for this view based on the ideas of synergic control, computational apparatus of the uncontrolled manifold hypothesis, and the equilibrium-point (referent configuration) hypothesis. In particular, large amounts of "good variance"-variance in the space of elements that has no effect on the overall performance-have been documented across a variety of natural actions. "Good variance" helps an abundant system to deal with secondary tasks and unexpected perturbations; its amount shows adaptive modulation across a variety of conditions. These data support the view that there is no problem of motor redundancy; there is bliss of motor abundance.

  13. A redundancy-removing feature selection algorithm for nominal data

    Directory of Open Access Journals (Sweden)

    Zhihua Li

    2015-10-01

    Full Text Available No order correlation or similarity metric exists in nominal data, and there will always be more redundancy in a nominal dataset, which means that an efficient mutual information-based nominal-data feature selection method is relatively difficult to find. In this paper, a nominal-data feature selection method based on mutual information without data transformation, called the redundancy-removing more relevance less redundancy algorithm, is proposed. By forming several new information-related definitions and the corresponding computational methods, the proposed method can compute the information-related amount of nominal data directly. Furthermore, by creating a new evaluation function that considers both the relevance and the redundancy globally, the new feature selection method can evaluate the importance of each nominal-data feature. Although the presented feature selection method takes commonly used MIFS-like forms, it is capable of handling high-dimensional datasets without expensive computations. We perform extensive experimental comparisons of the proposed algorithm and other methods using three benchmarking nominal datasets with two different classifiers. The experimental results demonstrate the average advantage of the presented algorithm over the well-known NMIFS algorithm in terms of the feature selection and classification accuracy, which indicates that the proposed method has a promising performance.

  14. Redundant correlation effect on personalized recommendation

    Science.gov (United States)

    Qiu, Tian; Han, Teng-Yue; Zhong, Li-Xin; Zhang, Zi-Ke; Chen, Guang

    2014-02-01

    The high-order redundant correlation effect is investigated for a hybrid algorithm of heat conduction and mass diffusion (HHM), through both heat conduction biased (HCB) and mass diffusion biased (MDB) correlation redundancy elimination processes. The HCB and MDB algorithms do not introduce any additional tunable parameters, but keep the simple character of the original HHM. Based on two empirical datasets, the Netflix and MovieLens, the HCB and MDB are found to show better recommendation accuracy for both the overall objects and the cold objects than the HHM algorithm. Our work suggests that properly eliminating the high-order redundant correlations can provide a simple and effective approach to accurate recommendation.

  15. 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

  16. Exploiting Redundancy in an OFDM SDR Receiver

    Directory of Open Access Journals (Sweden)

    Tomas Palenik

    2009-01-01

    Full Text Available Common OFDM system contains redundancy necessary to mitigate interblock interference and allows computationally effective single-tap frequency domain equalization in receiver. Assuming the system implements an outer error correcting code and channel state information is available in the receiver, we show that it is possible to understand the cyclic prefix insertion as a weak inner ECC encoding and exploit the introduced redundancy to slightly improve error performance of such a system. In this paper, an easy way to implement modification to an existing SDR OFDM receiver is presented. This modification enables the utilization of prefix redundancy, while preserving full compatibility with existing OFDM-based communication standards.

  17. Online Exhibits & Concept Maps

    Science.gov (United States)

    Douma, M.

    2009-12-01

    Presenting the complexity of geosciences to the public via the Internet poses a number of challenges. For example, utilizing various - and sometimes redundant - Web 2.0 tools can quickly devour limited time. Do you tweet? Do you write press releases? Do you create an exhibit or concept map? The presentation will provide participants with a context for utilizing Web 2.0 tools by briefly highlighting methods of online scientific communication across several dimensions. It will address issues of: * breadth and depth (e.g. from narrow topics to well-rounded views), * presentation methods (e.g. from text to multimedia, from momentary to enduring), * sources and audiences (e.g. for experts or for the public, content developed by producers to that developed by users), * content display (e.g. from linear to non-linear, from instructive to entertaining), * barriers to entry (e.g. from an incumbent advantage to neophyte accessible, from amateur to professional), * cost and reach (e.g. from cheap to expensive), and * impact (e.g. the amount learned, from anonymity to brand awareness). Against this backdrop, the presentation will provide an overview of two methods of online information dissemination, exhibits and concept maps, using the WebExhibits online museum (www.webexhibits.org) and SpicyNodes information visualization tool (www.spicynodes.org) as examples, with tips on how geoscientists can use either to communicate their science. Richly interactive online exhibits can serve to engage a large audience, appeal to visitors with multiple learning styles, prompt exploration and discovery, and present a topic’s breadth and depth. WebExhibits, which was among the first online museums, delivers interactive information, virtual experiments, and hands-on activities to the public. While large, multidisciplinary exhibits on topics like “Color Vision and Art” or “Calendars Through the Ages” require teams of scholars, user interface experts, professional writers and editors

  18. Does plant species richness guarantee the resilience of local medical systems? A perspective from utilitarian redundancy.

    Directory of Open Access Journals (Sweden)

    Flávia Rosa Santoro

    Full Text Available Resilience is related to the ability of a system to adjust to disturbances. The Utilitarian Redundancy Model has emerged as a tool for investigating the resilience of local medical systems. The model determines the use of species richness for the same therapeutic function as a facilitator of the maintenance of these systems. However, predictions generated from this model have not yet been tested, and a lack of variables exists for deeper analyses of resilience. This study aims to address gaps in the Utilitarian Redundancy Model and to investigate the resilience of two medical systems in the Brazilian semi-arid zone. As a local illness is not always perceived in the same way that biomedicine recognizes, the term "therapeutic targets" is used for perceived illnesses. Semi-structured interviews with local experts were conducted using the free-listing technique to collect data on known medicinal plants, usage preferences, use of redundant species, characteristics of therapeutic targets, and the perceived severity for each target. Additionally, participatory workshops were conducted to determine the frequency of targets. The medical systems showed high species richness but low levels of species redundancy. However, if redundancy was present, it was the primary factor responsible for the maintenance of system functions. Species richness was positively associated with therapeutic target frequencies and negatively related to target severity. Moreover, information about redundant species seems to be largely idiosyncratic; this finding raises questions about the importance of redundancy for resilience. We stress the Utilitarian Redundancy Model as an interesting tool to be used in studies of resilience, but we emphasize that it must consider the distribution of redundancy in terms of the treatment of important illnesses and the sharing of information. This study has identified aspects of the higher and lower vulnerabilities of medical systems, adding

  19. Image Registration Using Redundant Wavelet Transforms

    National Research Council Canada - National Science Library

    Brown, Richard

    2001-01-01

    .... In our research, we present a fundamentally new wavelet-based registration algorithm utilizing redundant transforms and a masking process to suppress the adverse effects of noise and improve processing efficiency...

  20. The Effects of Race Conditions When Implementing Single-Source Redundant Clock Trees in Triple Modular Redundant Synchronous Architectures

    Science.gov (United States)

    Berg, Melanie D.; Kim, Hak S.; Phan, Anthony M.; Seidleck, Christina M.; Label, Kenneth A.; Pellish, Jonathan A.; Campola, Michael J.

    2016-01-01

    We present the challenges that arise when using redundant clock domains due to their time-skew. Radiation data show that a singular clock domain provides an improved triple modular redundant (TMR) scheme over redundant clocks.

  1. Th17 Cells Exhibit Antitumor Effects in MDS Possibly through Augmenting Functions of CD8+ T Cells.

    Science.gov (United States)

    Li, Jing; Yue, Lanzhu; Wang, Huaquan; Liu, Chunyan; Liu, Hui; Tao, Jinglian; Qi, Weiwei; Wang, Yihao; Zhang, Wei; Fu, Rong; Shao, Zonghong

    2016-01-01

    Th17 cells are a newly found subset of distinct CD4+ Th effector cells' family and are found to play an important role in cancers. Myelodysplastic syndromes (MDS) are a common malignant hematological disease. Here, we showed that both the percentage and the function of Th17 cells were elevated in low-risk MDS while being decreased in high-risk MDS. Levels of upstream molecules of Th17 cells, IL-6 and IL-23, were higher in low-risk MDS but lower in high-risk MDS patients. The abnormal percentage of Th17 cells was closely related to clinical parameters including karyotype, morphologic blast percentage of bone marrow, peripheral absolute neutrophil count, and hemoglobin concentration. Furthermore, expression rates of perforin and granzyme B in BM CD3+CD8+ cells (cytotoxic T lymphocyte, CTL) positively correlated with levels of IL-17 but negatively correlated with BM blast percentage and could be significantly increased after stimulation with human recombinant IL-17 (rhIL-17). Our results suggested that Th17 cells might play an antitumor effect in the pathogenesis of MDS through IL-17/CTL pathway.

  2. Redundancy for electric motors in spacecraft applications

    Science.gov (United States)

    Smith, Robert J.; Flew, Alastair R.

    1986-01-01

    The parts of electric motors which should be duplicated in order to provide maximum reliability in spacecraft application are identified. Various common types of redundancy are described. The advantages and disadvantages of each are noted. The principal types are illustrated by reference to specific examples. For each example, constructional details, basic performance data and failure modes are described, together with a discussion of the suitability of particular redundancy techniques to motor types.

  3. Dynamic Control of Kinematically Redundant Robotic Manipulators

    Directory of Open Access Journals (Sweden)

    Erling Lunde

    1987-07-01

    Full Text Available Several methods for task space control of kinematically redundant manipulators have been proposed in the literature. Most of these methods are based on a kinematic analysis of the manipulator. In this paper we propose a control algorithm in which we are especially concerned with the manipulator dynamics. The algorithm is particularly well suited for the class of redundant manipulators consisting of a relatively small manipulator mounted on a larger positioning part.

  4. Few items in the thyroid-related quality of life instrument ThyPRO exhibited differential item functioning.

    Science.gov (United States)

    Watt, Torquil; Groenvold, Mogens; Hegedüs, Laszlo; Bonnema, Steen Joop; Rasmussen, Åse Krogh; Feldt-Rasmussen, Ulla; Bjorner, Jakob Bue

    2014-02-01

    To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis. A total of 838 patients with benign thyroid diseases completed the ThyPRO questionnaire (84 five-point items, 13 scales). Uniform and nonuniform DIF were investigated using ordinal logistic regression, testing for both statistical significance and magnitude (∆R(2) > 0.02). Scale level was estimated by the sum score, after purification. Twenty instances of DIF in 17 of the 84 items were found. Eight according to diagnosis, where the goiter scale was the one most affected, possibly due to differing perceptions in patients with auto-immune thyroid diseases compared to patients with simple goiter. Eight DIFs according to age were found, of which 5 were in positively worded items, which younger patients were more likely to endorse; one according to gender: women were more likely to report crying, and three according to educational level. The vast majority of DIF had only minor influence on the scale scores (0.1-2.3 points on the 0-100 scales), but two DIF corresponded to a difference of 4.6 and 9.8, respectively. Ordinal logistic regression identified DIF in 17 of 84 items. The potential impact of this on the present scales was low, but items displaying DIF could be avoided when developing abbreviated scales, where the potential impact of DIF (due to fewer items) will be larger.

  5. How Redundant Are Redundant Color Adjectives? An Efficiency-Based Analysis of Color Overspecification

    OpenAIRE

    Rubio-Fern?ndez, Paula

    2016-01-01

    Color adjectives tend to be used redundantly in referential communication. I propose that redundant color adjectives are often intended to exploit a color contrast in the visual context and hence facilitate object identification, despite not being necessary to establish unique reference. Two language-production experiments investigated two types of factors that may affect the use of redundant color adjectives: factors related to the efficiency of color in the visual context and factors relate...

  6. Case studies in configuration control for redundant robots

    Science.gov (United States)

    Seraji, H.; Lee, T.; Colbaugh, R.; Glass, K.

    1989-01-01

    A simple approach to configuration control of redundant robots is presented. The redundancy is utilized to control the robot configuration directly in task space, where the task will be performed. A number of task-related kinematic functions are defined and combined with the end-effector coordinates to form a set of configuration variables. An adaptive control scheme is then utilized to ensure that the configuration variables track the desired reference trajectories as closely as possible. Simulation results are presented to illustrate the control scheme. The scheme has also been implemented for direct online control of a PUMA industrial robot, and experimental results are presented. The simulation and experimental results validate the configuration control scheme for performing various realistic tasks.

  7. An efficient simulated annealing algorithm for the redundancy allocation problem with a choice of redundancy strategies

    International Nuclear Information System (INIS)

    Chambari, Amirhossain; Najafi, Amir Abbas; Rahmati, Seyed Habib A.; Karimi, Aida

    2013-01-01

    The redundancy allocation problem (RAP) is an important reliability optimization problem. This paper studies a specific RAP in which redundancy strategies are chosen. To do so, the choice of the redundancy strategies among active and cold standby is considered as decision variables. The goal is to select the redundancy strategy, component, and redundancy level for each subsystem such that the system reliability is maximized. Since RAP is a NP-hard problem, we propose an efficient simulated annealing algorithm (SA) to solve it. In addition, to evaluating the performance of the proposed algorithm, it is compared with well-known algorithms in the literature for different test problems. The results of the performance analysis show a relatively satisfactory efficiency of the proposed SA algorithm

  8. Extracts Obtained from Pterocarpus angolensis DC and Ziziphus mucronata Exhibit Antiplasmodial Activity and Inhibit Heat Shock Protein 70 (Hsp70 Function

    Directory of Open Access Journals (Sweden)

    Tawanda Zininga

    2017-07-01

    Full Text Available Malaria parasites are increasingly becoming resistant to currently used antimalarial therapies, therefore there is an urgent need to expand the arsenal of alternative antimalarial drugs. In addition, it is also important to identify novel antimalarial drug targets. In the current study, extracts of two plants, Pterocarpus angolensis and Ziziphus mucronata were obtained and their antimalarial functions were investigated. Furthermore, we explored the capability of the extracts to inhibit Plasmodium falciparum heat shock protein 70 (Hsp70 function. Heat shock protein 70 (Hsp70 are molecular chaperones whose function is to facilitate protein folding. Plasmodium falciparum the main agent of malaria, expresses two cytosol-localized Hsp70s: PfHsp70-1 and PfHsp70-z. The PfHsp70-z has been reported to be essential for parasite survival, while inhibition of PfHsp70-1 function leads to parasite death. Hence both PfHsp70-1 and PfHsp70-z are potential antimalarial drug targets. Extracts of P. angolensis and Z. mucronata inhibited the basal ATPase and chaperone functions of the two parasite Hsp70s. Furthermore, fractions of P. angolensis and Z. mucronata inhibited P. falciparum 3D7 parasite growth in vitro. The extracts obtained in the current study exhibited antiplasmodial activity as they killed P. falciparum parasites maintained in vitro. In addition, the findings further suggest that some of the compounds in P. angolensis and Z. mucronata may target parasite Hsp70 function.

  9. Interaction control of a redundant mobile manipulator

    International Nuclear Information System (INIS)

    Chung, J.H.; Velinsky, S.A.; Hess, R.A.

    1998-01-01

    This paper discusses the modeling and control of a spatial mobile manipulator that consists of a robotic manipulator mounted on a wheeled mobile platform. The Lagrange-d'Alembert formulation is used to obtain a concise description of the dynamics of the system, which is subject to nonholonomic constraints. The complexity of the model is increased by introducing kinematic redundancy, which is created when a multilinked manipulator is used. The kinematic redundancy is resolved by decomposing the mobile manipulator into two subsystems: the mobile platform and the manipulator. The redundancy resolution scheme employs a nonlinear interaction-control algorithm, which is developed and applied to coordinate the two subsystems' controllers. The subsystem controllers are independently designed, based on each subsystem's dynamic characteristics. Simulation results show the promise of the developed algorithm

  10. Self-Healing Networks: Redundancy and Structure

    Science.gov (United States)

    Quattrociocchi, Walter; Caldarelli, Guido; Scala, Antonio

    2014-01-01

    We introduce the concept of self-healing in the field of complex networks modelling; in particular, self-healing capabilities are implemented through distributed communication protocols that exploit redundant links to recover the connectivity of the system. We then analyze the effect of the level of redundancy on the resilience to multiple failures; in particular, we measure the fraction of nodes still served for increasing levels of network damages. Finally, we study the effects of redundancy under different connectivity patterns—from planar grids, to small-world, up to scale-free networks—on healing performances. Small-world topologies show that introducing some long-range connections in planar grids greatly enhances the resilience to multiple failures with performances comparable to the case of the most resilient (and least realistic) scale-free structures. Obvious applications of self-healing are in the important field of infrastructural networks like gas, power, water, oil distribution systems. PMID:24533065

  11. Motion compensation via redundant-wavelet multihypothesis.

    Science.gov (United States)

    Fowler, James E; Cui, Suxia; Wang, Yonghui

    2006-10-01

    Multihypothesis motion compensation has been widely used in video coding with previous attention focused on techniques employing predictions that are diverse spatially or temporally. In this paper, the multihypothesis concept is extended into the transform domain by using a redundant wavelet transform to produce multiple predictions that are diverse in transform phase. The corresponding multiple-phase inverse transform implicitly combines the phase-diverse predictions into a single spatial-domain prediction for motion compensation. The performance advantage of this redundant-wavelet-multihypothesis approach is investigated analytically, invoking the fact that the multiple-phase inverse involves a projection that significantly reduces the power of a dense-motion residual modeled as additive noise. The analysis shows that redundant-wavelet multihypothesis is capable of up to a 7-dB reduction in prediction-residual variance over an equivalent single-phase, single-hypothesis approach. Experimental results substantiate the performance advantage for a block-based implementation.

  12. Redundancy in Anaerobic Digestion Microbiomes during Disturbances by the Antibiotic Monensin

    Science.gov (United States)

    Spirito, Catherine M.; Daly, Sarah E.; Werner, Jeffrey J.

    2018-01-01

    ABSTRACT The antibiotic monensin is fed to dairy cows to increase milk production efficiency. A fraction of this monensin is excreted into the cow manure. Previous studies have found that cow manure containing monensin can negatively impact the performance of anaerobic digesters, especially upon first introduction. Few studies have examined whether the anaerobic digester microbiome can adapt to monensin during the operating time. Here, we conducted a long-term time series study of four lab-scale anaerobic digesters fed with cow manure. We examined changes in both the microbiome composition and function of the anaerobic digesters when subjected to the dairy antibiotic monensin. In our digesters, monensin was not rapidly degraded under anaerobic conditions. The two anaerobic digesters that were subjected to manure from monensin feed-dosed cows exhibited relatively small changes in microbiome composition and function due to relatively low monensin concentrations. At higher concentrations of monensin, which we dosed directly to control manure (from dairy cows without monensin), we observed major changes in the microbiome composition and function of two anaerobic digesters. A rapid introduction of monensin to one of these anaerobic digesters led to the impairment of methane production. Conversely, more gradual additions of the same concentrations of monensin to the other anaerobic digester led to the adaptation of the anaerobic digester microbiomes to the relatively high monensin concentrations. A member of the candidate OP11 (Microgenomates) phylum arose in this anaerobic digester and appeared to be redundant with certain Bacteroidetes phylum members, which previously were dominating. IMPORTANCE Monensin is a common antibiotic given to dairy cows in the United States and is partly excreted with dairy manure. An improved understanding of how monensin affects the anaerobic digester microbiome composition and function is important to prevent process failure for farm

  13. A control method for manipulators with redundancy

    International Nuclear Information System (INIS)

    Furusho, Junji; Usui, Hiroyuki

    1989-01-01

    Redundant manipulators have more ability than nonredundant ones in many aspects such as avoiding obstacles, avoiding singular states, etc. In this paper, a control algorithm for redundant manipulators working under the circumstance in the presence of obstacles is presented. First, the measure of manipulability for robot manipulators under obstacle circumstances is defined. Then, the control algorithm for the obstacle avoidance is derived by using this measure of manipulability. The obstacle avoidance and the maintenance of good posture are simultaneously achieved by this algorithm. Lastly, an experiment and simulation results using an eight degree of freedom manipulator are shown. (author)

  14. Redundancy Elimination in DTN via ACK Mechanism

    Directory of Open Access Journals (Sweden)

    Xiqing Zhang

    2015-08-01

    Full Text Available The traditional routing protocols for delay tolerant networks (DTN usually take the strategy of spreading multiple copies of one message to the networks. When one copy reaches destination, the transmission of other copies not only waste the bandwidth but also deprive other messages of the opportunities for transmission. This paper brings up a mechanism to eliminate the redundant copies. By adding an acknowledge field to the packet header to delete redundant copies, it can degrade the network overhead while improve the delivery ratio. Simulation results confirm that the proposed method can improve the performance of epidemic and Spray and Wait routing protocol.

  15. Superlinearly scalable noise robustness of redundant coupled dynamical systems.

    Science.gov (United States)

    Kohar, Vivek; Kia, Behnam; Lindner, John F; Ditto, William L

    2016-03-01

    We illustrate through theory and numerical simulations that redundant coupled dynamical systems can be extremely robust against local noise in comparison to uncoupled dynamical systems evolving in the same noisy environment. Previous studies have shown that the noise robustness of redundant coupled dynamical systems is linearly scalable and deviations due to noise can be minimized by increasing the number of coupled units. Here, we demonstrate that the noise robustness can actually be scaled superlinearly if some conditions are met and very high noise robustness can be realized with very few coupled units. We discuss these conditions and show that this superlinear scalability depends on the nonlinearity of the individual dynamical units. The phenomenon is demonstrated in discrete as well as continuous dynamical systems. This superlinear scalability not only provides us an opportunity to exploit the nonlinearity of physical systems without being bogged down by noise but may also help us in understanding the functional role of coupled redundancy found in many biological systems. Moreover, engineers can exploit superlinear noise suppression by starting a coupled system near (not necessarily at) the appropriate initial condition.

  16. Analysis of informational redundancy in the protein-assembling machinery

    Science.gov (United States)

    Berkovich, Simon

    2004-03-01

    Entropy analysis of the DNA structure does not reveal a significant departure from randomness indicating lack of informational redundancy. This signifies the absence of a hidden meaning in the genome text and supports the 'barcode' interpretation of DNA given in [1]. Lack of informational redundancy is a characteristic property of an identification label rather than of a message of instructions. Yet randomness of DNA has to induce non-random structures of the proteins. Protein synthesis is a two-step process: transcription into RNA with gene splicing and formation a structure of amino acids. Entropy estimations, performed by A. Djebbari, show typical values of redundancy of the biomolecules along these pathways: DNA gene 4proteins 15-40in gene expression, the RNA copy carries the same information as the original DNA template. Randomness is essentially eliminated only at the step of the protein creation by a degenerate code. According to [1], the significance of the substitution of U for T with a subsequent gene splicing is that these transformations result in a different pattern of RNA oscillations, so the vital DNA communications are protected against extraneous noise coming from the protein making activities. 1. S. Berkovich, "On the 'barcode' functionality of DNA, or the Phenomenon of Life in the Physical Universe", Dorrance Publishing Co., Pittsburgh, 2003

  17. Analysis of singularity in redundant manipulators

    International Nuclear Information System (INIS)

    Watanabe, Koichi

    2000-03-01

    In the analysis of arm positions and configurations of redundant manipulators, the singularity avoidance problems are important themes. This report presents singularity avoidance computations of a 7 DOF manipulator by using a computer code based on human-arm models. The behavior of the arm escaping from the singular point can be identified satisfactorily through the use of 3-D plotting tools. (author)

  18. Coded aperture imaging with uniformly redundant arrays

    International Nuclear Information System (INIS)

    Fenimore, E.E.; Cannon, T.M.

    1980-01-01

    A system is described which uses uniformly redundant arrays to image non-focusable radiation. The array is used in conjunction with a balanced correlation technique to provide a system with no artifacts so that virtually limitless signal-to-noise ratio is obtained with high transmission characteristics. The array is mosaicked to reduce required detector size over conventional array detectors. 15 claims

  19. On Redundancy in Describing Linguistic Systems

    Directory of Open Access Journals (Sweden)

    Vladimir Borissov Pericliev

    2015-12-01

    Full Text Available On Redundancy in Describing Linguistic Systems The notion of system of linguistic elements figures prominently in most post-Saussurian linguistics up to the present. A “system” is the network of the contrastive (or, distinctive features each element in the system bears to the remaining elements. The meaning (valeur of each element in the system is the set of features that are necessary and jointly sufficient to distinguish this element from all others. The paper addresses the problems of “redundancy”, i.e. the occurrence of features that are not strictly necessary in describing an element in a system. Redundancy is shown to smuggle into the description of linguistic systems, this infelicitous practice illustrated with some examples from the literature (e.g. the classical phonemic analysis of Russian by Cherry, Halle, and Jakobson, 1953. The logic and psychology of the occurrence of redundancy are briefly sketched and it is shown that, in addition to some other problems, redundancy leads to a huge and unresolvable ambiguity of descriptions of linguistic systems (the Buridan’s ass problem.

  20. Impedance Control of a Redundant Parallel Manipulator

    DEFF Research Database (Denmark)

    Méndez, Juan de Dios Flores; Schiøler, Henrik; Madsen, Ole

    2017-01-01

    This paper presents the design of Impedance Control to a redundantly actuated Parallel Kinematic Manipulator. The proposed control is based on treating each limb as a single system and their connection through the internal interaction forces. The controller introduces a stiffness and damping...

  1. REDUNDANT ARRAY CONFIGURATIONS FOR 21 cm COSMOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, Joshua S.; Parsons, Aaron R., E-mail: jsdillon@berkeley.edu [Department of Astronomy, UC Berkeley, Berkeley, CA (United States)

    2016-08-01

    Realizing the potential of 21 cm tomography to statistically probe the intergalactic medium before and during the Epoch of Reionization requires large telescopes and precise control of systematics. Next-generation telescopes are now being designed and built to meet these challenges, drawing lessons from first-generation experiments that showed the benefits of densely packed, highly redundant arrays—in which the same mode on the sky is sampled by many antenna pairs—for achieving high sensitivity, precise calibration, and robust foreground mitigation. In this work, we focus on the Hydrogen Epoch of Reionization Array (HERA) as an interferometer with a dense, redundant core designed following these lessons to be optimized for 21 cm cosmology. We show how modestly supplementing or modifying a compact design like HERA’s can still deliver high sensitivity while enhancing strategies for calibration and foreground mitigation. In particular, we compare the imaging capability of several array configurations, both instantaneously (to address instrumental and ionospheric effects) and with rotation synthesis (for foreground removal). We also examine the effects that configuration has on calibratability using instantaneous redundancy. We find that improved imaging with sub-aperture sampling via “off-grid” antennas and increased angular resolution via far-flung “outrigger” antennas is possible with a redundantly calibratable array configuration.

  2. Intraguild predation reduces redundancy of predator species in multiple predator assemblage.

    Science.gov (United States)

    Griffen, Blaine D; Byers, James E

    2006-07-01

    1. Interference between predator species frequently decreases predation rates, lowering the risk of predation for shared prey. However, such interference can also occur between conspecific predators. 2. Therefore, to understand the importance of predator biodiversity and the degree that predator species can be considered functionally interchangeable, we determined the degree of additivity and redundancy of predators in multiple- and single-species combinations. 3. We show that interference between two invasive species of predatory crabs, Carcinus maenas and Hemigrapsus sanguineus, reduced the risk of predation for shared amphipod prey, and had redundant per capita effects in most multiple- and single-species predator combinations. 4. However, when predator combinations with the potential for intraguild predation were examined, predator interference increased and predator redundancy decreased. 5. Our study indicates that trophic structure is important in determining how the effects of predator species combine and demonstrates the utility of determining the redundancy, as well as the additivity, of multiple predator species.

  3. Practical, redundant, failure-tolerant, self-reconfiguring embedded system architecture

    Science.gov (United States)

    Klarer, Paul R.; Hayward, David R.; Amai, Wendy A.

    2006-10-03

    This invention relates to system architectures, specifically failure-tolerant and self-reconfiguring embedded system architectures. The invention provides both a method and architecture for redundancy. There can be redundancy in both software and hardware for multiple levels of redundancy. The invention provides a self-reconfiguring architecture for activating redundant modules whenever other modules fail. The architecture comprises: a communication backbone connected to two or more processors and software modules running on each of the processors. Each software module runs on one processor and resides on one or more of the other processors to be available as a backup module in the event of failure. Each module and backup module reports its status over the communication backbone. If a primary module does not report, its backup module takes over its function. If the primary module becomes available again, the backup module returns to its backup status.

  4. Beyond redundancy how geographic redundancy can improve service availability and reliability of computer-based systems

    CERN Document Server

    Bauer, Eric; Eustace, Dan

    2012-01-01

    "While geographic redundancy can obviously be a huge benefit for disaster recovery, it is far less obvious what benefit is feasible and likely for more typical non-catastrophic hardware, software, and human failures. Georedundancy and Service Availability provides both a theoretical and practical treatment of the feasible and likely benefits of geographic redundancy for both service availability and service reliability. The text provides network/system planners, IS/IT operations folks, system architects, system engineers, developers, testers, and other industry practitioners with a general discussion about the capital expense/operating expense tradeoff that frames system redundancy and georedundancy"--

  5. The naked mole-rat exhibits an unusual cardiac myofilament protein profile providing new insights into heart function of this naturally subterranean rodent.

    Science.gov (United States)

    Grimes, Kelly M; Barefield, David Y; Kumar, Mohit; McNamara, James W; Weintraub, Susan T; de Tombe, Pieter P; Sadayappan, Sakthivel; Buffenstein, Rochelle

    2017-12-01

    The long-lived, hypoxic-tolerant naked mole-rat well-maintains cardiac function over its three-decade-long lifespan and exhibits many cardiac features atypical of similar-sized laboratory rodents. For example, they exhibit low heart rates and resting cardiac contractility, yet have a large cardiac reserve. These traits are considered ecophysiological adaptations to their dank subterranean atmosphere of low oxygen and high carbon dioxide levels and may also contribute to negligible declines in cardiac function during aging. We asked if naked mole-rats had a different myofilament protein signature to that of similar-sized mice that commonly show both high heart rates and high basal cardiac contractility. Adult mouse ventricles predominantly expressed α-myosin heavy chain (97.9 ± 0.4%). In contrast, and more in keeping with humans, β myosin heavy chain was the dominant isoform (79.0 ± 2.0%) in naked mole-rat ventricles. Naked mole-rat ventricles diverged from those of both humans and mice, as they expressed both cardiac and slow skeletal isoforms of troponin I. This myofilament protein profile is more commonly observed in mice in utero and during cardiomyopathies. There were no species differences in phosphorylation of cardiac myosin binding protein-C or troponin I. Phosphorylation of both ventricular myosin light chain 2 and cardiac troponin T in naked mole-rats was approximately half that observed in mice. Myofilament function was also compared between the two species using permeabilized cardiomyocytes. Together, these data suggest a cardiac myofilament protein signature that may contribute to the naked mole-rat's suite of adaptations to its natural subterranean habitat.

  6. The Grass Might Be Greener: Medical Marijuana Patients Exhibit Altered Brain Activity and Improved Executive Function after 3 Months of Treatment

    Directory of Open Access Journals (Sweden)

    Staci A. Gruber

    2018-01-01

    Full Text Available The vast majority of states have enacted full or partial medical marijuana (MMJ programs, causing the number of patients seeking certification for MMJ use to increase dramatically in recent years. Despite increased use of MMJ across the nation, no studies thus far have examined the specific impact of MMJ on cognitive function and related brain activation. In the present study, MMJ patients seeking treatment for a variety of documented medical conditions were assessed prior to initiating MMJ treatment and after 3 months of treatment as part of a larger longitudinal study. In order to examine the effect of MMJ treatment on task-related brain activation, MMJ patients completed the Multi-Source Interference Test (MSIT while undergoing functional magnetic resonance imaging (fMRI. We also collected data regarding conventional medication use, clinical state, and health-related measures at each visit. Following 3 months of treatment, MMJ patients demonstrated improved task performance accompanied by changes in brain activation patterns within the cingulate cortex and frontal regions. Interestingly, after MMJ treatment, brain activation patterns appeared more similar to those exhibited by healthy controls from previous studies than at pre-treatment, suggestive of a potential normalization of brain function relative to baseline. These findings suggest that MMJ use may result in different effects relative to recreational marijuana (MJ use, as recreational consumers have been shown to exhibit decrements in task performance accompanied by altered brain activation. Moreover, patients in the current study also reported improvements in clinical state and health-related measures as well as notable decreases in prescription medication use, particularly opioids and benzodiapezines after 3 months of treatment. Further research is needed to clarify the specific neurobiologic impact, clinical efficacy, and unique effects of MMJ for a range of indications and how it

  7. The Grass Might Be Greener: Medical Marijuana Patients Exhibit Altered Brain Activity and Improved Executive Function after 3 Months of Treatment.

    Science.gov (United States)

    Gruber, Staci A; Sagar, Kelly A; Dahlgren, Mary K; Gonenc, Atilla; Smith, Rosemary T; Lambros, Ashley M; Cabrera, Korine B; Lukas, Scott E

    2017-01-01

    The vast majority of states have enacted full or partial medical marijuana (MMJ) programs, causing the number of patients seeking certification for MMJ use to increase dramatically in recent years. Despite increased use of MMJ across the nation, no studies thus far have examined the specific impact of MMJ on cognitive function and related brain activation. In the present study, MMJ patients seeking treatment for a variety of documented medical conditions were assessed prior to initiating MMJ treatment and after 3 months of treatment as part of a larger longitudinal study. In order to examine the effect of MMJ treatment on task-related brain activation, MMJ patients completed the Multi-Source Interference Test (MSIT) while undergoing functional magnetic resonance imaging (fMRI). We also collected data regarding conventional medication use, clinical state, and health-related measures at each visit. Following 3 months of treatment, MMJ patients demonstrated improved task performance accompanied by changes in brain activation patterns within the cingulate cortex and frontal regions. Interestingly, after MMJ treatment, brain activation patterns appeared more similar to those exhibited by healthy controls from previous studies than at pre-treatment, suggestive of a potential normalization of brain function relative to baseline. These findings suggest that MMJ use may result in different effects relative to recreational marijuana (MJ) use, as recreational consumers have been shown to exhibit decrements in task performance accompanied by altered brain activation. Moreover, patients in the current study also reported improvements in clinical state and health-related measures as well as notable decreases in prescription medication use, particularly opioids and benzodiapezines after 3 months of treatment. Further research is needed to clarify the specific neurobiologic impact, clinical efficacy, and unique effects of MMJ for a range of indications and how it compares to

  8. Developmental and environmental regulation of Aquaporin gene expression across Populus species: divergence or redundancy?

    Science.gov (United States)

    Cohen, David; Bogeat-Triboulot, Marie-Béatrice; Vialet-Chabrand, Silvère; Merret, Rémy; Courty, Pierre-Emmanuel; Moretti, Sébastien; Bizet, François; Guilliot, Agnès; Hummel, Irène

    2013-01-01

    Aquaporins (AQPs) are membrane channels belonging to the major intrinsic proteins family and are known for their ability to facilitate water movement. While in Populus trichocarpa, AQP proteins form a large family encompassing fifty-five genes, most of the experimental work focused on a few genes or subfamilies. The current work was undertaken to develop a comprehensive picture of the whole AQP gene family in Populus species by delineating gene expression domain and distinguishing responsiveness to developmental and environmental cues. Since duplication events amplified the poplar AQP family, we addressed the question of expression redundancy between gene duplicates. On these purposes, we carried a meta-analysis of all publicly available Affymetrix experiments. Our in-silico strategy controlled for previously identified biases in cross-species transcriptomics, a necessary step for any comparative transcriptomics based on multispecies design chips. Three poplar AQPs were not supported by any expression data, even in a large collection of situations (abiotic and biotic constraints, temporal oscillations and mutants). The expression of 11 AQPs was never or poorly regulated whatever the wideness of their expression domain and their expression level. Our work highlighted that PtTIP1;4 was the most responsive gene of the AQP family. A high functional divergence between gene duplicates was detected across species and in response to tested cues, except for the root-expressed PtTIP2;3/PtTIP2;4 pair exhibiting 80% convergent responses. Our meta-analysis assessed key features of aquaporin expression which had remained hidden in single experiments, such as expression wideness, response specificity and genotype and environment interactions. By consolidating expression profiles using independent experimental series, we showed that the large expansion of AQP family in poplar was accompanied with a strong divergence of gene expression, even if some cases of functional redundancy

  9. Developmental and environmental regulation of Aquaporin gene expression across Populus species: divergence or redundancy?

    Directory of Open Access Journals (Sweden)

    David Cohen

    Full Text Available Aquaporins (AQPs are membrane channels belonging to the major intrinsic proteins family and are known for their ability to facilitate water movement. While in Populus trichocarpa, AQP proteins form a large family encompassing fifty-five genes, most of the experimental work focused on a few genes or subfamilies. The current work was undertaken to develop a comprehensive picture of the whole AQP gene family in Populus species by delineating gene expression domain and distinguishing responsiveness to developmental and environmental cues. Since duplication events amplified the poplar AQP family, we addressed the question of expression redundancy between gene duplicates. On these purposes, we carried a meta-analysis of all publicly available Affymetrix experiments. Our in-silico strategy controlled for previously identified biases in cross-species transcriptomics, a necessary step for any comparative transcriptomics based on multispecies design chips. Three poplar AQPs were not supported by any expression data, even in a large collection of situations (abiotic and biotic constraints, temporal oscillations and mutants. The expression of 11 AQPs was never or poorly regulated whatever the wideness of their expression domain and their expression level. Our work highlighted that PtTIP1;4 was the most responsive gene of the AQP family. A high functional divergence between gene duplicates was detected across species and in response to tested cues, except for the root-expressed PtTIP2;3/PtTIP2;4 pair exhibiting 80% convergent responses. Our meta-analysis assessed key features of aquaporin expression which had remained hidden in single experiments, such as expression wideness, response specificity and genotype and environment interactions. By consolidating expression profiles using independent experimental series, we showed that the large expansion of AQP family in poplar was accompanied with a strong divergence of gene expression, even if some cases of

  10. Polycomb complexes act redundantly to repress genomic repeats and genes

    DEFF Research Database (Denmark)

    Leeb, Martin; Pasini, Diego; Novatchkova, Maria

    2010-01-01

    Polycomb complexes establish chromatin modifications for maintaining gene repression and are essential for embryonic development in mice. Here we use pluripotent embryonic stem (ES) cells to demonstrate an unexpected redundancy between Polycomb-repressive complex 1 (PRC1) and PRC2 during...... the formation of differentiated cells. ES cells lacking the function of either PRC1 or PRC2 can differentiate into cells of the three germ layers, whereas simultaneous loss of PRC1 and PRC2 abrogates differentiation. On the molecular level, the differentiation defect is caused by the derepression of a set...

  11. Koumine exhibits anxiolytic properties without inducing adverse neurological effects on functional observation battery, open-field and Vogel conflict tests in rodents.

    Science.gov (United States)

    Chen, Chao-Jie; Zhong, Zhi-Feng; Xin, Zhi-Ming; Hong, Long-Hui; Su, Yan-Ping; Yu, Chang-Xi

    2017-04-01

    Koumine, an active alkaloid of neurotoxic plant Gelsemium, has been focused on its therapeutic uses, especially in central nervous system. Nevertheless, less is known about the neurological effects of koumine, which hampers its potential therapeutic exploitation. Moreover, as the anxiolytic potential of Gelsemium has raised many critical issues, its active principles on the anxiolytic and other neurological effects need to be further investigated. Here, we used functional observation battery (FOB) of mice to systematically measure the neurological effects of koumine at the effective doses, and then further confirmed its anxiolytic properties in open-field test (OFT) of mice and Vogel conflict test (VCT) of rats. Koumine exhibited anxiolytic-like activities but did not affect other autonomic, neurological and physical functions in FOB. Furthermore, koumine released anxiolytic responses and anti-punishment action in a manner similar to diazepam in OFT and VCT, respectively. The results constitutes solid set of fundamental data further demonstrating anxiolytic properties of koumine at the therapeutic doses without inducing adverse neurological effects, which supports the perspectives for the development of safe and effective koumine medicine against pathological anxiety.

  12. An improved method for calculating self-motion coordinates for redundant manipulators

    International Nuclear Information System (INIS)

    Reister, D.B.

    1997-04-01

    For a redundant manipulator, the objective of redundancy resolution is to follow a specified path in Cartesian space and simultaneously perform another task (for example, maximize an objective function or avoid obstacles) at every point along the path. The conventional methods have several drawbacks: a new function must be defined for each task, the extended Jacobian can be singular, closed cycles in Cartesian space may not yield closed cycles in joint space, and the objective is point-wise redundancy resolution (to determine a single point in joint space for each point in Cartesian space). The author divides the redundancy resolution problem into two parts: (1) calculate self-motion coordinates for all possible positions of a manipulator at each point along a Cartesian path and (2) determination of optimal self-motion coordinates that maximize an objective function along the path. This paper will discuss the first part of the problem. The path-wise approach overcomes all of the drawbacks of conventional redundancy resolution methods: no need to define a new function for each task, extended Jacobian cannot be singular, and closed cycles in extended Cartesian space will yield closed cycles in joint space

  13. Dynamically redundant particle components in mixtures

    International Nuclear Information System (INIS)

    Lukacs, B.; Martinas, K.

    1984-10-01

    Examples are shown for cases in which the number of different kinds of particles in a system is not necessarily equal to the number of particle degrees of freedom in thermodynamical sense, and at the same time, the observed dynamics of the evolution of the system does not indicate a definite number of degrees of freedeom. The possibility for introducing dynamically redundant particles is discussed. (author)

  14. Parameter identifiability and redundancy: theoretical considerations.

    Directory of Open Access Journals (Sweden)

    Mark P Little

    Full Text Available BACKGROUND: Models for complex biological systems may involve a large number of parameters. It may well be that some of these parameters cannot be derived from observed data via regression techniques. Such parameters are said to be unidentifiable, the remaining parameters being identifiable. Closely related to this idea is that of redundancy, that a set of parameters can be expressed in terms of some smaller set. Before data is analysed it is critical to determine which model parameters are identifiable or redundant to avoid ill-defined and poorly convergent regression. METHODOLOGY/PRINCIPAL FINDINGS: In this paper we outline general considerations on parameter identifiability, and introduce the notion of weak local identifiability and gradient weak local identifiability. These are based on local properties of the likelihood, in particular the rank of the Hessian matrix. We relate these to the notions of parameter identifiability and redundancy previously introduced by Rothenberg (Econometrica 39 (1971 577-591 and Catchpole and Morgan (Biometrika 84 (1997 187-196. Within the widely used exponential family, parameter irredundancy, local identifiability, gradient weak local identifiability and weak local identifiability are shown to be largely equivalent. We consider applications to a recently developed class of cancer models of Little and Wright (Math Biosciences 183 (2003 111-134 and Little et al. (J Theoret Biol 254 (2008 229-238 that generalize a large number of other recently used quasi-biological cancer models. CONCLUSIONS/SIGNIFICANCE: We have shown that the previously developed concepts of parameter local identifiability and redundancy are closely related to the apparently weaker properties of weak local identifiability and gradient weak local identifiability--within the widely used exponential family these concepts largely coincide.

  15. Redundant sensor validation by using fuzzy logic

    International Nuclear Information System (INIS)

    Holbert, K.E.; Heger, A.S.; Alang-Rashid, N.K.

    1994-01-01

    This research is motivated by the need to relax the strict boundary of numeric-based signal validation. To this end, the use of fuzzy logic for redundant sensor validation is introduced. Since signal validation employs both numbers and qualitative statements, fuzzy logic provides a pathway for transforming human abstractions into the numerical domain and thus coupling both sources of information. With this transformation, linguistically expressed analysis principles can be coded into a classification rule-base for signal failure detection and identification

  16. Redundancy Determination of HVDC MMC Modules

    Directory of Open Access Journals (Sweden)

    Chanki Kim

    2015-08-01

    Full Text Available An availability and a reliability prediction has been made for a high-voltage direct-current (HVDC module of VSC (Voltage Source Converter containing DC/DC converter, gate driver, capacitor and insulated gate bipolar transistors (IGBT. This prediction was made using published failure rates for the electronic equipment. The purpose of this prediction is to determinate the additional module redundancy of VSC and the used method is “binomial failure method”.

  17. Bone-derived mesenchymal stromal cells from HIV transgenic mice exhibit altered proliferation, differentiation capacity and paracrine functions along with impaired therapeutic potential in kidney injury

    International Nuclear Information System (INIS)

    Cheng, Kang; Rai, Partab; Lan, Xiqian; Plagov, Andrei; Malhotra, Ashwani; Gupta, Sanjeev; Singhal, Pravin C.

    2013-01-01

    Mesenchymal stem cells (MSCs) secrete paracrine factors that could be cytoprotective and serve roles in immunoregulation during tissue injury. Although MSCs express HIV receptors, and co-receptors, and are susceptible to HIV infection, whether HIV-1 may affect biological properties of MSCs needs more study. We evaluated cellular proliferation, differentiation and paracrine functions of MSCs isolated from compact bones of healthy control mice and Tg26 HIV-1 transgenic mice. The ability of MSCs to protect against cisplatin toxicity was studied in cultured renal tubular cells as well as in intact mice. We successfully isolated MSCs from healthy mice and Tg26 HIV-1 transgenic mice and found the latter expressed viral Nef, Vpu, NL4-3 and Vif genes. The proliferation and differentiation of Tg26 HIV-1 MSCs was inferior to MSCs from healthy mice. Moreover, transplantation of Tg26 HIV-1 MSCs less effectively improved outcomes compared with healthy MSCs in mice with acute kidney injury. Also, Tg26 HIV-1 MSCs secreted multiple cytokines, but at significantly lower levels than healthy MSCs, which resulted in failure of conditioned medium from these MSCs to protect cultured renal tubular cells from cisplatin toxicity. Therefore, HIV-1 had adverse biological effects on MSCs extending to their proliferation, differentiation, function, and therapeutic potential. These findings will help in advancing mechanistical insight in renal injury and repair in the setting of HIV-1 infection. -- Highlights: •MSCs isolated from HIV mice displayed HIV genes. •MSCs isolated from HIV mice exhibited attenuated growth and paracrine functions. •AKI mice with transplanted HIV-MSC displayed poor outcome. •HIV-1 MSC secreted multiple cytokines but at a lower level

  18. Bone-derived mesenchymal stromal cells from HIV transgenic mice exhibit altered proliferation, differentiation capacity and paracrine functions along with impaired therapeutic potential in kidney injury

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Kang; Rai, Partab; Lan, Xiqian; Plagov, Andrei; Malhotra, Ashwani [Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhassett, NY (United States); Gupta, Sanjeev [Departments of Medicine and Pathology, Marion Bessin Liver Research Center, Diabetes Center, Cancer Center, Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Institute for Clinical and Translational Research, Albert Einstein College of Medicine, Bronx, NY (United States); Singhal, Pravin C., E-mail: psinghal@nshs.edu [Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhassett, NY (United States)

    2013-08-15

    Mesenchymal stem cells (MSCs) secrete paracrine factors that could be cytoprotective and serve roles in immunoregulation during tissue injury. Although MSCs express HIV receptors, and co-receptors, and are susceptible to HIV infection, whether HIV-1 may affect biological properties of MSCs needs more study. We evaluated cellular proliferation, differentiation and paracrine functions of MSCs isolated from compact bones of healthy control mice and Tg26 HIV-1 transgenic mice. The ability of MSCs to protect against cisplatin toxicity was studied in cultured renal tubular cells as well as in intact mice. We successfully isolated MSCs from healthy mice and Tg26 HIV-1 transgenic mice and found the latter expressed viral Nef, Vpu, NL4-3 and Vif genes. The proliferation and differentiation of Tg26 HIV-1 MSCs was inferior to MSCs from healthy mice. Moreover, transplantation of Tg26 HIV-1 MSCs less effectively improved outcomes compared with healthy MSCs in mice with acute kidney injury. Also, Tg26 HIV-1 MSCs secreted multiple cytokines, but at significantly lower levels than healthy MSCs, which resulted in failure of conditioned medium from these MSCs to protect cultured renal tubular cells from cisplatin toxicity. Therefore, HIV-1 had adverse biological effects on MSCs extending to their proliferation, differentiation, function, and therapeutic potential. These findings will help in advancing mechanistical insight in renal injury and repair in the setting of HIV-1 infection. -- Highlights: •MSCs isolated from HIV mice displayed HIV genes. •MSCs isolated from HIV mice exhibited attenuated growth and paracrine functions. •AKI mice with transplanted HIV-MSC displayed poor outcome. •HIV-1 MSC secreted multiple cytokines but at a lower level.

  19. Functional α7β2 nicotinic acetylcholine receptors expressed in hippocampal interneurons exhibit high sensitivity to pathological level of amyloid β peptides

    Directory of Open Access Journals (Sweden)

    Liu Qiang

    2012-12-01

    Full Text Available Abstract Background β-amyloid (Aβ accumulation is described as a hallmark of Alzheimer’s disease (AD. Aβ perturbs a number of synaptic components including nicotinic acetylcholine receptors containing α7 subunits (α7-nAChRs, which are abundantly expressed in the hippocampus and found on GABAergic interneurons. We have previously demonstrated the existence of a novel, heteromeric α7β2-nAChR in basal forebrain cholinergic neurons that exhibits high sensitivity to acute Aβ exposure. To extend our previous work, we evaluated the expression and pharmacology of α7β2-nAChRs in hippocampal interneurons and their sensitivity to Aβ. Results GABAergic interneurons in the CA1 subregion of the hippocampus expressed functional α7β2-nAChRs, which were characterized by relatively slow whole-cell current kinetics, pharmacological sensitivity to dihydro-β-erythroidine (DHβE, a nAChR β2* subunit selective blocker, and α7 and β2 subunit interaction using immunoprecipitation assay. In addition, α7β2-nAChRs were sensitive to 1 nM oligomeric Aβ. Similar effects were observed in identified hippocampal interneurons prepared from GFP-GAD mice. Conclusion These findings suggest that Aβ modulation of cholinergic signaling in hippocampal GABAergic interneurons via α7β2-nAChRs could be an early and critical event in Aβ-induced functional abnormalities of hippocampal function, which may be relevant to learning and memory deficits in AD.

  20. Britain exhibition at CERN

    CERN Multimedia

    Bertin; CERN PhotoLab

    1969-01-01

    The United Kingdom inaugurated the Industrial Exhibitions in 1968, and it wasn't till 1971 that other countries staged exhibitions at CERN. This photo was taken in 1969, at the second British exhibition, where 16 companies were present.

  1. Nonlinear Redundancy Analysis. Research Report 88-1.

    Science.gov (United States)

    van der Burg, Eeke; de Leeuw, Jan

    A non-linear version of redundancy analysis is introduced. The technique is called REDUNDALS. It is implemented within the computer program for canonical correlation analysis called CANALS. The REDUNDALS algorithm is of an alternating least square (ALS) type. The technique is defined as minimization of a squared distance between criterion…

  2. How redundant are redundant color adjectives? An efficiency-based analysis of color overspecification

    Directory of Open Access Journals (Sweden)

    Paula eRubio-Fernández

    2016-02-01

    Full Text Available Color adjectives tend to be used redundantly in referential communication. I propose that redundant color adjectives are often intended to exploit a color contrast in the visual context and hence facilitate object identification, despite not being necessary to establish unique reference. Two language-production experiments investigated two types of factors that may affect the use of redundant color adjectives: factors related to the efficiency of color in the visual context and factors related to the semantic category of the noun. The results of Experiment 1 confirmed that people produce redundant color adjectives when color may facilitate object recognition; e.g., they do so more often in polychrome displays than in monochrome displays, and more often in English (pre-nominal position than in Spanish (post-nominal position. Redundant color adjectives are also used when color is a central property of the object category; e.g., people referred to the color of clothes more often than to the color of geometrical figures (Experiment 1, and they overspecified atypical colors more often than variable and stereotypical colors (Experiment 2. These results are relevant for pragmatic models of referential communication based on Gricean pragmatics and informativeness. An alternative analysis is proposed, which focuses on the efficiency and pertinence of color in a given referential situation.

  3. A new model for the redundancy allocation problem with component mixing and mixed redundancy strategy

    International Nuclear Information System (INIS)

    Gholinezhad, Hadi; Zeinal Hamadani, Ali

    2017-01-01

    This paper develops a new model for redundancy allocation problem. In this paper, like many recent papers, the choice of the redundancy strategy is considered as a decision variable. But, in our model each subsystem can exploit both active and cold-standby strategies simultaneously. Moreover, the model allows for component mixing such that components of different types may be used in each subsystem. The problem, therefore, boils down to determining the types of components, redundancy levels, and number of active and cold-standby units of each type for each subsystem to maximize system reliability by considering such constraints as available budget, weight, and space. Since RAP belongs to the NP-hard class of optimization problems, a genetic algorithm (GA) is developed for solving the problem. Finally, the performance of the proposed algorithm is evaluated by applying it to a well-known test problem from the literature with relatively satisfactory results. - Highlights: • A new model for the redundancy allocation problem in series–parallel systems is proposed. • The redundancy strategy of each subsystem is considered as a decision variable and can be active, cold-standby or mixed. • Component mixing is allowed, in other words components of any subsystem can be non-identical. • A genetic algorithm is developed for solving the problem. • Computational experiments demonstrate that the new model leads to interesting results.

  4. Utilizing Nested Normal Form to Design Redundancy Free JSON Schemas

    Directory of Open Access Journals (Sweden)

    Wai Yin Mok

    2016-12-01

    Full Text Available JSON (JavaScript Object Notation is a lightweight data-interchange format for the Internet. JSON is built on two structures: (1 a collection of name/value pairs and (2 an ordered list of values (http://www.json.org/. Because of this simple approach, JSON is easy to use and it has the potential to be the data interchange format of choice for the Internet. Similar to XML, JSON schemas allow nested structures to model hierarchical data. As data interchange over the Internet increases exponentially due to cloud computing or otherwise, redundancy free JSON data are an attractive form of communication because they improve the quality of data communication through eliminating update anomaly. Nested Normal Form, a normal form for hierarchical data, is a precise characterization of redundancy. A nested table, or a hierarchical schema, is in Nested Normal Form if and only if it is free of redundancy caused by multivalued and functional dependencies. Using Nested Normal Form as a guide, this paper introduces a JSON schema design methodology that begins with UML use case diagrams, communication diagrams and class diagrams that model a system under study. Based on the use cases’ execution frequencies and the data passed between involved parties in the communication diagrams, the proposed methodology selects classes from the class diagrams to be the roots of JSON scheme trees and repeatedly adds classes from the class diagram to the scheme trees as long as the schemas satisfy Nested Normal Form. This process continues until all of the classes in the class diagram have been added to some JSON scheme trees.

  5. Age effects on preattentive and early attentive auditory processing of redundant stimuli: is sensory gating affected by physiological aging?

    Science.gov (United States)

    Gmehlin, Dennis; Kreisel, Stefan H; Bachmann, Silke; Weisbrod, Matthias; Thomas, Christine

    2011-10-01

    The frontal hypothesis of aging predicts an age-related decline in cognitive functions requiring inhibitory or attentional regulation. In Alzheimer's disease, preattentive gating out of redundant information is impaired. Our study aimed to examine changes associated with physiological aging in both pre- and early attentive inhibition of recurrent acoustic information. Using a passive double-click paradigm, we recorded mid-latency (P30-P50) and late-latency (N100 and P200) evoked potentials in healthy young (26 ± 5 years) and healthy elderly subjects (72 ± 5 years). Physiological aging did not affect auditory gating in amplitude measures. Both age groups exhibited clear inhibition in preattentive P50 and attention-modulated (N100) components, whereas P30 was not attenuated. Irrespective of age, the magnitude of inhibition differed significantly, being most pronounced for N100 gating. Inhibition of redundant information seems to be preserved with physiological aging. Early attentive N100 gating showed the maximum effect. Further studies are warranted to evaluate sensory gating as a suitable biomarker of underlying neurodegenerative disease.

  6. Redundancy of Redundancy in Justifications of Verdicts of Polish The Constitutional Tribuna

    Directory of Open Access Journals (Sweden)

    Jan Winczorek

    2016-09-01

    Full Text Available The results of an empirical study of 150 justifications of verdicts of the Polish Constitutional Tribunal (CT are discussed. CT justifies its decisions mostly on authoritative references to previous decisions and other doxa- type arguments. It thus does not convince the audience of a decision's validity, but rather documents it. Further, the methodology changes depending on features of the case. The results are analysed using a conceptual    framework    of sociological systems theory. It is shown that CT's justification methodology ignores the redundancy (excess of references and dependencies of the legal system, finding redundancy redundant. This is a risky strategy of decision- making, enabling political influence.

  7. Language as an information system: redundancy and optimization

    Directory of Open Access Journals (Sweden)

    Irina Mikhaylovna Nekipelova

    2015-11-01

    Full Text Available The paper is devoted to research of the language system as an information system. The distinguishing feature of any natural living language system is redundant of elements of its structure. Redundancy, broken terms of universality peculiar to artificial information systems, makes language mobile in time and in space. It should be marked out informational redundancy of two types: language redundancy, when information overlay of language units within the system occurs and speech redundancy when condense of information into syntagmatic level occurs. Language redundancy is potential and speech redundancy is actual. In general, it should be noted that the language redundancy is necessary for language: complicating the relationships between language units, language redundancy creates in language situation of choice, leading to a disorder of language system, increasing of entropy and, as a result, the appearing of the information that can be accepted or cannot be by language system. Language redundancy is one of the reasons for growth of information in language. In addition, the information redundancy in language is one of the factors of language system development.

  8. Tomographical properties of uniformly redundant arrays

    International Nuclear Information System (INIS)

    Cannon, T.M.; Fenimore, E.E.

    1978-01-01

    Recent work in coded aperture imaging has shown that the uniformly redundant array (URA) can image distant planar radioactive sources with no artifacts. The performance of two URA apertures when used in a close-up tomographic imaging system is investigated. It is shown that a URA based on m sequences is superior to one based on quadratic residues. The m sequence array not only produces less obnoxious artifacts in tomographic imaging, but is also more resilient to some described detrimental effects of close-up imaging. It is shown that in spite of these close-up effects, tomographic depth resolution increases as the source is moved closer to the detector

  9. Sharing the cost of redundant items

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moulin, Hervé

    2014-01-01

    We ask how to share the cost of finitely many public goods (items) among users with different needs: some smaller subsets of items are enough to serve the needs of each user, yet the cost of all items must be covered, even if this entails inefficiently paying for redundant items. Typical examples...... are network connectivity problems when an existing (possibly inefficient) network must be maintained. We axiomatize a family cost ratios based on simple liability indices, one for each agent and for each item, measuring the relative worth of this item across agents, and generating cost allocation rules...... additive in costs....

  10. Designing Broadband Access Networks with Triple Redundancy

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Knudsen, Thomas Phillip

    2005-01-01

    An architecture is proposed for designing broadband access networks, which offer triple redundancy to the end users, resulting in networks providing connectivity even in case of any two independent node or line failures. Two physically independent connections are offered by fiber, and the last...... provided by some wireless solution. Based on experience with planning Fiber To The Home, the architecture is designed to meet a number of demands, making it practicable and useful in realworld network planning. The proposed wired topology is planar, and suitable for being fitted onto the road network...

  11. The human brain maintains contradictory and redundant auditory sensory predictions.

    Directory of Open Access Journals (Sweden)

    Marika Pieszek

    Full Text Available Computational and experimental research has revealed that auditory sensory predictions are derived from regularities of the current environment by using internal generative models. However, so far, what has not been addressed is how the auditory system handles situations giving rise to redundant or even contradictory predictions derived from different sources of information. To this end, we measured error signals in the event-related brain potentials (ERPs in response to violations of auditory predictions. Sounds could be predicted on the basis of overall probability, i.e., one sound was presented frequently and another sound rarely. Furthermore, each sound was predicted by an informative visual cue. Participants' task was to use the cue and to discriminate the two sounds as fast as possible. Violations of the probability based prediction (i.e., a rare sound as well as violations of the visual-auditory prediction (i.e., an incongruent sound elicited error signals in the ERPs (Mismatch Negativity [MMN] and Incongruency Response [IR]. Particular error signals were observed even in case the overall probability and the visual symbol predicted different sounds. That is, the auditory system concurrently maintains and tests contradictory predictions. Moreover, if the same sound was predicted, we observed an additive error signal (scalp potential and primary current density equaling the sum of the specific error signals. Thus, the auditory system maintains and tolerates functionally independently represented redundant and contradictory predictions. We argue that the auditory system exploits all currently active regularities in order to optimally prepare for future events.

  12. REDUNDANT ELECTRIC MOTOR DRIVE CONTROL UNIT DESIGN USING AUTOMATA-BASED APPROACH

    Directory of Open Access Journals (Sweden)

    Yuri Yu. Yankin

    2014-11-01

    Full Text Available Implementation of redundant unit for motor drive control based on programmable logic devices is discussed. Continuous redundancy method is used. As compared to segregated standby redundancy and whole system standby redundancy, such method provides preservation of all unit functions in case of redundancy and gives the possibility for continuous monitoring of major and redundant elements. Example of that unit is given. Electric motor drive control channel block diagram contains two control units – the major and redundant; it also contains four power supply units. Control units programming was carried out using automata-based approach. Electric motor drive control channel model was developed; it provides complex simulation of control state-machine and power converter. Through visibility and hierarchy of finite state machines debug time was shortened as compared to traditional programming. Control state-machine description using hardware description language is required for its synthesis with FPGA-devices vendor design software. This description was generated automatically by MATLAB software package. To verify results two prototype control units, two prototype power supply units, and device mock-up were developed and manufactured. Units were installed in the device mock-up. Prototype units were created in accordance with requirements claimed to deliverable hardware. Control channel simulation and tests results in the perfect state and during imitation of major element fault are presented. Automata-based approach made it possible to observe and debug control state-machine transitions during simulation of transient processes, occurring at imitation of faults. Results of this work can be used in development of fault tolerant electric motor drive control channels.

  13. Functional assessment of chronic illness therapy—the fatigue scale exhibits stronger associations with clinical parameters in chronic dialysis patients compared to other fatigue-assessing instruments

    Directory of Open Access Journals (Sweden)

    Chia-Ter Chao

    2016-03-01

    Full Text Available Background. Patients with end-stage renal disease (ESRD have a high symptom burden, among which fatigue is highly prevalent. Many fatigue-assessing instruments exist, but comparisons among instruments in this patient population have yet to be investigated. Methods. ESRD patients under chronic hemodialysis were prospectively enrolled and seven types of fatigue instruments were administered: Brief Fatigue Inventory (BFI, Functional Assessment of Chronic Illness Therapy–Fatigue (FACIT-F, Fatigue Severity Scale (FSS, Lee Fatigue Scale (LFS, Fatigue Questionnaire (FQ, Fatigue Symptom Inventory (FSI, and Short-Form 36-Vitality (SF36-V. Using these instruments, we investigated the correlation between fatigue severity and clinical/biochemical parameters, including demographic/comorbidity profile, dialysis-related complications, and frailty severity. We used regression analysis with serum albumin and frailty severity as the dependent variables to investigate the independent correlations. Results. A total of 46 ESRD patients were enrolled (average age of 67 ± 11.6 years, and 50% of them had type 2 diabetes mellitus. Results from the seven tested instruments showed high correlation with each other. We found that the fatigue severity by FACIT-F was significantly associated with age (p = 0.03, serum albumin (p = 0.003 and creatinine (p = 0.02 levels, while SF36-V scores were also significantly associated with age (p = 0.02 and serum creatinine levels (p = 0.04. However, the fatigue severity measured by the FSS, FSI, FQ, BFI, and LFS did not exhibit these associations. Moreover, regression analysis showed that only FACIT-F scores were independently associated with serum albumin levels and frailty severity in ESRD patients. Conclusion. Among the seven fatigue-assessing instruments, only the FACIT-F yielded results that demonstrated significant and independent associations with important outcome-related features in ESRD patients.

  14. A fully redundant power hinge for LANDSAT-D appendages

    Science.gov (United States)

    Mamrol, F. E.; Matteo, D. N.

    1981-01-01

    The configuration and testing of a power driven hinge for deployment of the solar array and antenna boom for the LANDSAT-D spacecraft is discussed. The hinge is fully mechanically and electrically redundant and, thereby, can sustain a single point failure of any one motor (or its power supply), speed reducer, or bearing set without loss of its ability to function. This design utilizes the capability of the stepper motor drive to remove the flexibility of the drive train from the joint stiffness equation when the hinge is loaded against its stop. This feature precludes gapping of the joint under spacecraft maneuver loads even in the absence of a latching feature. Thus, retraction is easily accomplished by motor reversal without the need for a solenoid function to remove the latch.

  15. Diabetes classification using a redundancy reduction preprocessor

    Directory of Open Access Journals (Sweden)

    Áurea Celeste Ribeiro

    Full Text Available Introduction Diabetes patients can benefit significantly from early diagnosis. Thus, accurate automated screening is becoming increasingly important due to the wide spread of that disease. Previous studies in automated screening have found a maximum accuracy of 92.6%. Methods This work proposes a classification methodology based on efficient coding of the input data, which is carried out by decreasing input data redundancy using well-known ICA algorithms, such as FastICA, JADE and INFOMAX. The classifier used in the task to discriminate diabetics from non-diaibetics is the one class support vector machine. Classification tests were performed using noninvasive and invasive indicators. Results The results suggest that redundancy reduction increases one-class support vector machine performance when discriminating between diabetics and nondiabetics up to an accuracy of 98.47% while using all indicators. By using only noninvasive indicators, an accuracy of 98.28% was obtained. Conclusion The ICA feature extraction improves the performance of the classifier in the data set because it reduces the statistical dependence of the collected data, which increases the ability of the classifier to find accurate class boundaries.

  16. Kinematically Optimal Robust Control of Redundant Manipulators

    Science.gov (United States)

    Galicki, M.

    2017-12-01

    This work deals with the problem of the robust optimal task space trajectory tracking subject to finite-time convergence. Kinematic and dynamic equations of a redundant manipulator are assumed to be uncertain. Moreover, globally unbounded disturbances are allowed to act on the manipulator when tracking the trajectory by the endeffector. Furthermore, the movement is to be accomplished in such a way as to minimize both the manipulator torques and their oscillations thus eliminating the potential robot vibrations. Based on suitably defined task space non-singular terminal sliding vector variable and the Lyapunov stability theory, we derive a class of chattering-free robust kinematically optimal controllers, based on the estimation of transpose Jacobian, which seem to be effective in counteracting both uncertain kinematics and dynamics, unbounded disturbances and (possible) kinematic and/or algorithmic singularities met on the robot trajectory. The numerical simulations carried out for a redundant manipulator of a SCARA type consisting of the three revolute kinematic pairs and operating in a two-dimensional task space, illustrate performance of the proposed controllers as well as comparisons with other well known control schemes.

  17. Learners misperceive the benefits of redundant text in multimedia learning.

    Science.gov (United States)

    Fenesi, Barbara; Kim, Joseph A

    2014-01-01

    Research on metacognition has consistently demonstrated that learners fail to endorse instructional designs that produce benefits to memory, and often prefer designs that actually impair comprehension. Unlike previous studies in which learners were only exposed to a single multimedia design, the current study used a within-subjects approach to examine whether exposure to both redundant text and non-redundant text multimedia presentations improved learners' metacognitive judgments about presentation styles that promote better understanding. A redundant text multimedia presentation containing narration paired with verbatim on-screen text (Redundant) was contrasted with two non-redundant text multimedia presentations: (1) narration paired with images and minimal text (Complementary) or (2) narration paired with minimal text (Sparse). Learners watched presentation pairs of either Redundant + Complementary, or Redundant + Sparse. Results demonstrate that Complementary and Sparse presentations produced highest overall performance on the final comprehension assessment, but the Redundant presentation produced highest perceived understanding and engagement ratings. These findings suggest that learners misperceive the benefits of redundant text, even after direct exposure to a non-redundant, effective presentation.

  18. Digital collections and exhibits

    CERN Document Server

    Denzer, Juan

    2015-01-01

    Today's libraries are taking advantage of cutting-edge technologies such as flat panel displays using touch, sound, and hands-free motions to design amazing exhibits using everything from simple computer hardware to advanced technologies such as the Microsoft Kinect. Libraries of all types are striving to add new interactive experiences for their patrons through exciting digital exhibits, both online and off. Digital Collections and Exhibits takes away the mystery of designing stunning digital exhibits to spotlight library trea

  19. Discrimination? - Exhibition of posters

    OpenAIRE

    Jakimovska, Jana

    2017-01-01

    Participation in the exhibition with the students form the Art Academy. The exhibition consisted of 15 posters tackling the subjects of hate speech and discrimination. The exhibition happened thanks to the invitation of the Faculty of Law at UGD, and it was a part of a larger event of launching books on the aforementioned subjects.

  20. CCF analysis of high redundancy systems safety/relief valve data analysis and reference BWR application

    International Nuclear Information System (INIS)

    Mankamo, T.; Bjoere, S.; Olsson, Lena

    1992-12-01

    Dependent failure analysis and modeling were developed for high redundancy systems. The study included a comprehensive data analysis of safety and relief valves at the Finnish and Swedish BWR plants, resulting in improved understanding of Common Cause Failure mechanisms in these components. The reference application on the Forsmark 1/2 reactor relief system, constituting of twelve safety/relief lines and two regulating relief lines, covered different safety criteria cases of reactor depressurization and overpressure protection function, and failure to re close sequences. For the quantification of dependencies, the Alpha Factor Model, the Binomial Probability Model and the Common Load Model were compared for applicability in high redundancy systems

  1. Analytical Redundancy Design for Aeroengine Sensor Fault Diagnostics Based on SROS-ELM

    Directory of Open Access Journals (Sweden)

    Jun Zhou

    2016-01-01

    Full Text Available Analytical redundancy technique is of great importance to guarantee the reliability and safety of aircraft engine system. In this paper, a machine learning based aeroengine sensor analytical redundancy technique is developed and verified through hardware-in-the-loop (HIL simulation. The modified online sequential extreme learning machine, selective updating regularized online sequential extreme learning machine (SROS-ELM, is employed to train the model online and estimate sensor measurements. It selectively updates the output weights of neural networks according to the prediction accuracy and the norm of output weight vector, tackles the problems of singularity and ill-posedness by regularization, and adopts a dual activation function in the hidden nodes combing neural and wavelet theory to enhance prediction capability. The experimental results verify the good generalization performance of SROS-ELM and show that the developed analytical redundancy technique for aeroengine sensor fault diagnosis based on SROS-ELM is effective and feasible.

  2. Fault detection in multiply-redundant measurement systems via sequential testing

    International Nuclear Information System (INIS)

    Ray, A.

    1988-01-01

    The theory and application of a sequential test procedure for fault detection and isolation. The test procedure is suited for development of intelligent instrumentation in strategic processes like aircraft and nuclear plants where redundant measurements are usually available for individual critical variables. The test procedure consists of: (1) a generic redundancy management procedure which is essentially independent of the fault detection strategy and measurement noise statistics, and (2) a modified version of sequential probability ratio test algorithm for fault detection and isolation, which functions within the framework of this redundancy management procedure. The sequential test procedure is suitable for real-time applications using commercially available microcomputers and its efficacy has been verified by online fault detection in an operating nuclear reactor. 15 references

  3. Fault-Tolerant Region-Based Control of an Underwater Vehicle with Kinematically Redundant Thrusters

    Directory of Open Access Journals (Sweden)

    Zool H. Ismail

    2014-01-01

    Full Text Available This paper presents a new control approach for an underwater vehicle with a kinematically redundant thruster system. This control scheme is derived based on a fault-tolerant decomposition for thruster force allocation and a region control scheme for the tracking objective. Given a redundant thruster system, that is, six or more pairs of thrusters are used, the proposed redundancy resolution and region control scheme determine the number of thruster faults, as well as providing the reference thruster forces in order to keep the underwater vehicle within the desired region. The stability of the presented control law is proven in the sense of a Lyapunov function. Numerical simulations are performed with an omnidirectional underwater vehicle and the results of the proposed scheme illustrate the effectiveness in terms of optimizing the thruster forces.

  4. Robust Redundant Input Reliable Tracking Control for Omnidirectional Rehabilitative Training Walker

    Directory of Open Access Journals (Sweden)

    Ping Sun

    2014-01-01

    Full Text Available The problem of robust reliable tracking control on the omnidirectional rehabilitative training walker is examined. The new nonlinear redundant input method is proposed when one wheel actuator fault occurs. The aim of the study is to design an asymptotically stable controller that can guarantee the safety of the user and ensure tracking on a training path planned by a physical therapist. The redundant degrees of freedom safety control and the asymptotically zero state detectable concept of the walker are presented, the model of redundant degree is constructed, and the property of center of gravity constant shift is obtained. A controller that can satisfy asymptotic stability is obtained using a common Lyapunov function for admissible uncertainties resulting from an actuator fault. Simulation results confirm the effectiveness of the proposed method and verify that the walker can provide safe sequential motion when one wheel actuator is at fault.

  5. Reliability Analysis Multiple Redundancy Controller for Nuclear Safety Systems

    International Nuclear Information System (INIS)

    Son, Gwangseop; Kim, Donghoon; Son, Choulwoong

    2013-01-01

    This controller is configured for multiple modular redundancy (MMR) composed of dual modular redundancy (DMR) and triple modular redundancy (TMR). The architecture of MRC is briefly described, and the Markov model is developed. Based on the model, the reliability and Mean Time To Failure (MTTF) are analyzed. In this paper, the architecture of MRC for nuclear safety systems is described. The MRC is configured for multiple modular redundancy (MMR) composed of dual modular redundancy (DMR) and triple modular redundancy (TMR). Markov models for MRC architecture was developed, and then the reliability was analyzed by using the model. From the reliability analyses for the MRC, it is obtained that the failure rate of each module in the MRC should be less than 2 Χ 10 -4 /hour and the MTTF average increase rate depending on FCF increment, i. e. ΔMTTF/ΔFCF, is 4 months/0.1

  6. Identification of Poxvirus Genome Uncoating and DNA Replication Factors with Mutually Redundant Roles.

    Science.gov (United States)

    Liu, Baoming; Panda, Debasis; Mendez-Rios, Jorge D; Ganesan, Sundar; Wyatt, Linda S; Moss, Bernard

    2018-04-01

    Genome uncoating is essential for replication of most viruses. For poxviruses, the process is divided into two stages: removal of the envelope, allowing early gene expression, and breaching of the core wall, allowing DNA release, replication, and late gene expression. Subsequent studies showed that the host proteasome and the viral D5 protein, which has an essential role in DNA replication, are required for vaccinia virus (VACV) genome uncoating. In a search for additional VACV uncoating proteins, we noted a report that described a defect in DNA replication and late expression when the gene encoding a 68-kDa ankyrin repeat/F-box protein (68k-ank), associated with the cellular SCF (Skp1, cullin1, F-box-containing complex) ubiquitin ligase complex, was deleted from the attenuated modified vaccinia virus Ankara (MVA). Here we showed that the 68k-ank deletion mutant exhibited diminished genome uncoating, formation of DNA prereplication sites, and degradation of viral cores as well as an additional, independent defect in DNA synthesis. Deletion of the 68k-ank homolog of VACV strain WR, however, was without effect, suggesting the existence of compensating genes. By inserting VACV genes into an MVA 68k-ank deletion mutant, we discovered that M2, a member of the poxvirus immune evasion (PIE) domain superfamily and a regulator of NF-κB, and C5, a member of the BTB/Kelch superfamily associated with cullin-3-based ligase complexes, independently rescued the 68k-ank deletion phenotype. Thus, poxvirus uncoating and DNA replication are intertwined processes involving at least three viral proteins with mutually redundant functions in addition to D5. IMPORTANCE Poxviruses comprise a family of large DNA viruses that infect vertebrates and invertebrates and cause diseases of medical and zoological importance. Poxviruses, unlike most other DNA viruses, replicate in the cytoplasm, and their large genomes usually encode 200 or more proteins with diverse functions. About 90 genes may

  7. Redundancy and Reliability for an HPC Data Centre

    OpenAIRE

    Erhan Yılmaz

    2012-01-01

    Defining a level of redundancy is a strategic question when planning a new data centre, as it will directly impact the entire design of the building as well as the construction and operational costs. It will also affect how to integrate future extension plans into the design. Redundancy is also a key strategic issue when upgrading or retrofitting an existing facility. Redundancy is a central strategic question to any business that relies on data centres for its operation. In th...

  8. Study of redundant Models in reliability prediction of HXMT's HES

    International Nuclear Information System (INIS)

    Wang Jinming; Liu Congzhan; Zhang Zhi; Ji Jianfeng

    2010-01-01

    Two redundant equipment structures of HXMT's HES are proposed firstly, the block backup and dual system cold-redundancy. Then prediction of the reliability is made by using parts count method. Research of comparison and analysis is also performed on the two proposals. A conclusion is drawn that a higher reliability and longer service life could be offered by taking a redundant equipment structure of block backup. (authors)

  9. Reliability of redundant structures of nuclear reactor protection systems

    International Nuclear Information System (INIS)

    Vojnovic, B.

    1983-01-01

    In this paper, reliability of various redundant structures of PWR protection systems has been analysed. Structures of reactor tip systems as well as the systems for activation of safety devices have been presented. In all those systems redundancy is achieved by means of so called majority voting logic ('r out of n' structures). Different redundant devices have been compared, concerning probability of occurrence of safe as well as unsafe failures. (author)

  10. A succession of theories: purging redundancy from disturbance theory.

    Science.gov (United States)

    Pulsford, Stephanie A; Lindenmayer, David B; Driscoll, Don A

    2016-02-01

    The topics of succession and post-disturbance ecosystem recovery have a long and convoluted history. There is extensive redundancy within this body of theory, which has resulted in confusion, and the links among theories have not been adequately drawn. This review aims to distil the unique ideas from the array of theory related to ecosystem change in response to disturbance. This will help to reduce redundancy, and improve communication and understanding between researchers. We first outline the broad range of concepts that have developed over the past century to describe community change in response to disturbance. The body of work spans overlapping succession concepts presented by Clements in 1916, Egler in 1954, and Connell and Slatyer in 1977. Other theories describing community change include state and transition models, biological legacy theory, and the application of functional traits to predict responses to disturbance. Second, we identify areas of overlap of these theories, in addition to highlighting the conceptual and taxonomic limitations of each. In aligning each of these theories with one another, the limited scope and relative inflexibility of some theories becomes apparent, and redundancy becomes explicit. We identify a set of unique concepts to describe the range of mechanisms driving ecosystem responses to disturbance. We present a schematic model of our proposed synthesis which brings together the range of unique mechanisms that were identified in our review. The model describes five main mechanisms of transition away from a post-disturbance community: (i) pulse events with rapid state shifts; (ii) stochastic community drift; (iii) facilitation; (iv) competition; and (v) the influence of the initial composition of a post-disturbance community. In addition, stabilising processes such as biological legacies, inhibition or continuing disturbance may prevent a transition between community types. Integrating these six mechanisms with the functional

  11. Handling data redundancy and update anomalies in fuzzy relational databases

    International Nuclear Information System (INIS)

    Chen, G.; Kerre, E.E.

    1996-01-01

    This paper discusses various data redundancy and update anomaly problems that may occur with fuzzy relational databases. In coping with these problems to avoid undesirable consequences when fuzzy databases are updated via data insertion, deletion and modification, a number of fuzzy normal forms (e.g., F1NF, 0-F2NF, 0-F3NF, 0-FBCNF) are used to guide the design of relation schemes such that partial and transitive fuzzy functional dependencies (FFDs) between relation attributes are restricted. Based upon FFDs and related concepts, particular attention is paid to 0-F3NF and 0-FBCNF, and to the corresponding decomposition algorithms. These algorithms not only produce relation schemes which are either in 0-F3NF or in 0-FBCNF, but also guarantee that the information (data content and FFDs) with original schemes can be recovered with those resultant schemes

  12. Redundant information encoding in QED during decoherence

    Science.gov (United States)

    Tuziemski, J.; Witas, P.; Korbicz, J. K.

    2018-01-01

    Broadly understood decoherence processes in quantum electrodynamics, induced by neglecting either the radiation [L. Landau, Z. Phys. 45, 430 (1927), 10.1007/BF01343064] or the charged matter [N. Bohr and L. Rosenfeld, K. Danske Vidensk. Selsk, Math.-Fys. Medd. XII, 8 (1933)], have been studied from the dawn of the theory. However, what happens in between, when a part of the radiation may be observed, as is the case in many real-life situations, has not been analyzed yet. We present such an analysis for a nonrelativistic, pointlike charge and thermal radiation. In the dipole approximation, we solve the dynamics and show that there is a regime where, despite the noise, the observed field carries away almost perfect and hugely redundant information about the charge momentum. We analyze a partial charge-field state and show that it approaches a so-called spectrum broadcast structure.

  13. Analysis and Design of Offset QPSK Using Redundant Filter Banks

    International Nuclear Information System (INIS)

    Fernandez-Vazquez, Alfonso; Jovanovic-Dolecek, Gordana

    2013-01-01

    This paper considers the analysis and design of OQPSK digital modulation. We first establish the discrete time formulation, which allows us to find the equivalent redundant filter banks. It is well known that redundant filter banks are related with redundant transformation of the Frame theory. According to the Frame theory, the redundant transformations and corresponding representations are not unique. In this way, we show that the solution to the pulse shaping problem is not unique. Then we use this property to minimize the effect of the channel noise in the reconstructed symbol stream. We evaluate the performance of the digital communication using numerical examples.

  14. Exhibition; Image display agency

    International Nuclear Information System (INIS)

    Normazlin Ismail

    2008-01-01

    This article touches on the role of Malaysian Nuclear Agency as nuclear research institutions to promote, develop and encourage the peaceful uses of nuclear technology in its agricultural, medical, manufacturing, industrial, health and environment for the development of the country running successfully. Maturity of Malaysian Nuclear Agency in dealing with nuclear technology that are very competitive and globalization cannot be denied. On this basis Malaysian Nuclear Agency was given the responsibility to strengthen the nuclear technology in Malaysia. One way is through an exhibition featuring the research, discoveries and new technology products of the nuclear technology. Through this exhibition is to promote the nuclear technology and introduce the image of the agency in the public eye. This article also states a number of exhibits entered by the Malaysian Nuclear Agency and achievements during the last exhibition. Authors hope that the exhibition can be intensified further in the future.

  15. Redundancy and divergence in the amyloid precursor protein family.

    Science.gov (United States)

    Shariati, S Ali M; De Strooper, Bart

    2013-06-27

    Gene duplication provides genetic material required for functional diversification. An interesting example is the amyloid precursor protein (APP) protein family. The APP gene family has experienced both expansion and contraction during evolution. The three mammalian members have been studied quite extensively in combined knock out models. The underlying assumption is that APP, amyloid precursor like protein 1 and 2 (APLP1, APLP2) are functionally redundant. This assumption is primarily supported by the similarities in biochemical processing of APP and APLPs and on the fact that the different APP genes appear to genetically interact at the level of the phenotype in combined knockout mice. However, unique features in each member of the APP family possibly contribute to specification of their function. In the current review, we discuss the evolution and the biology of the APP protein family with special attention to the distinct properties of each homologue. We propose that the functions of APP, APLP1 and APLP2 have diverged after duplication to contribute distinctly to different neuronal events. Our analysis reveals that APLP2 is significantly diverged from APP and APLP1. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  16. Redundant interferometric calibration as a complex optimization problem

    Science.gov (United States)

    Grobler, T. L.; Bernardi, G.; Kenyon, J. S.; Parsons, A. R.; Smirnov, O. M.

    2018-05-01

    Observations of the redshifted 21 cm line from the epoch of reionization have recently motivated the construction of low-frequency radio arrays with highly redundant configurations. These configurations provide an alternative calibration strategy - `redundant calibration' - and boost sensitivity on specific spatial scales. In this paper, we formulate calibration of redundant interferometric arrays as a complex optimization problem. We solve this optimization problem via the Levenberg-Marquardt algorithm. This calibration approach is more robust to initial conditions than current algorithms and, by leveraging an approximate matrix inversion, allows for further optimization and an efficient implementation (`redundant STEFCAL'). We also investigated using the preconditioned conjugate gradient method as an alternative to the approximate matrix inverse, but found that its computational performance is not competitive with respect to `redundant STEFCAL'. The efficient implementation of this new algorithm is made publicly available.

  17. Prioritising Redundant Network Component for HOWBAN Survivability Using FMEA

    Directory of Open Access Journals (Sweden)

    Cheong Loong Chan

    2017-01-01

    Full Text Available Deploying redundant component is the ubiquitous approach to improve the reliability and survivability of a hybrid optical wireless broadband access network (HOWBAN. Much work has been done to study the cost and impact of deploying redundant component in the network but no formal tools have been used to enable the evaluation and decision to prioritise the deployment of redundant facilities in the network. In this paper we show how FMEA (Failure Mode Effect and Analysis technique can be adapted to identify the critical segment in the network and prioritise the redundant component to be deployed to ensure network survivability. Our result showed that priority must be given to redundancy to mitigate grid power outage particularly in less developed countries which is poised for rapid expansion in broadband services.

  18. N + 1 redundancy on ATCA instrumentation for Nuclear Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Correia, Miguel, E-mail: miguelfc@ipfn.ist.utl.pt [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal); Sousa, Jorge; Rodrigues, António P.; Batista, António J.N.; Combo, Álvaro; Carvalho, Bernardo B.; Santos, Bruno; Carvalho, Paulo F.; Gonçalves, Bruno [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal); Correia, Carlos M.B.A. [Centro de Instrumentação, Departamento de Física, Universidade de Coimbra, Coimbra (Portugal); Varandas, Carlos A.F. [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal)

    2013-10-15

    Highlights: ► In Nuclear Fusion, demanding security and high-availability requirements call for redundancy to be available. ► ATCA standard features desirable redundancy features for Fusion instrumentation. ► The developed control and data acquisition hardware modules support additional redundancy schemes. ► Implementation of N + 1 redundancy of host processor and I/O data modules. -- Abstract: The role of redundancy on control and data acquisition systems has gained a significant importance in the case of Nuclear Fusion, as demanding security and high-availability requirements call for redundancy to be available. IPFN's control and data acquisition system hardware is based on an Advanced Telecommunications Computing Architecture (ATCA) set of I/O (DAC/ADC endpoints) and data/timing switch modules, which handle data and timing from all I/O endpoints. Modules communicate through Peripheral Component Interconnect Express (PCIe), established over the ATCA backplane and controlled by one or more external hosts. The developed hardware modules were designed to take advantage of ATCA specification's redundancy features, namely at the hardware management level, including support of: (i) multiple host operation with N + 1 redundancy – in which a designated failover host takes over data previously assigned to a suddenly malfunctioning host and (ii) N + 1 redundancy of I/O and data/timing switch modules. This paper briefly describes IPFN's control and data acquisition system, which is being developed for ITER fast plant system controller (FPSC), and analyses the hardware implementation of its supported redundancy features.

  19. Pedestrian detection based on redundant wavelet transform

    Science.gov (United States)

    Huang, Lin; Ji, Liping; Hu, Ping; Yang, Tiejun

    2016-10-01

    Intelligent video surveillance is to analysis video or image sequences captured by a fixed or mobile surveillance camera, including moving object detection, segmentation and recognition. By using it, we can be notified immediately in an abnormal situation. Pedestrian detection plays an important role in an intelligent video surveillance system, and it is also a key technology in the field of intelligent vehicle. So pedestrian detection has very vital significance in traffic management optimization, security early warn and abnormal behavior detection. Generally, pedestrian detection can be summarized as: first to estimate moving areas; then to extract features of region of interest; finally to classify using a classifier. Redundant wavelet transform (RWT) overcomes the deficiency of shift variant of discrete wavelet transform, and it has better performance in motion estimation when compared to discrete wavelet transform. Addressing the problem of the detection of multi-pedestrian with different speed, we present an algorithm of pedestrian detection based on motion estimation using RWT, combining histogram of oriented gradients (HOG) and support vector machine (SVM). Firstly, three intensities of movement (IoM) are estimated using RWT and the corresponding areas are segmented. According to the different IoM, a region proposal (RP) is generated. Then, the features of a RP is extracted using HOG. Finally, the features are fed into a SVM trained by pedestrian databases and the final detection results are gained. Experiments show that the proposed algorithm can detect pedestrians accurately and efficiently.

  20. Optimizing ISOCAM data processing using spatial redundancy

    Science.gov (United States)

    Miville-Deschênes, M.-A.; Boulanger, F.; Abergel, A.; Bernard, J.-P.

    2000-11-01

    Several instrumental effects of the Long Wavelength channel of ISOCAM, the camera on board the Infrared Space Observatory, degrade the processed images. We present new data-processing techniques that correct these defects, taking advantage of the fact that a position in the sky has been observed by several pixels at different times. We use this redundant information (1) to correct the long-term variation of the detector response, (2) to correct memory effects after glitches and point sources, and (3) to refine the deglitching process. As an example we have applied our processing to the gamma-ray burst observation GRB 970402. Our new data-processing techniques allow the detection of faint extended emission with contrast smaller than 1% of the zodiacal background. The data reduction corrects instrumental effects to the point where the noise in the final map is dominated by the readout and the photon noises. All raster ISOCAM observations can benefit from the data processing described here. This includes mapping of solar system extended objects (comet dust trails), nearby clouds and star forming regions, images from diffuse emission in the Galactic plane and external galaxies. These techniques could also be applied to other raster type observations (e.g. ISOPHOT). Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, The Netherlands and the UK) and with the participation of ISAS and NASA.

  1. Quantum Darwinism in an Everyday Environment: Huge Redundancy in Scattered Photons

    Science.gov (United States)

    Riedel, Charles; Zurek, Wojciech

    2011-03-01

    We study quantum Darwinism---the redundant recording of information about the preferred states of a decohering system by its environment---for an object illuminated by a blackbody. In the cases of point-source, small disk, and isotropic illumination, we calculate the quantum mutual information between the object and its photon environment. We demonstrate that this realistic model exhibits fast and extensive proliferation of information about the object into the environment and results in redundancies orders of magnitude larger than the exactly soluble models considered to date. We also demonstrate a reduced ability to create records as initial environmental mixedness increases, in agreement with previous studies. This research is supported by the U.S. Department of Energy through the LANL/LDRD program and, in part, by the Foundational Questions Institute (FQXi).

  2. The rise and fall of redundancy in decoherence and quantum Darwinism

    Science.gov (United States)

    Jess Riedel, C.; Zurek, Wojciech H.; Zwolak, Michael

    2012-08-01

    A state selected at random from the Hilbert space of a many-body system is overwhelmingly likely to exhibit highly non-classical correlations. For these typical states, half of the environment must be measured by an observer to determine the state of a given subsystem. The objectivity of classical reality—the fact that multiple observers can agree on the state of a subsystem after measuring just a small fraction of its environment—implies that the correlations found in nature between macroscopic systems and their environments are exceptional. Building on previous studies of quantum Darwinism showing that highly redundant branching states are produced ubiquitously during pure decoherence, we examine the conditions needed for the creation of branching states and study their demise through many-body interactions. We show that even constrained dynamics can suppress redundancy to the values typical of random states on relaxation timescales, and prove that these results hold exactly in the thermodynamic limit.

  3. The error performance analysis over cyclic redundancy check codes

    Science.gov (United States)

    Yoon, Hee B.

    1991-06-01

    The burst error is generated in digital communication networks by various unpredictable conditions, which occur at high error rates, for short durations, and can impact services. To completely describe a burst error one has to know the bit pattern. This is impossible in practice on working systems. Therefore, under the memoryless binary symmetric channel (MBSC) assumptions, the performance evaluation or estimation schemes for digital signal 1 (DS1) transmission systems carrying live traffic is an interesting and important problem. This study will present some analytical methods, leading to efficient detecting algorithms of burst error using cyclic redundancy check (CRC) code. The definition of burst error is introduced using three different models. Among the three burst error models, the mathematical model is used in this study. The probability density function, function(b) of burst error of length b is proposed. The performance of CRC-n codes is evaluated and analyzed using function(b) through the use of a computer simulation model within CRC block burst error. The simulation result shows that the mean block burst error tends to approach the pattern of the burst error which random bit errors generate.

  4. Council Chamber exhibition

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    To complete the revamp of CERN’s Council Chamber, a new exhibition is being installed just in time for the June Council meetings.   Panels will showcase highlights of CERN’s history, using some of the content prepared for the exhibitions marking 50 years of the PS, which were displayed in the main building last November. The previous photo exhibition in the Council Chamber stopped at the 1970s. To avoid the new panels becoming quickly out of date, photos are grouped together around specific infrastructures, rather than following a classic time-line. “We have put the focus on the accelerators – the world-class facilities that CERN has been offering researchers over the years, from the well-known large colliders to the lesser-known smaller facilities,” says Emma Sanders, who worked on the content. The new exhibition will be featured in a future issue of the Bulletin with photos and an interview with Fabienne Marcastel, designer of the exhibit...

  5. EXHIBITION: Accelerated Particles

    CERN Multimedia

    2004-01-01

    An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's 50th anniversary celebrations. Fifty candles for CERN, an international laboratory renowned for fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting exhibitions of plastic arts and performances entitled: Accelerated Particles. Several works will be exhibited and performed in two 'salons'. Salon des matières: An exhibition of plastic arts From Tues 12 October to Wed 3 November 2004 Tuesdays to Fridays: 16:00 to 19:00 Saturdays: 14:00 to 18:00 Exhibition open late on performance nights, entrance free Salon des particules: Musical and visual performances Tues 12 and Mon 25 October from 20:00 to 23:00 Preview evening for both events: Tues 12 October from 18:...

  6. Synergetic and Redundant Information Flow Detected by Unnormalized Granger Causality: Application to Resting State fMRI.

    Science.gov (United States)

    Stramaglia, Sebastiano; Angelini, Leonardo; Wu, Guorong; Cortes, Jesus M; Faes, Luca; Marinazzo, Daniele

    2016-12-01

    We develop a framework for the analysis of synergy and redundancy in the pattern of information flow between subsystems of a complex network. The presence of redundancy and/or synergy in multivariate time series data renders difficulty to estimate the neat flow of information from each driver variable to a given target. We show that adopting an unnormalized definition of Granger causality, one may put in evidence redundant multiplets of variables influencing the target by maximizing the total Granger causality to a given target, over all the possible partitions of the set of driving variables. Consequently, we introduce a pairwise index of synergy which is zero when two independent sources additively influence the future state of the system, differently from previous definitions of synergy. We report the application of the proposed approach to resting state functional magnetic resonance imaging data from the Human Connectome Project showing that redundant pairs of regions arise mainly due to space contiguity and interhemispheric symmetry, while synergy occurs mainly between nonhomologous pairs of regions in opposite hemispheres. Redundancy and synergy, in healthy resting brains, display characteristic patterns, revealed by the proposed approach. The pairwise synergy index, here introduced, maps the informational character of the system at hand into a weighted complex network: the same approach can be applied to other complex systems whose normal state corresponds to a balance between redundant and synergetic circuits.

  7. Reliability Equivalence to Symmetrical UHVDC Transmission Systems Considering Redundant Structure Configuration

    Directory of Open Access Journals (Sweden)

    Xing Jiang

    2018-03-01

    Full Text Available In recent years, the ultra-high voltage direct current (UHVDC transmission system has been developed rapidly for its significant long-distance, high-capacity and low-loss properties. Equipment failures and overall outages of the UHVDC system have increasingly vital influence on the power supply of the receiving end grid. To improve the reliability level of UHVDC systems, a quantitative selection and configuration approach of redundant structures is proposed in this paper, which is based on multi-state reliability equivalence. Specifically, considering the symmetry characteristic of an UHVDC system, a state space model is established as a monopole rather than a bipole, which effectively reduces the state space dimensions to be considered by deducing the reliability merging operator of two poles. Considering the standby effect of AC filters and the recovery effect of converter units, the number of available converter units and corresponding probability are expressed with in universal generating function (UGF form. Then, a sensitivity analysis is performed to quantify the impact of component reliability parameters on system reliability and determine the most specific devices that should be configured in the redundant structure. Finally, a cost-benefit analysis is utilized to help determine the optimal scheme of redundant devices. Case studies are conducted to demonstrate the effectiveness and accuracy of the proposed method. Based on the numerical results, configuring a set of redundant transformers is indicated to be of the greatest significance to improve the reliability level of UHVDC transmission systems.

  8. Reliability analysis of component-level redundant topologies for solid-state fault current limiter

    Science.gov (United States)

    Farhadi, Masoud; Abapour, Mehdi; Mohammadi-Ivatloo, Behnam

    2018-04-01

    Experience shows that semiconductor switches in power electronics systems are the most vulnerable components. One of the most common ways to solve this reliability challenge is component-level redundant design. There are four possible configurations for the redundant design in component level. This article presents a comparative reliability analysis between different component-level redundant designs for solid-state fault current limiter. The aim of the proposed analysis is to determine the more reliable component-level redundant configuration. The mean time to failure (MTTF) is used as the reliability parameter. Considering both fault types (open circuit and short circuit), the MTTFs of different configurations are calculated. It is demonstrated that more reliable configuration depends on the junction temperature of the semiconductor switches in the steady state. That junction temperature is a function of (i) ambient temperature, (ii) power loss of the semiconductor switch and (iii) thermal resistance of heat sink. Also, results' sensitivity to each parameter is investigated. The results show that in different conditions, various configurations have higher reliability. The experimental results are presented to clarify the theory and feasibility of the proposed approaches. At last, levelised costs of different configurations are analysed for a fair comparison.

  9. Global Energy-Optimal Redundancy Resolution of Hydraulic Manipulators: Experimental Results for a Forestry Manipulator

    Directory of Open Access Journals (Sweden)

    Jarmo Nurmi

    2017-05-01

    Full Text Available This paper addresses the energy-inefficiency problem of four-degrees-of-freedom (4-DOF hydraulic manipulators through redundancy resolution in robotic closed-loop controlled applications. Because conventional methods typically are local and have poor performance for resolving redundancy with respect to minimum hydraulic energy consumption, global energy-optimal redundancy resolution is proposed at the valve-controlled actuator and hydraulic power system interaction level. The energy consumption of the widely popular valve-controlled load-sensing (LS and constant-pressure (CP systems is effectively minimised through cost functions formulated in a discrete-time dynamic programming (DP approach with minimum state representation. A prescribed end-effector path and important actuator constraints at the position, velocity and acceleration levels are also satisfied in the solution. Extensive field experiments performed on a forestry hydraulic manipulator demonstrate the performance of the proposed solution. Approximately 15–30% greater hydraulic energy consumption was observed with the conventional methods in the LS and CP systems. These results encourage energy-optimal redundancy resolution in future robotic applications of hydraulic manipulators.

  10. The issue of redundant places of worship

    Directory of Open Access Journals (Sweden)

    Paolo Cavana

    2012-03-01

    Abstract: Nowadays one of the major issues concerning ecclesiastical, or religious, property in Europe, as elsewhere, consists of deciding what to do with redundant churches and places of worship of traditional Christian denominations, all of which have lost their original use, either due to a formal decision of the ecclesiastical authorities or to simple closure to the public. This might have been caused by a series of events, like a significant decrease in the church attendance, limited public resources, new urban planning projects and the fall in religious vocation. For these places there is either the prospect of a new use, or a slow process of decay which can ultimately end up in a sale, or demolition. This problem is faced today with singular urgency in Europe, where it determines an increased risk of decay of much of the historical-artistic heritage, together with the abandonment of the countryside and mountain locations and a progressive desertion of historical town centres. Consequently, the issue concerns not only the religious community but also the civil authorities and public opinion, more and more sensitive to the protection of cultural heritage and the historical memory of local communities. This paper examines many aspects of the issue in some countries (Italy, Germany, Switzerland, France, Québec, the United States, comparing the different legal frameworks and the documents of some national episcopal assemblies on the subject, especially about the change in the use of churches. Finally it concentrates on the situation in Italy, where the legal framework on this subject is strictly connected with the system of church-state relations, making some concluding remarks about future prospects and possible solutions to some of the more serious aspects of the issue.

  11. Overexpression of three TaEXPA1 homoeologous genes with distinct expression divergence in hexaploid wheat exhibit functional retention in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Zhaorong Hu

    Full Text Available Common wheat is a hexaploid species with most of the genes present as triplicate homoeologs. Expression divergences of homoeologs are frequently observed in wheat as well as in other polyploid plants. However, little is known about functional variances among homologous genes arising from polyploidy. Expansins play diverse roles in plant developmental processes related to the action of cell wall loosening. Expression of the three TaEXPA1 homoeologs varied dynamically at different stages and organs, and epigenetic modifications contribute to the expression divergence of three TaEXPA1 homoeologs during wheat development. Nevertheless, their functions remain to be clarified. We found that over expression of TaEXPA1-A, -B and -D produced similar morphological changes in transgenic Arabidopsis plants, including increased germination and growth rate during seedling and adult stages, indicating that the proteins encoded by these three wheat TaEXPA1 homoeologs have similar (or conserved functions in Arabidopsis. Collectively, our present study provided an example of a set of homoeologous genes expression divergence in different developmental stages and organs in hexaploid wheat but functional retention in transgenic Arabidopsis plants.

  12. HepG2/C3A 3D spheroids exhibit stable physiological functionality for at least 24 days after recovering from trypsination

    DEFF Research Database (Denmark)

    Wrzesinski, Krzysztof; Magnone, Maria Chiara; Hansen, Line Visby

    2013-01-01

    Primary human hepatocytes are widely used as an in vitro system for the assessment of drug metabolism and toxicity. Nevertheless a cell system with higher stability of physiological functions is required for the investigation of drugs’ mode of action, pathway analyses and biomarkers evaluations. ...

  13. EXHIBITION: Accelerated Particles

    CERN Multimedia

    2004-01-01

    http://www.cern.ch/cern50/ An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's fiftieth anniversary celebrations. The fiftieth anniversary of a world famous organization like CERN, an international laboratory specializing in fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting two "salons" consisting of an exhibition of plastic arts and evenings of music and visual arts performances with the collective title of "Accelerated Particles". Several works will be exhibited and performed. Salon des matières: An exhibition of plastic arts Until Wednesday 3 November 2004. Tuesdays to Fridays: 4.00 p.m. to 7.00 p.m. Saturdays: 2.00 p.m. to 6.00 p.m. Doors open late on the evening of the performances. Salon des ...

  14. A hybrid Jaya algorithm for reliability-redundancy allocation problems

    Science.gov (United States)

    Ghavidel, Sahand; Azizivahed, Ali; Li, Li

    2018-04-01

    This article proposes an efficient improved hybrid Jaya algorithm based on time-varying acceleration coefficients (TVACs) and the learning phase introduced in teaching-learning-based optimization (TLBO), named the LJaya-TVAC algorithm, for solving various types of nonlinear mixed-integer reliability-redundancy allocation problems (RRAPs) and standard real-parameter test functions. RRAPs include series, series-parallel, complex (bridge) and overspeed protection systems. The search power of the proposed LJaya-TVAC algorithm for finding the optimal solutions is first tested on the standard real-parameter unimodal and multi-modal functions with dimensions of 30-100, and then tested on various types of nonlinear mixed-integer RRAPs. The results are compared with the original Jaya algorithm and the best results reported in the recent literature. The optimal results obtained with the proposed LJaya-TVAC algorithm provide evidence for its better and acceptable optimization performance compared to the original Jaya algorithm and other reported optimal results.

  15. The Grass Might Be Greener: Medical Marijuana Patients Exhibit Altered Brain Activity and Improved Executive Function after 3 Months of Treatment

    OpenAIRE

    Gruber, Staci A.; Sagar, Kelly A.; Dahlgren, Mary K.; Gonenc, Atilla; Smith, Rosemary T.; Lambros, Ashley M.; Cabrera, Korine B.; Lukas, Scott E.

    2018-01-01

    The vast majority of states have enacted full or partial medical marijuana (MMJ) programs, causing the number of patients seeking certification for MMJ use to increase dramatically in recent years. Despite increased use of MMJ across the nation, no studies thus far have examined the specific impact of MMJ on cognitive function and related brain activation. In the present study, MMJ patients seeking treatment for a variety of documented medical conditions were assessed prior to initiating MMJ ...

  16. Wastewater remediation by TiO2-impregnated chitosan nano-grafts exhibited dual functionality: High adsorptivity and solar-assisted self-cleaning.

    Science.gov (United States)

    Essawy, Amr A; Sayyah, S M; El-Nggar, A M

    2017-08-01

    This work provides a very infrequent and unique avenue of a novel bio-based nanografted polymeric composites achieving encouraging results in green management of dye contaminants in wastewater. A chitosan-grafted-polyN-Methylaniline (Ch-g-PNMANI) and chitosan-grafted-polyN-Methylaniline imprinted TiO 2 nanocomposites (Ch-g-PNMANI/TiO 2 ) were prepared and efficiently applied in wastewater remediation. The nanocomposites were characterized by FT-IR spectroscopy, X-ray diffraction, transmission electron microscopy, UV-Vis diffuse reflectance spectroscopy and Brunauer-Emmett-Teller surface area (BET) measurements. The prepared composites exhibit higher adsorptivity in removing remazol red RB-133 (RR RB-133) dye compared to other adsorbents reported in literature. The effects of TiO 2 loadings, initial dye concentration, contact time, and pH on dye adsorption were investigated. The maximum adsorption of dye was found at low pH values. Furthermore, Ch-g-PNMANI/TiO 2 of the optimum TiO 2 loading has higher adsorption capacity (116.3mg/g) than the pristine Ch-g-PNMANI (108.7mg/g). Moreover, the prepared adsorbents are photoactive under sunlight-irradiation. The study addresses a nanocomposite of considerable adsorption and in the same time has the fastest self-cleaning photoactivity (t 1/2 =31.5min.) under sunlight irradiation where a plausible photodegradation mechanism was proposed. Interestingly, the presented photoactive adsorbents are still effective in removing dye after five adsorption/sunlight-assisted self-cleaning photoregeneration cycles and therefore, they can be potentially applied to the rapid, "green" and low-cost remediation of RR RB-133 enriched industrial printing and dyeing wastewater. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Gene prediction validation and functional analysis of redundant pathways

    DEFF Research Database (Denmark)

    Sønderkær, Mads

    2011-01-01

    have employed a large mRNA-seq data set to improve and validate ab initio predicted gene models. This direct experimental evidence also provides reliable determinations of UTR regions and polyadenylation sites, which are not easily predicted in plants. Furthermore, once an annotated genome sequence...... is available, gene expression by mRNA-Seq enables acquisition of a more complete overview of gene isoform usage in complex enzymatic pathways enabling the identification of key genes. Metabolism in potatoes This information is useful e.g. for crop improvement based on manipulation of agronomically important...

  18. Redundancy proves its worth in FR Germany [emergency power supplies

    International Nuclear Information System (INIS)

    Simon, M.

    1987-01-01

    An analysis of loss of power events at nuclear power stations in FR Germany has confirmed the data used in the German risk study and underlined the advantages of providing a high degree of redundancy in emergency power supplies. (author)

  19. Retraction: Redundant Publication of the article Dental caries and ...

    African Journals Online (AJOL)

    Retraction: Redundant Publication of the article Dental caries and oral health practices among 12 year old children in Nairobi West and Mathira West Districts, Kenya. Gladwell Gathecha et al. The Pan African Medical Journal. 2012;12:42.

  20. Signal validation in nuclear power plants using redundant measurements

    International Nuclear Information System (INIS)

    Glockler, O.; Upadhyaya, B.R.; Morgenstern, V.M.

    1989-01-01

    This paper discusses the basic principles of a multivariable signal validation software system utilizing redundant sensor readings of process variables in nuclear power plants (NPPs). The technique has been tested in numerical experiments, and was applied to actual data from a pressurized water reactor (PWR). The simultaneous checking within one redundant measurement set, and the cross-checking among redundant measurement sets of dissimilar process variables, results in an algorithm capable of detecting and isolating bias-type errors. A case in point occurs when a majority of the direct redundant measurements of more than one process variable has failed simultaneously by a common-mode or correlated failures can be detected by the developed approach. 5 refs

  1. Triple3 Redundant Spacecraft Subsystems (T3RSS), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Redefine Technologies, along with researchers at the University of Colorado, will use three redundancy methods to decrease the susceptibility of a spacecraft, on a...

  2. International Space Station exhibit

    Science.gov (United States)

    2000-01-01

    The International Space Station (ISS) exhibit in StenniSphere at John C. Stennis Space Center in Hancock County, Miss., gives visitors an up-close look at the largest international peacetime project in history. Step inside a module of the ISS and glimpse how astronauts will live and work in space. Currently, 16 countries contribute resources and hardware to the ISS. When complete, the orbiting research facility will be larger than a football field.

  3. Upcycling CERN Exhibitions

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    Summer is coming - and with it, a new Microcosm exhibition showcasing CERN (see here). But while the new exhibit is preparing to enchant visitors, many have been asking about the site's former content. Will it simply be out with the old and in with the new? Not as such!   The plasma ball from Microcosm is now on display at the LHCb site. As Microcosm's new content is moving in, its old content is moving up. From LHCb to IdeaSquare, former Microcosm displays and objects are being installed across the CERN site. "Microcosm featured many elements that were well suited to life outside of the exhibition," says Emma Sanders, Microcosm project leader in the EDU group. "We didn't want this popular content to go to waste, and so set out to find them new homes across CERN." The LHCb experiment has received a number of Microcosm favourites, including the Rutherford experiment, the cosmic ray display and the Thomson experiment. "We&...

  4. Obese First-Degree Relatives of Patients with Type 2 Diabetes with Elevated Triglyceride Levels Exhibit Increased β-Cell Function

    Science.gov (United States)

    Torres-Rasgado, Enrique; Porchia, Leonardo M.; Ruiz-Vivanco, Guadalupe; Gonzalez-Mejia, M. Elba; Báez-Duarte, Blanca G.; Pulido-Pérez, Patricia; Rivera, Alicia; Romero, Jose R.

    2015-01-01

    Abstract Background: Type 2 diabetes mellitus (T2DM) is characterized as a disease continuum that is marked by metabolic changes that are present for several years, sometimes well before frank diagnosis of T2DM. Genetic predisposition, ethnicity, geography, alterations in BMI, and lipid profile are considered important markers for the pathogenesis of T2DM through mechanisms that remain unresolved and controversial. The aim of this study was to investigate the relationship between triglycerides (TGs) and β-cell function, insulin resistance (IR), and insulin sensitivity (IS) in obese first-degree relatives of patients with T2DM (FDR-T2DM) among subjects from central Mexico with normal glucose tolerance (NGT). Methods: We studied 372 FDR-T2DM subjects (ages,18–65) and determined body mass index (BMI), fasting plasma glucose (FPG), oral glucose tolerance test (OGTT), insulin, and TGs levels. Subjects were categorized based on glycemic control [NGT, prediabetes (PT2DM), or T2DM]. NGT subjects were further categorized by BMI [normal weight (Ob−) or obese (Ob+)] and TGs levels (TG−, Mexico with NGT and revealed a class of obese subjects with elevated TGs and β-cell function, which may precede PT2DM. PMID:25423015

  5. Resolving Actuator Redundancy - Control Allocation vs. Linear Quadratic Control

    OpenAIRE

    Härkegård, Ola

    2004-01-01

    When designing control laws for systems with more inputs than controlled variables, one issue to consider is how to deal with actuator redundancy. Two tools for distributing the control effort among a redundant set of actuators are control allocation and linear quadratic control design. In this paper, we investigate the relationship between these two design tools when a quadratic performance index is used for control allocation. We show that for a particular class of linear systems, they give...

  6. Kinematic control of redundant robots and the motion optimizability measure.

    Science.gov (United States)

    Li, L; Gruver, W A; Zhang, Q; Yang, Z

    2001-01-01

    This paper treats the kinematic control of manipulators with redundant degrees of freedom. We derive an analytical solution for the inverse kinematics that provides a means for accommodating joint velocity constraints in real time. We define the motion optimizability measure and use it to develop an efficient method for the optimization of joint trajectories subject to multiple criteria. An implementation of the method for a 7-dof experimental redundant robot is present.

  7. Assessment of treatment response to splint therapy and evaluation of TMJ function using joint vibration analysis in patients exhibiting TMJ disc displacement with reduction: A clinical study

    Directory of Open Access Journals (Sweden)

    Jyoti Devi

    2017-01-01

    Full Text Available Context, Aim, and Objectives: Diagnosis of temporomandibular joint (TMJ disc displacement with reduction (DDR is difficult. Literature combining different subjective parameters of TMJ function with an objective evaluation of TMJ function using joint vibration analysis (JVA is limited. Hence, the study was planned to diagnose temporomandibular disorder accurately, to do a subjective and objective evaluation of TMJ function, and to assess the effectiveness of different types of splint therapy over the conventional anterior repositioning appliance (ARA group. Design: Single-blind, randomized, comparative clinical trial conducted in thirty patients, 18–55 years of age, allocated to three groups, i.e., ARA conventional group, centric stabilization splint (CSS, and Soft splint (SS groups. Subjects and Methods: Preoperative values of comfortable mouth opening (CMO in mm, maximum mouth opening (MMO in mm, TMJ clicking and tenderness (grading 0–3, visual analog scale pain score (0–10 cm, and total energy (TE integral values of both TMJs using JVA were recorded. Postoperative values were taken at the time of delivery of splint at 1st, 2nd, 6th, and 10th week. Statistical Analysis and Results: Intergroup comparison – Kruskal–Wallis test showed no statistically significant difference in CMO, MMO, and TE values of right TMJs among three groups at any point. No significant difference was seen in TMJ clicking and tenderness among groups at any point of time except at 10 weeks and at 2 weeks, respectively, by Chi-square test. Intragroup comparison - Wilcoxon signed-rank test showed the significance of difference (P < 0.05* in postoperative visits for CMO, MMO, pain score, and TE values. Clinical effect size, extent, consistency, and percentage of cases showing improvement were maximum for CSS group. Conclusions: The study concludes that the use of JVA for diagnosis along with history and clinical examination increases the accuracy of the diagnosis of

  8. ANALYSIS OF RELIABILITY OF THE PERIODICALLY AND CONTINUOUSLY CONTROLLED QUEUING SYSTEM WITH TIME REDUNDANCY

    International Nuclear Information System (INIS)

    Mikadze, I.; Namchevadze, T.; Gobiani, I.

    2007-01-01

    There is proposed a generalized mathematical model of the queuing system with time redundancy without preliminary checking of the queuing system at transition from the free state into the engaged one. The model accounts for various failures of the queuing system detected by continuous instrument control, periodic control, control during recovery and the failures revealed immediately after accumulation of a certain number of failures. The generating function of queue length in both stationary and nonstationary modes was determined. (author)

  9. A prenatal interruption of DISC1 function in the brain exhibits a lasting impact on adult behaviors, brain metabolism, and interneuron development.

    Science.gov (United States)

    Deng, Dazhi; Jian, Chongdong; Lei, Ling; Zhou, Yijing; McSweeney, Colleen; Dong, Fengping; Shen, Yilun; Zou, Donghua; Wang, Yonggang; Wu, Yuan; Zhang, Limin; Mao, Yingwei

    2017-10-17

    Mental illnesses like schizophrenia (SCZ) and major depression disorder (MDD) are devastating brain disorders. The SCZ risk gene, disrupted in schizophrenia 1 ( DISC1 ), has been associated with neuropsychiatric conditions. However, little is known regarding the long-lasting impacts on brain metabolism and behavioral outcomes from genetic insults on fetal NPCs during early life. We have established a new mouse model that specifically interrupts DISC1 functions in NPCs in vivo by a dominant-negative DISC1 (DN-DISC1) with a precise temporal and spatial regulation. Interestingly, prenatal interruption of mouse Disc1 function in NPCs leads to abnormal depression-like deficit in adult mice. Here we took a novel unbiased metabonomics approach to identify brain-specific metabolites that are significantly changed in DN-DISC1 mice. Surprisingly, the inhibitory neurotransmitter, GABA, is augmented. Consistently, parvalbumin (PV) interneurons are increased in the cingulate cortex, retrosplenial granular cortex, and motor cortex. Interestingly, somatostatin (SST) positive and neuropeptide Y (NPY) interneurons are decreased in some brain regions, suggesting that DN-DISC1 expression affects the localization of interneuron subtypes. To further explore the cellular mechanisms that cause this change, DN-DISC1 suppresses proliferation and promotes the cell cycle exit of progenitors in the medial ganglionic eminence (MGE), whereas it stimulates ectopic proliferation of neighboring cells through cell non-autonomous effect. Mechanistically, it modulates GSK3 activity and interrupts Dlx2 activity in the Wnt activation. In sum, our results provide evidence that specific genetic insults on NSCs at a short period of time could lead to prolonged changes of brain metabolism and development, eventually behavioral defects.

  10. Neural redundancy applied to the parity space for signal validation

    International Nuclear Information System (INIS)

    Mol, Antonio Carlos de Abreu; Pereira, Claudio Marcio Nascimento Abreu; Martinez, Aquilino Senra

    2005-01-01

    The objective of signal validation is to provide more reliable information from the plant sensor data The method presented in this work introduces the concept of neural redundancy and applies it to the space parity method [1] to overcome an inherent deficiency of this method - the determination of the best estimative of the redundant measures when they are inconsistent. The concept of neural redundancy consists on the calculation of a redundancy through neural networks based on the time series of the own state variable. Therefore, neural networks, dynamically trained with the time series, will estimate the current value of the own measure, which will be used as referee of the redundant measures in the parity space. For this purpose the neural network should have the capacity to supply the neural redundancy in real time and with maximum error corresponding to the group deviation. The historical series should be enough to allow the estimate of the next value, during transients and at the same time, it should be optimized to facilitate the retraining of the neural network to each acquisition. In order to have the capacity to reproduce the tendency of the time series even under accident condition, the dynamic training of the neural network privileges the recent points of the time series. The tests accomplished with simulated data of a nuclear plant, demonstrated that this method applied on the parity space method improves the signal validation process. (author)

  11. Neural redundancy applied to the parity space for signal validation

    Energy Technology Data Exchange (ETDEWEB)

    Mol, Antonio Carlos de Abreu; Pereira, Claudio Marcio Nascimento Abreu [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)]. E-mail: cmnap@ien.gov.br; Martinez, Aquilino Senra [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia]. E-mail: aquilino@lmp.br

    2005-07-01

    The objective of signal validation is to provide more reliable information from the plant sensor data The method presented in this work introduces the concept of neural redundancy and applies it to the space parity method [1] to overcome an inherent deficiency of this method - the determination of the best estimative of the redundant measures when they are inconsistent. The concept of neural redundancy consists on the calculation of a redundancy through neural networks based on the time series of the own state variable. Therefore, neural networks, dynamically trained with the time series, will estimate the current value of the own measure, which will be used as referee of the redundant measures in the parity space. For this purpose the neural network should have the capacity to supply the neural redundancy in real time and with maximum error corresponding to the group deviation. The historical series should be enough to allow the estimate of the next value, during transients and at the same time, it should be optimized to facilitate the retraining of the neural network to each acquisition. In order to have the capacity to reproduce the tendency of the time series even under accident condition, the dynamic training of the neural network privileges the recent points of the time series. The tests accomplished with simulated data of a nuclear plant, demonstrated that this method applied on the parity space method improves the signal validation process. (author)

  12. Joint optimization of redundancy level and spare part inventories

    International Nuclear Information System (INIS)

    Sleptchenko, Andrei; Heijden, Matthieu van der

    2016-01-01

    We consider a “k-out-of-N” system with different standby modes. Each of the N components consists of multiple part types. Upon failure, a component can be repaired within a certain time by switching the failed part by a spare, if available. We develop both an exact and a fast approximate analysis to compute the system availability. Next, we jointly optimize the component redundancy level with the inventories of the various spare parts. We find that our approximations are very accurate and suitable for large systems. We apply our model to a case study at a public organization in Qatar, and find that we can improve the availability-to-cost ratio by reducing the redundancy level and increasing the spare part inventories. In general, high redundancy levels appear to be useful only when components are relatively cheap and part replacement times are high. - Highlights: • We analyze a redundant system (k-out-of-N) with multiple parts and spares. • We jointly optimize the redundancy level and the spare part inventories. • We develop an exact method and an approximation to evaluate the system availability. • Adding spare parts and reducing the redundancy level cuts cost by 50% in a case study. • The availability is not very sensitive to the shape of the failure time distribution.

  13. Multi-objective reliability redundancy allocation in an interval environment using particle swarm optimization

    International Nuclear Information System (INIS)

    Zhang, Enze; Chen, Qingwei

    2016-01-01

    Most of the existing works addressing reliability redundancy allocation problems are based on the assumption of fixed reliabilities of components. In real-life situations, however, the reliabilities of individual components may be imprecise, most often given as intervals, under different operating or environmental conditions. This paper deals with reliability redundancy allocation problems modeled in an interval environment. An interval multi-objective optimization problem is formulated from the original crisp one, where system reliability and cost are simultaneously considered. To render the multi-objective particle swarm optimization (MOPSO) algorithm capable of dealing with interval multi-objective optimization problems, a dominance relation for interval-valued functions is defined with the help of our newly proposed order relations of interval-valued numbers. Then, the crowding distance is extended to the multi-objective interval-valued case. Finally, the effectiveness of the proposed approach has been demonstrated through two numerical examples and a case study of supervisory control and data acquisition (SCADA) system in water resource management. - Highlights: • We model the reliability redundancy allocation problem in an interval environment. • We apply the particle swarm optimization directly on the interval values. • A dominance relation for interval-valued multi-objective functions is defined. • The crowding distance metric is extended to handle imprecise objective functions.

  14. Video rate morphological processor based on a redundant number representation

    Science.gov (United States)

    Kuczborski, Wojciech; Attikiouzel, Yianni; Crebbin, Gregory A.

    1992-03-01

    This paper presents a video rate morphological processor for automated visual inspection of printed circuit boards, integrated circuit masks, and other complex objects. Inspection algorithms are based on gray-scale mathematical morphology. Hardware complexity of the known methods of real-time implementation of gray-scale morphology--the umbra transform and the threshold decomposition--has prompted us to propose a novel technique which applied an arithmetic system without carrying propagation. After considering several arithmetic systems, a redundant number representation has been selected for implementation. Two options are analyzed here. The first is a pure signed digit number representation (SDNR) with the base of 4. The second option is a combination of the base-2 SDNR (to represent gray levels of images) and the conventional twos complement code (to represent gray levels of structuring elements). Operation principle of the morphological processor is based on the concept of the digit level systolic array. Individual processing units and small memory elements create a pipeline. The memory elements store current image windows (kernels). All operation primitives of processing units apply a unified direction of digit processing: most significant digit first (MSDF). The implementation technology is based on the field programmable gate arrays by Xilinx. This paper justified the rationality of a new approach to logic design, which is the decomposition of Boolean functions instead of Boolean minimization.

  15. High performance 14-bit pipelined redundant signed digit ADC

    International Nuclear Information System (INIS)

    Narula, Swina; Pandey, Sujata

    2016-01-01

    A novel architecture of a pipelined redundant-signed-digit analog to digital converter (RSD-ADC) is presented featuring a high signal to noise ratio (SNR), spurious free dynamic range (SFDR) and signal to noise plus distortion (SNDR) with efficient background correction logic. The proposed ADC architecture shows high accuracy with a high speed circuit and efficient utilization of the hardware. This paper demonstrates the functionality of the digital correction logic of 14-bit pipelined ADC at each 1.5 bit/stage. This prototype of ADC architecture accounts for capacitor mismatch, comparator offset and finite Op-Amp gain error in the MDAC (residue amplification circuit) stages. With the proposed architecture of ADC, SNDR obtained is 85.89 dB, SNR is 85.9 dB and SFDR obtained is 102.8 dB at the sample rate of 100 MHz. This novel architecture of digital correction logic is transparent to the overall system, which is demonstrated by using 14-bit pipelined ADC. After a latency of 14 clocks, digital output will be available at every clock pulse. To describe the circuit behavior of the ADC, VHDL and MATLAB programs are used. The proposed architecture is also capable of reducing the digital hardware. Silicon area is also the complexity of the design. (paper)

  16. Skew redundant MEMS IMU calibration using a Kalman filter

    International Nuclear Information System (INIS)

    Jafari, M; Sahebjameyan, M; Moshiri, B; Najafabadi, T A

    2015-01-01

    In this paper, a novel calibration procedure for skew redundant inertial measurement units (SRIMUs) based on micro-electro mechanical systems (MEMS) is proposed. A general model of the SRIMU measurements is derived which contains the effects of bias, scale factor error and misalignments. For more accuracy, the effect of lever arms of the accelerometers to the center of the table are modeled and compensated in the calibration procedure. Two separate Kalman filters (KFs) are proposed to perform the estimation of error parameters for gyroscopes and accelerometers. The predictive error minimization (PEM) stochastic modeling method is used to simultaneously model the effect of bias instability and random walk noise on the calibration Kalman filters to diminish the biased estimations. The proposed procedure is simulated numerically and has expected experimental results. The calibration maneuvers are applied using a two-axis angle turntable in a way that the persistency of excitation (PE) condition for parameter estimation is met. For this purpose, a trapezoidal calibration profile is utilized to excite different deterministic error parameters of the accelerometers and a pulse profile is used for the gyroscopes. Furthermore, to evaluate the performance of the proposed KF calibration method, a conventional least squares (LS) calibration procedure is derived for the SRIMUs and the simulation and experimental results compare the functionality of the two proposed methods with each other. (paper)

  17. Reliability analysis of a complex standby redundant systems

    International Nuclear Information System (INIS)

    Subramanian, R.; Anantharaman, V.

    1995-01-01

    In any redundant system, the state of the standby unit is usually taken to be hot, warm or cold. In this paper, we present a new model of a two unit standby system wherein the standby unit is put in cold state for a certain amount of time before it is allowed to become warm. Upon failure of the online unit, the standby unit, if in warm state, instantaneously starts operating online; if it is in cold state, an emergency switching is made which takes it to warm state (and hence online) either instantaneously or non-instantaneously--each with some probability; if it is under repair, the system breaks down. Assuming all the associated distributions to be general except that of the life time of the standby unit in the warm state, various reliability characteristics that are of interest to reliability engineers and system designers are derived. A comprehensive cost function is also constructed and is then optimized with respect to three different control parameters numerically. In addition numerical results are presented to illustrate the behaviour of the various reliability characteristics derived

  18. FIZCON, ENDF/B Cross-Sections Redundancy Check

    International Nuclear Information System (INIS)

    Dunford, Charles L.

    2007-01-01

    1 - Description of program or function: FIZCON is a program for checking that an evaluated data file has valid data and conforms to recommended procedures. Version 7.01 (April 2005): set success flag after return from beginning; fixed valid level check for an isomer; fixed subsection energy range test in ckf9; changed lower limit on potential scattering test; fixed error in j-value test when l=0 and i=0; added one more significant figure to union grid check and sum up output messages; partial fission cross sections mt=19,20,21 and 38 did not require secondary energy distributions in file 5; corrected product test for elastic scattering; moved potential scattering test to psyche. Version 7.02 (May 2005): Fixed resonance parameter sum test. 2 - Method of solution: FIZCON can recognise the difference between ENDF-6 and ENDF-5 formats and performs its tests accordingly. Some of the tests performed include: data arrays are in increasing energy order; resonance parameter widths add up to the total; Q-values are reasonable and consistent; no required sections are missing and all cover the proper energy range; secondary distributions are normalized to 1.0; energy conservation in decay spectra. Optional tests can be performed to check the redundant cross sections, and algorithms can be used to check for possible incorrect entry of data values (Deviant Point test)

  19. Mobile exhibition in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1960-04-15

    Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

  20. Mobile exhibition in Mexico

    International Nuclear Information System (INIS)

    1960-01-01

    Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

  1. Comparison of Fresnel zone plates and uniformly redundant arrays

    International Nuclear Information System (INIS)

    Fenimore, E.E.; Cannon, T.M.; Miller, E.L.

    1978-01-01

    Several imaging systems in laser fusion, e-beam fusion, and astronomy employ a Fresnel zone plate (FZP) as a coded aperture. The recent development of uniformly redundant arrays (URAs) promises several improvements in these systems. The first advantage of the URA is the fact that its modulation transfer function (MTF) is the same as the MTF of a single pinhole, whereas the MTF of an FZP is an erratic function including some small values. This means that if inverse filtering is used, the URA will be less susceptible to noise. If a correlation analysis is used, the FZP will produce artifacts whereas the URA has no artifacts (assuming planar sources). Both the FZP and URA originated from functions which had flat MTFs. However, practical considerations in the implementation of the FZP detracted from its good characteristics whereas the URA was only mildly affected. The second advantage of the URA is that it better utilizes the available detector area. With the FZP, the aperture should be smaller than the detector in order to maintain the full angular resolution corresponding to the thinnest zone. The cyclic nature of the URA allows one to mosaic it in such a way that the entire detector area collects photons from all of the sources within the field of view while maintaining the full angular resolution. If the FZP is as large (or larger) than the detector, all parts of the source will not be resolved with the same resolution. The FZP does have some advantages, in particular its radial symmetry eases the alignment problem; it has a convenient optical decoding method; and higher diffraction order reconstruction might provide better spatial resolution

  2. Anniversary Exhibition. Nechvolodov.

    Directory of Open Access Journals (Sweden)

    - -

    2006-03-01

    Full Text Available On the 10th of August, 2005 in Tartu (the second biggest educational and cultural city in Estonia Stanislav Nechvolodov's exhibition was opened to show the 5-year cycle of his work, traditional for the author and his admirers. At the opening ceremony Nechvolodov said that the exhibition was the last one and appointed on his 70th anniversary.The architectural and building society in Irkutsk remembers Stanislav Nechvolodov as an architect working on dwelling and civil buildings in 1960-70s. Below are some extracts from the Estonian press.«Postimees» newspaper, December 1993. The interview «Expressionistic naturalist, conservative Nechvolodov» by journalist Eric Linnumyagi. He asks about all the details and describes the troubles experienced by Nechvolodov during the perestroika period in Estonia, for example: the Tartu University refused to install the sculpture of Socrat, the art school refused to engage him as an instructor, the sculpture of Socrat moved to Vrotzlav, Poland, and Nechvolodov moved to Poland to read lectures there.«Tartu» newspaper, November 2000. Mats Oun, artist, says in the article «Nechvolodov: a man of Renaissance»: «Nechvolodov works in Estonia, his works are placed in many local and foreign museums. Regardless some insignificant faults, he deserves a high estimation, and his manysided open exhibition can be an example for other artists. He is a man of Renaissance».

  3. 78 FR 76057 - Removal of Redundant Regulations

    Science.gov (United States)

    2013-12-16

    ... authority of certain civil rights functions, protection of human subjects, and care and use of animals in... related to delegation of authority of certain civil rights functions, protection of human subjects, and care and use of animals in the conduct of NASA activities. Therefore, NASA regulations will be...

  4. Coherent network detection of gravitational waves: the redundancy veto

    International Nuclear Information System (INIS)

    Wen Linqing; Schutz, Bernard F

    2005-01-01

    A network of gravitational wave detectors is called redundant if, given the direction to a source, the strain induced by a gravitational wave in one or more of the detectors can be fully expressed in terms of the strain induced in others in the network. Because gravitational waves have only two polarizations, any network of three or more differently oriented interferometers with similar observing bands is redundant. The three-armed LISA space interferometer has three outputs that are redundant at low frequencies. The two aligned LIGO interferometers at Hanford WA are redundant, and the LIGO detector at Livingston LA is nearly redundant with either of the Hanford detectors. Redundant networks have a powerful veto against spurious noise, a linear combination of the detector outputs that contains no gravitational wave signal. For LISA, this 'null' output is known as the Sagnac mode, and its use in discriminating between detector noise and a cosmological gravitational wave background is well understood. But the usefulness of the null veto for ground-based detector networks has been ignored until now. We show that it should make it possible to discriminate in a model-independent way between real gravitational waves and accidentally coincident non-Gaussian noise 'events' in redundant networks of two or more broadband detectors. It has been shown that with three detectors, the null output can even be used to locate the direction to the source, and then two other linear combinations of detector outputs give the optimal 'coherent' reconstruction of the two polarization components of the signal. We discuss briefly the implementation of such a detection strategy in realistic networks, where signals are weak, detector calibration is a significant uncertainty, and the various detectors may have different (but overlapping) observing bands

  5. Optimization of robustness of interdependent network controllability by redundant design.

    Directory of Open Access Journals (Sweden)

    Zenghu Zhang

    Full Text Available Controllability of complex networks has been a hot topic in recent years. Real networks regarded as interdependent networks are always coupled together by multiple networks. The cascading process of interdependent networks including interdependent failure and overload failure will destroy the robustness of controllability for the whole network. Therefore, the optimization of the robustness of interdependent network controllability is of great importance in the research area of complex networks. In this paper, based on the model of interdependent networks constructed first, we determine the cascading process under different proportions of node attacks. Then, the structural controllability of interdependent networks is measured by the minimum driver nodes. Furthermore, we propose a parameter which can be obtained by the structure and minimum driver set of interdependent networks under different proportions of node attacks and analyze the robustness for interdependent network controllability. Finally, we optimize the robustness of interdependent network controllability by redundant design including node backup and redundancy edge backup and improve the redundant design by proposing different strategies according to their cost. Comparative strategies of redundant design are conducted to find the best strategy. Results shows that node backup and redundancy edge backup can indeed decrease those nodes suffering from failure and improve the robustness of controllability. Considering the cost of redundant design, we should choose BBS (betweenness-based strategy or DBS (degree based strategy for node backup and HDF(high degree first for redundancy edge backup. Above all, our proposed strategies are feasible and effective at improving the robustness of interdependent network controllability.

  6. The heuristic value of redundancy models of aging.

    Science.gov (United States)

    Boonekamp, Jelle J; Briga, Michael; Verhulst, Simon

    2015-11-01

    Molecular studies of aging aim to unravel the cause(s) of aging bottom-up, but linking these mechanisms to organismal level processes remains a challenge. We propose that complementary top-down data-directed modelling of organismal level empirical findings may contribute to developing these links. To this end, we explore the heuristic value of redundancy models of aging to develop a deeper insight into the mechanisms causing variation in senescence and lifespan. We start by showing (i) how different redundancy model parameters affect projected aging and mortality, and (ii) how variation in redundancy model parameters relates to variation in parameters of the Gompertz equation. Lifestyle changes or medical interventions during life can modify mortality rate, and we investigate (iii) how interventions that change specific redundancy parameters within the model affect subsequent mortality and actuarial senescence. Lastly, as an example of data-directed modelling and the insights that can be gained from this, (iv) we fit a redundancy model to mortality patterns observed by Mair et al. (2003; Science 301: 1731-1733) in Drosophila that were subjected to dietary restriction and temperature manipulations. Mair et al. found that dietary restriction instantaneously reduced mortality rate without affecting aging, while temperature manipulations had more transient effects on mortality rate and did affect aging. We show that after adjusting model parameters the redundancy model describes both effects well, and a comparison of the parameter values yields a deeper insight in the mechanisms causing these contrasting effects. We see replacement of the redundancy model parameters by more detailed sub-models of these parameters as a next step in linking demographic patterns to underlying molecular mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Human genetics of infectious diseases: Unique insights into immunological redundancy.

    Science.gov (United States)

    Casanova, Jean-Laurent; Abel, Laurent

    2018-04-01

    For almost any given human-tropic virus, bacterium, fungus, or parasite, the clinical outcome of primary infection is enormously variable, ranging from asymptomatic to lethal infection. This variability has long been thought to be largely determined by the germline genetics of the human host, and this is increasingly being demonstrated to be the case. The number and diversity of known inborn errors of immunity is continually increasing, and we focus here on autosomal and X-linked recessive traits underlying complete deficiencies of the encoded protein. Schematically, four types of infectious phenotype have been observed in individuals with such deficiencies, each providing information about the redundancy of the corresponding human gene, in terms of host defense in natural conditions. The lack of a protein can confer vulnerability to a broad range of microbes in most, if not all patients, through the disruption of a key immunological component. In such cases, the gene concerned is of low redundancy. However, the lack of a protein may also confer vulnerability to a narrow range of microbes, sometimes a single pathogen, and not necessarily in all patients. In such cases, the gene concerned is highly redundant. Conversely, the deficiency may be apparently neutral, conferring no detectable predisposition to infection in any individual. In such cases, the gene concerned is completely redundant. Finally, the lack of a protein may, paradoxically, be advantageous to the host, conferring resistance to one or more infections. In such cases, the gene is considered to display beneficial redundancy. These findings reflect the current state of evolution of humans and microbes, and should not be considered predictive of redundancy, or of a lack of redundancy, in the distant future. Nevertheless, these observations are of potential interest to present-day biologists testing immunological hypotheses experimentally and physicians managing patients with immunological or infectious

  8. Redundant nerve roots of the cauda equina : MR findings

    International Nuclear Information System (INIS)

    Oh, Kyu Hyen; Lee, Jung Man; Jung, Hak Young; Lee, Young Hwan; Sung, Nak Kwan; Chung, Duck Soo; Kim, Ok Dong; Lee, Sang Kwon; Suh, Kyung Jin

    1997-01-01

    To evaluate MR findings of redundant nerve roots (RNR) of the cauda equina. 17 patients with RNR were studied; eight were men and nine were women, and their ages ranged from 46 to 82 (mean 63) years. Diagroses were established on the basis of T2-weighted sagittal and coronal MRI, which showed a tortuous or coiled configuration of the nerve roots of the cauda equina. MR findings were reviewed for location, magnitude, and signal intensity of redundant nerve roots, and the relationship between magnitude of redundancy and severity of lumbar spinal canal stenosis (LSCS) was evaluated. In all 17 patients, MR showed moderate or severe LSCS caused by herniation or bulging of an intervertebral disc, osteophyte from the vertebral body or facet joint, thickening of the ligamentum flavum, degenerative spondylolisthesis, or a combination of these. T2-weighted sagittal and coronal MR images well clearly showed the location of RNR of the cauda equina;in 16 patients(94%), these were seen above the level of constriction of the spinal canal, and in one case, they were observed below the level of constriction. T2-weighted axial images showed the thecal sac filled with numerous nerve roots. The magnitude of RNR was mild in six cases (35%), moderate in five cases (30%), and severe in six cases (35%). Compared with normal nerve roots, the RNR signal on T2-weighted images was iso-intense. All patients with severe redundancy showed severe LSCS, but not all cases with severe LSCS showed severe redundancy. Redundant nerve roots of cauda equina were seen in relatively older patients with moderate or severe LSCS and T2-weighted MR images were accurate in identifying redundancy of nerve roots and evaluating their magnitude and location

  9. FIXUP2007, ENDF Format Redundant Cross-Sections Check

    International Nuclear Information System (INIS)

    2007-01-01

    1 - Description of program or function: FIXUP is designed to read evaluated data in the ENDF/B format, perform corrections and output the results in the ENDF/B format. One of the most important functions of this code is to redefine all redundant cross sections to be exactly equal to the sum of its parts. IAEA1309/11: This version includes the updates up to January 30, 2007. Changes in ENDF/B-VII Format and procedures, as well as the evaluations themselves, make it impossible for versions of the ENDF/B pre-processing codes earlier than PREPRO 2007 (2007 Version) to accurately process current ENDF/B-VII evaluations. The present code can handle all existing ENDF/B-VI evaluations through release 8, which will be the last release of ENDF/B-VI. Modifications from previous versions: - Fixup VERS. 2007-1 (Jan. 2007): checked against all ENDF/B-VII; increased page size from 60,000 to 600,000 data points 2 - Method of solution: FIXUP: All MAT numbers on an ENDF/B tape are processed; each MAT is treated separately. Within each MAT, each section before and after MF=3 is read, checked/corrected and output. When MF=3 is located, all cross sections are read, sections deleted, created, checked/corrected (based on user input) and after several intermediate stages written to output. 3 - Restrictions on the complexity of the problem: The program uses only the ENDF/B BCD format tape and copy all sections except File 3 as read. It is assumed that the data is correctly coded. No error checking is performed. Since File 3 data are in identical format for ENDF/B versions I through VI, the program can be used with all these versions. - All data in file 3 and 23 must be linearly interpolable

  10. Radiation-Tolerance Assessment of a Redundant Wireless Device

    Science.gov (United States)

    Huang, Q.; Jiang, J.

    2018-01-01

    This paper presents a method to evaluate radiation-tolerance without physical tests for a commercial off-the-shelf (COTS)-based monitoring device for high level radiation fields, such as those found in post-accident conditions in a nuclear power plant (NPP). This paper specifically describes the analysis of radiation environment in a severe accident, radiation damages in electronics, and the redundant solution used to prolong the life of the system, as well as the evaluation method for radiation protection and the analysis method of system reliability. As a case study, a wireless monitoring device with redundant and diversified channels is evaluated by using the developed method. The study results and system assessment data show that, under the given radiation condition, performance of the redundant device is more reliable and more robust than those non-redundant devices. The developed redundant wireless monitoring device is therefore able to apply in those conditions (up to 10 M Rad (Si)) during a severe accident in a NPP.

  11. Working memory capacity and redundant information processing efficiency.

    Science.gov (United States)

    Endres, Michael J; Houpt, Joseph W; Donkin, Chris; Finn, Peter R

    2015-01-01

    Working memory capacity (WMC) is typically measured by the amount of task-relevant information an individual can keep in mind while resisting distraction or interference from task-irrelevant information. The current research investigated the extent to which differences in WMC were associated with performance on a novel redundant memory probes (RMP) task that systematically varied the amount of to-be-remembered (targets) and to-be-ignored (distractor) information. The RMP task was designed to both facilitate and inhibit working memory search processes, as evidenced by differences in accuracy, response time, and Linear Ballistic Accumulator (LBA) model estimates of information processing efficiency. Participants (N = 170) completed standard intelligence tests and dual-span WMC tasks, along with the RMP task. As expected, accuracy, response-time, and LBA model results indicated memory search and retrieval processes were facilitated under redundant-target conditions, but also inhibited under mixed target/distractor and redundant-distractor conditions. Repeated measures analyses also indicated that, while individuals classified as high (n = 85) and low (n = 85) WMC did not differ in the magnitude of redundancy effects, groups did differ in the efficiency of memory search and retrieval processes overall. Results suggest that redundant information reliably facilitates and inhibits the efficiency or speed of working memory search, and these effects are independent of more general limits and individual differences in the capacity or space of working memory.

  12. Mobility and Position Error Analysis of a Complex Planar Mechanism with Redundant Constraints

    Science.gov (United States)

    Sun, Qipeng; Li, Gangyan

    2018-03-01

    Nowadays mechanisms with redundant constraints have been created and attracted much attention for their merits. The mechanism of the redundant constraints in a mechanical system is analyzed in this paper. A analysis method of Planar Linkage with a repetitive structure is proposed to get the number and type of constraints. According to the difference of applications and constraint characteristics, the redundant constraints are divided into the theoretical planar redundant constraints and the space-planar redundant constraints. And the calculation formula for the number of redundant constraints and type of judging method are carried out. And a complex mechanism with redundant constraints is analyzed of the influence about redundant constraints on mechanical performance. With the combination of theoretical derivation and simulation research, a mechanism analysis method is put forward about the position error of complex mechanism with redundant constraints. It points out the direction on how to eliminate or reduce the influence of redundant constraints.

  13. Collision-free inverse kinematics of the redundant seven link manipulator used in a cucumber harvesting robot

    NARCIS (Netherlands)

    Henten, van E.J.; Schenk, E.J.J.; Willigenburg, van L.G.; Meuleman, J.; Barreiro, P.

    2010-01-01

    The paper presents results of research on an inverse kinematics algorithm that has been used in a functional model of a cucumber-harvesting robot consisting of a redundant P6R manipulator. Within a first generic approach, the inverse kinematics problem was reformulated as a non-linear programming

  14. Mathematical model of process of redundant measurements with uninterrupted influence of measurand on sensing element of sensor

    Directory of Open Access Journals (Sweden)

    Redko V. V.

    2011-12-01

    Full Text Available The paper discusses improvement of accuracy of measurands measurements with the use of measuring channel with nonlinear calibration curve. There is proposed a mathematical model, which describes process of redundant measurements for measuring channel when it’s measurement function is a polynomial of third power.

  15. Repetitive motion planning and control of redundant robot manipulators

    CERN Document Server

    Zhang, Yunong

    2013-01-01

    Repetitive Motion Planning and Control of Redundant Robot Manipulators presents four typical motion planning schemes based on optimization techniques, including the fundamental RMP scheme and its extensions. These schemes are unified as quadratic programs (QPs), which are solved by neural networks or numerical algorithms. The RMP schemes are demonstrated effectively by the simulation results based on various robotic models; the experiments applying the fundamental RMP scheme to a physical robot manipulator are also presented. As the schemes and the corresponding solvers presented in the book have solved the non-repetitive motion problems existing in redundant robot manipulators, it is of particular use in applying theoretical research based on the quadratic program for redundant robot manipulators in industrial situations. This book will be a valuable reference work for engineers, researchers, advanced undergraduate and graduate students in robotics fields. Yunong Zhang is a professor at The School of Informa...

  16. On Planning of FTTH Access Networks with and without Redundancy

    DEFF Research Database (Denmark)

    Riaz, M. Tahir; Haraldsson, Gustav; Gutierrez Lopez, Jose Manuel

    2010-01-01

    This paper presents a planning analysis of FTTH access network with and without redundancy. Traditionally, access networks are planned only without redundancy, which is mainly due to lowering the cost of deployment. As fiber optics provide a huge amount of capacity, more and more services are being...... offered on a single fiber connection. As a single point of failure in fiber connection can cause multiple service deprivation therefore redundancy is very crucial. In this work, an automated planning model was used to test different scenarios of implementation. A cost estimation is presented in terms...... of digging and amount of fiber used. Three topologies, including the traditional one “tree topology”, were test with combination of various passive optical technologies....

  17. Program management aid for redundancy selection and operational guidelines

    Science.gov (United States)

    Hodge, P. W.; Davis, W. L.; Frumkin, B.

    1972-01-01

    Although this criterion was developed specifically for use on the shuttle program, it has application to many other multi-missions programs (i.e. aircraft or mechanisms). The methodology employed is directly applicable even if the tools (nomographs and equations) are for mission peculiar cases. The redundancy selection criterion was developed to insure that both the design and operational cost impacts (life cycle costs) were considered in the selection of the quantity of operational redundancy. These tools were developed as aids in expediting the decision process and not intended as the automatic decision maker. This approach to redundancy selection is unique in that it enables a pseudo systems analysis to be performed on an equipment basis without waiting for all designs to be hardened.

  18. Multisensory processing in the redundant-target effect

    DEFF Research Database (Denmark)

    Gondan, Matthias; Niederhaus, Birgit; Rösler, Frank

    2005-01-01

    Participants respond more quickly to two simultaneously presented target stimuli of two different modalities (redundant targets) than would be predicted from their reaction times to the unimodal targets. To examine the neural correlates of this redundant-target effect, event-related potentials...... (ERPs) were recorded to auditory, visual, and bimodal standard and target stimuli presented at two locations (left and right of central fixation). Bimodal stimuli were combinations of two standards, two targets, or a standard and a target, presented either from the same or from different locations...

  19. Information filtering based on corrected redundancy-eliminating mass diffusion.

    Science.gov (United States)

    Zhu, Xuzhen; Yang, Yujie; Chen, Guilin; Medo, Matus; Tian, Hui; Cai, Shi-Min

    2017-01-01

    Methods used in information filtering and recommendation often rely on quantifying the similarity between objects or users. The used similarity metrics often suffer from similarity redundancies arising from correlations between objects' attributes. Based on an unweighted undirected object-user bipartite network, we propose a Corrected Redundancy-Eliminating similarity index (CRE) which is based on a spreading process on the network. Extensive experiments on three benchmark data sets-Movilens, Netflix and Amazon-show that when used in recommendation, the CRE yields significant improvements in terms of recommendation accuracy and diversity. A detailed analysis is presented to unveil the origins of the observed differences between the CRE and mainstream similarity indices.

  20. Redundant information from thermal illumination: quantum Darwinism in scattered photons

    Energy Technology Data Exchange (ETDEWEB)

    Jess Riedel, C; Zurek, Wojciech H, E-mail: criedel@physics.ucsb.edu [Theory Division, LANL, Los Alamos, NM 87545 (United States)

    2011-07-15

    We study quantum Darwinism, the redundant recording of information about the preferred states of a decohering system by its environment, for an object illuminated by a blackbody. We calculate the quantum mutual information between the object and its photon environment for blackbodies that cover an arbitrary section of the sky. In particular, we demonstrate that more extended sources have a reduced ability to create redundant information about the system, in agreement with previous evidence that initial mixedness of an environment slows-but does not stop-the production of records. We also show that the qualitative results are robust for more general initial states of the system.

  1. Redundant information from thermal illumination: quantum Darwinism in scattered photons

    Science.gov (United States)

    Jess Riedel, C.; Zurek, Wojciech H.

    2011-07-01

    We study quantum Darwinism, the redundant recording of information about the preferred states of a decohering system by its environment, for an object illuminated by a blackbody. We calculate the quantum mutual information between the object and its photon environment for blackbodies that cover an arbitrary section of the sky. In particular, we demonstrate that more extended sources have a reduced ability to create redundant information about the system, in agreement with previous evidence that initial mixedness of an environment slows—but does not stop—the production of records. We also show that the qualitative results are robust for more general initial states of the system.

  2. Reliability model for common mode failures in redundant safety systems

    International Nuclear Information System (INIS)

    Fleming, K.N.

    1974-12-01

    A method is presented for computing the reliability of redundant safety systems, considering both independent and common mode type failures. The model developed for the computation is a simple extension of classical reliability theory. The feasibility of the method is demonstrated with the use of an example. The probability of failure of a typical diesel-generator emergency power system is computed based on data obtained from U. S. diesel-generator operating experience. The results are compared with reliability predictions based on the assumption that all failures are independent. The comparison shows a significant increase in the probability of redundant system failure, when common failure modes are considered. (U.S.)

  3. Redundant control of migration and adhesion by ERM proteins in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Baeyens, Nicolas; Latrache, Iman; Yerna, Xavier; Noppe, Gauthier; Horman, Sandrine; Morel, Nicole

    2013-01-01

    Highlights: •The three ERM proteins are expressed in vascular smooth muscle cell. •ERM depletion inhibited PDGF-evoked migration redundantly. •ERM depletion increased cell adhesion redundantly. •ERM depletion did not affect PDGF-evoked Ca signal, Rac1 activation, proliferation. •ERM proteins control PDGF-induced migration by regulating adhesion. -- Abstract: Ezrin, radixin, and moesin possess a very similar structure with a C-terminal actin-binding domain and a N-terminal FERM interacting domain. They are known to be involved in cytoskeleton organization in several cell types but their function in vascular smooth muscle cells (VSMC) is still unknown. The aim of this study was to investigate the role of ERM proteins in cell migration induced by PDGF, a growth factor involved in pathophysiological processes like angiogenesis or atherosclerosis. We used primary cultured VSMC obtained from rat aorta, which express the three ERM proteins. Simultaneous depletion of the three ERM proteins with specific siRNAs abolished the effects of PDGF on cell architecture and migration and markedly increased cell adhesion and focal adhesion size, while these parameters were only slightly affected by depletion of ezrin, radixin or moesin alone. Rac1 activation, cell proliferation, and Ca 2+ signal in response to PDGF were unaffected by ERM depletion. These results indicate that ERM proteins exert a redundant control on PDGF-induced VSMC migration by regulating focal adhesion turn-over and cell adhesion to substrate

  4. Redundant control of migration and adhesion by ERM proteins in vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Baeyens, Nicolas; Latrache, Iman; Yerna, Xavier [Laboratory of Cell Physiology, IoNS, Université Catholique de Louvain (Belgium); Noppe, Gauthier; Horman, Sandrine [Pôle de Recherche Cardiovasculaire, IREC, Université Catholique de Louvain (Belgium); Morel, Nicole, E-mail: nicole.morel@uclouvain.be [Laboratory of Cell Physiology, IoNS, Université Catholique de Louvain (Belgium)

    2013-11-22

    Highlights: •The three ERM proteins are expressed in vascular smooth muscle cell. •ERM depletion inhibited PDGF-evoked migration redundantly. •ERM depletion increased cell adhesion redundantly. •ERM depletion did not affect PDGF-evoked Ca signal, Rac1 activation, proliferation. •ERM proteins control PDGF-induced migration by regulating adhesion. -- Abstract: Ezrin, radixin, and moesin possess a very similar structure with a C-terminal actin-binding domain and a N-terminal FERM interacting domain. They are known to be involved in cytoskeleton organization in several cell types but their function in vascular smooth muscle cells (VSMC) is still unknown. The aim of this study was to investigate the role of ERM proteins in cell migration induced by PDGF, a growth factor involved in pathophysiological processes like angiogenesis or atherosclerosis. We used primary cultured VSMC obtained from rat aorta, which express the three ERM proteins. Simultaneous depletion of the three ERM proteins with specific siRNAs abolished the effects of PDGF on cell architecture and migration and markedly increased cell adhesion and focal adhesion size, while these parameters were only slightly affected by depletion of ezrin, radixin or moesin alone. Rac1 activation, cell proliferation, and Ca{sup 2+} signal in response to PDGF were unaffected by ERM depletion. These results indicate that ERM proteins exert a redundant control on PDGF-induced VSMC migration by regulating focal adhesion turn-over and cell adhesion to substrate.

  5. Roles of HMGA proteins in cancer: Expression, pathways, and redundancies

    Directory of Open Access Journals (Sweden)

    Giancotti V

    2016-10-01

    Full Text Available The expression of the High Mobility Group A (HMGA proteins, their participation in cancer signalling pathways, and their redundant functions have been reviewed in seven types of cancer: breast, colorectal, prostate, lung, ovarian, thyroid, and brain. The analysis of cell lines and tumours revealed an elevated level of their expression in all fully transformed cancer systems, which represents a step of the main cancer signalling pathways. In breast, colorectal, prostate, and lung cancers Wnt/β-catenin pathway is a master inducer of cell transformation in which are deeply involved HMG A1 and A2 proteins. On the other hand, IL-6/Stat3 pathway is responsible for cancer transformation in breast, lung, and prostate. The expression of HMGA1 in lung and ovarian cancers is due to an active PI3K/Akt pathway. The let-7 family of microRNA represses the expression of HMGA showing specificity by its different forms: the let-7b form is able to inhibit both proteins A1 and A2, the last also inhibited by a, c, d, and g forms. Moreover, both proteins are down-regulated by the repressor couple p53/microRNA-34a. The protein A1 and A2 participate to the Epithelial-Mesenchymal Transition cooperating with the three couples of factors Twist1/2, Snai1/2, and Zeb1/2. Through a combination of pathways, there is the simultaneous presence of high levels of both A1 and A2 together with the expression of other factors: a high co-operating efficiency is reached that supplies the tumour cells with properties of self-renewal, resistance, and invasiveness.

  6. Paralogs hnRNP L and hnRNP LL exhibit overlapping but distinct RNA binding constraints.

    Directory of Open Access Journals (Sweden)

    Sarah A Smith

    Full Text Available HnRNP (heterogeneous nuclear ribonucleoprotein proteins are a large family of RNA-binding proteins that regulate numerous aspects of RNA processing. Interestingly, several paralogous pairs of hnRNPs exist that exhibit similar RNA-binding specificity to one another, yet have non-redundant functional targets in vivo. In this study we systematically investigate the possibility that the paralogs hnRNP L and hnRNP LL have distinct RNA binding determinants that may underlie their lack of functional redundancy. Using a combination of RNAcompete and native gel analysis we find that while both hnRNP L and hnRNP LL preferentially bind sequences that contain repeated CA dinucleotides, these proteins differ in their requirement for the spacing of the CAs. Specifically, hnRNP LL has a more stringent requirement for a two nucleotide space between CA repeats than does hnRNP L, resulting in hnRNP L binding more promiscuously than does hnRNP LL. Importantly, this differential requirement for the spacing of CA dinucleotides explains the previously observed differences in the sensitivity of hnRNP L and LL to mutations within the CD45 gene. We suggest that overlapping but divergent RNA-binding preferences, as we show here for hnRNP L and hnRNP LL, may be commonplace among other hnRNP paralogs.

  7. Filtering Redundant Data from RFID Data Streams

    Directory of Open Access Journals (Sweden)

    Hazalila Kamaludin

    2016-01-01

    Full Text Available Radio Frequency Identification (RFID enabled systems are evolving in many applications that need to know the physical location of objects such as supply chain management. Naturally, RFID systems create large volumes of duplicate data. As the duplicate data wastes communication, processing, and storage resources as well as delaying decision-making, filtering duplicate data from RFID data stream is an important and challenging problem. Existing Bloom Filter-based approaches for filtering duplicate RFID data streams are complex and slow as they use multiple hash functions. In this paper, we propose an approach for filtering duplicate data from RFID data streams. The proposed approach is based on modified Bloom Filter and uses only a single hash function. We performed extensive empirical study of the proposed approach and compared it against the Bloom Filter, d-Left Time Bloom Filter, and the Count Bloom Filter approaches. The results show that the proposed approach outperforms the baseline approaches in terms of false positive rate, execution time, and true positive rate.

  8. Inhibition and Language Pragmatic View in Redundant Data Problem Solving

    Science.gov (United States)

    Setti, Annalisa; Caramelli, Nicoletta

    2007-01-01

    The present study concerns redundant data problems, defined as problems in which irrelevant data is provided. This type of problem provides a misleading context [Pascual-Leone, J. (1987). Organismic process for neo-Piagetian theories: A dialectical causal account of cognitive development. "International Journal of Psychology," 22, 531-570] similar…

  9. Redundancy scheme for multi-layered accelerator control system

    International Nuclear Information System (INIS)

    Chauhan, Amit; Fatnani, Pravin

    2009-01-01

    The control system for SRS Indus-2 has three-layered architecture. There are VMEbus based stations at the lower two layers that are controlled by their respective CPU board. The 'Profibus' fieldbus standard is used for communication between these VME stations distributed in the field. There is a Profibus controller board at each station to implement the communication protocol. The mode of communication is master-slave (command-response) type. This paper proposes a scheme to implement redundancy at the lower two layers namely Layer-2 (Supervisory Layer / Profibus-master) and Layer-3 (Equipment Unit Interface Layer / Profibus-slave). The redundancy is for both the CPU and the communication board. The scheme uses two CPU boards and two Profi controller boards at each L-3 station. This helps in decreasing any downtime resulting either from CPU faults or communication board faults that are placed in the field area. Redundancy of Profi boards provides two active communication channels between the stations that can be used in different ways thereby increasing the availability on a communication link. Redundancy of CPU boards provides certain level of auto fault-recovery as one CPU remains active and the other CPU remains in standby mode, which takes over the control of VMEbus in case of any fault in the main CPU. (author)

  10. The restricted isometry property meets nonlinear approximation with redundant frames

    DEFF Research Database (Denmark)

    Gribonval, Rémi; Nielsen, Morten

    2013-01-01

    with a redundant frame. The main ingredients of our approach are: a) Jackson and Bernstein inequalities, associated to the characterization of certain approximation spaces with interpolation spaces; b) a proof that for overcomplete frames which satisfy a Bernstein inequality, these interpolation spaces are nothing...

  11. Virtual Modular Redundancy of Processor Module in the PLC

    International Nuclear Information System (INIS)

    Lee, Kwang-Il; Hwang, SungJae; Yoon, DongHwa

    2016-01-01

    Dual Modular Redundancy (DMR) is mainly used to implement these safety control systems. DMR is conveyed when components of a system are duplicated, providing another component in case one should fault or fail. This feature has a high availability and large fault tolerant. It provides zero downtime that is required for nuclear power plants. So nuclear power plant has been commercialized by multiple redundant systems. The following paper, we propose a Virtual Modular Redundancy (VMR) rather than physical triple of the Programmable Logic Controller (PLC) processor module to ensure the reliability of the nuclear power plant control system. VMR implementation minimizes design changes to continue to use the commercially available redundant system. Also, the purpose of the VMR is to improve the efficiency and reliability in many ways, such as fault tolerant and fail-safe and cost. VMR guarantees a wide range of reliable fault recovery, fault tolerance, etc. It is prevented before it causes great damages due to the continuous failure of the two modules. The reliable communication speed is slow and also it has a small bandwidth. It is a great loss in the safety control system. However, VMR aims to avoid nuclear power plants that were suspended due to fail-safe. It is not for the purpose of commonly used. Application of VMR is actually expected to require a lot of research and trial and error until they adapt to the nuclear regulatory and standards

  12. Testing the significance of canonical axes in redundancy analysis

    NARCIS (Netherlands)

    Legendre, P.; Oksanen, J.; Braak, ter C.J.F.

    2011-01-01

    1. Tests of significance of the individual canonical axes in redundancy analysis allow researchers to determine which of the axes represent variation that can be distinguished from random. Variation along the significant axes can be mapped, used to draw biplots or interpreted through subsequent

  13. Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    The Internet has provided advancement in the areas of network and networking facilities. Everyone connected to the Internet is concerned about two basic things: the availability of network services and the speed of the network. Network gateway redundancy technology falls within these categories and happens to be one of ...

  14. Simulator of a fail detector system for redundant sensors

    International Nuclear Information System (INIS)

    Assumpcao Filho, E.O.; Nakata, H.

    1990-01-01

    A failure detection and isolation system (FDI) simulation program has been developed for IBM-PC microcomputers. The program, based on the sequencial likelihood ratio testing method developed by A. Wald, was implemented with Monte-Carlo technique. The calculated failure detection rate was favorably compared against the wind-tunnel experimental redundant temperature sensors. (author)

  15. 75 FR 65238 - Loan Guaranty: Elimination of Redundant Regulations; Correction

    Science.gov (United States)

    2010-10-22

    ... DEPARTMENT OF VETERANS AFFAIRS 38 CFR Part 36 RIN 2900-AN71 Loan Guaranty: Elimination of... June 15, 2010 (75 FR 33704), amending its loan guaranty regulations to eliminate redundant regulations... INFORMATION CONTACT: William White, Acting Assistant Director for Loan Processing and Valuation (262...

  16. Virtual Modular Redundancy of Processor Module in the PLC

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang-Il; Hwang, SungJae; Yoon, DongHwa [SOOSAN ENS Co., Seoul (Korea, Republic of)

    2016-10-15

    Dual Modular Redundancy (DMR) is mainly used to implement these safety control systems. DMR is conveyed when components of a system are duplicated, providing another component in case one should fault or fail. This feature has a high availability and large fault tolerant. It provides zero downtime that is required for nuclear power plants. So nuclear power plant has been commercialized by multiple redundant systems. The following paper, we propose a Virtual Modular Redundancy (VMR) rather than physical triple of the Programmable Logic Controller (PLC) processor module to ensure the reliability of the nuclear power plant control system. VMR implementation minimizes design changes to continue to use the commercially available redundant system. Also, the purpose of the VMR is to improve the efficiency and reliability in many ways, such as fault tolerant and fail-safe and cost. VMR guarantees a wide range of reliable fault recovery, fault tolerance, etc. It is prevented before it causes great damages due to the continuous failure of the two modules. The reliable communication speed is slow and also it has a small bandwidth. It is a great loss in the safety control system. However, VMR aims to avoid nuclear power plants that were suspended due to fail-safe. It is not for the purpose of commonly used. Application of VMR is actually expected to require a lot of research and trial and error until they adapt to the nuclear regulatory and standards.

  17. The redundant target effect is affected by modality switch costs

    DEFF Research Database (Denmark)

    Gondan, Matthias; Lange, K.; Rösler, F.

    2004-01-01

    When participants have to respond to stimuli of two modalities, faster reaction times are observed for simultaneous, bimodal events than for unimodal events (the redundant target effect [RTE]). This finding has been interpreted as reflecting processing gains for bimodal relative to unimodal stimu...

  18. Mediated Instruction and Redundancy Remediation in Sciences in ...

    African Journals Online (AJOL)

    The data were analyzed using t-test statistics. Data analysis revealed that use of mediated instruction significantly removed redundancy for science students also the use of mediated instruction influenced academic achievement of science students in secondary schools. Some of the recommendations include that science ...

  19. Network Gateway Technology: The Issue of Redundancy towards ...

    African Journals Online (AJOL)

    Everyone connected to the Internet is concerned about two basic things: the availability of network services and the speed of the network. Network gateway redundancy technology falls within these categories and happens to be one of the newest technologies which only few companies, such as mobile companies and ...

  20. Redundancy Effect on Retention of Vocabulary Words Using Multimedia Presentation

    Science.gov (United States)

    Samur, Yavuz

    2012-01-01

    This study was designed to examine the effect of the redundancy principle in a multimedia presentation constructed for foreign language vocabulary learning on undergraduate students' retention. The underlying hypothesis of this study is that when the students are exposed to the material in multiple ways through animation, concurrent narration,…

  1. Bipartite structure and functional independence of adenovirus type 5 packaging elements.

    OpenAIRE

    Schmid, S I; Hearing, P

    1997-01-01

    Selectivity and polarity of adenovirus type 5 DNA packaging are believed to be directed by an interaction of putative packaging factors with the cis-acting adenovirus packaging domain located within the genomic left end (nucleotides 194 to 380). In previous studies, this packaging domain was mutationally dissected into at least seven functional elements called A repeats. These elements, albeit redundant in function, exhibit differences in the ability to support viral packaging, with elements ...

  2. The role of the ligamentum teres in the adult hip: redundant or relevant? A review

    Science.gov (United States)

    Devitt, Brian M; Arora, Manit

    2018-01-01

    ABSTRACT The ligamentum teres (LT) has traditionally been described as a redundant structure with no contribution to hip biomechanics or function. There has been renewed interest in the LT as a source of hip pathology due to the high prevalence of LT pathology observed at the time of hip arthroscopy. The LT acts a secondary stabilizer to supplement the work of the capsular ligaments and works in a sling-like manner to prevent subluxation of the hip at the extremes of motion. The presence of free nerve endings within the LT indicates a definite role in pain generation, with the LT undergoing various mechanical and histological adaptations to hip pathology. PMID:29423246

  3. Autonomous navigation - The ARMMS concept. [Autonomous Redundancy and Maintenance Management Subsystem

    Science.gov (United States)

    Wood, L. J.; Jones, J. B.; Mease, K. D.; Kwok, J. H.; Goltz, G. L.; Kechichian, J. A.

    1984-01-01

    A conceptual design is outlined for the navigation subsystem of the Autonomous Redundancy and Maintenance Management Subsystem (ARMMS). The principal function of this navigation subsystem is to maintain the spacecraft over a specified equatorial longitude to within + or - 3 deg. In addition, the navigation subsystem must detect and correct internal faults. It comprises elements for a navigation executive and for orbit determination, trajectory, maneuver planning, and maneuver command. Each of these elements is described. The navigation subsystem is to be used in the DSCS III spacecraft.

  4. SIMULATION MODEL FOR DESIGN SUPPORT OF INFOCOMM REDUNDANT SYSTEMS

    Directory of Open Access Journals (Sweden)

    V. A. Bogatyrev

    2016-09-01

    Full Text Available Subject of Research. The paper deals with the effectiveness of multipath transfer of request copies through the network and their redundant service without the use of laborious analytical modeling. The model and support tools for the design of highly reliable distributed systems based on simulation modeling have been created. Method. The effectiveness of many variants of service organization and delivery through the network to the query servers is formed and analyzed. Options for providing redundant service and delivery via the network to the servers of request copies are also considered. The choice of variants for the distribution and service of requests is carried out taking into account the criticality of queries to the time of their stay in the system. The request is considered successful if at least one of its copies is accurately delivered to the working server, ready to service the request received through a network, if it is fulfilled in the set time. Efficiency analysis of the redundant transmission and service of requests is based on the model built in AnyLogic 7 simulation environment. Main Results. Simulation experiments based on the proposed models have shown the effectiveness of redundant transmission of copies of queries (packets to the servers in the cluster through multiple paths with redundant service of request copies by a group of servers in the cluster. It is shown that this solution allows increasing the probability of exact execution of at least one copy of the request within the required time. We have carried out efficiency evaluation of destruction of outdated request copies in the queues of network nodes and the cluster. We have analyzed options for network implementation of multipath transfer of request copies to the servers in the cluster over disjoint paths, possibly different according to the number of their constituent nodes. Practical Relevance. The proposed simulation models can be used when selecting the optimal

  5. Exhibition

    CERN Multimedia

    Staff Association

    2014-01-01

    Energie sombre, matière noire J.-J. Dalmais - J. Maréchal Du 11 au 27 novembre 2014, CERN Meyrin, Bâtiment principal A l’image des particules atomiques qui ont tissé des liens pour créer la matière, deux artistes haut bugistes croisent leurs regards et conjuguent leurs expressions singulières pour faire naître une vision commune de l’univers, produit des forces primordiales. Les sculptures de Jean-Jacques Dalmais et les peintures de Jacki Maréchal se rencontrent pour la première fois et se racontent par un enrichissement mutuel la belle histoire de la Vie. Dialogue magique des œuvres en mouvement qui questionnent en écho l’énergie sombre et la matière noire. Cette harmonieuse confluence de jeux de miroir et de résonnance illumine de poésie et de sobriété l’espace expos&...

  6. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Gaïa Manuella Cany Du 10 au 28 avril 2017 CERN Meyrin, Bâtiment principal Oiseau - Manuella Cany. Tableaux abstraits inspirés de vues satellites ou photos prises du ciel. Certains sont à la frontière du figuratif alors que d'autres permettent de laisser libre cours à son imagination. Aux détails infinis, ces tableaux sont faits pour être vus de loin et de près grâce à une attention toute particulière apportée aux effets de matières et aux couleurs le long de volutes tantôt nuancées tantôt contrastées.   Pour plus d’informations : staff.association@cern.ch | Tél: 022 766 37 38

  7. Exhibition

    CERN Document Server

    Staff Association

    2018-01-01

    En dehors des frontières Maxence Piquet Du 2 au 11 mai 2018 | CERN Meyrin, Bâtiment principal Exposition de peinture d'un artiste autodidacte Maxence Piquet (signature artiste M-P), avec différentes techniques (acrylique, huile, fusain, collage...) et sur différents supports. Un art souvent brut et parfois provoquant, avec des touches expressionnistes et cubistes principale origine de son art. Des œuvres souvent vivent et colorées... Cette exposition est la première en dehors d ses frontières Lorraine et a pour but de faire voyager son art au regard du plus grand nombre . Pour plus d’informations et demandes d’accès : staff.association@cern.ch | Tél: 022 766 37 38

  8. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    The Elementary Particles of Painting Alfonso Fratteggiani Bianchi and Ermanno Imbergamo From September 26 to October 7, 2016 CERN Meyrin, Main Building With intentions similar to those of CERN physicists, the artist Alfonso Fratteggiani Bianchi investigates the color pigment, studying its interaction with light and with the support on which it is deposited. He creates monochrome paintings by spreading the color pigment in the pure state on stones, without using glue or any other type of adhesive. With intentions similar to artists, the physicist Ermanno Imbergamo investigates the use of luminescent wavelength shifters, materials commonly used in Particle Physics, for art. He creates other monochrome artworks, which disclose further aspects of interaction among light, color pigments and support. For more information: staff.association@cern.ch | Tel: 022 767 28 19

  9. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    COLORATION Sandra Duchêne From September 5 to 16, 2016 CERN Meyrin, Main Building La recherche de l’Universel. Après tout ! C’est de l’Amour ! What else to say ? …La couleur, l’ENERGIE de la vie…

  10. Exhibition

    CERN Multimedia

    Staff Association

    2014-01-01

      Parallels vision Astronomical subjects which evoke extrasensory kinetic visions Alberto Di Fabio From 8 to 10 October, CERN Meyrin, Main Building In the framework of Italy@cern, the Staff Association presents Alberto Di Fabio. Di Fabio’s work is inspired by the fundamental laws of the physical world, as well as organic elements and their interrelation. His paintings and works on paper merge the worlds of art and science, depicting natural forms and biological structures in vivid colour and imaginative detail. For all additional information: staff.association@cern.ch | Tel: 022 767 28 19

  11. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Le Point Isabelle Gailland Du 20 février au 3 mars 2017 CERN Meyrin, Bâtiment principal La Diagonale - Isabelle Gailland. Au départ, un toujours même point minuscule posé au centre de ce que la toile est un espace. Une réplique d'autres points, condensés, alignés, isolés, disséminés construiront dans leur extension, la ligne. Ces lignes, croisées, courbées, déviées, prolongées, seront la structure contenant et séparant la matière des couleurs. La rotation de chaque toile en cours d'exécution va offrir un accès illimité à la non-forme et à la forme. Le point final sera l'ouverture sur différents points de vue de ce que le point et la ligne sont devenus une représentation pour l'œil et l'im...

  12. Exhibition

    CERN Multimedia

    Staff Association

    2018-01-01

    La danse mécanique Daria Grigoryeva Du 22 mai au 1er juin 2018 | CERN Meyrin, Bâtiment principal La danse mécanique est une métaphore large. La mécanique établit les règles et les limites, les frontières dans lesquelles la vie et la créativité peuvent se développer. La musique est « mathématique », une poupée mécanique se tourne toujours dans la même direction, selon les règles prescrites par la nature les fleurs fleurissent au printemps. Même s'ils ne le voulaient pas. La participation à la "danse mécanique" est prédéterminée et inévitable. Il ne reste plus qu'à comprendre comment le faire "magnifiquement". En tout, il y a une signification cachée et un...

  13. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Still Life Jérémy Bajulaz Du 25 septembre au 6 octobre 2017 CERN Meyrin, Main Building (Aubergine - Jérémy Bajulaz) Né en 1991 en Haute-Savoie, France. Diplômé de l'Ecole Emile Cohl à Lyon, Jérémy Bajulaz intègre en 2014 le programme d'artiste en résidence au Centre Genevois de Gravure Contemporaine. C'est là que son travail prendra corps, autour de la lumière et de ses vibrations aux travers de sujets comme le portrait et la nature morte, dans le souci de l'observation; le regard prenant une place importante dans le processus créatif. Lauréat 2017 du VII Premio AAAC, son travail a été présenté dans de nombreuses expositions collectives, en 2015 au Bâtiment d’Art Contemporain de Genève, en 2016 au 89e Salon de Lyon et du ...

  14. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Œuvres recentes Fabienne Wyler Du 6 au 17 février 2017 CERN Meyrin, Bâtiment principal L'escalier du diable B - aquarelle, encre de Chine XLV - Fabienne Wyler. En relation avec certains procédés d’écriture contemporaine (par ex. Webern ou certaines musiques conçues par ordinateur), les compositions picturales de Fabienne Wyler s’élaborent à partir de « modules » (groupes de quadrangles) qu’elle reproduit en leur faisant subir toutes sortes de transformations et de déplacements : étirements, renversements, rotations, effet miroir, transpositions, déphasages, superpositions, etc., et ceci à toutes les échelles. Au fil des œuvres sont apparues des séries intitulées, Bifurcations, Intermittences, Attracteurs étranges, Polyrythmies. Ces titres ont un lien &e...

  15. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Les vibrantes Patrick Robbe-Grillet Du 30 octobre au 10 novembre 2017 CERN Meyrin, Main Building Patrick Robbe-Grillet - Feux d'artifices Qui est Patrick Robbe-Grillet ? Artiste Franco-Suisse, né en 1968 à Genève. En recherche du sentiment de paix, autodidacte, après un séjour en Chine en 2000, puis au Japon en 2002, suivi d’un long questionnement, il trouve sa voie dans la peinture, élément libérateur de sa créativité et expression de sa sensibilité à fleur de peau. « La Chine m’a enseigné les courbes, les nuances. Le Japon, la ligne droite, la rigueur. » Vous avez su rendre visible l'invisible ! - commentaire de Monsieur Fawaz Gruosi Pour plus d’informations et demandes d’accès : staff.association@cern.ch | Tél : 022 766 37 38

  16. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    La couleur des jours oriSio Du 2 au 12 mai 2017 CERN Meyrin, Bâtiment principal oriSio - Motus Suite à un fort intérêt pour la Chine et une curiosité pour un médium très ancien, la laque ! Je réinterprète cet art à travers un style abstrait. Je présente ici des laques sur aluminium, travaillés au plasma et ensuite colorés à l’aide de pigments pour l’essentiel. Mes œuvres je les veux brutes, déchirées, évanescentes, gondolées, voire trouées mais avec une belle approche de profondeur de la couleur.   Pour plus d’informations : staff.association@cern.ch | Tél: 022 766 37 38

  17. Exhibition

    CERN Multimedia

    Staff Association

    2011-01-01

    Jan Hladky, physicien de l'Institut de Physique de l'Académie des Sciences de la République tchèque, et membre de la collaboration Alice, expose ses œuvres au Bâtiment principal du 20 avril au 6 mai. Son exposition est dédiée aux victimes du séisme de Sendai. Des copies de ses œuvres seront mises en vente et les sommes récoltées seront versées au profit des victimes.

  18. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    La mosaïque ou quand détruire permet de construire Lauren Decamps Du 28 novembre au 9 décembre 2016 CERN Meyrin, Bâtiment principal Paysage d'Amsterdam - Lauren Decamps On ne doit jamais rien détruire qu'on ne soit sûr de pouvoir remplacer aussi avantageusement " écrivait Plutarque dans ses Œuvres morales du 1er siècle après JC. L'artiste mosaïste Lauren Decamps adhère à cette idée et tente à sa manière de donner une nouvelle vie à ses matériaux en les taillant puis les réassemblant, créant ainsi des œuvres abstraites et figuratives.

  19. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Firmament des toiles Joëlle Lalagüe Du 6 au 16 juin 2017 CERN Meyrin, Bâtiment principal Phylaë Voyage - Joëlle Lalagüe. Each picture is an invitation for a cosmic trip. This is a whispering of soul, which comes from origins. A symphony of the world, some notes of love, a harmony for us to fly to infinity. Pour plus d’informations et demandes d'accès : staff.association@cern.ch | Tél: 022 766 37 38

  20. Exhibition

    CERN Multimedia

    Staff Association

    2018-01-01

    Univers Du 9 au 20 avril 2018 | CERN Meyrin, Bâtiment principal Stéphanie Cousin Obsédée par les rêves, les mondes surréalistes et insolites, je m’empare de formes provenant des mes propres travaux photographiques ou d’images que je modifie et mixe. Je fais évoluer mes univers oniriques de femmes-animaux ainsi que mes espaces et natures imaginaires. Avec ma démarche artistique, je cherche à mettre en images nos rêves et nos cauchemars, l’irréel et le surréel, le mystique et les affres de notre inconscient. Je cherche à représenter tout ce qui sommeille au plus profond de nous-même à l’aide de symboles, parfois en utilisant des images de cultures ancestrales. Photographie-collage, je cherche à ajouter quelques notes à la définition de la photographie du 21iè...

  1. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Harmonie Nathalie Lenoir Du 4 au 15 septembre 2017 CERN Meyrin, Bâtiment principal Peindre est un langage. Le tracé du pinceau sur le lin en est l'expression. A qui appartient un tableau en définitive ? A celui qui l'a peint ? A celui qui le regarde ? A celui qui l'emporte ? La peinture est une émotion partagée... Laissez-vous projeter de l'autre côté de la toile, prenez un moment pour rêver, en harmonie avec les éléments, parce-que la peinture parle à votre âme… Pour plus d’informations et demandes d’accès : staff.association@cern.ch | Tél : 022 766 37 38

  2. Exhibition

    CERN Multimedia

    Staff Association

    2018-01-01

    Cosmos KOLI Du 15 au 26 janvier 2018 CERN Meyrin, Main Building (Nébuleuse d'Orion- KOLI) KOLI, Artiste confirmé, diplômé de l’Académie de Beaux Arts de Tirana, depuis 26 ans en Suisse, où il a participé à maintes expositions collectives et organisé 10 expositions privées avec  beaucoup de succès, s’exprime actuellement dans un bonheur de couleur et de matières qui côtoient des hautes sphères… le cosmos ! Gagnant d’un premier prix lors d’une exposition collective organisée par le consulat Italien, il s’est installé au bord du lac dans le canton de Vaud où il vit depuis maintenant déjà 13 ans. www.kolicreation.com Pour plus d’informations et demandes d’accès : staff.association@cern.ch | T&eacut...

  3. Exhibition at the AAA library

    DEFF Research Database (Denmark)

    2013-01-01

    Sonnesgade 11 The exhibition at the AAA library presents selected work produced by students prior to the exhibition of installations in project and praxis constructing an archive at Sonnesgade 11. The exhibition at Sonnesgade 11 was the culmination of collaboration with SLETH architects and studio...

  4. Susceptibility of Redundant Versus Singular Clock Domains Implemented in SRAM-Based FPGA TMR Designs

    Science.gov (United States)

    Berg, Melanie D.; LaBel, Kenneth A.; Pellish, Jonathan

    2016-01-01

    We present the challenges that arise when using redundant clock domains due to their clock-skew. Radiation data show that a singular clock domain (DTMR) provides an improved TMR methodology for SRAM-based FPGAs over redundant clocks.

  5. In-flight performance optimization for rotorcraft with redundant controls

    Science.gov (United States)

    Ozdemir, Gurbuz Taha

    A conventional helicopter has limits on performance at high speeds because of the limitations of main rotor, such as compressibility issues on advancing side or stall issues on retreating side. Auxiliary lift and thrust components have been suggested to improve performance of the helicopter substantially by reducing the loading on the main rotor. Such a configuration is called the compound rotorcraft. Rotor speed can also be varied to improve helicopter performance. In addition to improved performance, compound rotorcraft and variable RPM can provide a much larger degree of control redundancy. This additional redundancy gives the opportunity to further enhance performance and handling qualities. A flight control system is designed to perform in-flight optimization of redundant control effectors on a compound rotorcraft in order to minimize power required and extend range. This "Fly to Optimal" (FTO) control law is tested in simulation using the GENHEL model. A model of the UH-60, a compound version of the UH-60A with lifting wing and vectored thrust ducted propeller (VTDP), and a generic compound version of the UH-60A with lifting wing and propeller were developed and tested in simulation. A model following dynamic inversion controller is implemented for inner loop control of roll, pitch, yaw, heave, and rotor RPM. An outer loop controller regulates airspeed and flight path during optimization. A Golden Section search method was used to find optimal rotor RPM on a conventional helicopter, where the single redundant control effector is rotor RPM. The FTO builds off of the Adaptive Performance Optimization (APO) method of Gilyard by performing low frequency sweeps on a redundant control for a fixed wing aircraft. A method based on the APO method was used to optimize trim on a compound rotorcraft with several redundant control effectors. The controller can be used to optimize rotor RPM and compound control effectors through flight test or simulations in order to

  6. A Cause-Consequence Chart of a Redundant Protection System

    DEFF Research Database (Denmark)

    Nielsen, Dan Sandvik; Platz, O.; Runge, B.

    1975-01-01

    A cause-consequence chart is applied in analysing failures of a redundant protection system (a core spray system in a nuclear power plant). It is shown how the diagram provides a basis for calculating two probability measures for malfunctioning of the protection system. The test policy of compone...... of components is taken into account. The possibility of using parameter variation as a basis for the choice of test policy is indicated.......A cause-consequence chart is applied in analysing failures of a redundant protection system (a core spray system in a nuclear power plant). It is shown how the diagram provides a basis for calculating two probability measures for malfunctioning of the protection system. The test policy...

  7. Probability Model for Data Redundancy Detection in Sensor Networks

    Directory of Open Access Journals (Sweden)

    Suman Kumar

    2009-01-01

    Full Text Available Sensor networks are made of autonomous devices that are able to collect, store, process and share data with other devices. Large sensor networks are often redundant in the sense that the measurements of some nodes can be substituted by other nodes with a certain degree of confidence. This spatial correlation results in wastage of link bandwidth and energy. In this paper, a model for two associated Poisson processes, through which sensors are distributed in a plane, is derived. A probability condition is established for data redundancy among closely located sensor nodes. The model generates a spatial bivariate Poisson process whose parameters depend on the parameters of the two individual Poisson processes and on the distance between the associated points. The proposed model helps in building efficient algorithms for data dissemination in the sensor network. A numerical example is provided investigating the advantage of this model.

  8. Information filtering based on corrected redundancy-eliminating mass diffusion.

    Directory of Open Access Journals (Sweden)

    Xuzhen Zhu

    Full Text Available Methods used in information filtering and recommendation often rely on quantifying the similarity between objects or users. The used similarity metrics often suffer from similarity redundancies arising from correlations between objects' attributes. Based on an unweighted undirected object-user bipartite network, we propose a Corrected Redundancy-Eliminating similarity index (CRE which is based on a spreading process on the network. Extensive experiments on three benchmark data sets-Movilens, Netflix and Amazon-show that when used in recommendation, the CRE yields significant improvements in terms of recommendation accuracy and diversity. A detailed analysis is presented to unveil the origins of the observed differences between the CRE and mainstream similarity indices.

  9. Low-redundancy linear arrays in mirrored interferometric aperture synthesis.

    Science.gov (United States)

    Zhu, Dong; Hu, Fei; Wu, Liang; Li, Jun; Lang, Liang

    2016-01-15

    Mirrored interferometric aperture synthesis (MIAS) is a novel interferometry that can improve spatial resolution compared with that of conventional IAS. In one-dimensional (1-D) MIAS, antenna array with low redundancy has the potential to achieve a high spatial resolution. This Letter presents a technique for the direct construction of low-redundancy linear arrays (LRLAs) in MIAS and derives two regular analytical patterns that can yield various LRLAs in short computation time. Moreover, for a better estimation of the observed scene, a bi-measurement method is proposed to handle the rank defect associated with the transmatrix of those LRLAs. The results of imaging simulation demonstrate the effectiveness of the proposed method.

  10. Information theory and artificial grammar learning: inferring grammaticality from redundancy.

    Science.gov (United States)

    Jamieson, Randall K; Nevzorova, Uliana; Lee, Graham; Mewhort, D J K

    2016-03-01

    In artificial grammar learning experiments, participants study strings of letters constructed using a grammar and then sort novel grammatical test exemplars from novel ungrammatical ones. The ability to distinguish grammatical from ungrammatical strings is often taken as evidence that the participants have induced the rules of the grammar. We show that judgements of grammaticality are predicted by the local redundancy of the test strings, not by grammaticality itself. The prediction holds in a transfer test in which test strings involve different letters than the training strings. Local redundancy is usually confounded with grammaticality in stimuli widely used in the literature. The confounding explains why the ability to distinguish grammatical from ungrammatical strings has popularized the idea that participants have induced the rules of the grammar, when they have not. We discuss the judgement of grammaticality task in terms of attribute substitution and pattern goodness. When asked to judge grammaticality (an inaccessible attribute), participants answer an easier question about pattern goodness (an accessible attribute).

  11. Ageing behaviour of [(n-1)/n] active redundancy systems

    International Nuclear Information System (INIS)

    Eid, M.Y.

    1995-01-01

    Ageing of systems becomes a real concern if intelligent maintenance is required. Determining the ageing behaviour of a system necessitate having a powerful calculating tool and knowing the ageing behaviour of the basic components of the systems. Consequently, time dependent failure rates are required for basic components and need to be determined for systems. As, this is the general problem in reliability analysis, only (n-1)/n active redundancy system will be examined in the paper. Systems with (n-1)/n active redundancy are commonly used in a wide range of engineering fields. This should permit a priori improving the system reliability. Still, a deeper analysis of the ageing behaviour of such systems may reveal some particular aspects. (authors). 2 refs., 5 figs

  12. Industrial plant electrical systems: Simplicity, reliability, cost savings, redundancies

    International Nuclear Information System (INIS)

    Silvestri, A.; Tommazzolli, F.; Pavia Univ.

    1992-01-01

    This article represents a compact but complete design and construction manual for industrial plant electrical systems. It is to be used by design engineers having prior knowledge of local power supply routes and voltages and regards principally the optimum choice of internal distribution systems which can be radial or single, double ringed or with various network configurations, and with single or multiple supplies, and many or few redundancies. After giving guidelines on the choosing of these options, the manual deals with problematics relevant to suitable cable sizing. A cost benefit benefit analysis method is suggested for the choice of the number of redundancies. Recommendations are given for the choice of transformers, motorized equipment, switch boards and circuit breakers. Reference is made to Italian electrical safety and building codes

  13. . Redundancy and blocking in the spatial domain: A connectionist model

    Directory of Open Access Journals (Sweden)

    I. P. L. Mc Laren

    2002-01-01

    Full Text Available How can the observations of spatial blocking (Rodrigo, Chamizo, McLaren & Mackintosh, 1997 and cue redundancy (O’Keefe and Conway, 1978 be reconciled within the framework provided by an error-correcting, connectionist account of spatial navigation? I show that an implementation of McLaren’s (1995 better beta model can serve this purpose, and examine some of the implications for spatial learning and memory.

  14. State-space Generalized Predicitve Control for redundant parallel robots

    Czech Academy of Sciences Publication Activity Database

    Belda, Květoslav; Böhm, Josef; Valášek, M.

    2003-01-01

    Roč. 31, č. 3 (2003), s. 413-432 ISSN 1539-7734 R&D Projects: GA ČR GA101/03/0620 Grant - others:CTU(CZ) 0204512 Institutional research plan: CEZ:AV0Z1075907 Keywords : parallel robot construction * generalized predictive control * drive redundancy Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/historie/belda-0411126.pdf

  15. Estimation of component redundancy in optimal age maintenance

    OpenAIRE

    Siopa, Jorge; Garção, José; Silva, Júlio

    2012-01-01

    The classical Optimal Age-Replacement defines the maintenance strategy based on the equipment failure consequences. For severe consequences an early equipment replacement is recommended. For minor consequences the repair after failure is proposed. One way of reducing the failure consequences is the use of redundancies, especially if the equipment failure rate is decreasing over time, since in this case the preventive replacement does not reduce the risk of failure. The estimation of an ac...

  16. Incident detection and isolation in drilling using analytical redundancy relations

    DEFF Research Database (Denmark)

    Willersrud, Anders; Blanke, Mogens; Imsland, Lars

    2015-01-01

    must be avoided. This paper employs model-based diagnosis using analytical redundancy relations to obtain residuals which are affected differently by the different incidents. Residuals are found to be non-Gaussian - they follow a multivariate t-distribution - hence, a dedicated generalized likelihood...... measurements available. In the latter case, isolation capability is shown to be reduced to group-wise isolation, but the method would still detect all serious events with the prescribed false alarm probability...

  17. Systematic Luby Transform codes as incremental redundancy scheme

    CSIR Research Space (South Africa)

    Grobler, TL

    2011-09-01

    Full Text Available Transform Codes as Incremental Redundancy Scheme T. L. Grobler y, E. R. Ackermann y, J. C. Olivier y and A. J. van Zylz Department of Electrical, Electronic and Computer Engineering University of Pretoria, Pretoria 0002, South Africa Email: trienkog...@gmail.com, etienne.ackermann@ieee.org yDefence, Peace, Safety and Security (DPSS) Council for Scientific and Industrial Research (CSIR), Pretoria 0001, South Africa zDepartment of Mathematics and Applied Mathematics University of Pretoria, Pretoria 0002, South...

  18. Toward an Integrated Design, Inspection and Redundancy Research Program.

    Science.gov (United States)

    1984-01-01

    William Creelman William H. Silcox National Marine Service Standard Oil Company of California St. Louis, Missouri San Francisco, California .-- N...develop physical models and generic tools for analyzing the effects of redundancy, reserve strength, and residual strength on the system behavior of marine...probabilistic analyses to be applicable to real-world problems, this program needs to provide - the deterministic physical models and generic tools upon

  19. Flexible Procurement of Services with Uncertain Durations using Redundancy

    OpenAIRE

    Stein, S; Gerding, E; Rogers, A; Larson, K; Jennings, NR

    2009-01-01

    Emerging service-oriented technologies allow software agents to automatically procure distributed services to complete complex tasks. However, in many application scenarios, service providers demand financial remuneration, execution times are uncertain and consumers have deadlines for their tasks. In this paper, we address these issues by developing a novel approach that dynamically procures multiple, redundant services over time, in order to ensure success by the deadline. Specifically, we f...

  20. A comparison of Heuristic method and Llewellyn’s rules for identification of redundant constraints

    Science.gov (United States)

    Estiningsih, Y.; Farikhin; Tjahjana, R. H.

    2018-03-01

    Important techniques in linear programming is modelling and solving practical optimization. Redundant constraints are consider for their effects on general linear programming problems. Identification and reduce redundant constraints are for avoidance of all the calculations associated when solving an associated linear programming problems. Many researchers have been proposed for identification redundant constraints. This paper a compararison of Heuristic method and Llewellyn’s rules for identification of redundant constraints.

  1. Structural Equation Models in a Redundancy Analysis Framework With Covariates.

    Science.gov (United States)

    Lovaglio, Pietro Giorgio; Vittadini, Giorgio

    2014-01-01

    A recent method to specify and fit structural equation modeling in the Redundancy Analysis framework based on so-called Extended Redundancy Analysis (ERA) has been proposed in the literature. In this approach, the relationships between the observed exogenous variables and the observed endogenous variables are moderated by the presence of unobservable composites, estimated as linear combinations of exogenous variables. However, in the presence of direct effects linking exogenous and endogenous variables, or concomitant indicators, the composite scores are estimated by ignoring the presence of the specified direct effects. To fit structural equation models, we propose a new specification and estimation method, called Generalized Redundancy Analysis (GRA), allowing us to specify and fit a variety of relationships among composites, endogenous variables, and external covariates. The proposed methodology extends the ERA method, using a more suitable specification and estimation algorithm, by allowing for covariates that affect endogenous indicators indirectly through the composites and/or directly. To illustrate the advantages of GRA over ERA we propose a simulation study of small samples. Moreover, we propose an application aimed at estimating the impact of formal human capital on the initial earnings of graduates of an Italian university, utilizing a structural model consistent with well-established economic theory.

  2. Intuitive theories of information: beliefs about the value of redundancy.

    Science.gov (United States)

    Soll, J B

    1999-03-01

    In many situations, quantity estimates from multiple experts or diagnostic instruments must be collected and combined. Normatively, and all else equal, one should value information sources that are nonredundant, in the sense that correlation in forecast errors should be minimized. Past research on the preference for redundancy has been inconclusive. While some studies have suggested that people correctly place higher value on uncorrelated inputs when collecting estimates, others have shown that people either ignore correlation or, in some cases, even prefer it. The present experiments show that the preference for redundancy depends on one's intuitive theory of information. The most common intuitive theory identified is the Error Tradeoff Model (ETM), which explicitly distinguishes between measurement error and bias. According to ETM, measurement error can only be averaged out by consulting the same source multiple times (normatively false), and bias can only be averaged out by consulting different sources (normatively true). As a result, ETM leads people to prefer redundant estimates when the ratio of measurement error to bias is relatively high. Other participants favored different theories. Some adopted the normative model, while others were reluctant to mathematically average estimates from different sources in any circumstance. In a post hoc analysis, science majors were more likely than others to subscribe to the normative model. While tentative, this result lends insight into how intuitive theories might develop and also has potential ramifications for how statistical concepts such as correlation might best be learned and internalized. Copyright 1999 Academic Press.

  3. Advantage of redundancy in the controllability of remote handling manipulator

    International Nuclear Information System (INIS)

    Muhammad, Ali; Mattila, Jouni; Vilenius, Matti; Siuko, Mikko; Semeraro, Luigi

    2011-01-01

    To carry out a variety of remote handling operations inside the ITER divertor a Water Hydraulic MANipulator (WHMAN) and its control system have been designed and developed at Tampere University of Technology. The manipulator is installed on top of Cassette Multifunctional Mover (CMM) to assist during the cassette removal and installation operations. While CMM is designed to carry heavy components such as cassettes through the service ducts relying on positioning accuracy and repeatability, WHMAN is designed to execute a mix of remote handling operations using position trajectories and master-slave telemanipulation. WHMAN is composed of eight joints: six rotational and two translational. Since a manipulator requires only six joints to acquire the desired position and orientation in operational-space, the two additional joints of WHMAN provide the redundant degrees of mobility. This paper presents how this redundancy of WHMAN can be an advantage to optimize the execution of remote handling tasks. The paper also discusses an effective way to practically exploit the redundancy. The results show that the additional degrees of freedom can be utilized to improve the dynamic behavior of the manipulator.

  4. Fuzzy modeling of analytical redundancy for sensor failure detection

    International Nuclear Information System (INIS)

    Tsai, T.M.; Chou, H.P.

    1991-01-01

    Failure detection and isolation (FDI) in dynamic systems may be accomplished by testing the consistency of the system via analytically redundant relations. The redundant relation is basically a mathematical model relating system inputs and dissimilar sensor outputs from which information is extracted and subsequently examined for the presence of failure signatures. Performance of the approach is often jeopardized by inherent modeling error and noise interference. To mitigate such effects, techniques such as Kalman filtering, auto-regression-moving-average (ARMA) modeling in conjunction with probability tests are often employed. These conventional techniques treat the stochastic nature of uncertainties in a deterministic manner to generate best-estimated model and sensor outputs by minimizing uncertainties. In this paper, the authors present a different approach by treating the effect of uncertainties with fuzzy numbers. Coefficients in redundant relations derived from first-principle physical models are considered as fuzzy parameters and on-line updated according to system behaviors. Failure detection is accomplished by examining the possibility that a sensor signal occurred in an estimated fuzzy domain. To facilitate failure isolation, individual FDI monitors are designed for each interested sensor

  5. Joint redundancy and imperfect preventive maintenance optimization for series–parallel multi-state degraded systems

    International Nuclear Information System (INIS)

    Nourelfath, Mustapha; Châtelet, Eric; Nahas, Nabil

    2012-01-01

    This paper formulates a joint redundancy and imperfect preventive maintenance planning optimization model for series–parallel multi-state degraded systems. Non identical multi-state components can be used in parallel to improve the system availability by providing redundancy in subsystems. Multiple component choices are available in the market for each subsystem. The status of each component is considered to degrade with use. The objective is to determine jointly the maximal-availability series–parallel system structure and the appropriate preventive maintenance actions, subject to a budget constraint. System availability is defined as the ability to satisfy consumer demand that is represented as a piecewise cumulative load curve. A procedure is used, based on Markov processes and universal moment generating function, to evaluate the multi-state system availability and the cost function. A heuristic approach is also proposed to solve the formulated problem. This heuristic is based on a combination of space partitioning, genetic algorithms (GA) and tabu search (TS). After dividing the search space into a set of disjoint subsets, this approach uses GA to select the subspaces, and applies TS to each selected sub-space.

  6. Tabu search for the redundancy allocation problem of homogenous series-parallel multi-state systems

    International Nuclear Information System (INIS)

    Ouzineb, Mohamed; Nourelfath, Mustapha; Gendreau, Michel

    2008-01-01

    This paper develops an efficient tabu search (TS) heuristic to solve the redundancy allocation problem for multi-state series-parallel systems. The system has a range of performance levels from perfect functioning to complete failure. Identical redundant elements are included in order to achieve a desirable level of availability. The elements of the system are characterized by their cost, performance and availability. These elements are chosen from a list of products available in the market. System availability is defined as the ability to satisfy consumer demand, which is represented as a piecewise cumulative load curve. A universal generating function technique is applied to evaluate system availability. The proposed TS heuristic determines the minimal cost system configuration under availability constraints. An originality of our approach is that it proceeds by dividing the search space into a set of disjoint subsets, and then by applying TS to each subset. The design problem, solved in this study, has been previously analyzed using genetic algorithms (GAs). Numerical results for the test problems from previous research are reported, and larger test problems are randomly generated. Comparisons show that the proposed TS out-performs GA solutions, in terms of both the solution quality and the execution time

  7. The World of Virtual Exhibitions

    Directory of Open Access Journals (Sweden)

    Irena Eiselt

    2013-09-01

    Full Text Available EXTENDED ABSTRACTSpecial collections of the National and University Library (NUK hide a lot of items of precious value. The Slovenian cultural heritage is stored on paper or on other media as a part of the library’s Manuscripts, Incunabula and Rare Books Collection, Old Prints Collection, Maps and Pictorial Collection, Music Collection, Ephemera Collection, Serials Collection, and Slovenian Diaspora Publications Collection. Only a small part of the treasures is temporary revealed to the public on special exhibitions. The idea of virtual exhibitions of library treasures was born in 2005. The library aimed to exhibit precious items of special collections of high historical or artistic value. In 2008 the first two virtual exhibitions were created in-house offering access to the rich collections of old postcards of Ljubljana at the beginning of 20th century kept in the Maps and Pictorial Collection of NUK. They were soon followed by other virtual exhibitions. At the beginning they were organised in the same way as physical exhibitions, afterwards different programs were used for creation of special effects (for ex. 3D wall. About two years ago it was decided that the creation of virtual exhibitions will be simplified. Files of digitised and borndigital library materials in jpg format are imported to MS PowerPoint 2010. Each jpg file is now formatted by adding a frame, a description … to the slides which are saved as jpg files. The last step is the import of jpg files into Cooliris application used for NUK web exhibitions. In the paper the virtual exhibition design and creation, the technical point of view and criteria for the selection of exhibition content are explained following the example of the virtual exhibitions the Old Postcards of Ljubljana, Photo Ateliers in Slovenia, a collection of photographs Four Seasons by Fran Krašovec and photos of Post-Earthquake Ljubljana in 1895.

  8. Application study of EPICS-based redundant method for reactor control system

    International Nuclear Information System (INIS)

    Zhang Ning; Han Lifeng; Chen Yongzhong; Guo Bing; Yin Congcong

    2013-01-01

    In the reactor control system prototype development of TMSR (Thorium Molten Salt Reactor system, CAS) project, EPICS (Experimental Physics and Industrial Control System) is adopted as Instrument and Control software platform. For the aim of IOC (Input/Output Controller) redundancy and data synchronization of the system, the EPICS-based RMT (Redundancy Monitor Task ) software package and its data-synchronization component CCE (Continuous Control Executive) were introduced. By the development of related IOC driver, redundant switch-over control of server IOC was implemented. The method of redundancy implementation using RMT in server and redundancy performance test for power control system are discussed in this paper. (authors)

  9. Quantum Darwinism: Entanglement, branches, and the emergent classicality of redundantly stored quantum information

    International Nuclear Information System (INIS)

    Blume-Kohout, Robin; Zurek, Wojciech H.

    2006-01-01

    We lay a comprehensive foundation for the study of redundant information storage in decoherence processes. Redundancy has been proposed as a prerequisite for objectivity, the defining property of classical objects. We consider two ensembles of states for a model universe consisting of one system and many environments: the first consisting of arbitrary states, and the second consisting of 'singly branching' states consistent with a simple decoherence model. Typical states from the random ensemble do not store information about the system redundantly, but information stored in branching states has a redundancy proportional to the environment's size. We compute the specific redundancy for a wide range of model universes, and fit the results to a simple first-principles theory. Our results show that the presence of redundancy divides information about the system into three parts: classical (redundant); purely quantum; and the borderline, undifferentiated or 'nonredundant', information

  10. Quantum Darwinism: Entanglement, branches, and the emergent classicality of redundantly stored quantum information

    Science.gov (United States)

    Blume-Kohout, Robin; Zurek, Wojciech H.

    2006-06-01

    We lay a comprehensive foundation for the study of redundant information storage in decoherence processes. Redundancy has been proposed as a prerequisite for objectivity, the defining property of classical objects. We consider two ensembles of states for a model universe consisting of one system and many environments: the first consisting of arbitrary states, and the second consisting of “singly branching” states consistent with a simple decoherence model. Typical states from the random ensemble do not store information about the system redundantly, but information stored in branching states has a redundancy proportional to the environment’s size. We compute the specific redundancy for a wide range of model universes, and fit the results to a simple first-principles theory. Our results show that the presence of redundancy divides information about the system into three parts: classical (redundant); purely quantum; and the borderline, undifferentiated or “nonredundant,” information.

  11. Exploration of joint redundancy but not task space variability facilitates supervised motor learning.

    Science.gov (United States)

    Singh, Puneet; Jana, Sumitash; Ghosal, Ashitava; Murthy, Aditya

    2016-12-13

    The number of joints and muscles in a human arm is more than what is required for reaching to a desired point in 3D space. Although previous studies have emphasized how such redundancy and the associated flexibility may play an important role in path planning, control of noise, and optimization of motion, whether and how redundancy might promote motor learning has not been investigated. In this work, we quantify redundancy space and investigate its significance and effect on motor learning. We propose that a larger redundancy space leads to faster learning across subjects. We observed this pattern in subjects learning novel kinematics (visuomotor adaptation) and dynamics (force-field adaptation). Interestingly, we also observed differences in the redundancy space between the dominant hand and nondominant hand that explained differences in the learning of dynamics. Taken together, these results provide support for the hypothesis that redundancy aids in motor learning and that the redundant component of motor variability is not noise.

  12. Creating Virtual Exhibitions for Educational and Cultural Development

    Directory of Open Access Journals (Sweden)

    Gabriela DUMITRESCU

    2014-01-01

    Full Text Available The paper presents different tools and mechanisms to implement a virtual exhibition in different cultural areas, such as museums and libraries. Quality characteristics of virtual exhibitions are identified and described. The possibility to create native mobile applications for virtual exhibitions presentation is analyzed. The functional flow of creating a virtual exhibition is presented and discussed. The Seals - History Treasure exhibition is presented and significant historical documents are revealed.

  13. Time efficient signed Vedic multiplier using redundant binary representation

    Directory of Open Access Journals (Sweden)

    Ranjan Kumar Barik

    2017-03-01

    Full Text Available This study presents a high-speed signed Vedic multiplier (SVM architecture using redundant binary (RB representation in Urdhva Tiryagbhyam (UT sutra. This is the first ever effort towards extension of Vedic algorithms to the signed numbers. The proposed multiplier architecture solves the carry propagation issue in UT sutra, as carry free addition is possible in RB representation. The proposed design is coded in VHDL and synthesised in Xilinx ISE 14.4 of various FPGA devices. The proposed SVM architecture has better speed performances as compared with various state-of-the-art conventional as well as Vedic architectures.

  14. A case for Redundant Arrays of Inexpensive Disks (RAID)

    Science.gov (United States)

    Patterson, David A.; Gibson, Garth; Katz, Randy H.

    1988-01-01

    Increasing performance of CPUs and memories will be squandered if not matched by a similar performance increase in I/O. While the capacity of Single Large Expensive Disks (SLED) has grown rapidly, the performance improvement of SLED has been modest. Redundant Arrays of Inexpensive Disks (RAID), based on the magnetic disk technology developed for personal computers, offers an attractive alternative to SLED, promising improvements of an order of magnitude in performance, reliability, power consumption, and scalability. This paper introduces five levels of RAIDs, giving their relative cost/performance, and compares RAID to an IBM 3380 and a Fujitsu Super Eagle.

  15. Reliability and availability of redundant systems: Computational program and the use of nomograms

    International Nuclear Information System (INIS)

    Signoret, J.P.

    1975-01-01

    A rigorous mathematical approach to determining the reliability and availability of repairable actively redundant systems - (r/m) systems - is considered for the case where the m units comprising the system are identical and the failure and repair rates, lambda and μ respectively, are constant. The method used involves the Markov processes, operator calculus and matrix calculus. All the results of the study are handled by the FIDIAS program, which is a practical tool for calculating with a high degree of precision the reliability or availability of such (r/m) systems whatever the values of m and r. In the FIDIAS-TC version of FIDIAS it is possible to plot curves with a Benson plotter, so that nomograms are produced for rapid and simple determination of the probabilities of failure or non-availability of the (r/m) systems considered. The practical application of nomograms is of interest because (2/3) and (2/4) actively redundant systems are very often used in the control circuits of power reactors. It is shown how easily one can compare these two systems using nomograms and how one can determine lambda or μ as a function of the anticipated result

  16. A Simple Example of ``Quantum Darwinism'': Redundant Information Storage in Many-Spin Environments

    Science.gov (United States)

    Blume-Kohout, Robin; Zurek, Wojciech H.

    2005-11-01

    As quantum information science approaches the goal of constructing quantum computers, understanding loss of information through decoherence becomes increasingly important. The information about a system that can be obtained from its environment can facilitate quantum control and error correction. Moreover, observers gain most of their information indirectly, by monitoring (primarily photon) environments of the "objects of interest." Exactly how this information is inscribed in the environment is essential for the emergence of "the classical" from the quantum substrate. In this paper, we examine how many-qubit (or many-spin) environments can store information about a single system. The information lost to the environment can be stored redundantly, or it can be encoded in entangled modes of the environment. We go on to show that randomly chosen states of the environment almost always encode the information so that an observer must capture a majority of the environment to deduce the system's state. Conversely, in the states produced by a typical decoherence process, information about a particular observable of the system is stored redundantly. This selective proliferation of "the fittest information" (known as Quantum Darwinism) plays a key role in choosing the preferred, effectively classical observables of macroscopic systems. The developing appreciation that the environment functions not just as a garbage dump, but as a communication channel, is extending our understanding of the environment's role in the quantum-classical transition beyond the traditional paradigm of decoherence.

  17. Photowalk Exhibition opens at Microcosm

    CERN Document Server

    Katarina Anthony

    2011-01-01

    The winning photographs from the 2010 Global Particle Physics Photowalk competition will go on display at Microcosm from 11 February to 2 April. The exhibition is part of a global photography event taking place over three continents, with Photowalk exhibitions opening simultaneously at Fermilab in the US, KEK in Japan and here at CERN.   DESY wire chamber - First place people's choice; second place global jury competition. Photographer: Hans-Peter Hildebrandt  If you were one of the 1,300 photography lovers who voted in last year’s Photowalk competition, this exhibition is your chance to see the winning entries in print. The exhibition will take place in the downstairs gallery of Microcosm, overlooking the garden. 15 photographs will be on display, with each of the laboratories that participated in Photowalk represented by their 3 winning entries. Among them will be the “people’s choice” sunburst photo of a particle detector at DESY (Photo 1), and...

  18. Globe exhibit wins international acclaim

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    The Globe’s “Universe of Particles” exhibition has recently received four prestigious awards for its avant-garde design. This external praise is great encouragement for the CERN exhibitions currently on the drawing board.   The Universe of Particles exhibition has won 4 awards for its avant-garde design. Back in 2008, the design company Atelier Brückner was presented with a challenge: to design the layout of a new permanent exhibition for CERN, one that would epitomize both the Organization and its research. The brief was concise but complex: the exhibit had to be symbolic of the Organization, use modern technology, engage and immerse visitors, and, preferably, use touch-screen technology. With the help of IArt, an interactive technology firm, and based on the content provided by CERN’s Education Group, Atelier Brückner developed the “Universe of Particles” exhibit as it is today. Its principal concept centred on the s...

  19. Greenhouse Earth: A Traveling Exhibition

    International Nuclear Information System (INIS)

    Booth, W.H.; Caesar, S.

    1992-09-01

    The Franklin Institute Science Museum provided an exhibit entitled the Greenhouse Earth: A Traveling Exhibition. This 3500 square-foot exhibit on global climate change was developed in collaboration with the Association of Science-Technology Centers. The exhibit opened at The Franklin Institute on February 14, 1992, welcoming 291,000 visitors over its three-month stay. During its three-year tour, Greenhouse Earth will travel to ten US cities, reaching two million visitors. Greenhouse Earth aims to deepen public understanding of the scientific issues of global warming and the conservation measures that can be taken to slow its effects. The exhibit features hands-on exhibitry, interactive computer programs and videos, a theater production, a ''demonstration cart,'' guided tours, and lectures. supplemental educational programs at the Institute included a teachers preview, a symposium on climate change, and a ''satellite field trip.'' The development of Greenhouse Earth included front-end and formative evaluation procedures. Evaluation includes interviews with visitors, prototypes, and summative surveys for participating museums. During its stay in Philadelphia, Greenhouse Earth was covered by the local and national press, with reviews in print and broadcast media. Greenhouse Earth is the first large-scale museum exhibit to address global climate change

  20. Analysis of transitions at two-fold redundant sites in mammalian genomes. Transition redundant approach-to-equilibrium (TREx distance metrics

    Directory of Open Access Journals (Sweden)

    Liberles David A

    2006-03-01

    Full Text Available Abstract Background The exchange of nucleotides at synonymous sites in a gene encoding a protein is believed to have little impact on the fitness of a host organism. This should be especially true for synonymous transitions, where a pyrimidine nucleotide is replaced by another pyrimidine, or a purine is replaced by another purine. This suggests that transition redundant exchange (TREx processes at the third position of conserved two-fold codon systems might offer the best approximation for a neutral molecular clock, serving to examine, within coding regions, theories that require neutrality, determine whether transition rate constants differ within genes in a single lineage, and correlate dates of events recorded in genomes with dates in the geological and paleontological records. To date, TREx analysis of the yeast genome has recognized correlated duplications that established a new metabolic strategies in fungi, and supported analyses of functional change in aromatases in pigs. TREx dating has limitations, however. Multiple transitions at synonymous sites may cause equilibration and loss of information. Further, to be useful to correlate events in the genomic record, different genes within a genome must suffer transitions at similar rates. Results A formalism to analyze divergence at two fold redundant codon systems is presented. This formalism exploits two-state approach-to-equilibrium kinetics from chemistry. This formalism captures, in a single equation, the possibility of multiple substitutions at individual sites, avoiding any need to "correct" for these. The formalism also connects specific rate constants for transitions to specific approximations in an underlying evolutionary model, including assumptions that transition rate constants are invariant at different sites, in different genes, in different lineages, and at different times. Therefore, the formalism supports analyses that evaluate these approximations. Transitions at synonymous

  1. Mature neurons dynamically restrict apoptosis via redundant premitochondrial brakes.

    Science.gov (United States)

    Annis, Ryan P; Swahari, Vijay; Nakamura, Ayumi; Xie, Alison X; Hammond, Scott M; Deshmukh, Mohanish

    2016-12-01

    Apoptotic cell death is critical for the early development of the nervous system, but once the nervous system is established, the apoptotic pathway becomes highly restricted in mature neurons. However, the mechanisms underlying this increased resistance to apoptosis in these mature neurons are not completely understood. We have previously found that members of the miR-29 family of microRNAs (miRNAs) are induced with neuronal maturation and that overexpression of miR-29 was sufficient to restrict apoptosis in neurons. To determine whether endogenous miR-29 alone was responsible for the inhibition of cytochrome c release in mature neurons, we examined the status of the apoptotic pathway in sympathetic neurons deficient for all three miR-29 family members. Unexpectedly, we found that the apoptotic pathway remained largely restricted in miR-29-deficient mature neurons. We therefore probed for additional mechanisms by which mature neurons resist apoptosis. We identify miR-24 as another miRNA that is upregulated in the maturing cerebellum and sympathetic neurons that can act redundantly with miR-29 by targeting a similar repertoire of prodeath BH3-only genes. Overall, our results reveal that mature neurons engage multiple redundant brakes to restrict the apoptotic pathway and ensure their long-term survival. © 2016 Federation of European Biochemical Societies.

  2. Acquired tricuspid valve stenosis due to intentionally redundant transvenous lead placement for VDD pacing in two small dogs.

    Science.gov (United States)

    Gunther-Harrington, Catherine T; Michel, Adam O; Stern, Joshua A

    2015-12-01

    Placement of an endocardial VDD pacing lead in small dogs (stenosis in two small dogs between 8 months and 4 years after VDD pacemaker placement for third-degree atrioventricular block. Echocardiography and Doppler echocardiography identified elevated transtricuspid flow velocities, prolonged pressure half-times, decreased valve leaflet excursions, and tricuspid regurgitation in both cases. Both cases were euthanized secondary to this pacing complication. Necropsy was performed in one case and confirmed adherence between the redundant lead loop, atrial and valve tissue. While VDD pacing in dogs has proven hemodynamic benefits, these benefits have not been demonstrated in terms of survival benefit or clinical signs. The requirement of redundant lead placement in small dogs for appropriate VDD lead function creates potential deleterious effects that should be weighed against the possible clinical value of VDD pacing in these patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Moving force identification based on redundant concatenated dictionary and weighted l1-norm regularization

    Science.gov (United States)

    Pan, Chu-Dong; Yu, Ling; Liu, Huan-Lin; Chen, Ze-Peng; Luo, Wen-Feng

    2018-01-01

    Moving force identification (MFI) is an important inverse problem in the field of bridge structural health monitoring (SHM). Reasonable signal structures of moving forces are rarely considered in the existing MFI methods. Interaction forces are complex because they contain both slowly-varying harmonic and impact signals due to bridge vibration and bumps on a bridge deck, respectively. Therefore, the interaction forces are usually hard to be expressed completely and sparsely by using a single basis function set. Based on the redundant concatenated dictionary and weighted l1-norm regularization method, a hybrid method is proposed for MFI in this study. The redundant dictionary consists of both trigonometric functions and rectangular functions used for matching the harmonic and impact signal features of unknown moving forces. The weighted l1-norm regularization method is introduced for formulation of MFI equation, so that the signal features of moving forces can be accurately extracted. The fast iterative shrinkage-thresholding algorithm (FISTA) is used for solving the MFI problem. The optimal regularization parameter is appropriately chosen by the Bayesian information criterion (BIC) method. In order to assess the accuracy and the feasibility of the proposed method, a simply-supported beam bridge subjected to a moving force is taken as an example for numerical simulations. Finally, a series of experimental studies on MFI of a steel beam are performed in laboratory. Both numerical and experimental results show that the proposed method can accurately identify the moving forces with a strong robustness, and it has a better performance than the Tikhonov regularization method. Some related issues are discussed as well.

  4. Fault tolerance in protein interaction networks: stable bipartite subgraphs and redundant pathways.

    Directory of Open Access Journals (Sweden)

    Arthur Brady

    Full Text Available As increasing amounts of high-throughput data for the yeast interactome become available, more system-wide properties are uncovered. One interesting question concerns the fault tolerance of protein interaction networks: whether there exist alternative pathways that can perform some required function if a gene essential to the main mechanism is defective, absent or suppressed. A signature pattern for redundant pathways is the BPM (between-pathway model motif, introduced by Kelley and Ideker. Past methods proposed to search the yeast interactome for BPM motifs have had several important limitations. First, they have been driven heuristically by local greedy searches, which can lead to the inclusion of extra genes that may not belong in the motif; second, they have been validated solely by functional coherence of the putative pathways using GO enrichment, making it difficult to evaluate putative BPMs in the absence of already known biological annotation. We introduce stable bipartite subgraphs, and show they form a clean and efficient way of generating meaningful BPMs which naturally discard extra genes included by local greedy methods. We show by GO enrichment measures that our BPM set outperforms previous work, covering more known complexes and functional pathways. Perhaps most importantly, since our BPMs are initially generated by examining the genetic-interaction network only, the location of edges in the protein-protein physical interaction network can then be used to statistically validate each candidate BPM, even with sparse GO annotation (or none at all. We uncover some interesting biological examples of previously unknown putative redundant pathways in such areas as vesicle-mediated transport and DNA repair.

  5. Fault tolerance in protein interaction networks: stable bipartite subgraphs and redundant pathways.

    Science.gov (United States)

    Brady, Arthur; Maxwell, Kyle; Daniels, Noah; Cowen, Lenore J

    2009-01-01

    As increasing amounts of high-throughput data for the yeast interactome become available, more system-wide properties are uncovered. One interesting question concerns the fault tolerance of protein interaction networks: whether there exist alternative pathways that can perform some required function if a gene essential to the main mechanism is defective, absent or suppressed. A signature pattern for redundant pathways is the BPM (between-pathway model) motif, introduced by Kelley and Ideker. Past methods proposed to search the yeast interactome for BPM motifs have had several important limitations. First, they have been driven heuristically by local greedy searches, which can lead to the inclusion of extra genes that may not belong in the motif; second, they have been validated solely by functional coherence of the putative pathways using GO enrichment, making it difficult to evaluate putative BPMs in the absence of already known biological annotation. We introduce stable bipartite subgraphs, and show they form a clean and efficient way of generating meaningful BPMs which naturally discard extra genes included by local greedy methods. We show by GO enrichment measures that our BPM set outperforms previous work, covering more known complexes and functional pathways. Perhaps most importantly, since our BPMs are initially generated by examining the genetic-interaction network only, the location of edges in the protein-protein physical interaction network can then be used to statistically validate each candidate BPM, even with sparse GO annotation (or none at all). We uncover some interesting biological examples of previously unknown putative redundant pathways in such areas as vesicle-mediated transport and DNA repair.

  6. Exhibition - Mathematics, A Beautiful Elsewhere

    CERN Multimedia

    2011-01-01

    From 21 October 2011 to 18 March 2012, the Fondation Cartier pour l’art contemporain will present the exhibition Mathematics: A Beautiful Elsewhere, an exhibition developed in association with the Institut des Hautes Études Scientifiques (IHÉS) and under the patronage of UNESCO. For this unprecedented event, the foundation invited mathematicians to work with artists with whom it has previously worked to create an exhibition that allows visitors to see, hear, do, interpret and think about mathematics. By bringing mathematics into its premises, the Fondation Cartier is itself undergoing the “sudden change of scenery” described by mathematician Alexandre Grothendieck. More information is available here. Fondation Cartier pour l’art contemporain 261, boulevard Raspail 75014 Paris http://fondation.cartier.com Private Visit For professors, researchers and all the staff of Mathematics departments...

  7. Method and system for redundancy management of distributed and recoverable digital control system

    Science.gov (United States)

    Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

    2012-01-01

    A method and system for redundancy management is provided for a distributed and recoverable digital control system. The method uses unique redundancy management techniques to achieve recovery and restoration of redundant elements to full operation in an asynchronous environment. The system includes a first computing unit comprising a pair of redundant computational lanes for generating redundant control commands. One or more internal monitors detect data errors in the control commands, and provide a recovery trigger to the first computing unit. A second redundant computing unit provides the same features as the first computing unit. A first actuator control unit is configured to provide blending and monitoring of the control commands from the first and second computing units, and to provide a recovery trigger to each of the first and second computing units. A second actuator control unit provides the same features as the first actuator control unit.

  8. One size does not fit all: older adults benefit from redundant text in multimedia instruction

    OpenAIRE

    Fenesi, Barbara; Vandermorris, Susan; Kim, Joseph A.; Shore, David I.; Heisz, Jennifer J.

    2015-01-01

    The multimedia design of presentations typically ignores that younger and older adults have varying cognitive strengths and weaknesses. We examined whether differential instructional design may enhance learning in these populations. Younger and older participants viewed one of three computer-based presentations: Audio only (narration), Redundant (audio narration with redundant text), or Complementary (audio narration with non–redundant text and images). Younger participants learned better ...

  9. Education or business? - exhibition of human corpses

    Directory of Open Access Journals (Sweden)

    Grzegorz Wróbel

    2017-09-01

    Full Text Available Exhibition "BODY WORLDS" which are presented exhibits of human remains are presented all over the world and are a major problem for the modern man, as presented on the preparations of the human not only serve scientific research, are not transferred to the medical schools to educate future doctors, but they were made available to the general public in the form of commercial and ambiguous. The aim of this study was to assess the ethical commercialization of human corpses "BODY WORLDS" exhibitions. Individual approach to the problems presented the dignity and value of human remains after death, of course, strongly related to the professed worldview. In the exhibits can be seen in both the scientific interest anatomical structures, as well as desecrated human remains or beautiful by its functional perfection of the body, understood also in terms of art. The question of ethics determines the right to decide for themselves, on the other hand, allows you to protect bodily integrity even after death. "BODY WORLDS" exhibition goes for the moral and ethical boundaries. In terms of people Gunther von Hagens for plastination of human remains which became a very profitable business, and its current activities defined as "plastination business" should be firmly said about the lack of moral principles.

  10. Learning from Exhibitions: Chuck Close.

    Science.gov (United States)

    Johnson, Mark M.

    1998-01-01

    Discusses the artwork of Chuck Close, who is well known for his over-sized portraits of fellow artists and anonymous sitters, and the exhibition of his work that premiered at New York's Museum of Modern Art before traveling to other cities in the United States. (CMK)

  11. [Relationships between soil and rocky desertification in typical karst mountain area based on redundancy analysis].

    Science.gov (United States)

    Long, Jian; Liao, Hong-Kai; Li, Juan; Chen, Cai-Yun

    2012-06-01

    Redundancy analysis (RDA) was employed to reveal the relationships between soil and rocky desertification through vegetation investigation and analysis of soil samples collected in typical karst mountain area of southwest Guizhou Province. The results showed that except TP, TK and ACa, all other variables including SOC, TN, MBC, ROC, DOC, available nutrients and basal respiration showed significant downward trends during the rocky desertification process. RDA results showed significant correlations between different types of desertification and soil variables, described as non-degraded > potential desertification > light desertification > moderate desertification > severe desertification. Moreover, RDA showed that using SOC, TN, AN, and BD as soil indicators, 74.4% of the variance information on soil and rocky desertification could be explained. Furthermore, the results of correlation analysis showed that soil variables were significantly affected by surface vegetation. Considering the ecological function of the aboveground vegetation and the soil quality, Zanthoxylum would be a good choice for restoration of local vegetation in karst mountain area.

  12. Optimization of redundancy by using genetic algorithm for reliability of plant protection system

    International Nuclear Information System (INIS)

    Yoo, D. W.; Seong, S. H.; Kim, D. H.; Park, H. Y.; Gu, I. S.

    2000-01-01

    The design and development of a reliable protection system has been becoming a key issue in industry field because the reliability of system is considered as an important factor to perform the system's function successfully. Plant Protection System(PPS) guarantees the safety of plant by accident detection and control action against the transient conditions of plant. This paper presents the analysis of PPS reliability and the formal problem statement about optimal redundancy based on the reliability of PPS. And the optimization problem is solved by genetic algorithm. The genetic algorithm is a useful tool to solve the problems, in the case of large searching, complex gradient, existence local minimum. The effectiveness of the proposed optimization technique is proved by the target reliability of one channel of PPS, using the failure rate based on the MIL-HDBK-217

  13. Sensitivity analysis of repairable redundant system with switching failure and geometric reneging

    Directory of Open Access Journals (Sweden)

    Chandra Shekhar

    2017-09-01

    Full Text Available This study deals with the performance modeling and reliability analysis of a redundant machining system composed of several functional machines. To analyze the more realistic scenarios, the concepts of switching failure and geometric reneging are included. The time-to-breakdown and repair time of operating and standby machines are assumed to follow the exponential distribution. For the quantitative assessment of the machine interference problem, various performance measures such as mean-time-to-failure, reliability, reneging rate, etc. have been formulated. To show the practicability of the developed model, a numerical illustration has been presented. For the practical justification and validity of the results established, the sensitivity analysis of reliability indices has been presented by varying different system descriptors.

  14. Verification of Triple Modular Redundancy (TMR) Insertion for Reliable and Trusted Systems

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth A.

    2016-01-01

    We propose a method for TMR insertion verification that satisfies the process for reliable and trusted systems. If a system is expected to be protected using TMR, improper insertion can jeopardize the reliability and security of the system. Due to the complexity of the verification process, there are currently no available techniques that can provide complete and reliable confirmation of TMR insertion. This manuscript addresses the challenge of confirming that TMR has been inserted without corruption of functionality and with correct application of the expected TMR topology. The proposed verification method combines the usage of existing formal analysis tools with a novel search-detect-and-verify tool. Field programmable gate array (FPGA),Triple Modular Redundancy (TMR),Verification, Trust, Reliability,

  15. Coordination of dual robot arms using kinematic redundancy

    Science.gov (United States)

    Suh, Il Hong; Shin, Kang G.

    1988-01-01

    A method is developed to coordinate the motion of dual robot arms carrying a solid object, where the first robot (leader) grasps one end of the object rigidly and the second robot (follower) is allowed to change its grasping position at the other end of the object along the object surface while supporting the object. It is shown that this flexible grasping is equivalent to the addition of one more degree of freedom (dof), giving the follower more maneuvering capabilities. In particular, motion commands for the follower are generated by using kinematic redundancy. To show the utility and power of the method, an example system with two PUMA 560 robots carrying a beam is analyzed.

  16. Basic aspects of stochastic reliability analysis for redundancy systems

    International Nuclear Information System (INIS)

    Doerre, P.

    1989-01-01

    Much confusion has been created by trying to establish common cause failure (CCF) as an extra phenomenon which has to be treated with extra methods in reliability and data analysis. This paper takes another approach which can be roughly described by the statement that dependent failure is the basic phenomenon, while 'independent failure' refers to a special limiting case, namely the perfectly homogeneous population. This approach is motivated by examples demonstrating that common causes do not lead to dependent failure, so far as physical dependencies like shared components are excluded, and that stochastic dependencies are not related to common causes. The possibility to select more than one failure behaviour from an inhomogeneous population is identified as an additional random process which creates stochastic dependence. However, this source of randomness is usually treated in the deterministic limit, which destroys dependence and hence yields incorrect multiple failure frequencies for redundancy structures, thus creating the need for applying corrective CCF models. (author)

  17. Energy distribution for Coefficients of Redundant Signal Representations of Music

    DEFF Research Database (Denmark)

    Endelt, Line Ørtoft; la Cour-Harbo, Anders

    2005-01-01

    different time-frequency dictionaries. We have applied these methods to music to examine their ability to express music signals in a sparse manner for a number of dictionaries and window lengths. The evaluation is based on the m-term approximation needed to represent 90 %, 95 %, 99 % and 99......In this paper we investigate how the energy is distributed in the coefficients vector of various redundant signal representations of music signals. The representations are found using Basis Pursuit, Matching Pursuit, Alternating Projections, Best Orthogonal Basis and Method of Frames, with five.......9 % of the energy in the coefficients, also the time consummation for finding the representations are considered. The distribution of energy in the coefficients of the representations found using Basis Pursuit, Matching Pursuit, Alternating Projections and Best Orthogonal Basis depends mainly on the signal...

  18. Redundancies in Data and their Effect on the Evaluation of Recommendation Systems

    DEFF Research Database (Denmark)

    Basaran, Daniel; Ntoutsi, Eirini; Zimek, Arthur

    2017-01-01

    A collection of datasets crawled from Amazon, “Amazon reviews”, is popular in the evaluation of recommendation systems. These datasets, however, contain redundancies (duplicated recommendations for variants of certain items). These redundancies went unnoticed in earlier use of these datasets...... and thus incurred to a certain extent wrong conclusions in the evaluation of algorithms tested on these datasets. We analyze the nature and amount of these redundancies and their impact on the evaluation of recommendation methods. While the general and obvious conclusion is that redundancies should...

  19. Reliability Analysis and Calibration of Partial Safety Factors for Redundant Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    1998-01-01

    Redundancy is important to include in the design and analysis of structural systems. In most codes of practice redundancy is not directly taken into account. In the paper various definitions of a deterministic and reliability based redundancy measure are reviewed. It is described how reundancy can...... be included in the safety system and how partial safety factors can be calibrated. An example is presented illustrating how redundancy is taken into account in the safety system in e.g. the Danish codes. The example shows how partial safety factors can be calibrated to comply with the safety level...

  20. Multi-finger prehension: control of a redundant mechanical system.

    Science.gov (United States)

    Latash, Mark L; Zatsiorsky, Vladimir M

    2009-01-01

    The human hand has been a fascinating object of study for researchers in both biomechanics and motor control. Studies of human prehension have contributed significantly to the progress in addressing the famous problem of motor redundancy. After a brief review of the hand mechanics, we present results of recent studies that support a general view that the apparently redundant design of the hand is not a source of computational problems but a rich apparatus that allows performing a variety of tasks in a reliable and flexible way (the principle of abundance). Multi-digit synergies have been analyzed at two levels of a hypothetical hierarchy involved in the control of prehensile actions. At the upper level, forces and moments produced by the thumb and virtual finger (an imagined finger with a mechanical action equal to the combined mechanical action of all four fingers of the hand) co-vary to stabilize the gripping action and the orientation of the hand-held object. These results support the principle of superposition suggested earlier in robotics with respect to the control of artificial grippers. At the lower level of the hierarchy, forces and moments produced by individual fingers co-vary to stabilize the magnitude and direction of the force vector and the moment of force produced by the virtual finger. Adjustments to changes in task constraints (such as, for example, friction under individual digits) may be local and synergic. The latter reflect multi-digit prehension synergies and may be analyzed with the so-called chain effects: Sequences of relatively straightforward cause-effect links directly related to mechanical constraints leading to non-trivial strong co-variation between pairs of elemental variables. Analysis of grip force adjustments during motion of hand-held objects suggests that the central nervous system adjusts to gravitational and inertial loads differently. The human hand is a gold mine for researchers interested in the control of natural human

  1. False targets vs. redundancy in homogeneous parallel systems

    International Nuclear Information System (INIS)

    Levitin, Gregory; Hausken, Kjell

    2009-01-01

    System defense against natural threats and disasters that have a stochastic nature includes providing redundancy and protecting system elements. The defense against strategic intentional attacks can also include deploying false targets aimed at misleading the attacker. Distribution of the available resources among different defensive means is an important problem that arises in organizing the defense of complex civil infrastructures, industrial systems or military objects. The article considers defense resource allocation in a system exposed to external intentional attack. The expected damage caused by the attack is evaluated as system unsupplied demand. The defender distributes its limited resource between deploying redundant genuine elements and false elements, both of which are targets of attack. The attacker attacks a subset of the elements and distributes its limited resource evenly among the attacked elements. Two cases are considered: in the first one the number of attacked elements and the vulnerability of each genuine element are fixed and the defense resource distribution is determined as a solution of an optimization problem; in the second one the number of attacked elements is the attacker's free choice variable and the element's vulnerability depends on a contest determined by the defender's and attacker's resources allocated to each element. The defender's optimal resource distribution strategy is determined as a solution of a two-period minmax game. It is shown that the optimal number of genuine elements decreases monotonically with the growth of the element cost and vulnerability, whereas the optimal number of false elements demonstrates non-monotonic behavior. The contest intensity is an important factor influencing the optimal defense resource distribution. It cannot be ignored when the defense strategy is determined, and it thus also impacts the attack strategy

  2. Redundant mechanisms are involved in suppression of default cell fates during embryonic mesenchyme and notochord induction in ascidians.

    Science.gov (United States)

    Kodama, Hitoshi; Miyata, Yoshimasa; Kuwajima, Mami; Izuchi, Ryoichi; Kobayashi, Ayumi; Gyoja, Fuki; Onuma, Takeshi A; Kumano, Gaku; Nishida, Hiroki

    2016-08-01

    During embryonic induction, the responding cells invoke an induced developmental program, whereas in the absence of an inducing signal, they assume a default uninduced cell fate. Suppression of the default fate during the inductive event is crucial for choice of the binary cell fate. In contrast to the mechanisms that promote an induced cell fate, those that suppress the default fate have been overlooked. Upon induction, intracellular signal transduction results in activation of genes encoding key transcription factors for induced tissue differentiation. It is elusive whether an induced key transcription factor has dual functions involving suppression of the default fates and promotion of the induced fate, or whether suppression of the default fate is independently regulated by other factors that are also downstream of the signaling cascade. We show that during ascidian embryonic induction, default fates were suppressed by multifold redundant mechanisms. The key transcription factor, Twist-related.a, which is required for mesenchyme differentiation, and another independent transcription factor, Lhx3, which is dispensable for mesenchyme differentiation, sequentially and redundantly suppress the default muscle fate in induced mesenchyme cells. Similarly in notochord induction, Brachyury, which is required for notochord differentiation, and other factors, Lhx3 and Mnx, are likely to suppress the default nerve cord fate redundantly. Lhx3 commonly suppresses the default fates in two kinds of induction. Mis-activation of the autonomously executed default program in induced cells is detrimental to choice of the binary cell fate. Multifold redundant mechanisms would be required for suppression of the default fate to be secure. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Fps/Fes and Fer protein-tyrosinekinases play redundant roles in regulating hematopoiesis.

    Science.gov (United States)

    Senis, Yotis A; Craig, Andrew W B; Greer, Peter A

    2003-08-01

    The highly related protein-tyrosine kinases Fps (also called Fes) and Fer are sole members of a subfamily of kinases. In this study, knock-in mice harboring kinase-inactivating mutations in both fps and fer alleles were used to assess functional redundancy between Fps and Fer kinases in regulating hematopoiesis. Mice harboring kinase-inactivating mutations in fps and fer alleles were generated previously. Compound homozygous mice were bred that lack both Fps and Fer kinase activities and progeny were analyzed for potential defects in viability and fertility. Potential differences in hematopoiesis were analyzed by lineage analysis of bone marrow cells, peripheral blood counts, and hematopoietic progenitor cell colony-forming assays. Mice devoid of both Fps and Fer kinase activities were viable and displayed reduced fertility. Circulating levels of neutrophils, erythrocytes, and platelets were elevated in compound mutant mice compared to wild-type controls, suggesting that hematopoiesis is deregulated in the absence of Fps and Fer kinases. Compound mutant mice also showed reduced overall bone marrow cellularity, and lineage analysis revealed elevated CD11b(hi)Ly-6G(lo) myeloid cells, which may reflect increased granulocyte progenitors. Although no differences in the overall number of granulocyte/monocyte colony-forming progenitors were observed, qualitative differences in myeloid colonies from compound mutant mice suggested a role for Fps and Fer kinases in regulating cell-cell adhesion or a skewing in cellularity of colonies. Mice lacking both Fps and Fer kinase activities develop normally, show reduced fertility, and display defects in hematopoiesis, thus providing evidence for functional redundancy between Fps and Fer kinases in regulating hematopoiesis.

  4. Mobile Technologies in Museum Exhibitions

    OpenAIRE

    Sandra Medić; Nataša Pavlović

    2014-01-01

    In order to be up–to–date and give visitors a memorable and unique experience, museums are including usage of digital technologies in their exhibitions. Even though museums in Serbia are very important part of tourism offer, they still have traditional settings that are poorly interpreted. The majority of them have a scientific and historical review which is unattractive for various target groups of visitors and for museums it’s important to continually try out new ways in interpretation of t...

  5. A New Exhibition in Microcosm

    CERN Document Server

    2000-01-01

    Sebastien Pelletier explains states of matter to an enthusiastic group of youngsters during the opening of a new exhibition in Microcosm last week. The Fun with Physics workshop will be offered to all 13-14 year olds in school groups visiting CERN this year. The new Microcosm contents have been developed in collaboration with the local teaching community, and cover particles and the forces that act between them.

  6. "Big Science" exhibition at Balexert

    CERN Multimedia

    2008-01-01

    CERN is going out to meet those members of the general public who were unable to attend the recent Open Day. The Laboratory will be taking its "Big Science" exhibition from the Globe of Science and Innovation to the Balexert shopping centre from 19 to 31 May 2008. The exhibition, which shows the LHC and its experiments through the eyes of a photographer, features around thirty spectacular photographs measuring 4.5 metres high and 2.5 metres wide. Welcomed and guided around the exhibition by CERN volunteers, shoppers at Balexert will also have the opportunity to discover LHC components on display and watch films. "Fun with Physics" workshops will be held at certain times of the day. Main hall of the Balexert shopping centre, ground floor, from 9.00 a.m. to 7.00 p.m. Monday to Friday and from 10 a.m. to 6 p.m. on the two Saturdays. Call for volunteers All members of the CERN personnel are invited to enrol as volunteers to help welcom...

  7. Mobile Technologies in Museum Exhibitions

    Directory of Open Access Journals (Sweden)

    Sandra Medić

    2014-10-01

    Full Text Available In order to be up–to–date and give visitors a memorable and unique experience, museums are including usage of digital technologies in their exhibitions. Even though museums in Serbia are very important part of tourism offer, they still have traditional settings that are poorly interpreted. The majority of them have a scientific and historical review which is unattractive for various target groups of visitors and for museums it’s important to continually try out new ways in interpretation of their settings. Because technology continues to rapidly change the way we communicate, cultural institutions should adapt to new ways of communication with their visitors. This paper examines mobile technologies that can be used in museums to give visitors a different experience and transfer the knowledge innovatively. In that way it will be presented the modern concept of presentation of museum exhibitions, focusing on usage of mobile devices through mobile applications and QR codes. The paper provides the broad understanding of usage mobile technologies in museum exhibitions with its advantages and limitations. The research results can help the museums management to improve interpretation and communication with visitors and enrich the visitor experience.

  8. Contemporary Developments in Cinema Exhibition

    OpenAIRE

    Hanson, Stuart

    2014-01-01

    he work offered for this PhD by Published Works charts the history of cinema exhibition in Britain from the late 1950s to the present. At the start of this period, cinemagoing as a form of public entertainment entered a long period of decline that was only arrested with the development and growth of multiplex cinemas in the 1980s and 1990s. Despite these changes, the feature film itself remained a culturally and commercially valuable artefact, though increasingly this meant the Hollywood fil...

  9. Equivalence of velocity-level and acceleration-level redundancy-resolution of manipulators

    International Nuclear Information System (INIS)

    Cai Binghuang; Zhang Yunong

    2009-01-01

    The equivalence of velocity-level and acceleration-level redundancy resolution of robot manipulators is investigated in this Letter. Theoretical analysis based on gradient-descent method and computer simulations based on PUMA560 robot manipulator both demonstrate the equivalence of redundancy-resolution schemes at different levels.

  10. Minister wants age balance to play greater role in redundancy selection

    NARCIS (Netherlands)

    Grünell, M.

    2004-01-01

    In May 2004, the Dutch Minister of Social Affairs proposed changes to the statutory rules on selection for redundancy, with less emphasis on the last in, first out seniority-based principle and a greater focus on distributing the redundancies between employees of different ages. The social partners

  11. Solving the redundancy allocation problem with multiple strategy choices using a new simplified particle swarm optimization

    International Nuclear Information System (INIS)

    Kong, Xiangyong; Gao, Liqun; Ouyang, Haibin; Li, Steven

    2015-01-01

    In most research on redundancy allocation problem (RAP), the redundancy strategy for each subsystem is assumed to be predetermined and fixed. This paper focuses on a specific RAP with multiple strategy choices (RAP-MSC), in which both active redundancy and cold standby redundancy can be selected as an additional decision variable for individual subsystems. To do so, the component type, redundancy strategy and redundancy level for each subsystem should be chosen subject to the system constraints appropriately such that the system reliability is maximized. Meanwhile, imperfect switching for cold standby redundancy is considered and a k-Erlang distribution is introduced to model the time-to-failure component as well. Given the importance and complexity of RAP-MSC, we propose a new efficient simplified version of particle swarm optimization (SPSO) to solve such NP-hard problems. In this method, a new position updating scheme without velocity is presented with stochastic disturbance and a low probability. Moreover, it is compared with several well-known PSO variants and other state-of-the-art approaches in the literature to evaluate its performance. The experiment results demonstrate the superiority of SPSO as an alternative for solving the RAP-MSC. - Highlights: • A more realistic RAP form with multiple strategy choices is focused. • Redundancy strategies are to be selected rather than fixed in general RAP. • A new simplified particle swarm optimization is proposed. • Higher reliabilities are achieved than the state-of-the-art approaches.

  12. Redundancy of Supply in the International Nuclear Fuel Fabrication Market: Are Fabrication Services Assured?

    International Nuclear Information System (INIS)

    Seward, Amy M.; Toomey, Christopher; Ford, Benjamin E.; Wood, Thomas W.; Perkins, Casey J.

    2011-01-01

    For several years, Pacific Northwest National Laboratory (PNNL) has been assessing the reliability of nuclear fuel supply in support of the U.S. Department of Energy/National Nuclear Security Administration. Three international low enriched uranium reserves, which are intended back up the existing and well-functioning nuclear fuel market, are currently moving toward implementation. These backup reserves are intended to provide countries credible assurance that of the uninterrupted supply of nuclear fuel to operate their nuclear power reactors in the event that their primary fuel supply is disrupted, whether for political or other reasons. The efficacy of these backup reserves, however, may be constrained without redundant fabrication services. This report presents the findings of a recent PNNL study that simulated outages of varying durations at specific nuclear fuel fabrication plants. The modeling specifically enabled prediction and visualization of the reactors affected and the degree of fuel delivery delay. The results thus provide insight on the extent of vulnerability to nuclear fuel supply disruption at the level of individual fabrication plants, reactors, and countries. The simulation studies demonstrate that, when a reasonable set of qualification criteria are applied, existing fabrication plants are technically qualified to provide backup fabrication services to the majority of the world's power reactors. The report concludes with an assessment of the redundancy of fuel supply in the nuclear fuel market, and a description of potential extra-market mechanisms to enhance the security of fuel supply in cases where it may be warranted. This report is an assessment of the ability of the existing market to respond to supply disruptions that occur for technical reasons. A forthcoming report will address political disruption scenarios.

  13. Determination and compensation of the “reference surface” from redundant sets of surface measurements

    Energy Technology Data Exchange (ETDEWEB)

    Polack, François, E-mail: francois.polack@synchrotron-soleil.fr [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, BP48, 91192 Gif-sur-Yvette Cedex (France); Thomasset, Muriel, E-mail: muriel.thomasset@synchrotron-soleil.fr [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, BP48, 91192 Gif-sur-Yvette Cedex (France)

    2013-05-11

    When trying to measure an optical surface at utmost absolute precision, the problem of the missing or unknown “reference surface” is often encountered. It is obvious with Fizeau and Michelson's interferometry, where the height difference between the surface under test (SUT) and a reference surface is measured. It is also true from slope measurements in long trace profilers (LTP), where due to small construction errors, the response to a perfectly flat ideal surface can be considered as an unknown reference to be subtracted from the measurement data. As no “perfect artifact” can exist, these references cannot be directly determined. The addition of the unknown reference can severely bias the reconstructed surface when field stitching is applied. The results of ptychography have proved that when a measurement is a function of a unique object function with a translated but unique response function, the redundancy of a large set of data allows accurate reconstructions of the object and response function despite the presence of measurement noise. In the case of LTP and interferometry, the basic problem is linear and can be solved by linear algebra rather than iteratively. The method has been already applied to SOLEIL and ESRF LTPs and is succesfully used on a regular base. We show here that the method can be also applied to interferometry and improve stitching results.

  14. Collaborative virtual environments art exhibition

    Science.gov (United States)

    Dolinsky, Margaret; Anstey, Josephine; Pape, Dave E.; Aguilera, Julieta C.; Kostis, Helen-Nicole; Tsoupikova, Daria

    2005-03-01

    This panel presentation will exhibit artwork developed in CAVEs and discuss how art methodologies enhance the science of VR through collaboration, interaction and aesthetics. Artists and scientists work alongside one another to expand scientific research and artistic expression and are motivated by exhibiting collaborative virtual environments. Looking towards the arts, such as painting and sculpture, computer graphics captures a visual tradition. Virtual reality expands this tradition to not only what we face, but to what surrounds us and even what responds to our body and its gestures. Art making that once was isolated to the static frame and an optimal point of view is now out and about, in fully immersive mode within CAVEs. Art knowledge is a guide to how the aesthetics of 2D and 3D worlds affect, transform, and influence the social, intellectual and physical condition of the human body through attention to psychology, spiritual thinking, education, and cognition. The psychological interacts with the physical in the virtual in such a way that each facilitates, enhances and extends the other, culminating in a "go together" world. Attention to sharing art experience across high-speed networks introduces a dimension of liveliness and aliveness when we "become virtual" in real time with others.

  15. Management of redundancy in flight control systems using optimal decision theory

    Science.gov (United States)

    1981-01-01

    The problem of using redundancy that exists between dissimilar systems in aircraft flight control is addressed. That is, using the redundancy that exists between a rate gyro and an accelerometer--devices that have dissimilar outputs which are related only through the dynamics of the aircraft motion. Management of this type of redundancy requires advanced logic so that the system can monitor failure status and can reconfigure itself in the event of one or more failures. An optimal decision theory was tutorially developed for the management of sensor redundancy and the theory is applied to two aircraft examples. The first example is the space shuttle and the second is a highly maneuvering high performance aircraft--the F8-C. The examples illustrate the redundancy management design process and the performance of the algorithms presented in failure detection and control law reconfiguration.

  16. Past and Present Biophysical Redundancy of Countries as a Buffer to Changes in Food Supply

    Science.gov (United States)

    Fader, Marianela; Rulli, Maria Cristina; Carr, Joel; Dell' Angelo, Jampel; D' Odorico, Paolo; Gephart, Jessica A.; Kummu, Matti; Magliocca, Nicholas; Porkka, Miina; Prell, Christina; hide

    2016-01-01

    Spatially diverse trends in population growth, climate change, industrialization, urbanization and economic development are expected to change future food supply and demand. These changes may affect the suitability of land for food production, implying elevated risks especially for resource constrained, food-importing countries. We present the evolution of biophysical redundancy for agricultural production at country level, from 1992 to 2012. Biophysical redundancy, defined as unused biotic and abiotic environmental resources, is represented by the potential food production of 'spare land', available water resources (i.e., not already used for human activities), as well as production increases through yield gap closure on cultivated areas and potential agricultural areas. In 2012, the biophysical redundancy of 75 (48) countries, mainly in North Africa, Western Europe, the Middle East and Asia, was insufficient to produce the caloric nutritional needs for at least 50% (25%) of their population during a year. Biophysical redundancy has decreased in the last two decades in 102 out of 155 countries, 11 of these went from high to limited redundancy, and nine of these from limited to very low redundancy. Although the variability of the drivers of change across different countries is high, improvements in yield and population growth have a clear impact on the decreases of redundancy towards the very low redundancy category. We took a more detailed look at countries classified as 'Low Income Economies (LIEs)' since they are particularly vulnerable to domestic or external food supply changes, due to their limited capacity to offset for food supply decreases with higher purchasing power on the international market. Currently, nine LIEs have limited or very low biophysical redundancy. Many of these showed a decrease in redundancy over the last two decades, which is not always linked with improvements in per capita food availability.

  17. Past and present biophysical redundancy of countries as a buffer to changes in food supply

    Science.gov (United States)

    Fader, Marianela; Rulli, Maria Cristina; Carr, Joel; Dell'Angelo, Jampel; D'Odorico, Paolo; Gephart, Jessica A.; Kummu, Matti; Magliocca, Nicholas; Porkka, Miina; Prell, Christina; Puma, Michael J.; Ratajczak, Zak; Seekell, David A.; Suweis, Samir; Tavoni, Alessandro

    2016-05-01

    Spatially diverse trends in population growth, climate change, industrialization, urbanization and economic development are expected to change future food supply and demand. These changes may affect the suitability of land for food production, implying elevated risks especially for resource-constrained, food-importing countries. We present the evolution of biophysical redundancy for agricultural production at country level, from 1992 to 2012. Biophysical redundancy, defined as unused biotic and abiotic environmental resources, is represented by the potential food production of ‘spare land’, available water resources (i.e., not already used for human activities), as well as production increases through yield gap closure on cultivated areas and potential agricultural areas. In 2012, the biophysical redundancy of 75 (48) countries, mainly in North Africa, Western Europe, the Middle East and Asia, was insufficient to produce the caloric nutritional needs for at least 50% (25%) of their population during a year. Biophysical redundancy has decreased in the last two decades in 102 out of 155 countries, 11 of these went from high to limited redundancy, and nine of these from limited to very low redundancy. Although the variability of the drivers of change across different countries is high, improvements in yield and population growth have a clear impact on the decreases of redundancy towards the very low redundancy category. We took a more detailed look at countries classified as ‘Low Income Economies (LIEs)’ since they are particularly vulnerable to domestic or external food supply changes, due to their limited capacity to offset for food supply decreases with higher purchasing power on the international market. Currently, nine LIEs have limited or very low biophysical redundancy. Many of these showed a decrease in redundancy over the last two decades, which is not always linked with improvements in per capita food availability.

  18. Accurate and diverse recommendations via eliminating redundant correlations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Tao; Su Riqi; Liu Runran; Jiang Luoluo; Wang Binghong [Department of Modern Physics and Nonlinear Science Center, University of Science and Technology of China, Hefei Anhui 230026 (China); Zhang Yicheng [Department of Physics, University of Fribourg, Chemin du Musee 3, CH-1700 Fribourg (Switzerland)], E-mail: bhwang@ustc.edu.cn

    2009-12-15

    In this paper, based on a weighted projection of a bipartite user-object network, we introduce a personalized recommendation algorithm, called network-based inference (NBI), which has higher accuracy than the classical algorithm, namely collaborative filtering. In NBI, the correlation resulting from a specific attribute may be repeatedly counted in the cumulative recommendations from different objects. By considering the higher order correlations, we design an improved algorithm that can, to some extent, eliminate the redundant correlations. We test our algorithm on two benchmark data sets, MovieLens and Netflix. Compared with NBI, the algorithmic accuracy, measured by the ranking score, can be further improved by 23 per cent for MovieLens and 22 per cent for Netflix. The present algorithm can even outperform the Latent Dirichlet Allocation algorithm, which requires much longer computational time. Furthermore, most previous studies considered the algorithmic accuracy only; in this paper, we argue that the diversity and popularity, as two significant criteria of algorithmic performance, should also be taken into account. With more or less the same accuracy, an algorithm giving higher diversity and lower popularity is more favorable. Numerical results show that the present algorithm can outperform the standard one simultaneously in all five adopted metrics: lower ranking score and higher precision for accuracy, larger Hamming distance and lower intra-similarity for diversity, as well as smaller average degree for popularity.

  19. Accurate and diverse recommendations via eliminating redundant correlations

    Science.gov (United States)

    Zhou, Tao; Su, Ri-Qi; Liu, Run-Ran; Jiang, Luo-Luo; Wang, Bing-Hong; Zhang, Yi-Cheng

    2009-12-01

    In this paper, based on a weighted projection of a bipartite user-object network, we introduce a personalized recommendation algorithm, called network-based inference (NBI), which has higher accuracy than the classical algorithm, namely collaborative filtering. In NBI, the correlation resulting from a specific attribute may be repeatedly counted in the cumulative recommendations from different objects. By considering the higher order correlations, we design an improved algorithm that can, to some extent, eliminate the redundant correlations. We test our algorithm on two benchmark data sets, MovieLens and Netflix. Compared with NBI, the algorithmic accuracy, measured by the ranking score, can be further improved by 23 per cent for MovieLens and 22 per cent for Netflix. The present algorithm can even outperform the Latent Dirichlet Allocation algorithm, which requires much longer computational time. Furthermore, most previous studies considered the algorithmic accuracy only; in this paper, we argue that the diversity and popularity, as two significant criteria of algorithmic performance, should also be taken into account. With more or less the same accuracy, an algorithm giving higher diversity and lower popularity is more favorable. Numerical results show that the present algorithm can outperform the standard one simultaneously in all five adopted metrics: lower ranking score and higher precision for accuracy, larger Hamming distance and lower intra-similarity for diversity, as well as smaller average degree for popularity.

  20. Accurate and diverse recommendations via eliminating redundant correlations

    International Nuclear Information System (INIS)

    Zhou Tao; Su Riqi; Liu Runran; Jiang Luoluo; Wang Binghong; Zhang Yicheng

    2009-01-01

    In this paper, based on a weighted projection of a bipartite user-object network, we introduce a personalized recommendation algorithm, called network-based inference (NBI), which has higher accuracy than the classical algorithm, namely collaborative filtering. In NBI, the correlation resulting from a specific attribute may be repeatedly counted in the cumulative recommendations from different objects. By considering the higher order correlations, we design an improved algorithm that can, to some extent, eliminate the redundant correlations. We test our algorithm on two benchmark data sets, MovieLens and Netflix. Compared with NBI, the algorithmic accuracy, measured by the ranking score, can be further improved by 23 per cent for MovieLens and 22 per cent for Netflix. The present algorithm can even outperform the Latent Dirichlet Allocation algorithm, which requires much longer computational time. Furthermore, most previous studies considered the algorithmic accuracy only; in this paper, we argue that the diversity and popularity, as two significant criteria of algorithmic performance, should also be taken into account. With more or less the same accuracy, an algorithm giving higher diversity and lower popularity is more favorable. Numerical results show that the present algorithm can outperform the standard one simultaneously in all five adopted metrics: lower ranking score and higher precision for accuracy, larger Hamming distance and lower intra-similarity for diversity, as well as smaller average degree for popularity.

  1. Redundant unbalance compensation of an active magnetic bearing system

    Science.gov (United States)

    Hutterer, Markus; Kalteis, Gerald; Schrödl, Manfred

    2017-09-01

    To achieve a good running behavior of a magnetic levitated rotor, a well-developed position controller and different compensation methods are required. Two very important structures in this context are the reduction of the gyroscopic effect and the unbalance vibration. Both structures have in common that they need the angular velocity information for calculation. For industrial applications this information is normally provided by an angle sensor which is fixed on the rotor. The angle information is also necessary for the field oriented control of the electrical drive. The main drawback of external position sensors are the case of a breakdown or an error of the motor controller. Therefore, the magnetic bearing can get unstable, because no angular velocity information is provided. To overcome this problem the presented paper describes the development of a selfsensing unbalance rejection in combination with a selfsensing speed control of the motor controller. Selfsensing means in this context that no angle sensor is required for the unbalance or torque control. With such structures two redundant speed and angle information sources are available and can be used for the magnetic bearing and the motor controller without the usage of an angle sensor.

  2. The disposal of redundant teletherapy units from NHS hospitals

    International Nuclear Information System (INIS)

    Gaffka, A.P.; Ord, M.A.

    1994-01-01

    The removal/disposal of redundant teletherapy units from NHS hospitals is described, detailing the operational procedures and the transport package background. The Harwell section of the Transport Technology Department has been carrying out these operations since 1991, where initially the service was just offered to the NHS; however, today their specialist transport service has significantly widened and is now offered to other business sectors. Due to the level of radioactivity found in each teletherapy unit, it was necessary to design a special transport packaging to meet the requirements for shipment of these units. Approval was sought from the Department of Transport to adapt a standard Type B package as no other packaging could be found to comply with the necessary requirements. All work undertaken on the removal and disposal of these units complied with an approved scheme of work and was carried out in accordance with a Quality Assurance workplan. However, to keep abreast of modern standards in a manner which is cost effective to customers and acceptable to the general public, the full development of a new Type B packaging is taking place, which is specifically designed to undertake these removal/disposal duties. (author)

  3. Triple Modular Redundancy verification via heuristic netlist analysis

    Directory of Open Access Journals (Sweden)

    Giovanni Beltrame

    2015-08-01

    Full Text Available Triple Modular Redundancy (TMR is a common technique to protect memory elements for digital processing systems subject to radiation effects (such as in space, high-altitude, or near nuclear sources. This paper presents an approach to verify the correct implementation of TMR for the memory elements of a given netlist (i.e., a digital circuit specification using heuristic analysis. The purpose is detecting any issues that might incur during the use of automatic tools for TMR insertion, optimization, place and route, etc. Our analysis does not require a testbench and can perform full, exhaustive coverage within less than an hour even for large designs. This is achieved by applying a divide et impera approach, splitting the circuit into smaller submodules without loss of generality, instead of applying formal verification to the whole netlist at once. The methodology has been applied to a production netlist of the LEON2-FT processor that had reported errors during radiation testing, successfully showing a number of unprotected memory elements, namely 351 flip-flops.

  4. Qualitative processing of uncertainty, conflicts and redundancy in knowledge bases

    International Nuclear Information System (INIS)

    Zbytovsky, V.

    1994-01-01

    This paper describes two techniques, created and implemented in the course of development of the real-time on-line expert system Recon at the Nuclear Research Institute at Rez, Czech Republic. The first of them is the qualitative processing of uncertainty, which is based on the introduction of the third logic value to logic data objects, and the credibility flag to arithmetic data objects. The treatment of the third value and credibility flags during the inference, the explanation method based on the graphic representation and the uncertainty processing during the explanation are also mentioned. The second technique, is a semantic checking of knowledge bases, which enables us to recover parts of the bases, that are meaningless, either because of an error during their implementation into a base, or because they are redundant. The paper includes the explanation of basic terms of this method, such as so called conflicts, K-group and K-situation. The two types of the conflict (dead-end and bubble) are also discussed. The paper also offers the complete mathematical apparatus, which the checking method is based on. (author). 4 refs, tabs

  5. Design of a redundant meteorological station for a BWR reactor

    International Nuclear Information System (INIS)

    Ramirez S, R.; Celis del Angel, L.; Bucio, F.; Rivero, T.; Palacios, J.

    2008-01-01

    In this work the design of a meteorological station for a reactor type BWR is proposed. Two independent channels of data acquisition that allow him to have a bigger readiness is exposed. It is incorporate sensors without mobile parts to measure speed, wind direction and pluvial precipitation. It also counts, with sensors of global solar radiation, net radiation, barometric pressure, relative humidity and ambient temperature; with them they are possible to be calculated, moreover, other variables as temperature differential, dew point and atmospheric stability. The sensors are placed on a tower to different heights and send their information (each second) to a local registration system, the one which in turn, it remits the data to the monitoring office so that a computer is linked with the system, display and management the information in real time and automatic way. The redundant structure allows that in the event of maintenance the data acquisition is not interrupted, even if the information is transferred to another place. In all the station sections it is used protocols of standard communication to allow that a great quantity of devices can be connected without major problem. The above-mentioned would allow to the operators in the control room to have reliable information during the whole time of the reactor operation. (Author)

  6. A Reliable Bistable Board Implementation through I/O Redundancy

    International Nuclear Information System (INIS)

    Kim, Min Gyu; Chung, Tae Hyok; Lee, Youn Sang; Kim, Tae Hee; Song, Seung Hwan

    2010-01-01

    Nuclear power plant safety systems and related equipment used in the design, including an accident in all driving conditions that must be proven In addition, the safety-related equipment that is derived according to the digitization of the safety equipment is the most important factors. Therefore, it is necessary to prove that the device was satisfied the requirements for a given performance for safety-related digital equipment for the life of the installation. These proven is done through the process, design verification of the equipment, production management, such as installation and maintenance. Among other things, it is most important to implement of the performance and reliability features the safety-related equipment in the design phase. In this paper, Bistable Board implemented to generate a ESF sign-on signal throughout the signal processing of input signal from sensors. Also, for the reliable signal input and output, I/O Module that implements the redundancy increases the reliability of the Bistable Board , to verify the performance of safety-related equipment

  7. State Estimation for Robots with Complementary Redundant Sensors

    Directory of Open Access Journals (Sweden)

    Daniele Carnevale

    2015-10-01

    Full Text Available In this paper, robots equipped with two complementary typologies of redundant sensors are considered: one typology provides sharp measures of some geometrical entity related to the robot pose (e.g., distance or angle but is not univocally associated with this quantity; the other typology is univocal but is characterized by a low level of precision. A technique is proposed to properly combine these two kinds of measurement both in a stochastic and in a deterministic context. This framework may occur in robotics, for example, when the distance from a known landmark is detected by two different sensors, one based on the signal strength or time of flight of the signal, while the other one measures the phase-shift of the signal, which has a sharp but periodical dependence on the robot-landmark distance. In the stochastic case, an effective solution is a two-stage extended Kalman filter (EKF which exploits the precise periodic signal only when the estimate of the robot position is sufficiently precise. In the deterministic setting, an approach based on a switching hybrid observer is proposed, and results are analyzed via simulation examples.

  8. DID RAMSEY EVER ENDORSE A REDUNDANCY THEORY OF TRUTH?

    Directory of Open Access Journals (Sweden)

    María J. Frápolli

    2013-11-01

    Full Text Available This paper deals with Ramsey´s theory of truth and its aim is twofold: on the one hand, it will explain what position about truth Ramsey actually defended, and, on the other hand, we will pursue Ramsey’s insight in the XXth century. When the name of Frank Ramsey is mentioned, one of the things that comes to mind is the theory of truth as redundancy. In the following pages we will argue that Ramsey never supported such a theory, but rather an analysis of truth noticeably similar to the prosentential account. In fact, the very word “pro-sentence” appears for the first time in the XXth Century in Ramsey´s unfinished work “The nature of truth”, written around 1929. Besides, we will show that the prosentential account of truth is a neglected trend throughout the history of analytic philosophy, even though relevant analytic philosophers, such as Prior, Strawson, Williams, Grover and Brandom, have endorsed it.

  9. Recent Advances in Registration, Integration and Fusion of Remotely Sensed Data: Redundant Representations and Frames

    Science.gov (United States)

    Czaja, Wojciech; Le Moigne-Stewart, Jacqueline

    2014-01-01

    In recent years, sophisticated mathematical techniques have been successfully applied to the field of remote sensing to produce significant advances in applications such as registration, integration and fusion of remotely sensed data. Registration, integration and fusion of multiple source imagery are the most important issues when dealing with Earth Science remote sensing data where information from multiple sensors, exhibiting various resolutions, must be integrated. Issues ranging from different sensor geometries, different spectral responses, differing illumination conditions, different seasons, and various amounts of noise need to be dealt with when designing an image registration, integration or fusion method. This tutorial will first define the problems and challenges associated with these applications and then will review some mathematical techniques that have been successfully utilized to solve them. In particular, we will cover topics on geometric multiscale representations, redundant representations and fusion frames, graph operators, diffusion wavelets, as well as spatial-spectral and operator-based data fusion. All the algorithms will be illustrated using remotely sensed data, with an emphasis on current and operational instruments.

  10. Enrico Fermi exhibition at CERN

    CERN Multimedia

    2002-01-01

    A touring exhibition celebrating the centenary of Enrico Fermi's birth in 1901 will be on display at CERN (Main Building, Mezzanine) from 12-27 September. You are cordially invited to the opening celebration on Thursday 12 September at 16:00 (Main Building, Council Chamber), which will include speechs from: Luciano Maiani Welcome and Introduction Arnaldo Stefanini Celebrating Fermi's Centenary in Documents and Pictures Antonino Zichichi The New 'Centro Enrico Fermi' at Via Panisperna Ugo Amaldi Fermi at Via Panisperna and the birth of Nuclear Medicine Jack Steinberger Fermi in Chicago Valentin Telegdi A Close-up of Fermi and the screening of a documentary video about Fermi: Scienziati a Pisa: Enrico Fermi (Scientists at Pisa: Enrico Fermi) created by Francesco Andreotti for La Limonaia from early film, photographs and sound recordings (In Italian, with English subtitles - c. 30 mins). This will be followed by an aperitif on the Mezz...

  11. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Pigeons learn stimulus identity and stimulus relations when both serve as redundant, relevant cues during same-different discrimination training.

    Science.gov (United States)

    Gibson, Brett M; Wasserman, Edward A

    2003-01-01

    The authors taught pigeons to discriminate displays of 16 identical items from displays of 16 nonidentical items. Unlike most same-different discrimination studies--where only stimulus relations could serve a discriminative function--both the identity of the items and the relations among the items were discriminative features of the displays. The pigeons learned about both stimulus identity and stimulus relations when these 2 sources of information served as redundant, relevant cues. In tests of associative competition, identity cues exerted greater stimulus control than relational cues. These results suggest that the pigeon can respond to both specific stimuli and general relations in the environment.

  13. The Natural-CCD Algorithm, a Novel Method to Solve the Inverse Kinematics of Hyper-redundant and Soft Robots.

    Science.gov (United States)

    Martín, Andrés; Barrientos, Antonio; Del Cerro, Jaime

    2018-03-22

    This article presents a new method to solve the inverse kinematics problem of hyper-redundant and soft manipulators. From an engineering perspective, this kind of robots are underdetermined systems. Therefore, they exhibit an infinite number of solutions for the inverse kinematics problem, and to choose the best one can be a great challenge. A new algorithm based on the cyclic coordinate descent (CCD) and named as natural-CCD is proposed to solve this issue. It takes its name as a result of generating very harmonious robot movements and trajectories that also appear in nature, such as the golden spiral. In addition, it has been applied to perform continuous trajectories, to develop whole-body movements, to analyze motion planning in complex environments, and to study fault tolerance, even for both prismatic and rotational joints. The proposed algorithm is very simple, precise, and computationally efficient. It works for robots either in two or three spatial dimensions and handles a large amount of degrees-of-freedom. Because of this, it is aimed to break down barriers between discrete hyper-redundant and continuum soft robots.

  14. Tankyrase 1 and tankyrase 2 are essential but redundant for mouse embryonic development.

    Directory of Open Access Journals (Sweden)

    Y Jeffrey Chiang

    2008-07-01

    Full Text Available Tankyrases are proteins with poly(ADP-ribose polymerase activity. Human tankyrases post-translationally modify multiple proteins involved in processes including maintenance of telomere length, sister telomere association, and trafficking of glut4-containing vesicles. To date, however, little is known about in vivo functions for tankyrases. We recently reported that body size was significantly reduced in mice deficient for tankyrase 2, but that these mice otherwise appeared developmentally normal. In the present study, we report generation of tankyrase 1-deficient and tankyrase 1 and 2 double-deficient mice, and use of these mutant strains to systematically assess candidate functions of tankyrase 1 and tankyrase 2 in vivo. No defects were observed in development, telomere length maintenance, or cell cycle regulation in tankyrase 1 or tankyrase 2 knockout mice. In contrast to viability and normal development of mice singly deficient in either tankyrase, deficiency in both tankyrase 1 and tankyrase 2 results in embryonic lethality by day 10, indicating that there is substantial redundancy between tankyrase 1 and tankyrase 2, but that tankyrase function is essential for embryonic development.

  15. Nppa and Nppb act redundantly during zebrafish cardiac development to confine AVC marker expression and reduce cardiac jelly volume.

    Science.gov (United States)

    Grassini, Daniela R; Lagendijk, Anne K; De Angelis, Jessica E; Da Silva, Jason; Jeanes, Angela; Zettler, Nicole; Bower, Neil I; Hogan, Benjamin M; Smith, Kelly A

    2018-05-11

    Atrial natriuretic peptide ( nppa/anf ) and brain natriuretic peptide ( nppb/bnp ) form a gene cluster with expression in the chambers of the developing heart. Despite restricted expression, a function in cardiac development has not been demonstrated by mutant analysis. This is attributed to functional redundancy however their genomic location in cis has impeded formal analysis. Using genome-editing, we generated mutants for nppa and nppb and found single mutants indistinguishable from wildtype whereas nppa / nppb double mutants display heart morphogenesis defects and pericardial oedema. Analysis of atrioventricular canal (AVC) markers show expansion of bmp4 , tbx2b, has2 and versican expression into the atrium of double mutants. This expanded expression correlates with increased extracellular matrix in the atrium. Using a biosensor for Hyaluronic acid to measure the cardiac jelly (cardiac extracellular matrix), we confirm cardiac jelly expansion in nppa / nppb double mutants. Finally, bmp4 knockdown rescues the expansion of has2 expression and cardiac jelly in double mutants. This definitively shows that nppa and nppb function redundantly during cardiac development to restrict gene expression to the AVC, preventing excessive cardiac jelly synthesis in the atrial chamber. © 2018. Published by The Company of Biologists Ltd.

  16. 3D seismic denoising based on a low-redundancy curvelet transform

    International Nuclear Information System (INIS)

    Cao, Jingjie; Zhao, Jingtao; Hu, Zhiying

    2015-01-01

    Contamination of seismic signal with noise is one of the main challenges during seismic data processing. Several methods exist for eliminating different types of noises, but optimal random noise attenuation remains difficult. Based on multi-scale, multi-directional locality of curvelet transform, the curvelet thresholding method is a relatively new method for random noise elimination. However, the high redundancy of a 3D curvelet transform makes its computational time and memory for massive data processing costly. To improve the efficiency of the curvelet thresholding denoising, a low-redundancy curvelet transform was introduced. The redundancy of the low-redundancy curvelet transform is approximately one-quarter of the original transform and the tightness of the original transform is also kept, thus the low-redundancy curvelet transform calls for less memory and computational resource compared with the original one. Numerical results on 3D synthetic and field data demonstrate that the low-redundancy curvelet denoising consumes one-quarter of the CPU time compared with the original curvelet transform using iterative thresholding denoising when comparable results are obtained. Thus, the low-redundancy curvelet transform is a good candidate for massive seismic denoising. (paper)

  17. EU Climate Change Exhibition Held

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>On April 25, the CPAFFC, the China-EU Association (CEUA) and the Delegation of the European Commission to China jointly held the opening ceremony for the EU Exhibition on Climate Change in the CPAFFC. He Luli, former vice chairperson of the NPC Standing Committee and honorary president of the CEUA, Jose Manuel Barroso, president of the European Commission, and Li Jianping, vice president of the CPAFFC, attended the opening ceremony and made speeches. Honorary President He Luli highly praised the achievements made by China and the EU in their longtime cooperation of mutual benefits in various fields including environmental protection. She said, for many years China and EU have both committed to the development of all-round strategic partnership and establishment of a multi-level mechanism of political dialogue. She expressed, with increasing enthusiasm the CEUA would continue to actively carry out nongovernmental exchanges between China and the EU, and promote cooperation between the two sides in the fields of economy, society, environmental protection, science and technology, culture, etc.

  18. Reliability optimization of series–parallel systems with mixed redundancy strategy in subsystems

    International Nuclear Information System (INIS)

    Abouei Ardakan, Mostafa; Zeinal Hamadani, Ali

    2014-01-01

    Traditionally in redundancy allocation problem (RAP), it is assumed that the redundant components are used based on a predefined active or standby strategies. Recently, some studies consider the situation that both active and standby strategies can be used in a specific system. However, these researches assume that the redundancy strategy for each subsystem can be either active or standby and determine the best strategy for these subsystems by using a proper mathematical model. As an extension to this assumption, a novel strategy, that is a combination of traditional active and standby strategies, is introduced. The new strategy is called mixed strategy which uses both active and cold-standby strategies in one subsystem simultaneously. Therefore, the problem is to determine the component type, redundancy level, number of active and cold-standby units for each subsystem in order to maximize the system reliability. To have a more practical model, the problem is formulated with imperfect switching of cold-standby redundant components and k-Erlang time-to-failure (TTF) distribution. As the optimization of RAP belongs to NP-hard class of problems, a genetic algorithm (GA) is developed. The new strategy and proposed GA are implemented on a well-known test problem in the literature which leads to interesting results. - Highlights: • In this paper the redundancy allocation problem (RAP) for a series–parallel system is considered. • Traditionally there are two main strategies for redundant component namely active and standby. • In this paper a new redundancy strategy which is called “Mixed” redundancy strategy is introduced. • Computational experiments demonstrate that implementing the new strategy lead to interesting results

  19. On the value of redundancy subject to common-cause failures: Toward the resolution of an on-going debate

    International Nuclear Information System (INIS)

    Hoepfer, V.M.; Saleh, J.H.; Marais, K.B.

    2009-01-01

    Common-cause failures (CCF) are one of the more critical and challenging issues for system reliability and risk analyses. Academic interest in modeling CCF, and more broadly in modeling dependent failures, has steadily grown over the years in the number of publications as well as in the sophistication of the analytical tools used. In the past few years, several influential articles have shed doubts on the relevance of redundancy arguing that 'redundancy backfires' through common-cause failures, and that the latter dominate unreliability, thus defeating the purpose of redundancy. In this work, we take issue with some of the results of these publications. In their stead, we provide a nuanced perspective on the (contingent) value of redundancy subject to common-cause failures. First, we review the incremental reliability and MTTF provided by redundancy subject to common-cause failures. Second, we introduce the concept and develop the analytics of the 'redundancy-relevance boundary': we propose this redundancy-relevance boundary as a design-aid tool that provides an answer to the following question: what level of redundancy is relevant or advantageous given a varying prevalence of common-cause failures? We investigate the conditions under which different levels of redundancy provide an incremental MTTF over that of the single component in the face of common-cause failures. Recognizing that redundancy comes at a cost, we also conduct a cost-benefit analysis of redundancy subject to common-cause failures, and demonstrate how this analysis modifies the redundancy-relevance boundary. We show how the value of redundancy is contingent on the prevalence of common-cause failures, the redundancy level considered, and the monadic cost-benefit ratio. Finally we argue that general unqualified criticism of redundancy is misguided, and efforts are better spent for example on understanding and mitigating the potential sources of common-cause failures rather than deriding the concept

  20. LytB1 and LytB2 of Mycobacterium tuberculosis Are Not Genetically Redundant.

    Directory of Open Access Journals (Sweden)

    Amanda Claire Brown

    Full Text Available Mycobacterium tuberculosis synthesises isoprenoid precursors via the MEP/DOXP pathway and at least five enzymes in the pathway (Dxs1, Dxr/IspC, IspD, IspF, and GcpE/IspG are required for growth in vitro. We investigated the role of LytB (IspH in M. tuberculosis; M. tuberculosis is unusual in that it has two homologs-LytB1 and LytB2. We were unable to delete the lytB2 gene unless we provided an additional copy elsewhere, demonstrating that this is the essential homolog. We expressed lytB1 from the lytB2 promoter and confirmed that this could not complement for loss of function of lytB2, despite LytB1 possessing all the previously described conserved critical residues. Interestingly the sole LytB homolog of Mycobacterium smegmatis was able to compensate for loss of LytB2 in M. tuberculosis. We tested translational fusions of LytB1 and LytB2 for functionality in M. tuberculosis, but only a fusion with 90% N-terminal LytB2 and 10% C-terminal LytB1 was functional. In order to identify the key difference between the two proteins, site directed mutagenesis was used to change LytB2 residues into their counterparts in LytB1. None of these amino acid substitutions was essential for function and all lytB2 mutant alleles were functional. In contrast, mutation of the key residues for [Fe4S4] cluster formation, as well as a catalytic residue in LytB1 did not result in functional complementation. Thus, although LytB1 and LytB2 are not genetically redundant, this is not dependent on small amino acid changes, but is likely to be a result of major overall structural differences.

  1. Kinematics analysis of a novel planar parallel manipulator with kinematic redundancy

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Haibo; Guo, Sheng [Beijing Jiaotong University, Beijing (China)

    2017-04-15

    In this paper, a novel planar parallel manipulator with kinematic redundancy is proposed. First, the Degrees of freedom (DOF) of the whole parallel manipulator and the Relative DOF (RDOF) between the moving platform and fixed base are studied. The results indicate that the proposed mechanism is kinematically redundant. Then, the kinematics, Jacobian matrices and workspace of this proposed parallel manipulator with kinematic redundancy are analyzed. Finally, the statics simulation of the proposed parallel manipulator is performed. The obtained stress and displacement distribution can be used to determine the easily destroyed place in the mechanism configurations.

  2. Multisensory processing of redundant information in go/no-go and choice responses

    DEFF Research Database (Denmark)

    Blurton, Steven Paul; Greenlee, Mark W.; Gondan, Matthias

    2014-01-01

    In multisensory research, faster responses are commonly observed when multimodal stimuli are presented as compared to unimodal target presentations. This so-called redundant signals effect can be explained by several frameworks including separate activation and coactivation models. The redundant ...... of redundant information provided by different sensory channels and is not restricted to simple responses. The results connect existing theories on multisensory integration with theories on choice behavior....... processes (Schwarz, 1994) within two absorbing barriers. The diffusion superposition model accurately describes mean and variance of response times as well as the proportion of correct responses observed in the two tasks. Linear superposition seems, thus, to be a general principle in integration...

  3. Quantum Darwinism Requires an Extra-Theoretical Assumption of Encoding Redundancy

    Science.gov (United States)

    Fields, Chris

    2010-10-01

    Observers restricted to the observation of pointer states of apparatus cannot conclusively demonstrate that the pointer of an apparatus mathcal{A} registers the state of a system of interest S without perturbing S. Observers cannot, therefore, conclusively demonstrate that the states of a system S are redundantly encoded by pointer states of multiple independent apparatus without destroying the redundancy of encoding. The redundancy of encoding required by quantum Darwinism must, therefore, be assumed from outside the quantum-mechanical formalism and without the possibility of experimental demonstration.

  4. Redundant actuator development study. [flight control systems for supersonic transport aircraft

    Science.gov (United States)

    Ryder, D. R.

    1973-01-01

    Current and past supersonic transport configurations are reviewed to assess redundancy requirements for future airplane control systems. Secondary actuators used in stability augmentation systems will probably be the most critical actuator application and require the highest level of redundancy. Two methods of actuator redundancy mechanization have been recommended for further study. Math models of the recommended systems have been developed for use in future computer simulations. A long range plan has been formulated for actuator hardware development and testing in conjunction with the NASA Flight Simulator for Advanced Aircraft.

  5. Kinematics analysis of a novel planar parallel manipulator with kinematic redundancy

    International Nuclear Information System (INIS)

    Qu, Haibo; Guo, Sheng

    2017-01-01

    In this paper, a novel planar parallel manipulator with kinematic redundancy is proposed. First, the Degrees of freedom (DOF) of the whole parallel manipulator and the Relative DOF (RDOF) between the moving platform and fixed base are studied. The results indicate that the proposed mechanism is kinematically redundant. Then, the kinematics, Jacobian matrices and workspace of this proposed parallel manipulator with kinematic redundancy are analyzed. Finally, the statics simulation of the proposed parallel manipulator is performed. The obtained stress and displacement distribution can be used to determine the easily destroyed place in the mechanism configurations

  6. Differential effects of IL-2 and IL-21 on expansion of the CD4+ CD25+ Foxp3+ T regulatory cells with redundant roles in natural killer cell mediated antibody dependent cellular cytotoxicity in chronic lymphocytic leukemia.

    Science.gov (United States)

    Gowda, Aruna; Ramanunni, Asha; Cheney, Carolyn; Rozewski, Darlene; Kindsvogel, Wayne; Lehman, Amy; Jarjoura, David; Caligiuri, Michael; Byrd, John C; Muthusamy, Natarajan

    2010-01-01

    CD4(+) CD25(+) regulatory T cells are expanded in solid and hematological malignancies including chronic lymphocytic leukemia (CLL). Several cytokines and co-stimulatory molecules are required for generation, survival and maintenance of their suppressive effect. We and others have shown direct cytotoxic effect of the novel common gamma chain cytokine interleukin (IL)-21 on primary B cells from CLL patients. Since members of this family of cytokines are known to exhibit their effects on diverse immune cells, we have examined the effects of IL-21 on CLL patient derived regulatory T cell (Treg) induction, expansion and the inhibitory effect on natural killer cells in vitro. We demonstrate here the expression of IL-21 receptor in CD4(+)CD25(High) regulatory cells from CLL patients. In contrast to IL-2, the IL-21 cytokine failed to mediate expansion of regulatory T cells or induced expression of Foxp3 in CD4(+)CD25(Intermediate) or CD4(+)CD25(Dim/-) T cells in whole blood derived from CLL patients. Interestingly, in contrast to their differential effects on expansion of the CD4(+)CD25(+)Foxp3(+)T cells, IL-2 and IL-21 exhibited a redundant role in Treg mediated suppression of NK cell mediated antibody dependent cytotoxicity function. Given the infusion related toxicities and pro-survival effect of IL-2 in CLL, these studies provide a rationale to explore IL-21 as an alternate gamma chain cytokine in CLL therapy.

  7. Simplifying the EFT of Inflation: generalized disformal transformations and redundant couplings

    Energy Technology Data Exchange (ETDEWEB)

    Bordin, Lorenzo [SISSA, via Bonomea 265, 34136, Trieste (Italy); Cabass, Giovanni [Physics Department and INFN, Università di Roma ' La Sapienza' , P.le Aldo Moro 2, 00185, Rome (Italy); Creminelli, Paolo [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste (Italy); Vernizzi, Filippo, E-mail: lbordin@sissa.it, E-mail: giovanni.cabass@roma1.infn.it, E-mail: creminel@ictp.it, E-mail: filippo.vernizzi@cea.fr [Institut de physique théorique, Université Paris Saclay, CEA, CNRS, 91191 Gif-sur-Yvette (France)

    2017-09-01

    We study generalized disformal transformations, including derivatives of the metric, in the context of the Effective Field Theory of Inflation. All these transformations do not change the late-time cosmological observables but change the coefficients of the operators in the action: some couplings are effectively redundant. At leading order in derivatives and up to cubic order in perturbations, one has 6 free functions that can be used to set to zero 6 of the 17 operators at this order. This is used to show that the tensor three-point function cannot be modified at leading order in derivatives, while the scalar-tensor-tensor correlator can only be modified by changing the scalar dynamics. At higher order in derivatives there are transformations that do not affect the Einstein-Hilbert action: one can find 6 additional transformations that can be used to simplify the inflaton action, at least when the dynamics is dominated by the lowest derivative terms. We also identify the leading higher-derivative corrections to the tensor power spectrum and bispectrum.

  8. Configuration determination for k-out-of-n partially redundant systems

    International Nuclear Information System (INIS)

    Lu Lixuan; Lewis, Gregory

    2008-01-01

    The k-out-of-n configuration is a widely adopted structure for partially redundant safety systems. This configuration ensures a high level of reliability and safety with limited financial and space resources. It also facilitates on-line Test and Maintenance (T and M) without having to shut the system down. One question a decision maker needs to answer when adopting k-out-of-n systems is: what is the best configuration for the application, i.e. how many channels in total need to be utilized and among these channels, how many channels need to function simultaneously in order for the system to function. There are various factors to consider in order to make this decision. This paper looks at this problem from a reliability engineers point of view. A quantitative analysis is performed for both unavailability and probability of spurious operation due to independent failure. In particular, the relative gain and/or loss of these quantities that occurs due to changing from one configuration to another are compared through rigorous mathematical analysis. The results provide important information that can be used when choosing system configurations to meet regulatory requirements and financial constraints. The two different configurations for shutdown systems in Nuclear Power Plants, the 2-out-of-3 system and the 2-out-of-4 system, are utilized as an example to illustrate the theoretical results

  9. Deciphering a unique biotin scavenging pathway with redundant genes in the probiotic bacterium Lactococcus lactis.

    Science.gov (United States)

    Zhang, Huimin; Wang, Qingjing; Fisher, Derek J; Cai, Mingzhu; Chakravartty, Vandana; Ye, Huiyan; Li, Ping; Solbiati, Jose O; Feng, Youjun

    2016-05-10

    Biotin protein ligase (BPL) is widespread in the three domains of the life. The paradigm BPL is the Escherichia coli BirA protein, which also functions as a repressor for the biotin biosynthesis pathway. Here we report that Lactococcus lactis possesses two different orthologues of birA (birA1_LL and birA2_LL). Unlike the scenario in E. coli, L. lactis appears to be auxotrophic for biotin in that it lacks a full biotin biosynthesis pathway. In contrast, it retains two biotin transporter-encoding genes (bioY1_LL and bioY2_LL), suggesting the use of a scavenging strategy to obtain biotin from the environment. The in vivo function of the two L. lactis birA genes was judged by their abilities to complement the conditional lethal E. coli birA mutant. Thin-layer chromatography and mass spectroscopy assays demonstrated that these two recombinant BirA proteins catalyze the biotinylation reaction of the acceptor biotin carboxyl carrier protein (BCCP), through the expected biotinoyl-AMP intermediate. Gel shift assays were used to characterize bioY1_LL and BirA1_LL. We also determined the ability to uptake (3)H-biotin by L. lactis. Taken together, our results deciphered a unique biotin scavenging pathway with redundant genes present in the probiotic bacterium L. lactis.

  10. Southern California Seismic Network: New Design and Implementation of Redundant and Reliable Real-time Data Acquisition Systems

    Science.gov (United States)

    Saleh, T.; Rico, H.; Solanki, K.; Hauksson, E.; Friberg, P.

    2005-12-01

    The Southern California Seismic Network (SCSN) handles more than 2500 high-data rate channels from more than 380 seismic stations distributed across southern California. These data are imported real-time from dataloggers, earthworm hubs, and partner networks. The SCSN also exports data to eight different partner networks. Both the imported and exported data are critical for emergency response and scientific research. Previous data acquisition systems were complex and difficult to operate, because they grew in an ad hoc fashion to meet the increasing needs for distributing real-time waveform data. To maximize reliability and redundancy, we apply best practices methods from computer science for implementing the software and hardware configurations for import, export, and acquisition of real-time seismic data. Our approach makes use of failover software designs, methods for dividing labor diligently amongst the network nodes, and state of the art networking redundancy technologies. To facilitate maintenance and daily operations we seek to provide some separation between major functions such as data import, export, acquisition, archiving, real-time processing, and alarming. As an example, we make waveform import and export functions independent by operating them on separate servers. Similarly, two independent servers provide waveform export, allowing data recipients to implement their own redundancy. The data import is handled differently by using one primary server and a live backup server. These data import servers, run fail-over software that allows automatic role switching in case of failure from primary to shadow. Similar to the classic earthworm design, all the acquired waveform data are broadcast onto a private network, which allows multiple machines to acquire and process the data. As we separate data import and export away from acquisition, we are also working on new approaches to separate real-time processing and rapid reliable archiving of real-time data

  11. Designing Art Exhibitions in an Educational Virtual World

    Science.gov (United States)

    Julian, June; Crooks, Julian

    2011-01-01

    Demonstrating the multiple features of the Cerulean Gallery in Second Life, this research report showcases several exemplar exhibits created by students, artists, and museums. Located in The Educational Media Center, a Second Life teaching and social space, the Cerulean Gallery exhibits functioned as case studies that tested its effectiveness as…

  12. Informing the Development of Science Exhibitions through Educational Research

    Science.gov (United States)

    Laherto, Antti

    2013-01-01

    This paper calls for greater use of educational research in the development of science exhibitions. During the past few decades, museums and science centres throughout the world have placed increasing emphasis on their educational function. Although exhibitions are the primary means of promoting visitors' learning, educational research is not…

  13. The Risk Factors for Criminal Behaviour in High-Functioning Autism Spectrum Disorders (HFASDs): A Comparison of Childhood Adversities between Individuals with HFASDs Who Exhibit Criminal Behaviour and Those with HFASD and No Criminal Histories

    Science.gov (United States)

    Kawakami, Chihiro; Ohnishi, Masafumi; Sugiyama, Toshiro; Someki, Fumio; Nakamura, Kazuhiko; Tsujii, Masatsugu

    2012-01-01

    Most reports of the criminal behaviour of individuals with high-functioning autism spectrum disorder (HFASD) have been case studies, and few have empirically examined the risk factors of criminal behaviour among these individuals. This study examined 175 individuals with HFASD, including 36 individuals who had a prior history of criminal…

  14. Performance and delay analysis of hybrid ARQ with incremental redundancy over double rayleigh fading channels

    KAUST Repository

    Chelli, Ali; Zedini, Emna; Alouini, Mohamed-Slim; Barry, John R.; Pä tzold, Matthias

    2014-01-01

    the performance of HARQ from an information theoretic perspective. Analytical expressions are derived for the \\epsilon-outage capacity, the average number of transmissions, and the average transmission rate of HARQ with incremental redundancy assuming a maximum

  15. Quantifying Net Synergy/Redundancy of Spontaneous Variability Regulation via Predictability and Transfer Entropy Decomposition Frameworks.

    Science.gov (United States)

    Porta, Alberto; Bari, Vlasta; De Maria, Beatrice; Takahashi, Anielle C M; Guzzetti, Stefano; Colombo, Riccardo; Catai, Aparecida M; Raimondi, Ferdinando; Faes, Luca

    2017-11-01

    Objective: Indexes assessing the balance between redundancy and synergy were hypothesized to be helpful in characterizing cardiovascular control from spontaneous beat-to-beat variations of heart period (HP), systolic arterial pressure (SAP), and respiration (R). Methods: Net redundancy/synergy indexes were derived according to predictability and transfer entropy decomposition strategies via a multivariate linear regression approach. Indexes were tested in two protocols inducing modifications of the cardiovascular regulation via baroreflex loading/unloading (i.e., head-down tilt at -25° and graded head-up tilt at 15°, 30°, 45°, 60°, 75°, and 90°, respectively). The net redundancy/synergy of SAP and R to HP and of HP and R to SAP were estimated over stationary sequences of 256 successive values. Results: We found that: 1) regardless of the target (i.e., HP or SAP) redundancy was prevalent over synergy and this prevalence was independent of type and magnitude of the baroreflex challenge; 2) the prevalence of redundancy disappeared when decoupling inputs from output via a surrogate approach; 3) net redundancy was under autonomic control given that it varied in proportion to the vagal withdrawal during graded head-up tilt; and 4) conclusions held regardless of the decomposition strategy. Conclusion: Net redundancy indexes can monitor changes of cardiovascular control from a perspective completely different from that provided by more traditional univariate and multivariate methods. Significance: Net redundancy measures might provide a practical tool to quantify the reservoir of effective cardiovascular regulatory mechanisms sharing causal influences over a target variable. Objective: Indexes assessing the balance between redundancy and synergy were hypothesized to be helpful in characterizing cardiovascular control from spontaneous beat-to-beat variations of heart period (HP), systolic arterial pressure (SAP), and respiration (R). Methods: Net redundancy

  16. Performance of hybrid-ARQ with incremental redundancy over relay channels

    KAUST Repository

    Chelli, Ali; Alouini, Mohamed-Slim

    2012-01-01

    In this paper, we consider a relay network consisting of a source, a relay, and a destination. The source transmits a message to the destination using hybrid automatic repeat request (HARQ) with incremental redundancy (IR). The relay overhears

  17. An analytical and experimental study of the behaviour of redundant controllers applied to a nuclear plant

    International Nuclear Information System (INIS)

    Lawrence, L.A.J.

    1964-02-01

    The behaviour of a number of configurations of redundant controllers is examined and the design problems discussed in relation to the engineering of reliable control rod drive systems for nuclear plant. (author)

  18. Unified performance analysis of hybrid-ARQ with incremental redundancy over free-space optical channels

    KAUST Repository

    Zedini, Emna; Chelli, Ali; Alouini, Mohamed-Slim

    2014-01-01

    In this paper, we carry out a unified performance analysis of hybrid automatic repeat request (HARQ) with incremental redundancy (IR) from an information theoretic perspective over a point-to-point free-space optical (FSO) system. First, we

  19. Revisions to Conventional Clock Domain Crossing Methodologies in Triple Modular Redundant Circuits

    Science.gov (United States)

    Berg, Melanie D.; LaBel, Kenneth A.

    2018-01-01

    We present updates to the conventional methodology of triple modular redundancy (TMR) insertion as it pertains to clock domain crossings (CDCs). Three types of TMR schemes and their suggested corresponding CDC revisions are discussed.

  20. Multi-objective reliability optimization of series-parallel systems with a choice of redundancy strategies

    International Nuclear Information System (INIS)

    Safari, Jalal

    2012-01-01

    This paper proposes a variant of the Non-dominated Sorting Genetic Algorithm (NSGA-II) to solve a novel mathematical model for multi-objective redundancy allocation problems (MORAP). Most researchers about redundancy allocation problem (RAP) have focused on single objective optimization, while there has been some limited research which addresses multi-objective optimization. Also all mathematical multi-objective models of general RAP assume that the type of redundancy strategy for each subsystem is predetermined and known a priori. In general, active redundancy has traditionally received greater attention; however, in practice both active and cold-standby redundancies may be used within a particular system design. The choice of redundancy strategy then becomes an additional decision variable. Thus, the proposed model and solution method are to select the best redundancy strategy, type of components, and levels of redundancy for each subsystem that maximizes the system reliability and minimize total system cost under system-level constraints. This problem belongs to the NP-hard class. This paper presents a second-generation Multiple-Objective Evolutionary Algorithm (MOEA), named NSGA-II to find the best solution for the given problem. The proposed algorithm demonstrates the ability to identify a set of optimal solutions (Pareto front), which provides the Decision Maker (DM) with a complete picture of the optimal solution space. After finding the Pareto front, a procedure is used to select the best solution from the Pareto front. Finally, the advantages of the presented multi-objective model and of the proposed algorithm are illustrated by solving test problems taken from the literature and the robustness of the proposed NSGA-II is discussed.

  1. FON2 SPARE1 redundantly regulates floral meristem maintenance with FLORAL ORGAN NUMBER2 in rice.

    Directory of Open Access Journals (Sweden)

    Takuya Suzaki

    2009-10-01

    Full Text Available CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM in Arabidopsis thaliana. In rice (Oryza sativa, FLORAL ORGAN NUMBER2 (FON2, closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM. Here we show that the FON2 SPARE1 (FOS1 gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems.

  2. TAF10 and TAF10b partially redundant roles during Drosophila melanogaster morphogenesis.

    Science.gov (United States)

    Pahi, Z; Borsos, B N; Vedelek, B; Shidlovskii, Y V; Georgieva, S G; Boros, I M; Pankotai, T

    2017-01-01

    Transcription of eukaryotic genes requires the cooperative action of the RNA polymerase complex, the general transcription factors (TFIIB, TFIID, TFIIE, TFIIF and TFIIH) and chromatin modifiers. The TFIID complex contributes to transcriptional activation by several mechanisms and has a subunit with associated histone acetyltransferase (HAT) activity. The histone modifier SAGA complex has both HAT and deubiquitylase (DUB) activities. TFIID and SAGA share several TBP-associated factors (TAFs), but not their HAT subunit. Recently, several duplicated TAF proteins have been identified in higher eukaryotes, but their functional diversity has been so far poorly characterized. Here, we report the functional similarities and differences of TAF10 and TAF10b, the two TAF10 orthologs of Drosophila melanogaster. Results from in silico modeling suggest that dTAF10 and dTAF10b have similar secondary structures characterized by the presence of a histone-fold domain. Additionally, dTAF10 and dTAF10b share interaction partners and show similar expression patterns in neuronal tissues. Nonetheless, dTAF10 and dTAF10b seem to have partly distinct functions. To investigate their roles, we generated dTaf10-dTaf10b double-mutants and rescued the mutant flies with transgenes, which allowed the translation of either dTAF10 or dTAF10b protein. We found that the loss of dTAF10b resulted in pupal lethality, while animals lacking dTAF10 were able to form puparium. dTaf10 mutant adults showed distorted eye morphology. During DNA repair, dTAF10 and dTAF10b act redundantly, suggesting that these proteins have distinct but partially overlapping functions.

  3. An efficient particle swarm approach for mixed-integer programming in reliability-redundancy optimization applications

    International Nuclear Information System (INIS)

    Santos Coelho, Leandro dos

    2009-01-01

    The reliability-redundancy optimization problems can involve the selection of components with multiple choices and redundancy levels that produce maximum benefits, and are subject to the cost, weight, and volume constraints. Many classical mathematical methods have failed in handling nonconvexities and nonsmoothness in reliability-redundancy optimization problems. As an alternative to the classical optimization approaches, the meta-heuristics have been given much attention by many researchers due to their ability to find an almost global optimal solutions. One of these meta-heuristics is the particle swarm optimization (PSO). PSO is a population-based heuristic optimization technique inspired by social behavior of bird flocking and fish schooling. This paper presents an efficient PSO algorithm based on Gaussian distribution and chaotic sequence (PSO-GC) to solve the reliability-redundancy optimization problems. In this context, two examples in reliability-redundancy design problems are evaluated. Simulation results demonstrate that the proposed PSO-GC is a promising optimization technique. PSO-GC performs well for the two examples of mixed-integer programming in reliability-redundancy applications considered in this paper. The solutions obtained by the PSO-GC are better than the previously best-known solutions available in the recent literature

  4. Reliability-redundancy optimization by means of a chaotic differential evolution approach

    International Nuclear Information System (INIS)

    Coelho, Leandro dos Santos

    2009-01-01

    The reliability design is related to the performance analysis of many engineering systems. The reliability-redundancy optimization problems involve selection of components with multiple choices and redundancy levels that produce maximum benefits, can be subject to the cost, weight, and volume constraints. Classical mathematical methods have failed in handling nonconvexities and nonsmoothness in optimization problems. As an alternative to the classical optimization approaches, the meta-heuristics have been given much attention by many researchers due to their ability to find an almost global optimal solution in reliability-redundancy optimization problems. Evolutionary algorithms (EAs) - paradigms of evolutionary computation field - are stochastic and robust meta-heuristics useful to solve reliability-redundancy optimization problems. EAs such as genetic algorithm, evolutionary programming, evolution strategies and differential evolution are being used to find global or near global optimal solution. A differential evolution approach based on chaotic sequences using Lozi's map for reliability-redundancy optimization problems is proposed in this paper. The proposed method has a fast convergence rate but also maintains the diversity of the population so as to escape from local optima. An application example in reliability-redundancy optimization based on the overspeed protection system of a gas turbine is given to show its usefulness and efficiency. Simulation results show that the application of deterministic chaotic sequences instead of random sequences is a possible strategy to improve the performance of differential evolution.

  5. Input relegation control for gross motion of a kinematically redundant manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Unseren, M.A.

    1992-10-01

    This report proposes a method for resolving the kinematic redundancy of a serial link manipulator moving in a three-dimensional workspace. The underspecified problem of solving for the joint velocities based on the classical kinematic velocity model is transformed into a well-specified problem. This is accomplished by augmenting the original model with additional equations which relate a new vector variable quantifying the redundant degrees of freedom (DOF) to the joint velocities. The resulting augmented system yields a well specified solution for the joint velocities. Methods for selecting the redundant DOF quantifying variable and the transformation matrix relating it to the joint velocities are presented so as to obtain a minimum Euclidean norm solution for the joint velocities. The approach is also applied to the problem of resolving the kinematic redundancy at the acceleration level. Upon resolving the kinematic redundancy, a rigid body dynamical model governing the gross motion of the manipulator is derived. A control architecture is suggested which according to the model, decouples the Cartesian space DOF and the redundant DOF.

  6. One Size Does Not Fit All: Older Adults Benefit From Redundant Text in Multimedia Instruction

    Directory of Open Access Journals (Sweden)

    Barbara eFenesi

    2015-07-01

    Full Text Available The multimedia design of presentations typically ignores that younger and older adults have varying cognitive strengths and weaknesses. We examined whether differential instructional design may enhance learning in these populations. Younger and older participants viewed one of three computer-based presentations: Audio only (narration, Redundant (audio narration with redundant text, or Complementary (audio narration with non–redundant text and images. Younger participants learned better when audio narration was paired with relevant images compared to when audio narration was paired with redundant text. However, older participants learned best when audio narration was paired with redundant text. Younger adults, who presumably have a higher working memory capacity, appear to benefit more from complementary information that may drive deeper conceptual processing. In contrast, older adults learn better from presentations that support redundant coding across modalities, which may help mitigate the effects of age-related decline in working memory capacity. Additionally, several misconceptions of design quality appeared across age groups: both younger and older participants positively rated less effective designs. Findings suggest that one-size does not fit all, with older adults requiring unique multimedia design tailored to their cognitive abilities for effective learning.

  7. One size does not fit all: older adults benefit from redundant text in multimedia instruction.

    Science.gov (United States)

    Fenesi, Barbara; Vandermorris, Susan; Kim, Joseph A; Shore, David I; Heisz, Jennifer J

    2015-01-01

    The multimedia design of presentations typically ignores that younger and older adults have varying cognitive strengths and weaknesses. We examined whether differential instructional design may enhance learning in these populations. Younger and older participants viewed one of three computer-based presentations: Audio only (narration), Redundant (audio narration with redundant text), or Complementary (audio narration with non-redundant text and images). Younger participants learned better when audio narration was paired with relevant images compared to when audio narration was paired with redundant text. However, older participants learned best when audio narration was paired with redundant text. Younger adults, who presumably have a higher working memory capacity (WMC), appear to benefit more from complementary information that may drive deeper conceptual processing. In contrast, older adults learn better from presentations that support redundant coding across modalities, which may help mitigate the effects of age-related decline in WMC. Additionally, several misconceptions of design quality appeared across age groups: both younger and older participants positively rated less effective designs. Findings suggest that one-size does not fit all, with older adults requiring unique multimedia design tailored to their cognitive abilities for effective learning.

  8. Efficient exact optimization of multi-objective redundancy allocation problems in series-parallel systems

    International Nuclear Information System (INIS)

    Cao, Dingzhou; Murat, Alper; Chinnam, Ratna Babu

    2013-01-01

    This paper proposes a decomposition-based approach to exactly solve the multi-objective Redundancy Allocation Problem for series-parallel systems. Redundancy allocation problem is a form of reliability optimization and has been the subject of many prior studies. The majority of these earlier studies treat redundancy allocation problem as a single objective problem maximizing the system reliability or minimizing the cost given certain constraints. The few studies that treated redundancy allocation problem as a multi-objective optimization problem relied on meta-heuristic solution approaches. However, meta-heuristic approaches have significant limitations: they do not guarantee that Pareto points are optimal and, more importantly, they may not identify all the Pareto-optimal points. In this paper, we treat redundancy allocation problem as a multi-objective problem, as is typical in practice. We decompose the original problem into several multi-objective sub-problems, efficiently and exactly solve sub-problems, and then systematically combine the solutions. The decomposition-based approach can efficiently generate all the Pareto-optimal solutions for redundancy allocation problems. Experimental results demonstrate the effectiveness and efficiency of the proposed method over meta-heuristic methods on a numerical example taken from the literature.

  9. Developmental changes in children’s processing of redundant modifiers in definite object descriptions

    Directory of Open Access Journals (Sweden)

    Ruud Koolen

    2016-12-01

    Full Text Available This paper investigates developmental changes in children’s processing of redundant information in definite object descriptions. In two experiments, children of two age groups (six or seven, and nine or ten years old were presented with pictures of sweets. In the first experiment (pairwise comparison, two identical sweets were shown, and one of these was described with a redundant modifier. After the description, the children had to indicate the sweet they preferred most in a forced-choice task. In the second experiment (graded rating, only one sweet was shown, which was described with a redundant color modifier in half of the cases (e.g., the blue sweet and in the other half of the cases simply as the sweet. This time, the children were asked to indicate on a 5-point rating scale to what extent they liked the sweets. In both experiments, the results showed that the younger children had a preference for the sweets described with redundant information, while redundant information did not have an effect on the preferences for the older children. These results imply that children are learning to distinguish between situations in which redundant information carries an implicature and situations in which this is not the case.

  10. Comparing surgical trays with redundant instruments with trays with reduced instruments: a cost analysis.

    Science.gov (United States)

    John-Baptiste, A; Sowerby, L J; Chin, C J; Martin, J; Rotenberg, B W

    2016-01-01

    When prearranged standard surgical trays contain instruments that are repeatedly unused, the redundancy can result in unnecessary health care costs. Our objective was to estimate potential savings by performing an economic evaluation comparing the cost of surgical trays with redundant instruments with surgical trays with reduced instruments ("reduced trays"). We performed a cost-analysis from the hospital perspective over a 1-year period. Using a mathematical model, we compared the direct costs of trays containing redundant instruments to reduced trays for 5 otolaryngology procedures. We incorporated data from several sources including local hospital data on surgical volume, the number of instruments on redundant and reduced trays, wages of personnel and time required to pack instruments. From the literature, we incorporated instrument depreciation costs and the time required to decontaminate an instrument. We performed 1-way sensitivity analyses on all variables, including surgical volume. Costs were estimated in 2013 Canadian dollars. The cost of redundant trays was $21 806 and the cost of reduced trays was $8803, for a 1-year cost saving of $13 003. In sensitivity analyses, cost savings ranged from $3262 to $21 395, based on the surgical volume at the institution. Variation in surgical volume resulted in a wider range of estimates, with a minimum of $3253 for low-volume to a maximum of $52 012 for high-volume institutions. Our study suggests moderate savings may be achieved by reducing surgical tray redundancy and, if applied to other surgical specialties, may result in savings to Canadian health care systems.

  11. An efficient particle swarm approach for mixed-integer programming in reliability-redundancy optimization applications

    Energy Technology Data Exchange (ETDEWEB)

    Santos Coelho, Leandro dos [Industrial and Systems Engineering Graduate Program, LAS/PPGEPS, Pontifical Catholic University of Parana, PUCPR, Imaculada Conceicao, 1155, 80215-901 Curitiba, Parana (Brazil)], E-mail: leandro.coelho@pucpr.br

    2009-04-15

    The reliability-redundancy optimization problems can involve the selection of components with multiple choices and redundancy levels that produce maximum benefits, and are subject to the cost, weight, and volume constraints. Many classical mathematical methods have failed in handling nonconvexities and nonsmoothness in reliability-redundancy optimization problems. As an alternative to the classical optimization approaches, the meta-heuristics have been given much attention by many researchers due to their ability to find an almost global optimal solutions. One of these meta-heuristics is the particle swarm optimization (PSO). PSO is a population-based heuristic optimization technique inspired by social behavior of bird flocking and fish schooling. This paper presents an efficient PSO algorithm based on Gaussian distribution and chaotic sequence (PSO-GC) to solve the reliability-redundancy optimization problems. In this context, two examples in reliability-redundancy design problems are evaluated. Simulation results demonstrate that the proposed PSO-GC is a promising optimization technique. PSO-GC performs well for the two examples of mixed-integer programming in reliability-redundancy applications considered in this paper. The solutions obtained by the PSO-GC are better than the previously best-known solutions available in the recent literature.

  12. Minimizing Redundant Messages and Improving Search Efficiency under Highly Dynamic Mobile P2P Network

    Directory of Open Access Journals (Sweden)

    Ajay Arunachalam

    2016-02-01

    Full Text Available Resource Searching is one of the key functional tasks in large complex networks. With the P2P architecture, millions of peers connect together instantly building a communication pattern. Searching in mobile networks faces additional limitations and challenges. Flooding technique can cope up with the churn and searches aggressively by visiting almost all the nodes. But it exponentially increases the network traffic and thus does not scale well. Further the duplicated query messages consume extra battery power and network bandwidth. The blind flooding also suffers from long delay problem in P2P networks. In this paper, we propose optimal density based flooding resource discovery schemes. Our first model takes into account local graph topology information to supplement the resource discovery process while in our extended version we also consider the neighboring node topology information along with the local node information to further effectively use the mobile and network resources. Our proposed method reduces collision at the same time minimizes effect of redundant messages and failures. Overall the methods reduce network overhead, battery power consumption, query delay, routing load, MAC load and bandwidth usage while also achieving good success rate in comparison to the other techniques. We also perform a comprehensive analysis of the resource discovery schemes to verify the impact of varying node speed and different network conditions.

  13. Obstacle Avoidance for Redundant Manipulators Utilizing a Backward Quadratic Search Algorithm

    Directory of Open Access Journals (Sweden)

    Tianjian Hu

    2016-06-01

    Full Text Available Obstacle avoidance can be achieved as a secondary task by appropriate inverse kinematics (IK resolution of redundant manipulators. Most prior literature requires the time-consuming determination of the closest point to the obstacle for every calculation step. Aiming at the relief of computational burden, this paper develops what is termed a backward quadratic search algorithm (BQSA as another option for solving IK problems in obstacle avoidance. The BQSA detects possible collisions based on the root property of a category of quadratic functions, which are derived from ellipse-enveloped obstacles and the positions of each link's end-points. The algorithm executes a backward search for possible obstacle collisions, from the end-effector to the base, and avoids obstacles by utilizing a hybrid IK scheme, incorporating the damped least-squares method, the weighted least-norm method and the gradient projection method. Some details of the hybrid IK scheme, such as values of the damped factor, weights and the clamping velocity, are discussed, along with a comparison of computational load between previous methods and BQSA. Simulations of a planar seven-link manipulator and a PUMA 560 robot verify the effectiveness of BQSA.

  14. Optimally efficient swimming in hyper-redundant mechanisms: control, design, and energy recovery

    International Nuclear Information System (INIS)

    Wiens, A J; Nahon, M

    2012-01-01

    Hyper-redundant mechanisms (HRMs), also known as snake-like robots, are highly adaptable during locomotion on land. Researchers are currently working to extend their capabilities to aquatic environments through biomimetic undulatory propulsion. In addition to increasing the versatility of the system, truly biomimetic swimming could also provide excellent locomotion efficiency. Unfortunately, the complexity of the system precludes the development of a functional solution to achieve this. To explore this problem, a rapid optimization process is used to generate efficient HRM swimming gaits. The low computational cost of the approach allows for multiple optimizations over a broad range of system conditions. By observing how these conditions affect optimal kinematics, a number of new insights are developed regarding undulatory swimming in robotic systems. Two key conditions are varied within the study, swimming speed and energy recovery. It is found that the swimmer mimics the speed control behaviour of natural fish and that energy recovery drastically increases the system's efficiency. Remarkably, this efficiency increase is accompanied by a distinct change in swimming kinematics. With energy recovery, the swimmer converges to a clearly anguilliform gait, without, it tends towards the carangiform mode. (paper)

  15. How do we manage post-OLT redundant bile duct?

    Science.gov (United States)

    Torres, Victor; Martinez, Nicholas; Lee, Gabriel; Almeda, Jose; Gross, Glenn; Patel, Sandeep; Rosenkranz, Laura

    2013-04-28

    To address endoscopic outcomes of post-Orthotopic liver transplantation (OLT) patients diagnosed with a "redundant bile duct" (RBD). Medical records of patients who underwent OLT at the Liver Transplant Center, University Texas Health Science Center at San Antonio Texas were retrospectively analyzed. Patients with suspected biliary tract complications (BTC) underwent endoscopic retrograde cholangiopancreatography (ERCP). All ERCP were performed by experienced biliary endoscopist. RBD was defined as a looped, sigmoid-shaped bile duct on cholangiogram with associated cholestatic liver biomarkers. Patients with biliary T-tube placement, biliary anastomotic strictures, bile leaks, bile-duct stones-sludge and suspected sphincter of oddi dysfunction were excluded. Therapy included single or multiple biliary stents with or without sphincterotomy. The incidence of RBD, the number of ERCP corrective sessions, and the type of endoscopic interventions were recorded. Successful response to endoscopic therapy was defined as resolution of RBD with normalization of associated cholestasis. Laboratory data and pertinent radiographic imaging noted included the pre-ERCP period and a follow up period of 6-12 mo after the last ERCP intervention. One thousand two hundred and eighty-two patient records who received OLT from 1992 through 2011 were reviewed. Two hundred and twenty-four patients underwent ERCP for suspected BTC. RBD was reported in each of the initial cholangiograms. Twenty-one out of 1282 (1.6%) were identified as having RBD. There were 12 men and 9 women, average age of 59.6 years. Primary indication for ERCP was cholestatic pattern of liver associated biomarkers. Nineteen out of 21 patients underwent endoscopic therapy and 2/21 required immediate surgical intervention. In the endoscopically managed group: 65 ERCP procedures were performed with an average of 3.4 per patient and 1.1 stent per session. Fifteen out of 19 (78.9%) patients were successfully managed with

  16. EFFICIENCY OF REDUNDANT QUERY EXECUTION IN MULTI-CHANNEL SERVICE SYSTEMS

    Directory of Open Access Journals (Sweden)

    V. A. Bogatyrev

    2016-03-01

    Full Text Available Subject of Research.The paper deals with analysis of the effectiveness of redundant queries based on untrusted computing in computer systems, represented by multi-channel queuing systems with a common queue. The objective of research is the possibility of increasing the efficiency of service requests while performing redundant copies of requests in different devices of a multi-channel system under conditions of calculations unreliability. The redundant service of requests requires the infallibility of its implementation at least in one of the devices.Method. We have considered estimation of the average time spent in the system with and without the use of redundant requests at the presentation of a simple queuing model of the M / M / n type to analyze the effectiveness of redundant service of requests. Presented evaluation of the average waiting time in the redundant queries is the upper one, since it ignores the possibility of reducing the average waiting time as a result of the spread of the probability of time querying at different devices. The integrated efficiency of redundant service of requests is defined based on the multiplicative index that takes into account the infallibility of calculations and the average time allowance with respect to the maximum tolerated delay of service. Evaluation of error-free computing at reserved queries is received at the requirement of faultless execution of at least one copy of the request. Main Results. We have shown that the reservation of requests gives the gain in efficiency of the system at low demand rate (load. We have defined the boundaries of expediency (efficiency for redundant service of requests. We have shown the possibility of the effectiveness increasing of the adaptive changes in the multiplicity of the reservation of requests, depending on the intensity of the flow of requests. We have found out that the choice of service discipline in information service systems is largely determined by

  17. Redundancy, resilience, and host specificity of the ruminal microbiota: implications for engineering improved ruminal fermentations

    Science.gov (United States)

    Weimer, Paul J.

    2015-01-01

    The ruminal microbial community is remarkably diverse, containing 100s of different bacterial and archaeal species, plus many species of fungi and protozoa. Molecular studies have identified a “core microbiome” dominated by phyla Firmicutes and Bacteroidetes, but also containing many other taxa. The rumen provides an ideal laboratory for studies on microbial ecology and the demonstration of ecological principles. In particular, the microbial community demonstrates both redundancy (overlap of function among multiple species) and resilience (resistance to, and capacity to recover from, perturbation). These twin properties provide remarkable stability that maintains digestive function for the host across a range of feeding and management conditions, but they also provide a challenge to engineering the rumen for improved function (e.g., improved fiber utilization or decreased methane production). Direct ruminal dosing or feeding of probiotic strains often fails to establish the added strains, due to intensive competition and amensalism from the indigenous residents that are well-adapted to the historical conditions within each rumen. Known exceptions include introduced strains that can fill otherwise unoccupied niches, as in the case of specialist bacteria that degrade phytotoxins such as mimosine or fluoroacetate. An additional complicating factor in manipulating the ruminal fermentation is the individuality or host specificity of the microbiota, in which individual animals contain a particular community whose species composition is capable of reconstituting itself, even following a near-total exchange of ruminal contents from another herd mate maintained on the same diet. Elucidation of the interactions between the microbial community and the individual host that establish and maintain this specificity may provide insights into why individual hosts vary in production metrics (e.g., feed efficiency or milk fat synthesis), and how to improve herd performance. PMID

  18. A polar-region-adaptable systematic bias collaborative measurement method for shipboard redundant rotational inertial navigation systems

    Science.gov (United States)

    Wang, Lin; Wu, Wenqi; Wei, Guo; Lian, Junxiang; Yu, Ruihang

    2018-05-01

    The shipboard redundant rotational inertial navigation system (RINS) configuration, including a dual-axis RINS and a single-axis RINS, can satisfy the demand of marine INSs of especially high reliability as well as achieving trade-off between position accuracy and cost. Generally, the dual-axis RINS is the master INS, and the single-axis RINS is the hot backup INS for high reliability purposes. An integrity monitoring system performs a fault detection function to ensure sailing safety. However, improving the accuracy of the backup INS in case of master INS failure has not been given enough attention. Without the aid of any external information, a systematic bias collaborative measurement method based on an augmented Kalman filter is proposed for the redundant RINSs. Estimates of inertial sensor biases can be used by the built-in integrity monitoring system to monitor the RINS running condition. On the other hand, a position error prediction model is designed for the single-axis RINS to estimate the systematic error caused by its azimuth gyro bias. After position error compensation, the position information provided by the single-axis RINS still remains highly accurate, even if the integrity monitoring system detects a dual-axis RINS fault. Moreover, use of a grid frame as a navigation frame makes the proposed method applicable in any area, including the polar regions. Semi-physical simulation and experiments including sea trials verify the validity of the method.

  19. Specific gene expression responses to parasite genotypes reveal redundancy of innate immunity in vertebrates.

    Directory of Open Access Journals (Sweden)

    David Haase

    Full Text Available Vertebrate innate immunity is the first line of defense against an invading pathogen and has long been assumed to be largely unspecific with respect to parasite/pathogen species. However, recent phenotypic evidence suggests that immunogenetic variation, i.e. allelic variability in genes associated with the immune system, results in host-parasite genotype-by-genotype interactions and thus specific innate immune responses. Immunogenetic variation is common in all vertebrate taxa and this reflects an effective immunological function in complex environments. However, the underlying variability in host gene expression patterns as response of innate immunity to within-species genetic diversity of macroparasites in vertebrates is unknown. We hypothesized that intra-specific variation among parasite genotypes must be reflected in host gene expression patterns. Here we used high-throughput RNA-sequencing to examine the effect of parasite genotypes on gene expression patterns of a vertebrate host, the three-spined stickleback (Gasterosteus aculeatus. By infecting naïve fish with distinct trematode genotypes of the species Diplostomum pseudospathaceum we show that gene activity of innate immunity in three-spined sticklebacks depended on the identity of an infecting macroparasite genotype. In addition to a suite of genes indicative for a general response against the trematode we also find parasite-strain specific gene expression, in particular in the complement system genes, despite similar infection rates of single clone treatments. The observed discrepancy between infection rates and gene expression indicates the presence of alternative pathways which execute similar functions. This suggests that the innate immune system can induce redundant responses specific to parasite genotypes.

  20. Remote Autonomous Sensor Networks: A Study in Redundancy and Life Cycle Costs

    Science.gov (United States)

    Ahlrichs, M.; Dotson, A.; Cenek, M.

    2017-12-01

    The remote nature of the United States and Canada border and their extreme seasonal shifts has made monitoring much of the area impossible using conventional monitoring techniques. Currently, the United States has large gaps in its ability to detect movement on an as-needed-basis in remote areas. The proposed autonomous sensor network aims to meet that need by developing a product that is low cost, robust, and can be deployed on an as-needed-basis for short term monitoring events. This is accomplished by identifying radio frequency disturbance and acoustic disturbance. This project aims to validate the proposed design and offer optimization strategies by conducting a redundancy model as well as performing a Life Cycle Assessment (LCA). The model will incorporate topological, meteorological, and land cover datasets to estimate sensor loss over a three-month period, ensuring that the remaining network does not have significant gaps in coverage which preclude being able to receive and transmit data. The LCA will investigate the materials used to create the sensor to generate an estimate of the total environmental energy that is utilized to create the network and offer alternative materials and distribution methods that can lower this cost. This platform can function as a stand-alone monitoring network or provide additional spatial and temporal resolution to existing monitoring networks. This study aims to create the framework to determine if a sensor's design and distribution is appropriate for the target environment. The incorporation of a LCA will seek to answer if the data a proposed sensor network will collect outweighs the environmental damage that will result from its deployment. Furthermore, as the arctic continues to thaw and economic development grows, the methodology described in paper will function as a guidance document to ensure that future sensor networks have a minimal impact on these pristine areas.

  1. Artefacts and the performance of an exhibition

    DEFF Research Database (Denmark)

    Svabo, Connie

    2008-01-01

    The article explores the role of mediating artefacts in children's encounters with a museum of natural history. Using actor network theory it explores how a specific artefact shapes the way users relate to exhibited objects and how the artefact guides users' movements in the exhibition....... The mediated performance of an exhibition is explored through an empirical case....

  2. RSAT matrix-clustering: dynamic exploration and redundancy reduction of transcription factor binding motif collections.

    Science.gov (United States)

    Castro-Mondragon, Jaime Abraham; Jaeger, Sébastien; Thieffry, Denis; Thomas-Chollier, Morgane; van Helden, Jacques

    2017-07-27

    Transcription factor (TF) databases contain multitudes of binding motifs (TFBMs) from various sources, from which non-redundant collections are derived by manual curation. The advent of high-throughput methods stimulated the production of novel collections with increasing numbers of motifs. Meta-databases, built by merging these collections, contain redundant versions, because available tools are not suited to automatically identify and explore biologically relevant clusters among thousands of motifs. Motif discovery from genome-scale data sets (e.g. ChIP-seq) also produces redundant motifs, hampering the interpretation of results. We present matrix-clustering, a versatile tool that clusters similar TFBMs into multiple trees, and automatically creates non-redundant TFBM collections. A feature unique to matrix-clustering is its dynamic visualisation of aligned TFBMs, and its capability to simultaneously treat multiple collections from various sources. We demonstrate that matrix-clustering considerably simplifies the interpretation of combined results from multiple motif discovery tools, and highlights biologically relevant variations of similar motifs. We also ran a large-scale application to cluster ∼11 000 motifs from 24 entire databases, showing that matrix-clustering correctly groups motifs belonging to the same TF families, and drastically reduced motif redundancy. matrix-clustering is integrated within the RSAT suite (http://rsat.eu/), accessible through a user-friendly web interface or command-line for its integration in pipelines. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. Techno-Economic Assessment of Redundancy Systems for a Cogeneration Plant

    Directory of Open Access Journals (Sweden)

    Majid Mohd Amin Abd

    2014-07-01

    Full Text Available The use of distributed power generation has advantage as well as disadvantage. One of the disadvantages is that the plant requires a dependable redundancy system to provide back up of power during failure of its power generation equipment. This paper presents a study on techno-economic assessment of redundancy systems for a cogeneration plant. Three redundancy systems were investigated; using public utility, generator set and gas turbine as back up during failures. Results from the analysis indicate that using public utility provides technical as well as economic advantages in comparison to using generator set or turbine as back up. However, the economic advantage of the public utility depends on the frequency of failures the plant will experience as well on the maximum demand charge. From the break even analysis of the understudied plant, if the number of failures exceeds 3 failures per year for the case of maximum demand charge of RM56.80, it is more economical to install a generator set as redundancy. The study will be useful for the co-generator operators to evaluate the feasibility of redundancy systems.

  4. Redundancy of einselected information in quantum Darwinism: The irrelevance of irrelevant environment bits

    Science.gov (United States)

    Zwolak, Michael; Zurek, Wojciech H.

    2017-03-01

    The objective, classical world emerges from the underlying quantum substrate via the proliferation of redundant copies of selected information into the environment, which acts as a communication channel, transmitting that information to observers. These copies are independently accessible, allowing many observers to reach consensus about the state of a quantum system via its imprints in the environment. Quantum Darwinism recognizes that the redundancy of information is thus central to the emergence of objective reality in the quantum world. However, in addition to the "quantum system of interest," there are many other systems "of no interest" in the Universe that can imprint information on the common environment. There is therefore a danger that the information of interest will be diluted with irrelevant bits, suppressing the redundancy responsible for objectivity. We show that mixing of the relevant (the "wheat") and irrelevant (the "chaff") bits of information makes little quantitative difference to the redundancy of the information of interest. Thus, we demonstrate that it does not matter whether one separates the wheat (relevant information) from the (irrelevant) chaff: The large redundancy of the relevant information survives dilution, providing evidence of the objective, effectively classical world.

  5. Design method of redundancy of brace-anchor sharing supporting based on cooperative deformation

    Science.gov (United States)

    Liu, Jun-yan; Li, Bing; Liu, Yan; Cai, Shan-bing

    2017-11-01

    Because of the complicated environment requirement, the support form of foundation pit is diversified, and the brace-anchor sharing support is widely used. However, the research on the force deformation characteristics and the related aspects of the cooperative response of the brace-anchor sharing support is insufficient. The application of redundancy theory in structural engineering has been more mature, but there is little theoretical research on redundancy theory in underground engineering. Based on the idea of collaborative deformation, the paper calculates the ratio of the redundancy degree of the cooperative deformation by using the local reinforcement design method and the structural component redundancy parameter calculation formula based on Frangopol. Combined with the engineering case, through the calculation of the ratio of cooperative deformation redundancy in the joint of brace-anchor sharing support. This paper explores the optimal anchor distribution form under the condition of cooperative deformation, and through the analysis and research of displacement field and stress field, the results of the collaborative deformation are validated by comparing the field monitoring data. It provides theoretical basis for the design of this kind of foundation pit in the future.

  6. The impact of the operating environment on the design of redundant configurations

    International Nuclear Information System (INIS)

    Marseguerra, M.; Padovani, E.; Zio, E.

    1999-01-01

    Safety systems are often characterized by substantial redundancy and diversification in safety critical components. In principle, such redundancy and diversification can bring benefits when compared to single-component systems. However, it has also been recognized that the evaluation of these benefits should take into account that redundancies cannot be founded, in practice, on the assumption of complete independence, so that the resulting risk profile is strongly dominated by dependent failures. It is therefore mandatory that the effects of common cause failures be estimated in any probabilistic safety assessment (PSA). Recently, in the Hughes model for hardware failures and in the Eckhardt and Lee models for software failures, it was proposed that the stressfulness of the operating environment affects the probability that a particular type of component will fail. Thus, dependence of component failure behaviors can arise indirectly through the variability of the environment which can directly affect the success of a redundant configuration. In this paper we investigate the impact of indirect component dependence by means of the introduction of a probability distribution which describes the variability of the environment. We show that the variance of the distribution of the number, or times, of system failures can give an indication of the presence of the environment. Further, the impact of the environment is shown to affect the reliability and the design of redundant configurations

  7. Compliant behaviour of redundant robot arm - experiments with null-space

    Directory of Open Access Journals (Sweden)

    Petrović Petar B.

    2015-01-01

    Full Text Available This paper presents theoretical and experimental aspects of Jacobian nullspace use in kinematically redundant robots for achieving kinetostatically consistent control of their compliant behavior. When the stiffness of the robot endpoint is dominantly influenced by the compliance of the robot joints, generalized stiffness matrix can be mapped into joint space using appropriate congruent transformation. Actuation stiffness matrix achieved by this transformation is generally nondiagonal. Off-diagonal elements of the actuation matrix can be generated by redundant actuation only (polyarticular actuators, but such kind of actuation is very difficult to realize practically in technical systems. The approach of solving this problem which is proposed in this paper is based on the use of kinematic redundancy and nullspace of the Jacobian matrix. Evaluation of the developed analytical model was done numerically by a minimal redundant robot with one redundant d.o.f. and experimentally by a 7 d.o.f. Yaskawa SIA 10F robot arm. [Projekat Ministarstva nauke Republike Srbije, br. TR35007

  8. Displaying lives: the narrative of objects in biographical exhibitions

    Directory of Open Access Journals (Sweden)

    Caterina Albano

    2007-03-01

    Full Text Available Biographical exhibitions are a museum practice that asks for critical consideration. Grounding the argument in critical theory, social studies and museum theory, the article explores the narrative function of objects in biographical exhibitions by addressing the social significance of objects in relation to biography and their relevance when presented into an exhibition display. Central is the concept of objects as ‘biographical relics’ that are culturally fetishized in biographical narratives. This raises questions about biographical reliability and the cultural role that such objects plays in exhibition narratives as bearers of reality and as metonymical icons of the biographical subject. The article considers examples of biographical exhibitions of diverse figures such as Gregor Mendel, Madame de Pompadour and Roland Barthes, and the role that personal items, but also portraits and photographs, play in them.

  9. Affordances and distributed cognition in museum exhibitions

    DEFF Research Database (Denmark)

    Achiam, Marianne; May, Michael; Marandino, Martha

    2014-01-01

    consistent framework. Here, we invoke the notions of affordance and distributed cognition to explain in a coherent way how visitors interact with exhibits and exhibit spaces and make meaning from those interactions, and we exemplify our points using observations of twelve visitors to exhibits at a natural...... history museum. We show how differences in exhibit characteristics give rise to differences in the interpretive strategies used by visitors in their meaning-making process, and conclude by discussing how the notions of affordance and distributed cognition can be used in an exhibit design perspective....

  10. Functions of Ceramide Synthase Paralogs YPR114w and YJR116w of Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Shamroop K Mallela

    Full Text Available Ceramide is synthesized in yeast by two redundant acyl-CoA dependent synthases, Lag1 and Lac1. In lag1∆ lac1∆ cells, free fatty acids and sphingoid bases are elevated, and ceramides are produced through the redundant alkaline ceramidases Ypc1 and Ydc1, working backwards. Even with all four of these genes deleted, cells are surviving and continue to contain small amounts of complex sphingolipids. Here we show that these residual sphingolipids are not synthesized by YPR114w or YJR116w, proteins of unknown function showing a high degree of homology to Lag1 and Lac1. Indeed, the hextuple lag1∆ lac1∆ ypc1∆ ydc1∆ ypr114w∆ yjr116w∆ mutant still contains ceramides and complex sphingolipids. Yjr116w∆ exhibit an oxygen-dependent hypersensitivity to Cu2+ due to an increased mitochondrial production of reactive oxygen species (ROS and a mitochondrially orchestrated programmed cell death in presence of copper, but also a general copper hypersensitivity that cannot be counteracted by the antioxidant N-acetyl-cysteine (NAC. Myriocin efficiently represses the synthesis of sphingoid bases of ypr114w∆, but not its growth. Both yjr116w∆ and ypr114w∆ have fragmented vacuoles and produce less ROS than wild type, before and after diauxic shift. Ypr114w∆/ypr114w∆ have an increased chronological life span. Thus, Yjr116w and Ypr114w are related, but not functionally redundant.

  11. Application of Glass Fiber Reinforced Cement in Exhibition Decoration Project

    Science.gov (United States)

    Wang, Yao

    2018-02-01

    Through the study of GRC material and its application field, the aesthetic characteristics and functional characteristics of GRC materials are demonstrated. The decorative application and technology of GRC material in an art exhibition center are highlighted. The design, application and construction technology of GRC curtain wall and ceiling board in the interior and exterior decoration of art exhibition hall are discussed in detail. The unique advantages of GRC materials in exhibition engineering decoration are fully reflected. In practical design application, the application principle and method are summarized, and an application procedure is formed. The research proves that GRC materials in the art of building decoration engineering has an underrated advantage.

  12. Optimal design of a system containing mixed redundancies with respect to reliability and cost

    International Nuclear Information System (INIS)

    Misra, K.B.

    1975-01-01

    A nuclear system generally consists of subsystems that may employ any of the partial, standby, and active redundancies, and is, therefore, a system with mixed type of redundancies. Optimization of reliability or availability of such systems at the design stage is a difficult problem. There appears to be no published work on the optimal design of maintained systems consisting of mixed redundancies. An attempt is therefore made, to present the basis of design and the solution technique to achieve this. An algorithm is described which makes the solution of this mathematically difficult problem possible. Some examples are demonstrated. To achieve further efficiency a study was organized and the recommendations for obtaining a minimum solution time are provided. Although, in the illustration, only the linear constraints and reliability, as the only design parameter, have been considered, the algorithm works well with the nonlinear type of constraints and can be used with other design parameters also. (author)

  13. Effect of a certain class of potential common mode failures on the reliability of redundant systems

    International Nuclear Information System (INIS)

    Apostolakis, G.E.

    1975-11-01

    This is a theoretical investigation of the importance of common mode failures on the reliability of redundant systems. These failures are assumed to be the result of fatal shocks (e.g., from earthquakes, explosions, etc.) which occur at a constant rate. This formulation makes it possible to predict analytically results obtained in the past which showed that the probability of a common mode failure of the redundant channels of the protection system of a typical nuclear power plant was orders of magnitude larger than the probability of failure from chance failures alone. Furthermore, since most reliability analyses of redundant systems do not include potential common mode failures in the probabilistic calculations, criteria are established which can be used to decide either that the common-mode-failure effects are indeed insignificant or that such calculations are meaningless, and more sophisticated methods of analysis are required, because common mode failures cannot be ignored

  14. The Effect of Antenna Position Errors on Redundant-Baseline Calibration of HERA

    Science.gov (United States)

    Orosz, Naomi; Dillon, Joshua; Ewall-Wice, Aaron; Parsons, Aaron; HERA Collaboration

    2018-01-01

    HERA (the Hydrogen Epoch of Reionization Array) is a large, highly-redundant radio interferometer in South Africa currently being built out to 350 14-m dishes. Its mission is to probe large scale structure during and prior to the epoch of reionization using the 21 cm hyperfine transition of neutral hydrogen. The array is designed to be calibrated using redundant baselines of known lengths. However, the dishes can deviate from ideal positions, with errors on the order of a few centimeters. This potentially increases foreground contamination of the 21 cm power spectrum in the cleanest part of Fourier space. The calibration algorithm treats groups of baselines that should be redundant, but are not due to position errors, as if they actually are. Accurate, precise calibration is critical because the foreground signals are 100,000 times stronger than the reionization signal. We explain the origin of this effect and discuss weighting strategies to mitigate it.

  15. Electronic logic to enhance switch reliability in detecting openings and closures of redundant switches

    Science.gov (United States)

    Cooper, James A.

    1986-01-01

    A logic circuit is used to enhance redundant switch reliability. Two or more switches are monitored for logical high or low output. The output for the logic circuit produces a redundant and failsafe representation of the switch outputs. When both switch outputs are high, the output is high. Similarly, when both switch outputs are low, the logic circuit's output is low. When the output states of the two switches do not agree, the circuit resolves the conflict by memorizing the last output state which both switches were simultaneously in and produces the logical complement of this output state. Thus, the logic circuit of the present invention allows the redundant switches to be treated as if they were in parallel when the switches are open and as if they were in series when the switches are closed. A failsafe system having maximum reliability is thereby produced.

  16. Interactions between facial emotion and identity in face processing: evidence based on redundancy gains.

    Science.gov (United States)

    Yankouskaya, Alla; Booth, David A; Humphreys, Glyn

    2012-11-01

    Interactions between the processing of emotion expression and form-based information from faces (facial identity) were investigated using the redundant-target paradigm, in which we specifically tested whether identity and emotional expression are integrated in a superadditive manner (Miller, Cognitive Psychology 14:247-279, 1982). In Experiments 1 and 2, participants performed emotion and face identity judgments on faces with sad or angry emotional expressions. Responses to redundant targets were faster than responses to either single target when a universal emotion was conveyed, and performance violated the predictions from a model assuming independent processing of emotion and face identity. Experiment 4 showed that these effects were not modulated by varying interstimulus and nontarget contingencies, and Experiment 5 demonstrated that the redundancy gains were eliminated when faces were inverted. Taken together, these results suggest that the identification of emotion and facial identity interact in face processing.

  17. Ion pairs in non-redundant protein structures

    Indian Academy of Sciences (India)

    Ion pairs contribute to several functions including the activity of catalytic triads, fusion of viral membranes, stability in thermophilic proteins and solvent–protein interactions. Furthermore, they have the ability to affect the stability of protein structures and are also a part of the forces that act to hold monomers together.

  18. Spectro-temporal characterization of auditory neurons: redundant or necessary?

    NARCIS (Netherlands)

    Eggermont, J.J.; Aertsen, A.M.H.J.; Hermes, D.J.; Johannesma, P.I.M.

    1981-01-01

    For neurons in the auditory midbrain of the grass frog the use of a combined spectro-temporal characterization has been evaluated against the separate characterizations of frequency-sensitivity and temporal response properties. By factoring the joint density function of stimulus intensity, I(f, t),

  19. A novel redundant INS based on triple rotary inertial measurement units

    Science.gov (United States)

    Chen, Gang; Li, Kui; Wang, Wei; Li, Peng

    2016-10-01

    Accuracy and reliability are two key performances of inertial navigation system (INS). Rotation modulation (RM) can attenuate the bias of inertial sensors and make it possible for INS to achieve higher navigation accuracy with lower-class sensors. Therefore, the conflict between the accuracy and cost of INS can be eased. Traditional system redundancy and recently researched sensor redundancy are two primary means to improve the reliability of INS. However, how to make the best use of the redundant information from redundant sensors hasn’t been studied adequately, especially in rotational INS. This paper proposed a novel triple rotary unit strapdown inertial navigation system (TRUSINS), which combines RM and sensor redundancy design to enhance the accuracy and reliability of rotational INS. Each rotary unit independently rotates to modulate the errors of two gyros and two accelerometers. Three units can provide double sets of measurements along all three axes of body frame to constitute a couple of INSs which make TRUSINS redundant. Experiments and simulations based on a prototype which is made up of six fiber-optic gyros with drift stability of 0.05° h-1 show that TRUSINS can achieve positioning accuracy of about 0.256 n mile h-1, which is ten times better than that of a normal non-rotational INS with the same level inertial sensors. The theoretical analysis and the experimental results show that due to the advantage of the innovative structure, the designed fault detection and isolation (FDI) strategy can tolerate six sensor faults at most, and is proved to be effective and practical. Therefore, TRUSINS is particularly suitable and highly beneficial for the applications where high accuracy and high reliability is required.

  20. Objective past of a quantum universe: Redundant records of consistent histories

    Science.gov (United States)

    Riedel, C. Jess; Zurek, Wojciech H.; Zwolak, Michael

    2016-03-01

    Motivated by the advances of quantum Darwinism and recognizing the role played by redundancy in identifying the small subset of quantum states with resilience characteristic of objective classical reality, we explore the implications of redundant records for consistent histories. The consistent histories formalism is a tool for describing sequences of events taking place in an evolving closed quantum system. A set of histories is consistent when one can reason about them using Boolean logic, i.e., when probabilities of sequences of events that define histories are additive. However, the vast majority of the sets of histories that are merely consistent are flagrantly nonclassical in other respects. This embarras de richesses (known as the set selection problem) suggests that one must go beyond consistency to identify how the classical past arises in our quantum universe. The key intuition we follow is that the records of events that define the familiar objective past are inscribed in many distinct systems, e.g., subsystems of the environment, and are accessible locally in space and time to observers. We identify histories that are not just consistent but redundantly consistent using the partial-trace condition introduced by Finkelstein as a bridge between histories and decoherence. The existence of redundant records is a sufficient condition for redundant consistency. It selects, from the multitude of the alternative sets of consistent histories, a small subset endowed with redundant records characteristic of the objective classical past. The information about an objective history of the past is then simultaneously within reach of many, who can independently reconstruct it and arrive at compatible conclusions in the present.

  1. A novel redundant INS based on triple rotary inertial measurement units

    International Nuclear Information System (INIS)

    Chen, Gang; Li, Kui; Wang, Wei; Li, Peng

    2016-01-01

    Accuracy and reliability are two key performances of inertial navigation system (INS). Rotation modulation (RM) can attenuate the bias of inertial sensors and make it possible for INS to achieve higher navigation accuracy with lower-class sensors. Therefore, the conflict between the accuracy and cost of INS can be eased. Traditional system redundancy and recently researched sensor redundancy are two primary means to improve the reliability of INS. However, how to make the best use of the redundant information from redundant sensors hasn’t been studied adequately, especially in rotational INS. This paper proposed a novel triple rotary unit strapdown inertial navigation system (TRUSINS), which combines RM and sensor redundancy design to enhance the accuracy and reliability of rotational INS. Each rotary unit independently rotates to modulate the errors of two gyros and two accelerometers. Three units can provide double sets of measurements along all three axes of body frame to constitute a couple of INSs which make TRUSINS redundant. Experiments and simulations based on a prototype which is made up of six fiber-optic gyros with drift stability of 0.05° h −1 show that TRUSINS can achieve positioning accuracy of about 0.256 n mile h −1 , which is ten times better than that of a normal non-rotational INS with the same level inertial sensors. The theoretical analysis and the experimental results show that due to the advantage of the innovative structure, the designed fault detection and isolation (FDI) strategy can tolerate six sensor faults at most, and is proved to be effective and practical. Therefore, TRUSINS is particularly suitable and highly beneficial for the applications where high accuracy and high reliability is required. (paper)

  2. Curcuma longa and Curcuma mangga leaves exhibit functional food property.

    Science.gov (United States)

    Liu, Yunbao; Nair, Muraleedharan G

    2012-11-15

    Although leaves of Curcuma mangga and Curcuma longa are used in food preparations, the bioactive components in it are not known. In this study, antioxidant, antiinflammatory and anticancer activities of leave extracts and its isolates were investigated using established bioassay procedures in our laboratory. The leaf extracts of both plants gave similar bioassay and chromatographic profiles. The methanolic and water extracts of C. mangga (CMM and CMW) and C. longa (CLM and CLW), at 100 μg/mL, inhibited lipid peroxidation (LPO) by 78%, 63%, 81% and 43%, cyclooxygenase enzymes COX-1 by 55%, 33%, 43% and 24% and COX-2 by 65%, 55%, 77% and 69%, respectively. At same concentration, CMM, CMW, CLM and CLW showed growth inhibition of human tumour cell lines by 0-46%. Therefore, a bioassay-guided isolation of water and methanolic extracts of C. longa was carried out and afforded nine isolates. At 25 μg/mL, these compounds inhibited LPO by 11-87%, COX-1 and -2 enzymes by 0-35% and 0-82% and growth of human tumour cells by 0-36%, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. An overview of adaptive model theory: solving the problems of redundancy, resources, and nonlinear interactions in human movement control.

    Science.gov (United States)

    Neilson, Peter D; Neilson, Megan D

    2005-09-01

    Adaptive model theory (AMT) is a computational theory that addresses the difficult control problem posed by the musculoskeletal system in interaction with the environment. It proposes that the nervous system creates motor maps and task-dependent synergies to solve the problems of redundancy and limited central resources. These lead to the adaptive formation of task-dependent feedback/feedforward controllers able to generate stable, noninteractive control and render nonlinear interactions unobservable in sensory-motor relationships. AMT offers a unified account of how the nervous system might achieve these solutions by forming internal models. This is presented as the design of a simulator consisting of neural adaptive filters based on cerebellar circuitry. It incorporates a new network module that adaptively models (in real time) nonlinear relationships between inputs with changing and uncertain spectral and amplitude probability density functions as is the case for sensory and motor signals.

  4. Reliability optimization of series-parallel systems with a choice of redundancy strategies using a genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Tavakkoli-Moghaddam, R. [Department of Industrial Engineering, Faculty of Engineering, University of Tehran, P.O. Box 11365/4563, Tehran (Iran, Islamic Republic of); Department of Mechanical Engineering, The University of British Columbia, Vancouver (Canada)], E-mail: tavakoli@ut.ac.ir; Safari, J. [Department of Industrial Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)], E-mail: jalalsafari@pideco.com; Sassani, F. [Department of Mechanical Engineering, The University of British Columbia, Vancouver (Canada)], E-mail: sassani@mech.ubc.ca

    2008-04-15

    This paper proposes a genetic algorithm (GA) for a redundancy allocation problem for the series-parallel system when the redundancy strategy can be chosen for individual subsystems. Majority of the solution methods for the general redundancy allocation problems assume that the redundancy strategy for each subsystem is predetermined and fixed. In general, active redundancy has received more attention in the past. However, in practice both active and cold-standby redundancies may be used within a particular system design and the choice of the redundancy strategy becomes an additional decision variable. Thus, the problem is to select the best redundancy strategy, component, and redundancy level for each subsystem in order to maximize the system reliability under system-level constraints. This belongs to the NP-hard class of problems. Due to its complexity, it is so difficult to optimally solve such a problem by using traditional optimization tools. It is demonstrated in this paper that GA is an efficient method for solving this type of problems. Finally, computational results for a typical scenario are presented and the robustness of the proposed algorithm is discussed.

  5. Reliability optimization of series-parallel systems with a choice of redundancy strategies using a genetic algorithm

    International Nuclear Information System (INIS)

    Tavakkoli-Moghaddam, R.; Safari, J.; Sassani, F.

    2008-01-01

    This paper proposes a genetic algorithm (GA) for a redundancy allocation problem for the series-parallel system when the redundancy strategy can be chosen for individual subsystems. Majority of the solution methods for the general redundancy allocation problems assume that the redundancy strategy for each subsystem is predetermined and fixed. In general, active redundancy has received more attention in the past. However, in practice both active and cold-standby redundancies may be used within a particular system design and the choice of the redundancy strategy becomes an additional decision variable. Thus, the problem is to select the best redundancy strategy, component, and redundancy level for each subsystem in order to maximize the system reliability under system-level constraints. This belongs to the NP-hard class of problems. Due to its complexity, it is so difficult to optimally solve such a problem by using traditional optimization tools. It is demonstrated in this paper that GA is an efficient method for solving this type of problems. Finally, computational results for a typical scenario are presented and the robustness of the proposed algorithm is discussed

  6. Risk-based replacement strategies for redundant deteriorating reinforced concrete pipe networks

    International Nuclear Information System (INIS)

    Adey, B.; Bernard, O.; Gerard, B.

    2003-01-01

    This paper gives an example of how predictive models of the deterioration of reinforced concrete pipes and the consequences of failure can be used to develop risk-based replacement strategies for redundant reinforced concrete pipe networks. It also shows how an accurate deterioration prediction can lead to a reduction of agency costs, and illustrates the limitation of the incremental intervention step algorithm. The main conclusion is that the use of predictive models, such as those developed by Oxand S.A., in the determination of replacement strategies for redundant reinforced concrete pipe networks can lead to a significant reduction in overall costs for the owner of the structure. (author)

  7. Obstacle avoidance for kinematically redundant robots using an adaptive fuzzy logic algorithm

    International Nuclear Information System (INIS)

    Beheshti, M.T.H.; Tehrani, A.K.

    1999-05-01

    In this paper the Adaptive Fuzzy Logic approach for solving the inverse kinematics of redundant robots in an environment with obstacles is presented. The obstacles are modeled as convex bodies. A fuzzy rule base that is updated via an adaptive law is used to solve the inverse kinematic problem. Additional rules have been introduced to take care of the obstacles avoidance problem. The proposed method has advantages such as high accuracy, simplicity of computations and generality for all redundant robots. Simulation results illustrate much better tracking performance than the dynamic base solution for a given trajectory in cartesian space, while guaranteeing a collision-free trajectory and observation of a mechanical joint limit

  8. Statistical Redundancy Testing for Improved Gene Selection in Cancer Classification Using Microarray Data

    Directory of Open Access Journals (Sweden)

    J. Sunil Rao

    2007-01-01

    Full Text Available In gene selection for cancer classifi cation using microarray data, we define an eigenvalue-ratio statistic to measure a gene’s contribution to the joint discriminability when this gene is included into a set of genes. Based on this eigenvalueratio statistic, we define a novel hypothesis testing for gene statistical redundancy and propose two gene selection methods. Simulation studies illustrate the agreement between statistical redundancy testing and gene selection methods. Real data examples show the proposed gene selection methods can select a compact gene subset which can not only be used to build high quality cancer classifiers but also show biological relevance.

  9. A model for the coupling of failure rates in a redundant system

    International Nuclear Information System (INIS)

    Kleppmann, W.G.; Wutschig, R.

    1986-01-01

    A model is developed which takes into acount the coupling between failure rates or identical components in different redundancies of a safety system, i.e., the fact that the failure rates of identical components subjected to the same operating conditions will scatter less than the failure rates of any two components of the same type. It is shown that with increasing coupling the expectation value and the variance of the distribution of the failure probability of the redundant system increases. A consistent way to incorporate operating experience in a Bayesian framework is developed and the reults are presented. (orig.)

  10. A new way to improve the robustness of complex communication networks by allocating redundancy links

    International Nuclear Information System (INIS)

    Shi Chunhui; Zhuo Yue; Tang Jieying; Long Keping; Peng Yunfeng

    2012-01-01

    We investigate the robustness of complex communication networks on allocating redundancy links. The protecting key nodes (PKN) strategy is proposed to improve the robustness of complex communication networks against intentional attack. Our numerical simulations show that allocating a few redundant links among key nodes using the PKN strategy will significantly increase the robustness of scale-free complex networks. We have also theoretically proved and demonstrated the effectiveness of the PKN strategy. We expect that our work will help achieve a better understanding of communication networks. (paper)

  11. Anomalous course of the sigmoid colon and the mesosigmoid encountered during colectomy. A case report of a redundant loop of sigmoid colon

    Directory of Open Access Journals (Sweden)

    Maria Zarokosta

    Full Text Available Introduction Sigmoid colon constitutes a part of the large intestine that presents several congenital anatomic variations. In particular, the presence of a redundant loop of sigmoid colon is of tremendous importance for surgeons, obstetricians and radiologists, since it is closely related to multiple pathological conditions and functional implications of the neighboring anatomical structures. Presentation of case: An unusual anatomic variation in position and length of the sigmoid colon and its mesocolon was unexpectedly detected during right hemicolectomy to a 67-year-old Caucasian male patient due to colon cancer. The operation was uneventful. A meticulous review of the literature was conducted as well. Discussion: A redundant loop of sigmoid colon may go unnoticed or it might lead to urinary, digestive and vascular complications. Its presence is associated with acute and chronic pathological conditions, sigmoid volvulus and serious confusions in radiological diagnosis and instrumentation. Conclusion: Surgeons’ thorough knowledge concerning this rare anatomic variation is fundamental and crucial in order to establish a correct diagnosis and assert the appropriate management when performing operations including pelvis and abdomen. Keywords: Dolichocolon, Redundant sigmoid colon, Case report, Sigmoid volvulus, Dolichosigmoid colon

  12. Exhibition of Stochastic Resonance in Vestibular Perception

    Science.gov (United States)

    Galvan-Garza, R. C.; Clark, T. K.; Merfeld, D. M.; Bloomberg, J. J.; Oman, C. M.; Mulavara, A. P.

    2016-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transitions. Post flight sensorimotor changes include spatial disorientation, along with postural and gait instability that may degrade operational capabilities of the astronauts and endanger the crew. A sensorimotor countermeasure that mitigates these effects would improve crewmember safety and decrease risk. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor perception through the phenomenon of stochastic resonance (SR), when the response of a nonlinear system to a weak input signal is enhanced by the application of a particular nonzero level of noise. This study aims to advance the development of SVS as a potential countermeasure by 1) demonstrating the exhibition of stochastic resonance in vestibular perception, a vital component of sensorimotor function, 2) investigating the repeatability of SR exhibition, and 3) determining the relative contribution of the semicircular canals (SCC) and otolith (OTO) organs to vestibular perceptual SR. A constant current stimulator was used to deliver bilateral bipolar SVS via electrodes placed on each of the mastoid processes, as previously done. Vestibular perceptual motion recognition thresholds were measured using a 6-degree of freedom MOOG platform and a 150 trial 3-down/1-up staircase procedure. In the first test session, we measured vestibular perceptual thresholds in upright roll-tilt at 0.2 Hz (SCC+OTO) with SVS ranging from 0-700 µA. In a second test session a week later, we re-measured roll-tilt thresholds with 0, optimal (from test session 1), and 1500 µA SVS levels. A subset of these subjects, plus naive subjects, participated in two additional test sessions in which we measured thresholds in supine roll-rotation at 0.2 Hz (SCC) and upright y-translation at 1 Hz

  13. AN IMAGE-PLANE ALGORITHM FOR JWST'S NON-REDUNDANT APERTURE MASK DATA

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Alexandra Z. [Johns Hopkins University Department of Physics and Astronomy 3400 North Charles, Baltimore, MD 21218 (United States); Pueyo, Laurent; Sivaramakrishnan, Anand [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lacour, Sylvestre [LESIA, CNRS/UMR-8109, Observatoire de Paris, UPMC, Université Paris Diderot 5 place Jules Janssen, 92195 Meudon (France)

    2015-01-10

    The high angular resolution technique of non-redundant masking (NRM) or aperture masking interferometry (AMI) has yielded images of faint protoplanetary companions of nearby stars from the ground. AMI on James Webb Space Telescope (JWST)'s Near Infrared Imager and Slitless Spectrograph (NIRISS) has a lower thermal background than ground-based facilities and does not suffer from atmospheric instability. NIRISS AMI images are likely to have 90%-95% Strehl ratio between 2.77 and 4.8 μm. In this paper we quantify factors that limit the raw point source contrast of JWST NRM. We develop an analytic model of the NRM point spread function which includes different optical path delays (pistons) between mask holes and fit the model parameters with image plane data. It enables a straightforward way to exclude bad pixels, is suited to limited fields of view, and can incorporate effects such as intra-pixel sensitivity variations. We simulate various sources of noise to estimate their effect on the standard deviation of closure phase, σ{sub CP} (a proxy for binary point source contrast). If σ{sub CP} < 10{sup –4} radians—a contrast ratio of 10 mag—young accreting gas giant planets (e.g., in the nearby Taurus star-forming region) could be imaged with JWST NIRISS. We show the feasibility of using NIRISS' NRM with the sub-Nyquist sampled F277W, which would enable some exoplanet chemistry characterization. In the presence of small piston errors, the dominant sources of closure phase error (depending on pixel sampling, and filter bandwidth) are flat field errors and unmodeled variations in intra-pixel sensitivity. The in-flight stability of NIRISS will determine how well these errors can be calibrated by observing a point source. Our results help develop efficient observing strategies for space-based NRM.

  14. Redundant role of protein kinase C delta and epsilon during mouse embryonic development.

    Directory of Open Access Journals (Sweden)

    Sergio Carracedo

    Full Text Available Protein Kinase C delta and epsilon are mediators of important cellular events, such as cell proliferation, migration or apoptosis. The formation of blood vessels, i.e., vasculo- and angiogenesis, is a process where these isoforms have also been shown to participate. However, mice deficient in either Protein Kinase C delta or epsilon are viable and therefore their individual contribution to the formation of the vasculature appeared so far dispensable. In this study, we show that double null mutation of Protein Kinase C delta and epsilon causes embryonic lethality at approximately E9.5. At this stage, whole mount staining of the endothelial marker CD31 in double null embryos revealed defective blood vessel formation. Moreover, culture of double deficient mouse allantois showed impaired endothelial cell organization, and analyses of double deficient embryo sections showed dilated vessels, decreased endothelial-specific adherent junctions, and decreased contact of endothelial cells with mural cells. Protein kinase C delta and epsilon also appeared essential for vascular smooth muscle cell differentiation, since α-smooth muscle actin, a classical marker for vascular smooth muscle cells, was almost undetectable in double deficient embryonic aorta at E9.5. Subsequent qPCR analyses showed decreased VE-cadherin, Vegfr2, Cd31, Cdh2, Ets1, and Fli-1, among other angiogenesis related transcripts in double deficient embryos. Taken together, these data suggest for the first time an in vivo redundant role between members of the novel Protein Kinase C subfamily that allows for mutual compensation during mouse embryonic development, with vasculogenesis/angiogenesis as an obvious common function of these two Protein Kinase Cs. Protein Kinase C delta and epsilon might therefore be useful targets for inhibiting vasculo- and/or angiogenesis.

  15. Social biases modulate the loss of redundant forms in the cultural evolution of language.

    Science.gov (United States)

    Roberts, Gareth; Fedzechkina, Maryia

    2018-02-01

    According to the competitive exclusion principle (Gause, 1934), competition for the same niche must eventually lead one competitor to extinction or the occupation of a new niche. This principle applies in both biology and the cultural evolution of language, where different words and structures compete for the same function or meaning (Aronoff, 2016). Across languages, for example, word order trades off with case marking as a means of indicating who did what to whom in a sentence. Previous experimental work has shed light on how such trade-offs come about as languages adapt to human biases through learning and production, with biases becoming amplified through iterated learning over generations. At the same time, a large body of work has documented the impact of social biases on language change. However, little work has investigated how social biases interact with learning and production biases. In particular, the social dimension of language may provide alternative niches for otherwise redundant forms, preventing or slowing their extinction. We tested this hypothesis in an iterated-learning experiment in which participants were exposed to a language with two dialects, both of which had fixed word order, but differed in whether they employed case markers. In one condition, we biased participants socially towards speakers of the dialect that employed case; in other conditions we provided no bias, or biased participants for or against the dialect without case. As expected under our hypothesis, the use of case markers declined over time in all conditions, but the social bias in favor of case-dialect speakers slowed the decline. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Investigating Design Research Landscapes through Exhibition

    DEFF Research Database (Denmark)

    Jönsson, Li; Hansen, Flemming Tvede; Mäkelä, Maarit

    2013-01-01

    What characterizes a design research exhibition compared to a traditional design and art exhibition? How do you show the very materialities of the design experiments as a means for communicating knowledge of research and of practice? How do you present, review and utilize such an exhibition......? With those questions in mind, the intention and challenge for the Nordes 2013 Design Research Exhibition was to expand on current notions of staging research enquires in design research conference contexts. Artefacts, installations, performances, and other materialities that relate to the theme...... of the conference - Experiments in Design Research – were displayed as tools to express and communicate different design research enquires. Through this paper we will describe the Nordes exhibition as a specific case that renders questions visible in relation to how to utilize a design research exhibition...

  17. Ergotic / epistemic / semiotic functions

    OpenAIRE

    Luciani , Annie

    2007-01-01

    International audience; Claude Cadoz has introduced a typology of human-environment relation, identifying three functions. This typology allows characterizing univocally, i.e. in a non-redundant manner, the computer devices and interfaces that allow human to interact with environment through and by computers. These three functions are: the epistemic function, the semiotic function, the ergotic function. Conversely to the terms epistemic and semiotic that are usual, the term ergotic has been s...

  18. Superconductive microstrip exhibiting negative differential resistivity

    International Nuclear Information System (INIS)

    Huebener, R.P.; Gallus, D.E.

    1975-01-01

    A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor-depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current-induced resistive state

  19. Prediction of the electron redundant SinNn fullerenes

    Science.gov (United States)

    Yang, Huihui; Song, Yan; Zhang, Yan; Chen, Hongshan

    2018-05-01

    The stabilities and electronic structures of SimAln-mNn and SinNn (n = 16, 20, m = 12 and n = 24, m = 16) fullerene-like cages have been investigated using density functional method B3LYP and the second-order perturbation theory MP2. The results show that the SimAln-mNn and SinNn fullerenes are more stable than the AlN counterparts. Comparing with the corresponding AlnNn cages, one silicon atom in each Si2N2 square protrudes and the excess electrons reside as lone pair electrons at the outside of the protrudent Si atoms. Analyses on the electronic structures suggest that the Sisbnd N bonds are covalent bonding with strong polarity. The ELF (electron localization function) shows large electron pair probability between Si and N atoms. The orbital interactions between Si and N are stronger than that between Al and N atoms; the overlap integral is 0.40 per Sisbnd N bond in SinNn and 0.34 per Alsbnd N bond in AlnNn. The AIM (atoms in molecule) charges on the Al atoms in AlnNn and SimAln-mNn are 2.37 and 2.40. The charges on the in-plane and protrudent Si atoms are about 2.88 and 1.50 respectively. Considering the large local dipole moments around the protrudent Si atoms, the electrostatic interactions are also favorable to the SiN cages.

  20. Functional Redundancy and Ecological Innovation Shape the Circulation of Tick-Transmitted Pathogens

    Directory of Open Access Journals (Sweden)

    Agustín Estrada-Peña

    2017-05-01

    Full Text Available Ticks are vectors of pathogens affecting human and animal health worldwide. Nevertheless, the ecological and evolutionary interactions between ticks, hosts, and pathogens are largely unknown. Here, we integrated a framework to evaluate the associations of the tick Ixodes ricinus with its hosts and environmental niches that impact pathogen circulation. The analysis of tick-hosts association suggested that mammals and lizards were the ancestral hosts of this tick species, and that a leap to Aves occurred around 120 M years ago. The signature of the environmental variables over the host's phylogeny revealed the existence of two clades of vertebrates diverging along a temperature and vegetation split. This is a robust proof that the tick probably experienced a colonization of new niches by adapting to a large set of new hosts, Aves. Interestingly, the colonization of Aves as hosts did not increase significantly the ecological niche of I. ricinus, but remarkably Aves are super-spreaders of pathogens. The disparate contribution of Aves to the tick-host-pathogen networks revealed that I. ricinus evolved to maximize habitat overlap with some hosts that are super-spreaders of pathogens. These results supported the hypothesis that large host networks are not a requirement of tick survival but pathogen circulation. The biological cost of tick adaptation to non-optimal environmental conditions might be balanced by molecular mechanisms triggered by the pathogens that we have only begun to understand.