363 research outputs found

    Automation - Development of the Material-Technological Basis - Changed Conditions of Efficiency

    Get PDF
    This paper was presented at a joint seminar on flexible automation held in Berlin (East) from June 8-11, 1982. The seminar was a collaborative project between IIASA and the Academy of Sciences of the German Democratic Republic. The report and the working material presented to the conference deal, among other things, with the influence of the flexible automation on the further development of the material-technological basis and on the whole system of the productive forces. Hence the following questions arise: Does the qualitatively new level of automation mean in connection with the development and application of micro-electronics and what is flexible automation? What are the constituent elements of the new level of automation and which are the consequences for the development of the material-technological basis? and Which changes within the conditions of efficiency take place due to the new level of automation on the basis of micro-electronics? The presented paper offers some aspects regarding these questions

    On the Maximum Crossing Number

    Full text link
    Research about crossings is typically about minimization. In this paper, we consider \emph{maximizing} the number of crossings over all possible ways to draw a given graph in the plane. Alpert et al. [Electron. J. Combin., 2009] conjectured that any graph has a \emph{convex} straight-line drawing, e.g., a drawing with vertices in convex position, that maximizes the number of edge crossings. We disprove this conjecture by constructing a planar graph on twelve vertices that allows a non-convex drawing with more crossings than any convex one. Bald et al. [Proc. COCOON, 2016] showed that it is NP-hard to compute the maximum number of crossings of a geometric graph and that the weighted geometric case is NP-hard to approximate. We strengthen these results by showing hardness of approximation even for the unweighted geometric case and prove that the unweighted topological case is NP-hard.Comment: 16 pages, 5 figure

    Theory of commensurable magnetic structures in holmium

    Full text link
    The tendency for the period of the helically ordered moments in holmium to lock into values which are commensurable with the lattice is studied theoretically as a function of temperature and magnetic field. The commensurable effects are derived in the mean-field approximation from numerical calculations of the free energy of various commensurable structures, and the results are compared with the extensive experimental evidence collected during the last ten years on the magnetic structures in holmium. In general the stability of the different commensurable structures is found to be in accord with the experiments, except for the tau=5/18 structure observed a few degrees below T_N in a b-axis field. The trigonal coupling recently detected in holmium is found to be the interaction required to explain the increased stability of the tau=1/5 structure around 42 K, and of the tau=1/4 structure around 96 K, when a field is applied along the c-axis.Comment: REVTEX, 31 pages, 7 postscript figure

    Polytopality and Cartesian products of graphs

    Full text link
    We study the question of polytopality of graphs: when is a given graph the graph of a polytope? We first review the known necessary conditions for a graph to be polytopal, and we provide several families of graphs which satisfy all these conditions, but which nonetheless are not graphs of polytopes. Our main contribution concerns the polytopality of Cartesian products of non-polytopal graphs. On the one hand, we show that products of simple polytopes are the only simple polytopes whose graph is a product. On the other hand, we provide a general method to construct (non-simple) polytopal products whose factors are not polytopal.Comment: 21 pages, 10 figure

    Additional experimental evidence for a solar influence on nuclear decay rates

    Full text link
    Additional experimental evidence is presented in support of the recent hypothesis that a possible solar influence could explain fluctuations observed in the measured decay rates of some isotopes. These data were obtained during routine weekly calibrations of an instrument used for radiological safety at The Ohio State University Research Reactor using Cl-36. The detector system used was based on a Geiger-Mueller gas detector, which is a robust detector system with very low susceptibility to environmental changes. A clear annual variation is evident in the data, with a maximum relative count rate observed in January/February, and a minimum relative count rate observed in July/August, for seven successive years from July 2005 to June 2011. This annual variation is not likely to have arisen from changes in the detector surroundings, as we show here.Comment: 8 pages, 6 figure

    Irreducible triangulations of surfaces with boundary

    Get PDF
    A triangulation of a surface is irreducible if no edge can be contracted to produce a triangulation of the same surface. In this paper, we investigate irreducible triangulations of surfaces with boundary. We prove that the number of vertices of an irreducible triangulation of a (possibly non-orientable) surface of genus g>=0 with b>=0 boundaries is O(g+b). So far, the result was known only for surfaces without boundary (b=0). While our technique yields a worse constant in the O(.) notation, the present proof is elementary, and simpler than the previous ones in the case of surfaces without boundary

    Small grid embeddings of 3-polytopes

    Full text link
    We introduce an algorithm that embeds a given 3-connected planar graph as a convex 3-polytope with integer coordinates. The size of the coordinates is bounded by O(27.55n)=O(188n)O(2^{7.55n})=O(188^{n}). If the graph contains a triangle we can bound the integer coordinates by O(24.82n)O(2^{4.82n}). If the graph contains a quadrilateral we can bound the integer coordinates by O(25.46n)O(2^{5.46n}). The crucial part of the algorithm is to find a convex plane embedding whose edges can be weighted such that the sum of the weighted edges, seen as vectors, cancel at every point. It is well known that this can be guaranteed for the interior vertices by applying a technique of Tutte. We show how to extend Tutte's ideas to construct a plane embedding where the weighted vector sums cancel also on the vertices of the boundary face

    Improvement of regeneration in pepper: a recalcitrant species

    Full text link
    [EN] Organogenesis is influenced by factors like genotype, type of explant, culture medium components, and incubation conditions. The influence of ethylene, which can be produced in the culture process, can also be a limiting factor in recalcitrant species like pepper. In this work, bud induction was achieved from cotyledons and hypocotyls-from eight pepper cultivars-on Murashige and Skoog (MS) medium supplemented with 22.2 mu M 6-benzyladenine (6BA) and 5.71 mu M indole-3-acetic acid (IAA), in media with or without silver nitrate (SN) (58.86 mu M), a suppressor of ethylene action. In the SN-supplemented medium, the frequencies of explants with buds and with callus formation were lower in both kinds of explant, but higher numbers of developed shoots were isolated from explants cultured on SN. Bud elongation was better in medium with gibberellic acid (GA(3)) (2.88 mu M) than in medium free of growth regulators or supplemented with 1-aminocyclopropane-1-carboxylic acid (ACC) at 34.5 mu M. However, isolation of shoots was difficult and few plants were recovered. The effect of adding SN following bud induction (at 7 d) and that of dark incubation (the first 7 d of culture) was also assessed in order to improve the previous results. When SN was added after bud induction, similar percentages of bud induction were found for cotyledons (average frequency 89.37% without SN and 94.37% with SN) whereas they doubled in hypocotyls (50% without SN and 87.7% with SN). In addition, in both kinds of explant, the number of developed plants able to be transferred to soil (developed and rooted) was greatly increased by SN. Dark incubation does not seem to improve organogenesis in pepper, and hypocotyl explants clearly represent a better explant choice-with respect to cotyledonary explants-for the pepper cultivars assayed.We thank the COMAV germplasm bank at Universitat Politecnica de Valencia and the Arid Lands Institute for pepper seeds and the Tunisian Ministry of Higher Education and Scientific Research who fund N. Gammoudi's stay.Gammoudi, N.; San Pedro-Galan, T.; Ferchichi, A.; Gisbert Domenech, MC. (2018). Improvement of regeneration in pepper: a recalcitrant species. In Vitro Cellular & Developmental Biology - Plant. 54(2):145-153. https://doi.org/10.1007/s11627-017-9838-1S145153542Ashrafuzzaman M, Hossain MM, Razi Ismail M, Shahidul Haque M, Shahidullah SM, Uz Zaman S (2009) Regeneration potential of seedling explants of chilli (Capsicum annuum). Afr J Biotechnol 8:591–596Bortesi L, Fischer R (2015) The CRISPR/Cas9 system for plant genome editing and beyond. Biotechnol Adv 33:41–52Brooks C, Nekrasov V, Lippman ZB, Van Eck J (2014) Efficient gene editing in tomato in the first generation using the clustered regularly interspaced short palindromic repeats/CRISPR-associated9 system. Plant Physiol 166:1292–1297Brown DC, Thorpe TA (1995) Crop improvement through tissue culture. World J Microbiol Biotechnol 11:409–415Carvalho MAF, Paiva R, Stein VC, Herrera RC, Porto JMP, Vargas DP, Alves E (2014) Induction and morpho-ultrastructural analysis of organogenic calli of a wild passion fruit. Braz Arch Biol Technol 57:581–859Christopher T, Rajam MV (1996) Effect of genotype, explant and medium on in vitro regeneration of red pepper. Plant CellTiss Org Cult 46:245–250Dabauza M, Peña L (2001) High efficiency organogenesis in sweet pepper (Capsicum annuum L.) tissues from different seedling explants. Plant Growth Regul 33:221–229De Filippis LF (2014) Crop improvement through tissue culture. In: Ahmad P, Wani MR, Azooz MM, Tran LSP (eds) Improvement of crops in the era of climate changes, vol 1. Springer, New York, pp 289–346Gammoudi N, Ben Yahia L, Lachiheb B, Ferchichi A (2016) Salt response in pepper (Capsicum annuum L.): components of photosynthesis inhibition, proline accumulation and K+/Na+ selectivity. JJ Aridland Agri 2:1–12González A, Arigita L, Majada J, Sánchez Tamés R (1997) Ethylene involvement in in vitro organogenesis and plant growth of Populus tremula L. Plant Growth Regul 22:1–6Grozeva S, Rodeva V, Todorova V (2012) In vitro shoot organogenesis in Bulgarian sweet pepper (Capsicum annuum L.) varieties. EJBio 8:39–44Gunay AL, Rao PS (1978) In vitro plant regeneration from hypocotyls and cotyledon explants of red pepper (Capsicum). Plant Sci Lett 11:365–372Huxter TJ, Thorpe TA, Reid DM (1981) Shoot initiation in light- and dark-grown tobacco callus: the role of ethylene. Physiol Plant 53:319–326Hyde CL, Phillips GC (1996) Silver nitrate promotes shoot development and plant regeneration of chile pepper (Capsicum annuum L.) via organogenesis. In Vitro-Plant 32:72–80Kothari SL, Joshi A, Kachhwaha S, Ochoa-Alejo N (2010) Chilli peppers—a review on tissue culture and transgenesis. Biotechnol Adv 28:35–48Kumar AO, Rupavathi T, Tata SS (2012) Adventitious shoot bud induction in chili pepper (Capsicum annuum L. cv. X-235). In J Sci Nat 3:192–196Kumar PP, Lakshmanan P, Thorpe TA (1998) Regulation of morphogenesis in plant tissue culture by ethylene. In Vitro Cell Dev Biol Plant 34:94–103Liu W, Parrott WA, Hildebrand DF, Collins GB, Williams EG (1990) Agrobacterium induced gall formation in bell pepper (Capsicum annuum L.) and formation of shoot-like structures expressing introduced genes. Plant Cell Rep 9:360–364Maligeppagol M, Manjula R, Navale PM, Babu KP, Kumbar BM, Laxman RH (2016) Genetic transformation of chilli (Capsicum annuum L.) with Dreb1A transcription factor known to impart drought tolerance. Indian J Biotechnol 15:17–24Mantiri FR, Kurdyukov S, Chen SK, Rose RJ (2008) The transcription factor MtSERF1 may function as a nexus between stress and development in somatic embryogenesis in Medicago truncatula. Plant Signal Behav 3:498–500Mezghani N, Jemmali A, Elloumi N, Gargouri-Bouzid R, Kintzios S (2007) Morpho-histological study on shoot bud regeneration in cotyledon cultures of pepper (Capsicum annuum). Biologia 62:704–710Mohamed-Yasseen Y (2001) Influence of agar and activated charcoal on uptake of gibberellin and plant morphogenesis in vitro. In Vitro Cell Dev Biol - Plant 37:204–205Moshkov IE, Novikova GV, Hall MA, George EF (2008) Plant growth regulators III: ethylene. In: George EF, Hall MA, Klerk G-JD (eds) Plant propagation by tissue culture, vol 1, 3rdedn. Springer, Dordrecht, The Netherlands, pp 239–248Murashige T, Skoog F (1962) A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol Plant 15:473–497Nogueira RC, Paiva R, de Oliveira LM, Soares GA, Soares FP, Castro AHF, Paiva PDO (2007) Calli induction from leaf explants of murici-pequeno (Byrsonima intermedia A. Juss.) Ciênc Agrotec 31:366–370Ochoa-Alejo N, Ramirez-Malagon R (2001) In vitro chili pepper biotechnology. In Vitro Cell Devl Biol Plant 37:701–729Orlińska M, Nowaczy P (2015) In vitro plant regeneration of 4 Capsicum spp. genotypes using different explant types. Turk J Biol 39:60–68Reid MS (1995) Ethylene in plant growth, development and senescence. In: Davies PJ (ed) Plant hormones: physiology, biochemistry and molecular biology, 2nd edn. Kluwer Acad Publ, Dordrecht, The Netherlands, pp 486–508Sanatombi K, Sharma GJ (2008) In vitro plant regeneration in six cultivars of Capsicum spp. using different explants. Biol Plant 52:141–145Santana-Buzzy N, Canto-Flick A, Barahona-Pérez F, Montalvo-Peniche MC, Zapata-Castillo PY, Solís-Ruiz A, Zaldívar-Collí A, Gutiérrez-Alonso O, Miranda-Ham ML (2005) Regeneration of habanero pepper (Capsicum chinense Jacq.) via organogenesis. Hortscience 40:1829–1831Santana-Buzzy N, Canto-Flick A, Iglesias-Andreu LG, Montalvo-Peniche MC, López-Puc G, Barahona-Pérez F (2006) Improvement of in vitro culturing of habanero pepper by inhibition of ethylene effects. Hortscience 41:405–409Sawai S, Ohyama K, Yasumoto S, Seki H, Sakuma T, Yamamoto T, Takebayashi Y, Kojima M, Sakakibara H, Aoki T, Muranaka T, Saito K, Umemoto N (2014) Sterol side chain reductase 2 is a key enzyme in the biosynthesis of cholesterol, the common precursor of toxic steroidal glycoalkaloids in potato. Plant Cell 26:3763–3774Shah SH, Ali S, Jan SA, Din J, Ali GM (2014) Assessment of silver nitrate on callus induction and in vitro shoot regeneration in tomato (Solanum lycopersicum Mill.) Pakistan J Bot 46:2163–2172Steinitz B, Wolf D, Matzevitch-Josef T, Zelcer A (1999) Regeneration in vitro and genetic transformation of pepper (Capsicum spp.): the current state of the art. Capsicum Eggplant Plant Newsletter 18:9–15Tamimi SM (2015) Effects of ethylene inhibitors, silver nitrate (AgNO3), cobalt chloride (CoCl2) and aminooxyacetic acid (AOA), on in vitro shoot induction and rooting of banana (Musa acuminata L.) Afr J Biotechnol 14:2510–2516Trujillo-Moya C, Gisbert C (2012) The influence of ethylene and ethylene modulators on shoot organogenesis in tomato. Plant Cell Tissue Organ Cult 111:41–48Yasmin S, Mensuali-Sodi A, Perata P, Pucciariello C (2014) Ethylene influences in vitro regeneration frequency in the FR13A rice harbouring the SUB1A gene. Plant Growth Reg 72:97–103Zhao Y, Stiles AR, Saxena PK, Liu CZ (2013) Dark preincubation improves shoot organogenesis from Rhodiola crenulata leaf explants. Biol Plant 57:189–19

    GISualization: visualized integration of multiple types of data for knowledge co-production

    Get PDF
    Urban planning deals with multiple layers of information stemming from concurrent activities and stakeholders intervening in urban development. For a better management of complexity more comprehensiveness and data integration are needed. This study develops an adaptive and iterative mixed-method approach for knowledge production in urban transformation processes. Specific research questions relate to data integration from different sources and facilitation of co-production of knowledge beyond triangulation. A new multi-layer framework, GISualization, has been developed in the context of a research project exploring compact city qualities. The framework is structured through five data layers, representing different methods for data collection and different grades of complexity, richness and interpretation: basic statistics; advanced statistics; exogenous quali-quantitative descriptions; exogenous qualitative descriptions; and endogenous qualitative descriptions. Thus, data stem from both quantitative and qualitative sources. Our study has proven that GISualization is a methodological framework that enables analysis and visualization of complex data in a rich format. The approach is closely related to analytical eclecticism and abductivity. It embodies a collaborative communication platform that provides a language to navigate between heterogeneous data, information and methods. The GISualization framework opens up for broader stakeholder involvement and community participation extending research into the domain of transdisciplinary knowledge production

    Cancer risks in childhood and adolescence among the offspring of immigrants to Sweden

    Get PDF
    We used the nation-wide Swedish Family-Cancer Database to analyse the risk of nervous system tumours, leukaemia and non-Hodgkin's lymphoma in age groups 0–4 and 0–19 years among Swedish-born offspring of immigrants. The study included 850 000 individuals with an immigrant background, including European, Asian and American parents. We calculated standardised incidence ratios for the above three malignancies using Swedish offspring as a reference. Subjects were grouped by region or by selected countries of parental origin. No group differed significantly from Swedes in the occurrence of nervous system neoplasm or leukaemia. Offspring of Yugoslav fathers (SIR 2.27) and Turkish parents were at increased risk of non-Hodgkin's lymphoma. The highest risk was noted for non-Hodgkin's lymphoma among young offspring (0–4 years) of two Turkish parents (6.87). The currently available limited data on rates for childhood non-Hodgkin's lymphoma in these countries do not explain the risk in the offspring of immigrants. Yugoslavs and Turks are recent immigrant groups to Sweden, and their offspring have been subject to much population mixing, perhaps leading to recurring infections and immunological stimulation, which may contribute to their excess of lymphomas
    corecore