Quadratic deformation of Minkowski space

We present a deformation of the Minkowski space as embedded into the conformal space (in the formalism of twistors) based in the quantum versions of the corresponding kinematic groups. We compute explicitly the star product, whose Poisson bracket is quadratic. We show that the star product although defined on the polynomials can be extended differentiably. Finally we compute the Eucliden and Minkowskian real forms of the deformation.Comment: Presented at XVII European Workshop on String Theory 2011. Padova (Italy) September 05-09; Fortschr. Phys. 1-7 (2012

From historical map to online 3D recreation: the 1861 cadastral map of Horta (Barcelona)

The recent study and classification of over 200 cadastral maps created in the nineteenth century in Catalonia have provided a valuable source of information about the agricultural landscape country’s past, but by linking them with data recorded in tax books known as amillaramientos, it is possible to gain a better knowledge of the past. By applying this method to the 1861 cadastral map of Horta and its corresponding amillaramiento, a planimetric map showing the land use distribution in the town was created. The resulting land use map was subsequently overlaid on top of a digital elevation model to create 3D visualizations which show the altitudinal distribution of crops and other features. Finally, the article explores a way of distributing the results online, making them accessible to the public and increasing the research impact of future findings. Therefore, the method described in this article allows the systematic recreation and distribution of past landscapes by using Catalan cadastral maps of the nineteenth century, something which can help enrich the scientific knowledge of many disciplines

Topological Measure Locating the Effective Crossover between Segregation and Integration in a Modular Network

We introduce an easily computable topological measure which locates the effective crossover between segregation and integration in a modular network. Segregation corresponds to the degree of network modularity, while integration is expressed in terms of the algebraic connectivity of an associated hyper-graph. The rigorous treatment of the simplified case of cliques of equal size that are gradually rewired until they become completely merged, allows us to show that this topological crossover can be made to coincide with a dynamical crossover from cluster to global synchronization of a system of coupled phase oscillators. The dynamical crossover is signaled by a peak in the product of the measures of intra-cluster and global synchronization, which we propose as a dynamical measure of complexity. This quantity is much easier to compute than the entropy (of the average frequencies of the oscillators), and displays a behavior which closely mimics that of the dynamical complexity index based on the latter. The proposed toplogical measure simultaneously provides information on the dynamical behavior, sheds light on the interplay between modularity vs total integration and shows how this affects the capability of the network to perform both local and distributed dynamical tasks

Quantum twistors

We compute explicitly a star product on the Minkowski space whose Poisson bracket is quadratic. This star product corresponds to a deformation of the conformal spacetime, whose big cell is the Minkowski spacetime. The description of Minkowski space is made in the twistor formalism and the quantization follows by substituting the classical conformal group by a quantum group.Comment: 47 pages. references added, some parts rewritten. To appear in 'p-adic Numbers, Ultrametric Analysis and Applicarions

Intense myocyte formation from cardiac stem cells in human cardiac hypertrophy

It is generally believed that increase in adult contractile cardiac mass can be accomplished only by hypertrophy of existing myocytes. Documentation of myocardial regeneration in acute stress has challenged this dogma and led to the proposition that myocyte renewal is fundamental to cardiac homeostasis. Here we report that in human aortic stenosis, increased cardiac mass results from a combination of myocyte hypertrophy and hyperplasia. Intense new myocyte formation results from the differentiation of stem-like cells committed to the myocyte lineage. These cells express stem cell markers and telomerase. Their number increased >13-fold in aortic stenosis. The finding of cell clusters with stem cells making the transition to cardiogenic and myocyte precursors, as well as very primitive myocytes that turn into terminally differentiated myocytes, provides a link between cardiac stem cells and myocyte differentiation. Growth and differentiation of these primitive cells was markedly enhanced in hypertrophy, consistent with activation of a restricted number of stem cells that, through symmetrical cell division, generate asynchronously differentiating progeny. These clusters strongly support the existence of cardiac stem cells that amplify and commit to the myocyte lineage in response to increased workload. Their presence is consistent with the notion that myocyte hyperplasia significantly contributes to cardiac hypertrophy and accounts for the subpopulation of cycling myocytes

Fronts dynamics in the presence of spatio-temporal structured noises

Front dynamics modeled by a reaction-diffusion equation are studied under the influence of spatio-temporal structured noises. An effective deterministic model is analytical derived where the noise parameters, intensity, correlation time and correlation length appear explicitely. The different effects of these parameters are discussed for the Ginzburg-Landau and Schl\"ogl models. We obtain an analytical expression for the front velocity as a function of the noise parameters. Numerical simulations results are in a good agreement with the theoretical predictions.Comment: 11 pages, 6 figures; REVTEX; to be published in Phys.Rev.E, july 200

Branching Transition of a Directed Polymer in Random Medium

A directed polymer is allowed to branch, with configurations determined by global energy optimization and disorder. A finite size scaling analysis in 2D shows that, if disorder makes branching more and more favorable, a critical transition occurs from the linear scaling regime first studied by Huse and Henley [Phys. Rev. Lett. 54, 2708 (1985)] to a fully branched, compact one. At criticality clear evidence is obtained that the polymer branches at all scales with dimension ${\bar d}_c$ and roughness exponent $\zeta_c$ satisfying $({\bar d}_c-1)/\zeta_c = 0.13\pm 0.01$, and energy fluctuation exponent $\omega_c=0.26 \pm0.02$, in terms of longitudinal distanceComment: REVTEX, 4 pages, 3 encapsulated eps figure

Comparative study of the presence of latex and polychloroprene in the behavior of sintered powder EPDMCR, ethylene-propylenediene-monomer crumb rubber

In this work, the mechanical behavior of sintered waste material of ethylene-propylene-diene-monomer crumb rubber (EPDMCR) is analyzed, optimizing the temperature and compression pressure. The results obtained showed that an increase in temperature and compression pressure gives a significant improvement in the mechanical properties of the material. We later mixed the EPDMCR particles with different percentages of adhesives with the aim of further improving the mechanical performance obtained from the sintered particles. The adhesives used in this study were latex and polychloroprene, and the optimum mechanical performance obtained came from mixes with polychloroprene, using a mix with 50% adhesive. The study was concluded with an analysis of images of the material using a scanning electron microscope (SEM), in order to observe the EPDMCR-adhesive interaction.Crespo Amorós, JE.; Parres, F.; Nadal Gisbert, AV. (2012). Comparative study of the presence of latex and polychloroprene in the behavior of sintered powder EPDMCR, ethylene-propylenediene-monomer crumb rubber. Journal of Elastomers and Plastics. 44(2):127-144. doi:10.1177/0095244311418318S127144442Osman, H., Ismail, H., & Mariatti, M. (2007). The Effect of Recycled Newspaper Content and Size on the Properties of Polypropylene (PP)/Natural Rubber (NR) Composites. Polymer-Plastics Technology and Engineering, 47(1), 23-29. doi:10.1080/03602550701575961Crespo, J. E., Parres, F., & Nadal, A. (2009). Mechanical behavior analysis of sintered products of natural rubber crumb rubber (NRCR) using adhesives. Materialwissenschaft und Werkstofftechnik, 40(3), 211-217. doi:10.1002/mawe.200900429Setua, D. K., & Gupta, Y. N. (2007). On the use of micro thermal analysis to characterize compatibility of nitrile rubber blends. Thermochimica Acta, 462(1-2), 32-37. doi:10.1016/j.tca.2007.06.004Nakason, C., Kaesaman, A., Samoh, Z., Homsin, S., & Kiatkamjornwong, S. (2002). Rheological properties of maleated natural rubber and natural rubber blends. Polymer Testing, 21(4), 449-455. doi:10.1016/s0142-9418(01)00109-xJincheng, W., Yuehui, C., & Jihu, W. (2005). Novel Reinforcing Filler: Application to Natural Rubber (NR) System. Journal of Elastomers & Plastics, 37(2), 169-180. doi:10.1177/0095244305052010Sutanto, P., Picchioni, F., Janssen, L. P. B. M., Dijkhuis, K. A. J., Dierkes, W. K., & Noordermeer, J. W. M. (2006). State of the Art: Recycling of EPDM Rubber Vulcanizates. International Polymer Processing, 21(2), 211-217. doi:10.3139/217.1906Jacob, C., Bhowmick, A. K., De, P. P., & De, S. K. (2003). Utilization of Powdered EPDM Scrap in EPDM Compound. Rubber Chemistry and Technology, 76(1), 36-59. doi:10.5254/1.3547740Jacob, C., Bhattacharya, A. K., Bhowmick, A. K., De, P. P., & De, S. K. (2003). Recycling of ethylene propylene diene monomer (EPDM) waste. III. Processability of EPDM rubber compound containing ground EPDM vulcanizates. Journal of Applied Polymer Science, 87(14), 2204-2215. doi:10.1002/app.11474Jacob, C., Bhowmick, A. K., De, P. P., & De, S. K. (2002). Studies on ground EPDM vulcanisate as filler in window seal formulation. Plastics, Rubber and Composites, 31(5), 212-219. doi:10.1179/146580102225003029Jacob, C., De, P. P., Bhowmick, A. K., & De, S. K. (2001). Recycling of EPDM waste. II. Replacement of virgin rubber by ground EPDM vulcanizate in EPDM/PP thermoplastic elastomeric composition. Journal of Applied Polymer Science, 82(13), 3304-3312. doi:10.1002/app.2189Jacob, C., De, P. P., Bhowmick, A. K., & De, S. K. (2001). Recycling of EPDM waste. I. Effect of ground EPDM vulcanizate on properties of EPDM rubber. Journal of Applied Polymer Science, 82(13), 3293-3303. doi:10.1002/app.2188Grigoryeva, O. P., Fainleib, A. M., Tolstov, A. L., Starostenko, O. M., Lievana, E., & Karger-Kocsis, J. (2004). Thermoplastic elastomers based on recycled high-density polyethylene, ethylene-propylene-diene monomer rubber, and ground tire rubber. Journal of Applied Polymer Science, 95(3), 659-671. doi:10.1002/app.21177Mathew, G. (2003). Journal of Materials Science, 38(11), 2469-2481. doi:10.1023/a:1023965420749Morin, J. E., Williams, D. E., & Farris, R. J. (2002). A Novel Method to Recycle Scrap Tires: High-Pressure High-Temperature Sintering. Rubber Chemistry and Technology, 75(5), 955-968. doi:10.5254/1.3547695Rajeev, R. S., & De, S. K. (2004). Thermoplastic Elastomers Based on Waste Rubber and Plastics. Rubber Chemistry and Technology, 77(3), 569-578. doi:10.5254/1.3547837Yehia, A. A., Mull, M. A., Ismail, M. N., Hefny, Y. A., & Abdel-Bary, E. M. (2004). Effect of chemically modified waste rubber powder as a filler in natural rubber vulcanizates. Journal of Applied Polymer Science, 93(1), 30-36. doi:10.1002/app.20349Zhang, K., Shen, H., Zhang, X., Lan, R., & Chen, H. (2009). Preparation and Properties of a Waterborne Contact Adhesive Based on Polychloroprene Latex and Styrene-Acrylate Emulsion Blend. Journal of Adhesion Science and Technology, 23(1), 163-175. doi:10.1163/156856108x344658Park, S. W., Kim, B. C., & Lee, D. G. (2009). Tensile Strength of Joints Bonded With a Nano-particle-Reinforced Adhesive. Journal of Adhesion Science and Technology, 23(1), 95-113. doi:10.1163/156856108x344063Buchman, A., Dodiuk-Kenig, H., Dotan, A., Tenne, R., & Kenig, S. (2009). Toughening of Epoxy Adhesives by Nanoparticles. Journal of Adhesion Science and Technology, 23(5), 753-768. doi:10.1163/156856108x379209Likozar, B., & Krajnc, M. (2008). A study of heat transfer during molding of elastomers. Chemical Engineering Science, 63(12), 3181-3192. doi:10.1016/j.ces.2008.03.031Yan, L., Kou, K., Ji, T., Liang, G., & Ha, E. (2007). Application of a new modified epoxy adhesive for bonding fluorine rubber to metal. Journal of Adhesion Science and Technology, 21(15), 1483-1496. doi:10.1163/156856107782844792Smitthipong, W., Nardin, M., Schultz, J., & Suchiva, K. (2007). Adhesion and self-adhesion of rubbers, crosslinked by electron beam irradiation. International Journal of Adhesion and Adhesives, 27(5), 352-357. doi:10.1016/j.ijadhadh.2006.09.010Colom, X., Carrillo, F., & Cañavate, J. (2007). Composites reinforced with reused tyres: Surface oxidant treatment to improve the interfacial compatibility. Composites Part A: Applied Science and Manufacturing, 38(1), 44-50. doi:10.1016/j.compositesa.2006.01.022Liu, L., Luo, Y., Jia, D., Fu, W., & Guo, B. (2006). Structure and Properties of Natural Rubber-Organoclay Nanocomposites Prepared by Grafting and Intercalating Method in Latex. Journal of Elastomers & Plastics, 38(2), 147-161. doi:10.1177/0095244306057425Budrugeac, P. (2001). Thermal degradation of glass reinforced epoxy resin and polychloroprene rubber: the correlation of kinetic parameters of isothermal accelerated aging with those obtained from non-isothermal data. Polymer Degradation and Stability, 74(1), 125-132. doi:10.1016/s0141-3910(01)00112-4Arayasantiparb, D., McKnight, S., & Libera, M. (2001). Compositional variation within the epoxy/adherend interphase. Journal of Adhesion Science and Technology, 15(12), 1463-1484. doi:10.1163/156856101753213312Kim, J. I., Ryu, S. H., & Chang, Y. W. (2000). Mechanical and dynamic mechanical properties of waste rubber powder/HDPE composite. Journal of Applied Polymer Science, 77(12), 2595-2602. doi:10.1002/1097-4628(20000919)77:123.0.co;2-cCepeda-Jiménez, C. M., Pastor-blas, M. M., Ferrándiz-Gómez, T. P., & Martín-Martínez, J. M. (2000). Surface Characterization of Vulcanized Rubber Treated with Sulfuric Acid and its Adhesion to Polyurethane Adhesive. 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Drinking during low-risk labor: monocentric randomized clinical trial on patients' satisfaction, and maternal and neonatal outcomes.

This study aimed to assess satisfaction of patients affected by various fluid regimes during uncomplicated labor; to identify factors possibly associated with the level of satisfaction; to compare obstetrical and neonatal outcomes between the intervention groups. Between October and December 2014, 40 women were included in the study set at the Poitiers University Hospital, France. Women were randomly allocated to two study arms: 20 to strict and 20 to liberal fluid regime group. Women's satisfaction was assessed using visual analog scale. Categorical obstetrical and neonatal outcomes were analyzed using Chi-squared test and Fischer's exact test. The between-group difference was assessed with Mann-Whitney U-test. Overall satisfaction was higher among women from the liberal fluid regime than from the strict fluid regime group (median score: 88, interquartile range [IQR]: 21 vs. 72, IQR: 21; p = 0.03). The active phase of the second stage of labor was shorter in the liberal fluid regime than in the strict fluid regime group (median 9 min, IQR: 7 vs. 17 min, IQR: 12; p = 0.02). The length of stay in the delivery room was significantly shorter in liberal fluid regime than in strict fluid regime group (median 190 min, IQR: 128 vs. 340 min, IQR: 195, p = 0.04). There were no significant differences in other obstetrical and neonatal outcomes. Liberal fluid regime during labor was associated with significantly higher satisfaction of women. The active phase of the second stage of labor and the length of stay in the delivery room were significantly shorter in the liberal fluid regime group