Optical pattern recognition based on color vision models

A channel transformation based on opponent-color theory of the color vision models is applied to optical pattern recognition so that the conventional red, green, and blue (RGB) channels are transformed into bright-dark, red-green, and yellow-blue (ATD) channels. Matched filtering and correlation are performed over the new components of the target and the scene in the ATD system. The proposed transformation allows us to reduce the number of channels commonly used in color pattern recognition, passing from the three RGB channels to the two red-green and yellow-blue opponent-color channels

Complex-linear invariants of biochemical networks

The nonlinearities found in molecular networks usually prevent mathematical analysis of network behaviour, which has largely been studied by numerical simulation. This can lead to difficult problems of parameter determination. However, molecular networks give rise, through mass-action kinetics, to polynomial dynamical systems, whose steady states are zeros of a set of polynomial equations. These equations may be analysed by algebraic methods, in which parameters are treated as symbolic expressions whose numerical values do not have to be known in advance. For instance, an "invariant" of a network is a polynomial expression on selected state variables that vanishes in any steady state. Invariants have been found that encode key network properties and that discriminate between different network structures. Although invariants may be calculated by computational algebraic methods, such as Gr\"obner bases, these become computationally infeasible for biologically realistic networks. Here, we exploit Chemical Reaction Network Theory (CRNT) to develop an efficient procedure for calculating invariants that are linear combinations of "complexes", or the monomials coming from mass action. We show how this procedure can be used in proving earlier results of Horn and Jackson and of Shinar and Feinberg for networks of deficiency at most one. We then apply our method to enzyme bifunctionality, including the bacterial EnvZ/OmpR osmolarity regulator and the mammalian 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase glycolytic regulator, whose networks have deficiencies up to four. We show that bifunctionality leads to different forms of concentration control that are robust to changes in initial conditions or total amounts. Finally, we outline a systematic procedure for using complex-linear invariants to analyse molecular networks of any deficiency.Comment: 36 pages, 6 figure

Decide to Digitalize! Barriers, Drivers and the Entrepreneurial Cognition Perspective

This article introduces the special issue Decide to Digitalize! Barriers, Drivers and the Entrepreneurial Cognition Perspective. Nine research papers have been selected to reach two primary research aims: first, to understand how entrepreneurs, cognitively, make strategical decisions in order to be more competitive in the technology sector; second, to investigate how digital technologies and ICTs are being used in the context of SMEs and entrepreneurshi

Trombo intraventricular izquierdo en un gato con cardiomiopatía dilatada

Describimos el caso de un gato que presentaba un cuadro de disnea y derrame pleural, en el que tras realizar ecocardiografía se diagnosticó una cardiomiopatía dilatada (CMD), asociada a un trombo localizado dentro del ventrículo izquierdo. La localización habitual de estos trombos intracardiacos es el atrio izquierdo. El tromboembolismo es relativamente frecuente en gatos y ocurre principalmente como una complicación de enfermedades subyacentes. Los émbolos están mayoritariamente localizados en la aorta distal y en las arterias ilíacas.

Color pattern recognition with circular component whitening

Polychromatic object recognition based on circular whitening preprocessing of red-green-blue components and multichannel matched filtering is described. Computer simulations and experimental results are provided to facilitate recognizing a color target among objects of similar shape but with different color contents. Experimental results are obtained with an optical correlator with two spatial light modulators, one to introduce the scene and the second one to introduce the filter

Transitional dispersive scenarios driven by mesoscale flows on complex terrain under strong dry convective conditions

By experimentation and modelling, this paper analyses the atmospheric dispersion of the SO<sub>2</sub> emissions from a power plant on complex terrain under strong convective conditions, describing the main dispersion features as an ensemble of "stationary dispersive scenarios" and reformulating some "classical" dispersive concepts to deal with the systematically monitored summer dispersive scenarios in inland Spain. The results and discussions presented arise from a statistically representative study of the physical processes associated with the multimodal distribution of pollutants aloft and around a 343-m-tall chimney under strong dry convective conditions in the Iberian Peninsula. This paper analyses the importance of the identification and physical implications of transitional periods for air quality applications. The indetermination of a transversal plume to the preferred transport direction during these transitional periods implies a small (or null) physical significance of the classical definition of horizontal standard deviation of the concentration distribution

Concatenated non-stationary dispersive scenarios on complex terrain under summer conditions

International audienceThe results and discussions presented in this paper arise from a statistically representative study of the physical processes associated with the multimodal distribution of pollutants aloft and around a 343-m-tall chimney under summer conditions in the Iberian Peninsula. The indetermination of a transversal plume to the preferred transport direction during transitional periods implies a small (or null) physical significance of the classical definition of horizontal standard deviation of the concentration distribution. By experimentation and modelling, this paper analyses the atmospheric dispersion of the SO2 emissions from a power plant on complex terrain, describing the main dispersion features as an ensemble of "stationary dispersive scenarios" and reformulating some "classical" dispersive concepts to deal with the systematically monitored summer dispersive scenarios in inland Spain

Real-Time and Low-Cost Sensing Technique Based on Photonic Bandgap Structures

This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.36.002707. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law[EN] A technique for the development of low-cost and high-sensitivity photonic biosensing devices is proposed and experimentally demonstrated. In this technique, a photonic bandgap structure is used as transducer, but its readout is performed by simply using a broadband source, an optical filter, and a power meter, without the need of obtaining the transmission spectrum of the structure; thus, a really low-cost system and real-time results are achieved. Experimental results show that it is possible to detect very low refractive index variations, achieving a detection limit below 2 x 10(-6) refractive index units using this low-cost measuring technique. (C) 2011 Optical Society of America[This work was funded by the Spanish Ministerio de Ciencia e Innovacion (MICINN) under contracts TEC2008-06333, JCI-009-5805, and TEC2008-05490. Support by the Universidad Politecnica de Valencia through program PAID-06-09 and the Conselleria d'Educacio through program GV-2010-031 is acknowledged.García Castelló, J.; Toccafondo, V.; Pérez Millán, P.; Sánchez Losilla, N.; Cruz, JL.; Andres, MV.; García-Rupérez, J. (2011). Real-Time and Low-Cost Sensing Technique Based on Photonic Bandgap Structures. Optics Letters. 36(14):2707-2709. https://doi.org/10.1364/OL.36.002707S270727093614Fan, X., White, I. M., Shopova, S. I., Zhu, H., Suter, J. D., & Sun, Y. (2008). Sensitive optical biosensors for unlabeled targets: A review. Analytica Chimica Acta, 620(1-2), 8-26. doi:10.1016/j.aca.2008.05.022Homola, J., Yee, S. S., & Gauglitz, G. (1999). Surface plasmon resonance sensors: review. Sensors and Actuators B: Chemical, 54(1-2), 3-15. doi:10.1016/s0925-4005(98)00321-9Kersey, A. D., Davis, M. A., Patrick, H. J., LeBlanc, M., Koo, K. P., Askins, C. G., … Friebele, E. J. (1997). Fiber grating sensors. Journal of Lightwave Technology, 15(8), 1442-1463. doi:10.1109/50.618377De Vos, K., Bartolozzi, I., Schacht, E., Bienstman, P., & Baets, R. (2007). Silicon-on-Insulator microring resonator for sensitive and label-free biosensing. Optics Express, 15(12), 7610. doi:10.1364/oe.15.007610Iqbal, M., Gleeson, M. A., Spaugh, B., Tybor, F., Gunn, W. G., Hochberg, M., … Gunn, L. C. (2010). Label-Free Biosensor Arrays Based on Silicon Ring Resonators and High-Speed Optical Scanning Instrumentation. IEEE Journal of Selected Topics in Quantum Electronics, 16(3), 654-661. doi:10.1109/jstqe.2009.2032510Xu, D.-X., Vachon, M., Densmore, A., Ma, R., Delâge, A., Janz, S., … Schmid, J. H. (2010). Label-free biosensor array based on silicon-on-insulator ring resonators addressed using a WDM approach. Optics Letters, 35(16), 2771. doi:10.1364/ol.35.002771Skivesen, N., Têtu, A., Kristensen, M., Kjems, J., Frandsen, L. H., & Borel, P. I. (2007). Photonic-crystal waveguide biosensor. Optics Express, 15(6), 3169. doi:10.1364/oe.15.003169Lee, M. R., & Fauchet, P. M. (2007). Nanoscale microcavity sensor for single particle detection. Optics Letters, 32(22), 3284. doi:10.1364/ol.32.003284García-Rupérez, J., Toccafondo, V., Bañuls, M. J., Castelló, J. G., Griol, A., Peransi-Llopis, S., & Maquieira, Á. (2010). Label-free antibody detection using band edge fringes in SOI planar photonic crystal waveguides in the slow-light regime. Optics Express, 18(23), 24276. doi:10.1364/oe.18.024276Toccafondo, V., García-Rupérez, J., Bañuls, M. J., Griol, A., Castelló, J. G., Peransi-Llopis, S., & Maquieira, A. (2010). Single-strand DNA detection using a planar photonic-crystal-waveguide-based sensor. Optics Letters, 35(21), 3673. doi:10.1364/ol.35.003673Luff, B. J., Wilson, R., Schiffrin, D. J., Harris, R. D., & Wilkinson, J. S. (1996). Integrated-optical directional coupler biosensor. Optics Letters, 21(8), 618. doi:10.1364/ol.21.000618Sepúlveda, B., Río, J. S. del, Moreno, M., Blanco, F. J., Mayora, K., Domínguez, C., & Lechuga, L. M. (2006). Optical biosensor microsystems based on the integration of highly sensitive Mach–Zehnder interferometer devices. Journal of Optics A: Pure and Applied Optics, 8(7), S561-S566. doi:10.1088/1464-4258/8/7/s41Densmore, A., Vachon, M., Xu, D.-X., Janz, S., Ma, R., Li, Y.-H., … Schmid, J. H. (2009). Silicon photonic wire biosensor array for multiplexed real-time and label-free molecular detection. Optics Letters, 34(23), 3598. doi:10.1364/ol.34.003598Povinelli, M. L., Johnson, S. G., & Joannopoulos, J. D. (2005). Slow-light, band-edge waveguides for tunable time delays. Optics Express, 13(18), 7145. doi:10.1364/opex.13.007145Garcia, J., Sanchis, P., Martinez, A., & Marti, J. (2008). 1D periodic structures for slow-wave induced non-linearity enhancement. Optics Express, 16(5), 3146. doi:10.1364/oe.16.003146Pérez-Millán, P., Torres-Peiró, S., Cruz, J. L., & Andrés, M. V. (2008). Fabrication of chirped fiber Bragg gratings by simple combination of stretching movements. Optical Fiber Technology, 14(1), 49-53. doi:10.1016/j.yofte.2007.07.00