1,646 research outputs found

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

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    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

    Contrasting human perceptions of and attitudes towards two threatened small carnivores, Lycalopex fulvipes and Leopardus guigna, in rural communities adjacent to protected areas in Chile

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    Indexación: Scopus.The interaction between humans and small carnivores is a phenomenon especially frequent in rural fringes, as is the case of communities surrounding natural areas. In Chile, two species of threatened carnivores, the Darwin's Fox and the Guigna, have increased their contact with humans due to human-induced changes in their habitat. The objective of this study was to characterize the interactions of these species with humans by assessing human perceptions and attitudes toward them, and to assess livestock and poultry ownership and management practices in local communities to evaluate their possible roles in the phenomenon. We conducted semi-structured interviews in rural communities adjacent to natural protected areas of two different regions in southern Chile. We found that people have a more positive perception of Darwin's Foxes than Guignas, but both species are considered damaging due to poultry attacks. Livestock and poultry management was generally deficient. Improvements in animal management and education programs could lead to a significant decrease in negative interactions. © Sacristan et al. 2018.https://www.threatenedtaxa.org/index.php/JoTT/article/view/4030/442

    Optical pattern recognition based on color vision models

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    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

    "Test two, choose the better" leads to high cooperation in the Centipede game

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    Explaining cooperative experimental evidence in the Centipede game constitutes a challenge for rational game theory. Traditional analyses of Centipede based on backward induction predict uncooperative behavior. Furthermore, analyses based on learning or adaptation under the assumption that those strategies that are more successful in a population tend to spread at a higher rate usually make the same prediction. In this paper we consider an adaptation model in which agents in a finite population do adopt those strategies that turn out to be most successful, according to their own experience. However, this behavior leads to an equilibrium with high levels of cooperation and whose qualitative features are consistent with experimental evidence.Financial support from the Spanish State Research Agency (PID2020-118906GB-I00 / AEI / 10.13039/501100011033), from “Junta de Castilla y León - Consejería de Educación” through BDNS 425389, from the Spanish Ministry of Science, Innovation and Universities (PRX18-00182, PRX19/00113), and from the Fulbright Program (PRX19/00113), is gratefully acknowledged

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

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    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

    Shifted loops and coercivity from field imprinted high energy barriers in ferritin and ferrihydrite nanoparticles

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    We show that the coercive field in ferritin and ferrihydrite depends on the maximum magnetic field in a hysteresis loop and that coercivity and loop shifts depend both on the maximum and cooling fields. In the case of ferritin we show that the time dependence of the magnetization also depends on the maximum and previous cooling fields. This behavior is associated to changes in the intra-particle energy barriers imprinted by these fields. Accordingly, the dependence of the coercive and loop shift fields with the maximum field in ferritin and ferrihydrite can be described within the frame of a uniform-rotation model considering a dependence of the energy barrier with the maximum and the cooling fields.Comment: 8 pages, 5 figures. Accepted for publication in Phys. Rev. B. Final version with improved writing and figure

    Temperature dependence of antiferromagnetic susceptibility in ferritin

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    We show that antiferromagnetic susceptibility in ferritin increases with temperature between 4.2 K and 180 K (i. e. below the N\'{e}el temperature) when taken as the derivative of the magnetization at high fields (30×10430\times10^4 Oe). This behavior contrasts with the decrease in temperature previously found, where the susceptibility was determined at lower fields (5×1045\times10^4 Oe). At high fields (up to 50×10450 \times10^4 Oe) the temperature dependence of the antiferromagnetic susceptibility in ferritin nanoparticles approaches the normal behavior of bulk antiferromagnets and nanoparticles considering superantiferromagnetism, this latter leading to a better agreement at high field and low temperature. The contrast with the previous results is due to the insufficient field range used (<5×104< 5 \times10^4 Oe), not enough to saturate the ferritin uncompensated moment.Comment: 7 pages, 7 figures, accepted in Phys. Rev.
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