Distinguishing signatures of determinism and stochasticity in spiking complex systems

Acknowledgements: This work was supported in part by grant FA8655-12-1-2140 from EOARD US, grant FIS2009-13360 from the Spanish MCI and grant 2009 SGR 1168 from the Generalitat de Catalunya. C. Masoller acknowledges partial support from the ICREA Academia programme. N. Rubido acknowledges the Scottish University Physics Alliance.Peer reviewedPublisher PD

Investigating optical complexity of the phase transition in the intensity of a fibre laser radiation

Fibre lasers have been shown to manifest a laminar-to-turbulent transition when increasing its pump power. In order to study the dynamical complexity of this transition we use advanced statistical tools of time-series analysis. We apply ordinal analysis and the horizontal visibility graph to the experimentally measured laser output intensity. This reveal the presence of temporal correlations during the transition from the laminar to the turbulent lasing regimes. Both methods allow us to unveil coherent structures with well defined time-scales and strong correlations both, in the timing of the laser pulses and in their peak intensities

Multidimensional subwavelength position sensing using a semiconductor laser with optical feedback

We demonstrate experimentally how to harness quasi-periodic dynamics in a semiconductor laser with dual optical feedback for measuring subwavelength changes in each arm of the cavity simultaneously. We exploit the multifrequency spectrum of quasi-periodic dynamics and show that independent frequency shifts are mapped uniquely to two-dimensional displacements of the arms in the external cavity. Considering a laser diode operating at telecommunication wavelength λ≈1550nm, we achieve an average nanoscale resolution of approximately 9.8 nm (∼λ∕160).Peer ReviewedPostprint (published version

Hacia una cultura paliativa: nivel de conocimiento y creencias erróneas sobre cuidados paliativos, sedación paliativa y eutanasia

El presente estudio tuvo como objetivo analizar el nivel de conocimiento de los conceptos de cuidados paliativos, sedación paliativa y eutanasia, lo que podría influir en la toma de decisiones éticas relacionadas con final de vida. Para ello, se elaboró un cuestionario ad hoc administrado entre los asistentes a unas Jornadas de Cuidados Paliativos en la Comunidad de Madrid (n = 142). La T de Student mostró que existen diferencias significativas (p < 0.05) entre los tres pares de conceptos y se encontraron correlaciones entre el grado de conocimiento de los tres constructos. La experiencia laboral y el nivel de conocimientos en cuidados paliativos correlaciona con un mayor conocimiento sobre eutanasia y sedación paliativa, encontrando diferencias estadísticamente significativas por nivel de estudios. Estos resultados sugieren que fomentar el conocimiento de cuidados paliativos disminuirá la presencia de ideas erróneas en deliberaciones relacionadas con el final de la vida, sedación y eutanasia

Museos y exposiciones en Madrid como oportunidad de trabajar conceptos-clave de las Ciencias Sociales con estudiantes Erasmus+ Incoming en colaboración con estudiantes UCM, asociaciones de estudiantes, oficina de relaciones internacionales y PDI

Proyecto de Innovación que pone en contacto los recursos museísticos y expositivos de Madrid con los estudiantes internacionales para trabajar conceptos-clave en las ciencias sociales, como vulnerabilidad y comunicació

Compromisos de optimización de diferentes modos de transmisión en un virus de plantas

Plant viruses are important crop pathogens that cause huge loses in agricultural production and may also reduce ecosystem biodiversity by affecting the fitness of wild plants. One of the most important traits determining the extent and severity of plant virus epidemics is their transmission mode and efficiency. The two main modes of plant virus transmission are horizontally from-plant-to-plant, mainly through insect vectors, and vertically from-parents-to-offspring through seeds. Despite the importance of plant virus transmission, little is known on the genetic determinants of this process, particularly for vertical transmission, and on how plant viruses optimize them. One of the most accepted theories on this regard is the Continuum Hypothesis, which poses that the preferred transmission mode would depend on the pathogen virulence and multiplication level: vertically transmitted parasites would evolve towards lower virulence and multiplication, as they require the host to produce progeny to be transmitted, whereas horizontally transmitted pathogens would evolve towards higher virulence and multiplication, which would ensure short-term dispersal through vectors. This theory assumes that both transmission modes will have the same genetic control through virulence and multiplication determinants, and therefore cannot be simultaneously optimized. However, this hypothesis has been seldom experimentally tested. Moreover, whether the genetic determinants of both transmission modes are the same or not is currently unknown. The goal of this Bachelor Thesis is to experimentally test the Continuum Hypothesis, and to explore whether vertical and horizontal transmission have the same genetic determinants. To do so, seven Arabidopsis thaliana accessions were challenged with four different turnip mosaic virus (TuMV) genotypes mutated in domains known to control horizontal transmission such that this capacity is blocked, plus the wildtype. Then, multiplication, virulence and both vertical and horizontal transmission rates were quantified. The results show lesser or equal vertical transmission rate in the TuMV mutants than in the wildtype. Interestingly, mutants with lower vertical transmission rate tended to have lower multiplication and virulence, suggesting a positive correlation between these two traits and vertical transmission rate. These findings: (i) do not support for the Continuum Hypothesis, showing that multiplication and virulence promotes vertical and horizontal transmission in the same way; and (ii) provide evidence that the two transmission modes may share some common genetic determinants

Measuring Two-Dimensional Translations with Nanoscale-Resolution by Using Quasiperiodic Dynamics in a Laser Diode

International audienceWe describe a novel approach to perform position sensing of reflecting object by using complex dynamics of a laser diode and we demonstrate sub-wavelength precision of ∼λ/160. With telecom band wavelength, this corresponds to resolving position of object with nanoscale precision

Are the spikes emitted by a semiconductor laser with feedback similar to neuronal spikes?

We study experimentally a semiconductor laser operating in a feedback-induced regime known as low frequency fluctuations (LFFs), in which the laser emits a spiking output that resembles the spikes of biological neurons. We analyze the response to a weak periodic signal that is directly applied to the laser pump current, as a function of the frequency of the signal, and discuss the observations in relation to the response of sensory neurons.Peer ReviewedPostprint (published version

Relationship between arc light, current and arc length in TIG welding

SIGLEAvailable from British Library Document Supply Centre- DSC:7761.039(RD/M--1750/RR88) / BLDSC - British Library Document Supply CentreGBUnited Kingdo