Suppression of stimulated Brillouin scattering in high power fibre lasers and amplifiers

Fibre sources in high power devices have significant advantages over conventional gas and solid state lasers. However, for applications that require the so-called singlefrequency sources with narrow linewidths, the output power is low mainly because of the problem of the stimulated Brillouin scattering (SBS).A model that accounts for the SBS in dual-clad fibre lasers and amplifiers is presented. This was carried out in order to study the key parameters that affect the Brillouin threshold. Furthermore, the model was extended to account for the effect that the fibre axial temperature distribution has on the SBS threshold. Numerical solutions of the coupled differential equations for the evolution of the different beams showed a good agreement between the simulated data and reported experimental results. In addition, the model was used to study the relation of the core radius, the fibre length, and the fibre background loss on the SBS threshold. It was demonstrated that an adequate fibre structure design and a proper thermal management of the fibre amplifier lead to the suppression of SBS.Rare-earth doped fibre preforms with different compositions and geometries were fabricated by Modified Chemical Vapour Deposition technique in order to characterise the effect of doping and fibre structure on the Brillouin frequency and linewidth. Measurements using a microwave detection system for coherent detection of the anti-Stokes spontaneous Brillouin backscatter were performed on these fibres. The results showed that the actual Brillouin gain, linewidth and frequency shift widely differ from the values for pure fused silica fibres. It was confirmed that the fibre structure and composition play a big role in the Brillouin linewidth and Brillouin frequency shift of the fibr

Synchronization of the Frenet-Serret linear system with a chaotic nonlinear system by feedback of states

A synchronization procedure of the generalized type in the sense of Rulkov et al [Phys. Rev. E 51, 980 (1995)] is used to impose a nonlinear Malasoma chaotic motion on the Frenet-Serret system of vectors in the differential geometry of space curves. This could have applications to the mesoscopic motion of biological filamentsComment: 12 pages, 7 figures, accepted at Int. J. Theor. Phy

Bayesian perception of touch for control of robot emotion

In this paper, we present a Bayesian approach for perception of touch and control of robot emotion. Touch is an important sensing modality for the development of social robots, and it is used in this work as stimulus through a human-robot interaction. A Bayesian framework is proposed for perception of various types of touch. This method together with a sequential analysis approach allow the robot to accumulate evidence from the interaction with humans to achieve accurate touch perception for adaptable control of robot emotions. Facial expressions are used to represent the emotions of the iCub humanoid. Emotions in the robotic platform, based on facial expressions, are handled by a control architecture that works with the output from the touch perception process. We validate the accuracy of our system with simulated and real robot touch experiments. Results from this work show that our method is suitable and accurate for perception of touch to control robot emotions, which is essential for the development of sociable robots

EVALUACIÓN DEL BIENESTAR ANIMAL EN GANADO BOVINO EN UNA PLANTA DE SACRIFICIO UBICADA EN STANFIELD, ARIZONA, ESTADOS UNIDOS DE NORTEAMERICA

Las plantas de sacrificio han experimentado transformaciones radicales en los últimos años debido a la necesidad de aumentar la eficiencia e incorporar nuevas tecnologías para la mejora de la infraestructura, el bienestar animal y la calidad del producto. Sin embargo, las plantas de sacrificio se diseñan con base en criterios arquitectónicos convencionales, como la optimización del espacio o la facilitación de las actividades humanas, y no en las necesidades de comportamiento de los animales (Miranda-de la Lama et al., 2010, 2011a ). En esas condiciones, los animales pueden estar expuestos a muchos estímulos estresantes, como la descarga, el manejo, la sobrepoblación, la privación de alimentos, los sonidos, los olores novedosos (Gregory 2007) y las fallas operacionales. En este contexto, para ayudar a mantener y mejorar la calidad de los estándares operativos, es importante identificar los riesgos operativos (Villarroel et al., 2001) y es necesario desarrollar sistemas de auditoría eficientes y precisos que puedan detectar o prevenir problemas de bienestar animal. (Grandin 2010). Una auditoría puede contribuir al desarrollo de un sistema de puntos críticos de control para eliminar las malas prácticas y un manejo más eficiente de los animales, lo que mejorará la eficiencia de la logística y garantizará niveles mínimos de bienestar animal (Miranda-de la Lama et al., 2010)

Learning from sensory predictions for autonomous and adaptive exploration of object shape with a tactile robot

Humans use information from sensory predictions, together with current observations, for the optimal exploration and recognition of their surrounding environment. In this work, two novel adaptive perception strategies are proposed for accurate and fast exploration of object shape with a robotic tactile sensor. These strategies called (1) adaptive weighted prior and (2) adaptive weighted posterior, combine tactile sensory predictions and current sensor observations to autonomously adapt the accuracy and speed of active Bayesian perception in object exploration tasks. Sensory predictions, obtained from a forward model, use a novel Predicted Information Gain method. These predictions are used by the tactile robot to analyse ‘what would have happened’ if certain decisions ‘would have been made’ at previous decision times. The accuracy of predictions is evaluated and controlled by a confidence parameter, to ensure that the adaptive perception strategies rely more on predictions when they are accurate, and more on current sensory observations otherwise. This work is systematically validated with the recognition of angle and position data extracted from the exploration of object shape, using a biomimetic tactile sensor and a robotic platform. The exploration task implements the contour following procedure used by humans to extract object shape with the sense of touch. The validation process is performed with the adaptive weighted strategies and active perception alone. The adaptive approach achieved higher angle accuracy (2.8 deg) over active perception (5 deg). The position accuracy was similar for all perception methods (0.18 mm). The reaction time or number of tactile contacts, needed by the tactile robot to make a decision, was improved by the adaptive perception (1 tap) over active perception (5 taps). The results show that the adaptive perception strategies can enable future robots to adapt their performance, while improving the trade-off between accuracy and reaction time, for tactile exploration, interaction and recognition tasks

Consecuencias jurídicas que generaría en el derecho civil peruano la inscripción de bienes conyugales adquiridos por matrimonios de personas del mismo sexo celebrado en el extranjero

La investigación se basa en el estudio que generaría en el Derecho Civil Peruano, la inscripción de bienes conyugales en el registro de predios que conforman los bienes inmuebles, adquiridos por matrimonios de personas del mismo sexo celebrados en el extranjero, teniendo en cuenta la eficacia de los derechos adquiridos al amparo de un ordenamiento extranjero competente con el nuestro; normas de Derecho Internacional Privado que colisionan con instituciones naturales que protege el Estado como son matrimonio y familia; de ahí que, con la finalidad de analizar la correcta interpretación del artículo 2050 de nuestro Código Civil, es necesario e importante determinar si el acto jurídico celebrado en el extranjero por dos personas del mismo sexo corresponde a un supuesto de eficacia o uno de ineficacia en estricto, teniendo en cuenta que el matrimonio de personas del mismo sexo no es válido en el Perú; generando incertidumbre jurídica dentro de nuestro ordenamiento jurídico en cuanto a sus efectos. Planteándonos como problema la siguiente pregunta: ¿Cuáles son las consecuencias jurídicas que generaría en el Derecho Civil Peruano, la inscripción de bienes conyugales adquiridos por matrimonios del mismo sexo celebrados en el extranjero? Y como hipótesis propuesta a la pregunta planteada tenemos que las consecuencias jurídicas que generaría en el Derecho Civil Peruano, la inscripción de bienes conyugales adquiridos por matrimonios de personas del mismo sexo celebrados en el extranjero seria: la vulneración al principio protector de la familia, la trasgresión al instituto natural del matrimonio y la vulneración al orden público interno y buenas costumbres. El objetivo general es establecer las consecuencias jurídicas que generarían en el Derecho Civil Peruano la inscripción de bienes adquiridos por matrimonios de personas del mismo sexo celebrados en el extranjero. Del mismo modo, la investigación también pretende el recojo de información de los principales institutos naturales relacionados con el acto jurídico celebrado en el extranjero como son el matrimonio y que como consecuencia del mismo genera también confusión sobre algunas instituciones del derecho de familia; por consiguiente, la investigación establecerá cuales serían las consecuencias negativas que generaría en el Derecho Civil Peruano, la inscripción de un bien conyugal inmueble en el registro de predios por un matrimonio de personas del mismo sexo, al amparo de los derechos adquiridos bajo un ordenamiento extranjero civil competente, determinando su eficacia o ineficacia que le correspondería con la relación jurídica creada, situación que puede generar controversia con relación a la interpretación del artículo 2050 del Código Civil

Use of Prebiotics as an Alternative to Antibiotic Growth Promoters in the Poultry Industry

Nowadays there is a great concern about antimicrobial resistance (AMR), which has been recognized as one of the most serious global public health threats. Multilateral organizations focused on global health accept the use of antibiotics in animal production as one of the main drivers of AMR, so that many strategies to control this problem have been proposed, resulting in the total ban of antibiotics as growth-promoting agents. On the other hand, this ban has led to an increase in the incidence of bacterial infections or even to the use of antibiotics at therapeutic doses, which could cause a worse scenario of bacterial resistance. Poultry is one of the most commonly exploited species worldwide and a sector that continues to grow and industrialize in many parts of the world, so it was to be expected that a large part of the antibiotics used in animal production was destined to this industry. The reduction or complete abolition of antibiotics in poultry production would have a positive effect in the control of AMR, but this would also have negative economic and public health repercussions, caused by foodborne pathogens and the decrease of the productive parameters. For that, many specific alternatives have been evaluated and marketed, prebiotics being one of the most promising alternatives for the poultry industry