Development and characterisation of a near-infrared femtosecond optical parametric oscillator frequency comb

This thesis describes a 280 MHz MgO:PPLN-based optical parametric oscillator (OPO) synchronously pumped by a 50 fs Ti:sapphire laser to produce ultrafast pulses in the near-infrared. The OPO tuned over a wavelength range from 1450 - 1550 nm and 1624 - 1750 nm for the signal and idler respectively. The carrier-envelope-offset (CEO) frequency of the signal pulses was stabilised to a 10 MHz reference frequency without f-2f self-referencing, with an RMS phase variation of 0.56 rad over an observation time of 1 second. The relative intensity noise was measured for the CEO-stabilised OPO over an observation time of 64 seconds as 0.04%. The repetition frequency of the OPO was stabilised to 280 MHz using a frequency synthesiser at the eighth harmonic (2.24 GHz). This locking loop had an RMS phase variation of 0.98 mrad over a 1 second observation time. The CEO- and repetition frequencies were then locked simultaneously to a synthesiser referenced to a Rb-disciplined source, to generate a fully stabilised 1.5 μm frequency comb with an absolute uncertainty in comb mode position of 110 Hz. The upper limit for the fractional instability for a comb mode at 200 THz was found to be 2 x 10-11, limited by the stability of the Rb reference. A five-fold increase in comb mode spacing to 1.4 GHz was demonstrated with the stabilised frequency comb. This was achieved using a passive filter cavity, stabilised to a transmission peak via dither locking. The FWHM bandwidth of the optical spectrum for the filtered frequency comb was reduced to 8 nm, however no increase in comb linewidth was observed. An additional experiment was carried out where an external cavity diode laser was frequency-stabilised to a saturated absorption peak in Rb at 780.2 nm using dither locking, providing an optical frequency reference for future OPO frequency combs

An analysis of feminist essay comic through the work "The forbidden fruit" by Liv Strömquist

Liv Strömquist realiza con su cómic "El fruto prohibido" un ensayo académico sobre la construcción cultural en torno al genital femenino y su relación con las políticas de opresión patriarcales. En este estudio, se analiza como el medio del cómic permite una comunicación multifacética que utiliza las posibilidades de la conjunción de la comunicación visual y la textual para cubrir espacios donde solo uno de estos dos canales no puede llegar. El estudio busca señalar las múltiples formas en las que ambas esferas (cómic/ensayo académico) se fusionan y promocionan mutuamente, al basarse esta idea en teorías visuales y factores antropológicos, sociales y culturales.Liv Strömquist creates with her comic Fruit of Knowledge an academic essay on the cultural construction around the female genitalia and its relationship with patriarchal politics of oppression. This study analyses how comics, as a medium, allow a multimodal communication by combining visual and textual information to fill a gap that cannot be reached by just one of these two channels alone. The study aims to highlight the multiple ways in which both fields (comic / academic essay) overlap and encourage one another, while supporting this idea on visual theories and well as anthropological, social and cultural factors

Amino acid metabolism conflicts with protein diversity

The twenty protein coding amino acids are found in proteomes with different relative abundances. The most abundant amino acid, leucine, is nearly an order of magnitude more prevalent than the least abundant amino acid, cysteine. Amino acid metabolic costs differ similarly, constraining their incorporation into proteins. On the other hand, sequence diversity is necessary for protein folding, function and evolution. Here we present a simple model for a cost-diversity trade-off postulating that natural proteomes minimize amino acid metabolic flux while maximizing sequence entropy. The model explains the relative abundances of amino acids across a diverse set of proteomes. We found that the data is remarkably well explained when the cost function accounts for amino acid chemical decay. More than one hundred proteomes reach comparable solutions to the trade-off by different combinations of cost and diversity. Quantifying the interplay between proteome size and entropy shows that proteomes can get optimally large and diverse

Modelización y medida de la calidad percibida de la atención al parto en la comunidad gallega

En los últimos años hemos asistido a una auténtica “revolución” en todo lo que rodea a la asistencia al parto y, en consecuencia, al funcionamiento de los servicios hospitalarios de maternidad. Los avances tecnológicos y sanitarios incorporados al seguimiento del embarazo y al propio parto son innumerables. En nuestros días la mayoría de las mujeres dan a luz en hospitales (públicos o privados) y siempre con el apoyo continuo de personal sanitario cualificado y de diferentes elementos tecnológicos. Ello ha reducido espectacularmente las cifras de mortalidad y de las incidencias, pero ha traído consigo una sobremedicalización del proceso y una pérdida de protagonismo y control para la propia madre y la familia. Actualmente se recomienda que las intervenciones en torno al parto se basen únicamente en la evidencia científica y nunca se ejecuten de espaldas al propio usuario del servicio: las madres y sus familias. Las consecuencias acarreadas por intervenciones innecesarias terminan por convertirse en un problema, tanto en términos de salud, como de gasto de recursos

External cavity diode laser based upon an FBG in an integrated optical fiber platform

An external cavity diode laser is demonstrated using a Bragg grating written into a novel integrated optical fiber platform as the external cavity. The cavity is fabricated using flame-hydrolysis deposition to bond a photosensitive fiber to a silica-on-silicon wafer, and a grating written using direct UV-writing. The laser operates on a single mode at the acetylene P13 line (1532.83 nm) with 9 mW output power. The noise properties of the laser are characterized demonstrating low linewidth operation (< 14 kHz) and superior relative intensity noise characteristics when compared to a commercial tunable external cavity diode laser

Deaf bilingual education: key tenets for strategic change

Pese a los progresos logrados en la protección de los derechos fundamentales de salud y educación de las personas sordas usuarias de las lenguas de signos, a menudo se sigue negando a niños sordos su derecho a aprender y usar las lenguas de signos en su educación y en entornos físicos y psicosociales accesibles de conformidad con la Convención de los Derechos de las Personas con Discapacidad (CDPD) y con las recientes leyes 27/2007 y 17/2007. El objetivo principal de este estudio fue obtener información sobre los factores estratégicos que favorecen una escuela saludable e inclusiva, mediante programas de educación bilingüe sostenibles y de calidad para escolares sordos en España. La metodología utilizada consistió en un estudio descriptivo con componentes de investigación-acción participativa y un enfoque de análisis estratégico. Como resultados, cabe destacar que las principales macrotendencias que, en el ámbito internacional, han promovido el cambio hacia prácticas bilingües son dos: en primer lugar, los cambios sociales y políticos que tienden a una creciente aceptación de la diversidad y los temas relacionados con las personas sordas; y en segundo lugar, una tendencia a un activismo, una autoconciencia y un apoderamiento crecientes por parte de las personas sordas. Como contrapartida, las que lo han obstaculizado son, por un lado, la visión de la sordera como una condición médica, que puede solucionarse mediante la tecnología; y por otro lado, el fonocentrismo, unido a una cierta resistencia social a lo desconocido. Aunque en España algunas de las escuelas que han iniciado el cambio cumplen las recomendaciones de la CDPD, la mayoría están todavía en una fase preliminar de formulación o puesta en práctica de este nuevo modelo y distan mucho de encontrarse distribuidas de manera igualitaria en las diferentes comunidades autónomas. Como conclusión podemos decir que conseguir una educación más saludable e inclusiva para los escolares sordos implica poner en marcha una estrategia de actuación planificada en la que participen activamente todos los sectores y organismos relevantes implicados y, en particular, las comunidades sordas a través de las organizaciones que las representan. Sin un cambio radical de perspectiva, la salud y la educación no serán accesibles a todos y las desigualdades sociales se verán acentuadas.Although progress has been made in protecting deaf sign language users’ fundamental rights to health and education, all too often deaf children are still denied the right to learn and use sign languages in their education and in accessible physical and psycho-social environments in accordance with both the Convention on the Rights of Persons with Disabilities (CRPD) and recent Spanish laws (Act 27/2007 and Act 17/2007). The main objective of the present study was to collect information about some strategic factors that may facilitate healthy, inclusive schooling through sustainable, high-quality deaf bilingual programmes in Spain. A descriptive study was conducted, with some components of participatory action research and a strategic analysis framework. The two main megatrends found to have spurred the current change toward bilingual education in order of priority are: (1) societal and political changes towards a growing acceptance of diversity and Deaf issues and (2) growing Deaf activism, selfawareness and empowerment. The two main hindering megatrends are: (1) the view of deafness as a medical condition with a technological solution and (2) phonocentrism and societal resistance to the unknown. Although some schools have achieved CRPD-recommended standards, the majority of deaf bilingual programmes in Spain are still in a very early stage of formulation and implementation and are far from being equally distributed across the country. Transforming schools into healthier, more inclusive settings for deaf children implies the implementation of a well-planned strategy involving the active participation of relevant sectors and organizations, particularly deaf communities through their representative organizations. Unless there is a radical change of perspective, health and education will not be available to all, and therefore social inequalities will increase.Fondo de Investigación Sanitaria del Ministerio de Sanidad y Consumo; Vicerrectorado de Investigación, Desarrollo e Innovación; Vicerrectorado de Alumnado; y Grupo de Investigación en Salud Pública de la Universidad de Alicante

Learning of facial responses to faces associated with positive or negative emotional expressions

Subject to file availability and provided the posting includes a prominent statement of the full bibliographical details, a copyright notice in the name of the copyright holder (Cambridge University Press or the sponsoring Society, as appropriate), and a link to the online edition of the journal at Cambridge Journals Online.The possibility that facial expressions of emotion change the affective valence of faces through associative learning was explored using facial electromyography (EMG). In Experiment 1, EMG activity was registered while the participants (N = 57) viewed sequences of neutral faces (Stimulus 1 or S1) changing to either a happy or an angry expression (Stimulus 2 or S2). As a consequence of learning, participants who showed patterning of facial responses in the presence of angry and happy faces, that is, higher Corrugator Supercilii (CS) activity in the presence of angry faces and higher Zygomaticus Major (ZM) activity in the presence of happy faces, showed also a similar pattern when viewing the corresponding S1 faces. Explicit evaluations made by an independent sample of participants (Experiment 2) showed that evaluation of S1 faces was changed according to the emotional expression with which they had been associated. These results are consistent with an interpretation of rapid facial reactions to faces as affective responses that reflect the valence of the stimulus and that are sensitive to learned changes in the affective meaning of faces.This work was supported by Project SEJ2006-01576/PSIC, from the Spanish Ministerio de Ciencia y Tecnología. The participation of Francisco J. Román has been possible thanks to a FPI Grant (PSI2010- 20364) from the Spanish Ministerio de Ciencia y Tecnología

Preventing disability through understanding international megatrends in Deaf bilingual education

Background: Education is a basic prerequisite for d/Deaf people’s health. Deaf education varies considerably from country to country and we still know very little about the reasons for such variation. Objective: To identify international megatrends that influence the current Deaf bilingual education move (Deaf Bilingual–Bicultural education; DBiBi) worldwide. Methods: Using the Delphi technique, 41 experts in d/ Deaf education (nine Deaf, 32 hearing) from 18 countries identified, ranked, and rated international megatrends in DBiBi education. Results: The process revealed six main essential elements of the international implementation of DBiBi education and nine main barriers against it. The top five promoting forces in that list in order of priority were: (1) societal and political changes towards a growing acceptance of diversity and Deaf issues; (2) growing Deaf activism, self-awareness and empowerment; (3) scientific research in sign linguistics and bilingualism; (4) changes in the d/Deaf educational community; and (5) international cooperation. The top five hindering forces included: (1) the view of deafness as a medical condition with a technological solution; (2) phonocentrism and societal resistance to the unknown; (3) educational and d/Deaf educational policies; (4) DBiBi education weaknesses; and (5) invisibility, heterogeneity and underperformance of the d/Deaf population. Conclusion: The results of this study reveal that social/political changes and a medical/social model of Deaf people’s health can promote or limit Deaf people’s educational options much more than changes within the education system itself, and that a transnational perspective is needed in deciding how best to support DBiBi education at a national and local level in an increasingly globalised world.Spanish Medical Research Council

Microstructure, interfaces and properties of 3YTZP ceramic composites with 10 and 20 vol% different graphene-based nanostructures as fillers

The graphene family comprises not only single layer graphene but also graphene-based nanomaterials (GBN), with remarkably different number of layers, lateral dimension and price. In this work, two of these GBN, namely graphene nanoplatelets (GNP) with n~15–30 layers and few-layer graphene (FLG) with n < 3 layers have been evaluated as fillers in 3¿mol% yttria stabilized tetragonal zirconia (3YTZP) ceramic composites. Composites with 10 and 20¿vol% GNP or FLG have been fabricated by wet powder processing and spark plasma sintering (SPS) and the influence of the content and number of layers of the graphene-based filler has been assessed. For both graphene-based fillers, an intermediate zirconia oxycarbide has been detected in the grain boundaries. The lower stacking degree and much more homogeneous distribution of the FLG, revealed by transmission electron microscopy (TEM), can improve load transfer between the GBNs and the ceramic matrix. However, high FLG contents lower densification of the composites, due partly to the larger FLG interplanar spacing also estimated by TEM. The hardness (both Vickers and nanoindentation) and the elastic modulus decrease with increased GBN content and with improved graphene dispersion. The FLG greatly inhibit the crack propagation that occur perpendicular to their preferential orientation plane. The composites with thinner FLG have higher electrical conductivity than those with GNP. The highest electrical conductivity is achieved by composites with 20¿vol% FLG in the direction perpendicular to the compression axis during sintering, s¿¿=¿3400¿±¿500¿Sm-1.Peer ReviewedPostprint (published version