A Comparison of Front-Ends for Bitstream-Based ASR over IP

Automatic speech recognition (ASR) is called to play a relevant role in the provision of spoken interfaces for IP-based applications. However, as a consequence of the transit of the speech signal over these particular networks, ASR systems need to face two new challenges: the impoverishment of the speech quality due to the compression needed to fit the channel capacity and the inevitable occurrence of packet losses. In this framework, bitstream-based approaches that obtain the ASR feature vectors directly from the coded bitstream, avoiding the speech decoding process, have been proposed ([S.H. Choi, H.K. Kim, H.S. Lee, Speech recognition using quantized LSP parameters and their transformations in digital communications, Speech Commun. 30 (4) (2000) 223–233. A. Gallardo-Antolín, C. Pelàez-Moreno, F. Díaz-de-María, Recognizing GSM digital speech, IEEE Trans. Speech Audio Process., to appear. H.K. Kim, R.V. Cox, R.C. Rose, Performance improvement of a bitstream-based front-end for wireless speech recognition in adverse environments, IEEE Trans. Speech Audio Process. 10 (8) (2002) 591–604. C. Peláez-Moreno, A. Gallardo-Antolín, F. Díaz-de-María, Recognizing voice over IP networks: a robust front-end for speech recognition on the WWW, IEEE Trans. Multimedia 3(2) (2001) 209–218], among others) to improve the robustness of ASR systems. LSP (Line Spectral Pairs) are the preferred set of parameters for the description of the speech spectral envelope in most of the modern speech coders. Nevertheless, LSP have proved to be unsuitable for ASR, and they must be transformed into cepstrum-type parameters. In this paper we comparatively evaluate the robustness of the most significant LSP to cepstrum transformations in a simulated VoIP (voice over IP) environment which includes two of the most popular codecs used in that network (G.723.1 and G.729) and several network conditions. In particular, we compare ‘pseudocepstrum’ [H.K. Kim, S.H. Choi, H.S. Lee, On approximating Line Spectral Frequencies to LPC cepstral coefficients, IEEE Trans. Speech Audio Process. 8 (2) (2000) 195–199], an approximated but straightforward transformation of LSP into LP cepstral coefficients, with a more computationally demanding but exact one. Our results show that pseudocepstrum is preferable when network conditions are good or computational resources low, while the exact procedure is recommended when network conditions become more adverse.Publicad

Popular Music, Cognition, Affects and Interpellation. A Socio-semiotic Approach

En los últimos años el campo de las humanidades ha renovado su interés por la dimensión afectiva de los fenómenos sociales, en lo que se ha dado en llamar el giro afectivo. Entre estos fenómenos, la producción y recepción de músicas populares es, sin lugar a dudas, un campo de interés particular. Las músicas impactan en lo afectivo y, al mismo tiempo, las emociones y los sentimientos son un tópico recurrente en gran parte de las canciones. De modo que los modelos teóricos que reponen la importancia de lo afectivo son especialmente interesantes para los estudios sobre las músicas populares. Sin embargo, notamos que algunas de esas propuestas, en su afán por ponderar lo afectivo, terminan por reproducir una lógica dualista que separa lo que conciben como corporal, afectivo y no representacional de lo que entienden por mental, cognitivo y discursivo. Proponemos, en cambio, un enfoque que entiende la dimensión afectiva como parte de cualquier proceso cognitivo y sostenemos que una perspectiva sociodiscursiva brinda valiosas herramientas para la comprensión de esa dimensión en las músicas populares, incluyendo la capacidad que las mismas tienen para interpelar a determinados públicos y contribuir a la construcción de identidades.Nos últimos anos, o campo das humanidades tem renovado seu interesse pela dimensão afetiva dos fenômenos sociais, no que foi denominado virada afetiva. Entre esses fenômenos, a produção e recepção de músicas populares constituem-se, sem dúvida, como um campo de interesse particular. As músicas impactam no afetivo e, ao mesmo tempo, emoções e sentimentos são um tópico recorrente em grande parte das canções. Dessa maneira, as perspectivas teóricas que reposicionam a importância do afetivo são especialmente interessantes para os estudos sobre as músicas populares. No entanto, notamos que algumas dessas propostas, no afã de considerar o afetivo, acabam reproduzindo uma lógica dualista que separa aquilo que concebem como corporal, afetivo e não representacional daquilo que consideram como mental, cognitivo e discursivo. Propomos, em contrapartida, um enfoque que entende a dimensão afetiva como parte de qualquer processo cognitivo e sustentamos que uma perspectiva sociodiscursiva fornece valiosas ferramentas para a compreensão dessa dimensão nas músicas populares, incluindo a capacidade que elas têm de interpelar determinados públicos e contribuir para a construção de identidades.In recent years, the field of humanities has renewed its interest in the affective dimension of social phenomena, in what has been called the affective turn. Among these phenomena, the production and reception of popular music is undoubtedly a particular field of interest. Music has an impact on the affective sphere and, at the same time, emotions and feelings are a recurring topic in many songs. Therefore, theoretical models that reinstate the importance of the affective domain are especially interesting when it comes to popular music studies. However, it is worth mentioning that some of these proposals, in their eagerness to ponder the affects, end up reproducing a dualistic logic that separates what they conceive as corporal, affective and non-representational from what they understand as mental, cognitive and discursive. Instead, we propose an approach that understands the affective dimension as part of any cognitive process, and we maintain that a socio-discursive perspective provides valuable tools for understanding that dimension in popular music, including the ability that they have to challenge certain audiences, and contribute to the construction of identities

Consideraciones respecto al comportamiento físico y mecanico de hormigones ligeros estructurales

Resulta paradójico que a pesar de las enormes ventajas que supone en muchas aplicaciones de construcción el empleo del hormigón ligero estructural (HLE) frente a un hormigón convencional (HC), su uso todavía no se haya generalizado. Muy posiblemente, el desconocimiento de su comportamiento físico y mecánico contribuye de forma decisiva a la utilización de un HC en muchas ocasiones en las que su sustitución por HLE sería totalmente competitivo y ventajoso. Este trabajo pretende ampliar el conocimiento del comportamiento del HLE para contribuir a su utilización en todas las situaciones en donde su empleo supone una clara ventaja frente al HC

The four serotypes of dengue recognize the same putative receptors in Aedes aegypti midgut and Ae. albopictus cells

BACKGROUND: Dengue viruses (DENV) attach to the host cell surface and subsequently enter the cell by receptor-mediated endocytosis. Several primary and low affinity co-receptors for this flavivirus have been identified. However, the presence of these binding molecules on the cell surface does not necessarily render the cell susceptible to infection. Determination of which of them serve as bona fide receptors for this virus in the vector may be relevant to treating DENV infection and in designing control strategies. RESULTS: (1) Overlay protein binding assay showed two proteins with molecular masses of 80 and 67 kDa (R80 and R67). (2) Specific antibodies against these two proteins inhibited cell binding and infection. (3) Both proteins were bound by all four serotypes of dengue virus. (4) R80 and R67 were purified by affinity chromatography from Ae. aegypti mosquito midguts and from Ae albopictus C6/36 cells. (5) In addition, a protein with molecular mass of 57 kDa was purified by affinity chromatography from the midgut extracts. (6) R80 and R67 from radiolabeled surface membrane proteins of C6/36 cells were immunoprecipitated by antibodies against Ae. aegypti midgut. CONCLUSION: Our results strongly suggest that R67 and R80 are receptors for the four serotypes of dengue virus in the midgut cells of Ae. aegypti and in C6/36 Ae. albopictus cells

RepA-WH1 prionoid: Clues from bacteria on factors governing phase transitions in amyloidogenesis

10 p.-1 fig.In bacterial plasmids, Rep proteins initiate DNA replication by undergoing a structural transformation coupled to dimer dissociation. Amyloidogenesis of the ‘winged-helix’ N-terminal domain of RepA (WH1) is triggered in vitro upon binding to plasmid-specific DNA sequences, and occurs at the bacterial nucleoid in vivo. Amyloid fibers are made of distorted RepA-WH1 monomers that assemble as single or double intertwined tubular protofilaments. RepA-WH1 causes in E. coli an amyloid proteinopathy, which is transmissible from mother to daughter cells, but not infectious, and enables conformational imprinting in vitro and in vivo; i.e. RepA-WH1 is a ‘prionoid’. Microfluidics allow the assessment of the intracellular dynamics of RepA-WH1: bacterial lineages maintain two types (strains-like) of RepA-WH1 amyloids, either multiple compact cytotoxic particles or a single aggregate with the appearance of a fluidized hydrogel that it is mildly detrimental to growth. The Hsp70 chaperone DnaK governs the phase transition between both types of RepA-WH1 aggregates in vivo, thus modulating the vertical propagation of the prionoid. Engineering chimeras between the Sup35p/[PSI*] prion and RepA-WH1 generates [REP-PSI*], a synthetic prion exhibiting strong and weak phenotypic variants in yeast. These recent findings on a synthetic, self-contained bacterial prionoid illuminate central issues of protein amyloidogenesis.Research on RepA-WH1 amyloids at CIBCSIC is currently financed by Spanish MINECO grants BIO2012-30852 and CSD2009-00088.Peer reviewe

La Acción Tutorial en la Facultad de Económicas: perspectivas presentes y futuras

El Programa de Acción Tutorial de Económicas, conocido coloquialmente como PATEC, cumple su novena edición en el presente curso académico 2013-2014. Desde sus inicios el PATEC se ha adaptado a las distintas titulaciones adscritas al Centro gracias a su gran flexibilidad, aspecto fundamental si tenemos en cuenta el tamaño y la heterogeneidad de nuestro Centro y las diferentes características de nuestros estudiantes. El objetivo de esta comunicación es dar a conocer el PATEC, sus objetivos, características y datos más relevantes, así como analizar su evolución lo que nos permitirá obtener una radiografía completa del Programa. Teniendo en cuenta las dificultades encontradas en la implementación del Programa en sus distintas ediciones trataremos de abordar planteamientos alternativos entre los que se encuentra la creación de una Red de Tutores que persigue optimizar la labor tutorial y facilitar el trabajo de futuros tutores. Asimismo, se expondrán diferentes experiencias innovadoras llevadas a cabo con el objetivo de incrementar la participación del alumnado

Robust ASR using Support Vector Machines

The improved theoretical properties of Support Vector Machines with respect to other machine learning alternatives due to their max-margin training paradigm have led us to suggest them as a good technique for robust speech recognition. However, important shortcomings have had to be circumvented, the most important being the normalisation of the time duration of different realisations of the acoustic speech units. In this paper, we have compared two approaches in noisy environments: first, a hybrid HMM–SVM solution where a fixed number of frames is selected by means of an HMM segmentation and second, a normalisation kernel called Dynamic Time Alignment Kernel (DTAK) first introduced in Shimodaira et al. [Shimodaira, H., Noma, K., Nakai, M., Sagayama, S., 2001. Support vector machine with dynamic time-alignment kernel for speech recognition. In: Proc. Eurospeech, Aalborg, Denmark, pp. 1841–1844] and based on DTW (Dynamic Time Warping). Special attention has been paid to the adaptation of both alternatives to noisy environments, comparing two types of parameterisations and performing suitable feature normalisation operations. The results show that the DTA Kernel provides important advantages over the baseline HMM system in medium to bad noise conditions, also outperforming the results of the hybrid system.Publicad

Altered pathways in methylome and transcriptome longitudinal analysis of normal weight and bariatric surgery women

[Abstract] DNA methylation could provide a link between environmental, genetic factors and weight control and can modify gene expression pattern. This study aimed to identify genes, which are differentially expressed and methylated depending on adiposity state by evaluating normal weight women and obese women before and after bariatric surgery (BS). We enrolled 24 normal weight (BMI: 22.5 ± 1.6 kg/m2) and 24 obese women (BMI: 43.3 ± 5.7 kg/m2) submitted to BS. Genome-wide methylation analysis was conducted using Infinium Human Methylation 450 BeadChip (threshold for significant CpG sites based on delta methylation level with a minimum value of 5%, a false discovery rate correction (FDR) of q < 0.05 was applied). Expression levels were measured using HumanHT-12v4 Expression BeadChip (cutoff of p ≤ 0.05 and fold change ≥2.0 was used to detect differentially expressed probes). The integrative analysis of both array data identified four genes (i.e. TPP2, PSMG6, ARL6IP1 and FAM49B) with higher methylation and lower expression level in pre-surgery women compared to normal weight women: and two genes (i.e. ZFP36L1 and USP32) that were differentially methylated after BS. These methylation changes were in promoter region and gene body. All genes are related to MAPK cascade, NIK/NF-kappaB signaling, cellular response to insulin stimulus, proteolysis and others. Integrating analysis of DNA methylation and gene expression evidenced that there is a set of genes relevant to obesity that changed after BS. A gene ontology analysis showed that these genes were enriched in biological functions related to adipogenesis, orexigenic, oxidative stress and insulin metabolism pathways. Also, our results suggest that although methylation plays a role in gene silencing, the majority of effects were not correlated.São Paulo Research Foundation; 2017/07220-7São Paulo Research Foundation; #2016/05638-1São Paulo Research Foundation; #2013/12819-4São Paulo Research Foundation; #2015/18669-0Instituto de Salud Carlos III; PI17/01287Ministerio de Economía y Empresa; MTM2014-52876-RMinisterio de Economía y Empresa; MTM2017-82724-RXunta de Galicia; ED431C-2016-015Xunta de Galicia; ED431G/0

Cómo mejorar el PATEC: comparativa de experiencias en universidades públicas españolas

En este curso 2014-2015 se cumplen 10 años del inicio del Programa de Acción Tutorial de la Facultad de Económicas (PATEC). En estos años este programa se ha ido consolidando e incrementando su relevancia en la Facultad y, en especial, a través de su web. Además, este programa se ofrece a todos los alumnos del centro con independencia del curso o la titulación en la que estén matriculados y se diseñan actividades complementarias que contribuyen a la formación integral del alumnado. En este sentido, la experiencia acumulada permite tener una amplia perspectiva para reflexionar sobre cómo debe ser el PATEC en los próximos años. No sólo teniendo en cuenta esta experiencia sino también considerando la organización y funcionamiento de otros programas de acción tutorial que existen en otras universidades españolas. Así, el objetivo de este trabajo es analizar el funcionamiento de programas de acción tutorial implantados en otros centros para identificar las mejores prácticas con el fin de estudiar la posibilidad de introducirlas en el funcionamiento del PATEC. De esta manera podemos reflexionar sobre nuestras prácticas y mejorar la eficiencia del PATEC para ofrecer a todo su alumnado un servicio de calidad adaptado a sus necesidades académicas, profesionales y personales

Oil price volatility and stock returns in the G7 economies

This study examines the relationship between oil price volatility and stock returns in the G7 economies (Canada, France, Germany, Italy, Japan, the UK and the US) using monthly data for the period 1970 to 2014. In order to measure oil volatility we consider alternative specifications for oil prices (world, nominal and real prices). We estimate a vector autoregressive model with the following variables: interest rates, economic activity, stock returns and oil price volatility taking into account the structural break in the year 1986. We find a negative response of G7 stock markets to an increase in oil price volatility. Results also indicate that world oil price volatility is generally more significant for stock markets than the national oil price volatility