13 research outputs found

    Non-parallel articulatory-to-acoustic conversion using multiview-based time warping

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    In this paper, we propose a novel algorithm called multiview temporal alignment by dependence maximisation in the latent space (TRANSIENCE) for the alignment of time series consisting of sequences of feature vectors with different length and dimensionality of the feature vectors. The proposed algorithm, which is based on the theory of multiview learning, can be seen as an extension of the well-known dynamic time warping (DTW) algorithm but, as mentioned, it allows the sequences to have different dimensionalities. Our algorithm attempts to find an optimal temporal alignment between pairs of nonaligned sequences by first projecting their feature vectors into a common latent space where both views are maximally similar. To do this, powerful, nonlinear deep neural network (DNN) models are employed. Then, the resulting sequences of embedding vectors are aligned using DTW. Finally, the alignment paths obtained in the previous step are applied to the original sequences to align them. In the paper, we explore several variants of the algorithm that mainly differ in the way the DNNs are trained. We evaluated the proposed algorithm on a articulatory-to-acoustic (A2A) synthesis task involving the generation of audible speech from motion data captured from the lips and tongue of healthy speakers using a technique known as permanent magnet articulography (PMA). In this task, our algorithm is applied during the training stage to align pairs of nonaligned speech and PMA recordings that are later used to train DNNs able to synthesis speech from PMA data. Our results show the quality of speech generated in the nonaligned scenario is comparable to that obtained in the parallel scenario

    Retrieval of optical and microphysical properties of transported Saharan dust over Athens and Granada based on multi-wavelength Raman lidar measurements: Study of the mixing processes

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    In this paper we extract the aerosol microphysical properties for a collection of mineral dust cases measured by multi-wavelength depolarization Raman lidar systems located at the National Technical University of Athens (NTUA, Athens, Greece) and the Andalusian Institute for Earth System Research (IISTA-CEAMA, Granada, Spain). The lidar-based retrievals were carried out with the Spheroidal Inversion eXperiments software tool (SphInX) developed at the University of Potsdam (Germany). The software uses regularized inversion of a two-dimensional enhancement of the Mie model based on the spheroid-particle approximation with the aspect ratio determining the particle shape. The selection of the cases was based on the transport time from the source regions to the measuring sites. The aerosol optical depth as measured by AERONET ranged from 0.27 to 0.54 (at 500 nm) depending on the intensity of each event. Our analysis showed the hourly mean particle linear depolarization ratio and particle lidar ratio values at 532 nm ranging from 11 to 34% and from 42 to 79 sr respectively, depending on the mixing status, the corresponding air mass pathways and their transport time. Cases with shorter transport time showed good agreement in terms of the optical and SphInX-retrieved microphysical properties between Athens and Granada providing a complex refractive index value equal to 1.4 + 0.004i. On the other hand, the results for cases with higher transport time deviated from the aforementioned ones as well as from each other, providing, in particular, an imaginary part of the refractive index ranging from 0.002 to 0.005. Reconstructions of two-dimensional shape-size distributions for each selected layer showed that the dominant effective particle shape was prolate with diverse spherical contributions. The retrieved volume concentrations reflect overall the intensity of the episodes.Spanish Ministry of Sciences, Innovation and Universities through project CGL2016-81092,Spanish Ministry of Education, Culture and Sports through grant FPU14/0368

    Spread of a SARS-CoV-2 variant through Europe in the summer of 2020.

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    Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3–5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes. © 2021, The Author(s), under exclusive licence to Springer Nature Limited

    Effect of adding mucilage from Opuntia ficus-indica and Opuntia atropes to raw milk on mesophilic aerobic bacteria and total coliforms

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    Se evaluó la adición de mucílago líquido y deshidratado de Opuntia ficus-indica y Opuntia atropes a la leche cruda sobre el crecimiento de bacterias mesófilas aerobias y coliformes totales. Las muestras de leche cruda de vacas Holstein de un sistema de producción familiar se adicionaron con mucílago líquido o deshidratado de O. ficus-indica u O. atropes en concentraciones de 0.5, 1.0 y 2.0%. En las muestras se midió el crecimiento de bacterias mesófilas aerobias y coliformes totales. Los resultados se analizaron mediante los modelos de efectos fijos y las comparaciones entre grupos se realizaron por el método de medias de mínimo cuadrados. En general, las cuentas bacterianas para mesófilas aerobias y coliformes totales disminuyeron (P < 0,05) cuando se adicionó mucilago a la leche cruda al 0,5%, independientemente de la especie o de la forma física (deshidratado o líquido). Se observó disminución de cuentas bacterias para mesófilas aerobias (P < 0.05) cuando se adicionó mucílago deshidratado de O. ficus indica (Log10 2.6 UFC mL-1) y O. atropes (Log10 2,7 UFC mL-1) en concentración de 0.5%, respectivamente. Mientras que el grupo Control (leche cruda sin adición de mucílago) contenía Log10 3.6 UFC mL-1 de mesófilas aerobias. La mejor respuesta para coliformes totales se observó con el mucílago deshidratado de O. ficus-indica (Log10 3.0 UFC mL-1) y mucílago líquido de O. atropes (Log10 2,7 UFC mL1), ambos adicionados al 1%. El mucílago deshidratado o líquido de O. ficus-indica y O. atropes reducen el contenido microbiano de la leche cruda

    Characterization of Tajogaite volcanic plumes detected over the Iberian Peninsula from a set of satellite and ground-based remote sensing instrumentation

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    International audienceGuadiana-UGR), while in event II this variation was from 11 ± 7 μm 3 cm-3 (Badajoz) to 27 ± 10 μm 3 cm-3 (Guadiana-UGR). Due to the impact of volcanic events on atmospheric and economic fields, such as radiative forcing and airspace security, a proper characterization is required. This work undertakes it using advanced instrumentation and methods

    Nitrogen Assimilation and its Regulation

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