96 research outputs found
Spanish statistical parametric speech synthesis using a neural vocoder
During the 2000s decade, unit-selection based text-to-speech was the dominant commercial technology. Meanwhile, the TTS research community has made a big effort to push statistical-parametric speech synthesis to get similar quality and more flexibility on the synthetically generated voice. During last years, deep learning advances applied to speech synthesis have filled the gap, specially when neural vocoders substitute traditional signal-processing based vocoders. In this paper we propose to substitute the waveform generation vocoder of MUSA, our Spanish TTS, with SampleRNN, a neural vocoder which was recently proposed as a deep autoregressive raw waveform generation model. MUSA uses recurrent neural networks to predict vocoder parameters (MFCC and logF0) from linguistic features. Then, the Ahocoder vocoder is used to recover the speech waveform out of the predicted parameters. In the first system SampleRNN is extended to generate speech conditioned on the Ahocoder generated parameters (mfcc and logF0), where two configurations have been considered to train the system. First, the parameters derived from the signal using Ahocoder are used. Secondly, the system is trained with the parameters predicted by MUSA, where SampleRNN and MUSA are jointly optimized. The subjective evaluation shows that the second system outperforms both the original Ahocoder and SampleRNN as an independent neural vocoder.Peer ReviewedPostprint (published version
Stress-energy tensor in the Bel-Szekeres space-time
In a recent work an approximation procedure was introduced to calculate the
vacuum expectation value of the stress-energy tensor for a conformal massless
scalar field in the classical background determined by a particular colliding
plane wave space-time. This approximation procedure consists in appropriately
modifying the space-time geometry throughout the causal past of the collision
center. This modification in the geometry allows to simplify the boundary
conditions involved in the calculation of the Hadamard function for the quantum
state which represents the vacuum in the flat region before the arrival of the
waves. In the present work this approximation procedure is applied to the
non-singular Bel-Szekeres solution, which describes the head on collision of
two electromagnetic plane waves. It is shown that the stress-energy tensor is
unbounded as the killing-Cauchy horizon of the interaction is approached and
its behavior coincides with a previous calculation in another example of
non-singular colliding plane wave space-time.Comment: 17 pages, LaTex file, 2 PostScript figure
Particle creation in a colliding plane wave spacetime: wave packet quantization
We use wave packet mode quantization to compute the creation of massless
scalar quantum particles in a colliding plane wave spacetime. The background
spacetime represents the collision of two gravitational shock waves followed by
trailing gravitational radiation which focus into a Killing-Cauchy horizon. The
use of wave packet modes simplifies the problem of mode propagation through the
different spacetime regions which was previously studied with the use of
monocromatic modes. It is found that the number of particles created in a given
wave packet mode has a thermal spectrum with a temperature which is inversely
proportional to the focusing time of the plane waves and which depends on the
mode trajectory.Comment: 23, latex, figures available by fa
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The importance of including soil carbon changes, ecotoxicity and biodiversity impacts in environmental life cycle assessments of organic and conventional milk in Western Europe
Estimates of soil carbon changes, biodiversity and ecotoxicity have often been missing from life cycle assessment based studies of organic dairy products, despite evidence that the impacts of organic and conventional management may differ greatly within these areas. The aim of the present work was therefore to investigate the magnitude of including these impact categories within a comprehensive environmental impact assessment of organic and conventional dairy systems differing in basic production conditions. Three basic systems representative of a range of European approaches to dairy production were selected for the analysis, i.e. (i) low-land mixed crop-livestock systems, (ii) lowland grassland-based systems, (iii) and mountainous systems. As in previous publications, this study showed that when assessing climate change, eutrophication and acidification impact organic milk has similar or slightly lower impact than conventional, although land-use is higher under organic management. Including soil carbon changes reduced the global warming potential by 5â18%, mostly in organic systems with a high share of grass in the ration. The impacts of organic milk production on freshwater ecotoxicity, biodiversity and resource depletion were 2, 33 and 20% of the impacts of conventional management, respectively, across the basic systems considered. The study highlights the importance of including biodiversity, ecotoxicity and soil carbon changes in life cycle assessments when comparing organic and conventional agricultural products. Furthermore, the study shows that including more grass in the ration of dairy cows increases soil carbon sequestration and decreases the negative impact on biodiversity.info:eu-repo/semantics/acceptedVersio
Addition of hyaluronic acid improves tlerance to 7% hypertonic saline solution in bronchiectasis patients.
Background: The excessive retention of sputum in the airways, leading to pulmonary infections, is a common consequence of bronchiectasis. Although inhalation of 7% hypertonic saline (HS) has proven an effective method to help remove the mucus, many patients are intolerant of this treatment. The addition of 0.1% hyaluronic acid to HS (HS+HA) could increase tolerance to HS in these patients. The main objective of this study was to evaluate the tolerability of HS+HA in bronchiectasis patients who are intolerant to HS. Methods: This prospective, observational, open-label study analysed the outcomes of two groups of bronchiectasis patients previously scheduled to start HS therapy. Patients were assessed for tolerance to HS by a questionnaire, spirometry and clinical evaluation. Patients who were intolerant were evaluated for tolerance to HS+HA approximately one week later. All patients were evaluated for their tolerance to HS or HS+HA 4 weeks after the start of their treatment. Patients were also assessed with quality-of-life and adherence questionnaires, and all adverse events were registered. Results: A total of 137 bronchiectasis patients were enrolled in the study (age = 63.0 ± 14.7 years; 63.5% women). Of these, 92 patients (67.1%) were tolerant and 45 patients (32.9%) were intolerant to HS. Of the 45 patients intolerant to HS, 31 patients (68.9%) were tolerant and 14 patients (31.1%) intolerant to HS+HA. Of these 31 tolerant patients, 26 (83.9%) could complete the 4-week treatment with HS+HA. Conclusions: Two-thirds of bronchiectasis patients that presented intolerance to inhaled HS alone are tolerant to inhaled HS+HA, suggesting that HA improves tolerance to HS therapy
Incidence and molecular typing of Mycobacterium kansasii in a defined geographical area in Catalonia, Spain
A retrospective population-based study was conducted between January 1990 and December 1998 to investigate the incidence of Mycobacterium kansasii disease and the heterogeneity of the isolates in a well-defined geographical area in Catalonia, Spain. A total of 136 patients were identified. Overall incidence and incidence in AIDS patients was 1. 5 (95% CI 1.2-1.8) and 1089.6 (95% CI 689-1330) cases/100 000 persons per year respectively, which is comparable to that reported from most of other geographical areas. Surprisingly, although 7 subtypes of M. kansasii have been consistently reported, in the present study 91 of the 93 isolates (97.8%) tested for genotype were subtype I, regardless of HIV status of the patients. In conclusion, the high rate of infection observed in the AIDS population contributes significantly to the burden of the M. kansasii disease in our area. M. kansasii disease in our geographical area was almost exclusively caused by subtype I regardless of HIV status
Press hardening of alternative materials: conventional high- strength steels
he increase in strength of new high strength steels(HHS) and advanced high strength steels (AHHS) has led toforming issues, such as high springback, low formability, increase of forming forces and tool wear. These problems increase thecosts of manufacturing and maintainingstamping tools in the automotive industry. The aim of this research was to analyse the advantages of applyingthe press-hardening process toconventional HSS and AHSS steel to increase their formability and therefore reduce thenumber of forming steps and productioncosts. With this aimin mind, the press-hardening process was used to manufacturean industrialcomponent using four different automotive steelgrades: dual phase (DP),complex phase (CP), transformation-induced plasticity (TRIP) and martensitic (MS) grade.Springback measurements werecarried out, together with ananalysis of the obtained final mechanical properties and microstructures. The results showed that the formability of all thematerials increased. The mechanical properties of theCP800and TRIP700 materials were maintained or even improved, whereas those of the MS1200 and HCT980Xmaterials were significantly reduced. Weconclude thatpress hardening is a suitable manufacturing processforCP800 and TRIP700components
Braneworld Tensor Anisotropies in the CMB
Cosmic microwave background (CMB) observations provide in principle a
high-precision test of models which are motivated by M theory. We set out the
framework of a program to compute the tensor anisotropies in the CMB that are
generated in braneworld models. In the simplest approximation, we show the
braneworld imprint as a correction to the power spectra for standard
temperature and polarization anisotropies.Comment: Minor corrections and references added. Accepted for publication in
Phys. Rev.
Lung Transplant Improves Survival and Quality of Life Regardless of Telomere Dysfunction
Introduction: Fibrotic interstitial lung diseases (ILDs) are the first indication for lung transplantation (LT). Telomere dysfunction has been associated with poor post-transplant outcomes. The aim of the study was to evaluate the morbi-mortality and quality of life in fibrotic ILDs after lung transplant depending on telomere biology. Methods: Fibrotic ILD patients that underwent lung transplant were allocated to two arms; with or without telomere dysfunction at diagnosis based on the telomere length and telomerase related gene mutations revealed by whole-exome sequencing. Post-transplant evaluation included: (1) short and long-term mortality and complications and (2) quality of life. Results: Fifty-five percent of patients that underwent LT carried rare coding mutations in telomerase-related genes. Patients with telomere shortening more frequently needed extracorporeal circulation and presented a higher rate of early post-transplant hematological complications, longer stay in the intensive care unit (ICU), and a higher number of long-term hospital admissions. However, post-transplant 1-year survival was higher than 80% regardless of telomere dysfunction, with improvement in the quality of life and oxygen therapy withdrawal. Conclusions: Post-transplant morbidity is higher in patients with telomere dysfunction and differs according to elapsed time from transplantation. However, lung transplant improves survival and quality of life and the associated complications are manageable
Correlation between in vitro cytotoxicity and in vivo lethal activity in mice of epsilon toxin mutants from Clostridium perfringens
Epsilon toxin (Etx) from Clostridium perfringens is a pore-forming protein with a lethal effect on livestock, producing severe enterotoxemia characterized by general edema and neurological alterations. Site-specific mutations of the toxin are valuable tools to study the cellular and molecular mechanism of the toxin activity. In particular, mutants with paired cysteine substitutions that affect the membrane insertion domain behaved as dominant-negative inhibitors of toxin activity in MDCK cells. We produced similar mutants, together with a well-known non-toxic mutant (Etx-H106P), as green fluorescent protein (GFP) fusion proteins to perform in vivo studies in an acutely intoxicated mouse model. The mutant (GFP-Etx-I51C/A114C) had a lethal effect with generalized edema, and accumulated in the brain parenchyma due to its ability to cross the blood-brain barrier (BBB). In the renal system, this mutant had a cytotoxic effect on distal tubule epithelial cells. The other mutants studied (GFP-Etx-V56C/F118C and GFP-Etx-H106P) did not have a lethal effect or cross the BBB, and failed to induce a cytotoxic effect on renal epithelial cells. These data suggest a direct correlation between the lethal effect of the toxin, with its cytotoxic effect on the kidney distal tubule cells, and the ability to cross the BBB
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