Spectral Reconstruction and Noise Model Estimation Based on a Masking Model for Noise Robust Speech Recognition

An effective way to increase noise robustness in automatic speech recognition (ASR) systems is feature enhancement based on an analytical distortion model that describes the effects of noise on the speech features. One of such distortion models that has been reported to achieve a good trade-off between accuracy and simplicity is the masking model. Under this model, speech distortion caused by environmental noise is seen as a spectral mask and, as a result, noisy speech features can be either reliable (speech is not masked by noise) or unreliable (speech is masked). In this paper, we present a detailed overview of this model and its applications to noise robust ASR. Firstly, using the masking model, we derive a spectral reconstruction technique aimed at enhancing the noisy speech features. Two problems must be solved in order to perform spectral reconstruction using the masking model: (1) mask estimation, i.e. determining the reliability of the noisy features, and (2) feature imputation, i.e. estimating speech for the unreliable features. Unlike missing data imputation techniques where the two problems are considered as independent, our technique jointly addresses them by exploiting a priori knowledge of the speech and noise sources in the form of a statistical model. Secondly, we propose an algorithm for estimating the noise model required by the feature enhancement technique. The proposed algorithm fits a Gaussian mixture model to the noise by iteratively maximising the likelihood of the noisy speech signal so that noise can be estimated even during speech-dominating frames. A comprehensive set of experiments carried out on the Aurora-2 and Aurora-4 databases shows that the proposed method achieves significant improvements over the baseline system and other similar missing data imputation techniques

Audiovisual translation tools for the assessment of hard of hearing students

The Spanish University requires all its students to reach a specific level in a foreign language, as part of the requisites to obtain their degrees. At present, there is a lack of homogeneity in the criteria set for the assessment of hard of hearing students¿ skills. A preliminary survey reveals the current measures applied in a number of Spanish universities. Our suggestion is that a uniform listening test should be implemented for hard of hearing students. The main goal of our research was to check what kind of test is more adequate for these students. For that purpose, several hard of hearing students did different listening activities using audiovisual materials that had been previously edited and adapted to their special needs. They also responded to different question tasks: multiple-choice, true/false, gap-filling. The results throw some light on the type of test format that should be used with the hard of hearing community. La universidad española exige a sus graduados la obtención de un nivel específico en lengua extranjera. En la actualidad los criterios aplicados en la evaluación de las destrezas lingüísticas de estudiantes con discapacidad auditiva no son homogéneos. Una encuesta preliminar muestra la actuación al respecto de un buen número de universidades. Nuestra sugerencia es que debería aplicarse el mismo tipo de prueba de comprensión oral a este grupo de estudiantes. El principal objetivo de nuestra investigación era comprobar qué tipo de prueba es más adecuada para ellos. A tal fin varios estudiantes con discapacidad auditiva hicieron pruebas de comprensión oral con materiales audiovisuales previamente editados y adaptados a sus necesidades. Los tests presentaban asimismo varios formatos: opción múltiple, verdadero/falso y relleno de espacios. Los resultados indican qué tipo de formato y materiales resultarían más adecuados para la evaluación de este grupo de alumnos

Human metapneumovirus: Mechanisms and molecular targets used by the virus to avoid the immune system

Indexación: Scopus.This work was supported by Comisión Nacional de Investigación Científica y Tecnolígica (CONICYT) N◦21151028 and FONDECYT (N◦1070352 and N◦1170964) and the Millennium Institute on Immunology and Immunotherapy (P09/016-F).Human metapneumovirus (hMPV) is a respiratory virus, first reported the year 2001. Since then, it has been described as one of the main etiological agents that causes acute lower respiratory tract infections (ALRTIs), which is characterized by symptoms such as bronchiolitis, wheezing and coughing. Susceptible population to hMPV-infection includes newborn, children, elderly and immunocompromised individuals. This viral agent is a negative-sense, single-stranded RNA enveloped virus, that belongs to the Pneumoviridae family and Metapneumovirus genus. Early reports-previous to 2001-state several cases of respiratory illness without clear identification of the responsible pathogen, which could be related to hMPV. Despite the similarities of hMPV with several other viruses, such as the human respiratory syncytial virus or influenza virus, mechanisms used by hMPV to avoid the host immune system are still unclear. In fact, evidence indicates that hMPV induces a poor innate immune response, thereby affecting the adaptive immunity. Among these mechanisms, is the promotion of an anergic state in T cells, instead of an effective polarization or activation, which could be induced by low levels of cytokine secretion. Further, the evidences support the notion that hMPV interferes with several pattern recognition receptors (PRRs) and cell signaling pathways triggered by interferon-associated genes. However, these mechanisms reported in hMPV are not like the ones reported for hRSV, as the latter has two non-structural proteins that are able to inhibit these pathways. Several reports suggest that viral glycoproteins, such as G and SH, could play immune-modulator roles during infection. In this work, we discuss the state of the art regarding the mechanisms that underlie the poor immunity elicited by hMPV. Importantly, these mechanisms will be compared with those elicited by other common respiratory viruses. © 2018 Frontiers Media S.A. All rights reserved.https://www.frontiersin.org/articles/10.3389/fimmu.2018.02466/ful

Isotopic labelling reveals the efficient adaptation of wheat root TCA cycle flux modes to match carbon demand under ammonium nutrition

Proper carbon (C) supply is essential for nitrogen (N) assimilation especially when plants are grown under ammonium (NH4+) nutrition. However, how C and N metabolic fluxes adapt to achieve so remains uncertain. In this work, roots of wheat (Triticum aestivum L.) plants grown under exclusive NH4+ or nitrate (NO3−) supply were incubated with isotope-labelled substrates (15NH4+, 15NO3−, or [13C]Pyruvate) to follow the incorporation of 15N or 13C into amino acids and organic acids. Roots of plants adapted to ammonium nutrition presented higher capacity to incorporate both 15NH4+ and 15NO3− into amino acids, thanks to the previous induction of the NH4+ assimilative machinery. The 15N label was firstly incorporated into [15N]Gln vía glutamine synthetase; ultimately leading to [15N]Asn accumulation as an optimal NH4+ storage. The provision of [13C]Pyruvate led to [13C]Citrate and [13C]Malate accumulation and to rapid [13C]2-OG consumption for amino acid synthesis and highlighted the importance of the anaplerotic routes associated to tricarboxylic acid (TCA) cycle. Taken together, our results indicate that root adaptation to ammonium nutrition allowed efficient assimilation of N thanks to the promotion of TCA cycle open flux modes in order to sustain C skeleton availability for effective NH4+ detoxification into amino acids

Non-Finite Dimensional Closed Vector Spaces of Universal Functions for Composition Operators

AbstractLet H(Ω) be the space of analytic functions on a complex region Ω, which is not the punctured plane. In this paper, we prove that if a sequence of automorphisms {φn}n ≥ 0 of Ω has the property that for every compact subset K ⊂ Ω there is a positive integer n such that K ∩ φn(K) = 0, then there exists an infinite dimensional closed vector subspace F ⊂ H(Ω) such that for all f ∈ F\{0} the orbit (f ∘ φn)n ≥ 0 is dense in H(Ω). The corresponding result for the punctured plane is somewhat different and is also studied

Effects of foliar versus soil water application on ecophysiology, leaf anatomy and growth of pineapple

In the subtropics, pineapple [Ananas comosus (L.) Merr.] can be grown in plastic greenhouses to avoid low temperature, which is the main limiting factor to production outside of the tropics. Foliar water application and subsequent evaporative cooling can help avoid excessive leaf temperatures in greenhouses during the hot seasons. The effects of foliar versus soil irrigation on ecophysiology, leaf anatomy and leaf temperature of pineapple in protected culture were tested to determine if the crop could receive sufficient irrigation to avoid plant stress solely from misting the foliage. Materials and methods - Relative water content, relative chlorophyll content, normalized difference vegetation index, membrane stability, and cross sectional leaf anatomy were measured at periodic intervals. Pineapple plants were subjected to soil irrigation, misting and drought. At the beginning and at the end of the experiment, total leaf area, plant biomass and assimilate partitioning to leaves, stems and roots were measured. Results and discussion - The normalized difference vegetation index revealed differences among treatments after fifteen days without irrigation. Pineapple plants endured thirty days of water stress without membrane damage. Plants irrigated by applying water only to the leaves did not receive adequate water amounts and showed similar signs of drought stress as those of the non-irrigated treatment. Conclusion - Based on ecophysiological, anatomical and growth responses, soil water application alone is sufficient for avoiding water stress and excessively high leaf temperatures of pineapple plants grown in protected culture in the subtropics, whereas only misting the leaves does not provide adequate water supply to prevent water stress.Fil: Demarco, Paula. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Departamento de Produccion Vegetal.; ArgentinaFil: Gómez Herrera, Melanie Desirée. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Gonzalez, A.M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Alayón Luaces, Paula. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Departamento de Produccion Vegetal.; Argentin

Goodness-of-Fit Tests to study the Gaussianity of the MAXIMA data

Goodness-of-Fit tests, including Smooth ones, are introduced and applied to detect non-Gaussianity in Cosmic Microwave Background simulations. We study the power of three different tests: the Shapiro-Francia test (1972), the uncategorised smooth test developed by Rayner and Best(1990) and the Neyman's Smooth Goodness-of-fit test for composite hypotheses (Thomas and Pierce 1979). The Smooth Goodness-of-Fit tests are designed to be sensitive to the presence of ``smooth'' deviations from a given distribution. We study the power of these tests based on the discrimination between Gaussian and non-Gaussian simulations. Non-Gaussian cases are simulated using the Edgeworth expansion and assuming pixel-to-pixel independence. Results show these tests behave similarly and are more powerful than tests directly based on cumulants of order 3, 4, 5 and 6. We have applied these tests to the released MAXIMA data. The applied tests are built to be powerful against detecting deviations from univariate Gaussianity. The Cholesky matrix corresponding to signal (based on an assumed cosmological model) plus noise is used to decorrelate the observations previous to the analysis. Results indicate that the MAXIMA data are compatible with Gaussianity.Comment: MNRAS, in pres

Water requirements and footprint of a super intensive olive grove under Mediterranean climate

Abstract The water footprint of a product can be described as the volume of freshwater used to produce it, associated to a geographic and temporal resolution. For crops, the water footprint relates crop water requirements and yield. The components of water footprint, blue, green and grey water footprints, refer to the volumes of respectively, surface and groundwater, rainfall, and water required to assimilate pollution, used to produce the crop yield. The global standard for crop water footprint assessment relies on evapotranspiration models to estimate green and blue water evapotranspiration. This approach has been used in the present study to estimate the water footprint of a very high density drip irrigated olive grove and further compared with data obtained from evapotranspiration measurements or from its components: the eddy covariance method to quantify latent heat flux, a heat dissipation sap flow technique to determine transpiration and microlysimeters to evaluate soil evaporation. The eddy covariance technique was used for short periods in 2011 and 2012, while sap flow measurements were performed continuously, hence allowing the extension of the data series. Measurements of evapotranspiration with the eddy covariance method provided an average close to 3.4 mm d-1 (2011) and 2.5 mm d-1 (2012). The ratio of evapotranspiration to reference evapotranspiration approached 0.6 and 0.4 for the respective periods. The water footprint of the olive crop under study, calculated with field data, was higher than the water footprint simulated using the global standard assessment and was lower than that reported in literature for olives. Lower values are probably related to differences in cultural practices, e.g., the density of plantation, harvesting techniques and irrigation management. The irrigated high-density olive grove under study had a high yield, which compensates for high water consumption, thus leading to a water footprint lower than the ones of rainfed or less dense groves. Other differences may relate to the procedures used to determine evapotranspiration

Genetic determinants of breast cancer

Breast cancer is the most common malignancy in women in the Western world and it is estimated that women who survive to the age of 85 years will have a 1 in 9 lifetime probability of developing this type of neoplasia (1, 2). The degree of risk is not spread homogeneously across the general population (2). The vast majority of risk factors associated to breast cancer susceptibility are related to hormonal exposure, either from endogenous sources such as early age at menarche, late age at menopause, late pregnancy or nullliparity, overweight and obesity, or exogenous sources such as the use of hormone replacement therapy (HRT) (3). Other risk factors include alcohol intake, radiation exposure, current age, past history of breast cancer and the history of a breast biopsy (2). Additionally, a recent study has shown that the risk of breast cancer is increased by 3% per pack/year of cigarette smoking when it is done between menarche and first childbirth (4)

Repensando los derechos constitucionales de la persona jurídica a la luz del Obamacare

La titularidad de la libertad religiosa para las corporaciones con ánimo de lucro fue el tema central discutido en el emblemático caso de la Corte Suprema de Estados Unidos Burwell v. Hobby Lobby. En un ajustado fallo de cinco votos contra cuatro, la opinión mayoritaria dictaminó la transgresión de los derechos de la primera enmienda de tres corporaciones closely held, en razón de la imposición del mandato contraceptivo, obligación impuesta en el Obamacare. Este artículo explica el contexto del caso, con especial mención a los fundamentos de la figura de la corporación en Estados Unidos, el reconocimiento de los derechos fundamentales para personas jurídicas, la posibilidad o no de ejercer la libertad religiosa y las particularidades del sistema de seguridad social estadounidense. Recoge los principales argumentos y hechos del caso, así como el análisis de sus implicaciones.The corporations as right-holders of freedoom of religion was the main topic discussed in the emblematic case of the Supreme Court of the United States Burwell v. Hobby Lobby. In a tight ruling five to four votes, the majority opinion founds the transgression of the I Amendment rights to three closely held corporations due to the imposition of the contraceptive mandate contained in Obamacare. This article explains the context of the case delving into the evolution of the figure of the corporation in the United States, the recognition of the fundamental rights for legal entities and the peculiarities of the American healthcare system. Also summarizes the main arguments and facts of the case and the analysis of its implication