67 research outputs found

    Uso de microhábitats, actividad diaria y dieta de Dendrobates truncatus (cope, 1861) (Anura: Dendrobatidae) en bosque seco tropical del norte de Colombia

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    The use of microhabitats, daily activity and diet of three populations of Dendrobates truncatus in the tropical dry lowland forest of the Colombian Caribbean, using the method of visual and manual capture meeting was studied. The study was conducted between March and November, during the three climatic periods: dry, minor and higher rains. Seven microhabitats used were identified and sampled, the activity was measured using the relative number of individuals/hour in four hours daily, stomach contents of anurans were examined and percentage analysis method was applied. D. truncatus has increased activity in the morning (8:00 to 10:00) and late afternoon (16:00 to 18:00) and uses seven types of microhabitats, preferably forest cover and higher humidity. This species presents preference for the consumption of ants especially the family Myrmicinae and the genus Pheidole. These results suggest that the conservation of tropical dry forest relicts and developing rehabilitation strategies for it constitute fundamental elements for the survival of this species.Se estudió el uso de microhábitats, actividad diaria y dieta de tres poblaciones de Dendrobates truncatus en el bosque seco tropical de tierras bajas del Caribe colombiano, mediante la utilización del método de encuentro visual y captura manual. El estudio se realizó entre los meses de marzo y noviembre, durante los tres períodos climáticos del año: seco, lluvias menores y lluvias mayores. Se identificaron y muestrearon siete microhábitats usados por esta especie, la actividad se midió a través de la relación número de individuos/hora en cuatro horarios diarios. Se examinaron los contenidos estomacales de los anuros y se aplicó el método de análisis porcentual. D. truncatus presenta mayor actividad en la mañana (8:00 – 10:00) y final de la tarde (16:00 – 18:00) y usa siete tipos de microhábitats, preferentemente los de cobertura boscosa y con altos valores de humedad. Presenta preferencia marcada por el consumo de hormigas, especialmente la familia Myrmicinae y el género Pheidole. Estos resultados sugieren que la conservación de relictos de bosque seco tropical y el desarrollo de estrategias de rehabilitación del mismo se constituyen en elementos fundamentales para la supervivencia de esta especie

    Robust ASR using Support Vector Machines

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    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

    Using radio astronomical receivers for molecular spectroscopic characterization in astrochemical laboratory simulations: A proof of concept

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    We present a proof of concept on the coupling of radio astronomical receivers and spectrometers with chemical reactorsand the performances of the resulting setup for spectroscopy and chemical simulations in laboratory astrophysics. Several experiments including cold plasma generation and UV photochemistry were performed in a 40\,cm long gas cell placed in the beam path of the Aries 40\,m radio telescope receivers operating in the 41-49 GHz frequency range interfaced with fast Fourier transform spectrometers providing 2 GHz bandwidth and 38 kHz resolution. The impedance matching of the cell windows has been studied using different materials. The choice of the material and its thickness was critical to obtain a sensitivity identical to that of standard radio astronomical observations. Spectroscopic signals arising from very low partial pressures of CH3OH, CH3CH2OH, HCOOH, OCS,CS, SO2 (<1E-03 mbar) were detected in a few seconds. Fast data acquisition was achieved allowing for kinetic measurements in fragmentation experiments using electron impact or UV irradiation. Time evolution of chemical reactions involving OCS, O2 and CS2 was also observed demonstrating that reactive species, such as CS, can be maintained with high abundance in the gas phase during these experiments.Comment: Accepted for publication in Astronomy and Astrophysics in September 21, 2017. 16 pages, 18 figure

    Auditory-inspired morphological processing of speech spectrograms: applications in automatic speech recognition and speech enhancement

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    New auditory-inspired speech processing methods are presented in this paper, combining spectral subtraction and two-dimensional non-linear filtering techniques originally conceived for image processing purposes. In particular, mathematical morphology operations, like erosion and dilation, are applied to noisy speech spectrograms using specifically designed structuring elements inspired in the masking properties of the human auditory system. This is effectively complemented with a pre-processing stage including the conventional spectral subtraction procedure and auditory filterbanks. These methods were tested in both speech enhancement and automatic speech recognition tasks. For the first, time-frequency anisotropic structuring elements over grey-scale spectrograms were found to provide a better perceptual quality than isotropic ones, revealing themselves as more appropriate—under a number of perceptual quality estimation measures and several signal-to-noise ratios on the Aurora database—for retaining the structure of speech while removing background noise. For the second, the combination of Spectral Subtraction and auditory-inspired Morphological Filtering was found to improve recognition rates in a noise-contaminated version of the Isolet database.This work has been partially supported by the Spanish Ministry of Science and Innovation CICYT Project No. TEC2008-06382/TEC.Publicad

    The QUIJOTE experiment: project overview and first results

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    QUIJOTE (Q-U-I JOint TEnerife) is a new polarimeter aimed to characterize the polarization of the Cosmic Microwave Background and other Galactic and extragalactic signals at medium and large angular scales in the frequency range 10-40 GHz. The multi-frequency (10-20~GHz) instrument, mounted on the first QUIJOTE telescope, saw first light on November 2012 from the Teide Observatory (2400~m a.s.l). During 2014 the second telescope has been installed at this observatory. A second instrument at 30~GHz will be ready for commissioning at this telescope during summer 2015, and a third additional instrument at 40~GHz is now being developed. These instruments will have nominal sensitivities to detect the B-mode polarization due to the primordial gravitational-wave component if the tensor-to-scalar ratio is larger than r=0.05.Comment: To appear in "Highlights of Spanish Astrophysics VIII", Proceedings of the XI Scientific Meeting of the Spanish Astronomical Society, Teruel, Spain (2014

    Broad-band high-resolution rotational spectroscopy for laboratory astrophysics

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    We present a new experimental set-up devoted to the study of gas phase molecules and processes using broad-band high spectral resolution rotational spectroscopy. A reactor chamber is equipped with radio receivers similar to those used by radio astronomers to search for molecular emission in space. The whole range of the Q (31.5-50 GHz) and W bands (72-116.5 GHz) is available for rotational spectroscopy observations. The receivers are equipped with 16 × 2.5 GHz fast Fourier transform spectrometers with a spectral resolution of 38.14 kHz allowing the simultaneous observation of the complete Q band and one-third of the W band. The whole W band can be observed in three settings in which the Q band is always observed. Species such as CH3CN, OCS, and SO2 are detected, together with many of their isotopologues and vibrationally excited states, in very short observing times. The system permits automatic overnight observations, and integration times as long as 2.4 × 105 s have been reached. The chamber is equipped with a radiofrequency source to produce cold plasmas, and with four ultraviolet lamps to study photochemical processes. Plasmas of CH4, N2, CH3CN, NH3, O2, and H2, among other species, have been generated and the molecular products easily identified by the rotational spectrum, and via mass spectrometry and optical spectroscopy. Finally, the rotational spectrum of the lowest energy conformer of CH3CH2NHCHO (N-ethylformamide), a molecule previously characterized in microwave rotational spectroscopy, has been measured up to 116.5 GHz, allowing the accurate determination of its rotational and distortion constants and its search in space.We thank the European Research Council for funding support under Synergy Grant ERC-2013-SyG, G.A. 610256 (NANOCOSMOS). IT, VJH, and JLD acknowledge additional partial support from the Spanish State Research Agency (AEI) through grant FIS2016-77726-C3-1-P. JAMG, LM, and GS acknowledge additional partial support from the Spanish State Research Agency (AEI) through grant MAT2017-85089-C2-1R. We thank David López Romero for his help during the process of installation, commissioning, and cleaning of the chamber. We would like to thank Kremena Makasheva for the useful comments and suggestions during the experiments with Hexamethyldisiloxane. We would also like to thank Rosa Lebrón, Jesús Quintanilla, and Cristina Soria for providing us with the sample of N-ethylformamide. Sandra I. Ramírez acknowledges support from the FONCICYT under grant number 291842. Celina Bermúdez thanks the Spanish Ministerio de Ciencia Innovación y Universidades for the Juan de la Cierva grant FJCI-2016-27983

    Nutrición enteral domiciliaria en España: registro Nadya del año 2011-2012

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    Objective: To describe the results of the home enteral nutrition (HEN) registry of the NADYA-SENPE group in 2011 and 2012. Material and methods: We retrieved the data of the patients recorded from January 1st 2011 to December 31st 2012. Results: There were 3021 patients in the registry during the period from 29 hospitals, which gives 65.39 per million inhabitants. 97.95% were adults, 51.4% male. Mean age was 67.64 ± 19.1, median age was 72 years for adults and 7 months for children. Median duration with HEN was 351 days and for 97.5% was their first event with HEN. Most patients had HEN because of neurological disease (57.8%). Access route was nasogastric tube for 43.5% and gastrostomy for 33.5%. Most patients had limited activity level and, concerning autonomy, 54.8% needed total help. Nutritional formula was supplied from chemist’s office to 73.8% of patients and disposables, when necessary, was supplied from hospitals to 53.8% of patients. HEN was finished for 1,031 patients (34.1%) during the period of study, 56.6% due to decease and 22.2% due to recovery of oral intake. Conclusions: Data from NADYA-SENPE registry must be explained cautiously because it is a non-compulsory registry. In spite of the change in the methodology of the registry in 2010, tendencies regarding HEN have been maintained, other than oral routeObjetivos: Describir los resultados del registro de nutrición enteral domiciliaria (NED) del grupo NADYASENPE de los años 2011 y 12. Material y métodos: Se recopilaron los datos introducidos en el registro desde el 1 de enero de 2011 al 31 de diciembre de 2012. Resultados: Hubo 3021 pacientes en el registro durante el periodo, procedentes de 29 hospitales, lo que da una prevalencia de 65,39 casos por millón de habitantes. 97.95% fueron adultos, 51,4% varones. La edad media fue 67,64 ± 19,1 años y la mediana 72 años para los adultos y 7 meses para los niños. La duración media de la NED fue 351 días y para el 97,5% fue el primer episodio con NED. La mayoría de pacientes tenían NED por una enfermedad neurológica (57,8%). La vía de acceso fue sonda nasogástrica para el 43,5% y gastrostomía para el 33,5%. La mayoría de pacientes tuvieron un nivel de actividad física limitado y, respecto a la autonomía, 54,8% necesitaba ayuda total. La fórmula de nutrición se suministró desde las oficinas de farmacia para el 73,8% y los fungibles, cuando fueron necesarios, desde los hospitales para el 53,8%. La NED se suspendió en 1.031 pacientes (34,1%) durante el periodo de estudio, 56,6% debido a fallecimiento y 22,2% debido a recuperación de la vía oral. Conclusiones: Los datos del registro NADYA-SENPE deben ser interpretados con precaución ya que se trata de un registro voluntario. A pesar del cambio de metodología del registro en 2010, las tendencias en NED se han mantenido, salvo la importancia cuantitativa de la vía ora

    QUIJOTE-CMB experiment: a technical overview

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    The QUIJOTE-CMB experiment (Q-U-I JOint TEnerife CMB experiment) is an ambitious project to obtain polarization measurements of the sky microwave emission in the 10 to 47 GHz range. With this aim, a pair of 2,5m telescopes and three instruments are being sited at the Teide Observatory, in Tenerife (Canary Islands, Spain). The first telescope and the first instrument (the MFI: Multi Frequency Instrument) are both already operating in the band from 10 to 20 GHz, since November 2012. The second telescope and the second instrument (TGI: Thirty GHz instrument) is planned to be in commissioning by the end of summer 2014, covering the range of 26 to 36 GHz. After that, a third instrument named FGI (Forty GHz instrument) will be designed and manufactured to complete the sky survey in the frequency range from 37 to 47 GHz. In this paper we present an overview of the whole project current status, from the technical point of view

    Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

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    Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population
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