43 research outputs found
Importance of the resonance frequencies of the vocal tract in estimating articulatory positions
La inversión articulatoria, cuyo objetivo es estimar la posición de los órganos articuladores a partir de la
información contenida en la señal de voz, ofrece una variedad de potenciales aplicaciones en el campo de la voz; sin embargo,
este es un problema aún por resolver. En este sentido, buscar representaciones con la capacidad de incrementar el desempeño de
los sistemas de inversión articulatoria es una tarea importante. El presente trabajo analiza la relevancia de los formantes como
entrada para los sistemas de inversión articulatoria. Para ello se implementa un análisis analítico y estadístico. En el caso analítico
se utiliza un sintetizador articulario, el cual simula la ecuación de tubos concatenados que modelan el tracto vocal. Para el análisis
estadístico se estudian datos reales provenientes de un articulógrafo electromagnético para los cuales se estima la asociación entre
las características acústicas y los movimientos de los órganos articuladores. A modo de medida de asociación estadística se utiliza
la medida de información . Los resultados entregados por el análisis son corroborados en un sistema de inversión articulatoria
basado en redes neuronales. Se observa una mejora en el valor de error cuadrático medio del 2,2% y para el caso de la medida de
desempeño de la correlación, una mejora del 2,8%.Acoustic-to-Articulatory inversion, which seeks to estimate an articulator position using the acoustic information
in the speech signal, offers several potential applications in the field of speech processing. In this context, it is important to use
acoustic parameters with the ability to increase the performance of acoustic-to-articulatory inversion systems. This paper analyzes
the importance of formants as inputs to such inversion systems from an analytical and a statistical perspective. The former is
based on an articulatory synthesizer that simulates the voice signal from the vocal tract. The statistical analysis is based on real
data provided by an electromagnetic articulograph, for which we estimate the statistical association between acoustic features and
articulator movement. As a measure of statistical association, the information measure is utilized. The results are tested on a neuralnetwork-
based Acoustic-to-Articulatory inversion system. The use of formants as inputs led to an improvement of 2.2% and 2.8%
in the root-mean-square error and correlation values, respectively
Human candidate gene polymorphisms and risk of severe malaria in children in Kilifi, Kenya: a case-control association study
Background: Human genetic factors are important determinants of malaria risk. We investigated associations between multiple candidate polymorphisms—many related to the structure or function of red blood cells—and risk for severe Plasmodium falciparum malaria and its specific phenotypes, including cerebral malaria, severe malaria anaemia, and respiratory distress. Methods: We did a case-control study in Kilifi County, Kenya. We recruited as cases children presenting with severe malaria to the high-dependency ward of Kilifi County Hospital. We included as controls infants born in the local community between Aug 1, 2006, and Sept 30, 2010, who were part of a genetics study. We tested for associations between a range of candidate malaria-protective genes and risk for severe malaria and its specific phenotypes. We used a permutation approach to account for multiple comparisons between polymorphisms and severe malaria. We judged p values less than 0·005 significant for the primary analysis of the association between candidate genes and severe malaria. Findings: Between June 11, 1995, and June 12, 2008, 2244 children with severe malaria were recruited to the study, and 3949 infants were included as controls. Overall, 263 (12%) of 2244 children with severe malaria died in hospital, including 196 (16%) of 1233 with cerebral malaria. We investigated 121 polymorphisms in 70 candidate severe malaria-associated genes. We found significant associations between risk for severe malaria overall and polymorphisms in 15 genes or locations, of which most were related to red blood cells: ABO, ATP2B4, ARL14, CD40LG, FREM3, INPP4B, G6PD, HBA (both HBA1 and HBA2), HBB, IL10, LPHN2 (also known as ADGRL2), LOC727982, RPS6KL1, CAND1, and GNAS. Combined, these genetic associations accounted for 5·2% of the variance in risk for developing severe malaria among individuals in the general population. We confirmed established associations between severe malaria and sickle-cell trait (odds ratio [OR] 0·15, 95% CI 0·11–0·20; p=2·61 × 10−58), blood group O (0·74, 0·66–0·82; p=6·26 × 10−8), and –α3·7-thalassaemia (0·83, 0·76–0·90; p=2·06 × 10−6). We also found strong associations between overall risk of severe malaria and polymorphisms in both ATP2B4 (OR 0·76, 95% CI 0·63–0·92; p=0·001) and FREM3 (0·64, 0·53–0·79; p=3·18 × 10−14). The association with FREM3 could be accounted for by linkage disequilibrium with a complex structural mutation within the glycophorin gene region (comprising GYPA, GYPB, and GYPE) that encodes for the rare Dantu blood group antigen. Heterozygosity for Dantu was associated with risk for severe malaria (OR 0·57, 95% CI 0·49–0·68; p=3·22 × 10−11), as was homozygosity (0·26, 0·11–0·62; p=0·002). Interpretation: Both ATP2B4 and the Dantu blood group antigen are associated with the structure and function of red blood cells. ATP2B4 codes for plasma membrane calcium-transporting ATPase 4 (the major calcium pump on red blood cells) and the glycophorins are ligands for parasites to invade red blood cells. Future work should aim at uncovering the mechanisms by which these polymorphisms can result in severe malaria protection and investigate the implications of these associations for wider health. Funding: Wellcome Trust, UK Medical Research Council, European Union, and Foundation for the National Institutes of Health as part of the Bill & Melinda Gates Grand Challenges in Global Health Initiative
Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)
Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters.
Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs).
Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001).
Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio
Metabolic phenotyping of opioid and psychostimulant addiction: A novel approach for biomarker discovery and biochemical understanding of the disorder.
Despite the progress in characterising the pharmacological profile of drugs of abuse, their precise biochemical impact remains unclear. The metabolome reflects the multifaceted biochemical processes occurring within a biological system. This includes those encoded in the genome but also those arising from environmental/exogenous exposures and interactions between the two. Using metabolomics, the biochemical derangements associated with substance abuse can be determined as the individual transitions from recreational drug to chronic use (dependence). By understanding the biomolecular perturbations along this time course and how they vary across individuals, metabolomics can elucidate biochemical mechanisms of the addiction cycle (dependence/withdrawal/relapse) and predict prognosis (recovery/relapse). In this review, we summarise human and animal metabolomic studies in the field of opioid and psychostimulant addiction. We highlight the importance of metabolomics as a powerful approach for biomarker discovery and its potential to guide personalised pharmacotherapeutic strategies for addiction targeted towards the individual's metabolome
The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes
Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics
Aplicación del teorema del punto fijo de banach en la resolucion de la ecuacion del pendulo forzado.
In this paper we show a result of existence and uniqueness of solution for the
Forced Pendulum Equation using the Banach�s Fixed Point Theorem.En el presente artículo se muestra un resultado de existencia y unicidad de
solución para la ecuación general del péndulo forzado sin fricción, usando como
herramienta el Teorema del punto fijo de Banach
Aplicación del teorema del punto fijo de Banach en la resolución de la ecuación del péndulo forzado
En el presente artículo se muestra un resultado de existencia y unicidad de solución para la ecuación general del péndulo forzado sin fricción, usando como herramienta el Teorema del punto fijo de Banach.In this paper we show a result of existence and uniqueness of solution for the Forced Pendulum Equation using the Banach¿s Fixed Point Theore
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A source of isotopically light organic carbon in a low-pH anoxic marine zone.
Geochemical and stable isotope measurements in the anoxic marine zone (AMZ) off northern Chile during periods of contrasting oceanographic conditions indicate that microbial processes mediating sulfur and nitrogen cycling exert a significant control on the carbonate chemistry (pH, AT, DIC and pCO2) of this region. Here we show that in 2015, a large isotopic fractionation between DIC and POC, a DIC and N deficit in AMZ waters indicate the predominance of in situ dark carbon fixation by sulfur-driven autotrophic denitrification in addition to anammox. In 2018, however, the fractionation between DIC and POC was significantly lower, while the total alkalinity increased in the low-pH AMZ core, suggesting a predominance of heterotrophic processes. An isotope mass-balance model demonstrates that variations in the rates of sulfur- and nitrogen-mediated carbon fixation in AMZ waters contribute ~7-35% of the POC exported to deeper waters. Thus, dark carbon fixation should be included in assessments of future changes in carbon cycling and carbonate chemistry due to AMZ expansion
Destoxificación de los desechos líquidos agropecuarios usando la foto sensibilización con energía solar
IP 1115-13-199-99v.1 Informe final -- Anexos: Diseño, construccion y optimizacionde un sistema de destoxificacion con luz ultravioleta / Miguel Ayala, Gloria Mejia y Gustavo Peñuela ;Construccionde un sistema destoxificacion con luz ultravioleta en la Universidad de Medellin / Lothar Sanchez,Diego Peña, Margarita Hincapie Y Gustavo Peñuela ; Destoxificacion con luz ultravioleta de los pesticidasmetomil ymalation / Juan Miguel Marin, Diego Peña, Margarita Hincapie y Gustavo Peñuela ; Diseño y construccion de un colector solar para la destoxificacion de aguas / Juan Edison Sanchez, Jaime Valencia,Sergio Agudelo y Gustavo Peñuela ; Destoxificacion con luz solar del pesticida metonil / GinaHincapie, NelfiCuervo, Gloria Mejia, Gloria Restrepo y Gustavo Peñuela ; Destoxificaion con luz solardelpesticida malation / Joan Arroyave, Adrian Correa, Gloria Mejia y Gustavo Peñuela ; Resultados del carbonorganico total de las aguas destoxificadas en el laboratorio / Gloria Mejia ; Resultados de los analisisfisicoquimicosy microbiologicos del agua captada de la Quebrada Fray Juana para potabilizar en la finca dela montaña / Alexander Restrepo, Javier Restrepo, Gloria Restrepo y Gustavo Peñuela ; Fundamentacion de la destoxificacion por fotodegradacion sensibilizada ; Propuestas de soluciones de ingenieria a los problemas ambientales en la finca la montaña / Olga Pabon, Julio Saldarriaga, Joan Arroyave, Adrian Correa y Gustavo Peñuela ;Mapas de laregion para ubicar donde se realizo el proyecto ; Evaluacion de indicadores socioeconomicos para lagestion ambiental del agua : aplicacion al proyecto destoxificacion solar de desechos liquidos agropecuarios / Jessica Diaz, Paula Andrea Maya, Rafael Muriel y Adriana Posada -- v.2 anexos.light / G.Peñuela ... [et al.] -- En: Conference on WasteManagement (2002: Rhodes, Grecia). -- Cinetica de;degradacion en la fotocatalisis del Malation / G. Peñuela,J.M.Marin y G. Mejia. -- En: Congreso;latinoamericano de cromatografia y tecnicas afines : 3 congresocolombianode cromatografia (4 : 2002 ene. 2 :;Bucaramanga). -- Cinetica de degradacion en la fotocatalisis delmetomil /G. Peñuela, J. M. Marin y G. Mejia.;'-- en: Congreso latinoamericano de cromatografia y tecnicas afines : 3 congreso colombiano de cromatografia (4;: 2002 ene. 2 : Bucaramanga). -- Descontaminacion de aguasporfotosensibilizacion con energia solar. -- En:;soluciones a problemas ambientales en latinoamerica / foroColombia - Canada del medio ambiente (2000 may.;23-26 Cartagena de Indias). -- Descontaminacion de aguas usandoconcentradores solares. -- En: Una realidad;energetica / Seminario nacional energia alternativa (2000jun.6-8 : Medellin).;PONENCIA(S) EN CONGRESO: Photocatalysis of methomyl usingconcentrating solar collector and ultraviole