Diseño, implementación y validación de un script de Praat para medir el rendimiento diadococinético / Design, implementation, and validation of a Praat script to measure diadochokinetic rate

Introducción: El objetivo de esta investigación es implementar y validar un código de programación que ejecuta, en una muestra de habla digitalizada, los procedimientos necesarios para calcular automáticamente cuatro indicadores cuantitativos del rendimiento diadococinético: el promedio de sílabas por segundo, el coeficiente de variabilidad del promedio de sílabas por segundo, la duración promedio de la sílaba y el coeficiente de variabilidad de la duración promedio de la sílaba. Método: En primer lugar, se diseñó e implementó un script de Praat que segmenta las sílabas presentes en una emisión diadococinética y que calcula y entrega de manera automatizada los cuatro indicadores de interés. Luego, para validar el script, se compararon los resultados obtenidos de la aplicación a una muestra de 30 hablantes de este recurso con los datos provenientes de otras dos metodologías que cumplen la misma función (aplicadas sobre la misma muestra): un análisis y cálculo no automatizados realizados por una persona y un análisis y cálculo automatizados efectuados por un programa comercial disponible en el mercado. Resultados y conclusión: Los resultados del proceso de validación no revelan diferencias significativas en el rendimiento de las tres metodologías, lo que permite ratificar la validez de la herramienta propuesta en este trabajo.(AU)

Introduction: This research aims to implement and validate a Praat script for computing four quantitative metrics of diadochokinetic rate in digital speech samples. Notably, the script computes the average number of syllables per second, the coefficient of variability of the average number of syllables per second, average syllable length, and the coefficient of variability of average syllable length in diadochokinetic sequences. Methods: To do this, a Praat script was written and implemented to segment the syllables of diadochokinetic sequences and to calculate and deliver the four metrics above. Once the script had been implemented, and to validate the code, the results obtained for the four metrics from a sample of 30 speakers were compared with two sets of results from the same 30 speakers obtained from two different methods: (a)a single human non-automated analysis and calculation; (b)an automated analysis and calculation from a commercially available program. Results and conclusion: The validation process results did not reveal any significant differences in the performance of the three methods, which ratifies the validity of the script presented in this work.(AU)

Sulfate nutrition improves short-term Al3+-stress tolerance in roots of Lolium perenne L.

Trivalent aluminum ions (Al3+) in acidic soils are a major constraint for crop productivity inhibiting root elongation and promoting cell death. Al3+-toxicity has adverse biochemical and physiological effects on plant root growth. Sulfur is an essential macronutrient assimilated from the soil in the form of sulfate. However, the implication of sulfate nutritional status in the modulation of short-term Al3+-tolerance mechanisms in plant roots has not been previously reported. Here, we evaluated the effects of increased sulfate supply on short-term Al3+-toxicity in roots of Lolium perenne, measuring Al, Ca, Mg and S uptake, lipid peroxidation, total SOD activity, and transcriptional levels of Cu/Zn and Fe-SOD genes. First, the nitrogen sulfur ratio (N/S) in the TF nutrient solutions used in this study were computed to confirm that L. perenne plants were grown in sulfate deficiency (120 µM), optimal supply (240 µM), or overdoses conditions (360 µM), without affecting dry root biomass. Sulfate supplementation (>240 µM, and N/S ratio < 16) played a significant protection to Al3+-stress that prevents morphological changes in root tips, inhibits lipid peroxidation and differentially up-regulates total SOD activity, due changes in SOD gene expression. The results support the importance of sulfate nutritional status, on plant tissue homeostasis, enhancing the physiological tolerance mechanisms modulating lipid peroxidation damage induced by short-term Al3+-toxicity.

Bioaccessibility and arsenic speciation in carrots, beets and quinoa from a contaminated area of Chile.

Consumption of vegetables grown in arsenic (As)-contaminated soils is an important exposure route to the element for humans. The present study is focused on locally-grown, frequently-consumed vegetables, such as carrots (Daucus carota), beets (Beta vulgaris) and quinoa (Chenopodium) from the As-polluted Chiu Chiu area in Northern Chile. The latter region is affected both by As discharge from copper mining activity and natural As contamination, leading to a high As content in local food and water. For the selected vegetables, the following aspects were investigated: i) Their total As, Cu, Pb, Cr, Cd and Mn content; ii) Arsenic speciation in the edible part of the vegetables by liquid chromatography inductively-coupled plasma mass spectrometry (LC-ICPMS) analysis; iii) Arsenic bioaccessibility in the vegetables during in vitro gastrointestinal digestion; iv) Arsenic species present in the extracts obtained from in vitro gastrointestinal digestion; and v) Arsenic dietary exposure estimates for the assessment of the risk posed by the vegetables consumption. A significant degree of As contamination was found in the vegetables under study, their metal content having been compared with that of similar Spanish uncontaminated products. In vitro gastrointestinal digestion of the studied vegetables led to quantitative extraction of As from carrots and beets, whereas efficiency was about 40% for quinoa. For carrots, only As(III) and As(V) species were found, being their concentration levels similar. In the case of quinoa, around 85% of the element was present as As(V). For beets, inorganic As(V) and unknown overlapped As species (probably arsenosugars) were found. No significant transformation of the original As species was observed during in vitro gastrointestinal digestion. Arsenic dietary exposure values obtained for the three vegetables (0.017-0.021µg As person(-1)day(-1)) were much lower than the JFCFA's safety limit of 50µg As person(-1)day(-1). Therefore, no toxicological risk would be expected from the intake of these vegetables.

Identificación y cuantificación del arsénico unido a las proteínas de tejidos cardiovasculares de pacientes sometidos a cirugía de revascularización coronaria / Identification and quantification of protein-linked arsenic in cardiovascular tissues from patients submitted to coronary revascularization

Introducción: Los efectos de la intoxicación con Arsénico (As) como enfermedades cardiovasculares (CV), pigmentaciones y oclusiones arteriales coronarias están asociados con la ingestión de As inorgánico a través del agua de bebida y a exposiciones ambientales. La unión del As (III) a proteínas y la metilación del As podría ser una primera etapa en el mecanismo de detoxificación. Objetivo: Evaluar la unión de As a proteínas en aurícula derecha y vena safena (VS) en sujetos expuestos de la Región de Antofagasta. Métodos: Se estudió la asociación As-proteína en el citosol de AD y VS de 6 pacientes con enfermedad coronaria grave de la Región de Antofagasta. Para el fraccionamiento del citosol se utilizaron columnas de exclusión molecular de tres diferentes rangos de masas. El perfil del As se detectó por Espectrometría de Masas Inductivamente Acoplado (ICP-MS) y por Espectrosco-pía Ultra Violeta - Visible de las fracciones moleculares (enlaces As- tiolatos de proteínas). Resultados: En todos los casos el As estuvo ampliamente distribuido en todo el intervalo de fracciones para AUD y VS. Los porcentajes de As colectado en las fracciones de las diferentes columnas usadas fueron 10, 25 y 50 por ciento. En la especiación de As en el citosol, por Cromatografía Líquida de Alta Resolución acoplada a la Espectrometría de Masas (IC-HPLC-ICP-MS), solamente se encontró As(III) y As(V) con una distribución Gaussiana para ambas especies, siendo la relación As(III)/As(V) constante para AUD y VS. Conclusión: En los tejidos CV existe asociación As - proteína lo cual podría implicar que el As está unido a biocompuestos de diferente peso molecular a través de grupos sulfhidrilos vecinales. Es probable que el As en AUD y VS se una a fracciones proteicas de masa molecular superior a 80 kDA y a subunidades de la estructura cuaternaria de la proteína nativa.

Background: The effects of arsenic (As) toxi-city - cardiovascular disease, pigmentation, coronary artery occlusion- come from ingestion of contaminated drinking water and environmental exposure. Protein linkage or As(III) and As methylation may be a first step in detoxification. The aim of this study is to evaluate protein linkage of As in the right atrium (RA) and saphenous vein (SV) of As exposed subjects from Antofagasta, Chile Method: As-protein linkage was studied in the cytosol of AD and SV obtained from 6 patients operated on for coronary artery disease. Molecular exclusion columns of 3 different mass ranges were used to obtain the cytosol fraction. As species were detected by induction coupled mass spectrometry and visible ultraviolet spectrometry (links of As and protein thyolates). Results: As was widely distributed in AD and SV in all subjects. As collected in the 3 different columns used were 10 per cent, 25 per cent and 50 per cent. Only As(III) and As(V) were obtained through the method used (IC-HPLC-ICP-MS); a normal distribution was evident for both As species. The relation As(III)/As(V) was similar in AD and SV. Conclusion: A linkage of As and proteins through neighbor sulphidryl groups is present in cardiovascular tissues of exposed subjects. It is likely that As is linked to >80 kDA protein fractions and to quaternary subu-nits or the native protein.

Niveles de elementos traza en tejidos cardiovasculares de pacientes sometidos a cirugía cardíaca en la región de antofagasta: chile / Trace elements in cardiovascular tissues of patients undergoing cardiac surgery in a heavy metal contaminated area, the antofagasta region:chile

Introducción: La población de la Región de Antofagasta se encuentra expuesta a contaminación ambiental por metales pesados (MP). Los elementos traza (ET) podrían actuar con As como agonistas o antagonistas. El presente estudio detalla la determinación de las concentraciones totales (CT) de V, Cr, Mn, Co, Ni, Cu, As, Se y Boro en aurícula derecha (AD), arteria mamaria izquierda (AMI), vena safena (VS) y tejido adiposo (TA) de personas que padecen patologías cardiovasculares (CV) y han requerido cirugía cardíaca. Métodos: Se analizaron AMI, VS, AUD, y TA en un grupo de 50 pacientes con cardiopatía coronaria de la Región de Antofagasta que han sido sometidos a cirugía cardíaca (grupo expuesto, E), y en un grupo de 20 pacientes control sometidos a cirugía cardíaca en el mismo período en Santiago (grupo no expuesto, NE). Las determinaciones de ET y MP se realizaron mediante Técnicas Ópticas y Atómicas. Resultados: En el grupo de pacientes E residentes en la Región de Antofagasta Boro presenta correlaciones interelementales significativas (p=0,05), que no se presentan o son escasas en el grupo NE. El rango de CT de B en AD fue de 24,721 - 932,032 μg/g, niveles muy superiores a los encontrados en el resto de los elementos en estudio. El rango de CT de B encontrada para AD fue de 25,205 - 56,873 μg/g. Conclusión: Individualmente, el elemento más enriquecido en todos los tipos de tejidos del grupo E de la Región de Antofagasta es B, le siguen As y Mn. Cu está empobrecido en el grupo NE, en particular en AD y AMI.

The Antofagasta population is exposed to environmental contamination with heavy metals (HM). Trace elements (TE) might interact with As either as agonists or antagonists. The total concentracions of V, Cr, Mn, Co, Ni, Cu, Se and B in the right atrium (RA), left internal mammary artery (LIMA), saphenous vein (SV) and adipose tissue (AT) from patients undergoing cardiac surgery are reported. Methods: LIMA, SV, RA and AT from 50 patients with myocardial infarction submitted to revascularization surgery in Antofagasta (exposed group, E) or Santiago (non exposed group NE, 20 patients) were analyzed. Optical and atomic techniques were used for analysis of HM and TE. Results: Significant inter elemental correlations were observed for B in group E, (p<0.05), which are not present in group NE. The RA concentrarion of B in group A ranged from 24.72 to 932.03 ug/g, substancially higher than concentracion of the other elements under study. Corresponding concentra-rions of B in the NE group were 25.21 to 56. 87 ug/g. Conclusion: B was the most enriched element in the exposed group, followed by As and Mn. Cu content was significantly lower in RA and LIMA from patients in the non exposed group.

Urinary excretion of platinum, arsenic and selenium of cancer patients from the Antofagasta region in Chile treated with platinum-based drugs.

BACKGROUND: Arsenic exposure increases the risk of non-cancerous and cancerous diseases. In the Antofagasta region in Chile, an established relationship exists between arsenic exposure and the risk of cancer of the bladder, lung and skin. Platinum-based drugs are first-line treatments, and many works recognise selenium as a cancer-fighting nutrient. We characterised the short-term urinary excretion amounts of arsenic, selenium and platinum in 24-h urine samples from patients with lung cancer and those with cancer other than lung treated with cisplatin or/and carboplatin. As - Se - Pt inter-element relationships were also investigated. RESULTS: The amounts of platinum excreted in urine were not significantly different between patients with lung cancer and those with other cancers treated with cisplatin, despite the significant variation in platinum amounts supplied from platinum-based drugs. In general, the analytical amounts of excreted selenium were greater than those for arsenic, which could imply that platinum favours the excretion of selenium. For other types of cancers treated with drugs without platinum, excretion of selenium was also greater than that of arsenic, suggesting an antagonist selenium-anti-cancer drug relationship. CONCLUSIONS: Regards the baseline status of patients, the analytical amounts of excreted Se is greater than those for As, particularly, for cisplatin chemotherapy. This finding could imply that for over the As displacement Pt favours the excretion of Se. The analytical amounts of excreted Se were greater than those for As, either with and without Pt-containing drugs, suggesting an antagonist Se-anti-cancer drug relationship. However, it seemed that differences existed between As - Se - Pt inter-element associations in patients treated for lung cancer in comparison with those treated for cancer other than lung. Therefore, knowledge obtained in this work, can contribute to understanding the arsenic cancer mechanism and the As - Se - Pt inter-element association for lung cancer and other types of cancer, which in some cases respond at a linear mathematical model.

Exposure to low level of arsenic and lead in drinking water from Antofagasta city induces gender differences in glucose homeostasis in rats.

Populations chronically exposed to arsenic in drinking water often have increased prevalence of diabetes mellitus. The purpose of this study was to compare the glucose homeostasis of male and female rats exposed to low levels of heavy metals in drinking water. Treated groups were Sprague-Dawley male and female rats exposed to drinking water from Antofagasta city, with total arsenic of 30 ppb and lead of 53 ppb for 3 months; control groups were exposed to purified water by reverse osmosis. The two treated groups in both males and females showed arsenic and lead in the hair of rats. The δ-aminolevulinic acid dehydratase was used as a sensitive biomarker of arsenic toxicity and lead. The activity of δ-aminolevulinic acid dehydratase was reduced only in treated male rats, compared to the control group. Treated males showed a significantly sustained increase in blood glucose and plasma insulin levels during oral glucose tolerance test compared to control group. The oral glucose tolerance test and the homeostasis model assessment of insulin resistance demonstrated that male rats were insulin resistant, and females remained sensitive to insulin after treatment. The total cholesterol and LDL cholesterol increased in treated male rats vs. the control, and triglyceride increased in treated female rats vs. the control. The activity of intestinal Na+/glucose cotransporter in male rats increased compared to female rats, suggesting a significant increase in intestinal glucose absorption. The findings indicate that exposure to low levels of arsenic and lead in drinking water could cause gender differences in insulin resistance.

Metal contents in coastal waters of San Jorge Bay, Antofagasta, northern Chile: a base line for establishing seawater quality guidelines.

We measured the concentration of 12 metals in coastal waters of seven sites of San Jorge Bay in Antofagasta (northern Chile), in order to relate the presence of metals with the different uses of San Jorge Bay coastal border, and to evaluate the quality of the bay's bodies of water according to the proposed current Chilean Quality Guide for trace elements in seawater (CONAMA 2003). The results suggest that the coastal water of San Jorge Bay has very good quality according to the proposed regulation mentioned above. However, the distribution of metals such as Cu and Pb along the bay's coast line evidences a notorious effect of the industrial activity, which would involve different behavior patterns for some trace elements in some bodies of water, suggesting that the levels indicated in the environmental guideline of the Chilean legislation do not represent pollution-free environments.

Distribution and temporal variation of trace metal enrichment in surface sediments of San Jorge Bay, Chile.

Cu, Pb, and Hg concentrations were determined in surface sediment samples collected at three sites in San Jorge Bay, northern Chile. This study aims to evaluate differences in their spatial distribution and temporal variability. The highest metal concentrations were found at the site "Puerto", where minerals (Cu and Pb) have been loaded for more than 60 years. On the other hand, Hg does not pose a contamination problem in this bay. Cu and Pb concentrations showed significant variations from 1 year to another. These variations seem to be a consequence of the combination of several factors, including changes in the loading and/or storage of minerals in San Jorge Bay, the dredging of bottom sediments (especially at Puerto), and seasonal changes in physical-chemical properties of the water column that modify the exchange of metals at the sediment-water interface. Differences in the contamination factor and geoaccumulation index suggest that pre-industrial concentrations measured in marine sediments of this geographical zone, were better than geological values (average shale, continental crust average) for evaluating the degree of contamination in this coastal system. Based on these last two indexes, San Jorge Bay has a serious problem of Cu and Pb pollution at the three sampling locations. However, only Cu exceeds the national maximum values used to evaluate ecological risk and the health of marine environments. It is suggested that Chilean environmental legislation for marine sediment quality--presently under technical discussion--is not an efficient tool for protecting the marine ecosystem.