356 research outputs found

    Determinación de éteres difenil-polibromados en aguas superficiales de la cuenca del Río Mendoza mediante HS-SPME-GC-MS/MS

    Get PDF
    Polybrominated diphenyl ethers (PBDEs) are considered persistent organic pollutants because of their ubiquity, persistence and bioaccumulation. Its harmful effects on human health and the environment, has led to its inclusion of the Stockholm Convention. Little information is found about PBDEs in abiotic systems of the South America in open literature. This paper reports the presence and concentration level of four PBDEs congeners in Mendoza River, Argentina. The selected PBDEs were: 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), 2,2',4,4',5-pentabromodiphenyl ether (BDE-99), 2,2',4,4',6-pentabromodiphenyl ether (BDE- 100) and 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153). The analytical methodology used was head space-solid phase micro extraction combined with gas chromatographymass spectrometry (HS-SPME-GC-MS/MS). Several variables, including pH, salting out, extraction technique type and extraction time were studied and optimized over the relative response the target analytes. The precision of HS-SPME-GC-MS/MS evaluated over five replicate, leading RSDs values <13%, detection limits (S/N=3) ranging from 0.03 pg ml-1 to 0.12 pg ml-1 and the calibration graph was linear with r2=0.9959. BDE-47 and BDE-100 were the predominant congeners found in the analyzed samples. Their concentrations ranged from not detected to 1.9 pg ml-1 and to 0.5 pg ml-1, respectively.Los éteres difenil-polibromados (PBDEs) son considerados contaminantes orgánicos persistentes debido a su ubicuidad, persistencia y capacidad de bioacumulación. Sus efectos nocivos sobre la salud humana y el ambiente, han motivado su inclusión en el Convenio de Estocolmo. Poca información se dispone en la bibliografía internacional sobre la presencia de PBDEs en los sistemas ambientales de Sudamérica. Este trabajo reporta la distribución y niveles de concentración de cuatro congéneres de PBDEs en la cuenca del Río Mendoza, Argentina. Los congéneres seleccionados fueron: 2,2',4,4'-tetrabromodifenil éter (BDE-47), 2,2',4,4',5-pentabromodifenil éter (BDE-99), 2,2',4,4',6-pentabromodifenil éter (BDE-100) y 2,2',4,4',5,5'-hexabromodifenil éter (BDE-153). La metodología analítica es la microextracción en fase sólida en espacio de cabeza seguida de cromatografía gaseosa con detección de masas (HS-SPME-GC-MS/MS). Variables tales como pH, fuerza iónica, tipo, tiempo y temperatura de extracción fueron estudiadas y optimizadas. La precisión de HS-SPMEGC- MS/MS fue de RSD <13%, los límites de detección (S/N=3) se establecieron en el intervalo de 0,03 pg ml-1 a 0,12 pg ml-1 y la curva de calibración tuvo un r2=0,9959. BDE-47 y BDE-100 fueron los congéneres predominantes encontrados en las muestras de agua analizadas cuyas concentraciones máximas fueron 1,9 pg ml-1 y 0,5 pg ml-1, respectivamente.Fil: Lana, Nerina Belén. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Fontana, Ariel Ramón. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Ciocco, Nestor Fernando. Instituto Argentino de Investigaciones de las Zonas Áridas Fil: Altamirano, Jorgelina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnica

    Do Zero ao Milhão: O Dilema da Gestão Risco Versus Retorno

    Get PDF
    This teaching case tells the story of Pedro who, excited by false promises of quick and easy money, decides to venture into stock investments to fulfill his dream of reaching a million reais. When Pedro finally learn about personal finance and investing, he is torn between taking risks, investing in stocks, or opting for safety. The case allows reflection on personal finance and investment in the financial market and is recommended for courses in administration and accounting science, in subjects that deal with the theme of finance, financial market or financial planning.Este caso didáctico cuenta la historia de Pedro quien, emocionado por falsas promesas de dinero rápido y fácil, decide aventurarse a invertir en acciones para cumplir su sueño de alcanzar el millón de reales. Cuando Pedro tiene la oportunidad de aprender finalmente sobre finanzas personales e inversiones, se debate entre tomar riesgos, invertir en acciones u optar por la seguridad. El estuche permite la reflexión sobre las finanzas personales y la inversión en el mercado financiero y es recomendado para cursos de ciencias administrativas y contables, en materias de finanzas, mercado o planificación financieros.Este caso para ensino narra a história de Pedro que, empolgado com falsas promessas de dinheiro rápido e fácil, resolve se aventurar nos investimentos em ações para realizar o sonho de chegar ao milhão de reais. Quando Pedro tem a oportunidade de finalmente aprender sobre finanças pessoais e investimentos fica dividido entre assumir riscos, investindo em ações ou optar por segurança. O caso permite a reflexão sobre as finanças pessoais e o investimento no mercado financeiro e é recomendado para os cursos de administração e ciências contábeis, em disciplinas que tratem do tema finanças, mercado financeiro ou planejamento financeiro

    Foliar application of titanium on potato crop

    Get PDF
    Although titanium (Ti) is not considered a nutrient, researches demonstrate that Ti leaf application can provide beneficial effects on plants growth. The objective of this study was to evaluate the influence of foliar applications of Ti levels on the metabolism, nutrient uptake and yield of potato crop, Agate cultivar. The experiment was conducted in a randomized complete block design with five treatments and four replications. The treatments were composed of 0, 10.2, 15.3, 20.4 and 22.9 g Ti ha-1, divided into three applications during the growth stage, tuberization stage and tuber filling stage. Foliar applications of Ti increase the chlorophyll content (Spad value) in the tuber filling stage. Ti levels do not interfere with N, Zn and Cu nutrient accumulation. Increasing Ti levels linearly reduce the Mn, lipid peroxidation (PL) and urease content and increase the activity of peroxidase (POD), nitrate reductase (ANR), catalase (CAT), proline and Fe content in the growth stage, with maximum level around 3 to 6 g Ti ha-1. In the tuberization stage, at high levels of Ti, there is an increase in urease activity and CAT while ANR has its lowest value. In the tuber filling stage, high Ti levels are related to high Fe, Mn, high ANR and superoxide dismutase (SOD) activity and low PL activity. The ideal level of titanium applied by leaf for greater yield of tubers is 11.3 g of Ti ha-1

    Use of wild trout for PBDE assessment in freshwater environments: Review and summary of critical factors

    Get PDF
    Certain wild animals represent sentinels to address issues related to environmental pollution, since they can provide integrative data on both pollutant exposure and biological effects. Despite their technological benefits, PBDEs are considered a threat to environmental health due to their persistence, toxicity, and capacity to be accumulated. These pollutants have been found geographically widespread in fish, particularly in predator species such as trout. The aim of this work is to critically review the applicability and usefulness of wild trout for assessing PBDEs in freshwater environments. Reviewed reports include data from highly industrialized areas as well as areas from remote regions with relatively low human activity, including European and North American great lakes and freshwater environments in Europe, Greenland, subarctic areas and Patagonia, respectively. A summary of relevant factors were grouped into organism-specific factors (food habits, age, size, lipid content, sex and reproduction, tissue type, mechanism of contaminant uptake and metabolism), and PBDE levels in the surrounding environment (sediment). Five wild trout species [rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), lake trout (Salvelinus namaycush), arctic char (Salvelinus alpinus), and brook trout (Salvelinus fontinalis)], collected worldwide within the 1994 to present time frame, were considered. Multivariate techniques (principal component analysis-PCA) and mapping approach, showed clear differences in geographic distribution patterns of PBDE levels in trout depending on the region studied: wild trout from European and North American great lakes have the highest PBDE loads. This pattern could be due to high industrial activity at these locations. A correlational approach used to explore intraspecific relationships between PBDE levels and morphometry, showed positive relationships only for brown trout. Further, brown trout showed the highest trout-to-sediment ratios, which is suggestive of a relatively greater capacity of this species to accumulate PBDEs in relation to sediment levels. Overall, results suggest that adult wild trout could be useful as a PBDE bioindicator.Fil: Rios, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Lana, Nerina Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Bertón, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Ciocco, Nestor Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Altamirano, Jorgelina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentin

    Propiedades fisico-químicas de sedimentos condicionan la asociación de contaminantes : un estudio multivariado de éteres bifenilos polibromados en áreas de irrigación del Río Mendoza

    Get PDF
    This work is a multidisciplinary environmental study that provides new insights into the relationships between sediment-organic matter characteristics and polybrominated diphenyl ethers (PBDEs) concentration. The aim of the present multivariate study was to correlate factors influencing PBDEs accumulation in sediment by using principal component analysis (PCA). Organic matter studies by Fourier Transform-Infrared spectroscopy and physicochemical analyses (Total Organic Carbon, pH, electrical conductivity) of sediment samples were considered for PCA. Samples were collected from an artificial irrigation network on the Mendoza River irrigation areas. PCA provided a comprehensive analysis of the studied variables, identifying two components that explained 63% of the data variance. Those factors were mainly associated to organic matter degradation degree, which represent a new insight into the relationships between organic matter in sediments and PBDEs fate. In this sense it was possible to determine that not only the content but also the type of organic matter (chemical structure) could be relevant when evaluating PBDEs accumulation and transport in the environment. Typification of organic matter may be a useful tool to predict more feasible areas where PBDE, may accumulate, as well as sediment transportation capability.Este trabajo es un estudio ambiental multidisciplinario que proporciona nuevos conocimientos sobre las relaciones entre las características de la materia orgánica presente en sedimentos y la concentración de éteres difenilos polibromados (PBDEs). Se buscó correlacionar características físico-químicas de muestras de sedimento usando análisis de componentes principales (PCA). Las muestras fueron caracterizadas por su contenido de materia orgánica total, pH y conductividad eléctrica. Adicionalmente, la materia orgánica de dichas muestras fue analizada mediante Espectroscopía de Infrarrojos con Transformada de Fourier. Las muestras fueron colectadas en diferentes canales de irrigación de la red alimentada por el Río Mendoza. El PCA proporcionó un análisis exhaustivo de las variables estudiadas y su vinculación, resultando dos componentes que explicarían el 63% de la varianza de los datos. Ambas componentes se asociaron al estado de degradación de la materia orgánica. En este sentido, fue posible determinar que tanto la cantidad de materia orgánica de los sedimentos como el tipo (estructura química) de materia orgánica estarían condicionando la acumulación y el transporte de PBDEs en el ambiente. A partir de los resultados es posible proponer a la tipificación de la materia orgánica de sedimento como herramienta útil y efectiva para predecir áreas donde es más factible que se acumule PBDE, así como la capacidad de transporte en los sedimentos.Fil: Lana, Nerina Belén. Instituto Argentino de Nivología, Glaciología y Ciencias AmbientalesFil: Koch, Eduardo.Fil: D' Angelo, José Alejandro. Instituto Argentino de Nivología, Glaciología y Ciencias AmbientalesFil: Ciocco, Nestor Fernando.Fil: Altamirano, Jorgelina Cecilia. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientale

    U–Pb ages and Hf-isotope data of detrital zircons from the late Neoarchean-Paleoproterozoic Minas Basin, SE Brazil

    Get PDF
    Because of its world-class iron ore deposits and promising Au and U mineralizations, the late Neoarchean to Paleoproterozoic Minas Basin (Minas Supergroup, SE of Brazil) is one of the best-studied basins in South America. However, the lack of datable interlayered volcanic rocks prevented discourse over ages of the strata, the sources and the nature of its ore deposits. In this paper, we present detrital zircon U–Pb age patterns coupled with Lu–Hf data for 18 samples, representing different stages of the Minas Basin evolution (∼2000 analyzed zircons). Age spectra for the main basal unit (Moeda Formation) show a classic rift-related detrital zircon pattern, characterized by multiple autochthonous sources, which in turn are much older than the age of deposition. Maximum age for the rifting event is constrained at ca. 2600 Ma. Detritus accumulated at the base of the Minas Supergroup were derived from Archean source rocks and their sedimentation was marked by differential uplift of the Archean crust, shortly after the 2730–2600 Ma high-K calc-alkaline magmatism (Mamona Event). The age of the BIF deposits is younger than 2600 Ma, most likely coinciding with the great oxygenation event between 2400 and 2200 Ma and the precipitation of banded iron deposits worldwide. Detrital zircons from the topmost units of the Minas strata suggest that tectonic inversion and closure of the basin took place at ca. 2120 Ma with the deposition of the synorogenic Sabará Group. Rhyacian zircon supply showing juvenile Hf signatures gives evidence of a late Rhyacian amalgamation between the Mineiro Belt and the craton. The εHf signatures support the hypothesis that the Archean crystalline crust of the craton was mostly built by crust–mantle mixing processes, with a successive decrease of εHf values in zircons crystallized after 3250 Ma and minor mantle-like additions after Paleoarchean times. Regionally, our dataset supports previous interpretations of a long-lived evolution of the southern São Francisco Craton comprising a succession of convergent island arcs, small microplate collisions, and development of Archean convergent and divergent basins that evolved between Archean and Paleoproterozoic times.Fil: Martínez Dopico, Carmen Irene. Universidade Federal de Ouro Preto; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lana, Cristiano. Universidade Federal de Ouro Preto; BrasilFil: Moreira, Hugo S.. University of Portsmouth; Reino UnidoFil: Cassino, Lucas F.. Universidade Federal de Ouro Preto; BrasilFil: Alkmim, Fernando F.. Universidade Federal de Ouro Preto; Brasi

    Propiedades fisico-químicas de sedimentos condicionan la asociación de contaminantes: un estudio multivariado de éteres bifenilos polibromados en áreas de irrigación del Río Mendoza

    Get PDF
    This work is a multidisciplinary environmental study that provides new insights into the relationships between sediment-organic matter characteristics and polybrominated diphenyl ethers (PBDEs) concentration. The aim of the present multivariate study was to correlate factors influencing PBDEs accumulation in sediment by using principal component analysis (PCA). Organic matter studies by Fourier Transform-Infrared spectroscopy and physicochemical analyses (Total Organic Carbon, pH, electrical conductivity) of sediment samples were considered for PCA. Samples were collected from an artificial irrigation network on the Mendoza River irrigation areas. PCA provided a comprehensive analysis of the studied variables, identifying two components that explained 63% of the data variance. Those factors were mainly associated to organic matter degradation degree, which represent a new insight into the relationships between organic matter in sediments and PBDEs fate. In this sense it was possible to determine that not only the content but also the type of organic matter (chemical structure) could be relevant when evaluating PBDEs accumulation and transport in the environment. Typification of organic matter may be a useful tool to predict more feasible areas where PBDE, may accumulate, as well as sediment transportation capability.Este trabajo es un estudio ambiental multidisciplinario que proporciona nuevos conocimientos sobre las relaciones entre las características de la materia orgánica presente en sedimentos y la concentración de éteres difenilos polibromados (PBDEs). Se buscó correlacionar características físico-químicas de muestras de sedimento usando análisis de componentes principales (PCA). Las muestras fueron caracterizadas por su contenido de materia orgánica total, pH y conductividad eléctrica. Adicionalmente, la materia orgánica de dichas muestras fue analizada mediante Espectroscopía de Infrarrojos con Transformada de Fourier. Las muestras fueron colectadas en diferentes canales de irrigación de la red alimentada por el Río Mendoza. El PCA proporcionó un análisis exhaustivo de las variables estudiadas y su vinculación, resultando dos componentes que explicarían el 63% de la varianza de los datos. Ambas componentes se asociaron al estado de degradación de la materia orgánica. En este sentido, fue posible determinar que tanto la cantidad de materia orgánica de los sedimentos como el tipo (estructura química) de materia orgánica estarían condicionando la acumulación y el transporte de PBDEs en el ambiente. A partir de los resultados es posible proponer a la tipificación de la materia orgánica de sedimento como herramienta útil y efectiva para predecir áreas donde es más factible que se acumule PBDE, así como la capacidad de transporte en los sedimentos

    Dietary fat intake and risk of disabling hearing impairment: a prospective population-based cohort study

    Full text link
    Purpose: To examine the associations of specific dietary fats with the risk of disabling hearing impairment in the UK Biobank study. Methods: This cohort study investigated 105,592 participants (47,308 men and 58,284 women) aged ≥ 40 years. Participants completed a minimum of one valid 24-h recall (Oxford Web-Q). Dietary intake of total fatty acids, polyunsaturated fatty acids (PUFA), saturated fatty acids (SFA), and monounsaturated fatty acids (MUFA) was assessed at baseline. Functional auditory capacity was measured with a digit triplet test (DTT), and disabling hearing impairment was defined as a speech reception threshold in noise > − 3.5 dB in any physical exam performed during the follow-up. Results: Over a median follow-up of 3.2 (SD: 2.1) years, 832 men and 872 women developed disabling hearing impairment. After adjustment for potential confounders, including lifestyles, exposure to high-intensity sounds, ototoxic medication and comorbidity, the hazard ratios (HRs), and 95% confidence interval (CI) of disabling hearing function, comparing extreme quintiles of intakes were 0.91 (0.71–1.17) for total fat, 1.09 (0.83–1.44) for PUFA, 0.85 (0.64–1.13) for SFA and 1.01 (0.74–1.36) for MUFA among men. Among women, HRs comparing extreme intakes were 0.98 (0.78–1.24) for total fat, 0.69 (0.53–0.91) for PUFA, 1.26 (0.96–1.65) for SFA, and 0.91 (0.68–1.23) for MUFA. Replacing 5% of energy intake from SFA with an equivalent energy from PUFA was associated with 25% risk reduction (HR: 0.75; 95% CI: 0.74–0.77) among women. Conclusions: PUFA intake was associated with decreased risk of disabling hearing function in women, but not in menUK Biobank was established by the Wellcome Trust medical charity, Medical Research Council, Department of Health, Scottish Government and the Northwest Regional Development Agency. It has also had funding from the Welsh Government, British Heart Foundation, Cancer Research UK, and Diabetes UK. This work was supported by FIS grants 19/319 and 20/1040, (Instituto de Salud Carlos III, State Secretary of R + D + I and FEDER/FSE

    Association between neighborhood physical characteristics and mental health among older adults in Spain

    Full text link
    The aim was to assess the impact of neighborhood physical environment on mental health among non-institutionalized older adults. A cross-sectional analysis was conducted over a representative sample of 5,071 people 65 years from the Spanish National Health Survey. The survey included nine items addressing the self-perceived degree of discomfort due to neighborhood physical problems. Participants were categorized into groups with “no problems”, “some problems” (somewhat discomfort on 1 4 items) and “many problems” (somewhat discomfort on 5 items or very much discomfort on 1 item). Mental health status was assessed using the General Health Questionnaire, consisting of 12 items assessing the severity of a psychological distress over the past few weeks. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regressions. A dose-response association (p-trend<0.001) was found between living in neighborhoods with some (OR: 1.41; 95% CI: 1.14 1.75) or many problems (OR: 1.93; 95% CI: 1.55 2.42) affecting the physical environment with poor mental health of community dwelling older adults. Integrating and articulating health considerations into public policymaking regarding housing and the residential environment can have broad implications for healthy agin

    Leptin concentration and risk of impaired physical function in older adults: the Seniors-ENRICA cohort

    Full text link
    This is a pre-copyedited, author-produced PDF of an article accepted for publication in Age and Ageing following peer review. The version of record Alberto Lana, Ellen Struijk, Pilar Guallar-Castillón, Jose María Martín-Moreno, Fernando Rodríguez Artalejo, Esther Lopez-Garcia; Leptin concentration and risk of impaired physical function in older adults: the Seniors-ENRICA cohort. Age Ageing 45.6 (2016): 819-826 is available online at: http://dx.doi.org/ 10.1093/ageing/afw142Leptin resistance, which may develop during the aging process, stimulates the production of proinflammatory cytokines and insulin resistance that could impair the muscle function. However, the role of leptin on physical functioning among older adults has not yet been elucidated. Objective: To examine the association between serum leptin levels and physical function impairment in older adults. Design and setting: Prospective study of 1,556 individuals aged ≥60 years from the Seniors-ENRICA cohort, who were free of physical function limitation at baseline. Main outcome measure: Serum leptin was measured in 2008-2010, and incident functional limitation was assessed through 2012. Self-reported limitations in agility and mobility were assessed with the Rosow and Breslau scale, limitation in the lower extremity function was measured with the Short Physical Performance Battery, and impairment in the overall physical performance with the physical component summary of the SF-12. Results: After adjustment for potential confounders, and compared to individuals in the lowest quartile of leptin concentration, those in the highest quartile showed increased risk of impaired physical function; the odds ratio (95% confidence interval) and p-trend was: 1.95 (1.11-3.43), p=0.006 for self-reported impaired mobility; 1.76 (1.08-2.87), p=0.02 for self-reported impaired agility; 1.48 (1.02-2.15), p=0.04 for limitation in the lower extremity function; and 1.97 (1.20-3.22), p=0.01 for decreased overall physical performance. These associations were only modestly explained by C-reactive protein and insulin resistance. Moreover, the associations held across groups with varying health status and were independent of estimated total body fat. Conclusions: Higher leptin concentration was associated with increased risk of impaired physical function. Preserving metabolic function during the old age could help delaying physical function declineThis work was supported by FIS grants 12/1166 and 13/0288 (Instituto de Salud Carlos III, State Secretary of R+D+I, and FEDER/FSE), the CIBERESP, the FRAILOMIC Initiative (FP7-HEALTH-2012-Proposal no. 305483-2) and the ATHLOS project (EU H2020- Project ID: 635316
    corecore