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Sample records for contamination effects efectos

  1. Insulator contamination effects; Efectos de la contaminacion en aislamientos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Lucia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    Environmental contamination deteriorates the electric insulators, mechanically as well as electrically; the mechanical problems caused by contamination are related basically with materials corrosion and degradation and the electrical problems are related to the deterioration of their dielectric rigidity. From the electrical standpoint, the type of contamination that cause more problems are divided into: marine, desert and industrial. It is not uncommon to find various combinations of these types of contamination. When the electric installations operate in polluted environments, the insulator electric behavior deteriorates, provoking increments in the operation costs for maintenance as well as for replacement. Mexico has large extensions of coasts (marine contamination), where nowadays large cities and productions centers are developed (industrial pollution); also, in some cases for the energy transportation is necessary to go through large land extensions, where no vegetation of any kind exists. For this reason the contamination effect on the electric installations must be considered in order to obtain a reliable and economical energy supply. [Espanol] La contaminacion ambiental deteriora los aisladores electricos tanto mecanica como electricamente; los problemas mecanicos por contaminacion se relacionan en forma basica con la corrosion y degradacion de los materiales, y los electricos se vinculan con el deterioro de su rigidez dielectrica. Desde el punto de vista electrico, los tipos de contaminacion que mas problemas ocasionan se dividen en: marina, desertica e industrial. Es comun encontrar diversas combinaciones de estas. Cuando las instalaciones electricas operan en ambientes contaminados, el comportamiento electrico de los aisladores se deteriora, provocando incrementos en los costos de operacion, tanto por mantenimiento como por reposicion. Mexico cuenta con grandes extensiones de costas (contaminacion marina), donde actualmente se desarrollan ciudades y

  2. Insulator contamination effects; Efectos de la contaminacion en aislamientos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Lucia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    Environmental contamination deteriorates the electric insulators, mechanically as well as electrically; the mechanical problems caused by contamination are related basically with materials corrosion and degradation and the electrical problems are related to the deterioration of their dielectric rigidity. From the electrical standpoint, the type of contamination that cause more problems are divided into: marine, desert and industrial. It is not uncommon to find various combinations of these types of contamination. When the electric installations operate in polluted environments, the insulator electric behavior deteriorates, provoking increments in the operation costs for maintenance as well as for replacement. Mexico has large extensions of coasts (marine contamination), where nowadays large cities and productions centers are developed (industrial pollution); also, in some cases for the energy transportation is necessary to go through large land extensions, where no vegetation of any kind exists. For this reason the contamination effect on the electric installations must be considered in order to obtain a reliable and economical energy supply. [Espanol] La contaminacion ambiental deteriora los aisladores electricos tanto mecanica como electricamente; los problemas mecanicos por contaminacion se relacionan en forma basica con la corrosion y degradacion de los materiales, y los electricos se vinculan con el deterioro de su rigidez dielectrica. Desde el punto de vista electrico, los tipos de contaminacion que mas problemas ocasionan se dividen en: marina, desertica e industrial. Es comun encontrar diversas combinaciones de estas. Cuando las instalaciones electricas operan en ambientes contaminados, el comportamiento electrico de los aisladores se deteriora, provocando incrementos en los costos de operacion, tanto por mantenimiento como por reposicion. Mexico cuenta con grandes extensiones de costas (contaminacion marina), donde actualmente se desarrollan ciudades y

  3. Effect of the oyster contaminated in Salmonella typhimurium and Escherichia coli; Efecto del ostion contaminado en Salmonella typhimurium y Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Brena V, M

    1992-08-15

    In this work the effect of the oyster contaminated in the species of bacteria better studied by its genetic composition these are the Salmonella typhimurium and the Escherichia coli and that its have been starting point for later radiobiological studies in superior organisms. Of this its have arisen two general lines. The research about the genotoxic effect of substances or mixtures in bacteria with the collaboration of the groups of Drosophila and X-ray Fluorescence analysis and on the other hand the study of the low doses of radiation also in bacteria. It is also treated the topic about the genetic effect of aromatic hydrocarbons in different biological systems. (Author)

  4. Effect of marine contamination on the genetic population structure of the bivalve Crassostrea angulata; Efecto de la contaminacion marina sobre la estructura genetica poblacional del bivalvo Crassostrea angulata

    Energy Technology Data Exchange (ETDEWEB)

    Cross, Ismael; Rebordinos, Laureana [Laboratorio de Genetica, Facultad de Ciencias del Mar, Universidad de Cadiz, Cadiz (Spain)

    2003-06-15

    Seven enzyme loci were analyzed in three natural populations of Crassostrea angulata located on the southern Atlantic coast of the Iberian Peninsula. Two of the populations showed distinct levels of contamination by heavy metals, whereas the third was not contaminated and served as control. These seven loci were shown to be very variable in terms of the number of alleles, polymorphism and average heterozygosity. The Lap and Mdh1 loci presented null alleles. A significant positive correlation was found between the number of alleles and the concentration of iron that was fitted to a model of linear regression. However, this correlation was negative for the heterozygosity, and significant for cadmium and zinc. The Em, Lap, Mdh1 y Xdh loci showed a deficit of heterozygotes in all the populations. The values of heterozygotic deficit (D) were statistically significant between the contaminated populations and the control for Mdh1 and very close to a significant level for Em. In Pgm, a heterozygotic excess appeared in the control population and deficit, which was correlated to the increased levels of metal concentration, occurred in the other two populations. The differences between the D values of the three populations were also significant in this locus. Positive, negative and significant relationships were obtained between the concentration of metals and some alleles of the Em, Lap and Pgm loci. Also, the homozygotic genotypes of the alleles with positive correlation values were selected in the contaminated areas, while the heterozygotes were more favoured in the control population, showing an adaptive behavior and corroborating the utility of some of these loci as biomarkers in studies of population dynamics in areas subjected to environmental contamination. [Spanish] Se analizaron siete loci alozimicos en tres poblaciones naturales de Crassostrea angulata localizadas en la costa suratlantica de la Peninsula Iberica. Dos de las poblaciones mostraban distintos niveles

  5. Effect on the performance with the washing of the gas turbines Ruston TB5000 with a system of washing out of line in high contamination conditions; Efecto en el rendimiento con el lavado de las turbinas de gas Ruston TB5000 con un sistema de lavado fuera de linea en condiciones de alta contaminacion

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Diaz, Carlos Rodolfo; Aboites Davila, Fernando [CIATEQ, A.C., Queretaro (Mexico); Rocha Orozco, Moises [PEMEX Refinacion, Mexico, D.F. (Mexico)

    2007-11-15

    This paper shows the effects on the gas turbine performance with a washing system out of line, based on liquid detergent and water for the case of 2 Ruston TB5000 gas turbines located in conditions of high contamination in the atmosphere such as ashes, high humidity and temperature. The investigation was realized making periodical measurements of the main parameters of the turbo-pump during 1 year of operation with load conditions without stopping of about 125 mbpd (million of barrels per day) of gas LP. This article suggests how the low performance of the turbines in a hostile atmosphere can be improved and which could be the limitations of the washing systems based on liquid detergents. The data of the washing sessions were collected during a year and studied under statistical methods creating performance curves and comparing them with curves of other machines being washed with other washing systems. [Spanish] Este trabajo muestra los efectos en el rendimiento de la turbina de gas con un sistema de lavado fuera de linea, basado en detergente liquido y agua para el caso de 2 turbinas de gas Ruston TB5000 localizados en condiciones de alta contaminacion en el ambiente como cenizas, alta humedad y temperatura. La investigacion fue realizada haciendo mediciones periodicas de los parametros principales de turbo bomba durante 1 ano de operacion con condiciones de carga sin parar de alrededor de 125 mbpd (millones de barriles por dia) de gas LP. Este articulo sugiere como se puede mejorar el bajo desempeno de las turbinas en un ambiente hostil y cuales podrian ser las limitaciones de los sistemas de lavado basados en detergentes liquidos. Los datos de las sesiones de lavado fueron recolectados durante un ano y estudiados bajo metodos estadisticos creando curvas de rendimiento y comparandolas con curvas de otras maquinas siendo lavadas con otros sistemas de lavado.

  6. Degradation by synergistic effect in synthetic insulators; Degradacion por efecto sinergico en aisladores sinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Garza M, Anibal; Montesinos S, Jose I. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    A study is presented of the main degradation phenomena experimented by synthetic insulators and the simultaneous participation of such phenomena to propitiate a synergistic effect. [Espanol] Se presenta un estudio de los principales fenomenos de degradacion que sufren los aisladores sinteticos y la participacion simultanea de dichos fenomenos para propiciar un efecto sinergico.

  7. Degradation by synergistic effect in synthetic insulators; Degradacion por efecto sinergico en aisladores sinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Garza M, Anibal; Montesinos S, Jose I [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-12-31

    A study is presented of the main degradation phenomena experimented by synthetic insulators and the simultaneous participation of such phenomena to propitiate a synergistic effect. [Espanol] Se presenta un estudio de los principales fenomenos de degradacion que sufren los aisladores sinteticos y la participacion simultanea de dichos fenomenos para propiciar un efecto sinergico.

  8. Efectos y controversias de los ácidos grasos omega-3: effects and controversies Omega-3 fatty acids

    Directory of Open Access Journals (Sweden)

    Fernando Manzur

    Full Text Available Gracias al descubrimieno del mecanismo de acción de los ácidos grasos omega-3 para disminuir las arritmias ventriculares, éstos han vuelto a cobrar importancia por su efecto cardio-protector. La ingestión de ácidos grasos omega-3 disminuye el riesgo de trombosis y accidentes cerebro-vasculares al disminuir los lípidos sanguíneos, mejorando en esta forma la función endotelial. Sin embargo, algunos estudios epidemiológicos no han encontrado una relación directa a este respecto y además hay controversia respecto a las dosis necesarias para lograr este efecto cardio-protector. Hay estudios que reportan que el contenido de metil-mercurio en peces afecta la disposición de los ácidos grasos omega-3. En el Caribe colombiano se ha encontrado contaminación de peces con metil-mercurio.Thanks to the discovery of omega-3 fatty acids’ mechanism of action, these have regained importance due to its cardio-protective effect. The ingestion of omega-3 fatty acids diminishes the risk of thrombosis and cerebro-vascular accidents by lowering serum lipids and improving endothelial function. Nevertheless, some epidemiological studies have not found a direct relationship with them and there is controversy with regard to the doses needed in order to achieve this cardio-protective effect. There are studies reporting that the methyl-mercury content in fish affects omega-3 fatty acids’ disposal. In the Colombian Caribbean region, fish contamination with methyl-mercury has been found.

  9. Biological effects of ionizing radiation; Efectos biologicos de la radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Gisone, Pablo; Perez, Maria R [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    2001-07-01

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  10. Contamination Effects Due to Space Environmental Interactions

    Science.gov (United States)

    Chen, Philip T.; Paquin, Krista C. (Technical Monitor)

    2001-01-01

    Molecular and particulate contaminants are commonly generated from the orbital spacecraft operations that are under the influence of the space environment. Once generated, these contaminants may attach to the surfaces of the spacecraft or may remain in the vicinity of the spacecraft. In the event these contaminants come to rest on the surfaces of the spacecraft or situated in the line-of-sight of the observation path, they will create various degrees of contamination effect which may cause undesirable effects for normal spacecraft operations, There will be circumstances in which the spacecraft may be subjected to special space environment due to operational conditions. Interactions between contaminants and special space environment may alter or greatly increase the contamination effect due to the synergistic effect. This paper will address the various types of contamination generation on orbit, the general effects of the contamination on spacecraft systems, and the typical impacts on the spacecraft operations due to the contamination effect. In addition, this paper will explain the contamination effect induced by the space environment and will discuss the intensified contamination effect resulting from the synergistic effect with the special space environment.

  11. Mental contamination: The effects of religiosity.

    Science.gov (United States)

    Bilekli, Ilgun; Inozu, Mujgan

    2018-03-01

    Mental contamination, which occurs in the absence of contact with a contaminant, has a moral element. Previous studies evoked feelings of mental contamination via listening to a scenario, which described a non-consensual kiss. Since mental contamination has a moral element, we tested the effects of the level of religiosity on feelings of mental contamination and related variables in an experimental design. Female undergraduates of high religiosity (n = 48) and low religiosity (n = 44) were randomly assigned to listen to one of two audio recordings involving a consensual or non-consensual kiss from a man described as moral. Mental contamination feelings were evoked successfully in both groups. Effects of scenario condition and religiosity level were seen in mental contamination and related negative feelings. Participants who imagined a non-consensual kiss reported greatest feelings of mental contamination, and internal and external negative feelings. More importantly, high religiosity resulted in greater feelings of mental contamination, internal negative feelings, as well as urges to wash and actual washing behaviors. The current study was conducted on non-clinical Muslim females. This limits the generalization of the findings to the wider population. Mental contamination and related feelings can be seen in different forms at different levels of religiosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. A proximity effect in adults' contamination intuitions

    Directory of Open Access Journals (Sweden)

    Laura R. Kim

    2011-04-01

    Full Text Available Magical beliefs about contagion via contact (Rozin, Nemeroff, Wane, and Sherrod, 1989 may emerge when people overgeneralize real-world mechanisms of contamination beyond their appropriate boundaries (Lindeman and Aarnio, 2007. Do people similarly overextend knowledge of airborne contamination mechanisms? Previous work has shown that very young children believe merely being close to a contamination source can contaminate an item (Springer and Belk 1994; we asked whether this same hyper-avoidant intuition is also reflected in adults' judgments. In two studies, we measured adults' ratings of the desirability of an object that had made contact with a source of contamination, an object nearby that had made no contact with the contaminant, and an object far away that had also made no contact. Adults showed a clear proximity effect, wherein objects near the contamination source were perceived to be less desirable than those far away, even though a separate group of adults unanimously acknowledged that contaminants could not possibly have made contact with either the nearby or far-away object (Study 1. The proximity effect also remained robust when a third group of adults was explicitly told that no contaminating particles had made contact with the objects at any time (Study 2. We discuss implications of our findings for extending the scope of magical contagion effects beyond the contact principle, for understanding the persistence of intuitive theories despite broad acceptance of science-based theories, and for constraining interpretations of the developmental work on proximity beliefs.

  13. Audience and coactuacion effects in free throw El efecto audiencia y el efecto coactuación en el lanzamiento a canasta

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    C. Tuero

    2010-09-01

    Full Text Available

    The aim of this study was to analyse audience and coactor effects in a simple motor task, the free throw. Participants were 40 male high school students, aged 14 to 17 years, that were familiar (N = 20 or unfamiliar (N = 20 with the task proposed. Performance was examined while subjects acted in three different experimental situations: a alone; b in front of a passive audience of 10 peers; and c throwing together with a peer, with no external observation. Significant effects were observed for familiarity with the task (F1,38 = 79.9, P<0.001, experimental situation (alone, audience or coacting (F2,76 = 7.7, P< 0.001 and interaction (F2,76 = 4.7, P<0.01. Scores in each of the three sitautions were significantly higher for  the group familiar with the task. Both passive audience and presence of coactors significantly reduced number of scores in comparison to shots taken alone only in the group unfamiliar with the task. Our results confirm the importance of a better knowledge of social facilitation during performance of motor tasks in sport setting, and the necessity of considering both audience and coactor effects while learning new motor abilities.
    KEY WORDS: social facilitation, free throw, audience.

     

    El objeto del estudio fue analizar los efectos de audiencia y de la presencia de coactores en una tarea motora simple, el tiro a canasta.  Participaron un grupo de 40 estudiantes de ESO del sexo masculino, con edades comprendidas entre 14 y 17 años, familiarizados (N = 20 o no familiarizados (N = 20 con la tarea propuesta, encestes en 20 lanzamientos desde la línea de tiros libres. Se examinó la actuación de los sujetos mientras lanzaban en tres situaciones experimentales: a solos, b ante un grupo de 10 compañeros que actuaban como observadores pasivos, y c realizando los lanzamientos junto con un compañero sin que nadie más les observase

  14. Greenhouse effect gases (GEI) by energy consumption; Gases efecto invernadero (GEI) por consumo de energia

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Ledo C, Ramon; Bazan N, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2003-07-01

    The purpose of this article is to present the calculation methodology of greenhouse effect gases (GEI) emissions that are produced by the power sector in Mexico, as well as to discuss its possible impact in the subject of climatic change and the possible mitigating actions to lower the amount of emissions that can be taken and, therefore, the possible climate changes. In Mexico GEI inventories have been made since 1991, year in which the National Inventory of Gases with Greenhouse Effect was obtained for year 1988. The GEI include carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), methane (CH4), nitrous oxide (NO) and volatile organic carbides that are not methane (NMVOC) and are secondary products and harmful that are obtained from the processes that turn fuels into energy (combustion). The main sources of GEI are: fixed sources (industries, residences, commerce, public services and energy transformation, such as power generation); movable sources (that include all type of transport that uses fuel). The fuels that, by their volume and efficiency, generate more emissions of GEI are crude oil, natural gas and solid biomass (firewood-cane bagasse). Any effort to reduce these emissions is very important and remarkable if it affects the consumption of these fuels. [Spanish] El proposito de este articulo es presentar la metodologia de calculo de las emisiones de los gases con efecto invernadero (GEI) que son producidos por el sector energetico en Mexico, asi como discutir su posible impacto en las cuestiones de cambio climatico y las posibles acciones de mitigacion que se pueden realizar para abatir la cantidad de emisiones y, por ende, los posibles cambios de clima. En Mexico se han realizado inventarios de GEI desde 1991, ano en que se obtuvo el Inventario Nacional de Gases con Efecto Invernadero para el ano de 1988. Los GEI comprenden al dioxido de carbono (CO2), monoxido de carbono (CO), oxidos de nitrogeno (NOx), metano (CH4), oxido nitroso (N2O) y

  15. Efecto de la hidroxiurea en hemoglobina S Effect of hydroxyurea on hemoglobin S

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    A. Feliu Torres

    2003-04-01

    Full Text Available Estudios preliminares han determinado las modificaciones en la clínica, el laboratorio y la toxicidad del tratamiento con hidroxiurea (HU en pacientes con drepanocitosis y complicaciones clínicas severas. Se presenta la eficacia del tratamiento con HU en la prevención de las crisis vaso-oclusivas en un niño de 11 años de edad con drepanocitosis y manifestaciones graves. El número de crisis vaso-oclusivas, los días de internación y el número de transfusiones en el año previo al inicio del tratamiento con HU fueron comparados con los mismos parámetros a 6,12, 24, 36 y 72 meses de tratamiento. Se observó una disminución en la frecuencia de las crisis vaso-oclusivas, las transfusiones y los días de internación durante el tratamiento con HU comparado con el período previo. Las respuestas clínica y de laboratorio obtenidas le permitieron al paciente su inserción escolar y social. Los efectos adversos fueron leves y revirtieron al suspender la HU transitoriamente. Concluimos que el tratamiento crónico con HU en pacientes con drepanocitosis y manifestaciones graves parece posible y libre de efectos tóxicos serios.Previous studies have determined the laboratory alterations, clinical efficacy and toxicity profile associated with hydroxyurea (HU therapy in patients with severe sickle cell anemia. We report the efficacy of HU treatment in the prevention of vaso-occlusive crises in an 11-years-old boy with severe sickle cell disease. The number of vaso-occlusive crises, hospital days and blood transfusions in the year before HU treatment were compared with the same parameters at 6,12, 24, 36 and 72 months of treatment. A decrease in the frequency of vaso-occlusive crises, blood transfusions and days spent in hospital were demonstrated during the HU treatment period compared to the same period before hand. The clinical and laboratory response to HU was dramatic in this severely affected patient, allowing him a normal schooling and social

  16. Review: Personal Effects of Divorce in Relation to Children / Recension: Efectos personales del divorcio respecto de los hijos

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    Teresa Duplá Marín

    2013-05-01

    Full Text Available Review: Carmen López‐Rendo Rodríguez, Personal Effects of Divorce in Relation to Children, from Classical Rome to the Spanish Civil Code, RIDROM (online 9, 2012, pp. 249–270. Recension: Carmen López‐Rendo Rodríguez, Efectos personales del divorcio respecto de los hijos, De Roma al Codigo civil español, RIDROM (online 9, 2012, Pág. 249–270.

  17. Effect of Quail Litter Biochar on Productivity of Four New Physic Nut Varieties Planted in Cadmium-Contaminated Soil Efecto del Biocarbón de Cama de Codorniz en la Productividad de Cuatro Variedades Nuevas de Jatrofa Plantadas en Suelo Contaminado con Cadmio

    Directory of Open Access Journals (Sweden)

    Tawadchai Suppadit

    2012-03-01

    Full Text Available Biochar can improve soil structure and water retention, enhance nutrient availability and retention, ameliorate acidity, and reduce heavy metal toxicity to plant roots. In this study, a basin experiment was conducted to investigate the effects of quail litter biochar (QLB on the availability of Cd to physic nut (Jatropha curcas L. plants. QLB was applied to the soil in which four new physic nut varieties (Takfa, Doi Saket, Lao, and Rayong in factorial combinations at four levels (0, 5, 10, and 15 g kg-1 soil to soil that contained 60.8 mg Cd kg-1. After transplanting plant height and canopy radius were measured every 2-mo and the number of leaves and branches at 6-mo, while yield components and Cd residues were measured at 8-mo intervals. The contaminated soil was analyzed for chemical characteristics, nutrients, and Cd residue after the plant harvest. The addition of QLB to soil caused a significant increase in the soil's growth potential and physic nut yield components (P Se ha visto que el biocarbón mejora la estructura del suelo y la retención de agua, mejora la disponibilidad y la retención de nutrientes, controla la acidez y reduce la toxicidad de metales pesados en las raíces de las plantas. En este trabajo se investiga el uso de biocarbón de cama de codorniz (QLB en la disponibilidad de Cd para la planta de jatrofa (Jatropha curcas L. en un estudio de laboratorio. Se realiza una combinación factorial con cuatro variedades nuevas de jatrofa (Takfa, Doi Saket, Lao y Rayong sobre cuatro proporciones de QLB a 0, 5, 10, y 15 g kg-1 añadidos por separado a suelo contaminado con 60,8 mg Cd kg-1. Tras el trasplante se midió la altura de la planta y la cubierta vegetal cada 2 meses, el número de hojas y ramas a los 6 meses y los parámetros de rendimiento así como el residuo de Cd a los 8 meses. A continuación, tras la cosecha de la planta, se analizaron las características químicas, nutrientes y residuo de Cd en el suelo contaminado

  18. Effects of sorption behaviour on contaminant migration

    International Nuclear Information System (INIS)

    Melnyk, T.W.

    1985-11-01

    The effects of sorption behaviour on contaminant migration in groundwater systems are varied. Retardation of migration and dispersive effects can vary widely and contaminant concentration profiles can take a number of different shapes. This report examines the nature of some of these effects, especially those due to sorption behaviours that are dependent on the concentration of the contaminant in the groundwater. The effects are calculated using, in most cases, analytical solutions to the chemical equations imbedded in a simple reaction-cell or box-model transport algorithm. The hydrogeological parameters are held constant, and radioactive decay and hydrodynamic dispersion are excluded. A general discussion of the role of sorption equations in transport modelling is followed by presentation of migration results for a number of models of sorption behaviour varying from linear isotherms, Langmuir, Freundlich and ion-exchange isotherms, to precipitation reactions and multiple-site sorption reactions. The results are compared and general conclusions are drawn about the various migration behaviours calculated. The conclusions are that equilibrium sorption of trace contaminants can be modelled with linear isotherms (constant distribution coefficients or constant retardation factors) but the evaluation and extrapolation of the distribution coefficient are not easy. Nonlinear isotherms lead to unsymmetrical migration fronts. A comparison of Freundlich and linear isotherms is made. Sorption/desorption kinetic factors can be significant on the time scale of laboratory experiments and can cause large dispersive effects. Slow but important reactions can be missed altogether. Precipitation or mineralization behaviour cannot be modelled with constant distribution coefficients. Also, mineralization reactions can be kinetically slow even on the geological time scale. 89 refs

  19. SHAPIRO EFFECT IN INDUCTIVE QUANTUM CIRCUITS WITH CHARGE DISCRETENESS EFECTO SHAPIRO EN CIRCUITOS CUÁNTICOS INDUCTIVOS CON CARGA DISCRETA

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    Kristopher Chandía Valenzuela

    2006-08-01

    Full Text Available ABSTRACT As it is known, quantum inductive circuits with charge discreteness show Bloch-like oscillations in electrical current under a dc external voltage. In this paper, the effect of a superimposed ac voltage in the circuit is considered. The Shapiro effect is found to be related to the existence of resonance. Surprisingly, in the limit of low frequency (no resonance, the electrical averaged current exists and has always the same sign. Eventually this allows for an experimental method to measure discrete charge effect in quantum mesoscopic circuits.RESUMEN Es sabido que circuitos cuánticos inductivos con carga discreta, cuando se someten a un voltaje continuo externo, presentan oscilaciones de Bloch en la corriente. En este trabajo se considera, además, la superposición de un voltaje alterno en el circuito. El efecto Shapiro, relacionado con la existencia de resonancias, es encontrado de modo explícito. Sorprendentemente, en el límite de bajas frecuencias (sin resonancia la corriente eléctrica promediada existe y tiene siempre el mismo signo. Eventualmente, esto entrega un método experimental para medir los efectos de la discretización de la carga en circuitos cuánticos mesosocópicos.

  20. Network effects in the operation of electrical equipment; Efectos de la red en la operacion del equipo electrico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia T, Arturo; Rosales S, Inocente; Garcia P, Job; Ruiz F, L. Ivan; Robles P, Edgar [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2005-07-01

    In the nineties, the Instituto de Investigaciones Electricas (IIE) Electrical Equipment Management (GEE) was restricted to make the diagnosis of generators, transformers, switch boards and cables, without considering the global operating conditions. With the experience acquired in different services it was verified that, inclusively when this equipment is correctly designed, it can be subjected to unfavorable operative conditions, which causes an accelerated deterioration to the degree of producing a fault. In agreement with this, the GEE settled down new line of development named Analysis of the network effect on the electrical equipment, that analyzes the behavior of the equipment originated by work abnormal causes, including the network configuration effect. [Spanish] En la decada de los noventa, la Gerencia de Equipos Electricos (GEE) del IIE se limitaba a realizar el diagnostico de generadores, transformadores, tableros de distribucion y cables, sin considerar las condiciones globales de operacion. Con la experiencia adquirida en diferentes servicios se comprobo que, inclusive cuando estos equipos esten correctamente disenados, pueden verse sometidos a condiciones de operacion desfavorables, lo que ocasiona un deterioro acelerado al grado de producir una falla. De acuerdo con esto, la GEE establecio una nueva linea de desarrollo de nominada Analisis del efecto de la red en los equipos electricos, que analiza el comportamiento de los equipos originado por causas anormales de trabajo, incluido el efecto de la configuracion de la red.

  1. Efectos beneficiosos del chocolate en la salud cardiovascular Beneficial effects of chocolate on cardiovascular health

    OpenAIRE

    M. Gómez-Juaristi; L. González-Torres; L. Bravo; M. P. Vaquero; S. Bastida; F. J. Sánchez-Muniz

    2011-01-01

    Desde la antigüedad se ha atribuido al chocolate propiedades saludables que lo han aproximado más hacia un uso terapéutico que alimentario. El presente trabajo revisa algunos estudios relevantes de los efectos del chocolate (y sus componentes activos) sobre diferentes factores de riesgo cardiovascular y señala la necesidad de futuros estudios. El consumo de cacao/chocolate (i) incrementa la actividad antioxidante, (ii) modula la función plaquetaria e inflamación y (iii) disminuye la presión a...

  2. Beneficial effects of chocolate on cardiovascular health | Efectos beneficiosos del chocolate en la salud cardiovascular

    OpenAIRE

    Gómez Juaristi, Miren; González-Torres, L.; Bravo, Laura; Vaquero, M. Pilar; Bastida, Sara; Sánchez-Muniz, F. J.

    2011-01-01

    Desde la antigüedad se ha atribuido al chocolate propiedades saludables que lo han aproximado más hacia un uso terapéutico que alimentario. El presente trabajo revisa algunos estudios relevantes de los efectos del chocolate (y sus componentes activos) sobre diferentes factores de riesgo cardiovascular y señala la necesidad de futuros estudios. El consumo de cacao/chocolate (i) incrementa la actividad antioxidante, (ii) modula la función plaquetaria e inflamación y (iii...

  3. Effect of the technology in transmission, distribution and in the final uses; Efecto de la tecnologia en transmision, distribucion y en los usos finales

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, Elena [ed.; Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    At the moment one looks for the application of the superconductivity in the generation, transformation, transmission and storage of electrical energy. In this article recent technologies are briefly described , their advantages and their effects on the transmission and distribution networks. In some cases specific reference is made of the effect that they will have in Mexico. [Spanish] Actualmente se busca la aplicacion de la superconductividad en la generacion, transformacion, transmision y almacenamiento de energia eletrica. En este articulo se describen brevemente tecnologias recientes, sus ventajas y sus efectos sobre las redes de transmision y distribucion. En algunos casos se hace referencia especifica al efecto que tendran en Mexico.

  4. EFECTOS DE LOS MEDICAMENTOS CARDIOVASCULARES SOBRE EL GLOBO OCULAR / Effects of cardiovascular drugs on the eyeball

    Directory of Open Access Journals (Sweden)

    Caridad Peraza Martínez

    2013-01-01

    Full Text Available Resumen Introducción y objetivos: A las consultas de Oftalmología acuden pacientes con una alta incidencia de enfermedades cardiovasculares y muchos de los fármacos útiles para este tipo de afecciones pueden producir efectos indeseables sobre el globo ocular. El objetivo de esta investigación fue determinar las reacciones adversas que, sobre el órgano visual, provoca el consumo de estos medicamentos, y señalar sus contraindicaciones en personas afectadas por alguna enfermedad ocular. Método: Se realizó una búsqueda bibliográfica en textos especializados y se seleccionaron los medicamentos que podían producir reacciones adversas oculares, así como los que estaban contraindicados en las enfermedades oftalmológicas. Resultados: Se revisaron 276 medicamentos y se seleccionaron 72 (26,08 %. La visión borrosa (38/72, la disminución de la agudeza visual (21/72 y el vértigo (16/72 fueron las reacciones adversas más frecuentes asociadas al uso de los medicamentos cardiovasculares. Se exponen los 6 medicamentos que están contraindicados en este tipo de pacientes y los 14 que deben prescribirse con gran precaución en enfermedades como: el glaucoma, la atrofia óptica, la retinopatía hipertensiva y la migraña, entre otras. Conclusiones: Se encontró que 72 medicamentos (26,08 % utilizados en las enfermedades cardiovasculares presentan, dentro de sus reacciones adversas, alguna sintomatología ocular. Predominan la visión borrosa, la disminución de la agudeza visual y el vértigo. Es de extrema importancia realizar un buen interrogatorio a los pacientes para conocer sus antecedentes patológicos personales y así evitar el uso de fármacos que sean útiles para una enfermedad y perjudiciales para otra. El médico, con conocimiento de causa, valorará el riesgo/beneficio en aquellos fármacos imprescindibles. / AbstractIntroduction and Objectives: There is a high incidence of cardiovascular conditions among the patients who visit the

  5. Effects of processing techniques on the radioactive contamination of food

    International Nuclear Information System (INIS)

    Bovard, P.; Delmas, J.; Grauby, A.

    Following contamination of cultures of rice, grapes and various vegetables by 90 Sr and 137 Cs, the effect of processing and cooking techniques on the contamination of the food-stuff was investigated [fr

  6. Effect of aflatoxin B1 on growth and enzymatic activity of a native strain of Bacillus sp Efecto de la aflatoxina B1 sobre el crecimiento y actividad proteolítica de una cepa nativa de Bacillus sp

    Directory of Open Access Journals (Sweden)

    Márquez Edna Judith

    2004-07-01

    Full Text Available The effect of different aflatoxin B1 (AFAB1 concentrations on alkaline protease growth and enzymatic activity was evaluated; a native strain of alkalophilic Bacillus sp cultivated in CSL (Corn Steep Liquor was used. It was found that the effect of AFAB1 on the strain inhibited its growth and enzymatic activity to 1 ppm, showing that the strain is highly sensible to AFAB1, meaning that medium obtained f rom Colombian corn contaminated with this mycotoxin cannot be easily used. Concentrations less than 0.1 ppm did not affect growth and enzymatic activity. Key words: Bacillus, aflatoxin, alkaline proteases.Se evaluó el efecto de diferentes concentraciones de aflatoxina B1 (AFAB1 sobre el crecimiento y actividad enzimática de proteasas alcalinas de una cepa nativa de Bacillus sp Alcalofílico cultivada en LAM (Licor Agotado de Maíz. Se encontró que la cepa inhibe su crecimiento y actividad enzimática a 1 ppm, lo que demuestra una alta sensibilidad de la cepa evaluada a la AFAB1 e imposibilita utilizar fácilmente medios obtenidos de maíz nacional contaminado con esta micotoxina. Las concentraciones inferiores a 0.1 ppm no tienen ningún efecto sobre el crecimiento y la actividad enzimática. Palabras clave: Bacillus, aflatoxina, proteasas alcalinas.

  7. Medical effects of internal contamination with uranium.

    Science.gov (United States)

    Duraković, A

    1999-03-01

    The purpose of this work is to present an outline of the metabolic pathways of uranium isotopes and compounds, medical consequences of uranium poisoning, and an evaluation of the therapeutic alternatives in uranium internal contamination. The chemical toxicity of uranium has been recognized for more than two centuries. Animal experiments and human studies are conclusive about metabolic adverse affects and nephro- toxicity of uranium compounds. Radiation toxicity of uranium isotopes has been recognized since the beginning of the nuclear era, with well documented evidence of reproductive and developmental toxicity, as well as mutagenic and carcinogenic consequences of uranium internal contamination. Natural uranium (238U), an alpha emitter with a half-life of 4.5x10(9) years, is one of the primordial substances of the universe. It is found in the earth's crust, combined with 235U and 234U, alpha, beta, and gamma emitters with respective half-lives of 7.1x10(8) and 2.5x10(5) years. A special emphasis of this paper concerns depleted uranium. The legacy of radioactive waste, environmental and health hazards in the nuclear industry, and, more recently, the military use of depleted uranium in the tactical battlefield necessitates further insight into the toxicology of depleted uranium. The present controversy over the radiological and chemical toxicity of depleted uranium used in the Gulf War warrants further experimental and clinical investigations of its effects on the biosphere and human organisms.

  8. Does modifying personal responsibility moderate the mental contamination effect?

    Science.gov (United States)

    Kennedy, Tinisha S; Simonds, Laura M

    2017-12-01

    Mental contamination is the psychological sense of internal dirtiness that arises in the absence of physical contact with a perceived contaminant. Mental contamination can be evoked through imagining perpetrating a moral transgression. This study experimentally evoked mental contamination by asking men to imagine perpetrating a non-consensual kiss. It explored whether reducing sense of personal responsibility for the kiss moderated the mental contamination effect. Male students (N = 60) imagined giving either a consensual or non-consensual kiss. Personal responsibility for the kiss was manipulated in one of two non-consensual kiss conditions by way of the inclusion of social influence information. Feelings of mental contamination were assessed by self-report and through a behavioural index. Mental contamination was successfully induced in the two non-consensual kiss conditions. There was evidence to support the hypothesis that reducing personal responsibility might moderate specific components of mental contamination (shame, dirtiness and urge to cleanse). The effect of responsibility modification was evident in the self-report measures, but not in the behavioural index. The sample comprised male university students which limits generalizability of the findings. The behavioural assessment of mental contamination was limited to a proxy measure. Imagined moral violations are associated with increases in indices of mental contamination. Further research should investigate whether feelings of shame, dirtiness and urge to cleanse are particularly responsive to responsibility modifications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Total effective dose equivalent associated with fixed uranium surface contamination

    International Nuclear Information System (INIS)

    Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.

    1997-04-01

    This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm 2 and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels

  10. Efectos biológicos de los stents medicados en la circulación coronaria Biological effects of drug-eluting stents in the coronary circulation

    Directory of Open Access Journals (Sweden)

    Darío Echeverri

    2010-04-01

    Full Text Available Los stents medicados ofrecen la mejor alternativa disponible no quirúrgica para el tratamiento de la enfermedad coronaria gracias a su demostrada eficacia. Sin embargo, estos excelentes resultados han sido opacados en términos de seguridad, principalmente por la presencia de trombosis de stents de manera tardía o muy tardía. La comprensión de los efectos biológicos que ejercen a nivel de la arteria coronaria luego de su implante, se debe al efecto de la plataforma utilizada, el polímero y la droga que liberan. Los trastornos de reparación vascular inducidos favorecen la trombosis de stents y sus consecuencias clínicas. Se hace una revisión de los diferentes efectos biológicos de los stents medicados en las arterias coronarias, que permite comprender como han surgido rápidamente nuevas versiones en materiales, diseños, polímeros y medicamentos que reducen los efectos adversos a nivel coronario, mejorando su eficacia y seguridad.Drug-eluting stents offer the best available non-surgical alternative for the treatment of coronary disease, thanks to its demonstrated efficacy. However, in terms of security, these excellent results have been overshadowed by the late or very late appearance of stent thromboses.The biological effects they have in the coronary artery after its implantation are due to the effect of the platform used, the polymer and the medication released. The vascular healing disorders induced by drug-eluting stents favor stent thrombosis and its clinical consequences. This is a review of the different biological effects of drug-eluting stents in coronary arteries that allows to understand how the rapid onset of new versions of materials, designs, polymers and medications diminish adverse coronary effects and improve its efficacy and safety.

  11. Contamination effects on fixed-bias Langmuir probes

    Energy Technology Data Exchange (ETDEWEB)

    Steigies, C. T. [Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaet zu Kiel, 24098 Kiel (Germany); Barjatya, A. [Department of Physical Sciences, Embry-Riddle Aeronautical University, Daytona Beach, Florida 32114 (United States)

    2012-11-15

    Langmuir probes are standard instruments for plasma density measurements on many sounding rockets. These probes can be operated in swept-bias as well as in fixed-bias modes. In swept-bias Langmuir probes, contamination effects are frequently visible as a hysteresis between consecutive up and down voltage ramps. This hysteresis, if not corrected, leads to poorly determined plasma densities and temperatures. With a properly chosen sweep function, the contamination parameters can be determined from the measurements and correct plasma parameters can then be determined. In this paper, we study the contamination effects on fixed-bias Langmuir probes, where no hysteresis type effect is seen in the data. Even though the contamination is not evident from the measurements, it does affect the plasma density fluctuation spectrum as measured by the fixed-bias Langmuir probe. We model the contamination as a simple resistor-capacitor circuit between the probe surface and the plasma. We find that measurements of small scale plasma fluctuations (meter to sub-meter scale) along a rocket trajectory are not affected, but the measured amplitude of large scale plasma density variation (tens of meters or larger) is attenuated. From the model calculations, we determine amplitude and cross-over frequency of the contamination effect on fixed-bias probes for different contamination parameters. The model results also show that a fixed bias probe operating in the ion-saturation region is affected less by contamination as compared to a fixed bias probe operating in the electron saturation region.

  12. Title: Effect of abiotic stress on reduction of microbial contamination ...

    African Journals Online (AJOL)

    TERI

    2016-03-30

    Mar 30, 2016 ... Full Length Research Paper. Effect of osmotic stress on in vitro propagation of. Musa sp. ... In vitro propagation of banana preferably use sword sucker as explant source where microbial contamination poses a great problem in ... micropropagation. Endo-bacterial contamination is one of the major problems ...

  13. Effects of pesticides and contaminants on neotropical migrants

    Science.gov (United States)

    Nicholas W. Gard; Michael J. Hooper; Richard S. Bennett

    1993-01-01

    Many agricultural pesticides and industrial contaminants are capable of adversely affecting birds through direct effects such as elevated mortality rates and decreased reproductive success or indirectly by modifying habitat composition or food availability. Although neotropical migrants are potentially exposed to these contaminants on their breeding, migratory and...

  14. The tires and their effect in fuel consumption; Los neumaticos y su efecto en el consumo de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Barjau Peralta, Emilio; Fernandez Ramirez, Adrian; Maldonado Susano, Armando [Comision Nacional para el Ahorro de Energia, Mexico, D.F. (Mexico)

    1999-07-01

    In this paper are presented some of the impacts that the tire has in the fuel consumption in the light vehicles as well as in the heavy ones; emphasis is made in the measures that can be taken to diminish this effect and some of the results of the investigations or experiences obtained in other countries are also presented. Also mention is made of the most frequent faults of the tires and the cause of the same ones. This affects not so much the life of the tire as the operation cost, but also it involves energy costs when having to invest energy in the manufacture of new tires. [Spanish] En este trabajo se presentan algunas de los impactos que tienen el neumatico en el consumo de combustible en los vehiculos tanto ligeros como pesados, se hace enfasis en las medidas que pueden ser tomadas para disminuir este efecto y se muestran algunos resultados de las investigaciones o experiencias obtenidas en otros paises. Tambien se hace mencion de las fallas mas frecuentes en los neumaticos y la causa de las mismas. Esto afecta tanto la vida del neumatico como el costo de operacion, pero tambien involucra costos energeticos al tener que invertir energia en la fabricacion de neumaticos nuevos.

  15. Mushrooms preserved by the combined effect of refrigeration and gamma irradiation; Champinones conservados por el efecto combinado de refrigeracion e irradiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Domenech, A M; Bauza de Faliti, M; Bocklet, M F

    1991-12-31

    In this work, the combined effect of refrigeration and gamma irradiation on diverse physical parameters to be measured in mushrooms was studied. Mushrooms (Agaricus Campestris), `bisporus` variety, of closed cap, were used. From the treatments tested, it was concluded that 0.5 KGy is the most suitable dosis to delay elongation, cap opening, stem length and surface moss growth. (Author). [Espanol] En este trabajo se ha estudiado el efecto combinado de la refrigeracion y la irradiacion gamma sobre los diversos parametros fisicos medibles en el champinon. Se utilizaron hongos del genero Agaricus Campestris, variedad bisporus, de sombrero cerrado. De los tratamientos ensayados, se ha demostrado tener efecto util la dosis de 0,5 KGy ya que se logro retardar crecimiento, apertura del sombrero, largo del pie y desarrollo de mohos en superficie. (Autor).

  16. Groundwater pumping effects on contaminant loading management in agricultural regions.

    Science.gov (United States)

    Park, Dong Kyu; Bae, Gwang-Ok; Kim, Seong-Kyun; Lee, Kang-Kun

    2014-06-15

    Groundwater pumping changes the behavior of subsurface water, including the location of the water table and characteristics of the flow system, and eventually affects the fate of contaminants, such as nitrate from agricultural fertilizers. The objectives of this study were to demonstrate the importance of considering the existing pumping conditions for contaminant loading management and to develop a management model to obtain a contaminant loading design more appropriate and practical for agricultural regions where groundwater pumping is common. Results from this study found that optimal designs for contaminant loading could be determined differently when the existing pumping conditions were considered. This study also showed that prediction of contamination and contaminant loading management without considering pumping activities might be unrealistic. Motivated by these results, a management model optimizing the permissible on-ground contaminant loading mass together with pumping rates was developed and applied to field investigation and monitoring data from Icheon, Korea. The analytical solution for 1-D unsaturated solute transport was integrated with the 3-D saturated solute transport model in order to approximate the fate of contaminants loaded periodically from on-ground sources. This model was further expanded to manage agricultural contaminant loading in regions where groundwater extraction tends to be concentrated in a specific period of time, such as during the rice-growing season, using a method that approximates contaminant leaching to a fluctuating water table. The results illustrated that the simultaneous management of groundwater quantity and quality was effective and appropriate to the agricultural contaminant loading management and the model developed in this study, which can consider time-variant pumping, could be used to accurately estimate and to reasonably manage contaminant loading in agricultural areas. Copyright © 2014 Elsevier Ltd. All

  17. Bonding of radioactive contamination. IV. Effect of surface finish

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1983-01-01

    The mechanisms by which radioactive contamination would be bonded to a DWPF canister are being investigated. Previous investigations in this series have examined the effects of temperature, oxidation before contamination, and atmosphere composition control on the bonding of contamination. This memorandum describes the results of tests to determine the effect of special surface finishes on the bonding of contamination to waste glass canisters. Surface pretreatments which produce smoother canister surfaces actually cause radioactive contamination to be more tightly bonded to the metal surface than on an untreated surface. Based on the results of these tests it is recommended that the canister surface finish be specified as having a bright cold rolled mill finish equivalent to ASTM No. 2B. 7 references, 3 figures, 3 tables

  18. Integrating Individual-Based Indices of Contaminant Effects

    Directory of Open Access Journals (Sweden)

    Christopher L. Rowe

    2001-01-01

    Full Text Available Habitat contamination can alter numerous biological processes in individual organisms. Examining multiple individual-level responses in an integrative fashion is necessary to understand how individual health or fitness reflects environmental contamination. Here we provide an example of such an integrated perspective based upon recent studies of an amphibian (the bullfrog, Rana catesbeiana that experiences several, disparate changes when larval development occurs in a trace element�contaminated habitat. First, we present an overview of studies focused on specific responses of individuals collected from, or transplanted into, a habitat contaminated by coal combustion residues (CCR. These studies have reported morphological, behavioral, and physiological modifications to individuals chronically interacting with sediments in the CCR-contaminated site. Morphological abnormalities in the oral and tail regions in contaminant-exposed individuals influenced other properties such as grazing, growth, and swimming performance. Behavioral changes in swimming activities and responses to stimuli appear to influence predation risk in the contaminant-exposed population. Significant changes in bioenergetics in the contaminated habitat, evident as abnormally high energetic expenditures for survival (maintenance costs, may ultimately influence production pathways (growth, energy storage in individuals. We then present a conceptual model to examine how interactions among the affected systems (morphological, behavioral, physiological may ultimately bring about more severe effects than would be predicted if the responses were considered in isolation. A complex interplay among simultaneously occurring biological changes emerges in which multiple, sublethal effects ultimately can translate into reductions in larval or juvenile survival, and thus reduced recruitment of juveniles into the population. In systems where individuals are exposed to low concentrations of

  19. Immunotoxicological effects of environmental contaminants on marine bivalves.

    Science.gov (United States)

    Renault, T

    2015-09-01

    Coastal areas are complex environments frequently contaminated by numerous pollutants that represent a potential threat to marine organisms, especially bivalves. These pollutants may have major ecological consequences. Although effects of different environmental contaminants on the immune system in marine bivalves have been already reported, a few of reviews summarizes these effects. The main purpose of this chapter relies on summarizing recent body of data on immunotoxicity in bivalves subjected to contaminants. Immune effects of heavy metals, pesticides, HAP, PCB and pharmaceuticals are presented and discussed and a particular section is devoted to nanoparticle effects. A large body of literature is now available on this topic. Finally, the urgent need of a better understanding of complex interactions between contaminants, marine bivalves and infectious diseases is noticed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Prebióticos y su efecto en la biod sponibilidad del calcio Prebiotics and their effect on calcium bioavailability

    Directory of Open Access Journals (Sweden)

    Ivana Lavanda

    2011-04-01

    Full Text Available En la búsqueda de medidas de prevención de enfermedades crónicas no trasmisibles, se piensa en los prebióticos como una forma efectiva, saludable y relativamente barata para la optimización de la absorción de Ca. El aumento de la expectativa de vida de la población y el incremento de enfermedades como la osteoporosis traen graves consecuencias a la salud del individuo, acarreando importantes desembolsos económicos. En esta revisión se condensa el conocimiento presente sobre el efecto fisiológico del consumo de carbohidratos prebióticos y su posible interferencia en la biodisponibilidad del Ca, como también las posibilidades de su empleo en estrategias para combatir las deficiencias del mineral. Se elaboró una recopilación de los estudios originales realizados con mayor impacto en el tema, dando preferencia a los publicados en los últimos 6 años. Utilizamos las bases de datos PubMed, Lilacs e SciELO, usando las palabras claves calcio, prebióticos e probióticos.The increased life expectancy and prevalence of non-communicable chronic diseases have serious health and economic consequences on the population. Among the useful tools for preventing osteoporosis, prebiotics are thought to be an effective, healthy and relatively cheap way of optimizing calcium absorption. The objective of this review was to summarize the present knowledge on the physiological effects of prebiotic carbohydrate consumption and its possible interference with calcium bioavailability. The possibility of using prebiotics to fight calcium deficiency was also assessed. The keywords calcium, prebiotics and probiotics were used to search the PubMed, Lilacs and SciELO databases for the most significant original studies on the subject published in the last 6 years.

  1. Efecto del enriquecimiento con nutrientes en la degradación de clorpirifos, malatión y metil paratión Inorganic nutrients effect addition over the chlorpyrifos, malathion and methyl parathion degradation

    Directory of Open Access Journals (Sweden)

    S. A. Upegui

    2011-01-01

    Full Text Available Con el fin de evaluar el efecto del enriquecimiento con nutrientes (una sal de fósforo o un fertilizante comercial con N, P y K como alternativa para mejorar la capacidad de degradación de los microorganismos en una matriz sólida, contaminada con los pesticidas organofosforados: clorpirifos, malatión y metil paratión, se realizaron experimentos de cultivo bajo condiciones controladas de oscuridad, temperatura y humedad por 30 días. En todos los tratamientos hubo degradación de los pesticidas; sin embargo, en el tratamiento con fósforo los tiempos para degradar el clorpirifos y el metil paratión fueron mayores. La presencia de los pesticidas no generó efectos tóxicos detectables sobre la microflora en ninguno de los tratamientos evaluados. La actividad biológica de las matrices no presentó una relación directa con la capacidad de degradación.In order to evaluate the effect of inorganic nutrient addition (phosphorus or commercial fertilizer over the microbial degradation capacity present in a solid matrix contaminated with chlorpyrifos, malathion and methyl parathion, microcosms assays were held under controlled conditions of light, moisture and temperature for 30 days. Results showed that even though three treatments microorganisms were able to degrade the three organophosphorus pesticides, microorganisms of phosphorus-enrichment treatment were less efficient to degrade Chlorpyrifos and Methyl Parathion than microorganisms of Fertilizer-enrichment treatment. It was not observed a direct relation between mineralization and microbial pesticides degradation capacity. The microbial activity was not affected by the presence of organophosphorus pesticides.

  2. Effects of acoustic pollution on health Efectos de la contaminación acústica sobre la salud

    Directory of Open Access Journals (Sweden)

    Serafín Sánchez Gómez

    2007-12-01

    Full Text Available The physical parameters of sound amplitude, frequency and phase are received by the human senses as loudness, pitch, timbre and duration. The interest focuses on determining the threshold between the use of sound as a communication tool and enjoy and its conversion into an element of aggression. Noise pollutant pressure acoustic waves impact in the ear when its intensity exceeds its defensive mechanisms and cause hearing loss (typically affecting the 4,000 Hz. But still there are some extra-auditory pathways to the hippocampus and reticuloendothelial system, responsible for the other noise effects such as physical-somatic (cardiovascular, hormonal, respiratory, sleep, gastrointestinal, emotional, psychological (discomfort, alterations in the learning and performance and psychiatric problems. The component of the low-frequency vibration noise causes discomfort and disorders too.Los parámetros físicos del sonido: amplitud, frecuencia y fase, se reciben en el ser humano como variables sensoriales de sonoridad, altura, timbre y duración subjetiva. El interés se centra en determinar el umbral entre la utilización de los sonidos como herramienta de comunicación y disfrute y su conversión en elemento de agresión. Las ondas de presión sonora del contaminante acústico impactan en el oído cuando su intensidad supera sus mecanismos defensivos y causa hipoacusia (típicamente afectando los 4.000 Hz. Pero también siguen unas vías extraauditivas dirigidas al hipocampo y sistema reticuloendotelial, responsables de los demás efectos del ruido físicos-somáticos (cardiovasculares, hormonales, respiratorios, sobre el sueño, gastrointestinales, emocionales, psicológicos (malestar, alteraciones en el aprendizaje y el rendimiento y psiquiátricos. El componente vibratorio de las bajas frecuencias sonoras también es causa de malestar y enfermedades.

  3. Drought-induced effects on contaminant distribution

    International Nuclear Information System (INIS)

    Makdisi, R.S.

    1991-01-01

    The drought in California has caused significant redistribution of contaminants, particularly petroleum hydrocarbon and VOCs, at known hazardous waste sites. Free-floating petroleum hydrocarbon on the water table has been particularly susceptible to redistribution because it is easily removed by soil sorption. Sorption of petroleum hydrocarbon and VOCs onto the soil can result in soil hydrocarbon concentrations above the regulatory action levels requiring soil remediation. This phenomenon necessitated a reevaluation of the existing remedial action plans, particularly with respect to groundwater extraction and treatment systems designed to extract free-floating product and/or dissolved hydrocarbon. In this paper, the application of modifying an existing remedial action plan is illustrated by a case study involving the Atwater Elementary School site in Atwater, California. In response to leakage of an estimated 7,000 gallons of gasoline from the underground fuel storage tank, a radial-arm extraction well with a fuel product/water separation system was installed to remove the floating product layer from the unconfined aquifer. Additional extraction wells were installed and seventeen monitoring wells were installed into three discrete aquifers to evaluate the extent of hydrocarbon-contaminated groundwater to be treated after removal of the product layer

  4. Poultry manure effects on soil organisms; Efectos de los residuos avicolas sobre los organismos del suelo

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, M.; Martin, J. V.; Miralles de Imperial, R.; Leon-Cofreces, C.; Garcia, M. C.

    2009-07-01

    A study has been made to value the effects produces on the organisms of the ground (plants, invertebrates and microorganisms), after the application of two types of poultry manure (bed wood shaving or straw) on an agricultural ground. The use doses respond to agronomic and non environmental considerations. The test was made using a terrestrial microcosms, Multi-Species Soil System (MS.3) developed in the Environment department of the INIA, tool that allows in a single test to value of joint form, the effects of organic remainders on representative organisms of the ground. (Author) 1 refs.

  5. Biological radiation effects of Radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A E

    1996-12-31

    In order to contribute to the knowledge on the effects of radon and its decay products, the aim of this investigation is to study the biological effects of radon using Drosophila melanogaster throught the somatic mutation and recombination test (SMART) and the analysis of some adaptative factors exposing larvaes to controlled radon atmosphers, considering that this insect could be used as biological monitor. Using the somatic mutation test a mutagenic effect was observed proportional to radon concentration, into an interval of 1 {+-} 0.3 to 111 {+-} 7.4 KBq/m{sup 3} equivalent to doses under 0.0106 Gy. The correlation analysis gives a linear (r=0.80) relationship with a positive slope of 0.2217. The same happens when gamma rays are used in the interval of 1 to 20 Gy, given a linear dose-dependent effect (r=0.878) is obtained; nevetheless the slop is smaller (m=0.003) than for radon. Analysing the results of adaptative factors of the nine exposed generations, it was found that probably radon exposition induced dominant lethals during gametogenesis or/and a selection of the more component gamets of the treated individuals in larval state. It was reflected in the significant decrease on fecundity of the generation exposed. Nevertheless the laying eggs had an increase in egg-to-adult viability and the develop velocity was higher than in control for 3 KBq/m{sup 3}, this suggest that radon concentrations used were able to induce repair mechanisms. These data agree with the Hormesis hypothesis that says: low doses have positive effects on health. It was not possible to obtain a dose-effect relationship except with the develop velocity where it was found a dose-effect inverse proportion. In conclusion, Drosophila melanogaster could be a good system to obtain in vivo damaged induction concentration dependent of radon and its decay products, as well as to study the effects in an exposed population by the analysis of adaptative factors. (Author).

  6. Large blastholes in coal mining, canal effects. Barrenos largos en la mineria del carbon, efecto canal

    Energy Technology Data Exchange (ETDEWEB)

    Muniz Hevia, E.; Legorburu Zuazva, V.; Blanco Gonzalez, R. (Union Explosivos Rio Tinto SA, Madrid (Spain))

    1988-01-01

    The 'canal effect' has been known for a long time. It appears only in underground workings. It may be said that the coal industry has suffered from it less than other sectors, perhaps because of its rigorous safety legislation. The Spanish coal mining industry has now been without this phenomenon for many years. 3 refs., 3 figs.

  7. Resuspended contaminated sediments cause sublethal stress to oysters: A biomarker differentiates total suspended solids and contaminant effects.

    Science.gov (United States)

    Edge, Katelyn J; Dafforn, Katherine A; Simpson, Stuart L; Ringwood, Amy H; Johnston, Emma L

    2015-06-01

    Resuspended contaminated sediments represent an important route of contaminant exposure for aquatic organisms. During resuspension events, filter-feeding organisms are exposed to contaminants, in both the dissolved form (at the gills) and the particulate form (in the digestive system). In addition, these organisms must manage the physical stress associated with an increase in total suspended solids (TSS). To date, few studies have experimentally compared the contributions to biological stress of contaminated and clean suspended solids. The authors mixed field-collected sediments (cellular biomarkers (lysosomal membrane stability, lipid peroxidation, and glutathione) were measured to evaluate sublethal toxicity. Lysosomal membrane stability was the most sensitive biomarker for distinguishing effects from resuspended contaminated sediments, as increasing amounts of contaminated TSS increased lysosomal membrane destabilization. The authors' results illustrate the importance of considering contaminant exposures from resuspended sediments when assessing the toxicity of contaminants to aquatic organisms. © 2015 SETAC.

  8. Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A E; Tavera D, L; Cruces M, M P; Arceo M, C; Rosa D, M.E. de la

    1992-04-15

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  9. Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

    1992-04-15

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  10. Effect of the ionizing radiation in polymers; Efecto de la radiacion ionizante en polimeros

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M. E.; Carrasco A, H. [ININ, Gerencia de Aplicaciones Nucleares en la Salud, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Benavides C, R., E-mail: esther.martinez@inin.gob.m [Centro de Investigacion en Quimica Aplicada, Blvd. Enrique Reyna Hermosillo No. 140, Col. Los Pinos, 25250 Saltillo, Coahuila (Mexico)

    2010-07-01

    Particularly, the polymers present three main effects when are exposed to radiation: inter crossing or reticulation, degradation or breaking and tolerance. Depending on the polymer structure, of the energy quantity absorbed by mass unit (dose), the concentration and the inter crossing agent dispersion and of the irradiation conditions; inert atmosphere or air and the temperature to which the irradiation is made, some of those effects is favored. The polymers that are used as isolations of cables and electric wires for specific applications require mechanical and electric properties superiors to those of the conventional materials. So, it is desirable that an insulating subjected to the high temperature produced by an electric discharge is not melted, what is associated to an inter crossed structure. Among the years 1983 and 1984, the IAEA advised to the Instituto Nacional de Investigaciones Nucleares (ININ) in diverse uses of the irradiation technology in the polymers area. Starting from then, it is began to research the effect of the gamma radiation in formulations based on polyethylene of low density/copolymer of ethylene vinyl acetate, using trimethylol-propane trimetacrilate like inter cross agent and with conventional preservatives, such as flame dilators, antioxidants, lubricants, etc., used in the cables industry and electric wires. In this chapter the result of the researches realized by the area of the ININ are given. (Author)

  11. Solar Radiation effect on the bituminous binder; Efecto de la radiacion solar sobre el ligante bituminoso

    Energy Technology Data Exchange (ETDEWEB)

    Tadeo Rico, A.; Torres Perez, A.

    2010-07-01

    Asphalt, used as binder in road construction, becomes more brittle and harder during working life on the surface of the road pavement, conducting toward their deterioration. This is caused by the oxidation of the molecular functional groups of the asphalt molecular structure. Moreover, it is observed that ultraviolet radiation increases the oxidation process. However, the effect of solar light on the asphalt degradation has been poorly researched. The aim of this work is to study asphalt ageing caused by effect of solar radiation, by using standard test. Four commercial asphalts from different companies were selected: two with penetration number 50/70, and the other two polymer modified asphalts. From each of the asphalts forty samples were taken off and placed in four different aging conditions of temperature and radiation for a period ranging from 40 to 500 days. Ring and Ball test, and Fraass breaking Point test, were used to analyse the changes of asphalt properties after exposition to solar radiation. The results of the four analyzed asphalts showed a distinct behaviour; not only in the test temperature increase but also in the rate. Another experiment was carried out. Samples from a hot mix asphalt batch were placed under solar radiation, and were compacted by the Marshall procedure after increasing periods of time. Density and resistance to plastic flow using Marshall Apparatus were measured. Results showed an increase in the stability of samples under radiation. Both experiments show that the solar radiation is enough to cause changes in the asphalt molecular structure due to oxidation. So that, the study of the effect of the solar radiation on the asphalt properties could be a good tool to asses the performances of asphalt pavement. (Author) 26 refs.

  12. Efectos del herbicida Paraquat sobre el zooplancton Effects of Paraquat herbicide on zooplankton

    Directory of Open Access Journals (Sweden)

    Ana María Gagneten

    2002-09-01

    Full Text Available The effects of 0.1; 0.2; 0.4 and 0.8 mlPQ/L were analized on a zooplankton community, to determine the most sensitive species and to analize the occurence of physical abnormalities. A total of 40 taxa were determined. Paraquat affected significantly the zooplankton density but not the species richness. A progressive state of deformation of these organisms was also observed. Paraquat showed to be highly toxic for the zooplankton, so this herbicide should be strictly regulated in aquatic and terrestrial ecosystems.

  13. Incidencia y tipo de efectos adversos durante el procedimiento de hemodiálisis Incidence and type of adverse effects during the haemodialysis procedure

    Directory of Open Access Journals (Sweden)

    Estela María Matarán Robles

    2013-03-01

    Full Text Available Introducción: La seguridad del paciente constituye hoy día una prioridad para las principales organizaciones de salud como la Organización Mundial de la Salud, organismos internacionales como la Unión Europea, el Consejo de Europa, autoridades sanitarias, sociedades profesionales y organizaciones de pacientes. Objetivo: Describir las incidencias y tipos de efectos adversos derivados de la hemodiálisis en una unidad de nefrología. Metodología: Diseño: Estudio transversal en una unidad de hemodiálisis de 28 camas. Variables: como variable dependiente se consideró la presencia de efectos adversos y tipología, para ello se utilizó la Clasificación Internacional para la Seguridad del Paciente. Análisis estadísticos: se realizó una descripción de la muestra, para ello se utilizaron tanto los gráficos (histogramas, diagramas de barras y dispersión como los porcentajes, medias, desviaciones típicas, medianas, etc. Resultados: Durante el periodo a estudio se practicaron un total de 4.797 procedimientos de hemodiálisis, en un total de 681 sesiones produjeron efectos adversos, lo que supone una tasa de incidencia de 141,96 cada 1.000 diálisis. En cuanto a la gravedad el 97,5% de los efectos adversos fueron clasificados como leves, frente al 1,8% y 0,7% que fueron considerados como moderados y graves respectivamente. Conclusiones: Nuestra tasa de incidencia y gravedad de los efectos adversos es similar a la de otros centros. Este estudio nos permite identificar los problemas de seguridad en nuestra Unidad y en una segunda fase realizar un protocolo conjunto, que nos permita disminuir la tasa de incidencia actualmente existente. La hipotensión fue el efecto adverso más frecuente.Introdution: Nowadays patient safety is a priority for the main health organizations such as the World Health Organization, international bodies such as the European Union, the Council of Europe, healthcare authorities, professional associations and patient

  14. Hydrodebridement of wounds: effectiveness in reducing wound bacterial contamination and potential for air bacterial contamination.

    Science.gov (United States)

    Bowling, Frank L; Stickings, Daryl S; Edwards-Jones, Valerie; Armstrong, David G; Boulton, Andrew Jm

    2009-05-08

    The purpose of this study was to assess the level of air contamination with bacteria after surgical hydrodebridement and to determine the effectiveness of hydro surgery on bacterial reduction of a simulated infected wound. Four porcine samples were scored then infected with a broth culture containing a variety of organisms and incubated at 37 degrees C for 24 hours. The infected samples were then debrided with the hydro surgery tool (Versajet, Smith and Nephew, Largo, Florida, USA). Samples were taken for microbiology, histology and scanning electron microscopy pre-infection, post infection and post debridement. Air bacterial contamination was evaluated before, during and after debridement by using active and passive methods; for active sampling the SAS-Super 90 air sampler was used, for passive sampling settle plates were located at set distances around the clinic room. There was no statistically significant reduction in bacterial contamination of the porcine samples post hydrodebridement. Analysis of the passive sampling showed a significant (p air whilst using hydro surgery equipment compared with a basal count of 582 CFUs/m3. During removal of the wound dressing, a significant increase was observed relative to basal counts (p air samples was still significantly raised 1 hour post-therapy. The results suggest a significant increase in bacterial air contamination both by active sampling and passive sampling. We believe that action might be taken to mitigate fallout in the settings in which this technique is used.

  15. Effect of radiation on hydrotalcites with chromates; Efecto de la radiacion en hidrotalcitas con cromatos

    Energy Technology Data Exchange (ETDEWEB)

    Martinez G, S.; Bulbulian, S. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    Nowadays the generation of radioactive wastes is matter of several studies. In this work anion material, chromates, in hydrotalcite are retained which are anion exchangers. It was proposed to heat the hydrotalcite until temperature of 1200 C with the purpose to form the (MgAl{sub 2}O{sub 4}) spinel is very stable and in this way to immobilize strongly the anions. The effect of radiation on this compound and in particular the chromium lixiviation with solution 1N NaCl. It was found that in all case, the anions are strongly retained in the spinel formed. The radiation dose used for this was 100 Mrad, the samples were treated with NaCl 1N for studying the Cr lixiviation. The results show that for the calcined samples at 1200 C and irradiated there are not chromium escapes, which indicates that it is strongly retained in the spinel that is the formed structure after of the material calcination. (Author)

  16. Capsaicin effects on blinking Efectos de la capsaicina en el parpadeo

    Directory of Open Access Journals (Sweden)

    Fidias E. Leon-Sarmiento

    2005-09-01

    Full Text Available Blinking is a normal human phenomenom involving trigeminal and facial patways. To gain understanding on the neurobiology of blinking, five normal subjects were investigated before and after application of transdermal capsaicin at the forehead for two weeks. No effects of topical capsaicin were detected in eye blink rates. However, when capsaicin was applied to a female subject with blepharospasm, she showed a dramatic restoration of her vision subsequent to blinking modification. Deactivation of abnormal A-to-C fibers cross talks at the trigeminal-facial pathways seems to be the most likely mechanism of such improvement.El parpadeo es un fenómeno normal en los humanos que involucra las vías trigéminas faciales. Con el fin de conocer un poco más la neurobiología de este fenómeno estudiamos cinco individuos normales antes y después de aplicar capsaicina trasdérmica en la frente de cada uno de ellos, por dos semanas. La frecuencia de parpadeo no se alteró con la aplicación de capsaicina tópica. Sin embargo, cuando la misma sustancia se aplicó a una paciente con blefaroespasmo hubo dramática restauración de su visión, la cual fue secundaria a la modificación de la actividad muscular palpebral. La desactivación del cruce patológico de información que pasa de las fibras A a las fibras C, pertenecientes a las vías trigémino-faciales, parece ser el mecanismo de acción relacionado con la aplicación de capsaicina, el que estaría directamente relacionado con la recuperación clínica observada en la paciente con blefaroespasmo.

  17. Effect of photoactivation on the reduction of composite resin contamination.

    Science.gov (United States)

    Pauletti, Natalia A; Girotto, Luiza P S; Leite, Françoise H S; Mario, Débora N

    2017-06-01

    Composite resins are predominantly marketed in developing countries in tube form, and the contents of the tube may be used in numerous procedures for different patients. This represents a problem because of the risk of cross-contamination. This study aimed to evaluate contamination in vitro of the internal contents of composite resin tubes in the dental clinics of a higher-education institution, as well as the effect of photoactivation on the level of contamination. Twenty-five tubes containing composite resin were randomly chosen (by lottery). From each tube, two samples of approximately 2 mm of composite resin were removed, and then one sample, but not the other, was photoactivated. These samples were plated on Brain-Heart Infusion (BHI), Sabouraud and MacConkey agars, and the plates were incubated at 37°C for 24-48 h. Colony counting and Gram staining were performed for subsequent microscopic identification of fungi and bacteria. The non-photoactivated composite resin group presented significantly higher microbial contamination in relation to the photoactivated composite resin group. The photoactivation of camphorquinone present in composite resin produces reactive oxygen species, which might promote cell death of contaminant microorganisms. Thus, although the same tube of composite resin may be used for a number of different patients in the dental clinics of developing countries, the photoactivation process potentially reduces the risk of cross-contamination. © 2017 Eur J Oral Sci.

  18. Radioisotope studies of some effects and interactions of trace contaminants

    International Nuclear Information System (INIS)

    1976-01-01

    The coordinated programme of ''isotopic tracer-aided studies of the biological side-effects of foreign chemical residues in food and agriculture'', initiated in 1973, had involved the participation of 12 scientists from 10 countries. Pesticide residues, toxic metals, atmospheric sulphur dioxide were studied, and the use of radiotracer techniques as monitoring tools for existing contaminant levels or for their biological effects. The programme had been successful in the development and application of selected labelled substrate techniques. Specific aspects studied were the effects of environmental contaminants at the molecular level of the cell nucleus, the development and significance of radioimmunoassay procedure for trace contaminants, action and joint action of toxic elements, and the radiometric analysis of cholinesterase as an index of exposure to organophosphorus and carbamate pesticides. Ten papers were presented and 12 coordinated investigations discussed. A number of recommendations were made

  19. Radiolabelled substrates for studying biological effects of trace contaminants

    International Nuclear Information System (INIS)

    1975-01-01

    A programme of coordinated isotopic tracer-aided investigations of the biological side-effects of foreign chemical residues in food and agriculture, initiated in 1973, was reviewed. The current status of representative investigations from the point of view of techniques and priorities was assessed. Such investigations involved radioactive substrates for studying DNA injury and its repair; 14 C-labelled acetylcholine as substrate for measuring enzyme inhibition due to the presence of, or exposure to, anticholinesteratic contaminants; radioactive substrates as indication of side-effects in non-target organisms and of their comparative susceptibilities; radioactive substrates as indicators of persistence or biodegradability of trace contaminants of soil or water; and labelled pools for studying the biological side-effects of trace contaminants. Priorities were identified

  20. Honey irradiation: effect on hydroxymethylfurfural content; 'Irradiación de miel: efecto sobre el contenido de hidroximetilfurfural'

    Energy Technology Data Exchange (ETDEWEB)

    Cova, M. C.; Narvaiz, Patricia [Comisión Nacional de Energía Atómica, Ezeiza, (Argentina). Gerencia de Aplicaciones y Tecnología de Radiaciones

    2011-07-01

    Ionizing radiations can be used to inactivate thermo resistant microorganisms in honey, improving its hygienic and sanitary quality. 'American foulbrood' is a disease caused by the sporulated bacteria Paenibacillus larvae larvae which affects bees, diminishes honey production and impairs trade. Clostridium botulinum spores can also be present in honey and cause the disease in very young children. Considering that ionizing radiation can modify molecules, this work was undertaken to evaluate its effect on hydroxymethylfurfural (HMF) content along storage time. HMF is an aldehyde produced as sugars degrade due to excessive heating and/or time, so it is regulated as a freshness indicator in honey. Two varieties of honey, one fluid and the other creamy, of a commercial high quality brand were packaged in polypropylene recipes and stored at room temperature for 14 months. Irradiation was carried out at the semi industrial cobalt-60 facility of the Ezeiza Atomic Centre, about 600,000 Ci of activity, at doses of 0, 10, 20 and 40 kilo Grays, dose rate: 10 kGy/h, dose uniformity:1.1. HMF values, measured according to White ´s spectrophotometric method, increased along storage time in every sample. Irradiation initially diminished HMF content irrespective of dose, trend which was maintained throughout the storage period in creamy honey. Instead, in fluid honey since the fourth month the slopes corresponding to the irradiated samples curves were greater than that of the control one, as a function of dose, rendering higher HMF values in the 40 kGy sample as compared with control since the 10 th storage month. Possibly the prevailing first irradiation effect during storage time is HMF breakdown, followed by enhanced synthesis. (author) [Spanish] La radiación ionizante puede aplicarse a la miel para inactivar microorganismos termorresistentes y mejorar su calidad higiénico-sanitaria. La enfermedad 'Loque americana', que afecta a las abejas melíferas causando pérdidas de

  1. Overview of Emerging Contaminants and Associated Human Health Effects

    Directory of Open Access Journals (Sweden)

    Meng Lei

    2015-01-01

    Full Text Available In recent decades, because of significant progress in the analysis and detection of trace pollutants, emerging contaminants have been discovered and quantified in living beings and diverse environmental substances; however, the adverse effects of environmental exposure on the general population are largely unknown. This review summarizes the conclusions of the comprehensive epidemic literature and representative case reports relevant to emerging contaminants and the human body to address concerns about potential harmful health effects in the general population. The most prevalent emerging contaminants include perfluorinated compounds, water disinfection byproducts, gasoline additives, manufactured nanomaterials, human and veterinary pharmaceuticals, and UV-filters. Rare but statistically meaningful connections have been reported for a number of contaminants and cancer and reproductive risks. Because of contradictions in the outcomes of some investigations and the limited number of articles, no significant conclusions regarding the relationship between adverse effects on humans and extents of exposure can be drawn at this time. Here, we report that the current evidence is not conclusive and comprehensive and suggest prospective cohort studies in the future to evaluate the associations between human health outcomes and emerging environmental contaminants.

  2. Overview of Emerging Contaminants and Associated Human Health Effects

    Science.gov (United States)

    Lei, Meng; Zhang, Lun; Lei, Jianjun; Zong, Liang; Li, Jiahui; Wu, Zheng; Wang, Zheng

    2015-01-01

    In recent decades, because of significant progress in the analysis and detection of trace pollutants, emerging contaminants have been discovered and quantified in living beings and diverse environmental substances; however, the adverse effects of environmental exposure on the general population are largely unknown. This review summarizes the conclusions of the comprehensive epidemic literature and representative case reports relevant to emerging contaminants and the human body to address concerns about potential harmful health effects in the general population. The most prevalent emerging contaminants include perfluorinated compounds, water disinfection byproducts, gasoline additives, manufactured nanomaterials, human and veterinary pharmaceuticals, and UV-filters. Rare but statistically meaningful connections have been reported for a number of contaminants and cancer and reproductive risks. Because of contradictions in the outcomes of some investigations and the limited number of articles, no significant conclusions regarding the relationship between adverse effects on humans and extents of exposure can be drawn at this time. Here, we report that the current evidence is not conclusive and comprehensive and suggest prospective cohort studies in the future to evaluate the associations between human health outcomes and emerging environmental contaminants. PMID:26713315

  3. Energy scenarios and greenhouse effect gases emissions model for Mexico; Modelo de escenarios energeticos y de emisiones de gases de efecto invernadero para Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum Pardo, Claudia; Rodriguez Viqueira, Luis [Instituto de Ingenieria de la UNAM, Mexico, D. F. (Mexico)

    1998-12-31

    This paper presents the bases for the Model of Energy and Greenhouse Emission Scenarios (MEEEM) developed by the Instituto de Ingenieria de la UNAM (Universidad Nacional Autonoma de Mexico`s Engineering Institute). This model was built with the objective of analyzing the different technological options for the mitigation of the greenhouse gases effect on Mexico. The MEEEM is a model for the end uses that simulate in a simple way the energy demand, transformation and supply and calculates the differential leveled costs among a basic scenario and several mitigation scenarios of the greenhouse emissions. The article also presents some of the results in evaluating three technologies of renewable energy sources. Although the model is perfectible, its development shows its usefulness in this type of models in the decision taking for the energy and environmental planning of the country. [Espanol] Este articulo presenta las bases del Modelo de Escenarios Energeticos y de Emisiones de Gases de Efecto Invernadero para Mexico (MEEEM), desarrollado por el Instituto de Ingenieria de la Universidad Nacional Autonoma de Mexico (UNAM). Este modelo fue construido con el objetivo de analizar las diversas opciones tecnologicas de mitigacion de gases de efecto invernadero para Mexico. El MEEEM es un modelo de usos finales que simula de una manera sencilla, la demanda, transformacion y oferta de la energia y calcula la diferencia de costos nivelados entre un escenario base y diversos escenarios de mitigacion de emisiones de gases de efecto invernadero. El articulo presenta tambien algunos resultados obtenidos al evaluar tres tecnologias de fuentes renovables de energia. Aun cuando el modelo es perfectible, su desarrollo demuestra la utilidad de este tipo de modelos en la toma de decisiones para planeacion energetica y ambiental del pais.

  4. Energy scenarios and greenhouse effect gases emissions model for Mexico; Modelo de escenarios energeticos y de emisiones de gases de efecto invernadero para Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum Pardo, Claudia; Rodriguez Viqueira, Luis [Instituto de Ingenieria de la UNAM, Mexico, D. F. (Mexico)

    1999-12-31

    This paper presents the bases for the Model of Energy and Greenhouse Emission Scenarios (MEEEM) developed by the Instituto de Ingenieria de la UNAM (Universidad Nacional Autonoma de Mexico`s Engineering Institute). This model was built with the objective of analyzing the different technological options for the mitigation of the greenhouse gases effect on Mexico. The MEEEM is a model for the end uses that simulate in a simple way the energy demand, transformation and supply and calculates the differential leveled costs among a basic scenario and several mitigation scenarios of the greenhouse emissions. The article also presents some of the results in evaluating three technologies of renewable energy sources. Although the model is perfectible, its development shows its usefulness in this type of models in the decision taking for the energy and environmental planning of the country. [Espanol] Este articulo presenta las bases del Modelo de Escenarios Energeticos y de Emisiones de Gases de Efecto Invernadero para Mexico (MEEEM), desarrollado por el Instituto de Ingenieria de la Universidad Nacional Autonoma de Mexico (UNAM). Este modelo fue construido con el objetivo de analizar las diversas opciones tecnologicas de mitigacion de gases de efecto invernadero para Mexico. El MEEEM es un modelo de usos finales que simula de una manera sencilla, la demanda, transformacion y oferta de la energia y calcula la diferencia de costos nivelados entre un escenario base y diversos escenarios de mitigacion de emisiones de gases de efecto invernadero. El articulo presenta tambien algunos resultados obtenidos al evaluar tres tecnologias de fuentes renovables de energia. Aun cuando el modelo es perfectible, su desarrollo demuestra la utilidad de este tipo de modelos en la toma de decisiones para planeacion energetica y ambiental del pais.

  5. Biological effects of water reservoir radioactive contamination

    International Nuclear Information System (INIS)

    Mashneva, N.I.

    1983-01-01

    Radiation damage to fresh water fishes at early stages of ontogenesis is revealed only during the spawn incubation in a solution with 10 -5 to 10 -3 Cu/l radioactivity and at relatively high dosages exceeding 500-1000 rad. Damaging effect of a fission product mixture of 9, 30 and 100 day age as well as of several separate radionuclides on embryogenesis of freshwater fishes depends mainly on fish species, concentration, toxicity, chemical form of radionuclides in the residence medium, on peculiarities of metabolism between the aqueous medium and an organism, stage of the embryo development by the moment of radiation effect and duration of this effect

  6. Health effects estimation for contaminated properties

    International Nuclear Information System (INIS)

    Marks, S.; Denham, D.H.; Cross, F.T.; Kennedy, W.E. Jr.

    1984-05-01

    As part of an overall remedial action program to evaluate the need for and institute actions designed to minimize health hazards from inactive tailings piles and from displaced tailings, methods for estimating health effects from tailings were developed and applied to the Salt Lake City area. 2 references, 2 tables

  7. Cross-contamination in the kitchen: effect of hygiene measures

    NARCIS (Netherlands)

    Jong, de A.E.I.; Verhoeff-Bakkenes, L.; Nauta, M.J.; Jonge, de R.

    2008-01-01

    Aims: To determine the effect of hygiene measures on cross-contamination of Campylobacter jejuni at home and to select a safe tracer organism for C. jejuni. Methods and Results: Comparative tests were conducted with nonpathogenic Escherichia coli and Lactobacillus casei and L. casei was chosen as

  8. Effects of PAH-Contaminated Soil on Rhizosphere Microbial Communities

    DEFF Research Database (Denmark)

    Pritchina, Olga; Ely, Cairn; Smets, Barth F.

    2011-01-01

    Bacterial associations with plant roots are thought to contribute to the success of phytoremediation. We tested the effect of addition of a polycyclic aromatic hydrocarbon contaminated soil on the structure of the rhizosphere microbial communities of wheat (Triticum aestivum), lettuce (Lactuca...

  9. Application of effective variance method for contamination monitor calibration

    International Nuclear Information System (INIS)

    Goncalez, O.L.; Freitas, I.S.M. de.

    1990-01-01

    In this report, the calibration of a thin window Geiger-Muller type monitor for alpha superficial contamination is presented. The calibration curve is obtained by the method of the least-squares fitting with effective variance. The method and the approach for the calculation are briefly discussed. (author)

  10. Effective dielectric mixture model for characterization of diesel contaminated soil

    International Nuclear Information System (INIS)

    Al-Mattarneh, H.M.A.

    2007-01-01

    Human exposure to contaminated soil by diesel isomers can have serious health consequences like neurological diseases or cancer. The potential of dielectric measuring techniques for electromagnetic characterization of contaminated soils was investigated in this paper. The purpose of the research was to develop an empirical dielectric mixture model for soil hydrocarbon contamination application. The paper described the basic theory and elaborated in dielectric mixture theory. The analytical and empirical models were explained in simple algebraic formulas. The experimental study was then described with reference to materials, properties and experimental results. The results of the analytical models were also mathematically explained. The proposed semi-empirical model was also presented. According to the result of the electromagnetic properties of dry soil contaminated with diesel, the diesel presence had no significant effect on the electromagnetic properties of dry soil. It was concluded that diesel had no contribution to the soil electrical conductivity, which confirmed the nonconductive character of diesel. The results of diesel-contaminated soil at saturation condition indicated that both dielectric constant and loss factors of soil were decreased with increasing diesel content. 15 refs., 2 tabs., 9 figs

  11. Efecto a corto plazo de la vigabatrina en los espasmos infantiles Short term effect of vigabatrin in infantile spasms

    Directory of Open Access Journals (Sweden)

    Albia J. Pozo Alonso

    2007-03-01

    Full Text Available El objetivo de este trabajo fue valorar el efecto a corto plazo de la vigabatrina en 18 pacientes con el diagnóstico de espasmos infantiles. Trece pacientes fueron tratados en monoterapia, y 6 de ellos de primera intención. La dosis máxima promedio utilizada de vigabatrina fue de 130 mg/ (kg∙día (rango de 75 a 170 mg/ [kg∙día]. Los espasmos epilépticos cesaron en el 44,4 % de los casos a los 18,4 días como promedio tras el inicio del tratamiento con vigabatrina (rango de 3 a 43 días. La dosis promedio de respuesta a la vigabatrina fue de 103 mg/ (kg∙día (rango de 50 a 156 mg/ [kg∙día]. En el 16,7 % de los niños se logró la disminución de las crisis en más del 90 % y en el 5,6 % se redujeron los espasmos epilépticos en más del 50 %. Los espasmos epilépticos persistieron en el 33,3 %. Se obtuvo mejoría electroencefalográfica en el 55,6 % de los casos y en el 5,6 % desaparecieron las descargas. La hipsarritmia desapareció en el 75 % de los pacientes. Se debe continuar empleando la vigabatrina en monoterapia o como terapia adjunta en pacientes con espasmos infantiles.The purpose of this paper was to assess the short term effect of vigabatrin in 18 patients that were diagnosed infantile spasms. Thirteen of them were treated with monotherapy, and six of them were treated of first intention. The average maximum dose of vigabatrin was 130 mg/(kg∙day (range 75-170 mg/[kg∙day]. The epileptic spasms ceased in 44.4 % of the cases at 18.4 days as an average after the beginning of the treatment with vigabatrin (range 3 to 43 days. The average dose of response to vigabatrin was 103 mg/(kg∙day (range 50 to 156 mg/[kg∙day]. In 16.7 % of the children it was possible to reduce the crises more than 90 % , whereas in 5.6 % the epileptic spasms decreased more than 50 %. The epileptic spasms persisted in 33.3 %. An electroencephalographic improvement was observed in 55.6 % of the cases, and in 5.6 % the discharges vanished

  12. Effects of maximum dynamic exercise on electrocardiograms Efectos del ejercicio dinámico máximo sobre electrocardiograma

    Directory of Open Access Journals (Sweden)

    J. Ponce

    2010-09-01

    Full Text Available

     

    The effects of maximal dynamic exercise (sprint has been studied on the ECG of 100 greyhound who run in programmed 350 m races. Two ECG were taken in each animal: one before the race and the other after the effort. After the race there is a significant increase of the voltage in the waves P, R and T in DII, DIII and aVF, and the T waves are symetrical in 96% of the subjets. The highest voltage and duration of the P wawes represent the efficacy of the atrial function on the maintenance of the cardiac output. The increase of the amplitude of the R and T waves would be a consequence of the systolic volumen increase and the establishment of transitory myocardial ischemia. The average heart rate increases in 21.740"30.109 b.p.m., beeing the difference significant. When we analyse the ECG after exercise with the resting ECG in relation with age, weight, sex, category and rank we deduce that the differences arent related with those groups, except to the heart rate and age, observing that the capacity in increasing it decreases with age.
    KEY WORDS: Oxygen deficit, anaerobic capacity, performance, validity, fitness.

    Se han estudiado los efectos del ejercicio dinámico máximo (sprint sobre el ECG en 100 galgos greyhound que participaban en carreras programadas de 350 m. Se realizaron dos ECG en cada animal: uno antes de la carrera y otro postesfuerzo. Después de la carrera hay un aumento significativo del voltaje de las ondas P, R y T en DII, DIII y aVF, y las ondas T son simétricas en el 96% de los sujetos. El mayor voltaje y duración de las ondas P representan la eficacia de la función auricular para el mantenimiento del volumen minuto. El incremento de la amplitud de las ondas R y T sería consecuencia del aumento del volumen sistólico y de la instauración de isquemia miocárdica relativa transitoria. La

  13. Groundwater contamination and its effect on health in Turkey.

    Science.gov (United States)

    Baba, Alper; Tayfur, Gokmen

    2011-12-01

    The sources of groundwater pollution in Turkey are identified, and pathways of contaminants to groundwater are first described. Then, the effects of groundwater quality on health in Turkey are evaluated. In general, sources of groundwater contamination fall into two main categories: natural and anthropogenic sources. Important sources of natural groundwater pollution in Turkey include geological formations, seawater intrusion, and geothermal fluid(s). The major sources of anthropogenic groundwater contamination are agricultural activities, mining waste, industrial waste, on-site septic tank systems, and pollution from imperfect well constructions. The analysis results revealed that natural contamination due to salt and gypsum are mostly found in Central and Mediterranean regions and arsenic in Aegean region. Geothermal fluids which contain fluoride poses a danger for skeleton, dental, and bone problems, especially in the areas of Denizli, Isparta, and Aydın. Discharges from surface water bodies contaminate groundwater by infiltration. Evidence of such contamination is found in Upper Kızılırmak basin, Gediz basin, and Büyük Melen river basin and some drinking water reservoirs in İstanbul. Additionally, seawater intrusion causes groundwater quality problems in coastal regions, especially in the Aegean coast. Industrial wastes are also polluting surface and groundwater in industrialized regions of Turkey. Deterioration of water quality as a result of fertilizers and pesticides is another major problem especially in the regions of Mediterranean, Aegean, Central Anatolia, and Marmara. Abandoned mercury mines in the western regions of Turkey, especially in Çanakkale, İzmir, Muğla, Kütahya, and Balıkesir, cause serious groundwater quality problems.

  14. The Effect of Canal Contamination with Saliva on Apical Sealing

    Directory of Open Access Journals (Sweden)

    S Sabaghi

    2014-08-01

    Full Text Available Introduction: Root canal obturation aims at sealing the root canal system to prevent re-contamination of canal and periapical space. Presence of moisture in canal before obturation may posit a negative effect on the quality of canal sealing. Therefore, this study was conducted to investigate the effect of canal contamination with saliva on apical microleakage. Methods: In this laboratory study, 58 human uni-root teeth were cleaned and shaped for obturation with gutta percha and sealer AH26. In the case group, specimens were contaminated with human saliva immediately before obturation, whereas the teeth in the control group were kept dry. All canals were filled by lateral condensation technique. Moreover, the teeth were placed in methylene blue dye for 3 days. Dye penetration was measured using a stereomicrosope. As a matter of fact, the study data were analyzed via utilizing t-test. Results: A significant difference was found between the two groups in regard with the apical leakage(P<0.001. The microleakage mean of dye in the dry group was 3/48mm, whereas it was 6/36mm in the saliva contaminated group. Conclusion: The study findings revealed that complete drying of canal can improve apical sealing.

  15. The effect of compliance on contact lens case contamination.

    Science.gov (United States)

    Tilia, Daniel; Lazon de la Jara, Percy; Zhu, Hua; Naduvilath, Thomas J; Holden, Brien A

    2014-03-01

    To determine the efficacy of written instructions on contact lens case hygiene and to quantify the effect of noncompliance on contact lens case contamination. Data were retrospectively analyzed from 16 prospective, 3-month daily-wear studies during which six commercially available silicone hydrogel contact lenses and seven lens care solutions (LCS) were tested following a similar protocol. Verbal instructions regarding case hygiene (rinse case with LCS, not tap water) were given in nine studies, while the same instructions were given verbally and in written format in seven studies. A survey on contact lens, LCS, and lens case hygiene was completed at 1- and 3-month visits and compliance with case hygiene instructions was determined. Regular contact lens cases were used for 1 month and collected for microbial analysis at the 1- and 3-month visits. The rate of case contamination and the types of microbes contaminating cases were evaluated. Participants given verbal and written instructions were more likely to be compliant with case hygiene instructions than those just given verbal instructions (odds ratio [OR]: 2.19, p hygiene can be improved by effective communication of instructions. Contact lens wearers should be actively discouraged from rinsing contact lens cases with tap water because of the increased risk of GNB contamination.

  16. Evaluation of the effectiveness of countermeasures in contaminated forests

    International Nuclear Information System (INIS)

    Fesenko, S.; Voigt, G.; Spiridonov, S.; Gontarenko, I.

    2004-01-01

    In many regions subjected to the contamination forest products play an important role in radiation impact on the population. The contribution of mushrooms and berries to the internal doses varies depending on the time after the accident up to 40-45%. To protect people against additional exposure associated with forest contamination an appropriate system of countermeasures should be applied. The decision making framework to optimise implementation of forest countermeasures in the long term after the ChNPP accident is described. The approach is based on the analysis of the main exposure pathways related to contaminated forest and application of different criteria (reduction of individual dose to population and members of critical groups, cost for countermeasures implementation; cost of averted dose of 1 man-Sv; secondary ecological effect and psycho-social impact) for the selection of optimal countermeasures strategies. Because of diversity of these criteria for selection of optimal countermeasures a decision support technology based on a multi-attributive analysis is applied. Results of the application of the approach proposed for the study area (Novozybkov district, Bryansk region, Russian Federation) are presented. Applicability of twelve forest countermeasure options is evaluated and their effectiveness in terms of cost and dose reduction is estimated for the current period. It has been found that limitation on mushrooms or berries collections to the species with low accumulation of radionuclides and mushrooms processing before consumption (for the population) and combined application of Prussian Blue with limitation of tree harvesting to the area with low doses to decrease exposure of the critical groups members are most justified for the long term after the accident in the most contaminated regions of Russia. The results emphasize the effectiveness of the application of a flexible technique to provide the optimization of forest countermeasures taking into

  17. Efectos subletales de la lambda-cialotrina sobre Eisenia fetida (Annelida, Oligochaeta, Lumbricidae Sublethal effects of lambda-cyhalothrin on Eisenia fetida (Annelida, Oligochaeta, Lumbricidae

    Directory of Open Access Journals (Sweden)

    Tamara Ricardo

    2010-07-01

    Full Text Available El uso intensivo de agroquímicos provoca efectos dañinos sobre la fauna no blanco. Dentro de la misma, los oligoquetos contribuyen a mantener la estructura y fertilidad del suelo. La lambda-cialotrina es uno de los insecticidas piretroides más utilizados en la Argentina, pero son escasos los datos existentes acerca de su toxicidad sobre oligoquetos. Los objetivos de este trabajo fueron evaluar mediante bioensayos de toxicidad crónica los efectos de lambda-cialotrina (producto comercial al 5% en Eisenia fetida sobre los parámetros de comportamiento, sobrevivencia, biomasa, reproducción y bioacumulación, así como la persistencia en suelo OECD de dicho tóxico. Los resultados muestran un comportamiento de huída intenso a partir de la concentración más baja, con un EC50 de 1,36 mg kg-1 (95% C.L. 0,24 - 2,80. No se observaron efectos en sobrevivencia y alimentación. La reproducción fue afectada significativamente (F= 11,94, PThe intensive use of agrochemicals has deleterious effects on non-target organisms. Among these organisms, earthworms are important because of their role in keeping the soil structure and fertility. Lambda-cyhalothrin is one of the most widely used pyrethroid insecticide in Argentina, but there are not enough studies of the effects of this pesticide on earthworms. The goals of this work were to perform chronic toxicity bioassays to determine the effects of commercial lambda-cyhalothrin (at 5% on Eisenia fetida. The parameters of behaviour, survival, biomass, reproduction, bioaccumulation and the degradation time of lambda-cyhalotrin in an OECD standard soil were also estimated. Results showed a hard avoidance behaviour in the lowest lambda-cyhalothrin concentration with an EC50 of 1.36 mg kg-1 (95% C.L 0.24-2.80. Eisenia fetida chronic test survival and feeding were not affected by lambda-cyhalothrin but negative effects on reproduction were significant (P<0.05. Cocoon production and fertility were reduced and

  18. Contaminants as viral cofactors: assessing indirect population effects

    Science.gov (United States)

    Springman, Katherine R.; Kurath, Gael; Anderson, James J.; Emlen, John M.

    2005-01-01

    Current toxicological methods often miss contaminant effects, particularly when immune suppression is involved. The failure to recognize and evaluate indirect and sublethal effects severely limits the applicability of those methods at the population level. In this study, the Vitality model is used to evaluate the population level effects of a contaminant exerting only indirect, sublethal effects at the individual level. Juvenile rainbow trout (Oncorhynchus mykiss) were injected with 2.5 or 10.0 mg/kg doses of the model CYP1A inducer, β-naphthoflavone (BNF) as a pre-stressor, then exposed to a challenge dose of 102 or 104 pfu/fish of infectious hematopoietic necrosis virus (IHNV), an important viral pathogen of salmonids in North America. At the end of the 28-d challenge, the mortality data were processed according to the Vitality model which indicated that the correlation between the average rate of vitality loss and the pre-stressor dose was strong:R2 = 0.9944. Average time to death and cumulative mortality were dependent on the BNF dose, while no significant difference between the two viral dosages was shown, implying that the history of the organism at the time of stressor exposure is an important factor in determining the virulence or toxicity of the stressor. The conceptual framework of this model permits a smoother transfer of results to a more complex stratum, namely the population level, which allows the immunosuppressive results generated by doses of a CYP1A inducer that more accurately represent the effects elicited by environmentally-relevant contaminant concentrations to be extrapolated to target populations. The indirect effects of other environmental contaminants with similar biotransformation pathways, such as polycyclic aromatic hydrocarbons (PAH), could be assessed and quantified with this model and the results applied to a more complex biological hierarchy.

  19. Atmospheric contamination

    International Nuclear Information System (INIS)

    Gruetter, Juerg

    1997-01-01

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  20. Confirmatory research program: effects of atmospheric contaminants on commercial charcoals

    International Nuclear Information System (INIS)

    Bellamy, R.R.; Dietz, V.R.

    1979-01-01

    The increased use of activated charcoals in engineered-safety-feature and normal ventilation systems of nuclear power stations to continually remove radioiodine from flowing air prior to release to the environment has added importance to the question of the effect of atmospheric contaminants on the useful life of the charcoal. In January of 1977 the Naval Research Laboratory (NRL) began an investigation to determine the extent to which atmospheric contaminants in ambient concentrations degrade the efficiency of various commercially-available charcoals for removing methyl iodide. The approach employed by NRL is two-fold. First, charcoal samples are exposed to unmodified outdoor air for periods of one to nine months, then examined for methyl iodide retention, increase in weight, and the pH of water extract. The atmospheric contaminants are identified by the NRL Air Quality Monitoring Station, and concentrations of the various contaminants (ozone, SO 2 , NO 2 , CO 2 , methane and total hydrocarbons) are also available. Second, additional charcoal samples are exposed to the same pollutants under controlled laboratory conditions in various pollutant combinations. Results indicate that the water vapor-charcoal interaction is an important factor in the degradation of the commercial charcoals. Laboratory results indicate the pollutant sulfur dioxide plus water vapor can result in significant charcoal deterioration, as did ozone plus water vapor. Conversely, carbon monoxide did not appear to affect the charcoal. Also, differences were observed for various charcoals

  1. Effects of some sesquiterpenes on the stored-product insect Tenebrio molitor (Coleoptera: Tenebrionidae Efectos de algunos sesquiterpenos sobre el insecto de productos almacenados, Tenebrio molitor (Coleoptera: Tenebrionidae

    Directory of Open Access Journals (Sweden)

    Matías García

    2003-12-01

    Full Text Available In order to evaluate the allelochemical activity of some sesquiterpenes isolated from the native plant Tessaria absinthioides (Hook. et Arn. DC, and some semi synthetic derivatives against Tenebrio molitor L. larvae, we have developed bioassays directed to quantify repellency, larval mortality, and its effects on the development. Although costic aldehyde caused the maximum repellent effect, all the compounds showed a significant effect at some dose or time, indicating behavioral avoidance. The topical application of costic aldehyde produced the largest increase on the duration of the pupal stage. Tessaric acid exhibited the highest toxicity by topical application at the experiment closure. Both eremophilane-1(10,2,11(13-triene-12-oic, and -costic acids induced some morphological deformities.Con el objeto de evaluar sesquiterpenos aislados de la planta nativa Tessaria absinthioides (Hook et Arn y algunos derivados semisintéticos frente a larvas de Tenebrio molitor L., se desarrollaron bioensayos orientados a la cuantificación de la repelencia, mortalidad de larvas y efectos sobre el desarrollo. Aldehído cóstico produjo el mayor incremento en la duración del estado pupal por aplicación tópica. Acido tessárico exhibió el más alto porcentaje de mortalidad al finalizar el período de experimentación. Los productos eremophilan-1(10,2, 11(13-trien-12-oico y ácido -cóstico dieron lugar al mayor número de malformaciones. Si bien aldehído cóstico mostró la máxima actividad de repelencia, todos los compuestos evaluados produjeron efectos significativos en el ensayo de elección.

  2. Riesgo de aparición del efecto boomerang en las comunicaciones contra la violencia The Risk of Emergence of Boomerang Effect in Communication against Violence

    Directory of Open Access Journals (Sweden)

    José Antonio Ruiz San Román

    2011-10-01

    Full Text Available Los comportamientos violentos causan inquietud entre los responsables públicos (políticos, educadores, asistentes sociales, asociaciones de madres y padres, etc. que, desde diversos ámbitos, toman medidas que tratan de dar solución al problema de la violencia. La difusión de campañas institucionales de comunicación en contra de la violencia y el fomento de la publicación de noticias relacionadas con sucesos violentos suelen ser algunas de las acciones utilizadas. No obstante, parte de los datos y de la literatura disponible han demostrado que su eficacia no siempre es la esperada e, incluso, dichas acciones pueden llegar a tener efectos contrarios al deseado y reforzar las actitudes de los que piensan que la violencia es necesaria. Se sostiene la hipótesis de que la mayoría de la población asumiría como propios los mensajes contrarios a la violencia. Sin embargo –y esto es la cuestión clave y más problemática– son justo aquellos individuos con mayor propensión a la violencia (precisamente aquellos a quienes deberían dirigirse tales comunicaciones quienes podrían reaccionar ante el mensaje antiviolencia de un modo no deseado. Se da una dramática paradoja: el mensaje antiviolencia podría aumentar la predisposición a desarrollar comportamientos violentos. Estaríamos ante un caso de lo que cierta literatura denomina efecto boomerang. Por último, se señala la necesidad de un estudio detallado sobre determinados efectos de los medios de comunicación (insensibilización, imitación, accesibilidad y reactancia, que podrían ayudar a explicar la aparición de dicho efecto boomerang.Violent behaviors cause concern among people, policy makers, politicians, educators, social workers, parents associations, etc. From different fields and perspectives, measures are taken to try to solve the problem of violence. Institutional communication campaigns against violence and the publication of news related to violent events are often

  3. Predicted effects of countermeasures on radiation doses from contaminated food

    International Nuclear Information System (INIS)

    Yamamoto, Hideaki; Nielsen, S.P.; Nielsen, F.

    1993-02-01

    Quantitative assessments of the effects on radiation-dose reductions from nine typical countermeasures against accidental fod contamination have been carried out with dynamic radioecological models. The foodstuffs are assumed to be contaminated with iodine-131, caesium-134 and caesium-137 after a release of radioactive materials from the Ringhals nuclear power station in Sweden resulting from a hypothetical core melt accident. The release of activity of these radionuclides is assumed at 0.07% of the core inventory of the unit 1 reactor (1600 TBq of I-131, 220 TBq of Cs-134 and 190 TBq of Cs-137). Radiation doses are estimated for the 55,000 affected inhabitants along the south-eastern coast of Sweden eating locally produced foodstuffs. The average effective dose equivalent to an individual in the critical group is predicted to be 2.9 mSv from food consumption contaminated with I-131. An accident occurring during winter is estimated to cause average individual doses of 0.32 mSv from Cs-134 and 0.47 mSv from Cs-137, and 9.4 mSv and 6.8 mSv from Cs-134 and Cs-137, respectively, for an accident occurring during summer. Doses from the intake of radioiodine may be reduced by up to a factor of 60 by rejecting contaminated food for 30 days. For the doses from radiocaesium, the largest effect is found form deep ploughing which may reduce the dose by up to a factor of 80. (au) (12 tabs., 6 ills., 19 refs.)

  4. Effect of biodegradable amendments on uranium solubility in contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Duquene, L. [Belgian Nuclear Research Centre, Environment Health and Safety, Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium)], E-mail: lduquene@sckcen.be; Tack, F.; Meers, E. [Ghent University, Laboratory for Analytical Chemistry and Applied Ecochemistry, Coupure Links 653, B-9000 Gent (Belgium); Baeten, J. [Katholieke Hogeschool Kempen, Departement of Health-Care and Chemistry, Kleinhoefstraat 4, B-2440 Geel (Belgium); Wannijn, J.; Vandenhove, H. [Belgian Nuclear Research Centre, Environment Health and Safety, Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium)

    2008-02-25

    Chelate-assisted phytoextraction has been proposed as a potential tool for phytoremediation of U contaminated sites. In this context, the effects of five biodegradable amendments on U release in contaminated soils were evaluated. Three soils were involved in this study, one with a relatively high background level of U, and two which were contaminated with U from industrial effluents. Soils were treated with 5 mmol kg{sup -1} dry weight of either citric acid, NH{sub 4}-citrate/citric acid, oxalic acid, S,S-ethylenediamine disuccinic acid or nitrilotriacetic acid. Soil solution concentration of U was monitored during 2 weeks. All amendments increased U concentration in soil solution, but citric acid and NH{sub 4}-citrate/citric acid mixture were most effective, with up to 479-fold increase. For oxalic acid, S,S-ethylenediamine disuccinic acid and nitrilotriacetic acid, the increase ranged from 10-to 100-fold. The highest concentrations were observed 1 to 7 days after treatment, after which U levels in soil solution gradually decreased. All amendments induced a temporary increase of soil solution pH and TOC that could not be correlated with the release of U in the soil solution. Thermodynamic stability constants (log K) of complexes did not predict the relative efficiency of the selected biodegradable amendments on U release in soil solution. Amendments efficiency was better predicted by the relative affinity of the chelate for Fe compared to U.

  5. Aging effects on oil-contaminated Kuwaiti sand

    International Nuclear Information System (INIS)

    Al-Sanad, H.A.; Ismael, N.F.

    1997-01-01

    Large quantities of oil-contaminated sands resulted from the destruction of oil wells and the formation of oil lakes in Kuwait at the end of the Gulf Wa/r. A laboratory testing program was carried out to determine the geotechnical properties of this material and the effect of aging on their properties. Tests included direct shear, triaxial, and consolidation tests on clean and contaminated sand at the same relative density. The influence of aging was examined by testing uncontaminated sand after aging for one, three, and six months in natural environmental conditions. The results indicated increased strength and stiffness due to aging and a reduction of the oil content due to evaporation of volatile compounds. The factors that influence the depth of oil penetration in compacted sand columns were also examined including the type of oil, relative density, and the amount of fines

  6. Effects of environmental contaminants on reptiles: A review

    Science.gov (United States)

    Hall, R.J.

    1980-01-01

    The literature relating to the effects of environmental contaminants on reptiles is reviewed and certain generalizations based on studies of other kinds of vertebrates are presented. Reports of reptilian mortality from pesticide applications are numerous enough to establish the sensitivity of reptiles to these materials. Reports of residue analyses demonstrate the ability of reptiles to accumulate various contaminants. but the significance of the residues to reptilian populations is unknown. A few authors have reported the distribution of residues in reptilian tissues; others have investigated uptake or loss rates. Physiological studies have shown that organochlorines may inhibit enzymes involved in active transport and have correlated the activity of potential detoxifying enzymes with residue levels. There is some suggestion that pesticide residues may interfere with reproduction in oviparous snakes. Needs for future research are discussed.

  7. Efectos de tratamientos de labranza sobre la resistencia a la penetración de un Andisol Effects of tillage treatments on penetration resistance on an andisol

    Directory of Open Access Journals (Sweden)

    Jiménez Javier

    1992-06-01

    Full Text Available Se evaluó el efecto sobre la resistencia a la penetración de cuatro implementos de labranza (arado de cinceles, arado de discos, rastrillo californiano y arado rotatorio en un Andisol (Andic-Eutropept serie Tibaitatá. Para las medidas, se utilizó un penetrómetro registrador digital. Los resultados mostraron que los tratamientos que involucraron arado rotatorio y arado de discos y rastrillo fueron los que causaron el mayor grado de aflojamiento del suelo. Sin embargo, dichos tratamientos fueron los más susceptibles a la compactación por pase de llantas. No se pudo concluir lo planteado por la literatura de que el fondo de surco de arado es una zona de alto
    riesgo de compactación del subsuelo. La resistencia a la penetración resultó un buen indicador para evaluar efectos físicos sobre el suelo causarlos por implementos de labranza y él tránsito de maquinaria.The effects on Cone Penetration Resistance caused by four tillage implements (chisel plow, disk plough, disk harrow and rotatiller were assesed on an Andisol, using a digital penetrometer. The results showed the treatments using rota-tiller and those using disk plough and disk harrow caused
    the maximun soilloosening. However those treatments were the most sensitive to compaction due to the traffic of tractor
    wheels. This work did not present conclusive evidence that bottom of furrow made by disk plough is a place of high risk for subsoil cornpactlon. Cone penetration resistance looks like a good index to assess changes in physical properties of the soil caused by tillage operations and machinery traffic.

  8. Estimation of biological effects of phytocenosis radioactive contamination

    International Nuclear Information System (INIS)

    Suvorova, L.I.; Smirnov, E.G.; Shejn, G.N.

    1990-01-01

    Biological effects of argicultural field contamination in the Chernobyl NPP 30-km zone in the period of 1986-1988 are studies. Depth of some kings of herbs is noted in spite of natural phytocenosis high stability. It is revealed that increased mutageneous effect is observed for seeds from phytocenosis subjected to radiation factor effects. The genetic radiation effects at cell level will be observed in the nearest years as the radiation factor will not disappear in the 30-km zone (chronic irradiation of plants in the dose range from 0.1x10 -4 up to 0.1 Gy/day). These injuries visually will not effect greatly on natural populations

  9. Effects of Biofertilizers Combined with Different Soil Amendments on Potted Rice Plants Efecto de Biofertilizantes Combinado con Enmiendas del Suelo sobre Plantas de Arroz en Macetas

    Directory of Open Access Journals (Sweden)

    Arshad Javaid

    2011-03-01

    Full Text Available This pot study investigated the effect of the combined application of two commercial biofertilizers viz. Biopower and EM (Effective Microorganisms on rice (Oryza sativa L. growth and yield in soils amended with farmyard manure, green manure, and NPK fertilizers. Biopower is a product of the Nuclear Institute for Biotechnology and Genetic Engineering (NIBGE, Pakistan, which contains species of associative and endophytic diazotrophs. EM (effective microorganisms, a product developed by Japanese scientists, consists of co-existing beneficial microorganisms, mainly species of photosynthetic and lactic acid bacteria, as well as yeast. Applying Biopower adversely affected plant growth and yield in NPK fertilizer amendment. Conversely, this biofertilizer markedly enhanced plant growth and yield in green manure amended soil while its effect was not significant in farmyard manure amendment. In green manure amendment, applying EM enhanced grain yield by 46%. Co-inoculation of Biopower and EM evidently improved root and shoot growth in farmyard manure amended soil. This study concludes that the two biofertilizers clearly enhanced shoot biomass and grain yield in green manure amended soils.El presente estudio en macetas fue realizado para investigar el efecto de la aplicación combinada de dos biofertilizantes comerciales, Biopower y EM (Effective Microorganisms, en el crecimiento y producción de arroz (Oryza sativa L. en suelos enmendados con estiércol de granja, abono verde y fertilizantes NPK. Biopower es un producto del Nuclear Institute for Biotechnology and Genetic Engineering (NIBGE, Pakistán, que contiene especies de diazótrofos asociativos y endofíticos. Effective Microorganisms es un producto desarrollado por científicos japoneses que consiste en microorganismos benéficos co-existentes, principalmente especies de bacterias fotosintéticas y ácido lácticas, y levadura. La aplicación de Biopower afectó adversamente el crecimiento y

  10. [Stabilization and long-term effect of chromium contaminated soil].

    Science.gov (United States)

    Wang, Jing; Luo, Qi-Shi; Zhang, Chang-Bo; Tan, Liang; Li, Xu

    2013-10-01

    Short-term (3 d and 28 d) and long-term (1 a) stabilization effects of Cr contaminated soil were investigated through nature curing, using four amendments including ferrous sulfide, ferrous sulfate, zero-valent iron and sodium dithionite. The results indicated that ferrous sulfide and zero-valent iron were not helpful for the stabilization of Cr(VI) when directly used because of their poor solubility and immobility. Ferrous sulfate could effectively and rapidly decrease total leaching Cr and Cr(VI) content. The stabilization effect was further promoted by the generation of iron hydroxides after long-term curing. Sodium dithionite also had positive effect on soil stabilization. Appropriate addition ratio of the two chemicals could help maintain the soil pH in range of 6-8.

  11. Study of the effect of the NO{sub 2} in the atmospheric corrosion of copper; Estudio del efecto del NO{sub 2} en la corrosion atmosferica del cobre

    Energy Technology Data Exchange (ETDEWEB)

    Mariaca Rodriguez, Liboria

    1997-12-31

    Factors as the increase of the power consumption and the development of new combustion technologies, together with the increasing campaigns for the diminution of the SO{sub 2} emissions, have given rise to an increase of the relative importance of other atmospheric polluting agents, among which the nitrogen oxides occupy preponderant place. This new situation has motivated that during the last years greater attention is appearing to the effect these oxides can have on the stability of the materials. However, the results still are scarce and sometimes contradictory. With the purpose of contributing to the understanding of the effect of the NO{sub x} in the atmospheric corrosion, the investigation that is shown here was made. The effect that the NO{sub 2} has in the atmospheric corrosion of copper was studied, considering cases with and without the simultaneous presence of SO{sub 2}, with different relative humidities (RH) and temperatures of the atmospheric air. For this purpose one resorted to the simulation of atmospheres of interest by means of laboratory chambers that allowed the control of the temperature, RH and the contamination level. In each atmosphere completely clean copper coupons were exposed, and withdrawn at 7, 14, 21 and 28 days. Gravimetric analyses of gain and loss of mass and one complete characterization the corrosion products formed was made, mainly by means of X ray diffraction techniques by grazing angle (DRS), and photo electronic X ray spectroscopy (XPS or ESCA). Also, the applicability in these conditions of the electrochemical techniques of DC (RP, CP and RE) and of alternating current (EIE). From the results obtained it is worth mentioning as the more important the following ones: The corrosion of copper in atmospheres contaminated solely with NO{sub 2} depends fundamentally on the RH, not existing, as in the case of other metals, a critical RH (CRH), from which the kinetics of the corrosion process increases; all the opposite, the copper

  12. Efecto de la nueva regulación antitabaco en Italia Effects of new smoking regulations in Italy

    Directory of Open Access Journals (Sweden)

    Teresa Rodríguez

    2006-01-01

    Full Text Available OBJETIVO: Se realizó un estudio poblacional para conocer las actitudes relacionadas con la Nueva Ley Italiana Antitabaco y el efecto sobre el consumo. MATERIAL Y MÉTODOS: Se analizó una muestra de 3 114 individuos mayores de 15 años representativos de la población general adulta italiana. RESULTADOS: Tras la entrada en vigor de las políticas antitabaquismo, el apoyo a ellas aumentó y además contribuyeron con 8% al descenso del consumo de cigarrillos en el corto plazo. Las prohibiciones antitabaco se aceptaron casi de modo unánime y al parecer no afectaron de manera desfavorable a restaurantes y cafeterías. CONCLUSIONES: Los resultados muestran las ventajas de esta nueva legislación, que puede tener importantes implicaciones en la salud pública.OBJETIVE: A population-based survey was conducted to know the attitudes towards new Italian smoke-free regulations and its impact on tobacco consumption. MATERIAL AND METHODS: We considered 3 114 subjects aged 15 or over, representative of the general adult Italian population. RESULTS: Once smoke-free policies were introduced, support for them tended to increase. Smoke-free policies accounted for 8% decrease in cigarette consumption in the short run. Tobacco bans were almost universally accepted, and do not seem to unfavourably affect the business of restaurants or cafes. CONCLUSIONS: The results of our study, show the advantages of smoke-free legislations, which may have major public health implications.

  13. Uranium: properties and biological effects after internal contamination

    International Nuclear Information System (INIS)

    Souidi, M.; Tissandie, E.; Racine, R.; Ben Soussan, H.; Rouas, C.; Grignard, E.; Dublineau, I.; Gourmelon, P.; Lestaevel, P.; Gueguen, Y.

    2009-01-01

    Uranium is a radionuclide present in the environment since the origin of the Earth. In addition to natural uranium, recent deposits from industrial or military activities are acknowledged. Uranium's toxicity is due to a combination of its chemical (heavy metal) and radiological properties (emission of ionizing radiations). Acute toxicity induces an important weight loss and signs of renal and cerebral impairment. Alterations of bone growth, modifications of the reproductive system and carcinogenic effects are also often seen. On the contrary, the biological effects of a chronic exposure to low doses are unwell known. However, results from different recent studies suggest that a chronic contamination with low levels of uranium induces subtle but significant levels. Indeed, an internal contamination of rats for several weeks leads to detection of uranium in many cerebral structures, in association with an alteration of short-term memory and an increase of anxiety level. Biological effects of uranium on the metabolisms of xenobiotics, steroid hormones and vitamin D were described in the liver, testis and kidneys. These recent scientific data suggest that uranium could participate to increase of health risks linked to environmental pollution. (authors)

  14. Efectos del D-002, el extracto de semilla de uva y su terapia combinada sobre marcadores oxidativos en ratas - Effects of D-002, a grape seed extract and their combined therapy on oxidative markers in rats

    OpenAIRE

    Oyarzábal Yera, Ambar; Molina Cuevas, Vivian; Mas Ferreiro, Rosa; Jiménez Despaigne, Sonia; Curveco Sánchez, Dayisell

    2012-01-01

    ABSTRACTD-002, a mixture of high molecular weight alcohols from beeswax (Appis mellifera), and grape seed extract (Vitis vinifera, L), rich in flavonoids, presents antioxidant effects, but no previous study had compared such effects.RESUMEN El D-002, mezcla de alcoholes de alto peso molecular obtenida de la cera de las abejas (Appis mellifera) y el extracto de semillas de uva (Vitis vinifera, L), rico en flavonoides, presentan efectos antioxidantes, pero estudios previos no han comparado tale...

  15. Efecto de diferentes dosis de aspirina sobre el precondicionamiento contra el atontamiento en ovejas Effect of different doses of aspirin on preconditioning against stunning in conscious sheep

    Directory of Open Access Journals (Sweden)

    Elena C. Lascano

    2004-02-01

    Full Text Available Se ha postulado que los antiinflamatorios no esteroides que actuan inhibiendo la ciclooxigenasa (COX podrían tener efectos nocivos sobre el corazón. Recientemente se ha demostrado que los inhibidores de la COX-2 bloquean la protección por precondicionamiento tardío (PT. Se desconoce sin embargo, el efecto que pudiera tener la aspirina, el antiinflamatorio no esteroide más ampliamente utilizado en la clínica, sobre el PT en mamíferos grandes. La aspirina actúa inhibiendo las dos isoenzimas de la ciclooxigenasa (COX-1 y COX-2, siendo empleada en dosis altas como droga antiinflamatoria y en dosis bajas como agente antitrombótico. El propósito de este estudio fue analizar qué efecto tienen distintas dosis de aspirina sobre la protección del PT contra el atontamiento y las arritmias en ovejas conscientes. Se consideraron 5 grupos; control (C: 12 min de isquemia (I y 2 hr de reperfusión (R; PT: 6 períodos de 5 min I-5 min R, 24 hr antes de la I de 12 min, y tres grupos igual que PT, pero con 1.5 (PTA1.5, 8 (PTA8 y 20 (PTA20 mg/kg de aspirina respectivamente, administrados 10 min antes de la primera I de precondicionamiento. Los resultados demostraron que la dosis antiinflamatoria de aspirina (20 mg/kg fue capaz de inhibir el PT contra el atontamiento (C vs PTA20, NS, mientras que las dosis bajas (1.5 mg/kg e intermedia (8 mg/kg no afectaron la protección (C vs PT, PT1.5 y PT8, pNon-steroid antiinflammatory drugs, inhibitors of cyclooxigenase (COX, have been postulated to have deletereous effects on the heart. Recently, COX-2 inhibitors have also been found to block late preconditioning (LP protection. Aspirin is the most widely clinically used non-steroid antiinflammatory drug; yet its effect on LP in big mammals has not been determined. It inhibits the two cyclooxigenase isoenzymes (COX-1 and COX-2, at high doses being used as an antiinflammatory drug and at low doses as an antithrombotic agent. The goal of this study was thus, to

  16. Influencia del reclutamiento alveolar sobre los efectos del surfactante exógeno Influence of pulmonary recruitment on exogenous surfactant effects

    Directory of Open Access Journals (Sweden)

    Néstor R. Herrera

    2006-02-01

    Full Text Available Se investigaron los efectos producidos por una maniobra de insuflación sostenida previa a la administración de surfactante exógeno y los producidos por diferentes patrones ventilatorios sobre la respuesta al mismo. Se estudiaron 20 ratas albinas adultas a las que se les produjo una injuria pulmonar por repetidos lavados con solución fisiológica. Se evaluó el pH, PaO2, PaCO2, la presión arterial sistólica, la compliance toracopulmonar y la histología. Los animales se dividieron en 2 grupos según se les hubiera aplicado o no insuflación sostenida para evaluar el efecto inmediato de la misma. Posteriormente los grupos citados fueron subdivididos en función de la capacidad residual funcional (CRF aplicada, quedando conformados 4 grupos experimentales. El grupo 1 recibió previo al surfactante una insuflación sostenida de 30 cm H2O durante 15 segundos y se ventiló posteriormente con presión al final de la espiración (PEEP de10 cm H2O. El grupo 2, no recibió insuflación sostenida y se ventiló con PEEP 10 cm H2O. El grupo 3, recibió insuflación sostenida y se ventiló con PEEP 4 cm H2O y el grupo 4, sin insuflación sostenida se ventiló con PEEP 4 cm H2O. Los efectos inmediatos del surfactante no fueron modificados por la aplicación previa de insuflación sostenida. Se verificó durante el transcurso de la experiencia un aumento de la PaO2 asociada al aumento de la capacidad residual funcional (Grupo1 p=0.0001; Grupo2 p= 0.0001, e independiente de la insuflación sostenida. El uso de insuflación sostenida previo a la administración de surfactante sumado a la ventilación con capacidad residual funcional alta se asoció con infiltración de polimorfonucleares debajo del epitelio bronquiolar (p = 0.008. Nuestros resultados no avalan el uso de insuflación sostenida previo a la administración de surfactante exógeno.An experimental modelwas devised to study the effects of a sustained insufflation maneuver on the immediate

  17. Effects of blood contamination on resin-resin bond strength.

    Science.gov (United States)

    Eiriksson, Sigurdur O; Pereira, Patricia N R; Swift, Edward J; Heymann, Harald O; Sigurdsson, Asgeir

    2004-02-01

    Incremental placement and curing of resin composites has been recommended. However, this requires longer operating time, and therefore, increased risk of contamination. The purpose of this study was to evaluate the effects of blood contamination on microtensile bond strengths (microTBS) between resin interfaces and to determine the best decontamination method to re-establish the original resin-resin bond strength. The top surfaces of 64, 4-mm composite blocks (Z-250, Renew, APX, Pertac II) were untreated as the control, or were treated as follows: blood applied and dried on the surface (Treatment 1), blood applied, rinsed, dried (Treatment 2), blood applied, rinsed, and an adhesive applied (Single Bond, One-Step, Clearfil SE, Prompt L-Pop) (Treatment 3). Fresh composite was applied and light-cured in 2-mm increments. After 24 h storage in water, the specimens were sectioned into 0.7-mm thick slabs, trimmed to a cross-sectional area of 1 mm(2), and loaded to failure at a crosshead speed of 1 mm/min using an Instron universal testing machine. Data were analyzed using two-way ANOVA and Fisher's PLSD test (pcontamination resulted in resin-resin bond strengths of only 1.0-13.1 MPa. Rinsing raised bond strengths to over 40 MPa for each material. Use of an adhesive further increased bond strengths except for Pertac II. Rinsing blood from contaminated surfaces increases the resin-resin bond strength significantly and the application of an appropriate adhesive increases the bond strength to control levels.

  18. Acumulación de plomo en hueso y sus efectos en la salud Lead storage in bone and its effects on health

    Directory of Open Access Journals (Sweden)

    Luz Helena Sanín

    1998-07-01

    Full Text Available Los efectos nocivos del plomo han sido conocidos desde tiempos antiguos por su amplia gama; este metal afecta prácticamente todos los órganos y sistemas del cuerpo humano. Recientemente se han documentado efectos tóxicos crónicos en los sistemas cardiovascular y nervioso, con niveles que antes se consideraban seguros. El sitio primario de almacenamiento de plomo en el organismo es el hueso, pero sólo hasta fechas recientes se ha clarificado la significancia toxicológica de este hecho. En este artículo se analiza el papel del plomo en hueso como fuente de exposición endógena, como biomarcador de exposición crónica y como tejido blanco. Se presentan además los avances recientes para la medición de plomo en hueso mediante los rayos X-fluorescentes (XRF. Finalmente se revisa la importancia, para la salud pública, de estudiar y medir el plomo en hueso en lugares con una historia de exposición crónica como la Ciudad de México y en los ambientes ocupacionales, especialmente como fuente remanente de exposición. Se analiza especialmente el caso de mujeres en edad reproductiva, quienes pueden convertirse en fuentes de exposición para el feto y para el niño amamantado.The adverse effects of lead have been known for long since the metal affects practically all organs and systems of the human body. Recently, toxic effects have been reported in the cardiovascular and nervous systems at lead levels previously considered to be secure. The main lead storage site in the body is bone. The toxicologic significance of this fact has been clarified only recently. The present study analyzes the role of lead as an endogenous source of exposure, as a chronic exposure biomarker and as a target organ. Recent advances to measure bone lead through fluorescent X-Rays are discussed. Additionally, the importance of bone lead from a public health perspective in places with a chronic history of exposure such as Mexico City, and in some occupational

  19. Los efectos placebo de la relación médico-paciente The placebo effects of the physician-patient relationship

    Directory of Open Access Journals (Sweden)

    Ricardo González Menéndez

    2004-12-01

    Full Text Available Luego de breves comentarios históricos que abordan la influencia del primer modelo psicoterapéutico en la ya superada tendencia a considerar la psicoterapia como fuera del alcance del médico generalista, se comentan los aportes de Carl Rogers al enfatizar la trascendencia de las actitudes del facultativo en la relación interpersonal y su mayor trascendencia sobre los métodos y recursos psicoterapéuticos elegidos. Se destaca igualmente los resultados similares obtenidos en estudios orientados a comparar diferentes modalidades psicoterapéuticas, hallazgos que ratifican la importancia de los vínculos afectivos establecidos entre el profesional de la salud y sus pacientes cuando la relación médico-paciente es exitosa. Se describen los 6 efectos placebo de esta relación descritos por Shapiro y Frank desde 1971 y se agregan otros 4 surgidos de las reflexiones del equipo de trabajo del autor. Se insiste en que las limitaciones iniciales establecidas al médico generalista sobre sus responsabilidades psicoterapéuticas, resultan actualmente insostenibles para los facultativos capaces de sensibilizarse ante el drama humano de un paciente. Se concluye que las pontecialidades terapéuticas implícitas en los efectos placebos descritos justifican cada vez más la incursión del médico generalista en la relación de ayuda psicológica.After some brief historical comments dealing with the influence of the first psychotherapeutic model on the already overcome trend to consider psychotherapy as out of the reach of the general physcian, the contributions of Carl Rogers are exposed on emphasizing the transcendency of the physcian's attitudes in the interpersonal relation and its greater transcendence in relation to the selected psychotherapeutic methods and resources. The similar results attained in the studies oriented to compare different psychotherapeutic modalities are also stressed. These findings ratify the importance of the affective links

  20. El efecto invernadero

    OpenAIRE

    Sánchez Vega, Marco Vinicio

    2016-01-01

    El aumento de la concentración de los gases conocidos como de efecto invernadero, tales como el dióxido de carbono, el metano y los óxidos de nitrógeno, entre otros, hace que la atmósfera retenga un porcentaje superior del calor emitido por la Tierra, produciéndose un calentamiento global. Este calentamiento podría, si alcanzara niveles críticos, fundir parte de los casquetes polares, lo que elevaría el nivel de los mares, provocando inundaciones de algunas zonas costeras donde se concentra u...

  1. Osteoporosis grave con aplastamientos vertebrales en dermatomiositis juvenil: Efecto del tratamiento con alendronato oral Severe osteoporosis with vertebral crushes in juvenile dermatomyositis: Effect of oral alendronate therapy

    Directory of Open Access Journals (Sweden)

    Cristina Tau

    2007-02-01

    Full Text Available Los glucocorticoides son usados comúnmente para el tratamiento de enfermedades inflamatorias, autoinmunes, enfermedades malignas, y en la prevención de rechazo de órganos trasplantados. Un efecto secundario frecuente del tratamiento prolongado es la pérdida de masa ósea que se produce por varios mecanismos y es causa de osteoporosis y fracturas vertebrales. El tratamiento con disfosfonatos ha sido propuesto para esta situación. Presentamos un caso clínico de osteoporosis grave en una niña con dermatomiositis juvenil, que respondió favorablemente al tratamiento con disfosfonatos orales.Glucocorticoids are used for the treatment of inflammatory and autoimmune diseases, cancer, and in prevention of organ rejects. A frequent secondary effect of longterm treatment with corticoids is the loss of bone mass, caused by several mechanisms: decrease in the intestinal calcium absorption, increase of the renal calcium excretion at the distal renal tubule, suppressive effect on the osteoblast and also in apoptosis of osteoclasts, inhibition in local production of IGF I (Insulin-like growth factor and IGFBPs (binding IGF I proteins necessary for bone metabolism, and decrease on osteocalcin production. Longterm treatment with corticoids is associated with osteoporosis and vertebral fractures. To improve this condition, treatment with bisphosphonates has been proposed. We present here a clinical case of a girl with dermatomyositis and severe osteoporosis with vertebral crushes, who responded well to oral bisphophonate treatment.

  2. Groundwater arsenic contamination and its health effects in India

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Das, Bhaskar; Chatterjee, Amit; Das, Dipankar; Nayak, Biswajit; Pal, Arup; Chowdhury, Uttam Kumar; Ahmed, Sad; Biswas, Bhajan Kumar; Sengupta, Mrinal Kumar; Hossain, Md. Amir; Samanta, Gautam; Roy, M. M.; Dutta, Rathindra Nath; Saha, Khitish Chandra; Mukherjee, Subhas Chandra; Pati, Shyamapada; Kar, Probir Bijoy; Mukherjee, Adreesh; Kumar, Manoj

    2017-06-01

    During a 28-year field survey in India (1988-2016), groundwater arsenic contamination and its health effects were registered in the states of West Bengal, Jharkhand, Bihar and Uttar Pradesh in the Ganga River flood plain, and the states of Assam and Manipur in the flood plain of Brahamaputra and Imphal rivers. Groundwater of Rajnandgaon village in Chhattisgarh state, which is not in a flood plain, is also arsenic contaminated. More than 170,000 tubewell water samples from the affected states were analyzed and half of the samples had arsenic >10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.

  3. Efectos de los factores de edificabilidad sobre la productividad laboral de moldajes de vigas en fundaciones The effects of buildability factors on formwork labor productivity of grade beams

    Directory of Open Access Journals (Sweden)

    Abdulaziz M Jarkas

    2010-08-01

    Full Text Available La edificabilidad es uno de los factores principales que afecta la productividad laboral. Sin embargo, una extensa revisión de la literatura reveló la ausencia de investigación sobre sus efectos en obras de construcción de concreto reforzado, especialmente a nivel del oficio del trabajo de moldeado. A pesar de la importancia de este oficio para el concreto reforzado en obras, la influencia de los factores de edificabilidad sobre la productividad del oficio del moldeado sobre elementos estructurales mayores, aún está por ser cuantificada en términos medibles. Las vigas en fundaciones son elementos estructurales importantes, usados para proporcionar una, o una combinación de las siguientes funciones: (1 amarrar los cimientos de la edificación y proporcionar la rigidez lateral en los niveles sub-estructurales; (2 reducir la longitud libre de las columnas sin soporte, bajo el nivel de la rasante; (3 limitar el excesivo diferencial de asentamientos en los cimientos aislados. Por lo tanto, el objetivo de esta investigación es analizar y cuantificar los efectos e influencia relativa de los siguientes factores de edificabilidad, sobre la eficiencia del trabajo de moldeado de esta actividad: (a la variabilidad del tamaño de las vigas, (b tamaño de las vigas, (c cantidad de juntas resultantes de las intersecciones de las vigas. Con el fin de lograr este objetivo, un gran volumen de datos sobre la productividad ha sido recopilado usando un método de regresión múltiple. Como resultado, se determinaron los efectos e influencia relativa de los factores de edificabilidad investigados. A parte de la variabilidad de tamaño de las vigas, los descubrimientos indican significativos efectos de estos factores sobre la productividad del trabajo de moldeado, la que puede ser empleada para entregar un comentario a los diseñadores sobre cuan bien sus diseños consideran las necesidades de los principios de edificabilidad, y las consecuencias de sus

  4. Electrochemical migration in electronics: effect of contamination and bias conditions

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    A number of reliability issues are caused by mechanisms different from the conventional corrosion due to specific aspects of the printed circuit board assembly (PCBA). The size of the components and the distance between them, combinations of dissimilar metals, voltage and temperature gradients...... – all together influence susceptibility of electronic PCBA to corrosion. When electronics is operating under humid conditions, the cleanliness of the PCBA becomes essential, since corrosion related failures in electronics can occur at extremely low levels of moisture and contamination. A synergetic...... effect of the aspects mentioned above makes it challenging to predict the lifetime of electronic device. The aim of this work is to investigate corrosion influencing factors, which at a later stage improve capabilities of predicting the functioning and herewith reliability of electronics under certain...

  5. El Acuerdo TransPacífico y su efecto en América Latina/ The TransPacific Partnership Agreement and its effects on Latin America

    Directory of Open Access Journals (Sweden)

    Sergio Caballero Santos

    2013-12-01

    Full Text Available Actualmente se están negociando un Acuerdo TransPacífico en comercio e inversión, que abarca a un gran número de países bañados por el océano del mismo nombre, al mismo tiempo que se avanza en un acuerdo trans-Atlántico entre Estados Unidos y la Unión Europea. En este trabajo se aborda este escenario de megabloques comerciales desde la óptica de los efectos que pueda acarrear para América Latina y se visibiliza cómo estas formas de inserción internacional también ponen de manifiesto las diferentes lógicas existentes en el contexto latinoamericano. A TransPacific Trade and Investment Partnership Agreement is currently being negotiated among a great amount of countries in both sides of the Pacific ocean, while developing a TransAtlantic Partnership between the US and the EU. In this work this commercial scenario, covering several continents, is presented from a Latin American perspective, emphasizing the effects that these agreements could produce on this region. And furthermore, the analysis of these ways of international insertion shows us the competing logics which coexist across the Latin American region.

  6. Efecto del pedaleo de brazos sobre el sistema cardiorrespiratorio de las personas con tetraplejia. (Effect of armcrank pedaling on the cardiorespiratory system of the people with tetraplegia.

    Directory of Open Access Journals (Sweden)

    Gabriel Brizuela Costa

    2010-10-01

    Full Text Available Resumen Objetivos: Determinar el efecto de un programa de entrenamiento de pedaleo de brazos (PB estacionario, sobre el sistema cardiorrespiratorio de personas con tetraplejia. Método: Se estudiaron 11 participantes con tetraplejia por lesión medular (LM de origen traumático a niveles entre C4 y C6. Se midieron variables espirométricas (VC, FVC y MVV y de Variabilidad de la Frecuencia Cardíaca VFC (HR, STDHR, RMSSD, LF, HF y HRVPOWER, antes y después de 8 semanas de entrenamiento. Resultados: Todas las variables mostraron cambios significativos (p Abstract Objective: The aim of the study was to determine the effect, in subjects with tetraplejia, of a stationary armcrank pedaling (AP training program on their cardiorespiratory system. Method: 11 participants with tetraplegia, originated by traumatic spinal cord injury (SCI at levels between C4 and C6, were included in the study. Spirometric (VC, FVC and MVV and Heart Rate Variability (HRV indices (HR, STDHR, RMSSD, LF, HF, HRVPOWER were measured before and after an 8 weeks of armcrank pedaling training program. Results: Spirometric and HRV variables showed changes (p

  7. Efectos colaterales del voto preferente

    Directory of Open Access Journals (Sweden)

    Luis Diego Brenes Villalobos

    2012-07-01

    Full Text Available El artículo describe la multiplicidad de potenciales efectos que la implementación del voto preferente podría acarrear en el ordenamiento jurídico y el sistema de partidos. La primera parte del análisis se dirige a caracterizar y definir el voto preferencial. En segunda instancia, el estudio comprenderá la revista de los efectos colaterales del voto preferente como modalidad de votación.

  8. Microbial contamination and effects of combination treatments and gamma irradiation on reducing microbial contamination of dried cuttle fish

    International Nuclear Information System (INIS)

    Yen, B.T.

    1989-01-01

    Dried cuttle fish is one of the most valuable sea products but it rapidly becomes mouldy and spoiled. To solve this problem, the studies on microbial contamination and effects of combination treatments and gamma irradiation for dried cuttle fish have been caried out base on IAEA Research Contracts No 4397/AG and 4397/R1/AG

  9. Chernobyl and its effects in terms of food contamination

    International Nuclear Information System (INIS)

    Diehl, J.F.

    1986-01-01

    The contamination of plant surfaces and roots is gone into. There is a continuous decrease in contamination as a result of washout and dilution from plant growth. In animals, contamination decreases as a result of biological secretion. The isotopes I-131, Cs-137, and Sr-90 were investigated. To avoid high radiation, the author recommends to banish mushrooms, game, goat's meat, and mutton from the table. (PW) [de

  10. Shuttle on-orbit contamination and environmental effects

    Science.gov (United States)

    Leger, L. J.; Jacobs, S.; Ehlers, H. K. F.; Miller, E.

    1985-01-01

    Ensuring the compatibility of the space shuttle system with payloads and payload measurements is discussed. An extensive set of quantitative requirements and goals was developed and implemented by the space shuttle program management. The performance of the Shuttle system as measured by these requirements and goals was assessed partly through the use of the induced environment contamination monitor on Shuttle flights 2, 3, and 4. Contamination levels are low and generally within the requirements and goals established. Additional data from near-term payloads and already planned contamination measurements will complete the environment definition and allow for the development of contamination avoidance procedures as necessary for any payload.

  11. Radiation Resistant Hybrid Lotus Effect Photoelectrocatalytic Self-Cleaning Anti-Contamination Coatings, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop radiation resistant hybrid Lotus Effect photoelectrocatalytic self-cleaning anti-contamination coatings for application to Lunar...

  12. Ecological effects of contaminants and remedial actions in Bear Creek

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, G.R.; Loar, J.M.; Ryon, M.G.; Smith, J.G.; Stewart, A.J. (Oak Ridge National Lab., TN (United States)); Burris, J.A. (C. E. Environmental, Inc., Tallahassee, FL (United States))

    1992-01-01

    Ecological studies of the Bear Creek watershed, which drains the area surrounding several Oak Ridge Y-12 Plant waste disposal facilities, were initiated in May 1984 and are continuing at present. These studies consisted of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek, and they were followed by a presently ongoing monitoring phase that involves reduced sampling intensities. The characterization phase utilized two approaches: (1) instream sampling of benthic invertebrate and fish communities in Bear Creek to identify spatial and temporal patterns in distribution and abundance and (2) laboratory bioassays on water samples from Bear Creek and selected tributaries to identify potential sources of toxicity to biota. The monitoring phase of the ecological program relates to the long-term goals of identifying and prioritizing contaminant sources and assessing the effectiveness of remedial actions. It continues activities of the characterization phase at less frequent intervals. The Bear Greek Valley is a watershed that drains the area surrounding several closed Oak Ridge Y-12 Plant waste disposal facilities. Past waste disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. Extensive remedial actions have been proposed at waste sites, and some of the have been implemented or are now underway. The proposed study plan consists of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek in the first year followed by a reduction in sampling intensity during the monitoring phase of the plan. The results of sampling conducted from May 1984 through early 1989 are presented in this report.

  13. Ecological effects of contaminants and remedial actions in Bear Creek

    International Nuclear Information System (INIS)

    Southworth, G.R.; Loar, J.M.; Ryon, M.G.; Smith, J.G.; Stewart, A.J.; Burris, J.A.

    1992-01-01

    Ecological studies of the Bear Creek watershed, which drains the area surrounding several Oak Ridge Y-12 Plant waste disposal facilities, were initiated in May 1984 and are continuing at present. These studies consisted of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek, and they were followed by a presently ongoing monitoring phase that involves reduced sampling intensities. The characterization phase utilized two approaches: (1) instream sampling of benthic invertebrate and fish communities in Bear Creek to identify spatial and temporal patterns in distribution and abundance and (2) laboratory bioassays on water samples from Bear Creek and selected tributaries to identify potential sources of toxicity to biota. The monitoring phase of the ecological program relates to the long-term goals of identifying and prioritizing contaminant sources and assessing the effectiveness of remedial actions. It continues activities of the characterization phase at less frequent intervals. The Bear Greek Valley is a watershed that drains the area surrounding several closed Oak Ridge Y-12 Plant waste disposal facilities. Past waste disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. Extensive remedial actions have been proposed at waste sites, and some of the have been implemented or are now underway. The proposed study plan consists of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek in the first year followed by a reduction in sampling intensity during the monitoring phase of the plan. The results of sampling conducted from May 1984 through early 1989 are presented in this report

  14. Efectos subletales de la lambda-cialotrina sobre Eisenia fetida (Annelida, Oligochaeta, Lumbricidae) Sublethal effects of lambda-cyhalothrin on Eisenia fetida (Annelida, Oligochaeta, Lumbricidae)

    OpenAIRE

    Tamara Ricardo; Maria Inés Maitre; Alba Rut Rodríguez

    2010-01-01

    El uso intensivo de agroquímicos provoca efectos dañinos sobre la fauna no blanco. Dentro de la misma, los oligoquetos contribuyen a mantener la estructura y fertilidad del suelo. La lambda-cialotrina es uno de los insecticidas piretroides más utilizados en la Argentina, pero son escasos los datos existentes acerca de su toxicidad sobre oligoquetos. Los objetivos de este trabajo fueron evaluar mediante bioensayos de toxicidad crónica los efectos de lambda-cialotrina (producto comercial al 5%)...

  15. [Effects and Biological Response on Bioremediation of Petroleum Contaminated Soil].

    Science.gov (United States)

    Yang, Qian; Wu, Man-li; Nie, Mai-qian; Wang, Ting-ting; Zhang, Ming-hui

    2015-05-01

    Bioaugmentation and biostimulation were used to remediate petroleum-contaminated soil which were collected from Zichang city in North of Shaanxi. The optimal bioremediation method was obtained by determining the total petroleum hydrocarbon(TPH) using the infrared spectroscopy. During the bioremediation, number of degrading strains, TPH catabolic genes, and soil microbial community diversity were determined by Most Probable Number (MPN), polymerase chain reaction (PCR) combined agarose electrophoresis, and PCR-denaturing gradient electrophoresis (DGGE). The results in different treatments showed different biodegradation effects towards total petroleum hydrocarbon (TPH). Biostimulation by adding N and P to soils achieved the best degradation effects towards TPH, and the bioaugmentation was achieved by inoculating strain SZ-1 to soils. Further analysis indicated the positive correlation between catabolic genes and TPH removal efficiency. During the bioremediation, the number of TPH and alkanes degrading strains was higher than the number of aromatic degrading strains. The results of PCR-DGGE showed microbial inoculums could enhance microbial community functional diversity. These results contribute to understand the ecologically microbial effects during the bioremediation of petroleum-polluted soil.

  16. Efecto del tiempo de exposición a PM10 en las urgencias por bronquitis aguda Effect of exposure time to PM10 on emergency admissions for acute bronchitis

    Directory of Open Access Journals (Sweden)

    Franz Muñoz

    2009-03-01

    Full Text Available Este trabajo analiza el efecto de las horas de exposición a PM10 en las urgencias diarias por bronquitis aguda, controlando por temperatura y humedad. El estudio fue realizado en seis sectores de la ciudad de Santiago, Chile, durante el período de invierno de los años 2002 al 2004, para lactantes ( 65 años. Analizamos el retraso de la respuesta mediante una función polinomial distributiva (pdl, incluida en un modelo lineal generalizado (GLM-pdl, y la estructura del efecto de la exposición, mediante modelos aditivos generalizados (GAM, utilizando regresión spline como técnica de estimación. Los resultados mostraron que al cuarto día de retardo, el efecto de la exposición fue mayor, especialmente en lactantes, y varió en la medida que incrementó la concentración atmosférica de PM10. El efecto de las horas de exposición a PM10 mostró una variación significativa, según el sector geográfico. Al estimar linealmente este efecto en el sector Oeste, notamos que el incremento de consultas diarias en lactantes fue de 3% por cada hora de exposición sobre os 150µg/m³.To study the health effect of air pollution, measured as particulate matter greater than 10mm in diameter (PM10, we analyzed the effect of daily hours of exposure on the number of urgency admissions for acute bronchitis, adjusting for temperature and humidity on the same day. The study was conducted in six regions of Santiago, Chile, during the winter of years 2002 to 2004, for infants and elders. The delay between pollution time series and disease was modeled using a polynomial distributed lag (PDL function included in a generalized linear model. The linearity assumption was evaluated using a smooth-spline model approach. The highest effect for exposure to PM10 was detected with 4 days of delay. For both groups, the effect of temperature was linear, but that of humidity was not. Air pollution effect varied according to level of exposure and geographic region, increasing

  17. Radioprotective effect of microelements at the territories contaminated by radionuclides

    International Nuclear Information System (INIS)

    Gudkov, I.N.

    2007-01-01

    The most radioactively contaminated region of Ukrainian and Byelorussian Palesse belongs to a biogeochemical province where soils, plants, and, accordingly, forage for animals and food stuffs are poor with biologically important microelements - iodine, zinc, copper, cobalt, fluorine, manganese, lithium, boron. It is a cause of specific diseases of plants, animals and people known as hypomicroelementhoses. Carrying out the radioprotective measures (countermeasures), particularly liming of soils and applying the heightened doses of phosphoric fertilizers, reduces transfer of radionuclides from soil to plants and also elements of mineral nutrition included the microelements. It aggravates the deficiency of microelements following the decrease of productivity and quality of production in plant and animal breeding and exacerbation of the mentioned diseases. It is known, that many microelements have radioprotective properties, and same of them can influence on uptake of other elements in plants. Therefore, considering the situation with microelements, we can expect of their role in radiation protection of living organisms in a zone affected by accident in Chernobyl NPP. It was shown the applying (root injection) of zinc, manganese, cobalt, copper in the sulfates and chlorides (4-6 kg of metal per hectare) on soddy-podsolic soil, reduced the Sr 90 and Cs 137 transfer factor. Zinc was the most effective: the content of both radionuclides in grain of oats and lupine decreased in 1,5-2 times. Lesser efficiency was observed with manganese and cobalt, much less - with copper. Moreover, in some cases the increase of Sr 90 accumulation was observed. Influence of microelements was stronger in variants without fertilizers, than with their heightened doses. It happened because, firstly, fertilizers contain some various microelements. And, secondly, in favorable conditions for growth and development of plants provided by fertilizers, the action of both factors, positive, and

  18. Efectos cardiovasculares debido al consumo de cannabinoides

    Directory of Open Access Journals (Sweden)

    Oscar J. León

    2018-05-01

    Full Text Available Resumen: Objetivo: dar a conocer los efectos cardiovasculares secundarios al consumo de marihuana según lo reportado en la literatura médica. Métodos: se realizó una búsqueda con los términos MESH “Cannabis”, “Marijuana smoking” y “adverse effects” en la base de datos PubMed hasta el año 2016. Se obtuvieron 265 referencias. Se excluyeron cartas de editores, protocolos de investigación en proceso, población pediátrica (menores de 18 años, embarazadas, referencias en idiomas diferentes a inglés y español y se escogieron solo referencias relacionadas con efectos cardiovasculares. Resultados: se han establecido dos tipos de receptores de cannabinoides, los CB1 y los CB2, con localizaciones a nivel del sistema nervioso central, endotelial, renal y músculo liso. En la actualidad el consumo de marihuana ha venido en aumento y los médicos poco conocen de sus efectos y los diferentes nombres comerciales para esta sustancia. Existen efectos protectores a nivel vascular con detención de la progresión de la placa aterosclerótica y a la vez múltiples efectos no deseados como taquicardia, hipotensión y bradicardia. Múltiples reportes de caso documentan la relación de la marihuana con el infarto agudo de miocardio con o sin lesión de las arterias coronarias, así como con hemorragia subaracnoidea, pero no existen mecanismos claramente descritos que expliquen una relación directa con estos desenlaces. Conclusiones: se conoce la fisiopatología y los receptores donde actúan los cannabinoides generando efectos tanto protectores como dañinos. Existe fuerte correlación con enfermedad cardiovascular, principalmente síndrome coronario agudo, pero el mecanismo fisiopatológico aún no es claro. Abstract: Objective: To determine the cardiovascular side-effects of smoking marihuana according to that reported in the medical literature. Methods: A search was performed using the MeSH terms, “Cannabis”, “Marijuana smoking” and

  19. Wind effected redistribution of surface contamination. Progress report, September 1974--August 1975

    International Nuclear Information System (INIS)

    Amato, A.J.

    1975-01-01

    Theoretical resuspension ratios were computed through the extension of a one-dimensional model used to simulate the wind effected movement of surface contaminants. The surface movement of contamination associated with inhalable size particles was considered in relation to time, space, wind velocity, distance from the source, soil resuspension ratios, and other variables. A computer program was developed to calculate the wind effected distribution of surface contaminants. (U.S.)

  20. Effective dose rate coefficients for exposure to contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Veinot, K.G. [Easterly Scientific, Knoxville, TN (United States); Y-12 National Security Complex, Oak Ridge, TN (United States); Eckerman, K.F.; Easterly, C.E. [Easterly Scientific, Knoxville, TN (United States); Bellamy, M.B.; Hiller, M.M.; Dewji, S.A. [Oak Ridge National Laboratory, Center for Radiation Protection Knowledge, Oak Ridge, TN (United States); Hertel, N.E. [Oak Ridge National Laboratory, Center for Radiation Protection Knowledge, Oak Ridge, TN (United States); Georgia Institute of Technology, Atlanta, GA (United States); Manger, R. [University of California San Diego, Department of Radiation Medicine and Applied Sciences, La Jolla, CA (United States)

    2017-08-15

    The Oak Ridge National Laboratory Center for Radiation Protection Knowledge has undertaken calculations related to various environmental exposure scenarios. A previous paper reported the results for submersion in radioactive air and immersion in water using age-specific mathematical phantoms. This paper presents age-specific effective dose rate coefficients derived using stylized mathematical phantoms for exposure to contaminated soils. Dose rate coefficients for photon, electron, and positrons of discrete energies were calculated and folded with emissions of 1252 radionuclides addressed in ICRP Publication 107 to determine equivalent and effective dose rate coefficients. The MCNP6 radiation transport code was used for organ dose rate calculations for photons and the contribution of electrons to skin dose rate was derived using point-kernels. Bremsstrahlung and annihilation photons of positron emission were evaluated as discrete photons. The coefficients calculated in this work compare favorably to those reported in the US Federal Guidance Report 12 as well as by other authors who employed voxel phantoms for similar exposure scenarios. (orig.)

  1. Effect of risk information exposure on consumers' responses to foods with insect contamination.

    Science.gov (United States)

    Kimura, Atsushi; Magariyama, Yukio; Miyanoshita, Akihiro; Imamura, Taro; Shichiri, Kumiko; Masuda, Tomohiro; Wada, Yuji

    2014-02-01

    This study explores the impact that scientific information about insect contamination of food has on consumer perceptions. Participants (n = 320, Japanese consumers) were randomly assigned to 1 of 8 information-type conditions: (1) information about insect type, (2) information about contamination processes, (3) information about the safety of contaminated food, (4, 5, 6) combinations of 2 of (1), (2), and (3) above, (7) all information, and (8) no-information, and asked to rate their valuation, behavioral intention, and attitude toward food with insect contamination. Results demonstrated that some combinations of scientific information that include the safety of the contaminated food are effective to reduce consumers' compulsive rejection of insect contamination in food, whereas the single presentation of information about insect type increases consumers' explicit rejection of both the contaminated product and the manufacturer. These findings have implications for the coordination of risk communication strategies. © 2014 Institute of Food Technologists®

  2. La inmigración sudamericana en Italia: Efectos sobre el mercado de trabajo Southamerican Migration in Italy: Labour Market Effects

    Directory of Open Access Journals (Sweden)

    María Andrea Grasso

    2010-05-01

    Full Text Available Las migraciones sudamericanas no son las más numerosas ni las más preocupantes para el gobierno italiano y, quizás por ese motivo, no son las más estudiadas. Sin embargo, desde la década de 1970, las economías sudamericanas, en su mayoría, pasaron de ser receptoras de inmigrantes a expulsoras de su propia fuerza de trabajo, siendo Italia uno de los principales destinos elegidos. En qué trabajan los inmigrantes sudamericanos, cómo y en qué contribuyen a la economía italiana es uno de los interrogantes que busca elucidar este trabajo. El disparador para desarrollarlo fue un afiche de la campaña de gobierno del 2008 de la Liga Nord. En la gráfica se veía un indio Sioux y el texto rezaba: "ellos sufrieron la inmigración primero", haciendo alusión a los efectos negativos de la inmigración. Fue mi interés analizar estos efectos en lo económico y en lo social, restringiéndolo a la población de nuestro subcontinente. El artículo se basa en una experiencia personal de un año de residencia en el país como investigadora, trabajadora flexibilizada, italiana de segunda generación y partícipe de una red de contactos informales que movilizaron este análisis. Se identifica la coexistencia de una división del mercado laboral mediante una complementariedad de trabajos utilizando diferentes formas de acceso, trayectorias, y características en general. Para el segmento que ocupan los nativos se imponen barreras explícitas o no, que se traducen en exclusión. Éstas, se configuran en función de una tipificación que se hace del "otro", en particular los inmigrantes, como no apto, incapaz de realizar esa tarea, o poco "presentable".South American are neither the most numerous nor preoccupant migrations for the Italian government. Maybe that is the reason why they are not the most studied ones. However, since the seventy decade, South American economies- one day mainly receptives of inmigrants-, turned into emigration countries, being

  3. Efectos del masaje en el recién nacido y el lactante Massage effects at the newborn and suckling baby

    Directory of Open Access Journals (Sweden)

    Francisca Márquez Doren

    2007-09-01

    Full Text Available Antecedentes: masaje infantil, técnica relativamente nueva en occidente, importada desde India por el Dr. Leboyer, quien observó sus beneficios para los niños. Diseño: revisión bibliográfica de 10 estudios, cuyos límites de búsqueda fueron "infant massage", "infant tactile stimulation", ensayos clínicos randomizados, con menos de 7 años de antigüedad, de bases de datos Pubmed, Cinhal, Medline y Cochrane. Propósito: determinar el efecto del masaje en el recién nacido y lactante, considerando niños de pretérmino y término, con o sin patologías, que recibieron masaje. Resultados: mejor ganancia de peso, mejor desarrollo neurosensorial, periodos de alerta prolongados, aumento del tono vagal y motilidad gástrica, efectos analgésicos. También, mejor organización del sueño, disminución de hormonas del stress y recepción precoz de alimentos por vía oral, menos días de hospitalización y se observó una interacción madre hijo positiva. El masaje no mostró resultados significativos en disminuir cólicos en niños normales ni disminución del llanto en niños con lesiones cerebrales. Conclusiones: el masaje infantil demostró tener múltiples beneficios para el niño, su madre y su interacción, pero existen situaciones especiales en las que no fue efectivo.Background: infant massage is a relatively new technic in the western society, concerned from India by Dr. Leboyer, who observed his benefits for the children. Design: bibliographical review of 10 studies, whose limits search were infant massage, infant tactile stimulation, with just of 6 years of antiquity, randomized control trail, of data bases Pubmed, Cinhal, Medline and Cochrane. Intention: to determine the effect of the massage in new born and child, considering of preterm and term babys, with or without pathologies, that received massage. Main results: better gain of weight, better neurosensorial development, prolonged periods of alert, increase in vagal tone and

  4. Quantitative analysis of education effect by the number of contamination in an unsealed radioisotope facility

    International Nuclear Information System (INIS)

    Matsuda, Naoki; Yoshida, Masahiro; Takao, Hideaki; Kaneko, Mamoru; Yamaguchi, Yukiko; Okumura, Yutaka

    2002-01-01

    The educational program for radiation workers is essential for the safety of radiation facility that stands on radiation protection practice by each worker. However, there appears no distinct criterion for quantitative evaluation of the education effect on radiation safety. The effectiveness of education was assessed by the number and the frequency (number of contamination/number of users) of contamination, a major incident involving radioactive materials, based on the long-term contamination surveillance data from 1996 to 2001 in Nagasaki University Radioisotope Center. Facility staffs monitored contamination in the facility every day. In 1996 and 1997, the yearly total number and the frequency of contamination found in a molecular biology room, a most frequently-used laboratory, were 150 and 1.21, respectively. The improvement of education program, including introduction of technical procedures to avoid contamination in molecular biological experiments, pre-entry instruction for fresh workers to demonstrate radiation safety practices on site, and spreading the new concept 'contamination happens by all means' through the radiation workers, markedly reduced both the number and the frequency of contamination to 33 and 0.48, respectively. This reduction seemed to be attributable for two different reasons; improvement of skills to avoid contamination, and thorough execution of monitoring and decontamination. These results suggested that contamination was a possible criterion for evaluating effectiveness of education program for radiation workers. (author)

  5. Beyond the bed: Effects of metal contamination on recruitment to bedded sediments and overlying substrata

    International Nuclear Information System (INIS)

    Hill, Nicole A.; Simpson, Stuart L.; Johnston, Emma L.

    2013-01-01

    Metal-contaminated sediments pose a recognised threat to sediment-dwelling fauna. Re-mobilisation of contaminated sediments however, may impact more broadly on benthic ecosystems, including on diverse assemblages living on hard substrata patches immediately above sediments. We used manipulative field experiments to simultaneously test for the effects of metal contamination on recruitment to marine sediments and overlying hard substrata. Recruitment to sediments was strongly and negatively affected by metal contamination. However, while assemblage-level effects on hard-substratum fauna and flora were observed, most functional groups were unaffected or slightly enhanced by exposure to contaminated sediments. Diversity of hard-substratum fauna was also enhanced by metal contamination at one site. Metal-contaminated sediments appear to pose less of a hazard to hard-substratum than sediment-dwelling assemblages, perhaps due to a lower direct contaminant exposure or to indirect effects mediated by contaminant impacts on sediment fauna. Our results indicate that current sediment quality guidelines are protective of hard-substrata organisms. - Highlights: ► Potential for contaminated sediments to exert impacts beyond the sediment communities. ► We examine effects on recruitment to sediments and overlying hard substrata simultaneously. ► Metal-contaminated sediments had a strong negative impact on sediment fauna. ► Metal-contaminated sediments pose less of a hazard to hard-substratum fauna. ► Sediment quality guidelines are likely protective of hard-substrata organisms. - Under natural disturbance regimes, metal-contaminated sediments pose less of a direct risk to hard-substratum fauna than to sediment-dwelling fauna and SQG appear appropriate.

  6. Effect of NaCl upon an Al-Si casting alloy hipoeutec; Efecto del NaCl sobre una aleacion de Al-Si hipoeutectica vaciada

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Delgado, E.J.; Ortega de la Rosa, R. [Istituto Tecnologico de Zacatecas, Zacatecas (Mexico)]. E-mail: enriquemartinez_1999@yahoo.com; rubin_ortega_2002@yahoo.com.mx; Cisneros Guerrero, M.A. [Instituto Tecnologico de Saltillo, Saltillo, Coahuila (Mexico)]. E-mail: cisneros@its.mx; Haro Rodriguez, S. [Universidad Autonoma de Zacatecas, Zacatecas, Zacatecas (Mexico)]. E-mail: haros907@hotmail.com

    2009-10-15

    This work, comprehends the study about the effect of NaCl kind Halite upon the morphology of eutectic Silicon and porosity in a cast hipoeutectic Al-Si alloy. The melting was carried out in two furnaces, the first to combustion of LP gas in graphite crucible to increase the content of Si in the alloy from 0.13 to 5% wt using metallic silicon with a purity of 99.35% wt, and the second of electric resistances in the same kind of crucible to control the temperature at 750 degrees Celsius. The melting material was casting into molds of sand shell. To add the salt into the metallic bath, two techniques were used; one with injection by means of Argon gas and the other on by gravity, both cases three quantities of salt were used, 0.5, 1.5 and 2.5% wt respectively, powdered and preheated at 150 degrees Celsius during 60 min. The obtained samples were analyzed metallographily evidencing the modification of the eutectic Si, presenting the best results the samples with 1.5 and 2.5% wt of salt added by gravity. Too was obtained effect of Salt upon the degassing of bath metallic, where the simples with 1.5% wt presented the best results. Finally, by means of Scanning Electron Microscopy, the precipitates present were characterized in the samples. [Spanish] Este trabajo comprende el estudio del efecto del NaCl tipo Halita sobre la morfologia del Si eutectico y la porosidad en una aleacion fundida Al-Si hipoeutectica. La fusion se llevo a cabo en dos hornos, el primero a combustion con gas LP en crisol de grafito con la finalidad de incrementar el contenido de Si en la aleacion de 0.13 a 5% en peso, utilizando silicio metalico con una pureza de 99.35%, y el segundo de resistencias electricas en el mismo tipo de crisol para controlar la temperatura a 750 grados Celsios. El material fundido fue vaciado en modelos de arena. La sal se anadio al bano metalico a 0.5, 1.5 y 2.5% en peso, respectivamente, pulverizada y precalentada a 150 grados Celsios durante 60 min, mediante dos

  7. Title: Effect of abiotic stress on reduction of microbial contamination ...

    African Journals Online (AJOL)

    TERI

    2016-03-23

    Mar 23, 2016 ... to 36% reduced microbial contamination in aseptic culture establishment ... collected from farmer's field of Assam, India. .... Average weight loss (%) ± SE. 0 .... Asian J. Plant Sci. 6:496-501. Holdgate DP, Zandvoort EA (1997).

  8. Source Reduction Effectiveness at Fuel Contaminated Sites, Technical Summary Report

    National Research Council Canada - National Science Library

    2000-01-01

    This report assesses the degree to which various types or engineered source-reduction efforts at selected fuel-contaminated sites have resulted in decreasing concentrations of fuel constituents dissolved in groundwater...

  9. Efecto de la ganancia de peso gestacional en la madre y el neonato The effect of gestational weight gain on maternal and neonatal outcomes

    Directory of Open Access Journals (Sweden)

    Abraham Zonana-Nacach

    2010-06-01

    Full Text Available OBJETIVO: Evaluar el efecto de la ganancia de peso gestacional (GPG en la madre y el neonato. MATERIAL Y MÉTODOS: Se incluyeron 1 000 mujeres en puerperio inmediato atendidas en el Hospital de Ginecología del Instituto Mexicano del Seguro Social, en Tijuana, Baja California, México. Se consideró una GPG óptima si en las mujeres con bajo peso, peso normal, sobrepeso u obesidad previo al embarazo, la GPG fue OBJECTIVE: To evaluate the effects of gestational weight gain (GWG on maternal and neonatal outcomes. MATERIALS AND METHODS: During 2009, women in the immediate puerperium were assessed at the Gynecology and Obstetrics Hospital in Tijuana, Baja California, Mexico. GWG was considered optimal when < 18 kg, < 16 kg, < 11.5 kg and <9 kg for women who, before pregnancy, were underweight, normal weight, overweight and obese, respectively. RESULTS: A total of 38% of women gained more than the recommended weight during pregnancy Women with normal weight previous to pregnancy who exceeded gestational weight-gain recommendations had a risk of oligo/polyhydramnios (OR 2.1, CI 95% 1.04-4.2 and cesarean delivery; overweight women previous to pregnancy had an increased risk of preeclampsia (OR 2.2 CI 95% I.I-4.6 and newborn macrosomia (OR 2.5, CI 95% 1.1-5.6; and obese women had a risk of newborn macrosomía (OR 6.6 IC 95% I.8-23. Pre-pregnancy weight was more greatly associated with gestational diabetes than gestational weight gain. CONCLUSIONS: Women whose weight gain during pregnancy is outside of the recommended ranges had an increased risk of adverse obstetric and neonatal outcomes.

  10. Efecto del entrenamiento combinado de pliometría y electroestimulación en salto vertical. (Effect of combined plyometric and electrostimulation training on vertical jump.

    Directory of Open Access Journals (Sweden)

    Elisa Benito Martínez

    2010-10-01

    Full Text Available Resumen En este estudio se han analizado los efectos del entrenamiento combinado de pliometría y electroestimulación en un entrenamiento de fuerza muscular de los miembros inferiores. El estudio incluyó tres grupos experimentales, que trabajaron ambos métodos en orden diferente y de forma simultánea, y uno de control. Participaron 78 atletas, 40 mujeres y 38 hombres, de disciplinas de velocidad (100 y 200 m lisos y 100 y 110 m vallas, con una edad de 17,94 ± 1,44 años y una masa de 58,53 ± 8,05 kg. El programa incluyó dos días / sem de entrenamiento pliométrico y dos sesiones utilizando un electroestimulador Megasonic 313-P4. Tras dos meses de entrenamiento, se midió con plataforma de contacto ORGANISER PSION 2 la altura de salto vertical y potencia del tren inferior en test de Abalakov y Drop Jump. Las mayores diferencias pre/post test (p Abstract This paper analyses the effects of combined electrostimulation and plyometric training on lower body strength training. The training programme was applied to three experimental groups and one control group. The experimental groups used both methods simultaneously but in different order. The participants were 78 sprinters (100m and 200m, and 100m and 110m hurdles, 38 male and 40 female. Their average age was 15,9 ± 1,4 years and their average weight was 58,53 ± 8,05kg. The training programme consisted in two days a week of plyometric training and two sessions with a Megasonic 313-P4 electrostimulation unit. After two months training, vertical jump height and lower body power were measured in Abalakov test and Drop Jump test with PSION ORGANISER II. The most significant pre- and post-test (p

  11. Interactive effects of Cd and PAHs on contaminants removal from co-contaminated soil planted with hyperaccumulator plant Sedum alfredii

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Kai; Huang, Huagang; Li, Tingqiang; Yang, Xiaoe [Zhejiang Univ., Hangzhou (China). MOE Key Lab. of Environment Remediation and Ecosystem Health; Zhu, Zhiqiang [Zhejiang Univ., Hangzhou (China). MOE Key Lab. of Environment Remediation and Ecosystem Health; Hainan Univ., Haikou (China). College of Agriculture; He, Zhenli [Florida Univ., Port Pierce, FL (United States). Inst. of Food and Agricultural Sciences; Alva, Ashok [US Department of Agriculture, Prosser, WA (United States). Agricultural Research Service

    2012-04-15

    Purpose: Soil contamination by multiple organic and inorganic contaminants is common but its remediation by hyperaccumulator plants is rarely reported. The growth of a cadmium (Cd) hyperaccumulator Sedum alfredii and removal of contaminants from Cd and polycyclic aromatic hydrocarbons (PAHs) co-contaminated soil were reported in this study. Materials and methods: Soil slightly contaminated by Cd (0.92 mg kg{sup -1} DW) was collected from a vegetable field in Hangzhou and was spiked with two levels (0 and 6 mg kg{sup -1} DW) of Cd and three levels (0, 25, and 150 mg kg{sup -1} DW) of phenanthrene (PHE) or pyrene (PYR). A pot experiment was conducted in a greenhouse using S. alfredii with unplanted controls for 60 days. Shoot and root biomass of plants, dehydrogenase activity (DHA), and microbial biomass carbon in the soil were measured. Concentrations of Cd and PAHs in the plant and soil were determined. Results and discussion: Elevated Cd level (6.38 mg kg{sup -1} DW) increased S. alfredii growth. The presence of PAHs decreased the stimulatory effects of Cd on plant biomass and Cd concentrations in shoots in Cd spiked soil, thus decreasing Cd phytoextraction efficiency. Cadmium removal by S. alfredii after 60 days of growth varied from 5.8% to 6.7% and from 5.7% to 9.6%, in Cd unspiked and spiked soils, respectively. Removal rate of PAHs in the soil was similar with or without the plants. Removal rate of PYR decreased at the elevated Cd level in the soil. This appears to be due to a decrease in soil microbial activity. This is confirmed by a decrease in DHA, which is a good indicator of soil microbial activity. Conclusions: Our results demonstrate that S. alfredii could effectively extract Cd from Cd-contaminated soils in the presence of PHE or PYR; however, both PAHs exhibited negative effects on phytoextraction of Cd from Cd spiked soil (6.38 mg kg{sup -1} DW). S. alfredii is not suitable for remediation of PAHs. The effects of Cd and PAHs concentrations on the

  12. Effects of microelements on soil nematode assemblages seven years after contaminating an agricultural field

    NARCIS (Netherlands)

    Nagy, P.; Bakonyi, G.; Bongers, A.M.T.; Kádár, I.; Fábián, M.; Kiss, I.

    2004-01-01

    Long-term effects of Cd, Cr, Cu, Se and Zn were studied 7 years after artificially contaminating plots of an agricultural field on a calcareous chernozem soil. Effects of three to four different contamination levels (originally 10, 30, 90 and 270 mg kg(-1)) were studied. Nematode density was

  13. The effect of holographic wristbands on body balance. [El efecto de las pulseras holográficas en el equilibrio corporal].

    Directory of Open Access Journals (Sweden)

    Iván Gonzalo

    2014-10-01

    Full Text Available Balance is a complex ability essential for the performance of any motor task and for preventing injuries and falls. The appearance of holographic wristbands, the supposed benefits of which include improved balance, received the attention of the public and the media alike. However, there is no scientific evidence that holograms improve any physical attribute. The aim of this study was to evaluate the effect of Power Balance® holographic wristbands on balance. Following a triple-blind method, 25 healthy and physically active university students (14 women, 11 men underwent the sensory organization test (SOT on two separate days while wearing a wristband with or without holograms (the tests being performed in a random but counterbalanced order. The SOT provides details on total balance and the relative contribution of the three main sensory systems (somatosensory, vestibular and visual involved in balance. The results for the group as a whole revealed the wearing of a holographic wristband to have no significant effect on any of these variables. However, when the women’s results were analyzed separately, the wearing of holographic wristbands was associated with significant differences in the scores of two SOT variables: composite balance (86.5±3.7 with the holographic wristband compared to 85.5±4.5 without it; p≤0.05 and overall mean (93.5±2.0 compared to 92.8±2.4; p≤0.05. Although these statistical differences were discovered, the magnitude of these differences was so small that balance could not have been improved in any practical sense. In conclusion, Power Balance® holographic wristbands exert no meaningful effect on balance in healthy young adults. Resumen El equilibrio es una habilidad compleja esencial para la realización de cualquier tarea motriz y para la prevención de lesiones y caídas. La aparición de las pulseras holográficas, con supuestos beneficios entre los cuales se incluye la mejora del equilibrio, recibió la

  14. The Effect of Airborne Contaminants on Fuel Cell Performance and Durability

    Energy Technology Data Exchange (ETDEWEB)

    St-Pierre, Jean [Univ. of Hawaii, Manoa, HI (United States); Pasaogullari, Ugur [Univ. of Connecticut, Storrs, CT (United States); Cheng, Tommy [Ballard Power Systems, Burnaby, BC (Canada); Collins, William [WPCSOL, East Windsor, CT (United States)

    2017-09-18

    The impact of contaminants on fuel cell performance was examined to document air filter specifications (prevention) and devise recovery procedures (maintenance) that are effective at the system level. Eight previously undocumented airborne contaminants were selected for detailed studies and characterization data was used to identify operating conditions that intensifying contamination effects. The use of many and complementary electrochemical, chemical and physical characterization methods and the derivation of several mathematical models supported the formulation of contamination mechanisms and the development of recovery procedures. The complexity of these contamination mechanisms suggests a shift to prevention and generic maintenance measures. Only two of the selected contaminants led to cell voltage losses after injection was interrupted. Proposed recovery procedures for calcium ions, a component of road de-icers, dessicants, fertilizers and soil conditioners, were either ineffective or partly effective, whereas for bromomethane, a fumigant, the cell voltage was recovered to its initial value before contamination by manipulating and sequencing operating conditions. However, implementation for a fuel cell stack and system remains to be demonstrated. Contamination mechanisms also led to the identification of membrane durability stressors. All 8 selected contaminants promote the formation of hydrogen peroxide, a known agent that can produce radicals that attack the ionomer and membrane molecular structure whereas the dehydrating effect of calcium ions on the ionomer and membrane increases their brittleness and favors the creation of pinholes under mechanical stresses. Data related to acetylene, acetonitrile and calcium ions are emphasized in the report.

  15. Síndrome de ingesta nocturna como efecto colateral del zolpidem Sleep related eating disorders as a side effect of zolpidem

    Directory of Open Access Journals (Sweden)

    Stella Maris Valiensi

    2010-06-01

    Full Text Available El zolpidem es una droga hipnótica utilizada para el tratamiento del insomnio. Disminuye la latencia del sueño, el número total de despertares y aumenta el tiempo total del sueño respetando en general su arquitectura. Se cree que aumenta la fase 3 del sueño lento profundo. Nuestro objetivo es comunicar 8 casos de síndrome de ingesta nocturna relacionado al sueño y conductas automáticas complejas asociadas a sonambulismo como efecto colateral del zolpidem. Se analizaron las historias clínicas de 8 pacientes tratados con zolpidem que referían ingesta nocturna de alimentos con amnesia total o parcial del episodio. Se presentan 6 mujeres y 2 hombres, entre 32 y 72 años (media: 58 años, 7 tratados con zolpidem 10 mg/noche y 1 con zolpidem 12.5 mg/noche de liberación prolongada. El tiempo de exposición previo al desarrollo de eventos fue de 1 a 180 días (media de 39.8. El número de episodios relatados era de 1 a 8/noche (media 2.5 asociado con amnesia. Los episodios desaparecieron por completo en el 100% de los casos al suspender la medicación. El síndrome de ingesta nocturna relacionado al sueño es una parasomnia de sueño lento profundo que consiste en episodios de ingesta de alimento o bebida durante la noche, con amnesia parcial o completa del episodio. El zolpidem podría inducir el síndrome de ingesta nocturna relacionado al sueño en aproximadamente el 1% de pacientes, aunque creemos que es un efecto adverso que está subdiagnosticado. Se resuelve simplemente suspendiendo la medicación.Zolpidem is a hypnotic drug used in sleep disorders. It binds selectively to alpha 1 subunit of the GABA A benzodiazepine receptor. Zolpidem reduces sleep latency, number of arousals and increases the total time of sleep. However, it is considered that it may increase phase 3 of non rapid eye movement sleep, where somnambulism can take place. Our aim is to report 8 cases of sleep related eating disorders associated with the use of this drug

  16. Study of the effects of radon in three biological systems; Estudio de los efectos del radon en tres sistemas biologicos

    Energy Technology Data Exchange (ETDEWEB)

    Tavera, L. [Instituto Mexicano del Petroleo, Av. Eje Central Lazaro Cardenas No. 152, Edif. 23, Col. San Mateo Atepehuacan, 07730 Mexico D.F. (Mexico); Balcazar, M.; Lopez, A.; Brena, M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Rosa, M.E. De la [Facultad de Quimica, UNAM, 04510 Mexico D.F. (Mexico); Villalobos P, R. [Centro de Estudios de la Atmosfera, UNAM, 04510 Mexico D.F. (Mexico)

    2002-07-01

    The radon and its decay products are responsible of the 3/4 parts of the exposure of the persons to the environmental radiation. The discovery at the end of XIX Century of the illnesses, mainly of cancer, which appeared in the presence of radon, lead to an accelerated growing of the radon studies: monitoring, dosimetry, effects on the persons, etc. Several epidemiological studies of radon in miners and population in general have been realized; advancing in the knowledge about the concentration-lung cancer risk relationship, but with discrepancies in the results depending on the concentration levels. Therefor, studies which consuming time, efforts and money go on doing. The research of the radon effects in biological systems different to human, allows to realize studies in less time, in controlled conditions and generally at lower cost, generating information about the alpha radiation effects in the cellular field. Therefor it was decided to study the response of three biological systems exposed to radon: an unicellular bacteria Escherichia Coli which was exposed directly to alpha particles from an electrodeposited source for determining the sensitivity limit of the chose technique. A plant, Tradescantia, for studying the cytogenetic effect of the system exposed to controlled concentrations of radon. An insect, Drosophila Melanogaster, for studying the genetic effects and the accumulated effects in several generations exposed to radon. In this work the experimental settlements are presented for the expositions of the systems and the biological results commenting the importance of these. (Author)

  17. Shear Bond Strength of Orthodontic Brackets and Disinclusion Buttons: Effect of Water and Saliva Contamination

    OpenAIRE

    Sfondrini, Maria Francesca; Fraticelli, Danilo; Gandini, Paola; Scribante, Andrea

    2013-01-01

    Purpose. The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons. Materials and Methods. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a) dry, (b) water contamination, and (c) saliva contamination. Brackets and buttons...

  18. Effects of lead-contaminated sediment on Rana sphenocephala tadpoles

    Science.gov (United States)

    Sparling, D.W.; Krest, S.K.; Ortiz-Santaliestra, M.

    2006-01-01

    We exposed larval southern leopard frogs (Rana sphenocephala) to lead-contaminated sediments to determine the lethal and sublethal effects of this metal. Tadpoles were laboratory-raised from early free-swimming stage through metamorphosis at lead concentrations of 45, 75, 180, 540, 2360, 3940, 5520, and 7580 mg/kg dry weight in sediment. Corresponding pore water lead concentrations were 123, 227, 589, 1833, 8121, 13,579, 19,038, and 24,427 ug/L. Tadpoles exposed to lead concentrations in sediment of 3940 mg/kg or higher died within 2 to 5 days of exposure. At lower concentrations, mortality through metamorphosis ranged from 3.5% at 45 mg/kg lead to 37% at 2360 mg/kg lead in sediment. The LC50 value for lead in sediment was 3728 mg/kg (95% CI=1315 to 72,847 mg/kg), which corresponded to 12,539 ug/L lead in pore water (95% CI= 4000 to 35,200 ug/L). Early growth and development were depressed at 2,360 mg/kg lead in sediment (8100 ug/L in pore water) but differences were not evident by the time of metamorphosis. The most obvious effect of lead was its pronounced influence on skeletal development. Whereas tadpoles at 45 mg/kg lead in sediment did not display permanent abnormalities, skeletal malformations increased in frequency and severity at all higher lead concentrations. By 2360 mg/kg, 100% of surviving metamorphs displayed severe spinal problems, reduced femur and humerus lengths, deformed digits, and other bone malformations. Lead concentrations in tissues correlated positively with sediment and pore water concentrations.

  19. Sweet Sorghum crop. Effect of the Compost Application; Cultivo de Sorgo Dulce. Efecto de la Aplicacion de Compost

    Energy Technology Data Exchange (ETDEWEB)

    Negro, M J; Solano, M L; Carrasco, J; Ciria, P

    1998-12-01

    A 3 year-plot experiments were performed to determined the possible persistence of the positive effects of treating soil with compost. For this purpose, a sweet sorghum bagasse compost has been used. Experiments were achieved with sweet sorghum (Sorghum bicolor. L. Moench) vr Dale as energy crop. Similar sorghum productivities were obtained both in plots with consecutive compost applications and in plots amended with mineral fertilizers. No residual effect after three years has been detected. It could be due to the low dose of compost application. (Author) 27 refs.

  20. The time-dependent effect of the biological component of 137Cs soil contamination

    International Nuclear Information System (INIS)

    Dederichs, H.; Pillath, J.; Lennartz, R.; Hill, P.; Hille, R.

    2004-01-01

    In investigations of the long-term development of the population dose in the highly contaminated regions of the Commonwealth of Independence States it was found that the external dose has not decreased as strongly as expected since 1992. Further investigations have shown that, contrary to expectations, no linear correlation can be observed between soil contamination and measured area dose rate. As a contribution towards clarifying these issues, the area dose rate and the soil contamination including the plant fraction were investigated in the Korma district, Belarus. It was found that it is necessary to cover and average over larger areas in order to determine from ground contamination the long-term development of the external dose commitment. This means that for this purpose the introduction of an ''effective'' surface contamination (sum of mineral and organic contamination components) is necessary. The phenomena observed are described in a model, which permits an analytical calculation of the contamination profile in soil taking migration and transfer effects into account. The differences observed between the measured soil contamination and the resulting external doses or the directly measured dose rate can be explained by the proposed model. Moreover, their long-term development can be calculated. The results show that a time decade after the accident the biological part of the ''effective'' soil contamination becomes dominant and cannot be neglected. (orig.)

  1. Effects produced by nuclear radiation in powdery milk; Efectos producidos por radiaciones nucleares en leches en polvo

    Energy Technology Data Exchange (ETDEWEB)

    Urena N, F; Reyes G, A [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    The objective of this work is to determine the chemical effects produced by the gamma rays and beta particles radiations on the powdery milk. This work treats on the Pre-dose analysis, sampling radiating, electron spin resonance, acidity, proteins, aminoacids, lactose, fatty acids, peroxides, as well as its experimental results. (Author)

  2. Effect of ultrasonic pretreatment on purified water disinfection; Efecto del pretratamiento con ultrasonidos sobre la desinfeccion de agua depurada

    Energy Technology Data Exchange (ETDEWEB)

    Simon Andreu, P.; Lardin Mifsut, C.; Vergara Romero, L.; Polo Canas, P. M.; Perez Sanchez, P.; Rancano Perez, A.

    2009-07-01

    Due to the importance of a suitable water disinfection in order to insure a pollutant effect minimization against environment, this work has been carried out to determine how can affect an ultrasonic pre-treatment upon disinfection step. It has been confirmed the ultrasonic disintegration of bacterial cells in treated water and disinfectant power of treatment by itself, which is not enough to be used as a single method in water disinfection. It has also been proved that from a technical and economical point of view the combination of UV and ultrasound improves the UV treatment performance. Finally, it has been detected that an ultrasonic pre-treatment increases chlorination effectiveness, however the high cost in this combination makes it unfeasible of industrial scale. (Author) 6 refs.

  3. Effects of Contamination Upon the Performance of X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Elsner, Ronald F.; Oosterbroek, Tim

    2010-01-01

    Particulate and molecular contamination can each impact the performance of x-ray telescope systems. Furthermore, any changes in the level of contamination between on-ground calibration and in-space operation can compromise the validity of the calibration. Thus, it is important to understand the sensitivity of telescope performance, especially the net effective area and the wings of the point spread function to contamination. Here, we quantify this sensitivity and discuss the flow-down of science requirements to contamination-control requirements. As an example, we apply this methodology to the International X-ray Observatory (IXO), currently under joint study by ESA, JAXA, and NASA.

  4. Effects of lag and maximum growth in contaminant transport and biodegradation modeling

    International Nuclear Information System (INIS)

    Wood, B.D.; Dawson, C.N.

    1992-06-01

    The effects of time lag and maximum microbial growth on biodegradation in contaminant transport are discussed. A mathematical model is formulated that accounts for these effects, and a numerical case study is presented that demonstrates how lag influences biodegradation

  5. Effect of the ionizing radiation in polyurethane of medical grade; Efecto de la radiacion ionizante en poliuretano de grado medico

    Energy Technology Data Exchange (ETDEWEB)

    Ceron, P.; Rivera, T.; Calderon, J. A. [IPN, Centro de investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Paredes, L., E-mail: victceronr@hotmail.com [ININ, Carretera Mexico-Toluca, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-10-15

    The polyurethane is a material broadly used in implant medical devices, such as the connection blocks of the pacemakers and the insulator of the electrodes. Some patients that are users of these devices possibly have the necessity to receive external radiotherapy. For that reason is necessary to know the effects induced by the ionizing radiation in this polymer. In this study samples of Pellethane 2363 80a (thermoplastic polyurethane of medical grade) were irradiated. It was used the same energy and absorbed dose of a treatment of external radiotherapy in pelvis, by means of a linear accelerator of X-rays of 6 MeV and absorbed dose of 60 Gy to isocenter. The irradiation corresponding to the gamma sterilization of the material was reproduced (1, 5, 7.5, 10 and 25 kGy for the Co 60) the effects induced by the radiotherapy and for the sterilization in the material were studied by means of an analysis of the chemical connection, the molecular structure and identification of the functional groups of the polymer, by means of the infrared spectroscopy by Fourier transform in the infrared half region. (Author)

  6. Effects of the neutronic irradiation on the impact tests. Efectos de la irradiacion neutronica sobre los ensayos de resiliencia

    Energy Technology Data Exchange (ETDEWEB)

    Lapea, J.; Perosanz, F.J.; Hernandez, M.T.

    1993-01-01

    The changes that the Charpy curves suffer when steel is exposed to neutronic fluence are studied. Three steels with different chemical composition were chosen, two of them (JPF and JPJ) being treated at only one neutronic fluence, while the last one (JRQ) was irradiated at three fluences. In this way, it was possible to compare the effect of increasing the neutronic dose, and to study the experimental results as a function of the steel chemical composition. Two characteristic facts have been observed: the displacement of the curve at higher temperatures, and decrease of the upper shelf energy (USE). The mechanical recovery of the materials after two different thermal treatments is also described, and a comparation between the experimental results obtained and the damage prediction formulas given by different regulatory international organisms in the nuclear field is established. Author. 11 refs.

  7. The effect of exercise on cardiovascular risk markers in Mexican school-aged children: comparison between two structured group routines Efecto del ejercicio sobre marcadores de riesgo cardiovascular en escolares mexicanos: comparación entre dos rutinas grupales

    Directory of Open Access Journals (Sweden)

    Margie Balas-Nakash

    2010-10-01

    Full Text Available Objective. To assess the effects of two groups of exercise routines on cardiovascular disease risk markers. Material and Methods. An intervention study was conducted with 319 Mexican school-aged children in which routines were implemented Monday through Friday for 12 weeks. Routine A was the reference group, with 20 min of less intense activity and routine B was the new group with 40 min of aerobic exercises. Body mass index (BMI, waist circumference, fat mass percentage (FM%, systolic and diastolic blood pressure, lipids, lipoproteins, glucose and insulin were measured before and after the intervention. Results. Routine A had an effect on diastolic pressure, while routine B had an effect on BMI, FM%, blood pressure and triglycerides. Routine B had a greater effect on blood pressure than routine A. The prevalence of obesity, high blood pressure and hypertriglyceridemia decreased in both groups. Conclusion. Aerobic exercise is an effective health promotion strategy to reduce some cardiovascular disease risk markers.Objetivo. Evaluar el efecto de dos rutinas grupales de ejercicio sobre marcadores de riesgo cardiovascular. Material y métodos. Intervención en 319 escolares mexicanos. Las rutinas fueron implementadas por 12 semanas (rutina A (referencia: 20 min con ejercicios menos intensos vs rutina B (nueva: 40 min con ejercicios aeróbicos. Se midieron al inicio y al final el índice de masa corporal (IMC, masa grasa (%MG, presión arterial sistólica y diastólica, lípidos, lipoproteínas, glucosa e insulina. Resultados. La rutina A tuvo efecto sobre la presión diastólica; la B tuvo efecto sobre el IMC, %MG, presión arterial y triglicéridos. La rutina B tuvo mayores efectos en la presión arterial que la rutina A. Las prevalencias de obesidad, hipertensión arterial e hipertrigliceridemia disminuyeron en ambos grupos. Conclusiones. El ejercicio aeróbico es una estrategia de promoción exitosa para reducir algunos marcadores de riesgo

  8. Effects of comprehensive smoke-free legislation in Europe Efectos de la legislación antitabaco en Europa

    Directory of Open Access Journals (Sweden)

    Lucia Maria Lotrean

    2008-01-01

    Full Text Available This paper reviews data regarding the effects of the legislation banning smoking in enclosed public places, including workplaces, restaurants and bars which entered into force in several countries of Europe starting with the year 2004. The source of data is represented by articles and short information published in peer reviewed journals or in electronic format between the years 2005 and 2008. Highlights include a consideration of the effects of these laws on the attitudes of the population regarding their implementation, exposure to passive smoking in public places as well as the scientific evidence on the public health and economic impact of these laws. The results of smoking ban in public places observed in several parts of Europe support initiatives in many countries toward implementing smoke-free legislation, particularly those who have ratified the Framework Convention on Tobacco Control, which calls for legislation to reduce tobacco smoke pollution.Se revisaron datos sobre el impacto de las leyes que prohíben fumar en espacios públicos cerrados, incluyendo centros de trabajo, restaurantes y bares, las cuales entraron en vigor en varios países de Europa en 2004. La fuente de datos incluye artículos indexados y notas breves publicadas en revistas científicas o en formato electrónico entre 2005 y 2008. Los hallazgos incluyen una descripción del impacto de estas leyes sobre las actitudes de la población con respecto a su implementación, la exposición al humo de tabaco ambiental en espacios públicos cerrados, así como la evidencia científica sobre el impacto de estas leyes en la salud pública y en la economía. Los resultados de la prohibición de fumar en lugares públicos que se observaron en varios países de Europa confirman la importancia de promulgar iniciativas legislativas para crear ambientes libres de humo de tabaco en varios países del mundo, en particular en aquellos que han ratificado en Convenio Marco para el

  9. Analysis of the anisotropy effects with the AZTRAN code; Analisis de los efectos de la anisotropia con el codigo AZTRAN

    Energy Technology Data Exchange (ETDEWEB)

    Xolocostli, V.; Vargas, S.; Gomez, A. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Del Valle, E., E-mail: vicente.xolocostli@inin.gob.mx [IPN, Escuela Superior de Fisica y Matematicas, Av. IPN s/n, 07738 Ciudad de Mexico (Mexico)

    2017-09-15

    Among the improvements that are made for the deterministic codes with which nuclear reactors are analyzed, is the implementation of the dispersion anisotropic dispersion section, which can obtain better results. With the current computing technology is possible to carry out these implementations, since the computation time is no longer a considerable problem as in the past. In this paper we analyze some effects of anisotropy in the AZTRAN code, a code that solves the Boltzmann transport equation in one, two and three dimensions at steady state, using the multigroup technique, the nodal method RTN-0 and ordered discrete, which is part of the AZTLAN platform for analysis of nuclear reactors, which is currently under development. The implementation of the anisotropy in the AZTRAN code is one of the latest improvements that have been made to the code, leading to different tests and analyzes regarding the anisotropic dispersion, some as a test with homogeneous fuel assemblies. In the case presented here, the benchmark problem of a fuel assembly type BWR is analyzed, which is part of the Benchmark problem suite for reactor physics study of LWR next generation fuels, proposed by the Committee on Reactor Physics organized by the Japan Atomic Energy Research Institute (JAERI). In this problem the behavior of the infinite multiplication factor (k{sub inf}) is analyzed, as well as the behavior of using odd and even anisotropy approximation with respect to the symmetry in the radial power of the assembly. (Author)

  10. Effect of the gamma radiation in hydrotalcite with chromates; Efecto de la Radiacion Gamma en Hidrotalcitas con Cromatos

    Energy Technology Data Exchange (ETDEWEB)

    Martinez G, S. [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario No. 100 Col. Centro, 50000 Toluca, Estado de Mexico (Mexico); Bulbulian, S. [ININ, Carr. Mexico-Toluca Km. 36.5, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: soniakorn@yahoo.com

    2004-07-01

    At the moment the generation of radioactive wastes is topic of numerous studies. In this work was retained anionic material, chromates, in hydrotalcite that are anionic exchangers. It was proposed to warm the HT at different temperatures of 600 C up to 1200 C with the purpose of immobilizing the chromium inside the hydrotalcite. To high temperatures (1000 and 1200 C) it was formed one spinel (MgCr{sub 2}O{sub 4}) that is a very stable compound. It was found that when increasing the heating temperature, the anions are retained strongly. The immobilization of the Cr was determined through the chromium lixiviation with solutions 1N and 5N of NaCl. Also it was studied the effect of the radiation on the heated materials. The radiation dose used for it was of 1000 and 6000 kGy. The results show that for the calcined samples at 1000 and 1200 C irradiated or no irradiated, the chromium is strongly retained in form of spinels that is the structure formed after the calcination of the material. (Author)

  11. External electromagnetic transient sources: analysis of its effect in underground power cables; Fuentes transitorias electromagneticas externas: analisis de su efecto en los cables de potencia subterraneos

    Energy Technology Data Exchange (ETDEWEB)

    Escamilla Paz, Antonio

    2009-07-01

    In most of the electrical power systems that operate at present, the subterranean cables are only a complement. The cost of these cables is generally higher than the one of the aerial power lines, thus its use is restricted only to those areas where the construction of the aerial power lines is not feasible. It is estimated that for voltages lower than 110 kV this cost is up to seven times greater than the one of an aerial power line and for voltages higher than 380 kV it can be up to twenty times greater. Nevertheless, important reasons exist to construct a subterranean cable system such as: a) the fast growth of the urban centers and the industrial zones, which brings about restrictions of the rights of way for the construction of aerial power lines, b) the crossing of large water bodies, c) the congestion of aerial power lines near the generating substations or power plants, d) the crossing of air lines and e) the laws and the regulations, to mention some of them. The importance of the underground transmission systems of high and extra high voltage will be increased in the medium and the long term, therefore, it is considered that the effects of the external phenomena in these systems, like the inductions produced by the electromagnetic transient sources, will be more severe. In this research work the atmospheric discharges are defined as the external electromagnetic transient sources. The large dimension cables such as the power cables, behave as large collectors of the interferences produced by the atmospheric discharges, which can bring about damages in the components of a system. In order to avoid the damages and to increase the reliability of the subterranean cable systems it is necessary to use protective devices and appropriate insulation levels, mainly. If the phenomenon and the behavior of the system are properly represented, it is possible to more accurately determine the characteristics that the equipment must have to resist the over voltages and the

  12. Investigation of elements contamination and analysis of electrical effect of this contamination in silicon on the neutron transmutation doping in the RSG-GAS

    International Nuclear Information System (INIS)

    Sudjadi, U.

    1998-01-01

    The elements of the contamination on the Neutron Transmutation Doping Process (NTD) have investigated by Multi Channel Analyser (MCA). This Investigation is important to know the quality of silicon doping in NTD. We have found that Mn-45, Ga-72 and Au-198 are elements of contamination in silicon after NTD process. Analysis of electrical effect of this elements contamination on semiconductor silicon is described also in this paper

  13. Effective sampling strategy to detect food and feed contamination

    NARCIS (Netherlands)

    Bouzembrak, Yamine; Fels, van der Ine

    2018-01-01

    Sampling plans for food safety hazards are aimed to be used to determine whether a lot of food is contaminated (with microbiological or chemical hazards) or not. One of the components of sampling plans is the sampling strategy. The aim of this study was to compare the performance of three

  14. Soil microbial effects of smelter induced heavy metal contamination

    Energy Technology Data Exchange (ETDEWEB)

    Nordgren, A

    1986-01-01

    The soil concentrations of Cu and Zn at the secondary smelter were 20 00 mu g/g dry soil. Close to the primary smelter the soil was contaminated with more than ten elements including Pb, Zn, Cu and As at levels ranging between 6000 and 1000 mu g/g dry soil. The correlations between the concentrations of the metals were high at both smelters. Soil respiration rate decreased by about 75% close to both smelters. Total and fluorescein diacetate stained mycelial lengths decrease with increasing heavy metal pollution at the secondary but not at the primary smelter. The fungal community structure was strongly affected by the contamination. General common in coniferous forest soils such as Penicillium and Oidiodendron virtually vanished, while less frequent species like Paecilomyces farinosus and Geomyces pannorum dominated the site close to the smelter. Colony forming units of a number of functional groups of bacteria were found to be very sensitive to metal contamination. The urease activity of the soil was inhibited. Multivariate statistical analyses showed that the metal contamination was the major environmental influence on the microbiotain the soils studied. A study of about 200 decomposition curves resulting from glutamic acid additions to the different soils produced four microbially related parameters: basal respiration rate, initial respiration rate after the addition of the glutamic acid, specific respiration rate during the exponential increase of the respiration rate and the lag time before the exponential phase. With 53 refs.

  15. The effect of environmental parameters on contaminant uptake by a ...

    African Journals Online (AJOL)

    There was also no discernable relationship between pH and contaminants uptake by the sampling devices as was expected with non polar, non-ioniseable solutes. The uptake of compounds with lower molar volumes was most susceptible to the presence oh humic materials. Journal of Applied Sciences and Environmental ...

  16. Effects of Ingested Crude Oil Contaminated Diets on Antioxidant ...

    African Journals Online (AJOL)

    ADOWIE PERE

    vein of the eyes of the rats with the aid of a capillary tube and the plasma samples prepared for the biochemical tests. Also, one ... contaminated diets has been reported to cause liver ... as gastrointestinal disorders, burns, foot rot, leg ulcer,.

  17. Efectos del desarrollo en la memoria de trabajo y el aprendizaje de categorías en niños Developmet effects on working memory and category learning in children

    Directory of Open Access Journals (Sweden)

    Federico José Sánchez

    2009-12-01

    Full Text Available Se han reportado diferencias relacionadas con la edad en el desempeño de diversas tareas dependientes del lóbulo frontal, incluyendo tareas de memoria de trabajo (Luciana and Nelson, 1998; Luna et al. 2001; Bunge et al., 2002. Se han encontrado también efectos de edad y género sobre la memoria de trabajo en niños (Vuontela et. al, 2003. Además, el aprendizaje de categorías ha sido asociado con la actividad del lóbulo frontal (Dickins, 2000; Schlund 2007. El presente trabajo investigó los efectos de la edad y el género sobre la memoria de trabajo y el aprendizaje de categorías en niños de 8 a 13 años. Se encontraron efectos de edad y género sobre la memoria de trabajo, y en la tarea de aprendizaje de categorías sólo se observaron efectos de la edad. Los resultados sugieren que el desempeño de memoria de trabajo podría estar asociado con la velocidad de procesamiento en el aprendizaje de categorías.Age-related differences have been reported in the performance of several frontal lobe-dependent tasks, including working memory (Luciana and Nelson, 1998; Luna et al. 2001; Bunge et al., 2002. Effects of age and gender on working memory have been found in children (Vuontela et. al, 2003. On the other hand, category learning has also been associated with frontal lobe activity (Dickins, 2000; Schlund 2007. The present study addressed the effects of age and gender on working memory and category learning, in 8-13 year old children. Age and gender effects were found on the working memory task, and age effects only were observed on category learning. The results suggest that working memory performance might be associated with processing speed in the category learning task.

  18. Light contamination

    International Nuclear Information System (INIS)

    Cepeda Pena, William Enrique

    1998-01-01

    The article tries on the wrong use of the artificial light, of the main problems of the light contamination, dispersion of the light, noxious effects of the light contamination, ecological effects, effects on the man's biological rhythm, economic effects and effects about the civic and vial security, among other topics

  19. Efecto del hialuronato de zinc sobre las úlceras en pacientes con diabetes Zinc hyaluronate effects on ulcers in diabetic patients

    Directory of Open Access Journals (Sweden)

    Fernando Ramos Cuevas

    2007-06-01

    assesed through the time in weeks required to getting complete closure of ulcer with epitelial tissue (Average healing time. Material and methods: Controlled clinical test. Patients with own ulcers on the diabetic foot. July 1st- September 30th, 2004. Twent-five patients by group. Results: Ulcer area in zinc hyaluronate group was 12,48 cm2 ± 10,92 versus 7 cm2 ± 5,3 (p< 0,05. Average healing time in zinc hyaluronate group was 7,8 weeks ± 3,49 and all patients' ulcers healed, with only two patients in control group showed complete closure after twelve weeks folowing period (p< 0,05. Two patients in zinc hyaluronate group reported paresthesia and another hypergranulation as adverse effects that were resolved spontaneously without treatment interruption. Conclusions: Zinc hyaluronate achieved complete closure of diabetic foot ulcers in lesser time than conventional treatment with minimal adverse effects.

  20. Glove and gown effects on intraoperative bacterial contamination.

    Science.gov (United States)

    Ward, William G; Cooper, Joshua M; Lippert, Dylan; Kablawi, Rawan O; Neiberg, Rebecca H; Sherertz, Robert J

    2014-03-01

    Experiments were performed to determine the risk of bacterial contamination associated with changing outer gloves and using disposable spunlace paper versus reusable cloth gowns. Despite decades of research, there remains a lack of consensus regarding certain aspects of optimal aseptic technique including outer glove exchange while double-gloving and surgical gown type selection. In an initial glove study, 102 surgical team members were randomized to exchange or retain outer gloves 1 hour into clean orthopedic procedures; cultures were obtained 15 minutes later from the palm of the surgeon's dominant gloved hand and from the surgical gown sleeve. Surgical gown type selection was recorded. A laboratory strike-through study investigating bacterial transmission through cloth and paper gowns was performed with coagulase-negative staphylococci. In a follow-up glove study, 251 surgical team members, all wearing paper gowns, were randomized as in the first glove study. Glove study 1 revealed 4-fold higher levels of baseline bacterial contamination (31% vs 7%) on the sleeve of surgical team members wearing cloth gowns than those using paper gowns [odds ratio (95% confidence interval): 4.64 (1.72-12.53); P = 0.0016]. The bacterial strike-through study revealed that 26 of 27 cloth gowns allowed bacterial transmission through the material compared with 0 of 27 paper gowns (P < 0.001). In glove study 2, surgeons retaining outer gloves 1 hour into the case had a subsequent positive glove contamination rate of 23% compared with 13% among surgeons exchanging their original outer glove [odds ratio (95% confidence interval): 1.97 (1.02-3.80); P = 0.0419]. Paper gowns demonstrated less bacterial transmission in the laboratory and lower rates of contamination in the operating room. Disposable paper gowns are recommended for all surgical cases, especially those involving implants, because of the heightened risk of infection. Outer glove exchange just before handling implant materials

  1. Effects of electrocardiography contamination and comparison of ECG removal methods on upper trapezius electromyography recordings.

    Science.gov (United States)

    Marker, Ryan J; Maluf, Katrina S

    2014-12-01

    Electromyography (EMG) recordings from the trapezius are often contaminated by the electrocardiography (ECG) signal, making it difficult to distinguish low-level muscle activity from muscular rest. This study investigates the influence of ECG contamination on EMG amplitude and frequency estimations in the upper trapezius during muscular rest and low-level contractions. A new method of ECG contamination removal, filtered template subtraction (FTS), is described and compared to 30 Hz high-pass filter (HPF) and averaged template subtraction (ATS) methods. FTS creates a unique template of each ECG artifact using a low-pass filtered copy of the contaminated signal, which is subtracted from contaminated periods in the original signal. ECG contamination results in an over-estimation of EMG amplitude during rest in the upper trapezius, with negligible effects on amplitude and frequency estimations during low-intensity isometric contractions. FTS and HPF successfully removed ECG contamination from periods of muscular rest, yet introduced errors during muscle contraction. Conversely, ATS failed to fully remove ECG contamination during muscular rest, yet did not introduce errors during muscle contraction. The relative advantages and disadvantages of different ECG contamination removal methods should be considered in the context of the specific motor tasks that require analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Effects of human disturbance on a burrow nesting seabird Efectos de la presencia de humanos en aves marinas que anidan en madrigueras

    Directory of Open Access Journals (Sweden)

    Yuri V. Albores-Barajas

    2011-12-01

    Full Text Available During 2004, we followed 72 natural burrows to determine the effects of disturbance on breeding success of Cassin's auklets (Ptychoramphus aleuticus. We used distance from a human settlement or path in the analysis of disturbance. Birds whose burrows were closer to the path or the village had a higher rate of nest abandonment and lower breeding success compared to birds nesting further away from the path or the village. Also, older and more experienced individuals represented a larger proportion of the breeding population on less disturbed areas than on highly disturbed ones, probably as older individuals tend to arrive earlier at the breeding grounds, and failed breeders may change burrow sites to move away from disturbance. P. aleuticus are adversely affected by human activity at colonies even if birds are not handled and burrows are not opened, and this has implications for conservation, and planning of ecotourism. On the long term, this can have negative consequences for this species and others with similar characteristics.Durante el 2004 seguimos 72 nidos de la alcuela (Ptychoramphus aleuticus para determinar los efectos de disturbio en el éxito reproductivo. Utilizamos la distancia del nido a áreas asentamientos humanos o al camino como medidas de disturbio. Los nidos que estaban más cerca de los asentamientos o del camino tuvieron una tasa de abandono mayor y un éxito reproductivo menor en comparación con los nidos que estaban más alejados de las fuentes de disturbio. También observamos que en las zonas menos expuestas la proporción de adultos, con mayor experiencia, era más alta, posiblemente porque los individuos con mayor experiencia llegan antes a la zona de anidación. Las alcuelas son afectadas negativamente por la presencia de los humanos y sus actividades, aunque las aves no entren en contacto directo con los humanos. A largo plazo, esto puede acarrear consecuencias graves para esta especie y otras con caracter

  3. Effect of the acid rain in the constituent material of the Mayan Mexican monuments; Efecto de la lluvia acida en el material constituyente de los monuments mayas mexicanos

    Energy Technology Data Exchange (ETDEWEB)

    Bravo Alvarez, H; Soto Ayala, R; Sosa Echeverria, R; Sanchez Alvarez, P [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2003-10-15

    Actually, acid rain is considered as a potential problem that affects materials and ecosystems. The effect on monuments, made mainly from limestone, has been studied for long time. In this work, a sample of limestone from Tulum, Qintana Roo, was studied. The following parameters were measured: density, porosity and percentage of water adsorption. Also, the sample was irrigated with acid rain prepared in the laboratory (pH = 4.6), based in the chemical composition of 56 rain samples from Puerto Morelos, Quintana Roo, in 1994 and 1995. The results obtained show that acid rain is neutralized by calcium carbonate from the limestone. The high calcium concentrations in the effluent, show that limestone is dissolved by acid rain. Superficial recession was 4.4 {mu}m/year under experimental conditions used. [Spanish] Actualmente la lluvia acida se ha convertido en un problema potencial que afecta en mayor o menor grado a materiales y a los ecosistemas. El efecto que causa la lluvia acida en monumentos construidos fundamentalmente de roca caliza, ha sido objeto de muchas investigaciones realizadas, prioritariamente, por paises que poseen estructuras, cuyo material de construccion es caliza. En este trabajo de investigacion se estudio una muestra de roca caliza proveniente de los monumentos mayas de Tulum, Quintana Roo. Se determinaron los parametros de densidad, porosidad y porcentaje de adsorcion de agua. Asimismo, se efectuo la irrigacion de la muestra con lluvia acida (pH aprox.4.6), preparada en el laboratorio con base en la composicion quimica que se determino en 56 muestras de agua de lluvia provenientes de Puerto Morelos, punto cercano a los monumentos de Tulum, Quintana Roo, durante los anos 1994 y 1995. Los resultados permiten concluir que la lluvia acida sufre un proceso de naturalizacion con el carbonato de calcio de la roca caliza. Las altas concentraciones de calcio en el efluente, mostraron que la roca caliza sufrio una disolucion con la lluvia acida. La

  4. Acid rain effect in the constituent material of Mexican Mayan monuments; Efecto de la lluvia acida en el material constituyente de los monumentos Mayas mexicanos

    Energy Technology Data Exchange (ETDEWEB)

    Bravo Alvarez, H.; Soto Ayala, R.; Sosa Echeverria, R.; Sanchez Alvarez, P. [Facultad de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2003-12-01

    Actually, acid rain is considered as a potential problem that affects materials and ecosystems. The effect on monuments, made mainly from limestone, has been studied for long time. In this work, a sample of limestone from Tulum, Quintana Roo, was studied. The following parameters were measured: density, porosity and percentage of water adsorption. Also, the sample was irrigated with acid rain prepared in the laboratory (pH 4.6), based in the chemical composition of 56 rain samples from Puerto Morelos, Quintana Roo, in 1994 and 1995. The results obtained show that acid rain is neutralized by calcium carbonate from the limestone. The high calcium concentrations in the effluent show that limestone is dissolved by acid rain. Superficial recession was 4.4 {mu}m/year under experimental conditions used. [Spanish] Actualmente la lluvia acida se ha convertido en un problema potencial que afecta en mayor o menor grado a materiales y a los ecosistemas. El efecto que causa la lluvia acida en monumentos construidos fundamentalmente de roca caliza, ha sido objeto de muchas investigaciones realizadas, prioritariamente, por paises que poseen estructuras, cuyo material de construccion es caliza. En este trabajo de investigacion se estudio una muestra de roca caliza proveniente de los monumentos mayas de Tulum, Quintana Roo. Se determinaron los parametros de densidad, porosidad y porcentaje de adsorcion de agua. Asimismo, se efectuo la irrigacion de la muestra con lluvia acida (pH aprox. 4.6), preparada en el laboratorio con base en la composicion quimica que se determino en 56 muestras de agua de lluvia provenientes de Puerto Morelos, punto cercano a los monumentos de Tulum, Quintana Roo, durante los anos 1994 y 1995. Los resultados permiten concluir que la lluvia acida sufre un proceso de neutralizacion con el carbonato de calcio de la roca caliza. Las altas concentraciones de calcio en el efluente, mostraron que la roca caliza sufrio una disolucion con la lluvia acida. La

  5. Efecto del sustrato sobre las propiedades biológicas en la planta de fresa Effect of growth media on biological properties in strawberry plants

    Directory of Open Access Journals (Sweden)

    Fátima Martínez

    2011-07-01

    Full Text Available El objetivo de este trabajo fue evaluar el efecto que diferentes sustratos ejercen sobre las características microbiológicas en la rizosfera de la planta de fresa en un sistema de cultivo sin suelo cerrado. Se ensayaron 3 sustratos: compost de corcho más cascarilla de arroz 1:1 v:v (CC, turba (T y fibra de coco (FC. Se evaluó la comunidad microbiana y las propiedades químicas de los sustratos. El CC presentó valores de pH significativamente superiores a la FC y a la T y una densidad de bacterias copiotrofas, Bacillus sp. y actinomycetes oligotrofos superior a la de la T, tanto al inicio del ensayo como a los 2.5 meses de cultivo. La T mostró una densidad de hongos superior al CC, tanto al inicio del ensayo como a los 2.5 meses de cultivo. El sustrato de FC mostró a los 2.5 meses de cultivo mayor densidad de bacterias copiotrofas, Pseudomonas fluorescentes y hongos en la rizosfera que en la no rizosfera.The aim of this research was to study the effect of different growth media on the microbiologic characteristics in rhizosphere of strawberry plants in closed soilless growing systems. We used 3 substrates: composted cork and rice hulls (CC (1:1 v:v, peat (P and coir fiber (CF. Chemical variables and microbial community profile of the growth media were evaluated. The CC showed a higher pH than CF and P. At the beginning and at two and a half months after transplantation, copiotrophic bacteria, Bacillus sp. and oligotrophic actinomycetes were higher in CC than in P. At the beginning and at two and a half months after transplantation fungi were higher in P than in CC. At two and a half months after transplantation, in CF copiotrophic bacteria, fluorescent Pseudomonas sp. and fungi were higher in rhizosphere than in non-rhizosphere substrate.

  6. Efectos del contacto piel con piel del recién nacido con su madre Skin to skin contact effects in newborns and their mothers

    Directory of Open Access Journals (Sweden)

    Camila Lucchini Raies

    2012-12-01

    Full Text Available Antecedentes: el contacto piel con piel ha sido una práctica ancestral en toda cultura, que debido a la institucionalización de la atención del parto, disminuyó en occidente. Se retomó en el marco de la atención humanizada del parto. Objetivo principal: determinar los efectos del contacto piel con piel del recién nacido con su madre. Metodología: revisión bibliográfica de 26 estudios. Límites de búsqueda: new borns, humans, clinical trials, de 10 años de publicación, en bases de datos: Pubmed, ProQuest, CINHAL, Lilacs. Resultados principales: Se observaron beneficios en las variables: duración de lactancia materna, comportamiento neurosensorial, regulación de temperatura, como alternativa al cuidado estándar, disminución en días hospitalización y niveles de cortisol, favorecedor de la interacción madre-hijo y desarrollo infantil. Conclusión principal: el contacto piel con piel brinda múltiples beneficios a recién nacidos. Se presenta como alternativa de cuidado segura, factible de implementar.Background: skin to skin contact has been an ancient practice in all cultures, that due to the institutionalization of care delivery, decreased in the west. Was revived as part of humanized care delivery. Main objective: to determine effects of skin contact of the newborn with her mother. Methodology: a review of 26 studies. Search limits: new borns, Humans, clinical trials, 10 years of publication, database PubMed, ProQuest, CINAHL, Lilacs. Main results: benefits were seen in the following variables: duration of breastfeeding, neurosensorial behavior, temperature regulation, as an alternative to standard care, decreased of hospitalization days and cortisol levels, favoring the mother-child interaction and child development. Main conclusion: skin to skin contact provides multiple benefits to newborns. It is presented as an alternative to secure care, feasible to implement.

  7. Efecto in vitro de la hemina sobre la proliferación de los linfocitos humanos Effect in vitro of hemin on the proliferation of human lymphocytes

    Directory of Open Access Journals (Sweden)

    Lázaro del Valle Pérez

    2002-08-01

    Full Text Available Se estudió el efecto in vitro de la hemina sobre los linfocitos humanos. Se seleccionaron 30 donantes del Banco de Sangre del Instituto de Hematología e Inmunología a los que se les realizaron las pruebas de roseta activa, transformación blástica con criterio de timidina tritiada y la expresión de los antígenos de activación HLA-DR y CD-25 por el ultramicrométodo inmunocitoquímico en presencia y ausencia de la hemina. Se hallaron diferencias estadísticamente significativas en las condiciones experimentales con y sin hemina. Se comprobó que la hemina sola es capaz de promover la transformación blástica, aumentar la formación de roseta activa y aumentar la expresión de los antígenos de activación HLA-DR y CD25. En la literatura revisada no se hallaron resultados similares a los expresados anteriormente. La hemina es un producto capaz de activar a los linfocitos humanos induciendo su proliferación, y por lo tanto, la expresión de antígenos de activación. Se sugiere realizar estudios preclínicos y clínicos para evaluar la hemina como un probable medicamento para el tratamiento de las inmunodeficiencias celularesThe effect in vitro of hemin on human lymphocytes was studied. Thirty donors from the blood bank of the Institute of Hematology and Immunology were selected, who were performed tests of active rosette, of blastic transformation with tritiated thymidine and the expression of HLA-DR and CD-25 activation antigens by immunocytochemical ultramicromethod with and without hemin. Statistically significant differences under experimental conditions with and without hemin were found. It was confirmed that hemin by itself is capable of promoting blastic transformation, increasing the formation of active rosette and the expression of HLA-DR and CD25 activation antigens. In the literature review, no results similar to the above-mentioned were found. Hemin is a product that can activate human lymphocytes by inducing their

  8. The Effect of Canal Contamination with Saliva on Apical Sealing

    Directory of Open Access Journals (Sweden)

    S Sabaghi

    2014-08-01

    Methods: In this laboratory study, 58 human uni-root teeth were cleaned and shaped for obturation with gutta percha and sealer AH26. In the case group, specimens were contaminated with human saliva immediately before obturation, whereas the teeth in the control group were kept dry. All canals were filled by lateral condensation technique. Moreover, the teeth were placed in methylene blue dye for 3 days. Dye penetration was measured using a stereomicrosope. As a matter of fact, the study data were analyzed via utilizing t-test. Results: A significant difference was found between the two groups in regard with the apical leakage(P<0.001. The microleakage mean of dye in the dry group was 3/48mm, whereas it was 6/36mm in the saliva contaminated group. Conclusion: The study findings revealed that complete drying of canal can improve apical sealing.

  9. Knowing for controlling: ecological effects of invasive vertebrates in Tierra del Fuego Conocer para controlar: efectos ecológicos de vertebrados invasores en Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    CLAUDIA A SILVA

    2008-03-01

    Full Text Available The Tierra del Fuego (TDF archipelago is recognized as part o the last places on Earth that may still be considered wild. However, this condition may be threatened by the large number of invasive species present on the archipelago. These species can have significant effects on the ecology of the invaded ecosystems, at the genetic as well as at population, community and ecosystem levels. The aim of this study is to, by a bibliographic review, systematize existing information on the ecological impacts these species would be having on the TDF archipelago and detect information gaps in order to orient future research and effective management programs on these species. We restricted our review to vertebrate, non-marine invaders. We determined which species have invaded TDF, described their impacts on the archipelago and evaluated their potential impacts; this last issue was determined by reviewing some of the impacts these species have had in other geographic areas. Our findings indicate that at least nine vertebrate species (Salmo trutta, Salvelinus fontinalis, Oncorhynchus mykiss, Castor canadensis, Ondatra zibethicus, Oryctolagus cuniculus, Pseudalopex griseus, Mustela vison and Sus seroja have wild populations established away from human settlements in TDF. There is some scientific evidence on ecological impacts on the area for only five of these invaders, with the American beaver (Castor canadensis being the species monopolizing the greatest number of studies. These results contrast with the recognition, both in TDF and worldwide, of the potential of most of these species to cause significant ecological impacts, which makes it unlikely that the lack of verified impacts on TDF reflects an absence of significant effects of these invaders on the archipelago. We suggest that future research should focus on determining population density and distribution of these and other (i.e., feral species invasive vertebrates, as well as their impacts mainly on

  10. Adverse effects of salivary contamination for adhesives in restorative dentistry. A literature review.

    Science.gov (United States)

    Nair, Pooja; Hickel, Reinhard; Ilie, Nicoleta

    2017-06-01

    To review and critically analyze the literature concerning the influence of salivary contamination on the bond quality of adhesives used in restorative materials by comparing and contrasting the different adhesive materials. A detailed search on PUBMED, Cochrane Library, Google Scholar and Web of Science was carried out to identify publications on salivary contamination and dental adhesive materials, from 1990-2017 (March) which resulted in a total of 6,202 web-identified publications. After screening titles/abstracts and de-duplicating, 54 publications were selected that matched the requirements for this review. The condition for selection was English literature concerning the effect of salivary contamination on the adhesives used in restorative dentistry. The obtained articles were systematically evaluated. Salivary contamination of adhesives during restorative procedures statistically (64.6%) showed an adverse effect on adhesives, occurring either at one or many stages of restoration. Methodological dissimilarities impeded the direct comparison of the selected studies. Nevertheless, the 2-step etch and rinse adhesives were relatively less vulnerable to salivary contamination than the others. 65% of the evaluated studies for decontamination achieved improved bonding when the contaminated surface was subjected to some kind of decontamination procedure. However, the duration and other specificities were not standard in all the evaluations and need further research to assess the course of action. It is necessary to do long term studies to evaluate the effectiveness of contaminated adhesive over time. Salivary contamination is a potential cause for poor bond quality of adhesive systems during restorative procedures and to provide a successful treatment, proper care must be taken to ensure the operating area is free from contamination. Understanding the properties of the materials and its constituents as well as considering measures to manage the potential

  11. Consideraciones sobre el efecto de los armónicos de tiempo en motores trifásicos asincrónicos; Considerations about the Effect of Time Harmonics on Three Phase Induction Motor

    Directory of Open Access Journals (Sweden)

    Persy R Viego Felipe

    2011-02-01

    Full Text Available Se analiza el origen de los armónicos de tiempo en los sistemas eléctricos, tanto de los múltiplos integralescomo de los no integrales de la fundamental (interarmónicos y subarmónicos. Se consideran las causas y losefectos fundamentales de los mismos sobre las pérdidas en los motores asincrónicos. A partir de un estudio decaso, se evalúa el comportamiento de un motor en presencia de los principales armónicos y a partir del espectroarmónico de un circuito del CAI Ciudad Caracas, se ponen en evidencia los efectos negativos que sobre unmotor conectado en el mismo tendría esa distorsión armónica. Se establece, que para evaluar estos efectos,resulta conveniente emplear métodos de inteligencia artificial. The source of time harmonics in electric systems, no only integral multiples, but also non multiples of thefundamental (inter and subharmonics, are analyzed. The main causes and effects on induction motor losses areconsidered. On the base of a case study, the operation of an induction motor considering the most importantharmonics is evaluated. From a harmonic spectrum, the negative effects that would have a motor connected toa circuit of the sugar factory "Ciudad Caracas" are shown. The convenience of using tolls based on artificialintelligence for evaluating these effects is remarked 

  12. Effects of DTPA aerosol on lung contamination by lanthanum; Influence du DTPA en aerosol sur les contaminations pulmonaires au lanthane

    Energy Technology Data Exchange (ETDEWEB)

    Pasquier, C; Voisin, D; Thieblement, P; Perrault, G; Bayard, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    Applying DTPA aerosol for the treatment of lung contamination by lanthanum we were able to determine its effectiveness as a function of time. Provided it was administered early during the two hours after exposure, over 50 per cent could be removed using lower therapeutic doses than those prescribed for other routes of administration. Its association with some enzymes did not enhance the chelator therapeutic effect. We also calculated the constant of passage of lanthanum through the alveolar wall and found a value of 0.016 mn{sup -1}. Finally, as we have discovered a large part cannot be mobilized by DTPA, we shall now study the physico-chemical mechanisms involved in this protection. (authors) [French] L'emploi du DTPA en aerosol dans le traitement des contaminations pulmonaires par le lanthane, nous a permis d'etablir et d'evaluer son efficacite en fonction du temps. A condition d'etre utilise precocement, dans les deux heures qui suivent la contamination, une fraction superieure a 50 pour cent peut etre eliminee et ceci avec des doses therapeutiques inferieures a celles preconisees pour les autres voies d'administration. L'association avec quelques autres enzymes n'a pas permis d'ameliorer l'effet therapeutique de ce chelateur. Nous avons egalement chiffre la constante de passage du lanthane a travers la barriere alveolaire dont la valeur est de l'ordre de 0.016 mn{sup -1} Enfin, la decouverte d'une importante partie non piegeable par le DTPA nous amene maintenant a etudier les mecanismes physico-chimiques de cette protection. (auteurs)

  13. Effects of chemical contamination on HDPE - thermo-mechanical and characterisation properties

    International Nuclear Information System (INIS)

    Ashraf, G.

    2002-01-01

    Studying the effects of chemical contamination on HDPE is an important precursor in recycling of plastic packaging and polymer reprocessing. This research involves and discusses the results of an in-depth investigation into the effects of chemically contaminating, using various acids, commercial grade high density polyethylene (HDPE) used commonly in packaging applications. An extensive formulation study was conducted and it became obvious that in some cases degradation had occurred to HDPE when chemically contaminated with particular functional group types. The functional groups in contaminated HDPE were successfully identified. A variety of analytical techniques such as Fourier transform Infra-red spectroscopy, X-ray Florescence, x-ray photo electron spectroscopy could identify compounds such as HCl acid, HNO/sub 3/ acid and other related contaminants. Some chemical additives had effects on the mechanical and thermal properties when added in the most appropriate concentration. The results have shown lower tensile modulus and strength tensile elongation, lower modular weight, melt flow index and crystallinity. The amount of contaminant concentration, the type of chemical functional groups used and the type of test selected to affect degradation are important factors in proving the effects of chemical contamination on HDPE in the melt state. (author)

  14. Efecto secuestrador del D-002 sobre radicales hidroxilo en mucosa gástrica Scavenger effect of D-002 on hydroxyl radicals in the gastric mucosa

    Directory of Open Access Journals (Sweden)

    Yohani Pérez Guerra

    2012-03-01

    Full Text Available Introducción: el agente causal de la ulceración gástrica está asociado al desequilibrio entre factores agresivos y defensivos que actúan sobre la mucosa gástrica. El D-002, mezcla de seis alcoholes alifáticos primarios superiores purificada de la cera de abejas, produce efectos gastroprotectores mediados por múltiples mecanismos y reducción de la peroxidación lipídica en la mucosa gástrica. Objetivo: determinar si el D-002 es capaz de capturar el radical hidroxilo añadido in vitro o generado in vivo en ratas con úlcera gástrica inducida por indometacina. Métodos: En la experiencia in vitro el D-002 se añadió a concentraciones entre 0,9 y 1 000 mg/mL. En la experiencia in vivo las ratas se distribuyeron en seis grupos: un control negativo y cinco que recibieron indometacina: un control positivo tratado con el vehículo, tres con D-002 (5, 25, y 100 mg/kg, respectivamente, p.o. y otro con omeprazol (20 mg/kg i.p.. Los tratamientos se administraron una hora (vehículo y D-002 o 30 min (omeprazol, respectivamente, antes de inducir las úlceras. En ambas experiencias se tomaron alícuotas de mucosa gástrica, y se determinó el daño a la 2-desoxirribosa por el radical hidroxilo. Resultados: la administración oral del D-002, no in vitro, protegió a la 2-desoxirribosa del daño oxidativo de modo marcado, significativo y dependiente de la dosis con respecto al control positivo. Conclusiones: los resultados indican que la capacidad del D-002 (25 y 100 mg/kg administrado por vía oral para secuestrar el radical hidroxilo, generado en la mucosa gástrica por la indometacina, pudiera contribuir a sus efectos antioxidantes y gastroprotectores sobre el daño que los antiinflamatorios no esteroideos producen sobre la mucosa gástrica.Introduction: the etiology of the gastric ulceration is associated to the imbalance between aggressive and defensive factors acting upon the gastric mucosa. D-002, a mixture of 6 higher primary alcohols

  15. The effect of slaughter operations on the contamination of chicken carcasses with thermotolerant Campylobacter

    DEFF Research Database (Denmark)

    Rosenquist, Hanne; Sommer, Helle Mølgaard; Nielsen, Niels L.

    2006-01-01

    To evaluate the effect of specific slaughter operations on the contamination of broiler carcasses with naturally occurring thermotolerant Campylobacter, experiments were carried out in two Danish commercial slaughter plants (Plant I and Plant 11). Six broiler flocks determined Campylobacter...

  16. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  17. Comparación de los efectos del D-004, imipramina y sertralina en el modelo de nado forzado en ratones Comparative effects of D-004, Imipramine and Sertraline in the forced swimming test in mice

    Directory of Open Access Journals (Sweden)

    Daisy Carbajal Quintana

    2012-09-01

    Full Text Available Introducción: La finasterida, inhibidor de la 5 a-reductasa, se emplea en el tratamiento de la hiperplasia prostática benigna, y ocasiona entre sus efectos adversos un aumento de cuadros de depresión. El D-004 es un extracto lipídico extraído a partir del fruto de la palma real (Roystonea regia, inhibe la 5 a-reductasa y previene la hiperplasia prostática benigna, y muestra un efecto antidepresivo moderado en el ensayo de nado forzado y suspensión por la cola. Objetivo: comparar el efecto del D-004 con la imipramina y la sertralina sobre la duración de las conductas de inmovilidad, nado y escalado en el ensayo de nado forzado. Métodos: se distribuyeron los ratones en ocho grupos: control (vehículo, tres tratados con D-004 (100, 250 y 500 mg/kg, dos con sertralina y dos con imipramina (30 y 50 mg/kg respectivamente. Estos se colocaron en un cilindro de cristal que contenía agua a una altura de 6 cm y se cuantificaron las conductas. Resultados: la administración oral de D-004 (100, 250 y 500 mg/kg durante 14 días redujo significativamente el tiempo de inmovilidad con respecto al grupo control (17, 22 y 25 % y aumentó significativamente la conducta de nado en 1,58, 1,68 y 1,74 veces. Este efecto resulta moderado (25 % comparado con las reducciones alcanzadas por la sertralina y la imipramina (³ 60 %. Las dosis mayores (250 y 500 mg/kg ocasionaron incrementos de la conducta de escalado, 2,79 y 3,55 veces superiores a la del grupo control, lo que mostró semejanza con la imipramina, aunque con una menor eficacia. Conclusiones: el D-004 ejerce un moderado efecto antidepresivo, lo que pudiera contribuir al manejo de los pacientes con hiperplasia prostática benigna en los cuales se informa coincidencia de cuadros depresivos.Introduction: Finasteride is a 5 a-reductase inhibitor to treat benign prostatic hyperplasia (BPH and one of the adverse effects is the increase of depressive symptoms. D-004 is a lipid extract from the real palm

  18. Cumulative health risk assessment: integrated approaches for multiple contaminants, exposures, and effects

    International Nuclear Information System (INIS)

    Rice, Glenn; Teuschler, Linda; MacDonel, Margaret; Butler, Jim; Finster, Molly; Hertzberg, Rick; Harou, Lynne

    2007-01-01

    Available in abstract form only. Full text of publication follows: As information about environmental contamination has increased in recent years, so has public interest in the combined effects of multiple contaminants. This interest has been highlighted by recent tragedies such as the World Trade Center disaster and hurricane Katrina. In fact, assessing multiple contaminants, exposures, and effects has long been an issue for contaminated sites, including U.S. Department of Energy (DOE) legacy waste sites. Local citizens have explicitly asked the federal government to account for cumulative risks, with contaminants moving offsite via groundwater flow, surface runoff, and air dispersal being a common emphasis. Multiple exposures range from ingestion and inhalation to dermal absorption and external gamma irradiation. Three types of concerns can lead to cumulative assessments: (1) specific sources or releases - e.g., industrial facilities or accidental discharges; (2) contaminant levels - in environmental media or human tissues; and (3) elevated rates of disease - e.g., asthma or cancer. The specific initiator frames the assessment strategy, including a determination of appropriate models to be used. Approaches are being developed to better integrate a variety of data, extending from environmental to internal co-location of contaminants and combined effects, to support more practical assessments of cumulative health risks. (authors)

  19. Fundamento estadístico del efecto aleatorio del viento para el cálculo de estructuras delgadas. // Statistical foundation of wind random effect for the calculation of slender structures.

    Directory of Open Access Journals (Sweden)

    C. Fabré Sentile

    2006-05-01

    Full Text Available En el presente artículo se muestra una interesante recopilación estadística de las características aleatorias del viento convistas a considerar sus efectos de carga sobre estructuras esbeltas, se muestra el resultado hallado en varias fuentesbibliográficas tomando en cuenta además lo planteado por diversas normas al respecto. Se establecen parámetrosestadísticos, tales como autocorrelación, autocovarianza, función de densidad espectral, etc., en función de la acción delviento.Palabras claves: Estructuras esbeltas, efecto aleatorio, análisis estadístico de cargas, estadística.________________________________________________________________________________Abstract.In this paper is shown an interesting statistical summary of the random characteristics of the wind with a view toconsidering its load effects on slender structures, considering several bibliographical sources and taking into account thatoutlined by diverse norms in this respect. Statistical parameters are settle down in function of the wind action.Key words: Slender structures, random effect, statistical analysis, statistic.

  20. Ecotoxicological effects of decabromodiphenyl ether and cadmium contamination on soil microbes and enzymes.

    Science.gov (United States)

    Zhang, Wei; Zhang, Meng; An, Shuai; Xiong, Bang; Li, Hui; Cui, Changzheng; Lin, Kuangfei

    2012-08-01

    The ecotoxicological effects of decabromodiphenyl ether (BDE209) and cadmium (Cd) contamination on soil culturable microbial population, enzyme activity and bacterial community structure were investigated. Results of the indoor incubation test runs performed on many series of control and contaminated soil samples have demonstrated some notable toxic effects due to long term exposure to either or both contaminants. The two contaminants produced notable yet different toxic effects on the test microbes; the population of the exposed species generally declined according to certain dose-response relationships. The soil culturable microbial population and enzyme activity data show that the sensitivity to one or both contaminants followed the order of: bacteria>fungi>actinomycete and urease>saccharase, respectively. The interaction between BDE209 and Cd was dependent on both the exposure dose and time and that the joint toxic effects were synergistic, antagonistic or additive. The PCR-DGGE analysis data of species composition and richness suggest the synergistic combined effects on bacterial community structure during the 30d exposure. Pseudomonas tuomuerensis strain CCM 7280 and Pseudomonas alcaliphila strain AL15-21 were enriched, indicating these species might be major functional populations and highly tolerant. Such observations have provided the useful information of potential ecotoxicological effects of BDE209 and Cd contamination in the environment. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Numerical Study of Contaminant Effects on Combustion of Hydrogen, Ethane, and Methane in Air

    Science.gov (United States)

    Lai, H. T.; Thomas, S. R.

    1995-01-01

    A numerical study was performed to assess the effects of vitiated air on the chemical kinetics of hydrogen, ethane, and methane combustion with air. A series of calculations in static reacting systems was performed, where the initial temperature was specified and reactions occurred at constant pressure. Three different types of test flow contaminants were considered: NP, H2O, and a combustion of H2O and CO2. These contaminants are present in the test flows of facilities used for hypersonic propulsion testing. The results were computed using a detailed reaction mechanism and are presented in terms of ignition and reaction times. Calculations were made for a wide range of contaminant concentrations, temperatures and pressures. The results indicate a pronounced kinetic effect over a range of temperatures, especially with NO contamination and, to a lesser degree, with H2O contamination. In all cases studied, CO2 remained kinetically inert, but had a thermodynamic effect on results by acting as a third body. The largest effect is observed with combustion using hydrogen fuel, less effect is seen with combustion of ethane, and little effect of contaminants is shown with methane combustion.

  2. Combined effects of microplastics and chemical contaminants on the organ toxicity of zebrafish ( Danio rerio )

    DEFF Research Database (Denmark)

    Rainieri, Sandra; Conlledo, Nadia; Larsen, Bodil Katrine

    2018-01-01

    3 weeks of exposure fish were dissected and liver, intestine, muscular tissue and brain were extracted. After visual observation, evaluation of differential gene expression of some selected biomarker genes in liver, intestine and brain were carried out. Additionally, quantification of perfluorinated...... compounds in liver, brain, muscular tissue and intestine of some selected samples were performed. The feed supplemented with microplastics with sorbed contaminants produced the most evident effects especially on the liver. The results indicate that microplastics alone does not produce relevant effects......-contaminants of different nature in living organisms. Persistent organic pollutants and metals have been the co-contaminants majorly investigated in this field. The combined effect of microplastics and sorbed co-contaminants in aquatic organisms still needs to be properly understood. To address this, we have subjected...

  3. Effects of arbuscular mycorrhizal inoculation on plants growing on arsenic contaminated soil.

    Science.gov (United States)

    Jankong, P; Visoottiviseth, P

    2008-07-01

    Arbuscular mycorrhizal fungi (AMF) may play an important role in phytoremediation of As-contaminated soil. In this study the effects of AMF (Glomus mosseae, Glomus intraradices and Glomus etunicatum) on biomass production and arsenic accumulation in Pityrogramma calomelanos, Tagetes erecta and Melastoma malabathricum were investigated. Soil (243 +/- 13 microg As g(-1)) collected from Ron Phibun District, an As-contaminated area in Thailand, was used in a greenhouse experiment. The results showed different effects of AMF on phytoremediation of As-contaminated soil by different plant species. For P. calomelanos and T. erecta, AMF reduced only arsenic accumulation in plants but had no significant effect on plant growth. In contrast, AMF improved growth and arsenic accumulation in M. malabathricum. These findings show the importance of understanding different interactions between AMF and their host plants for enhancing phytoremediation of As-contaminated soils.

  4. EFFECT OF CONTAMINANT AND ORGANIC MATTER BIOAVAILABILITY ON THE MICROBIAL DEHALOGENATION OF SEDIMENT-BOUND CHLOROBENZENES. (R825513C007)

    Science.gov (United States)

    The extent of reductive dechlorination occurring in contaminated, estuarine sediments was investigated. Contaminant and organic matter bioavailability and their effect on the reductive dechlorination of sediment-bound chlorobenzenes was the main focus of the work presented her...

  5. The effect of water contamination on the dew-point temperature scale realization with humidity generators

    Science.gov (United States)

    Vilbaste, M.; Heinonen, M.; Saks, O.; Leito, I.

    2013-08-01

    The purpose of this paper is to study the effect of contaminated water in the context of humidity generators. Investigation of different methods to determine the drop in dew-point temperature due to contamination and experiments on actual contamination rates are reported. Different methods for calculating the dew-point temperature effect from electrical conductivity and density measurements are studied with high-purity water and aqueous solutions of NaCl and LiCl. The outcomes of the calculation methods are compared with the results of direct humidity measurements. The results show that the often applied Raoult's law based calculation method is in good agreement with other methods. For studying actual contamination, water samples were kept in glass, plastic, copper and stainless-steel vessels for up to 13 months to investigate natural ionic and organic contamination in vessels with different wall materials. The amount of ionic contamination was found to be higher in copper and glass vessels than in stainless-steel and plastic vessels. The amount of organic contamination was found to be highest in the plastic vessel. In all the cases, however, the corresponding drop in dew-point temperature due to natural contamination was found to be below 0.1 mK. The largest rate of change of dew-point temperature was 26 µK/month. Thus, if proper cleanness is maintained in a humidity generator the effect of contamination of water in the saturator is insignificant compared with the major uncertainty components even in the most accurate generators today.

  6. The effects of mycoplasma contamination upon the ability to form bioengineered 3D kidney cysts.

    Directory of Open Access Journals (Sweden)

    Teresa M DesRochers

    Full Text Available Mycoplasma contamination of cell cultures is a pervasive, often undiagnosed and ignored problem in many laboratories that can result in reduced cell proliferation and changes in gene expression. Unless contamination is specifically suspected, it is often undetected in two dimensional (2D cultures and the resulting effects of mycoplasma contamination are rarely appreciated and can lead to incorrect conclusions. Three dimensional (3D tissue cultures are increasingly utilized to explore tissue development and phenotype. However, 3D cultures are more complex than 2D cell cultures and require a more controlled cellular environment in order to generate structures necessary to mimic in vivo responses and are often maintained for longer time periods. Changes to the microenvironment are assumed to have a more extreme effect upon the success of 3D tissue cultures than 2D cell cultures, but the effects of mycoplasma have not been studied. To test this hypothesis, we grew 2D cell cultures and 3D tissues from pig kidney epithelial cells (LLC-PK1 that were contaminated with mycoplasma and the same stock of cells after mycoplasma removal. We did not observe an effect of mycoplasma contamination on proliferation in 2D monolayer cell culture. However, cyst formation in 3D tissues was altered, with effects upon the number, size and structure of cysts formed. These data serve to reinforce the necessity of testing cell stocks for mycoplasma contamination.

  7. Combined Contamination and Space Environmental Effects on Solar Cells and Thermal Control Surfaces

    Science.gov (United States)

    Dever, Joyce A.; Bruckner, Eric J.; Scheiman, David A.; Stidham, Curtis R.

    1994-01-01

    For spacecraft in low Earth orbit (LEO), contamination can occur from thruster fuel, sputter contamination products and from products of silicone degradation. This paper describes laboratory testing in which solar cell materials and thermal control surfaces were exposed to simulated spacecraft environmental effects including contamination, atomic oxygen, ultraviolet radiation and thermal cycling. The objective of these experiments was to determine how the interaction of the natural LEO environmental effects with contaminated spacecraft surfaces impacts the performance of these materials. Optical properties of samples were measured and solar cell performance data was obtained. In general, exposure to contamination by thruster fuel resulted in degradation of solar absorptance for fused silica and various thermal control surfaces and degradation of solar cell performance. Fused silica samples which were subsequently exposed to an atomic oxygen/vacuum ultraviolet radiation environment showed reversal of this degradation. These results imply that solar cells and thermal control surfaces which are susceptible to thruster fuel contamination and which also receive atomic oxygen exposure may not undergo significant performance degradation. Materials which were exposed to only vacuum ultraviolet radiation subsequent to contamination showed slight additional degradation in solar absorptance.

  8. Effects of different remediation treatments on crude oil contaminated saline soil.

    Science.gov (United States)

    Gao, Yong-Chao; Guo, Shu-Hai; Wang, Jia-Ning; Li, Dan; Wang, Hui; Zeng, De-Hui

    2014-12-01

    Remediation of the petroleum contaminated soil is essential to maintain the sustainable development of soil ecosystem. Bioremediation using microorganisms and plants is a promising method for the degradation of crude oil contaminants. The effects of different remediation treatments, including nitrogen addition, Suaeda salsa planting, and arbuscular mycorrhiza (AM) fungi inoculation individually or combined, on crude oil contaminated saline soil were assessed using a microcosm experiment. The results showed that different remediation treatments significantly affected the physicochemical properties, oil contaminant degradation and bacterial community structure of the oil contaminated saline soil. Nitrogen addition stimulated the degradation of total petroleum hydrocarbon significantly at the initial 30d of remediation. Coupling of different remediation techniques was more effective in degrading crude oil contaminants. Applications of nitrogen, AM fungi and their combination enhanced the phytoremediation efficiency of S. salsa significantly. The main bacterial community composition in the crude oil contaminated saline soil shifted with the remediation processes. γ-Proteobacteria, β-Proteobacteria, and Actinobacteria were the pioneer oil-degraders at the initial stage, and Firmicutes were considered to be able to degrade the recalcitrant components at the later stage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Interactions between eutrophication and contaminants - partitioning, bioaccumulation and effects on sediment-dwelling organisms

    Energy Technology Data Exchange (ETDEWEB)

    Hylland, Ketil; Schaanning, Morten; Skei, Jens; Berge, John Arthur; Eriksen, Dag Oe.; Skoeld, Mattias; Gunnarsson, Jonas

    1997-12-31

    This report describes an experiment on the interactions between eutrophication and contaminants in marine sediments. The experiment was performed in 24 continuously flushed glass aquaria within which three sediment-dwelling species were kept in a marine sediment. A filter-feeder, blue mussel, was kept in downstream aquaria. The experiment combined three environmental factors: oxygen availability, the presence or absence of contaminants, the addition of organic matter. The objectives were: (1) to quantify differences in the partitioning of contaminants between sediment, pore water and biota as a result of the treatment, (2) to quantify effects of treatments and interactions between treatments on sediment-dwelling organisms, (3) to identify differences, if any, in the release of contaminants from the sediment as the result of treatments. All three contaminants bio accumulated to higher levels in sediments with increased levels of organic material. Feeding directly or indirectly appeared to be the major route for bioaccumulation of benzo(a)pyrene and mercury. Cadmium was also controlled by the concentration in pore water. Sediment in enriched aquaria released more contaminants than sediment with low organic content. Organic enrichment strongly affected growth in the three sediment-dwelling organisms. Growth was less affected by decreased oxygen availability. The presence of contaminants had little effect on the three sediment-dwelling species at the concentrations used in the experiment. 103 refs., 14 figs., 12 tabs.

  10. EFFECT OF REFINED PETROLEUM PRODUCTS CONTAMINATION ON BACTERIAL POPULATION AND PHYSICOCHEMICAL CHARACTERISTICS OF CULTIVATED AGRICULTURAL SOIL

    Directory of Open Access Journals (Sweden)

    Adewale Sogo Olalemi

    2012-10-01

    Full Text Available An investigation into the effect of refined petroleum products contamination on bacterial population and physicochemical characteristics of cultivated agricultural soil was carried out. The soil samples obtained from the Teaching and Research Farm, Obakekere, Federal University of Technology, Akure, Ondo State were contaminated with varying volumes of petrol, diesel and kerosene. The results revealed higher bacterial populations in uncontaminated soils than contaminated soils. The counts of bacteria ranged from 3.0 × 105 to 5.0 × 105 cfu/g in uncontaminated soils and 1.0 × 105 to 3.0 × 105 cfu/g in contaminated soils. The isolated bacteria were identified as Bacillus subtilis, Flavobacterium lutescens, Micrococcus luteus, Corynebacterium variabilis, Pseudomonas fluorescens. The contamination had no significant effect on pH, potassium, sodium, organic carbon and nitrogen content of the soils, while the moisture, calcium, phosphorus and magnesium content of the contaminated soils were significantly different (P < 0.05 compared with the uncontaminated soils. The ability of Bacillus subtilis, Flavobacterium lutescens, Micrococcus luteus, and Pseudomonas fluorescens to utilize the refined petroleum products suggest that these bacteria had potential to bioremediate petroleum contaminated soils.

  11. Efecto de la terapia hormonal de reemplazo sobre la mamografía: nuestra experiencia Effect of replacement hormone therapy on mammography: our experience in this field

    Directory of Open Access Journals (Sweden)

    Daysi Navarro Despaigne

    2005-12-01

    Full Text Available Se realizó un estudio retrospectivo, cuyo objetivo fue describir el efecto de la terapia hormonal de reemplazo (THR sobre las mamografías de mujeres de edad mediana que asistieron a la Clínica de Climaterio y Osteoporosis (ClimOs entre enero de 1998 y diciembre de 2003. A cada mujer se le realizó mamografía (Mx inicial y durante el uso de la THR, las cuales fueron informadas como: 1 mamografías sin alteraciones, 2 con cambios menores [densidad irregular y microcalcificaciones] y 3 con cambios mayores [nódulos, quistes u otra alteración]. Como tratamiento recibieron estrógenos solos (E, estrógenos y progestagenos combinados continuos (EP y terapia no estrogénica (fitoestrógenos, tibolona. La muestra estuvo constituida por 112 mujeres, con edades entre 34 y 59 años. La Mx inicial mostró: no alteraciones en el 85,5 %, cambios menores en el 9,1 y cambios mayores en el 5,4. En la posTHR (tiempo promedio entre ambos estudios: 2,5 años, el 66 % continuó con mamografías normales, en el 29,0 hubo cambios menores (pA retrospective study was conducted, with the objective of describing the effect of hormone replacement therapy (HRT on mammography performed on middle-aged females, who had been seen at climacterics and osteoporosis clinics from January 1998 to December 2003. Mammography had been performed on each woman at the beginning and during the use of the HRT, being the results as follows: 1 mammography showing no changes; 2 mammography with slight changes irregular density and microcalcification and 3 mammography with major changes nodules, cysts or any other change . As a treatment, they received estrogen (E, continuos combined estrogen and progestagen (EP and nonestrogen therapy (phytoestrogen, tibolone. The sample was composed of 112 women aged 34 to 59 years. The initial Mx showed no changes in 85,5 %, slight changes in 9,1 and major changes in 5,4 of females. After the application of HRT (average time between both mammographic

  12. Health effects associated with measured levels of contaminants in the Arctic

    DEFF Research Database (Denmark)

    Weihe, Pál; Debes, Fróði; Halling, Jónrit

    2016-01-01

    vulnerable, effect studies are often prospective child cohort studies. The emphasis in this article is on a description of the effects associated with contaminant exposure in the Arctic. The main topics addressed are neurobehavioural, immunological, reproductive, cardiovascular, endocrine and carcinogenic...... effect. For each topic, the association between exposure and effects is described, and some results are reported for similar studies outside the Arctic....

  13. Cyclophosphamide effect on coccidioidomycosis in the rat Efecto de la ciclofosfamida en la infección por Coccidioides immitis en la rata

    Directory of Open Access Journals (Sweden)

    Mirta C. Remesar

    1989-12-01

    Full Text Available Coccidioidomycosis is a systemic mycosis, endemic in arid areas of the American continent. The rat was employed as an experimental host, since it had been shown to reproduce human lesions and present a chronic course of disease with granulomas mainly restricted to lungs. Given the influence of immunosuppressive therapy on the clinical course of human coccidioidomycosis, we studied the effect of cyclophosphamide (CY in the experimental rat model. Accordingly, animals were inoculated with 400 Coccidioides immitis arthroconidia of the Acosta strain, by intracardiacal route. As single CY doses failed to alter the course of disease, three schedules were used: A 4 daily doses of 20 mg/kg each, prior to C. immitis inoculation; B 4 similar daily doses after infection; and C; 6 doses of 20 mg/kg each, given from day +1 to +4, then on days +8 and +9, post infection (pi, taking day 0 as the time of fungal inoculation. The first two schedules inhibited antibody formation up to day 28 pi, without modifying cellular response to coccidioidin as measured by foodpad swelling. Initially, there was greater fungal spread than in controls receiving C. immitis alone, which proved self-limiting in the latter. In contrast, schedule C led to 559r mortality, with both humoral and cellular response abrogation, accompanied by extensive C. immitis dissemination. Histology disclosed significant alterations, such as the persistence of primary infection sporangia, corresponding to the acute stage of coccidioidomycosis in the absence of granuloma development. Therefore, the observed depression in cellular immunity seems responsible for the lack of inflammatory reaction capable of restricting sporangia proliferation in tissues which, in turn, enhances pathogen spread and mortality rate.El propósito de este trabajo fue estudiar el efecto de la inmunosupresión causada por la droga ciclofosfamida (CY sobre la infección de la rata con Coccidioides immitis por vía intracard

  14. Efecto del sistema silvopatoril en el comportamiento productivo de vacas Holstein Effect of the silvopastoral system on the productive performance of Holstein cows

    Directory of Open Access Journals (Sweden)

    L Lamela

    2009-06-01

    Full Text Available Con el objetivo de evaluar el comportamiento productivo de vacas Holstein en sistemas asociados de Leucaena leucocephala y Cynodon nlemfuensis, sin la aplicación de fertilizante químico, se realizó el presente trabajo en dos vaquerías: las unidades 98 y 100 de la Empresa Genética de Matanzas, Cuba, las cuales tenían un área de pastos de 35,5 ha y 3 ha para la producción de forraje de caña de azúcar. Se determinó la producción de leche por vaca en ordeño y la producción por vaca total, así como la influencia del bimestre de producción, la época del año y el año en el comportamiento productivo. La leucaena tuvo valores de PB superiores al 20% y la gramínea entre 7,4-9,5%; la disponibilidad de MS fue de 3,4 y 2,5 t/ha/rotación para el período lluvioso y el poco lluvioso, respectivamente. Se encontraron diferencias significativas dentro de cada vaquería para el efecto bimestre de producción. A su vez, el 86 y 65% de las vacas tuvieron una condición corporal (CC entre 3,0 y 3,5 para el período lluvioso y el poco lluvioso, respectivamente. La producción de leche promedio de las vacas, para la CC de 2,5; 3,0; 3,5 y 4,0 fue de 6,5; 8,0; 7,7 y 6,0 kg/vaca/día, respectivamente. Se concluye que el sistema presentó una aceptable disponibilidad de MS (3 t/ha/rotación y los animales mantuvieron una condición corporal favorable para la producción de leche, con valores de 6,8-8,8 kg/vaca/día.With the objective of evaluating the productive performance of Holstein cows in associated systems of Leucaena leucocephala and Cynodon nlemfuensis, without applying chemical fertilizers, this work was carried out in two dairy units: 98 and 100 of the Livestock Production Genetic Enterprise of Matanzas, Cuba, which had an area for pastures of 35,5 ha and 3 ha for producing sugarcane forage. The milk production per milking cow and total production per cow were determined, as well as the influence of the two-month period of production, season

  15. Entrenamiento Aeróbico: Efecto Sobre el Estado Oxidativo Hepático. [Aerobic Training: Effect on Liver Oxidative Stress].

    Directory of Open Access Journals (Sweden)

    Nyurky Josefina Matheus

    2016-07-01

    Full Text Available El ob­jetivo de este estudio fue evaluar en un modelo animal el efecto del entrenamiento aeróbico y del ejercicio eventual sobre el estado oxidativo hepático. Se utilizaron 30 ratones machos NMRI, divididos en 3 grupos de 10: Control (sin ejercicio, Entrenamiento Aeróbico (EA y Ejercicio Eventual (EE. La actividad física se realizó en una rueda de ejercicio que giraba a 50 rpm/ (30 minutos. día por 6 semanas para el grupo con EA y a 50 rpm/ 30 minutos, una vez para el EE. Se determinó en sangre la concentración de albúmina, y en hígado se cuantificó la concentración de Dienos Conjugados, Malondialdehido, Glutatión Reducido (GSH, y se realizó el estudio histopatológico. Los resultados muestran que los animales que realizaron EE presentaron un aumento marcado de la lipoperoxidación (LPO hepática comparado con el grupo control y con los de EA. Con respecto a la respuesta antioxidante, la concentración de GSH aumentó en los animales de EA y disminuyó en los de EE, la albúmina fue menor en los animales que se ejercitaron. El cociente GSH/LPO fue mayor en los animales de EA, lo que indica una disminución de la LPO en relación con la respuesta antioxidante dada por el GSH. Los resultados de este estudio muestran que a pesar de que ocurre un aumento de la lipoperoxidación hepática durante el ejercicio, esta oxidación no altera la estructura histológica del órgano y dependiendo del tipo de ejercicio, el organismo se adapta produciendo aumento de la defensa antioxidante, base esta del entrenamiento. Abstract The aim of this study was to evaluate in an animal model the effect of aerobic training on hepatic oxidative status. Control (without exercise Aerobic Training (EA and Exercise Eventually (EE: 30 NMRI male mice were divided into 3 groups of 10 were used. Physical activity was conducted in an exercise wheel rotating at 50 rpm / 30 minutes / day / six weeks for the group with AD and 50 rpm / 30 minutes / once for EE. Albumin

  16. Modeling the effect of the seismic wave propagation in buried continuous pipelines; Modelacion del efecto de propagacion de ondas sismicas en tuberias continuas enterradas

    Energy Technology Data Exchange (ETDEWEB)

    Melchor Garcia, Nicolas Ageo

    2005-02-15

    This work presents the state of art of the behavior of buried pipelines facing the effect of the propagation of seismic waves. Special attention has been given to the modeling of the soil-piping system. Some analytical models are presented and discussed in great detail. The purpose of this is to contribute, in particular, to the following aspects: First, it attempts to be a reference work for the geotechnical engineers facing problems related to the seismic wave propagation phenomenon in buried structures, since within the consulted literature there are many of the principles presented in here, that are related with the seismic engineering, the reaction module, as well as expressions or investigations performed in piles. Second, a cuasi-static numerical model is presented that analyzes the continuous piping through a stress vector of sinusoidal type. The analysis of the stresses and deformations that the ground transmits to the pipe is made using a ground-to-pipe interaction model. For a low level of deformations an elastic behavior of transference in the interface is considered in the inter-phase ground-piping. In the case of greater deformations it is assumed that sliding is presented because the surrounding ground presents fault by shearing stress in the surrounding ground. The analysis covers solely the case with axial deformations in straight sections. Finally, it intends to give a series of recommendations for future research works on the modeling of buried pipelines. In this work, the influence of several aspects on the response of the pipelines to the propagation of seismic waves is analyzed and discussed; such as the conditions of topography, geology, ground stratigraphy and the rigidity changes in the surrounding ground of the pipe. [Spanish] Este trabajo presenta el estado del arte sobre el comportamiento de tuberias enterradas ante efecto de programacion de ondas sismicas. Una especial atencion ha sido dada a la modelacion del sistema suelo

  17. Usos del nudo. Efectos de nominación en el autismo. (Uses of the Knot. Effects of Naming in Autism.

    Directory of Open Access Journals (Sweden)

    Marcela Beatriz Piaggi

    2016-07-01

    Full Text Available Resumen Este texto forma parte del estado de trabajo de la tesis de maestría en Psicoanálisis que actualmente estamos desarrollando en la Facultad de Psicología de la Universidad de Buenos Aires. Uno de los aportes más interesantes será interrogarnos sobre el uso de los nudos en la clínica del autismo. Tomaremos como eje de la enseñanza de Lacan los años 1974-1976, donde aborda el nudo borromeo en el del pasaje del nudo triádico al tetrádico con la función de nominación, punto de partida para llegar con la lógica de los nudos al autismo caracterizado por la forclusión del agujero. Será central desarrollar el concepto de nominación como efectos para comprender el planteo del escrito. Palabras claves: Autismo- nudos- escritura-nominación- agujeros- sinthome. Abstract This paper is part of an ongoing thesis of the Master's Degree at the Faculty of Psychology of the University of Buenos Aires. The reflection on the use of the knots in the autism clinic is one of the most interesting contributions of this work. Lacan's teaching between 1974-1976 is the base of this study, in which he addresses the Borromean knot in the passage from the triadic to the tetradic knot with the naming function as starting point, to arrive with the logic of knots to autism, characterized by the foreclosure of the gap. The development of the concept of naming as effects is essential to understand the approach of this paper. Keywords: autism- knots- writing-naming- gaps- sinthome. Résumé Ce texte fait partie de l'avancement d’un travail de recherche pour l'obtention du Master en psychanalyse de la faculté de psychologie de l'Université de Buenos Aires. La réflexion sur l'usage des nœuds dans la pratique clinique de l'autisme est l'une des contributions les plus intéressantes de ce travail. Les enseignements de Lacan des années 1974-1976 sont la base de cette étude, enseignements où il aborde le Nœud borroméen dans le passage du nœud triadique

  18. Efecto de la temperatura sobre la viabilidad de larvas de Trichinella spiralis Effect of temperature on the viability of Trichinella spiralis larvae

    Directory of Open Access Journals (Sweden)

    Viviana R Randazzo

    2011-12-01

    Full Text Available El objetivo de este estudio fue determinar el efecto de diferentes temperaturas sobre la viabilidad de larvas libres y enquistadas de Trichinella spiralis aisladas en el sudoeste de la provincia de Buenos Aires, Argentina. Se trataron larvas libres y enquistadas a diferentes temperaturas (-30 °C, -20 °C, 4 °C, 20 °C, calentamiento gradual entre 0-100 °C. Se determinó el tiempo necesario para matar el 100 % de las larvas. Durante los primeros días, la mortalidad larvaria en todos los tratamientos con frío aumentó signifcativamente en función del tiempo. En todos los casos, las larvas libres sobrevivieron menor cantidad de días que las enquistadas. A -30 °C, -20 °C y 20 °C no se observaron diferencias signifcativas entre las curvas de mortalidad de cada estadio larvario, pero a 4 °C la mortalidad fue menos intensa entre las larvas enquistadas. El calentamiento disminuyó la viabilidad, sin observarse diferencias entre estadios larvarios. La totalidad de las larvas libres y enquistadas había muerto a los 61 y 95 días (-30 °C, a los 160 y 180 días (-20 °C, a los 280 y 330 días (4° C, y a los 460 y 590 días (20 °C, respectivamente. Fue necesaria una cocción durante 15 minutos a 90 °C para matar al 100 % de las larvas libres y a 100 °C para lograr igual mortalidad de las enquistadas. Nuestros resultados indican que la temperatura y los tiempos tradicionalmente utilizados para tratar productos cárnicos con potencial de transmisión de T. spiralis no serían los más efectivos para lograr la inactivación de la totalidad de larvas vivas de este parásito.The aim of this work was to study the effect of temperature on the viability of free and encysted larvae of Trichinella spiralis from southwest Buenos Aires province, Argentina. Larvae were treated at variable temperatures (-30 °C, -20 °C, 4 °C, 20 °C, gradual heating between 0-100 °C. The time necessary to kill 100 % of larvae was calculated. During the frst days of

  19. EFECTO DEL PROPILENGLICOL SOBRE LA UREMIA, GLICEMIA Y LA PRODUCCIÓN DE COMPONENTES DE LA LECHE EFFECT OF PROPYLENEGLYCOL ON URAEMIA, GLYCAEMIA AND MILK COMPONENTS PRODUCTION

    Directory of Open Access Journals (Sweden)

    Sandra Guisela Durango Morales

    2010-12-01

    Full Text Available Con el objetivo de determinar el efecto de la inclusión de propilenglicol (PG sobre las concentraciones plasmáticas de urea y glucosa y sobre la cantidad de leche producida y su concentración de sólidos, se analizó un grupo de 10 vacas entre su segunda y quinta lactancia. Los animales recibieron al día 45 posparto PG y durante 3 días consecutivos, éste se suministró diariamente en dosis de 250 g durante cada ordeño con la ración de suplemento comercial. Los animales fueron muestreados antes y después de suministrar el PG. Se estimaron balances de proteína degradable en rumen (PDR, proteína no degradable en rumen (PNDR y energía neta de lactancia (ENL. El balance promedio de PDR antes y después de suministrar el PG fue de 53,17 (+/-7,32 y 59,79 (+/-12,7 como porcentaje de los requerimientos respectivamente. Se encontró una diferencia estadísticamente significativa para el balance de ENL. Respecto al contenido de sólidos en leche no hubo una diferencia significativa para los porcentajes de grasa y de proteína, sin embargo se evidenció una disminución en la cantidad total de grasa producida por vaca y un aumento en la cantidad total de proteína producida por vaca. Ni la producción de leche ni las concentraciones plasmáticas de glucosa y urea se afectaron con el suministro del PG.In order to determine the effect of including propyleneglycol (PrGl on plasmatic concentrations of urea and glucose as well as milk produced and solids concentration, a group of 10 cows was studied between second and fifth lactation. The animals received PrGl at 45 day postpartum during 3 consecutive days. The estimated variables were rumen degradable protein (RDP, undegradable rumen protein (URP, and net energy for lactation (NEL. The RDP average before and after administering PrGl, was 53.17 (±7.32 and 59.79 (±12.7 as a percentage of requirements, respectively. There was a statistically significant difference for the balance NEL. Regarding

  20. ECG contamination of EEG signals: effect on entropy.

    Science.gov (United States)

    Chakrabarti, Dhritiman; Bansal, Sonia

    2016-02-01

    Entropy™ is a proprietary algorithm which uses spectral entropy analysis of electroencephalographic (EEG) signals to produce indices which are used as a measure of depth of hypnosis. We describe a report of electrocardiographic (ECG) contamination of EEG signals leading to fluctuating erroneous Entropy values. An explanation is provided for mechanism behind this observation by describing the spread of ECG signals in head and neck and its influence on EEG/Entropy by correlating the observation with the published Entropy algorithm. While the Entropy algorithm has been well conceived, there are still instances in which it can produce erroneous values. Such erroneous values and their cause may be identified by close scrutiny of the EEG waveform if Entropy values seem out of sync with that expected at given anaesthetic levels.

  1. Health effects associated with exposure to radioactively contaminated gold rings

    International Nuclear Information System (INIS)

    Baptiste, M.S.; Rothenberg, R.; Nasca, P.C.; Janerich, D.T.; Stutzman, C.D.; Rimawi, K.; O'Brien, W.; Matuszek, J.

    1984-01-01

    This study was designed to assess the health risks associated with exposure to radioactively contaminated gold rings. A group of 135 exposed individuals, who were identified through a statewide jewelry screening program, were studied to determine the frequency of carcinoma and other skin problems on the ring finger. Severity of skin problems increased with increasing length of wear. Forty-one of the exposures were associated with mild to severe skin problems. Nine of the individuals studied were diagnosed as having histologically confirmed squamous cell carcinomas at the site of exposure. The incidence of skin cancer on the ring finger was eleven times that expected for men and forty-five times that expected for women. These data indicate that physicians who have patients with skin lesions of the ring finger should be aware of the possibility of exposure to a radioactive gold ring

  2. Effect of Hadron Contamination on Dielectron Signal Reconstruction in Heavy Flavor Production Measurements

    International Nuclear Information System (INIS)

    Kikoła, Daniel

    2015-01-01

    Dielectron signal reconstruction is an important tool for heavy flavor measurements because of its trigger feasibility and its relatively straightforward particle identification process. However, in the case of time projection chamber detectors, some hadron contamination is unavoidable, even if additional means are used to improve the particle identification process. In this paper, we investigate the effects of hadron (protons, pions, and kaons) contamination on the dielectron signal reconstruction process in the measurement of J/ψ and electrons from heavy flavor hadron decays

  3. Effect of a New Salivary Contaminant Removal Method on Bond Strength

    Science.gov (United States)

    2014-08-31

    was to evaluate the effect of various salivary- contaminant removal methods on the shear bond strength of resin cement to hydrofluoric-acid (HF) etched...mold (Ultradent) to a height of 3mm and light cured . Specimens were stored for 24 hours in 37°C distilled water and then tested in shear in a... contamination which may compromise the bond strength of the resin cement to the ceramic (Aboush, 1998; van Schalkwyk et al., 2003). Saliva affects bond

  4. Combined effects of microplastics and chemical contaminants on the organ toxicity of zebrafish (Danio rerio).

    Science.gov (United States)

    Rainieri, Sandra; Conlledo, Nadia; Larsen, Bodil K; Granby, Kit; Barranco, Alejandro

    2018-04-01

    Microplastics contamination of the aquatic environment is considered a growing problem. The ingestion of microplastics has been documented for a variety of aquatic animals. Studies have shown the potential of microplastics to affect the bioavailability and uptake route of sorbed co-contaminants of different nature in living organisms. Persistent organic pollutants and metals have been the co-contaminants majorly investigated in this field. The combined effect of microplastics and sorbed co-contaminants in aquatic organisms still needs to be properly understood. To address this, we have subjected zebrafish to four different feeds: A) untreated feed; B) feed supplemented with microplastics (LD-PE 125-250µm of diameter); C) feed supplemented with 2% microplastics to which a mixture of PCBs, BFRs, PFCs and methylmercury were sorbed; and D) feed supplemented with the mixture of contaminants only. After 3 weeks of exposure fish were dissected and liver, intestine, muscular tissue and brain were extracted. After visual observation, evaluation of differential gene expression of some selected biomarker genes in liver, intestine and brain were carried out. Additionally, quantification of perfluorinated compounds in liver, brain, muscular tissue and intestine of some selected samples were performed. The feed supplemented with microplastics with sorbed contaminants produced the most evident effects especially on the liver. The results indicate that microplastics alone does not produce relevant effects on zebrafish in the experimental conditions tested; on the contrary, the combined effect of microplastics and sorbed contaminants altered significantly their organs homeostasis in a greater manner than the contaminants alone. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

    OpenAIRE

    Bonzom , Jean-Marc; Hättenschwiler , Stephan; Lecomte-Pradines , Catherine; Chauvet , Eric; Gaschak , Sergey; Beaugelin-Seiller , Karine; Della-Vedova , Claire; Dubourg , Nicolas; Maksimenko , Andrey; Garnier-Laplace , Jacqueline; Adam-Guillermin , Christelle

    2016-01-01

    International audience; The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely un- known. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the function- ing of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black a...

  6. Sublethal effects of contamination on the Mediterranean sponge Crambe crambe: metal accumulation and biological responses

    International Nuclear Information System (INIS)

    Cebrian, E.; Marti, R.; Uriz, J.M.; Turon, X.

    2003-01-01

    The effect of low levels of pollution on the growth, reproduction output, morphology and survival of adult sponges and settlers of the sponge Crambe crambe were examined. We transplanted sponges from a control area to a contaminated site and measured the main environmental variables (chemical and physical) of both sites during the study period. Except some punctual differences in particulate organic matter, silicates, nitrates, and water motion, most environmental variables in the water were similar at both sites during the study months. Mainly copper, lead and OM concentrations in the sediment, and water motion were significantly higher at the polluted site and may be implicated in the biological effects observed: decrease in the percentage of specimens with embryos, increase in shape irregularity and decrease in growth rate. Individuals naturally occurring at the polluted site and those transplanted there for four months accumulated ten times more copper than either untouched or transplant controls. Although lead concentration in sediment did not differ between sites, native specimens from the contaminated site accumulated this metal more than untouched controls. Vanadium concentration also tended to increase in the sponges living at or transplanted to the contaminated site but this difference was not significant. C. crambe is a reliable indicator of metal contamination since it accumulates copper, lead and vanadium in high amounts. At the contaminated site, sponge growth, fecundity and survival were inhibited, whereas sponge irregularity ending in sponge fission was promoted. All these effects may compromise the structure and dynamics of the sponge populations in sheltered, metal-contaminated habitats

  7. Nutrients versus emerging contaminants-Or a dynamic match between subsidy and stress effects on stream biofilms.

    Science.gov (United States)

    Aristi, I; Casellas, M; Elosegi, A; Insa, S; Petrovic, M; Sabater, S; Acuña, V

    2016-05-01

    Freshwater ecosystems are threatened by multiple anthropogenic stressors, which might be differentiated into two types: those that reduce biological activity at all concentrations (toxic contaminants), and those that subsidize biological activity at low concentrations and reduce it at high concentrations (assimilable contaminants). When occurring in mixtures, these contaminants can have either antagonistic, neutral or synergistic effects; but little is known on their joint effects. We assessed the interaction effects of a mixture of assimilable and toxic contaminants on stream biofilms in a manipulative experiment using artificial streams, and following a factorial design with three nutrient levels (low, medium or high) and either presence or absence of a mixture of emerging contaminants (ciprofloxacin, erythromycin, diclofenac, methylparaben, and sulfamethoxazole). We measured biofilm biomass, basal fluorescence, gross primary production and community respiration. Our initial hypotheses were that biofilm biomass and activity would: increase with medium nutrient concentrations (subsidy effect), but decrease with high nutrient concentrations (stress effect) (i); decrease with emerging contaminants, with the minimum decrease at medium nutrient concentrations (antagonistic interaction between nutrients subsidy and stress by emerging contaminants) and the maximum decrease at high nutrient concentrations (synergistic interaction between nutrients and emerging contaminants stress) (ii). All the measured variables responded linearly to the available nutrients, with no toxic effect at high nutrient concentrations. Emerging contaminants only caused weak toxic effects in some of the measured variables, and only after 3-4 weeks of exposure. Therefore, only antagonistic interactions were observed between nutrients and emerging contaminants, as medium and high nutrient concentrations partly compensated the harmful effects of emerging contaminants during the first weeks of the

  8. Mercury: Aspects of its ecology and environmental toxicity. [physiological effects of mercury compound contamination of environment

    Science.gov (United States)

    Siegel, S. M.

    1973-01-01

    A study was conducted to determine the effects of mercury pollution on the environment. The possible sources of mercury contamination in sea water are identified. The effects of mercury on food sources, as represented by swordfish, are analyzed. The physiological effects of varying concentrations of mercury are reported. Emphasis is placed on the situation existing in the Hawaiian Islands.

  9. El Efecto Malthus

    DEFF Research Database (Denmark)

    Dean, Mitchell

    2015-01-01

    This paper identifies and elucidates what it calls the Malthus Effect from two perspectives: a genealogical-theoretical one and an empirical-diagnostic one. The first concerns its implications for Michel Foucault’s genealogy and conceptions of modern governmentality. The second suggests that Malt...

  10. Efecto del aceite de sacha inchi (plukenetia volúbilis l sobre el perfil lipídico en pacientes con hiperlipoproteinemia Effect of sacha inchi oil (plukenetia volúbilis l on the lipid profile of patients with hyperlipoproteinemia

    Directory of Open Access Journals (Sweden)

    Fausto Garmendia

    2011-12-01

    Full Text Available El presente es un trabajo experimental piloto, abierto, para conocer el efecto, dosis efectiva y efectos secundarios del aceite de sacha inchi (Plukenetia volúbilis L en el perfil lipídico de pacientes con hipercolesterolemia; para ello, se incluyó a 24 pacientes de 35 a 75 años, en quienes se determinó los valores sanguíneos de colesterol total (CT, HDL, triglicéridos (Tg, glucosa, ácidos grasos no esterificados (AGNE e insulina Se aleatorizó a los participantes para recibir 5 mL o 10 mL de una suspensión conteniendo 2gr/5ml de aceite de sacha inchi, durante cuatro meses. La ingesta del aceite produjo caída en los valores promedio del CT, y AGNE con elevación del c-HDL en ambos grupos. La dosis de 10 mL se asoció a mayores niveles de insulina en el grupo aleatorizado a recibir 10 ml. El aceite de sacha inchi parece tener efectos benéficos sobre el perfil lipídico en pacientes con dislipidemia, requiriéndose la evaluación de su eficacia y seguridad en ensayos clínicos aleatorizados.We performed a pilot, experimental, open study in order to know the effect, effective dosage and secondary effects of sacha inchi´s (Plukenetia volúbilis L oil on the lipid profiles of patients with hypercholesterolemia. We included 24 patients of ages 35 to 75, to whom we measured total cholesterol (TC, HDL, triglycerides (Tg, glucose (G, non-esterified fatty acids (NEFA and insulin (I levels in blood, then we randomized them to receive sacha inchi oil orally 5 ml or 10 ml of a suspension of sacha inchi oil (2gr/5ml for four months. The oil intake produced a decrease in the mean values of TC, and NEFA, and a rise in HDL in both subgroups. The subgroup receiving 10 ml was associated to an increase in the insulin levels. Sacha inchi oil appears to have beneficial effects on the lipid profile of patients with dyslipidemia, but their efficacy and security should be evaluated in randomized clinical trials.

  11. Living in highly dynamic polluted river floodplains, do contaminants contribute to population and community effects?

    International Nuclear Information System (INIS)

    Klok, Chris; Kraak, Michiel H.S.

    2008-01-01

    The aim of this paper was to collect evidence for the effects of contaminants on biota in a highly dynamic river Rhine floodplain. To this purpose we reviewed the results of circa 10 studies performed in this floodplain. The floodplain was contaminated with elevated levels of cadmium, copper, PAHs, and PCBs and high levels of zinc which were at some sites above legislative values. The results showed that the present contaminants were accumulated by the floodplain inhabiting organisms, but meanwhile population and community effects were ambiguous. Only for the mayfly Ephoron virgo clear effects were detected at the level of the single floodplain. The absence of clear population and community effects is puzzling since at lower contaminant concentrations adverse effects were detected in other environments. Factors that may mask toxic effects include flooding and food quality and quantity. We conclude that given the site specific conditions, being an open, eutrophic system with a highly dynamic flooding pattern, assessment of the contribution of toxicants to observed population density or biomass and community composition requires 1] an increase in number of replicates; 2] a larger scale of investigation and 3] comparison to stable systems with comparable contamination levels

  12. Climatic Reliability of Electronics: Early Prediction and Control of Contamination and humidity effects

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas

    were to a significant extent guided by the climatic reliability issues the electronic companies are currently facing. The research in this thesis is focused on the synergistic effects of process related contamination, humidity, potential bias, and PCBA design related aspects, while various tests...... assuming parasitic circuit due to water layer formation on the PCBA surface. The chapters 2-5 review the factors influencing the climatic reliability of electronics namely humidity interaction with materials and ionic contamination on the PCBA surface, common types and sources of ionic contamination...... in electronics, the test methods and techniques, and failure mechanisms related to climate and contamination. Chapter 6 summarizes the materials and experimental methods employed in this thesis. The results of various investigations are presented as individual research papers as published or in the draft form...

  13. Effect of metal contamination on recombination properties of extended defects in multicrystalline Si

    Energy Technology Data Exchange (ETDEWEB)

    Feklisova, O.V.; Yakimov, E.B. [Institute of Microelectronics Technology, RAS, Chernogolovka 142432 (Russian Federation); Yu, X.; Yang, D. [State Key Lab of Silicon Materials, Zhejiang University, Hangzhou 310027 (China)

    2012-10-15

    The effect of iron and copper contamination on the recombination properties of extended defects in multicrystalline Si is investigated by the Electron Beam Induced Current (EBIC) method. Plastically deformed Si samples containing dislocations and dislocation trails are also studied for a comparison. It is shown that Fe contamination leads to an essential increase of the EBIC contrast of electrically active grain boundaries and dislocation trails. The EBIC contrast of deformation induced dislocations also increases after iron diffusion while the recombination activity of grown-in dislocations in multicrystalline Si does not practically change after such treatment. Cu contamination also leads to an essential increase of the EBIC contrast of electrically active grain boundaries and dislocation trails. But dislocation contrast in both plastically deformed Si and multicrystalline Si does not practically increase after Cu contamination. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Microbial contamination of dental unit waterlines and effect on quality of indoor air.

    Science.gov (United States)

    Kadaifciler, Duygu Göksay; Cotuk, Aysin

    2014-06-01

    The microbiological quality in dental unit waterlines (DUWLs) is considered to be important because patients and dental staff with suppressed immune systems are regularly exposed to water and aerosols generated from dental units (DUs). Opportunistic pathogens like Pseudomonas, Legionella, Candida, and Aspergillus can be present in DUWLs, while during consultations, bioaerosols can be dispersed in the air, thus resulting in effects on microbiological quality of indoor air. This present study represents microbiological air and water quality in dental offices (DOs) and also concerns the relationship between the quality of DO air and dental unit water. This study aimed to assess both the microbial quality of dental unit water and the indoor air in 20 DOs and to survey the effect on the quality of the indoor air with the existing microorganisms in dental unit water. Fourteen out of 20 (70 %) DUWLs were found to be contaminated with a high number of aerobic mesophilic heterotrophic bacteria. In terms of bacterial air contamination levels, in 90 % of DOs, a medium level (contamination was determined, while in terms of microfungal air contamination, in all DOs, a low level (contamination was determined. Potential infection or allergen agents, such as Pseudomonas, Micrococcus, Staphylococcus, Alternaria, Cladosporium, Penicillium, Aspergillus, and Paecilomyces were isolated from water and air samples. This study's determination of contamination sources and evaluation of microbial load in DOs could contribute to the development of quality control methods in the future.

  15. Effects of acute and chronic experimental contamination on direct cesium 137 uptake by the eel, Anguilla anguilla L

    International Nuclear Information System (INIS)

    Foulquier, Luc; Lambrechts, Alain.

    1982-03-01

    This study covers the effects of different types of contamination on direct cesium 137 uptake by the eel. In the first experiment (acute contamination), simulating a waste discharge, the fish were kept in water with a rapidly decreasing cesium 137 activity. In a second experiment (chronic contamination), the water activity increased constantly, simulating increasing waste frequency and activity levels. Irrespective of the type of contamination, radiocesium retention by eels is low ( [fr

  16. Modelación de los efectos de la compensación de potencia reactiva en sistemas de suministro eléctrico Modelation of effects on reactive power compensation in secondary power systems

    Directory of Open Access Journals (Sweden)

    Davel Borges Vasconcellos

    2012-08-01

    Full Text Available Se presentan los inconvenientes de la potencia reactiva y a partir de allí se realiza la modelación matemática de los efectos económicos de ésta, aplicable a sistemas de suministro eléctrico. Los efectos tomados en cuenta son: los costos de inversión de los bancos de capacitores, los gastos de amortización de los bancos, los gastos de pérdidas de energía activa de los bancos, los beneficios por la mejora del factor de potencia, incluida la reducción de pérdidas de energía activa en el sistema, así como los beneficios por la liberación de la capacidad de carga, para el caso de empresas donde este aspecto pueda representar un atractivo económico. Para el análisis de los estados de carga antes y después de la compensación se utilizan algoritmos de flujos de potencia trifásicos, con el empleo de modelos de gráficos de carga ajustados, como aspecto novedoso. Estos efectos, de acuerdo con el sistema de tarifas eléctricas de Cuba, son integrados en una función de análisis económico, en este caso el Valor Actual Neto (VAN, la cual sirve de base para el planteamiento del problema de optimización, que puede derivar en la correcta selección de los dispositivos compensadores.The inconveniences of the reactive power are presented and from this are carried out the mathematical models of its economic effects applicable to secondary power systems. The effects taken into account are: the costs of the capacitors banks, the expenses of paying-off to the banks, the expenses of power losses to the banks, the benefits for the improvement of the power factor, included the reduction of power loss in the system, as well as the benefits for the liberation of the load capacity, to the case of companies where the latest aspect can represent an economic attractiveness. For the analysis after and before compensation, are consider load flow algorithm witch load model adjust. According to electrical tariff structures in Cuba, these effects are

  17. Efectos del ejercicio físico sobre la memoria episódica en ancianas chilenas sanas (Effects of Physical Exercise on the Episodic Memory in Healthy Elderly Chileans

    Directory of Open Access Journals (Sweden)

    Norman López

    2015-06-01

    Full Text Available Resumen: El objetivo de esta investigación fue analizar el efecto de un programa de actividad física regular sobre la memoria episódica verbal y visuoespacial en ancianas chilenas mentalmente sanas. Participaron 74 ancianas sin deterioro cognitivo, divididas en un grupo de intervención, integrado por 34 de ellas, que realizaron actividad física por seis meses; y un grupo control integrado por 40 sedentarias. Se utilizó el Test de Aprendizaje Auditivo Verbal de Rey (TAAVR y el Test de la Figura Compleja de Rey (TFCR para la evaluación de la memoria episódica. Asimismo, se realizaron análisis inter e intragrupales con t student y d de Cohen para medir el tamaño de efecto de las pruebas t. Los resultados evidenciaron diferencias estadísticamente significativas en el postest entre el grupo de intervención (GI y grupo control (GC, observándose mejor rendimiento en las pruebas de memoria episódica verbal y visual del GI con un tamaño de efecto alto. Se concluye que la actividad física regular aumenta la capacidad de procesamiento, retención y evocación de la información verbal y visual episódica en mujeres ancianas sanas. Abstract: Our objective was to analyze the effect of a regular physical activity program on the verbal and visuospatial episodic memory on mentally healthy elderly Chileans. Participated 74 elderly women without cognitive impairment – divided into an intervention group = 34 elderly women, who carried out physical activity for six months; and a control group = 40 sedentary women. We used the Rey Auditory Verbal Learning Test (RAVLT, and the Rey Complex Figure Test (RCFT for the evaluation of the episodic memory. Analysis were performed inter- and intra-group with t student and d of Cohen to measure the effect size of t-tests. The results showed statistically significant differences in the post-test between the Intervention Group (IG and Control Group (CG; noticing better yields in the verbal and visual episodic

  18. Effects of feeding grains naturally contaminated with Fusarium mycotoxins on performance and metabolism of broiler breeders.

    Science.gov (United States)

    Yegani, M; Smith, T K; Leeson, S; Boermans, H J

    2006-09-01

    A study was conducted to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins on performance and metabolism of broiler breeders. Forty-two 26-wk-old broiler breeder hens and nine 26-wk-old roosters were fed the following diets: (1) control, (2) contaminated grains, and (3) contaminated grains + 0.2% polymeric glucomannan mycotoxin adsorbent (GMA) for 12 wk. The major contaminant was deoxynivalenol (12.6 mg/kg of feed), with lesser amounts of zearalenone and 15-acetyl-deoxynivalenol. Feed consumption and BW were not affected by diet. The feeding of contaminated grains did not significantly affect egg production. Decreased eggshell thickness was seen, however, at the end of wk 4, and dietary supplementation with GMA prevented this effect. There was no effect of diet on other egg parameters measured. There was a significant increase in early (1 to 7 d) embryonic mortality in eggs from birds fed contaminated grains at wk 4, but mid- (8 to 14 d) and late- (15 to 21 d) embryonic mortalities were not affected by diet. There were no differences in newly hatched chick weights or viability. The ratio of chick weight to egg weight was not affected by the feeding of contaminated grains. Weight gains of chicks fed a standard broiler starter diet at 7, 14, and 21 d of age were not significantly affected by previous dietary treatments for the dam. It was found that rooster semen volume and sperm concentration, viability, and motility were not affected by the feeding of contaminated diets. There was no effect of diet on the relative weights of liver, spleen, kidney, and testes. The feeding of contaminated grains decreased antibody titers against infectious bronchitis virus at the end of wk 12, and this was prevented by dietary supplementation with GMA. There was no effect of the diet on serum antibody titers against Newcastle disease virus. It was concluded that the feeding of blends of grains contaminated with Fusarium mycotoxins could affect

  19. The Effects of Environmental Factors on Biological Remediation of Petroleum Hydrocarbon Contaminated Soil

    Directory of Open Access Journals (Sweden)

    Mohammad reza Moslemi

    2005-09-01

    Full Text Available Among the consequences of discharging industrial wastes to land and water bodies, is the widespread accumulation and migration of toxic chemical mixtures in soil and groundwater resources. It is believed that the accumulation of contaminants in the environment constitutes a serious threat to ecological and human health. Bioremediation is an effective measure in dealing with such contaminations particularly those from petroleum hydrocarbon sources; moreover bioremediation is emerging as a promising technology for the treatment of soil and groundwater contamination. Therefore the goal of this study is discussing the theory and practice of biological remediation of petroleum hydrocarbon contaminated soils and assessing the effects of operational conditions and parameters such as: temperature, dissolved oxygen concentration and  pH on the removal rate of the target contaminant which is handled in the designed reactor. Due to large production and consumption rate of diesel fuel inIran and many other countries, diesel fuel has been selected as target contaminant. In this study TOC and COD testing methods have been used to measure and assess the removal rate of the contaminant in the reactor. The experimental results indicate that, considering the operational conditions the indigenous microorganisms which have been separated from the soil are able to remove 50 to 83 percent of the contaminant after 30 days. Thereafter on the base of the results and considering the laboratorial specifications and conditions applied in this project, the optimum values of temperature, dissolved oxygen concentration andpH were respectively determined as 35°C, 4mg/L and 7.

  20. Effect of salivary contamination on shear bond strength of two adhesives: An in vitro study

    Directory of Open Access Journals (Sweden)

    Shruti B Patil

    2014-01-01

    Full Text Available Introduction: Composite material used with bonding system are technique sensitive and contamination of an etched surface by saliva or blood plays a key role in bonding efficacy. Achieving good moisture control is a common problem encountered and is of importance while treating a pediatric age group since rubber dam in dental office is commonly applied in fewer than 10% of restorative treatment. Despite the advantage of rubber dam application, usage of rubber dam depends on child′s behavior and its level of co-operation for which pediatric dentists compromise with its usage. This study was conducted to evaluate the effect of salivary contamination of enamel and dentin on bond strength of two adhesives. Materials and Methods: An in vitro study comprised of test group of 112 central incisors divided into 4 groups for testing on enamel and dentin separately. These are Group I: Control group without salivary contamination; Group II: Contaminated with saliva and air-dried; Group III: Contaminated with saliva, rinsed and air-dried; Group IV: Coated with adhesive, light cured and then contaminated. Shear bond strength was calculated using universal testing machine. Results: For testing on enamel and dentin, significantly decreased bond strength was seen with Group II (P 0.05, when compared with control Group I. Conclusion: The decontamination method used in this study by rinsing the contaminated cured adhesive layer that did not reverse the harmful effect of salivary contamination. As most of the children are active and restless with swinging mood, it is important not to negotiate with the procedural steps during treatment.

  1. Copper Contamination Impairs Herbivore Initiation of Seaweed Inducible Defenses and Decreases Their Effectiveness.

    Directory of Open Access Journals (Sweden)

    Alexandria M Warneke

    Full Text Available Seaweed-herbivore interactions are often mediated by environmental conditions, yet the roles of emerging anthropogenic stressors on these interactions are poorly understood. For example, chemical contaminants have unknown consequences on seaweed inducible resistance and herbivore response to these defenses despite known deleterious effects of contaminants on animal inducible defenses. Here, we investigated the effect of copper contamination on the interactions between a snail herbivore and a brown seaweed that displays inducible resistance to grazing. We examined seaweed inducible resistance and its effectiveness for organisms exposed to copper at two time points, either during induction or after herbivores had already induced seaweed defenses. Under ambient conditions, non-grazed tissues were more palatable than grazed tissues. However, copper additions negated the preference for non-grazed tissues regardless of the timing of copper exposure, suggesting that copper decreased both how herbivores initiated these inducible defenses and their subsequent effectiveness. Copper decreased stimulation of defenses, at least in part, by suppressing snail grazing pressure-the cue that turns inducible defenses on. Copper decreased effectiveness of defenses by preventing snails from preferentially consuming non-grazed seaweed. Thus, contaminants can potentially stress communities by changing seaweed-herbivore interactions mediated via inducible defenses. Given the ubiquity of seaweed inducible resistance and their potential influence on herbivores, we hypothesize that copper contamination may change the impact of these resistant traits on herbivores.

  2. Black Swans and the Effectiveness of Remediating Groundwater Contamination

    Science.gov (United States)

    Siegel, D. I.; Otz, M. H.; Otz, I.

    2013-12-01

    Black swans, outliers, dominate science far more than do predictable outcomes. Predictable success constitutes the Black Swan in groundwater remediation. Even the National Research Council concluded that remediating groundwater to drinking water standards has failed in typically complex hydrogeologic settings where heterogeneities and preferential flow paths deflect flow paths obliquely to hydraulic gradients. Natural systems, be they biological or physical, build upon a combination of large-scale regularity coupled to chaos at smaller scales. We show through a review of over 25 case studies that groundwater remediation efforts are best served by coupling parsimonious site characterization to natural and induced geochemical tracer tests to at least know where contamination advects with groundwater in the subsurface. In the majority of our case studies, actual flow paths diverge tens of degrees from anticipated flow paths because of unrecognized heterogeneities in the horizontal direction of transport, let alone the vertical direction. Consequently, regulatory agencies would better serve both the public and the environment by recognizing that long-term groundwater cleanup probably is futile in most hydrogeologic settings except to relaxed standards similar to brownfielding. A Black Swan

  3. Quantifying the effect of sorption and bioavailability of hydrophobic organic contaminants

    International Nuclear Information System (INIS)

    Zhang, W.; Bouwer, E.; Cunningham, A.

    1994-01-01

    In-situ bioremediation has been applied successfully at a few sites. Several restrictions presently exist which could greatly limit the effectiveness of this promising technology. Hydrophobic organic contaminants tend to sorb onto soil. However, microorganisms are most effective in utilizing substrates from the aqueous phase. Sorption tends to separate the direct contact between microorganisms and contaminants necessary for biodegradation to occur. A series of experiments, which represented scenarios with fast sorption/desorption, slow sorption/desorption, mass transfer across boundary layer and mass transfer within attached microorganisms (biofilm), was conducted to demonstrate the concentration effect and the mass transfer effect. A method has been developed to quantify bioavailability of organic contaminants in aquatic environments. Bioavailability Factor (B f ), a dimensionless parameter derived from mathematical models and verified by experimental results, has been formulated to describe the impact of equilibrium sorption, nonequilibrium sorption, and mass transfer processes on the rate and extent of biodegradation of petroleum hydrocarbons

  4. Contaminant Effects on California Bay–Delta Species and Human Health

    Directory of Open Access Journals (Sweden)

    Stephanie Fong

    2016-12-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2016v14iss4art5Many contaminants in the California Bay–Delta (Bay–Delta exceed regulatory standards, affect aquatic species, and potentially affect human health. Recent studies provide multiple lines of evidence that contaminants affect species of concern in the Bay–Delta (e.g., the decline of several important fish species referred to as the “Pelagic Organism Decline” or POD. Contaminants occur as dynamic complex mixtures and exert effects at multiple levels of biological organization. Multiple chemicals impair processes at cellular and physiological levels (measured as growth, development, and behavior abnormalities, and when viability and reproductive output are affected, populations are affected. As an important example, the population decline of the endangered Delta Smelt (Hypomesus transpacificus is significantly associated with multiple stressors, including insecticide use. New analyses presented in this paper show significant correlations between pyrethroid use and declining abundance of POD fish species. Water sampled from the Bay–Delta causes multiple deleterious effects in fish, and Delta Smelt collected from the Bay–Delta exhibit contaminant effects. Fish prey items are also affected by contaminants; this may have an indirect effect on their populations. Co-occurrence with thermal changes or disease can exacerbate contaminant effects. Contaminants also pose threats to human health via consumption of fish and shellfish, drinking water, and contact recreation, in particular, mercury, cyanobacteria toxins, disinfection byproducts, pathogens, pesticides, and pharmaceuticals and personal care products. The role of contaminants in the decline of Bay–Delta species is difficult to accurately assess in a complex, dynamic system. However, tools and approaches are available to evaluate contaminant effects on Bay–Delta species, and separate the effects of multiple stressors. Integrated

  5. Rutas de glicosilación en Candida albicans: circuitos reguladores y efectos sobre virulencia

    OpenAIRE

    Domínguez Cantero, María del Pilar

    2011-01-01

    [ES]Esta tesis trata sobre las rutas de glicosilación en Candida albicans: circuitos reguladores y efectos sobre virulencia. [EN]This thesis is about glycosylation pathways in Candida albicans: regulatory circuits and effects on virulence.

  6. Finite element modeling of contaminant transport in soils including the effect of chemical reactions.

    Science.gov (United States)

    Javadi, A A; Al-Najjar, M M

    2007-05-17

    The movement of chemicals through soils to the groundwater is a major cause of degradation of water resources. In many cases, serious human and stock health implications are associated with this form of pollution. Recent studies have shown that the current models and methods are not able to adequately describe the leaching of nutrients through soils, often underestimating the risk of groundwater contamination by surface-applied chemicals, and overestimating the concentration of resident solutes. Furthermore, the effect of chemical reactions on the fate and transport of contaminants is not included in many of the existing numerical models for contaminant transport. In this paper a numerical model is presented for simulation of the flow of water and air and contaminant transport through unsaturated soils with the main focus being on the effects of chemical reactions. The governing equations of miscible contaminant transport including advection, dispersion-diffusion and adsorption effects together with the effect of chemical reactions are presented. The mathematical framework and the numerical implementation of the model are described in detail. The model is validated by application to a number of test cases from the literature and is then applied to the simulation of a physical model test involving transport of contaminants in a block of soil with particular reference to the effects of chemical reactions. Comparison of the results of the numerical model with the experimental results shows that the model is capable of predicting the effects of chemical reactions with very high accuracy. The importance of consideration of the effects of chemical reactions is highlighted.

  7. Educación compensatoria. Efectos perdurables de la temprana implicación paterna (y III: el C.P.C.. [Compensatory education: Long-term effects of early parental implication (and III: The C.P.C.

    Directory of Open Access Journals (Sweden)

    López López, Eduardo

    2007-12-01

    Full Text Available After describing the program of early compensatory education (from age 3 to 9, called Chicago Child-Parent Centers (CPC, this article collects and analyses the evaluation studies of that Program from a longitudinal perspective –Chicago Longitudinal Study (CLS-, focusing primarily on methodological problems and afterwards on the short and, mainly, long terms effects, until the targeted subjects of the Program reached the age of 24. The studies confirm the Program has lasting educational (higher performance and educational achievements and social (higher social adjustment effects. Subsequently, it analyses which elements of the Program can produce these beneficial effects, which are basically its early inception and parent involvement in their children’s education. Finally, it concludes that the Program is highly profitable, based on the educational implications that stem from the study. En este artículo, después de describir brevemente el Programa de educación compensatoria temprana (de 3 a 9 años llamado Chicago Child-Parent Centers (CPC, se recogen y analizan los estudios de evaluación de dicho programa desde una perspectiva longitudinal –Chicago Longitudinal Study (CLS-, centrando primeramente la atención en los problemas metodológicos y posteriormente en los resultados de dicho programa tanto a corto como sobre todo a largo plazo, hasta que los destinatarios del programa alcanzan la edad de 24 años. Los estudios prueban que el programa tiene efectos duraderos de tipo educativo (más alto rendimiento y logros educativos y social (mayor integración social. Posteriormente se analiza a qué elementos del programa son achacables los efectos beneficiosos, que son básicamente el ser temprano y la implicación de los padres en la educación de sus hijos. Se concluye que el programa es altamente rentable, finalizando con las implicaciones educativas que del estudio derivan.

  8. Effect of Sporosarcina Pasteurii on the strength properties of compressed earth specimens; Efecto de la Sporosarcina Pasteurii en las propiedades resistentes de especímenes de tierra comprimida

    Energy Technology Data Exchange (ETDEWEB)

    Bernat-Maso, E.; Gil, L.; Escrig, C.; Barbé, J.; Cortés, P.

    2018-04-01

    Microbial biodeposition of calcite induction for improving the performance of rammed earth is a research area that must be analysed in a representative environment. This analysis must consider the compaction force, particle size distribution and curing process as production variables. This paper investigates the effects of adding specific bacteria, Sporosarcina Pasteurii, into compressed earth cubes and the effect of production variables. Uniaxial compressive tests and direct shear tests have been conducted for 80 specimens. The results indicate that calcite precipitation interacts with the drying process of clay/silt resulting in reducing the compressive strength, the apparent cohesion and the friction angle. Finally, bacterial activity, which is more likely in samples cured in a high humidity environment, tends to reduce the dilatancy effect. [Spanish] Inducir la biodeposición microbiana de calcita para mejorar las prestaciones de la tapia es una líneade investigación que necesita ser analizada en condiciones representativas y teniendo en cuenta variables de producción como la fuerza de compactación, la granulometría o el curado a diferentes humedades. Se estudia el efecto de añadir Sporosarcina Pasteurii en cubos de tierra comprimida y la influencia de estas variables de producción. Se han realizado ensayos de compresión simple y corte directo sobre 80 especímenes producidos con dos niveles de compactación y dos granulometrías. Los resultados indican que la precipitación de calcita interactúa con el proceso de secado de los limos/arcillas dando como resultado una reducción de la resistencia a compresión, de la cohesión aparente y del ángulo de fricción. Finalmente, la actividad bacteriana, más probable en las muestras curadas en un entorno de alta humedad, tiende a reducir el efecto de la dilatancia.

  9. Efecto del Tostado Sobre los Metabolitos Secundarios y la Actividad Antioxidante de Clones de Cacao Colombiano / Effect of Roasting on the Secondary Metabolites and Antioxidant Activity of Colombian Cocoa Clones

    Directory of Open Access Journals (Sweden)

    Sandra Zapata Bustamante

    2014-12-01

    Full Text Available Resumen. El tostado es una de las operaciones tecnológicas másimportantes en el procesamiento de los granos de cacao; esteproceso conduce a la formación de los productos de la reacciónde Maillard (RM los cuales son cruciales para el desarrollo dela calidad organoléptica de los granos de cacao y sus productosasociados. En el presente estudio se evaluó el efecto del tostadosobre el contenido de metabolitos secundarios y la actividadantioxidante en cinco clones de cacao cultivados en Colombia.En los extractos metanólicos de los diferentes clones de cacao sedeterminó el contenido de fenoles totales, taninos condensados,antocianinas totales, catequina y epicatequina, teobromina ycafeína. Además, se determinó la actividad antioxidante pormedio de la actividad atrapadora del radical ABTS•+, el métodoORAC y la capacidad atrapadora de radicales superóxido. Enconclusión, el efecto del tostado en los clones de cacao no tuvo uncomportamiento uniforme sobre los cambios en los contenidos delos diversos metabolitos secundarios y la actividad antioxidante. /  Abstract. Roasting is one of the most important technologicaloperations in the processing of cocoa beans; this process leads tothe formation of products of the Maillard reaction (RM, which arecrucial for the development of organoleptic quality of cocoa beansand its associated products. The aim of this study was to evaluatethe effect of roasting on the content of secondary metabolites andantioxidant activity in five Colombian cocoa clones, by differentmethodologies. The methanolic extracts of the cocoa beans wereanalyzed for total phenols content, condensed tannins, totalantiocianins, catechin and epicatechin, theobromine and caffeine.The antioxidant activity was determined by ABTS assay, ORACmethod and superoxide radical scavenging method. The effect ofroasting on cocoa clones did not have an unspecified behavior. Inconclusion, the effect of roasting of cacao clones was not uniformon the

  10. Effects of fluorine contamination on spin-on dielectric thickness in semiconductor manufacturing

    Science.gov (United States)

    Kim, Hyoung-ryeun; Hong, Soonsang; Kim, Samyoung; Oh, Changyeol; Hwang, Sung Min

    2018-03-01

    In the recent semiconductor industry, as the device shrinks, spin-on dielectric (SOD) has been adopted as a widely used material because of its excellent gap-fill, efficient throughput on mass production. SOD film must be uniformly thin, homogeneous and free of particle defects because it has been perfectly perserved after chemical-mechanical polishing (CMP) and etching process. Spin coating is one of the most common techniques for applying SOD thin films to substrates. In spin coating process, the film thickness and uniformity are strong function of the solution viscosity, the final spin speed and the surface properties. Especially, airborne molecular contaminants (AMCs), such as HF, HCl and NH3, are known to change to surface wetting characteristics. In this work, we study the SOD film thickness as a function of fluorine contamination on the wafer surface. To examine the effects of airborne molecular contamination, the wafers are directly exposed to HF fume followed by SOD coating. It appears that the film thickness decreases by higher contact angle on the wafer surface due to fluorine contamination. The thickness of the SOD film decreased with increasing fluorine contamination on the wafer surface. It means that the wafer surface with more hydrophobic property generates less hydrogen bonding with the functional group of Si-NH in polysilazane(PSZ)-SOD film. Therefore, the wetting properties of silicon wafer surfaces can be degraded by inorganic contamination in SOD coating process.

  11. Toxicological benchmarks for screening potential contaminants of concern for effects on terrestrial plants

    International Nuclear Information System (INIS)

    Suter, G.W. II; Will, M.E.; Evans, C.

    1993-09-01

    One of the initial stages in ecological risk assessment for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as ''contaminants of potential concern.'' This process is termed ''contaminant screening.'' It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to plants. This report presents a standard method for deriving benchmarks for this purpose (phytotoxicity benchmarks), a set of data concerning effects of chemicals in soil or soil solution on plants, and a set of phytotoxicity benchmarks for 34 chemicals potentially associated with US Department of Energy (DOE) sites. Chemicals that are found in soil at concentrations exceeding both the phytotoxicity benchmark and the background concentration for the soil type should be considered contaminants of potential concern. The purpose of this report is to present plant toxicity data and discuss their utility as benchmarks for determining the hazard to terrestrial plants caused by contaminants in soil. Benchmarks are provided for soils and solutions

  12. Toxicological benchmarks for screening potential contaminants of concern for effects on terrestrial plants. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Suter, G.W. II; Will, M.E.; Evans, C.

    1993-09-01

    One of the initial stages in ecological risk assessment for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as ``contaminants of potential concern.`` This process is termed ``contaminant screening.`` It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to plants. This report presents a standard method for deriving benchmarks for this purpose (phytotoxicity benchmarks), a set of data concerning effects of chemicals in soil or soil solution on plants, and a set of phytotoxicity benchmarks for 34 chemicals potentially associated with US Department of Energy (DOE) sites. Chemicals that are found in soil at concentrations exceeding both the phytotoxicity benchmark and the background concentration for the soil type should be considered contaminants of potential concern. The purpose of this report is to present plant toxicity data and discuss their utility as benchmarks for determining the hazard to terrestrial plants caused by contaminants in soil. Benchmarks are provided for soils and solutions.

  13. Means to remove electrode contamination effect of Langmuir probe measurement in space

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, K.-I.; Lee, C. H.; Fang, H. K.; Cheng, C. Z. [Plasma and Space Science Center, National Cheng Kung University, No.1 Ta-Hsueh Rd., Tainan 70101, Taiwan (China)

    2012-05-15

    Precaution to remove the serious effect of electrode contamination in Langmuir probe experiments has not been taken in many space measurements because the effect is either not understood or ignored. We stress here that one should pay extra attention to the electrode contamination effect to get accurate and reliable plasma measurements so that the long time effort for sounding rocket/satellite missions does not end in vain or becomes less fruitful. In this paper, we describe two main features of voltage-current characteristic curves associated with the contaminated Langmuir probe, which are predicted from the equivalent circuit model, which we proposed in 1970's. We then show that fast sweeping dc Langmuir probes can give reliable results in the steady state regime. The fast sweeping probe can also give reliable results in transient situations such as satellite moves through plasma bubble in the ionosphere where the electron density drastically changes. This fact was first confirmed in our laboratory experiment.

  14. Effects of remediation train sequence on decontamination of heavy metal-contaminated soil containing mercury.

    Science.gov (United States)

    Hseu, Zeng-Yei; Huang, Yu-Tuan; Hsi, Hsing-Cheng

    2014-09-01

    When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (> 50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550 degrees C with a heating rate of 5 degrees C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550 degrees C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg. Implications: A remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants.

  15. Allee effect in polar bears: a potential consequence of polychlorinated biphenyl contamination.

    Science.gov (United States)

    Pavlova, Viola; Nabe-Nielsen, Jacob; Dietz, Rune; Sonne, Christian; Grimm, Volker

    2016-11-30

    Polar bears (Ursus maritimus) from East Greenland and Svalbard exhibited very high concentrations of polychlorinated biphenyls (PCBs) in the 1980s and 1990s. In Svalbard, slow population growth during that period was suspected to be linked to PCB contamination. In this case study, we explored how PCBs could have impacted polar bear population growth and/or male reproductive success in Svalbard during the mid-1990s by reducing the fertility of contaminated males. A dose-response relationship linking the effects of PCBs to male polar bear fertility was extrapolated from studies of the effects of PCBs on sperm quality in rodents. Based on this relationship, an individual-based model of bear interactions during the breeding season predicted fertilization success under alternative assumptions regarding male-male competition for females. Contamination reduced pregnancy rates by decreasing the availability of fertile males, thus triggering a mate-finding Allee effect, particularly when male-male competition for females was limited or when infertile males were able to compete with fertile males for females. Comparisons of our model predictions on age-dependent reproductive success of males with published empirical observations revealed that the low representation of 10-14-year-old males among breeding males documented in Svalbard in mid-1990s could have resulted from PCB contamination. We conclude that contamination-related male infertility may lead to a reduction in population growth via an Allee effect. The magnitude of the effect is largely dependent on the population-specific mating system. In eco-toxicological risk assessments, appropriate consideration should therefore be given to negative effects of contaminants on male fertility and male mating behaviour. © 2016 The Author(s).

  16. Efectos pleiotrópicos de las estatinas: Características farmacológicas útiles en la prevención, tratamiento y regresión de la enfermedad cardiovascular Pleiotropic effect of statins: Useful pharmacological characteristics in prevention, treatment and regression of cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Darío Echeverri

    2005-09-01

    Full Text Available Los resultados benéficos de las estatinas en el manejo de la hipercolesterolemia en los múltiples estudios clínicos, han demostrado, además, efectos no relacionados con la acción hipolipemiante. Estudios experimentales in-vitro y ex-vivo han documentado una gran evidencia de efectos tales como incremento en la expresión de óxido nítrico y efectos anti-inflamatorios, inmunomodulatorios, anti-trombóticos, anti-proliferativos y anti-oxidantes los cuales reciben el nombre de pleiotrópicos. Los potentes efectos hipolipemiantes y pleiotrópicos podrían explicar los beneficios en aterosclerosis, hipertensión arterial, diabetes mellitus, estenosis aórtica, psoriasis, esclerosis múltiple y rechazo post-transplante entre otras patologías. Sin embargo, la cantidad de información experimental a favor de estos efectos, debería estimular a la iniciación de mejores estudios para clarificar de una manera mayor el significado clínico.Among the beneficial results of statins in the treatment of hypercholesterolemia, other effects not related to the hypolipemic action have been demonstrated in multiple studies. Experimental in vitro and ex-vivo studies have documented a great evidence of different effects such as an increment in the nitric oxide (NO expression, as well as anti-inflammatory, immunomodulatory, anti-thrombotic, anti-proliferative, and anti-oxidant effects. These are the pleiotropic effects. The potent hypolipemic and pleiotropic effects could explain the benefit in atherosclerosis, arterial hypertension, diabetes mellitus, aortic stenosis, psoriasis, multiple sclerosis and post-transplant rejection, among other pathologies. Nevertheless, the amount of experimental information in favour of these effects should stimulate the initiation of better studies in order to clarify in an accurate way its clinical significance.

  17. EFECTO ANTIALIMENTARIO DE LOS EXTRACTOS DE SUSPENSIONES CELULARES DE Azadirachta indica SOBRE Spodoptera frugiperda J. E. Smith EN CONDICIONES DE LABORATORIO ANTIFEEDANT EFFECT OF CELL SUSPENSION EXTRACTS OF Azadirachta indica ON Spodoptera frugiperda J. E. Smith UNDER LABORATORY CONDITIONS

    Directory of Open Access Journals (Sweden)

    Jacqueline Capataz Tafur

    2007-06-01

    Full Text Available Los extractos de neem (Azadirachta indica y sus ingredientes activos como la azadiractina, presentan acción antialimentaria e inhibición del desarrollo de muchos insectos. El objetivo de este estudio fue examinar el efecto antialimentario de los extractos de suspensiones celulares de neem elicitadas a diferentes condiciones de luz y temperatura. Los extractos fueron aplicados en discos de hojas de maíz y sometidas a bioensayos en larvas de segundo instar de Spodoptera frugiperda J. E. Smith (Lepidptera: Noctuidae. Los extractos intracelulares y del medio de cultivo de las suspensiones celulares de A. indica mostraron efecto biológico sobre larvas de S. frugiperda L2, con valores del 100 % de índice antialimentario para los extractos intracelulares de suspensiones de A. indica elicitadas a 15 °C y oscuridad, y del 39,3% para extractos extracelulares (medio de cultivo de suspensiones elicitadas a 35 °C y oscuridad.Extracts of neem (Azadirachta indica and their active ingredients as azadirachtin, present an action and inhibition of the development of many insects. In this study, the antifeedant effect of cell suspension extracts elicited to different conditions of light and temperature was examined. The extracts were applied in corn leaves disks and submitted to bioassays in larvae of second instar of Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae. The intracellular extracts and the culture media (supernatant of the cell suspensions of A. indica showed a biological effect on larvae of S. frugiperda L2, with values of the 100 % of antifeeding index for the intracellular extracts of cells elicited to 15 °C and darkness, and 39,3% of antifeeding index for extracellular extracts (medium of cultivation of elicited suspensions to 35°C , and darkness.

  18. The effect of mycorrhizal inoculation on hybrid poplar fine root dynamics in hydrocarbon contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, J.; Knight, J.D.; Van Rees, K.C.J. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Soil Science

    2006-07-01

    The biological remediation of contaminated soils using plants was discussed. Hybrid poplars are good candidates for phytoremediation because they root deeply, cycle large amounts of water and grow quickly. Their fine root system is pivotal in nutrient and water acquisition. Therefore, in order to maximize the phytoremediation potential, it is important to understand the response of the fine root system. In addition to degrading organic chemicals, ectomycorrhizal (ECM) fungi provide the host with greater access to nutrients. This study determined the relationship between residual soil hydrocarbons and soil properties at a field site. The effects of residual contamination on hybrid poplar fine root dynamics was also examined along with the effect of ectomycorrhizal colonization on hybrid poplar fine root dynamics when grown in diesel contaminated soil under controlled conditions. A minirhizotron camera inside a growth chamber captured images of mycorrhizal inoculation on hybrid poplar fine root production. Walker hybrid poplar seedlings were grown for 12 weeks in a control soil and also in a diesel contaminated soil. Seedlings were also grown in control and diesel contaminated, ectomycorrhizal inoculated soils. The inoculum was a mycorrhizal mix containing Pisolithus tinctorius and Rhizopogon spp. The images showed that colonization by ECM fungi increased hybrid poplar fine root production and aboveground biomass in a diesel contaminated soil compared to non-colonized trees in the same soil. Root:shoot ratios were much higher in the diesel contaminated/non-inoculated treatment than in either of the control soil treatments. Results of phytoremediation in diesel contaminated soil were better in the non-colonized treatment than in the colonized treatment. Both treatments removed more contaminants from the soil than the unplanted control. Much higher quantities of hydrocarbons were found sequestered in the roots from the inoculated treatment than from the non

  19. Effect of Thymus vulgaris and Bunium persicum essential oils on the oxidative stability of virgin olive oil; Efecto de aceites esenciales de tomillo y comino negro sobre la estabilidad oxidativa de aceites de oliva virgen

    Energy Technology Data Exchange (ETDEWEB)

    Keramat, M.; Golmakani, M.T.

    2016-07-01

    Natural antioxidants are becoming a major focus because natural food ingredients are safer than synthetic types. The aim of this study was to investigate the protective effects of Thymus vulgaris and Bunium persicum essential oils (EO) on the oxidation of virgin olive oil (VOO) during accelerated storage. The antioxidant activities of EOs were compared with those of α-tocopherol and BHT. GC/MS analyses revealed that thymol (28.50%), p-cymene (27.14%), carvacrol (18.36%), and γ-terpinene (4.97%) are the main components of T. vulgaris EO, while cuminaldehyde (32.81%), γ-terpinene (16.02%) and p-cymene (14.07%) are the main components of B. persicum EO. Both EOs provided protection for the VOO, inhibiting the formation of primary and secondary oxidation products although T. vulgaris EO showed greater protection against the oxidation process than B. persicum EO. The effect of T. vulgaris essential oil on the oxidation inhibition of VOO was similar to that of BHT. α-Tocopherol showed no measurable effect on improving the oxidative stability of VOO. This study suggests that T. vulgaris and B. persicum EOs can be used to improve the oxidative stability of VOO. [Spanish] En los antioxidantes naturales se está centrando actualmente más la atención dado que los ingredientes naturales son más seguros que los sintéticos. El objetivo de este estudio fue estudiar el efecto protector de aceites esenciales (AE) de tomillo y comino negro en la oxidación del aceite de oliva virgen (AOV) durante un almacenamiento acelerado. Las actividades antioxidantes de los AE se compararon con las del α-tocoferol y BHT. Los análisis de GC/MS mostraron que timol (28,50%), p-cimeno (27,14%), carvacrol (18,36%), y γ-terpineno (4,97%) son los principales componentes de AE de tomillo, mientras que cuminaldehido (32,81%), γ-terpineno (16,02%) y p-cimeno (14,07%) lo son de AE de comino negro. Ambos AE proporcionan protección al AOV, inhibiendo la formación de productos de oxidaci

  20. Mixture effects of 30 environmental contaminants on incident metabolic syndrome-A prospective study.

    Science.gov (United States)

    Lind, Lars; Salihovic, Samira; Lampa, Erik; Lind, P Monica

    2017-10-01

    Several cross-sectional studies have linked different environmental contaminants to the metabolic syndrome (MetS). However, mixture effects have not been investigated and no prospective studies exist regarding environmental contaminants and the MetS. To study mixture effects of contaminants on the risk of incident MetS in a prospective fashion. Our sample consisted of 452 subjects from the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study (50% women, all aged 70years) free from the MetS at baseline, being followed for 10years. At baseline, 30 different environmental contaminants were measured; 6 polychlorinated biphenyls (PCBs), 3 organochlorine (OC) pesticides, one dioxin, one polybrominated diphenyl ether (all in plasma), 8 perfluoroalkyl substances (in plasma) and 11 metals (in whole blood). The MetS was defined by the ATPIII/NCEP criteria. Gradient boosted Classification and Regression Trees (CARTs) was used to evaluate potential synergistic and additive mixture effects on incident MetS. During 10-year follow-up, 92 incident cases of the MetS occurred. PCB126, PCB170, hexachlorobenzene (HCB) and PCB118 levels were all associated with incident MetS in an additive fashion (OR 1.73 for a change from 10th to 90th percentile (95%CI 1.24-3.04) for PCB126, OR 0.63 (0.42-0.78) for PCB170, OR 1.44 (1.09-2.20) for HCB and OR 1.46 (1.13-2.43) for PCB118). No synergistic effects were found. A mixture of environmental contaminants, with PCB126, PCB170, HCB and PCB118 being the most important, showed associations with future development of the MetS in an additive fashion in this prospective study. Thus, mixture effects of environmental contaminants could contribute to the development of cardio-metabolic derangements. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Plant residues--a low cost, effective bioremediation treatment for petrogenic hydrocarbon-contaminated soil.

    Science.gov (United States)

    Shahsavari, Esmaeil; Adetutu, Eric M; Anderson, Peter A; Ball, Andrew S

    2013-01-15

    Petrogenic hydrocarbons represent the most commonly reported environmental contaminant in industrialised countries. In terms of remediating petrogenic contaminated hydrocarbons, finding sustainable non-invasive technologies represents an important goal. In this study, the effect of 4 types of plant residues on the bioremediation of aliphatic hydrocarbons was investigated in a 90 day greenhouse experiment. The results showed that contaminated soil amended with different plant residues led to statistically significant increases in the utilisation rate of Total Petroleum Hydrocarbon (TPH) relative to control values. The maximum TPH reduction (up to 83% or 6800 mg kg(-1)) occurred in soil mixed with pea straw, compared to a TPH reduction of 57% (4633 mg kg(-1)) in control soil. A positive correlation (0.75) between TPH reduction rate and the population of hydrocarbon-utilising microorganisms was observed; a weaker correlation (0.68) was seen between TPH degradation and bacterial population, confirming that adding plant materials significantly enhanced both hydrocarbonoclastic and general microbial soil activities. Microbial community analysis using Denaturing Gradient Gel Electrophoresis (DGGE) showed that amending the contaminated soil with plant residues (e.g., pea straw) caused changes in the soil microbial structure, as observed using the Shannon diversity index; the diversity index increased in amended treatments, suggesting that microorganisms present on the dead biomass may become important members of the microbial community. In terms of specific hydrocarbonoclastic activity, the number of alkB gene copies in the soil microbial community increased about 300-fold when plant residues were added to contaminated soil. This study has shown that plant residues stimulate TPH degradation in contaminated soil through stimulation and perhaps addition to the pool of hydrocarbon-utilising microorganisms, resulting in a changed microbial structure and increased alkB gene

  2. DFT Study On Effects of CO2 Contamination in Non-Aqueous Li-Air Batteries

    DEFF Research Database (Denmark)

    Mekonnen, Yedilfana Setarge; Mýrdal, Jón Steinar Garðarsson; Vegge, Tejs

    2013-01-01

    Density Functional Theory (DFT) studies on the effects of carbon dioxide (CO2) contamination at the cathode of rechargeable non-aqueous Li-O2 batteries, where the insulating material Lithium peroxide (Li2O2) is the main discharge product. The Li2O2 growth mechanism and overpotentials are investig...... and result in an increased battery capacity. However, CO2 contamination on the Li2O2 surface confirms an asymmetric increase in the overpotentials; particularly the charging overvoltage exhibits sustantial increase, which would reduce the efficiency of the Li-air battery.......Density Functional Theory (DFT) studies on the effects of carbon dioxide (CO2) contamination at the cathode of rechargeable non-aqueous Li-O2 batteries, where the insulating material Lithium peroxide (Li2O2) is the main discharge product. The Li2O2 growth mechanism and overpotentials...

  3. Environmental analysis of endocrine disrupting effects from hydrocarbon contaminants in the ecosystem. 1997 annual progress report

    International Nuclear Information System (INIS)

    1997-01-01

    'The overall objective of the basic research grant is to characterize the potential of common hydrocarbon contaminants in ecosystems to act as endocrine disruptors. The three major lines of research include (1) a biotechnology based screening system to identify potential hormone mimics and antagonists; (2) an animal screening system to identify biomarkers of endocrine effects. and (3) a literature review to identify compounds at a variety of DOE sites that need to be examined for endocrine disrupting effects. By relating results obtained from this research project to contamination problems at various DOE sites. CBR will provide data and information on endocrine disrupting contaminants to DOE for consideration in risk analyses for determining clean-up levels and priorities needed at the sites.'

  4. Deuteriding of thin titanium films: the effect of carbon monoxide surface contamination

    International Nuclear Information System (INIS)

    Malinowski, M.W.

    1976-02-01

    The effect of adsorbed CO on the deuteriding of thin titanium films at room temperature was measured at D 2 pressures between 10 to 25 mtorr on films contaminated with CO exposures ranging between approximately 10 -8 torr-seconds (''clean'') to 10 -4 torr-seconds. In all measurements, for deuterium/titanium atom ratios greater than .2, the deuteriding appeared to be initally limited by the sticking of D 2 on the clean or contaminated titanium deuteride surface; the effective sticking coefficient on a clean titanium deuteride surface was approximately 3 x 10 -3 , while on a surface contaminated with 10 -4 torr-seconds of CO, the coefficient was reduced to approximately, 2 x 10 -4 . The pumping speeds of Ti films were dramatically different when the films were evaporated over TiD 2 . These changes were attributed to the presence of deuterium which diffused from the substrate film into the overlayer film

  5. Effect of the salinity in the adsorption of a herbicide in agricultural soils; Efecto de la salinidad en la adsorcion de un herbicida en suelos agricolas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, L. C. [Universidad de Occidente, Unidad Guasave, Departamento de Ingenieria y Tecnologia, Av. Universidad s/n, Centro, 81000 Guasave, Sinaloa (Mexico); Hansen, A. M., E-mail: ahansen@tlaloc.imta.mx [Instituto Mexicano de Tecnologia del Agua, Coordinacion de Hidrologia, Subcoordinacion de Hidrologia Subterranea, Paseo Cuauhnahuac 8532, Col. Progreso, 62550 Jiutepec, Morelos (Mexico)

    2014-10-01

    To understand the effect of salinity in the adsorption of the herbicide atrazine in two soils from a Mexican agricultural area, the influence of sodium and calcium chloride concentrations were determined. Adsorption experiments were performed with soil samples from Irrigation District 063 (Dr 063), Guasave, Sinaloa, Mexico, suspended in 10 mm CaCl{sub 2}, in the presence of several concentrations of different electrolytes and atrazine (0.01, 0.05, 0.1, 0.5 and 1.0 mg/L) with radioactive tracer (347.4 Bq U-ring-{sup 14}C, Sigma Chemical Company, St. Louis, Mo, USA). It was found that for all the electrolytes,the time required to reach equilibrium adsorption of atrazine was less than 24 h and the adsorption isotherms were adjusted to Freundlich model. The presence of sodium in the aqueous solution favored the adsorption and inhibited desorption of atrazine in soils. Increasing the concentrations of sodium and calcium to about 40 nm and 60 mm, respectively, did not significantly affect (P <0.05), the adsorption of atrazine. However, there were differences in desorption of the herbicide with the increase of salts concentrations. The results of this study indicate that increased salinity, mainly caused by increased sodium concentrations in the soil-water system, has important effects on the fate of atrazine, due to salinization of soils favors the adsorption of atrazine, and inhibits its desorption. It is important to consider these properties when application options are analyzed as well as in the management and remediation of soils contaminated with atrazine. (Author)

  6. Effectiveness of alcohol gelin stethoscopes disinfection contaminated with methicillinresistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Arthur Alves Teixeira

    2015-10-01

    Full Text Available Background and Objectives: Although widely used, little attention has been given to basic-care in handling and disinfection of stethoscopes. Methicillin-resistant Staphylococcus aureus is frequently found and a major risk for hospitalized patients. Alcohol gel contains properties admittedly effective to exterminate germs that are frequently involved in infections. This study aims to verify the effectiveness of alcohol gel in stethoscopes disinfection contaminated with MRSA used by healthcare professionals of a University Hospital in Rio de Janeiro State. Methods: Health care professionals were selected randomly from August to November 2012, and collected samples with sterile swab of 105 stethoscopes before and after cleaning with alcohol gel 70% and performed cultures and bacterial identification. Results: Bacterial contamination was present in 87 (82.85% of the analyzed stethoscopes. Gram positive bacteria were identified in 76 (72.38%. S. aureus was present in 7.61% of stethoscopes and MRSA in 87.5% of them. After using the alcohol gel, there was a reduction of 71,44% of the general bacterial contamination and MRSA elimination of 100% of the analyzed stethoscopes. Conclusion: One should improve care in cleaning of stethoscopes due to the risk of carrying pathogenic bacteria involved in hospital infections. The alcohol gel showed to be adequate for disinfection of stethoscopes contaminated with MRSA. KEYWORDS: Stethoscopes. Contamination. Ethanol. Disinfection. Methicillinresistant Staphylococcus aureus.

  7. HISTOLOGICAL PREPARATION OF INVERTEBRATES FOR EVALUATING CONTAMINANT EFFECTS

    Science.gov (United States)

    Although many studies in toxicologic pathology evaluate the effects of toxicants on fishes because of their similarities with other vertebrates, invertebrates can also provide insights into toxicant impacts on ecosystems. Invertebrates not only serve as food resources (e.g., ...

  8. Tidal effects on groundwater contamination at Pekan, Pahang

    International Nuclear Information System (INIS)

    Nor Dalila Desa; Dominic, J.A.; Mohd Muzamil Mohd Hashim; Kamarudin Samuding; Mohd Faizun Khalid; Mod Omar Hassan; Kamaruzaman Mohamad

    2014-01-01

    The meeting of coastal ground water and the sea is a unique and dynamic hydro geologic boundary phenomenon that has fascinated groundwater engineers and scientists for the past century. The variation of seawater level resulting from tidal fluctuations is usually neglected in regional groundwater flow studies. In this study the effects of seawater tidal on groundwater are investigated using geophysical together with conventional method. Comparative result between these two methods shown how tidal fluctuations effects groundwater in study area. (author)

  9. Effect of n-3 polyunsaturated fatty acids on the lipidic profile of healthy Mexican volunteers Efecto de los ácidos grasos polinsaturados n-3 en el perfil lipídico de mexicanos voluntarios

    Directory of Open Access Journals (Sweden)

    OCTAVIO CARVAJAL

    1997-05-01

    Full Text Available Objective. The effect of n-3 polyunsaturated fatty acids on the serum lipid profile in a Mexican population was evaluated. Material and methods. Three g of salmon oil was the daily intake during four weeks. Total cholesterol, triglycerides, low density lipoproteins, high density lipoproteins and erythrocyte fatty acid composition were analyzed. Results. The hypertriglyceridemic group showed a statistically significant (pObjetivo. Estudiar el efecto de los ácidos grasos polinsaturados n-3 en el perfil lipídico sérico de una población mexicana. Material y métodos. La ingesta diaria del suplemento de aceite de salmón fue de 3 gramos durante cuatro semanas. Se evaluaron los niveles de colesterol total, triglicéridos, lipoproteínas de baja densidad, lipoproteínas de alta densidad y la composición en ácidos grasos de los eritrocitos. Resultados. Muestran una reducción significativa (p< 0.05 en los niveles de triglicéridos y un aumento significativo (p< 0.01 en los niveles de lipoproteínas de alta densidad en los sujetos con hipertrigliceridemia. El grupo con hipercolesterolemia presentó reducción en los niveles de colesterol total y triglicéridos y aumento significativo en los niveles de lipoproteínas de alta densidad (p< 0.01. Conclusiones. El efecto hipolipidemiante de los ácidos grasos polinsaturados n-3 se puso de manifiesto en voluntarios mexicanos bajo las condiciones aquí evaluadas.

  10. Perilous Effects of Heavy Metals Contamination on Human Health

    Directory of Open Access Journals (Sweden)

    Naseem Zahra

    2017-06-01

    Full Text Available Heavy metals form a versatile group of high density elements that vary considerably in their biological roles and chemical properties. Although many heavy metals are essential trace elements yet they have long been recognized as environmental pollutants due their toxic effects. Increased industrialization, urbanization anthropogenic activities like mining, smelting and other agricultural activities have resulted in accumulation of heavy metals in the environment. Heavy metals such as nickel, cadmium, zinc, copper, mercury, arsenic and chromium are not easily degradable and tend to build up in soil. These heavy metals through various routes such as fish and plants make their way into the human body and are known to have serious detrimental effects on human health at elevated levels. The harmful effects of some important heavy metals on human health have been discussed.

  11. Effects of contaminants on reproductive success of aquatic birds nesting at Edwards Air Force Base, California

    Science.gov (United States)

    Hothem, R.L.; Crayon, J.J.; Law, M.A.

    2006-01-01

    Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may indicate the potential for negative effects on avian populations. From 1996 to 1999, we conducted studies at the Piute Ponds area of EAFB to evaluate the impacts of contaminants on nesting birds. Avian reproduction was evaluated in 1999. Eggs were collected for chemical analyses in 1996 and 1999, and African clawed frogs (Xenopus laevis), a likely food source, were collected for chemical analyses in 1998. Avian species occupying the higher trophic levels-black-crowned night-heron (Nycticorax nycticorax), white-faced ibis (Plegadis chihi), and American avocet (Recurvirostra americana)-generally bioaccumulated higher concentrations of contaminants in their eggs. Reproductive success and egg hatchability of night-herons and white-faced ibises in the Piute Ponds were similar to results observed at other western colonies. Deformities were observed in only one embryo in this study, but concentrations of contaminants evaluated in this ibis embryo were considered insufficient to have caused the deformities. Because clawed frogs, a primary prey item for night-herons at Piute Ponds, had no detectable levels of any OCs, it is likely that OCs found in night-heron eggs were acquired from the wintering grounds rather than from EAFB. The presence of isomers of dichlorodiphenyltrichloroethane (DDT) in ibis eggs indicated recent exposure, but invertebrates used for food by ibises were not sampled at Piute Ponds, and conclusions about the source of OCs in ibis eggs could not be made. Concentrations of contaminants in random and failed eggs of individual species were not different, and we concluded

  12. In situ and laboratory bioassays with Chironomus riparius larvae to assess toxicity of metal contamination in rivers: the relative toxic effect of sediment versus water contamination.

    Science.gov (United States)

    Faria, Mafalda S; Lopes, Ricardo J; Nogueira, António J A; Soares, Amadeu M V M

    2007-09-01

    We used bioassays employing head capsule width and body length increase of Chironomus riparius larvae as end points to evaluate metal contamination in streams. Bioassays were performed in situ near an abandoned Portuguese goldmine in the spring of 2003 and 2004. Bioassays also were performed under laboratory conditions with water and sediment collected from each stream to verify if laboratory bioassays could detect in situ toxicity and to evaluate the relative contribution of sediment and water to overall toxicity. We used field sediments with control water and control sediments with field water to discriminate between metal contamination in water and sediment. Field water with dry and sieved, organic matter-free, and nontreated sediments was used to determine the toxicity of heavy metals that enter the organism through ingested material. In both in situ and laboratory bioassays, body length increase was significantly inhibited by metal contamination, whereas head capsule width was not affected. Body length increase was more affected by contaminated sediment compared to contaminated water. The lowest-effect level of heavy metals was observed in the dry and sieved sediment that prevented ingestion of sediment particles by larvae. These results suggest that body length increase of C. riparius larvae can be used to indicate the impact of metal contamination in rivers. Chironomus riparius larvae are more affected by heavy metals that enter the organism through ingested sediment than by heavy metals dissolved in the water column. Nevertheless, several factors, such as the particle size and organic matter of sediment, must be taken into account.

  13. Effect of Aflatoxin B1 - contaminated feed on goat erythrocyte ...

    African Journals Online (AJOL)

    ... action was concentration-dependent, typical of a saturation kinetic effect. The degree of stimulation varied from 20% to more than 90% between the lowest (0.1 M) and highest (1000 M) contentrations. AFB1 induced changes in the apparent kinetic parameters, Km and Vmax, of the erythrocyte membrane-bound enzyme.

  14. Effect of Coal Contaminants on Solid Oxide Fuel System Performance and Service Life

    Energy Technology Data Exchange (ETDEWEB)

    Gopala Krishnan; P. Jayaweera; J. Bao; J. Perez; K. H. Lau; M. Hornbostel; A. Sanjurjo; J. R. Albritton; R. P. Gupta

    2008-09-30

    The U.S. Department of Energy's SECA program envisions the development of high-efficiency, low-emission, CO{sub 2} sequestration-ready, and fuel-flexible technology to produce electricity from fossil fuels. One such technology is the integrated gasification-solid oxide fuel cell (SOFC) that produces electricity from the gas stream of a coal gasifier. SOFCs have high fuel-to-electricity conversion efficiency, environmental compatibility (low NO{sub x} production), and modularity. Naturally occurring coal has many impurities and some of these impurities end in the fuel gas stream either as a vapor or in the form of fine particulate matter. Establishing the tolerance limits of SOFCs for contaminants in the coal-derived gas will allow proper design of the fuel feed system that will not catastrophically damage the SOFC or allow long-term cumulative degradation. The anodes of Ni-cermet-based SOFCs are vulnerable to degradation in the presence of contaminants that are expected to be present in a coal-derived fuel gas stream. Whereas the effects of some contaminants such as H{sub 2}S, NH{sub 3} and HCl have been studied, the effects of other contaminants such as As, P, and Hg have not been ascertained. The primary objective of this study was to determine the sensitivity of the performance of solid oxide fuel cells to trace level contaminants present in a coal-derived gas stream in the temperature range 700 to 900 C. The results were used to assess catastrophic damage risk and long-term cumulative effects of the trace contaminants on the lifetime expectancy of SOFC systems fed with coal-derived gas streams.

  15. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone.

    Science.gov (United States)

    Bonzom, Jean-Marc; Hättenschwiler, Stephan; Lecomte-Pradines, Catherine; Chauvet, Eric; Gaschak, Sergey; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas; Maksimenko, Andrey; Garnier-Laplace, Jacqueline; Adam-Guillermin, Christelle

    2016-08-15

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22-15μGyh(-1)) and (ii) along a short distance gradient of radioactive contamination (1.2-29μGyh(-1)) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150μGyh(-1). This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Effects of Two Kinds of Biochars on Soil Cu Availability in Contaminated Soil

    Directory of Open Access Journals (Sweden)

    WANG Xiao-qi

    2016-07-01

    Full Text Available This paper is aimed to research the impacts of different biochars(0,1%,2%,4%, including maize biochar and phytolacca root biochar, on rape growth and the soil Cu availability in the Cu-contaminated red soil via a series of pot experiments. The results showed that, compared with the control, the addition of two kinds of biochars could increase the biomass of the rape. In low Cu-contaminated red soil, added 4% maize biochar and phytolacca root biochar increased the biomass by 21.2 times and 67.9 times; however, the biomass were increased by 8.6 times and 109.6 times under high Cu-contaminated soil. The addition of phytolacca root biochar could increase the soil pH significantly, which has been increased by 0.4~1.6 units with the addition of phytolacca root biochar in low Cu-contaminated red soil, and it had 0.25~1.35 units more than that with maize biochar; In high Cu-contaminated red soil, with the addition of phytolacca root biochar, soil pH was increased by 0.33~1.52 units, which was 0.3~1.25 units higher than maize biochar. There was a significant effect on reducing the soil Cu availability with the addition of the two biochars. Among them, 4% addition of maize biochar and phytolacca root biochar could reduce soil available Cu content by 21.9% and 45.2% in low Cu-contaminated soil, however, it was decreased by 41.9% and 53.8% in high Cu-contaminated soil. Both of the two biochars were able to reduce the Cu accumulation in rape, where there was a decrease by 21.2% and 67.8% with he addition of 4% maize biochar and phytolacca root biochar under low Cu-contaminated soil, and it was decreased by 19.9% and 66.8% in high Cu-contaminated soil respectively. Both of the biochars could ameliorate the acidity and Cu availability in the red soil, enhance the biomass of the rape and reduce the Cu accumulation in rape, but phytolacca root biochar had more effective influence than maize biochar.

  17. Niveles de aterramiento y rayo: simulación de sus efectos sobre el consumidor; Earthing Levels and Lightning:Modeling and Simulation of Effects on Consumer

    Directory of Open Access Journals (Sweden)

    Miguel Castro Fernández

    2011-02-01

    Full Text Available El objetivo del trabajo es el análisis, a través de MatLab, de los efectos que tienen, sobre las tensionesy corrientes que circulan por la carga y el neutro de una instalación, la condición de considerar lossistemas de puesta a tierra (SPT del Centro de Transformación (CT que alimenta una determinadainstalación de uso y de la propia IU, separados físicamente e independientes, y sus valores de puesta atierra cuando una descarga eléctrica atmosférica (DEA impacta en el neutro o en una fase de línea dealimentación de la instalación.  Los autores establecen la necesidad e importancia que tiene el definir losniveles de aterramiento en una instalación teniendo en cuenta de quién se va a alimentar y de suscondiciones de operación.  In this paper the authors, using MatLab, propose to analyze the influence in low voltage system of anelectric atmospheric discharge when it impacts directly on neutral and/or phases conductor feeding aninstallation. Currents and voltage in the load are obtained and the authors analyze the relationship betweensystem and consumer earth levels in these values under conditions previously mentioned.

  18. Arsenic contamination of underground water in Bangladesh: cause, effect, separation, determination and remedy

    International Nuclear Information System (INIS)

    Ahmed, M.J.

    2003-01-01

    Arsenic contamination of underground water of Bangladesh has become the gravest concern for the lives of millions of people of this land. Probable causes and effects of arsenic contamination of underground water of Bangladesh have been extensively discussed. The extent of current knowledge regarding the specification of arsenic in environmental waters in delineated. A simple, non-extractive, highly sensitive and selective quench photometric methods for the rapid determination of arsenic at trace levels in aqueous medium has been developed. This paper also presents a short review of the technologies used for arsenic removal of underground water in Bangladesh. (author)

  19. Effect of surface contaminants on the light emission spectrum of LiF TLDs

    International Nuclear Information System (INIS)

    Abhold, M.E.

    1987-01-01

    Recent results show the differences between the light emissions spectra from LiF Thermoluminescent Dosimeters (TLDs) for gamma vs. alpha irradiations to be due to contaminants on the surface of the TLD. The light emission spectrum for thermal neutron irradiations was observed to be identical to that for a Cs-137 gamma irradiation in Harshaw TLD-100. Further experiments with surface treatments on TLD-100 indicate trace contaminants introduced by the standard methanol cleansing rinse in reagent grade methanol to have a substantial effect on the light emission spectrum for Am-241 alpha irradiations

  20. Effects of (α,n) contaminants and sample multiplication on statistical neutron correlation measurements

    International Nuclear Information System (INIS)

    Dowdy, E.J.; Hansen, G.E.; Robba, A.A.; Pratt, J.C.

    1980-01-01

    The complete formalism for the use of statistical neutron fluctuation measurements for the nondestructive assay of fissionable materials has been developed. This formalism includes the effect of detector deadtime, neutron multiplicity, random neutron pulse contributions from (α,n) contaminants in the sample, and the sample multiplication of both fission-related and background neutrons

  1. Mass Balance Model, A study of contamination effects in AMS 14C sample analysis

    NARCIS (Netherlands)

    Prokopiou, Markella

    2010-01-01

    In this training thesis a background correction analysis, also known as mass balance model, was implemented to study the contamination effects in AMS 14C sample processing. A variety of backgrounds and standards with sizes ranging from 50 μg C to 1500 μg

  2. Framework to determine the effectiveness of dietary exposure mitigation to chemical contaminants

    NARCIS (Netherlands)

    Fels, van der H.J.; Edwards, S.; Kennedy, M.; O'Hagan, A.; O'Mahony, C.; Scholz, G.; Steinberg, P.; Tennant, D.; Chiodini, A.

    2014-01-01

    In order to ensure the food safety, risk managers may implement measures to reduce human exposure to contaminants via food consumption. The evaluation of the effect of a measure is often an overlooked step in risk analysis process. The aim of this study was to develop a systematic approach for

  3. Effects of Land Use Types on the Levels of Microbial Contamination ...

    African Journals Online (AJOL)

    The effects of land use types on levels of microbial contamination based on total coliforms and E. coli (faecal coliform) levels was investigated in the Mara River system, Kenya and Tanzania. Water samples were taken from five sampling sites with different land uses and the Most Probable Number (MPN) method used to ...

  4. Evaluation of Carbonation Effects on Cement-Solidified Contaminated Soil Used in Road Subgrade

    Directory of Open Access Journals (Sweden)

    Yundong Zhou

    2018-01-01

    Full Text Available Cement solidification/stabilization is widely used towards contaminated soil since it has a low price and significant improvement for the structural capacity of soil. To increase the usage of the solidified matrix, cement-solidified contaminated soil was used as road subgrade material. In this study, carbonation effect that reflected the durability on strength characteristics of cement-solidified contaminated soil and the settlement of pavement were evaluated through experimental and numerical analysis, respectively. According to results, compressive strengths of specimens with 1% Pb(II under carbonation and standard curing range from 0.44 MPa to 1.17 MPa and 0.14 MPa to 2.67 MPa, respectively. The relatively low strengths were attributed to immobilization of heavy metal, which consumed part of SiO2, Al2O3, and CaO components in the cement or kaolin and reduced the hydration and pozzolanic reaction materials. This phenomenon further decreased the strength of solidified soils. The carbonation depth of 1% Cu(II or Zn(II contaminated soils was 18 mm, which significantly increased with the increase of curing time and contamination concentration. Furthermore, the finite element calculation results showed that surface settlements decreased with the increase of modulus of subgrade and the distance away from the center. At the center, the pavement settlement was proportional to the level of traffic load.

  5. Effects of environmental contaminants on snapping turtles of a tidal wetland

    Energy Technology Data Exchange (ETDEWEB)

    Albers, P H; Sileo, L; Mulhern, B M

    1986-01-01

    Snapping turtles (Chelydra serpentina) were collected from a brackish-water and a nearly freshwater area in the contaminated Hackensack Meadowlands of New Jersey and an uncontaminated freshwater area in Maryland to determine the effects of environmental contaminants on a resident wetland species. No turtles were observed or caught in Meadowlands at two trapping sites that were the most heavily contaminated by metals. Snapping turtles from the brackish-water area had an unusually low lipid content of body fat and reduced growth compared to turtles from the freshwater areas in New Jersey and Maryland. Despite the serious metal contamination of the Hackensack Meadowlands, the metal content of kidneys and livers from New Jersey turtles was low and not greatly different from that of the Maryland turtles. Organochlorine pesticide concentrations in body fat were generally low at all three study areas. Polychlorinated biphenyls (PCBs) concentrations in fat were highest in male turtles from the New Jersey brackish-water area. Analysis of blood for amino-levulinic acid dehydratase, albumin, glucose, hemoglobin, osmolatility, packed cell volume, total protein, triglycerides, and uric acid failed to reveal any differences among groups that would indicated physiological impairment related to contaminants.

  6. Effects of environmental contaminants on snapping turtles of a tidal wetland

    Science.gov (United States)

    Albers, P.H.; Sileo, L.; Mulhern, B.M.

    1986-01-01

    Snapping turtles (Chelydra serpentina) were collected from a brackish-water and a nearly freshwater area in the contaminated Hackensack Meadowlands of New Jersey and an uncontaminated freshwater area in Maryland to determine the effects of environmental contaminants on a resident wetland species. No turtles were observed or caught in the Meadowlands at two trapping sites that were the most heavily contaminated by metals. Snapping turtles from the brackish-water area had an unusually low lipid content of body fat and reduced growth compared to turtles from the fresh-water areas in New Jersey and Maryland. Despite the serious metal contamination of the Hackensack Meadowlands, the metal content of kidneys and livers from New Jersey turtles was low and not greatly different from that of the Maryland turtles. Organochlorine pesticide concentrations in body fat were generally low at all three study areas. Polychlorinated biphenyls (PCBs) concentrations in fat were highest in male turtles from the New Jersey brackish-water area. Analysis of blood for amino-levulinic acid dehydratase, albumin, glucose, hemoglobin, osmolality, packed cell volume, total protein, triglycerides, and uric acid failed to reveal any differences among groups that would indicate physiological impairment related to contaminants.

  7. Effect of Co-Contaminant on Denitrification Removal of Nitrate in Drinking Water

    Directory of Open Access Journals (Sweden)

    Arzu KILIÇ

    2012-12-01

    Full Text Available In recent years, nitrogenous fertilizers used in agriculture, unconscious and without treatment wastewater is discharged led to an increase in groundwater nitrate pollution. In many countries, nitrate concentration in the ground waters used as drinking water source exceeded the maximum allowable concentration of 10 mg/L NO3-N. According to a study, some wells in the Harran Plain contain nitrate as high as 180 mg/L NO3--N and the average concentration for whole plain is 35 mg/L NO3--N (Yesilnacar et al., 2008. Additionally, increased water consumption, unconscious use of fertilizers and pesticides has led to the emergence of co-contaminant in drinking water. Recently, hazardous to human health co-contaminant such as arsenic, pesticides, perchlorate, selenate, chromate, uranium are observed in the nitrate pollution drinking water. There are many processes used for the removal of nitrate. The physical–chemical technologies that can be used for nitrate removal are reverse osmosis, ion exchange and electrodialysis (Alvarez et al., 2007. Important disadvantages of these processes are their poor selectivity, high operation and maintenance costs and the generation of brine wastes after treatment. Consequently, biological treatment processes to convert nitrates to benign dinitrogen gas, could be an interesting alternative for the remediation of groundwater contaminated with nitrates. The aim of this article, effective and cheap method for the removal of nitrate from drinking water biological denitrification is to examine the usability of contaminated drinking water with co-contaminant pollutions.

  8. Toxicological benchmarks for screening potential contaminants of concern for effects on terrestrial plants: 1994 revision

    International Nuclear Information System (INIS)

    Will, M.E.; Suter, G.W. II.

    1994-09-01

    One of the initial stages in ecological risk assessment for hazardous waste sites is screening contaminants to determine which of them are worthy of further consideration as contaminants of potential concern. This process is termed contaminant screening. It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to plants. This report presents a standard method for deriving benchmarks for this purpose (phytotoxicity benchmarks), a set of data concerning effects of chemicals in soil or soil solution on plants, and a set of phytotoxicity benchmarks for 38 chemicals potentially associated with United States Department of Energy (DOE) sites. In addition, background information on the phytotoxicity and occurrence of the chemicals in soils is presented, and literature describing the experiments from which data were drawn for benchmark derivation is reviewed. Chemicals that are found in soil at concentrations exceeding both the phytotoxicity benchmark and the background concentration for the soil type should be considered contaminants of potential concern

  9. Shear bond strength of orthodontic brackets and disinclusion buttons: effect of water and saliva contamination.

    Science.gov (United States)

    Sfondrini, Maria Francesca; Fraticelli, Danilo; Gandini, Paola; Scribante, Andrea

    2013-01-01

    The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a) dry, (b) water contamination, and (c) saliva contamination. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values) and Chi squared test (ARI Scores). Noncontaminated enamel surfaces showed the highest bond strengths for both brackets and buttons. Under water and saliva contamination orthodontic brackets groups showed significantly lower shear strengths than disinclusion buttons groups. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Water and saliva contamination of enamel during the bonding procedure lowers bond strength values, more with orthodontic brackets than with disinclusion buttons.

  10. Toxicological benchmarks for screening potential contaminants of concern for effects on terrestrial plants: 1994 revision

    Energy Technology Data Exchange (ETDEWEB)

    Will, M.E.; Suter, G.W. II

    1994-09-01

    One of the initial stages in ecological risk assessment for hazardous waste sites is screening contaminants to determine which of them are worthy of further consideration as contaminants of potential concern. This process is termed contaminant screening. It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to plants. This report presents a standard method for deriving benchmarks for this purpose (phytotoxicity benchmarks), a set of data concerning effects of chemicals in soil or soil solution on plants, and a set of phytotoxicity benchmarks for 38 chemicals potentially associated with United States Department of Energy (DOE) sites. In addition, background information on the phytotoxicity and occurrence of the chemicals in soils is presented, and literature describing the experiments from which data were drawn for benchmark derivation is reviewed. Chemicals that are found in soil at concentrations exceeding both the phytotoxicity benchmark and the background concentration for the soil type should be considered contaminants of potential concern.

  11. Effects of petroleum and metal contaminated soil on plants and earthworms: Survival and bioaccumulation

    International Nuclear Information System (INIS)

    Tatem, H.E.; Simmers, J.W.; Skogerboe, J.G.; Lee, C.R.

    1993-01-01

    Earthworms, Eisenia foetida, and bermudagrass, Cynodon dactylon, were used in the laboratory to test the toxicity of contaminated sediment taken from a small fresh water lake in North Carolina. This work was part of an investigation to determine the potential effects of upland disposal of this sediment. The contaminated sediment contained As, Cr, Cu, Pb, Hg, Ni, Zn and petroleum hydrocarbons at concentrations much greater than nearby soils. Test cylinders were planted with bermudagrass; earthworms were added 30 days later. Both species were harvested at 60 days, weighed and submitted for chemical analyses. Cynodon was affected by the contaminated sediment but grew well in the mixtures of sediment and upland soil. Similar results were obtained with the Eisenia. These species did not accumulate hydrocarbons from the sediment with the possible exception of pyrene. The metals Cd, Pb, and Zn were elevated in plants exposed to the contaminated sediment. Earthworms exposed to this sediment accumulated Pb to concentrations greater than animals exposed to the manure control. This work demonstrated that a contaminated freshwater sediment was not toxic to plants or earthworms and that most petroleum hydrocarbons were not accumulated. The only metal that may be of some concern was Pb

  12. Shear Bond Strength of Orthodontic Brackets and Disinclusion Buttons: Effect of Water and Saliva Contamination

    Science.gov (United States)

    Sfondrini, Maria Francesca; Fraticelli, Danilo; Gandini, Paola

    2013-01-01

    Purpose. The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons. Materials and Methods. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a) dry, (b) water contamination, and (c) saliva contamination. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values) and Chi squared test (ARI Scores). Results. Noncontaminated enamel surfaces showed the highest bond strengths for both brackets and buttons. Under water and saliva contamination orthodontic brackets groups showed significantly lower shear strengths than disinclusion buttons groups. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Conclusions. Water and saliva contamination of enamel during the bonding procedure lowers bond strength values, more with orthodontic brackets than with disinclusion buttons. PMID:23762825

  13. Shear Bond Strength of Orthodontic Brackets and Disinclusion Buttons: Effect of Water and Saliva Contamination

    Directory of Open Access Journals (Sweden)

    Maria Francesca Sfondrini

    2013-01-01

    Full Text Available Purpose. The aim of this study was to assess the effect of water and saliva contamination on the shear bond strength and failure site of orthodontic brackets and lingual buttons. Materials and Methods. 120 bovine permanent mandibular incisors were randomly divided into 6 groups of 20 specimens each. Both orthodontic brackets and disinclusion buttons were tested under three different enamel surface conditions: (a dry, (b water contamination, and (c saliva contamination. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values and Chi squared test (ARI Scores. Results. Noncontaminated enamel surfaces showed the highest bond strengths for both brackets and buttons. Under water and saliva contamination orthodontic brackets groups showed significantly lower shear strengths than disinclusion buttons groups. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Conclusions. Water and saliva contamination of enamel during the bonding procedure lowers bond strength values, more with orthodontic brackets than with disinclusion buttons.

  14. Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Terrestrial Plants

    Energy Technology Data Exchange (ETDEWEB)

    Suter, G.W. II

    1993-01-01

    One of the initial stages in ecological risk assessment for hazardous waste sites is screening contaminants to determine which of them are worthy of further consideration as contaminants of potential concern. This process is termed contaminant screening. It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to plants. This report presents a standard method for deriving benchmarks for this purpose (phytotoxicity benchmarks), a set of data concerning effects of chemicals in soil or soil solution on plants, and a set of phytotoxicity benchmarks for 38 chemicals potentially associated with United States Department of Energy (DOE) sites. In addition, background information on the phytotoxicity and occurrence of the chemicals in soils is presented, and literature describing the experiments from which data were drawn for benchmark derivation is reviewed. Chemicals that are found in soil at concentrations exceeding both the phytotoxicity benchmark and the background concentration for the soil type should be considered contaminants of potential concern.

  15. A test to illustrate the effects of BioSolve on the mobility of contaminated soils

    International Nuclear Information System (INIS)

    Jackson, Lorri M.

    1999-01-01

    Mountain States BioSolve manufactures products for in-situ bioremediation projects. One of their products, BioSolve, desorbs and emulsifies hydrocarbons in a contaminated substrate. BioSolve is a blend of water-based, biodegradable surfactants which were engineered as a clean-up and mitigation agent for hydrocarbon products. Its basic mechanism is to emulsify the hydrocarbon into small encapsulated particles in a water/oxygen-bearing solution, desorbing hydrocarbon molecules from soil particles. This allows bacteria to more effectively metabolize the contaminate. During desorption, Total Petroleum Hydrocarbons (TPH) levels may increase shortly after application due to the removal of contaminate from soil particles which increases the total recoverable hydrocarbon. This allows the hydrocarbon, in the pump and treat process, to become mobile, and thus carried with the water to the recovery wells where it can be removed. This testing does not address pump and treat technology but only the increased surface area for bioremediation enhancement

  16. Health effects estimation: Methods and results for uranium mill tailings contaminated properties

    International Nuclear Information System (INIS)

    Denham, D.H.; Cross, F.T.; Soldat, J.K.

    1990-01-01

    This paper describes methods for estimating potential health effects from exposure to uranium mill tailings and presents a summary of risk projections for 50 contaminated properties (residences, schools, churches, and businesses) in the US. The methods provide realistic estimates of cancer risk to exposed individuals based on property-specific occupancy and contamination patterns. External exposure to gamma radiation, inhalation of radon daughters, and consumption of food products grown in radium-contaminated soil are considered. Most of the projected risk was from indoor exposure to radon daughters; however, for some properties the risk from consumption of locally grown food products is similar to that from radon daughters. In all cases, the projected number of lifetime cancer deaths for specific properties is less than one, but for some properties the increase in risk over that normally expected is greater than 100%

  17. Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type

    DEFF Research Database (Denmark)

    Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

    2015-01-01

    Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero...... nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used...... as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two...

  18. The gamma irradiation of tragacanth: effect on microbial contamination and rheology

    International Nuclear Information System (INIS)

    Jacobs, G.P.

    1979-01-01

    The use of gamma radiation for the sterilization of tragacanth, which is used in pharmaceuticals as a thickening and suspending agent, was investigated. The effect of different gamma doses on the rheological profile of tragacanth mucilage, prepared from tragacanth irradiated in the dry state, and the efficiency of such treatments in reducing the pre-irradiation microbial load were studied. A decrease in viscosity with increasing dose was found in the range 0.1-5 Mrads. All irradiated samples were found to be free from contamination, although the 0.1 Mrad irradiation was only carried out on a less contaminated sample. The radiation chemistry of tragacanth is discussed. It is concluded that although even small doses affect the viscosity, minimal doses of (say) 0.1 Mrad may be used for reducing microbial load particularly if the initial contamination is not excessive. (author)

  19. Efeito protetor da lactoferrina humana no trato gastrintestinal Efecto protector de la lactoferrina humana en el sistema gastrointestinal Protective effect of human lactoferrin in the gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Valterlinda Alves de O. Queiroz

    2013-03-01

    ón de morbilidades gastrointestinales. FUENTES DE DATOS: Revisión no sistemática de la literatura utilizando como estrategia de búsqueda investigación bibliográfica en bases de datos, que incluyeron SciELO, Lilacs y MedLine entre 1990 y 2011. Los descriptores utilizados fueron: lactoferrina, leche materna/humana, gastrointestinal e inmunidad, en los idiomas portugués e inglés. SÍNTESIS DE LOS DATOS: La lactoferrina es la segunda proteína predominante en la leche humana, con concentraciones más elevadas en el calostro (5,0 a 6,7mg/mL respecto a la leche madura (0,2 a 2,6mg/mL. En contraste, la leche de vaca contiene tenores inferiores, 0,83mg/mL en el calostro y 0,09mg/mL en la leche madura. La lactoferrina desempeña diversas funciones fisiológicas en la protección del sistema gastrointestinal. La actividad antimicrobiana está relacionada a la capacidad de secuestrar hierro de los fluidos biológicos y/o de desestructurar la membrana de microorganismos. La lactoferrina posee además la capacidad de estimular la proliferación celular. La acción antiinflamatoria desempeñada por la lactoferrina está asociada a la capacidad de penetrar en el núcleo del leucocito y bloquear la transcripción del nuclear factor Kappa B. Frente a la importancia de la lactoferrina en la prevención de enfermedades infecciosas en niños amamantados al pecho, la industria viene, por medio de ingeniería genética, desarrollando tecnologías para expresar esta proteína recombinante humana en plantas y animales en el intento de adecuar la composición de las fórmulas infantiles a aquella de la leche humana. CONCLUSIONES: La lactoferrina humana es un péptido con potencial para prevenir morbilidades, especialmente las gastrointestinales. Evidencias científicas de los efectos protectores de la lactoferrina humana fortalecen todavía más la recomendación para la práctica de la lactancia materna.OBJECTIVE: To describe mechanisms of action of human lactoferrin to protect

  20. Contaminant exposure and effects in pinnipeds: implications for Steller sea lion declines in Alaska.

    Science.gov (United States)

    Barron, Mace G; Heintz, Ron; Krahn, Margaret M

    2003-07-20

    After nearly 3 decades of decline, the western stock of Steller sea lions (SSL; Eumetopias jubatus) was listed as an endangered species in 1997. While the cause of the decline in the 1970s and 1980s has been attributed to nutritional stress, recent declines are unexplained and may result from other factors including the presence of environmental contaminants. SSL tissues show accumulation of butyltins, mercury, PCBs, DDTs, chlordanes and hexachlorobenzene. SSL habitats and prey are contaminated with additional chemicals including mirex, endrin, dieldrin, hexachlorocyclohexanes, tetrachlorodibenzo-p-dioxin (TCDD) and related compounds, cadmium and lead. In addition, many SSL haulouts and rookeries are located near other hazards including radioactivity, solvents, ordnance and chemical weapon dumps. PCB and DDT concentrations measured in a few SSL during the 1980s were the highest recorded for any Alaskan pinniped. Some contaminant exposures in SSL appear to be elevated in the Gulf of Alaska and Bering Sea compared to southeast Alaska, but there are insufficient data to evaluate geospatial relationships with any certainty. Based on very limited blubber data, current levels of PCBs may not pose a risk to SSL based on comparison to immunotoxicity tissue benchmarks, but SSL may have been at risk from pre-1990 PCB exposures. While exposure to PCBs and DDTs may be declining, SSL are likely exposed to a multitude of other contaminants that have not been monitored. The impacts of these exposures on SSL remain unknown because causal effects have not been established. Field studies with SSL have been limited in scope and have not yet linked contaminant exposures to adverse animal health or population effects. Several biomarkers may prove useful for monitoring exposure and additional research is needed to evaluate their utility in SSL. We conclude that there are insufficient data to reject the hypothesis that contaminants play a role in the continued decline of SSL, and suggest

  1. To study the effects of groundwater contamination in Kasur due to Nallah Rohi

    International Nuclear Information System (INIS)

    Ghumman, A.R.; Shamim, M.A.

    2005-01-01

    Groundwater contamination is a worldwide known problem. Pakistan, being a developing country, is also facing the problem created by groundwater pollution. Disposal of domestic wastes and agricultural treatments has been reported to be a considerable factor for causing the pollution, especially the groundwater contamination. In the rural areas of Pakistan, latrines and septic tanks have become common because of the advancement in the living standards. All of the domestic wastes is disposed off into the ponds or nearby passing streams. In the similar fashion, drains in the big and well developed cities of Pakistan lead the domestic waste, along with the industrial waste, into the passing by streams, canals and rivers. All of such disposed off waste is untreated because of the lack of legislation and its improper implementation. The contaminated water affects the health of human beings and also destroys the crops when this water is used for irrigation. So this paper deals with the effects and condition of the disposal of the harmful chemicals, which ultimately through seepage reach the groundwater and make it hazardous. Also, the lateral distances of the contaminated groundwater were found out. For experimentation, major city of Kasur which is in the vicinity of Nullah Rohi, was selected. All the wastes including both the industrial as well as domestic, of the whole area, is disposed off into the Nullah. The percolation of the harmful chemicals and its mixing with groundwater has resulted in the hazardous effects on the inhabitants of the area on the irrigation land as well. So the water in the vicinity, at different locations was tested and the degree of contamination and the lateral distances of contaminated water were also worked out. (author)

  2. Effects of predicted climatic changes on distribution of organic contaminants in brackish water mesocosms

    Energy Technology Data Exchange (ETDEWEB)

    Ripszam, M., E-mail: matyas.ripszam@chem.umu.se [Department of Chemistry, Umea University, 901 87 Umeå (Sweden); Gallampois, C.M.J. [Department of Chemistry, Umea University, 901 87 Umeå (Sweden); Berglund, Å. [Department of Ecology and Environmental Sciences, Umeå University, 901 87 Umeå (Sweden); Larsson, H. [Umeå Marine Sciences Centre, Umeå University, Norrbyn, 905 71 Hörnefors (Sweden); Andersson, A. [Department of Ecology and Environmental Sciences, Umeå University, 901 87 Umeå (Sweden); Tysklind, M.; Haglund, P. [Department of Chemistry, Umea University, 901 87 Umeå (Sweden)

    2015-06-01

    Predicted consequences of future climate change in the northern Baltic Sea include increases in sea surface temperatures and terrestrial dissolved organic carbon (DOC) runoff. These changes are expected to alter environmental distribution of anthropogenic organic contaminants (OCs). To assess likely shifts in their distributions, outdoor mesocosms were employed to mimic pelagic ecosystems at two temperatures and two DOC concentrations, current: 15 °C and 4 mg DOC L{sup −1} and, within ranges of predicted increases, 18 °C and 6 mg DOC L{sup −1}, respectively. Selected organic contaminants were added to the mesocosms to monitor changes in their distribution induced by the treatments. OC partitioning to particulate matter and sedimentation were enhanced at the higher DOC concentration, at both temperatures, while higher losses and lower partitioning of OCs to DOC were observed at the higher temperature. No combined effects of higher temperature and DOC on partitioning were observed, possibly because of the balancing nature of these processes. Therefore, changes in OCs' fates may largely depend on whether they are most sensitive to temperature or DOC concentration rises. Bromoanilines, phenanthrene, biphenyl and naphthalene were sensitive to the rise in DOC concentration, whereas organophosphates, chlorobenzenes (PCBz) and polychlorinated biphenyls (PCBs) were more sensitive to temperature. Mitotane and diflufenican were sensitive to both temperature and DOC concentration rises individually, but not in combination. - Highlights: • More contaminants remained in the ecosystem at higher organic carbon levels. • More contaminants were lost in the higher temperature treatments. • The combined effects are competitive with respect to contaminant cycling. • The individual properties of each contaminant determine their respective fate.

  3. Effects of predicted climatic changes on distribution of organic contaminants in brackish water mesocosms

    International Nuclear Information System (INIS)

    Ripszam, M.; Gallampois, C.M.J.; Berglund, Å.; Larsson, H.; Andersson, A.; Tysklind, M.; Haglund, P.

    2015-01-01

    Predicted consequences of future climate change in the northern Baltic Sea include increases in sea surface temperatures and terrestrial dissolved organic carbon (DOC) runoff. These changes are expected to alter environmental distribution of anthropogenic organic contaminants (OCs). To assess likely shifts in their distributions, outdoor mesocosms were employed to mimic pelagic ecosystems at two temperatures and two DOC concentrations, current: 15 °C and 4 mg DOC L −1 and, within ranges of predicted increases, 18 °C and 6 mg DOC L −1 , respectively. Selected organic contaminants were added to the mesocosms to monitor changes in their distribution induced by the treatments. OC partitioning to particulate matter and sedimentation were enhanced at the higher DOC concentration, at both temperatures, while higher losses and lower partitioning of OCs to DOC were observed at the higher temperature. No combined effects of higher temperature and DOC on partitioning were observed, possibly because of the balancing nature of these processes. Therefore, changes in OCs' fates may largely depend on whether they are most sensitive to temperature or DOC concentration rises. Bromoanilines, phenanthrene, biphenyl and naphthalene were sensitive to the rise in DOC concentration, whereas organophosphates, chlorobenzenes (PCBz) and polychlorinated biphenyls (PCBs) were more sensitive to temperature. Mitotane and diflufenican were sensitive to both temperature and DOC concentration rises individually, but not in combination. - Highlights: • More contaminants remained in the ecosystem at higher organic carbon levels. • More contaminants were lost in the higher temperature treatments. • The combined effects are competitive with respect to contaminant cycling. • The individual properties of each contaminant determine their respective fate

  4. Potential for effects of land contamination on human health. 2. The case of waste disposal sites.

    Science.gov (United States)

    Kah, Melanie; Levy, Len; Brown, Colin

    2012-01-01

    This review of the epidemiological literature shows that evidence for negative impacts of land contaminated by waste disposal on human health is limited. However, the potential for health impacts cannot be dismissed. The link between residence close to hazardous waste disposal sites and heightened levels of stress and anxiety is relatively well established. However, studies on self-reported outcomes generally suffer from interpretational problems, as subjective symptoms may be due to increased perception and recall. Several recent multiple-site studies support a plausible linkage between residence near waste disposal sites and reproductive effects (including congenital anomalies and low birth weight). There is some conflict in the literature investigating links between land contamination and cancers; the evidence for and against a link is equally balanced and is insufficient to make causal inferences. These are difficult to establish because of lack of data on individual exposures, and other socioeconomic and lifestyle factors that may confound a relationship with area of residence. There is no consistently occurring risk for any specific tumor across multiple studies on sites expected to contain similar contaminants. Further insights on health effects of land contamination are likely to be gained from studies that consider exposure pathways and biomarkers of exposure and effect, similar to those deployed with some success in investigating impacts of cadmium on human health.

  5. Effects on inhaled uranium mine air contaminants in beagle dogs

    International Nuclear Information System (INIS)

    Filipy, R.E.; Stuart, B.O.; Palmer, R.F.; Ragan, H.A.; Hackett, P.L.

    1974-01-01

    The high incidence of lung cancer among uranium miners of the Colorado plateau is a matter of national concern in a period of increasing demand for uranium ore. These miners are exposed to a variety of inhalation hazards, including radon daughters, uranium ore dust, and cigarette smoking, that may cause or contribute to respiratory tract pathology. Over 98 percent of the miners developing lung cancer have had histories of cigarette smoking. In order to determine the combined or separate roles of radon daughters and cigarette smoking in the development of lung cancer and other respiratory tract pathology, groups of 20 dogs each received daily life span exposures to 4 hours of 600 working levels of radon daughters with ore dust, and/or cigarette smoking over 16 hours per day, 7 days per week, or both; control dogs received sham smoking. After 4 years of exposure, respiratory tract pathology included macrophage accumulation, septal fibrosis, epithelial hyperplasia, endothelial proliferation, vesicular and bullous emphysema, and extensive epithelial changes involving squamous metaplasia with atypical nuclei. These effects were primarily related to exposure to radon daughters and uranium ore dust, with and without cigarette smoke

  6. Cover crop with Teramnus labialis in a citrus orchard: effects on some physical properties of the soil / Cubierta vegetal con Teramnus labialis en plantaciones citrícolas: efectos sobre algunas propiedades físicas del suelo Cubierta vegetal con Teramnus labialis en plantaciones citrícolas: efectos sobre algunas propiedades físicas del suelo

    Directory of Open Access Journals (Sweden)

    Leydis Castellano Rodríguez

    2009-03-01

    Full Text Available The use of leguminous cover crops in citrus orchards constitutes a viable alternative for the improvement of soil properties, whenever they are appropriately managed. In Ciego de Avila University, Cuba, it was evaluated the effect of a leguminous cover crop on some properties of an orchard soil. The work was carried out during four years in an orange plantation of Valencia late (Citrus sinensis L. Osbeck in a 22 years-old orchard, with a plantation frame of 8 X 4 m, planted on a typical red Ferralitic soil, belonging to the CPA ¨José Martí¨, in Ciego de Avila. It was used a random block design with three treatments: one with covering of Teramnus labialis (T1, one with expontaneous vegetation (T2 and the third with no vegetation (T3. The functional structure properties of the soil were determined, and also the composition of macroaggregates expressed in the structure coefficient and the percentage of stable added in water, soil density, humidity and porosity. The increments in the humidity of the soil, the specific volume of pores and air, the structure coefficient, as well as the percentage of stable added in water, in the soil where the covering of Teramnus labialis was stablished, show the efficiency of cover crops in these citrus orchards.El uso de coberturas vivas de leguminosas en plantaciones citrícolas constituye una alternativa viable para el mejoramiento de las propiedades de los suelos, siempre que ellas se manejan adecuadamente en estas áreas. En la universidad de Ciego de Ávila, Cuba se viene trabajando en la evaluación del efecto de coberturas vivas de leguminosas en plantaciones citrícolas en producción, con el objetivo de evaluar el efecto que ejerce la cobertura de leguminosa sobre algunas propiedades del suelo. El trabajo se realizó durante cuatro años (2001-2005 en una plantación de naranja Valencia Late ( Citrus sinensis L. Osbeck en producción de 22 años, con marco de plantación de 8 X 4 m, plantada sobre un

  7. Riesgos y consecuencias de las prácticas sexuales en adolescentes bajo los efectos de alcohol y otras drogas Risks and consequences of the sexual practices in adolescents under the effects of alcohol and other drug consumption

    Directory of Open Access Journals (Sweden)

    Guillermo Castaño Pérez

    2013-03-01

    = 561 bajo el efecto de las drogas, el 12,47 % no han usado métodos de protección, y las consecuencias más significativas han sido las infecciones de trasmisión sexual (2,0 % y el embarazo no deseado (2,8 %. No se encontró asociación estadísticamente significativa (p= 0,711 entre tener relaciones sexuales bajo el efecto de alcohol o estar sobrios, y el uso de métodos de protección. Conclusiones: se constata lo evidenciado en otras investigaciones, sobre la frecuente asociación entre el consumo de drogas y las prácticas sexuales en adolescentes. Lo que aporta de nuevo este estudio, es dar cuenta del tipo de prácticas bajo el efecto de sustancias psicoactivas, muchas de ellas no exentas de riesgo, y reforzar la necesidad de incluir en los programas de prevención para sexo seguro, acciones para minimizar los daños de tener prácticas sexuales bajo el efecto de sustancias psicoactivas.Introduction: sexuality, and alcohol and drug consumption by adolescents currently appear as high priority issues for the public health. The concern lies in reducing the risks of sexually transmitted infections, the human immunodeficiency virus and the early unwanted pregnancies. Objectives: to analyze the sexual behaviors under the effect of alcohol and other drug consumption and the inherent risks in adolescents living in Medellin city. Methods: the sample was selected through the random and cluster probabilistic method. The universe of study covered the total number of 8th, 9th, 10th and 11th students from the public and private schools of Medellin in 2010. The age of the 91 857 students ranged 14 to 17 years. The final sample included 955 students, using a 95 % confidence interval. A cross-sectional descriptive study was designed to find out the sexual practices and risks of adolescents under the influence of alcohol and other drug consumption. The SPSS program, version 19.0 served to set frequencies, percentages and statistical associations. Results: taking alcohol or other

  8. Efecto de extractos de la esponja calcarea Leucetta aff. floridana sobre el ciclo de líneas celulares leucemoides Effect of extracts from the calcareous sponge Leucetta aff. floridana on the cell cycle of leukemoid cell lines

    Directory of Open Access Journals (Sweden)

    Diana Margarita Márquez Fernández

    2012-12-01

    Full Text Available Introducción: la esponja Leucetta aff. floridana produce compuestos con actividad antiproliferativa diferencial en células tumorales de pulmón y mama, la cual no ha sido explorada en otras líneas tumorales y se desconoce si su potencial antiproliferativo está relacionado con la progresión de células a través del ciclo celular. Objetivo: evaluar el potencial antiproliferativo, anticlonogénico y el efecto sobre el ciclo celular de los extractos hexánico y metanólico de la esponja Leucetta aff. floridana del Caribe colombiano en las líneas celulares leucemoides Jurkat y K562. Métodos: la viabilidad y proliferación celular se determinaron mediante el ensayo de azul de tripano a 0, 24, 48, 72 y 96 h. La eficiencia de clonación y el efecto sobre el ciclo celular se evaluaron a 10 y 100 µg/mL. Los datos se analizaron usando ANOVA multifactorial y la prueba Tukey. Resultados: el extracto hexánico presentó actividad antiproliferativa en ambas líneas celulares siendo Jurkat más sensible que K562, lo cual se corroboró con los ensayos de clonogenicidad. Este extracto también mostró un efecto de acumulación de células Sub-G1 dependiente de la dosis, el cual fue diferencial entre las dos líneas celulares. La duración del tratamiento con el extracto hexánico no fue significativa para las células K562 pero sí para la línea celular Jurkat. Además, el porcentaje de acumulación de las células Sub-G1 fue mayor para células K562 comparado con Jurkat. El extracto metanólico presentó un efecto antiproliferativo similar al hexánico, pero fue más potente con la menor concentración (10 µg/mL en la clonogenicidad de K562. El efecto sobre el ciclo celular, también fue similar al hexánico, pero la duración del tratamiento no fue significativa en la acumulación de células en Sub-G1. Conclusiones: los resultados muestran el potencial diferencial de los extractos sobre el ciclo celular de las líneas leucemoides evaluadas

  9. Effect of EDTA and citric acid on phytoremediation of Cr- B[a]P-co-contaminated soil.

    Science.gov (United States)

    Chigbo, Chibuike; Batty, Lesley

    2013-12-01

    Polycyclic aromatic hydrocarbons and heavy metals in the environment are a concern, and their removal to acceptable level is required. Phytoremediation, the use of plants to treat contaminated soils, could be an interesting alternative to conventional remediation processes. This work evaluates the role of single and combined applications of chelates to single or mixed Cr + benzo[a]pyrene (B[a]P)-contaminated soil. Medicago sativa was grown in contaminated soil and was amended with 0.3 g citric acid, 0.146 g ethylenediaminetetraacetic acid (EDTA), or their combination for 60 days. The result shows that in Cr-contaminated soil, the application of EDTA + citric acid significantly (psoil. The soluble Cr concentration in single Cr or Cr + B[a]P-contaminated soil was enhanced with the amendment of all chelates; however, only the application of citric acid in Cr-contaminated soil (44 %) or EDTA and EDTA + citric acid in co-contaminated soil increased the removal of Cr from the soil (34 and 54 %, respectively). The dissipation of B[a]P in single B[a]P-contaminated soil was effective even without planting and amendment with chelates, while in co-contaminated soil, it was related to the application of either EDTA or EDTA + citric acid. This suggests that M. sativa with the help of chelates in single or co-contaminated soil can be effective in phytoextraction of Cr and promoting the biodegradation of B[a]P.

  10. Efectos del policosanol, el extracto de semillas de uva y su terapia combinada sobre marcadores oxidativos en ratas Effect of Polycosanol, a grape seed extract and its combined therapy on oxidation markers in rats

    Directory of Open Access Journals (Sweden)

    Ambar Oyarzábal Yera

    2010-03-01

    Full Text Available El policosanol, mezcla de alcoholes alifáticos primarios superiores obtenida de la cera de caña de azúcar (Saccharum officinarum, L. y el extracto de semillas de uva (Vitis vinífera, L, producen efectos antioxidantes demostrados experimental y clínicamente. El objetivo del trabajo consistió en comparar los efectos del policosanol, el extracto de semilla de uva y su terapia combinada sobre marcadores oxidativos en plasma e hígado de ratas. Las ratas se distribuyeron en 4 grupos: un control y 3 tratados con policosanol, extracto de semilla de uva y su terapia combinada, respectivamente, todos a dosis de 25 mg/kg, durante 4 semanas. Las monoterapias redujeron significativamente las concentraciones plasmáticas de malondialdehído y de grupos carbonilos asociados a proteínas con respecto al control, lo que mostró similar eficacia. La terapia combinada redujo (p The Polycosanol, a mixture of superior primary aliphatic alcohols obteined from the sugarcane wax (Sacharum officinarum, L. and the grape seeds extract (Vitis vinífera, L. produces antioxidant effects experimentally and clinically demonstrated. The aim of present paper was to compare the effects of Polycosanol, the grape seed extract, and its combined therapy on oxidative markers in plasma and liver of rats. The rats were distributed into 4 groups: a control one and three treated with Polycosanol, grape seed extract and its combined therapy, respectively, using a 25 mg/kg dose over 4 weeks. The single-therapies significantly reduced the plasmatic concentrations of malonyldialdehyde and of proetin-associated carbonyl groups regarding the control, showing a similar efficacy. Combined therapy reduced in a more effective way (p < 0,001 the malonyldialdehyde concentrations of carbonyl groups, and also decreased (p < 0,01 the concentrations of carbonyl groups, but no more than the single-therapies. Each single-therapy reduced the malonyldialdehyde concentrations generated by spontaneous

  11. Effects-based spatial assessment of contaminated estuarine sediments from Bear Creek, Baltimore Harbor, MD, USA.

    Science.gov (United States)

    Hartzell, Sharon E; Unger, Michael A; McGee, Beth L; Wilson, Sacoby M; Yonkos, Lance T

    2017-10-01

    Estuarine sediments in regions with prolonged histories of industrial activity are often laden to significant depths with complex contaminant mixtures, including trace metals and persistent organic pollutants. Given the complexity of assessing risks from multi-contaminant exposures, the direct measurement of impacts to biological receptors is central to characterizing contaminated sediment sites. Though biological consequences are less commonly assessed at depth, laboratory-based toxicity testing of subsurface sediments can be used to delineate the scope of contamination at impacted sites. The extent and depth of sediment toxicity in Bear Creek, near Baltimore, Maryland, USA, was delineated using 10-day acute toxicity tests with the estuarine amphipod Leptocheirus plumulosus, and chemical analysis of trace metals and persistent organic pollutants. A gradient of toxicity was demonstrated in surface sediments with 21 of 22 tested sites differing significantly from controls. Effects were most pronounced (100% lethality) at sites proximate to a historic industrial complex. Sediments from eight of nine core samples to depths of 80 cm were particularly impacted (i.e., caused significant lethality to L. plumulosus) even in locations overlain with relatively non-toxic surface sediments, supporting a conclusion that toxicity observed at the surface (top 2 cm) does not adequately predict toxicity at depth. In seven of nine sites, toxicity of surface sediments differed from toxicity at levels beneath by 28 to 69%, in five instances underestimating toxicity (28 to 69%), and in two instances overestimating toxicity (44 to 56%). Multiple contaminants exceeded sediment quality guidelines and correlated positively with toxic responses within surface sediments (e.g., chromium, nickel, polycyclic aromatic hydrocarbon (PAH), total petroleum hydrocarbon). Use of an antibody-based PAH biosensor revealed that porewater PAH concentrations also increased with depth at most sites. This

  12. Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on growth and immunological parameters of broiler chickens.

    Science.gov (United States)

    Swamy, H V L N; Smith, T K; Karrow, N A; Boermans, H J

    2004-04-01

    An experiment was conducted to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins on growth and immunological parameters of broiler chickens. Three hundred sixty, 1-d-old male broiler chicks were fed 1 of 4 diets containing grains naturally contaminated with Fusarium mycotoxins for 56 d. The diets included (1) control; (2) low level of contaminated grains (5.9 mg/kg deoxynivalenol (DON), 19.1 mg/kg fusaric acid (FA), 0.4 mg/kg zearalenone, and 0.3 mg/kg 15-acetyldeoxynivalenol; (3) high level of contaminated grains (9.5 mg/kg DON, 21.4 mg/kg FA, 0.7 mg/kg zearalenone, and 0.5 mg/kg 15-acetyldeoxynivalenol); and (4) high level of contaminated grains + 0.2% polymeric glucomannan mycotoxin adsorbent (GM polymer). Body weight gains and feed consumption of chickens fed contaminated grains decreased linearly with the inclusion of contaminated grains during the grower phase (d 21 to 42). Efficiency of feed utilization, however, was not affected by diet. Production parameters were not significantly affected by the supplementation of GM polymer to the contaminated grains. Peripheral blood monocytes decreased linearly in birds fed contaminated grains. The feeding of contaminated diets linearly reduced the B-cell count at the end of the experiment, whereas the T-cell count on d 28 responded quadratically to the contaminated diets. The feeding of contaminated diets did not significantly alter serum or bile immunoglobulin concentrations, contact hypersensitivity to dinitrochlorobenzene, or antibody response to SRBC. Supplementation with GM polymer in the contaminated diet nonspecifically increased white blood cell count and lymphocyte count, while preventing mycotoxin-induced decreases in B-cell counts. It was concluded that broiler chickens are susceptible during extended feeding of grains naturally contaminated with Fusarium mycotoxins.

  13. Effect of irradiation dose on sensory characteristics and microbiological contamination of chosen seasonings

    International Nuclear Information System (INIS)

    Kaminski, E.; Wasowicz, E.; Zawirska-Wojtasiak, R.; Czaczyk, K.; Trojanowska, K.

    1991-01-01

    The effects of gamma irradiation (3, 5, 10 kGy) on sensory characteristics, volatiles constituents and microbiological contamination of several seasonings were studied. The dose of 3 kGy reduced microflora effectively, and did not cause evident changes in aroma. Complete sterilization, however, required 7 or 10 kGy particularly in the case of paprika. Such doses substantially changed the smell and taste of seasonings. Is some of them (paprika, mustard, coriander) the total volatiles content increased after radiation

  14. Bioremediation of oil-contaminated shorelines: Effects of different nitrogen sources

    International Nuclear Information System (INIS)

    Ramstad, S.; Sveum, P.

    1995-01-01

    The present study was designed to examine the fate and effect of various nitrogen sources in oil-contaminated sediments in a continuous-flow seawater column system fed with nutrient-enriched seawater. Degradation of oil components is stimulated by a supply of an enhanced concentration of nitrogen. The most pronounced effect was found with nitrate, compared to ammonium and organic nitrogen. Ammonium was more readily sorbed by the sediment system, either by chemical adsorption or by microbial immobilization

  15. Effects of organic contaminants in sewage sludge on soil fertility, plants and animals

    International Nuclear Information System (INIS)

    Hall, J.E.; Sauerbeck, D.R.; L'Hermite, P.

    1992-01-01

    Sewage sludge production in Europe will continue to rise as a result of higher environmental standards, making disposal increasingly difficult in the future. A considerable part of this sludge is spread beneficially on agricultural land as an organic fertilizer, however, this outlet is very sensitive to the problems associated with the inorganic and organic contaminants which sludge inevitably contains. Much research has been devoted to the problems of contaminants in sludge and their potential effects on soil, plants, animals and man in recent years, and the European Commission's Concerted Action COST 681 has provided a valuable forum for the exchange of views and progress of research on sludge treatment and disposal. This book contains 19 papers presented to a joint meeting of Working Party 4 (Agricultural Value) and Working Party 5 (Environmental Effects) of COST 681, held at the German Federal Research Centre of Agriculture (FAL), Braunschweig on 6-8 June 1990. The meeting addressed two areas of current concern; the occurrence, behaviour and transfer of sludge-derived organic contaminants (Session 1), and the influence of inorganic and organic contaminants on soil micro-organisms and their activities (Session 2)

  16. Effect of long-term zinc pollution on soil microbial community resistance to repeated contamination.

    Science.gov (United States)

    Klimek, Beata

    2012-04-01

    The aim of the study was to compare the effects of stress (contamination trials) on the microorganisms in zinc-polluted soil (5,018 mg Zn kg(-1) soil dry weight) and unpolluted soil (141 mg Zn kg(-1) soil dw), measured as soil respiration rate. In the laboratory, soils were subjected to copper contamination (0, 500, 1,500 and 4,500 mg kg(-1) soil dw), and then a bactericide (oxytetracycline) combined with a fungicide (captan) along with glucose (10 mg g(-1) soil dw each) were added. There was a highly significant effect of soil type, copper treatment and oxytetracycline/captan treatment. The initial respiration rate of chronically zinc-polluted soil was higher than that of unpolluted soil, but in the copper treatment it showed a greater decline. Microorganisms in copper-treated soil were more susceptible to oxytetracycline/captan contamination. After the successive soil contamination trials the decline of soil respiration was greater in zinc-polluted soil than in unpolluted soil.

  17. VELOCITY AND GRAVITATIONAL EFFECTS ON GPS SATELLITES: AN OUTLINE OF EARLY PREDICTION AND DETECTION OF STRONG EARTHQUAKES EFECTOS DE VELOCIDAD Y DE GRAVITACIÓN EN GPS SATELITALES: UN ESQUEMA PARA LA PREDICCIÓN Y DETECCIÓN TEMPRANA DE FUERTES TERREMOTOS

    Directory of Open Access Journals (Sweden)

    H Torres-Silva

    2010-12-01

    Full Text Available Today, the global navigation satellite systems, GPS used as global positioning systems, are based on a gravitational model and hence they are only operative when several relativistic effects are taken into account. The most important relativistic effects (to order 1/c² are: the Doppler red shift of second order, due to the motion of the satellite (special relativity and the Einstein gravitational blue shift effect of the satellite clock frequency (equivalence principle of general relativity. Both of these effects can be treated at a basic level, making for an appealing application of relativity to every life. This paper examines the significant effects that must be taken into account in the design and operation of systems GPS without resorting to the theory of special and general relativity, yielding the same results for these systems, where one of the effects can be treated with the time contraction approach proposed here and the other using the Newton's theory as an approximation of the General Relativity. This approach allow us to propose an outline of early prediction and detection on strong earthquake phenomena.Hoy en día, los sistemas de navegación global por satélite, GPS utilizados como sistemas de posicionamiento global, se basan en un modelo gravitacional y por lo tanto solo son operativos cuando varios efectos relativistas son tenidos en cuenta. Los efectos relativistas más importantes (hasta el orden 1/c² son: el desplazamiento Doppler al rojo de segundo orden, debido al movimiento del satélite (la relatividad especial y el efecto gravitacional de Einstein corrimiento al azul de la frecuencia de reloj del satélite (principio de equivalencia de la relatividad general. Ambos efectos pueden ser tratados en un nivel básico, apelando a la relatividad del día a día. Este artículo examina los efectos significativos que deben tenerse en cuenta en la operación de sistemas de GPS sin tener que recurrir a las teorías de la

  18. Evaluation of Integrated Time-Temperature Effect in Pyrolysis Process of Historically Contaminated Soils with Cadmium (Cd) and Lead (Pb)

    OpenAIRE

    Bulmău C; Cocârță D. M.; Reșetar-Deac A. M.

    2013-01-01

    It is already known that heavy metals pollution causes important concern to human and ecosystem health. Heavy metals in soils at the European level represents 37.3% between main contaminates affecting soils (EEA, 2007). This paper illustrates results obtained in the framework of laboratory experiments concerning the evaluation of integrated time-temperature effect in pyrolysis process applied to contaminated soil by two different ways: it is about heavy metals historically contaminated soil f...

  19. EFECTOS HETERÓTICOS Y HABILIDAD COMBINATORIA PARA EL RENDIMIENTO POR PLANTA EN Cucurbita moschata DUCH. Ex Poir HETEROTIC EFFECTS AND COMBINING ABILITY FOR YIELD PER PLANT IN Cucurbita moschata DUCH. Ex Poir

    Directory of Open Access Journals (Sweden)

    Miguel Mariano Espitia Camacho

    2006-06-01

    Full Text Available El estudio tuvo como objetivos estimar los efectos heteróticos y de habilidad combinatoria (HCG y específica (HCE, para el rendimiento/planta (RFP, en dos dialelos [uno entre cinco variedades (VAR y el otro entre cinco líneas endogámicas S1 (LS1, derivadas de éstas], mediante las metodologías propuestas por Gardner y Eberhart (GyE: 1966: Análisis II y Hallauer y Miranda (HyM:1981. Los genotipos se evaluaron en Candelaria (Valle del Cauca, Colombia, en un diseño de bloques completos al azar con cinco repeticiones. Las diferencias entre genotipos en el dialelo de LS1 por GyE, fueron explicadas por los efectos de variedades (v j: p jj’: p : p The purpose of this study was to estimate the heterotic effects, general combining ability (GCA, and specific (SCA for fruit yield per plant (RFP in two diallelic [one among five cross pollinated varieties (VAR and the other among five self-pollinated lines S1 (LS1, derived from these], according to the methodologies designed by Gardner y Eberhart (GyE: 1966: Analysis II and Hallauer and Miranda (HyM: 1981 using a complete randomized design with five replicates in Candelaria (Valle del Cauca, Colombia. The differences between genotypes observed in the diallelic of LS1 by GyE, were explained by the effects of varieties (v j: p (h jj’: p : p < 0,01 and specific heterosis (Sjj’: p < 0,05 explained the differences for h jj in the diallelic of LS1. According to the methodology of HyM, the additive (GCA: p < 0,01 and non additive genic action (SCA: p < 0,05 controlled the expression of RFP in the diallele of LS1 with greater importance of the GCA. In the diallele of VAR, only the GCA (p < 0,01 explained such control. The genotypes Bolo Verde (RFP = 17,8 kg/plant; v j = 3,34**; g i = 1,73* and Soler (PFP = 17 kg/plant; v j = 2,89*; g i = 175* are the recommended genotypes to exploit the additives effects and the hybrid LA34 x LSO (RFP = 26 kg/plant; Sjj’= 3,55** to exploit the additive and non

  20. Impact of Climate Change Effects on Contamination of Cereal Grains with Deoxynivalenol

    DEFF Research Database (Denmark)

    van der Fels-Klerx, H J; van Asselt, E D; Madsen, M S

    2013-01-01

    Climate change is expected to aggravate feed and food safety problems of crops; however, quantitative estimates are scarce. This study aimed to estimate impacts of climate change effects on deoxynivalenol contamination of wheat and maize grown in the Netherlands by 2040. Quantitative modelling...... the impacts of climate change effects on food safety, and of considering both direct and indirect effects when assessing climate change impacts on crops and related food safety hazards....... two different global and regional climate model combinations were used. A weather generator was applied for downscaling climate data to local conditions. Crop phenology models and prediction models for DON contamination used, each for winter wheat and grain maize. Results showed that flowering...

  1. Effects of Organic Acids and Sylvite on Phytoextraction of 241Am Contaminated Soil.

    Science.gov (United States)

    Wang, Ping; Du, Liang; Tan, Zhaoyi; Su, Rongbo; Li, Taowen

    2017-03-01

    Contamination of soil with Americium ( 241 Am) at nuclear sites in China poses a serious problem. We screened six plants, from five families, for their 241 Am-enrichment potential. Europium (Eu), which is morphologically and chemically similar to the highly toxic 241 Am, was used in its place. Moreover, the effects of sylvite, citric acid (CA), malic acid (MA), and humic acid (HA) on the absorption of 241 Am by the plants, and its transport within them, were evaluated along with their effect on plant biomass and 241 Am extraction volume. Barley and cabbage showed relatively stronger Eu accumulation capacities. Citric acid promoted the absorption of 241 Am by barley roots and its transport within the plants. The effects of sylvite were not obvious and those of HA were the weakest in case of sunflower; HA, however, maximally increased the biomass of the plants. Our results could provide the basis for future radionuclide phytoremediation of contaminated soils.

  2. Effect of Coal Contaminants on Solid Oxide Fuel System Performance and Service Life

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Gopala N.; Jayaweera, Palitha; Perez, Jordi; Hornbostel, M.; Albritton, John R.; Gupta, Raghubir P.

    2007-10-31

    The U.S. Department of Energy’s SECA program envisions the development of high-efficiency, low-emission, CO2 sequestration-ready, and fuel-flexible technology to produce electricity from fossil fuels. One such technology is the integrated gasification-solid oxide fuel cell (SOFC) that produces electricity from the gas stream of a coal gasifier. SOFCs have high fuel-to-electricity conversion efficiency, environmental compatibility (low NOx production), and modularity. The primary objective of the Phase I study was to determine the sensitivity of the performance of solid oxide fuel cells to trace level contaminants present in a coal-derived gas stream in the temperature range 700° to 900°C. Laboratory-scale tests were performed with 1-inch diameter solid oxide fuel cells procured from InDec B.V., Netherlands. These cells produce 0.15, 0.27, and 0.35 W/cm2 at 700°, 750°, and 800°C, respectively, in a H2 anode feed and are expected to be stable within 10% of the original performance over a period of 2000 h. A simulated coal-derived gas containing 30.0% CO, 30.6% H2 11.8% CO2, 27.6% H2O was used at a rate of ~100 standard cm3/min to determine the effect of contaminants on the electrical performance of the cells. Alumina or zirconia components were used for the gas manifold to prevent loss of contaminants by reaction with the surfaces of the gas manifold Short-term accelerated tests were conducted with several contaminants including As, P, CH3Cl, HCl, Hg, Sb, and Zn vapors. In these tests, AsH3, PH3, Cd vapor and CH3Cl identified as the potential contaminants that can affect the electrical performance of SOFCs. The effect of some of these contaminants varied with the operating temperature. Cell failure due to contact break inside the anode chamber occurred when the cell was exposed to 10 ppm arsenic vapor at 800°C. The electrical performance of SOFC

  3. Genotoxic, radioprotective and radiosensitizing effect of curcumin and trans-resveratrol in vitro cultures of human lymphocytes; Efecto genotóxico, radioprotector y radiosensibilizante de la curcumina y el trans-resveratrol en cultivos in vitro de linfocitos humanos

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, V.A.; Tirsa Muñoz, B.; Sebastià, N.; Gómez-Cabrero, L.; La Parra, V.; Hervás, D.; Rodrigo, R.; Villaescusa, J.I.; Soriano, J.M.; Montoro, A.

    2015-07-01

    Curcumin and trans-resveratrol are natural polyphenol compounds. Curcumin is obtained from the rhizomes of the Curcumin plant (Curcuma longa), while trans-resveratrol is found in grapes, blackberries and other types of berry. These compounds have antioxidant, anti-inflammatory, immunostimulant and anticarcinogenic properties among others. In addition, they are also known for their radiomodulating properties since they are capable of providing radioprotection or radiosensitization for normal or tumours cells depending on different factors. This dual action may be the result of their properties, such as free radicals scavenging, as well as their influence on cell cycle checkpoints or control mechanisms. These are activated in response to the genetic damage induced by radiation. Despite the many beneficial properties attributed to these polyphenol compounds, some studies suggest that they are able to be genotoxic agents for some cellular lines. The results obtained indicate that both compounds possess a radioprotective effect on the lymphocytes of peripheral blood in the quiescent phase of the cellular cycle (G0). Nevertheless, they are capable of induce radiosensitivity on these type of cells in the growth phase (G2), and in addition, a different genotoxic effect can be seen according to the concentration of each compound. This study suggests, therefore, that curcumin and trans-resveratrol are able to exert a triple effect, genotoxic, radioprotective and radiosensitizing on in vitro cultures of human lymphocytes depending on the study parameters. [Spanish] La curcumina y el trans-resveratrol son compuestos polifenólicos de origen natural. La curcumina es obtenida a partir de los rizomas de la planta de la cúrcuma (Curcuma longa), mientras que el trans-resveratrol se encuentra en uvas, moras y otras bayas. Estos compuestos presentan propiedades antioxidantes, antiinflamatorias, inmunoestimulantes y anticancerígenas, entre otras. Además, también se les conoce por

  4. El Sistema Cubano de Farmacovigilancia: seis años de experiencia en la detección de efectos adversos The Cuban system of drug surveillance: six years of experience in detecting adverse effects

    Directory of Open Access Journals (Sweden)

    Giset Jiménez López

    2006-04-01

    Full Text Available El Centro para el Desarrollo de la Farmacoepidemiología cuenta entre sus principales líneas de trabajo con la investigación, docencia, información de medicamentos, consulta terapéutica, Programa para el Uso Racional de los Medicamentos (PURMED y la farmacovigilancia con su Unidad Nacional Coordinadora. El objetivo de este trabajo es exponer los principales resultados de trabajo en 6 años de creado este sistema de vigilancia. Se realizó un estudio descriptivo retrospectivo para caracterizar los reportes de sospechas de reacciones adversas recibidas en la Unidad Coordinadora Nacional de Farmacovigilancia. Se recibieron en este periodo un total de 89 540 notificaciones de reacciones adversas medicamentosas, lo que da un promedio 17 908 sospechas de notificación/año, y una tasa de reporte de más de 1 000 notificaciones por millón de habitantes. Con estos resultados queda identificado un comportamiento regular en algunos de estos indicadores, como es el predominio de efectos adversos en el sexo femenino, la afectación de la piel y el sistema digestivo entre las reacciones más reportadas y el predominio en todos los años de los antimicrobianos, antiinflamatorios no esteroideos y los antihipertensivos como grupos farmacológicos; de igual modo han aumentado las reacciones adversas de baja frecuencia de aparición y se han seguido los efectos adversos graves. La farmacovigilancia en el mundo sigue siendo una disciplina científica y clínica muy dinámica, la cual resulta imprescindible para afrontar los problemas que pueda plantear un arsenal de medicamentos que no deja de crecer en variedad y potencia. Por ello es tan necesario que, en cuanto surjan efectos adversos o toxicidad -sobre todo si aún no están descritos-, se notifique y analice el episodio y se comunique adecuadamente su importancia a los profesionales sanitariosThe Center for the Development of Pharmacological Epidemiology has several working lines such as research

  5. Efecto del EcoMic® en la emergencia de plántulas de Jatropha curcas (Nota Técnica Effect of EcoMic® on the emergence of Jatropha curcas seedlings (Technical Note

    Directory of Open Access Journals (Sweden)

    Yolai Noda

    2012-12-01

    Full Text Available Con el objetivo de estudiar el efecto del EcoMic® en la emergencia de las plántulas de Jatropha curcas, se hizo una prueba de observación en el laboratorio de análisis químico de la Estación Experimental de Pastos y Forrajes «Indio Hatuey». Se usaron semillas recién cosechadas, en dos tratamientos: semillas inoculadas con EcoMic® (T1, y sin inóculo (T2, con cuatro réplicas de 100 semillas cada una. Se utilizó un diseño totalmente aleatorizado y se realizaron 15 observaciones (a los 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 y 16 días de emergencia. Las medias se compararon a través de un análisis descriptivo. El efecto del T1 fue notable durante todo el período; a partir del cuarto día se observaron 45 plántulas emergidas, lo que representó el 11,2% del total de las tratadas con este biofertilizante, y el último día del estudio había emergido el 96,2%. En el T2 no se observaron plántulas emergidas en ningún momento. Se concluye que el EcoMic® ejerció un efecto positivo en la emergencia de las plántulas de J. curcas al ser utilizado como inóculo en condiciones de laboratorio. Se recomienda realizar estudios pregerminativos para determinar la dormancia en la semilla de Jatropha, teniendo en cuenta el empleo del EcoMic® como uno de los tratamientos.In order to study the effect of EcoMic® on the emergence of Jatropha curcas seedlings, an observation test was conducted in the laboratory of chemical analysis of the Experimental Station of Pastures and Forages «Indio Hatuey». Newly-harvested seeds were used, in two treatments: seeds inoculated with EcoMic® (T1, and without inoculation (T2, with four replications of 100 seeds each. A completely randomized design was used and 15 observations were made (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 days after emergence. The means were compared through a descriptive analysis. The effect of T1 was remarkable throughout the period; since the fourth day 45

  6. Efecto del secado en ambiente de servicio en la evolución de las propiedades mecánicas de hormigones livianos estructurales Effect of drying under service environment on the mechanical properties of structural lightweight concretes

    Directory of Open Access Journals (Sweden)

    Carlos Videla

    2007-08-01

    Full Text Available En este trabajo se evalúa el efecto de la humedad relativa del ambiente de servicio en las resistencias a compresión y a tracción y en el módulo de elasticidad de hormigones livianos estructurales. Además se establecen relaciones que permiten estimar estas propiedades en función de la humedad relativa del ambiente y del tiempo de secado. Los hormigones se fabricaron con dos tipos de áridos gruesos livianos, piedra pómez y pellets de ceniza volante, y con un árido fino de densidad normal. Los hormigones se sometieron a dos condiciones ambientales de servicio: una a 90% de humedad relativa y otra a 90% de humedad relativa durante los 7 primeros días y luego a 50% de humedad relativa hasta la edad de ensayo. Los ensayos se efectuaron a 7, 28, 60 y 90 días de edad. Se observó un deterioro importante de las propiedades medidas por efecto de las condiciones de secado; a 83 días de secado, en promedio las pérdidas de resistencia a tracción y compresión fueron de 20% y 15%, respectivamente, y de módulo de elasticidad de 40% respecto a hormigones a 90% de humedad relativa. Se concluye que hay dos variables principales que regulan el efecto del secado en el hormigón liviano. La primera de éstas corresponde a razón agua-cemento y que define entre otras cosas la permeabilidad de la fase resistente. La otra variable corresponde al contenido relativo de árido liviano en la mezclaIn this paper the effect of the ambient relative humidity at service on the compressive and splitting strengths and in the modulus of elasticity of structural lightweight concretes is evaluated. Also, relationships are proposed allowing estimating these properties as a function of the ambient relative humidity and drying time. The concretes were made with two types of coarse lightweight aggregates, pumice and fly ash pellets, and with normal density fine aggregate. The concretes were subjected to two different environmental service conditions: 90% relative

  7. Effect of Two Entomopathogenic Fungi in Controlling Aleurodicus cocois (Curtis, 1846 (Hemiptera: Aleyrodidae Efecto de Dos Hongos Entomopatógenos en el Control de Aleurodicus cocois (Curtis, 1846 (Hemiptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Elizabeth Núñez del Prado

    2008-03-01

    Full Text Available Aleurodicus cocois (Curtis, 1846, the coconut whitefly, is a very damaging pest in Peru, mainly in avocado trees (Persea americana Mill.. It has been determined that entomopathogenic fungi can infect and kill white flies and can be used as biological control agents. The object of this research was to determine if there is any synergic action of the entomopathogenic fungi Paecilomyces fumosoroseus (Wize Brown & Smith 1957 and Verticillium lecanii (Zimmerman, 1892 Viégas 1939, in controlling A. cocois. Plastic sterile dishes were prepared where 5 mL 2% agar were used for each stage; leaves infested with A. cocois were placed upon these. Three different treatments were applied by sprinkling: P. fumosoroseus (P, V. lecanii (V or the mixture of the two fungi. These treatments were evaluated at one, two and seven days in the case of nymph I and eggs, and after four, eight and 12 days for nymph II, NIII and NIV. The lethal effect of V. lecanii on the second nymph instar of A. cocois was better than that of P. fumosoroseus and than the mixture of both fungi; the highest mortality percentage appeared from day eight to day 12. A small increase was observed in the effect of the mixture of the two entomopathogenic fungi on the IV nymph instar; and the effect of P. fumosoroseus was the lowestAleurodicus cocois (Curtis, 1846, la mosca blanca del cocotero, constituye una plaga muy importante en el Perú, principalmente en el palto (Persea americana Mill.. Se ha determinado que los hongos entomopatógenos pueden infectar y matar a la mosca blanca, por lo que podrían ser usados como agentes de control biológico. El objetivo del presente trabajo fue determinar si existe alguna acción conjunta de dos hongos entomopatógenos Paecilomyces fumosoroseus (Wize Brown & Smith 1957 y Verticillium lecanii (Zimmerman, 1892 Viégas 1939, en el control de A. cocois. Para ello se prepararon previamente placas de plástico estériles en las que se sirvieron aproximadamente

  8. Elementos para la evaluación eficaz de productos naturales con posibles efectos antihipertensivos Elements for the effective evaluation of natural products with possible antihypertensive effects

    Directory of Open Access Journals (Sweden)

    Mario Francisco Guerrero

    2009-12-01

    Full Text Available Desde el contexto de la farmacología experimental, en este ensayo se discuten algunos criterios que pueden ser útiles para estimar el potencial de productos naturales con posible actividad farmacológica para el tratamiento de la hipertensión, una de las enfermedades de mayor impacto epidemiológico en Colombia y en el mundo. Se acude para ello al análisis de algunas pruebas farmacológicas accesibles en nuestro medio: modelos de hipertensión arterial en la rata de laboratorio, pruebas in vitro e in vivo, y análisis microscópicos, que implementados con los protocolos adecuados y cotejadas en conjunto, pueden arrojar información valiosa a la hora de considerar las perspectivas de un producto natural en el campo de la hipertensión arterial.Within the context of experimental pharmacology, some criteria are discussed for estimating the potential of natural products with possible pharmacological activity for the treatment of hypertension. This disorder has great epidemiological impact in Colombia as well as elsewhere. Discovery of these products can be accomplished by use of accessible pharmacological tests such as the following: developing models of arterial hypertension in the laboratory rat, in vitro tests, in vivo tests and microscopic analysis. Suitable protocols associated with these techniques can capture valuable information about possible effects on hypertension during the evaluation phase of a natural product.

  9. Effects of hydrocarbon contamination on a free living marine nematode community: Results from microcosm experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudi, E.; Essid, N.; Beyrem, H.; Hedfi, A.; Boufahja, F.; Aissa, P. [Laboratoire de Biosurveillance de l' Environnement, Zarzouna (Tunisia). Faculte des Sciences de Bizerte; Vitiello, P. [Centre d' Oceanologie de Marseille (France)

    2005-11-15

    Anthropogenic inputs of crude and refined petroleum hydrocarbons into the sea require knowledge of the effects of these contaminants on the receiving assemblages of organisms. A microcosm experiment was carried out to study the influence of diesel on a free living nematode community of a Tunisian lagoon. Sediments were contaminated by diesel that ranged in concentration from 0.5 to 20 mg diesel kg{sup -1} dry weight (dw), and effects were examined after 90 days. Gradual changes in community structure were revealed depending on the quantity of diesel administrated. In the medium (1 mg diesel kg{sup -1} and 5 mg diesel kg{sup -1} (dw)) and high (10 mg diesel kg{sup -1}, 15 mg diesel kg{sup -1} and 20 mg kg{sup -1} (dw)) treated microcosms, most univariate measures, including diversity and species richness, decreased significantly with increasing level of diesel contamination whereas nematode assemblage from the low treated microcosm (0.5 mg diesel kg{sup -1} (dw)) remained unaffected. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the diesel treatments were varied: Chaetonema sp. was eliminated at all doses tested and seemed to be intolerant species to diesel contamination; Pomponema sp. and Oncholaimus campylocercoides were significantly affected at all diesel contamination levels but they were not eliminated, these species were categorized as 'diesel-sensitive'; Hypodontolaimus colesi, Daptonema trabeculosum and Daptonema fallax which significantly increased respectively at 0.5, 1 and 5 mg diesel kg{sup -1} (dw) concentrations and appeared to be 'opportunistic' species at these doses whereas Marylynnia stekhoveni which increased at all high doses (10, 15 and 20 mg diesel kg{sup -1} (dw)) seemed to be a 'diesel-resistant' species. (author)

  10. Extractability and bioavailability of Pb and As in historically contaminated orchard soil: Effects of compost amendments

    International Nuclear Information System (INIS)

    Fleming, Margaret; Tai, Yiping; Zhuang, Ping; McBride, Murray B.

    2013-01-01

    The availability of Pb and As in an historically contaminated orchard soil, after amendment with compost and aging in the field, was determined by single-step chemical extraction with 1.0 M ammonium acetate at pH 4.8, sequential extraction using the modified BCR test, and a redworm bioassay in the laboratory. The efficiency of soil Pb extraction by ammonium acetate was greater at higher total soil Pb but was reduced by compost amendment. Conversely, the extraction efficiency of total soil As increased with compost amendment, but was not sensitive to total soil As. The redworm bioassay indicated Pb (but not As) bioavailability to be reduced by soil amendment with compost, a result consistent with the ammonium acetate extraction test but not reflected in modified BCR test. Electron microprobe studies of the orchard soil revealed Pb and As to be spatially associated in discrete particles along with phosphorus and iron. -- Highlights: ► Soil Pb and As in an old orchard were concentrated in discrete particles. ► Compost amendment of contaminated soil reduced Pb bioavailability. ► Compost amendment of contaminated soil did not reduce As bioavailability. ► Ammonium acetate extraction test reflected bioavailability of soil Pb and As. -- Remediating metal-contaminated orchard soils with compost reduced lead bioavailability but had little effect on arsenic

  11. In vivo effects of chronic contamination with 137 cesium on testicular and adrenal steroidogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Grignard, Elise; Gueguen, Yann; Grison, Stephane; Gourmelon, Patrick; Souidi, Maamar [Institute for Radiological Protection and Nuclear Safety, Radiological Protection and Human Health Division, Radiobiology and Epidemiology Department, Laboratory of Experimental Toxicology, BP no 17, Fontenay-aux-Roses Cedex (France); Lobaccaro, Jean-Marc A. [UMR Universite Blaise Pascal-CNRS 6547, Physiologie Comparee et Endocrinologie Moleculaire, Centre de Recherche en Nutrition Humaine d' Auvergne, Aubiere Cedex (France)

    2008-09-15

    More than 20 years after Chernobyl nuclear power plant explosion, radionuclids are still mainly bound to the organic soil layers. The radiation exposure is dominated by the external exposure to gamma-radiation following the decay of {sup 137}Cs and by soil-to-plant-to-human transfer of {sup 137}Cs into the food chain. Because of this persistence of contamination with {sup 137}Cs, questions regarding public health for people living in contaminated areas were raised. We investigated the biological effects of chronic exposure to {sup 137}Cs on testicular and adrenal steroidogenesis metabolisms in rat. Animals were exposed to radionuclide in their drinking water for 9 months at a dose of 6,500 Bq/l (610 Bq/kg/day). Cesium contamination decreases the level of circulating 17{beta}-estradiol, and increases corticosterone level. In testis, several nuclear receptors messenger expression is disrupted; levels of mRNA encoding Liver X receptor {alpha} (LXR{alpha}) and LXR{beta} are increased, whereas farnesoid X receptor mRNA presents a lower level. Adrenal metabolism presents a paradoxical decrease in cyp11a1 gene expression. In conclusion, our results show for the first time molecular and hormonal modifications in testicular and adrenal steroidogenic metabolism, induced by chronic contamination with low doses of {sup 137}Cs. (orig.)

  12. In vivo effects of chronic contamination with 137 cesium on testicular and adrenal steroidogenesis

    International Nuclear Information System (INIS)

    Grignard, Elise; Gueguen, Yann; Grison, Stephane; Gourmelon, Patrick; Souidi, Maamar; Lobaccaro, Jean-Marc A.

    2008-01-01

    More than 20 years after Chernobyl nuclear power plant explosion, radionuclids are still mainly bound to the organic soil layers. The radiation exposure is dominated by the external exposure to gamma-radiation following the decay of 137 Cs and by soil-to-plant-to-human transfer of 137 Cs into the food chain. Because of this persistence of contamination with 137 Cs, questions regarding public health for people living in contaminated areas were raised. We investigated the biological effects of chronic exposure to 137 Cs on testicular and adrenal steroidogenesis metabolisms in rat. Animals were exposed to radionuclide in their drinking water for 9 months at a dose of 6,500 Bq/l (610 Bq/kg/day). Cesium contamination decreases the level of circulating 17β-estradiol, and increases corticosterone level. In testis, several nuclear receptors messenger expression is disrupted; levels of mRNA encoding Liver X receptor α (LXRα) and LXRβ are increased, whereas farnesoid X receptor mRNA presents a lower level. Adrenal metabolism presents a paradoxical decrease in cyp11a1 gene expression. In conclusion, our results show for the first time molecular and hormonal modifications in testicular and adrenal steroidogenic metabolism, induced by chronic contamination with low doses of 137 Cs. (orig.)

  13. Effect of Disinfectants on Preventing the Cross-Contamination of Pathogens in Fresh Produce Washing Water

    Science.gov (United States)

    Banach, Jennifer L.; Sampers, Imca; Van Haute, Sam; van der Fels-Klerx, H.J. (Ine)

    2015-01-01

    The potential cross-contamination of pathogens between clean and contaminated produce in the washing tank is highly dependent on the water quality. Process wash water disinfectants are applied to maintain the water quality during processing. The review examines the efficacy of process wash water disinfectants during produce processing with the aim to prevent cross-contamination of pathogens. Process wash water disinfection requires short contact times so microorganisms are rapidly inactivated. Free chlorine, chlorine dioxide, ozone, and peracetic acid were considered suitable disinfectants. A disinfectant’s reactivity with the organic matter will determine the disinfectant residual, which is of paramount importance for microbial inactivation and should be monitored in situ. Furthermore, the chemical and worker safety, and the legislative framework will determine the suitability of a disinfection technique. Current research often focuses on produce decontamination and to a lesser extent on preventing cross-contamination. Further research on a sanitizer’s efficacy in the washing water is recommended at the laboratory scale, in particular with experimental designs reflecting industrial conditions. Validation on the industrial scale is warranted to better understand the overall effects of a sanitizer. PMID:26213953

  14. Effects of Aflatoxin-Contaminated Feed on Immunological Parameters of Common Carp (Cyprinus Carpio

    Directory of Open Access Journals (Sweden)

    Amal Bitsayah

    2018-01-01

    Full Text Available Background: Aflatoxin contamination is a common natural phenomenon that is difficult to avoid or control and it can occur during pre and post-harvest periods under high humidity and temperature conditions, and are potentially dangerous to fish. In the present study, a feeding trial evaluated the effects of diets contaminated with aflatoxin on certain immunological parameters of common carp. Methods: The immunotoxicity assessment of juvenile common carp was performed on 180 fish divided into five groups with triplicate: Control group received normal feed (Group I; group II was fed diets contaminated with extraction solution (methanol, acetone and diluted water as a positive control. Group III-V was respectively fed diets contaminated with 0.5, 0.7 and 1.4 mg kg-1 feed for 3 wk. Results: Lysozyme activities, total immunoglobulin contents, complement C3 and C4 activities in plasma of common carp fed with different concentrations of aflatoxins significantly decreased when compared to that of the control fish. Although plasma ACH50 contents remained unchanged in 0.5 mg kg-1 aflatoxins, ACH50 contents decreased in 0.7 and 1.4 mg kg-1 groups after 21 d of aflatoxin treatment. No significant changes were observed in immunological parameters between the control positive and control groups throughout the experimental periods. Conclusion: Oral exposure to aflatoxin (0.5 mg kg-1≤ could adversely affect immunological parameters of common carp.

  15. Performance effects of coal-derived contaminants on the carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pigeaud, A. [Energy Research Corp., Danbury, CT (United States); Wilemski, G. [Physical Sciences, Inc., Andover, MA (United States)

    1993-05-01

    Coal-derived contaminant studies have been pursued at ERC since the early 1980`s when the pace of carbonate fuel cell development began to markedly increase. Initial work was concerned with performance effects on laboratory and bench-scale carbonate fuel cells primarily due to sulfur compounds. Results have now also been obtained with respect to nine additional coal-gas contaminants, including volatile trace metal species. Thermochemical calculations, out-of-cell experiments, and cell performance as well as endurance testshave recently been conducted which have involved the following species: NH{sub 3}, H{sub 2}S [COS], HCl, AsH{sub 3}[As{sub 2}(v)], Zn(v), Pb(v), Cd(v), H{sub 2} Se, Hg(v), Sn(v). Employing thermochemically calculated results, thermogravimetric (TGA) and pre-, and post-test analytical data as well as fuel cell performance observations, it has been shown that there are four main mechanisms of contaminant interaction with the carbonate fuel cell. These have been formulated into performance models for six significant contaminant species, thus providing long-term endurance estimations.

  16. Performance effects of coal-derived contaminants on the carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pigeaud, A. (Energy Research Corp., Danbury, CT (United States)); Wilemski, G. (Physical Sciences, Inc., Andover, MA (United States))

    1993-01-01

    Coal-derived contaminant studies have been pursued at ERC since the early 1980's when the pace of carbonate fuel cell development began to markedly increase. Initial work was concerned with performance effects on laboratory and bench-scale carbonate fuel cells primarily due to sulfur compounds. Results have now also been obtained with respect to nine additional coal-gas contaminants, including volatile trace metal species. Thermochemical calculations, out-of-cell experiments, and cell performance as well as endurance testshave recently been conducted which have involved the following species: NH[sub 3], H[sub 2]S [COS], HCl, AsH[sub 3][As[sub 2](v)], Zn(v), Pb(v), Cd(v), H[sub 2] Se, Hg(v), Sn(v). Employing thermochemically calculated results, thermogravimetric (TGA) and pre-, and post-test analytical data as well as fuel cell performance observations, it has been shown that there are four main mechanisms of contaminant interaction with the carbonate fuel cell. These have been formulated into performance models for six significant contaminant species, thus providing long-term endurance estimations.

  17. Effective radiological contamination control and monitoring techniques in high alpha environments.

    Science.gov (United States)

    Funke, Kevin C

    2003-02-01

    In the decommissioning of a highly contaminated alpha environment, such as the one at Hanford's 233-S Plutonium Concentration Facility, one of the key elements of a successful radiological control program is an integrated safety approach. This approach begins with the job-planning phase where the scope of the work is described. This is followed by a brainstorming session involving engineering and craft to identify how to perform the work in a logical sequence of events. Once the brainstorming session is over, a Job Hazard Analysis is performed to identify any potential problems. Mockups are utilized to enable the craft to get hands on experience and provide feedback and ideas to make the job run smoother. Ideas and experience gained during mockups are incorporated into the task instruction. To assure appropriate data are used in planning and executing the job, our principal evaluation tools included lapel and workplace air sampling, plus continuous air monitors and frequent surveys to effectively monitor job progress. In this highly contaminated alpha environment, with contamination levels ranging from 0.3 Bq cm-2 to approximately 100,000 Bq cm-2 (2,000 dpm per 100 cm2 to approximately 600 million dpm per 100 cm2), with average working levels of 1,600-3,200 Bq cm-2 (10-20 million dpm per 100 cm2) without concomitant ambient radiation levels, control of the spread of contamination is key to keeping airborne levels As Low As Reasonably Achievable.

  18. Effect of Disinfectants on Preventing the Cross-Contamination of Pathogens in Fresh Produce Washing Water

    Directory of Open Access Journals (Sweden)

    Jennifer L. Banach

    2015-07-01

    Full Text Available The potential cross-contamination of pathogens between clean and contaminated produce in the washing tank is highly dependent on the water quality. Process wash water disinfectants are applied to maintain the water quality during processing. The review examines the efficacy of process wash water disinfectants during produce processing with the aim to prevent cross-contamination of pathogens. Process wash water disinfection requires short contact times so microorganisms are rapidly inactivated. Free chlorine, chlorine dioxide, ozone, and peracetic acid were considered suitable disinfectants. A disinfectant’s reactivity with the organic matter will determine the disinfectant residual, which is of paramount importance for microbial inactivation and should be monitored in situ. Furthermore, the chemical and worker safety, and the legislative framework will determine the suitability of a disinfection technique. Current research often focuses on produce decontamination and to a lesser extent on preventing cross-contamination. Further research on a sanitizer’s efficacy in the washing water is recommended at the laboratory scale, in particular with experimental designs reflecting industrial conditions. Validation on the industrial scale is warranted to better understand the overall effects of a sanitizer.

  19. Effect of blood contamination on shear bond strength of orthodontic brackets and disinclusion buttons.

    Science.gov (United States)

    Sfondrini, Maria Francesca; Gatti, Sara; Scribante, Andrea

    2011-07-01

    Our aim was to assess the effect of blood contamination on the shear bonding strength and sites of failure of orthodontic brackets and bondable buttons. We randomly divided 160 bovine permanent mandibular incisors into 8 groups of 20 specimens each. Both orthodontic brackets (Step brackets, Leone, Sesto Fiorentino, Italy) and bondable buttons (Flat orthodontic buttons, Leone, Sesto Fiorentino, Italy) were tested on four different enamel surfaces: dry; contamination with blood before priming; after priming; and before and after priming. Brackets and buttons were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bonding strength and the rate of adhesive failures were recorded. Data were analysed using the analysis of variance (ANOVA), Scheffè tests, and the chi-square test. Uncontaminated enamel surfaces showed the highest bonding strengths for both brackets and buttons. When they were contaminated with blood, orthodontic brackets had significantly lower shear strengths than bondable buttons (P=0.0001). There were significant differences in sites of failure among the groups for the various enamel surfaces (P=0.001). Contamination of enamel by blood during bonding lowers the strength of the bond, more so with orthodontic brackets than with bondable buttons. Copyright © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  20. Effect of biosludge and biofertilizer amendment on growth of Jatropha curcas in heavy metal contaminated soils.

    Science.gov (United States)

    Juwarkar, Asha Ashok; Yadav, Santosh Kumar; Kumar, Phani; Singh, Sanjeev Kumar

    2008-10-01

    The pot experiments were conducted to evaluate the effect of different concentrations of arsenic, chromium and zinc contaminated soils, amended with biosludge and biofertilizer on the growth of Jatropha curcas which is a biodiesel crop. The results further showed that biosludge alone and in combination with biofertilizer significantly improved the survival rates and enhanced the growth of the plant. With the amendments, the plant was able to grow and survive upto 500, 250 and 4,000 mg kg(-1) of As, Cr and Zn contaminated soils, respectively. The results also showed that zinc enhanced the growth of J. curcas more as compared to other metals contaminated soils. The heavy metal accumulation in plant increased with increasing concentrations of heavy metals in soil, where as a significant reduction in the metal uptake in plant was observed, when amended with biosludge and biofertilizer and biosludge alone. It seems that the organic matter present in the biosludge acted as metal chelator thereby reducing the toxicity of metals to the plant. Findings suggest that plantation of J. curcas may be promoted in metal contaminated soils, degraded soils or wasteland suitably after amending with organic waste.

  1. Effect of Co-Contaminants Uranium and Nitrate on Iodine Remediation

    Energy Technology Data Exchange (ETDEWEB)

    Szecsody, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lee, Brady D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lawter, Amanda R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Resch, Charles T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baum, Steven R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leavy, Ian I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Freedman, Vicky L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-09-01

    The objective of this study is to evaluate the significance of co-contaminants on the migration and transformation of iodine species in the Hanford subsurface environment. These impacts are relevant because remedies that target individual contaminants like iodine, may not only impact the fate and transport of other contaminants in the subsurface, but also inhibit the effectiveness of a targeted remedy. For example, iodine (as iodate) co-precipitates with calcite, and has been identified as a potential remedy because it immobilizes iodine. Since uranium also co-precipitates with calcite in field sediments, the presence of uranium may also inhibit iodine co-precipitation. Another potentially significant impact from co-existing contaminants is iodine and nitrate. The presence of nitrate has been shown to promote biogeochemical reduction of iodate to iodide, thereby increasing iodine species subsurface mobility (as iodide exhibits less sorption). Hence, this study reports on both laboratory batch and column experiments that investigated a) the change in iodate uptake mass and rate of uptake into precipitating calcite due to the presence of differing amounts of uranium, b) the amount of change of the iodate bio-reduction rate due to the presence of differing nitrate concentrations, and c) whether nitrite can reduce iodate in the presence of microbes and/or minerals acting as catalysts.

  2. Feasibility study to combine the evaluation of radiological and chemical-toxicological effects of old contaminated sites

    International Nuclear Information System (INIS)

    Jacob, P.; Proehl, G.

    1997-01-01

    The uranium mining regions of the German Federal States Saxony, Thuringia and Saxony-Anhalt are contaminated by radionuclides and by chemical substances. For both, ionizing radiations and chemicals, concepts and models exists to assess possible health effects for the population living in such areas. However, these assessment models were developed independently for both kinds of contaminants. Therefore, the 9 th Conference of the State Ministers for Environmental Protection have claimed that for the evaluation of contaminated sites the radiological and chemical contaminants should be integrated into a joint assessment. This feasibility study describes the state of the art of the concepts and models used for the evaluation of radiological and chemical contaminants. The similarities and differences of these evaluation methods are identified and discussed. Suggestions are made for an integrated assessment to standardize the evaluation of sites contaminated by radionuclides or chemicals. (orig.) [de

  3. Effects of heavy-metal-contaminated soil on growth, phenology and biomass turnover of Hieracium piloselloides

    International Nuclear Information System (INIS)

    Ryser, Peter; Sauder, Wendy R.

    2006-01-01

    The effects of low levels of heavy metals on plant growth, biomass turnover and reproduction were investigated for Hieracium pilosella. Plants were grown for 12 weeks on substrates with different concentrations of heavy metals obtained by diluting contaminated soils with silica sand. To minimize effects of other soil factors, the substrates were limed, fertilized, and well watered. The more metal-contaminated soil the substrate contained, the lower the leaf production rate and the plant mass were, and the more the phenological development was delayed. Flowering phenology was very sensitive to metals. Leaf life span was reduced at the highest and the lowest metal levels, the latter being a result of advanced seed ripening. Even if the effect of low metal levels on plant growth may be small, the delayed and reduced reproduction may have large effects at population, community and ecosystem level, and contribute to rapid evolution of metal tolerance. - Flowering phenology shows a very sensitive response to heavy metal contamination of soils

  4. Evaluation of bio-materials’ rejuvenating effect on binders for high-reclaimed asphalt content mixtures; Evaluación del efecto rejuvenecedor de bio-materiales sobre ligantes para mezclas con alto contenido de asfalto recuperado

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez del Barco-Carrión, A.; Pérez-Martínez, M.; Themeli, A.; Lo Presti, D.; Marsac, P.; Pouget, S.; Hammoum, F.; Chailleux, E.; Airey, G.D.

    2017-07-01

    The interest in using bio-materials in pavement engineering has grown significantly over the last decades due to environmental concerns about the use of non-recoverable natural resources. In this paper, bio-materials are used together with Reclaimed Asphalt (RA) to restore some of the properties of the aged bitumen present in mixtures with high RA content. For this purpose, two bio-materials are studied and compared to conventional and polymer modified bitumens. Blends of these materials with RA bitumen were produced and studied to simulate a 50% RA mixture. The rejuvenating effect of the two bio-materials on RA has been assessed and compared with the effect of the conventional binders. Apparent Molecular Weight Distribution of the samples (obtained by the ?-method) and different rheological parameters were used for this purpose. Results revealed the power of bio-materials to rejuvenate RA bitumen, showing their capability to be used as fresh binders in high-RA content mixtures. [Spanish] El interés en la utilización de bio-materiales en ingeniería de pavimentos ha crecido significantemente en las últimas décadas debido a la conciencia ambiental sobre el uso de recursos naturales no renovables. En este artículo, se utilizan bio-materiales para recuperar las propiedades iniciales del betún envejecido presente en mezclas con alto contenido de asfalto reciclado (RA). Para ello, se ha estudiado y comparado el comportamiento de dos bio-materiales con betunes convencionales y betunes modificados con polímeros. Con este objetivo, se fabricaron mezclas de bio-materiales y betún reciclado simulando mezclas asfálticas con 50% de contenido de reciclado. El efecto rejuvenecedor de los bio-materiales se ha evaluado y comparado con el efecto rejuvenecedor de ligantes convencionales mediante el cálculo de las distribuciones de peso molecular aparente y diferentes pará-metro reológicos. Los resultados muestran el poder rejuvenecedor de los bio-materiales, poniendo de

  5. The effects of task organization on skill and knowledge in physical education. (Efecto de la forma de organización sobre el aprendizaje técnico y conceptual en educación física.

    Directory of Open Access Journals (Sweden)

    Antonio Calderón

    2013-01-01

    Full Text Available AbstractThe study examined the effects of different methods of practice three track and field skills (hurdles, high jump and shot put on students performance, from both qualitative (systematic observation, and quantitative (time, height, and distance perspectives, and also their knowledge of the events. One hundred and twenty-two students (71 boys and 51 girls of 13.4±1.2 years from a high school participated in nine lessons in which they used three different types organization of practice. Results show that the organization of practice had a significant effect on performance for lower and medium skill level students, but improvements differed across events. For example, students made significant improvements in shot put when practicing in lines, and for hurdles when practiced in games. These results reinforce the idea that is important for physical education teachers these variables when planning lessons.ResumenEl estudio examinó el efecto de tres formas de organización (filas, circuitos y juegos sobre el aprendizaje técnico y conceptual de tres habilidades atléticas (vallas, salto de altura y lanzamiento de peso. Ciento veinte y dos estudiantes (71 chicos y 51 chicas de 13,4 ± 1,2 años de Educación Secundaria, participaron en nueve sesiones de enseñanza-aprendizaje durante la clase de educación física, en las que se utilizaron los tres tipos de organización de la práctica. Los resultados muestran que el tipo de organización tuvo un efecto significativo sobre el aprendizaje técnico y conceptual, en alumnos con nivel de habilidad bajo y medio, aunque con diferencias entre las disciplinas. Así por ejemplo, los alumnos mejoraron significativamente en lanzamiento de peso cuando practicaron en filas, y en vallas cuando practicaron en juegos. Estos resultados refuerzan por tanto la idea que es estas variables deben ser tenidas en consideración por los profesores de educación física cuando planifican sus sesiones

  6. Dimethylhydrazine model is not appropriate for evaluating effect of ethanol on colorectal cancer El modelo de la dimetilhidrazina no sirve para evaluar el efecto del etanol sobre el cáncer colorrectal

    Directory of Open Access Journals (Sweden)

    M. Perše

    2007-08-01

    Full Text Available 1,2 dimethylhydrazine (DMH rat model has been proven to be a valuable animal model of colorectal cancer. Because of its morphological similarity to human colorectal cancer, DMH rat model was used to produce information in histology and biochemistry of tumours development as well as on factors that retard or enhance tumorigenesis. Nevertheless, it has been shown that DMH model has limitations, which raise the question, whether experiments evaluating effect of ethanol on DMH model are ethically justified. In this paper authors summarize experimental results evaluating effect of ethanol consumption on DMH rat model with aim to prevent unnecessary duplication of animal experimentation or execution of ethically unjustified animal experiments in the future and to warn scientists that results from studies evaluating ethanol on DMH rat model can not be generalized to humans.Se ha observado que el modelo de la 1,2-dimetilhidrazina (DMH en la rata es un valioso modelo animal de cáncer colorrectal. Debido a su parecido morfológico con el cáncer colorrectal humano, el modelo de la DMH en la rata se ha empleado para conseguir información acerca de la histología y la bioquímica del desarrollo tumoral, además de sobre los factores que retrasan o potencian la tumorigénesis. No obstante, se ha visto que el modelo de la DMH tiene sus limitaciones, lo que lleva a preguntarse si están justificados, desde el punto de vista ético, los experimentos que evalúan el efecto del etanol sobre este modelo. En este documento, los autores resumen los resultados experimentales que evalúan el efecto del consumo de etanol sobre el modelo de la DMH en la rata con el fin de evitar la duplicación innecesaria de la experimentación animal o la ejecución de experimentos con animales sin justificación ética en el futuro, además de avisar a los científicos de que los resultados obtenidos de los estudios que han evaluado el etanol con el modelo de la DMH en la rata no

  7. Sentirse apoyado: Experiencia de pacientes en Ventilación Mecánica sin efectos de sedación continua To feel leaning: Experience of patient in mechanical ventilation without continuous sedation effects

    Directory of Open Access Journals (Sweden)

    Ángela María Henao Castaño

    2010-09-01

    Full Text Available Objetivo: Describir los mecanismos de afrontamiento utilizados por los pacientes que se encuentran sometidos a ventilación mecánica sin efectos de sedación continúa en una UCI. Metodología: se realizó una investigación con enfoque fenomenológico que contó con la participación de siete hombres y dos mujeres con edades entre 24 y 75 años. La técnica de recolección de la información fue la entrevista a profundidad. Resultados: "Sentirse apoyado y magnificar la espiritualidad", estar críticamente enfermo hace que se vivan situaciones de sufrimiento y soledad, convirtiendo a la familia y a la creencia religiosa como partes del proceso de recuperación. Conclusión: vivir la experiencia de la ventilación mecánica sin efectos de sedación fue para los participantes trascendental debido a que percibieron durante su proceso de enfermedad el apoyo que la familia y la creencia religiosa les brindó para poder recuperarse; la familia son personas que dan palabras de aliento, brindan ayuda emocional y espiritual.Objective: to describe the confrontation mechanisms used by the patients that are subjected to mechanical ventilation without effects of continues sedation in an ICU. Methodology: it was carried out an investigation with phenomelogycal focus that had the participation of seven men and two women between 24 and 75 years old. The technique of gathering of the information was the interview in depth. Results: "to feel leaning and to magnify the spirituality". To be critically sick makes that situations of suffering and solitude been lived, converting the family and religious belief as parts of the recovery process. Conclusion: to live the experience of the mechanical ventilation without sedation effects was for the participants deeply significant because they perceived during their illness the support that the family and the religious belief offer them to be able to recover; the family is people that give words of encouragement, they

  8. Efectos secundarios de los anticonceptivos hormonales en usuarias del método asistentes a las consultas de planificación familiar Side effects of hormonal contraceptives methods in women attending family planning departments

    Directory of Open Access Journals (Sweden)

    Maria Mercedes Arrate Negret

    2013-03-01

    Full Text Available Se realizó un estudio descriptivo, longitudinal y prospectivo de las 375 mujeres en edad fértil (de 15 a 49 años que acudieron a la consulta de Planificación Familiar del Policlínico Docente Municipal de Santiago de Cuba, desde septiembre del 2010 hasta febrero del 2011, a fin de identificar los efectos secundarios más frecuentes producidos por los anticonceptivos hormonales ofertados en este servicio, para lo cual se midieron las variables: edad, hábitos tóxicos, factor de riesgo preconcepcional, anticoncepción hormonal, aparición de efectos colaterales o no y modo en que fueron solucionados. En la casuística predominaron el grupo etario de 20-34 años, el cafeísmo, el déficit nutricional como causa de visita a la consulta y el uso del contraceptivo Triquilar®. La mayoría de las pacientes presentó reacciones adversas, fundamentalmente trastornos gastrointestinales y ganancia de peso, no obstante, gran parte de las afectaciones clínicas se resolvieron espontáneamente. Se recomendó implementar un programa de educación en salud reproductiva para médicos y enfermeros de la familia, con vistas a mejorar la calidad en dicha atención preconceptiva y desarrollar una campaña de divulgación en la población sobre los diferentes métodos anticonceptivos, su uso y complicaciones.A descriptive, longitudinal and prospective study was carried out in 375 women in reproductive age (15 to 49 years, who attended the family planning department of the Municipal Teaching Polyclinic in Santiago de Cuba, from September 2010 to February 2011, in order to identify the most common side effects caused by hormonal contraceptives offered in this service, for which variables such as age, toxic habits, preconception risk factors, hormonal contraception, occurrence of side effects and ways to solve them were measured. Age group of 20-34 years, coffeeholism, nutritional deficiency as a cause of visit and use of the contraceptive Triquilar® prevailed in

  9. Effects of processing techniques on oxidative stability of Prunus pedunculatus seed oil; Efectos de las técnicas de procesamiento sobre la estabilidad oxidativa del aceite de semilla de Prunus pedunculatus

    Energy Technology Data Exchange (ETDEWEB)

    Yan, J.; Guo, M.M.; Shen, Y. H.; Wang, Y.Y.; Luan, X.; Li, C.

    2017-07-01

    This paper investigated the effects of Prunus pedunculatus (P. pedunculatus) seed pre-treatment, including microwaving (M), roasting (R), steaming (S) and roasting plus steaming (RS) on crude oil quality in terms of yield, color change, fatty acid composition, and oxidative stability. The results showed an increase in monounsaturated fatty acid content and oxidative stability of the oils obtained from different processing treatments compared to the oil obtained from raw seeds (RW) without processing. The oils, obtained from pretreated seeds, had higher conjugated diene (CD) and 2-thiobarbituric acid (2-TBA) values, compared to that obtained from RW when stored in a Schaal oven at 65 °C for 168 h. However, polyphenol and tocopherol contents decreased in all oil samples, processed or unprocessed. The effect of pre-treating the seeds was more prominent in the oil sample obtained through the RS technique, and showed higher oxidative stability than the other processed oils and the oil from RW. [Spanish] Se investigó los efectos del pretratamiento de las semillas de Prunus pedunculatus, incluyendo microondas (M), tostado (R), cocción al vapor (S) y torrefacción más vapor (RS), sobre la calidad del aceite crudo, el rendimiento, cambio de color, composición en ácidos grasos y estabilidad oxidativa. Los resultados mostraron un aumento en el contenido de ácidos grasos monoinsaturados y en la estabilidad oxidativa de los aceites obtenidos con diferentes tratamientos de procesamiento en comparación con el aceite obtenido a partir de semillas crudas (RW) sin procesamiento. Los aceites obtenidos a partir de semillas pretratadas presentaron mayores valores de dienos conjugados (CD) y de ácido 2-tiobarbitúrico (2-TBA), comparado con el obtenido de RW cuando se almacenaron en horno a 65 °C durante 168 h. Sin embargo, el contenido de polifenoles y tocoferoles disminuyó en todas las muestras de aceites, procesadas o no procesadas. El efecto del pretratamiento de las

  10. Uso de la variabilidad de la frecuencia cardiaca como marcador de los efectos cardiovasculares asociados con la contaminación del aire Use of heartrate variability as a marker of cardiovascular effects associated with air pollution

    Directory of Open Access Journals (Sweden)

    Horacio Riojas-Rodríguez

    2006-08-01

    Full Text Available Estudios epidemiológicos han demostrado la relación entre los contaminantes atmosféricos y el incremento en la mortalidad por causas cardiovasculares, en especial en personas con enfermedad cardiopulmonar previa. Sin embargo, los mecanismos fisiopatológicos mediante los cuales estos padecimientos ocurren no son bien conocidos. Se ha sugerido que una de las vías mediante las cuales las partículas suspendidas respirables y otros contaminantes producen su efecto es alterar la regulación del corazón por el sistema nervioso autónomo. El análisis de los cambios en la variabilidad de la frecuencia cardiaca (VFC es un indicador de efecto sobre este mecanismo. En este trabajo se realiza una revisión de las bases fisiológicas de este método, de sus ventajas y limitaciones y de los resultados que se obtienen al relacionarlo con la exposición a contaminantes atmosféricos. A partir del análisis de la literatura disponible, se sugieren alternativas relacionadas con el diseño de los estudios, la selección de poblaciones en riesgo, los métodos para evaluar la exposición y los métodos de análisis estadístico que pueden servir para utilizar mejor el análisis del registro electrocardiográfico ambulatorio en relación con los riesgos cardiacos por exposición a contaminantes atmosféricos.Epidemiological studies have shown the association between atmospheric pollutants and increase in mortality due to cardiovascular causes, especially in patients with previous cardio-respiratory diseases. However, the pathophysiological mechanisms by which these events take place have not been elucidated. One of the proposed mechanisms by which suspended respirable particles and other pollutants produce their effect is that they modify autonomic heart control. The analysis of changes in heart rate variability (HRV is an indicator of pollutant effect on this mechanism. The article reviews the physiologic basis of this non-invasive method, its advantages and

  11. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Bonzom, Jean-Marc, E-mail: jean-marc.bonzom@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Hättenschwiler, Stephan [Centre d' Ecologie Fonctionnelle et Evolutive (CEFE UMR 5175, CNRS–Université de Montpellier–Université Paul-Valéry Montpellier–EPHE), 1919 Route de Mende, F-34293 Montpellier (France); Lecomte-Pradines, Catherine [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Chauvet, Eric [EcoLab, Université de Toulouse, CNRS, UPS, INPT, 118 Route de Narbonne, 31062 Toulouse cedex (France); Gaschak, Sergey [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS, Cadarache, Bât. 183, BP 3, 13115 St Paul-lez-Durance (France); Maksimenko, Andrey [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); and others

    2016-08-15

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22–15 μGy h{sup −1}) and (ii) along a short distance gradient of radioactive contamination (1.2–29 μGy h{sup −1}) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150 μGy h{sup −1}. This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. - Highlights: • The effects of radioactivity on

  12. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone

    International Nuclear Information System (INIS)

    Bonzom, Jean-Marc; Hättenschwiler, Stephan; Lecomte-Pradines, Catherine; Chauvet, Eric; Gaschak, Sergey; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas; Maksimenko, Andrey

    2016-01-01

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22–15 μGy h −1 ) and (ii) along a short distance gradient of radioactive contamination (1.2–29 μGy h −1 ) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150 μGy h −1 . This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. - Highlights: • The effects of radioactivity on ecosystem processes

  13. Presence and biological effects of emerging contaminants in Llobregat River basin: A review

    International Nuclear Information System (INIS)

    González, Susana; López-Roldán, Ramón; Cortina, Jose-Luis

    2012-01-01

    Llobregat River (North-East Spain) is the most important drinking water source for Barcelona and its surrounding area. As one of the only water sources in the area the river water have been overexploited and effluents from more than 30 urban wastewater treatment plants, industries and agriculture runoffs have been discharged into the river. This article reviews the presence of emerging contaminants published during the last decades, emphasizing on the observed effects on ecosystems caused by the contamination. Pesticides, surfactants, estrogens, pharmaceuticals and personal care products and even abuse drugs are the main groups detected in different studies, reporting alterations in species composition, abundance or biomass and endocrine disruption measured by alterations in enzymatic activity or specific protein production. The information available provides an overview of the river status according to the Water Framework Directive. - The presence of different pollutants (mainly pesticides, pharmaceuticals, surfactants and estrogens) and their biological effects in the Llobregat River are reviewed.

  14. Long-Term Effects of Legacy Copper Contamination on Microbial Activity and Soil Physical Properties

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Møldrup, Per; Holmstrup, Martin

    Soils heavily contaminated with copper (Cu) are considered unsuitable for agricultural use due to adverse impacts on microbial activity, soil physical properties, and direct toxicity to crops. This study investigated effects of Cu pollution from timber preservation activities between 1911 and 1924...... on soil micro-organisms and subsequent effects on physical properties of a sandy loam soil. Tillage operations over the last 70 years have caused spreading of the initially localized contamination and have created a Cu concentration gradient from 20 to 3800 mg kg-1 across an agricultural field in Hygum......, Denmark. Soil samples obtained from the fallow field were used to determine total microbial activity using fluorescein diacetate and dehydrogenase assays. The physical properties measured included water-dispersible clay, bulk density, air permeability and air-filled porosity. Significant differences...

  15. Effect of ionizing radiation on fresh vegetables artificially contaminated with Vibrio cholerae

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, T; Espinoza, J; Vargas, M [Comision Chilena de Energia Nuclear (Chile); Araya, E [Facultad de Ciencias Agrarias y Forestales, Universidad de Chile (Chile); Avendano, S; Lopez, L [Facultad de Quimica y Farmacia, Universidad de Chile (Chile)

    2001-04-01

    Lettuce, cabbage and celery were artificially contaminated with Vibrio cholerae El Tor 01 Inaba, and irradiated at 0.50, 0.75 and 1.00 kGy. Non-irradiated samples were used as controls. The effect of irradiation was measured during 7-days storage under refrigeration, from the viewpoints of microbiological (MPN), nutritional (Vitamin C content), and sensory quality. Irradiation proved to be an effective technique to eliminate V. cholerae in fresh vegetables. Doses of less than 0.75 kGy were sufficient to eliminate an initial contamination of 10{sup 5} cells/g of V. cholerae; neither sensory properties or nutritional quality (Vitamin C content) were adversely affected by the treatment. The cost of irradiating the vegetables at 0.5 kGy under the conditions of the study was US$ 0.131, 0.067 and 0.445 per unit of lettuce, cabbage and celery, respectively. (author)

  16. Effect of ionizing radiation on fresh vegetables artificially contaminated with Vibrio cholerae

    International Nuclear Information System (INIS)

    Rubio, T.; Espinoza, J.; Vargas, M.; Araya, E.; Avendano, S.; Lopez, L.

    2001-01-01

    Lettuce, cabbage and celery were artificially contaminated with Vibrio cholerae El Tor 01 Inaba, and irradiated at 0.50, 0.75 and 1.00 kGy. Non-irradiated samples were used as controls. The effect of irradiation was measured during 7-days storage under refrigeration, from the viewpoints of microbiological (MPN), nutritional (Vitamin C content), and sensory quality. Irradiation proved to be an effective technique to eliminate V. cholerae in fresh vegetables. Doses of less than 0.75 kGy were sufficient to eliminate an initial contamination of 10 5 cells/g of V. cholerae; neither sensory properties or nutritional quality (Vitamin C content) were adversely affected by the treatment. The cost of irradiating the vegetables at 0.5 kGy under the conditions of the study was US$ 0.131, 0.067 and 0.445 per unit of lettuce, cabbage and celery, respectively. (author)

  17. Effect of contaminant concentration on in situ bacterial sulfate reduction and methanogenesis in phenol-contaminated groundwater

    International Nuclear Information System (INIS)

    Baker, Kieran M.; Bottrell, Simon H.; Thornton, Steven F.; Peel, Kate E.; Spence, Michael J.

    2012-01-01

    The availability of dissolved O 2 can limit biodegradation of organic compounds in aquifers. Where O 2 is depleted, biodegradation proceeds via anaerobic processes, including NO 3 -, Mn(IV)-, Fe(III)- and SO 4 -reduction and fermentation/methanogenesis. The environmental controls on these anaerobic processes must be understood to support implementation of management strategies such as monitored natural attenuation (MNA). In this study stable isotope analysis is used to show that the relative significance of two key anaerobic biodegradation processes (bacterial SO 4 reduction (BSR) and methanogenesis) in a phenol-contaminated sandstone aquifer is sensitive to spatial and temporal changes in total dissolved phenols concentration (TPC) (= phenol + cresols + dimethylphenols) over a 5-a period. In general, 34 SO 4 -enrichment (characteristic of bacterial SO 4 reduction) is restricted spatially to locations where TPC −1 . In contrast, 13 C-depleted CH 4 and 13 C-enriched CO 2 isotope compositions (characteristic of methanogenesis) were measured at TPC up to 8000 mg L −1 . This is consistent with previous studies that demonstrate suppression of BSR at TPC of >500 mg L −1 , and suggests that methanogenic microorganisms may have a higher tolerance for TPC in this contaminant plume. It is concluded that isotopic enrichment trends can be used to identify conditions under which in situ biodegradation may be limited by the properties of the biodegradation substrate (in this case TPC). Such data may be used to deduce the performance of MNA for contaminated groundwater in similar settings.

  18. Health effects of swimming in fecally-contaminated recreational water: Results from studies at nine coastal beaches

    Science.gov (United States)

    Exposure to fecally-contaminated water has long been known to transmit infectious disease. In 2003, EPA and the CDC initiated studies to better describe the health effects associated with exposure to fecal contamination in recreational waters and to test faster ways of measuring ...

  19. The effectiveness of electro-remediation of aged, metal-contaminated sediment in relation to sequential extraction of metals

    NARCIS (Netherlands)

    Merkx, O.K.; Loch, J.P.G.; Lima, A.T.; Dijk, J.A.; Kreuk, J.F. de; Kleingeld, P.J.

    2013-01-01

    Soil pollution is a universal environmental issue, and the clean-up of contaminated soils can be costly and time consuming. Traditional methods often do not provide an effective solution when it comes to fine-grained and highly impermeable soils and/or immobile contaminants. Electro-remediation,

  20. Immunostimulatory Potential of β-Lactoglobulin Preparations: Effects Caused by Endotoxin Contamination

    DEFF Research Database (Denmark)

    Pedersen, Susanne Brix; Bovetto, L.; Fritsche, R.

    2003-01-01

    Background: The immunomodulating potential residing in cow's milk proteins is currently receiving increasing attention because of growing interest in functional foods and the complex problem of cow's milk allergy. One of the major cow's milk allergens, whey protein beta-lactoglobulin, has...... the immunomodulatory activity. Eventually, the immunostimulatory effect was found to be caused by endotoxin contamination.Conclusion: These results identify endotoxin as the main immunostimulatory component present in some commercial beta-lactoglobulin preparations. Moreover, the present study makes it evident...

  1. Direct and indirect effects of a potential aquatic contaminant on grazer-algae interactions.

    Science.gov (United States)

    Evans-White, Michelle A; Lamberti, Gary A

    2009-02-01

    Contaminants have direct, harmful effects across multiple ecological scales, including the individual, the community, and the ecosystem levels. Less, however, is known about how indirect effects of contaminants on consumer physiology or behavior might alter community interactions or ecosystem processes. We examined whether a potential aquatic contaminant, an ionic liquid, can indirectly alter benthic algal biomass and primary production through direct effects on herbivorous snails. Ionic liquids are nonvolatile organic salts being considered as an environmentally friendly potential replacement for volatile organic compounds in industry. In two greenhouse experiments, we factorially crossed four concentrations of 1-N-butyl-3-methylimidazolium bromide (bmimBr; experiment 1: 0 or 10 mg/L; experiment 2: 0, 1, or 100 mg/L) with the presence or absence of the snail Physa acuta in aquatic mesocosms. Experimental results were weighted by their respective control (no bmimBr or P. acuta) and combined for statistical analysis. When both bmimBr and snails were present, chlorophyll a abundance and algal biovolume were higher than would be expected if both factors acted additively. In addition, snail growth rates, relative to those of controls, declined by 41 to 101% at 10 and 100 mg/L of bmimBr. Taken together, these two results suggest that snails were less efficient grazers in the presence of bmimBr, resulting in release of algae from the grazer control. Snails stimulated periphyton primary production in the absence, but not in the presence, of bmimBr, suggesting that bmimBr also can indirectly alter ecosystem function. These findings suggest that sublethal contaminant levels can negatively impact communities and ecosystem processes via complex interactions, and they provide baseline information regarding the potential effects of an emergent industrial chemical on aquatic systems.

  2. Combined Effects of Biochar and Fertilizer on Cadmium Contaminated Soil Remediation

    OpenAIRE

    WANG Qi-kai; GUO Wen-juan; SUN Guo-hong; LIN Da-song; XU Ying-ming; LIU Jing-ru; YU Shi-lei

    2015-01-01

    The field experiment was employed to study on the combined effects of biochar and chicken manure and N, P and K compound chemical fertilizer on cadmium contaminated soil remediation, and the immobilization mechanism was elucidated through fractionation of cadmium in the tested soil. Results showed that the addition of these ammendments could significantly reduce the edible Cd accumulation in Lactuca sativa L., decreased from 32.6% to 54.8% compared with the control. The application of these a...

  3. EFFECTS OF FOOD CONTAMINATION WITH DIOXIN ON THE ROMANIAN MILK MARKET

    Directory of Open Access Journals (Sweden)

    Silvius STANCIU

    2014-06-01

    Full Text Available Milk products contaminated with dioxin scandal is an example of how the milk market may be substantially affected by intense rumour in the media broadcast. Although the crisis was recorded at a multinational company, the lack of maturity of the local market and improper management led to significant loss in image, lower consumer confidence and substantial decrease in sales. The positive effects are increased consumer focus on buying, check the information contained on the label, check demanding products for children.

  4. In vitro and in vivo effects of low dose HTO contamination modulated by dose rate

    International Nuclear Information System (INIS)

    Petcu, I.; Savu, D.; Moisoi, N.; Koeteles, G.J.

    1997-01-01

    The experiment performed in vitro intended to examine whether an adaptive response could be elicited on lymphocytes by low-level contamination of whole blood with tritiated water and if the modification of the dose rate has any influence on it. Lymphocytes pre-exposed to 3 HOH (0.2 - 6.6 MBq/ml) and subsequently irradiated with I Gy γ-rays showed micronuclei frequency significantly lower (40% - 45%) than the expected member (sum of the yields induced by 3 HOH and γ-rays separately). The degree of the radioresistance induced by HTO pre-treatments became higher with decreasing dose-rate for a rather similar total adapting dose. In vivo, the aim of the study was to investigate if different dose rates are inducing modulation of the lipid peroxidation level and of the thymidine uptake in different tissues of animals contaminated by HTO ingestion. The total doses varied between 5 and 20 cGy and were delivered as chronic (100 days) or acute contamination (5 days). It was observed that only doses about 20 cGy caused a dose-rate dependent increase of the lipid peroxidation level in the tissues of small intestine, kidney and spleen. Both chronic and acute contamination did produce reduced incorporation of thymidine in the cells of bone marrow. The most effective decrease of thymidine uptake was induced by the acute contamination in the lower dose domain (approx. 5 cGy). Our hypothesis is that in this dose domain the modification of thymidine uptake could be due to changes at the level of membrane transport. (author)

  5. Mixture effects in samples of multiple contaminants - An inter-laboratory study with manifold bioassays.

    Science.gov (United States)

    Altenburger, Rolf; Scholze, Martin; Busch, Wibke; Escher, Beate I; Jakobs, Gianina; Krauss, Martin; Krüger, Janet; Neale, Peta A; Ait-Aissa, Selim; Almeida, Ana Catarina; Seiler, Thomas-Benjamin; Brion, François; Hilscherová, Klára; Hollert, Henner; Novák, Jiří; Schlichting, Rita; Serra, Hélène; Shao, Ying; Tindall, Andrew; Tolefsen, Knut-Erik; Umbuzeiro, Gisela; Williams, Tim D; Kortenkamp, Andreas

    2018-05-01

    Chemicals in the environment occur in mixtures rather than as individual entities. Environmental quality monitoring thus faces the challenge to comprehensively assess a multitude of contaminants and potential adverse effects. Effect-based methods have been suggested as complements to chemical analytical characterisation of complex pollution patterns. The regularly observed discrepancy between chemical and biological assessments of adverse effects due to contaminants in the field may be either due to unidentified contaminants or result from interactions of compounds in mixtures. Here, we present an interlaboratory study where individual compounds and their mixtures were investigated by extensive concentration-effect analysis using 19 different bioassays. The assay panel consisted of 5 whole organism assays measuring apical effects and 14 cell- and organism-based bioassays with more specific effect observations. Twelve organic water pollutants of diverse structure and unique known modes of action were studied individually and as mixtures mirroring exposure scenarios in freshwaters. We compared the observed mixture effects against component-based mixture effect predictions derived from additivity expectations (assumption of non-interaction). Most of the assays detected the mixture response of the active components as predicted even against a background of other inactive contaminants. When none of the mixture components showed any activity by themselves then the mixture also was without effects. The mixture effects observed using apical endpoints fell in the middle of a prediction window defined by the additivity predictions for concentration addition and independent action, reflecting well the diversity of the anticipated modes of action. In one case, an unexpectedly reduced solubility of one of the mixture components led to mixture responses that fell short of the predictions of both additivity mixture models. The majority of the specific cell- and organism

  6. Combined Effects of Biochar and Fertilizer on Cadmium Contaminated Soil Remediation

    Directory of Open Access Journals (Sweden)

    WANG Qi-kai

    2015-12-01

    Full Text Available The field experiment was employed to study on the combined effects of biochar and chicken manure and N, P and K compound chemical fertilizer on cadmium contaminated soil remediation, and the immobilization mechanism was elucidated through fractionation of cadmium in the tested soil. Results showed that the addition of these ammendments could significantly reduce the edible Cd accumulation in Lactuca sativa L., decreased from 32.6% to 54.8% compared with the control. The application of these additives could also significantly decrease extractable Cd concentration by 7.04%~21.85%. Biochar could significantly improve soil pH value, promote the inactivation of Cd contaminated soil, while the application of chicken manure significantly decreased soil pH value, which showed the effect of activating Cd in soil. Soil pH value had significant positive correlation with root Cd concentration of tested cultivars, but did not reach the significant effect level with the shoot Cd concentration. The research can provide a theoretical basis for the application of biochar combined with chicken manure and N, P and K compound chemical fertilizer on remediation of sewage irrigated Cd contaminated soil.

  7. Dynamic Effects of Biochar on the Bacterial Community Structure in Soil Contaminated with Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Song, Yang; Bian, Yongrong; Wang, Fang; Xu, Min; Ni, Ni; Yang, Xinglun; Gu, Chenggang; Jiang, Xin

    2017-08-16

    Amending soil with biochar is an effective soil remediation strategy for organic contaminants. This study investigated the dynamic effects of wheat straw biochar on the bacterial community structure during remediation by high-throughput sequencing. The wheat straw biochar amended into the soil significantly reduced the bioavailability and toxicity of polycyclic aromatic hydrocarbons (PAHs). Biochar amendment helped to maintain the bacterial diversity in the PAH-contaminated soil. The relationship between the immobilization of PAHs and the soil bacterial diversity fit a quadratic model. Before week 12 of the incubation, the incubation time was the main factor contributing to the changes in the soil bacterial community structure. However, biochar greatly affected the bacterial community structure after 12 weeks of amendment, and the effects were dependent upon the biochar type. Amendment with biochar mainly facilitated the growth of rare bacterial genera (relative abundance of 0.01-1%) in the studied soil. Therefore, the application of wheat straw biochar into PAH-contaminated soil can reduce the environmental risks of PAHs and benefit the soil microbial ecology.

  8. The effect of vadose zone heterogeneities on vapor phase migration and aquifer contamination by volatile organics

    Energy Technology Data Exchange (ETDEWEB)

    Seneviratne, A.; Findikakis, A.N. [Bechtel Corporation, San Francisco, CA (United States)

    1995-03-01

    Organic vapors migrating through the vadose zone and inter-phase transfer can contribute to the contamination of larger portions of aquifers than estimated by accounting only for dissolved phase transport through the saturated zone. Proper understanding of vapor phase migration pathways is important for the characterization of the extent of both vadose zone and the saturated zone contamination. The multiphase simulation code T2VOC is used to numerically investigate the effect of heterogeneties on the vapor phase migration of chlorobenzene at a hypothetical site where a vapor extraction system is used to remove contaminants. Different stratigraphies consisting of alternate layers of high and low permeability materials with soil properties representative of gravel, sandy silt and clays are evaluated. The effect of the extent and continuity of low permeability zones on vapor migration is evaluated. Numerical simulations are carried out for different soil properties and different boundary conditions. T2VOC simulations with zones of higher permeability were made to assess the role of how such zones in providing enhanced migration pathways for organic vapors. Similarly, the effect of the degree of saturation of the porous medium on vapor migration was for a range of saturation values. Increased saturation reduces the pore volume of the medium available for vapor diffusion. Stratigraphic units with higher aqueous saturation can retard the vapor phase migration significantly.

  9. Effect of clorophilic juice from germinated corn on seric lipids, hemoglobin, and uric acid Efecto del germinado de maíz sobre el perfil lipídico, la hemoglobina y la uricemia

    Directory of Open Access Journals (Sweden)

    María Luisa Bravo Aguiar

    1998-01-01

    Full Text Available The effect was studied of clorophilic juice from germinated corn on blood seric lipids, uric acid, glucose, hemoglobine and hematocrite. Nine adults with average age 44 years and who presented hypertriglyceridemia received daily 30 ml doses of the juice during 2 months. Initial average concentrations in mg/dl were 6.9 (uric acid, 259 (triglycerides and 199 (total cholesterol; they decreased progressively and significantly at 30, 45 and 60 days of treatment reaching values of 5.0, 171 and 169 respectively (p:0.01 0,0.015 and 0.034. Hemoglobin increased significantly (p:0.008. This natural treatment could be useful in regulating blood lipids and other biologic risk factors for coronary arteriosclerosis, without the toxic efects shown by some lipid control drugs. Se investigó el efecto del jugo clorofílico de germinado de maíz, con una dosis de 30 ml diarios durante dos meses, sobre el perfil lipídico, la glicemia, la uricemia, la hemoglobina y el hematocrito, en nueve adultos con edad promedio de 44 años y que presentaban hipertrigliceridemia como trastorno principal. Las concentraciones promedio iniciales en mgl dl que eran de 6.9 (ácido úrico, 259 (triglicéridos y 199 (colesterol total descendieron en forma progresiva y significativa a los 30, 45 y 60 días de tratamiento hasta valores respectivos de 5.0, 171 y 169 (p = 0.010,0.015 y 0.034 respectivamente. La hemoglobina ascendió de manera progresiva y significativa (p = 0.008 durante el experimento. Este tratamiento natural podría ser útil en la regulación de los lípidos sanguíneos y otros factores biológicos de riesgo para el desarrollo de ateromatosis coronaría, sin los efectos tóxicos que se han demostrado con algunas drogas hipolipemiantes.

  10. Effect of the oyster contaminated in Salmonella typhimurium and Escherichia coli

    International Nuclear Information System (INIS)

    Brena V, M.

    1992-08-01

    In this work the effect of the oyster contaminated in the species of bacteria better studied by its genetic composition these are the Salmonella typhimurium and the Escherichia coli and that its have been starting point for later radiobiological studies in superior organisms. Of this its have arisen two general lines. The research about the genotoxic effect of substances or mixtures in bacteria with the collaboration of the groups of Drosophila and X-ray Fluorescence analysis and on the other hand the study of the low doses of radiation also in bacteria. It is also treated the topic about the genetic effect of aromatic hydrocarbons in different biological systems. (Author)

  11. The effect of precipitation on contaminant dissolution and transport: Analytic solutions

    International Nuclear Information System (INIS)

    Light, W.B.; Chambre, P.L.; Pigford, T.H.; Lee, W.W.L.

    1988-09-01

    We analysed the effect of precipitation on the dissolution and transport rates of a nondecaying contaminant. Precipitation near the waste surface can have a profound effect on dissolution and transport rates. The mass-transfer rate at the waste surface is controlled by the solid-liquid reaction rate to an extent determined by the modified reaction-rate modulus, α. At later times extending to steady state, the mass-transfer rate depends on the location of the precipitation front r/sub p/ and on the solubility ratio C/sub o//C/sub p/. A precipitation front very near the waste surface can change the dissolution mechanism from solubility-diffusion-controlled to chemical-reaction-rate controlled. Precipitation limits the concentration of the contaminant at r > r/sub p/ to C/sub p/, steepening the concentration gradient for dissolution on the waste package side of the front and flattening the gradient for transport in the region outside the front. This increases the rate of contaminant transport from the waste to the front while decreasing the rate of transport away from the front, when compared to the situation without precipitation. The difference in the transport rates at the front is the rate of precipitation. For large changes in solubility, most of the contaminant is immobilized by precipitation, as was observed in a parallel study. The effect of a precipitation front located nearby in surrounding rock is to increase the release rate at the waste surface/rock interface. The increase in release rate at the waste surface is greater the closer the precipitation and the larger the ratio C/sub o//C/sub p/, also observed by others. The release rates of other waste constituents that dissolve congruently with the solubility-controlling matrix can be increased by a local high-solubility region between the waste surface and the precipitation front. 10 refs., 5 figs

  12. Ecotoxicological Effects of Chemical Contaminants Adsorbed to Microplastics in the Clam Scrobicularia plana

    Directory of Open Access Journals (Sweden)

    Sarit O'Donovan

    2018-04-01

    Full Text Available Although microplastics (MPs are distributed globally in the marine environment, a great deal of unknowns relating to their ecotoxicological effects on the marine biota remains. Due to their lipophilic nature, microplastics have the potential to adsorb persistent organic pollutants present in contaminated regions, which may increase their detrimental impact once assimilated by organisms. This study investigates the ecotoxicological effects of exposure to low-density polyethylene (LDPE microplastics (11–13 μm, with and without adsorbed contaminants (benzo[a]pyrene—BaP and perfluorooctane sulfonic acid—PFOS, in the peppery furrow shell clam, Scrobicularia plana. Environmentally relevant concentrations of contaminants (BaP−16.87 ± 0.22 μg g−1 and PFOS−70.22 ± 12.41 μg g−1 were adsorbed to microplastics to evaluate the potential role of plastic particles as a source of chemical contamination once ingested. S. plana were exposed to microplastics, at a concentration of 1 mg L−1, in a water-sediment exposure setup for 14 days. Clams were sampled at the beginning of the experiment (day 0 and after 3, 7, and 14 days. BaP accumulation, in whole clam tissues, was analyzed. A multi-biomarker assessment was conducted in the gills, digestive gland, and haemolymph of clams to clarify the effects of exposure. This included the quantification of antioxidant (superoxide dismutase, catalase, glutathione peroxidase and biotransformation (glutathione-S-transferases enzyme activities, oxidative damage (lipid peroxidation levels, genotoxicity (single and double strand DNA breaks, and neurotoxicity (acetylcholinesterase activity. Results suggest a potential mechanical injury of gills caused by ingestion of microplastics that may also affect the analyzed biomarkers. The digestive gland seems less affected by mechanical damage caused by virgin microplastic exposure, with the MPs-adsorbed BaP and PFOS exerting a negative influence over the assessed

  13. Efecto del tratamiento erradicador para Helicobacter pylori en pacientes con dispepsia funcional Effect to Helicobacter pylori eradication on patients with functional dyspepsia

    Directory of Open Access Journals (Sweden)

    T. de Artaza Varasa

    2008-09-01

    Full Text Available Objetivo: este estudio ha tenido un doble objetivo: por un lado, evaluar el efecto del tratamiento erradicador para Helicobacter pylori en la respuesta sintomática de pacientes diagnosticados de dispepsia funcional y, por otro, determinar si los hallazgos histológicos podían servir como predictor de la efectividad de la terapia. En particular, se trató de averiguar si la presencia de gastritis antral (la que se asocia a la enfermedad ulcerosa péptica podría predecir una mayor respuesta sintomática al tratamiento erradicador en los pacientes con dispepsia funcional e infección por Helicobacter pylori. Pacientes y métodos: estudio prospectivo, monocéntrico y aleatorizado, que incluyó a 48 pacientes con dispepsia funcional e infección por Helicobacter pylori (27 mujeres y 21 hombres, con edad media de 37 ± 13,5 años. Veintisiete pacientes recibieron el tratamiento erradicador (rabeprazol, claritromicina y amoxicilina durante 10 días, seguido de 20 mg/día de rabeprazol 3 meses y 21 el tratamiento control (20 mg/día de rabeprazol 3 meses. Los pacientes fueron seguidos durante un año. Todos rellenaron el Cuestionario de calidad de vida asociada a dispepsia, que evalúa cuatro apartados: intensidad de los síntomas habituales, intensidad del dolor de estómago, incapacidad debida al dolor y satisfacción con la salud. Resultados: existió una mejoría significativa (p Objective: this study evaluated Helicobacter pylori eradication therapy in terms of symptomatic response in patients with functional dyspepsia. On the other hand, we analyzed the importance of histologic findings as a predictor of treatment response. In particular, we studied whether antral gastritis (which is associated with peptic ulcer may predict a greater symptomatic response to Helicobacter pylori eradication in functional dyspepsia. Patients and methods: this prospective, randomized, single-center trial included 48 patients with functional dyspepsia and

  14. LOS PREVISIBLES EFECTOS DE LA NIC 32 EN EL SECTOR COOPERATIVO/THE PREDICTABLE EFFECTS OF THE NIC 32 IN THE COOPERATIVE SECTOR

    Directory of Open Access Journals (Sweden)

    Carlos VARGAS VASSEROT

    2007-01-01

    Full Text Available De la NIC 32 se desprende que las aportaciones de los socios al capital se reconocerán como patrimonio neto sólo si la cooperativa tiene un derecho incondicional a rehusar su reembolso. Lo que ocurre es que nuestro ordenamiento cooperativo, en aras de proteger al máximo al socio, incluso frente al riesgo de amenazar la estabilidad de la cooperativa, históricamente ha reconocido un derecho cuasi absoluto al reembolso de sus aportaciones, que la cooperativa tiene que atender aunque esto signifique tener que reducir el capital estatutario o incluso la disolución de la misma. Esto, tal como está en nuestra legislación cooperativa reconocido el derecho al reembolso de las aportaciones del socio, que aunque es posible someterlo a una serie de limitaciones impuestas temporales e incluso cuantitativa, no se puede impedir su ejercicio, significa que todas las aportaciones al capital social de las cooperativas que hayan hecho o que hagan los socios deberán ser calificados a efectos contables como pasivos exigibles y no como hasta ahora como recursos propios. Por tanto, en el ordenamiento cooperativo español, si se quiere evitar que todas las aportaciones de los socios al capital cooperativo sean consideradas recursos ajenos, es necesario realizar una serie de modificaciones legales en la articulación del derecho de reembolso y en el propio régimen del capital social. En el presente estudio se abordará la proyectada reforma de la Ley 27/1999 de Cooperativas para adaptarse al contenido de la NIC 32 y se estudiarán cuáles son las consecuencias de calificar contablemente las aportaciones sociales de los socios como recursos ajenos y no como neto patrimonial como hasta ahora habíamos hecho. /According the IAS 32 co-operative social shares will no longer be considered as elements of capital. They will be recognised as net worth just if the co-operative has an unconditional right to reject its redemption. However, in order to protect to members

  15. EFFECTS OF COMPACTIVE EFFORTS ON GEOTECHNICAL PROPERTIES OF SPENT ENGINE OIL CONTAMINATED LATERITE SOIL

    Directory of Open Access Journals (Sweden)

    OLUREMI, J. ROTIMI

    2017-03-01

    Full Text Available Investigation of the effects of compactive efforts and spent engine oil (SEO contamination on the geotechnical properties of lateritic soils was made. Contaminated specimens were prepared by mixing lateritic soil with up to 10 % SEO by dry weight of the soil in step concentration of 2 % and subjected to geotechnical tests. Results indicated a decrease in the fine content, decrease in liquid limit, maximum dry density (MDD and unconfined compressive strength (UCS with up to 10 % SEO content. No general trend was observed in the optimum moisture content (OMC with increasing SEO content. The MDD, OMC and UCS values increased with increase in the compactive effort. Regression analysis of the results showed that optimum moisture content, fine content and compactive effort significantly influence the soils UCS values. Analysis of variance showed that SEO and compactive effort has significant effect on the parameters with the exception in one case. The results of laboratory tests showed that geotechnical properties of the SEO contaminated soil were immensely impaired.

  16. Individual, population and community level effects of subtle anthropogenic contamination in estuarine meiobenthos

    International Nuclear Information System (INIS)

    Rubal, Marcos; Guilhermino, Lucia M.; Medina, Matias H.

    2009-01-01

    The study presented here searched for the level of taxonomic resolution required to detect the effects of low-level chronic pollution on estuarine meiobenthic communities. Meiofauna from two sites, with special attention to harpacticoid copepods, was analysed at different taxonomic levels of aggregation using uni- and multivariate methods. Adaptation processes that could buffer biodiversity disruptions were also considered through the analysis of fitness-related and tolerance traits in the harpacticoid copepod Paronychocamptus nanus. Results showed that uni- and multivariate analyses could be inadequate when assessing subtle anthropogenic contamination. Instead, the assessment of inter-population differences in tolerance to the main source of stress rises as a required procedure if potential effects of this type of contamination are being investigated. Specifically, a 96 h acute toxicity test performed with populations from the affected site appears as a faster and reliable general tool to assess impacts of low-level chronic pollution in estuaries. - Tolerance of local populations as a reliable tool to assess impacts of subtle anthropogenic contamination in estuaries.

  17. Individual, population and community level effects of subtle anthropogenic contamination in estuarine meiobenthos

    Energy Technology Data Exchange (ETDEWEB)

    Rubal, Marcos [CIIMAR/CIMAR-LA - Centro Interdisciplinar de Investigacao Marinha e Ambiental, Universidade do Porto, Laboratorio de Ecotoxicologia, Rua dos Bragas 289, 4050-123 Porto (Portugal); Guilhermino, Lucia M. [CIIMAR/CIMAR-LA - Centro Interdisciplinar de Investigacao Marinha e Ambiental, Universidade do Porto, Laboratorio de Ecotoxicologia, Rua dos Bragas 289, 4050-123 Porto (Portugal); ICBAS - Instituto de Ciencias Biomedicas de Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Lg. Prof. Abel Salazar 2, 4099-003 Porto (Portugal); Medina, Matias H., E-mail: matias.medina@avs-chile.c [AVS Chile SA, Imperial 0655, Off. 3A, Puerto Varas (Chile); Centro i-mar, Universidad de Los Lagos, Camino Chinquihue km 6, Puerto Montt (Chile)

    2009-10-15

    The study presented here searched for the level of taxonomic resolution required to detect the effects of low-level chronic pollution on estuarine meiobenthic communities. Meiofauna from two sites, with special attention to harpacticoid copepods, was analysed at different taxonomic levels of aggregation using uni- and multivariate methods. Adaptation processes that could buffer biodiversity disruptions were also considered through the analysis of fitness-related and tolerance traits in the harpacticoid copepod Paronychocamptus nanus. Results showed that uni- and multivariate analyses could be inadequate when assessing subtle anthropogenic contamination. Instead, the assessment of inter-population differences in tolerance to the main source of stress rises as a required procedure if potential effects of this type of contamination are being investigated. Specifically, a 96 h acute toxicity test performed with populations from the affected site appears as a faster and reliable general tool to assess impacts of low-level chronic pollution in estuaries. - Tolerance of local populations as a reliable tool to assess impacts of subtle anthropogenic contamination in estuaries.

  18. Effects of PCB contamination on the reproduction of the DAB Limanda limanda L. under laboratory conditions

    Science.gov (United States)

    Fonds, Mark; Casal, Elizabeth; Schweizer, Dominik; Boon, Jan P.; Van der Veer, Henk W.

    The effect of PCB contamination on the reproduction of female dab was studied under laboratory conditions. Females were contaminated during gonad maturation by multiple oral administration of capsules containing the technical PCB mixture Clophen A40. PCB contamination resulted in increased levels in the eggs, with concentrations of selected PCB congeners of 35 to 86 μg·g -1 lipid for PCB-exposed fish, 10 μg·g -1 lipid for eggs from fish fed with mussel meat and fish fed with shrimp. A statistically significant dose-effect relationship was found between the PCB content of the eggs and the PCB dose ingested by the fish. For eggs from the PCB-treated fish the mean fertilization rate was 61% and mean hatching 45%, compared to 67% fertilization and 59% hatching for eggs from untreated fish. Rate of development and survival of the eggs and mortality of the larvae after hatching were mainly related to incubation temperature. No statistically significant differences between untreated and PCB-treated fish could be found in egg production, egg quality, fertilization rate, hatching rate and survival of larvae.

  19. Effect of Rhizosphere Enzymes on Phytoremediation in PAH-Contaminated Soil Using Five Plant Species

    Science.gov (United States)

    Liu, Rui; Dai, Yuanyuan; Sun, Libo

    2015-01-01

    A pot experiment was performed to study the effectiveness of remediation using different plant species and the enzyme response involved in remediating PAH-contaminated soil. The study indicated that species Echinacea purpurea, Festuca arundinacea Schred, Fire Phoenix (a combined F. arundinacea), and Medicago sativa L. possess the potential for remediation in PAH-contaminated soils. The study also determined that enzymatic reactions of polyphenol oxidase (except Fire Phoenix), dehydrogenase (except Fire Phoenix), and urease (except Medicago sativa L.) were more prominent over cultivation periods of 60d and 120d than 150d. Urease activity of the tested species exhibited prominently linear negative correlations with alkali-hydrolyzable nitrogen content after the tested plants were cultivated for 150d (R2 = 0.9592). The experiment also indicated that alkaline phosphatase activity in four of the five tested species (Echinacea purpurea, Callistephus chinensis, Festuca arundinacea Schred and Fire Phoenix) was inhibited during the cultivation process (at 60d and 120d). At the same time, the study determined that the linear relationship between alkaline phosphatase activity and effective phosphorus content in plant rhizosphere soil exhibited a negative correlation after a growing period of 120d (R2 = 0.665). Phytoremediation of organic contaminants in the soil was closely related to specific characteristics of particular plant species, and the catalyzed reactions were the result of the action of multiple enzymes in the plant rhizosphere soil. PMID:25822167

  20. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    CERN Document Server

    Martins, D R; Verdonck, P; Brown, I G

    2002-01-01

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

  1. Soil science basis and the effect of oil contamination on chemical properties of soils

    International Nuclear Information System (INIS)

    Wagner, A.; Miehlich, G.

    1993-01-01

    The changes in soil chemistry properties due to oil contamination and decontamination are examined. One main point of the work is the determination of the effect of oil on the availability of nutrients in the soil. Nutrients are not only present dissolved in the soil solution, but are for the most part reversibly adsorbed by exchangers on loaded surfaces. The clay minerals, the organic substance and iron and manganese oxide act as exchangers. Knowledge on surface structure and reactions in soils contaminated by oil is to be obtained via examination of the exchange behaviour of different bio-elements. The results supply the basis for the cleaning up technique, the judgement of cleaned materials and their reusability. (orig.) [de

  2. Effect of low-cost irrigation methods on microbial contamination of lettuce irrigated with untreated wastewater

    DEFF Research Database (Denmark)

    Keraita, Bernard; Konradsen, Flemming; Drechsel, P.

    2007-01-01

    OBJECTIVE: To assess the effectiveness of simple irrigation methods such as drip irrigation kits, furrow irrigation and use of watering cans in reducing contamination of lettuce irrigated with polluted water in urban farming in Ghana. METHODS: Trials on drip kits, furrow irrigation and watering...... cans were conducted with urban vegetable farmers. Trials were arranged in a completely randomised block design with each plot having all three irrigation methods tested. This was conducted in both dry and wet seasons. Three hundred and ninety-six lettuce, 72 soil, 15 poultry manure and 32 water samples...... were analysed for thermotolerant coliforms and helminth eggs. RESULTS: Lettuce irrigated with drip kits had the lowest levels of contamination, with, on average, 4 log units per 100 g, fewer thermotolerant coliforms than that irrigated with watering cans. However, drip kits often got clogged, required...

  3. Potential Ecological Effects of Contaminants in the Exposed Par Pond Sediments

    International Nuclear Information System (INIS)

    Paller, M.H.; Wike, L.D.

    1996-08-01

    Sediment and small mammal samples were collected from the exposed sediments of Par Pond in early 1995, shortly before the reservoir was refilled after a 4-year drawdown. Sampling was confined to elevations between 58 and 61 meters (190 and 200 feet) above mean sea level, which includes the sediments likely to be exposed if the Par Pond water level is permitted to fluctuate naturally. Both soil and small mammal samples were analyzed for a number of radionuclides and metals. Some of the soil samples were also analyzed for organic contaminants. The objective of the study was to determine if contaminant levels in the Par Pond sediments were high enough to cause deleterious ecological effects

  4. Effect of soil contamination with oil substances on the growth of selected plants

    International Nuclear Information System (INIS)

    Sara, V.; Kult, L.; Vavra, J.

    1993-12-01

    The growth of barley, maize, wheat and alfalfa was studied in dependence on the level of soil pollution with crude oil. Attention was also paid to the effect of such contamination on the vanadium and nickel contents of the above-ground parts of the plants. Experiments revealed that, with the exception of alfalfa, the vanadium content of plants which had been grown in the contaminated soil was about one-half with respect to the values observed in plants grown in uncontaminated soil, and the nickel content was also lower than in control plants. Introduced into the soil by injection in concentrations of 180 to 500 ppm, crude oil was found to induce local damage in the plants, resulting in a smaller size of the plants and a delayed or missing earing phase, with repercussions on the grain size and quantity. (J.B.). 2 tabs., 6 figs

  5. Effect of Long-Term Zinc Pollution on Soil Microbial Community Resistance to Repeated Contamination

    OpenAIRE

    Klimek, Beata

    2012-01-01

    The aim of the study was to compare the effects of stress (contamination trials) on the microorganisms in zinc-polluted soil (5,018 mg Zn kg−1 soil dry weight) and unpolluted soil (141 mg Zn kg−1 soil dw), measured as soil respiration rate. In the laboratory, soils were subjected to copper contamination (0, 500, 1,500 and 4,500 mg kg−1 soil dw), and then a bactericide (oxytetracycline) combined with a fungicide (captan) along with glucose (10 mg g−1 soil dw each) were added. There was a highl...

  6. Electrodialytic Remediation of Pb Contaminated Soil - Effects of Soil Properties and Pb Distribution

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Jensen, Pernille Erland

    1999-01-01

    The aim of this work was to investigate the effects of soil properties and Pb distribution on the electrodialytic remediation of Pb contaminated soil. Two naturally Pb contaminated soils were compared with respect to total Pb content, Pb distribution, pH, carbonate content, clay content and organic...... matter, and an electrodialytic remediation experiment was made on each soil.It was concluded that soil pH was the most important factor limiting the mobilisation of Pb. In one of the remediation experiments it was possible to mobilise and reduce the amount of Pb significantly, whereas in the other only...... a small amount of the initial Pb was mobilised at similar experimental conditions. A high buffering capacity of one of the soils, which was partly due to a high carbonate content, led to a bad remediation result....

  7. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    International Nuclear Information System (INIS)

    Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.

    2002-01-01

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the stopping and range of ions in matter code. We find film contamination of the order of 10 -4 -10 -3 , and the memory of the prior history of the deposition hardware can be relatively long lasting

  8. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    Energy Technology Data Exchange (ETDEWEB)

    Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.

    2002-08-13

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

  9. La eficacia del efecto látigo en el drag flick en el hockey hierba The effectiveness of the bullwhip effect in the Drag-flick in field hockey

    Directory of Open Access Journals (Sweden)

    C. López de Subijana

    2010-09-01

    Full Text Available

    El penalty córner es una de las jugadas más importantes en el hockey hierba. El drag-flick es la técnica de golpeo más eficaz en las jugadas de penalty córner (McLaughin, 1997. Los objetivos del presente estudio fueron el describir los parámetros cinemáticos del drag-flick en jugadores de nivel internacional y analizar las diferencias intergénero. La muestra fueron trece sujetos, un modelo, seis hombres y seis mujeres. El sistema de captura automático VICON registró 20 lanzamientos de cada jugador con una frecuencia de muestreo de 250 Hz. Las velocidades máximas angulares de las caderas, hombros y stick  fueron superiores  (p<0.01 en el modelo que en ambos grupos de género. Mediante la comparación estadística del modelo con ambos grupos de género se han podido determinar las claves de este gesto técnico, siendo necesario un movimiento hacia atrás del stick (efecto látigo antes de la aceleración de caderas y hombros, para terminar el gesto con la máxima aceleración del stick.
    Palabras Clave: Biomecánica, drag-flick, hockey hierba, cinemática

    The penalty corner is one of the most important goal plays in field hockey. The drag-flick is more efficient than other techniques when playing a penalty corner. The aims of this study were to describe the kinematics of international field hockey players during the drag-flick and to analyse gender differences. Thirteen participants, one male drag-flicker, six males and six females participated in the study. VICON optoelectronic system measured the kinematic parameters from the drag-flick with six cameras sampling at 250 Hz. Twenty trials were captured from each subject. Ball velocity at release, hips maximum angular velocity, stick minimum and maximum angular velocities were higher (p<0.01 in the drag-flicker than in both gender groups. Comparing with the drag-flicker we have found the cues of the skill, being necessary a

  10. Conformation evolution of oil contaminants onto aluminum oxide surface in aqueous solution: The effect of surface coverage

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wenkun; Liu, Haitao, E-mail: xwk584523412@126.com; Sun, Yazhou; Fu, Hongya; Liang, Yingchun

    2017-01-15

    Highlights: • The dynamic conformational change of oil contaminations, at various surface coverages onto perfect α-Al{sub 2}O{sub 3}(0001) surface in aqueous solution is given. • The effect of surface coverage of oil molecules on the driving forces for the conformational change of oil contaminations is described. • The effect of interfacial water on the conformational change and even detachment of oil contaminations is considered. - Abstract: The microscopic conformational change process of oil contaminants adhered onto perfect α-Al{sub 2}O{sub 3} (0001) surface in aqueous solution was investigated by using all-atom classic molecular dynamics simulations. The change in removal mechanism of oil contaminants induced by surface coverage (surface area per molecule) was emphatically explored. Our simulation results strongly reveal that the increase in oil surface coverage induces an evident difference in microscopic detachment processes of oil contaminants. At a low surface coverage, oil contaminants can be thoroughly detached from solid surface. The whole detachment process could be divided into multi stages, including conformational change of oil contaminants on solid surface, dynamic motion of those in bulk solution and rapid migration of those from bulk solution to air/water interface. With surface coverage increasing, water diffusion becomes the key to induce conformational change and promote the detachment of oil contaminants. When oil surface coverage exceeds a threshold value, oil contaminants also undertake an evident conformational change process exhibiting typical characteristics but an incomplete detachment process occurs. All findings of the present study are helpful for the interpretation of the removal mechanism of oil contaminants on solid surface.

  11. Changes in the utilization of residential energy in nine countries of the OECD and its possible effects in Mexico; Cambios en el uso de la energia residencial en nueve paises de la OECD y sus posibles efectos en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Schipper, Lee; Sheinbaum, Claudia [Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1994-12-31

    This paper analyzes the changes in the residential energy utilization in nine countries of the Organization for Economic Co-operation and Development (OECD) between 1973 and 1990. An analysis is presented for the end uses and the changes for the periods 1973-1979, 1979-1985 and 1985-1990 are studied. The influence of the energy saving and conservation programs as well as the changes in the price of the energy is also discussed. It is also described how in the last period the rate of decrement in the energy intensity has diminished due to the lower energy prices. Finally the potential effects of this experience in the Third World Countries, specially in Mexico, are studied. [Espanol] En este trabajo se analizan los cambios en el uso de la energia residencial en nueve paises de la Organizacion para la Cooperacion y el Desarrollo Economico (OECD) entre 1973 y 1990. Se presenta un analisis por usos finales y se estudian los cambios en los periodos 1973-1979, 1979-1985 y 1985-1990. Se discute la influencia de los programas de ahorro y conservacion asi como de los cambios en el precio de la energia. Se describe como en el ultimo periodo la tasa de decremento de la intensidad energetica ha disminuido debido al bajo precio de la energia. Finalmente se discuten los posibles efectos de esta experiencia en los paises del Tercer Mundo, en especial en Mexico.

  12. Del espectáculo cultural y sus efectos: arte y políticas culturales en Santiago de Compostela = The cultural spectacle and its effects: arts and cultural policies in Santiago de Compostela

    Directory of Open Access Journals (Sweden)

    Miguel Anxo Rodríguez González

    2015-01-01

    Full Text Available En los años noventa Santiago de Compostela se convirtió en un ejemplo destacado de aplicación de políticas culturales a gran escala. Con una generosa financiación se llevaron a cabo proyectos arquitectónicos y programaciones culturales ambiciosas. Aunque la valoración general de sus efectos, a nivel urbanístico y económico, es muy positiva, en el ámbito específico de las artes las opiniones son encontradas. Esta investigación intenta dilucidar cuales fueron las repercusiones de estas políticas en el campo de las artes plásticas, a partir de una aproximación a los debates en el seno de la comunidad de creadores y gestores de espacios culturales.In the nineties Santiago de Compostela became a prominent implementing of largescale cultural policies example. With generous funding, ambitious architectural projects and cultural programs were conducted. Although the overall assessment of their effects on urban and economic level is very positive, in the specific field of arts opinions are problematic. This research aims to clarify the implications of these policies in the field of visual arts, from an approach to the debates within the community of creators and managers of cultural spaces.

  13. Efecto de la Adición de dos Tipos de Almidones en las Propiedades Texturales de Queso Análogo / Effect of the Addition of Two Types of Starch in the Textural Properties of Analogue Cheese

    Directory of Open Access Journals (Sweden)

    Jacqueline Agudelo Chaparro

    2014-12-01

    Full Text Available Resumen. Se estudió el efecto que tienen dos tipos de almidónmodificado, maíz ceroso y papa, en las propiedades texturalesde un queso análogo con fibra prebiótica soluble. Se elaboraronquesos semiblandos, con humedad de 48%, reemplazando el10% de proteína por los almidones modificados, dando lugar atres tratamientos: Formulación control (FC, formulación maízceroso (FMC y formulación papa (FP. Se observó que la adiciónde los almidones afecta significativamente (P<0,05 la dureza, laadhesividad, la gomosidad, la elasticidad y la masticabilidad delproducto. /  Abstract. The effect they have two types of modified starch (waxycorn and potato in the textural properties of an analogue cheesewas studied. Semi-soft cheeses were made with 48% moisture,replacing the 10% protein by modified starches, resulting in threetreatments: Control formulation (CF, waxy corn formulation(WCF and potato formulation (PF. The study allowed note thatthe addition of starches significantly affect (P<0.05 the hardness,adhesiveness, gumminess, elasticity and chewiness of the product

  14. Efecto antioxidante del extracto acuoso de propóleos sobre la hepatotoxicidad inducida por el octilfenol en ratas macho Antioxidant effect of aqueous extract of propolis on hepatotoxicity induced by octylphenol in male rats

    Directory of Open Access Journals (Sweden)

    Eman M Saleh

    2012-12-01

    Full Text Available El 4-terc-octilfenol (4-terc-OP es un alquilfenol que afecta a la salud humana mediante la estimulación de la producción de radicales libres. El extracto acuoso de propóleos es un producto natural rico en favonoides que tienen actividad antioxidante. Este estudio fue diseñado para investigar la capacidad del extracto de propóleos de reducir la hepatotoxicidad inducida por el 4-terc-OP en ratas macho. Los animales fueron asignados a 5 grupos y tratados durante 6 semanas. Grupo 1: control; grupo 2: 100 mg de 4-terc-OP/kg/día; grupo 3: 100 mg de extracto de propóleos/kg/día; grupo 4: 100 mg de 4-terc-OP/ kg/día más 100 mg de extracto de propóleos/kg/día, grupo 5: 100 mg de 4-terc-OP/kg/día durante 6 semanas, seguidos de 100 mg de extracto de propóleos/kg/día durante 6 semanas. El grupo 4-terc-OP mostró niveles signifcativamente elevados de AST, ALT, ALP, GGT, bilirrubina, creatinina, urea, lípidos totales, colesterol total, triglicéridos, LDL-C y MDA, con una disminución signi-fcativa de proteínas totales, albúmina, globulina, HDL-C, la capacidad antioxidante total, SOD, CAT y GST, en comparación con el grupo control. La administración de extracto de propóleos, ya sea solo o combinado con 4-terc-OP redujo la hepatotoxicidad inducida por 4-terc-OP. Los estudios de fragmentación del ADN apoyan el efecto deletéreo observado por el tratamiento con 4-terc-OP y el efecto protector del extracto de propóleos, sobre las proteínas y las enzimas celulares hepáticas. Los resultados histopatológicos revelaron la hepatotoxicidad por 4-terc-OP y efecto protector inducido por el extracto de propóleos. En conclusión, el extracto de propóleos podría reducir el daño hepático y los efectos celulares de toxicidad en las células del hígado inducidos por 4-terc-OP.4-tertiary-octylphenol (4-tert-OP is an alkylphenol that affects human health by stimulating free radical production. Aqueous propolis extract is a natural product rich in

  15. Acceptability and perceived side effects of insecticide indoor residual spraying under different resistance management strategies Aceptabilidad y efectos secundarios percibidos del rociado residual intradomiciliario de insecticidas bajo diferentes esquemas de manejo de resistencia

    Directory of Open Access Journals (Sweden)

    Américo David Rodríguez

    2006-08-01

    Full Text Available OBJECTIVE: To assess household acceptability and perceived side effects of residual indoor pyrethroid (PYR, carbamate and organophosphate insecticides sprayed by annual rotation (ROT, spatial mosaic (MOS, and a single insecticide (DDT or PYR in communities of the coastal plain of Chiapas, Mexico. MATERIAL AND METHODS: A questionnaire to assess the acceptability and perceived side effects of indoor insecticides was administered to one member of 30% of the families in eight villages of Chiapas. The association of different insecticide treatments with their responses was evaluated (Chi-square. The intensity of side effects indicated under different treatments was compared in an ordered logistic model, using a severity index as the response variable. RESULTS: Insecticide spraying as a probable cause of symptoms was identified by 2.1% of interviewees. A significantly high percentage of persons with blurred vision, dizziness, sneezing, coughing, numbness, watery eyes, and itching lived in villages under MOS and ROT and a high severity index was significantly associated with ROT treatment. Reduction of mosquito bites and cockroaches were the perceived main benefits, and most villagers that perceived no benefits lived in DDT treated villages. Most of the interviewees welcomed spraying (83.7%, but the smell and having to remove furniture from houses were the main arguments against it. CONCLUSIONS: Acceptability correlated with insecticide spray coverage, although the most frequent suggestion for improvement was to increase the understanding of the objectives of spraying in the communities. The frequency of side effects was low, but higher in localities where a combination of insecticides was applied. This is a limitation for the use of this type of resistance management strategy in public health.OBJETIVO: Evaluar la aceptabilidad y los efectos secundarios del rociado intradomiciliar de insecticidas pyrethroides (PYR, carbamato y organophosphato rociados

  16. Changes in the utilization of residential energy in nine countries of the OECD and its possible effects in Mexico; Cambios en el uso de la energia residencial en nueve paises de la OECD y sus posibles efectos en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Schipper, Lee; Sheinbaum, Claudia [Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1993-12-31

    This paper analyzes the changes in the residential energy utilization in nine countries of the Organization for Economic Co-operation and Development (OECD) between 1973 and 1990. An analysis is presented for the end uses and the changes for the periods 1973-1979, 1979-1985 and 1985-1990 are studied. The influence of the energy saving and conservation programs as well as the changes in the price of the energy is also discussed. It is also described how in the last period the rate of decrement in the energy intensity has diminished due to the lower energy prices. Finally the potential effects of this experience in the Third World Countries, specially in Mexico, are studied. [Espanol] En este trabajo se analizan los cambios en el uso de la energia residencial en nueve paises de la Organizacion para la Cooperacion y el Desarrollo Economico (OECD) entre 1973 y 1990. Se presenta un analisis por usos finales y se estudian los cambios en los periodos 1973-1979, 1979-1985 y 1985-1990. Se discute la influencia de los programas de ahorro y conservacion asi como de los cambios en el precio de la energia. Se describe como en el ultimo periodo la tasa de decremento de la intensidad energetica ha disminuido debido al bajo precio de la energia. Finalmente se discuten los posibles efectos de esta experiencia en los paises del Tercer Mundo, en especial en Mexico.

  17. Efeitos do treinamento resistido sobre a pressão arterial de idosos Efectos del entrenamiento de resistencia sobre la presión arterial de añosos Effects of resistance training on blood pressure in the elderly

    Directory of Open Access Journals (Sweden)

    Andréia Cristiane Carrenho Queiroz

    2010-07-01

    de presión arterial de reposo, siendo importante analizar los efectos del ejercicio de resistencia sobre la presión arterial de individuos añosos. El objetivo de este estudio es evaluar el conocimiento científico existente sobre la respuesta de la presión arterial a los ejercicios de resistencia y sus mecanismos en añosos. Para esto, se realizó una revisión bibliográfica basada en la literatura portuguesa e inglesa relacionadas al tema. Con base en los estudios encontrados, el corpus actual, a pesar de ser escaso y controvertido, sugiere que, de forma crónica, los ejercicios de resistencia pueden tener efecto hipotensor en individuos añosos. Entre tanto, este efecto ocurre, principalmente en añosos normotensos y con entrenamiento de baja intensidad. Los mecanismos envueltos en esa respuesta hipotensora todavía precisan ser elucidados. Aunque el entrenamiento con resistencia esté siendo recomendado para añosos y haya algunos indicativos de que pueda tener efecto hipotensor crónico, todavía hay carencia de datos científicos y muchas controversias en el asunto, lo que evidencia que éste todavía es un campo abierto a la investigación.The aging process drastically reduces muscle mass, strength and power, decreasing the capacity to perform the activities of daily living. The practice of resistance exercises can reverse this picture, helping to maintain the muscular mass and improving muscular strength and resistance. However, the aging process causes cardiovascular alterations, which can result in increased blood pressure levels at rest and it is important to analyze the effects of resistance exercises on the blood pressure of elderly individuals. The objective of this study is to evaluate the current scientific knowledge on the responses of the blood pressure to resistance exercises and their mechanisms in elderly individuals. In order to do that, we carried out a literature review related to the theme, in both Portuguese and English. Based on the

  18. Effects of teacher expectations on the development of verbal creativity in childhood education / Efectos de las expectativas docentes sobre el desarrollo de la creatividad verbal en la educación infantil

    Directory of Open Access Journals (Sweden)

    Franco Justo, Clemente

    2008-12-01

    Full Text Available Abstract: In this study, we have assessed the effect that teachers’ positive expectations may have on their student’s verbal creativity. To this end, we have worked with an experimental teacher who holds high expectations of the creativity of students, and a control teacher, where this was not the case and whose positive, favourable expectations of pupils were not high. The statistical analyses carried out have showed a significant increase in the verbal creativity variables evaluated (fluency, flexibility and originality in the experimental group in comparison to the scores of the control group.Resumen:En este estudio se evaluó el efecto que una expectativa positiva y favorable por parte del docente podía tener sobre los niveles de creatividad verbal de sus estudiantes. Para ello se contó con la participación de un grupo experimental en el cual se trató de implantar una alta expectativa sobre los niveles de creatividad de sus alumnos, y un grupo control donde no se creó dicha expectativa positiva. Los análisis estadísticos realizados mostraron un incremento significativo en el grupo experimental en las diferentes variables de creatividad verbal evaluadas (fluidez, flexibilidad y originalidad, al comparar sus puntuaciones con las del grupo control.

  19. Effect of Maize Hybrid Maturity and Grain Hardness on Fumonisin and Zearalenone Contamination

    Directory of Open Access Journals (Sweden)

    Amedeo Reyneri

    2011-02-01

    Full Text Available The level of resistance in commercial hybrids for Fusarium ear rot is still not in general adequate to prevent unacceptable toxin concentrations in field. The purpose of this experiment was to verify the behaviour of commercial dent maize hybrids for fumonisin and zearalenone contamination and to identify the variety traits that influence the production of these toxins. Field experiments were carried out in 2000, 2001 and 2002 to evaluate the effect of maize hybrid maturity and endosperm hardness on European Corn Borer (ECB incidence, fungal ear rot incidence and severity and on fumonisin B1 and zearalenone contents. Nineteen yellow soft commercial hybrids, from the 500, 600 and 700 FAO maturity groups, were compared in 4 sites in NW Italy. Hybrid were grouped in 3 endosperm hardness categories (hard, intermediate, soft in function of Hard/Soft (H/S endosperm ratio. No effect due to endosperm hardness or hybrid maturity on the ECB infestation or fungal ear rot incidence and severity was observed. Grain hardness significant influenced fumonisin B1 content: hard endosperm hybrids showed 50% lower contamination than soft hybrids. The presence of fumonisin B1 in the grain of different maturity hybrids only resulted to be significantly different in 2001 experiment, with a mean concentration 2 times higher in the later hybrids (FAO rating 700 compared to the medium and medium-late hybrids. The zearalenone content never resulted to be significantly different in function of the endosperm hardness, while, late maturing hybrids, in which grain moisture content decreases slowly below 30%, are more susceptible to zearalenone contamination. This research has highlighted the presence of variety traits that can influence mycotoxin contamination. An accurate choice of hybrid, considering the territorial and cultivation context, could contribute to achieve products, that contain mycotoxins, which do not exceed the maximum international and UE regulation levels.

  20. Transport of Aquatic Contaminant and Assessment of Radioecological Exposure with Spatial and Temporal Effects

    Science.gov (United States)

    Feng, Ying

    1995-01-01

    A comprehensive study of the radioecological exposure assessment for a contaminated aquatic ecosystem has been performed in this dissertation. The primary objectives of this research were to advance the understanding of radiation exposure in nature and to increase current capabilities for estimating aquatic radiation exposure with the consideration of spatial and temporal effect in nature. This was accomplished through the development of a two-dimensional aquatic exposure assessment framework and by applying the framework to the contaminated Chernobyl cooling lake (pond). This framework integrated spatial and temporal heterogeneity effects of contaminant concentration, abundance and distribution of ecosystem populations, spatial- and temporal-dependent (or density-dependent) radionuclide ingestion, and alternative food web structures. The exposure model was built on the population level to allow for the integration of density dependent population regulation into the exposure assessment. Plankton population dynamics have been integrated into the hydrodynamic-transport model to determine plankton biomass density changes and distributions. The distribution of contaminant in water was also calculated using a hydrodynamic-transport model. The significance of adding spatial and temporal effects, spatial and temporal related ecological functions, and hydrodynamics in the exposure assessment was illustrated through a series of case studies. The results suggested that the spatial and temporal heterogeneity effects of radioactive environments were substantial. Among the ecological functions considered, the food web structure was the most important contributor to the variations of fish exposure. The results obtained using a multiple prey food web structure differed by a factor of 20 from the equilibrium concentration, and by a factor of 2.5 from the concentration obtained using a single-prey food web. Impacts of changes in abundance and distribution of biomass on contaminant

  1. Thallium in the marine environment: first ecotoxicological assessments in the Guadalquivir estuary and its potential adverse effect on the donana european natural reserve after the Aznalcollar mining spill (SW Spain); Talio en el medio marino: primera valoracion ecotoxicologica en el estuario del Guadalquivir y su efecto potencial adverso en la reserva natural de donana despues del vertido minero de Aznalcollar (SW de Espana).

    Energy Technology Data Exchange (ETDEWEB)

    DelValls, T.A [Departamento de Quimica Fisica, Facultad de Ciencias del Mar, Universidad de Cadiz, Puerto Real, Cadiz (Spain); Saenz, V; Arias, A.M; Blasco, J [Instituto de Ciencias Marinas de Andalucia, CSIC, Puerto Real, Cadiz (Spain)

    1999-06-01

    Thallium (Tl) is an extremely toxic but little-studied element in the marine environment and practically no information has been reported on the levels of Tl in marine organisms. After the Aznalcollar mining Spill (April 1998), high levels of metals were put into the environment. This acud-contaminated medium was responsible for the initial pollution effects measured in the Guadiamar River, which is an affluent of the Guadalquivir River and very close to the biggest natural reserve in Europe (Donana). Four different species were used in the monitoring from April to September 1998 and a sediment field bioassay to check bioacumulation was performed. We present the first ecotoxicological evaluation of the mining spill in the Guadalquivir River, with reference to Tl, a little-known metal. Also, Pb and Cd data were compared to Tl during field sediment testing. Results show low levels of this metal in all of the organisms studied and they do not show any increase in the level of this metal, ranging from 40 to 90 ng g{sup -}1, 80 to 210 ng g{sup -}1, 15 to 98 ng g{sup -}1 and 75 to 125 whole body dry weight for Scrobicularia plana, Liza ramada (muscle), Crassostrea angulata and Uca Tangeri, respectively. These are the first field data of Tl concentration measured using estuarine organisms. Field sediment toxicity test results confirm those obtained during the monitoring: Tl is not bioaccumulated by the organisms (C. angulata) used in the test. The sequence in bioaccumulation of metals was Cd > Pb > Tl. Both studies, bioaccumulation and sediment toxicity, should be maintained during the next few years to really evaluate the potential effect of the mining spill on the ecosystem and society. [Spanish] El talio (Tl) es un elemento extremadamente toxico aunque poco estudiado en el medio marino y la informacion sobre niveles de Tl en organismos marinos con anterioridad al presente trabajo es practicamente nula. Despues del vertido minero de Aznalcollar (abril de 1998) se

  2. Toxina botulínica tipo A tópica con iontoforesis para el tratamiento de la hiperhidrosis axilar: Efecto y persistencia Topic type A botulinum toxin with iontophoresis in the treatment of armpit hyperhidrosis: effect and persistency

    Directory of Open Access Journals (Sweden)

    J.F. Silva-Gavarrete

    2011-09-01

    Full Text Available La sobreproducción de sudor se denomina hiperhidrosis (HH y frecuentemente conlleva en el ser humano tanto problemas dermatológicos como de índole social. En la actualidad, existen múltiples tratamientos para controlar la HH axilar, siendo entre ellos el uso de la terapia con Toxina Botulínica tipo A (TXB-A uno de los más efectivos, con la limitante de que la toxina tiene que ser inyectada mediante múltiples punciones en la axila, por lo que tiende a ser un tratamiento rechazado por los pacientes. La iontoforesis es un método que utiliza corriente galvánica y se emplea de forma clínica para la introducción transdermal de medicamentos. Realizamos un ensayo clínico simple ciego sobre 10 pacientes a los que se les aplicó gel inerte mezclado con Toxina Botulínica tipo A (TXB-A de la marca Dysport® mediante una sesión de iontoforesis en una axila al tiempo que en la otra axila se les aplicó la TXB-A de forma tradicional, inyectada. Los resultados fueron evaluados con el Minor Test (Test Yodo-almidón comparativamente en ambas axilas y en cada paciente a los 10 días, 2 meses y 5 meses de la aplicación. Empleamos el mismo número de unidades y la misma dilución de TXB-A tanto para la administrada vía tópica, como para la inyectada. Los resultados presentaron una disminución de la HH axilar en ambas axilas durante todo el estudio, siendo la forma inyectada la que más altos porcentajes de efecto presentó. En general un 74.67% de disminución de la secreción sudoral para la forma tópica con iontoforesis y un 90.33% para la forma inyectada. En cuanto a la duración del efecto, ambas aplicaciones tuvieron resultados estadísticamente significativos para la persistencia del efecto a los 5 meses. Por lo tanto, en base al presente trabajo, concluimos que la TXBA aplicada tópicamente mediante iontoforesis mejora la HH axilar y además presenta una persistencia del efecto de un mínimo de 5 meses.The overproduction of sweat by the

  3. The effect of organic contaminants on the spectral induced polarization response of porous media - mechanistic approach

    Science.gov (United States)

    Schwartz, N.; Huisman, J. A.; Furman, A.

    2012-12-01

    In recent years, there is a growing interest in using geophysical methods in general and spectral induced polarization (SIP) in particular as a tool to detect and monitor organic contaminants within the subsurface. The general idea of the SIP method is to inject alternating current through a soil volume and to measure the resultant potential in order to obtain the relevant soil electrical properties (e.g. complex impedance, complex conductivity/resistivity). Currently, a complete mechanistic understanding of the effect of organic contaminants on the SIP response of soil is still absent. In this work, we combine laboratory experiments with modeling to reveal the main processes affecting the SIP signature of soil contaminated with organic pollutant. In a first set of experiments, we investigate the effect of non-aqueous phase liquids (NAPL) on the complex conductivity of unsaturated porous media. Our results show that addition of NAPL to the porous media increases the real component of the soil electrical conductivity and decreases the polarization of the soil (imaginary component of the complex conductivity). Furthermore, addition of NAPL to the soil resulted in an increase of the electrical conductivity of the soil solution. Based on these results, we suggest that adsorption of NAPL to the soil surface, and exchange process between polar organic compounds in the NAPL and inorganic ions in the soil are the main processes affecting the SIP signature of the contaminated soil. To further support our hypothesis, the temporal change of the SIP signature of a soil as function of a single organic cation concentration was measured. In addition to the measurements of the soil electrical properties, we also measured the effect of the organic cation on the chemical composition of both the bulk and the surface of the soil. The results of those experiments again showed that the electrical conductivity of the soil increased with increasing contaminant concentration. In addition

  4. Aquatic ecosystems within the Chernobyl NPP exclusion zone: radioactive contamination, doses and effects

    International Nuclear Information System (INIS)

    Gudkov, D.I.; Kuzmenko, M.I.; Krot, Y.G.; Kipnis, L.S.; Mardarevich, M.G.; Ponomaryov, A.V.; Derevets, V.V.; Nazarov, A.B.

    2003-01-01

    ecosystems; (4) the possibility to use of hydrobionts as biological indicators of radioactive contamination of water objects; (5) the absorbed dose for aquatic organisms living in water reservoirs with different levels and nature of radioactive contamination; (6) some somatic and citogenetic effects of radiation exposure on hydrobionts within the Chernobyl NPP exclusion zone

  5. Effect of gamma irradiation on microbial contamination and volatile oils of spices

    International Nuclear Information System (INIS)

    Singh, Rita; Tak, B.B.

    1997-01-01

    The effect of different doses of gamma irradiation, viz., 6, 10 and 14 kGy on the microbial contamination and the volatile oil content of coriander whole, coriander ground and cumin was studied. Exposure to 10 kGy was effective in the decontamination of spices. Fungi and coliforms in spices were inactivated on irradiation to a dose of 6 kGy. No significant change in the GC volatile profile of the irradiated spices was observed. (author). 3 refs., 1 fig., 1 tab

  6. [Effect of inorganic amendments on the stabilization of heavy metals in contaminated soils].

    Science.gov (United States)

    Cao, Meng-hua; Zhu, Xi; Liu, Huang-cheng; Wang, Lin-ling; Chen, Jing

    2013-09-01

    Effects of single and mixed inorganic amendments on the stabilization of heavy metals in contaminated soils were investigated. Significant synergistic effects on the stabilization of Zn and Cu were observed with the mixed inorganic amendments of KH2PO4 and Ca(OH)2 in the laboratory test. In the field test, the stabilization ratios of Zn, Cu and Cd were 41.8%, 28.2% and 48.4%, respectively, with the dosage of 0.5 kg x m(-2). The growth of peanut was inhibited by the addition of the inorganic amendments. Meanwhile, the uptake of heavy metals was reduced in peanut.

  7. El efecto fotoeléctrico

    Directory of Open Access Journals (Sweden)

    M. A. Rodríguez-Meza

    2006-01-01

    Full Text Available Se presenta una revisión del trabajo de Albert Einstein de 1905 que popularmente se conoce como del efecto fotoeléctrico, y por el cual se le otorgó el premio Nobel en 1921. Mostramos que para Einstein el efecto en sí no era importante, sino que estaba interesado en entender los procesos de emisión y absorción de radiación por la materia. Veremos también que al entender la termodinámica de la radiación electromagnética en una cavidad en equilibrio térmico a una temperatura dada, Einstein pudo plantear su hipótesis de los quanta que aplicó a tres fenómenos de interés en esos años, entre ellos el efecto fotoeléctrico.

  8. cytogenetic effects in populations of amphibians Rana arvalis living on the radio-contaminated area

    Energy Technology Data Exchange (ETDEWEB)

    Yushkova, E.; Bodnar, I.; Zainullin, V. [Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences (Russian Federation)

    2014-07-01

    The study of the features reactions of the animals a differing complicated individual development (metamorphosis) and living in conditions of radioactive contamination is an important trend in the modern radio-ecology. This information is of interest not only from the point of view of detection the mechanisms of radiobiological effects (hyper-radiosensitivity, hormesis, radio-adaptation, etc.) but also viewpoint of predicting delayed radiation effects that is necessary at account the normalization of technogeneous loading on natural ecosystems. An assessment of the level of cytogenetic damages (single-strand and double-strand DNA breaks) in the blood cells of tadpoles of Rana arvalis living in areas contaminated of wastes radium production (Russia, Komi Republic, Ukhta district) was conducted. Using this biological matter as a bioindicator due to the fact that development amphibian is carried out by metamorphosis and includes larval stage. At this stage post-embryonic development of an individual are the most sensitive to anthropogenic impact. To exclude the effects of other factors (temperature, age-specific peculiarities, overpopulation, etc.) on the formation of DNA damages from the studied reservoirs were taken laying eggs of amphibians (12-15 egg laying from the area) which afterwards are contain in strictly controlled laboratory conditions using water, belt silt, plants of native pond. The reaction of amphibians on the contamination was assessed by the level of DNA damage by method Comet assay was determined. With each egg laying were selected for 7 even-aged individuals. Total for cytogenetic analysis was used 189 individuals. It is shown that in animals that develop on the radio-contaminated area the level of single-strand DNA (alkaline pH version of the Comet assay) was higher than in the control area. According an estimate to the level of double-strand DNA (neutral pH version of the Comet assay) significant differences not was found. The high variability

  9. Harmful effects of DU in the offspring of the military personnel employed in DU contaminated regions

    International Nuclear Information System (INIS)

    Atlagic, N.; Lisov, Lj.; Barjaktarovic, V.; Djurovic, B.; Spasic, Jokic V.

    2008-01-01

    Full text: In 1999, during the NATO attacks on Kosovo, from AT-10 aircraft has been shot over 50000 30-mm projectiles which contained approximately 15 tones of DU. Besides DU, projectiles contained products of DU radioactive decay as well as americium, neptunium, plutonium and technetium. Due to DU contamination military personnel employed near hit targets could be contaminated and irradiated. Besides the harmful effects in exposed military personnel, harmful effects were noticed in their offsprings, too. DU can cause genetic and teratogenic harmful effects in the embryos/fetus. It is concentrated in semen of contaminated males and also can contaminate the embryo/fetus through placenta. DU, as a toxic and radioactive element, can cause variety of harmful effects, but the most important are the effects on DNA which are the cause of many diseases. The aim of this paper is to examine is there any change in the incidence in heritable effects, congenital malformations, malignant diseases, endocrine and immune disorders. For that reason we compared the incidence of these diseases in the offspring's of military personnel born from 1995-1999 (1204) with the children born from 2000-2004 (1131) / and 2005-2008. Our results showed higher incidence of congenital malformations and chromosomal abnormalities (12.55 % vs 4.57 %), with highest incidence of foot deformity-52.04 % and hip deformity. These abnormalities were followed with immunological disorders and dysfunction of the urine bladder. Endocrine diseases were increased too(2.16 % :1.63 %). In this period higher incidence of malignant diseases was not noticed, but in the second period (from 5-9 year) after 1999, higher incidence of malignant hematological diseases was noticed, as well as Down Sy. During the conflicts future parents as well as embryo/fetus are exposed to many harmfulness and it is very hard to separate the influence of each. Considering the fact that the effects of DU, could be delayed and synergistic with

  10. Fundamentos para la clasificación del trigo argentino por calidad: efectos del cultivar, la localidad, el año y sus interacciones Bases for the segregation of Argentine bread wheat by quality: effects of cultivar, location, year and their interactions

    Directory of Open Access Journals (Sweden)

    P.E. Abbate

    2010-06-01

    Full Text Available Regularmente se analiza la producción triguera argentina para conocer su calidad industrial, pero no se comparan formalmente los efectos del cultivar, localidad, año y sus interacciones. El objetivo de este estudio fue cuantificar la magnitud de los efectos de esos factores. Durante tres campañas se realizaron experimentos, en cuatro localidades con ocho cultivares. Se evaluaron peso medio del grano, peso hectolítrico, rendimiento de harina, gluten húmedo, gluten seco, gluten index, concentración de proteína, variables alveográficas, absorción de agua y volumen de pan. Se calculó un índice para definir grupos de calidad. Para comparar el efecto de cada factor, se calculó su coeficiente de variación. Para la mayoría de las variables, los factores presentaron diferencias significativas (P=0,05, los efectos de localidad y año fueron tanto o más importantes que el de cultivar, y la interacción localidad × año fue la de mayor magnitud. La clasificación en grupos de calidad fue afectada por la localidad y el efecto de la localidad cambió entre años. Los resultados justifican incluir la localidad para definir protocolos de producción y para clasificar cultivares y la producción triguera argentina.Regularly, quality analyses of Argentine wheat production are performed in order to know its industrial quality. These analyses are insufficient to compare effects of cultivar, location, year and their interactions. The aim of this work is to quantify the effects of these factors. Eight cultivars were grown in four Argentine locations during three cropping seasons. Ten quality traits were evaluated: mean weight of grain, hectolitric weight, flour yield, wet gluten, dry gluten, gluten index, protein concentration, alveographic variables, water absorption, bread volume. A wheat quality index was calculated and quality groups were established. Coefficient of variation was calculated in order to compare the effect of each factor. For most

  11. The effect of contaminated groundwater on tree growth: A tree-ring analysis

    International Nuclear Information System (INIS)

    LeBlanc, D.C.; Loehle, C.

    1990-10-01

    A study was conducted on the effect of contaminated groundwater seepage on tree growth downslope from F- and H-Area seepage basins of the Savannah River Site. Trees in wetlands along Four Mile Creek began to show localized stress and mortality in the late 1970s. Extreme winter temperatures and high rainfall were ruled out as potential causal factors of tree stress. Drought was shown to affect trees in both contaminated and uncontaminated zones, but trees in uncontaminated areas exhibit better recovery after drought than trees in contaminated areas. Pollution-mediated alteration of soil acidity and aluminum, sodium, and heavy metal concentrations likely acted to predispose trees to decline, with severe drought acting as the trigger for decline initiation and tree death. Thus, a moderate pollution loading, not sufficient to cause visible damage of itself, may create conditions in which sudden, severe decline could result from natural stresses. This mechanism of forest decline is common, and should be considered in evaluations of the impact of pollution on wetland forest systems. 28 refs., 4 figs., 6 tabs

  12. Combined effect of microwave and activated carbon on the remediation of polychlorinated biphenyl-contaminated soil.

    Science.gov (United States)

    Liu, Xitao; Yu, Gang

    2006-04-01

    The application of microwave and activated carbon for the treatment of polychlorinated biphenyl (PCB) contaminated soil was explored in this study with a model compound of 2,4,5-trichlorobiphenyl (PCB29). PCB-contaminated soil was treated in a quartz reactor by microwave irradiation at 2450MHz with the addition of granular activated carbon (GAC). In this procedure, GAC acted as microwave absorbent for reaching high temperature and reductant for dechlorination. A sheltered type-K thermocouple was applied to record the temperature rising courses. It was shown that the addition of GAC could effectively promote the temperature rising courses. The determination of PCB residues in soil by gas chromatography (GC) revealed that rates of PCB removal were highly dependent on microwave power, soil moisture content, and the amount of GAC added. GC with mass spectrum (MS) detector and ion chromatography were employed for the analysis of degradation intermediates and chlorine ions, respectively. It was suggested that microwave irradiation with the assistance of activated carbon might be a potential technology for the remediation of PCB-contaminated soil.

  13. Solanum nigrum grown in contaminated soil: Effect of arbuscular mycorrhizal fungi on zinc accumulation and histolocalisation

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Ana P.G.C. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)]. E-mail: amarques@mail.esb.ucp.pt; Oliveira, Rui S. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)]. E-mail: rsoliveira@mail.esb.ucp.pt; Samardjieva, Kalina A. [Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal)]. E-mail: kas@ibmc.up.pt; Pissarra, Jose [Faculdade de Ciencias da Universidade do Porto, Departamento de Botanica, Rua do Campo Alegre, 1191, 4150-181 Porto (Portugal)]. E-mail: jpissarr@fc.up.pt; Rangel, Antonio O.S.S. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)]. E-mail: arangel@esb.ucp.pt; Castro, Paula M.L. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)]. E-mail: plcastro@esb.ucp.pt

    2007-02-15

    Zn tissue accumulation in Solanum nigrum grown in a non-contaminated and a naturally contaminated Zn matrix and the effect of inoculation with different arbuscular mycorrhizal fungi (AMF) on metal uptake were assessed. S. nigrum grown in the contaminated soil always presented higher Zn accumulation in the tissues, accumulating up to 1622 mg Zn kg{sup -1}. The presence of both Glomus claroideum and Glomus intraradices enhanced the uptake and accumulation of Zn by S. nigrum (up to 83 and 49% higher Zn accumulation, respectively). The main deposits of the metal were found in the intercellular spaces and in the cell walls of the root tissues, as revealed by autometallography, with the inoculation with different AMF species causing no differences in the location of Zn accumulation. These findings indicate that S. nigrum inoculated with selected heavy metal tolerant AMF presents extracting and accumulating capacities, constituting a potentially suitable remediation method for Zn polluted soils. - Zn accumulation by S. nigrum is enhanced by AMF and the metal storage in the tissues at the root level occurs mainly in the cell walls and in the intercellular spaces.

  14. Effect of Some Therapeutic Agents on the Radionuclides Excretion from Internally Contaminated Rats

    International Nuclear Information System (INIS)

    Aziz, M.; Mangood, Sh.A.; Sohsah, M.A.

    2009-01-01

    The present work was oriented to investigate the effectiveness of Prussian blue (PB), vermiculite and diethylenetriaminepentaacetic acid (CaDTPA) as therapeutic agents for the elimination of either 134 Cs or 60 Co from contaminated rats after intake of one of the isotopes. The study was performed by using 48 adult rats divided into 8 identical groups each of six rats having approximately the same body weight. The groups included a reference group, without isotope or therapeutic agent administration, four groups given one of the isotopes and four groups given the isotopes and treated with different therapeutic regimes. The isotope content of the treated and untreated contaminated rats were followed by daily whole body radiometric counting for three weeks. On plotting log % radionuclide retained as a function of time, elapsed between radionuclide administration and radiometric counting, straight lines were obtained. The results indicate that excretion can mostly be represented by two stages; the first is fast followed by a second slow stage. The % radionuclide excreted, the corresponding rate constant and the biological half-life of each stage was estimated. It was found that the application of PB + vermiculite is more efficient, to remove 134 Cs, from contaminated rats, than PB only and CaDTPA is more efficient to remove 60Co. Therefore, it is recommended to use the three therapeutic agents to remove both isotopes when taken simultaneously

  15. Comparison between TG-51 and TRS-398: electron contamination effect on photon beam-quality specification

    International Nuclear Information System (INIS)

    Medina, Antonio Lopez; Teijeiro, Antonio; Salvador, Francisco; Medal, Daniela; Vazquez, Julio; Salgado, Manuel; Carrion, MarIa C

    2004-01-01

    Two dosimetry protocols based on absorbed dose to water have recently been implemented: TG-51 and TRS-398. These protocols use different beam-quality indices. The effect of electron contamination in measurements of %dd(10) x has been proposed as a disadvantage of the TG-51. For actual measurements of %dd(10) x in five clinical beams ) a purging magnet was employed to remove the electron contamination. Also, %dd(10) x was measured in the different ways described in TG-51 for high-energy beams: with a lead foil at 50 cm from the phantom surface, at 30 cm, and for open beam. Moreover, TPR 20,10 was determined. Also, periodic quality-control measurements were used for comparing both quality indices and variation over time, but D 20,10 was used instead of TPR 20,10 and measurements in open beam for the %dd(10) x determination. Considering both protocols, S w,air and k Q were calculated in order to compare the results with the experimental data. Significant differences (0.3% for k Q ) were only found for the two high-energy beams, but when the electron contamination is underestimated by TG-51, the difference in k Q is lower. Differences in the other cases and variations over time were less than 0.1%

  16. Cholinesterase activities in the scallop Pecten jacobaeus: Characterization and effects of exposure to aquatic contaminants

    International Nuclear Information System (INIS)

    Stefano, Bonacci; Ilaria, Corsi; Silvano, Focardi

    2008-01-01

    Nearshore marine environments of industrialized countries are increasingly threatened by anthropogenic pollution. It is therefore a priority task to investigate the sensitivity of new ecotoxicological warning signals of the occurrence and effects of aquatic pollutants. The main aims of the present study were: 1) to characterize the biochemical properties of ChEs in tissues of the bivalve Pecten jacobaeus, using different specific substrates and selective inhibitors; 2) to measure sensitivity of ChE activities to in vitro exposure to the OPs azamethiphos and DFP and to the heavy metals cadmium and zinc. Our final aim was to carry out a preliminary evaluation of the suitability of ChEs measurement in tissues of the scallop for monitoring marine environmental quality and neurotoxic compounds contamination in the Mediterranean Sea. Responses to specific inhibitors have suggested that ChEs in adductor muscle share many characteristics with vertebrate acetylcholinesterase. Dose-dependent inhibition of ChE was observed in response to in vitro exposure to environmental contaminants such as cadmium and azamethiphos. Sensitivity to zinc and DFP was lower. ChEs in P. jacobaeus might therefore have potential as a sensitive biomarker for monitoring marine pollution. Results of the present study will be useful to focus further experiment of exposure to pollutants under in vivo conditions. Capsule: Cholinesterase activities in scallop Pecten jacobaeus were observed to be sensitive to contaminants in vitro and may therefore have potential as biomarkers for monitoring water pollution

  17. Cholinesterase activities in the scallop Pecten jacobaeus: Characterization and effects of exposure to aquatic contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Stefano, Bonacci [Department of Environmental Sciences ' G. Sarfatti' , University of Siena, Via P.A. Mattioli 4, I-53100 Siena (Italy)], E-mail: bonacci@unisi.it; Ilaria, Corsi [Department of Environmental Sciences ' G. Sarfatti' , University of Siena, Via P.A. Mattioli 4, I-53100 Siena (Italy)], E-mail: corsii@unisi.it; Silvano, Focardi [Department of Environmental Sciences ' G. Sarfatti' , University of Siena, Via P.A. Mattioli 4, I-53100 Siena (Italy)], E-mail: focardi@unisi.it

    2008-03-15

    Nearshore marine environments of industrialized countries are increasingly threatened by anthropogenic pollution. It is therefore a priority task to investigate the sensitivity of new ecotoxicological warning signals of the occurrence and effects of aquatic pollutants. The main aims of the present study were: 1) to characterize the biochemical properties of ChEs in tissues of the bivalve Pecten jacobaeus, using different specific substrates and selective inhibitors; 2) to measure sensitivity of ChE activities to in vitro exposure to the OPs azamethiphos and DFP and to the heavy metals cadmium and zinc. Our final aim was to carry out a preliminary evaluation of the suitability of ChEs measurement in tissues of the scallop for monitoring marine environmental quality and neurotoxic compounds contamination in the Mediterranean Sea. Responses to specific inhibitors have suggested that ChEs in adductor muscle share many characteristics with vertebrate acetylcholinesterase. Dose-dependent inhibition of ChE was observed in response to in vitro exposure to environmental contaminants such as cadmium and azamethiphos. Sensitivity to zinc and DFP was lower. ChEs in P. jacobaeus might therefore have potential as a sensitive biomarker for monitoring marine pollution. Results of the present study will be useful to focus further experiment of exposure to pollutants under in vivo conditions. Capsule: Cholinesterase activities in scallop Pecten jacobaeus were observed to be sensitive to contaminants in vitro and may therefore have potential as biomarkers for monitoring water pollution.

  18. The effects of heavy metal contamination on the soil arthropod community of a shooting range

    International Nuclear Information System (INIS)

    Migliorini, Massimo; Pigino, Gaia; Bianchi, Nicola; Bernini, Fabio; Leonzio, Claudio

    2004-01-01

    Soils in clay pigeon shooting ranges can be seriously contaminated by heavy metals. The pellets contained in ammunition are composed of Pb, Sb, Ni, Zn, Mn and Cu. The total concentrations of these metals in soils, and the effects of their increasing levels on the arthropod community were investigated at seven sampling sites in a clay pigeon shooting range and compared with two controls. Research revealed that the spatial distribution of Pb and Sb contamination in the shot-fall area was strongly correlated with the flight path of the pellets. Ordination obtained through Redundance Analysis showed that Collembola, Protura and Diplura were positively correlated with major detected contaminants (Pb, Sb), while Symphyla showed a negative correlation with these pollutants. Determination of the soluble lead fraction in soil, and of its bioaccumulation in the saprophagous Armadillidium sordidum (Isopoda) and the predator Ocypus olens (Coleoptera), showed that a significant portion of metallic Pb from spent pellets is bioavailable in the soil and can be bioaccumulated by edaphic organisms, entering the soil trophic network, but without biomagnification. - Significant relationships were found between lead accumulation in soil from a shooting range and inhabiting arthropod communities

  19. In situ metal ion contamination and the effects on proton exchange membrane fuel cell performance

    Science.gov (United States)

    Sulek, Mark; Adams, Jim; Kaberline, Steve; Ricketts, Mark; Waldecker, James R.

    Automotive fuel cell technology has made considerable progress, and hydrogen fuel cell vehicles are regarded as a possible long-term solution to reduce carbon dioxide emissions, reduce fossil fuel dependency and increase energy efficiency. Even though great strides have been made, durability is still an issue. One key challenge is controlling MEA contamination. Metal ion contamination within the membrane and the effects on fuel cell performance were investigated. Given the possible benefits of using stainless steel or aluminum for balance-of-plant components or bipolar plates, cations of Al, Fe, Ni and Cr were studied. Membranes were immersed in metal sulfide solutions of varying concentration and then assembled into fuel cell MEAs tested in situ. The ranking of the four transition metals tested in terms of the greatest reduction in fuel cell performance was: Al 3+ ≫ Fe 2+ > Ni 2+, Cr 3+. For iron-contaminated membranes, no change in cell performance was detected until the membrane conductivity loss was greater than approximately 15%.

  20. Solanum nigrum grown in contaminated soil: Effect of arbuscular mycorrhizal fungi on zinc accumulation and histolocalisation

    International Nuclear Information System (INIS)

    Marques, Ana P.G.C.; Oliveira, Rui S.; Samardjieva, Kalina A.; Pissarra, Jose; Rangel, Antonio O.S.S.; Castro, Paula M.L.

    2007-01-01

    Zn tissue accumulation in Solanum nigrum grown in a non-contaminated and a naturally contaminated Zn matrix and the effect of inoculation with different arbuscular mycorrhizal fungi (AMF) on metal uptake were assessed. S. nigrum grown in the contaminated soil always presented higher Zn accumulation in the tissues, accumulating up to 1622 mg Zn kg -1 . The presence of both Glomus claroideum and Glomus intraradices enhanced the uptake and accumulation of Zn by S. nigrum (up to 83 and 49% higher Zn accumulation, respectively). The main deposits of the metal were found in the intercellular spaces and in the cell walls of the root tissues, as revealed by autometallography, with the inoculation with different AMF species causing no differences in the location of Zn accumulation. These findings indicate that S. nigrum inoculated with selected heavy metal tolerant AMF presents extracting and accumulating capacities, constituting a potentially suitable remediation method for Zn polluted soils. - Zn accumulation by S. nigrum is enhanced by AMF and the metal storage in the tissues at the root level occurs mainly in the cell walls and in the intercellular spaces

  1. Are exhaust fans effective in reducing contamination to staff from the Technegas ventilation process?

    International Nuclear Information System (INIS)

    Sam, S.; Ring, M.; Chu, J.; Lin, P.

    2002-01-01

    Full text: To investigate the effectiveness of a Nederman exhaust fan (Edward Keller Industrial products Australia) in removing aerosol contamination released from the Technegas generator. A yellow impermeable gown was worn by the technologist administering the Technegas as per departmental protocol. The exhaust fan was used during administration on alternate day. After each ventilation scan the gown was placed into a clear plastic bag and sealed with tape. A new gown was used for each ventilation scan. The gowns were surveyed for contamination using a Geiger counter, then imaged for 5 minutes using a Picker 2000XP dual head camera. This process was repeated for each ventilation scan Factors such as patient compliance, breathing difficulties, age and sex were documented for each study. Twenty patients were studied 11 - without the exhaust fan and 9 with. The use of the exhaust fan has the potential to significantly reduce contamination from Technegas. Routine use should be considered to maintain the As Low As Reasonably Achievable (ALARA) principle. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  2. Effects of anthropogenic heavy metal contamination on litter decomposition in streams – A meta-analysis

    International Nuclear Information System (INIS)

    Ferreira, Verónica; Koricheva, Julia; Duarte, Sofia; Niyogi, Dev K.; Guérold, François

    2016-01-01

    Many streams worldwide are affected by heavy metal contamination, mostly due to past and present mining activities. Here we present a meta-analysis of 38 studies (reporting 133 cases) published between 1978 and 2014 that reported the effects of heavy metal contamination on the decomposition of terrestrial litter in running waters. Overall, heavy metal contamination significantly inhibited litter decomposition. The effect was stronger for laboratory than for field studies, likely due to better control of confounding variables in the former, antagonistic interactions between metals and other environmental variables in the latter or differences in metal identity and concentration between studies. For laboratory studies, only copper + zinc mixtures significantly inhibited litter decomposition, while no significant effects were found for silver, aluminum, cadmium or zinc considered individually. For field studies, coal and metal mine drainage strongly inhibited litter decomposition, while drainage from motorways had no significant effects. The effect of coal mine drainage did not depend on drainage pH. Coal mine drainage negatively affected leaf litter decomposition independently of leaf litter identity; no significant effect was found for wood decomposition, but sample size was low. Considering metal mine drainage, arsenic mines had a stronger negative effect on leaf litter decomposition than gold or pyrite mines. Metal mine drainage significantly inhibited leaf litter decomposition driven by both microbes and invertebrates, independently of leaf litter identity; no significant effect was found for microbially driven decomposition, but sample size was low. Overall, mine drainage negatively affects leaf litter decomposition, likely through negative effects on invertebrates. - Highlights: • A meta-analysis was done to assess the effects of heavy metals on litter decomposition. • Heavy metals significantly and strongly inhibited litter decomposition in streams.

  3. Effectiveness of remediation of metal-contaminated mangrove sediments (Sydney estuary, Australia).

    Science.gov (United States)

    Birch, Gavin; Nath, Bibhash; Chaudhuri, Punarbasu

    2015-04-01

    Industrial activities and urbanization have had a major consequence for estuarine ecosystem health and water quality globally. Likewise, Sydney estuary has been significantly impacted by widespread, poor industrial practices in the past, and remediation of legacy contaminants have been undertaken in limited parts of this waterway. The objective of the present investigation was to determine the effectiveness of remediation of a former Pb-contaminated industrial site in Homebush Bay on Sydney estuary (Australia) through sampling of inter-tidal sediments and mangrove (Avicennia marina) tissue (fine nutritive roots, pneumatophores, and leaves). Results indicate that since remediation 6 years previously, Pb and other metals (Cu, Ni and Zn) in surficial sediment have increased to concentrations that approach pre-remediation levels and that they were considerably higher than pre-settlement levels (3-30 times), as well as at the reference site. Most metals were compartmentalized in fine nutritive roots with bio-concentration factors greater than unity, while tissues of pneumatophores and leaves contained low metal concentrations. Lead concentrations in fine nutritive root, pneumatophore, and leaf tissue of mangroves from the remediated site were similar to trees in un-remediated sites of the estuary and were substantially higher than plants at the reference site. The situation for Zn in fine nutritive root tissue was similar. The source of the metals was either surface/subsurface water from the catchment or more likely remobilized contaminated sediment from un-remediated parts of Homebush Bay. Results of this study demonstrate the problems facing management in attempting to reduce contamination in small parts of a large impacted area to concentrations below local base level.

  4. Effect of milk sample delivery methods and arrival conditions on bacterial contamination rates.

    Science.gov (United States)

    Dinsmore, R P; English, P B; Matthews, J C; Sears, P M

    1990-07-01

    A cross sectional study was performed of factors believed to contribute to the contamination of bovine milk sample cultures submitted to the Ithaca Regional Laboratory of the Quality Milk Promotion Services/New York State Mastitis Control. Of 871 samples entered in the study, 137 (15.7%) were contaminated. There were interactions between the sample source (veterinarian vs dairyman), delivery method, and time between sample collection and arrival at the laboratory. If only those samples collected and hand delivered by the dairyman within 1 day of collection were compared to a like subset of samples collected and hand delivered by veterinarians, no statistically significant differences in milk sample contamination rate (MSCR) were found. Samples were delivered to the laboratory by hand, US Postal Service, United Parcel Service, via the New York State College of Veterinary Medicine Diagnostic Laboratory, or Northeast Dairy Herd Improvement Association Courier. The MSCR was only 7.6% for hand delivered samples, while 26% of Postal Service samples were contaminated. These rates differed significantly from other delivery methods (P less than 0.0001). The USPS samples arrived a longer time after sampling than did samples sent by other routes, and time had a significant effect on MSCR (0 to 1 day, 8.9%; greater than 1 day, 25.9%; P less than 0.01). Samples packaged with ice packs sent by routes other than the Postal Service had a lower MSCR than those not packaged with ice packs, but ice packs did not reduce the MSCR for samples sent by the Postal Service.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Potential effects of groundwater and surface water contamination in an urban area, Qus City, Upper Egypt

    Science.gov (United States)

    Abdalla, Fathy; Khalil, Ramadan

    2018-05-01

    The potential effects of anthropogenic activities, in particular, unsafe sewage disposal practices, on shallow groundwater in an unconfined aquifer and on surface water were evaluated within an urban area by the use of hydrogeological, hydrochemical, and bacteriological analyses. Physicochemical and bacteriological data was obtained from forty-five sampling points based on33 groundwater samples from variable depths and 12 surface water samples. The pollution sources are related to raw sewage and wastewater discharges, agricultural runoff, and wastewater from the nearby Paper Factory. Out of the 33 groundwater samples studied, 17 had significant concentrations of NO3-, Cl- and SO42-, and high bacteria counts. Most of the water samples from the wells contained high Fe, Mn, Pb, Zn, Cd, and Cr. The majority of surface water samples presented high NO3- concentrations and high bacteria counts. A scatter plot of HCO3- versus Ca indicates that 58% of the surface water samples fall within the extreme contamination zone, while the others are within the mixing zone; whereas 94% of groundwater samples showed evidence of mixing between groundwater and wastewater. The bacteriological assessment showed that all measured surface and groundwater samples contained Escherichia coli and total coliform bacteria. A risk map delineated four classes of contamination, namely, those sampling points with high (39.3%), moderate (36.3%), low (13.3%), and very low (11.1%) levels of contamination. Most of the highest pollution points were in the middle part of the urban area, which suffers from unmanaged sewage and industrial effluents. Overall, the results demonstrate that surface and groundwater in Qus City are at high risk of contamination by wastewater since the water table is shallow and there is a lack of a formal sanitation network infrastructure. The product risk map is a useful tool for prioritizing zones that require immediate mitigation and monitoring.

  6. The effect of plants on the degradation and toxicity of petroleum contaminants in soil: a field assessment.

    Science.gov (United States)

    Banks, M K; Schwab, P; Liu, B; Kulakow, P A; Smith, J S; Kim, R

    2003-01-01

    A field project located at the US Naval Base at Port Hueneme, California was designed to evaluate changes in contaminant concentrations and toxicity during phytoremediation. Vegetated plots were established in petroleum (diesel and heavy oil) contaminated soil and were evaluated over a two-year period. Plant species were chosen based on initial germination studies and included native California grasses. The toxicity of the impacted soil in vegetated and unvegetated plots was evaluated using Microtox, earthworm, and seed germination assays. The reduction of toxicity was affected more by contaminant aging than the establishment of plants. However, total petroleum hydrocarbon concentrations were lower by the end of the study in the vegetated plots when compared to the unvegetated soil. Although phytoremediation is an effective approach for cleaning-up of petroleum contaminated soil, a long-term management plan is required for significant reductions in contaminant concentrations.

  7. EFECTOS DEL EMBARAZO ADOLESCENTE EN CHILE

    OpenAIRE

    Loyola Heufemann, AMANDA

    2014-01-01

    Los efectos del embarazo adolescente en Chile han sido poco estudiados aun cuando existe diversa literatura para el resto del mundo, en especial para países desarrollados. Este trabajo estima el efecto del embarazo adolescente sobre la asistencia o completitud de la educación secundaria, años de escolaridad y participación laboral. Usando datos de corte transversal del a˜no 2012 y un enfoque de variable instrumental a trav´es del uso de la entrega comunal de la píldora anticoncept...

  8. Estudio del Efecto de la Altitud sobre el Comportamiento de Motores de Combustión Interna. Parte 1: Funcionamiento Study of the Altitude Effect on Internal Combustion Engine Operation. Part 1: Performance

    OpenAIRE

    Magín Lapuerta; Octavio Armas; John R Agudelo; Carlos A Sánchez

    2006-01-01

    En este trabajo se estudia el efecto de la altitud sobre la potencia en motores de aspiración natural y turbosobrealimentados sin sistemas correctores, en función de la presión ambiental. La altitud sobre el nivel del mar tiene un notable efecto sobre la densidad del aire y su composición. Dado que los motores de combustión interna tienen sistemas de admisión y de inyección de combustible volumétricos, la altitud modifica el ciclo termodinámico de operación, y en consecuencia las prestaciones...

  9. Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on small intestinal morphology of turkeys.

    Science.gov (United States)

    Girish, C K; Smith, T K

    2008-06-01

    An experiment was conducted to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins on morphometric indices of duodenum, jejunum, and ileum in turkeys. The possible preventative effect of a polymeric glucomannan mycotoxin adsorbent (GMA) was also determined. Three hundred 1-d-old male turkey poults were fed wheat, corn, and soybean meal-based starter (0 to 3 wk), grower (4 to 6 wk), developer (7 to 9 wk), and finisher (10 to 12 wk) diets formulated with control grains, contaminated grains, and contaminated grains + 0.2% GMA. Morphometric indices were measured at the end of each growth phase and included villus height (VH), crypt depth, villus width, thicknesses of submucosa and muscularis, villus-to-crypt ratio, and apparent villus surface area (AVSA). At the end of the starter phase, feedborne mycotoxins significantly decreased the VH in the duodenum, and supplementation of the contaminated diet with GMA prevented this effect. The feeding of contaminated grains also reduced (P effects in jejunum and ileum. No effects of diets were seen on morphometric variables at the end of the developer and finisher phases. It was concluded that consumption of grains naturally contaminated with Fusarium mycotoxins results in adverse effects on intestinal morphology during early growth phases of turkeys, and GMA can prevent many of these effects.

  10. Efecto in vitro del D-002 sobre la actividad enzimática de la 5-lipoxigenasa (5-LOX Effect of D-002 on 5-lipooxygenase (5-LOX enzyme activity in vitro

    Directory of Open Access Journals (Sweden)

    Yohani Pérez Guerra

    2012-06-01

    Full Text Available Introducción: el D-002, mezcla de seis alcoholes alifáticos primarios de alto peso molecular purificada de la cera de abejas, ha mostrado efectos antiinflamatorios, sin gastrotoxicidad secundaria, enmodelos experimentales. El tratamiento oral con D-002 reduce las concentraciones de leucotrieno B4 (LTB4 en exudados pleurales de ratas con pleuresía por carragenina, sugiriendo que podría inhibir la actividad enzimática de la 5-lipooxigenasa (5-LOX, si bien los mecanismos de la acción antiinflamatoria del D-002 no habían sido aún explorados. Objetivo: evaluar el efecto in vitro del D-002 sobre la actividad de la 5-LOX, utilizando la fracción citosólica de homogenatos de hígado de ratas. Métodos: las condiciones de ensayo utilizadas fueron las siguientes: fracción citosólica (50 µg de proteína disuelta en solución reguladora borato 0,2 mol/L (pH 9 y ácido linoleico (7,8-250 mmol/L como sustrato, ensayándose muestras paralelas incubadas con Tween-20/H2O (2 % (vehículo, muestras controles, D-002 (0,9-1 000 µg/mL o Lyprinol (500 µg/mL (sustancia de referencia. La actividad enzimática se evaluó mediante el cambio de absorbancia a 234 nm producido por la formación de dienos conjugados y medido en espectrofotómetro UV-visible. Resultados: la adición in vitro del D-002 produjo una inhibición significativa, dependiente de la dosis (r= 0,980; pIntroduction: D-002, a mixture of six high molecular weight primary aliphatic alcohols purified from beeswax, has been shown to produce anti-inflammatory effects with no secondary gastrotoxicity in experimental models. Oral treatment with D-002 was effective for lowering the concentrations of B4 leukotriene (LTB4 in pleural exudates of rats with carragenin-induced pleurisy, suggesting that it could inhibit 5-lipooxigenase (5-LOX enzyme activity. The mechanisms of the anti-inflammatory action of D-002, however, had not been explored yet. Objective: to evaluate the effects of D-002 on 5-LOX

  11. [Effect of saliva contamination on microleakage around class-5 cavities restored with three different types of adhesive materials].

    Science.gov (United States)

    Iovan, Gianina; Stoleriu, Simona; Andrian, S; Dia, V; Căruntu, Irina Draga

    2004-01-01

    The recent improvement of adhesive materials should decrease the risk related to saliva contamination. The aim of this study was to evaluate the effect of saliva contamination on the microleakage within class V cavities restored with three different types of materials: conventional glass ionomer cement, composite resin and compomer. 30 human extracted teeth were randomly divided in 3 equal groups. In each group, class V cavities were prepared on both facial and lingual surfaces (but joint for glass ionomer cement and bevelled incisal margin for composite resin and compomer). The lingual cavities were contaminated with saliva prior to restoration, while the facial cavities were not contaminated, serving as control. After water storage for 24 hours, teeth were immersed in 1% methylene blue solution for 24 hours. The axial sections were viewed under an optical microscope and the extent of dye penetration along cervical, axial and incisal margins was measured in millimetres. Statistic analysis showed that under salivary contamination, microleakage increased along the cervical margin of restoration for all three tested materials. Saliva contamination resulted in microleakage within the axial wall of the cavity only for the conventional glass ionomer cement. These data indicate that composite resin and compomer used together with new adhesives seem to be less sensitive to saliva contamination compared to conventional materials. However, under saliva contamination, cervical microleakage cannot be completely prevented and proper isolation should still be mandatory.

  12. Effect of Arbuscular Mycorrhizal Fungi Glomus spp. Inoculation on Alfalfa Growth in Soils with Copper Efecto de la Inoculación con Hongos Micorrízicos Arbusculares Glomus spp. sobre el Crecimiento de Alfalfa en Suelos con Cobre

    Directory of Open Access Journals (Sweden)

    Daniela Novoa M

    2010-06-01

    Full Text Available Soils near mining centers usually have high heavy metal (HM levels. It has been found that some plants associated with arbuscular mycorrhizal fungi (AMF improve growth and tolerance to HM in soils. This symbiosis is a biological resource for degraded soil recovery. The objective of this study was to determine the effect of inoculating AMF (Glomus spp. on alfalfa (Medicago sativa L. growth in agricultural soils with different copper (Cu levels for degraded soil recovery. To this effect, alfalfa seeds were grown in soils from the Catemu and Casablanca valleys and inoculated with AMF. Plant height, stem diameter, and number of leaves were measured weekly. Dry matter, mycorrhizal colonization, and Cu concentration in alfalfa plant tissues were measured after 81 days. Inoculation increased plant height by 24%, stem diameter by 11%, and number of leaves by 34%. Inoculation had a significant effect (p ≤ 0.05 on alfalfa plants that were grown in soil with the highest Cu concentration, but had no effect on Cu accumulation in alfalfa plant tissues. A direct relationship was observed between Cu accumulation in alfalfa and Cu concentration in soils. It was concluded that alfalfa inoculated with Glomus spp. is applicable to the soil recovery process whenever soil properties can ensure inoculum effectiveness on alfalfa growth, and avoid toxicity by excessive Cu in alfalfa plant tissues.Los suelos cercanos a centros de actividad minera suelen presentar altos niveles de metales pesados (HM. Se ha encontrado que algunas plantas asociadas a hongos micorrízicos arbusculares (AMF mejoran su crecimiento y tolerancia a los HM presentes en los suelos. Esta simbiosis constituye un recurso biológico para la recuperación de suelos degradados. El objetivo de este estudio fue determinar el efecto de la inoculación con AMF (Glomus spp. sobre el crecimiento de alfalfa (Medicago sativa L. en suelos agrícolas con distintos niveles de cobre (Cu para la recuperación de

  13. Use of liquid nitrogen during storage in a cell and tissue bank: contamination risk and effect on the detectability of potential viral contaminants.

    Science.gov (United States)

    Mirabet, Vicente; Alvarez, Manuel; Solves, Pilar; Ocete, Dolores; Gimeno, Concepción

    2012-04-01

    Cryopreservation is widely used for banking cells and tissues intended for transplantation. Liquid nitrogen provides a very stable ultra-low temperature environment. Thus, it is used for longterm storage. Unlike the exhaustive microbiological monitoring of the environmental conditions during tissue processing, storage is not usually considered as a critical point of potential contamination risk in professional standards for cell and tissue banking. We have analysed the presence of microbial agents inside our nitrogen tanks. We have mainly detected environmental and water-borne bacteria and fungi. In addition, we have studied the effect of liquid nitrogen exposure on virus detectability. Only differences for hepatitis C virus RNA were observed. Measures for contamination risk reduction during storage must be mandatory in cell and tissue banking. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. The effects of a perturbed source on contaminant transport near the Weldon Spring quarry

    International Nuclear Information System (INIS)

    Tomasko, D.

    1989-03-01

    The effects of a perturbed contamination source at the Weldon Spring quarry in St. Charles County, Missouri, on downstream solute concentrations were investigated using one-dimensional analytical solutions to an advection-dispersion equation developed for both constant-strength and multiple-stepped source functions. A sensitivity study using parameter base-case values and ranges consistent with the geologic conceptualization of the quarry area indicates that the parameters having the greatest effect on predicted concentrations are the distance from the quarry to the point of interest, the average linear groundwater velocity, the contaminant retardation coefficient, and the amplitude and duration of the source perturbation caused by response action activities. Use of base-case parameter value and realistic values for the amplitude and duration of the source perturbation produced a small effect on solute concentrations near the western extremity of the nearby municipal well field, as well as small uncertainties in the predicted results for the assumed model. The effect of simplifying assumptions made in deriving the analytic solution is unknown: use of a multidimensional flow and transport model and additional field work are needed to validate the model. 13 refs., 18 figs

  15. The Effect of Handwashing with Water or Soap on Bacterial Contamination of Hands

    Directory of Open Access Journals (Sweden)

    Wolf-Peter Schmidt

    2011-01-01

    Full Text Available Handwashing is thought to be effective for the prevention of transmission of diarrhoea pathogens. However it is not conclusive that handwashing with soap is more effective at reducing contamination with bacteria associated with diarrhoea than using water only. In this study 20 volunteers contaminated their hands deliberately by touching door handles and railings in public spaces. They were then allocated at random to (1 handwashing with water, (2 handwashing with non-antibacterial soap and (3 no handwashing. Each volunteer underwent this procedure 24 times, yielding 480 samples overall. Bacteria of potential faecal origin (mostly Enterococcus and Enterobacter spp. were found after no handwashing in 44% of samples. Handwashing with water alone reduced the presence of bacteria to 23% (p < 0.001. Handwashing with plain soap and water reduced the presence of bacteria to 8% (comparison of both handwashing arms: p < 0.001. The effect did not appear to depend on the bacteria species. Handwashing with non-antibacterial soap and water is more effective for the removal of bacteria of potential faecal origin from hands than handwashing with water alone and should therefore be more useful for the prevention of transmission of diarrhoeal diseases.

  16. The effects of soil amendments on heavy metal bioavailability in two contaminated Mediterranean soils

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.J.; Clemente, Rafael; Roig, Asuncion; Bernal, M.P

    2003-04-01

    The effects of organic amendments on metal bioavailability were not always related to their degree of humification. - Two heavy metal contaminated calcareous soils from the Mediterranean region of Spain were studied. One soil, from the province of Murcia, was characterised by very high total levels of Pb (1572 mg kg{sup -1}) and Zn (2602 mg kg{sup -1}), whilst the second, from Valencia, had elevated concentrations of Cu (72 mg kg{sup -1}) and Pb (190 mg kg{sup -1}). The effects of two contrasting organic amendments (fresh manure and mature compost) and the chelate ethylenediaminetetraacetic acid (EDTA) on soil fractionation of Cu, Fe, Mn, Pb and Zn, their uptake by plants and plant growth were determined. For Murcia soil, Brassica juncea (L.) Czern. was grown first, followed by radish (Raphanus sativus L.). For Valencia soil, Beta maritima L. was followed by radish. Bioavailability of metals was expressed in terms of concentrations extractable with 0.1 M CaCl{sub 2} or diethylenetriaminepentaacetic acid (DTPA). In the Murcia soil, heavy metal bioavailability was decreased more greatly by manure than by the highly-humified compost. EDTA (2 mmol kg{sup -1} soil) had only a limited effect on metal uptake by plants. The metal-solubilising effect of EDTA was shorter-lived in the less contaminated, more highly calcareous Valencia soil. When correlation coefficients were calculated for plant tissue and bioavailable metals, the clearest relationships were for Beta maritima and radish.

  17. Carbon Contamination During Ion Irradiation - Accurate Detection and Characterization of its Effect on Microstructure of Ferritic/Martensitic Steels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing; Toloczko, Mychailo B.; Kruska, Karen; Schreiber, Daniel K.; Edwards, Danny J.; Zhu, Zihua; Zhang, Jiandong

    2017-11-17

    Accelerator-based ion beam techniques have been used to study radiation effects in materials for decades. Although carbon contamination induced by ion beam in target materials is a well-known issue, it has not been fully characterized nor quantified for studies in ferritic/martensitic (F/M) steels that are candidate materials for applications such as core structural components in advanced nuclear reactors. It is an especially important issue for this class of material because of the effect of carbon level on precipitate formation. In this paper, the ability to quantify carbon contamination using three common techniques, namely time-of-flight secondary ion mass spectroscopy (ToF-SIMS), atom probe tomography (APT) and transmission electron microscopy (TEM) is compared. Their effectiveness and short-comings in determining carbon contamination will be presented and discussed. The corresponding microstructural changes related to carbon contamination in ion irradiated F/M steels are also presented and briefly discussed.

  18. Evaluation of targeted and untargeted effects-based monitoring tools to assess impacts of contaminants of emerging concern on fish in the South Platte River, CO

    Science.gov (United States)

    Rivers in the arid Western United States face increasing influences from anthropogenic contaminants due to population growth, urbanization, and drought. To better understand and more effectively track the impacts of these contaminants, biologically-based monitoring tools are incr...

  19. The effect of soil type on the electrodialytic remediation of lead-contaminated soil

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Ottosen, Lisbeth M.; Harmon, Thomas C.

    2007-01-01

    experiments with ten representative industrially Pb-contaminated surface soils. Results indicate that Pb-speciation is of primary importance. Specifically, organic matter and stable compounds like PbCrO4 can impede and possibly even preclude soil remediation. In soils rich in carbonate, where the acidic front...... to the catholyte. Thus, the presence of carbonate negatively influences the remediation time. Pb bound to soluble organic matter is also transported towards the anolyte during EDR. The primary effect of the mainly insoluble organic matter commonly present in surface soil is however to immobilize Pb and impede...

  20. Effect of Air Stability on the Dispersal of Exhaled Contaminant in Rooms

    DEFF Research Database (Denmark)

    Xu, Chunwen; Gong, Guangcai; Nielsen, Peter V.

    2013-01-01

    the manikin, indicating that the person who exhales the contaminant may not be polluted by himself as the protective effect of the thermal boundary layer around the body, especially in stable condition with two concentration zones and clean air drawn from the inlets. However, other persons facing......Experiments are conducted in a full-scale chamber equipped with whole floor and whole ceiling supply or exhaust to form approximately zero and larger temperature gradients corresponding to unstable and stable air conditions. It can be observed that the air with smoke exhaled from a life...

  1. Effect of anaerobic contributions to the uranium content in marine sediments; Efecto de aportes anaerobios en el contenido de uranio en sedimentos marinos

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Ruiz F, A. C. [UNAM, Instituto de Ciencias del Mar y Limnologia, Unidad Academica Mazatlan, Cap. Joel Montes Camarena, Cerro del Vigia, 82040 Mazatlan, Sinaloa (Mexico); Jimenez D, E.; Guerrero J, M., E-mail: eduardo.ordonez@inin.gob.mx [Universidad Autonoma del Estado de Mexico, Facultad de Planeacion Urbana y Regional, Paseo Tollocan esq. Mariano Matamoros, 50130 Toluca, Estado de Mexico (Mexico)

    2014-10-15

    In this work a sediment group obtained in the seabed near the mouth of the Santiago River, physical analyzes show that there is little activity of microscopic marine life, revealed by exoskeletons of foraminifera. Although the amount of organic matter occurs normally, around 20%, is assumed that this contribution is due to the large amount of organic waste scattered by the effluent of the river, causing an abnormally high anaerobic activity, clearly shown by the large amount of pyrite specific framboids found along the nucleus profile of 23 cm of sediment. In the analyzed fractions the uranium concentration and its isotope ratio was studied: which vary from 3.19 Bq/kg for the more superficial fractions down gradually to less than 1 Bq/kg for deeper fractions. An outstanding fact is that the surface fractions have an isotope ratio {sup 234}U/{sup 238}U unusually low for fractions 1-4 cm of deep, close to 0.4, indicating a strong reaction of few years ago on the radiogenic descendants of {sup 238}U, leaching essentially the {sup 234}Th and causing this abnormal radioactive imbalance. The plutonium has become an element found commonly in the surface layers of the sea and coastlines, finding in the top layer an activity of 2.78 Bq/kg ({sup 239}Pu + {sup 240}Pu). The high contamination of the mouth of Santiago River has changed the conditions of the micro fauna as well as of the chemical equilibrium of the natural elements. (Author)

  2. Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on performance, hematology, metabolism, and immunocompetence of turkeys.

    Science.gov (United States)

    Girish, C K; Smith, T K; Boermans, H J; Karrow, N A

    2008-03-01

    An experiment was conducted to investigate the effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on performance, hematology, metabolism, and immunological parameters of turkeys. The efficacy of polymeric glucomannan mycotoxin adsorbent (GMA) in preventing these adverse effects was also evaluated. Three hundred 1-d-old male turkey poults were fed wheat-, corn-, and soybean meal-based starter (0 to 3 wk), grower (4 to 6 wk), developer (7 to 9 wk), and finisher (10 to 12 wk) diets formulated with uncontaminated grains, contaminated grains, and contaminated grains + 0.2% GMA. Feeding contaminated grains significantly decreased BW gains during the grower and developer phases, and GMA supplementation prevented these effects. There was no effect of diet, however, on feed intake or feed efficiency. The feeding of contaminated grains reduced total lymphocyte counts at wk 3 (P effect. Feeding contaminated grains significantly increased the percentage of CD4(+) lymphocyte populations during wk 6; however, there was no change in the percentage of CD8(+) and B-lymphocyte populations. Contact hypersensitivity to dinitrochlorobenzene, which is a CD8(+) T cell-mediated delayed-type hypersensitivity response, was significantly decreased after 24 and 72 h by feedborne mycotoxins compared with controls. Supplementation of the contaminated diet with GMA prevented the decrease in response after 24 h. Secondary antibody (IgG titer) response against SRBC antigens (CD4(+) T cell-dependent) was significantly decreased after feeding contaminated grains compared with controls. It was concluded that turkey performance and some blood and immunological parameters were adversely affected by feedborne Fusarium mycotoxins, and GMA prevented many of these effects.

  3. Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on performance and metabolism of laying hens.

    Science.gov (United States)

    Chowdhury, S R; Smith, T K

    2004-11-01

    An experiment was conducted to evaluate the effects of feeding laying hens grains naturally contaminated with a combination of Fusarium mycotoxins. Parameters measured included performance, organ weights, and plasma chemistry. One hundred and forty-four, 45-wk-old laying hens were fed diets including: (1) control, (2) contaminated grains, and (3) contaminated grains + 0.2% polymeric glucomannan mycotoxin adsorbent (GMA) for a 12-wk period. The feeding of contaminated grains decreased feed consumption compared with controls in the first 4 wk. Feed consumption increased, however, from 4 to 8 wk and from 8 to 12 wk. The efficiency of feed utilization (feed consumption/egg mass) decreased compared with controls in the periods from 4 to 8 and from 8 to 12 wk when birds were fed contaminated grains. Supplementation with GMA decreased feed consumption and increased the efficiency of feed utilization in the period from 8 to 12 wk. Egg production and egg mass decreased in wk 4 and 8 compared with controls when contaminated grains were fed, whereas egg and eggshell weights decreased in the fourth wk. Plasma uric acid concentrations increased throughout the experiment and relative kidney weights increased at the end of the experiment compared with controls when birds were fed contaminated grains. The feeding of GMA prevented the elevation in uric acid concentrations and relative kidney weights. It was concluded that layer performance and metabolism were adversely affected by chronic feeding of a combination of Fusarium mycotoxins, and that GMA prevented many of these effects.

  4. Effect of blood contamination with 1-step self-etching adhesives on microtensile bond strength to dentin.

    Science.gov (United States)

    Yoo, H M; Pereira, P N R

    2006-01-01

    This study evaluated the effect of blood contamination and decontamination methods on the microtensile bond strength of 1-step self-etching adhesive systems to dentin contaminated after adhesive application and light curing. Three commercially available "all-in-one" adhesives (One Up Bond F, Xeno III and Adper Prompt L-Pop) and 1 resin composite (Clearfil AP-X) were used. Third molars that had been stored in distilled water with 0.5% thymol at 4 degrees C were ground with #600 SiC paper under running water to produce a standardized smear layer. The specimens were randomly divided into groups according to the 3 adhesive systems. The adhesive systems were used under 3 conditions: no contamination, which was the control (C); contamination of the light-cured adhesive surface with blood and reapplication of adhesive (Contamination 1) and contamination of the light-cured adhesive surface with blood, then washing, drying and reapplication of the adhesive (Contamination 2). Following light curing of the adhesive, the resin composite was placed in 3 increments up to a 5-mm-thick layer on the bonded surface. All specimens were stored in distilled water at 37 degrees C for 24 hours. The microtensile bond strength was measured using a universal testing machine (EZ test), and data were analyzed by 1-way ANOVA followed by the Duncan test to make comparisons among the groups (p=0.05). After debonding, 5 specimens were selected from each group and examined in a scanning electron microscope to evaluate the modes of fracture. For all adhesives, contamination groups showed lower bond strength than the control (p0.05). For Xeno III and Adper Prompt L-Pop, contamination group #2 showed the lowest bond strength among the groups (pcontamination group #2 showed higher bond strength than contamination group #1 but showed no statistical significance between them (p>0.05).

  5. Respuesta hemodinámica al estrés mental y físico en sujetos normotensos hiperreactivos: Efectos del Betabloqueo Cardiovascular response to mental and physical stress in hyper-reactive normotensive subjects: Beta blockade effect

    Directory of Open Access Journals (Sweden)

    Julio Przybylski

    2004-10-01

    Full Text Available El objetivo de nuestro trabajo fue estudiar la reactividad cardiovascular en personas sanas normotensas sin medicación, mediante la técnica, de Stroop de conflicto entre el color y la palabra (SCWCT, la respuesta anticipatoria de la presión arterial con el ejercicio (RA y la prueba ergométrica graduada (PEG. Se analizó el efecto de un betabloqueante beta1 selectivo: bisoprolol (B sobre la reactividad cardiovascular al estrés mental (EM y físico en personas hiperreactivas. Se estudiaron 42 personas, de los cuales fueron incluidas sólo 30 (21 mujeres y 9 varones que resultaron hiperreactivas, con una edad media de 42.5 años. Los mayores valores de la presión arterial sistólica (PAS y diastólica (PAD durante el EM fueron tomados como medida de reactividad, considerándose como respuesta hiperreactiva un aumento de 30 mm de Hg o mayor y/o 15 mm de Hg o mayor respectivamente. El efecto de una dosis diaria oral de 5 mg de B vs placebo (P fue estudiado en forma prospectiva, randomizada y doble ciego. Se analizaron los datos acerca de la reactividad en el SCWCT mediante el test exacto de Fisher. En los resultados, se observó una menor sensibilidad de RA y PEG vs SCWCT. Las 15 personas que recibieron P continuaron hiperreactivas en tanto que 6 de las 15 personas tratadas con B dejaron de ser reactivas (pThe aim of our study was to evaluate the cardiovascular reactivity in healthy normotensive subjects without medication, using mental and physical stress techniques: Stroop color word conflict test (SCWCT, anticipatory blood pressure response to exercise (ARE and stress testing (ST. We analized the effects of a selective beta 1 betablocker: bisoprolol (B on cardiovascular reactivity in our subjects (s. We studied 42 s, but only 30 (21 females and 9 males were included who were hyperreactives. The mean age was 42,5 years. The higher values of systolic (SBP and diastolic blood pressure (DBP during the mental stress (MS were taken as a measure of

  6. Efecto de la exposición a ruido en entornos laborales sobre la calidad de vida y rendimiento Effects of noise exposure in working places on quality of life and performance

    Directory of Open Access Journals (Sweden)

    Ordaz Castillo Elena

    2009-09-01

    Full Text Available Objetivos: La exposición laboral a ruido origina efectos sobre la salud de carácter no auditivo. El objetivo de este estudio es estimar la asociación entre exposición a ruido en entornos laborales y la aparición de alteraciones en la conducta, rendimiento y síntomas psicosomáticos. Metodología: Estudio de prevalencia a partir de datos de la VI Encuesta Nacional de Condiciones de Trabajo analizando como variable independiente la exposición a ruido y como variables dependientes los "síntomas que manifiesta el trabajador" tratados de forma individual o por grupo de síntomas según su naturaleza: conductual, psicosomáticos y rendimiento. La asociación entre exposición y efecto se analizó mediante la prueba de X² y se calculó el OR de prevalencias ajustado por ritmo de trabajo (IC95% para medir la asociación entre "exposición a ruido" y grupos de síntomas de forma cruda en el conjunto de la población y de forma estratificada por ramas de actividad. Resultados: El 36,5% de la población trabajadora está expuesta a ruido en su puesto de trabajo. Se observa una mayor prevalencia de los grupos de síntomas conductuales, psicosomáticos y de rendimiento (pAims: Occupational noise exposure could produce extra-auditory effects. The purpose of this study was to investigate whether occupational noise exposure can influence human behaviour, performance and development of psychosomatic symptoms. Methodology: Cross-sectional study, from the Data-base of Spanish VI National Survey on Working Conditions, "noise exposure" has been analyzed as independent variable and: "symptoms self-reportered by workers" as effect variable, considering them independently or grouped variables in behavioural, psychosomatic and performance symptoms. The relationship between exposure and effect was analyzed by X2 test. Prevalence adjusted Odds Ratio by work rhythm (95% CI, were estimated to measure the association between perceived noise annoyance and grouped

  7. EFECTO DE VINAZAS SOBRE HONGOS QUE FORMAN MICORRIZA ARBUSCULAR EN UN MOLISOL DEL VALLE DEL CAUCA, COLOMBIA EFFECT OF VINASSE ON ARBUSCULAR MYCORRHIZAL FUNGI IN A MOLLISOL OF CAUCA VALLEY (COLOMBIA

    Directory of Open Access Journals (Sweden)

    Diana Cristina Velásquez Pomar

    2011-06-01

    Full Text Available La adición de etanol a la gasolina busca disminuir la contaminación ambiental; sin embargo, su producción genera vinaza, un material contaminante en cuerpos de agua. Por su alta concentración de K y potencialidad como fertilizante, los ingenios azucareros del Valle del Cauca (Colombia, adelantan investigaciones dirigidas a mejorar la productividad y efectos en propiedades químicas y físicas del suelo. Son escasas las publicaciones sobre su influencia en propiedades biológicas como hongos formadores de micorriza arbuscular (HMA, componente sensible y estrechamente asociado con la nutrición de las plantas y condiciones físicas del suelo. Con el fin de conocer si algunos componentes de HMA se afectan por vinazas, se sembró maíz blanco (Zea mays L. SV1127 en un Pachic Haplustolls del Valle deficiente en K, bajo condiciones de invernadero. Se utilizó un diseño completamente al azar con 5 tratamientos: testigo absoluto y 4 correspondientes a vinaza: KCl en proporciones de 100:0, 75:25, 50:50 y 0:100. La longitud de micelio externo (LME, micelio externo vivo y activo (MEV, glomalina fácilmente extractable (GFE y glomalina total (GT, fueron estimados a los 36 y 70 días después de siembra. Con excepción de la GFE, las demás variables respondieron significativamente a los tratamientos. Al suplir el K por vía orgánica (vinaza o inorgánica KCl, LME y MEV se incrementaron. El máximo valor para LME fue 10,4 m•g-1, con 100% vinaza. GT fue sensible a la fuente de K utilizada y se deprimió con KCl 100%. Incrementos en la actividad biológica pueden estar relacionados con los efectos de la vinaza sobre LME y MEV. Estudios indican que gradientes de fertilidad pueden afectar la GT, asociados a tasas de descomposición de esta molécula.In order to reduce environmental pollution, a mix of ethanol gasoline has been used; however, the ethanol production generates vinasse, a pollutant in water. Because vinasse has a high concentration of K and

  8. The Effect of Handwashing with Water or Soap on Bacterial Contamination of Hands

    Science.gov (United States)

    Burton, Maxine; Cobb, Emma; Donachie, Peter; Judah, Gaby; Curtis, Val; Schmidt, Wolf-Peter

    2011-01-01

    Handwashing is thought to be effective for the prevention of transmission of diarrhoea pathogens. However it is not conclusive that handwashing with soap is more effective at reducing contamination with bacteria associated with diarrhoea than using water only. In this study 20 volunteers contaminated their hands deliberately by touching door handles and railings in public spaces. They were then allocated at random to (1) handwashing with water, (2) handwashing with non-antibacterial soap and (3) no handwashing. Each volunteer underwent this procedure 24 times, yielding 480 samples overall. Bacteria of potential faecal origin (mostly Enterococcus and Enterobacter spp.) were found after no handwashing in 44% of samples. Handwashing with water alone reduced the presence of bacteria to 23% (p soap and water reduced the presence of bacteria to 8% (comparison of both handwashing arms: p soap and water is more effective for the removal of bacteria of potential faecal origin from hands than handwashing with water alone and should therefore be more useful for the prevention of transmission of diarrhoeal diseases. PMID:21318017

  9. Effect of thin-film coating on wear in EGR-contaminated oil

    International Nuclear Information System (INIS)

    Ajayi, O. O.; Aldajah, S. H.; Erdemir, A.; Fenske, G. R.

    2001-01-01

    Increased use of higher-efficiency compression ignition direct injection (CIDI) diesel engines instead of today's gasoline engines will result in reduced fuel consumption and greenhouse gases emissions. However, NO(sub x) and particulate exhaust emissions from diesel engines must be significantly reduced due to their possible adverse health effects. Exhaust gas recirculation (EGR) is an effective way to reduce NO(sub x) emissions from diesel engines, but the particulates and acidic exhaust products in the recirculated gas will contaminate engine lubricant oil by increasing the soot content and total acid number (TAN). These factors will increase the wear rate in many critical engine components and seriously compromise engine durability. We have investigated the use of commercially available thin and hard coatings (TiN, TiCN, TiAlN, and CrN) to mitigate the negative effects of EGR on wear. In tests with the four-ball machine according to ASTM D4172, we found that all the four coatings deposited on M-50 steel significantly reduced wear in EGR-contaminated oils when compared with uncoated M50 steel balls

  10. Numerical investigation on the effect of balcony open and solid upstand on smoke contamination in atrium balconies

    Science.gov (United States)

    Mutafi, M. A.; Nasif, M. S.; Pao, W.; Ismail, F. B.

    2017-10-01

    Atrium is a modern architectural design of buildings that has an open space at the middle and contains several floors. In atrium structure the smoke due to fire can easily flow through the open spaces and causes smoke contamination. CFD simulation using fire dynamic simulator (FDS) software is conducted in this work, to investigate the effect of balcony open upstand on smoke contamination in atrium’s balconies and compare it with balconies with solid upstand. It was found that in case of open upstand, the smoke contamination occurrence decreased inside the balcony comparing with balconies with solid upstand.

  11. Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on production and metabolism in broilers.

    Science.gov (United States)

    Swamy, H V L N; Smith, T K; Cotter, P F; Boermans, H J; Sefton, A E

    2002-07-01

    Three hundred sixty, 1-d-old male broiler chicks were fed diets containing grains naturally contaminated with Fusarium mycotoxins for 56 d. The four diets included control (0.14 mg/kg deoxynivalenol, 18 mg/ kg fusaric acid, effect on serum albumin and y-glutamyltransferase activity. Blood hemoglobin and biliary IgA concentrations, however, responded in significant linear and quadratic fashions. Supplementation of E-GM counteracted most of the blood parameter alterations caused by the Fusarium mycotoxin-contaminated grains and reduced breast muscle redness. It was concluded that broiler chickens may be susceptible to Fusarium mycotoxicoses when naturally contaminated grains are fed containing a combination of mycotoxins.

  12. Urban atmospheric contamination

    International Nuclear Information System (INIS)

    Baldasano Jose, M.

    1997-01-01

    The problems of contamination are not only limited to this century, pale pathology evidences of the effects of the contamination of the air exist in interiors in the health of the old ones; the article mention the elements that configure the problem of the atmospheric contamination, atmospheric pollutants and emission sources, orography condition and effects induced by the urbanization process

  13. Effective hepatitis A virus inactivation during low-heat dehydration of contaminated green onions.

    Science.gov (United States)

    Laird, David T; Sun, Yan; Reineke, Karl F; Shieh, Y Carol

    2011-08-01

    Preserving fruits and vegetables by dehydration is common; however, information is limited concerning viral survival on the produce during the process. This work demonstrated the effects of low heat dehydration on inactivating hepatitis A virus (HAV) on contaminated green onions. Inoculated and uninoculated onion samples were dehydrated at target temperatures of 45-65 °C for 20 h. HAV from artificially contaminated onions (fresh or dehydrated) was eluted by shaking at 145 rpm at 20 °C for 20 min with 3% beef extract, pH 8, and followed by 0.2 μM-membrane filtration before plaque assay and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis. Dilutions of the filtrates were made for obtaining countable plaques on FRhK-4 cell monolayers in 6-well plates, and also for eliminating inhibitors in qRT-PCR. Average water activity of the onions after 20 h-dehydration was 0.227, regardless of temperature used (47.9 °C or 65.1 °C). Eight dehydration trials resulted in a linear relationship between HAV inactivation and dehydration temperature, with HAV log reduction = 0.1372x(°C) - 5.5572, r(2) = 0.88. Therefore, the 20 h-heating at 47.8, 55.1, and 62.4 °C reduced infectious HAV in onions by 1, 2, and 3 logs respectively, the Z value being 7.3 °C. It was concluded that low heat dehydration using 62.5 °C or above could effectively inactivate HAV on contaminated onions by >3 logs. Published by Elsevier Ltd.

  14. Effects of humic acid on phytodegradation of petroleum hydrocarbons in soil simultaneously contaminated with heavy metals

    Institute of Scientific and Technical Information of China (English)

    Soyoung Park; Ki Seob Kim; Jeong-Tae Kim; Daeseok Kang; Kijune Sung

    2011-01-01

    The use of humic acid (HA) to enhance the efficiency of phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel was evaluated in this study.A sample of soil was artificially contaminated with commercially available diesel fuel to an initial total petroleum hydrocarbons (TPH) concentration of 2300 mg/kg and four heavy metals with concentrations of 400 mg/kg for Pb,200 mg/kg for Cu,12 mg/kg for Cd,and 160 mg/kg for Ni.Three plant species,Brassica campestris,Festuca arundinacea,and Helianthus annuus,were selected for the phytodegradation experiment.Percentage degradation of TPH in the soil in a control pot supplemented with HA increased to 45% from 30% without HA.The addition of HA resulted in an increases in the removal of TPH from the soil in pots planted with B.campestris,F.arundinacea,and H.annuus,enhancing percentage degradation to 86%,64%,and 85% from 45%,54%,and 66%,respectively.The effect of HA was also observed in the degradation of n-alkanes within 30 days.The rates of removal of n-alkanes in soil planted with B.campestris and H.annuus were high for n-alkanes in the range of C11-C28.A dynamic increase in dehydrogenase activity was observed during the last 15 days of a 30-day experimental period in all the pots amended with HA.The enhanced biodegradation performance for TPHs observed might be due to an increase in microbial activities and bioavailable TPH in soils caused by combined effects of plants and HA.The results suggested that HA could act as an enhancing agent for phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel and heavy metals.

  15. Effect of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil.

    Science.gov (United States)

    Kim, Seong-Hye; Han, Hyo-Yeol; Lee, You-Jin; Kim, Chul Woong; Yang, Ji-Won

    2010-07-15

    Electrokinetic remediation has been successfully used to remove organic contaminants and heavy metals within soil. The electrokinetic process changes basic soil properties, but little is known about the impact of this remediation technology on indigenous soil microbial activities. This study reports on the effects of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil. The main removal mechanism of diesel was electroosmosis and most of the bacteria were transported by electroosmosis. After 25 days of electrokinetic remediation (0.63 mA cm(-2)), soil pH developed from pH 3.5 near the anode to pH 10.8 near the cathode. The soil pH change by electrokinetics reduced microbial cell number and microbial diversity. Especially the number of culturable bacteria decreased significantly and only Bacillus and strains in Bacillales were found as culturable bacteria. The use of EDTA as an electrolyte seemed to have detrimental effects on the soil microbial activity, particularly in the soil near the cathode. On the other hand, the soil dehydrogenase activity was enhanced close to the anode and the analysis of microbial community structure showed the increase of several microbial populations after electrokinetics. It is thought that the main causes of changes in microbial activities were soil pH and direct electric current. The results described here suggest that the application of electrokinetics can be a promising soil remediation technology if soil parameters, electric current, and electrolyte are suitably controlled based on the understanding of interaction between electrokinetics, contaminants, and indigenous microbial community. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Effective radium concentration in topsoils contaminated by lead and zinc smelters

    Energy Technology Data Exchange (ETDEWEB)

    Girault, Frédéric, E-mail: girault@ipgp.fr [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, CNRS, Paris, France. (France); Perrier, Frédéric; Poitou, Charles; Isambert, Aude [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, CNRS, Paris, France. (France); Théveniaut, Hervé; Laperche, Valérie [Bureau de Recherches Géologiques et Minières, Orléans, France. (France); Clozel-Leloup, Blandine [Bureau de Recherches Géologiques et Minières, Villeurbanne, France. (France); Douay, Francis [Laboratoire Génie Civil et géo Environnement, ISA Lille, Lille, France. (France)

    2016-10-01

    Trace elements (TE) are indicative of industrial pollution in soils, but geochemical methods are difficult to implement in contaminated sites with large numbers of samples. Therefore, measurement of soil magnetic susceptibility (MS) has been used to map TE pollutions, albeit with contrasted results in some cases. Effective radium concentration (EC{sub Ra}), product of radium concentration by the emanation factor, can be measured in a cost-effective manner in the laboratory, and could then provide a useful addition. We evaluate this possibility using 186 topsoils sampled over about 783 km{sup 2} around two former lead and zinc smelters in Northern France. The EC{sub Ra} values, obtained from 319 measurements, range from 0.70 ± 0.06 to 12.53 ± 0.49 Bq·kg{sup −1}, and are remarkably organized spatially, away from the smelters, in domains corresponding to geographical units. Lead-contaminated soils, with lead concentrations above 100 mg·kg{sup −1} < 3 km from the smelters, are characterized on average by larger peak EC{sub Ra} values and larger dispersion. At large scales, away from the smelters, spatial variations of EC{sub Ra} correlate well with spatial variations of MS, thus suggesting that, at distance larger than 5 km, variability of MS contains a significant natural component. Larger EC{sub Ra} values are correlated with larger fine fraction and, possibly, mercury concentration. While MS is enhanced in the vicinity of the smelters and is associated with the presence of soft ferrimagnetic minerals such as magnetite, it does not correlate systematically with metal concentrations. When multiple industrial and urban sources are present, EC{sub Ra} mapping, thus, can help in identifying at least part of the natural spatial variability of MS. More generally, this study shows that EC{sub Ra} mapping provides an independent and reliable assessment of the background spatial structure which underlies the structure of a given contamination. Furthermore, EC{sub Ra

  17. Effective radium concentration in topsoils contaminated by lead and zinc smelters

    International Nuclear Information System (INIS)

    Girault, Frédéric; Perrier, Frédéric; Poitou, Charles; Isambert, Aude; Théveniaut, Hervé; Laperche, Valérie; Clozel-Leloup, Blandine; Douay, Francis

    2016-01-01

    Trace elements (TE) are indicative of industrial pollution in soils, but geochemical methods are difficult to implement in contaminated sites with large numbers of samples. Therefore, measurement of soil magnetic susceptibility (MS) has been used to map TE pollutions, albeit with contrasted results in some cases. Effective radium concentration (EC_R_a), product of radium concentration by the emanation factor, can be measured in a cost-effective manner in the laboratory, and could then provide a useful addition. We evaluate this possibility using 186 topsoils sampled over about 783 km"2 around two former lead and zinc smelters in Northern France. The EC_R_a values, obtained from 319 measurements, range from 0.70 ± 0.06 to 12.53 ± 0.49 Bq·kg"−"1, and are remarkably organized spatially, away from the smelters, in domains corresponding to geographical units. Lead-contaminated soils, with lead concentrations above 100 mg·kg"−"1 < 3 km from the smelters, are characterized on average by larger peak EC_R_a values and larger dispersion. At large scales, away from the smelters, spatial variations of EC_R_a correlate well with spatial variations of MS, thus suggesting that, at distance larger than 5 km, variability of MS contains a significant natural component. Larger EC_R_a values are correlated with larger fine fraction and, possibly, mercury concentration. While MS is enhanced in the vicinity of the smelters and is associated with the presence of soft ferrimagnetic minerals such as magnetite, it does not correlate systematically with metal concentrations. When multiple industrial and urban sources are present, EC_R_a mapping, thus, can help in identifying at least part of the natural spatial variability of MS. More generally, this study shows that EC_R_a mapping provides an independent and reliable assessment of the background spatial structure which underlies the structure of a given contamination. Furthermore, EC_R_a may provide a novel index to identify soils

  18. Estimation of Potential Population Level Effects of Contaminants on Wildlife; FINAL

    International Nuclear Information System (INIS)

    Loar, J.M.

    2001-01-01

    The objective of this project is to provide DOE with improved methods to assess risks from contaminants to wildlife populations. The current approach for wildlife risk assessment consists of comparison of contaminant exposure estimates for individual animals to literature-derived toxicity test endpoints. These test endpoints are assumed to estimate thresholds for population-level effects. Moreover, species sensitivities to contaminants is one of several criteria to be considered when selecting assessment endpoints (EPA 1997 and 1998), yet data on the sensitivities of many birds and mammals are lacking. The uncertainties associated with this approach are considerable. First, because toxicity data are not available for most potential wildlife endpoint species, extrapolation of toxicity data from test species to the species of interest is required. There is no consensus on the most appropriate extrapolation method. Second, toxicity data are represented as statistical measures (e.g., NOAEL s or LOAELs) that provide no information on the nature or magnitude of effects. The level of effect is an artifact of the replication and dosing regime employed, and does not indicate how effects might increase with increasing exposure. Consequently, slight exceedance of a LOAEL is not distinguished from greatly exceeding it. Third, the relationship of toxic effects on individuals to effects on populations is poorly estimated by existing methods. It is assumed that if the exposure of individuals exceeds levels associated with impaired reproduction, then population level effects are likely. Uncertainty associated with this assumption is large because depending on the reproductive strategy of a given species, comparable levels of reproductive impairment may result in dramatically different population-level responses. This project included several tasks to address these problems: (1) investigation of the validity of the current allometric scaling approach for interspecies extrapolation

  19. Differential effects of habitat fragmentation on birds and mammals in Valdivian temperate rainforests Efectos diferenciales de la fragmentación del hábitat sobre aves y mamíferos del bosque valdiviano

    Directory of Open Access Journals (Sweden)

    DOUGLAS A. KELT

    2001-12-01

    Full Text Available Four recent studies on Chilean vertebrates underscore the very different effects that habitat fragmentation may have under different conditions. In southern Chile, birds exhibited significant species-area relationships, whereas the more depauperate small mammal community did not. The avifauna of highly isolated rainforest remnants in Fray Jorge National Park (IV Región presented steeper species-area relations than those in southern Chile, reminiscent of land-bridge islands after faunal relaxation. The small mammal results were unexpected but may reflect the reduced vagility and immigration potential of this group. Additionally, the inter-remnant matrix habitat may support large populations of only some species, allowing them to capitalize on resources that are available in forest remnants. Such an effect is less likely for birds due to their greater vagility. Although the influence of remnant area is more clearly demonstrated for birds in Chile, it appears that small mammal assemblages may be more immediately impacted by habitat fragmentation than are birds, and that further fragmentation of temperate rainforests will seriously impoverish the small mammal assemblage, many of whose members are endemic to this region. Further research should emphasize the role of the inter-remnant matrix, of habitat corridors, and of the relative sensitivity of different species to matrix/corridor quality and remnant isolationCuatro estudios recientes en vertebrados chilenos subrayan los efectos muy diversos que la fragmentación del hábitat puede tener bajo diversas condiciones. En el sur de Chile, las aves exhibieron relaciones significativas entre la riqueza de especies y el área de hábitat ("especies-area", mientras que tal relación no se observó en la comunidad de pequeños mamíferos, la cual tiene menos especies. La avifauna de los fragmentos remanentes altamente aislados del Parque Nacional Fray Jorge (IV Región presentaron relaciones especies

  20. Efecto de la temperatura de la Rizosfera sobre la distribución de la materia seca en uchuva (Physalis peruviana L. Effect of rizosphere temperature on the dry matter distribution in cape gooseberry (Physalis peruviana L.

    Directory of Open Access Journals (Sweden)

    Fischer Gerhard

    1998-12-01

    Full Text Available En el hábitat natural de la uchuva en Colombia (de 1.600 a 2.800 msnm la temperatura edáfica varía de acuerdo con los
    factores climatológicos determinados por la altitud y por el manejo que se le de al suelo y al cultivo. Para estudiar el efecto de la temperatura en la rizosfera sobre la distribución
    de la materia seca en la uchuva y encontrar mecanismos de adaptación al altiplano colombiano, se cultivaron durante 11 semanas los ecotipos 'Colombia' y 'Sudáfrica' con temperaturas edáficas de 8, 15, 22 y 29°C bajo invernadero en Berlín, Alemania. Se utilizaron macetas plásticas de 2,5 L de capacidad y arena de cuarzo como substrato. Con el
    aumento de la temperatura en la rizosfera creció la producción de biomasa hasta un máximo a 22 y 29°C dependiendo del órgano de la planta y del ecotipo. La mayor acumulación de materia seca la obtuvo 'Colombia' a 29°C y 'Sudáfrica' a 22°C. Con 8°C de temperatura radical las plantas produjeron poca masa seca radical y foliar, mientras la materia de los frutos disminuyó en menor proporción, debido posiblemente a mecanismos de adaptación a los suelos fríos del altiplano. Los 22°C fomentaron más el crecimiento de las ramas principales, mientras las laterales tuvieron su óptimo a 29°C, posiblemente debido a un efecto hormonal. La mayor acumulación de materia seca en raíces,
    hojas y frutos del ecotipo 'Colombia' a 29°C se puede interpretar como una adaptación a los suelos calientes de las laderas expuestas al sol.
    In the natu ral habitat of cape gooseberry in Colombia, on sites from 1.600 to 2.800 m.a.s.l., soil temperature is affected by c1imatologicfactors, which are determined by the altitud and cultural and soil management practices. In order to study the effect of rizosphere temperature on the distribution of dry matter in the cape gooseberry plant and to find mecanisms of adaptation to the Colombian highland conditions, during 11 weeks 'Colombia' and

  1. Effects of differents bandwidths knowledge of results on the acquisition of a serial motor skill Los efectos del conocimiento del resultado en el aprendizaje de una tarea motora seriada utilizando distintos márgenes de error

    Directory of Open Access Journals (Sweden)

    M. Colen

    2010-09-01

    Full Text Available

    The aim of this study was to investigate the effects of three different ranks of bandwidth KR in the learning of a serial motor task. The participants were 45 undergraduate students, of both genders, randomly assigned to tree groups: (1 wide bandwidth was 10% of the total time; (2 narrow bandwidth was 5% of the total time, and (3 precision of error (BW.0 where the bandwidth was 0%.. The serial task consisted on putting a tennis ball respecting a previously determined time in six holes made on a wooden platform. The experiment was done in three phases, acquisition, immediate retention and retention delayed 24 hours after the acquisition test. The statistical analysis did not point out differences among the three groups regarding precision and consistency at any phases. I spite of not seen significant differences among the ranks, we concluded that the design of bandwidth KR is beneficial for a serial task motor learning and the utilization of bandwidth KR is positive for learning, but can present short-term effects, since long time limits on improvements of performance were not verified. On the other hand we encourage further studies designs that combine other ranks of KR with other variables, and using more complex tasks on the attempt of obtaining more significant results relating to the influence of the bandwidth KR in the motor learning. 
    Key Words: Motor learning; Knowledge of results; Bandwidth

     

    El objetivo de ese estudio fue investigar los efectos de tres distintos rangos de conocimiento del resultado (CR en margen de error en el aprendizaje de una tarea motora seriada. Fueron utilizados 45 sujetos voluntarios de ambos sexos de la Universidad de León divididos al azar en tres grupos experimentales: con un margen de error amplio del 10% del tiempo total, con un margen de error estrecho  del 5% del tiempo total y sin

  2. Effect of WO{sub x} on Co and Ni/Hydrotalcite catalysts to obtain hydrogen from bioethanol; Efecto del WO{sub x} sobre catalizadores de Co, Ni/hidrotalcita para obtener hidrogeno a partir de bioetanol

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, M.A.; Contreras, J. L. [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D.F. (Mexico)]. E-mail: jlcl@correo.azc.uam.mx; Fuentes, G.A. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D.F. (Mexico); Luna, R. [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D.F. (Mexico); Salmones, J.; Zeifert, B. [ESIQIE, Instituto Politecnico Nacional, Mexico, D.F. (Mexico)] Vazquez, A. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexi