WorldWideScience

Sample records for ambiente estuarial rasgos

  1. Banco arenoso en un ambiente estuarial: rasgos de fondo y dinámica sedimentaria

    Directory of Open Access Journals (Sweden)

    Laura G. Vecchi

    2008-09-01

    Full Text Available Los bancos de arena son rasgos comunes en la boca de los canales de marea del estuario de Bahía Blanca (sur de la provincia de Buenos Aires. Este estudio tiene por objetivo incrementar el conocimiento sobre los procesos y mecanismos de formación y mantenimiento de los bancos estuariales. La investigación se centró en un banco elongado, de 4 km de largo, ubicado en la boca del canal La Lista, denominado banco La Lista. A través de datos acústicos (ecosonda y sonar lateral se determinaron rasgos morfológicos de fondo. Estos, conjuntamente con muestras de sedimento y mediciones de corrientes, posibilitaron definir la hidrodinámica y el transporte sedimentario. La arena movilizada desde el interior del canal La Lista por la corriente de bajante constituye la principal fuente de sedimento del banco. Sobre el flanco norte del banco, el transporte neto de arena como carga de fondo se produce hacia el sureste debido a la corriente de reflujo. Aquí, el transporte de sedimento estimado fue de 0,02188 gr cm-1 seg-1. En oposición, en el flanco sur, la dominancia del flujo produce un transporte de 0,00451 gr cm-1 seg-1. Por lo tanto el mantenimiento del banco es el resultado de una asimetría de flujo/reflujo sobre sus flancos, generándose un transporte sedimentario residual en sentido horario. En consecuencia en los últimos años el banco ha experimentado cambios en la configuración de la cresta y crecido vertical y longitudinalmente.

  2. Banco arenoso en un ambiente estuarial: rasgos de fondo y dinámica sedimentaria Sandbanks in a tidal environment: Bottom features and sedimentary dynamics

    Directory of Open Access Journals (Sweden)

    Laura G. Vecchi

    2008-09-01

    Full Text Available Los bancos de arena son rasgos comunes en la boca de los canales de marea del estuario de Bahía Blanca (sur de la provincia de Buenos Aires. Este estudio tiene por objetivo incrementar el conocimiento sobre los procesos y mecanismos de formación y mantenimiento de los bancos estuariales. La investigación se centró en un banco elongado, de 4 km de largo, ubicado en la boca del canal La Lista, denominado banco La Lista. A través de datos acústicos (ecosonda y sonar lateral se determinaron rasgos morfológicos de fondo. Estos, conjuntamente con muestras de sedimento y mediciones de corrientes, posibilitaron definir la hidrodinámica y el transporte sedimentario. La arena movilizada desde el interior del canal La Lista por la corriente de bajante constituye la principal fuente de sedimento del banco. Sobre el flanco norte del banco, el transporte neto de arena como carga de fondo se produce hacia el sureste debido a la corriente de reflujo. Aquí, el transporte de sedimento estimado fue de 0,02188 gr cm-1 seg-1. En oposición, en el flanco sur, la dominancia del flujo produce un transporte de 0,00451 gr cm-1 seg-1. Por lo tanto el mantenimiento del banco es el resultado de una asimetría de flujo/reflujo sobre sus flancos, generándose un transporte sedimentario residual en sentido horario. En consecuencia en los últimos años el banco ha experimentado cambios en la configuración de la cresta y crecido vertical y longitudinalmente.Tidal sandbanks are sedimentary features com monly found at the inlets of the tidal channels of Bahía Blanca Estuary (south Buenos Aires Province. To improve our understanding of the processes and mechanisms responsible for the formation and maintenance of the tidal sandbanks in estuaries, we carry out this study. We focus in a tidal sandbank located at La Lista channel mouth, denominated La Lista bank. It has an elongate shape with 4 km long. Bathymetric surveys, side-scan sonar records, grain

  3. rasgos funcionales

    Directory of Open Access Journals (Sweden)

    J.P. González-Varo

    2015-01-01

    Full Text Available Muchas especies de mamíferos carnívoros (Orden Carnivora consumen frutos carnosos, transportan semillas en sus tractos digestivos y las defecansin dañarlas en condiciones apropiadas para la germinación. En este artículo, revisamos el conocimiento adquirido sobre este mutualismo en lasúltimas tres décadas, desde que tres trabajos pioneros revelaron la importancia de los carnívoros como dispersores de semillas en ecosistemastemplados. Nos centramos en los rasgos funcionales de los carnívoros consumiendo frutos y diseminando semillas, haciendo especial énfasis ensus diferencias con las aves, el principal grupo de vertebrados frugívoros en ecosistemas templados. Los carnívoros no están sujetos a las restriccionesfenológicas o morfológicas que típicamente limitan el consumo de determinados frutos en muchas especies de aves. Consumen preferentementefrutos cuyos atributos son compartidos con muchas especies de frutos cultivados por el hombre, lo que explica el consumo frecuente deéstos en paisajes antrópicos. Sus amplios requerimientos espaciales favorecen la dispersión de semillas a larga distancia, mientras que su generalismoen relación al hábitat favorece el flujo de semillas entre hábitats contrastados. De este modo, los carnívoros promueven la conectividadentre poblaciones vegetales y la colonización. Estas funciones ecológicas son clave para las comunidades vegetales nativas, especialmente en escenariosde cambios de uso de suelo. Sin embargo, estos patrones de dispersión de semillas pueden contribuir a la invasión de plantas exóticas.Aún ignoramos en gran medida el papel de los carnívoros en términos cuantitativos de la dispersión de semillas y las diferencias funcionales entreespecies dentro del gremio. La integración de muestreos clásicos e innovadoras técnicas moleculares y de análisis espacial promete aportar conocimientoinédito en estas cuestiones.

  4. Rasgos postmodernos de la educación ambiental. Una formación pertinente con las nuevas corrientes de pensamiento

    Directory of Open Access Journals (Sweden)

    Francisco Javier Perez Rodriguez

    2015-02-01

    Full Text Available Los problemas ambientales que se suscitan a escala global son evidencia de una crisis, la cual es expresión de una coyuntura más profunda que trastoca los fundamentos del pensamiento de la humanidad en toda una era. Esta situación tiene sus causas primigenias en el modo general de conocer que desde el Renacimiento se implantó en gran parte del mundo occidental y que erigió al desarrollo y al progreso como idearios, hecho que finalmente se tradujo en una relación insostenible entre los humanos y la naturaleza. Esto expone la necesidad que desde las canteras de la educación se dé apertura a una formación ambiental cónsona con las nuevas corrientes de pensamiento. Es por ello que este ensayo pretende esgrimir los rasgos postmodernos de la Educación Ambiental como proceso pedagógico formal y no escolarizado en los planos epistemológicos, ontológicos y axiológicos, estableciendo la pertinencia del estudio de los problemas ambientales a partir de la crítica a los logos de la ciencia clásica, dando a su vez apertura a la concatenación de ideas y tópicos para la generación de un pensamiento complejo, un conocimiento interdisciplinario y saberes con grandes cimientos éticos que garanticen el cumplimiento de los propósitos de la Educación Ambiental.

  5. RASGOS DE PERSONALIDAD EN PACIENTES CON OBESIDAD

    Directory of Open Access Journals (Sweden)

    Alejandra Bravo Del Toro

    2011-01-01

    Full Text Available El presente estudio analizó los rasgos de personalidad con mayor incidencia en una población mexicana con obesidad. Se distinguieron los rasgos que intervienen en el funcionamiento diario de los sujetos. La muestra estuvo conformada por 60 pacientes: 31 hombres y 29 mujeres, con edades de 30 a 40 años, casados, con nivel educativo básico y que acudían a consulta médica en un centro de diagnóstico clínico, con antecedentes de obesidad. Se utilizó el perfil-inventario de la personalidad de Gordon, según el cual se comprobó que los pacientes con obesidad tienden a mostrar rasgos de personalidad por debajo de la norma. Los análisis demostraron relaciones significativas entre la gente obesa y cada uno de los rasgos de personalidad con menor prevalencia que mide la escala.

  6. ambiental

    Directory of Open Access Journals (Sweden)

    Roque Leal Salcedo

    2008-01-01

    Full Text Available El derecho internacional ambiental es un conocimiento de carácter transversal, que entre otras consideraciones refleja las preocupaciones de la sociedad por la implementación de un modelo de desarrollo sustentable para el respeto a las reglas del medio natural que garantizan la integridad y renovación de los sistemas naturales. El presente artículo enfoca esta visión a través del análisis de material documental revisado, entre ellos tratados internacionales que permiten distinguir el desarrollo del derecho internacional ambiental y el papel de Organización de las Naciones Unidas (ONU, en el propósito común del derecho individual y colectivo de disfrutar de una vida, un ambiente seguro, sano y ecológicamente equilibrado. En función a estas disertaciones las consideraciones finales exponen parte de la visión que ha estructurado la ONU y que representan un aporte considerable en el fomento de la conciencia mundial sobre la necesidad de establecer vínculos entre las naciones para el continuo desarrollo de esta rama del derecho.

  7. Distimia: estudio descriptivo y rasgos de personalidad.

    Directory of Open Access Journals (Sweden)

    Sergio Ocio León

    1994-01-01

    Full Text Available Se exponen los resultados de una investigación sobre una muestra de pacientes distímicos, diagnosticados siguiendo criterios CIE-10, Ya los que se realizó la sección E (Depresión de la CIDI Medular (primera versión autorizada de la Entrevista Diagnóstica Compuesta. Los datos en que se ha centrado el estudio son: sociodemografía, antecedentes de trastorno psiquiátrico, características clínicas y rasgos de personalidad (según el cuestionario de personalidad 16-PF. Los resultados nos acercaron al conocimiento del trastorno distímico, así como al manejo de la CIE-10. Destaca el carácter objetivamente moderado de la sintomatología distímica, su frecuente asociación a lo largo de la evolución con otro trastorno depresivo, y la existencia de unos rasgos de personalidad predominantes en este tipo de pacientes

  8. Matutinidad-vespertinidad y ansiedad rasgo en adolescentes

    Directory of Open Access Journals (Sweden)

    Mª. José Collado-Mateo

    2013-01-01

    Full Text Available El objetivo de este trabajo fue estudiar la relación entre la matutinidad-vespertinidad y la ansiedad rasgo en adolescentes. La muestra estaba formada por 638 adolescentes de 12 a 14 años. Se midió la matutinidad-vespertinidad mediante la Escala de Matutinidad-Vespertinidad para Niños, MESC (Carskadon, Vieira y Acebo, 1993 y la ansiedad rasgo mediante el Inventario de Ansiedad Estado-Rasgo para niños, STAIC (Spielberger, Edwards, Lushene, Montuori y Platzek, 1973; Spielberger, Edwards y Lushene, 1990. Los resultados indicaron que las chicas eran más vespertinas, que la vespertinidad aumentaba con la edad y una relación negativa entre matutinidad y ansiedad rasgo. Aquellos adolescentes más vespertinos obtuvieron una mayor ansiedad rasgo, posiblemente debido a un mayor desajuste entre los ritmos biológicos y sociales (horarios escolares matutinos.

  9. Algunos rasgos del lenguaje del niño ciego

    OpenAIRE

    Pérez Pereira, Miguel

    1991-01-01

    Se somete a crítica la denominada perspectiva tradicional sobre el desarrollo del lenguaje de los niños ciegos. Según ésta, los niños ciegos, debido a los efectos que sobre su desarrollo cognitivo tendrá la carencia de información visual, presentarán un retraso en su desarrollo lingüístico, así como ciertos rasgos de éste que lo hacen defectuoso. Los análisis efectuados, en que se compara una niña ciega de nacimiento con su hermana gemela con visión, indica...

  10. Rasgos del temperamento de los perros domésticos (Canis familiaris: evaluaciones conductuales

    Directory of Open Access Journals (Sweden)

    ADRIANA JAKOVCEVIC

    2009-01-01

    Full Text Available Los rasgos del temperamento se definen como tendencias conductuales estables entre situaciones similares y a lo largo del tiempo. En el presente trabajo se revisan las pruebas conductuales diseñadas para la evaluación de rasgos aislados del temperamento en los perros domésticos. Para cada dimensión se describen los estímulos empleados, las respuestas evaluadas y el correlato psiológico de las mismas. Los rasgos más estudiados fueron la temerosidad, la agresividad y la sociabilidad. Sin embargo, sólo la primera cuenta con correlatos psiológicos bien establecidos. Finalmente, las evaluaciones conductuales resultan de suma importancia para la selección de los perros para las distintas funciones que cumplen en la sociedad humana: detección de drogas, compañía, guardia, rescate de personas, etc.

  11. El docente investigador: su génesis teórica y sus rasgos

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    Natalia Campos Saborío

    2003-01-01

    Full Text Available El propósito de este artículo es enunciar los rasgos que caracterizan al docente investigador. Para ello, me ubico en el contexto teórico, desde dónde conceptualizo sus calidades, a saber: visión de mundo, de paradigma curricular, y de investigación educativa

  12. Prediction in Ungauged Estuaries

    OpenAIRE

    J. I. A. Gisen

    2015-01-01

    Estuaries have been used for settlement by humans since 5000-9000 years ago [Day et al., 2012]. The calm environment and nutrient-rich soil encouraged the development of ports and agriculture. Over-development however has put estuaries in unhealthy condition, where the water is polluted (excessive nutrient or salt intrusion problem) and natural morphodynamic equilibrium is disturbed. This implies that the need for effective estuarine management is crucial. Unfortunately, most of the estuaries...

  13. Estuary Classification Revisited

    OpenAIRE

    Guha, Anirban; Lawrence, Gregory A.

    2012-01-01

    This paper presents the governing equations of a tidally-averaged, width-averaged, rectangular estuary in completely nondimensionalized forms. Subsequently, we discover that the dynamics of an estuary is entirely controlled by only two variables: (i) the Estuarine Froude number, and (ii) a nondimensional number related to the Estuarine Aspect ratio and the Tidal Froude number. Motivated by this new observation, the problem of estuary classification is re-investigated. Our analysis shows that ...

  14. Prediction in Ungauged Estuaries

    NARCIS (Netherlands)

    Gisen, J.I.A.

    2015-01-01

    Estuaries have been used for settlement by humans since 5000-9000 years ago [Day et al., 2012]. The calm environment and nutrient-rich soil encouraged the development of ports and agriculture. Over-development however has put estuaries in unhealthy condition, where the water is polluted (excessive n

  15. Estuary Classification Revisited

    CERN Document Server

    Guha, Anirban

    2012-01-01

    The governing equations of a tidally averaged, width averaged, rectangular estuary has been investigated. It's theoretically shown that the dynamics of an estuary is entirely controlled by three parameters: (i) the Estuarine Froude number, (ii) the Tidal Froude number and (iii) the Estuarine Aspect ratio. The momentum, salinity and integral salt balance equations can be completely expressed in terms of these control variables. The estuary classification problem has also been reinvestigated. It's found that these three control variables can completely specify the estuary type. Comparison with real estuary data shows very good match. Additionally, we show that the well accepted leading order estuarine integral salt balance equation is inconsitent with the leading order salinity equation in an order of magnitude sense.

  16. La influencia de los rasgos psicológicos en las actitudes hacia el empleo

    Directory of Open Access Journals (Sweden)

    Antonia Mercedes García Cabrera

    2008-01-01

    Full Text Available Esta investigación explica la influencia que el rasgo psicológico locus de control, conjuntamente con las variables que definen el capital humano de un país -género, edad y educación-, ejercen sobre las actitudes hacia el empleo en la República de Cabo Verde. De entre estos rasgos demográficos del individuo, el género es analizado más profundamente debido al interés actual por reducir las desigualdades en razón de género en el mercado laboral. Los 448 cuestionarios recabados muestran que, en este país, los atributos demográficos edad y nivel de estudios, así como el rasgo de personalidad locus de control, son importantes determinantes de las actitudes hacia el empleo de la población activa. Los resultados ofrecen las bases sobre las que redirigir las políticas de empleo en Cabo Verde para afrontar los puntos débiles que limitan el desarrollo del mercado de trabajo y amenazan la integración social.

  17. Penobscot Estuary (Maine) Monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's NEFSC collects fisheries data from the Penobscot Estuary using several types of fishing gear. The data is used to determine species presence, relative...

  18. Bibliography on Alaska estuaries

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This bibliography was compiled to assist in working up “profiles” for the estuaries in Alaska. The purpose of the profiles is to list in a narrative form the...

  19. Evaluación del rasgo textura en tubérculos de Solanum tuberosum grupo Phureja y búsqueda de genes candidatos asociados al rasgo

    OpenAIRE

    Guateque Alba, Magda Alejandra

    2014-01-01

    Solanum tuberosum, es una especie de la familia de las solanáceas. En Colombia, es un alimento básico tanto como consumo en fresco o procesado. Sin embargo, el rasgo de textura no se ha estudiado en profundidad en los tubérculos de papa colombianos. Por tal razón en esta investigación se realizó la fenotipificación precisa de este carácter complejo y se realizó un análisis de asociación genética con marcadores moleculares tipo SNPs, con el fin de acercarse a la comprensión gené...

  20. RASGOS DEL TEMPERAMENTO DE LOS PERROS DOMÉSTICOS (CANIS FAMILIARIS: EVALUACIONES CONDUCTUALES

    Directory of Open Access Journals (Sweden)

    ADRIANA JAKOVCEVIC

    2009-08-01

    Full Text Available

    Los rasgos del temperamento se definen como tendencias conductuales estables entre situaciones similares y a lo largo del tiempo. En el presente trabajo se revisan las pruebas conductuales diseñadas para la evaluación de rasgos aislados del temperamento en los perros domésticos. Para cada dimensión se describen los estímulos empleados, las respuestas evaluadas y el correlato fisiológico de las mismas. Los rasgos más estudiados fueron la temerosidad, la agresividad y la sociabilidad. Sin embargo, sólo la primera cuenta con correlatos fisiológicos bien establecidos. Finalmente, las evaluaciones conductuales resultan de suma importancia para la selección de los perros para las distintas funciones que cumplen en la sociedad humana: detección de drogas, compañía, guardia, rescate de personas, etc.

  1. NEPmap (National Estuary Program Mapper)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The NEPmap is designed to provide information in context with National Estuary Program Study Areas. There are 28 National Estuary Programs (NEPs) in the U.S.that...

  2. Personalidad, ansiedad estado-rasgo e ingreso a la universidad en alumnos preuniversitarios

    OpenAIRE

    Isabel Niño de Guzmán; Arturo Calderón; Marisa Escalante; Tula Lira; Roxanna Morote; Lourdes Ruda

    2000-01-01

    Estudio correlacional que identifica las dimensiones de personalidad, el tipo de ansiedad y las características sociodemográficas de alumnos de un centropreuniversitario. Se trabajó con 318 participantes de ambos sexos (43.8% mujeres y 56.2% hombres), que entre 16 y 19 años. Se los evaluó con los siguientes instrumentos: (a) NEO PI-R de Costa y McCrae (1992), (b) Inventario de Ansiedad Estado-Rasgo de Spielberger (IDARE, 1975) y (c) reporte de los tutores. Los resultados confirman la pre...

  3. Detector automático de rasgos oculares mediante filtros de Gabor

    OpenAIRE

    Cachazo Maroco, Daniel

    2010-01-01

    Proyecto Fin de Carrera leído en la Universidad Rey Juan Carlos en el curso académico 2009/2010. Tutor del Proyecto: Ángel Serrano Sánchez de León En esta investigación biométrica se ha creado un detector automático de rasgos oculares capaz de localizar la ubicación de éstos en la imagen facial de una persona. Los puntos que hemos localizado son los extremos de los ojos y las pupilas. Para ello se van a emplear una serie de wavelets de Gabor, filtros bidimensionales pasabanda c...

  4. Explorando los rasgos de personalidad en adolescentes que manifiestan conductas problemáticas

    OpenAIRE

    Molina Martín, Susana; Inda Caro, Mª de las Mercedes; Fernández García, Carmen María

    2009-01-01

    El objetivo de esta investigación es doble. En primer lugar, estudiamos la adecuación de los datos al modelo de cinco factores, y, en segundo lugar, identificamos los rasgos de personalidad que manifiestan aquellos adolescentes que dicen tener ciertas problemáticas en su vida cotidiana. Para ello utilizamos dos instrumentos de evaluación: el Cuestionario de Personalidad para Adolescentes (16PF-APQ ) y el Cuestionario Autoaplicado de Síntomas que elaboramos a pa...

  5. Especies leñosas nativas claves para la restauración ecológica del Embalse de Chisacá, Colombia, con base en rasgos importantes de su historia de vida

    Directory of Open Access Journals (Sweden)

    Rodríguez Ramírez Natalia

    2006-12-01

    Full Text Available Se determinaron cinco especies nativas leñosas, como claves para la restauración de plantaciones de Pinus patula
    y Corredor ripario potrerizado del embalse de Chisacá (localidad de Usme, Bogotá, Colombia 3.000-3.250
    msnm; 4°08’59’’ N; 74°17’62’’ W, con base en Rasgos de de Historia de Vida (RHV y otras características de
    especies presentes en estas áreas. Teniendo en cuenta el objetivo del estudio y las características de las áreas
    degradadas se seleccionaron y analizaron 23 rasgos a cada una de las especies evaluadas en los distintos ambientes. En la zona de pinos se estudiaron 23 especies, 21 en el corredor ripario potrerizado y 20 en el Matorral Bajo. Se estableció un sistema de calificación para las posibles respuestas de cada uno de los rasgos según su incidencia en la restauración ecológica de las áreas a restaurar. Posteriormente, se calificaron los resultados de los rasgos de cada una de las especies y se calculó una calificación final de éstas. Se recomiendan como especies claves para la restauración las cinco especies que obtuvieron mayor calificación final. Teniendo en cuenta lo anterior se recomiendan como especies claves para la restauración de la zona de pinos las especies Hesperomeles goudotiana (72,41%, Vallea stipularis (67,82%, Symplocos s theiformis (67,82%, Holodiscus argenteus (65,52%, y Myrcianthes leucoxyla (65,52% y para el corredor ripario potrerizado las especies Hesperomeles goudotiana (75,86%, Brugmansia sanguinea (74,71%, Myrcianthes leucoxyla (68,97%, Berberis goudotii (65,48% y Vallea stipularis (64,37%. La selección de especies claves para la restauración con base en RHV parece ser una metodología adecuada, siempre y cuando la selección de rasgos se haga cuidadosamente, teniendo en cuenta
    los objetivos del estudio y que las especies consideradas se estudien en cada ambiente donde se desarrollen. En
    efecto, se observó que los rasgos responden de

  6. Ambient Space and Ambient Sensation

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    The ambient is the aesthetic production of the sensation of being surrounded. As a concept, 'ambient' is mostly used in relation to the music genre 'ambient music' and Brian Eno's idea of environmental background music. However, the production of ambient sensations must be regarded as a central...... aspect of the aesthetization of modern culture in general, from architecture, transport and urbanized lifeforms to film, sound art, installation art and digital environments. This presentation will discuss the key aspects of ambient aesthetization, including issues such as objectlessness...

  7. Nivel de pensamiento, rasgos de personalidad y promedios académicos en estudiantes universitarios

    Directory of Open Access Journals (Sweden)

    Elda Cerchiaro

    2013-10-01

    Full Text Available El presente artículo recoge los aspectos más destacados de la investigación desarrollada en el año 2004 en la Universidad del Magdalena, centrada en establecer la relación entre nivel de pensamiento, rasgos de personalidad y promedios académicos en estudiantes universitarios. Los resultados arrojados por este estudio nos permitieron aproximarnos a una caracterización de los estudiantes de la Universidad del Magdalena en relación con el nivel de pensamiento que poseen, asociado a unos rasgos o factores de personalidad que, de alguna forma, se relacionan con altos promedios académicos, llevándonos a establecer tendencias por programas académicos, fundamentales para construir estrategias de intervención cognitiva muy acordes con las necesidades detecta-das. Así mismo, estos hallazgos ofrecen una oportunidad para revisar el verdadero sentido del rendimiento académico como expresión de las competencias que el estudiante ha desarrollado a través de su proceso formativo. (Duazary; 2006: 80-88

  8. Anthropogenic Carbon Pump in an Urbanized Estuary

    Science.gov (United States)

    Park, J. H.; Yoon, T. K.; Jin, H.; Begum, M. S.

    2015-12-01

    The importance of estuaries as a carbon source has been increasingly recognized over the recent decades. However, constraining sources of CO2 evasion from urbanized estuaries remains incomplete, particularly in densely populated river systems receiving high loads of organic carbon from anthropogenic sources. To account for major factors regulating carbon fluxes the tidal reach of the Han River estuary along the metropolitan Seoul, characterization of organic carbon in the main stem and major urban tributaries were combined with continuous, submersible sensor measurements of pCO2 at a mid-channel location over a year and continuous underway measurements using a submersible sensor and two equilibrator sytems across the estuarine section receiving urban streams. Single-site continuous measurements exhibited large seasonal and diurnal variations in pCO2, ranging from sub-ambient air levels to exceptionally high values approaching 10,000 ppm. Diurnal variations of pCO2 were pronounced in summer and had an inverse relationship with dissolved oxygen, pointing to a potential role of day-time algal consumption of CO2. Cruise measurements displayed sharp pCO2 pulses along the confluences of urban streams as compared with relatively low values along the upper estuary receiving low-CO2 outflows from upstream dams. Large downstream increases in pCO2, concurrent with increases in DOC concentrations and fluorescence intensities indicative of microbially processed organic components, imply a translocation and subsequent dilution of CO2 carried by urban streams and/or fast transformations of labile C during transit along downstream reaches. The unique combination of spatial and temporal continuous measurements of pCO2 provide insights on estuarine CO2 pulses that might have resulted from the interplay between high loads of CO2 and organic C of anthropogenic origin and their priming effects on estuarine microbial processing of terrigenous and algal organic matter.

  9. Atención y ansiedad: relaciones de la alerta y el control cognitivo con la ansiedad rasgo

    OpenAIRE

    Alberto Acosta; Juan Lupiáñez; Antonia Pilar Pacheco-Unguetti

    2009-01-01

    En este trabajo se describe un experimento en el que se evalúa el funcionamiento de las redes atencionales de alerta, orientación y control cognitivo en participantes con ansiedad rasgo alta vs. baja, con el fin de precisar su eficiencia diferencial. La red de alerta se manipuló incorporando sonidos afectivos agradables y desagradables, además de neutros. Se observó un efecto de los niveles de ansiedad sobre la red de control. Los participantes con alta ansiedad rasgo tuvieron mayores niveles...

  10. Validación del Inventario de Ansiedad Rasgo-Estado para Niños en adolescentes cubanos

    OpenAIRE

    Lorenzo Ruiz, Alexis; Hospital Pediátrico de Tarará; Grau Abalo, Jorge; Instituto Nacional de Oncología y Radiobiología (INOR); Fumero Madam, Angelina; Hospital Pediátrico de Tarará; Vizcaíno Londián, María de los A.; Hospital Universitario “William Soler”; Martín Carbonell, Martha; Instituto de Angiología y Cirugía Vascular; Prado Torres, Francisco C.; Instituto Superior Politécnico “J. A. Echevarría”

    2014-01-01

    Existe una amplia variedad de conceptualizaciones e instrumentos sobre la ansiedad. Fue Charles D. Spielberger, en 1966, quien destacó la necesidad de distinguir entre la ansiedad como un estado emocional transitorio (ansiedad-estado) y como un rasgo de personalidad relativamente estable (ansiedad-rasgo). De conformidad con esta distinción, desarrolló el State-Trait Anxiety Inventory for Children (STAIC) para el estudio de la ansiedad en niños estadounidenses. En el presente trabajo se utiliz...

  11. Rasgos del componente ético en el cumplimiento de la gestión empresarial social de la pequeña y mediana empresa de la región Paraguaná

    Directory of Open Access Journals (Sweden)

    Mercy Narváez

    2009-01-01

    Full Text Available Para ser una empresa de avanzada no sólo es necesario poseer capacidades distintivas y hacer el mejor uso de los recursos disponibles, sino se hace imprescindible construir la empresa sobre la base de una mayor solidaridad y cooperación social. Bajo esta premisa se plantea el presente artículo, el cual tiene como propósito analizar los rasgos del componente ético en la gestión empresarial del sector de las PyME´s proveedor de servicios a la industria petrolera nacional. En tal sentido, se elaboró un estudio de tipo descriptivo, no experimental transeccional; estableciéndose un censo poblacional de doce (12 empresas ubicadas en la Península de Paraguaná. Los resultados de la investigación muestran una alta presencia en las empresas de los rasgos: calidad, confianza y credibilidad, los cuales son considerados necesarios para funcionar sobre la base de ser organizaciones socialmente admisibles. Sin embargo, se destaca la poca valoración otorgada a los rasgos de innovación y responsabilidad social. Se concluye que es necesario fortalecer las relaciones de las empresas objeto de estudio en su dimensión interna - externa; legitimar la imagen de las mismas por su vinculación con los empleados, su entorno social-ambiental; difundir sus logros económicos y sociales. De esta manera, las acciones que emprendan las distinguirán de sus competidores, generando así un patrón de prestación de servicios que las harán más atractivas a los clientes.

  12. Ambient Sensors

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under th

  13. Det ambiente

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Om begrebet "det ambiente", der beskriver, hvad der sker, når vi fornemmer baggrundsmusikkens diskrete beats, betragter udsigten gennem panoramavinduet eller tager 3D-brillerne på og læner os tilbage i biografsædet. Bogen analyserer, hvorfan ambiente oplevelser skabes, og hvilke konsekvenser det...

  14. Transformaciones actuales del poder punitivo. Caracterización de sus principales rasgos

    Directory of Open Access Journals (Sweden)

    Ricardo Antonio Cita Triana

    2012-12-01

    Full Text Available El documento aborda el tema de las recientes transformaciones del poder punitivo, a partir de dos niveles de análisis: el primero se ocupa de la descripción de los principales elementos contextuales en los que se insertan los cambios; el segundo desarrolla los rasgos generales que caracterizan estas transformaciones del poder punitivo en este momento. El propósito central es desarrollar un diagnóstico que permita detectar los principales y actuales problemas que enfrenta el discurso jurídico-penal y político criminal y, de este modo, contribuir a la determinación de nuevos escenarios de investigación de relevancia en la actualidad.

  15. Actitudes de docentes mujeres de nivel primaria con respecto a rasgos femeninos en alumnos varones

    Directory of Open Access Journals (Sweden)

    Jorge Armando Revilla Fajardo

    2008-01-01

    Full Text Available La presente investigación tuvo como propósito detectar la actitud de las docentes mujeres de escuela primaria acerca de la presencia de rasgos femeninos en alumnos varones. Se llevaron a cabo entrevistas con tres docentes mujeres de escuelas públicas de nivel primario. En el análisis de los resultados se ponen de relieve dos conclusiones básicas: las prácticas sociales como constituyentes de las expectativas individuales de cada docente y la presencia constante de procesos de evaluación social sobre el comportamiento del niño, los cuales se justifican en términos del bien del niño.

  16. Personalidad, ansiedad estado-rasgo e ingreso a la universidad en alumnos preuniversitarios

    Directory of Open Access Journals (Sweden)

    Isabel Niño de Guzmán

    2000-12-01

    Full Text Available Estudio correlacional que identifica las dimensiones de personalidad, el tipo de ansiedad y las características sociodemográficas de alumnos de un centropreuniversitario. Se trabajó con 318 participantes de ambos sexos (43.8% mujeres y 56.2% hombres, que entre 16 y 19 años. Se los evaluó con los siguientes instrumentos: (a NEO PI-R de Costa y McCrae (1992, (b Inventario de Ansiedad Estado-Rasgo de Spielberger (IDARE, 1975 y (c reporte de los tutores. Los resultados confirman la presencia de una estructura factorial básica de cinco dimensiones. Asimismo, revelan correlaciones significativas entre el C.I., características de personalidad asociadas al factor conciencia e ingreso a la universidad. Entre las facetas que correlacionan con el ingreso destaca la autodisciplina. Finalmente, se discuten los resultados.

  17. Det Ambiente

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Det ambiente er iscenesættelsen af en karakteristisk sanseoplevelse, der er kendetegnet ved fornemmelsen af at være omgivet. I dag bliver begrebet om det ambiente mest anvendt i forbindelse med musikgenren ’ambient musik’. Det ambiente er dog ikke essentielt knyttet til det musikalske, men må...... forstås som et betydeligt bredere fænomen i den moderne æstetiske kultur, der spiller en væsentlig rolle i oplevelsen af moderne transportformer, arkitektur, film, lydkunst, installationskunst og digitale multimedieiscenesættelser. En forståelse af det ambiente er derfor centralt for forståelsen af en...... moderne æstetiseret oplevelseskultur i almindelighed. Da det ambiente ikke hidtil har været gjort til genstand for en mere indgående teoretisk behandling, er der dog stor usikkerhed omkring, hvad fænomenet overhovedet indebærer. Hovedformålet med Det ambiente – Sansning, medialisering, omgivelse er derfor...

  18. Trazos de método para detectar los rasgos institucionales en académicos de universidades públicas mexicanas ante los estímulos federales

    Directory of Open Access Journals (Sweden)

    Rosalía S. Lastra B.

    2008-01-01

    Full Text Available El contenido del presente artículo esboza los rasgos más generales detectados como subyacentes en el ambiente universitario mexicano en torno al sistema público de evaluación y estímulos federales a académicos. Dichos rasgos se presentan a partir de la depuración de información que resultó relevante en la revisión sociohistórica de la educación superior, apoyados en el enfoque del Nuevo Institucionalismo Sociológico (NIS. A continuación se establecen las preguntas esenciales que resultaron significativas, y la propuesta de un método para detectar los componentes institucionales que se afirma, permiten acceder al conocimiento de la percepción -armónica o contradictoria con la visión oficial- de los integrantes de cada ápice académico universitario.1 El fin último es establecer dispositivos comunicacionales que faciliten el logro de consensos universitarios, mejoren el funcionamiento organizacional y el análisis de la consciencia con que desde el sector educativo público superior son emitidas señales axiológicas a la sociedad.

  19. Ambient Gestures

    OpenAIRE

    Karam, Maria; Hare, Jonathon; Lewis, Paul; schraefel, m.c.

    2006-01-01

    We present Ambient Gestures, a novel gesture-based system designed to support ubiquitous ‘in the environment’ interactions with everyday computing technology. Hand gestures and audio feedback allow users to control computer applications without reliance on a graphical user interface, and without having to switch from the context of a non-computer task to the context of the computer. The Ambient Gestures system is composed of a vision recognition software application, a set of gestures to be p...

  20. Rasgos de personalidad asociados con la ejecucion de determinados instrumentos musicales

    Directory of Open Access Journals (Sweden)

    Viviana Noemí Lemos de Ciuffardi

    2000-01-01

    Full Text Available El presente estudio tuvo como objetivo evaluar la relación existente entre la ejecución de determinados instrumentos musicales y los rasgos recurrentes de personalidad, en una muestra compuesta por 222 músicos profesionales y alumnos avanzados en el estudio de un instrumento musical. Se utilizó el Revised NEO Personality Inventory (NEO-PI-R de Costa y McCrae (1992, que permite evaluar diferentes rasgos de personalidad basándose en el modelo teórico de los cinco grandes factores de personalidad. Los resultados indicaron que existe una relación significativa entre las familias de instrumentos musicales (cuerdas, vientos bronce, vientos madera y las distintas facetas de personalidad contempladas por el NEO-PI-R (F de Hotelling = .97; P = .017. Esta relación significativa también se observó en los instrumentos específicamente seleccionados: (a flauta traversa, (b clarinete, (c trompeta, (d piano, (e guitarra, y (f saxofón; (F de Hotelling = 2.07; P = .002 Ylos cinco"grandes factores de personalidad que operacionaliza el NEO-PI-R. También se encontró una asociación significativa entre el sexo de los sujetos y la elección de ejecutar determinados instrumentos musicales. Los resultados por familias de instrumentos musicales dieron X2 (4, N~ 208 = 2.23; P = .000 y los resultados por instrumentos específicos elegidos dieron X2 (5, N=76 = 5.37 ; P = .000. Los factores cuyas relaciones resultaron significativas fueron: 1.- Extraversión: (cantidad e intensidad de las interacciones interpersonales. Dentro de este factor las facetas cuyas relaciones puntuaron estadísticamente significativas fueron: (a Sentimiento Gregario, (b Asertividad, (c Búsqueda de Excitación, y (d Emociones Positivas. Los instrumentistas que obtuvieron puntajes más altos en estas facetas fueron los ejecutantes de vientos bronces y quienes obtuvieron los puntajes más bajos fueron los ejecutantes de cuerdas, especialmente la guitarra y también al piano. 2

  1. Rasgos de personalidad, bienestar psicologico y rendimiento academico en adolescentes argentinos

    Directory of Open Access Journals (Sweden)

    Alejandro Castro Solano

    2001-01-01

    Full Text Available Las diferencias individuales en el rendimiento escolar obedecen a tres tipos de factores: los intelectuales, los de aptitud para el estudio y los de personalidad. Los dos primeros han sido ampliamente estudiados. Recientemente comenzaron a surgir investigaciones que señalan que los factores exclusivamente intelectuales son pobres predictores del rendimiento académico a largo plazo y del éxito laboral fuera de los entornos educativos. Una gran cantidad de estudios revela que las variables de personalidad son importantes predictores de las adaptaciones que las personas realizan a los diferentes contextos en los cuales les toca vivir. El enfoque de los cinco factores de personalidad ha sido ampliamente estudiado, sin embargo casi no existen estudios con este enfoque en población adolescente, específicamente estudios locales. El presente trabajo tiene como objetivo replicar la estructura pentafactorial de los rasgos de personalidad en adolescentes de 13 a 19 años. Asimismo se analiza cuales son los rasgos de personalidad que están más relacionados con el logro académico y si existe alguna asociación entre el rendimiento académico y el bienestar autopercibido derivado de la adaptación efectiva a determinados contextos vitales relevantes para los jóvenes. Participaron de este estudio 337 jóvenes que vivían en la Ciudad de Buenos Aires y en el conurbano bonaerense (Argentina. Se aplicó el Cuestionario de los Cinco Factores de Personalidad (BFI de John (1990, como así también una encuesta sobre rendimiento esco- lar y otra sobre satisfacción vital por áreas (Escala D-1 de Andrews y Withey, 1976. Los resultados señalan que en adolescentes argentinos se verifica la misma estructura pentafactorial que en jóvenes estadounidenses. La dimensión conciencia apareció como el componente más relacionado con el mejor rendimiento. La dimensión neuroticismo no diferenciaba entre jóvenes con alto y bajo rendimiento.

  2. Rasgos de personalidad en trastornos de la conducta alimentaria, evolución y gravedad de los síntomas

    OpenAIRE

    Camarillo Gutiérrez, Leticia

    2015-01-01

    El trabajo estudia la relación e influencia de los rasgos de personalidad en los diferentes diagnósticos así como en la gravedad de la sintomatología de los Trastornos de la Conducta Alimentaria. Estos rasgos pueden influir en diferentes síntomas asociados a los Trastornos de la Conducta Alimentaria como son la ansiedad, depresión, abuso de alcohol, impulsividad, la actitud frente a la alimentación y la actitud frente a la propia enfermedad. Se trabaja con el esquema de rasgos de personalida...

  3. Rasgos psicopáticos infanto-juveniles: evaluación e implicaciones en un estudio prospectivo

    Directory of Open Access Journals (Sweden)

    Estrella Romero

    2016-01-01

    Full Text Available En este trabajo se analizan los datos de un estudio longitudinal a largo plazo con el objetivo de examinar las implicaciones de los rasgos psicopáticos infanto-juveniles, evaluados a través de la mCPS (modified Child Psychopathy Scale, en la conducta antisocial en la adolescencia. Se analizan los datos recogidos en 141 niños (edad media = 7.80, que fueron seguidos seis y diez años más tarde. Los resultados muestran que los niños con altas puntuaciones en rasgos psicopáticos presentan en la adolescencia temprana niveles relativamente altos de problemas de conducta. Además, a lo largo de la adolescencia se produce en ellos un mayor incremento en implicación con amigos antisociales, consumo de cannabis y agresión proactiva. Así, los resultados muestran que los rasgos psicopáticos medidos en la niñez se asocian con un desarrollo más desfavorable, particularmente en indicadores que, como la agresión proactiva, se han vinculado clásicamente a la personalidad psicopática en adultos.

  4. Indicadores de ansiedad en el DFH y rasgos de personalidad en niños: un estudio de validez

    Directory of Open Access Journals (Sweden)

    Marcos Antonio Batista

    2014-01-01

    Full Text Available Este estudio tuvo como objetivo la búsqueda de evidencias de validez por medio del análisis de correlación entre los indicadores de ansie - dad de Dibujo de la Figura Humana – DFH - de Karen Machover y la Escala de Rasgos de Personalidad para Niños (ETPPC . Participaron 240 niños, de ambos sexos, con edades comprendidas entre 8 y 10 años, estudiantes de enseñanza básica de la red pública de Brasil. Por medio de los análisis de correlación se demostró que cuando los indicadores DFH son agrupados, existen correlaciones significativas con los rasgos de personalidad, y corroborado con lo esperado, se puede inferir que hay características que convergen una vez que la ansiedad es apenas parte del constructo de rasgos de personalidad como el neuroticismo y la extroversión.

  5. A growth model of the cockle (Cerastoderma edule L.) tested in the Ooosterschelde estuary (The Netherlands)

    NARCIS (Netherlands)

    Rueda, J.; Smaal, A.C.; Scholten, H.

    2005-01-01

    The authors present an ecophysiological model of the bivalve Cerastoderma edule that simulates individual growth and reproduction under ambient conditions in temperature and food availability in the Oosterschelde estuary, SW Netherlands. The model contains feedback loops in the uptake and metabolism

  6. Rasgos Pedagógicos de los Objetos de Aprendizaje Pedagogical Features of Learning Objects

    Directory of Open Access Journals (Sweden)

    Chiappe Laverde Andres

    2008-07-01

    Full Text Available Los objetos de aprendizaje (OA son considerados hoy como una alternativa viable e interesante para el desarrollo de contenidos para programas educativos mediados por las Tecnologías de la Información y la Comunicación (TIC. No obstante la pertinencia del tema para el momento actual de la educación superior en toda Latinoamérica, es preciso reflexionar más en profundidad acerca de lo que significan los OA y su impacto en el proceso educativo. El estudio de los rasgos pedagógicos de los objetos de aprendizaje coloca a la comunidad académica frente a un escenario que requiere la pronta identificación de sus retos y limitaciones de cara a la inminente ejecución de procesos de incorporación de los OA en las dinámicas de las instituciones educativas. Learning objects (LO are regarded today as a viable and interesting alternative for development of content for educational programs mediated by information and communication technologies (ICT. Attending the relevance of this topic just for this historic moment of higher education throughout Latin America, we need to think more deeply about what LO means and its impact on the educational process. The study of the pedagogical features of learning objects placed to the academic community in front of a scenario that requires prompt identification of their challenges and constraints facing the imminent execution of incorporation processes of LO in educational institutions dynamics.

  7. FLORA OF MOLOCHNYI ESTUARY COASTS

    Directory of Open Access Journals (Sweden)

    Kolomiychuk V.P.

    2013-09-01

    Full Text Available Present-day characteristic of the coastal flora of Molochnyi eastury is given, that is one of the largest estuaries in Ukraine, the shores and waters of which in 2009 became a part of the Pryazov’ya National Nature Park. The analysis of the main parameters of the flora is made. Rare component of the estuary coastal flora is characterized, further steps to conserve the nature of Pryazov’ya are proposed.

  8. Análisis intra e inter poblacional de rasgos craneanos no metricos en aborigenes prehispanicos del actual territorio de Córdoba

    Directory of Open Access Journals (Sweden)

    Fabra, Mariana

    2005-01-01

    Full Text Available Recientes investigaciones acerca de la arqueología de sociedades agroalfareras del territorio que actualmente ocupa la provincia de Córdoba, señalan que existió un proceso de diversificación e intensificación diferencial, que terminó definiendo modalidades regionales en los estilos de vida de dichas comunidades. Desde esta perspectiva, los desarrollos llevados a cabo en las sierras y la llanura extraserrana de las zonas centro y sur de Córdoba, difieren en algunos aspectos de aquellos implementados en la zona norte y a su vez, estos dos de los grupos de Traslasierra y San Luis. En este estudio se investigó, a través del análisis de rasgos craneanos no métricos, si esta diversificación cultural se correspondió con diferencias biológicas regionales. Varias técnicas de análisis utilizadas (cluster análisis, autocorrelación espacial y multi-response permutation procedure, permitieron identificar un patrón de agrupamiento regional entre las poblaciones que se asentaron en los diferentes valles serranos, no así las que ocuparon los ambientes de llanura. Por otra parte, al confrontarse la serie Córdoba con otras de Argentina a partir de datos extraídos de la literatura, se puso de manifiesto que Córdoba presenta una mayor similitud con los grupos de Patagonia y Tierra del Fuego, que con los del Noroeste y Noreste de Argentina. A su vez, se evidenció una neta diferenciación entre Córdoba y las restantes series.

  9. Rasgos instrumentales (masculinos y expresivos (femeninos, normativos (típicos e ideales en México

    Directory of Open Access Journals (Sweden)

    Rolando Díaz Loving

    2001-01-01

    Full Text Available Diversas investigaciones han demostrado reiteradamente que los rasgos instrumentales (masculinos y expresivos (femeninos, asignados tradicionalmente de manera diferencial a hombres y mujeres, en realidad se derivan de procesos de socialización y endoculturación que en la actualidad y en algunas culturas ha hecho que estos rasgos.se presenten intensiva e indistintamente en ambos sexos. El desarrollo de instrumentos de medición de estas características y su validación en diversas culturas ha mostrado lo robusto de un constructo teórico multidimensional y dualista que permite no sólo describir de manera clara a las personas, sino que además, demuestra el papel central que juega la normatividad sociocultural en el desarrollo de dichas características. Estos conocimientos y la teoría que los sustenta, han permitido el desarrollo de medidas nuevas de masculinidad y feminidad, que por demostrar el predominio de factores sociales sobre los genéticos, pudieran manifestarse a través de distintas definidoras al ir de una cultura a otra. Con el objeto de identificar los atributos instrumentales y expresivos que describen a hombres y mujeres mexicanas, se realizaron una serie de grupos de enfoque de donde se derivaron 323 adjetivos correspondientes a estas dos dimensiones. Posteriormente, para obtener la normatividad de cada atributo, se aplicó un inventario en el que se pidió a 856 sujetos divididos por sexo y nivel educativo que indicaran qué tan típico e ideal era que hombres y mujeres poseyeran dichos rasgos. Los resultados muestran listados de características expresivas e instrumentales típicas e ideales que fueron reportadas como socialmente deseables o indeseables tanto para hombres como para mujeres. Las listas obtenidas se discuten en términos de género y cultura.

  10. Análisis ontogénico de rasgos craneofaciales robustos en poblaciones humanas de Patagonia

    OpenAIRE

    González, Paula N.

    2007-01-01

    Las poblaciones humanas que habitaron el sur de Patagonia durante el Holoceno tardío presentan rasgos craneofaciales robustos que las diferencian del resto de los humanos modernos. El estudio de los factores causales de la robustez se ha basado en el análisis de individuos adultos, por lo tanto los mecanismos ontogénicos involucrados en la diferenciación de estas poblaciones son aún desconocidos. El objetivo de este trabajo es analizar la ontogenia de la robustez craneofacial en diversas pobl...

  11. Rasgos funcionales en el género Quercus: estrategias adquisitivas frente a conservativas en el uso de recursos

    Directory of Open Access Journals (Sweden)

    E. G. de la Riva

    2014-01-01

    Full Text Available Las especies del género Quercus constituyen uno de los grupos más abundantes e importantes de plantas leñosas de la Península Ibérica, estando su distribución determinada por la disponibilidad de agua, el tipo de suelo y la historia del manejo. El conocimiento de la variación de sus características morfo-funcionales puede ayudarnos a comprender el grado de diversificación de las especies del mismo género y los mecanismos que controlan sus patrones de distribución. Los objetivos principales de este estudio son: (i analizar las relaciones existentes entre los diferentes rasgos funcionales dentro del género Quercus y testar cómo se ajustan a las estrategias de captación de recursos; y (ii comprobar si existe coordinación entre los rasgos medidos a nivel de hoja, tallo y raíz. El muestreo se llevó a cabo en Sierra Morena (Córdoba y la Sierra del Aljibe (Cádiz, cuantificándose rasgos funcionales claves a nivel de hoja, tallo, raíz, tamaño de planta y fisiología en cinco especies de Quercus (Q. canariensis, Q. coccifera, Q. faginea, Q. ilex y Q. suber. Los resultados muestran que las diferentes especies de Quercus presentan claros patrones en sus estrategias funcionales que están relacionados con su distribución, encontrando un gradiente desde especies más conservativas en el uso de recursos en condiciones de menor disponibilidad de agua a especies más adquisitivas en zonas más húmedas. A su vez, se aprecia una coordinación entre los patrones de rasgos funcionales encontrados a nivel de hoja, tallo y de raíz que apoya la existencia de un “espectro de economía” a nivel de la planta entera.

  12. Competencias y rasgos de la ética profesional en los posgrados de la Universidad Iberoamericana-Puebla

    Directory of Open Access Journals (Sweden)

    J. Martín López Calva

    2009-01-01

    Full Text Available En este artículo presentamos los avances de la investigación sobre las competencias y los rasgos de la ética profesional entre los docentes y estudiantes de posgrado de la Universidad Iberoamericana-Puebla, que constituyen los resultados parciales de un proyecto interuniversitario en el que participan quince instituciones mexicanas de educación superior. El objetivo es llegar a proponer lineamientos para la formación de una profesionalidad ética en los posgrados de las universidades del país.

  13. KNOW YOUR ESTUARY: THE WATER THROUGH TIME

    Science.gov (United States)

    This presentation will focus on historical changes in water quality in the Yaquina Estuary, Oregon, and factors which influence water quality within this estuary. Topics presented will include the importance of ocean conditions on water quality in the estuary; historical changes...

  14. Depresión y ansiedad estado/rasgo en internos adscritos al "Programa de Inducción al Tratamiento Penitenciario" en Bucaramanga, Colombia

    Directory of Open Access Journals (Sweden)

    Ana Fernanda Uribe Rodríguez

    2012-12-01

    Full Text Available El artículo describe las características de la depresión y la ansiedad estado/rasgo y su prevalencia en internos adscritos al "Programa de Inducción al Tratamiento Penitenciario" del Instituto Nacional Penitenciario y Carcelario -INPEC- en Bucaramanga, Colombia. La muestra comprendió 112 internos con un promedio de edad de 33 años, a quienes se les aplicó el Inventario de Depresión Estado Rasgo (IDER y el Inventario de Ansiedad Estado Rasgo (STAI. Los resultados indican que un 43,1% realizó su primera transgresión a la norma entre los 8 y 18 años de edad, y un 74,1% presentó consumo de sustancias psicoactivas, mientras los registros de manifestaciones depresivas revelan que el 16,7% la calificó como estado y un 43,68% como rasgo. Por su parte, la afectación ansiosa se mostró en un 8,03% como estado y en un 85,7% como rasgo. De acuerdo con esto, hubo mayor proporción de personas con experiencias previas que desarrollaron cuadros sintomatológicos, que aquellas en las que la situación de encarcelamiento constituye un causante o detonante.

  15. Conciencia ambiental y conducta sustentable relacionada con el uso de energía para iluminación

    Directory of Open Access Journals (Sweden)

    Graciela Lucía Tonello

    2015-06-01

    Full Text Available La conciencia ambiental es definida como un concepto multidimensional que constituye la dimensión actitudinal del comportamiento pro ambiental. En un contexto global y local de crisis energética, el presente trabajo tuvo como objetivos investigar las interrelaciones entre las diferentes dimensiones de la conciencia ambiental y la posible sustentabilidad detrás de conductas relacionadas con el uso de la iluminación, en una muestra de estudiantes universitarios. La metodología incluyó el desarrollo y administración de una encuesta con diferentes secciones para estimar la conciencia ambiental mediante escalas clasificatorias y preguntas sobre percepción de problemas ambientales, la atribución de responsabilidades, escalas estandarizadas de preocupación ambiental, conocimientos ambientales y la propensión al futuro como un rasgo de la personalidad sustentable. Los resultados en general muestran que la temática energética, al menos la referida a la iluminación tomada en este estudio, no es percibida como problemática ambiental sino como una problemática que afecta a nivel individual, y la perspectiva temporal de futuro evidenciada por la muestra está referida al tiempo futuro en sí mismo, más que como rasgo de personalidad sustentable.

  16. Los rasgos de la lírica del exilio en la poética de Luis Cernuda

    Directory of Open Access Journals (Sweden)

    Ana Martínez García

    2015-01-01

    Full Text Available La obra literaria creada en el destierro por los españoles tuvo ciertos caracteres esenciales que le llevan a formar parte de una tendencia distinta, a no ligarse a los movimientos literarios coetáneos que se manifestaban en la península. La lírica fue el género más influenciado por la situación que los exiliados estaban experimentando, razón por la que sus textos pueden dividirse en periodos, con diferentes rasgos, dependientes de la situación histórica que experimentaban: Segunda Guerra Mundial, final de la guerra y afianzamiento del Franquismo, etc. Entre los muchos autores exiliados, Luis Cernuda fue uno de los más reconocidos, donde los rasgos de la poética del destierro estaban presentes, de una forma velada, trágica y sucinta, como era propio de toda su producción.

  17. Mantenimiento o sustitución de rasgos lingüísticos indexados socialmente: migrantes de zonas andinas en Lima

    OpenAIRE

    Carola Mick; Azucena Palacios

    2013-01-01

    ResumenEste artículo investiga la relación entre la formación de “mundos de vida comunicativos individuales” y la construcción de la identidad en migrantes peruanas procedentes de la zona de los Andes en Lima. A partir del análisis lingüístico y discursivo de un corpus de entrevistas semidirigidas con veintidós mujeres migrantes mostramos cómo las ideologías lingüísticas, las que menosprecian rasgos dialectales considerados como típicos de migrantes andinos y las que prestigian los “rasgos li...

  18. Biogeochemical budgets for Tapi Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Bapardekar, M.V.; DeSousa, S.N.; Zingde, M.D.

    Guidelines were followed to calculate the biogeochemical budges for water, salt and nutrients (DIN and DIP) utilizing the above data. For this purpose, the estuary was split into two boxes based on the salinity gradient. The outer box had an average salinity...

  19. El papel del mercado del suelo en la configuración de algunos rasgos socioespaciales de las ciudades latinoamericanas

    Directory of Open Access Journals (Sweden)

    Samuel Jaramillo

    1999-01-01

    Full Text Available Una interrogación central orienta la exploración adelantada en este artículo, ¿existen peculiaridades en el funcionamiento de los mercados de tierra en las ciudades latinoamericanas? En contra de lo que suele pensarse entre los especialistas de este tema, este trabajo sostiene que las formas de operación del mercado del suelo urbano en las ciudades latinoamericanas obedece a los patrones generales encontrados en ciudades capitalistas. No obstante, a causa de la presencia de condiciones sociales, políticas y económicas muy particulares de la ciudad latinoamericana, la organización socioespacial de esta ciudad tiene rasgos muy peculiares, presentes a lo largo y ancho del continente. Estos rasgos derivan en parte de las especificidades del proceso de acumulación latinoamericano, caracterizado por ser un régimen de bajos salarios, con grandes desigualdades sociales, un acelerado crecimiento urbano, debilidad estructural del aparato estatal, con presencia de significativos obstáculos a la homogeneización capitalista de la producción de espacio construído. A pesar de la diversidad nacional latinoamericana, sus ciudades han ido configurándose en torno de ciertos rasgos comunes, muy específicos de la región: alejamiento permanente de las élites en una misma dirección, cada vez más lejana del centro histórico, una aparente decadencia socioeconómica de este mismo centro, y una secular segregación socioespacial y heterogeneidad en la producción del espacio. En cada uno de estos casos el mercado ha operado como uno de los reguladores centrales del comportamiento económico, contribuyendo a la gestación de las características mencionadas. No obstante, en algunos casos, sus formas de operación han sido opuestas a las comunmente aceptadas: la salida de las elites del centro sería en parte voluntaria y en parte obligada por la competencia impuesta por otros usos, más populares, altamente rentables; esta salida esta léjos de

  20. Rasgos de historia de vida de especies pioneras en la Reserva Natural Ibanasca (Ibagué, Tolima, Colombia

    Directory of Open Access Journals (Sweden)

    Gómez Ruíz, Pilar Angélica

    2006-12-01

    Full Text Available Los rasgos de historia de vida (RHV son cualidades o atributos propios de cada individuo que representan
    respuestas en aspectos fisiológicos, morfológicos, anatómicos y ecológicos ante las condiciones ambientales
    presentes. En la Reserva Natural Ibanasca se seleccionaron 17 especies de plantas leñosas pioneras y en cada una se evaluaron 18 rasgos relacionados con las fases de dispersión, establecimiento y persistencia con el fin de establecer agrupaciones entre las especies. Con base en un Análisis de Conglomerados se obtuvieron cinco
    grupos en los análisis general y morfológico y cuatro grupos en el análisis de semilla. Además, se estableció
    las correlaciones entre algunas variables obteniendo que altura-área foliar y número de semillas por fruto-área
    foliar se correlacionaban positivamente. Solanum sycophanta, Croton magdalenesis y Brunellia colombiana se agruparon por ser las especies de mayor altura mientras que Inga sp. y Citharexylum subflavecens son las especies de semillas más grandes y pesadas, también están Montanoa quadrangularis y Bocconia frutescens como las especies de mayor tase relativa de crecimiento al tener las mayores áreas específicas foliares y siempre aparte se encontró a Cecropia cf. mutisiana por ser de las más altas, mayor área foliar y mayor producción de semillas. Con
    base en los resultados obtenidos se considera que los rasgos que mejor caracterizan a este grupo de especies son: abundante producción de semillas de fácil dispersión, tasa de crecimiento rápida representada en un área específica foliar grande, tamaños de hoja grandes manifestados en áreas foliares grandes, capacidad de
    regeneración vegetativa, abundante producción de hojarasca y ser heliófilas (tolerantes a la luz. Con base en
    lo anterior pueden proponerse las siguientes especies para una futura restauración ecológica de la Reserva:
    Cecropia cf. mutisiana, Bocconia

  1. El lenguaje de los niños ciegos y la cuestión de los rasgos autistas

    Directory of Open Access Journals (Sweden)

    Miguel Pérez Pereira

    2000-12-01

    Full Text Available Hobson et al. (Brown, Hobson. Lee y Stevenson, 1997; Hobson, Brown, Minter y Lee, 1997 han investigado la similitud entre el autismo y la ceguera congénita. En este artículo se revisa la evidencia empírica a favor de la existencia de rasgos autistas en el lenguaje de los niños ciegos de nacimiento, a la vez que se aportan nuevos datos de investigaciones del autor. Se centra el interés en (a el uso de los pronombres personales, (b el uso de imitaciones y habla formuláica, (c el uso egocéntrico del lenguaje, y (d la capacidad de iniciar conversaciones y de contingencia conversacional. El análisis pone en cuestión la supuesta similitud entre los niños ciegos y los autistas, además parece refutar la teoría de Hobson.

  2. Análisis ontogénico de rasgos craneofaciales robustos en poblaciones humanas de Patagonia

    Directory of Open Access Journals (Sweden)

    González, Paula N.

    2007-01-01

    Full Text Available Las poblaciones humanas que habitaron el sur de Patagonia durante el Holoceno tardío presentan rasgos craneofaciales robustos que las diferencian del resto de los humanos modernos. El estudio de los factores causales de la robustez se ha basado en el análisis de individuos adultos, por lo tanto los mecanismos ontogénicos involucrados en la diferenciación de estas poblaciones son aún desconocidos. El objetivo de este trabajo es analizar la ontogenia de la robustez craneofacial en diversas poblaciones humanas. Se analizaron 5 muestras de individuos subadultos (Sad, de 5 a 15 años y adultos (Ad, procedentes del Noroeste Argentino y Patagonia (n=201. Se emplearon landmarks y semilandmarks con el fin de describir la glabela, los procesos frontal y zigomático, y el mastoides. Para establecer si los rasgos poblacionales específicos se encuentran presentes en Sad se compararon los patrones de ordenación de Ad y Sad obtenidos mediante un análisis de PROTEST. Los resultados indican que el patrón de variación morfológica se establece tempranamente en Sad. Se evaluó si la diferenciación en los Ad de las diversas poblaciones es atribuible al escalamiento ontogénico o a diferencias en las trayectorias. Los resultados muestran que si bien las poblaciones del sur alcanzan un mayor tamaño, las trayectorias ontogénicas entre las poblaciones estudiadas difieren significativamente. Por lo tanto, la robustez se establece tempranamente en la ontogenia postnatal y es modificada por la divergencia en los patrones de cambio en forma asociados a los cambios en tamaño.

  3. Rasgos de sentido de vida del enfoque de resiliencia en personas mayores entre 65 y 75 años

    Directory of Open Access Journals (Sweden)

    Jiménez Segura, Flor

    2004-12-01

    Full Text Available La resiliencia es la capacidad para activar las fortalezas y proteger la integridad personal al enfrentar adversidades, construyendo a partir de éstas. En este estudio se identificaron los ocho rasgos de sentido de vida según el enfoque de resiliencia (Intereses especiales, Metas, Motivación para el logro, Aspiraciones educativas, Optimismo, Persistencia, Fe y Espiritualidad y Sentido de propósito, que han presentado personas adultas mayores de 65 a 75 años durante sus vidas. Los principios teórico-metodológicos utilizados son los del paradigma cualitativo. Se efectuaron entrevistas en profundidad a cuatro mujeres y cuatro hombres que pertenecen al grupo de Envejecimiento Integral de la Universidad de Costa Rica o a la Asociación Gerontológica Costarricense. Aunque la mayoría de las personas adultas mayores participantes en el estudio no identificaron metas claras en la actualidad, durante sus vidas contaron con las condiciones y herramientas personales que contribuyeron con el desarrollo de los rasgos de sentido de vida del enfoque de resiliencia. The concept of resilience centers around the human capacity to rise from adversities and to be strengthened by them. Traits of the Sense of Purpose component of a resilience model (Special interests, Goal directedness, Achievement motivation, Educational aspirations, Hopefulness, Persistence, Faith and Spirituality, and Meaningfulness were identified in older persons 65 to 75 years of age. In-depth interviews were conducted with four women and men who participate in programs that promote healthy development in older adults. Although most of the persons interviewed had difficulty specifying present goals, during their lives and currently they have had the environmental and personal conditions for the strengthening of the traits identified with the presence of a sense of purpose.

  4. Salmon habitat use, tidal-fluvial estuary - Columbia River Estuary Tidal Habitats

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the tidal-fluvial estuary study is to determine the estuary's contribution to the spatial structure and life history diversity of Columbia River salmon...

  5. In-stream PIT detection, estuary wetlands - Columbia River Estuary Tidal Habitats

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the tidal-fluvial estuary study is to determine the estuary's contribution to the spatial structure and life history diversity of Columbia River salmon...

  6. Estuary-wide genetic stock distribution - Columbia River Estuary Tidal Habitats

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the tidal-fluvial estuary study is to determine the estuary's contribution to the spatial structure and life history diversity of Columbia River salmon...

  7. Fluxes of nitrogen in Chaliyar River Estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Xavier, J.K.; Joseph, T.; Paimpillii, J.S.

    The Chaliyar river estuary is a positive coastal plain estuary with total drainage area of 2923 km2. We investigated the estuary's functions as sink and transformer of nutrients (uptake and release, retaining and recycling of nutrients) and relative...

  8. Rasgos postmodernos de la educación ambiental. Una formación pertinente con las nuevas corrientes de pensamiento

    OpenAIRE

    Francisco Javier Perez Rodriguez; Joselin del Valle Albujar Sánchez

    2015-01-01

    Los problemas ambientales que se suscitan a escala global son evidencia de una crisis, la cual es expresión de una coyuntura más profunda que trastoca los fundamentos del pensamiento de la humanidad en toda una era. Esta situación tiene sus causas primigenias en el modo general de conocer que desde el Renacimiento se implantó en gran parte del mundo occidental y que erigió al desarrollo y al progreso como idearios, hecho que finalmente se tradujo en una relación insostenible entre los humanos...

  9. Morphodynamic equilibrium of alluvial estuaries

    Science.gov (United States)

    Tambroni, Nicoletta; Bolla Pittaluga, Michele; Canestrelli, Alberto; Lanzoni, Stefano; Seminara, Giovanni

    2014-05-01

    The evolution of the longitudinal bed profile of an estuary, with given plan-form configuration, subject to given tidal forcing at the mouth and prescribed values of water and sediment supply from the river is investigated numerically. Our main goal is to ascertain whether, starting from some initial condition, the bed evolution tends to reach a unique equilibrium configuration asymptotically in time. Also, we investigate the morphological response of an alluvial estuary to changes in the tidal range and hydrologic forcing (flow and sediment supply). Finally, the solution helps characterizing the transition between the fluvially dominated region and the tidally dominated region of the estuary. All these issues play an important role also in interpreting how the facies changes along the estuary, thus helping to make correct paleo-environmental and sequence-stratigraphic interpretations of sedimentary successions (Dalrymple and Choi, 2007). Results show that the model is able to describe a wide class of settings ranging from tidally dominated estuaries to fluvially dominated estuaries. In the latter case, the solution is found to compare satisfactory with the analytical asymptotic solution recently derived by Seminara et al. (2012), under the hypothesis of fairly 'small' tidal oscillations. Simulations indicate that the system always moves toward an equilibrium configuration in which the net sediment flux in a tidal cycle is constant throughout the estuary and equal to the constant sediment flux discharged from the river. For constant width, the bed equilibrium profile of the estuarine channel is characterized by two distinct regions: a steeper reach seaward, dominated by the tide, and a less steep upstream reach, dominated by the river and characterized by the undisturbed bed slope. Although the latter reach, at equilibrium, is not directly affected by the tidal wave, however starting from an initial uniform stream with the constant 'fluvial' slope, the final

  10. La mineralización aurífera en Cuba: clasificación y rasgos geológico-geoquímicos para la prospección

    Directory of Open Access Journals (Sweden)

    Roberto Díaz-Martínez

    2001-03-01

    Full Text Available En Cuba existe una gran diversidad de yacimientos y manifestaciones minerales auríferos, de tipo oro epitermal, asociados a VMS, relacionados con pórfidos, residuales, placeres, etc.; sin embargo, no existe aún una clasificación de los mismos que considere el tipo de depósito y sus diferentes estilos, los rasgos esenciales del marco geológico, las particularidades de la mineralización, los tipos de alteraciones acompañantes, los indicadores geoquímicos y mineralógicos, entre otros aspectos de interés. En este artículo se propone una clasificación para los depósitos auríferos cubanos, tomando como referencia la clasificación propuesta por Corbett y Leach (1995, en la cual se integran criterios de numerosos autores. Especial atención se le presta a algunos distritos poco estudiados y con una mineralización aurífera muy particular, como son los distritos Santa Clara, Holguín y Sagua-Baracoa, desarrollados fundamentalmente dentro de un ambiente geológico con predominio de los complejos de la asociación ofiolítica

  11. Mercury enrichment in sediments of Amba estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Rokade, M.A.; Zingde, M.D.

    -grained bed material in water resulting in high and variable suspended particulate matter (SPM) in the estuary. The estuary receives treated effluent from a petrochemical complex directly in the segment off Mankule and several other industries via... that the Hg load transferred via the plume of the Patalganga Estuary is distributed throughout the Amba Estuary. The minimum in the Hg profiles generally falls at stations 4-5 (Fig. 2). This is also the segment of low Al and/or Fe content of sediment...

  12. ambientes mediterráneos

    Directory of Open Access Journals (Sweden)

    G. Escribano-Ávila

    2015-01-01

    Full Text Available A nivel global, dos tendencias opuestas gobiernan el uso de la tierra: la intensificación y el abandono. Esta última supone una oportunidad para larecuperación de los ecosistemas, una necesidad urgente dada la actual crisis ambiental. La comunidad de dispersores frugívoros es determinantepara recuperar la estructura y complejidad de la vegetación en campos abandonados, ya que éstos suelen estar desprovistos de propágulos.Recientes estudios han resaltado la especial relevancia de los mamíferos frugívoros en el proceso de dispersión de semillas en ambientesdegradados como los campos abandonados. Esto es debido a una serie de rasgos morfológicos y de comportamiento que caracterizan a losfrugívoros mamíferos y que les hace ser dispersores especialmente efectivos. Generalmente los mamíferos frugívoros tienen un mayor tamañocorporal, mayores áreas de campeo y distancias de dispersión, frecuente uso de hábitats abiertos, movilizando así más semillas hasta los camposabandonados que otros grupos de frugívoros (e.g. aves. Una vez que una semilla ha sido depositada tiene que superar las sucesivas etapas hastael establecimiento (depredación post-dispersiva, germinación, supervivencia y crecimiento. Los mamíferos frugívoros favorecen todo este procesoen mayor medida que otros dispersores. A nivel interespecífico pueden dispersar mayor diversidad de especies al estar generalmente menoslimitados por el tamaño de fruto, y a nivel intra-especifico no seleccionan semillas de pequeño tamaño. Además, suelen depositar las semillas enmicrohábitats que resultan especialmente adecuados para el reclutamiento. En consecuencia, los mamíferos son un elemento clave en los ensamblesde frugívoros que propician la regeneración de los campos abandonados y su función ecológica debe ser considerada en la restauración y manejode hábitats degradados.Palabras clave: áreas degradadas; bosque remanente; cambio de los usos del suelo; dispersi

  13. Diet-induced developmental plasticity in life histories and energy metabolism in a beetle La dieta induce plasticidad del desarrollo en los rasgos de historia de vida y metabolismo energético en un escarabajo

    Directory of Open Access Journals (Sweden)

    SERGIO URREJOLA

    2011-12-01

    Full Text Available Adaptive phenotypic plasticity, has been recognized as an important strategy by which organisms maximize fitness in variable environments, which vary through development. A disassociation among stages should represent a null effect of the environment experienced during early ontogeny in the expression of adult traits. Food quality greatly influences survival, development and reproduction in many arthropod herbivores. We examined the effects of diet protein in physiological and life-history traits in the yellow mealworm beetle Tenebrio molitor through ontogeny. We established four experimental treatments: Low Protein (LP, Low Protein Control (LPC, High Protein (HP, and High Protein Control (HPC with recently eclosioned larvae each. Individuals were maintained on the same diet or transferred to the opposite diet for all pupae period and almost all adult period. Contrary to the expected, the duration of life-cycle, larval growth rate and body mass in T. molitor were similar in diet treatments. We found intra-individual trade-offs between environmental diet (rich or poor in protein content during larval phase and egg number. Larvae fed on a protein-deficient diet exhibited significantly higher respiratory rates than larvae fed on a rich protein diet. Compensatory feeding could act in T. molitor larvae indicating differences in metabolism but not in growth rate, body mass and life-cycle characteristics. Our results demonstrate the plasticity of reproductive and metabolic traits and life-cycle characteristics of T. molitor and how changes that occur in relation to diet can have profound effects on progeny and female fitness.La plasticidad fenotípica adaptativa ha sido reconocida como una estrategia importante por el cual los organismos maximizan su adecuación biológica en ambientes variables y la cual varía a lo largo del desarrollo. En los organismos la plasticidad fenotípica generalmente se refiere a como los diferentes tipos de rasgos pueden

  14. ANSIEDAD, DEPRESIÓN Y RASGOS DE PERSONALIDAD EN PACIENTES CON INSUFICIENCIA VENOSA CRÓNICA PERIFÉRICA

    Directory of Open Access Journals (Sweden)

    L A Carmona-López

    2016-07-01

    Full Text Available Introducción: La Insuficiencia Venosa Crónica Periférica (IVCP es un cambio clínico que se produce como resultado de la dilatación patológica de las venas en los miembros inferiores, de la incompetencia de sus válvulas y de la hipertensión venosa resultante. Pudiera cursar dentro de la categoría de trastornos sistémicos que producen depresión y ansiedad, las cuales a su vez son alteraciones psiquiátricas relacionadas con toda la esfera cardiovascular. Objetivo: Determinar la frecuencia de ansiedad, depresión y su relación con los rasgos de personalidad, en pacientes con Insuficiencia Venosa Crónica Periférica. Metodología: Se realizó un trabajo de tipo descriptivo, de corte transversal. Se utilizó la escala de Hamilton para ansiedad y depresión; la personalidad fue evaluada con el cuestionario Factorial de Personalidad 16 FP de Catell además de otras variables sociodemográficas. Resultados: Se evaluaron 30 pacientes; 93% (N=28 de sexo femenino, 7% (N=2 de sexo masculino diagnosticados. Con edades entre 25 y 74 años; encontrándose 36,7% (N=11 ansiedad severa, seguida de ansiedad menor en 33,3% (N=10. 50% de los pacientes no presentó depresión, y 50% se distribuyó de forma homogénea en leve, moderada y severa. Predominando personalidad que se le dificulta manejar las frustraciones, suelen ser nerviosos o ansiosos ante ciertas circunstancias, suspicaces, inteligentes y leales a nivel grupal. El rasgo de personalidad que predominó en el grupo de estudio es el de tipo ansioso. Conclusión: Los pacientes con insuficiencia venosa crónica periférica tienen inclinación a la ansiedad con dificultades para manejar la frustración. Palabras claves: Insuficiencia venosa, Ansiedad, Depresión, Personalidad

  15. Organic matter processing in tidal estuaries

    NARCIS (Netherlands)

    Middelburg, J.J.; Herman, P.M.J.

    2007-01-01

    Processing of organic matter in tidal estuaries modifies its transfer from the river to the sea. We examined the distribution and the elemental and isotopic composition of organic matter in nine tidal estuaries along the Atlantic coast of Europe (Elbe, Ems, Thames, Rhine, Scheldt, Loire, Gironde, Do

  16. Prediction in ungauged estuaries: An integrated theory

    NARCIS (Netherlands)

    Savenije, H.H.G.

    2015-01-01

    Many estuaries in the world are ungauged. The International Association of Hydrological Sciences completed its science decade on Prediction in Ungauged Basins (PUB) in 2012 (Hrachowitz et al., 2013). Prediction on the basis of limited data is a challenge in hydrology, but not less so in estuaries, w

  17. Rasgos socioculturales de los jóvenes en México: bienestar, cultura y política

    Directory of Open Access Journals (Sweden)

    Luz María Ortega Villa

    2016-01-01

    Full Text Available Con base en dos encuestas nacionales aplicadas por el gobierno mexicano, se presenta un análisis secundario de las bases de datos de la Encuesta Nacional de Juventud 2010 y la Encuesta Nacional de Cultura Política de 2012, para analizar la situación de los jóvenes mexicanos en algunos aspectos de su bienestar y sexualidad, consumo y acceso a bienes culturales, sus interacciones con otros, y la cultura política que practican. A pesar de las limitaciones de la Encuesta Nacional de Juventud 2010 y su aplicación, se delinean algunos rasgos que permiten conocer a las y los jóvenes mexicanos: condición laboral y educativa, patrones de interacción específicos según edad, un marcado sedentarismo, escasas expresiones de la subjetividad, muy poco interés y participación en la política institucional, y la desconfianza hacia sus protagonistas.

  18. Teoría de los rasgos: contribución a la teoría del comportamiento del empresario

    Directory of Open Access Journals (Sweden)

    Manuel Gutiérrez Roa

    1992-01-01

    Full Text Available El autor propone un nuevo punto de vista que relaciona la sicología con la Administración de Empresas. Se da una nueva explicación sobre el comportamiento del empresario mediante la formulación de hipótesis basadas en las teorías del comportamiento y en los hechos y actitudes que caracterizan al industrial en su actividad cotidiana. Las hipótesis son: - El empresario tiene una formación valorativa fruto de un proceso de interiorización y maduración del yo, a partir de una formación temprana en este sentido. - El conjunto de valores derivados de la anterior, determina en el individuo un conjunto de rasgos, que orientan su actuación y predominan en su personalidad. Un solo rasgo no tiene valor, es el conjunto el que interesa y explica su comportamiento.

  19. Psicologia do Ambiente

    OpenAIRE

    Antunes, Dalila; Bernardo, Fátima; Palma-Oliveira, José-Manuel

    2011-01-01

    Na aplicação da Psicologia à área do AMBIENTE importa em primeiro lugar definir o que se entende, neste contexto, por ambiente. O conceito é entendido como toda a envolvente que rodeia o ser humano. Referimo-nos pois ao espaço físico e aos estímulos que nele existem (som, ar, paisagem…), dirigindo-se a Psicologia do Ambiente ao estudo e intervenção sobre a forma como o ambiente influencia o indivíduo ou grupos, e sobre o modo como o comportamento dos indivíduos e grupos influenciam o ambiente...

  20. Relaciones entre ansiedad escolar, ansiedad rasgo, ansiedad estado y depresión en una muestra de adolescentes españoles

    OpenAIRE

    Martínez-Monteagudo, Mari Carmen; García-Fernández, José Manuel; Cándido J. Inglés

    2013-01-01

    Diferentes estudios han analizado la ansiedad escolar como un constructo unitario sin atender a las diferentes situaciones y sistemas de respuesta que conforman este constructo. El presente estudio considera la ansiedad escolar como un constructo multidimensional y su objetivo fue analizar las relaciones y capacidad predictiva de las situaciones y sistemas de respuesta de la ansiedad escolar sobre la ansiedad rasgo, la ansiedad estado y la depresión. El Inventario de Ansiedad Escolar (IAES), ...

  1. Atmosphere and Ambient Space

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Atmosphere and Ambient Space This paper explores the relation between atmosphere and ambient space. Atmosphere and ambient space share many salient properties. They are both ontologically indeterminate, constantly varying and formally diffuse and they are both experienced as a subtle, non......-signifying property of a given space. But from a certain point of view, the two concepts also designate quite dissimilar experiences of space. To be ’ambient’ means to surround. Accordingly, ambient space is that space, which surrounds something or somebody. (Gibson 1987: 65) Since space is essentially...... of a surrounding character, all space can thus be described as having a fundamentally ambient character. So what precisely is an ambient space, then? As I will argue in my presentation, ambient space is a sensory effect of spatiality when a space is experienced as being particularly surrounding: a ‘space effect...

  2. Diferencias en ansiedad estado-rasgo y en atención selectiva en Trastorno por Déficit de Atención con Hiperactividad (TDAH

    Directory of Open Access Journals (Sweden)

    Paloma González-Castro

    2015-01-01

    Full Text Available Uno de los trastornos que más afecta al rendimiento escolar es el Trastorno por Déficit de Atención con Hiperactividad (TDAH. El criterio establecido por el DSM diferencia tres subtipos: inatento, hiperactivo-impulsivo y combinado. Sin embargo, el perfil de este trastorno podría verse alterado por la asociación con otros como la ansiedad. El objetivo de esta investigación es determinar si hay diferentes patrones de atención (selectiva y sostenida y ansiedad (estado y rasgo en los tres subtipos de TDAH. Además, el objetivo es analizar cómo la ansiedad predice el rendimiento de los estudiantes con TDAH en una tarea de atención selectiva. La muestra estaba formada por 220 estudiantes (6-12 años: 56 en el grupo control, 54 con TDAH-Inatento, 53 con TDAH-Hiperactivo impulsivo y 56 con el subtipo combinado. Los resultados obtenidos mostraron que los cuatro grupos resultaban significativamente diferentes en las variables atencionales y en los niveles de ansiedad estado y rasgo. Al mismo tiempo, la ansiedad rasgo predijo el rendimiento en la variable de concentración analizada. Los resultados revelan un nuevo patrón de gran interés de cara a la evaluación diagnóstica objetiva y fiable en el TDAH.

  3. Pasea: senderismo, cultura y naturaleza con Ecologistas en Acción. Una propuesta de Educación Ambiental

    OpenAIRE

    C. Lumbreras

    2005-01-01

    Pasea es un programa de educación ambiental, impulsado desde la asociación Ecologistas en Acción de Salamanca, bajo el formato de senderismo y convivencia con el fin de poner en valor los rasgos naturales y culturales de Salamanca, ayudado de los antiguos caminos, veredas, cordeles y calzadas, en visitas mensuales a cada una de las comarcas naturales, y bajo un clima amable de entretenimiento. En última instancia, y como base común a todas las salidas, cada paseo de Pasea está permit...

  4. Carbon isotope geochemistry in the Yalujiang estuary

    Institute of Scientific and Technical Information of China (English)

    吴莹; 张经

    2001-01-01

    The distribution of particulate organic carbon (POC) along the lower reaches is similar between the dry season and the flood season in the Yalujiang Estuary, North China. However, the values of particulate organic carbon of the upperstream in the dry season are one magnitude lower than the concentrations in the flood season. Stable carbon isotope ratios have been used to study the sources of particulate organic carbon in the Yalujiang Estuary. The isotopic composition of POC shows a range from -23.1‰ to -29.4‰ with a little seasonal variation. The isotopic evidence indicates that the POC in the Yalujiang Estuary is predominantly of terrestrial origin rather than a result of in situ plankton. The study of the ratio of POC: Chla shows that the turbidity maximum plays an important role in POC cycle in the Yalujiang Estuary. Organic detritus and soil erosion are the main contributions to POC in the turbidity maximum, especially in the flood season.

  5. National Estuary Program Study Area Boundaries

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are 28 National Estuary Programs (NEPs) in the U.S.that implement habitat protection and restoration projects with their partners. This work takes place...

  6. Microplastic in three urban estuaries, China.

    Science.gov (United States)

    Zhao, Shiye; Zhu, Lixin; Li, Daoji

    2015-11-01

    Estuarine Microplastics (MPs) are limited to know globally. By filtering subsurface water through 330 μm nets, MPs in Jiaojiang, Oujiang Estuaries were quantified, as well as that in Minjiang Estuary responding to Typhoon Soulik. Polymer matrix was analyzed by Raman spectroscopy. MP (plastics. The highest MPs density was found in Minjiang, following Jiaojiang and Oujiang. Fibers and granules were the primary shapes, with no pellets found. Colored MPs were the majority. The concentrations of suspended microplastics determine their bioavailability to low trophic organisms, and then possibly promoting the transfer of microplastic to higher trophic levels. Polypropylene and polyethylene were the prevalent types of MPs analyzed. Economic structures in urban estuaries influenced on MPs contamination levels. Typhoon didn't influence the suspended MP densities significantly. Our results provide basic information for better understanding suspended microplastics within urban estuaries and for managerial actions. PMID:26312741

  7. Mixing in the Amazon estuary

    Science.gov (United States)

    Bezerra, M. O.

    2010-05-01

    The research area of this work is located at the estuary of the Amazon River (Brazil), near the river mouth. The results of air movement analysis on the surface atmospheric circulation over the Mouth of the Amazonas River, salinity and temperature measures as well as measurements of currents, carried out along a longitudinal section in the navigation canal region of the Northern Bar of the Amazon River (Barra Norte do Rio Amazonas) in June 2006, during the river flood season in the quadrature tide. The dynamics effects affect hydrodynamic,meteorological and hydrographical parameters at the river mouth. The conclusion drawn include that: a) the saline wedge-type stratification can be detected approximately 100km away from the mouth of the Amazon River during the end of the rainy season in the quadrature tide; b) probably, at the Amazon estuary the quadrature entrainment processes are dominant and they are the ones responsible for increased salinity detected in the surface layer, whereas turbulence scattering mixing is not so important. c) The large flow of fresh water from the Amazon River at the end of the rainy season implies the displacement of the saline front position over the internal Amazon continental platform, and d) The tidal wave shows a positive asymmetry in the canal, with floods lasting less than in the ebb tide. This asymmetry decreases towards the ocean, eventually becoming reversed in the presence of a saline wedge. The speeds, however, have a negative asymmetry, with more intense ebb tides, due to the river flow and is more evident by the existence of quadrature tides.

  8. The Design and Development of Online Course Materials: Some Features and Recommendations El diseño y desarrollo de materiales para cursos en línea: algunos rasgos y recomendaciones

    Directory of Open Access Journals (Sweden)

    Liliana Cuesta

    2010-04-01

    Full Text Available This article discusses various features in the design and implementation of online course materials. The author provides a critical review of some instructional design patterns and expands on the alignment among instruction, motivation and learners' performances as part of a curriculum design process. In this context, the author emphasizes the value of permanent analysis and assessment to support an efficient management of online environments in which knowledge construction and interaction find common ground on which to evolve. The author argues in favor of steady and competent efforts to implement varied educational strategies posed both for online instructors and learners. Practical recommendations are espoused for the designers of online courses.Este artículo discute distintos rasgos relacionados con el diseño y el uso de materiales en cursos virtuales. La autora ofrece una reseña crítica de algunos patrones del diseño instruccional y ahonda en la alineación existente entre instrucción, motivación y desempeño de los estudiantes como parte de un proceso de diseño curricular. En este contexto, la autora hace énfasis en el valor que tienen el análisis y la evaluación permanentes para apoyar el manejo eficiente de los ambientes virtuales en los que la construcción de conocimiento y la interacción encuentran un lugar común para su evolución. La autora defiende la idea de hacer esfuerzos constantes y competentes para usar distintas estrategias educativas, planteadas tanto para instructores virtuales como para sus estudiantes. Finalmente, se presentan recomendaciones practicas para los diseñadores de cursos virtuales.

  9. Bar dimensions and bar shapes in estuaries

    Science.gov (United States)

    Leuven, Jasper; Kleinhans, Maarten; Weisscher, Steven; van der Vegt, Maarten

    2016-04-01

    Estuaries cause fascinating patterns of dynamic channels and shoals. Intertidal sandbars are valuable habitats, whilst channels provide access to harbors. We still lack a full explanation and classification scheme for the shapes and dimensions of bar patterns in natural estuaries, in contrast with bars in rivers. Analytical physics-based models suggest that bar length in estuaries increases with flow velocity, tidal excursion length or estuary width, depending on which model. However, these hypotheses were never validated for lack of data and experiments. We present a large dataset and determine the controls on bar shape and dimensions in estuaries, spanning bar lengths from centimeters (experiments) to 10s of kilometers length. First, we visually identified and classified 190 bars, measured their dimensions (width, length, height) and local braiding index. Data on estuarine geometry and tidal characteristics were obtained from governmental databases and literature on case studies. We found that many complex bars can be seen as simple elongated bars partly cut by mutually evasive ebb- and flood-dominated channels. Data analysis shows that bar dimensions scale with estuary dimensions, in particular estuary width. Breaking up the complex bars in simple bars greatly reduced scatter. Analytical bar theory overpredicts bar dimensions by an order of magnitude in case of small estuarine systems. Likewise, braiding index depends on local width-to-depth ratio, as was previously found for river systems. Our results suggest that estuary dimensions determine the order of magnitude of bar dimensions, while tidal characteristics modify this. We will continue to model bars numerically and experimentally. Our dataset on tidal bars enables future studies on the sedimentary architecture of geologically complex tidal deposits and enables studying effects of man-induced perturbations such as dredging and dumping on bar and channel patterns and habitats.

  10. Carbon dioxide and methane emissions from estuaries

    OpenAIRE

    Abril, G.; Borges, Alberto

    2005-01-01

    Carbon dioxide and methane emissions from estuaries are reviewed in relationwith biogeochemical processes and carbon cycling. In estuaries, carbondioxide and methane emissions show a large spatial and temporalvariability, which results from a complex interaction of river carbon inputs,sedimentation and resuspension processes, microbial processes in watersand sediments, tidal exchanges with marshes and flats and gas exchangewith the atmosphere. The net mineralization of land-derived organic ca...

  11. Rasgos de simplificación en el habla rural de dos localidades de Chile: descripción fonotáctica y discursiva

    Directory of Open Access Journals (Sweden)

    Miriam Elizabeth Cid Uribe

    2008-01-01

    Full Text Available El habla rural de Chile, variedad dialectal recurrente en alrededor del 14% de la población del país, según el último censo nacional, manifiesta rasgos particulares a nivel fonotáctico y discursivo que la caracterizan y la diferencian de otras variedades dialectales recurrentes en el país. Dentro de los aspectos fonotácticos se encuentran simplificaciones segméntales -elisiones, asimilaciones, sinalefas, sinéresis, sustituciones, entre otros- a las que se recurre con mayor o menor frecuencia; en el aspecto discursivo, la presencia y recurrencia de pausas llenas o vacías, las partidas falsas, las repeticiones, el alargamiento segmental se manifiestan en forma constante en esta variedad. En este artículo damos cuenta del comportamiento de los rasgos de simplificación en el habla rural de dos localidades de la Región Metropolitana desde el punto de vista de la manifestación fonotáctica de cada uno de estos rasgos en la elaboración de su discurso semiespontáneo.Chilean rural speech, variety spoken by nearly 14% of the population of the country according to the latest national census, shows specfñcphonotactic and discourse fea-tures which characterise and differentiate itfrom other dialectal varieties found in the country. Segmental simplfñcations like elisión, assimilation, gradation, compression, substitution,amongstothers,are tobe found as recurrentfeaturesat the phonotactic level; at the discourse level, phenomena like pauses -filled or empty-, false starts, repetitions, segmental lengthening are recurrent in this variety. In this article we give an account of the behaviour of such fea tures as they are manifested -phonotactically and discoursally- in two rural communities of the Metropolitan Región at the moment of producing semi spontaneous speech.

  12. La inteligencia emocional rasgo, la autoeficacia para el liderazgo y su vinculación a procesos afectivos grupales, cognitivos y de desempeño

    OpenAIRE

    Villanueva Sierra, José Juan

    2008-01-01

    El presente estudio explora el papel de la inteligencia emocional rasgo y la autoeficacia para el liderazgo sobre determinados procesos grupales tanto afectivos como cognitivos. A su vez se analiza la repercusión de dichas dinámicas en el rendimiento grupal al llevar a cabo una tarea compleja.La muestra estuvo constituida por 176 estudiantes universitarios, con un promedio de edad de 22 años (17% varones y 83% mujeres). Dichos estudiantes participaron de forma voluntaria en un experimento qu...

  13. Diferencias en ansiedad estado-rasgo y en atención selectiva en Trastorno por Déficit de Atención con Hiperactividad (TDAH)

    OpenAIRE

    Paloma González-Castro; Celestino Rodríguez; Marisol Cueli; Trinidad García; David Álvarez

    2015-01-01

    Uno de los trastornos que más afecta al rendimiento escolar es el Trastorno por Déficit de Atención con Hiperactividad (TDAH). El criterio establecido por el DSM diferencia tres subtipos: inatento, hiperactivo-impulsivo y combinado. Sin embargo, el perfil de este trastorno podría verse alterado por la asociación con otros como la ansiedad. El objetivo de esta investigación es determinar si hay diferentes patrones de atención (selectiva y sostenida) y ansiedad (estado y rasgo) en los tr...

  14. Descripción de los rasgos de personalidad y las características neuropsicológicas en excombatientes del conflicto armado colombiano

    OpenAIRE

    Bettin Osorio, Miguel

    2016-01-01

    La presente investigación establece, correlaciona y describe en 46 sujetos (25 Guerrilleros y 21 Paramilitares); el Grado de Filiación Ideológica a la organización armada ilegal de la guerra civil colombiana a la que pertenecieron, y por ende, a su participación en los crímenes particularmente violentos, de tipo depredador, frío, psicopático, cometidos por la misma, así como a los Déficits Neuropsicológicos, los Rasgos Psicopáticos, las Formas de Razonamiento Moral y las Características Psico...

  15. Skagit IMW - Skagit River Estuary Intensively Monitored Watershed Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study evaluates system-level effects of several estuary restoration projects on juvenile Chinook salmon production in the Skagit River estuary. The monitoring...

  16. Otolith Sr concentration analyzed by PIXE in Ariake estuary-dependent sea bass juveniles

    International Nuclear Information System (INIS)

    Japanese sea bass (Lateolabrax japonicus) is a typical euryhaline marine fish and frequently migrates from salt to freshwater environments during early life stages. We hypothesized that strontium concentrations in the otolith could be a useful index to examine freshwater entry because of its lower concentration in freshwater. Otoliths of Japanese sea bass juveniles collected in the Chikugo river and estuary were analyzed by Particle Induced X-ray Emission (PIXE) to see relationship between strontium concentration and ambient salinity. Strontium concentrations in otoliths of sea bass juveniles are significantly lower in the river samples than in brackish water samples. (author)

  17. Hydrodynamic and Sediment Modelling within a Macro Tidal Estuary: Port Curtis Estuary, Australia

    Directory of Open Access Journals (Sweden)

    Ryan J. K. Dunn

    2015-07-01

    Full Text Available An understanding of sediment transport processes and resultant concentration dynamics in estuaries is of great importance to engineering design awareness and the management of these environments. Predictive modelling approaches provide an opportunity to investigate and address potential system responses to nominated events, changes, or conditions of interest, often on high temporal and spatial resolution scales. In this study, a three-dimensional hydrodynamic model and wave model were validated and applied to generate forcing conditions for input into a sediment transport model for the period 7 May 2010–30 October 2010 within a macro tidal estuary, Port Curtis estuary (Australia. The hydrodynamic model was verified against surface and near-bottom current measurements. The model accurately reproduced the variations of surface and near-bottom currents at both a mid-estuary and upper-estuary location. Sediment transport model predictions were performed under varying meteorological conditions and tidal forcing over a 180-day period and were validated against turbidity data collected at six stations within Port Curtis estuary. The sediment transport model was able to predict both the magnitudes of the turbidity levels and the modulation induced by the neap and spring tides and wind-wave variations. The model-predicted (converted turbidity levels compared favourably with the measured surface water turbidity levels at all six stations. The study results have useful practical application for Port Curtis estuary, including providing predictive capabilities to support the selection of locations for monitoring/compliance sites.

  18. Análisis factorial exploratorio del Inventario de Depresión Estado-Rasgo (ST-DEP en adolescentes

    Directory of Open Access Journals (Sweden)

    César Merino Soto

    2012-01-01

    Full Text Available El Inventario de Depresión Estado-Rasgo (IDER evalúa de forma breve distintos síntomas depresivos. El objetivo es evaluar algunas propiedades psicométricas del IDER en Perú. La muestra estuvo formada por 314 estudiantes entre 11 y 18 años de secundaria en un colegio limeño. Los resultados indican una estructura bidimensional –que corresponde con la delimitación conceptual del inventario original–. Sin embargo, algunos ítems presentaron cargas comparativamente bajas, probablemente debido a variaciones culturales. Adicionalmente, la consistencia interna para la dimensión de Estado y Rasgo presentó valores alfa de Cronbach de 0.76 y 0.68, respectivamente. El cuestionario IDER satisface el criterio de invariabilidad de la estructura interna y puede dar una alternativa favorable para el diagnóstico y evaluación de la depresión en adolescentes peruanos.

  19. Estuary wader capacity following severe weather mortality

    International Nuclear Information System (INIS)

    The building of a tidal power barrage across an estuary may lead to substantial changes in its ecology. Many of Britain's estuaries hold internationally important numbers of waders. Careful consideration, therefore, needs to be given to the likely effects of tidal power barrages on wader populations. The opportunity for increased understanding of the mechanisms which govern wader populations was provided by a period of severe winter weather in 1991, which resulted in a substantial mortality of waders in eastern England. Such conditions are known to be stressful to birds and the study objectives were to investigate both the effects of and recovery from severe weather. (author)

  20. Ambient Dried Aerogels

    Science.gov (United States)

    Jones, Steven M.; Paik, Jong-Ah

    2013-01-01

    A method has been developed for creating aerogel using normal pressure and ambient temperatures. All spacecraft, satellites, and landers require the use of thermal insulation due to the extreme environments encountered in space and on extraterrestrial bodies. Ambient dried aerogels introduce the possibility of using aerogel as thermal insulation in a wide variety of instances where supercritically dried aerogels cannot be used. More specifically, thermoelectric devices can use ambient dried aerogel, where the advantages are in situ production using the cast-in ability of an aerogel. Previously, aerogels required supercritical conditions (high temperature and high pressure) to be dried. Ambient dried aerogels can be dried at room temperature and pressure. This allows many materials, such as plastics and certain metal alloys that cannot survive supercritical conditions, to be directly immersed in liquid aerogel precursor and then encapsulated in the final, dried aerogel. Additionally, the metalized Mylar films that could not survive the previous methods of making aerogels can survive the ambient drying technique, thus making multilayer insulation (MLI) materials possible. This results in lighter insulation material as well. Because this innovation does not require high-temperature or high-pressure drying, ambient dried aerogels are much less expensive to produce. The equipment needed to conduct supercritical drying costs many tens of thousands of dollars, and has associated running expenses for power, pressurized gasses, and maintenance. The ambient drying process also expands the size of the pieces of aerogel that can be made because a high-temperature, high-pressure system typically has internal dimensions of up to 30 cm in diameter and 60 cm in height. In the case of this innovation, the only limitation on the size of the aerogels produced would be in the ability of the solvent in the wet gel to escape from the gel network.

  1. Estuary fish data - Juvenile salmon in migratory corridors of lower Columbia River estuary

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sampling juvenile salmon and associated fishes in open waters of the lower Columbia River estuary. Field work includes bi-weekly sampling during the spring...

  2. Carbon dioxide emissions from Indian monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Viswanadham, R.; Rao, G.D.; Prasad, V.R.; Kumar, B.S.K.; Naidu, S.A.; Kumar, N.A.; Rao, D.B.; Sridevi, T.; Krishna, M.S.; Reddy, N.P.C.; Sadhuram, Y.; Murty, T.V.R.

    estuaries. The mean pCO sub(2) and particulate organic carbon (POC) showed positive relation with rate of discharge suggesting availability of high quantities of organic matter that led to enhanced microbial decomposition. The annual CO sub(2) fluxes from...

  3. Geochemical studies in the Godavari Estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Somayajulu, B.L.K.; Martin, J.M.; Eisma, D.; Thomas, A.J.; Borole, D.V.; Rao, K.S.

    are reported. The DOC and Fe concentrations are lower compared with those in other estuaries of the world and are below the average value reported for world rivers. Silicon behaves non-conservatively; its depletion which is most likely due to biological...

  4. Reversing circulation patterns in a tropical estuary

    Science.gov (United States)

    Valle-Levinson, Arnoldo; Bosley, Kathryn T.

    2003-10-01

    A combination of current velocity and water density measurements was used to characterize the basic patterns of water exchange in the Gulf of Fonseca, a tropical estuary on the Pacific Ocean side of Central America. The measurements were obtained during spring and neap tides in March (dry season) and June (wet season) of 2001 and consisted of profiles of current velocity and density along four transects. From mid-March to mid-April a time series of hourly surface current velocity maps was also obtained with a high-frequency radar system of two antennas. The sampling transects and the radar coverage concentrated in the portion of the estuary that has open communication with the ocean. During the dry season, water exchange at the entrance to the gulf suggested an inverse estuarine circulation that was more robust, and its dynamics were closer to geostrophy during neap than during spring tides. It is likely that salinity increased toward the tributaries of the system and then decreased within those tributaries because of the persistent influence of fresh water. In contrast, during the wet season, salinity decreased into the estuary, and the circulation resembled that of a typical estuary. In this season the fortnightly modulation of exchange flows was masked by wind effects, which also played a relevant role in the dynamics. The net volume inflows measured in both seasons suggested that the residence time of the Gulf of Fonseca varies from 2 weeks to 1 month.

  5. Kaua'i: Streams and Estuaries.

    Science.gov (United States)

    Hawkins, John, Ed.; Murakami, Colleen, Ed.

    Designed to help teachers develop students' awareness and understanding of some of Hawaii's endangered aquatic resources, this module contains activities and instructional suggestions for use with intermediate as well as high school students. The module is divided into two sections which explore the streams and estuaries of Kauai. Activities in…

  6. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  7. Species-specific variation in the phosphorus nutritional sources by microphytoplankton in a Mediterranean estuary

    Directory of Open Access Journals (Sweden)

    MARLY CAROLINA MARTINEZ SOTO

    2015-08-01

    Full Text Available We investigated the species-specific phosphorus (P nutrition sources in the microphytoplankton community in the Mahon estuary (Minorca, Western Mediterranean in 2011, under two contrasting hydrographic scenarios. Estuarine flow, nutrient concentrations, phytoplankton community composition and enzyme-labeled fluorescence (ELF were measured in June and October, corresponding to the beginning and the end of summer. Dissolved inorganic nitrogen (DIN and inorganic phosphate (Pi exhibited enhanced concentrations in the inner estuary where N:P molar ratios suggested P-limitation in both surveys. Pi was low and variable (0.09±0.02 μmol•l-1 in June and 0.06±0.02 μmol•l-1 in October, whereas organic phosphorus remained a more reliable P source. Even though ambient Pi concentrations were slightly higher on June, when the microphytoplankton assemblage was dominated by dinoflagellates, the percentage of cells expressing ELF labeling was notably higher (65% of total cells than in October (12%, when the presence of diatoms characterized the microphytoplankton community. ELF was mainly expressed by dinoflagellate taxa, whereas diatoms only expressed significant AP in the inner estuary during the June survey. A P-addition bioassay in which response of AP to Pi enrichment was evaluated showed remarkable reduction in AP with increasing Pi. However, some dinoflagellate species maintained AP even when Pi was supplied in excess. We suggest that in the case of some dinoflagellate species AP is not as tightly controlled by ambient Pi as previously believed. AP activity in these species could indicate selective use of organic phosphorus, or slow metabolic response to changes in P forms, rather than physiological stress to low Pi availability. We emphasize the importance of identifying the links between the different P sources and the species-specific requirements, in order to understand the ecological response to anthropogenic biogeochemical perturbations.

  8. Rasgos morfosedimentarios, procesos y evolución de la plataforma continental Argentina desde el último máximo glacial

    Directory of Open Access Journals (Sweden)

    Roberto A Violante

    2014-06-01

    Full Text Available La plataforma continental argentina es una de las plataformas submarinas más extensas del mundo, localizada en un contexto geotectónico dominado por un margen continental pasivo, aunque en su porción más austral se asocia a sectores de márgenes activos. Su extensión y escaso relieve han favorecido un profundo efecto modelador producto de las sucesivas transgresiones y regresiones marinas del Cuaternario, que le imprimieron variados rasgos morfosedimentarios. La transgresión postglacial dejó los rasgos finales que pueden ser reconocidos en las características superficiales y subsuperficiales, como ser las terrazas escalonadas asociadas a variaciones en la velocidad de ascenso del nivel del mar así como evidencias de paleolíneas de costas hoy sumergidas. Numerosos rasgos demuestran aspectos de la exposición subaérea durante el Último Máximo Glacial, como relictos de redes fluviales, depósitos glacifluviales y remanentes de suelos. La acción conjunta de los procesos actuantes favoreció la redistribución de los sedimentos aportados por la erosión de las sucesivas líneas de costas durante los avances y retrocesos marinos, además de aquellos incorporados desde el continente por acción eólica y fluvial. De esta manera, la cobertura sedimentaria resultante es terrígena de tipo relíctico y palimpséstico. Las características del borde exterior de la plataforma en transición al talud demuestran complejos procesos tanto litorales (durante etapas de bajo nivel del mar como profundos (erosión retrocederte asociada a la dinámica de cañones submarinos, mientras que la disposición diferente de las terrazas entre los sectores bonaerense y patagónico de la plataforma estaría asociada a ajustes hidroisostáticos.

  9. "Coeficientes de herencia, correlaciones, repetibilidad e índice de selección de rasgos reproductivos en porcinos"

    Directory of Open Access Journals (Sweden)

    Arango B. Humherto

    1989-12-01

    fueron: a Hermanos medios: PN =0.38, P 21 = 0.23, PD.=0.41, NN =0.23, N21 =0.17, ND=tl.27, 121 = 1.54,156=0.38, PCN =0.75,PC21 = 0.13, PCD =0.41 (PC = peso de la camada. b Por, regresión: PN=0.21, P21 =0.33, PD=0.23, NN =0.32, N21= 0.19, ND=0.39, 121 =0.53,1-56=0.41. Las correlaciones genéticas y fenotípicas calculadas se pueden considerar entre bajas y medias, con algunas de sentido opuesto. Las repetibilidades resultaron altas, por ser las h2 altas. Los índices calculados involucraron dos y tres variables (PN, PD e 156 días. 1a=37 X 1 + 1633 X2 + 22209Xs Ib = 0.34 Xl + 18 X2. El avance genético resultan1e de la aplicación del índice para dos variables fue de 5.3 % mayor para peso al nacer y 342 % para peso al destete. Para el de tres variables fue de 34 % para peso al nacer y 419 % para peso al destete y 311 para incremento de peso  más que el avance por selección de rasgos individuales.

  10. Mujer y medio ambiente

    OpenAIRE

    Zuluaga Sánchez, Gloria Patricia

    1998-01-01

    El debate sobre mujer y medio ambiente es bastante nuevo y, por lo tanto, aun no hay consenso sobre como abordarlo, ni análisis muy profundos sobre la interacción de estas dos problemáticas tan complejas y que además atraviesan las demás temáticas. Con ello no se quiere negar el importante aporte que se ha hecho en tal sentido, por parte de colectividades y de algunas personas. Selene Herculano y Jacqueline Pitanguy (1993), mencionan que el medio ambiente no es una categoría específica y que ...

  11. Nutrient budgets for large Chinese estuaries

    Directory of Open Access Journals (Sweden)

    S. M. Liu

    2009-10-01

    Full Text Available Chinese rivers deliver about 5–10% of global freshwater input and 15–20% of the global continental sediment to the world ocean. We report the riverine fluxes and concentrations of major nutrients (nitrogen, phosphorus, and silicon in the rivers of the contiguous landmass of China and Korea in the northeast Asia. The rivers are generally enriched with dissolved inorganic nitrogen (DIN and depleted in dissolved inorganic phosphate (PO43− with very high DIN: PO43− concentration ratios. DIN, phosphorus, and silicon levels and loads in rivers are mainly affected by agriculture activities and urbanization, anthropogenic activities and adsorption on particulates, and rock types, climate and physical denudation intensity, respectively. Nutrient transports by rivers in the summer are 3–4 times higher than those in the winter with the exception of NH4+. The flux of NH4+ is rather constant throughout the year due to the anthropogenic sources such as the sewer discharge. As nutrient composition has changed in the rivers, ecosystems in estuaries and coastal sea have also changed in recent decades. Among the changes, a shift of limiting nutrients from phosphorus to nitrogen for phytoplankton production with urbanization is noticeable and in some areas silicon becomes the limiting nutrient for diatom productivity. A simple steady-state mass-balance box model was employed to assess nutrient budgets in the estuaries. The major Chinese estuaries export <15% of nitrogen, <6% of phosphorus required for phytoplankton production and ~4% of silicon required for diatom growth in the Chinese Seas (Bohai, Yellow Sea, East China Sea, South China Sea. This suggests that land-derived nutrients are largely confined to the immediate estuaries, and ecosystem in the coastal sea beyond the estuaries is mainly supported by other nutrient sources such as regeneration, open ocean and

  12. El proceso de la apropiación: un rasgo distintivo en la educación energética

    Directory of Open Access Journals (Sweden)

    Ernesto Ramón Ávila-Guerra

    2012-01-01

    Full Text Available Al proponer la conceptualización de la Educación Energética para el Desarrollo Sostenible, se destacó como un rasgo esencial el proceso de apropiación del contenido y de esta forma se contribuyó a la teoría pedagógica del Desarrollo Sostenible, como complemento de las prioridades de las Cumbres de la Tierra, los llamamientos realizados por la Asamblea General de las Naciones Unidas y la UNESCO para implementar el Decenio de la Educación para el Desarrollo Sostenible en los sistemas educativos. También, se favoreció el aprendizaje de los contenidos con potencialidades para esta educación en el área de Ciencias Exacta del nivel medio superior.

  13. Rasgos de la cultura política de los indígenas en México. Una revisión a inicios del siglo XXI

    Directory of Open Access Journals (Sweden)

    Rafael Cedillo Delgado

    2009-01-01

    Full Text Available En este trabajo se analizan los rasgos de cultura política que manifiestan los indígenas de México. A través de la revisión de su percepción sobre la política, de la forma como se relacionan con las estructuras de poder y de su participación en los asuntos públicos, se argumenta que éstos manifiestan una peculiar forma de cultura política, caracterizada por la conformación de una organización política comunal y de autogestión, desarrollada en forma paralela a los modos tradicionales de organización política institucional: la partidista-electoral.

  14. La radioactividad ambiental

    Directory of Open Access Journals (Sweden)

    Rafael Núñez-Lagos Roglá

    2011-01-01

    Full Text Available Se explican los conceptos fundamentales relacionados con la radiactividad y se utilizan para describir la radiactividad ambiental. Se explican también los isótopos de largo periodo y las principales familias radioactivas junto con la radiación cósmica y los radionucleidos cosmogénicos.

  15. Mantenimiento o sustitución de rasgos lingüísticos indexados socialmente: migrantes de zonas andinas en Lima

    Directory of Open Access Journals (Sweden)

    Carola Mick

    2013-12-01

    Full Text Available ResumenEste artículo investiga la relación entre la formación de “mundos de vida comunicativos individuales” y la construcción de la identidad en migrantes peruanas procedentes de la zona de los Andes en Lima. A partir del análisis lingüístico y discursivo de un corpus de entrevistas semidirigidas con veintidós mujeres migrantes mostramos cómo las ideologías lingüísticas, las que menosprecian rasgos dialectales considerados como típicos de migrantes andinos y las que prestigian los “rasgos limeños”, condicionan el comportamiento lingüístico de las migrantes y se transforman en herramientas útiles para el posicionamiento discursivo individual de las informantes frente a estos estereotipos.AbstractThis article enquires the relationship between the formation of “individual communicative lifeworlds” and the construction of identity in 22 semidirective interviews with Peruvian migrant domestic workers in Lima originating from the Andean regions. With the help of a combined linguistic and discursive analysis we demonstrate the way in which language ideologies condition and enable the formation of individual communicative lifeworlds of the speakers. The stigmatization of linguistic characteristics that are considered as typical of “Andean” speakers and the high esteem of linguistic forms considered as typical for people originating in Lima favour linguistic accommodation, but in order to explain all the variation in the corpus we need to take into consideration the individual linguistic and discursive positioning of each speaker.

  16. Historical changes in the Columbia River Estuary

    Science.gov (United States)

    Sherwood, Christopher R.; Jay, David A.; Bradford Harvey, R.; Hamilton, Peter; Simenstad, Charles A.

    Historical changes in the hydrology, sedimentology, and physical oceanography of the Columbia River Estuary have been evaluated with a combination of statistical, cartographic, and numerical-modelling techniques. Comparison of data digitized from US Coast and Geodetic Survey bathymetric surveys conducted in the periods 1867-1875, 1926-1937, and 1949-1958 reveals that large changes in the morphology of the estuary have been caused by navigational improvements (jetties, dredged channels, and pile dikes) and by the diking and filling of much of the wetland area. Lesser changes are attributable to natural shoaling and erosion. There has been roughly a 15% decrease in tidal prism and a net accumulation of about 68 × 10 6m 3 of sediment in the estuary. Large volumes of sediment have been eroded from the entrance region and deposited on the continental shelf and in the balance of the estuary, contributing to formation of new land. The bathymetric data indicate that, ignoring erosion at the entrance, 370 to 485 × 10 6m 3 of sediment has been deposited in the estuary since 1868 at an average rate of about 0.5 cm y -1, roughly 5 times the rate at which sea level has fallen locally since the turn of the century. Riverflow data indicate that the seasonal flow cycle of the Columbia River has been significantly altered by regulation and diversion of water for irrigation. The greatest changes have occurred in the last thirty years. Flow variability over periods greater than a month has been significantly damped and the net discharge has been slightly reduced. These changes in riverflow are too recent to be reflected in the available in the available bathymetric data. Results from a laterally averaged, multiple-channel, two-dimensional numerical flow model (described in HAMILTON, 1990) suggest that the changes in morphology and riverflow have reduced mixing, increased stratification, altered the response to fortnightly (neap-spring) changes in tidal forcing, and decreased the

  17. A sensitivity analysis of low salinity habitats simulated by a hydrodynamic model in the Manatee River estuary in Florida, USA

    Science.gov (United States)

    Chen, XinJian

    2012-06-01

    This paper presents a sensitivity study of simulated availability of low salinity habitats by a hydrodynamic model for the Manatee River estuary located in the southwest portion of the Florida peninsula. The purpose of the modeling study was to establish a regulatory minimum freshwater flow rate required to prevent the estuarine ecosystem from significant harm. The model used in the study was a multi-block model that dynamically couples a three-dimensional (3D) hydrodynamic model with a laterally averaged (2DV) hydrodynamic model. The model was calibrated and verified against measured real-time data of surface elevation and salinity at five stations during March 2005-July 2006. The calibrated model was then used to conduct a series of scenario runs to investigate effects of the flow reduction on salinity distributions in the Manatee River estuary. Based on simulated salinity distribution in the estuary, water volumes, bottom areas and shoreline lengths for salinity less than certain predefined values were calculated and analyzed to help establish the minimum freshwater flow rate for the estuarine system. The sensitivity analysis conducted during the modeling study for the Manatee River estuary examined effects of the bottom roughness, ambient vertical eddy viscosity/diffusivity, horizontal eddy viscosity/diffusivity, and ungauged flow on the model results and identified the relative importance of these model parameters (input data) to the outcome of the availability of low salinity habitats. It is found that the ambient vertical eddy viscosity/diffusivity is the most influential factor controlling the model outcome, while the horizontal eddy viscosity/diffusivity is the least influential one.

  18. Mesozooplankton affinities in a recovering freshwater estuary

    Science.gov (United States)

    Chambord, Sophie; Maris, Tom; Colas, Fanny; Van Engeland, Tom; Sossou, Akoko-C.; Azémar, Frédéric; Le Coz, Maïwen; Cox, Tom; Buisson, Laetitia; Souissi, Sami; Meire, Patrick; Tackx, Michèle

    2016-08-01

    Water quality of the Scheldt estuary (Belgium/The Netherlands) has considerably improved in recent years, especially in the upstream, freshwater reaches. Within the zooplankton community, the copepod Eurytemora affinis, typically abundant in brackish water and quasi-absent from freshwater before 2007, has since substantially developed in the latter, where it now represents 90% of the crustacean mesozooplankton community. Simultaneously, cyclopoid copepod abundance has greatly decreased, while cladoceran abundance did not change. The study aim was: 1) to verify if the zooplankton community described for the period 2007-2009 by Mialet et al. (2011) has stabilized until present, and 2) to look for the environmental conditions favouring E. affinis development and causing changes in the upstream freshwater zooplankton community. The 2002-2012 temporal evolution of the zooplankton distribution at three stations in the upstream freshwater Scheldt estuary was analyzed. Water quality remained better after 2007 than before, and some factors revealed continuous improvement in annual mean concentrations (e.g. increase in O2, decrease in BOD5 and NH4sbnd N concentration). The increase in oxygen and the decrease in NH4sbnd N concentration, together with low discharge during summer were the main environmental factors explaining the development and timing of E. affinis in the upstream freshwater reach. In this reach, E. affinis maximal abundance is shifted to higher temperatures (summer) compared to its typical maximum spring abundance peak in the brackish zone of the Scheldt estuary and in most temperate estuaries. The changes in zooplankton community followed a temporal and spatial gradient induced by the spatio-temporal evolution of water quality improvement. The most downstream station (3) allowed E. affinis development (oxygen concentration > 4 mg L-1; NH4sbnd N concentration oxygen, etc.), there is no clear cause for their decline. Water quality improvement in the freshwater

  19. Seasonal stratification and property distributions in a tropical estuary (Cochin estuary, west coast, India)

    Science.gov (United States)

    Shivaprasad, A.; Vinita, J.; Revichandran, C.; Reny, P. D.; Deepak, M. P.; Muraleedharan, K. R.; Naveen Kumar, K. R.

    2013-01-01

    The intratidal, spring-neap and seasonal variations in stratification were examined in the Cochin estuary. The observations established a strong connection with the distribution of chemical and biological properties. The influence of tides and river discharge forcing in water column stability was quantified using potential energy anomaly (PEA) and stratification parameter. Partially mixed (neap) and well-mixed (spring) conditions during low river discharge (dry) period were altered in monsoon by the salt wedge intrusions. The ecological impact of salt wedge propagation on high tides bringing upwelled water to the system was evident from the bottom hypoxic, high chlorophyll a and nutrient-rich conditions. Phosphate and nitrite concentrations were higher at the bottom saline conditions but silicate and nitrate were clearly supplied by river water. However, during ebb tide this front was driven out of the estuary. The periodic advance and retreat of the salt wedge was inevitable in making the system immune from extended hypoxia/anoxia and maintaining the health of the Cochin estuary. For the seasonally varying river flow in the estuary, salt intrusion receded with increasing river flow in monsoon and rebounded with decreasing river flow in dry season. During monsoon, the intense flushing and reduction in salinity field expansion seemed to be responsible for the limited chlorophyll a levels along the surface of the Cochin estuary.

  20. A predictive model for salt intrusion in estuaries applied to the Yangtze estuary

    Science.gov (United States)

    Cai, Huayang; Savenije, Hubert H. G.; Zuo, Shuhua; Jiang, Chenjuan; Chua, Vivien P.

    2015-10-01

    Understanding the way salinity distribution in an estuary reacts to external drivers (e.g., tide, fresh water discharge, dredging, etc.) is important for both water quality and water resources management in estuaries. The salinity distribution depends strongly on the geometry of an estuary, but also on the fresh water discharge that counteracts the salt intrusion. In estuaries it is notoriously hard to estimate this discharge and subsequently to predict the parameters that determine the mixing behaviour depending on it. Recently a method has been developed to predict the fresh water discharge on the basis of water level observations. In addition, predictive equations for tidal mixing have been updated and revised. In this paper, these two predictive methods are combined and subsequently applied to the Yangtze estuary under a wide variation of fresh water discharge. The predicted salt distribution appears to be in good agreement with observations. To provide insight into the optimum use of water resources (e.g., to determine the amount of fresh water discharge required to maintain a specific salt intrusion length), we further study the salt intrusion pattern under different tide and fresh water discharge conditions.

  1. The ecological condition of estuaries in the Gulf of Mexico

    OpenAIRE

    1999-01-01

    This document is intended for use by scientists and other citizens concerned with the ecological condition of estuaries, as well as by managers and lawmakers interested in the sustained use of estuaries for commercial and recreational purposes. It also addresses public concerns about the aesthetic quality of coastal areas vital to tourism and recreation. By producing this report on the ecological condition of estuaries in the Gulf of Mexico, we have taken one step in assessing the health of t...

  2. Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Office of Air and Radiation's (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as...

  3. Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Office of Air and Radiation??s (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as...

  4. Marine geology of the St. Lawrence Estuary

    Energy Technology Data Exchange (ETDEWEB)

    St-Onge, Guillaume [Canada Research Chair in Marine Geology, Institut des sciences de la mer de Rimouski (ISMER) and GEOTOP Research Center, 310 allee des Ursulines, Rimouski, Quebec, G5L 3A1 (Canada); Duchesne, Mathieu J [Geological Survey of Canada, Quebec Division, 490 de la Couronne, Quebec City, Quebec, G1K 9A9 (Canada); Lajeunesse, Patrick, E-mail: guillaume_st-onge@uqar.qc.ca [Departement de geographie and Centre d' etudes nordiques, Universite Laval, Quebec City, Quebec, G1V 0A6 (Canada)

    2011-05-15

    The St. Lawrence Estuary, Eastern Canada, contains a very thick (>450 m) Quaternary sedimentary sequence. The results from recently conducted geophysical surveys in conjunction with piston coring indicate that these sediments were deposited under very high sedimentation rates, sometimes as high as {approx}30 m/ka during the last deglaciation. Results also reveal evidence of large submarine landslides during the Holocene, changes in sedimentation rates and the significant role of submarine canyons and channels to transfer sediments from the coast to the deeper marine environment. Finally, this paper highlights the presence of more than 1900 pockmarks on the seafloor of the St. Lawrence Estuary and discusses their possible origins: active hydrocarbon seeps in the Laurentian Channel and biogenic gas seepage on the northwestern shoulder of the Laurentian Channel.

  5. NIF Ambient Vibration Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Noble, C.R.; Hoehler, M.S., S.C. Sommer

    1999-11-29

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B.

  6. NIF Ambient Vibration Measurements

    International Nuclear Information System (INIS)

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B

  7. Deschutes estuary feasibility study: hydrodynamics and sediment transport modeling

    Science.gov (United States)

    George, Douglas A.; Gelfenbaum, Guy; Lesser, Giles; Stevens, Andrew W.

    2006-01-01

    Continual sediment accumulation in Capitol Lake since the damming of the Deschutes River in 1951 has altered the initial morphology of the basin. As part of the Deschutes River Estuary Feasibility Study (DEFS), the United States Geological Survey (USGS) was tasked to model how tidal and storm processes will influence the river, lake and lower Budd Inlet should estuary restoration occur. Understanding these mechanisms will assist in developing a scientifically sound assessment on the feasibility of restoring the estuary. The goals of the DEFS are as follows. - Increase understanding of the estuary alternative to the same level as managing the lake environment.

  8. Current Characterization at the Amazon estuary

    Science.gov (United States)

    Bezerra, M. O.

    2009-04-01

    At the estuary there are several mechanisms that cause turbulence: influence of solid contours (estuary bottom and shores), speed vertical shearing (fluid inside), wind shearing stress (free surface) and surface and internal gravity waves. Turbulence intensity controls vertical distribution of estuary water mass property concentration. As flow into the estuary takes place during the transition or turbulent regimen, produced by small space and time scale movements, entrainment, turbulent scattering and advection are the processes responsible for fresh water mixing up with the sea and for local salinity variation, as well as for concentration of natural properties and man-made ones. According to this focus, we shall describe general circulation, conveyance and mixing characteristics of the Amazon low estuary waters. Amazon estuary shows unusual characteristics: it is of vast length and enormous outflow. It is extremely wide - 150 Km - and its discharge into the Atlantic amounts to 180,000 m3s-1 (Otman, 1968, Figueiredo et al, 1991), which means 18% of all water discharged by rivers into oceans; this is the largest punctual source of fresh water for oceans (Milliman and Meade, 1983). Maximum outflow is 2.5 x 105 m3s-1, and it happens at the end of May. Minimum outflow is 1.2 x 105 m3 s-1, and it takes place in November. At Amazon River, the Mixing Zone occurs where the Coastal Zone usually is. The reason for that is the extension of fresh water plume moves Northeast for over 1000 Km (Gibbs, 1970; Muller-Karger et al 1988). This is the most extensive estuarine plume ever found in the ocean. During low fluvial discharge (June-November) plume reaches 300 Km; however, on high discharge (November-May) plume reaches 500 Km. Plume already is 3 to 10 m thick and 80 to 300 Km wide (Lentz and Limeburner, 1995). From June to January plume moves towards Africa, from whence 70% of it goes east carried by North Brazil Current retroflection and 30% goes towards the Caribbean. From

  9. Ambiente il nostro futuro

    OpenAIRE

    Canigiani, Franca

    2016-01-01

    L’ambiente è il quadro di vita, la casa comune, il patrimonio di base delle società umane – scriveva un indimenticabile maestro della geografia italiana: Giuseppe Barbieri. Due gli avvenimenti che nel 2015 hanno segnato il passo dell’umanità sulla strada di una più matura coscienza ambientale, fino a comprendere che è necessario e urgente prendersi cura della Terra: primo, la pubblicazione della lettera enciclica di papa Francesco, Laudato si’ sulla cura della casa comune, straordinario saggi...

  10. AOX y medio ambiente.

    OpenAIRE

    Riva Juan, Mª del Carmen; López Ribas, David

    1996-01-01

    Los productos organohalogenados son muy utilizados por la industria y su presencia en el medio ambiente está siendo controlada. En los últimos años se han desarrollado varias técnicas de detección, siendo desde finales de los 80 los AOX (adsorbable organic halogens) uno de los parámetros sobre los que se han realizado más estudios. En muchos paises de la Unión Europea y en E.E.U.U. de América, la presencia de compuestos organohalogenados en aguas continentales y suelos está legislada indicand...

  11. Arquitectura y medio ambiente

    OpenAIRE

    Saura Carulla, Magdalena

    2003-01-01

    La arquitectura y la planificación son el resultado de una integración ponderada de conocimientos técnicos y una multiplicidad de aspectos relacionados con el conocimiento natural y social. En este trabajo el autor propone, desde el ámbito de las ciencias del medio ambiente, diversos planteamientos teóricos y prácticos relacionados con la arquitectura y el urbanismo. El conocimiento de la naturaleza de los sistemas naturales y de los sistemas ecosociales permite al diseñador aplicar un marco ...

  12. Rasgos morfológicos de semillas y su implicación en la conservación ex situ de especies leñosas en los bosques secos Tumbesinos

    Directory of Open Access Journals (Sweden)

    J. M. Romero-Saritama

    2016-01-01

    Full Text Available Actualmente existe un gran interés por describir y estudiar rasgos funcionales en las plantas, estos nos ayudan a predecir ciertos comportamientos e interacciones ecológicas de las especies ante cambios ambientales o antropológicos en los ecosistemas. Los rasgos morfológicos de las semillas están involucrados en procesos durante el ciclo de vida de las plantas. Sin embargo, dichos rasgos no han sido bien estudiados desde el punto de vista funcional en diferentes hábitats, especialmente en zonas secas tropicales, donde existe gran diversidad de especies con alto riesgo de amenaza. Los bosques secos Tumbesinos compartidos entre el suroccidente del Ecuador y noroccidente del Perú, son considerados un hotspot por su alta diversidad y endemismo. No obstante están muy amenazados y algunas especies forestales han sido ya incluidas en listas rojas con algún grado de amenaza. Por ello, es urgente generar investigación e información que permita la conservación de los recursos genéticos forestales de las es- pecies de los bosques secos. Una de las alternativas más práctica e inmediata es la colección y almacenamiento ex situ de semillas. Sin embargo, en hábitats secos tropicales hay un gran desconocimiento de la ecología, fisiología y morfología de semillas lo que dificulta llevar a cabo esta estra- tegia de conservación. Conocer los rasgos morfológicos de las semillas nos podrían ayudar a establecer la mejor manera de colectar y conservar las especies forestales. El presente artículo analiza e incorpora información sobre rasgos morfológicos de semillas de especies leñosas que han sido poco o nada estudiados desde el punto de vista funcional en los bosques secosTumbesinos, y analiza cómo la información de los rasgos mor- fológicos de semillas podrían servir como una herramienta para optimizar el proceso de conservación ex situ de estas especies.

  13. The branching channel network in the Yangtze Estuary

    NARCIS (Netherlands)

    Wang, Z.B.; Ding, P.X.

    2012-01-01

    The channels in the Yangtze Estuary have an ordered-branching structure: The estuary is first divided by the Chongming Island into the North Branch and the South Branch. Then the South Branch is divided into the North Channel and South Channel by the Islands Changxing and Hengsha. The South Channel

  14. Comparative-Study of the Hyperbenthos of 3 European Estuaries

    NARCIS (Netherlands)

    Mees, J.; Fockedey, N.; Hamerlynck, O.

    1995-01-01

    The hyperbenthic fauna of the subtidal channels of the Eems (N. Netherlands), Westerschelde (S.W. Netherlands), and Gironde (S.W. France) estuaries was sampled within a 15-day period in summer 1991. In each estuary, quantitative samples were taken at regularly spaced stations covering the entire sal

  15. Nitrogen Source and Loading Data for EPA Estuary Data Mapper

    Science.gov (United States)

    Nitrogen source and loading data have been compiled and aggregated at the scale of estuaries and associated watersheds of the conterminous United States, using the spatial framework in EPA's Estuary Data Mapper (EDM) to provide system boundaries. Original sources of data include...

  16. Conditions for tidal bore formation in convergent alluvial estuaries

    Science.gov (United States)

    Bonneton, Philippe; Filippini, Andrea Gilberto; Arpaia, Luca; Bonneton, Natalie; Ricchiuto, Mario

    2016-04-01

    Over the last decade there has been an increasing interest in tidal bore dynamics. However most studies have been focused on small-scale bore processes. The present paper describes the first quantitative study, at the estuary scale, of the conditions for tidal bore formation in convergent alluvial estuaries. When freshwater discharge and large-scale spatial variations of the estuary water depth can be neglected, tide propagation in such estuaries is controlled by three main dimensionless parameters: the nonlinearity parameter ε0 , the convergence ratio δ0 and the friction parameter ϕ0. In this paper we explore this dimensionless parameter space, in terms of tidal bore occurrence, from a database of 21 estuaries (8 tidal-bore estuaries and 13 non tidal-bore estuaries). The field data point out that tidal bores occur for convergence ratios close to the critical convergence δc. A new proposed definition of the friction parameter highlights a clear separation on the parameter plane (ϕ0,ε0) between tidal-bore estuaries and non tidal-bore estuaries. More specifically, we have established that tidal bores occur in convergent estuaries when the nonlinearity parameter is greater than a critical value, εc , which is an increasing function of the friction parameter ϕ0. This result has been confirmed by numerical simulations of the two-dimensional Saint Venant equations. The real-estuary observations and the numerical simulations also show that, contrary to what is generally assumed, tide amplification is not a necessary condition for tidal bore formation. The effect of freshwater discharge on tidal bore occurrence has been analyzed from the database acquired during three long-term campaigns carried out on the Gironde/Garonne estuary. We have shown that in the upper estuary the tidal bore intensity is mainly governed by the local dimensionless tide amplitude ε. The bore intensity is an increasing function of ε and this relationship does not depend on freshwater

  17. Crisis ambiental y cristianismo

    Directory of Open Access Journals (Sweden)

    Felipe Cárdenas

    2008-01-01

    Full Text Available En el artículo se identifican y reconocen algunas opciones que se pueden desarrollar en el cristianismo en relación con la problemática ambiental. Se aborda el dilema bíblico suscitado por interpretaciones antiecológicas y ecológicas. Con base en una lectura de la Biblia, de testimonios cristianos, y en una rememoria de estructuras institucionales, como la parroquia, se analiza el valor que tiene el mensaje cristiano en lo referido a la mitigación de la crisis ambiental.This article identifies and recognizes some options that can be developed in Christianity in relation to the environmental problem. It starts by analyzing the biblical dilemma provoked by both ecological and antiecological interpretations. Based on a reading of the Bible, testimonies from Christians and with a rememory of institutional structures, like the parish, the valué of the Christian message for mitigating the environmental crisis is analyzed.

  18. Greenhouse gas (N2O emission from Portuguese estuaries

    Directory of Open Access Journals (Sweden)

    Célia Gonçalves

    2014-07-01

    Tagus, Minho and Lima estuaries are source of N2O to the atmosphere. Particularly, in Lima estuary anthropogenic N input seems to play an important role on N2O emission. However, in a global perspective N2O attained emissions represent a reduced fraction (2O yr-1, Barnes and Upstill-Goddard, 2011. Values are comparable with those registered in some Portuguese estuaries and other European less eutrophic estuaries. However, it is known that higher N2O emissions in estuaries may occur during winter and spring (Sun et al., 2014. Thus, these systems may represent on an annual basis a larger source of N2O, which can only be clarified in future studies. Only a full comprehension of the global estuarine nitrogen cycle will provide an efficient basis of scientific knowledge for sustainably management of such ecosystems and ultimately reduce N2O emissions.

  19. Propiedades Psicométricas del Inventario de Depresión Estado Rasgo (IDER con una muestra de población general colombiana

    Directory of Open Access Journals (Sweden)

    Diana María Agudelo Vélez

    2014-01-01

    Full Text Available This study provides information regarding the psychometric properties of the IDER (Inventario de Depresión Estado/Rasgo with a non-clinical Colombian sample (N= 1043. Data for validity and reliability are reported. The findings are similar to data obtained with Spanish, American, and Chilean samples. Data from exploratory and confirmatory factorial analyses confirm the bifactorial structure (dysthymia and euthymia of the instrument. Reliability levels range from .71 to .86. The convergent validity indexes in relation to the CBD are moderate and significant (.59. On the other hand, correlations with the STAI and STAXI-2, as measures of discriminant validity, were lower, although still significant (between .25 and .38 for anxiety and between .25 and .43 for anger. Women obtained higher scores than men, similar to previous studies. The findings from this new sample confirm the adequate psychometric properties of the instrument. Nevertheless, it is important to note that the IDER is valuable as a measure of negative negativity but not as a diagnostic instrument for depression.

  20. Rasgos estructurales en la Sierra Pampeana de Velasco y alrededores a partir de los campos gravimétricos y magnetrométricos

    Directory of Open Access Journals (Sweden)

    Marcos A Sánchez

    2013-06-01

    Full Text Available La región que comprende la sierra de Velasco y el Sistema de Famatina, en el centro-oeste de la Provincia de La Rioja - Argentina, es un área clave para el estudio de la amalgamación de terrenos y tectónica vinculada con el levantamiento andino. En éste trabajo, se definen algunos rasgos de la estructura cortical de ésta región. Para ello, mediante la aplicación de métodos potenciales (gravedad y magnetismo, adecuadamente procesados e interpretados a través de técnicas semiautomáticas y de resalto de anomalías, se logró determinar: a una región que respondería a la zona de sutura entre los terrenos Famatina y Pampia y b fallas relacionadas al levantamiento de las sierras de Famatina y de Velasco. Los resultados anteriores se representan en una sección este - oeste en un modelo estructural de bloques de basamento entre Famatina y Velasco, hasta 12 km de profundidad. En él señalamos además la distribución de las fallas y sus buzamientos.

  1. Relación entre variabilidad biogeoquímica y rasgos estructurales de la comunidad microbiana en suelos forestales: Bosques de Abies pinsapo como caso de estudio

    Directory of Open Access Journals (Sweden)

    P. Torres-Cañabate

    2009-01-01

    Full Text Available Relación entre variabilidad biogeoquímica y rasgos estructurales de la comunidad microbiana en suelos forestales: Bosques de Abies pinsapo como caso de estudio. Tradicionalmente, los estudios biogeoquímicos consideraban el suelo como una "caja negra", conectada con el resto del ecosistema mediante flujos de entrada y de salida de nutrientes, en la que éstos experimentan transformaciones mediadas engran parte por microorganismos desconocidos. El desarrollo de nuevas técnicas moleculares ha incrementado el conocimiento sobre lascomunidades microbianas del suelo. Estudios recientes han puesto de manifiesto correspondencias entre la variabilidad de la disponibilidad de nutrientes y la estructura de la comunidad microbiana en suelos forestales. A este respecto, hemos empleado bosques de Abies pinsapo como modelo ya que muestran una gran variabilidad biogeoquímica asociada a diferencias litológicas y sucesionales, mientras que la estacionalidad mediterránea provoca una alta variabilidad intra-anual en la disponibilidad de nutrientes. Además, existen pinsapares sujetos alimitación o a saturación de nitrógeno. Mediante análisis del polimorfismo de longitud de fragmentos de restricción terminal (T-RFLP, hemos puesto de manifiesto que los patrones de variabilidad biogeoquímica descritos en los pinsapares se corresponden con cambios en la composición y estructura de sus comunidades bacterianas.

  2. Types for BioAmbients

    Directory of Open Access Journals (Sweden)

    Sara Capecchi

    2010-02-01

    Full Text Available The BioAmbients calculus is a process algebra suitable for representing compartmentalization, molecular localization and movements between compartments. In this paper we enrich this calculus with a static type system classifying each ambient with group types specifying the kind of compartments in which the ambient can stay. The type system ensures that, in a well-typed process, ambients cannot be nested in a way that violates the type hierarchy. Exploiting the information given by the group types, we also extend the operational semantics of BioAmbients with rules signalling errors that may derive from undesired ambients' moves (i.e. merging incompatible tissues. Thus, the signal of errors can help the modeller to detect and locate unwanted situations that may arise in a biological system, and give practical hints on how to avoid the undesired behaviour.

  3. Types for BioAmbients

    CERN Document Server

    Capecchi, Sara; 10.4204/EPTCS.19.7

    2010-01-01

    The BioAmbients calculus is a process algebra suitable for representing compartmentalization, molecular localization and movements between compartments. In this paper we enrich this calculus with a static type system classifying each ambient with group types specifying the kind of compartments in which the ambient can stay. The type system ensures that, in a well-typed process, ambients cannot be nested in a way that violates the type hierarchy. Exploiting the information given by the group types, we also extend the operational semantics of BioAmbients with rules signalling errors that may derive from undesired ambients' moves (i.e. merging incompatible tissues). Thus, the signal of errors can help the modeller to detect and locate unwanted situations that may arise in a biological system, and give practical hints on how to avoid the undesired behaviour.

  4. Algae and water pollution in Mahi Estuary

    OpenAIRE

    Jiyalal Ram, M.

    1991-01-01

    Distribution of phytoplankton, chlorophyll A and phaeophytin was studied at different locations in the Mahi Estuary, Gujarat, India during 1982. The water quality at the discharge point was poor while the region away from it was relatively unpolluted. The results indicated a wide range of variation in phytoplankton population (7.68-5010, 96 x 10 super(4) cells/l, chl. a 2.22-58.22 mg/m super(3) and phaeophytin [0.20-10.21 mg/m super(3)]. The ratio of chl. a/phaeophytin were remarkably low at ...

  5. Mercury in sediments of Ulhas estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Rokade, M.A.; Borole, D.V.; Zingde, M.D.

    3 d C01 of process and 6000 m 3 d C01 of domestic effluents in the estuarine segment between stations 14 and 18. These units, set-up in 1951–1964, until recently manufactured caustic soda through Hg cell process but, since 1998–1999, they have been... to progressive enhancement in treatment given to the effluents emanating from indus- tries along the Ulhas estuary. Moreover in the period 1995–1997 the two chlor-alkali industries partially adopted membrane cell process for the manufacture of caustic soda...

  6. Discriminación experimental de los rasgos técnicos en la talla bipolar y a mano alzada en lascas a través los cuarzos de Naibor Soit (Garganta de Olduvai, Tanzania

    Directory of Open Access Journals (Sweden)

    Domínguez Rodrigo, M.

    2012-01-01

    Full Text Available La identificación de la talla bipolar puede ser controvertida debido fundamentalmente a la naturaleza petrográfica del cuarzo y a su fracturación heterogénea. Este trabajo pretende superar este problema mediante el desarrollo de un marco explicativo experimental destinado al reconocimiento de los rasgos diagnósticos en las lascas producidas por ambos métodos de talla en la reducción del cuarzo de Naibor Soit (Garganta de Olduvai, Tanzania. El objetivo final de este trabajo es el de utilizar un conjunto de variables relacionadas con la respuesta de esta materia prima a la fractura a mano alzada y bipolar en dos experimentos destinados a individualizar estadísticamente los rasgos técnicos diagnósticos que mejor identifican a la talla bipolar en este tipo de materia prima.

  7. Ambient mass spectrometry imaging

    DEFF Research Database (Denmark)

    Janfelt, Christian; Nørgaard, Asger W

    2012-01-01

    Easy ambient sonic spray ionization (EASI) and desorption electrospray ionization (DESI) were used for imaging of a number of samples, including sections of rat brain and imprints of plant material on porous Teflon. A novel approach termed Displaced Dual-mode Imaging was utilized for the direct...... comparison of the two methods: Images were recorded with the individual rows alternating between EASI and DESI, yielding a separate image for each technique recorded under perfectly similar conditions on the same sample. EASI works reliably for imaging of all samples, but the choice of spray solvent and flow...... rate is more critical in tissue imaging with EASI than with DESI. The overall sensitivity of EASI is, in general, slightly lower than that of DESI, and the representation of the dynamic range is different in images of the two techniques for some samples. However, for abundant compounds, EASI works well...

  8. MEIO AMBIENTE E DESENVOLVIMENTO

    OpenAIRE

    Suely Salgueiro Chacon; Daniel Rodriguez de Carvalho Pinheiro; Francisco Correia de Oliveira; Elizabeth Castelo Branco de Souza

    2009-01-01

    O objetivo deste artigo é resgatar elementos para subsidiar uma reflexão crítica sobre o modelo de desenvolvimento econômico prevalente na sociedade e as relações com o meio ambiente, sob a ameaça que ronda o destino da espécie humana, conforme afirmação de Lovelock (2006, p. 20) sobre o conceito de desenvolvimento sustentável: “uma ideia adorável se a tivéssemos aplicado 200 anos atrás, quando havia um bilhão de pessoas no mundo. Agora é tarde demais. Não há mais espaço para nenhum tipo de d...

  9. Reforma constitucional y ambiente

    Directory of Open Access Journals (Sweden)

    Teodoro Bustamante

    2013-09-01

    Full Text Available América Latina está atravesada por una ola de reformas constitucionales. Sus causas, las expectativas que ellas despiertan, los riesgos que se han asociado al proceso de lucha política en su entorno, son temas de un análisis fundamentalmente político; pero hay algunos aspectos en los cuales ese debate tiene una directa repercusión sobre el tema ambiental. En el caso del Ecuador, esto se refleja en el hecho de que una de las innovaciones que se proponen, se refieren a una nueva forma de abordar los temas ambientales, básicamente se establecen Derechos de la Naturaleza.

  10. CCN activation of ambient and "synthetic ambient" urban aerosol

    Science.gov (United States)

    Burkart, Julia; Reischl, Georg; Steiner, Gerhard; Bauer, Heidi; Leder, Klaus; Kistler, Magda; Puxbaum, Hans; Hitzenberger, R.

    2013-05-01

    In this study, the Cloud Condensation Nuclei (CCN) activation properties of the urban aerosol in Vienna, Austria, were investigated in a long term (11 month) field study. Filter samples of the aerosol below 100 nm were taken in parallel to these measurements, and later used to generate "synthetic ambient" aerosols. Activation parameters of this "synthetic ambient" aerosol were also obtained. Hygroscopicity parameters κ [1] were calculated both for the urban and the "synthetic ambient" aerosol and also from the chemical composition. Average κ for the "synthetic ambient" aerosol ranged from 0.20 to 0.30 with an average value of 0.24, while the κ from the chemical composition of this "synthetic ambient" aerosol was significantly higher (average 0.43). The full results of the study are given elsewhere [2,3].

  11. SEDIMENT TRANSPORT IN YALU RIVER ESTUARY

    Institute of Scientific and Technical Information of China (English)

    GAO Jian-hua; GAO Shu; CHENG Yan; DONG Li-xian; ZHANG Jing

    2003-01-01

    Tidal cycle measurements of tidal currents, salinity and water temperature, and suspended sediment conc entra-tions were measured at four stations, together with surveys along two profiles short core collection within the Yalu River estuary.Grain size analysis of the three core sediment showed that: 1) the sediment from B1 to B3 became finer, worse sorting andpositively skewed; 2) the diversification of matter origin became more and more evident from east to west; 3) the sediments overthe region were of the same origin, as indicated by their similar colors and grain sizes. The data indicated that stratiticationoccurred in the flood season, from upstream to downstream, and a salt wedge was formed. The water column was well mixed, butthe longitudinal gradient of the salinity was larger on spring tide. The results also showed that the dominating mechanisnt ofsuspended sediment transport in the Yalu River estuary was T1, T2, T3 and T5. The non-tidal steady advection transport wasrestricted by the net transport of suspended sediment induced by mass Stoked drift directed to landwards, then the net sedimenttransport rate were decreased and the turbidity maxima was also favored to forming and extending.

  12. Study of Bed Friction Factor for the Wu River Estuary

    Institute of Scientific and Technical Information of China (English)

    Chin-Wu LAN; Cyuan-Chen LEE

    2006-01-01

    In this research the bed friction effect is estimated of a river estuary by use of hydrodynamic analysis. The on-site sampled data of the Wu River estuary is applied to the analysis. There are many dynamic factors that affect the flow characteristics in the estuary. The effect of tide on the generation of tidal current, bottom friction and geometry effect is the focus of this paper. The Wu River estuary is about 15 km in length, with a small bottom slope and no physical obstruction; thus the incident wave at the estuary is considered a progressive wave with damping effect. The amplitude reduction and phase shift of the incident wave are analyzed. By the analysis of celerity reduction factor of the estuary, the estimated value of mean resistance coefficient M(μ,κ), damping modulus μ, and wave number κ for the sections at observation stations can be determined. Furthermore, data gathered from on-site observations are applied for validation. Finally, Manning's coefficient for each section of the observation stations can be determined. It is found that the value of Manning's coefficient is small downstream and increases towards upstream, and that the bed friction effect of an estuary varies largely. The estimated results of the paper are compared with the empirical formulas and the modified solution for practical application is discussed.

  13. River flow and ammonium discharge determine spring phytoplankton blooms in an urbanized estuary

    Science.gov (United States)

    Dugdale, Richard; Wilkerson, Frances; Parker, Alexander E.; Marchi, Al; Taberski, Karen

    2012-12-01

    Nutrient loadings to urbanized estuaries have increased over the past decades in response to population growth and upgrading to secondary sewage treatment. Evidence from the San Francisco Estuary (SFE) indicates that increased ammonium (NH4) loads have resulted in reduced primary production, a counter-intuitive finding; the NH4 paradox. Phytoplankton uptake of nitrate (NO3), the largest pool of dissolved inorganic nitrogen, is necessary for blooms to occur in SFE. The relatively small pool of ambient NH4, by itself insufficient to support a bloom, prevents access to NO3 and bloom development. This has contributed to the current rarity of spring phytoplankton blooms in the northern SFE (Suisun Bay), in spite of high inorganic nutrient concentrations, improved water transparency and seasonally low biomass of bivalve grazers. The lack of blooms has likely contributed to deleterious bottom-up impacts on estuarine fish. This bloom suppression may also occur in other estuaries that receive large amounts of anthropogenic NH4. In 2010 two rare diatom blooms were observed in spring in Suisun Bay (followed by increased abundances of copepods and pelagic fish), and like the prior bloom observed in 2000, chlorophyll accumulated after NH4 concentrations were decreased. In 2010, low NH4 concentrations were apparently due to a combination of reduced NH4 discharge from a wastewater treatment plant and increased river flow. To understand the interactions of river flow, NH4 discharge and bloom initiation, a conceptual model was constructed with three criteria; 1) NH4 loading must not exceed the capacity of the phytoplankton to assimilate the inflow of NH4, 2) the NH4 concentration must be ≤4 μmol L-1 to enable phytoplankton NO3 uptake, 3) the dilution rate of phytoplankton biomass set by river flow must not exceed the phytoplankton growth rate to avoid "washout". These criteria were determined for Suisun Bay; with sufficient irradiance and present day discharge of 15 tons NH4-N d

  14. Validating Firewalls in Mobile Ambients

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Hansen, René Rydhof;

    1999-01-01

    The ambient calculus is a calculus of computation that allows active processes (mobile ambients) to move between sites. A firewall is said to be protective whenever it denies entry to attackers not possessing the required passwords. We devise a polynomial time algorithm for rejecting proposed...

  15. Foro Ambiental : CEDENMA, Asamblea Constituyente

    Directory of Open Access Journals (Sweden)

    Anne-Lise Naizot

    2013-09-01

    Full Text Available Resumen de la Mesa redonda: Orientaciones de la nueva Constitución ecuatoriana en materia ambiental: ¿avances o retrocesos en relación con el marco político y filosófico ambiental vigente en algunos países de la región?

  16. Changes in the diet composition of transitory fishes in coastal systems, estuary and continental shelf

    Directory of Open Access Journals (Sweden)

    Paulo T. C. Chaves

    2003-01-01

    Full Text Available The feeding habits of five species of teleosts in the southern coast of Brazil were analyzed comparatively between estuary and continental shelf. The displacement between the two sites caused expressive qualitative alterations, the proportion of different items varying from 50% in the diet of Micropogonias furnieri to 89% in Isopisthus parvipinnis. In the group of species, 57% of the items were exclusive to one of the environments and, within the three most common items in the estuary - fish, Polychaeta and plants, only the former was also among the most common items in the shelf. In spite of these differences, the high spectrum of items in both environments and the nature of the item that was most consumed in each one, indicate that there was a certain similarity of patterns between estuary and shelf: Chloroscombrus chrysurus had a carnivorous diet, with a predominance of copepods; M. furnieri and Menticirrhus americanus showed a tendency towards an omnivorous diet; and Cynoscion leiarchus and I. parvipinnis showed a tendency towards ichthyophagy.A alimentação de cinco espécies de teleósteos do litoral sul do Brasil foi analisada comparativamente entre estuário e plataforma continental. Constatou-se que o deslocamento entre os locais acarreta expressivas alterações qualitativas, a proporção de itens diferentes variando de 50% em Micropogonias furnieri a 89% em Isopisthus parvipinnis. No conjunto das espécies, 57% dos itens foram exclusivos de um ambiente ou de outro, e dentre os três mais comuns no estuário - peixes, Polychaeta e vegetais superiores, apenas o primeiro também esteve entre os mais comuns na plataforma. Apesar dessas diferenças, o grande espectro de itens em ambos os ambientes e a natureza daquele mais consumido em cada um indicam que há uma certa similaridade de padrões entre estuário e plataforma: em Chloroscombrus chrysurus, dieta carnívora, com predomínio de copépodos; em M. furnieri e Menticirrhus

  17. Mass and salt transfers and halocline depths in an estuary

    OpenAIRE

    LONG, ROBERT R.

    2011-01-01

    The paper considers fluxes of brackish and ocean water out of and into an estuary as well as the depth of the halocline in the estuary. The discussion ignores the details of the mass distribution and circulations in the main body of the estuary (except for the halocline depth) and concentrates on determining the flow conditions and interface depths in the vicinity of the mouth. The flow there is considered to be frictionless and the pressure hydrostatic, and the first part of the analysis, wh...

  18. Waterfowl migration and distribution in North West estuaries. V. 1

    International Nuclear Information System (INIS)

    Waterfowl populations may be affected by proposed tidal barrage across the Mersey. This study had three objectives:-(1) to evaluate the patterns of usage of the intertidal flats of the Mersey estuary by waders and wildfowl and to establish which are the preferred areas; (2) to identify the places of origin and movement patterns of the populations of waders and wildfowl that visit the Mersey Estuary; and (3) to evaluate evidence regarding the capacity of British estuaries to absorb waders and wildfowl populations which might be displaced by a Mersey Barrage. The text and tables and results only are presented in Volume 1. (author)

  19. Time-dependence of salinity in monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Vijith, V.; Sundar, D.; Shetye, S.R.

    T . For the Mandovi, η T ~5. We now compare values of the above two parameters for ten better known partially-mixed estuaries of the world with those for the Mandovi and three other monsoonal estuaries along the coast of India. Table 2 lists all the 14.... There are virtually no studies that have addressed this issue in the monsoonal estuaries of India. Future research will need to enlarge our understanding of these systems. Acknowledgements V. Vijith acknowledges the financial support from Council of Scientific...

  20. Seasonal stratification and property distributions in a tropical estuary (Cochin estuary, west coast, India)

    Digital Repository Service at National Institute of Oceanography (India)

    Shivaprasad, A.; Vinita, J.; Revichandran, C.; Reny, P.D.; Deepak, M.P.; Muraleedharan, K.R.; NaveenKumar, K.R.

    the surrounding city and riverine water carrying industrial and agricultural wastes are respon- sible for nutrient enrichment influencing the estuarine water quality (Joseph and Ouseph, 2010). Numerous studies reveal the dynamics of the energetic en- vironment.... The strong ebb veloc- ity of about 130 cm s−1 at the Cochin inlet (Udaya Varma et al., 1981), which is comprised in the central estuary, main- tains an effective flushing through the channel in this region (Balachandran et al., 2008). For an ecological study...

  1. Aptitud Física y su Relación con Rasgos Depresivos en Personas Adultas Mayores que Realizan Actividad Física

    Directory of Open Access Journals (Sweden)

    Mynor Rodríguez-Hernández

    2014-08-01

    Full Text Available El propósito de esta investigación fue determinar la relación entre la aptitud física y los niveles depresivos en las personas adultas mayores que participan en programas de actividad física en el área de San Ramón, Alajuela. Un total de 138 personas mayores con edades entre los 60 y 86 años (67.94 ± 5.26 años, fueron medidas en los componentes de la aptitud física mediante la prueba “Senior Fitness Test” (SFT y los niveles de depresión mediante la Escala de Depresión Geriátrica de “Yesavage” (GDS, “Geriatric Depression Scale” por sus siglas en Inglés. Los resultados sugieren que el 97,8 % de las personas analizadas se ubicó dentro de los parámetros normales y excelentes de aptitud física, mientras tanto, el 86,2 % se encontró en la etapa normal de la depresión. Por su parte, la depresión geriátrica correlacionó negativamente con la aptitud física en las variables: fuerza muscular y resistencia corporal de la parte baja del cuerpo, resistencia de la fuerza muscular del brazo, la agilidad y equilibrio dinámico, y flexibilidad parte baja del cuerpo (p <0,05. Se concluye que a mayor nivel de aptitud física menor son los rasgos depresivos en personas adultas mayores.

  2. La democracia mexicana, presa de una cultura política con rasgos autoritarios Mexican Democracy, Overcome by a Political Culture with Authoritarian Features

    Directory of Open Access Journals (Sweden)

    María Aidé Hernández

    2008-06-01

    Full Text Available A pesar de las transformaciones políticas que han ocurrido en México durante los últimos 20 años, la cultura política del mexicano ha dejado ver pocos avances. Actualmente siguen predominando características que no fomentan una participación autónoma y propositiva que ayude al éxito de la democracia. Entre ellas destacan el conocimiento e interés por la política; la confianza interpersonal, en las instituciones y en la democracia; la tolerancia; y la competencia subjetiva. Este panorama propicia que sigan prevaleciendo rasgos autoritarios como el clientelismo y el corporativismo, los cuales no fortalecen la democracia. Los pequeños cambios culturales se han dado en el ámbito electoral, donde no sólo hay una gran aceptación a la pluralidad y competencia entre los partidos políticos: ahora los ciudadanos consideran el voto ya no como un derecho sino como un arma política.In spite of the political transformations occurred in Mexico during the last 20 years, the Mexican citizen's political culture has shown few improvements, since certain characteristics keep on prevailing and do not encourage an autonomous participation contribuing to the success of the democratic process. Some of the most relevant advances for such process are knowledge and interest in politics; confidence in the interpersonal relationships, in institutions and in democracy; tolerance; and subjective competence. Their absence favours the prevalence of authoritarian features as clientelism and corporativism. Small cultural changes have taken place in the electoral domain though, where there is a great acceptance of plurality and competition among the political parties and citizens consider suffrage not as a right but as a political weapon.

  3. Influence of allochthonous input on autotrophiceheterotrophic switch-over in shallow waters of a tropical estuary (Cochin Estuary), India

    Digital Repository Service at National Institute of Oceanography (India)

    Thottathil, S.D.; Balachandran, K.K.; Gupta, G.V.M.; Madhu, N.V.; Nair, S.

    Author's personal copy Influence of allochthonous input on autotrophiceheterotrophic switch-over in shallow waters of a tropical estuary (Cochin Estuary), India Shoji D. Thottathil a , K.K. Balachandran a , G.V.M. Gupta b , N.V. Madhu a , Shanta Nair c... heterotrophic and vice versa. Studies on planktonic biomass, production and respiration along with dissolved gases (O 2 and CO 2 ) have identified several estuaries to be ‘‘net heterotrophic’’ due to allochthonous organic matter input (Smith and Hollibaugh, 1993...

  4. Seasonal shift in net ecosystem production in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.S.P.; Nair, S.; Chandramohan, D.

    was not significant, and net heterotrophy was prevalent whenever measurements were made, thereby potentially serving as the net source of carbon dioxide to the atmosphere. Results suggest that the excess organic matter from these tropical estuaries supports...

  5. Bacterial contamination of mussels at Mahe estuary, Malabar coast

    Digital Repository Service at National Institute of Oceanography (India)

    Gore, P.S.; Raveendran, O.; Iyer, T.S.G.; Varma, P.R.G.; Sankaranarayanan, V.N.

    Mussel samples from the mussel bed and near-by market, beach sand, sediment and water from the Mahe Estuary, Kerala, India were analysed for the bacterial quality. Indicator bacteria such as Escherichia coli and faecal streptococci were isolated...

  6. MODIS water quality algorithms for northwest Florida estuaries

    Science.gov (United States)

    Synoptic and frequent monitoring of water quality parameters from satellite is useful for determining the health of aquatic ecosystems and development of effective management strategies. Northwest Florida estuaries are classified as optically-complex, or waters influenced by chlo...

  7. The application of Yangtze Estuary Tidal Wetlands Geographic Information System

    Institute of Scientific and Technical Information of China (English)

    WANGJun; CHENZhenlou; XUShiyuan; WANGDongqi; LIUJie

    2005-01-01

    Yangtze Estuary Tidal Wetlands Geographic Information System (YETWGIS) is a comprehensive software system for environmental management and decision of Yangtze estuary tidal wetlands. Based on MapObjects components technology, Data Mining technology, mathematical modeling method and Visual Basic language, this software system has many functions such as displaying, editing, querying and searching, spatial statistics and analysis, thematic map compiling, and environmental quality evaluation. This paper firstly outlined the system structure, key techniques, and achieving methods of YETWGIS, and then, described the core modules (the thematic map compiling module and environmental quality evaluation model module) in detail. In addition, based on information entropy model, it thoroughly discussed the methods of environmental quality evaluation and indicators' weight calculation. Finally, by using YETWGIS, this paper analyzed the spatial distribution characteristics of Heavy Metal and Persistent Organic Pollutants (POPs) of the Yangtze estuary tidal wetlands in 2002, and evaluated the environmental quality of the Yangtze estuary tidal wetlands in 2003.

  8. Toxicity of sediments and pore water from Brunswick Estuary, GA

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A chlor-alkali plant in Brunswick, Ga, discharged >2 kg mercury/day into a tributary of the Turtle River-Brunswick Estuary from 1966 to 1971. Mercury...

  9. Habitat Scale Mapping of Fisheries Ecosystem Service Values in Estuaries

    Directory of Open Access Journals (Sweden)

    Steve J. Jordan

    2010-12-01

    Full Text Available Little is known about the variability of ecosystem service values at spatial scales most relevant to local decision makers. Competing definitions of ecosystem services, the paucity of ecological and economic information, and the lack of standardization in methodology are major obstacles to applying the ecosystem-services approach at the estuary scale. We present a standardized method that combines habitat maps and habitat–faunal associations to estimate ecosystem service values for recreational and commercial fisheries in estuaries. Three case studies in estuaries on the U.S. west coast (Yaquina Bay, Oregon, east coast (Lagoon Pond, Massachusetts, and the Gulf of Mexico (Weeks Bay, Alabama are presented to illustrate our method’s rigor and limitations using available data. The resulting spatially explicit maps of fisheries ecosystem service values show within and between estuary variations in the value of estuarine habitat types that can be used to make better informed resource-management decisions.

  10. Behaviour of aluminium, silicon and iron in Tapi Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, P.; Zingde, M.D.

    suspended particulate materials (SPM) dispersed by strong tidal currents to low dissolved Si containing coastal water and its subsequent removal in the estuary, enriching the estuarine SPM. This view was supported by markedly high Al content of estuarine SPM...

  11. St. Louis River Estuary 2011 - 2013 Faucet snail location data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset consists of GPS coordinates for benthic invertebrate collections made in the St. Louis River Estuary in 2011 through 2013, and information on whether...

  12. Aspectos computacionais do ambiente IMAGUS

    OpenAIRE

    Raabe, André Luís Alice; Giraffa, Lúcia Maria Martins

    2000-01-01

    Este artigo apresenta a descrição do ambiente IMAGUS enfatizando aspectos da implementação do protótipo do ambiente. O IMAGUS permite a construção de materiais com fins pedagógicos que se utilizam de vídeos acessado via Internet. O protótipo foi desenvolvido para validar a arquitetura proposta para o ambiente. São apresentadas as soluções a nível de modelagem e a implementação do protótipo baseada na utilização da interface Java Media Framework

  13. Contamination and restoration of an estuary affected by phosphogypsum releases

    Energy Technology Data Exchange (ETDEWEB)

    Villa, M., E-mail: mvilla@us.es [Centro de Investigacion, Tecnologia e Innovacion, Universidad de Sevilla CITIUS, Av. Reina Mercedes 4B, E41012-Sevilla (Spain); Mosqueda, F. [Dpto. de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus de El Carmen, 21007-Huelva (Spain); Hurtado, S. [Centro de Investigacion, Tecnologia e Innovacion, Universidad de Sevilla CITIUS, Av. Reina Mercedes 4B, E41012-Sevilla (Spain); Mantero, J.; Manjon, G. [E. T. S. Arquitectura, Universidad de Sevilla, Departamento de Fisica Aplicada II, Av. Reina Mercedes, 2. 41012-Sevilla (Spain); Perianez, R. [E.U.I.T.A., Universidad de Sevilla, Departamento de Fisica Aplicada III, Carretera de Utrera, Km. 1, 41013 Sevilla (Spain); Vaca, F. [Dpto. de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus de El Carmen, 21007-Huelva (Spain); Garcia-Tenorio, R. [E. T. S. Arquitectura, Universidad de Sevilla, Departamento de Fisica Aplicada II, Av. Reina Mercedes, 2. 41012-Sevilla (Spain)

    2009-12-15

    The Huelva Estuary in Huelva, Spain, has been one of the most studied environmental compartments in the past years from the point of view of naturally occurring radioactive material (NORM) releases. It has been historically affected by waste releases, enriched in radionuclides from the U-decay series, from factories located in the area devoted to the production of phosphoric acid and phosphate fertilizers. Nevertheless, changes in national regulations forced a new waste management practice in 1998, prohibiting releases of phosphogypsum into the rivers. The input of natural radionuclides from phosphate factories to rivers was drastically reduced. Because of this there was a unique opportunity for the study of the response of a contaminated environmental compartment, specifically an estuary affected by tidal influences, after the cessation of the contaminant releases to, in this case, the Huelva Estuary (henceforth referred to as the Estuary). To investigate the environmental response to this new discharge regime, the specific activities of radionuclides {sup 226}Ra and {sup 210}Pb in water and sediment samples collected in four campaigns (from 1999 to 2005) were determined and compared with pre-1998 values. From this study it is possible to infer the most effective mechanisms of decontamination for the Estuary. Decontamination rates of {sup 210}Pb and {sup 226}Ra in the sediments and water have been calculated using exponential fittings and corresponding half-lives have been deduced from them. The cleaning half-life in the whole area of the Estuary is about 6 and 3.5 years for {sup 226}Ra and {sup 210}Pb respectively. The observed trend clearly shows that contamination of the Estuary by natural radionuclides is now decreasing and radioactive levels in waters and sediments are approaching the natural background references. This work attempts to evaluate whether it can be expected that the decontamination of the enhanced levels of natural radioactivity in the Estuary

  14. Mathematical modeling of sediment transport jn estuaries and coastal regions

    Institute of Scientific and Technical Information of China (English)

    窦国仁; 董凤舞; 窦希萍; 李禔来

    1995-01-01

    Based on the suspended sediment transport equation and transport capacity formula under the action of tidal currents and wind waves, a horizontal 2-D mathematical model of suspended sediment transport for estuaries and coastal regions is established. The verification of calculations shows that the sediment concentration distribution and sea bed deformation in the estuaries and coastal regions can be successfully simulated. Therefore, a new method for studying and solving the sediment problems in the estuarine and coastal engineering is presented.

  15. Contamination and restoration of an estuary affected by phosphogypsum releases

    International Nuclear Information System (INIS)

    The Huelva Estuary in Huelva, Spain, has been one of the most studied environmental compartments in the past years from the point of view of naturally occurring radioactive material (NORM) releases. It has been historically affected by waste releases, enriched in radionuclides from the U-decay series, from factories located in the area devoted to the production of phosphoric acid and phosphate fertilizers. Nevertheless, changes in national regulations forced a new waste management practice in 1998, prohibiting releases of phosphogypsum into the rivers. The input of natural radionuclides from phosphate factories to rivers was drastically reduced. Because of this there was a unique opportunity for the study of the response of a contaminated environmental compartment, specifically an estuary affected by tidal influences, after the cessation of the contaminant releases to, in this case, the Huelva Estuary (henceforth referred to as the Estuary). To investigate the environmental response to this new discharge regime, the specific activities of radionuclides 226Ra and 210Pb in water and sediment samples collected in four campaigns (from 1999 to 2005) were determined and compared with pre-1998 values. From this study it is possible to infer the most effective mechanisms of decontamination for the Estuary. Decontamination rates of 210Pb and 226Ra in the sediments and water have been calculated using exponential fittings and corresponding half-lives have been deduced from them. The cleaning half-life in the whole area of the Estuary is about 6 and 3.5 years for 226Ra and 210Pb respectively. The observed trend clearly shows that contamination of the Estuary by natural radionuclides is now decreasing and radioactive levels in waters and sediments are approaching the natural background references. This work attempts to evaluate whether it can be expected that the decontamination of the enhanced levels of natural radioactivity in the Estuary can be performed via natural

  16. Biological effects of anthropogenic contaminants in the San Francisco Estuary

    Science.gov (United States)

    Thompson, B.; Adelsbach, T.; Brown, C.; Hunt, J.; Kuwabara, J.; Neale, J.; Ohlendorf, H.; Schwarzbach, S.; Spies, R.; Taberski, K.

    2007-01-01

    Concentrations of many anthropogenic contaminants in the San Francisco Estuary exist at levels that have been associated with biological effects elsewhere, so there is a potential for them to cause biological effects in the Estuary. The purpose of this paper is to summarize information about biological effects on the Estuary's plankton, benthos, fish, birds, and mammals, gathered since the early 1990s, focusing on key accomplishments. These studies have been conducted at all levels of biological organization (sub-cellular through communities), but have included only a small fraction of the organisms and contaminants of concern in the region. The studies summarized provide a body of evidence that some contaminants are causing biological impacts in some biological resources in the Estuary. However, no general patterns of effects were apparent in space and time, and no single contaminant was consistently related to effects among the biota considered. These conclusions reflect the difficulty in demonstrating biological effects due specifically to contamination because there is a wide range of sensitivity to contaminants among the Estuary's many organisms. Additionally, the spatial and temporal distribution of contamination in the Estuary is highly variable, and levels of contamination covary with other environmental factors, such as freshwater inflow or sediment-type. Federal and State regulatory agencies desire to develop biological criteria to protect the Estuary's biological resources. Future studies of biological effects in San Francisco Estuary should focus on the development of meaningful indicators of biological effects, and on key organism and contaminants of concern in long-term, multifaceted studies that include laboratory and field experiments to determine cause and effect to adequately inform management and regulatory decisions. ?? 2006 Elsevier Inc. All rights reserved.

  17. Physical drivers of saltmarsh change in enclosed microtidal estuaries

    OpenAIRE

    Gardiner, Sarah

    2015-01-01

    Estuaries are among the most biologically productive ecosystems on the planet, per unit area, with intertidal habitats and particularly saltmarshes providing a variety or ecosystem services and supporting large numbers of both primary and secondary producers. These habitats are globally important and are found throughout tropical to temperate climates. Micro-tidal estuaries are found throughout the world and particularly sensitive to sea-level rise, as they are limited in their ability to adj...

  18. Biota and abiotic environment in the Westerschelde estuary

    OpenAIRE

    Heip, C. H. R.

    1988-01-01

    An estuary such as the Westerschelde is a highly dynamic environment, both on an ecological time scale where climatic and hydrodynamic forces, mainly the tides, shape a very variable environment and on a geological, evolutionary time scale, since estuaries are young and very unstable habitats. Low species diversity and high adaptability of the resident animal and plant populations are characteristic of estuarine habitats where large fluctuations in submersion, salinity, temperature etc. occur...

  19. Spatial variation of the longitudinal dispersion coefficient in an estuary

    OpenAIRE

    D. C. Shaha; Y.-K. Cho; M.-T. Kwak; S. R. Kundu; K. T. Jung

    2011-01-01

    The effective longitudinal dispersion is a primary tool for determining property distributions in estuaries. Most previous studies have examined the longitudinal dispersion coefficient for the average tidal condition. However, information on spatial and temporal variations of this coefficient at low and high tide is scarce. Three years of hydrographic data taken at low and high tide along the main axis of the Sumjin River Estuary (SRE), Korea are used to estimate the spatial and temporal vari...

  20. Sources, Ages, and Alteration of Organic Matter in Estuaries

    Science.gov (United States)

    Canuel, Elizabeth A.; Hardison, Amber K.

    2016-01-01

    Understanding the processes influencing the sources and fate of organic matter (OM) in estuaries is important for quantifying the contributions of carbon from land and rivers to the global carbon budget of the coastal ocean. Estuaries are sites of high OM production and processing, and understanding biogeochemical processes within these regions is key to quantifying organic carbon (Corg) budgets at the land-ocean margin. These regions provide vital ecological services, including nutrient filtration and protection from floods and storm surge, and provide habitat and nursery areas for numerous commercially important species. Human activities have modified estuarine systems over time, resulting in changes in the production, respiration, burial, and export of Corg. Corg in estuaries is derived from aquatic, terrigenous, and anthropogenic sources, with each source exhibiting a spectrum of ages and lability. The complex source and age characteristics of Corg in estuaries complicate our ability to trace OM along the river-estuary-coastal ocean continuum. This review focuses on the application of organic biomarkers and compound-specific isotope analyses to estuarine environments and on how these tools have enhanced our ability to discern natural sources of OM, trace their incorporation into food webs, and enhance understanding of the fate of Corg within estuaries and their adjacent waters.

  1. Urea degradation rates by size-fractionated plankton populations in a temperate estuary

    Science.gov (United States)

    Savidge, G.; Johnston, J. P.

    1987-04-01

    The distribution of the rates of remineralisation and assimilation of labelled urea by bacteria was determined in a temperate estuary in winter and related to the activities of planktonic populations separated by filtration into a large fraction (LF > 3 μm) and small fractions (SF urea concentrations, whereas corresponding relationships between the LF in situ and urea concentrations were inconsistent. A series of comparable artificial dilution experiments demonstrated consistent effects of salinity on rates of urea remineralisation with opposing relationships observed for the LF and SF. However interpretation of the data obtained from the in situ samples in relation to those obtained experimentally indicated only minimal control of the in situ rates of urea remineralisation by salinity, thus confirming the greater influence on these rates of the ambient urea concentrations. Remineralisation activity was approximately an order of magnitude greater than the assimilation activity with no clear trends being shown between assimilation rates and environmental variables. Highest ambient concentrations of urea were consistently recorded adjacent to the freshwater inflow.

  2. Risky behavior, personality traits and road accidents among university students Comportamiento de riesgo, rasgos de personalidad y accidentes de carretera en estudiantes universitarios.

    Directory of Open Access Journals (Sweden)

    Aristides I. Ferreira

    2009-06-01

    Full Text Available The personality traits that mediate risky driving and accidents among university students drivers were investigated. Study 1 (N=132 tested for the relation between risky behaviors and personality (16PF-5 second order dimensions. Three factors were extracted concerning risky driving: driving errors of commission, distraction, and driving errors of omission. Individuals with low self-control and high levels of anxiety were more prone to commit distractive behavior and driving errors of omission. Low self-control and high independence levels were associated with driving errors of commission. In study 2 (N=540, we tested if the number of road accidents for which an individual has been responsible was related to risky driving behavior. Drivers who committed more accidents presented higher scores in three new risky driving factors obtained: reckless driving, impaired concentration and division of attention.

    Key words: Risky driving, personality, accidents, behavior.
    En este estudio se investigaron los rasgos de personalidad relacionados con la conducción de riesgo y los accidentes en estudiantes universitarios. El primer estudio (N=132 evaluó la relación entre los comportamientos de riesgo y la personalidad (16PF-5 dimensiones de segundo orden. Tres factores fueron extraídos en relación con la conducción de riesgo: cometer errores de conducción, distracción, errores de omisión en la conducción. Los individuos con bajo autocontrol y altos niveles de ansiedad eran más propensos a tener comportamientos distractores y cometer errores de omisión en la conducción. Mientras que sujetos con bajo autocontrol y altos niveles de independencia se asociaron con el factor cometer errores de conducción. En el segundo estudio (N=540 evaluamos si el número de accidentes de tráfico, de los que una persona ha sido responsable, está relacionado con el comportamiento de riesgo en la conducción. Los resultados muestran que los conductores

  3. Urban microbial ecology of a freshwater estuary of Lake Michigan

    Directory of Open Access Journals (Sweden)

    Jenny C. Fisher

    2015-07-01

    Full Text Available Abstract Freshwater estuaries throughout the Great Lakes region receive stormwater runoff and riverine inputs from heavily urbanized population centers. While human and animal feces contained in this runoff are often the focus of source tracking investigations, non-fecal bacterial loads from soil, aerosols, urban infrastructure, and other sources are also transported to estuaries and lakes. We quantified and characterized this non-fecal urban microbial component using bacterial 16S rRNA gene sequences from sewage, stormwater, rivers, harbor/estuary, and the lake surrounding Milwaukee, WI, USA. Bacterial communities from each of these environments had a distinctive composition, but some community members were shared among environments. We used a statistical biomarker discovery tool to identify the components of the microbial community that were most strongly associated with stormwater and sewage to describe an “urban microbial signature,” and measured the presence and relative abundance of these organisms in the rivers, estuary, and lake. This urban signature increased in magnitude in the estuary and harbor with increasing rainfall levels, and was more apparent in lake samples with closest proximity to the Milwaukee estuary. The dominant bacterial taxa in the urban signature were Acinetobacter, Aeromonas, and Pseudomonas, which are organisms associated with pipe infrastructure and soil and not typically found in pelagic freshwater environments. These taxa were highly abundant in stormwater and sewage, but sewage also contained a high abundance of Arcobacter and Trichococcus that appeared in lower abundance in stormwater outfalls and in trace amounts in aquatic environments. Urban signature organisms comprised 1.7% of estuary and harbor communities under baseflow conditions, 3.5% after rain, and >10% after a combined sewer overflow. With predicted increases in urbanization across the Great Lakes, further alteration of freshwater communities is

  4. THE CHARACTERISTIC OF MARINE ENVIRONMENT IN LINGDINGYANG ESTUARY

    Institute of Scientific and Technical Information of China (English)

    CHEN; Bing-lu

    2001-01-01

    [1]LIN Zhi-qing, 1985. The Nutrient salts in the water between Guangzhou and Humen [J] . Tropical Oceanography, 4(2):52-59. (in Chinese)[2]LUO Zhang-ren, YING Zhi-pu et al., 1992. The Harbours in South China[M]. Guangzhou: Zhongshan University Press,101-126. (in Chinese)[3]PENG Yun-hui et al., 1991. The relationship of phosphate and dissolved oxygen in Pearl River Estuary [J]. Marine Report,10(6): 25-29. (in Chinese)[4]PENG Yun-hui et al., 1994. The relationship of dissolved oxygen and nutrient salts in Pearl River Estuary[J]. Tropical Oceanography, 13(1): 96-100. (in Chinese)[5]TAN Wei-guang et al., 1993. Assessment of eutrophication of Pearl River Estuary [J] . Research & Exploration of Nanhai, (2): 17-21. (in Chinese)[6]TANG Yong-Luan, 1984. The Characteristic of the dispersion model of the substances of Pearl River Estuary and Lingding Estuary [J] . Marine Environmental Science, 3(3): 1-11.(in Chinese)[7]ZHOU Yan-xia, 1994. Analysis of the water quality of Pearl River Estuary and neighboring sea area [J]. Marine Report, 13(3):24-30. (in Chinese)[8]ZHAO Huan-ting, 1981. The topograghy of Lingding Estuary [J]. Journal of Oceanography, 3(2): 20-27. (in Chinese)

  5. Biogeography of dinoflagellate cysts in northwest Atlantic estuaries.

    Science.gov (United States)

    Price, Andrea M; Pospelova, Vera; Coffin, Michael R S; Latimer, James S; Chmura, Gail L

    2016-08-01

    Few biogeographic studies of dinoflagellate cysts include the near-shore estuarine environment. We determine the effect of estuary type, biogeography, and water quality on the spatial distribution of organic-walled dinoflagellate cysts from the Northeast USA (Maine to Delaware) and Canada (Prince Edward Island). A total of 69 surface sediment samples were collected from 27 estuaries, from sites with surface salinities >20. Dinoflagellate cysts were examined microscopically and compared to environmental parameters using multivariate ordination techniques. The spatial distribution of cyst taxa reflects biogeographic provinces established by other marine organisms, with Cape Cod separating the northern Acadian Province from the southern Virginian Province. Species such as Lingulodinium machaerophorum and Polysphaeridinium zoharyi were found almost exclusively in the Virginian Province, while others such as Dubridinium spp. and Islandinium? cezare were more abundant in the Acadian Province. Tidal range, sea surface temperature (SST), and sea surface salinity (SSS) are statistically significant parameters influencing cyst assemblages. Samples from the same type of estuary cluster together in canonical correspondence analysis when the estuaries are within the same biogeographic province. The large geographic extent of this study, encompassing four main estuary types (riverine, lagoon, coastal embayment, and fjord), allowed us to determine that the type of estuary has an important influence on cyst assemblages. Due to greater seasonal variations in SSTs and SSSs in estuaries compared to the open ocean, cyst assemblages show distinct latitudinal trends. The estuarine context is important for understanding present-day species distribution, the factors controlling them, and to better predict how they may change in the future. PMID:27547344

  6. Biogeography of dinoflagellate cysts in northwest Atlantic estuaries.

    Science.gov (United States)

    Price, Andrea M; Pospelova, Vera; Coffin, Michael R S; Latimer, James S; Chmura, Gail L

    2016-08-01

    Few biogeographic studies of dinoflagellate cysts include the near-shore estuarine environment. We determine the effect of estuary type, biogeography, and water quality on the spatial distribution of organic-walled dinoflagellate cysts from the Northeast USA (Maine to Delaware) and Canada (Prince Edward Island). A total of 69 surface sediment samples were collected from 27 estuaries, from sites with surface salinities >20. Dinoflagellate cysts were examined microscopically and compared to environmental parameters using multivariate ordination techniques. The spatial distribution of cyst taxa reflects biogeographic provinces established by other marine organisms, with Cape Cod separating the northern Acadian Province from the southern Virginian Province. Species such as Lingulodinium machaerophorum and Polysphaeridinium zoharyi were found almost exclusively in the Virginian Province, while others such as Dubridinium spp. and Islandinium? cezare were more abundant in the Acadian Province. Tidal range, sea surface temperature (SST), and sea surface salinity (SSS) are statistically significant parameters influencing cyst assemblages. Samples from the same type of estuary cluster together in canonical correspondence analysis when the estuaries are within the same biogeographic province. The large geographic extent of this study, encompassing four main estuary types (riverine, lagoon, coastal embayment, and fjord), allowed us to determine that the type of estuary has an important influence on cyst assemblages. Due to greater seasonal variations in SSTs and SSSs in estuaries compared to the open ocean, cyst assemblages show distinct latitudinal trends. The estuarine context is important for understanding present-day species distribution, the factors controlling them, and to better predict how they may change in the future.

  7. Prácticas de crianza y su relación con rasgos resilientes de niños y niñas / Practices of parenting and the relationship resilient traits of the children

    OpenAIRE

    Aguirre Forero, Ana Mireya

    2010-01-01

    En la investigación se analizan las relaciones existentes entre rasgos resilientes: autoconcepto y autoevaluación, autoestima, autonomía, empatía, humor y creatividad, con las categorías de las prácticas de crianza en las dimensiones de apoyo afectivo y regulación de comportamiento tales como: expresiones de afecto, orientación positiva, involucramiento, prácticas de cuidado, sensibilización e inducción. Con el fin de determinar relaciones existentes entre ellas, y encontrar prácticas de cria...

  8. Diagenesis and bioavailability of mercury in the contaminated sediments of Ulhas Estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Borole, D.V.; Rokade, M.A.; Zingde, M.D.

    Sequential extraction of Hg was performed in a core collected from intertidal area in Ulhas Estuary in order to characterize the downward distribution and diagenetic behavior of Hg in a polluted estuary. Concentration of total Hg ranged between 0...

  9. Tidal influence on the diel vertical migration pattern of zooplankton in a tropical monsoonal Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Vineetha, G.; Jyothibabu, R.; Madhu, N.V.; Kusum, K.K.; Sooria, P.M.; Shivaprasad, A.; Reny, P.D.; Deepak, M.P.

    Monsoonal estuaries, located along the coastline of the Indian subcontinent, differ from other estuaries by their time dependence on the salinity characteristics. Effective sustenance and retention of the mesozooplankton community in the estuarine...

  10. Suspended sediment fluxes in a tropical estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    AnilKumar, N.; DineshKumar, P.K.; Srinivas, K.

    Annual transport processes of suspended sediments in Beypore estuary - a tropical estuary along the south west coast of India - were investigated based on time series measurements within the system. It's observed that the sediment transport...

  11. High CO2 emissions from the tropical Godavari estuary (India) associated with monsoon river discharges

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Kumar, N.A.; Prasad, V.R.; Venkataramana, V.; Appalanaidu, S.; Sridevi, B.; Kumar, B.S.K.; Bharati, M.D.; Subbaiah, C.V.; Acharyya, T.; Rao, G.D.; Viswanadham, R.; Gawade, L.; Manjary, D.T.; Kumar, P.P.; Rajeev, K.; Reddy, N.P.C.; Sarma, V.V.; Kumar, M.D.; Sadhuram, Y.; Murty, T.V.R.

    Estuaries have been under sampled to establish them as sources or sinks of the atmospheric carbon dioxide. Such poor coverage is well known for tropical, particularly monsoon driven, estuaries. In an attempt to study the variability in CO sub(2...

  12. Maturation of the penaeid prawn Metapenaeus moyebi in Mandovi Estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Achuthankutty, C.T.; Parulekar, A

    Metapenaeus moyebi contributed a good share of penaeid prawn population in the Mandovi Estuary of Goa, India throughout the year. Both males and females of this species with fully mature gonads were observed in the estuary, suggesting further...

  13. Ambiente juvenil: discurso ambiental entre jóvenes universitarios

    OpenAIRE

    Quinn-Anderson, William C.

    2008-01-01

    Esta tesis pretende hacer una aportación al conocimiento del medio ambiente del occidente de México, específicamente de la zona metropolitana de Guadalajara, a partir del estudio de la cultura ambiental manifestada en el discurso de los jóvenes universitarios del ITESO. La apuesta es que puede ser provechoso considerar dentro del concepto de “medio ambiente” no solamente componentes bióticos y abióticos, sino también elementos socioculturales como cultura y significado. Es evidente que hay in...

  14. Contrasting behaviour of trace metals in the Scheldt estuary in 1978 compared to recent years

    OpenAIRE

    Nolting, R.F.; Helder, W.; De Baar, H. J. W.; Gerringa, L.J.A.

    1999-01-01

    Dissolved and particulate trace metals (Cu, Cd, Pb, Zn, Ni, Fe and Mn) measured at six stations along the Scheldt estuary in October/November 1978 are compared with more recent data. Based on Ca content in the suspended matter, three distinct geochemical regions could be distinguished: the upper estuary (salinity 1–7) dominated by fluvial mud, mid-estuary (salinity 7–17) where the composition of the suspended matter remained relatively constant, and the lower estuary where marine mud prevaile...

  15. Life in an extreme environment: phytoplankton blooms in the upper Scheldt estuary

    OpenAIRE

    Muylaert, K.; Kromkamp, J.

    2002-01-01

    Being extremely turbid environments characterised by short residence times and rapid changes in salinity, the upper reaches of estuaries comprise an extreme environment for phytoplankton to live and grow in. Nevertheless, in many estuaries including the Schelde estuary, these reaches often support dense phytoplankton populations. In the past, these phytoplankton blooms in the upper reaches of estuaries have often been found difficult to explain. In this presentation, we will describe the exte...

  16. Horizontal distribution and population dynamics of the dominant mysid Hyperacanthomysis longirostris along a temperate macrotidal estuary (Chikugo River estuary, Japan)

    Science.gov (United States)

    Suzuki, Keita W.; Nakayama, Kouji; Tanaka, Masaru

    2009-08-01

    The estuarine turbidity maximum (ETM) that develops in the lower salinity areas of macrotidal estuaries has been considered as an important nursery for many fish species. Mysids are one of the dominant organisms in the ETM, serving as a key food source for juvenile fish. To investigate the horizontal distribution and population dynamics of dominant mysids in relation to the fluctuation of physical conditions (temperature, salinity, turbidity, and freshwater discharge), we conducted monthly sampling (hauls of a ring net in the surface water) along the macrotidal Chikugo River estuary in Japan from May 2005 to December 2006. Hyperacanthomysis longirostris was the dominant mysid in the estuary, usually showing peaks of density and biomass in or close to the ETM (salinity 1-10). In addition, intra-specific differences (life-cycle stage, sex, and size) in horizontal distribution were found along the estuary. Larger males and females, particularly gravid females, were distributed upstream from the center of distribution where juveniles were overwhelmingly dominant. Juveniles increased in size toward the sea in marked contrast with males and females. The findings suggest a possible system of population maintenance within the estuary; gravid females release juveniles in the upper estuary, juveniles grow during downstream transport, young males and females mature during the upstream migration. Density and biomass were primarily controlled by seasonal changes of temperature, being high at intermediate temperatures (ca. 15-25 °C in late spring and fall) and being low at the extreme temperatures (ca. 10 °C in midwinter and 30 °C in midsummer). High density (up to 666 ind. m -3) and biomass (up to 168 mg dry weight m -3) of H. longirostris were considered to be comparable with those of copepods in the estuary.

  17. The chemistry of trace elements in estuaries

    International Nuclear Information System (INIS)

    Estuarine mixing processes can be generally divided into two stages. In the low-salinity region (226Ra is removed through adsorption by resuspended particles, and added through desorption from riverine suspended particles and input from the pore water. This is shown by the data collected from the Mullica River estuary. Equilibrium-speciation calculation for estuarine water predict that Al and Cu are complexed largely with organic ligands. The extent of Ni complexes with organic ligands in estuarine water depends largely on the concentration of organic ligands. Dissolved Mn and Zn do not form significant fraction of metal-organic complexes. Complexing of Fe with organics can delay precipitation of Fe-hydroxides in the course of estuarine mixing. Metal concentrations in estuarine sediments of the Mullica River are primarily controlled by physical processes. The dominant processes are resuspension and sedimentation for suspended sediments, and longitudinal mixing for bottom sediments. In suspended particles, Fe, Mn, and Zn are largely associated with amorphous material, which is clearly in contrast to those for bottom sediments in which most metals are associated with clay minerals. The coastal waters of New Jersey receive considerable Cu, Ni Mn and Zn from anthropogenic sources, and these metals are largely added in the high salinity region

  18. Assessment of trophic status in Changjiang (Yangtze) River estuary

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The integrated methodology for the assessment of estuarine trophic status (ASSETS),which was extended and refined from the United States National Estuarine Eutrophication Assessment (NEEA), is a multi-parameter assessment system and has been widely used in eutrophication assessment in estuarine and coastal waters. The ASSETS was applied to evaluate the trophic status of the Changjiang (Yangtze) River estuary, one of the largest estuaries in the world. The following main results were obtained: (i) The estuarine export potential is "moderate susceptibility" due to the "moderate" dilution potential and "moderate" flushing potential; (ii) The overall human influence (OHI) index classified the impact of nutrients in the system as "high" due to the high level of nutrient discharge by the river which channels anthropogenic impacts in the catchments to the estuarine system; (iii) The overall eutrophic condition (OEC) in the estuary was classified into the "high" category due to frequent occurrence of nuisance and toxic algal blooms in the mixing and seawater zones; (iv) Since the nutrient loadings (e.g.,DIN) in the river is expected to continue to increase in the near future following the population increase and rapid economic growth throughout the drainage basin, the nutrient-related symptoms in the estuary are likely to substantially worsen, which leads to the "worsen high" category for the definition of future outlook (DFO). The combinations of the three components (i.e., OHI, OEC, and DFO) lead to an overall grade as "bad" for the trophic status in the Changjiang River estuary.

  19. Conhecimento, interdisciplinaridade e Psicologia Ambiental

    Directory of Open Access Journals (Sweden)

    Ombretta Romice

    2005-01-01

    Full Text Available Responde às questões - como os métodos da Psicologia Ambiental devem ser discutidos em um enquadramento interdisciplinar; a Psicologia Ambiental pede alguma abordagem metodológica especial; como a intervenção ambiental é determinada pela interdisciplinaridade; quais são estas disciplinas e como elas se relacionam entre si - baseando-se em experiências profissionais como orientador em um projeto com comunidade, com habitação popular e exclusão social em vários países da Europa, e como consultora. Conclui que as abordagens usadas pelas diferentes profissões são muito separadas, e que apenas metas comuns não são suficientes, sendo também necessários um treino conjunto e identidade de valores.

  20. Distribution and sources of particulate organic matter in the Indian monsoonal estuaries during monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Krishna, M.S.; Prasad, V.R.; Kumar, B.S.K.; Naidu, S.A.; Rao, G.D.; Viswanadham, R.; Sridevi, T.; Kumar, P.P.; Reddy, N.P.C.

    in estuaries with deeper photic zone than other estuaries receiving higher suspended matter. The delta13CPOC and delta15CPN data suggest that relatively higher delta13CPOC (-27.9 to -22.6‰) and lower delta15CPN (0.7 to 5.8‰) were noticed in the estuaries...

  1. Dissolved organic carbon in the freshwater tidal reaches of the Schelde estuary

    DEFF Research Database (Denmark)

    Muylaert, K.; Dasseville, R.; De Brabandere, Loreto;

    2005-01-01

    To unravel the factors that regulate DOC dynamics in the freshwater tidal reaches of the Schelde estuary, DOC concentration and biodegradability were monitored in the upper Schelde estuary and its major tributaries. Although the Schelde estuary possesses a densely populated and industrialized cat...

  2. Eco-Morphological Problems in the Yangtze Estuary and the Western Scheldt

    NARCIS (Netherlands)

    Vriend, de H.J.; Wang, Z.B.; Ysebaert, T.; Herman, P.M.J.; Ding, P.X.

    2011-01-01

    This paper compares the Yangtze Estuary in China and the Western Scheldt Estuary in The Netherlands by their morphodynamic and ecological systems, their engineering works and estuarine management issues, and the major challenges in studying them. Physically speaking, the two estuaries are very diffe

  3. LA LARGA MARCHA DE LA ACCIÓN AMBIENTAL EN LOS CENTROS EDUCATIVOS. UN ESTUDIO DE CASO EN ARAGÓN

    Directory of Open Access Journals (Sweden)

    Carmelo Marcén Albero

    2012-01-01

    Full Text Available La ambientalización curricular de los centros educativos es una tarea compleja. Se apoya en el crecienteinterés por las cuestiones ambientales pero tiene un difícil encaje en la metodología presente, muypreocupada por los contenidos. Aún así, es posible porque existe una cierta práctica profesional para trabajar determinadas cuestiones ambientales. Programar investigaciones para reconocer los rasgos de las actuaciones ambientalizadores presentes es un buen camino para construir a partir de ellas proyectos con nuevas dimensiones. Estas necesitan conocer los contenidos clave en la dinámica ambiental, diseñar los contextos de la intervención y concertar los procesos que se deberían recorrer para lograr una verdadera ambientalización. Ese es el camino que se recorrió en la investigación que aquí se presenta.

  4. Ambient cosmology and spacetime singularities

    CERN Document Server

    Antoniadis, Ignatios

    2015-01-01

    We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary.

  5. Ambient cosmology and spacetime singularities

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios [Bern University, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland); Ecole Polytechnique, Palaiseau (France); Cotsakis, Spiros [CERN, Theory Division, Department of Physics, Geneva 23 (Switzerland); National Technical University, School of Applied Mathematics and Physical Sciences, Athens (Greece)

    2015-01-01

    We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary. (orig.)

  6. Medio ambiente y responsabilidad social

    OpenAIRE

    Roa Buitrago, Rosa Isabel

    2012-01-01

    Las organizaciones, dentro de los procesos de responsabilidad social y con el fin de mejorar la calidad de vida de las comunidades que impactan, han optado por proteger y preservar el medio ambiente de acuerdo a ciertos protocolos y normas internacionales que generan una cultura al respecto. Este cuaderno de investigación aborda la norma ISO 26000, la cual asume el tema de la Responsabilidad Social Empresarial (RSE) en materia de medio ambiente y es una guía para ser implementada en las orga...

  7. Los estudios sobre el ambiente y la ciencia ambiental

    Directory of Open Access Journals (Sweden)

    Amelia Nancy Giannuzzo

    2010-03-01

    Full Text Available La existencia de la ciencia ambiental es reconocida en libros, revistas de publicación científica y carreras de grado y posgrado. Sin embargo, se desconoce su existencia en forma literal o indirecta, al no ser considerado su aporte, por ejemplo, en los planteos referidos sobre la ciencia y la tecnología de la sustentabilidad. En este trabajo se presentan estos antecedentes, relacionándolos con el objetivo del mismo, que es el de aportar a la dilucidación de la existencia y conformación de la ciencia ambiental. Para esto, se analiza la relación de las disciplinas con la dimensión compleja del ambiente como objeto de estudio y aspectos metodológicos derivados. A los fines de aportar al esclarecimiento conceptual, se identifican las distintas acepciones de ambiente comúnmente referidas en la bibliografía. Además, se discuten aspectos relacionados de multidisciplinariedad, interdisciplinariedad y transdisciplinariedad, y sobre el status epistémico de la ciencia ambiental. Se concluye que una mayor precisión conceptual embasada en un marco compartido por las disciplinas que estudian el ambiente, incluida la ciencia ambiental, y los distintos actores involucrados en las problemáticas ambientales, favorecerá el refinamiento de las metodologías tendientes a disminuir la fragmentación de las investigaciones concernientes y las aplicaciones para su resolución.The existence of an environmental science is recognized in books, journals of science as well as in undergraduate and graduate studies. Its existence, however, is unknown either literally or indirectly when, for instance, its contribution to topics connected to the science and technology of sustainability is not considered. This background is presented in this paper and connected to its objective, which is to elucidate the existence and structure of the environmental science. To this goal, I analyse the relationship of the disciplines with the complex dimension of the environment

  8. Impact of the Clean Water Act on the levels of toxic metals in urban estuaries: The Hudson River estuary revisited

    Energy Technology Data Exchange (ETDEWEB)

    Sanudo-Wilhelmy, S.A.; Gill, G.A.

    1999-10-15

    To establish the impact of the Clean Water Act on the water quality of urban estuaries, dissolved trace metals and phosphate concentrations were determined in surface waters collected along the Hudson River estuary between 1995 and 1997 and compared with samples collected in the mid-1970s by Klinkhammer and Bender. The median concentrations along the estuary have apparently declined 36--56% for Cu, 55--89% for Cd, 53--85% for Ni, and 53--90% for Zn over a period of 23 years. These reductions appear to reflect improvements in controlling discharges from municipal and industrial wastewater treatment plants since the Clean Water Act was enacted in 1972. In contrast, levels of dissolved nutrients (PO{sub 4}) have remained relatively constant during the same period of time, suggesting that wastewater treatment plant improvements in the New York/New Jersey Metropolitan area have not been as effective at reducing nutrient levels within the estuary. While more advanced wastewater treatment could potentially reduce the levels of Ag and PO{sub 4} along the estuary, these improvements would have a more limited effect on the levels of other trace metals.

  9. Waterfowl migration and distribution in North West estuaries. V. 2

    International Nuclear Information System (INIS)

    Waterfowl populations may be affected by the proposed tidal barrage across the Mersey. A study was performed with three objectives: (1) to evaluate the patterns of usage of the intertidal flats of the Mersey estuary by waders and wildfowl and to establish which are the preferred areas; (2) to identify the places of origin and movement patterns of the populations of waders and wildfowl that visit the Mersey estuary; and (3) to evaluate evidence regarding the capacity of British estuaries to absorb waders and wildfowl populations which might be displaced by a Mersey Barrage. The text and tables of results of this study have already been presented in Volume 1. Volume 2 contains the figures describing the results (U.K)

  10. Fitorremediación, una tecnología que involucra a plantas y microorganismos en el saneamiento ambiental

    Directory of Open Access Journals (Sweden)

    Jeannette Marrero-Coto

    2012-01-01

    Full Text Available Uno de los rasgos distintivos de la sociedad moderna es la creciente generación de contaminantes ambientales, lo que trae consigo daños considerables a la salud humana y a la diversidad biológica. Los metales pesados son contaminantes que necesitan especial atención porque pueden permanecer varias décadas en el suelo y concentrarse en las cadenas tróficas. Las tecnologías desarrolladas para el saneamiento de ambientes contaminados con metales pesados son costosas y requieren un largo período de tiempo para su ejecución. La fitorremediación es una vertiente de la biorremediación que surge recientemente como alternativa ante esta problemática ambiental, y se basa en el uso de plantas que acumulan elevadas concentraciones de metales en sus tejidos para contener, remover o neutralizar contaminantes, mediante mecanismos de captura de metales propios de estas plantas y/o por los microorganismos que se desarrollan en la rizosfera. Estudios previos sugieren que los microorganismos rizosféricos poseen mecanismos capaces de alterar la circulación de metales en el medio ambiente, con efectos subsecuentes en el potencial de la planta para su captación en la raíz. En la actualidad, la fitorremediación no es una tecnología disponible comercialmente. Los progresos en el campo son limitados por falta de conocimiento de las interacciones complejas en la rizosfera y los mecanismos de plantas hiperacumuladoras que permiten la translocación del metal y su acumulación. Esta revisión responde a la necesidad de brindar mayores conocimientos que aumenten la rentabilidad y eficacia de estas plantas, debido a que su aplicación resulta muy importante en la protección del medio ambiente.

  11. Hierarchical Mapping of Landforms along the Columbia River Estuary

    Science.gov (United States)

    Cannon, C. M.

    2015-12-01

    Mapping and hierarchical classification of landforms along the Columbia River estuary provides insight into formative geologic, hydrologic, and biologic processes and their associated ecosystems, thereby aiding assessment of future trajectories and restoration approaches. The Columbia River Estuary Ecosystem Classification includes an inventory of landforms along 230 km of riverine estuary between the Pacific Ocean and Bonneville Dam in Oregon and Washington, USA. Landforms were mapped by interpretation of lidar topography supplemented with high-resolution bathymetry, aerial photographs, soil maps, and historical maps. Groupings of landforms were assigned to formative process regimes. These landform groupings relate ecosystems to geophysical processes. Assessment of historical changes to the processes that form and maintain landforms thus has implications for the types of ecosystems that can form and persist along the estuary. The estuary was historically a complex system of channels with a floodplain dominated by extensive tidal wetlands in the lower reaches and backswamp lakes and wetlands in upper reaches. Natural levees flank most channels in the upper reaches, locally including areas of ridge and swale topography and crevasse splays that intrude into backswamps. Other Holocene process regimes affecting floodplain morphology have included volcanogenic deltas, tributary fans, eolian dunes, and landslides. Pre-Holocene landforms are locally prominent and include ancient fluvial deposits and bedrock. Historical changes to streamflow regimes, floodplain isolation, and direct anthropogenic disturbance have resulted in channel narrowing and limited the amount of floodplain that can be shaped by flowing water. Floodplain isolation has caused relative subsidence of tidal floodplains along much of the lower estuary. Most extant landforms are on trajectories strongly influenced by humans and new landforms are mostly created by humans.

  12. Mud transport in the Microtidal San Jacinto Estuary

    Science.gov (United States)

    Salehi, M.

    2013-12-01

    The overall objective of this research is to better understand the sediment transport processes in the microtidal San Jacinto Estuary (near Houston, TX) under variable hydrologic conditions. A numerical modeling approach is selected to answer the main question of; how will changes in freshwater input change the sedimentation pattern of the region? In this computational work, no new numerical method or code is developed, but rather an existing technology (MIKE 3D developed by DHI) is used to build a virtual San Jacinto Estuary laboratory where boundary conditions could be applied and altered to the domain to observe the general functional response of the system. Two synthetic freshwater inflows, simulating dry and wet conditions, were used in the numerical modeling experiments. Simulations showed that change in freshwater inflow has major impact on the salinity magnitude within the estuary. In dry conditions, the 5 ppt isohaline traveled all the way upstream of Morgans Point, almost to the confluence of San Jacinto River with Buffalo Bayou. During the extreme wet weather conditions, the 5 ppt isohaline of the surface water was pushed almost as far as Galveston Island. Overall erosion and deposition pattern showed little change between extreme dry and wet years. In general, part of the shallow areas experienced erosion whereas deeper parts of the estuary were under deposition. High freshwater inflow caused around 30% higher deposition in some parts of the channel compared with the low freshwater. Furthermore, examining the mass balance within the whole San Jacinto Estuary showed that around 28% of the input sediment was flushed out during the wet season. But in dry season, not only no sediment left the domain but also it received around 17% of the total available sediment within the estuary from the shelf.

  13. Modelling sediment transport processes in macro-tidal estuary

    Institute of Scientific and Technical Information of China (English)

    Rauen; William; B.

    2009-01-01

    This paper outlines a numerical modeling study to predict the sediment transport processes in a macro-tidal estuary, namely the Mersey Estuary, UK. An integrated numerical model study is conducted to investigate the interaction between the hydrodynamic, morphological and sediment transport processes occurring in the estuary. The numerical model widely used in environmental sediment transport studies worldwide, namely ECOMSED is used to simulate flow and sediment transport in estuary. A wetting and drying scheme is proposed and applied to the model, which defines "dry" cells as regions with a thin film of fluid O (cm). The primitive equations are solved in the thin film as well as in other regular wet cells. A model for the bed load transport is included in the code to account for the dynamics of the mobile bed boundary. The bed evolution due to bed load transport which is calculated according to van Rijn (1984a) is obtained by solving the sediment mass-balance equation. An estuary-related laboratory flume experiment is used to verify the model. Six sets of field measured hydrodynamic data are used to verify the corresponding predictions of the model, with the model-predicted water elevations and salinity levels generally agreeing well with the field measurements. The numerical model results show that in the Mersey Estuary both the tidal level and river discharge affect significantly the sediment transport. Reasonable agreement between the model results and field data has been obtained, indicating that the model can be used as computer-based tool for the environment management of estuarine system.

  14. TERCEIRO SETOR E MEIO AMBIENTE

    OpenAIRE

    Melo, Marina Félix de

    2012-01-01

    Objetivamos discutir, brevemente, como têm se dado as discussões sobre o Terceiro Setor brasileiro e, particularmente, sobre as ONGs que atuam em defesa do meio ambiente, levantando questionamentos acerca das limitações enfrentadas pelo Terceiro Setor neste contexto

  15. Shape analysis for mobile ambients

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming

    2001-01-01

    The ambient calculus is a calculus of computation that allows active processes to move between sites. We present an analysis inspired by state-of-the-art pointer analyses that safely and accurately predicts which processes may turn up at what sites during the execution of a composite system...

  16. Abstract Interpretation of Mobile Ambients

    DEFF Research Database (Denmark)

    Hansen, René Rydhof; Jensen, J. G.; Nielson, Flemming;

    1999-01-01

    We demonstrate that abstract interpretation is useful for analysing calculi of computation such as the ambient calculus (which is based on the p-calculus); more importantly, we show that the entire development can be expressed in a constraint-based formalism that is becoming exceedingly popular...

  17. Shape analysis for Mobile Ambients

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming

    2000-01-01

    The ambient calculus is a calculus of computation that allows active processes to move between sites. We present an analysis inspired by state-of-the-art pointer analyses that safety and accurately predicts which processes may turn up at what sites during the execution of a composite system...

  18. La crisis del medio ambiente

    Directory of Open Access Journals (Sweden)

    Juan Carlos Quintero Vélez

    2013-07-01

    Full Text Available Este artículo, introducción al tema del medio ambiente, pretende proporcionar conceptos básicos para analizar y dimensionar el impacto que genera el hombre sobre los sistemas que soportan la vida. Para entender estos problemas, es indispensable partir de un análisis básico de la relación entre el hombre actual, su medio ambiente, sus necesidades y sus actividades. El autor revisa los antecedentes, las causas y las consecuencias de la crisis ambiental internacional, e intenta dar explicación a la problemática nacionalen este campo, y establecer los puntos más críticos en Colombia. Finalmente, con base en los parámetros establecidos por el gobierno, se presenta el concepto de“desarrollo sostenible" como modelo que interrelaciona los procesos económicos, sociales y tecnológicos con el medio ambiente.

  19. Digital identity in ambient environments

    NARCIS (Netherlands)

    Schouten, Ben; Ambekar, Onkar

    2006-01-01

    Embedded systems and ambient technology enable users to interact at any time and anywhere. In the BASIS project for identity management, CWI investigates transparent biometrics in home environments. Possible application areas are user profiling for shopping , listening to one's favourite music and o

  20. Hacia un constructivismo realista: de la naturaleza al medio ambiente

    Directory of Open Access Journals (Sweden)

    Arias Maldonado, Manuel

    2011-06-01

    Full Text Available The relationship between society and nature has an outstanding importance in the fields of environmental philosophy and sociology. It is dominated by the opposition between realism and constructivism, i.e.: between those who argue that nature is an entity independent of society and those who respond that nature is a social construction. Such conflict is usually solved accepting that nature exists but our knowledge of it can only be socially mediated. However, a new version of constructivism is to be defended, one which pays enough attention to the material dimension of society-nature’s interaction. Society has always intervened upon nature and the final outcome of such historical process is but the transformation of nature into human environment. A realistic constructivism allows us to highlight that decisive feature of socio-natural interaction.

    Si hay un campo en el que tiene importancia el debate acerca de la relación de la sociedad con la naturaleza, es la filosofía y sociología medioambientales. Es un debate dominado por el enfrentamiento entre realismo y constructivismo: entre quienes sostienen que la naturaleza es una entidad independiente de la sociedad y quienes alegan que la naturaleza es una construcción social. Es habitual que esta querella se resuelva mediante la afirmación de que la naturaleza existe, pero sólo la conocemos mediadamente. Sin embargo, es hora de defender una versión del constructivismo que preste la debida atención a la dimensión material de la relación socionatural. La sociedad nunca ha dejado de intervenir en la naturaleza y el resultado final de ese proceso histórico es, de hecho, la transformación de la sociedad en medio ambiente humano. Sólo un constructivismo realista permite poner de manifiesto este rasgo decisivo de la interacción socionatural.

  1. Research, Monitoring, and Evaluation for the Federal Columbia River Estuary Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Diefenderfer, Heida L.; Ebberts, Blaine D.; Tortorici, Cathy; Yerxa, Tracey; Leary, J.; Skalski, John R.

    2008-02-05

    The purpose ofthis document is to describe research, monitoring, and evaluation (RME) for the Federal Columbia River Estuary Program. The intent of this RME effort is to provide data and information to evaluate progress toward meeting program goals and objectives and support decision-making in the Estuary Program. The goal of the Estuary Program is to understand, conserve, and restore the estuary ecosystem to improve the performance of listed salmonid populations. The Estuary Program has five general objectives, designed to fulfill the program goal, as follows. 1. Understand the primary stressors affecting ecosystem controlling factors, such as ocean conditions and invasive species. 2. Conserve and restore factors controlling ecosystem structures and processes, such as hydrodynamics and water quality. 3. Increase the quantity and quality of ecosystem structures, i.e., habitats, juvenile salmonids use during migration through the estuary. 4. Maintain the food web to benefit salmonid performance. 5. Improve salmonid performance in terms of life history diversity, foraging success, growth, and survival. The goal of estuary RME is to provide pertinent and timely research and monitoring information to planners, implementers, and managers of the Estuary Program. In conclusion, the estuary RME effort is designed to meet the research and monitoring needs of the estuary Program using an adaptive management process. Estuary RME's success and usefulness will depend on the actual conduct of adaptive management, as embodied in the objectives, implrementation, data, reporting, and synthesis, evaluation, and decision-making described herein.

  2. Temporal variability of phytoplankton in a salt wedge estuary, the Swan-Canning Estuary, Western Australia

    Science.gov (United States)

    Thompson, Peter A.

    2001-09-01

    The temporal cycles of variation in salinity, temperature and river flow in the Swan-Canning Estuary plus rainfall in the vicinity are examined. A normal pattern is defined for rainfall and river flow based on long-term median monthly values from available historical data. Long-term monthly median rainfall and median monthly river flow were highly correlated. Deviations from the normal patterns of rainfall and river flow are documented. Three years of detailed data on the temporal distribution of the algal biomass and phytoplankton community composition from the Swan-Canning Estuary are presented and discussed. Significant interannual variability in the phytoplankton biomass was observed with 1996 having a significantly lower median chlorophyll a concentration than 1995 or 1997. Different years also had pronounced differences in the timing, persistence and occurrence of algal blooms. Links with, and between, rainfall, river flow, nutrient concentrations and phytoplankton biomass are made by careful examination of the temporal patterns. Deviations from the proposed normal temporal pattern of physical and chemical environmental factors relevant to the growth of phytoplankton biomass are assessed. Deviations from normal rainfall and river flow, depending upon their timing and intensity, appear to be associated with occurrence of algal blooms. For example, the lack of a dinoflagellate bloom in December 1996 or January 1997 appears to be associated with a wetter than normal spring. Based upon the observed data, published reports and basic principles of algal ecology a set of predicted responses to variation in the major environmental variables (rainfall and river flow) are tabulated. The tabulated predictions are proposed as a useful tool for resource managers.

  3. Historical Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Historical Ambient Air Quality Data Inventory contains measured and estimated data on ambient air pollution for use in assessing air quality, assisting in...

  4. Man's Impact on the Environment: The Estuary as an Ecosystem.

    Science.gov (United States)

    Brevard County School Board, Cocoa, FL.

    This environmental education guide focuses on man's impact on the estuary. The program contained in the guide is developed around the following nine questions: (1) What is a definition of the ecosystem being investigated?; (2) What are some of the biotic and abiotic features of the ecosystem and how do these features interrelate?; (3) Where are…

  5. A model of nematode dynamics in the Westerschelde estuary

    NARCIS (Netherlands)

    Li, J.; Vincx, M.; Herman, P.M.J.

    1996-01-01

    We developed a time dynamic model to investigate the temporal dynamics of nematode community in the brackish zone of the Westerschelde Estuary. The biomass of four nematode feeding groups observed from March 1991 to February 1992 is used to calibrate the model. Using environmental data as the input,

  6. Contaminants of emerging concern in a large temperate estuary.

    Science.gov (United States)

    Meador, James P; Yeh, Andrew; Young, Graham; Gallagher, Evan P

    2016-06-01

    This study was designed to assess the occurrence and concentrations of a broad range of contaminants of emerging concern (CECs) from three local estuaries within a large estuarine ecosystem. In addition to effluent from two wastewater treatment plants (WWTP), we sampled water and whole-body juvenile Chinook salmon (Oncorhynchus tshawytscha) and Pacific staghorn sculpin (Leptocottus armatus) in estuaries receiving effluent. We analyzed these matrices for 150 compounds, which included pharmaceuticals, personal care products (PPCPs), and several industrial compounds. Collectively, we detected 81 analytes in effluent, 25 analytes in estuary water, and 42 analytes in fish tissue. A number of compounds, including sertraline, triclosan, estrone, fluoxetine, metformin, and nonylphenol were detected in water and tissue at concentrations that may cause adverse effects in fish. Interestingly, 29 CEC analytes were detected in effluent and fish tissue, but not in estuarine waters, indicating a high potential for bioaccumulation for these compounds. Although concentrations of most detected analytes were present at relatively low concentrations, our analysis revealed that overall CEC inputs to each estuary amount to several kilograms of these compounds per day. This study is unique because we report on CEC concentrations in estuarine waters and whole-body fish, which are both uncommon in the literature. A noteworthy finding was the preferential bioaccumulation of CECs in free-ranging juvenile Chinook salmon relative to staghorn sculpin, a benthic species with relatively high site fidelity. PMID:26907702

  7. Sediment transport investigations in Hugli estuary using radiotracer technique

    International Nuclear Information System (INIS)

    This paper describes sediment transport investigations carried out at two different locations in Hugli estuary along the shipping channel leading to Haldia Dock Complex of the Kolkata Port Trust, Kolkata. The objectives of these investigations were to evaluate the suitability of the proposed dumping sites for optimizing the dredging operation and implementing the recommendations of the River Regulatory Measures, Kolkata Port Trust, Kolkata

  8. Revised predictive equations for salt intrusion modelling in estuaries

    Directory of Open Access Journals (Sweden)

    J. I. A. Gisen

    2015-06-01

    Full Text Available For one-dimensional salt intrusion models to be predictive, we need predictive equations to link model parameters to observable hydraulic and geometric variables. The one-dimensional model of Savenije (1993b made use of predictive equations for the Van der Burgh coefficient $K$ and the dispersion at the seaward boundary D0. Here we have improved these equations by using an expanded database, including new previously un-surveyed estuaries. Furthermore, we derived a revised predictive equation for the dispersion at tidal average condition and with the boundary situated at the well identifiable inflection point where the estuary changes from wave-dominated to tide-dominated geometry. We used 89 salinity profiles in 30 estuaries (including seven recently studied estuaries in Malaysia, and empirically derived a range of equations using various combinations of dimensionless parameters. We split our data in two separated data sets: (1 with more reliable data for calibration, and (2 with less reliable data for validation. The dimensionless parameters that gave the best performance depended on the geometry, tidal strength, friction and the Richardson number. The limitation of the equations is that the friction is generally unknown. In order to overcome this problem, a coupling has been made with the analytical hydraulic model of Cai et al. (2012, which makes use of observed tidal damping and by which the friction can be determined.

  9. Revised predictive equations for salt intrusion modelling in estuaries

    Directory of Open Access Journals (Sweden)

    J. I. A. Gisen

    2015-01-01

    Full Text Available For one-dimensional salt intrusion models to be predictive, we need predictive equations to link model parameters to observable hydraulic and geometric variables. The one-dimensional model of Savenije (1993b made use of predictive equation for the Van der Burgh coefficient K and the dispersion at the seaward boundary D0. Here we have improved these equations by using an expanded database, including new previously un-surveyed estuaries. Furthermore, we derived a revised predictive equation for the dispersion at tidal average (TA condition and with the boundary situated at the well identifiable inflection point where the estuary changes from wave-dominated to tide-dominated geometry. We used 89 salinity profiles in 30 estuaries (including 7 recently studied estuaries in Malaysia, and empirically derived a range of equations using various combinations of dimensionless parameters. We split our data in two separated datasets: (1 with more reliable data for calibration, and (2 with less reliable data for validation. The dimensionless parameters that gave the best performance depended on the geometry, tidal strength, friction and the Richardson Number. The limitation of the equations is that the friction is generally unknown. In order to overcome this problem, a coupling has been made with the analytical hydraulic model of Cai et al. (2012, which makes use of observed tidal damping and by which the friction can be determined.

  10. Estuaries May Face Increased Parasitism as Sea Levels Rise

    Science.gov (United States)

    Wendel, JoAnna

    2014-12-01

    Invertebrates in estuaries could be at a greater risk of parasitism as climate change causes sea levels to rise. A new paper published 8 December in Proceedings of the National Academy of Sciences of the United States of America (doi:10.1073/pnas.1416747111) describes how rapid sea level rise in the Holocene affected the population of parasitic flatworms called trematodes.

  11. Organic carbon in the sediments of Mandovi estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Alagarsamy, R.

    Total organic carbon (TOC) in surficial sediments in Mandovi Estuary, Goa, India varies widely from 0.1 to 3% (av. 1.05%). Highest values of TOC (2.4-3%) lie close to the mouth region and indicate no definite trend in its variation in the estuarine...

  12. A new analytical framework for tidal propagation in estuaries

    NARCIS (Netherlands)

    Cai, H.

    2014-01-01

    The ultimate aim of this thesis is to enhance our understanding of tidal wave propagation in convergent alluvial estuaries (of infinite length). In the process, a new analytical model has been developed as a function of externally defined dimensionless parameters describing friction, channel converg

  13. Tidal freshwater wetlands, the fresh dimension of the estuary

    NARCIS (Netherlands)

    Barendregt, A.

    2016-01-01

    Upstream in the estuary, where the river ends, the tidal energy is still present but the constant input from the river creates permanent fresh water conditions. The physical, chemical and biological conditions differ from the brackish part of the tidal area, but by processes from the tidal wave also

  14. Optical Changes in a Eutrophic Estuary During Reduced Nutrient Loadings

    DEFF Research Database (Denmark)

    Pedersen, Troels Møller; Sand-Jensen, Kaj; Markager, Stiig;

    2014-01-01

    Loss of water clarity is one of the consequences of coastal eutrophication. Efforts have therefore been made to reduce external nutrient loadings of coastal waters. This paper documents improvements to water clarity between 1985 and 2008–2009 at four stations in the microtidal estuary Roskilde...

  15. Production and consumption of biological particles in temperate tidal estuaries

    NARCIS (Netherlands)

    Heip, C.H.R.; Goosen, N.K.; Herman, P.M.J.; Kromkamp, J.C.; Middelburg, J.J.; Soetaert, K.E.R.

    1995-01-01

    The question is reviewed whether a balance exists between production and consumption of biological particles in temperate tidal estuaries and what the relationships are between the magnitude of production and consumption processes and system carbon metabolism. The production terms considered are pri

  16. Laboratory Investigations on Estuary Salinity Mixing: Preliminary Analysis

    Directory of Open Access Journals (Sweden)

    F. H. Nuryazmeen

    2014-05-01

    Full Text Available Estuaries are bodies of water along the coasts that are formed when fresh water from rivers flows into and mixes with salt water from the ocean. The estuaries serve as a habitat to some aquatic lives, including mangroves. Human-induced activities such as dredging of shipping lanes along the bottom estuarine, the disposal of industrial wastes into the water system and shoreline development influence estuarine dynamics which include mixing process. These activities might contribute to salinity changes and further adversely affect the estuarine ecosystem. In order to study at the characteristics of the mixing between salt water (estuary and freshwater (river, a preliminary investigation had been done in the laboratory. Fresh water was released from one end of the flume and overflowing at weir at the other end. Meanwhile, salt water was represented by the red dye tracer released through a weir and intruded upstream as a gravity current. The isohalines are plotted to see the salinity patterns. Besides, to examine the spatial and temporal salinity profiles along the laboratory investigations, the plotted graphs have been made. The results show that the changes in salinity level along the flume due to mixing between fresh water and salt water. This showed typical salt-wedge estuary characteristics.

  17. Maturation of Metapenaeus moyebi (Kishinouye) in Goa estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Achuthankutty, C.T.; Parulekar, A

    An assessment of the stake net fishery in the Mandovi and Zuari estuaries of Goa revealed that Metapenaeus moyebi, a penaeid prawn hitherto rarely recorded in Indian waters, formed a good percentage of the estuarine prawn fishery of Goa. At one...

  18. The larvae of decapods and fishes of Amba estuary, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Paulinose, V.T.; Devi, C.B.L.; Govindan, K.; Gajbhiye, S.N.; Nair, V.R.

    potential as compared to the nearshore coastal waters of Mumbai. The total fish catch showed an increasing trend during September (av. 21.1 kg/hr). Harpadon nehereus, Coilia dussumieri and Johnius dussumieri were recorded in the estuary irrespective of tide...

  19. Moveable flood barriers in the Rhine-Meuse estuary

    NARCIS (Netherlands)

    Rijcken, T.; Kok, M.

    2011-01-01

    It is possible to reduce flood risk in estuaries without having to drastically modify the river banks by levees or to block shipping routes and ecological flows by dams. ‘Storm surge barriers’ close off a river mouth at times of high sea water levels, but keep the river open during calmer times. ‘Mo

  20. Time-dependent stratification in the Gauthami-Godavari Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.V.N.

    associated with the density driven flow. Destratification occurs around the high water slacks in the lower reaches fairly close to the mouth of the estuary. The variations in the fields of mass will strongly affect the response of the velocity field...

  1. Biogeochemistry of Nutrient Elements in the Changjiang (Yangtze River) Estuary

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Based on the biogeochemical studies on nutrient elements in the Changjiang estuary,the main results and recent progresses are reviewed in this paper, such as the nutrient fluxes into the sea, the mixing behaviors, the distribution characteristics and transportation as well as the biogeochemical behaviors of nutrients in the plume frontal region. The exploring directions and research emphases in the future are proposed.

  2. Phytoplankton diversity and primary production in Poonthura estuary, south Kerala

    OpenAIRE

    Ritakumari, S.D.; Shibu, S.

    2007-01-01

    Seasonal variations in the phytoplankton density, diversity, gross production and related physicochemical parameters of Poonthura estuary have been followed for a period of one year. The polluted nature of the water body favored a higher density of phytoplankters, which exhibited a positive correlation with gross production. The influence of various physicochemical parameters, phytoplankton density and species diversity on gross production is discussed.

  3. Reference Condition Approach for Numeric Nutrient Criteria for Oregon Estuaries

    Science.gov (United States)

    Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

  4. ¿Es Despistado o Está Despistado?: Infiriendo la Estabilidad de los Rasgos Psicológicos Is He Spaced Out (Just Now or Is He (Always Spaced Out?: Inferring the Stability of Psychological Traits

    Directory of Open Access Journals (Sweden)

    Paula Alonqueo

    2011-11-01

    Full Text Available Un rasgo psicológico descrito con el verbo ser se considera más estable que uno descrito con estar (Heyman & Diesendruck, 2002. Para establecer si esta distinción lingüística afecta a las inferencias sobre características personales se realizaron 2 estudios complementarios con 62 escolares en diferente nivel de desarrollo (7 y 12 años y 108 estudiantes universitarios monolingües de español peninsular, de nivel socioeconómico medio, residentes en Madrid, España. En ambos los participantes se distribuyeron en dos condiciones experimentales (ser y estar y respondieron a una tarea de inferencias en que se describían características psicológicas y conductas asociadas a estas. Se realizaron análisis multivariados y de medidas repetidas considerando la edad y la condición experimental. Solo los adultos y los niños mayores infirieron que los rasgos descritos con ser eran más estables que los descritos con estar, pero los menores en ambas condiciones experimentales infirieron que los rasgos eran estables. El efecto de ser y estar en las inferencias es relevante, pero debe interpretarse considerando las diferencias evolutivas.A psychological trait described with the verb ser is considered more stable than one expressed by using estar (Heyman & Diesendruck, 2002. In order to establish whether ser/estar verbal forms affect inferences about psychological traits, 2 studies were carried out on school children in different developmental levels (N = 62, 7 and 12 years and university students (N = 108, monolingual speakers of Peninsular Spanish, from medium socioeconomic status, resident in Madrid, Spain. In both studies participants were randomly assigned to one of 2 experimental conditions (ser and estar and responded to an inference task which consisted of the description of psychological characteristics and behaviors associated with them. Factorial and repeated measures analysis of variance were performed. Only the adults and older children

  5. Rasgos de historia de vida de especies en una comunidad vegetal alterada principalmente por pastoreo en un páramo húmedo (Parque Nacional Natural Chingaza, Colombia

    Directory of Open Access Journals (Sweden)

    Vargas Ríos Jesús Orlando

    2007-04-01

    Full Text Available Se estudiaron once rasgos de historia de vida (morfológicos y de regeneración de plantas vasculares, en
    cuatro sitios con diferente grado de alteración, que hacen parte de una misma unidad de paisaje y condiciones
    topográficas similares. Ubicados en los valles de los ríos Tunjo y Piedras Gordas, páramo de Palacio, parque nacional natural Chingaza, Cundinamarca, Colombia. Entre 3.400-3.600 m de altitud, a los 4º45’03’’N, 73º50’50’’W. Estos valles, principalmente el valle del río Tunjo tienen una larga historia de disturbio por quema y pastoreo de ganado vacuno. La comunidad natural es de Espeletia killipii, Chusquea tessellata y Calamagrostis effusa. Mediante un análisis de clasificación y un procedimiento de componentes principales (ACP se agruparon las especies de acuerdo a rasgos similares y se analizó su abundancia de acuerdo con el grado de alteración. Se identificaron tres grupos de especies, diferenciados principalmente por los rasgos morfológicos: tipo de planta, forma de crecimiento, hábito y altura. El grupo uno se caracteriza principalmente por especies graminoides (73%, erectas (100% en macolla (68% con alturas mayores a 5 cm (60%; el grupo dos por hierbas rastreras o postradas (76 % que forman cojines o tapetes (86% con alturas menores a 5 cm (79% y el grupo tres por hierbas (88% en roseta (100% que no forman cojines o tapetes. Cada uno de estos grupos, presentaron una máxima abundancia-cobertura a un grado de alteración en particular; el grupo uno, no es favorecido en su abundancia-cobertura al aumentar el grado de
    alteración, presenta su mayor abundancia en los sitios con alteración leve y sin alteración (33 y 30%; el grupo dos es característico del sitio con alteración alta, donde presento la mayor abundancia (44% y el grupo tres presentó su menor abundancia en el sitio con mayor grado de alteración (8%.

  6. Structural lubricity under ambient conditions

    Science.gov (United States)

    Cihan, Ebru; İpek, Semran; Durgun, Engin; Baykara, Mehmet Z.

    2016-01-01

    Despite its fundamental importance, physical mechanisms that govern friction are poorly understood. While a state of ultra-low friction, termed structural lubricity, is expected for any clean, atomically flat interface consisting of two different materials with incommensurate structures, some associated predictions could only be quantitatively confirmed under ultra-high vacuum (UHV) conditions so far. Here, we report structurally lubric sliding under ambient conditions at mesoscopic (∼4,000–130,000 nm2) interfaces formed by gold islands on graphite. Ab initio calculations reveal that the gold–graphite interface is expected to remain largely free from contaminant molecules, leading to structurally lubric sliding. The experiments reported here demonstrate the potential for practical lubrication schemes for micro- and nano-electromechanical systems, which would mainly rely on an atomic-scale structural mismatch between the slider and substrate components, via the utilization of material systems featuring clean, atomically flat interfaces under ambient conditions. PMID:27350035

  7. Fiscalidad ambiental (curso 2011-2012)

    OpenAIRE

    Gil Maciá, Lorenzo

    2012-01-01

    Tema fiscalidad ambiental. 1. Necesidad económica y jurídica de la protección del medio ambiente. 2. Características, naturaleza y clasificación de los tributos ambientales. 3. Competencias tributarias en el ámbito estatal, autonómico y local. 4. La fiscalidad ambiental en la legislación fiscal española. 5. Perspectivas de futuro en materia de imposición ambiental.

  8. Hypermedia in the Ambient Wood

    OpenAIRE

    Weal, Mark J; Michaelides, Danius T.; Thompson, Mark K.; De Roure, David C

    2003-01-01

    The Ambient Wood project, carried out as part of the Equator IRC, set out to provide an augmented learning experience for children in an outdoor environment. Using a variety of devices, the children gathered information about the woodland habitats performing basic scientific enquiry and hypothesis testing. In this paper we describe the supporting information infrastructure used in the project, focusing on how hypermedia tools and techniques were used to structure and deliver the information t...

  9. Crumpling under an ambient pressure

    OpenAIRE

    Lin, Y C; Wang, Y. L.; Liu, Y; Hong, T.M.

    2008-01-01

    A pressure chamber is designed to study the crumpling process under an ambient force. The compression force and its resulting radius for the ball obey a power law with an exponent that is independent of the thickness and initial size of the sheet. However, the exponent is found to be material-dependent and less than the universal value, 0.25, claimed by the previous simulations. The power law behavior disappears at high pressure when the compressibility drops discontinuously, which is suggest...

  10. Estrategia para la sustentabilidad ambiental

    Directory of Open Access Journals (Sweden)

    Cecilia Erbiti

    2006-01-01

    Full Text Available En el contexto de los postulados conceptuales y metodológicos de la planificación estratégica y de sustentabilidad ambiental, el objetivo de esta investigación es describir el proceso de formulación del Plan de Ordenamiento Territorial del Municipio de Tandil (POTM y analizar su potencialidad para avanzar hacia la sustentabilidad ambiental del sistema. Los resultados de la misma muestran que el POTM no sólo prioriza principios, objetivos y estrategias que materializan las diferentes manifestaciones de la sustentabilidad (económica, social, ecológica y política, sino que la totalidad del Plan se fundamenta en el concepto de desarrollo sostenible y, con ello, se establecen prioridades de actuación que posibilitarán la gestión ambiental urbana. Si bien el POTM muestra una gran potencialidad para avanzar hacia la sustentabilidad del territorio, la implementación y cumplimiento del mismo constituye un fuerte desafío para las autoridades de aplicación.

  11. Three-dimensional semi-idealized model for tidal motion in tidal estuaries: an application to the Ems estuary

    NARCIS (Netherlands)

    Kumar, Mohit; Schuttelaars, H.M.; Roos, P.C.; Möller, M.

    2016-01-01

    In this paper, a three-dimensional semi-idealized model for tidal motion in a tidal estuary of arbitrary shape and bathymetry is presented. This model aims at bridging the gap between idealized and complex models. The vertical profiles of the velocities are obtained analytically in terms of the firs

  12. Feeding preferences of estuarine mysids Neomysis integer and Rhopalophthalmus tartessicus in a temperate estuary (Guadalquivir Estuary, SW Spain)

    Science.gov (United States)

    Vilas, César; Drake, Pilar; Fockedey, Nancy

    2008-04-01

    Mysid shrimps are an important component of estuarine food webs because they play a key role in energy transfer as intermediate prey. We investigated the seasonal, tidal and depth specific variation in the diet of the estuarine mysids Neomysis integer and Rhopalophthalmus tartessicus and explored its implications for the planktonic community structure of a temperate estuary (Guadalquivir Estuary, SW Spain). Neomysis integer is an opportunistic omnivore feeding mainly on mesozooplankton and on members of the detrital-microbial loop, shifting prey seasonally according to availability. In contrast, R. tartessicus showed a more carnivorous diet and shifted its target prey during seasons of low resource availability. Despite statistically significant differences in diet composition, both species shared prey of similar size, particularly juvenile Mesopodopsis slabberi, the most abundant mysid species in this estuary, and copepods. Although these similarities imply inter-specific resource competition, their co-existence is achieved by niche partitioning and spatial segregation: the higher osmoregulatory capacity and foraging plasticity of N. integer confers a broader niche breadth for this species allowing N. integer to inhabit the more stressful oligohaline region of the estuary where R. tartessicus cannot survive. We propose that this mechanism relaxes the potential for competition between N. integer and R. tartessicus.

  13. Eelgrass Enhancement and Restoration in the Lower Columbia River Estuary, Period of Performance: Feb 2008-Sep 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Judd, C.; Thom, R; Borde, A. [Pacific Northwest National Laboratory

    2009-09-08

    The purpose of this study was to evaluate the ability to enhance distribution of eelgrass (Zostera marina) in the Columbia River Estuary to serve as refuge and feeding habitat for juvenile salmon, Dungeness crab, and other fish and wildlife. We strongly suspected that limited eelgrass seed dispersal has resulted in the present distribution of eelgrass meadows, and that there are other suitable places for eelgrass to survive and form functional meadows. Funded as part of the Bonneville Power Administration's call for Innovative Projects, we initiated a multistage study in 2008 that combined modeling, remote sensing, and field experimentation to: (1) Spatially predict habitat quality for eelgrass; (2) Conduct experimental plantings; and (3) Evaluate restoration potential. Baseline in-situ measurements and remote satellite observations were acquired for locations in the Lower Columbia River Estuary (LCRE) to determine ambient habitat conditions. These were used to create a habitat site-selection model, using data on salinity, temperature, current velocity, light availability, wave energy, and desiccation to predict the suitability of nearshore areas for eelgrass. Based on this model and observations in the field, five sites that contained no eelgrass but appeared to have suitable environmental conditions were transplanted with eelgrass in June 2008 to test the appropriateness of these sites for eelgrass growth. We returned one year after the initial planting to monitor the success rate of the transplants. During the year after transplanting, we carried out a concurrent study on crab distribution inside and outside eelgrass meadows to study crab usage of the habitat. One year after the initial transplant, two sites, one in Baker Bay and one in Young's Bay, had good survival or expansion rates with healthy eelgrass. Two sites had poor survival rates, and one site had a total loss of the transplanted eelgrass. For submerged aquatic vegetation (SAV) restoration

  14. Caracterización de los rasgos esenciales de la identidad profesional de los trabajadores sociales, que integraban el Consejo de Graduados en Trabajo Social de la Provincia de Santa Cruz, durante los años 1970-1980

    Directory of Open Access Journals (Sweden)

    Lorena Lucia Julieta Meoniz

    2014-06-01

    Full Text Available El presente trabajo da cuenta de los avances realizados en la línea de indagación dedicada al estudio de los rasgos de la identidad profesional de los Trabajadores Sociales adscriptos al Consejo de Graduados en Trabajo Social de la Provincia de Santa Cruz durante los años 1970-1980. Para dicho análisis se tuvo en cuenta los datos y materiales aportados por la sistematización de los Libros de Actas N° 1 y 2 del Consejo Profesional de Graduados en Trabajo Social de la Provincia de Santa Cruz, incluyendo asimismo la lectura de los avances teóricos producidos por el equipo de trabajo del proyecto de investigación en el cual participamos como becadas.

  15. Perennial grasses traits as functional markers of grazing intensity in basaltic grasslands of Uruguay Rasgos de gramíneas perennes como marcadores funcionales de la intensidad de pastoreo en pastizales de basalto en Uruguay

    Directory of Open Access Journals (Sweden)

    Martin Jaurena

    2012-12-01

    Full Text Available Natural grasslands in the basaltic region of Uruguay are threatened by an increase in stocking rates and changes in land use. To assess the effect of grazing intensification, plant functional types are proposed as simple tools to aid the monitoring and management of vegetation. In the present study we evaluated the effect of stocking rate increase at community level taking into account plant traits of 23 dominant perennial grass species. In order to identify plant functional types, we determined the grazing response in an experiment with two wethers stocking rates (0.78 and 1.56 livestock units ha-1 quantifying species cover and traits values. Leaf dry matter content (LDMC and specific leaf area (SLA were the traits that best described the perennial grasses response to the stocking rate increase and therefore are suggested to be used as functional markers. Three functional types were identified. Low stocking rates were related to functional type A (tall, warm season species with low SLA and high LDMC and functional type B (tall, cool-season species, with intermediate levels of leaf traits. On the other hand, high stocking rate encouraged functional type C (prostrate, warm season species, with high SLA and low LDMC. The classification of a highly diverse community into three functional types and the selection of traits as functional markers candidates is an innovative approach to develop simple and general methods to diagnosis the state of basaltic grasslands in Uruguay and to advise on its management.Las praderas naturales de la region bas áltica de Uruguay están amenazadas por el incremento de la carga animal y cambios en el uso del suelo. Para evaluar el efecto del pastoreo se han propuesto los grupos funcionales como una herramienta simple para el monitoreo y manejo de la vegetación. El presente estudio evaluó el efecto del incremento de la carga animal considerando rasgos de 23 especies de gramineas perennes dominantes. Para identificar

  16. Especies leñosas nativas claves para la restauración ecológica del Embalse de Chisacá, Colombia, con base en rasgos importantes de su historia de vida

    OpenAIRE

    Rodríguez Ramírez Natalia; Vargas Orlando

    2006-01-01

    Se determinaron cinco especies nativas leñosas, como claves para la restauración de plantaciones de Pinus patula
    y Corredor ripario potrerizado del embalse de Chisacá (localidad de Usme, Bogotá, Colombia 3.000-3.250
    msnm; 4°08’59’’ N; 74°17’62’’ W), con base en Rasgos de de Historia de Vida (RHV) y otras características de
    especies presentes en estas áreas. Teniendo en cuenta el objetivo del estudio y las características de las áreas
    degradadas se s...

  17. Circulation and suspended particulate matter transport in a tidally dominated estuary: caravelas estuary, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Augusto França Schettini

    2010-03-01

    Full Text Available The circulation and transport of suspended particulate matter in the Caravelas Estuary are assessed. Nearly-synoptic hourly hydrographic, current (ADCP velocity and volume transport and suspended particulate matter data were collected during a full semidiurnal spring tide, on the two transects Boca do Tomba and Barra Velha and on longitudinal sections at low and high tide. On the first transect the peak ebb currents (-1.5 ms-1 were almost twice as strong as those of the wider and shallow Barra Velha inlet (-0.80 ms-1 and the peak flood currents were 0.75 and 0.60 ms-1, respectively. Due to the strong tidal currents both inlets had weak vertical salinity stratification and were classified with the Stratification-circulation Diagram as Type 2a (partially mixed-weakly stratified and Type 1a (well mixed. Volume transports were very close, ranging from -3,500 to 3,100 m³s-1 at the ebb and flood, respectively, with a residual -630 m³s-1. The concentration of the suspended particulate matter was closely related to the tidal variation and decreased landwards from 50 mg.L-1 at the estuary mouth, to 10 mg.L-1 at distances of 9 and 16 km for the low and high tide experiments, respectively. The total residual SPM transport was out of the estuary at rates of -18 tons per tidal cycle.A circulação e o transporte de material particulado em suspensão no Estuário de Caravelas são pesquisados. Dados quase-sinóticos hidrográficos, de correntes (velocidade e transporte de volume com ADCP e de material particulado em suspensão, foram medidos em intervalos horários durante um ciclo semidiurno de maré de sizígia, em duas seções transversais na Boca do Tomba e na Barra Velha e também em seções longitudinais na baixa-mar e na preamar. Na primeira transversal as correntes máximas de vazante (-1,50 m s-1 foram quase duas vezes mais intensas do que na seção transversal mais larga e rasa Barra Velha, (-0,80 m s-1 e as maiores velocidades das correntes de

  18. Measuring the contribution of benthic ecosystem engineering species to the ecosystem services of an estuary: A case study of burrowing shrimps in Yaquina Estuary, Oregon - April 2009

    Science.gov (United States)

    Burrowing shrimps are regarded as ecosystem engineering species in many coastal ecosystems worldwide, including numerous estuaries of the west coast of North America (Baja California to British Columbia). In estuaries of the U.S. Pacific Northwest, two species of large burrowing...

  19. Measuring the contribution of benthic ecosystem engineering species to the ecosystem services of an estuary: A case study of burrowing shrimps in Yaquina Estuary, Oregon

    Science.gov (United States)

    Burrowing shrimps are regarded as ecosystem engineering species in many coastal ecosystems worldwide, including numerous estuaries of the west coast of North America (Baja California to British Columbia). In estuaries of the U.S. Pacific Northwest, two species of large burrowing...

  20. Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States

    Science.gov (United States)

    The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

  1. Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States. (UNH)

    Science.gov (United States)

    The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

  2. Nonlinear Elasticity in a Deforming Ambient Space

    Science.gov (United States)

    Yavari, Arash; Ozakin, Arkadas; Sadik, Souhayl

    2016-07-01

    In this paper, we formulate a nonlinear elasticity theory in which the ambient space is evolving. For a continuum moving in an evolving ambient space, we model time dependency of the metric by a time-dependent embedding of the ambient space in a larger manifold with a fixed background metric. We derive both the tangential and the normal governing equations. We then reduce the standard energy balance written in the larger ambient space to that in the evolving ambient space. We consider quasi-static deformations of the ambient space and show that a quasi-static deformation of the ambient space results in stresses, in general. We linearize the nonlinear theory about a reference motion and show that variation of the spatial metric corresponds to an effective field of body forces.

  3. Research, Monitoring, and Evaluation for the Federal Columbia River Estuary Program.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Diefenderfer, Heida L. (Pacific Northwest National Laboratory)

    2008-02-20

    The purpose of this document is to describe research, monitoring, and evaluation (RME) for the Federal Columbia River Estuary Program, hereafter called 'the Estuary Program'. The intent of this RME effort is to provide data and information to evaluate progress toward meeting program goals and objectives and support decision making in the Estuary Program. The goal of the Estuary Program is to understand, conserve, and restore the estuary ecosystem to improve the performance of listed salmonid populations. The Estuary Program has five general objectives, designed to fulfill the program goal, as follows: (1) Understand the primary stressors affecting ecosystem controlling factors, such as ocean conditions and invasive species. (2) Conserve and restore factors controlling ecosystem structures and processes, such as hydrodynamics and water quality. (3) Increase the quantity and quality of ecosystem structures, i.e., habitats, juvenile salmonids use during migration through the estuary. (4) Maintain the food web to benefit salmonid performance. (5) Improve salmonid performance in terms of life history diversity, foraging success, growth, and survival. The goal of estuary RME is to provide pertinent and timely research and monitoring information to planners, implementers, and managers of the Estuary Program. The goal leads to three primary management questions pertaining to the main focus of the Estuary Program: estuary habitat conservation and restoration. (1) Are the estuary habitat actions achieving the expected biological and environmental performance targets? (2) Are the offsite habitat actions in the estuary improving juvenile salmonid performance and which actions are most effective at addressing the limiting factors preventing achievement of habitat, fish, or wildlife performance objectives? (3) What are the limiting factors or threats in the estuary/ocean preventing the achievement of desired habitat or fish performance objectives? Performance measures

  4. The variations of suspended sediment concentration in Yangtze River Estuary

    Institute of Scientific and Technical Information of China (English)

    杨云平; 张明进; 李义天; 张为

    2015-01-01

    With the Yangtze River Estuary as an example, this paper analyzes the influence of human activity on the sea water content, the sediment content and the regional transport situation. In both flood seasons and dry seasons, as well as in the whole year, the sediment discharge rate and the suspended sediment concentration (SSC) in the estuary area of the Yangtze River show decreasing trends. In the estuary area, the amount of sediment transported into the South and North Branches and the offshore area is also in a decreasing trend over the years. The SSCs at the sections at the entrances of the South Branch, the South Channel, the North Channel and the South Passage in the Yangtze River Estuary show decreasing trends during 1959-2011. The remote-sensing data reveal that for the same runoff and tidal current combination, the SSC in the surface water is decreased, caused by the dramatic decrease in the sediment discharge and the sediment content from the watershed. Although the SSC in the offshore area does not exhibit an apparent decreasing trend, the SSC in the nearshore area drops by 21.42% during the period of 2003-2011 as compared with that during the period of 1985-2002 before the impounding of the Three Gorges Reservoir. The sediment re-suspension in the estuary slows down the reduction of the SSC. The period of 2003-2011 is dry years for the Yangtze River, when the flow is relatively low. The peak value of the SSC in the coast area shifts inwards for about 1/6°degree of longitude. Due to the deepwater channel improvement project in the North Passage at the Yangtze River Estuary in 1998, the SSC in the waterway area is decreased. With the decrease of the divided flow ratio and the sediment splitting ratio in the entrance and the exit of the North Passage, the SSC in the upper and lower reaches of the North Passage during the period of 2008-2011 is decreased by about 14.25% as compared with that during the period of 2000-2007. Primarily due to the jetty at the

  5. How hydrodynamics control algal blooms in the Ythan estuary, Scotland

    Science.gov (United States)

    Champangern, Khruewan; Hoey, Trevor; Thomas, Rhian

    2016-04-01

    The Ythan estuary, northeast Scotland, was designated in 2000 as a Nitrate Vulnerable Zone (NVZ) under the European Commission (EC) Nitrates Directive. Much of the catchment is intensively farmed and water quality has been adversely affected by nutrients from agricultural fertilizers. As a result, algal mats develop annually on tidal flats where sediment from upstream and from the adjacent dune systems is deposited. Understanding the patterns of water (river and ocean) circulation in the estuary as well as understanding how nutrients and sediments are transported in the estuary is crucial for understanding the role of several factors (elevation; sediment characteristics; nutrient flux) control the locations and scale of annual algal blooms. In order to understand those controls, study of interactions between hydrodynamic factors and water quality, in particular chlorophyll levels, at different time scales has been carried out. The results from the study reveal complex seasonal and event-scale relationships of river flow with the amount of chlorophyll, which provide an initial comprehension of controls over the concentrations of chlorophyll in the estuary. The concentration of chlorophyll changes, whether increasing or decreasing, with regards to changes in river flow. During high flow events, high amounts of chlorophyll are found when the tide is low. During low flow events, high amounts of chlorophyll are found at high tides. These phenomena reveal that both river flow and tidal cycle affect the amount of chlorophyll in the estuary. In addition, the Delft3d flow model, which has been extensively applied to many coastal and estuarine studies is used to simulate hydrodynamic patterns in the estuary during high flow and low flow events. The model is composed of 36,450 fine resolution grids and the upstream/ downstream boundary that represents water level is based on time-series data from river flow and tidal measurements. The bathymetry used for the model domain is

  6. Hidrogeología ambiental

    OpenAIRE

    Auge, Miguel

    2004-01-01

    La finalidad de este libro es introducir a aquellos que trabajan en agua subterránea, en una temática relativamente moderna pero que en los últimos 15 a 20 años, ha concentrado la mayor demanda laboral de geólogos en los países desarrollados del Hemisferio Norte. En el tomo I se analiza la relación del agua subterránea con el ambiente, tratando especialmente, el origen, las características, y los procesos de contaminación. Se describe la relación agua superficial-subterránea y su incidencia e...

  7. Pediatria ambiental: um tema emergente

    Directory of Open Access Journals (Sweden)

    Patricia M. Valenzuela

    2011-04-01

    Full Text Available OBJETIVO: Revisar os artigos mais relevantes sobre a pediatria ambiental, seus efeitos potenciais para a saúde e, especialmente, seus avanços na prevenção. FONTES DOS DADOS: Foi realizada uma pesquisa utilizando as bases de dados MEDLINE/PubMed e SciELO. Foram revisados artigos de 1990 a 2010, além de capítulos de livros relacionados à pediatria ambiental. SÍNTESE DOS DADOS: Há uma variedade significativa de fatores que tornam as crianças altamente vulneráveis à exposição a riscos ambientais, associados principalmente ao consumo comparativamente maior de água, comida e ar por parte da criança, em relação ao seu peso corporal. De acordo com a Organização Mundial de Saúde, mais de 3 milhões de crianças menores de 5 anos morrem devido a doenças relacionadas ao meio ambiente. Aproximadamente 30-40% das doenças pediátricas estão relacionadas a fatores ambientais. As crianças estão constantemente expostas a vários riscos ambientais para a saúde, dentre os quais se destacam: água contaminada, falta de condições adequadas de saneamento, poluição do ar, vetores de doenças, perigos químicos, injúrias e acidentes. CONCLUSÕES: Atualmente, os pediatras são desafiados a tratar das necessidades de saúde ligadas à pediatria ambiental. A história pediátrica deve ser mais abrangente, acrescentando-se questões pontuais que ajudem a identificar potenciais riscos ambientais. A conscientização e o entendimento sobre os efeitos nocivos das várias condições ambientais e o conhecimento sobre as medidas de prevenção relacionadas resultarão em intervenções oportunas e adequadas que melhorarão a saúde e o desenvolvimento das nossas crianças.

  8. Responsabilidades municipales en materia ambiental

    OpenAIRE

    Ignacio Pichardo Pagaza

    2009-01-01

    Los municipios tienen una responsabilidad directa, inmediata e ineludible hacia el medio ambiente que hasta hace pocos años no reconocían como pri mor dial sino como una función secundaria. Hoy es más que una obligación jurídica, es un compromiso so cial del nivel de gobierno más cercano a la sociedad. Este trabajo reflexiona en torno a las responsabilidades que la Constitución política impone de manera exclusiva a los municipios y que por su naturaleza tienen efectos directos en el medio amb...

  9. Modern and relict features in clayey cryogenic coils: Morphological and micromorphological identification Rasgos modernos y actuales en suelos criogénicos arcillosos: identificación morfológica y micromorfológica Características modernas e ancestrais de solos criogénicos argilosos: identificação morfológica e micromorfológica

    Directory of Open Access Journals (Sweden)

    Marina Lebedeva

    2013-11-01

    ímicas, los suelos representan un complejo edáfico que incluye Phaeozems Vérticos Lúvicos (Argílicos y Túrbicos y Phaeozems Lúvicos (Argílicos y Túrbicos. Los procesos de descomposición, agregación, eluviación, iluviación, edafoturbación, mineralización y endurecimiento resultan de la acumulación y transformación de la material orgánica, hielo-deshielo, contracción-expansión, translocación y crioturbación. El complejo edáfico se interpreta como poligenético. Las interpretaciones se han realizado para diferenciar los procesos de edafogénesis modernos de los relictos. Los rasgos más antiguos están datados del periodo glaciar frío del Pleistoceno e incluyen cuñas criogénicas, involuciones del permafrost, horizontes edáficos desorganizados, distribución criogénica del material grueso y acumulación de materia orgánica sobre el permafrost. Una posterior edafogénesis asociada a un ambiente más cálido y húmedo se refleja en rellenos de grietas con humus negro, presencia de agregados de humus negro en profundidad, translocación vertical de materia orgánica y formación de revestimientos de arcilla. Finalmente, el clima actual es más cálido pero más árido y esto se refleja a través de humus fúlvico pardo y la formación de rasgos vérticos. Incluso en este último periodo cálido los rasgos vérticos formados por procesos de contracción y expansion coexisten con la congelación anual en profundidad de los suelos y el desarrollo de permafrost a una profundidad de ~300 cm.Esta investigação foi realizada na parte sudeste da Rússia, e os solos em causa formaram-se sobre materiais parentais argilosos em condições de clima continental extremo favorável à congelação dos níveis profundos do solo e à manutenção do permafrost. De acordo com as suas características morfológicas, micromorfológicas, físicas e químicas, os solos representam um complexo que inclui Phaeozems Vérticos Lúvicos (Argílicos e Túrbicos e Phaeozems Lúvicos

  10. Plastic pollution in five urban estuaries of KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Naidoo, Trishan; Glassom, David; Smit, Albertus J

    2015-12-15

    Monitoring plastic concentrations in estuaries is vital in assessing the magnitude of terrestrial inputs to oceanic environments. Data on plastics ≤ 5 mm in estuaries are scant. This study determined microplastic levels within five estuaries along the Durban coastline and on intervening beaches. Plastics were isolated from estuarine sediment, beach sediment and the surface water of each estuary and characterised. Sediment at the Bayhead area of Durban harbour had the highest average plastic concentrations (745.4 ± 129.7 particles per 500 ml) and an attenuating concentration trend away from the city centre was found. Prevailing south to north longshore drift was hypothesised to result in plastic accumulation on the northern shores of beaches with estuarine effluents, however, this was not found. Fragments composed the largest percent of plastics (59%) found in Bayhead, whereas fibres dominated other estuaries with proportions ranging from 38% of total plastics in the uMgeni estuary to 66% in the Mdloti. PMID:26476863

  11. A comparative study on selected marine actinomycetes from Pulicat, Muttukadu, and Ennore estuaries

    Institute of Scientific and Technical Information of China (English)

    SChacko Vijai Sharma; Ernest David

    2012-01-01

    Objective: To isolate and make a comparative study of marine sediments actinomycetes from Pulicat estuary, Muttukadu estuary and Ennore estuary, TamilNadu, India. Methods: A unique selective enrichment procedure has resulted in the isolation and identification a total of 304 actinomycetes colonies which were isolated from different stations of marine soil sediments in Pulicat estuary, Muttukadu estuary and Ennore estuary, TamilNadu, India. Results: Among them, 277 isolates were morphologically distinct on the basis of spore mass colour, aerial and substrate mycelium formation and production of diffusible pigment. The majority (60%; 162 isolates) were assigned to the genus Streptomyces. (35%; 104 isolates) were assigned to the genus Actinopolyspora, (5%; 11 isolates) were assigned to the genus Nocardiodes. Conclusions: The present study concluded that the physiological characteristics of actinomycetes Streptomyces, Actinopolyspora and Nocardiodes varied by available nutrients in the medium and the physical conditions.

  12. Pollutant Flux Estimation in an Estuary Comparison between Model and Field Measurements

    OpenAIRE

    Yen-Chang Chen; Wu-Seng Lung; Han-Chung Yang; Bo-Jhih Chen; Chien-Hung Chen

    2014-01-01

    This study proposes a framework for estimating pollutant flux in an estuary. An efficient method is applied to estimate the flux of pollutants in an estuary. A gauging station network in the Danshui River estuary is established to measure the data of water quality and discharge based on the efficient method. A boat mounted with an acoustic Doppler profiler (ADP) traverses the river along a preselected path that is normal to the streamflow to measure the velocities, water depths and water qua...

  13. Linking behavior, physiology, and survival of Atlantic Salmon smolts during estuary migration

    Science.gov (United States)

    Stich, Daniel S.; Zydlewski, Gayle B.; Kocik, John F.; Zydlewski, Joseph

    2015-01-01

    Decreased marine survival is identified as a component driver of continued declines of Atlantic Salmon Salmo salar. However, estimates of marine mortality often incorporate loss incurred during estuary migration that may be mechanistically distinct from factors affecting marine mortality. We examined movements and survival of 941 smolts (141 wild and 800 hatchery-reared fish) released in freshwater during passage through the Penobscot River estuary, Maine, from 2005 to 2013. We related trends in estuary arrival date, movement rate, and survival to fish characteristics, migratory history, and environmental conditions in the estuary. Fish that experienced the warmest thermal history arrived in the estuary 8 d earlier than those experiencing the coolest thermal history during development. Estuary arrival date was 10 d later for fish experiencing high flow than for fish experiencing low flow. Fish released furthest upstream arrived in the estuary 3 d later than those stocked further downstream but moved 0.5 km/h faster through the estuary. Temporally, movement rate and survival in the estuary both peaked in mid-May. Spatially, movement rate and survival both decreased from freshwater to the ocean. Wild smolts arrived in the estuary later than hatchery fish, but we observed no change in movement rate or survival attributable to rearing history. Fish with the highest gill Na+, K+-ATPase activity incurred 25% lower mortality through the estuary than fish with the lowest gill Na+, K+-ATPase activity. Smolt survival decreased (by up to 40%) with the increasing number of dams passed (ranging from two to nine) during freshwater migration. These results underscore the importance of physiological preparedness on performance and the delayed, indirect effects of dams on survival of Atlantic Salmon smolts during estuary migration, ultimately affecting marine survival estimates.

  14. Morphodynamics of a gravel-dominated macrotidal estuary: Rio Grande, Tierra del Fuego

    OpenAIRE

    Federico I. Isla; Gustavo G. Bujalesky

    2004-01-01

    Rio Grande city (Tierra del Fuego) is located on two attached beach systems, one of Upper Pleistocene (Sangamonian) and the other of Holocene age. Both gravel spits grew from north to south modifying the inlet of the Rio Grande estuary. The present estuary is constrained by the modern and recurved spit Popper Spit. The main characteristic of this macrotidal estuary is that both margins and the bottom are mainly composed of rounded gravel. Expansion of the city is limited by oceanic and estuar...

  15. The contribution of scientific research for integrated coastal management: the Mondego estuary as study case

    OpenAIRE

    Costa, Sonia; Azeiteiro, Ulisses; Pardal, Miguel

    2013-01-01

    The present paper quantifies and summarizes the research performed in the Mondego estuary (Portugal) over the last decades. Online databases were used to quantitatively assess the international publications, the master dissertations and PhD theses focused in the research about that estuary, from 1989 to 2012. In general, there had been a notable growth trend in publication output. Estuarine, Coastal and Shelf Science was the most active journal publishing on Mondego estuary. Field studies wer...

  16. Persistence and Non-target Impact of Imazapyr Associated with Smooth Cordgrass Control in an Estuary

    OpenAIRE

    Patten, Kim

    2003-01-01

    The herbicide (±-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)- 5-oxo-1 H -imidazol-2-yl]-3-pyridinecarboxylic acid (imazapyr) has shown potential to control smooth cordgrass (Spartina alterniflora Loisel), a noxious weed in many estuaries throughout the world. Research was conducted under tidal estuary conditions in Willapa Bay, Washington, to determine imazapyr’s persistence and aquatic risk and impact to non-target estuary species. Persistence of imazapyr in water...

  17. Multibiomarker assessment of three Brazilian estuaries using oysters as bioindicators

    International Nuclear Information System (INIS)

    Oysters have been largely employed as bioindicators of environmental quality in biomonitoring studies. Crassostrea rhizophorae was selected to evaluate the health status of three estuarine areas impacted by anthropogenic activities along the Brazilian coast, in three estuarine complexes, ranging in latitude from 7 to 25 deg. S. In each estuary three sites were sampled in Winter and in Summer: a site considered as reference, and two sites next to contamination sources. Condition index was similar at all sites and estuaries, with the highest values found for Itamaraca oysters in Summer. Necrosis, hyperplasia, mucocyte hypertrophy and fusion of ordinary filaments were the main histopathological lesions observed. Muscle cholinesterase activity was overall similar, but with a strong seasonal effect. Inhibition or activation of branchial total ATPase and Na,K-ATPase activities at the contaminated sites was observed. The health status of these estuarine areas is quite similar, and the combined use of biomarkers is recommended

  18. STUDY OF RED TIDE PREDICTION MODEL FOR THE CHANGJIANG ESTUARY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper based on field data (on red tide water quality monitoring at the Changjiang River mouth and Hutoudu mariculture area in Zhejiang Province from May to August in 1995, and May to September in 1996) presents an effective model for short term prediction of red tide in the Changjiang Estuary. The measured parameters include: depth, temperature, color diaphaneity, density, DO, COD and nutrients (PO4-P, NO2-N, NO3-N, NH4-N). The model was checked by field-test data, and compared with other related models.The model: Z=SAL-3.95 DO-2.974 PH-5.421 PO4-P is suitable for application to the Shengsi aquiculture area near the Changjiang Estuary.

  19. Modeling centuries of estuarine morphodynamics in the Western Scheldt estuary

    Science.gov (United States)

    Dam, G.; Wegen, M.; Labeur, R. J.; Roelvink, D.

    2016-04-01

    We hindcast a 110 year period (1860-1970) of morphodynamic behavior of the Western Scheldt estuary by means of a 2-D, high-resolution, process-based model and compare results to a historically unique bathymetric data set. Initially, the model skill decreases for a few decades. Against common perception, the model skill increases after that to become excellent after 110 years. We attribute this to the self-organization of the morphological system which is reproduced correctly by the numerical model. On time scales exceeding decades, the interaction between the major tidal forcing and the confinement of the estuary overrules other uncertainties. Both measured and modeled bathymetries reflect a trend of decreasing energy dissipation, less morphodynamic activity, and thus a more stable morphology over time, albeit that the estuarine adaptation time is long (approximately centuries). Process-based models applied in confined environments and under constant forcing conditions may perform well especially on long (greater than decades) time scales.

  20. Estimation of bed shear stresses in the pearl river estuary

    Science.gov (United States)

    Liu, Huan; Wu, Jia-xue

    2015-03-01

    Mean and fluctuating velocities were measured by use of a pulse coherent acoustic Doppler profiler (PC-ADP) and an acoustic Doppler velocimeter in the tidal bottom boundary layer of the Pearl River Estuary. The bed shear stresses were estimated by four different methods: log profile (LP), eddy correlation (EC), turbulent kinetic energy (TKE), and inertial dissipation (ID). The results show that (a) all four methods for estimating bed stresses have advantages and disadvantages, and they should be applied simultaneously to obtain reliable frictional velocity and to identify potential sources of errors; (b) the LP method was found to be the most suitable to estimate the bed stresses in non-stratified, quasi-steady, and homogeneous flows; and (c) in the estuary where the semi-diurnal tidal current is dominant, bed shear stresses exhibit a strong quarter-diurnal variation.

  1. Estimation of Bed Shear Stresses in the Pearl River Estuary

    Institute of Scientific and Technical Information of China (English)

    刘欢; 吴加学

    2015-01-01

    Mean and fluctuating velocities were measured by use of a pulse coherent acoustic Doppler profiler (PC-ADP) and an acoustic Doppler velocimeter in the tidal bottom boundary layer of the Pearl River Estuary. The bed shear stresses were estimated by four different methods: log profile (LP), eddy correlation (EC), turbulent kinetic energy (TKE), and inertial dissipation (ID). The results show that (a) all four methods for estimating bed stresses have advantages and disadvantages, and they should be applied simultaneously to obtain reliable frictional velocity and to identify potential sources of errors; (b) the LP method was found to be the most suitable to estimate the bed stresses in non-stratified, quasi-steady, and homogeneous flows; and (c) in the estuary where the semi-diurnal tidal current is dominant, bed shear stresses exhibit a strong quarter-diurnal variation.

  2. Mercury bioaccumulation in organisms from three Puerto Rican estuaries.

    Science.gov (United States)

    Burger, J; Cooper, K; Saliva, J; Gochfeld, D; Lipsky, D; Gochfeld, M

    1992-09-01

    We analyzed mercury levels in shrimp (Palaemonetes sp.), Blue Crabs (Callinectes sp.), fish (Tarpon Megalops atlantica and Tilapia Tilapia mossambica), lizards (Ameiva exsul), Cattle Egret (Bubulcus ibis) and Moorhen (Gallinula chloropus) in three estuaries in Puerto Rico in 1988. There were no quantifiable concentrations greater than the method detection limit of mercury in shrimp, crabs and lizards from any site. Mercury levels were also below detection limits in Tilapia, except for specimens collected at Frontera Creek, allegedly contaminated with mercury. However, mercury levels ranged from 92-238 μg/kg (wet weight) in Tarpon, a predaceous fish that feeds on smaller fish. Few of the birds had detectable levels of mercury. Our results indicate relatively low concentrations of mercury in biota collected in all of the three estuaries at most trophic levels, although 10 of 12 Tarpon fillet samples from Frontera had detectable mercury compared to 3 of 12 fillet samples for the other two lagoons. PMID:24226951

  3. Salinity response to seasonal runoff in a complex estuarine system (Cochin estuary, west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Vinita, J.; Shivaprasad, A.; Revichandran, C.; Manoj, N.T.; Muraleedharan, K.R.; Jacob B

    starting point for additional characterization of mixing processes in Cochin estuary. Flushing time (TF) is the time required to renew existing volume (Ve) of water in an estuary at a volumetric flow rate (Q) through the estuary (Monsen et al., 2002), i.e... of the estuary is contributed by the diffusive component induced by tides which countered the seaward advection of salt. Richard, Robert, and Kuo-Chuin, 1992 documented that the response of salinity due to runoff was weakened by the effect of axial diffusivity...

  4. Macrobenthic community in the Xiaoqing River Estuary in Laizhou Bay, China

    Science.gov (United States)

    Luo, Xianxiang; Zhang, Shanshan; Yang, Jianqiang; Pan, Jinfen; Tian, Lin; Zhang, Longjun

    2013-09-01

    The macrobenthic community of the Xiaoqing River Estuary and the adjacent sea waters was investigated in May and November 2008, August 2009, and May and September 2010, respectively. A total of 95 species of macrobenthos were identified in the five cruises and most of them were polychaetes (46.39%), mollusks (28.86%) and crustaceans (20.62%). The Shannon-Wiener index of macrobenthos was lower than 2 in 67% sites. Along the stream channel, estuary and the coastal waters, the species of polychaetes reduced gradually, while the abundance increased at first and then decreased. The abundance was the biggest at regions with salinity of 5-20 in the estuary. The species and abundance of mollusks and crustaceans increased gradually. As for seasonal distribution, the species, abundance and biomass were higher in spring and lower in summer and autumn. Contemporaneously compared with Laizhou Bay and Yellow River Estuary, the species of macrobenthos appeared in the Xiaoqing River Estuary were much less, while the percentage of polychaetes was higher. Abundance and biomass were higher in Xiaoqing River estuary, then consequently followed by Laizhou Bay and Yellow River Estuary. The dominant species in Xiaoqing River Estuary was polychaete, and Layzhou Bay mollusk. The community structure characteristics of macrobenthos in the Xiaoqing River Estuary revealed a significant pollution status in this region.

  5. Effects of environmental stress on the condition of Littorina littorea along the Scheldt estuary (The Netherlands).

    Science.gov (United States)

    Van den Broeck, Heidi; De Wolf, Hans; Backeljau, Thierry; Blust, Ronny

    2007-04-15

    The condition of the periwinkle Littorina littorea, expressed in terms of its shell morphology, reproductive impairment (i.e. female sterility/intersex, male penis shedding), trematode infestation load, lipid reserves and dry/wet weight ratio, was determined in function of environmental stress along the polluted Western and relatively clean Eastern Scheldt estuary (The Netherlands). The upstream increasing pollution and decreasing salinity levels along the Western Scheldt estuary (Fig. 1) are reflected in the dry/wet weight ratio and lipid content of the periwinkles. Compared to the Eastern Scheldt, female intersex (i.e. indicator of TBT pollution) and sterility occurred more frequently in the Western Scheldt estuary, while male penis shedding was even restricted to the latter estuary. The highest population intersex and sterility incidence was found near the harbour of Vlissingen and reflects potential nautical activities. The number of trematode infested periwinkles did not differ between both estuaries, although local sampling site differences were detected within each estuary, reflecting the complex interactions that exist among parasites, hosts and the local environment. Finally, both estuaries were maximally discriminated from each other based on the shell weight of the periwinkles using a canonical discriminant analysis. Periwinkles with the heaviest shells were found in the Western Scheldt estuary and may reflect growth rate or structural population differences caused by the less favourable living conditions in the Western Scheldt estuary. PMID:17343899

  6. Estimation of dissolved inorganic nutrients fluxes from the Changjiang River into estuary

    Institute of Scientific and Technical Information of China (English)

    刘新成; 沈焕庭

    2001-01-01

    Because the estuary acts as either a trap or a source or both for nutrient elements and will modify greatly the riverine transport to the ocean, it is necessary to calculate the flux from river into estuary and that from estuary into sea, respectively. The present work aims to use a long-term record of nutrients concentrations and runoff discharges on H.e Datong section (625 km inland from the Changjiang River mouth) to identify the variability of nutrients concentrations and to estimate nutrients fluxes from the Changjiang River into the estuary.

  7. Macrobenthic Community in the Xiaoqing River Estuary in Laizhou Bay, China

    Institute of Scientific and Technical Information of China (English)

    LUO Xianxiang; ZHANG Shanshan; YANG Jianqiang; PAN Jinfen; TIAN Lin; ZHANG Longjun

    2013-01-01

    The macrobenthic community of the Xiaoqing River Estuary and the adjacent sea waters was investigated in May and November 2008,August 2009,and May and September 2010,respectively.A total of 95 species of macrobenthos were identified in the five cruises and most of them were polychaetes (46.39%),mollusks (28.86%) and crustaceans (20.62%).The Shannon-Wiener index of macrobenthos was lower than 2 in 67% sites.Along the stream channel,estuary and the coastal waters,the species of polychaetes reduced gradually,while the abundance increased at first and then decreased.The abundance was the biggest at regions with salinity of 5-20 in the estuary.The species and abundance of mollusks and crustaceans increased gradually.As for seasonal distribution,the species,abundance and biomass were higher in spring and lower in summer and autumn.Contemporaneously compared with Laizhou Bay and Yellow River Estuary,the species of macrobenthos appeared in the Xiaoqing River Estuary were much less,while the percentage of polychaetes was higher.Abundance and biomass were higher in Xiaoqing River estuary,then consequently followed by Laizhou Bay and Yellow River Estuary.The dominant species in Xiaoqing River Estuary was polychaete,and Layzhou Bay mollusk.The community structure characteristics of macrobenthos in the Xiaoqing River Estuary revealed a significant pollution status in this region.

  8. Environmental restoration of the Guadiaro river estuary, Cadiz (Spain)

    OpenAIRE

    2000-01-01

    During 1998, the Spanish Ministry of Environmental Protection has developed the restoration of the Guadiaro estuary, near the Strait of Gibraltar, through the Coastal General Directorate. The main environmental problems, amongst others, detected at the area were a high eutrophication level of the estuarine waters and fish mortality mainly due to the low summer river effluent, the urban sewage inputs and no tidal renovation caused by the blockage of the sand bar at the mouth...

  9. Possible estuary-associated syndrome: symptoms, vision, and treatment.

    OpenAIRE

    Shoemaker, R C; Hudnell, H.K.

    2001-01-01

    The human illness designated as possible estuarine-associated syndrome (PEAS) by the Centers for Disease Control and Prevention (CDC) has been associated with exposure to estuaries inhabited by toxin-forming dinoflagellates, including members of the fish-killing toxic Pfiesteria complex (TPC), Pfiesteria piscicida and Pfiesteria shumwayae. Humans may be exposed through direct contact with estuarine water or by inhalation of aerosolized or volatilized toxin(s). The five cases reported here dem...

  10. 5.04 - Carbon Dioxide and Methane Dynamics in Estuaries

    OpenAIRE

    Borges, Alberto; Abril, Gwenaël

    2011-01-01

    Estuaries profoundly transform the large amounts of carbon delivered from rivers before their transfer to the adjacent coastal zone. As a consequence of the complex biogeochemical reworking of allochthonous carbon in the sediments and the water column, CO2 and CH4 are emitted into the atmosphere. We attempt to synthesize available knowledge on biogeochemical cycling of CO2 and CH4 in estuarine environments, with a particular emphasis on the exchange with the atmosphere. Unlike CH4, the global...

  11. Nutrients, hypoxia and mass fishkill events in Tapi estuary, India.

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; JiyalalRam, M.J.; Rokade, M.A.; Bharti, S.; Vishwasrao, C.; Majithiya, D.

    ecosystem (Villate et al. 2013). The flushing out of contaminants entering an estuary is further impacted due to impounding of water in dams, weirs and barrages for hydropower, navigation, aquaculture, diversion for urban water supply, agriculture, due...., 2008. Eutrophic waters, algal bloom and fish kill in fish farming areas in Bolinao, Pangasinan, Philippines. Marine Pollution Bulletin 57, 295–301 Sargaonkar, A., 2006. Estimation of land use specific runoff and pollutant concentration for Tapi...

  12. Phosphorus fractionation distribution in Guapimirim estuary: SE Brazil.

    Science.gov (United States)

    Vicente, Michel Arthur Faria; de Melo, Gustavo Vaz; Baptista Neto, José Antonio; de Oliveira, Allan Sandes

    2016-01-01

    The Guapimirim estuary is the main tributary of Guanabara bay and is located in the northeast portion. Although it is protected, this estuary has been experiencing strong anthropogenic pressure, which has led to changes in the natural characteristics. Large amounts of sewage are dumped into the bay through tributaries, thereby changing the water and bottom sediment quality. One of the main elements of sewage is phosphorus. Despite its importance to life, a high concentration of this nutrient in the environment can result in eutrophication. This work describes the phosphorus distribution in its different fractions in the bottom sediment at 16 stations located in the main channel of the Guapimirim estuary. These results are correlated with data on grain size, organic matter and calcium carbonate content in the bottom sediment and with physicochemical parameters of the bottom water. The grain size decreases toward the mouth of the estuary, whereas the organic matter and carbonate content increase. The salinity increases significantly at 3.5 km upstream from the mouth, where there is also a notable increase in fine sediments; the same site is the mean position of the salinity front. The temperature and pH increase in the same direction. The Pinorg-total ranges between 3.18 and 7.13 µmol g(-1), increasing toward the mouth. The same trend is observed for the other phosphorus fractions P-Ca, P-Fe and P-f.a., which range from 0.68 to 1.91, 0.79 to 1.71 and 0.03 to 0.93 µmol g(-1), respectively. The P-Ca and P-Fe fractions are the most representative in the Pinorg-total, occurring at 26.3 and 26.0 %, respectively. PMID:27610325

  13. Water quality modelling of the western Scheldt estuary

    OpenAIRE

    Ouboter, M.R.L.; Van Eck, B.T.M.; Van Gils, J.A.G.; Sweerts, J.P.; Villars, M.T.

    1998-01-01

    1n 1987 the National Institute for Coastal and Marine Management (the Netherlands) initiated the SAWES project (Systems Analysis WEstern Scheldt). The main goals of the project were to acquire knowledge with respect to the pollution problems in the Scheldt estuary and to apply this knowledge to management issues of the Scheldt on an operational level. The main interest was to understand quantitatively the relation between inputs of polluting substances and effects on the ecosystem. In the fra...

  14. Habitat Scale Mapping of Fisheries Ecosystem Service Values in Estuaries

    OpenAIRE

    Steve J. Jordan; Darrin D. Dantin; Steven P. Ferraro; Timothy G. O’Higgins; Marnita M. Chintala

    2010-01-01

    Little is known about the variability of ecosystem service values at spatial scales most relevant to local decision makers. Competing definitions of ecosystem services, the paucity of ecological and economic information, and the lack of standardization in methodology are major obstacles to applying the ecosystem-services approach at the estuary scale. We present a standardized method that combines habitat maps and habitat–faunal associations to estimate ecosystem service values for recr...

  15. Radiocaesium distribution in the sediment of a Fukushima river estuary

    Science.gov (United States)

    Hagiwara, Hiroki; Konishi, Hiromi; Nakanishi, Takahiro; Harada, Hisaya; Tsuruta, Tadahiko

    2016-04-01

    On fluvial discharge, paticulate fractions are the main carrier of radiocaesium from land to aquatic bodies such as rivers, lakes and the sea [1]. However, within river estuaries, where there is a drastic increase in salinity, fine particles generally flocculate (in the size order of several tens μm) before settling out and being deposited on the river bed [2]. In this study, we investigated the sediment records and the distribution of radiocaesium within the estuary of the Odaka river in January 2014, located approximately 17 km north of the Fukushima Dai-ichi Nuclear Power Plant. Based on distribution of salinity, the environment of the Odaka river is divided into three areas; the freshwater area, the estuarine marine area that was filled with saline water from surface to bottom and the brackish area between these two. Radiocaesium deposition ranged from 45 to 1070 kBq m-2 with the inventory of radiocaesium in the estuary being significantly greater in the brackish area relative to both the freshwater and estuarine marine areas. Particle size dependency of radiocaesium concentration in the sediments showed that the distribution with relatively higher concentration was expected in the brackish area. The possibility of flocculation in the brackish area will be discussed. References [1] Nagao, S., Kanamori, M., Ochiai, S., Tomihara, S., Fukushi, K., and Yamamoto, M., 2013, Biogeosciences, v. 10, no. 10, p. 6215-6223. [2] Droppo, I. G., and Ongley, E. D., 1994, Water Research, v. 28, no. 8, p. 1799-1809.

  16. Production by microphytobenthos in the Swan-Canning Estuary

    Science.gov (United States)

    Masini, R. J.; McComb, Arthur J.

    2001-09-01

    Intact sediment cores containing microphytobenthos, dominated by episammic diatoms, were collected from shallow sand flats of the Swan-Canning Estuary, Perth, southwestern Australia, and their photosynthesis-light relations deduced from changes in oxygen (17 cores) or pH (13 cores). The theoretical saturating light intensity Ik determined from O2 was 107 µE m-2 s-1, and the light intensity at which photosynthesis is saturated, Isat, was about 1100 µE m-2 s-1. Mean gross production and respiration increased with temperature. Infaunal contributions to total respiration were measured for two cores at about 30%.The sediment photic zone was estimated as 0·5 mm in fine sediments of the upper estuary and 3·5 mm in coarse sediments of the lower estuary. Microalgae from below the photic zone photosynthesized on exposure to light. Biomass (measured as chlorophyll a) decreased down the sediment profile and was linearly correlated with net and gross maximum photosynthesis. Relative photosynthetic efficiencies were high, and light compensation increased with increasing depth in the sediment.Q

  17. Leaf litter ecological fate in the Schelde estuary in Belgium

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Two dominant species of Willow (Salix triandra) and Reed(Phragmites australis) along the Schelde estuary (in Belgium) wereselected in this research. The pigments of higher plant was used asbiomarkers, the decomposition process of the two species werestudied after they fall into the Schelde estuary. After statisticalanalysis (Spearman rank order correlation, p<0.05), the results hasshown the decomposition dynamics pattern of the pigments, and thewillow showed different pattern in comparing with the reed, eg.Chlorophyll-a decomposition dynamics for willow is: y1 = 12196x2 -175895x + 1E + 06 + k, R2 = 0.5706 while for reed is: y2 = -37878x2+ 229782x + 734282 + k, R2 = 0.9065. The precise time of the leaflitter spent in the water was also calculated as were less than 24days, 24-37 days, longer than 37 days (willow) and less than 24days, longer than 24 days (reed), the leaf litter fate of the two -Process, Institute of Applied Ecology, Chinese Academy of Sciencesdominant species in the Schelde estuary was also compared.

  18. Dissolved oxygen conditions in northern Gulf of Mexico estuaries

    Science.gov (United States)

    Engle, V.D.; Kevin, Summers J.; Macauley, J.M.

    1999-01-01

    Because deficient dissolved oxygen (DO) levels may have severe detrimental effects on estuarine and marine life, DO has been widely used as an indicator of ecological conditions by environmental monitoring programs. The U.S. EPA's Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) monitored DO conditions in the estuaries of the Gulf of Mexico from 1991 to 1994. DO was measured in two ways: 1)instantaneous profiles from the surface to the bottom were taken during the day, and 2) continuous measurements were taken near the bottom at 15 min intervals for at least 12 h. This information was summarized to assess the spatial distribution and severity of DO conditions in these estuaries. Depending on the criteria used to define hypoxia (DO concentrations usually < 2 mg L-1 or 15 mg L-1) and the method by which DO is measured, we estimate that between 5.2 and 29.3% of the total estuarine area in the Louisianian Province was affected by low DO conditions.

  19. Turbine airfoil with ambient cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Jr, Christian X.; Marra, John J.; Marsh, Jan H.

    2016-06-07

    A turbine airfoil usable in a turbine engine and having at least one ambient air cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels configured to receive ambient air at about atmospheric pressure. The ambient air cooling system may have a tip static pressure to ambient pressure ratio of at least 0.5, and in at least one embodiment, may include a tip static pressure to ambient pressure ratio of between about 0.5 and about 3.0. The cooling system may also be configured such that an under root slot chamber in the root is large to minimize supply air velocity. One or more cooling channels of the ambient air cooling system may terminate at an outlet at the tip such that the outlet is aligned with inner surfaces forming the at least one cooling channel in the airfoil to facilitate high mass flow.

  20. Eelgrass Enhancement and Restoration in the Lower Columbia River Estuary, Period of Performance: Feb 2008-Sep 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Judd, C.; Thom, R; Borde, A. [Pacific Northwest National Laboratory

    2009-09-08

    The purpose of this study was to evaluate the ability to enhance distribution of eelgrass (Zostera marina) in the Columbia River Estuary to serve as refuge and feeding habitat for juvenile salmon, Dungeness crab, and other fish and wildlife. We strongly suspected that limited eelgrass seed dispersal has resulted in the present distribution of eelgrass meadows, and that there are other suitable places for eelgrass to survive and form functional meadows. Funded as part of the Bonneville Power Administration's call for Innovative Projects, we initiated a multistage study in 2008 that combined modeling, remote sensing, and field experimentation to: (1) Spatially predict habitat quality for eelgrass; (2) Conduct experimental plantings; and (3) Evaluate restoration potential. Baseline in-situ measurements and remote satellite observations were acquired for locations in the Lower Columbia River Estuary (LCRE) to determine ambient habitat conditions. These were used to create a habitat site-selection model, using data on salinity, temperature, current velocity, light availability, wave energy, and desiccation to predict the suitability of nearshore areas for eelgrass. Based on this model and observations in the field, five sites that contained no eelgrass but appeared to have suitable environmental conditions were transplanted with eelgrass in June 2008 to test the appropriateness of these sites for eelgrass growth. We returned one year after the initial planting to monitor the success rate of the transplants. During the year after transplanting, we carried out a concurrent study on crab distribution inside and outside eelgrass meadows to study crab usage of the habitat. One year after the initial transplant, two sites, one in Baker Bay and one in Young's Bay, had good survival or expansion rates with healthy eelgrass. Two sites had poor survival rates, and one site had a total loss of the transplanted eelgrass. For submerged aquatic vegetation (SAV) restoration

  1. Evolución de la sociabilidad en Hymenoptera: Rasgos conductuales vinculados a niveles sociales y precursores de sociabilidad en especies solitarias Evolution of sociality in Hymenoptera: Behavioural traits linked to social levels and precursors of sociality in solitary species

    Directory of Open Access Journals (Sweden)

    LUIS FLORES-PRADO

    2012-09-01

    Full Text Available En Hymenoptera, los niveles de sociabilidad han sido asociados a rasgos conductuales, tales como los comportamientos de nidificación y agonísticos, y la capacidad de reconocimiento entre conespecíficos. El reconocimiento de compañeros de nido es un fenómeno de amplia difusión entre especies eusociales, y puede ser inferido por el resultado de las interacciones agonísticas entre hembras; estas son más tolerantes hacia compañeras de nido que hacia no compañeras de nido. Contrariamente, en la mayor parte de las especies solitarias las hembras son agresivas hacia otras hembras conespecíficas. En especies eusociales, la descendencia inmadura es alimentada directamente por la madre, o por obreras; así, el contacto frecuente entre progenie y hembras adultas puede contribuir a entender el reconocimiento social. En el extremo opuesto, las especies solitarias construyen nidos que no permiten interacciones entre adultos e inmaduros. A pesar de esto, estudios recientes sugieren que el aprendizaje del fenotipo propio podría explicar la capacidad de reconocimiento y, tal vez, corresponde al punto de partida en el desarrollo y evolución de la sociabilidad. La subfamilia Xylocopinae (Apidae ha emergido como un valioso modelo para estudiar la evolución de la sociabilidad pues contiene especies que presentan un amplio rango de sociabilidad. En particular, la tribu Manueliini representa un taxón interesante desde el punto de vista de la evolución de la sociabilidad en Xylocopinae pues ha sido propuesto como el grupo hermano de todos los demás Xylocopinae, es un taxón relicto que retiene rasgos morfológicos ancestrales, contiene solo especies fundamentalmente solitarias (aunque en una de estas se ha demostrado recientemente reconocimiento de compañeras de nido y de parientes y algunas especies exhiben rasgos conductuales precursores de vida social. En este trabajo se revisa en Hymenoptera los grados de sociabilidad asociados con rasgos

  2. Predicateμ-Calculus for Mobile Ambients

    Institute of Scientific and Technical Information of China (English)

    Hui-Min Lin

    2005-01-01

    Ambient logics have been proposed to describe properties for mobile agents which may evolve over time as well as space. This paper takes a predicate-based approach to extending an ambient logic with recursion, yielding a predicate t-calculus in which fixpoint formulas are formed using predicate variables. An algorithm is developed for model checking finite-control mobile ambients against formulas of the logic, providing the first decidability result for model checking a spatial logic with recursion.

  3. Det ambientes fænomenologi

    DEFF Research Database (Denmark)

    Walther-Hansen, Mads

    2014-01-01

    Det ambiente: sansning, medialisering, omgivelse er et aktuelt og ambitiøst værk. Bogen skildrer hvordan ambiente fænomener har fået en stigende betydning i den moderne verden, og redegør for måden hvorpå det ambiente virker ind på hele vores oplevelseskultur. Det er en levende, uprætentiøs og fr...

  4. Evolution of mid-Atlantic coastal and back-barrier estuary environments in response to a hurricane: Implications for barrier-estuary connectivity

    Science.gov (United States)

    Miselis, Jennifer L.; Andrews, Brian D.; Nicholson, Robert S.; Defne, Zafer; Ganju, Neil K.; Navoy, Anthony S.

    2015-01-01

    Assessments of coupled barrier island-estuary storm response are rare. Hurricane Sandy made landfall during an investigation in Barnegat Bay-Little Egg Harbor estuary that included water quality monitoring, geomorphologic characterization, and numerical modeling; this provided an opportunity to characterize the storm response of the barrier island-estuary system. Barrier island morphologic response was characterized by significant changes in shoreline position, dune elevation, and beach volume; morphologic changes within the estuary were less dramatic with a net gain of only 200,000 m3 of sediment. When observed, estuarine deposition was adjacent to the back-barrier shoreline or collocated with maximum estuary depths. Estuarine sedimentologic changes correlated well with bed shear stresses derived from numerically simulated storm conditions, suggesting that change is linked to winnowing from elevated storm-related wave-current interactions rather than deposition. Rapid storm-related changes in estuarine water level, turbidity, and salinity were coincident with minima in island and estuarine widths, which may have influenced the location of two barrier island breaches. Barrier-estuary connectivity, or the transport of sediment from barrier island to estuary, was influenced by barrier island land use and width. Coupled assessments like this one provide critical information about storm-related coastal and estuarine sediment transport that may not be evident from investigations that consider only one component of the coastal system.

  5. Topographic monitoring of a middle estuary mudflat, Humber estuary, UK--anthropogenic impacts and natural variation.

    Science.gov (United States)

    Boyes, Suzanne J; Allen, James H

    2007-01-01

    Annual topographic surveys were carried out at the Saltend mudflat (Humber estuary, UK) between 1998 and 2006. These surveys formed part of an ongoing monitoring programme to examine the potential effects on the mudflat topography of the construction and operation of a waste water treatment works (WwTW) development by Yorkshire Water. Of particular concern was the potential disruption to the sedimentological regime within the special protection area (SPA) and candidate special area of conservation (cSAC) which could affect the invertebrate communities and ornithological functioning of the site. In addition to the development of the WwTW located to the extreme north-west of the site, a port extension removing 10ha of the Saltend intertidal mudflat (outside the SPA but immediately south east of the WwTW) also occurred between 1999 and 2006. Minimal change was noted across the site following the construction and operation of the WwTW between 1998 and 2000. However, the construction of the bund in closer proximity to the SPA and cSAC masked any potential impact the WwTW could have had across the site after 2000. Profiles and contour mapping indicate that significant mudflat accretion occurred in the immediate area of the bund, with a general increase recorded across the western section of the site since 2000. In contrast the alternations to channel planform and subsequent rapid accretion of the mudflat to the east of the jetty, being a significant distance from the developments, are attributed to natural cyclical changes.

  6. Response of phytoplankton to nutrient enrichment with high growth rates in a tropical monsoonal estuary - Zuari estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Mochemadkar, S.; Gauns, M.; Pratihary, A.K.; Thorat, B.R.; Roy, R.; Pai, I.K.; Naqvi, S.W.A.

    of animals and plants, act as an important linkage and buffer zone between the ocean and land. They are also sites of high rates of production of organic matter, which not only sustain a secondary food chain internally, but also influence biological... productivity of adjacent coastal water in turn sustaining fisheries2,3. The extent to which estuaries exchange dissolved and particulate nutrients with adjacent marine ecosystems depends upon several factors, including geomorphology, tidal regime, climate...

  7. Ambient noise near the sea-route

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shallow water near the sea-route.

  8. Ambient noise near the sea-route

    Institute of Scientific and Technical Information of China (English)

    HE Li; LI ZhengLin; PENG ZhaoHui

    2009-01-01

    Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shal-low water near the sea-route.

  9. Ambient temperature signalling in plants.

    Science.gov (United States)

    Wigge, Philip A

    2013-10-01

    Plants are exposed to daily and seasonal fluctuations in temperature. Within the 'ambient' temperature range (about 12-27°C for Arabidopsis) temperature differences have large effects on plant growth and development, disease resistance pathways and the circadian clock without activating temperature stress pathways. It is this developmental sensing and response to non-stressful temperatures that will be covered in this review. Recent advances have revealed key players in mediating temperature signals. The bHLH transcription factor PHYTOCHROME INTERACTING FACTOR4 (PIF4) has been shown to be a hub for multiple responses to warmer temperature in Arabidopsis, including flowering and hypocotyl elongation. Changes in chromatin state are involved in transmitting temperature signals to the transcriptome. Determining the precise mechanisms of temperature perception represents an exciting goal for the field.

  10. Three-dimensional semi-idealized model for tidal motion in tidal estuaries. An application to the Ems estuary

    Science.gov (United States)

    Kumar, Mohit; Schuttelaars, Henk M.; Roos, Pieter C.; Möller, Matthias

    2016-01-01

    In this paper, a three-dimensional semi-idealized model for tidal motion in a tidal estuary of arbitrary shape and bathymetry is presented. This model aims at bridging the gap between idealized and complex models. The vertical profiles of the velocities are obtained analytically in terms of the first-order and the second-order partial derivatives of surface elevation, which itself follows from an elliptic partial differential equation. The surface elevation is computed numerically using the finite element method and its partial derivatives are obtained using various methods. The newly developed semi-idealized model allows for a systematic investigation of the influence of geometry and bathymetry on the tidal motion which was not possible in previously developed idealized models. The new model also retains the flexibility and computational efficiency of previous idealized models, essential for sensitivity analysis. As a first step, the accuracy of the semi-idealized model is investigated. To this end, an extensive comparison is made between the model results of the semi-idealized model and two other idealized models: a width-averaged model and a three-dimensional idealized model. Finally, the semi-idealized model is used to understand the influence of local geometrical effects on the tidal motion in the Ems estuary. The model shows that local convergence and meandering effects can have a significant influence on the tidal motion. Finally, the model is applied to the Ems estuary. The model results agree well with observations and results from a complex numerical model.

  11. Size Matters: The Contribution of Mega-Infauna to the Food Webs and Ecosystem Services of an Oregon Estuary

    Science.gov (United States)

    Large-bodied, invertebrates are common to infaunal communities of NE Pacific estuaries (e.g., bivalves, polychaetes, burrowing shrimps), but their contribution to the ecological structure, function and ecosystem services of most estuaries has been poorly characterized because the...

  12. Modelling of tidal hydrodynamics for a tropical ecosystem with implications for pollutant dispersion (Cochin Estuary, Southwest India)

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.; Reddy, G.S.; Revichandran, C.; Srinivas, K.; Vijayan, P.R.; Thottam, T.J.

    Tidal circulation in the Cochin Estuary, a moderately polluted estuary along the southwest coast of India, was studied using a 2D hydrodynamic model. The predicted tides and currents showed very good agreement with measured tides. Particle...

  13. Environmental controls on the speciation and distribution of mercury in surface sediments of a tropical estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Babu, P.V.R.

    Distribution and speciation of mercury (Hg) in the sediments from a tropical estuary (Godavari estuary) was influenced by the changing physico-chemical parameters of the overlying water column. The sediments from the upstream and downstream...

  14. Distribution and abundance of Cladocera (Branchiopoda in the Paraíba do Sul River estuary, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    José Mauro Sterza

    2006-12-01

    Full Text Available To characterize the cladoceran community of the Paraíba do Sul River estuary, located in the district of São João da Barra, Rio de Janeiro, Brazil, cladocerans were collected monthly in nine sampling stations from September 2002 until August 2003. Samples were obtained by subsurface tows using a plankton net with a 30 cm opening mouth and 70 micron mesh size, fitted with a mechanical flowmeter. Environmental parameters such as salinity and temperature were also obtained. Seventeen species of Cladocera were identified: Pseudoevadne tergestina, Penilia avirostris, Macrothrix triserialis, Moina micrura, Simocephalus kerhervei, Simocephalus vetalus, Simocephalus latirostris, Simocephalus serrulatus, Alona rectangula, Alona quadrangularis, Bosmina longirostris, Bosminopsis deitersi, Camptocercus dadayi, Ceriodaphnia richardi, Diaphanosoma fluviatile, Kurzia latissima and Pleuroxus similis. The highest total abundance of Cladocera occurred in April in the marine zone of the estuary. The most abundant species during this period was Penilia avirostris. At the mixing and freshwater zones of the estuary, the most abundant species were Moina micrura, mainly in January; and Simocephalus vetalus and Bosmina longirostris during spring. From this scenario, it can be inferred that the cladoceran community of the Paraíba do Sul River estuary presents characteristics of marine, brackish and freshwater environments. Temperature and salinity seem to limit the occurrence and distribution of cladocerans in the estuary.O presente estudo teve como objetivo caracterizar a comunidade zooplanctônica de cladóceros no estuário do Rio Paraíba do Sul, localizado no município de São João da Barra, RJ. O zooplâncton foi coletado mensalmente de setembro/2002 a agosto/2003 em nove estações através de arrastos subsuperficiais com uma rede de plâncton com abertura de boca de 30 cm e malha de 70 mµ, dotada de fluxômetro mecânico. Foram medidas simultaneamente a

  15. The dynamics of a frictionally-dominated Amazonian estuary

    Directory of Open Access Journals (Sweden)

    Nils Edvin Asp

    2012-09-01

    Full Text Available The hydrodynamics, morphology and sedimentology of the Taperaçu estuary were investigated. This is one of several estuaries located within the largest mangrove fringe in the world, bordering the Amazon region, subject to a macrotidal regime and regionally atypical negligible fresh water supply. The results reveal widespread sand banks that occupy the central portion of the estuarine cross-section. Well-sorted very fine sandy sediments of marine origin prevail. Shorter flood phases, with substantially higher current velocities, were observed in the upper sector of Taperaçu, as expected for a shallow, friction-dominated estuary. However, ebb domination can be expected for estuaries with large associated mangrove areas and substantial estuarine infilling, both of which situations occur on the Taperaçu. The tidal asymmetry favoring flood currents could be the result of the absence of an effective fluvial discharge. Furthermore, it was observed that the Taperaçu is connected by tidal creeks to the neighboring Caeté estuary, allowing a stronger flux during the flood and intensifying the higher flood currents. As a whole, the results have shown a complex interaction of morphological aspects (friction, fluvial drainage, connections with neighbor estuaries, infilling and large storage area in determining hydrodynamic patterns, thus improving the understanding of Amazon estuaries.A hidrodinâmica, morfologia e sedimentologia do estuário do Taperaçu foram investigadas. Este é um entre vários estuários do litoral amazônico que integram a maior extensão contínua de manguezais do mundo, apresentando uma descarga de água doce muito reduzida, atípica para a região. Os resultados revelam grandes bancos arenosos que ocupam em grande parte a porção central do estuário. Areias muito finas e bem selecionadas de origem marinha prevalecem. Fases de enchente mais curtas, com velocidades de corrente substancialmente mais altas, são observadas na por

  16. Hydrobiological characteristics of Shark River estuary, Everglades National Park, Florida

    Science.gov (United States)

    McPherson, B.F.

    1970-01-01

    Water quality in the Shark River estuary was strongly influenced by seasonal patterns of rainfall, water level and temperature. During the rainy season (summer and early fall) the salinity in the 20-mile long estuary ranged from that of fresh water to half that of sea water while concentrations of dissolved oxygen were low, 2-5 milligrams per liter (mg/l) presumably because, among other factors, microbial activity and respiration were accelerated by high temperatures (30-33 degrees C). During the dry season (late fall through spring) the salinity ranged from 18 grams per liter (g/l) in the headwaters to 36 g/l at the Gulf during a dry year such as 1967 and from 1 to 25 g/l during a wet year such as 1969. Concentrations of dissolved oxygen increased from 2-3 mg/l in the summer of 1967 to 4-7 mg/l in the winter of 1968, and temperature decreased from an average of about 30 degrees C in summer to 20 degrees C in winter. Water level declined 5 to 10 decimeters in the headwaters during the dry season, and salinity and tidal action increased. Large amounts of submerged vegetation died in some headwater creeks at the end of the dry season, presumably killed by salinities above 3 g/l. The decaying organic matter and the decrease in photosynthesis resulted in low dissolved oxygen (1-2 mg/l). Fish died at this time probably as a result of the low dissolved oxygen. Trace elements, heavy metals and insecticides occurred in the waters of the estuary in concentrations below those indicated as harmful for aquatic life by current standards established by the Federal Water Pollution Control Administration (1968). The insecticides detected were concentrated in sediment and in various organisms. The patterns of distribution of planktonic and small nektonic animals in the estuary were related to salinity. Copepods (Arcatia tonsa, Labidocera aestiva, Pseudodiaptomus coronatus), cumaceans (Cyclaspis sp.), chaetognaths (Sagitta hispida), bay anchovies (Anchoa mitchilli), and scaled

  17. Southwest monsoon influences the water quality and waste assimilative capacity in the Mandovi estuary (Goa state, India)

    Digital Repository Service at National Institute of Oceanography (India)

    VishnuRadhan, R.; Sagayadoss, J.; Seelan, E.; Vethamony, P.; Shirodkar, P.V.; Zainudin, Z.; Shirodkar, S.

    , International Islamic University Malaysia (IIUM), Kuala Lumpur- 50728, Malaysia. Abstract The monsoon dominated Mandovi estuary is located in Goa state - a global tourist destination along the central west coast of India. In addition...-monsoon period. The AOU in the estuary during the three seasons indicates that the assimilative capacity is comparatively good throughout the estuary. The freshwater runoff is high in the estuary during the monsoon season, providing an additional advantage...

  18. Monsoons and habitat influence trophic pathways and the importance of terrestrial-marine linkages for estuary sharks

    OpenAIRE

    Yeung, JWY; Lam, VYY; Williams, GA; Wai, TC; Leung, KMY; Dudgeon, D

    2012-01-01

    Tropical estuaries often receive enhanced fluxes of terrestrial derived organic matter and phytoplankton during the wet season, and such monsoonal events may significantly influence the trophic dynamics of these systems. This study examined spatio-temporal terrestrial-marine linkages in a tropical estuary, the Pearl River Estuary (PRE), southern China, by investigating trophic pathways leading to estuary sharks. We investigated spatial (inshore vs. offshore) and seasonal (wet vs. dry season) ...

  19. Identificación de rasgos morfológicos para una rápida diferenciación de sardina austral (Sprattus fuegensis y sardina común (Strangomera bentincki

    Directory of Open Access Journals (Sweden)

    Antonio Aranis

    2014-11-01

    Full Text Available La pesquería artesanal de cerco multiespecífica que opera en aguas interiores de Chiloé captura sardina común (Strangomera bentincki y sardina austral (Sprattus fuegensis al mismo tiempo y en la misma área. Debido a la gran similitud morfológica externa que presentan estas dos especies de peces óseos, la identificación específica en terreno es difícil, aún para observadores científicos experimentados. Por lo tanto, el objetivo de este trabajo es proponer cual o cuales rasgos morfométricos externos debiesen ser considerados para una rápida identificación de estas especies en terreno. Se analizaron 60 ejemplares de sardina común y 79 de sardina austral. Se identificaron los ejemplares a nivel de especie y se registraron las siguientes medidas: longitud total, longitud de la cabeza, preórbita, órbita y posórbita. Todas las medidas morfométricas fueron estandarizadas para evitar colinealidad. Las diferencias en las medidas morfométricas entre especies fueron probadas mediante métodos estadísticos multivariados que incluyen el análisis de componentes principales, análisis de varianza y covarianza (ANOVA y ANCOVA, análisis multivariado de covarianza (MANOVA y análisis lineal discriminante. La medida posórbita fue el rasgo morfométrico que presentó mayor diferenciación entre especies. Se concluye que la medida de posórbita es por sí sola un carácter morfométrico externo que permitiría una rápida identificación de estas especies en terreno. Los resultados de esta investigación pueden ser tomados como línea base para la generación de guías de campo que apoyen el trabajo de identificación de especies de los observadores científicos.

  20. E-Estuary: Developing a Decision Support System for Coastal Management in the Conterminous United States (IAHR)

    Science.gov (United States)

    Ready access to geographic information is needed to support management decisions for estuaries at local, state, regional, and national scales. The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for coastal management. E-Estuary ...

  1. Minimal ambient nuclear C*-algebras

    OpenAIRE

    Suzuki, Yuhei

    2015-01-01

    We provide examples of ambient nuclear C*-algebras of non-nuclear C*-algebras with no proper intermediate C*-algebras. In particular this gives the first examples of minimal ambient nuclear C*-algebras of non-nuclear C*-algebras. For this purpose, we study generic Cantor systems of infinite free product groups.

  2. Control Flow Analysis for BioAmbients

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Priami, C.;

    2007-01-01

    This paper presents a static analysis for investigating properties of biological systems specified in BioAmbients. We exploit the control flow analysis to decode the bindings of variables induced by communications and to build a relation of the ambients that can interact with each other. We...

  3. 76 FR 8345 - Endangered and Threatened Species; Recovery Plan Module for Columbia River Estuary Salmon and...

    Science.gov (United States)

    2011-02-14

    ... public awareness and involvement, and promote information-based problem solving. The Estuary Partnership... convened by Washington State, by the State of Oregon in conjunction with stakeholder teams, and by NMFS in... comments on the Proposed Estuary Module was published in the Federal Register on January 8, 2008 (73 FR...

  4. Benthic macrofaunal dynamics and environmental stress across a salt wedge Mediterranean estuary.

    Science.gov (United States)

    Nebra, Alfonso; Alcaraz, Carles; Caiola, Nuno; Muñoz-Camarillo, Gloria; Ibáñez, Carles

    2016-06-01

    The spatial distribution of benthic macroinvertebrate community in relation to environmental factors was studied along the Ebro Estuary (NE Iberian Peninsula), a salt wedge Mediterranean estuary. Both ordination methods and generalized additive models were performed to identify the different benthic assemblages and their relationship to abiotic factors. Our results showed a strong relationship between macrofaunal assemblages and the predominant environmental gradients (e.g. salinity); thus revealing spatial differences in their structure and composition. Two different stretches were identified, namely the upper (UE) and the lower Ebro Estuary (LE). UE showed riverine characteristics and hence was colonized by a freshwater community; whereas LE was influenced by marine intrusion and sustained a complex marine-origin community. However, within each stretch, water and sediment characteristics played an important role in explaining species composition differences among sampling stations. Moreover, outcomes suggested a total species replacement pattern, instead of the nestedness pattern usually associated with well-mixed temperate estuaries. The sharp species turnover together with the estuarine stratification point out that the Ebro Estuary is working, in terms of ecological boundaries, under an ecotone model. Finally, despite obvious differences with well mixed estuaries (i.e. lack of tidal influence, stratification and species turnover), the Ebro Estuary shares important ecological attributes with well-mixed temperate estuaries. PMID:27062106

  5. Second international symposium on the biogeochemistry of model estuaries: Estuarine processes in global change

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    This report consists of abstracts of papers presented at the symposium of Biogeochemistry. The main topics discussed at the meeting are; nutrient and mineral cycling, trace element distribution, sources and sinks of estuaries, sedimentation, importance of organic matter, and other biogeochemical processes of estuaries.

  6. Water pollution in estuaries and coastal zones. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The bibliography contains citations concerning the studies of water pollution in estuaries and coastal zones. Citations examine the development, management, and protection of estuary and coastal resources. Topics include pollution sources, environmental monitoring, water chemistry, eutrophication, models, land use, government policy, and laws and regulations. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. 78 FR 68995 - Safety Zone: Vessel Removal From the Oakland Estuary, Alameda, CA

    Science.gov (United States)

    2013-11-18

    ...: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone: Vessel Removal From the Oakland Estuary... Street Bridge in Alameda, CA in support of the Oakland Estuary Closure for the Vessel Removal Project...

  8. Concentration and Distribution of Hydrophobic Organic Contaminants and Metals in the Estuaries of Ukraine

    Science.gov (United States)

    In this baseline study of Ukrainian estuaries, sediments and organisms from the Dnieper and Boh estuaries and Danube Delta on the mainland, Sevastopol and Balaklava Bays on the Crimean Peninsula, and coastal Black Sea along the Crimean Peninsula were collected in 2006. Contamina...

  9. Demonstration and Hands-on Exercises with the Estuary Data Mapper

    Science.gov (United States)

    The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for applications of the Clean Water Act in coastal management. E-Estuary has three elements: an estuarine geo-referenced relational database, watershed GIS coverages, and tools t...

  10. Nitrous oxide in the Schelde estuary: production by nitrification and emission to the atmosphere

    NARCIS (Netherlands)

    De Wilde, H.; De Bie, M.J.M.

    2000-01-01

    Concentrations of nitrous oxide (N2O), oxygen, nitrate, and ammonium, as well as nitrification activity were determined along the salinity gradient of the Schelde Estuary, Northwest Europe, in October 1993, March 1994, and July 1996, The entire estuary was always supersaturated with N2O. Concentrati

  11. The relationship between dissolved humic acids and soluble iron in estuaries

    Science.gov (United States)

    Fox, L. E.

    1984-01-01

    Dissolved humic acid and soluble iron appear to be chemically unassociated in estuaries despite their coincident removal. This conclusion is supported by differences in the aggregation kinetics of soluble iron and dissolved humic acid, the inability of extracted humic acid to stabilize laboratory preparations of ferric hydroxide, and decreasing ratios of humic acid carbon to soluble iron along the axes of some estuaries.

  12. Hydrologic data for the Salt Bayou estuary near Sabine Pass, Texas, October 1984 to March 1986

    Science.gov (United States)

    Fisher, J.C.

    1988-01-01

    The Salt Bayou estuary, located in extreme southeast Texas near Sabine Pass, has been altered by construction of the Gulf Intracoastal Waterway. The waterway has interrupted the historical saltwater-freshwater exchange in this important estuary. This alteration may have had a detrimental effect on fish production because of increased salinity, and on waterfowl production because of lower water levels.

  13. Salt intrusion in multi-channel estuaries: a case study in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    A. D. Nguyen

    2006-01-01

    Full Text Available There is a well-tested theory for the computation of salt intrusion in alluvial estuaries that is fully analytical and predictive. The theory uses analytical equations to predict the mixing behaviour of the estuary based on measurable quantities, such as channel topography, river discharge and tidal characteristics. It applies to single-channel topographies and estuaries that demonstrate moderate tidal damping. The Mekong delta is a multi-channel estuary where the tide is damped due to a relatively strong river discharge (in the order of 2000 m3/s, even during the dry season. As a result the Mekong is a strongly riverine estuary. This paper aims to test if the theory can be applied to such a riverine multi-channel estuary, and to see if possible adjustments or generalisations need to be made. The paper presents salt intrusion measurements that were done by moving boat in 2005, to which the salt intrusion model was calibrated. The theory has been expanded to cater for tidal damping. Subsequently the model has been validated with observations made at fixed locations over the years 1998 and 1999. Finally it has been tested whether the Mekong calibration fits the overall predictive equations derived in other estuaries. The test has been successful and led to a slight adjustment of the predictive equation to cater for estuaries that experience a sloping bottom.

  14. Mixing and flushing time scales in the Azhikode Estuary, southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Revichandran, C.; Pylee, A.

    Flushing time scales of the Azhikode Estuary, Kerala, India showed pronounced dry season and wet season signals as well as large inter-annual variation. Cumulative flushing time of the estuary varies from 4.8 tide cycles in April to 1.22 tide cycles...

  15. Temporal variability of macrofauna from a disturbed habitat in Zuari estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sivadas, S.; Ingole, B.S.; Nanajkar, M.

    and Zuari estuaries. In Shetye, S.R, M. DileepKumar, D. Shankar, D (eds) The Mandovi and Zuari estuaries. National Institute of Oceanography Goa, India, (pp. 3-27). Shin, P.K.S. (1985). A trawl survey of the subtidal mollusca of Tolo Harbour and Mirs Bat...

  16. Sub-tidal water-level oscillations in the Mandovi estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Vijith, V.

    at periods longer than two days. We then examine the causes behind the variability using data on wind and current measured near the mouth of the estuary. The main channel of the estuary is 50 km long and March–April is a period when local winds are weak. Our...

  17. The effects of changes to estuarine hydrology on system phosphorous retention capacity: The Mondego estuary, Portugal

    DEFF Research Database (Denmark)

    Lillebo, A. I.; Otero, M.; Coelho, J. P.;

    2012-01-01

    The Mondego estuary is a mainly polyhaline estuary in central Portugal in which eutrophication increased during the last decades of the 20th century. In 1998 the system hydrology was changed, aiming to reverse the eutrophication process. A long environmental monitoring database showed that the mean...

  18. Modelling the transverse distribution of velocity and suspended sediment in tidal estuaries

    NARCIS (Netherlands)

    Huijts, K.M.H.

    2011-01-01

    An estuary is a semi-enclosed coastal body of water which has a free connection with the open sea and within which sea water is measurably diluted with fresh water derived from land drainage. Examples are the Western Scheldt River Estuary and the Chesapeake Bay. Within these environments complex pat

  19. Estuary Data Mapper: A virtual portal to coastal data informing environmental management decisions

    Science.gov (United States)

    The Estuary Data Mapper (EDM) is a free, interactive graphical application under development at the US EPA that allows environmental researchers and managers to quickly and easily retrieve, view and save subsets of online US coastal estuary-related data. Accessible data include ...

  20. Ordenamento jurídico ambiental

    OpenAIRE

    Costa, Paulo Manuel

    2014-01-01

    Neste artigo iremos fazer uma breve análise das normas jurídicas mais importantes para a protecção do ambiente. Para isso, começaremos por conhecer as principais normas sobre o ambiente que constam da Constituição Portuguesa e que constituem a denominada «Constituição do ambiente». Depois iremos ver um pouco mais em pormenor a Lei de Bases da Política do Ambiente, a qual enuncia os princípios, as medidas e as políticas orientadoras da protecção jurídica do ambiente. Por fim, iremos examinar o...

  1. Implications of the divergent use of a suite of estuaries by two exploited marine fish species.

    Science.gov (United States)

    Potter, I C; Chuwen, B M; Hesp, S A; Hall, N G; Hoeksema, S D; Fairclough, D V; Rodwell, T M

    2011-09-01

    Biological characteristics of the marine species King George whiting Sillaginodes punctatus and Australian herring Arripis georgianus in three seasonally open estuaries (Broke, Irwin and Wilson Inlets), one permanently open estuary (Oyster Harbour) and one normally closed estuary (Wellstead Estuary) on the south coast of Western Australia have been determined and compared. Sillaginodes punctatus enters the seasonally and permanently open estuaries early in life and reaches total lengths (L(T)) >280 mm at which it can be legally retained and thus contributes to commercial and recreational fisheries in these systems. This sillaginid almost invariably emigrates from these estuaries before reaching its typical size at maturity (L(T50)) and does not return after spawning in marine waters. In contrast, virtually all female A. georgianus (≥ 98%) in the three seasonally open estuaries and the majority in the normally closed (89·5%) and permanently open estuaries (83%) exceeded the L(T50) of this species at maturity, reflecting the fact that the nursery areas of this species are predominantly located much further to the east. Although adult females of A. georgianus in seasonally open and normally closed estuaries had developed mature ovaries by autumn, at which time they were prevented from migrating to the sea by closure of the estuary mouths, this species did not spawn in those estuaries. The oocytes in their ovaries were undergoing extensive atresia, a process that had been incipient prior to oocyte maturation. As the adult females of A. georgianus in the permanently open Oyster Harbour at this time all possessed resting gonads, i.e. their oocytes were all previtellogenic, the adults that were present in that estuary earlier and were destined to spawn in autumn must have emigrated from that permanently open estuary to their marine spawning areas prior to the onset of gonadal recrudescence. The body masses at length of A. georgianus, which were almost invariably higher

  2. Distribution and sources of aliphatic hydrocarbons and fatty acids in surface sediments of a tropical estuary south west coast of India (Cochin estuary)

    Digital Repository Service at National Institute of Oceanography (India)

    Gireeshkumar, T.R.; Deepulal, P.M.; Chandramohanakumar, N.

    Surface sediments samples from the Cochin estuary were measured for elemental, stable isotopic and molecular biomarkers (aliphatic hydrocarbons and fatty acids) to study the sources and distribution of sedimentary organic matter. Concentrations...

  3. Ambiguities in the classification of Cochin Estuary, West Coast of India

    Directory of Open Access Journals (Sweden)

    A. Shivaprasad

    2013-03-01

    Full Text Available Cochin Estuary is a unique complex system along Indian coastline with a widespread area at the upstream. The fluctuations in salinity are of extreme kind ranging from entirely riverine to entirely saline. The high runoff months are characterized by monsoonal spells causing intense flushing. During the peak dry period, the runoff is less but steady providing a stable environment. River runoff is controlled by short term variations rather than long term variations. Using large comprehensive data sets, an attempt is made to evaluate several classification schemes for the estuary. The existing methods proved to be insufficient to represent the real salient features of this typical estuary. Arguments are also presented to illustrate the confusion in the names by which the estuary is commonly known. Therefore, a new nomenclature is proposed as "Cochin Monsoonal Estuarine Bay" embodying the physiographic, hydrographic and biological features of the estuary.

  4. Cruise observation and numerical modeling of turbulent mixing in the Pearl River estuary in summer

    Science.gov (United States)

    Pan, Jiayi; Gu, Yanzhen

    2016-06-01

    The turbulent mixing in the Pearl River estuary and plume area is analyzed by using cruise data and simulation results of the Regional Ocean Model System (ROMS). The cruise observations reveal that strong mixing appeared in the bottom layer on larger ebb in the estuary. Modeling simulations are consistent with the observation results, and suggest that inside the estuary and in the near-shore water, the mixing is stronger on ebb than on flood. The mixing generation mechanism analysis based on modeling data reveals that bottom stress is responsible for the generation of turbulence in the estuary, for the re-circulating plume area, internal shear instability plays an important role in the mixing, and wind may induce the surface mixing in the plume far-field. The estuary mixing is controlled by the tidal strength, and in the re-circulating plume bulge, the wind stirring may reinforce the internal shear instability mixing.

  5. EL RACISMO AMBIENTAL EN CHILE

    Directory of Open Access Journals (Sweden)

    MATÍAS MEZA-LOPEHANDÍA

    2011-06-01

    Full Text Available El problema de la desigualdad en Chile ha sido abordado desde diferentes puntos de vista como la cuestión de la distribución de la riqueza o el acceso a los derechos sociales. Es este trabajo se observa el mismo problema pero desde la perspectiva recientemente esbozada por los movimientos sociales: la del racismo ambiental o la desigual distribución de los deshechos del desarrollo y el consumo. De esta manera se revisan sucintamente los principales conflictos que han surgido en el último tiempo a lo largo del país entre empresas públicas y privadas y comunidades locales y originarias. Así mismo se examinan las formas de organización que estas últimas han asumido y el estado actual de articulación entre ellas. De la revisión de la situación se concluye que estamos ante el surgimiento de un actor de nuevo tipo, que surge de las contradicciones del Chile neoliberal y que se diferencia del movimiento ecologista por vincular sus reivindicaciones a la defensa del territorio y al derecho a la autodeterminación de los pueblos.

  6. An Experimental Study on Major Element Release from the Sediments in the Changjiang (Yangtze River) Estuary

    Institute of Scientific and Technical Information of China (English)

    GUO Yanwei; YANG Shouye

    2015-01-01

    With the enhanced warming and acidification of global ocean, whether and to what extent the naturally-weathered fluvial sediment into the sea can release elements and thus influence the geochemical process and ecosystem of global ocean remain to be resolved. In this contribution, an experimental study was carried out to examine the release rates of major elements (Ca, K, Mg and Al) from the surface sediments in the Changjiang (Yangtze River) Estuary under the pH values of 4.0, 6.0 and 7.0. The two studied sediments consist primarily of quartz, plagioclase, calcite and clay minerals, with the BET (Brunauer, Emmett and Teller) surface areas of 61.7m2g-1 and 23.1m2g-1. Major elements of Ca, K, Mg and Al show different release rates under different solution pH values. With the decreasing solution pH, the release rates of Ca and K increase obviously, while the release rates of Mg and Al increase with the initial solution pH varying from 6.0 to 7.0. The different release rates of these elements are closely related to the original mineral composition of the sediments and the reaction kinetics. Based on the experimental observation, quartz and clay minerals that have low dissolution rates may dominate the major element release to the aqueous phase. This study reveals that the en-hancing ocean acidification could cause considerable release of major elements from natural terrigenous sediments into the ambient marine environment, which has to be considered carefully in the future study on global change.

  7. Nutrient transport to the Swan-Canning Estuary, Western Australia

    Science.gov (United States)

    Peters, Norman E.; Donohue, Robert

    2001-09-01

    Catchment nutrient availability in Western Australia is primarily controlled by the disposal of animal waste and the type and rate of fertilizer application, particularly on the relatively narrow (25 km wide), sandy coastal plain. Nitrogen (N) and phosphorus (P) concentrations and fluxes during the wet season of 15 tributaries, including four urban drains to the Swan-Canning Estuary, were evaluated from 1986 to 1992 and additionally concentrations only were evaluated throughout the year from 1993 to 1996. Concentrations of filtered reactive P (FRP) and total P (TP) were generally low, with the volume-weighted means for all sites being 0·06 mg l-1 and 0·12 mg l-1 respectively. The urban drains had higher TP concentrations (volume-weighted mean of 0·21 mg l-1) than the streams (0·12 mg l-1), with the high concentrations associated with particulate matter. Total inorganic N (TIN, NH4N plus NO3N) and total N (TN), which is of interest to eutrophic status of the N-limited estuary, were likewise low, compared with other developed areas having a similar climate. Both TIN and TN were higher in the urban drains (0·76 mg l-1 and 1·5 mg l-1 respectively) than the streams (0·31 mg l-1 and 1·2 mg l-1 respectively). The Avon River, which drains 98·5% of the 121 000 km2 catchment area, contributes most of the N (0·03 kg ha-1 year-1 or 65%) and a high percentage of the P (<0·01 kg ha-1estuaries. The Avon River nutrient fluxes are much less than other tributaries closer to the estuary. The coastal plain receives significantly higher rainfall (1,200 mm year

  8. Lattice Boltzmann Hydrodynamic and Transport Modeling of Everglades Mangrove Estuaries

    Science.gov (United States)

    Sukop, M. C.; Engel, V.

    2010-12-01

    Lattice Boltzmann methods are being developed and applied to simulate groundwater and surface water flows, and heat, solute, and particle transport. Their ability to solve Navier-Stokes, St. Venant, or Darcy equations with closely coupled solute transport and density-dependent flow effects in geometrically complex domains is attractive for inverse modeling of tracer release data and forward modeling of carbon transport in mangrove estuaries under various future conditions. Key physical processes to be simulated include tidal cycles, storm surge, sea level change, variable upstream stage, subsurface groundwater inputs, and precipitation/recharge and their effects on estuary salinity and carbon transport in the estuaries and groundwater beneath the mangroves. Carbon sources and storage in the aquifer and exchanges at the mangrove-estuary interface and carbon transformations in the water column also need to be simulated. Everglades tidal mangrove estuaries are characterized by relatively high velocity (approaching 1 m s-1) tidal flows. The channels are generally less than 2 m in depth. Tidal fluctuations approach 2 m leading to significant areas of periodic inundation and emergence of oyster beds, shell beaches, mangrove root masses, and sandy beaches. Initial models are two-dimensional, although a three-dimensional model explicitly incorporating bathymetry, density-dependent flow, and wind-driven circulation could be developed. Preliminary work highlights some of the abilities of early models. A satellite image of a 64-km2 area surrounding a CO2 flux tower is used to provide the model geometry. Model resolution is 15 m per grid node. A sinusoidal tidal stage variation and constant, high salinity are applied to the Gulf side of the model while a constant stage (corresponding to mean tide), zero salinity boundary is applied on the inland side. The Navier-Stokes equations coupled with the advection-diffusion equation are solved in the open channels. The mangrove areas

  9. Feeding preferences of estuarine mysids Neomysis integer and Rhopalophthalmus tartessicus in a temperate estuary (Guadalquivir Estuary, SW Spain)

    OpenAIRE

    Vilas, C.; Drake, P.; Fockedey, N.

    2008-01-01

    Mysid shrimps are an important component of estuarine food webs because they play a key role in energy transfer as intermediate prey. We investigated the seasonal, tidal and depth specific variation in the diet of the estuarine mysids Neomysis integer and Rhopalophthalmus tartessicus and explored its implications for the planktonic community structure of a temperate estuary (Guadalquivir Estuary, SW Spain). Neomysis integer is an opportunistic omnivore feeding mainly on mesozooplankton and on...

  10. El estudio de rasgos semánticos en cuasisinónimos y términos relacionados: un modo de crear conciencia léxico-semántica en una segunda lengua

    Directory of Open Access Journals (Sweden)

    Paula Jullian R.

    1998-09-01

    Full Text Available Este artículo da a conocer una actividad para alumnos avanzados de inglés con el fin de crear en ellos conciencia léxico-semántica y así enriquecer su vocabulario activo. Esta actividad introduce a los alumnos al estudio del significado de la palabra, investigando toda la carga semántica de términos relacionados. La metodología consiste en la colección de conjuntos léxicos, el estudio de rasgos distintivos, la identificación de las colocaciones apropiadas, las restricciones contextuales y los posibles usos metafóricos de cada palabra del conjunto. Esta metodología será de especial interés para profesores preocupados del estilo y que esperan que el habla de sus alumnos avanzados gane en precisión y fuerza léxica. (This paper reports on an activity carried out with upper advanced learnersto help them raise word meaning awareness and eventually expand theiractive vocabulary. The activity here described introduces learners to the study of word meaning, by looking into the full semantic contents of related words. The task consists in collecting lexical sets, the study of their semantic features, the identification of their appropriate collocations, contextual limitations, and possible figurative uses. This paper will be of special interest to teachers who wish their learners' discourse to gain in accuracy and lexical force.

  11. Temporal changes in physical, chemical and biological sediment parameters in a tropical estuary after mangrove deforestation

    Science.gov (United States)

    Ellegaard, Marianne; Nguyen, Ngoc Tuong Giang; Andersen, Thorbjørn Joest; Michelsen, Anders; Nguyen, Ngoc Lam; Doan, Nhu Hai; Kristensen, Erik; Weckström, Kaarina; Son, Tong Phuoc Hoang; Lund-Hansen, Lars Chresten

    2014-04-01

    Dated sediment cores taken near the head and mouth of a tropical estuary, Nha-Phu/Binh Cang, in south central Viet Nam were analyzed for changes over time in physical, chemical and biological proxies potentially influenced by removal of the mangrove forest lining the estuary. A time-series of satellite images was obtained, which showed that the depletion of the mangrove forest at the head of the estuary was relatively recent. Most of the area was converted into aquaculture ponds, mainly in the late 1990's. The sediment record showed a clear increase in sedimentation rate at the head of the estuary at the time of mangrove deforestation and a change in diatom assemblages in the core from the mouth of the estuary indicating an increase in the water column turbidity of the entire estuary at the time of the mangrove deforestation. The proportion of fine-grained sediment and the δ13C signal both increased with distance from the head of the estuary while the carbon content decreased. The nitrogen content and the δ15N signal were more or less constant throughout the estuary. The proportion of fine-grained material and the chemical proxies were more or less stable over time in the core from the mouth while they varied synchronously over time in the core from the head of the estuary. The sediment proxies combined show that mangrove deforestation had large effects on the estuary with regard to both the physical and chemical environment with implications for the biological functioning.

  12. Morphodynamic evolution of the Xiaoqing River mouth:a Huanghe River-derived mixed energy estuary

    Institute of Scientific and Technical Information of China (English)

    HUANG Haijun; LIU Yanxia; QIU Zhongfeng

    2012-01-01

    In an estuary,tidal,wave and other marine powers interact with the coast in different ways and affect estuary morphology as well as its evolution.In the Huanghe(Yellow)River estuaries and nearby delta,there are many small sediment-affected estuaries with a unique morphology,such as the Xiaoqing River estuary.In this study,we investigated the special evolution and genetic mechanism of the Xiaoqing River estuary by analyzing graphic and image data with a numerical simulation method.The results show that NE and NE-E tide waves are the main driving force for sandbar formation.Sediment shoals have originated from huge amounts of sediment from the Huanghe River,with consequent deposition at the Xiaoqing River mouth.The lateral suspended sediments beyond the river mouth move landward.Siltation takes place on the northern shoreline near the river mouth whereas erosion occurs in the south.The deposits come mainly from scouring of the shallow seabed on the northern side of the estuary.Storm surges speed up deposition in the estuary.Development of the sediment shoals has occurred in two steps involving the processes of growth and further southward extension.Although the southward shift increases the river curvature and length,the general eastward orientation of the estuary is unlikely to change.Processes on the adjacent shorelines do not affect the development of the sediment shoals.The study presents a morphodynamic evolutionary model for the Xiaoqing River estuary,with a long-term series cycle,within which a relatively short cycle occurs.

  13. Aggregate Settling Velocities in San Francisco Estuary Margins

    Science.gov (United States)

    Allen, R. M.; Stacey, M. T.; Variano, E. A.

    2015-12-01

    One way that humans impact aquatic ecosystems is by adding nutrients and contaminants, which can propagate up the food web and cause blooms and die-offs, respectively. Often, these chemicals are attached to fine sediments, and thus where sediments go, so do these anthropogenic influences. Vertical motion of sediments is important for sinking and burial, and also for indirect effects on horizontal transport. The dynamics of sinking sediment (often in aggregates) are complex, thus we need field data to test and validate existing models. San Francisco Bay is well studied and is often used as a test case for new measurement and model techniques (Barnard et al. 2013). Settling velocities for aggregates vary between 4*10-5 to 1.6*10-2 m/s along the estuary backbone (Manning and Schoellhamer 2013). Model results from South San Francisco Bay shoals suggest two populations of settling particles, one fast (ws of 9 to 5.8*10-4 m/s) and one slow (ws of < 1*10-7 to 1.4*10-5 m/s) (Brand et al. 2015). While the open waters of San Francisco Bay and other estuaries are well studied and modeled, sediment and contaminants often originate from the margin regions, and the margins remain poorly characterized. We conducted a 24 hour field experiment in a channel slough of South San Francisco Bay, and measured settling velocity, turbulence and flow, and suspended sediment concentration. At this margin location, we found average settling velocities of 4-5*10-5 m/s, and saw settling velocities decrease with decreasing suspended sediment concentration. These results are consistent with, though at the low end of, those seen along the estuary center, and they suggest that the two population model that has been successful along the shoals may also apply in the margins.

  14. The main phosphorous sources in the Changjiang estuary

    Institute of Scientific and Technical Information of China (English)

    YANG Dongfang; WANG Fan; MIAO Zhenqing; CHEN Yongli; TONG Yuanzheng

    2008-01-01

    Analysis using historical data on the phosphate sources in Changjiang (Yangtze River) estuary show that phosphate was supplied equally from the east, south, west and north of the estuary. These sources include the Changjiang River, the Taiwan Warm Current (TWC), a cyclone-type eddy, and the 32°N Upwelling, supplying different phosphates in different times, ways and intensities. The magnitude of their supplying phosphate concentration was related with the size in the order of the Changjiang River < the TWC < the 32°N Upwelling < the cyclone-type eddy, and the duration of the supplying was: the Changjiang River the TWC the cyclone-type eddy the 32°N Upwelling. The four sources supplied a great deal of phosphate so that the phosphate concentration in the estuary was kept above 0.2 μmol/L in previous years, satisfying the phytoplankton growth. The horizontal and vertical distribution of the phosphate concentration showed that near shallow marine areas at 122°E/31°N, the TWC in low nutrient concentration became an upwelling through sea bottom and brought up nutrients from sea bottom to marine surface. In addition, horizontal distribution of phosphate concentration was consistent with that of algae: Rhizosolenia robusta, Rhizosolenia calcaravis and Skeletonema, which showed that no matter during high water or low water of Changjiang River, these species brought by the TWC became predominant species. Therefore, the authors believe that the TWC flowed from south to north along the coast and played a role in deflecting the Changjiang River flow from the southern side.

  15. Occurrence of Anaerobic Ammonium Oxidation in the Yangtze Estuary

    Science.gov (United States)

    Hou, L.

    2013-12-01

    Over the past several decades, a large quantity of reactive nitrogen has been transported into the Yangtze estuarine and coastal water, due to intense human activities in the Yangtze River Basin. At present, it annually receives a high load of anthropogenic inorganic nitrogen (about 1.1 × 1011 mol N) from increased agricultural activities, fish farming, and domestic and industrial wastewater discharge in the Yangtze River Basin, consequently leading to severe eutrophication and frequent occurrences of harmful algal blooms in the estuary and adjacent coastal areas. Hence, the microbial nitrogen transformations are of major concern in the Yangtze Estuary. Anaerobic ammonium oxidation (anammox) has been reported to play a significant role in the removal of reactive nitrogen in aquatic ecosystems. In this study, the occurrences of anammox bacteria and associated activity in the Yangtze Estuary were evidenced with molecular and isotope-tracing techniques. It is observed that the anammox bacteria at the study area mainly consisted of Candidatus Scalindua, Brocadia, Kuenenia. Salinity was found to be a key environmental factor controlling distribution and diversity of the anammox bacterial community at the estuarine ecosystem. Also, temperature and organic carbon had significant influences on anammox bacterial biodiversity. Q-PCR assays of anammox bacteria indicated that their abundance had a range of 2.63 ×106 - 9.48 ×107 copies g-1 dry sediment, with high spatiotemporal heterogeneity. The potential anammox activities measured in the present work varied between 0.94 - 6.61nmol N g-1 dry sediment h-1, which were related to temperature, nitrite and anammox bacterial abundance. On the basis of the 15N tracing experiments, the anammox process was estimated to contribute 6.6 - 12.9 % to the total nitrogen loss whereas the remainder was attributed to denitrification.

  16. Environmental monitoring of the Zhujiang Estuary and its coastal waters

    Institute of Scientific and Technical Information of China (English)

    J. C. Chen(陈介中); L. Dong; L. A. Wong; G. W. Heinke

    2002-01-01

    The Zhujiang (Pearl River ) Estuary is a complex water system whose catchments basin coveers a very large part of southern China. The large quantity of fresh water carried by the river system flows into the northern coast of the South China Sea through its eight inlets. The Zhujiang River Delta has experienced the fastest economic growth in China during the past two decades. Rapid population expansion and increased industrial development coupled with insufficient waste management turned the Zhujiang Estuary into waste disposal channels just before entering the coastal waters. The water quality of the estuaries and the coastal oceans has become polluted. Dttfing the past two years, an intensive study and monitoring efforts of the pollutions of these waters have been made. A systematic and integrated monitoring task including shore-based measurements, shipboard in-situ measurements, and satellite and radar remote sensing surveys has been completed. Conprehensive collection of physical,chemical and biological parameters has been accomplished and a database has been established. Unlike the previous large scale-monitoring task in which the various pollutant concentrations were the objective,the present study aims to understand the process of the pollution from their initial disposal to their final states. The understanding of the processes makes it possible to evaluate the severity of the pollution with respect to the sustainability. Also the objective is to incorporate these processes into the mathematical models from which a predictive capability of the pollution situation can be realized. The present presentation will describe the planning, methodology and the results of this effort.

  17. Heavy Metals (Cd, Cu, Cr, Pb and Zn) in Meretrix meretrix Roding, Water and Sediments from Estuaries in Sabah, North Borneo

    Science.gov (United States)

    Abdullah, Mohd. Harun; Sidi, Jovita; Aris, Ahmad Zaharin

    2007-01-01

    Concentrations of heavy metals (Cd, Cu, Cr, Pb and Zn) in tissues of Meretrix meretrix Roding (M. meretrix R.), water and sediments from two estuaries were determined. One estuary is located in an urban area of Kota Kinabalu (Likas estuary) and the other in a rural district of Kota Belud (Kota Belud estuary), where both are in Sabah, North of…

  18. Influence of habitat structure and mouth dynamics on avifauna of intermittently-open estuaries: A study of four small South African estuaries

    Science.gov (United States)

    Terörde, Anja I.; Turpie, Jane K.

    2013-07-01

    Habitat composition was a major factor in determining waterbird species composition and abundance, particularly the area of floodplain and vegetated channel in four intermittently open estuaries (IOEs) in the warm-temperate coastal biogeographical region of South Africa. Average bird densities on the four estuaries varied from 0.5 to 4.2 birds per hectare, and community composition differed significantly between estuaries. However, the considerable variation in abundance of macrophytes did not have a detectable effect on waterbirds. Under closed mouth conditions, piscivorous birds dominated the avifauna. Each estuary's avifauna responded differently in terms of changes in feeding guild composition when the mouth opened. Bird abundance changed immediately after breaching, but not consistently. Diversity was significantly higher under open-mouth conditions for three of the four estuaries, and species composition was significantly different from that under closed-mouth conditions at all four estuaries. Changes in mouth dynamics as a result of climate change, water abstraction and artificial breaching could lead to significant changes in estuarine fauna.

  19. The importance of estuary head waters as nursery areas for young estuary- and marine-spawned fishes in temperate South Africa

    Science.gov (United States)

    Wasserman, Ryan J.; Strydom, Nadine A.

    2011-07-01

    The restriction of freshwater flow into estuaries, the presence of in-stream barriers and the occurrence of invasive fish species in these habitats are identified as major threats to these young estuary- and marine-spawned fish species. These aspects have been investigated using the distribution and abundance of young estuary- and marine-spawned fish species in the headwater environments of four permanently open estuaries of the Eastern Cape, South Africa. Fishes were collected twice per season over the 2009 and 2010 period, using mixed method sampling with seine net hauls and overnight fyke net deployments. Of the 74,751 fishes collected, 37,444 fishes, 18 families and 34 species were taken in fyke net catches, while 34,308 fishes, 21 families and 38 species were caught in seine nets. In the Great Fish, Kowie, Kariega and Sundays River systems, juveniles of estuarine residents dominated headwater catches, followed by juveniles of estuary-dependent marine species. The prevalence of larval and small juvenile stages of estuary- and marine-spawned fish species highlights the potential importance of these transitional areas for young fish.

  20. Primary productivity in Mandovi-Zuari estuaries in Goa

    Digital Repository Service at National Institute of Oceanography (India)

    KrishnaKumari, L.; Bhattathiri, P.M.A.; Matondkar, S.G.P.; John

    -1 Primary productivity in Mandovi-Zuari estuaries in Goa L. Krishna Kumari, P. M. A. Bhattathiri, S.G.P. Matondkar and Julie John National Institute of Oceanography, Dona Paula, Goa - 403 004, India Abstract Measurement on primary production.... The annual net primary production works out to be 632.9 gC/m2 at St. 1, 224.9 g/m2 at St. 2, and 299.67 gC/m2 at S. 3. Scatter diagram of chl , phytoplankton cell numbers and primary production ver- sus salinity at different stations are given in Fig 4...

  1. Bacterioplankton production in dilution zone of the Changjiang (Yangtze) Estuary

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hacterioplankton production and bacterioplankton abundance were surveyed in dilution zone of the Changjiang Estuary and a mesocosm experimental device for enriched phosphate experiment and oil contaminated experiment was placed in the waters nearby Luhua Island during October 1997 and May 1998. The results showed that the average bacterioplankton production in spring was higher than that in autumn, the production at the surface water was higher than that at the bottom in the surveyed area; the higher values appeared in the middle of the area. The results from mesocosm experiment with adding phosphate and oil contaminated showed that the bacterioplankton production increased rising trend day by day during the experiment period.

  2. The Mattole River Estuary: Restoration Efforts in a Dynamic System

    Science.gov (United States)

    Barber, D.; Liquori, M.

    2010-12-01

    Despite extensive scientific advancement integrating our understanding of hydrology, geomorphology, and ecology in recent decades, the application of restoration in the field has been slow to evolve. This presentation will highlight 20 years of restoration practices in the Mattole River Estuary and how these practices have informed our understanding of this complex system. The Mattole River Watershed is a 304 square-mile basin located near the Mendocino Triple Junction in a remote region of California known as the “The Lost Coast” for its rugged mountains and undeveloped coastline. In addition to numerous species of fish, mammals, and over 250 bird species, the Mattole Watershed is home to three Federally-listed Threatened salmonids: California Coastal Chinook salmon, Southern Oregon/Northern California Coasts coho salmon, and Northern California steelhead trout. The 64 mile-long river meets the Pacific Ocean at the northern end of the 64,000 acre King Range National Conservation Area (KRNCA), managed by the Bureau of Land Management (BLM). The watershed is dynamic, with some of the nation’s highest annual rainfall (mean = 158 cm/yr), naturally occurring steep slopes, erosive sedimentary geology, and frequent earthquakes. All of these factors have amplified the negative effects of extensive logging and associated road building between 1945 and 1970, which left a legacy of increased sediment loads and high water temperatures that have yet to recover to pre-disturbance levels, severely impairing riparian and aquatic habitats. Prior to major land disturbances, the Mattole estuary/lagoon was notable for its deep, thermally-stratified pools and numerous functioning north and south bank slough channels that flushed sediments from the river and received marine water. As flows decline in late spring, a sandbar closes off surface flow from the river to the Pacific Ocean, forming a lagoon, which persists until flows increase in the fall. Today, the estuary is poor

  3. Hydrodynamics and Water Quality: Modeling Rivers, Lakes, and Estuaries

    Science.gov (United States)

    Opdyke, Daniel

    2008-09-01

    The modeling of lakes, rivers, and estuaries is a fascinating subject that combines interesting facets of mathematics, statistics, physics, chemistry, and biology. Because of the complexity of natural systems, such modeling is always an approximation of the real world-and sometimes not a very good one. It is for this reason that modeling is not just science but also art. It is also for this reason that there are few good texts offering practical advice on modeling. Hydrodynamics and Water Quality makes a valiant attempt but is only partially successful because of the book's narrow focus on one family of models and an inconsistent presentation.

  4. Fatty acids in recent sediments in the St. Lawrence estuary

    Science.gov (United States)

    Rodier, L.; Khalil, M. F.

    1982-11-01

    Surface sediments along the Rimouski section in the St. Lawrence estuary were sampled at the surface and at 10 cm depth. Fatty acids were extracted and analysed. Saturated and unsaturated fatty acid contents at the two depths vary with the nature of the sediments. The clay sediments rich in organic matter contain more fatty acids than the corresponding sand or gravel. Unsaturated fatty acids were more abundant in the surface sediments. Some iso- and anteiso-odd carbon fatty acids were detected in the sediments; these acids could indicate a microbial activity. Correlation is made with the fatty acid contents of the water column together with the surface microlayer of the estuarine water.

  5. Finite element solution methods for circulation in estuaries

    Science.gov (United States)

    Walters, Roy A.; Laible, J. P.; Brebbia, C.A.; Gray, W.; Pinder, G.

    1984-01-01

    In this paper, the shallow water equations are used to approximate the depth-mean circulation in estuaries.  The time scales of the motions can be conveniently divided into three ranges: 1) low-frequency (residual) variations with periods of two days or longer, 2) tidal-frequency variations, and 3) high-frequency variations with periods of an hour or shorter.  The emphasis here will be on the tidal-period variations that are characterized by line spectra and thus allow a harmonic decomposition of the governing equations.

  6. The environment that conditions the Mandovi and Zuari estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Shankar, D.; Neetu, S.; Suprit, K.; Michael, G.S.; Chandramohan, P.

    to the health of the estuarine networks and their ability to absorb additional impacts has gained importance. Addressing these issues requires understanding of how these estuaries June 13, 2007 19:40 RPS rpb001ch01 6 S. R. SHETYE ET AL. work, i.e., how... of the world, including the area along the coastline of the Indian subcontinent. The effect of the phenomenon is felt over both land and sea. Aparna et al. (2005), quoting earlier studies, noted that the landward extent along the Indian coast is 110?150 km...

  7. The herbicide Glyphosate affects nitrification in the Elbe estuary, Germany

    Science.gov (United States)

    Sanders, Tina; Lassen, Stephan

    2015-04-01

    The Elbe River is one of the biggest European rivers discharging into the North Sea. It also transports high amounts of nutrients and pollutants like pesticides. Important source regions of both nutrients and pollutants are located within the river catchment, which is dominated by agricultural land-use. From these agricultural soils, pesticides can be carried via the river and estuary into the North Sea. Glyphosate (N-(phosphonomethyl) glycine) is the most commonly used herbicide worldwide and mainly used to regulate unwanted plant growth and for the expedition of crop ripening. In Germany, ~ 6000 tons of glyphosate are applied yearly in agriculture and private use. Glyphosate is degradable by microorganisms and has a half-life in water of 35 to 60 days. This herbicide specifically inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), an enzyme that catalyzes the biosynthesis of essential aromatic amino acids in plants, fungi, and bacteria. Nitrifying bacteria, which play an important role in the internal nitrogen cycling in the Elbe estuary, also possess this enzyme. The aim of our study was to quantify the concentration of glyphosate in water and sediment samples of the Elbe to get an overview about relevant environmental levels and to assess the impact of glyphosate on inhibition of nitrifying activities. To quantify the effect of glyphosate on nitrification activity, natural samples as well as pure cultures of Nitrosomonas europea (strain Nm50) were incubated with different concentrations of glyphosate over a period of some weeks. The nitrifying activity was determined according to changes of the nitrite and nitrate concentration as well as the cell number. Glyphosate was detectable in water and sediment samples in the Elbe estuary with up to 5 ppb mainly in the Port of Hamburg region. In both incubation experiments an inhibiting effect of glyphosate on nitrification could be shown. The incubated natural water sample was affected by a glyphosate

  8. Measurement frequency and sampling spatial domains required to characterize turbidity and salinity events in the Guadalquivir estuary (Spain

    Directory of Open Access Journals (Sweden)

    E. Contreras

    2012-08-01

    Full Text Available Estuaries are complex systems in which long water quality data series are not always available at the proper scale. Data proceeding from several water quality networks, with different measuring frequencies (monthly, weekly and 15 min and different numbers of sampling points, were compared throughout the main channel of the Guadalquivir estuary. Higher frequency of turbidity sampling in the upper estuary is required. In the lower estuary, sampling points help to find out the ETM, and higher frequency sampling of EC is required because of the effect of the tidal and river components. This could be a feedback for the implementation of monitoring networks in estuaries.

  9. Phytoplankton of the Swan-Canning Estuary: a comparison of nitrogen uptake by different bloom assemblages

    Science.gov (United States)

    Horner Rosser, S. M. J.; Thompson, Peter A.

    2001-09-01

    Spring chlorophyte-, summer dinophyte- and autumn cryptophyte-dominated phytoplankton blooms occurring in the upper reaches of the Swan-Canning Estuary have been studied to compare species composition and diurnal distribution and to determine preferential uptake rates for different nitrogen sources. Species distribution patterns over diurnal cycles showed dinophyte and cryptophyte species exhibiting diurnal vertical migration patterns which changed over a three-week bloom period. The dinophyte and cryptophyte behaviour appeared to be related to measured changes in ambient nitrogen profiles over the course of the bloom. Chlorophyte species were not shown to be strongly migratory over diurnal periods. Absolute uptake rates (, approximating Pmax) for nitrogen, in the form of 15NO3-, 15NH4+ or 15N-urea, were compared between seasonal bloom assemblages and ranged between 0·02 and 12 µg N l-1 h-1 (NO3 0·02-7; NH4 0·4-9; urea 0·1-12 µg N l-1Ambient NHambient NH

  10. Calidad ambiental interior: bienestar, confort y salud

    Directory of Open Access Journals (Sweden)

    Francisco Vargas Marcos

    2005-01-01

    Full Text Available Distintas formas de interpretar las condiciones ambientales han llevado al desarrollo de conceptos tales como edificio enfermo, calidad del aire o calidad ambiental interior, todos ellos encaminados a entender la complejidad de los contaminantes en los ambientes cerrados y las implicaciones sobre la salud de la población. La propuesta de "Calidad ambiental interior" es un avance conceptual y operativo que supera ampliamente a los anteriores, puesto que orienta las acciones hacia ambientes saludables sin limitar al aire la idea de contaminación. El objetivo del trabajo es identificar las competencias y el marco legislativo que permiten actuar en la prevención de riesgos asociados a la exposición de contaminantes en ambientes interiores. Óptimas condiciones en los ambientes interiores deben redundar en salud, bienestar y confort, tanto en lo que respecta a la vida laboral como a los ámbitos donde se desarrollan las actividades cotidianas extralaborales, escolares, de descanso y de ocio. La sociedad actual exige lugares seguros, limpios y bien climatizados, para lo que es necesario integrar percepciones y exigencias de los habitantes y alcanzar un óptimo equilibrio entre estándares sociales, uso de la energía y desarrollo sostenible, buscando confort sin contaminar y sin aumentar el consumo de fuentes energéticas que degraden el medio ambiente. El desarrollo legislativo se orienta a la seguridad y la salud en los lugares de trabajo y la regulación de las sustancias químicas. La Sanidad Ambiental lleva a cabo tareas de prevención y control, participa en la ejecución de convenios internacionales de reducción de contaminantes y desechos y promueve acciones para el desarrollo de la Estrategia Europea de Salud y Medio Ambiente.

  11. Residual fluxes of water and nutrient transport through the main inlet of a tropical estuary, Cochin estuary, West Coast, India.

    Science.gov (United States)

    Vinita, J; Lallu, K R; Revichandran, C; Muraleedharan, K R; Jineesh, V K; Shivaprasad, A

    2015-11-01

    Determining robust values for estuarine material fluxes has been a complex task and an interdisciplinary research challenge. With the advent of acoustic Doppler profilers (ADPs) having bottom-track capability and which provides three-dimensional current velocity profiles, more accurate estimation of cross-sectional fluxes is far accomplished in unsteady and bidirectional flow conditions of estuaries. This paper reports for the first time the discharge measurements conducted across Cochin inlet using ADP to examine the spring-neap variability in residual fluxes of water and nutrients during dry season. Cross-sectional current velocity profiles and salinity profiles were captured using ADP and conductivity temperature depth (CTD) instrumentation. Samples of surface and bottom water were also collected at 3-h intervals. The results indicated that there is a distinct transition from the neap to spring tides related to flow and salinity structure. The neap tide was partially mixed with large diurnal inequalities whereas the spring tide was well-mixed with symmetric tides. During ebb, an increase in the concentrations of nitrate, nitrite, phosphate, and silicate was noticed indicating upstream sources for their inputs. In contrast, elevated levels of ammonia were found in the estuary throughout the period of observation. There was net residual outflow during both tides, and the computed residual water fluxes of neap doubled that of spring. The strong ebb currents and the increased nutrient concentrations during ebb resulted in the export of all nutrients (except ammonia during spring) into the sea. The findings of this study highlight the consequences of anthropogenic interventions in the estuary and their effects on the fluxes of ecologically relevant substances. PMID:26446129

  12. Development of an estuarine assessment scheme for the management of a highly urbanised catchment/estuary system, Sydney estuary, Australia.

    Science.gov (United States)

    Birch, G F; Gunns, T J; Chapman, D; Harrison, D

    2016-05-01

    As coastal populations increase, considerable pressures are exerted on estuarine environments. Recently, there has been a trend towards the development and use of estuarine assessment schemes as a decision support tool in the management of these environments. These schemes offer a method by which complex environmental data is converted into a readily understandable and communicable format for informed decision making and effective distribution of limited management resources. Reliability and effectiveness of these schemes are often limited due to a complex assessment framework, poor data management and use of ineffective environmental indicators. The current scheme aims to improve reliability in the reporting of estuarine condition by including a concise assessment framework, employing high-value indicators and, in a unique approach, employing fuzzy logic in indicator evaluation. Using Sydney estuary as a case study, each of the 15 sub-catchment/sub-estuary systems were assessed using the current scheme. Results identified that poor sediment quality was a significant issue in Blackwattle/Rozelle Bay, Iron Cove and Hen and Chicken Bay while poor water quality was of particular concern in Duck River, Homebush Bay and the Parramatta River. Overall results of the assessment scheme were used to prioritise the management of each sub-catchment/sub-estuary assessed with Blackwattle/Rozelle Bay, Homebush Bay, Iron Cove and Duck River considered to be in need of a high priority management response. A report card format, using letter grades, was employed to convey the results of the assessment in a readily understood manner to estuarine managers and members of the public. Letter grades also provide benchmarking and performance monitoring ability, allowing estuarine managers to set improvement targets and assesses the effectiveness of management strategies. The current assessment scheme provides an effective, integrated and consistent assessment of estuarine health and

  13. Context Dependent Analysis of BioAmbients

    DEFF Research Database (Denmark)

    Pilegaard, Henrik; Nielson, Flemming; Nielson, Hanne Riis

    2006-01-01

    BioAmbients is a derivative of mobile ambients that has shown promise of describing interesting features of the behaviour of biological systems. The technical contribution of this paper is to extend the Flow Logic approach to static analysis with a couple of new techniques in order to give precise...... information about the behaviour of systems written in BioAmbients. Applying the development to a simple model of a cell releasing nutrients from food compunds we illustrate how the proposed analysis does indeed improve on previous efforts....

  14. Economía y medio ambiente

    OpenAIRE

    Ciro Alfonso Serna Mendoza

    2010-01-01

    En ciertos escenarios académicos, políticos, sociales y ambientales se declara que el modelo económico dominante o los conceptos que lo integran son responsables de que el bienestar económico implique malestar ecológico.Al partir de este supuesto, una forma de comprender las causas y de contribuir a la solución de la problemática ambiental es develar en qué consisten, en qué términos plantean la relación ombre-medio ambiente, las propuestas que incluyen la dimensión ambiental en el campo de l...

  15. Ecología y ambiente

    OpenAIRE

    Malacalza, Leonardo

    2013-01-01

    Ecología y Ambiente es un libro que hemos escrito para quienes comienzan estudios universitarios y también para todos los que estén interesados en iniciarse en temas del medio ambiente. Los contenidos del libro están divididos en dos partes; en la primera estudiamos temas básicos de biología y los fundamentos de la teoría ecológica; en la segunda se describen y analizan algunos grandes temas directamente relacionados con el medio ambiente en que vivimos. Sobre tales temas hemos invitado a ...

  16. Sedimentology and ichnology of the fluvial reach to inner estuary of the Ogeechee River estuary, Georgia, USA

    Science.gov (United States)

    Shchepetkina, Alina; Gingras, Murray K.; Pemberton, S. George

    2016-08-01

    Through the integration of sedimentological and ichnological observations, this paper explores the character of sediments deposited across the fluvio-tidal transition zone of the upper microtidal, mixed-energy, sand-dominated Ogeechee River estuary, Georgia, USA. A transect of tidally influenced to fluvial channel-bars and their facies variability is reported. Field and laboratory methods were employed, including observation of physical and biogenic sedimentary structures on the point-bar surfaces and in trenches, collection of grab samples, suction and box coring, grain size and total organic carbon analyses, optical microscopy, core logging, and daylight photography. The data presented in the paper can help in predicting facies changes across the fluvio-tidal transition of sand-dominated fluvio-tidal deposits in the rock record. The lower inner estuary is characterized by medium-fine and fine-medium sand with planar and trough cross-bedding, small-scale ripple lamination, tidal sedimentary structures (flaser and wavy bedding, herringbone cross-stratification), abundant organic debris, and mud rip-up clasts. Bioturbation of the intertidal point bars is low, but cryptobioturbation is locally observed. Upper inner estuary deposits comprise coarse-medium- and medium-coarse-grained sand, and are characterized by faint high-angle planar and trough cross-bedding. Organic debris, mud rip-up clasts, herringbone and current-ripple lamination are rarely observed. Bioturbation is absent to sparse. The fluvio-tidal transition is represented by very-coarse- to coarse-grained sand and granules. Physical sedimentary structures constitute massive, graded planar and trough cross-bedding with abundant plant detritus. Except for rare Siphonichnus- and Lockeia-like traces, bioturbation is absent. The fluvial setting is characterized by coarse-medium sand with unidirectional cross-bedding, current-ripple lamination, and rare organic-rich mud clasts. Bioturbation is absent. Inner

  17. Modeling Residual Circulation and Stratification in Oujiang River Estuary

    Institute of Scientific and Technical Information of China (English)

    LIN Wei-bo; WANG Yi-gang; RUAN Xiao-hong; XU Qun

    2012-01-01

    A 3D,time-dependent,baroclinic,hydrodynamic and salinity model was implemented and applied to the Oujiang River estuarine system in the East China Sea.The model was driven by the forcing of tidal elevations along the open boundaries and freshwater inflows from the Oujiang River.The bottom friction coefficient and vertical eddy viscosity were adjusted to complete model calibration and verification in simulations.It is demonstrated that the model is capable of reproducing observed temporal variability in the water surface elevation and longitudinal velocity,presenting skill coefficient higher than 0.82.This model was then used to investigate the influence of freshwater discharge on residual current and salinity intrusion under different freshwater inflow conditions in the Oujiang River estuary.The model results reveal that the river channel presents a two-layer structure with flood currents near the bottom and ebb currents at the top layer in the region of seawater influenced on north shore under high river flow condition.The river discharge is a major factor affecting the salinity stratification in the estuarine system.The water exchange is mainly driven by the tidal forcing at the estuary mouth,except under high river flow conditions when the freshwater extends its influence from the river's head to its mouth.

  18. Oxygen depletion off the Changjiang (Yangtze River)Estuary

    Institute of Scientific and Technical Information of China (English)

    LI; Daoji; (李道季); ZHANG; Jing; (张经); HUANG; Daji; (黄大吉); WU; Ying; (吴莹); LIANG; Jun; (梁俊)

    2002-01-01

    In a survey on the Yellow Sea and the East China Sea on August 20-30 of 1999, we found a hypoxic zone (<2 mg/L) of 13700 km2 with an average thickness of 20m at the bottom of the Changjiang (Yangtze River) Estuary, with an oxygen minimum value of 1 mg/L. The extension of the dissolved oxygen deficiency extended to the 100m isobath in a southeastward direction along the bottom of the continental shelf of the East China Sea. During the last two decades, the minimum dissolved oxygen values in the low oxygen region of the Changjiang Estuary have decreased from 2.85 mg/L to 1 mg/L. In the hypoxic zone, the apparent oxygen utilization (AOU) was 5.8 mg/L and the total oxygen depletion approximately 1.59×106 t. The strong halocline above the hypoxic zone, as a result of affluent water from the Changjiang, Taiwan Warm Current (TWC), and the high concentrations of particle organic carbon (POC) and nitrogen (PON) are the major factors causing the formation of the hypoxic zone. The POC: PON ratios and nutrient concentration distributions in the hypoxic zone suggest that the oxygen deficiency in the bottom water during the summer in the East China Sea off the Changjiang is the result of organic carbon production enhanced by nutrients from the Changjiang and fluvial organic matter input, followed by a shift in regeneration of nutrients in the East China Sea.

  19. Mathematical simulation of sediment and radionuclide transport in estuaries

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Y.; Trent, D.S.

    1982-11-01

    The finite element model LFESCOT (Flow, Energy, Salinity, Sediment and Contaminant Transport Model) was synthesized under this study to simulate radionuclide transport in estuaries to obtain accurate radionuclide distributions which are affected by these factors: time variance, three-dimensional flow, temperature, salinity, and sediments. Because sediment transport and radionuclide adsorption/desorption depend strongly on sizes or types of sediments, FLESCOT simulates sediment and a sediment-sorbed radionuclide for the total of three sediment-size fractions (or sediment types) of both cohesive and noncohesive sediments. It also calculates changes of estuarine bed conditions, including bed elevation changes due to sediment erosion/deposition, and three-dimensional distributions of three bed sediment sizes and sediment-sorbed radionuclides within the bed. Although the model was synthesized for radionuclide transport, it is general enough to also handle other contaminants such as heavy metals, pesticides, or toxic chemicals. The model was checked for its capability for flow, water surface elevation change, salinity, sediment and radionuclide transport under various simple conditions first, confirming the general validity of the model's computational schemes. These tests also revealed that FLESCOT can use large aspect ratios of computational cells, which are necessary in handling long estuarine study areas. After these simple tests, FLESCOT was applied to the Hudson River estuary between Chelsea and the mouth of the river to examine how well the model can predict radionuclide transport through simulating tidally influenced three-dimensional flow, salinity, sediment and radionuclide movements with their interactions.

  20. The occurrence of selected human pharmaceutical compounds in UK estuaries.

    Science.gov (United States)

    Thomas, Kevin V; Hilton, Martin J

    2004-09-01

    This report describes a scoping study conducted in order to establish whether pharmaceutical compounds may be present in UK estuaries. Surface water samples collected from five UK estuaries were analysed for the presence of 14 pharmaceutical compounds selected from the priority lists of the UK Environment Agency and the Oslo and Paris Commission (OSPAR). The pharmaceutical compounds/metabolites clofibric acid, clotrimazole, dextropropoxyphene, diclofenac, ibuprofen, mefenamic acid, propranolol, tamoxifen and trimethoprim were detected at measurable concentrations in the samples collected. The concentrations of erythromycin, lofepramine, paracetamol, sulfamethoxazole and acetyl-sulfamethoxazole were all below the limits of detection of the methods used (between 4 and 20 ng l(-1)). The anti-fungal agent clotrimazole was the most frequently detected at a maximal concentration of 22 ng l(-1) and a median concentration of 7 ng l(-1). The analgesic compound ibuprofen was detected at a maximal concentration of approximately 930 ng l(-1) and a median concentration of 48 ng l(-1), whilst the other pharmaceutical compounds were detected between the limits of detection of the method used and 570 ng l(-1). PMID:15325211

  1. Mathematical simulation of sediment and radionuclide transport in estuaries

    International Nuclear Information System (INIS)

    The finite element model LFESCOT (Flow, Energy, Salinity, Sediment and Contaminant Transport Model) was synthesized under this study to simulate radionuclide transport in estuaries to obtain accurate radionuclide distributions which are affected by these factors: time variance, three-dimensional flow, temperature, salinity, and sediments. Because sediment transport and radionuclide adsorption/desorption depend strongly on sizes or types of sediments, FLESCOT simulates sediment and a sediment-sorbed radionuclide for the total of three sediment-size fractions (or sediment types) of both cohesive and noncohesive sediments. It also calculates changes of estuarine bed conditions, including bed elevation changes due to sediment erosion/deposition, and three-dimensional distributions of three bed sediment sizes and sediment-sorbed radionuclides within the bed. Although the model was synthesized for radionuclide transport, it is general enough to also handle other contaminants such as heavy metals, pesticides, or toxic chemicals. The model was checked for its capability for flow, water surface elevation change, salinity, sediment and radionuclide transport under various simple conditions first, confirming the general validity of the model's computational schemes. These tests also revealed that FLESCOT can use large aspect ratios of computational cells, which are necessary in handling long estuarine study areas. After these simple tests, FLESCOT was applied to the Hudson River estuary between Chelsea and the mouth of the river to examine how well the model can predict radionuclide transport through simulating tidally influenced three-dimensional flow, salinity, sediment and radionuclide movements with their interactions

  2. A numerical study of local variations in tidal regime of Tagus estuary, Portugal.

    Directory of Open Access Journals (Sweden)

    João Miguel Dias

    Full Text Available Tidal dynamics of shallow estuaries and lagoons is a complex matter that has attracted the attention of a large number of researchers over the last few decades. The main purpose of the present work is to study the intricate tidal dynamics of the Tagus estuary, which states as the largest estuary of the Iberian Peninsula and one of the most important wetlands in Portugal and Europe. Tagus has large areas of low depth and a remarkable geomorphology, both determining the complex propagation of tidal waves along the estuary of unknown manner. A non-linear two-dimensional vertically integrated hydrodynamic model was considered to be adequate to simulate its hydrodynamics and an application developed from the SIMSYS2D model was applied to study the tidal propagation along the estuary. The implementation and calibration of this model revealed its accuracy to predict tidal properties along the entire system. Several model runs enabled the analysis of the local variations in tidal dynamics, through the interpretation of amplitude and phase patterns of the main tidal constituents, tidal asymmetry, tidal ellipses, form factor and tidal dissipation. Results show that Tagus estuary tidal dynamics is extremely dependent on an estuarine resonance mode for the semi-diurnal constituents that induce important tidal characteristics. Besides, the estuarine coastline features and topography determines the changes in tidal propagation along the estuary, which therefore result essentially from a balance between convergence/divergence and friction and advection effects, besides the resonance effects.

  3. Understanding the fate of iron in a modern temperate estuary: Leirarvogur, Iceland

    International Nuclear Information System (INIS)

    Highlights: → Fluvial Fe (aq) and Fe (total) concentrations drop upon mixing with seawater in estuaries. → The majority of Fe in estuaries is lost in the bay-head delta. → Our results suggest that the bay-head delta is a key location in Fe-mineral formation. → Isotopic variation in estuarine waters may play a role in the formation of Fe-minerals. - Abstract: Fluvial dissolved Fe concentrations decrease upon mixing with seawater, resulting in the formation of Fe-floccules. However, a clear understanding of the fate of these floccules has yet to be established. Assessing how tidal processes affect the formation of Fe-colloids in the Leirarvogur estuary, SW Iceland, is an important step in understanding the formation and potential deposition of estuarine Fe-rich minerals within this estuarine system. The Leirarvogur estuary drains predominately Fe-rich basalt, increasing the likelihood of detecting changes in Fe-phases. Fluvial waters and local lake waters that drain into the estuary were compared and the effects of seasonal changes were considered, in an attempt to understand how varying end-members and external factors play a role in Fe-rich mineral formation. Aqueous and colloidal Fe concentrations were found to be greater towards the head of the Leirarvogur estuary, suggesting that potential Fe-rich minerals and complexes are forming at sites of fluvial input. Increasing suspended colloidal Fe towards the estuary mouth suggests that Fe-colloids are readily transported seaward.

  4. Assessment of heavy metals bioavailability and toxicity toward Vibrio fischeri in sediment of the Huelva estuary.

    Science.gov (United States)

    Rosado, Daniel; Usero, José; Morillo, José

    2016-06-01

    Relationship between toxicity and bioavailable metals in sediments from the Huelva estuary and its littoral of influence was analyzed. Toxicity was assessed with Microtox(®) bioassay using a marine luminescent bacterium: Vibrio fischeri. Bioavailable metals were considered as both, acid extractable fraction of BCR procedure and the sum of exchangeable and bound to carbonates fractions of Tessier sequential extraction. A bioavailable metals index was calculated to integrate results in a single figure. Toxicity and bioavailable metals showed a similar pattern. Higher levels were found in the estuary than in the littoral (140 TU/g). In Huelva estuary, highest levels were found in the Tinto estuary (5725 TU/g), followed by the Odiel estuary (5100 TU/g) and the Padre Santo Canal (2500 TU/g). Results in this area were well over than those in nearby estuaries. Furthermore, they are similar to or even higher than those in other polluted sediments around the world. Bioavailable metal index showed a stronger correlation with acid extractable fraction of BCR (R(2) = 0.704) than that for the sum of exchangeable and bound to carbonates fractions of Tessier (R(2) = 0.661). These results suggest that bioavailable metals are an important source of sediment toxicity in the Huelva estuary and its littoral of influence, an area with one of the highest mortality risks of Spain. PMID:27002282

  5. Trace elements and radionuclides in the Connecticut River and Amazon River estuary

    International Nuclear Information System (INIS)

    The Connecticut River, its estuary, and the Amazon River estuary were studied to elucidate some of the processes which control river water chemistry and the flux of elements to the sea. The approach taken was to identify inputs to the Connecticut River and to investigate geochemical processes which modify the dissolved load. The form and quantity of nuclides which are in turn supplied to the estuary are altered by processes unique to that transition zone to the ocean. The Connecticut River estuary was sampled on a seasonal basis to investigate the role of the estuary in controlling the flux of elements to the sea. The knowledge gained from the Connecticut River study was applied to the quantitatively more significant Amazon River estuary. There a variety of samples were analyzed to understand the processes controlling the single greatest flux of elements to the Atlantic Ocean. The results indicate that estimates of the total flux of nuclides to the oceans can best be calculated based on groundwater inputs. Unless significant repositories for nuclides exist in the river-estuarine system, the groundwater flux of dissolved nuclides is that which will eventually be delivered to the ocean despite the reactions which were shown to occur in both rivers and estuaries. 153 references, 63 figures, 28 tables

  6. Pollutant Flux Estimation in an Estuary Comparison between Model and Field Measurements

    Directory of Open Access Journals (Sweden)

    Yen-Chang Chen

    2014-08-01

    Full Text Available This study proposes a framework for estimating pollutant flux in an estuary. An efficient method is applied to estimate the flux of pollutants in an estuary. A gauging station network in the Danshui River estuary is established to measure the data of water quality and discharge based on the efficient method. A boat mounted with an acoustic Doppler profiler (ADP traverses the river along a preselected path that is normal to the streamflow to measure the velocities, water depths and water quality for calculating pollutant flux. To know the characteristics of the estuary and to provide the basis for the pollutant flux estimation model, data of complete tidal cycles is collected. The discharge estimation model applies the maximum velocity and water level to estimate mean velocity and cross-sectional area, respectively. Thus, the pollutant flux of the estuary can be easily computed as the product of the mean velocity, cross-sectional area and pollutant concentration. The good agreement between the observed and estimated pollutant flux of the Danshui River estuary shows that the pollutant measured by the conventional and the efficient methods are not fundamentally different. The proposed method is cost-effective and reliable. It can be used to estimate pollutant flux in an estuary accurately and efficiently.

  7. Carbon budgets for two Portuguese estuaries: implications for the management and conservation of coastal waters

    Directory of Open Access Journals (Sweden)

    Ana P. Oliveira

    2014-07-01

    The results presented illustrate that Tagus and Sado estuaries represent an important land/ocean boundary for carbon transformation and emission, and confirm the anthropogenic pressure that these estuaries are subject to. Carbon budgets vary markedly within and between these two estuaries reflecting the human pressure. Anthropogenic inputs, autochthonous carbon production and primary production are indicated as the main responsible for the carbon production within the estuaries. Both estuaries export carbon to the ocean and to the atmosphere. The inorganic carbon faction has a major role in the carbon budget, enriching the ocean in carbon dioxide, contributing this for the greenhouse effect. Our understanding of organic and inorganic carbon fluxes in Tagus and Sado estuaries is vital for an efficient protection and preservation of such ecosystems being helpful in limit human-caused damage and in restoring damaged estuarine/coastal ecosystems. In addition, the economic impact of the carbon fluxes to the atmosphere, estimated as €375,000 per year, creates the appropriate incentives to reduce emissions and shift them to higher-value uses. Suggesting, therefore, a coastal management re-oriented towards a more adaptive approach through the use of carbon market-based policies. This study is a contribution to the integration of coastal and global carbon cycles. However, additional efforts are required to fully merge other components subsystems, such as salt marshes, with these budgets. Moreover, a fully comprehension of the community metabolism in these estuaries will greatly improve this integration.

  8. Estimation of total suspended matter in the Zhujiang (Pearl)River estuary from Hyperion imagery

    Institute of Scientific and Technical Information of China (English)

    LIU Dazhao; FU Dongyang; XU Bing; SHEN Chunyan

    2012-01-01

    Although remote sensing data have been used to estimate total suspended matter (TSM) in coastal waters,it has limitations when applied to estuary waters in low spatial resolution situations.The spatial resolution of ocean color satellites such as SeaWiFS and MODIS is usually ~1 km,and therefore is not adequate for small,local-scale areas such as the Zhujiang (Pearl) River estuary.In contrast,30 m-resolution EO-1 Hyperion imagery has potential for studying TSM in localized areas.We measured the surface spectral radiance reflectance of the river estuary water in the visible and near infra-red spectral range.Sensitivity analysis indicated that the ratio of remote sensing reflectance at 813 nm (Rrs(813)) to reflectance at 559 nm (Rrs(559)) could be used to estimate TSM concentration,and a linear relationship was established between the ratio and in-situ TSM concentration.We applied the linear relationship to Hyperion imagery to map TSM concentration in the estuary.The Hyperion imagery provided sufficient spatial resolution to detect spatiotemporal changes in TSM concentrations in the estuary small estuary area.This study demonstrated the usefulness of Hyperion imagery for mapping the distribution of TSM in estuary waters.

  9. Trophic interactions of Platichthys flesus and Solea solea juveniles in the Lima estuary nursery (NW Portugal

    Directory of Open Access Journals (Sweden)

    Cláudia Mendes

    2015-12-01

    Full Text Available Trophic interactions play a key role in nursery habitats, and by affecting growth and condition of the juveniles, may control the quality of a given estuarine nursery. This study investigated the trophic ecology of flounder (Platichthys flesus and common sole (Solea solea juveniles in the Lima estuary nursery. Feeding location, main organic matter sources, and prey of the target species were assessed by carbon (δ13C and nitrogen (δ15N stable isotopes, as well as by stomach content analysis. The juveniles, macroinvertebrates, and sediment and water column samples were collected in August 2014 in the lower, middle and upper sections of the Lima estuary. The diet of 0+ flounder relied upon prey from the upper estuary (salinity >5, namely Chironomid larvae and Corophium spp. which showed the role of the upper estuary prey to the 0+ flounder diet and suggest the relative site fidelity of the young juveniles. In contrast, 1+ flounder juveniles had a diverse diet based on bivalves, polychaetes and crustaceans, and a variable stable isotope signature indicating they fed in different areas along the estuary. The 1+ sole juveniles also fed on polychaetes, crustaceans, and bivalves, but the stable isotope values suggested a dependence on the lower estuary (salinity >30 and marine food web sources. Such differential use of food may be understood as a strategic approach to reduce intra- and interspecific competition and thus ensuring the use of Lima estuary as nursery area for these two flatfish species.

  10. 2011 NATA - Risks and Annual Ambient Concentrations

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes the modeled annual ambient concentrations and risks at the census tract level for the 2011 National Air Toxics Assessment. All concentrations...

  11. Economía y medio ambiente

    Directory of Open Access Journals (Sweden)

    Ciro Alfonso Serna Mendoza

    2010-12-01

    Full Text Available En ciertos escenarios académicos, políticos, sociales y ambientales se declara que el modelo económico dominante o los conceptos que lo integran son responsables de que el bienestar económico implique malestar ecológico.Al partir de este supuesto, una forma de comprender las causas y de contribuir a la solución de la problemática ambiental es develar en qué consisten, en qué términos plantean la relación ombre-medio ambiente, las propuestas que incluyen la dimensión ambiental en el campo de la economía. Y si, al igual que las teorías ambientales, acuden a la ética como factor adecuado para disminuir las externalidades negativas generadas en el ambiente por la actividad económica.

  12. Evaluation of abiotic stresses of temperate estuaries by using resident zooplankton: A community vs. population approach

    Science.gov (United States)

    Paul, Sourav; Wooldridge, Tris; Perissinotto, Renzo

    2016-03-01

    By using permanently resident zooplankton, we assessed the ecological level (i.e. community and or population) that provides more in-depth indication of the stress related to salinity and temperature fluctuations in temperate estuaries. In the semi-arid warm temperate South Africa, the Gamtoos estuary experiences a full salinity gradient maintained by irregular but relatively frequent freshwater pulses, whereas the Kromme estuary is euhaline throughout its extent and receives only occasional freshwater inputs when the storage reservoir six km upstream overtops. Changes in the species evenness index of Pielou and the abundances of estuarine resident zooplankton species were modelled against salinity and temperature variations of respective estuaries. In the Gamtoos estuary, response of individual populations provided more in-depth information regarding zooplankton variability. However the most abundant resident zooplankton i.e. Acartia longipatella a copepod was not the best predictor of the salinity and temperature fluctuations. Conversely, the Kromme estuary study provided insights into the potential vulnerability of the resident estuarine zooplankton community to cold. Further, the population level study exposed responses of specific species against salinity changes. We discuss the pros and cons of designing ecological indicators of abiotic stress based on specific species, targeted to specific ecological level, and needs of considering the frequency and magnitude of fresh water inflow in an estuary. A suggestion is to use specific taxonomic group(s) (e.g. Copepods) to better understand the abiotic stress factors of specific set of estuaries (e.g. freshwater rich/starved) until a 'one size fits all' indicator is found for temperate estuaries.

  13. Food web analysis in two permanently open temperate estuaries: consequences of saltmarsh loss?

    Science.gov (United States)

    Svensson, Carl J; Hyndes, Glenn A; Lavery, Paul S

    2007-09-01

    Saltmarsh vegetation, seston and microphytobenthos are all conspicuous components of most temperate estuaries and they potentially contribute to the estuarine food chain. Yet their relative contributions are unclear, as is the significance of saltmarsh losses through natural and human-induced impacts. This study aimed to quantitatively determine the contribution of various types of primary producers to detritus in the Walpole-Nornalup Estuary and Leschenault Inlet, two permanently open estuaries in SW Australia, and, estimate the flow of different types of detritus to higher trophic levels, using carbon ((13)C) and nitrogen ((15)N) stable isotopes as tracers. Results of the mixing model indicated that seston, microphytobenthos and to some extent seagrass and fringing saltmarsh were the main contributors to the detrital pool in both estuaries. However, the relative contribution of different primary producers varied both within and between estuaries. The contribution of saltmarsh was higher at sites close to rivers and dense fringing vegetation, while seston, microphytobenthos and seagrass dominated the detrital material at other sites. Benthic harpacticoid copepods were shown to feed on detritus though they appeared to actively select for different components of the detritus depending on site and estuary. Isotopic signatures of other consumers indicated that fish and invertebrates derived nutrients from MPB and detritus, either directly as food or indirectly through feeding on invertebrates. The overall contribution of saltmarsh to detritus was lower in Leschenault Inlet than in Walpole-Nornalup Estuary, possibly as a result of increased clearing of fringing vegetation around Leschenault Inlet. This pattern was however not reflected in harpacticoid food. Therefore, although losses of fringing saltmarsh around estuaries have the potential to significantly affect estuarine food webs, the significance of such losses will be site- and estuary-dependent. PMID:17382379

  14. Spatial Analysis of BioAmbients

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming; Pilegaard, Henrik

    2004-01-01

    Programming language technology can contribute to the development and understanding of Systems Biology by providing formal calculi for specifying and analysing the dynamic behaviour of biological systems. Our focus is on BioAmbients, a variation of the ambient calculi developed for modelling mobi...... mobility in computer systems. We present a static analysis for capturing the spatial structure of biological systems and we illustrate it on a few examples....

  15. Ambient air pollution and low birthweight

    DEFF Research Database (Denmark)

    Pedersen, Marie; Giorgis-Allemand, Lise; Bernard, Claire;

    2013-01-01

    BACKGROUND: Ambient air pollution has been associated with restricted fetal growth, which is linked with adverse respiratory health in childhood. We assessed the effect of maternal exposure to low concentrations of ambient air pollution on birthweight. METHODS: We pooled data from 14 population...... air pollutants and traffic during pregnancy is associated with restricted fetal growth. A substantial proportion of cases of low birthweight at term could be prevented in Europe if urban air pollution was reduced. FUNDING: The European Union....

  16. ANÁLISE DA QUALIDADE AMBIENTAL URBANA

    OpenAIRE

    Cíntia Minaki; Margarete Cristiane de Costa Trindade Amorim

    2012-01-01

    Con el intenso proceso de urbanización en Brasil, la calidad del medio ambiente se presenta como un factor extremadamente importante para evaluar las condiciones que los espacios urbanos pueden ofrecer a la población. En este sentido, este trabajo tuvo como objetivo verificar algunos de los indicadores ambientales urbanos en Guararapes, situada en el noroeste de Sao Paulo, con el fin de evaluar su calidad ambiental, con el objetivo de contribuir a sus estrategias de desarrollo. Los indicadore...

  17. Ambient ionization mass spectrometry: A tutorial

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Min-Zong; Cheng, Sy-Chi; Cho, Yi-Tzu [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Shiea, Jentaie, E-mail: jetea@fac.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Cancer Center, Kaohsiung Medical University, Kaohsiung, Taiwan (China)

    2011-09-19

    Highlights: {yields} Ambient ionization technique allows the direct analysis of sample surfaces with little or no sample pretreatment. {yields} We sort ambient ionization techniques into three main analytical strategies, direct ionization, direct desorption/ionization, and two-step ionization. {yields} The underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques are described and compared. - Abstract: Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food safety screening; detection of pharmaceuticals and drug abuse; monitoring of environmental pollutants; detection of explosives for antiterrorism and forensics; characterization of biological compounds for proteomics and metabolomics; molecular imaging analysis; and monitoring chemical and biochemical reactions). Electrospray ionization and atmospheric pressure chemical ionization are the two main ionization principles most commonly used in ambient ionization mass spectrometry. This tutorial paper provides a review of the publications related to ambient ionization techniques. We describe and compare the underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques.

  18. Trace metal partitioning over a tidal cycle in an estuary affected by acid mine drainage (Tinto estuary, SW Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Hierro, A. [Department of Physics, Universitat Autònoma de Barcelona, 08193 Bellaterra (Spain); Department of Applied Physics, Facultad de Ciencias Experimentales, University of Huelva, Campus de El Carmen, Campus de Excelencia Internacional del Mar CEIMAR, 21071 Huelva (Spain); Olías, M., E-mail: manuel.olias@dgyp.uhu.es [Department of Geodynamics and Paleontology, Facultad de Ciencias Experimentales, University of Huelva, Campus de El Carmen, Campus de Excelencia Internacional del Mar CEIMAR, 21071 Huelva (Spain); Cánovas, C.R. [Department of Geodynamics and Paleontology, Facultad de Ciencias Experimentales, University of Huelva, Campus de El Carmen, Campus de Excelencia Internacional del Mar CEIMAR, 21071 Huelva (Spain); Martín, J.E.; Bolivar, J.P. [Department of Applied Physics, Facultad de Ciencias Experimentales, University of Huelva, Campus de El Carmen, Campus de Excelencia Internacional del Mar CEIMAR, 21071 Huelva (Spain)

    2014-11-01

    The Tinto River estuary is highly polluted with the acid lixiviates from old sulphide mines. In this work the behaviour of dissolved and particulate trace metals under strong chemical gradients during a tidal cycle is studied. The pH values range from 4.4 with low tide to 6.9 with high tide. Precipitation of Fe and Al is intense during rising tides and As and Pb are almost exclusively found in the particulate matter (PM). Sorption processes are very important in controlling the mobility (and hence bioavailability) of some metals and particularly affect Cu below pH 6. Above pH ∼ 6 Cu is desorbed, probably by the formation of Cu(I)–chloride complexes. Although less pronounced than Cu, also Zn desorption above pH 6.5 seems to occur. Mn and Co are affected by sorption processes at pH higher than ca. 6. Cd behaves conservatively and Ni is slightly affected by sorption processes. - Highlights: • The Tinto estuary shows strong pH gradients and high trace elements concentrations. • PM has a hysteretic relationship with tides and high contents of Fe, Al, As and Pb. • Co and Mn are controlled by river and sea water mixing and sorption processes. • Sorption processes strongly affect Cu below pH 6, above this value Cu is desorpted. • Cadmium behaves conservatively along the pH range studied (4.4–6.9)

  19. Trace metal partitioning over a tidal cycle in an estuary affected by acid mine drainage (Tinto estuary, SW Spain)

    International Nuclear Information System (INIS)

    The Tinto River estuary is highly polluted with the acid lixiviates from old sulphide mines. In this work the behaviour of dissolved and particulate trace metals under strong chemical gradients during a tidal cycle is studied. The pH values range from 4.4 with low tide to 6.9 with high tide. Precipitation of Fe and Al is intense during rising tides and As and Pb are almost exclusively found in the particulate matter (PM). Sorption processes are very important in controlling the mobility (and hence bioavailability) of some metals and particularly affect Cu below pH 6. Above pH ∼ 6 Cu is desorbed, probably by the formation of Cu(I)–chloride complexes. Although less pronounced than Cu, also Zn desorption above pH 6.5 seems to occur. Mn and Co are affected by sorption processes at pH higher than ca. 6. Cd behaves conservatively and Ni is slightly affected by sorption processes. - Highlights: • The Tinto estuary shows strong pH gradients and high trace elements concentrations. • PM has a hysteretic relationship with tides and high contents of Fe, Al, As and Pb. • Co and Mn are controlled by river and sea water mixing and sorption processes. • Sorption processes strongly affect Cu below pH 6, above this value Cu is desorpted. • Cadmium behaves conservatively along the pH range studied (4.4–6.9)

  20. Intra- and inter-seasonal variability of nutrients in a tropical monsoonal estuary (Zuari, India).

    Digital Repository Service at National Institute of Oceanography (India)

    Anand, S.S.; Sardessai, S.; Muthukumar, C.; Mangalaa, K.R.; Sundar, D.; Parab, S.G.; DileepKumar, M.

    dissolved oxygen and nutrient variability in Zuari estuary have been studied for a year through a high resolution sampling strategy (comprising daily or alternate day measurements at a fixed location in the mid-estuary region and a transect along... facilitate well mixed water column. The effect of tides is found to reach upto Sanguem and even to 4 km upstream of Uguem (Shetye et al., 1999). Hence, in dry seasons the estuary transforms to an extended body of the sea. 2.2 Sampling Strategies We have...

  1. Linking biogeochemistry to hydro-geometrical variability in tidal estuaries: a generic modeling approach

    Science.gov (United States)

    Volta, Chiara; Gildas Laruelle, Goulven; Arndt, Sandra; Regnier, Pierre

    2016-03-01

    This study applies the Carbon-Generic Estuary Model (C-GEM) modeling platform to simulate the estuarine biogeochemical dynamics - in particular the air-water CO2 exchange - in three idealized tidal estuaries characterized by increasing riverine influence, from a so-called "marine estuary" to a "riverine estuary". An intermediate case called "mixed estuary" is also considered. C-GEM uses a generic biogeochemical reaction network and a unique set of model parameters extracted from a comprehensive literature survey to perform steady-state simulations representing average conditions for temperate estuaries worldwide. Climate and boundary conditions are extracted from published global databases (e.g., World Ocean Atlas, GLORICH) and catchment model outputs (GlobalNEWS2). The whole-system biogeochemical indicators net ecosystem metabolism (NEM), C and N filtering capacities (FCTC and FCTN, respectively) and CO2 gas exchanges (FCO2) are calculated across the three idealized systems and are related to their main hydrodynamic and transport characteristics. A sensitivity analysis, which propagates the parameter uncertainties, is also carried out, followed by projections of changes in the biogeochemical indicators for the year 2050. Results show that the average C filtering capacities for baseline conditions are 40, 30 and 22 % for the marine, mixed and riverine estuary, respectively, while N filtering capacities, calculated in a similar fashion, range from 22 % for the marine estuary to 18 and 15 % for the mixed and the riverine estuaries. Sensitivity analysis performed by varying the rate constants for aerobic degradation, denitrification and nitrification over the range of values reported in the literature significantly widens these ranges for both C and N. Simulations for the year 2050 suggest that all estuaries will remain largely heterotrophic, although a slight improvement of the estuarine trophic status is predicted. In addition, our results suggest that, while the

  2. Modeling 226Ra behaviour in a Spanish estuary affected by the phosphate industry

    International Nuclear Information System (INIS)

    The behaviour of 226Ra in a system like this estuary is complex since radionuclides are affected by tidal actions and interactions with sediments through adsorption/desorption reactions and erosion/deposition processes. A numerical 2D depth-averaged model of the estuary has been developed, including processes mentioned above. It has been applied to reproduce experimental data measured after a release from the industrial complex in the Odiel River and after an accidental release in the Tinto River from the gypsum piles. The model has also been applied to simulate the self-cleaning process observed in the estuary after the direct releases from the fertilizer complex were stopped

  3. A Numerical Study of Local Variations in Tidal Regime of Tagus Estuary, Portugal

    OpenAIRE

    Dias, João Miguel; Valentim, Juliana Marques; Sousa, Magda Catarina

    2013-01-01

    Tidal dynamics of shallow estuaries and lagoons is a complex matter that has attracted the attention of a large number of researchers over the last few decades. The main purpose of the present work is to study the intricate tidal dynamics of the Tagus estuary, which states as the largest estuary of the Iberian Peninsula and one of the most important wetlands in Portugal and Europe. Tagus has large areas of low depth and a remarkable geomorphology, both determining the complex propagation of t...

  4. Modelling nitrogen and phosphorus cycles and dissolved oxygen in the Zhujiang Estuary Ⅱ. Model results

    Institute of Scientific and Technical Information of China (English)

    Guan Weibing; Wong Lai-Ah; Xu Dongfeng

    2001-01-01

    In the present study, the ecosystem-based water quality model was applied to the Pearl River (Zhujiang) Estuary. The model results successfully represent the distribution trend of nutrients and dissolved oxygen both in the horizontal and vertical planes during the flood season, and it shows that the model has taken into consideration the key part of the dynamical, chemical and biological processes existing in the Zhujiang Estuary. The further studies illustrate that nitrogen is in plenty while phosphorus and light limit the phytoplankton biomass in the Zhujiang Estuary during the flood season.

  5. Carbon budgets for two Portuguese estuaries: implications for the management and conservation of coastal waters

    OpenAIRE

    Oliveira, Ana P

    2014-01-01

    Abstract: Carbon budgets vary markedly within and between Tagus and Sado estuaries reflecting the human pressure. These estuaries seem to generate carbon within a total of 0.13 MtC yr-1 for Tagus and 0.02 MtC yr-1 for Sado. Anthropogenic inputs, autochthonous carbon production and primary production are indicated as the main responsible for the carbon production within the estuaries. Carbon exported to the ocean and to the atmosphere by both estuarine systems is higher during the non-producti...

  6. Greenhouse gas (N2O) emission from Portuguese estuaries

    OpenAIRE

    Célia Gonçalves

    2014-01-01

    Abstract: The contribution of nitrous oxide (N2O) emissions to the estuarine nitrogen (N) balance are investigated for Tagus (May 2006), Minho and Lima estuaries (September 2006). N load to Tagus (3.48 Mg N yr-1) and Minho (3.25 Mg N yr-1) are similar in both estuaries but higher then Lima (0.34 Mg N yr-1), being well related to freshwater inflow. Estuaries act as sink of N. In Tagus and Minho most of the N is removed within the system (67% to 70%), while in Lima this value falls to 38.6 %. A...

  7. Food web dynamics in a temperate temporarily open/closed estuary (South Africa)

    Science.gov (United States)

    Froneman, P. W.

    2004-01-01

    Size fractionated chlorophyll- a (chl- a), primary production and zooplankton (mesozooplankton (200-2000 μm) and microheterotrophs (freshwater inflow into the estuary. The inflow of freshwater into the estuary also coincided with a shift in the size structure of the phytoplankton community with large cells (>5 μm) dominating total chl- a and production. During periods of reduced freshwater inflow into the estuary, total chl- a and production were dominated by small (preferred food particle size between the microheterotrophs and mesozooplankton.

  8. O meio ambiente no meio ambiente da TV brasileira: percursos histórico-discursivos

    OpenAIRE

    Gomes, Ana Ângela Farias; Pereira, Claudio Luiz

    2010-01-01

    Este trabalho propõe uma investigação das interrelações entre a temática ambiental e a produção televisiva brasileira. O objetivo é traçar um panorama histórico das produções que tratyam especificamente da questão ambiental, e perceber como o meio ambiente vem sendo tematizado pela televisão ao longo do tempo. Ao mesmo tempo, pereceber as correlações entre as transformações/significados que a temática ambiental vai passando e as operações dircursivas implicadas.

  9. Towards New Ambient Light Systems: a Close Look at Existing Encodings of Ambient Light Systems

    Directory of Open Access Journals (Sweden)

    Andrii Matviienko

    2015-10-01

    Full Text Available Ambient systems provide information in the periphery of a user’s attention. Their aim is to present information as unobtrusively as possible to avoid interrupting primary tasks (e.g. writing or reading. In recent years, light has been used to create ambient systems to display information. Examples of ambient light systems range from simple notification systems such as displaying messages or calendar event reminders, to more complex systems such as focusing on conveying information regarding health activity tracking. However, for ambient light systems, there is a broad design space that lacks guidelines on when to make use of light displays and how to design them. In this paper we provide a systematic overview of existing ambient light systems over four identified information classes derived from 72 existing ambient light systems. The most prominent encoding parameters among the surveyed ambient light systems are color, brightness, and their combination. By analyzing existing ambient light systems, we provide a first step towards developing guidelines for designing future ambient light systems.

  10. Biotecnologia Ambiental. Aplicacions biotecnològiques a la millora del medi ambient

    OpenAIRE

    Blanch i Gisbert, Anicet

    2010-01-01

    La biotecnología ambiental comprende el conjunto de actividades tecnológicas que facilitan la comprensión y la gestión de los sistemas biológicos en el medio ambiente, con el fin de proveer productos y servicios. Actualmente, la gestión del medio ambiente y de sus recursos naturales no se comprende si no se realiza de manera sostenible. Los avances científicos y tecnológicos le están permitiendo a la biotecnología ambiental, el desarrollo de nuevas herramientas y aplicaciones con los que resp...

  11. LA JUSTICIA AMBIENTAL EN EL ORDENAMIENTO JURÍDICO AMBIENTAL CHILENO

    OpenAIRE

    Dominique Hervé Espejo; Sebastián Rebolledo

    2013-01-01

    El presente trabajo desarrolla la noción de justicia ambiental y sus elementos configurativos. En virtud de aquel marco se revisan dos instituciones jurídicas del ordenamiento jurídico ambiental chileno, con el objeto de evaluar si en las normas que las consagran se incorporan o reflejan dichos elementos. Los instrumentos jurídicos analizados son la participación ciudadana en el Sistema de Evaluación de Impacto Ambiental y la Evaluación Ambiental Estratégica.

  12. Análisis intra e interpoblacional de rasgos craneanos no métricos en aborígenes pre-hispánicos del actual territorio de Córdoba

    Directory of Open Access Journals (Sweden)

    Fabra, Mariana

    2003-01-01

    Full Text Available Recientes investigaciones de la arqueología de sociedades agroalfareras de la actual provincia de Córdoba señalan que existió un proceso de diversificación e intensificación diferencial que terminó definiendo modalidades regionales en los estilos de vida de dichas comunidades. Desde esta perspectiva, los desarrollos llevados a cabo en las sierras y la llanura extraserrana de las zonas centro y sur de Córdoba, difieren en algunos aspectos de aquellos implementados en la zona norte y, a su vez, estos dos de aquellos de los grupos de Traslasierra y San Luis. En este estudio se investigó, a través de 32 rasgos craneanos no métricos, si esta diversificación cultural se correspondió con diferencias biológicas regionales. Varias técnicas de análisis utilizadas (cluster análisis, correlación de matrices, autocorrelación espacial y multi-response permutation procedure, no pudieron identificar un patrón geográfico de variación, sugiriendo que no existió tal diferenciación biológica regional. Por otra parte, al confrontarse la serie Córdoba con otras de Argentina y Chile, extraídas de la literatura (González-José et al., Hum. Biol. 73:333-348, 2001, se puso de manifiesto una neta diferenciación entre Córdoba y las restantes series. El cluster analysis, a su vez, evidenció que Córdoba presenta una mayor similitud con los grupos de Patagonia y Tierra del Fuego, que con los del noroeste y noreste de Argentina

  13. Plutonium and cesium radionuclides in the Hudson River Estuary. Annual technical progress report, December 1, 1974--November 30, 1975

    International Nuclear Information System (INIS)

    We have obtained a large set of gravity cores from the Hudson Estuary through much of the ambient salinity range. A number of core sections have been analyzed for 137Cs, 134Cs, 60Co, and 40K by direct gamma counting, and for 239,240Pu by alpha-spectrometry. The distribution of both 137Cs and 239,240Pu indicates rapid accumulation in marginal cove areas and in the harbor region adjacent to New York City. The distribution of both 137Cs and 239,240Pu in the sediments is quite similar in surface sediments, and the trends with depth in cores are also similar. The ratio of sediment 239,240Pu to 137Cs throughout the sampled salinity range (0-20 0/00) approximates that in fallout, except near the nuclear reactor at Indian Point where releases of 137Cs result in a ratio lower (0.004 to 0.008) than typical of fallout (0.015). Measurement amounts of reactor-derived 134Cs, 60Co, and 54Mn are found in nearly all of the samples containing appreciable 137Cs. These samples were between 15 km upstream of Indian Point reactor site and the downstream extent of our sampling, 70 km south of the reactor

  14. Survey of Morphological Changes on Tidal Flats in Estuaries

    Science.gov (United States)

    Albers, Thorsten; von Lieberman, Nicole

    2010-05-01

    Tidal flat areas in estuaries are affected by strong morphodynamics. Changes of sedimentation and erosion occur on very different time and spatial scales. These changes challenge the responsible authorities due to the high importance of sufficient navigation channel depths and the ecological importance of those unique zones. The Hamburg University of Technology in cooperation with the Hamburg Port Authority runs broad field measurements on different tidal flat areas in the Elbe estuary. The results provide a fundamental data set, which improves the knowledge about morphodynamic processes and verifies mathematical descriptions. The field measurements focus on two investigation areas: One area is located in the mouth of the estuary and represents a marine tidal flat. The other one is located near the city of Hamburg and typifies a limnic tidal flat area. For more than 3 years water levels, waves, current parameters and suspended sediment concentrations are being recorded continuously and in a high resolution at different positions. Altogether, three measuring positions are operated at any time. To observe the consequences of the morphodynamic processes, the bathymetry of the investigation areas is determined with a multi-beam echo sounder (MBES) in frequent intervals. The main goal of the research project is to improve the knowledge about morphodynamic processes on tidal flats. Derived from the field data certain patterns of erosion, sediment transport and sedimentation could be observed depending on tidal currents, waves and large scale weather conditions. Seasonal effects are analysed as well as the influence of extreme events. A comparison of the processes observed on marine and limnic areas is done, whereas the latter additionally is affected by upstream water discharge. For example, on the marine tidal flats the sediment transport capacity was analysed: Extreme events cause a short peak, which does not result in significant bathymetric changes. Larger

  15. Modelling of tidal hydrodynamics for a tropical ecosystem with implications for pollutant dispersion (Cohin Estuary, Southwest India)

    Science.gov (United States)

    Balachandran, Kizhakkepat Kalathil; Reddy, Guddemmari Sidha; Revichandran, Chenicherry; Srinivas, Kotamarpi; Vijayan, Panachikkal Ramakrishnan; Thottam, Tony Joseph

    2008-11-01

    Tidal circulation in the Cochin Estuary, a moderately polluted estuary along the southwest coast of India, was studied using a 2D hydrodynamic model. The predicted tides and currents showed very good agreement with measured tides. Particle trajectories and residual currents computed from the model have been used to classify the study region into three zones: northern estuary, central estuary, and southern estuary. The central estuary is dynamic, whereas the other two zones are relatively weak. An amplification of measured tides in the south estuary during March indicates the presence of standing waves caused by the hydraulic barrier at Thanneermukkom. Model results suggest that the northern and southern zones are sensitive to environmental pollution. The present level of pollution in the northern estuary is due to the direct release of industrial effluents into the river Periyar, which can be minimized if they are brought down to central estuary for disposal. The concept of different zones in the estuary will be useful to planners in protecting the vulnerable regions of this productive ecosystem from human interventions.

  16. Magnetic properties of sediments in cores from the Mandovi estuary, western India: Inferences on provenance and pollution.

    Science.gov (United States)

    Prajith, A; Rao, V Purnachandra; Kessarkar, Pratima M

    2015-10-15

    Magnetic properties of sediments were investigated in 7 gravity cores recovered along a transect of the Mandovi estuary, western India to understand their provenance and pollution. The maximum magnetic susceptibility of sediments was at least 6 times higher in the upper/middle estuary than in lower estuary/bay. The χfd% and χARM/SIRM of sediments indicated coarse, multi-domain and pseudo-single domain magnetic grains, resembling ore material in the upper/middle estuary and coarse stable single domain (SSD) to fine SSD grains in the lower estuary/bay. Mineralogy parameters indicated hematite and goethite-dominated sediments in the upper/middle estuary and magnetite-dominated sediments in the lower estuary/bay. Two sediment types were discernible because of deposition of abundant ore material in the upper/middle estuary and detrital sediment in the lower estuary/bay. The enrichment factor and Index of geo-accumulation of metals indicated significant to strong pollution with respect to Fe and Mn in sediments from the upper/middle estuary.

  17. Benthic fluxes in a tropical estuary and their role in the ecosystem

    Digital Repository Service at National Institute of Oceanography (India)

    Pratihary, A.K.; Naqvi, S.W.A.; Naik, H.; Thorat, B.R.; Narvenkar, G.; Manjunatha, B.R.; Rao, V.P.

    In-situ measurements of benthic fluxes of oxygen and nutrients were made in the subtidal region of the Mandovi estuary during premonsoon and monsoon seasons to understand the role of sediment-water exchange processes in the estuarine ecosystem...

  18. Characteristics of Sediments in the James River Estuary, Virginia, 1968 (NODC Accession 7001081)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report presents data on the physical and chemical characteristics of bottom sediments in the James River estuary, Virgina. The data were generated as part of a...

  19. Drivers of Variability of Diel-Cycling and Episodic Hypoxia In Northern Gulf of Mexico Estuaries

    Science.gov (United States)

    Eutrophication of coastal ecosystems is a longstanding environmental concern, exacerbated by population growth and associated nutrient pollution, and ultimately resulting in increased incidence of hypoxia. Shallow and highly productive estuaries and embayments are particularly su...

  20. Biological characteristics of the Vashishti Estuary, Maharashtra (west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Mustafa, S.; Mehta, P.; Govindan, K.; JiyalalRam, M.; Gajbhiye, S.N.

    in zooplankton faunal group diversity from inner estuary to the coastal waters was evident. There was no marked change in faunal group diversityb of macrobenthos between estuarine and coastal system. Selected water quality parameters were correlated...

  1. San Francisco Estuary Midwinter Waterfowl Survey: 2012 Survey Results and Trend Analysis (1981-2012)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides results of the 2012 San Francisco Estuary Midwinter Waterfowl Survey and presents an analysis of trends in waterfowl counts from 1981-2012. The...

  2. Sources, distribution and preservation of organic matter in a tropical estuary (Godavari, India)

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, M.S.; Naidu, S.A.; Subbaiah, Ch.V.; Gawade, L.; Sarma, V.V.S.S.; Reddy, N.P.C.

    Major sources and distribution of organic matter (OM) were examined in a tropical monsoonal estuary, the Godavari, using content and isotopic signatures in suspended particulate matter and surface sediments during no-discharge period. The lower (<10...

  3. Studies on fouling diatoms from the Zuari Estuary, Goa (west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Redekar, P.D.; Wagh, A.B.

    estuary. Of these 39 species (14 genera) belonged to Pennales and 10 (5 genera) to Centrales. The dominant genera were Navicula, Nitzschia and Amphora. Pennales were dominant over Centrales in diversity. The minima and maxima of number of cells showed...

  4. A study on the seasonal dynamics of Beypore estuary, Kerala coast

    Digital Repository Service at National Institute of Oceanography (India)

    AnilKumar, N.; DineshKumar, P.K.

    Mixing characteristics of the Beypore estuary were determined up to 15 km upstream of Chaliyar river. The study area was divided into four sections (5km interval) with two transverse stations on either side of each section. The diffusivity values...

  5. Tides in the Mandovi and Zuari estuaries, Goa, west coast of India

    Indian Academy of Sciences (India)

    D Sundar; S R Shetye

    2005-10-01

    Mandovi and Zuari are two estuaries located in Goa,west coast of India.Variation of water level in the estuaries was monitored for a month at 13 locations using tide-poles during March –April 2003.Analysis of this data has provided for the first time,characteristics of how tidal constituents vary in the narrow and shallow estuaries,typical of those found along the west coast of India.At a distance of 45 km from the mouth the tidal range increased in both estuaries by approximately 20%.The tidal range at the upstream end of the two channels at the stations dropped sharply because of the increase in elevation of the channels.

  6. Sediment Data from Great Bay Estuary, New Hampshire (ARMSTRONG74 shapefile)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The sediment data presented in this data layer were from a geochemical study sited in Great Bay Estuary, New Hampshire. The analog data were originally converted...

  7. Distribution and composition characteristics of heavy minerals in surficial sediment of Minjiang Estuary

    Institute of Scientific and Technical Information of China (English)

    XU Maoquan; XU Wenbin; SUN Meiqin

    2005-01-01

    Heavy minerals with a size range of 0.125~0.250 mm in the surficial sediment of Minjiang Estuary are studied. Thirty-four heavy minerals have been identified, with an average content of 1.92%. Major minerals include magnetite, epidote, hematite, hornblende, ilmenite, and zircon mica. These types are the same as those in the 0.063~0.125 mm range; however, the average content is lower, which reveals that the heavy minerals in Minjiang Estuary are mainly enriched in the very-fine sand fraction. According to the content and distribution characteristics of the major heavy minerals, Minjiang Estuary can be divided into 4 mineral assemblage zones. In each zone the assemblage of heavy minerals is greatly affected by the hydrodynamic condition and the sedimentary environment. Heavy mineral types also show that detrital matters in Minjiang Estuary are originated from the weathering and erosion of the bedrock in the Minjiang River drainage area.

  8. CREEK Project's Oyster Biomass Database for Eight Creeks in the North Inlet Estuary, South Carolina

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — A group of eight tidal creeks dominated by oysters, Crassostrea virginica, in North Inlet Estuary, South Carolina, USA were studied using a replicated BACI (Before...

  9. Biochemical composition and caloric content in the sand whiting Sillago sihama (Forsskal), from Zuari Estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Shamsan, E.F.; Ansari, Z.A.

    Fish condition as well as the seasonal variation in biochemical composition (moisture content, lipid, protein and carbohydrate) of an economically important fish, Sillago sihama (Forsskal), from Zuari estuary, Goa were monitored over a period...

  10. Particle-associated bacterial dynamics in a tropical tidal plain (Zuari estuary, India)

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

    The dynamics of particle-associated bacteria (PAB) in a tropical estuary, Zuari, in Goa on the west coast of India, was studied for a year from September 1997 to October 1998. Bacterial abundance, productivity and enzymatic activities were measured...

  11. Bacterial growth efficiency in a tropical estuary: Seasonal variability subsidized by allochthonous carbon

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.S.P.; Nair, S.; Chandramohan, D.

    Bacterial growth efficiency (BGE) is a key factor in understanding bacterial influence on carbon flow in aquatic ecosystems. Intra-annual variability in BGE, and bacteria-mediated carbon flow in the tropical Mandovi and Zuari estuaries (southwest...

  12. Impact of freshwater influx on microzooplankton mediated food web in a tropical estuary (Cochin backwaters - India)

    Digital Repository Service at National Institute of Oceanography (India)

    Jyothibabu, R.; Madhu, N.V.; Jayalakshmi, K.V.; Balachandran, K.K.; Shiyas, C.C.; Martin, G.D.; Nair, K.K.C.

    result in a weak transfer of primary and bacterial carbon to higher trophic levels, eventually leaving behind much unconsumed basic food in the estuary during summer monsoon. Thus a major portion of the primary carbon either settles down or gets...

  13. Heterotrophic utilization of extracellular products of phytoplankton in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Gomes, H.; Pant, A.; Goes, J.I.; Parulekar, A.H.

    Bacterial uptake of algal exudates has been estimated in a tropical estuary, Dona Paula, Goa, India, where the seasonal fluctuations in hydrographic and nutrient parameters as well as dissolved organic matter concentrations and phytoplankton species...

  14. PARASITIC AND SYMBIONIC FAUNA IN OYSTERS (CRASSOSTREA VIRGINICA) COLLECTED FROM THE CALOOSAHATCHEE RIVER AND ESTUARY, FLORIDA

    Science.gov (United States)

    Studies of oysters, Crassostrea virginica, collected from ten sites in the Caloosahatchee River and Estuary, Florida, revealed a varied parasite and symbiotic fauna that have never been reported from this area. Organisms observed included ovacystis virus infecting gametes...

  15. From headwaters to coast: influence of human activities on water quality of the Potomac River Estuary

    Science.gov (United States)

    Bricker, Suzanne B.; Rice, Karen C.; Bricker, Owen P.

    2014-01-01

    The natural aging process of Chesapeake Bay and its tributary estuaries has been accelerated by human activities around the shoreline and within the watershed, increasing sediment and nutrient loads delivered to the bay. Riverine nutrients cause algal growth in the bay leading to reductions in light penetration with consequent declines in sea grass growth, smothering of bottom-dwelling organisms, and decreases in bottom-water dissolved oxygen as algal blooms decay. Historically, bay waters were filtered by oysters, but declines in oyster populations from overfishing and disease have led to higher concentrations of fine-sediment particles and phytoplankton in the water column. Assessments of water and biological resource quality in Chesapeake Bay and tributaries, such as the Potomac River, show a continual degraded state. In this paper, we pay tribute to Owen Bricker’s comprehensive, holistic scientific perspective using an approach that examines the connection between watershed and estuary. We evaluated nitrogen inputs from Potomac River headwaters, nutrient-related conditions within the estuary, and considered the use of shellfish aquaculture as an in-the-water nutrient management measure. Data from headwaters, nontidal, and estuarine portions of the Potomac River watershed and estuary were analyzed to examine the contribution from different parts of the watershed to total nitrogen loads to the estuary. An eutrophication model was applied to these data to evaluate eutrophication status and changes since the early 1990s and for comparison to regional and national conditions. A farm-scale aquaculture model was applied and results scaled to the estuary to determine the potential for shellfish (oyster) aquaculture to mediate eutrophication impacts. Results showed that (1) the contribution to nitrogen loads from headwater streams is small (about 2 %) of total inputs to the Potomac River Estuary; (2) eutrophic conditions in the Potomac River Estuary have improved in

  16. Studies on organic carbon, nitrogen and phosphorous in the sediments of Mandovi Estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Nasnolkar, C.M.; Shirodkar, P.V.; Singbal, S.Y.S.

    Sediment organic carbon, total nitrogen, total phosphorous and hydrography of the overlying waters of the estuarine region in Mandovi Estuary, Goa, India have been studied. The relationship of carbon and nutrients with sediment characteristics...

  17. Dissolved organic matter (DOM) export to a temperate estuary: Seasonal variations and implications of land use

    DEFF Research Database (Denmark)

    Stedmon, C. A.; Markager, S.; Søndergaard, M.;

    2006-01-01

    nutrient inputs to the estuary, dissolved inorganic nitrogen (DIN) and dissolved organic phosphorus dominated the loadings. Although 81% of the nitrogen annually supplied to the estuary was DIN, 83% of the nitrogen exported from the estuary was dissolved organic nitrogen (DON). Results show that increasing......, and the percentage of catchment area used for agriculture. Colored DOM (CDOM) loading measurements were found to be a good predictor of dissolved organic carbon (DOC) loading across the different subcatchments, offering a rapid and inexpensive alternative of operationally monitoring DOC export. For all the dissolved...... the area of the catchment covered by forest and natural pastures would have a positive effect on the trophic status of the estuary, leading to a considerable decrease in the phosphorus loading and a shift in the nitrogen loading from DIN to DON. Such a change in land use would also increase the export...

  18. An analysis of MODIS algorithms for surface salinity and dissolved organic carbon in northwest Florida estuaries

    Science.gov (United States)

    Synoptic and frequent monitoring of water quality parameters from satellite is useful for determining the health of aquatic ecosystems and development of effective management strategies. Northwest Florida estuaries are classified as optically-complex, or waters influenced by chlo...

  19. National Status and Trends: Bioeffects Assessment Program, St Lucie Estuary Summary Database (2001-2004)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The foundation of this study was based on a sediment quality triad (SQT) approach with a probabilistic sampling design, which characterized the estuary in terms of...

  20. Circulation and mixing process in Vasishta-Godavari estuary, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, A.R.S.; Murty, T.V.R.; Rao, M.M.M.; Rao, V.R.; Reddy, B.S.R.

    content gradually from September to January. Model studies based on these observations may be more useful in understanding the basic mechanisms involved in circulation, mixing and flushing aspects of the estuary...

  1. Stable isotopes of carbon and nitrogen in suspended matter and sediments from the Godavari estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Arya, J.; Subbaiah, Ch.V.; Naidu, S.A.; Gawade, L.; PraveenKumar, P.; Reddy, N.P.C.

    Spatial distribution of the carbon and nitrogen content and their isotopic enrichment in suspended matter and sediments were measured in the Godavari estuary to identify the sources and transformation mechanism of organic matter. Significant...

  2. Modeling transportation of suspended solids in Zhujiang River estuary, South China

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaohong; CHEN Yongqin; LAI Guoyou

    2005-01-01

    A three-dimensional transportation model for suspended solids (SS) in Zhujiang (Pearl) River estuary, South China, was developed by coupling with a three-dimensional hydrodynamic model. The model was validated using hourly measured data of sediment contents during 25-26, July 1999. The results showed that modeled contents matched well with measured ones and that the modeled top layer distribution agreed with the remotely sensed image of suspended solids in summer. The modeled results showed clearly the layers of suspended solids in depth, with larger sediment contents in lower layers though in the interface between salt water and freshwater the lowest contents appeared in middle layer. In overall, the suspended solids inflow from 8 rivers, transport southwestward, and carried by strong coastal flow in Zhujiang River estuary. Contours of sediment contents in the estuary spread further to the open sea during ebb tide rather than flood tide which reflects that the suspended solids in the estuary are land sourced.

  3. Temporal and Spatial Dynamics of Diel-Cycling Hypoxia in Four Northern Gulf of Mexico Estuaries

    Science.gov (United States)

    Eutrophication of coastal ecosystems has accelerated in recent decades due to population growth and associated nutrient pollution, resulting in increased incidence of hypoxia. Shallow and highly productive estuaries and embayments are particularly susceptible to diel-cycling hypo...

  4. Seasonal variability in penaeid prawn larval abundance in the Mandovi and Zuari estuaries, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Goswami, U.

    Seasonal variations in the occurrence and abundance of penaeid prawn larvae in the Mandovi and Zuari estuaries of Goa, India were studied. Larvae and postlarvae of commercially important species viz. Metapenaeus dobsoni (Miers), M. affinis (H. Milne...

  5. Freshwater flushing time scales of the Vashishti Estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Sarma, R.V.; Zingde, M.D.

    method indicated that the load retained in the estuary after infinite number of tidal cycles was 44 to 54 times the load introduced per tidal cycles during premonsoon and 47 to 61 times during postmonsoon periods. Calculations on longitudinal diffusion...

  6. Tidal switch on metabolic activity: Salinity induced responses on bacterioplankton metabolic capabilities in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Thottathil, S.D.; Balachandran, K.K.; Jayalakshmy, K.V.; Gupta, G.V.M.; Nair, S.

    Biolog plates were used to study the changes in the metabolic capabilities of bacterioplankton over a complete tidal cycle in a tropical ecosystem (Cochin Estuary, Kerala, India) along southwest coast of India. The pattern of utilization of carbon...

  7. Physical aspects of estuarine pollution - A case study in Amba river estuary

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Josanto, V.; Sarma, R.V.; Zingde, M.D.

    Tide dominated Amba river estuary was studied to evaluate it's physical characteristics with a point on application to locate a suitable release point of industrial effluents. It is important to site the outfall in a manner ensuring that the water...

  8. Diel-Cycling Hypoxia in Northern Gulf of Mexico Estuaries: Impacts and Protection of Aquatic Life

    Science.gov (United States)

    Eutrophication of coastal ecosystems is a longstanding environmental concern, exacerbated by population growth and associated nutrient pollution, and ultimately resulting in increased incidence of hypoxia. Shallow and highly productive estuaries and embayments are particularly su...

  9. Predicting submerged aquatic vegetation cover and occurrence in a Lake Superior estuary

    Science.gov (United States)

    Submerged aquatic vegetation (SAV) provides the biophysical basis for multiple ecosystem services in Great Lakes estuaries. Understanding sources of variation in SAV is necessary for sustainable management of SAV habitat. From data collected in 2011 using hydroacoustic survey met...

  10. THE CHARACTERISTIC OF MARINE ENVIRONMENT IN LINGDINGYANG ESTUARY

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Hydrologic features, load of main pollutants and current condition of water quality in Lingdingyang Estu ary are discussed by references and monitoring data. Affected by topography, runoff and tide, its dynamic condition is very complicated. Different water areas have different hydrologic features. The topography under the water of Lingdingyang Estuary is higher in the northwest than that in the southeast. The shoal alternates with the deep trough with in the bay. The distribution of the salinity and the contents of the mud and the main pollutants tally with the topography tendency. Change in water quality goes through four stages. Current condition of water quality is fairly good. Inorganic nitrogen is the primary pollutant, and then phosphorus. Rich in nutrition of nitrogen and phosphorus become a more and more prominent problem.

  11. Guidelines for determining inputs of inorganic contaminants into estuaries

    International Nuclear Information System (INIS)

    This publication describes sampling and sample preparation procedures suitable to obtain unpolluted samples for the purpose of determining river inputs of inorganic pollutants into estuaries. Emphasis is placed on heavy metal pollutants but procedures are suitable, with appropriate modifications for other inorganic pollutants. For example, the collection of samples for mercury may require modifications of handling procedures. River water samples are collected at the most down-river point where no estuarine influences effect results. Samples are collected using a peristaltic pump and separated into aqueous and particulate phases for pollutant analysis. As is the case of all trace pollutant analyses, meticulous care is required to prevent pollution of the sample and in addition to the precautions described in this method, great personal attention is required to minimize sample handling, pollution by smoke, hands, hair, dust, talc from gloves, etc., and to avoid all contact of the samples and reagents with skin and metallic objects. 1 ref., 3 figs, 1 tab

  12. Hydrodynamic and Salinity Intrusion Model in Selangor River Estuary

    Science.gov (United States)

    Haron, N. F.; Tahir, W.

    2016-07-01

    A multi-dimensional hydrodynamic and transport model has been used to develop the hydrodynamic and salinity intrusion model for Selangor River Estuary. Delft3D-FLOW was applied to the study area using a curvilinear, boundary fitted grid. External boundary forces included ocean water level, salinity, and stream flow. The hydrodynamic and salinity transport used for the simulation was calibrated and confirmed using data on November 2005 and from May to June 2014. A 13-day period for November 2005 data and a 6-day period of May to June 2014 data were chosen as the calibration and confirmation period because of the availability of data from the field-monitoring program conducted. From the calibration results, it shows that the model was well suited to predict the hydrodynamic and salinity intrusion characteristics of the study area.

  13. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  14. Quantifying nitrogen inputs to the Choptank River estuary

    Science.gov (United States)

    Mccarty, G.; Hapeman, C. J.; Sadeghi, A. M.; Hively, W. D.; Denver, J. M.; Lang, M. W.; Downey, P. M.; Rice, C. P.

    2015-12-01

    The Chesapeake Bay is the largest estuary in the US, and over 50% of its streams have been rated as poor or very poor, based on the biological integrity yearly index. The Choptank River, a Bay tributary on the Delmarva Peninsula, is dominated by intensive corn and soybean farming associated with poultry and some dairy production. The Choptank River is under Environmental Protection Agency (USEPA) total maximum daily load restrictions. However, reducing nonpoint source pollution contributions from agriculture requires that source predictions be improved and that mitigation and conservation measures be properly targeted. Therefore, new measurement strategies have been implemented. In-situ sensors have been deployed adjacent to US Geological Survey gauging stations in the Tuckahoe and Greensboro sub-basins of the Choptank River watershed. These sensors measure stream water concentrations of nitrate along and water quality parameters every 30 min. Initial results indicate that ~40% less nitrate is exported from the Greensboro sub-basin, even though the total amount of agricultural land use is similar to that in the Tuckahoe sub-basin. This is most likely due to more efficient nitrate processing in the Greensboro sub-basin where the amount of cropland on poorly-drained soils is much larger. Another potential nitrogen source to the Choptank River estuary is atmospheric deposition of ammonia. Over 550 million broilers are produced yearly on the Delmarva Peninsula potentially leading to the release of 20,000 Mtons of ammonia. USEPA recently estimated that as much as 22% of nitrogen in the Bay is due to ammonia deposition. We have initiated a collaborative effort within the LTAR network to increase coverage of ammonia sampling and to explore the spatial and temporal variability of ammonia, particularly in the Choptank River watershed. All these measurements will be useful in improving the handling of nitrogen sources and its fate and transport in the Chesapeake Bay model.

  15. Rare earth element analysis indicates micropollutants in an urban estuary

    Science.gov (United States)

    Mohajerin, T. J.; Johannesson, K. H.; Kolker, A.; Burdige, D. J.; Chevis, D.

    2011-12-01

    Rare earth element analysis of Bayou Bienvenue waters shows anomalously high gadolinium, Gd, concentrations relative to its nearest neighbors in the REE series, europium and terbium. The anomalously high Gd concentrations indicate anthropogenic input from waste-water treatment plants in the area as anthropogenic Gd input can be traced back to its use as a contrast agent in magnetic resonance imaging in hospitals. Others have shown that anomalously high levels of Gd in natural waters are likely to be associated with other micropollutants that also occur in hospital effluent and that are not removed in the wastewater treatment process, including pharmaceuticals in the form of steroids, antihistamines, and antibiotics. Estuaries serve as many important ecological roles and have been shown to act as a filter for pollutants. To better understand the transport, biogeochemical cycling, and ultimate fate of trace elements in estuaries, I collected surface water samples from Bayou Bienvenue, a wetland triangle that covers an area of 427 acres directly adjacent to New Orleans, Louisiana. Water samples from Bayou Bienvenue were collected along the salinity gradient and subsequently filtered through progressively smaller pore-size filters. The resulting fractions were analyzed for trace element concentions, including the REEs, by magnetic sector ICP-MS. The attached figure shows the Gd anomaly present in the particulate (>0.45μm) fraction. Upper continental crust (UCC)-normalized plots of colloidal REEs (0.02μm - 0.45μm) fraction is lacking this anomaly indicating anthropogenic Gd is found chiefly in the particulate fraction in Bayou Bienvenue. No clear relationship between Gd concentration and salinity was apparent.

  16. Numerical simulation of water quality in Yangtze Estuary

    Directory of Open Access Journals (Sweden)

    Xi LI

    2009-12-01

    Full Text Available In order to monitor water quality in the Yangtze Estuary, water samples were collected and field observation of current and velocity stratification was carried out using a shipboard acoustic Doppler current profiler (ADCP. Results of two representative variables, the temporal and spatial variation of new point source sewage discharge as manifested by chemical oxygen demand (COD and the initial water quality distribution as manifested by dissolved oxygen (DO, were obtained by application of the Environmental Fluid Dynamics Code (EFDC with solutions for hydrodynamics during tides. The numerical results were compared with field data, and the field data provided verification of numerical application: this numerical model is an effective tool for water quality simulation. For point source discharge, COD concentration was simulated with an initial value in the river of zero. The simulated increments and distribution of COD in the water show acceptable agreement with field data. The concentration of DO is much higher in the North Branch than in the South Branch due to consumption of oxygen in the South Branch resulting from discharge of sewage from Shanghai. The DO concentration is greater in the surface layer than in the bottom layer. The DO concentration is low in areas with a depth of less than 20 m, and high in areas between the 20-m and 30-m isobaths. It is concluded that the numerical model is valuable in simulation of water quality in the case of specific point source pollutant discharge. The EFDC model is also of satisfactory accuracy in water quality simulation of the Yangtze Estuary.

  17. LED illuminant on the ambient light

    Science.gov (United States)

    Liu, Anqing; Sandipan, Mishra; Shur, Michael

    2014-09-01

    We develop an approach for combining illuminance and spectral power distribution of the LED and ambient light and apply our technique for developing an LED camera flashlight balancing the illuminance contrast between object and background. Our method uses the closed loop, multiobjective optimization comprising: (1) characterizing the lighting task by illuminance, correlated color temperature (CCT), and statistical color quality indices that include a set of Statistical Color Quality Metrics and the Color Rendition Index (CRI) implemented with indexes of S (saturation) or D (dulling); (2) measuring the illuminance and the spectrum of the ambient light on the target lighting surface, which might depend on all the sources proving illumination and on the reflected light; (3) determining the desired illuminance of the LED source on the target lighting surface; (4) calculating the desired luminous flux of the LED source according to the desired illuminance; (5) constituting the SPD of the LED source; (6) calculating the relative spectra counts of the LED source and the ambient light on the target lighting surface (7) calculating the CCT and statistical color quality indexes of the combined light; (8) repeating the above steps until the resulting SPD is close enough to the expectation. Using the above method, an LED camera flashlight has been designed, which works together with usual fluorescent ambient light and generates working lighting environment with high fidelity and high CCT (6000K). The spectrum and luminous flux of the LED lamp is automatically tunable with a change of the ambient light.

  18. OS CONCEITOS DE AMBIENTE, MEIO AMBIENTE E NATUREZA NO CONTEXTO DA TEMÁTICA AMBIENTAL: DEFININDO SIGNIFICADOS

    Directory of Open Access Journals (Sweden)

    Job Antonio Garcia Ribeiro

    2014-01-01

    Full Text Available Apresentamos alguns esclarecimentos que nos possibilitam identificar diferenças entre as expressões natureza, ambiente e meio ambiente. Não se trata de um estudo epistemológico, mas sim de reflexões sobre a que se referem essas expressões e as implicações para a temática ambiental e, consequentemente para o Ensino de Ciências. A natureza foi compreendida como um complexo de entidades reais, as quais são passíveis de pensamento através da percepção. Essa mesma entidade ao ser representada por uma mente, passa a constituir o que denominamos de ambiente. Este, por sua vez, caracteriza-se não somente pela soma dos meios ambientes das espécies conhecidas, mas por ser uma abstração humana. Ao considerarmos a singularidade de cada espécie e organismo que nesse ambiente se insere, passamos a denominar de meio ambiente os elementos que podem ser percebidos e sobre as quais determinado ser pode atuar. Assim, buscamos elaborar um conceito de meio ambiente mais amplo, que não se restrinja à espécie humana.The concepts of environment, environment and nature in the context of environmental issue: defining meaningsABSTRACTWe present some clarifications that enable us to identify differences between the expressions nature, the environment and environment. This is not an epistemological approach, but rather reflections on these expressions refer and the implications for environmental issues and hence to Science Teaching. The nature was understood as a complex of real entities, which are capable to be thinking through perception. This same entity when is represented by a mind, become what we call the environment. This expression, in turn, is characterized not only by adding the environments species that are known, but to be a human abstraction. When we consider the uniqueness of each species and organism, which in this environment is inserted, we call environment, this is, the elements that can be seen and on which the organism can act

  19. Sediment abiotic patterns in current and newly created intertidal habitats from an impacted estuary

    OpenAIRE

    Beauchard, O.; Teuchies, J.; Jacobs, S; E. Struyf; Van der Spiet, T.; P. Meire

    2014-01-01

    The controlled reduced tide system (CRT) is a new technique for restoring tidal marshes and is being tested in the Schelde estuary (Belgium). Biogeochemical processes within a CRT were hypothesized to support and improve several estuarine functions such as sediment trapping and nutrient burial. In 2006, the first pilot CRT was implemented in the freshwater zone of the estuary. Fifteen sediment physicochemical descriptors were intensively monitored over 3 years in the newly created CRT and in ...

  20. Investigation on Water Pollution of Four Rivers in Coastal Wetland of Yellow River Estuary

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The study aimed at analysing water pollution of four rivers in coastal wetland of Yellow River estuary. [Method] Taking four seriously polluted rivers (Guangli River, Shenxian Ditch, Tiao River and Chao River) in coastal wetland of Yellow River estuary as study objects, water samples were collected from the four rivers in May (dry period), August (wet period) and November (normal period) in 2009 and 2010 respectively, then pollution indices like nutritive salts, COD, chlorophyll-a, petroleum, et...

  1. Seasonal variations in abundance, biomass and grazing rates of microzooplankton in a tropical monsoonal estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Gauns, M.; Mochemadkar, S.; Patil, S.; Pratihary, A.K.; Naqvi, S.W.A.; Madhupratap, M.

    of bacterial communities and energy fluxes. Some of the tintinnid ciliates like Favella sp., Tintinnopsis lobiancoi and T. kofoidii are known to ingest flagellates (Stoecker et al., 1981). These predator species are commonly found in the Zuari estuary. Thus... of carbon in the Zuari estuary, carbon requirement to sustain the observed standing stocks of microzooplankton was calculated based on the gross growth efficiency. The highest requirement of microzooplankton was during the postmonsoon period (Table 2...

  2. Assessment of water quality of a river-dominated estuary with hydrochemical parameters: A statistical approach.

    Digital Repository Service at National Institute of Oceanography (India)

    Padma, P.; Sheela, V.S.; Suryakumari, S.; Jayalakshmy, K.V.; Nair, S.M.; Kumar, N.C.

    in developmental and urbanization activ- ities, demands on our natural resources also shoot up and hence protection of rivers and estuaries for all their natural, economic and aesthetic values is very important (Song et al. 2011; USEPA 2012). When a river... or estuary is altered in its natural functions, it becomes polluted and can harm living beings. The rivers play a pivotal role in carrying industrial and urban wastes and this makes rivers more susceptible to environmental problems like pollution. Hence...

  3. OCCURRENCE OF Charybdis hellerii (Milne Edwards, 1867 (CRUSTACEA, DECAPODA, PORTUNIDAE IN AN AMAZONIAN ESTUARY.

    Directory of Open Access Journals (Sweden)

    Alessandra Batista Bentes

    2013-12-01

    Full Text Available For the first time specimens of Charybdis hellerii (Milne Edwards 1867, an Indo Pacific specie, were caught in Amazon estuary, Bragança, Pará, North of Brazil. Palavras-chave: Crustacea, Charybdis hellerii , Amazonian Estuary. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v3n3p181-184

  4. The influence of turbidity on juvenile marine fish in the estuaries of Natal, South africa

    Science.gov (United States)

    Cyrus, D. P.; Blaber, S. J. M.

    1987-11-01

    Results from field studies in Natal estuaries show that the distribution of juvenile marine fish is influenced by turbidity. Laboratory studies on turbidity preference, with other variables excluded, showed good correlation with the field data for eight of ten species tested. The importance of turbidity and other factors to juvenile fish is discussed in relation to the role which estuaries play as nursery areas for juveniles of numerous marine species.

  5. Environmental Settings and Harmful Algal Blooms in the Sea Area Adjacent to the Changjiang River Estuary

    OpenAIRE

    Zhou, Mingjiang

    2010-01-01

    The characteristics of the environmental settings of the sea area adjacent to the Changjiang River estuary include complex currents and water masses, the diluted water plume and its redirection, upwelling, front, and nutrients and their sources. The Changjiang River estuary characteristics also include the phytoplankton community, which can affect the growth, migration, assembling, resting and competition of algae to form red tides in this area.. The features of red tide events recorded in th...

  6. Nitrification in the Schelde estuary: methodological aspects and factors influencing its activity

    OpenAIRE

    Bie, M.J.M. de; Starink, M.; Boschker, H.T.S.; Peene, J.J.; Laanbroek, H. J.

    2002-01-01

    We present a 15-month dataset on nitrification measurements in the Schelde estuary (Belgium and The Netherlands). Nitrification was estimated using the N-serve sensitive dark 14C-bicarbonate incorporation technique. A peak of nitrification activity was observed in the freshwater part of the estuary. Downstream from this peak, nitrification declined, probably because of ammonium limitation. A range of nitrification inhibitors was tested on both a Nitrosomonas europaea culture and estuarine sam...

  7. Spatial distribution of subtidal Nematoda communities along the salinity gradient in southern European estuaries

    Science.gov (United States)

    Adão, Helena; Alves, Ana Sofia; Patrício, Joana; Neto, João Magalhães; Costa, Maria José; Marques, João Carlos

    2009-03-01

    This study investigated the spatial distribution of subtidal nematode communities along the salinity gradients of two Portuguese estuaries exposed to different degrees of anthropogenic stress: the Mira and the Mondego. The nematode communities were mainly composed of Sabatieria, Metachromadora, Daptonema, Anoplostoma, Sphaerolaimus and Terschellingia species, closely resembling the communities of Northern European estuaries. In both estuaries, nematode density and community composition followed the salinity gradient, naturally establishing three distinct estuarine sections: (i) freshwater and oligohaline - characterised by the presence of freshwater nematodes, low nematode density and diversity; (ii) mesohaline - dominated by Terschellingia, Sabatieria and Daptonema, with low total density and diversity; and (iii) polyhaline and euhaline - where nematodes reached the highest density and diversity, and Paracomesoma, Synonchiella, and Odontophora were dominant. Despite the similarities in community composition and total nematode density, the proportion of different nematode feeding types were remarkably different in the two estuaries. In Mira, selective deposit feeders were dominant in the oligohaline section, while non-selective deposit feeders were dominant in the other sections. On the contrary, in the Mondego estuary, epigrowth-feeders and omnivores/predators were dominant in the freshwater sections and in the euhaline sector of the southern arm. Differences observed along each estuarine gradient were much stronger than overall differences between the two estuaries. In the Mondego estuary, the influence of anthropogenic stressors seemed not to be relevant in determining the nematodes' spatial distribution patterns, therefore suggesting that mesoscale variability responded essentially to natural stressors, characteristic of estuarine gradients. Nevertheless, the proportion of the different feeding types was different between the two estuaries, indicating that the

  8. Intra-annual variability in nutrients in the Godavari estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Prasad, V.R.; Kumar, B.S.K.; Rajeev, K.; Devi, B.M.M.; Reddy, N.P.C.; Sarma, V.V.; DileepKumar, M.

    (Mukhopadhyay et al., 2006). However, seasonal P limitation has been found in several estuaries (eg. Gle et al. 2008; Xu et al. 2008). Higher rates of nutrient inputs (Nixon et al. 1986) lead to higher organic carbon production (Kelly and Levin 1986...) in estuarine ecosystems where the active biological pump transfers significant amounts of organic carbon to the sediments (Wollast 1998; Smith and Hollibaugh 1993). Particulate organic carbon (POC) in the estuary may not be available for metabolic breakdown...

  9. Distribution of nitrifying activity in the Seine River (France) from Paris to the estuary

    OpenAIRE

    Brion, N; Billen, G.; Guézennec, J.; Ficht, A.

    2000-01-01

    The distribution of nitrification has been measured with the H14CO3- incorporation method in the Seine River and its estuary during summer conditions. The Seine River below Paris receives large amounts of ammonium through wastewater discharge. In the river itself, this ammonium is only slowly nitrified, while in the estuary nitrification is rapid and complete. We show that this contrasting behavior is related to the different hydrosedimentary conditions of the two systems, as nitrifying bacte...

  10. Developing a coupled analytical model for analyzing salt intrusion in alluvial estuaries

    Science.gov (United States)

    Savenije, H.; CAI, H.; Gisen, J.

    2013-12-01

    A predictive assessment technique to estimate the salt intrusion length and longitudinal salinity distribution in estuaries is important for policy makers and managers to maintain a healthy estuarine environment. In this study, the salt intrusion model of Savenije (2005, 2012) is applied and coupled to an explicit solution for tidal dynamics developed by Cai and Savenije (2013). The objective of the coupling is to reduce the number of calibration parameters, which subsequently strengthens the reliability of the salt intrusion model. Moreover, the fully analytical treatment allows assessing the effect of model forcing (i.e., tide and river discharge) and geometry adjustments (e.g., by dredging) on system performance. The coupled model has been applied to a wide range of estuaries, and the result shows that the correspondence between analytical estimations and observations is very good. As a result, the coupled model is a useful tool for decision makers to obtain first order estimates of salt intrusion in estuaries based on a minimum of information required. References Savenije, H.H.G. (2005), Salinity and Tides in Alluvial Estuaries, Elsevier. Savenije, H.H.G. (2012), Salinity and Tides in Alluvial Estuaries, completely revised 2nd edition, www.salinityandtides.com. Cai, H., and H. H. G. Savenije (2013), Asymptotic behavior of tidal damping in alluvial estuaries, Journal of Geophysical Research, submitted.

  11. Pollution in the estuary of the Baracoa river, La Habana, Cuba

    Directory of Open Access Journals (Sweden)

    Regla Duthit Somoza

    2011-04-01

    Full Text Available The environmental quality of the Baracoa river estuary was studied from the physic (temperature and salinity, chemic variables (dissolved oxygen, oxygen biochemical demand (DBO, oxygen chemical demand (DQO, nitrogen cycle, inorganic phosphorus and total phosphorus and the microbiological variables (total and thermotolerant coliforms and faecal streptococci. The samplings were made on February 2006, May and October 2007. Spatial distribution of the physical and chemical parameters measured suggests that the estuary is dominated by the marine conditions. The salinity and temperature analyses show that in general the characteristics of the estuary could be influenced by the contribution of the river basin drainage. In general, the concentrations of the measured parameters in the Baracoa river estuary, strongly suggest that this area is under influence of human activities on the river basin, due to the low levels of dissolved oxygen and an oxygen average deficit of -1.6 mg/L. nthropogenic actions in this estuary are mainly related to the emission of domestic and farming rejects without suitable treatment. This is visibly associated with the observed values of the total coliforms concentrations as well as the concentration of faecal streptococci, that surpassed reference values from the Cuban norm for water quality, following on bad or doubtful quality levels pointing out negatively measurements made next to the communication channel the estuary and the El Doctor lagoon.

  12. Potential Impacts and Management Implications of Climate Change on Tampa Bay Estuary Critical Coastal Habitats

    Science.gov (United States)

    Sherwood, Edward T.; Greening, Holly S.

    2014-02-01

    The Tampa Bay estuary is a unique and valued ecosystem that currently thrives between subtropical and temperate climates along Florida's west-central coast. The watershed is considered urbanized (42 % lands developed); however, a suite of critical coastal habitats still persists. Current management efforts are focused toward restoring the historic balance of these habitat types to a benchmark 1950s period. We have modeled the anticipated changes to a suite of habitats within the Tampa Bay estuary using the sea level affecting marshes model under various sea level rise (SLR) scenarios. Modeled changes to the distribution and coverage of mangrove habitats within the estuary are expected to dominate the overall proportions of future critical coastal habitats. Modeled losses in salt marsh, salt barren, and coastal freshwater wetlands by 2100 will significantly affect the progress achieved in "Restoring the Balance" of these habitat types over recent periods. Future land management and acquisition priorities within the Tampa Bay estuary should consider the impending effects of both continued urbanization within the watershed and climate change. This requires the recognition that: (1) the Tampa Bay estuary is trending towards a mangrove-dominated system; (2) the current management paradigm of "Restoring the Balance" may no longer provide realistic, attainable goals; (3) restoration that creates habitat mosaics will prove more resilient in the future; and (4) establishing subtidal and upslope "refugia" may be a future strategy in this urbanized estuary to allow sensitive habitat types (e.g., seagrass and salt barren) to persist under anticipated climate change and SLR impacts.

  13. Movements and residency of juvenile white steenbras Lithognathus lithognathus in a range of contrasting estuaries

    Science.gov (United States)

    Bennett, Rhett H.; Cowley, Paul D.; Childs, Amber-Robyn; Næsje, Tor F.

    2015-01-01

    Acoustic telemetry was used to assess estuarine area use and movements of an overexploited, endemic fishery species in three South African estuaries; two permanently open systems with contrasting salinity gradients and an intermittently open system. Forty juvenile white steenbras Lithognathus lithognathus (215-379 mm FL) were surgically equipped with acoustic transmitters and tracked for up to 355 days. Tagged fish exhibited high levels of site fidelity and long-term residency within each estuary. Most of their time was spent in the lower reaches of all three estuaries and hypersalinity restricted movements into the upper reaches of the freshwater-deprived estuary. All tagged fish exhibited a distinct diel movement pattern. Most individuals (91%) in the two permanently open estuaries also exhibited a tidal-associated pattern, which comprised mainly small-scale (tens to hundreds of metres) transverse movements between deep channels and shallow banks. Observed behaviour was consistent across a range of estuary sizes, types and physico-chemical conditions. This study has identified critical habitats for juvenile white steenbras across a range of estuarine environments. Estuarine management initiatives need to consider these critical habitats, in order to enhance abundance of juveniles and ultimately recruitment to the marine (adult) population.

  14. Facilitation of the Estuary/Ocean Subgroup for Research, Monitoring, and Evaluation, FY06 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.

    2006-10-03

    This annual report is a deliverable for fiscal year 2006 (FY06) for Project 2002-077-00, Facilitation of the Estuary/Ocean Subgroup (EOS). The EOS is part of the research, monitoring, and evaluation (RME) effort the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) developed in response to the 2000 and 2004 Biological Opinions on operation of the Federal Columbia River Power System. The goal of the EOS project is to facilitate activities of the estuary/ocean RME subgroup as it coordinates implementation of the Estuary RME Plan. In FY06, EOS project accomplishments included: 1) subgroup meetings; 2) participation in the estuary work group of the Pacific Northwest Aquatic Monitoring Partnership; 3) project management via the project tracking system, PISCES; 4) quarterly project status reports; and 5) a major revision to the Estuary RME Plan (new version May 2006) based on comments by EOS members, the Independent Scientific Review Panel, and other reviewers. In the context of uncertainty about the direction of the federal RME due to litigation on the FCRPS Biological Opinion, FY06 activities for the EOS project resulted in expanded substantive coordination with other regional RME forums, project tracking infrastructure, and a new version of the Estuary RME Plan.

  15. Migration dynamics of clupeoids in the Schelde estuary: A stable isotope approach

    Science.gov (United States)

    Guelinckx, Jef; Maes, Joachim; De Brabandere, Loreto; Dehairs, Frank; Ollevier, Frans

    2006-02-01

    Large numbers of young of the year herring ( Clupea harengus L.) and sprat ( Sprattus sprattus (L.)) typically enter and remain within North Sea estuaries during the winter months. The main purpose of this study was to examine their migration dynamics between the North Sea and the Schelde estuary using C and N stable isotopes. Prior to this, stomach contents were used to verify the isotopic differences between the food sources at the sampling stations. From May 2000 to April 2001 fish were collected monthly in the upper and lower estuary. Muscle tissue and stomach contents were analyzed for δ13C and δ15N using an EA-IRMS. Based on the stomach contents, it was demonstrated that δ15N could not be used as a tracer for fish migration because the longitudinal estuarine δ15N gradient had reversed completely during autumn. The δ13C gradient, however, was found to be reliable for studying fish movement in the Schelde estuary. Seasonal movements of clupeoids in the Schelde estuary were analyzed by separating the temporal abundance patterns into migration groups based on their muscle isotopic composition. Immigration and emigration seem to occur continuously throughout the year. Most exchange occurred in November. During winter, immigration remained high but gradually decreased. Although the herring and sprat abundance further declined in the estuary during February and March, large seaward emigration was not fully demonstrated. As temporal overlap between immigration and emigration is concluded the results support the hypothesis that migration to estuarine nurseries is individually based.

  16. A classification of U.S. estuaries based on physical and hydrologic attributes

    Science.gov (United States)

    Engle, V.D.; Kurtz, J.C.; Smith, L.M.; Chancy, C.; Bourgeois, P.

    2007-01-01

    A classification of U.S. estuaries is presented based on estuarine characteristics that have been identified as important for quantifying stressor-response relationships in coastal systems. Estuaries within a class have similar physical and hydrologic characteristics and would be expected to demonstrate similar biological responses to stressor loads from the adjacent watersheds. Nine classes of estuaries were identified by applying cluster analysis to a database for 138 U.S. estuarine drainage areas. The database included physical measures of estuarine areas, depth and volume, as well as hydrologic parameters (i.e., tide height, tidal prism volume, freshwater inflow rates, salinity, and temperature). The ability of an estuary to dilute or flush pollutants can be estimated using physical and hydrologic properties such as volume, bathymetry, freshwater inflow and tidal exchange rates which influence residence time and affect pollutant loading rates. Thus, physical and hydrologic characteristics can be used to estimate the susceptibility of estuaries to pollutant effects. This classification of estuaries can be used by natural resource managers to describe and inventory coastal systems, understand stressor impacts, predict which systems are most sensitive to stressors, and manage and protect coastal resources. ?? Springer Science+Business Media B.V. 2007.

  17. Timing and route of migration of mature female blue crabs in a tidal estuary.

    Science.gov (United States)

    Eggleston, David B; Millstein, Erika; Plaia, Gayle

    2015-05-01

    Information on migration patterns is critical to using no-take migratory corridors and marine reserves to protect the spawning stock of commercially exploited species. Both active and passive acoustic tracking methods quantified movement of commercially and ecologically important blue crabs in the White Oak River estuary, NC, USA. We targeted post-mating female crabs migrating down-estuary to oceanic spawning grounds. Crabs travelled approximately 14.1 km mainly in deeper channels and over 12-26 days from mating areas to spawning grounds. No crabs were detected migrating down-estuary in the autumn and only 30% were detected migrating down-estuary in spring. None of the crabs detected near spawning grounds were detected or recaptured back up-estuary, suggesting that they either (i) do not return to the estuary after a one to two week period in the spawning area or (ii) were captured by fishermen. The results from this study demonstrate that (1) acoustic transmitters coupled with passive acoustic receivers provided reliable and valuable data on migration patterns of mature female blue crabs and (2) mature female blue crabs are capable of migrating primarily within deep channels to spawning grounds shortly after insemination.

  18. Metabarcoding of benthic eukaryote communities predicts the ecological condition of estuaries

    International Nuclear Information System (INIS)

    DNA-derived measurements of biological composition have the potential to produce data covering all of life, and provide a tantalizing proposition for researchers and managers. We used metabarcoding to compare benthic eukaryote composition from five estuaries of varying condition. In contrast to traditional studies, we found biotic richness was greatest in the most disturbed estuary, with this being due to the large volume of extraneous material (i.e. run-off from aquaculture, agriculture and other catchment activities) being deposited in the system. In addition, we found strong correlations between composition and a number of environmental variables, including nutrients, pH and turbidity. A wide range of taxa responded to these environmental gradients, providing new insights into their sensitivities to natural and anthropogenic stressors. Metabarcoding has the capacity to bolster current monitoring techniques, enabling the decisions regarding ecological condition to be based on a more holistic view of biodiversity. - Highlights: • We used metabarcoding to examine the benthic eukaryote composition of five estuaries. • Biotic richness (based on MOTUs) was greater in the most impacted estuary. • Similarities among estuaries reflected their environmental condition. • Composition was strongly correlated with nutrients, turbidity and pH. • Metabarcoding can provide fast, comprehensive and ecologically informative data. - Using metabarcoding we were able discriminate benthos from five estuaries, and identify those taxa which responded negatively and positivity to the key environmental stressors

  19. Rapid water quality change in the Elwha River estuary complex during dam removal

    Science.gov (United States)

    Foley, Melissa M.; Duda, Jeffrey J.; Beirne, Matthew M.; Paradis, Rebecca; Ritchie, Andrew; Warrick, Jonathan A.

    2015-01-01

    Dam removal in the United States is increasing as a result of structural concerns, sedimentation of reservoirs, and declining riverine ecosystem conditions. The removal of the 32 m Elwha and 64 m Glines Canyon dams from the Elwha River in Washington, U.S.A., was the largest dam removal project in North American history. During the 3 yr of dam removal—from September 2011 to August 2014—more than ten million cubic meters of sediment was eroded from the former reservoirs, transported downstream, and deposited throughout the lower river, river delta, and nearshore waters of the Strait of Juan de Fuca. Water quality data collected in the estuary complex at the mouth of the Elwha River document how conditions in the estuary changed as a result of sediment deposition over the 3 yr the dams were removed. Rapid and large-scale changes in estuary conditions—including salinity, depth, and turbidity—occurred 1 yr into the dam removal process. Tidal propagation into the estuary ceased following a large sediment deposition event that began in October 2013, resulting in decreased salinity, and increased depth and turbidity in the estuary complex. These changes have persisted in the system through dam removal, significantly altering the structure and functioning of the Elwha River estuary ecosystem.

  20. Spatial distribution and risk assessment of heavy metals in sediments of Shuangtaizi estuary, China

    International Nuclear Information System (INIS)

    Highlights: • Five heavy metals are analyzed in the sediments from Shuangtaizi estuary. • Particle size of the sediment effects the concentration of heavy metals. • Pb, Cu, Zn and Hg pose low ecological risks in the Shuangtaizi estuary. • Heavy metal pollution in Shuangtaizi estuary is mainly dominated by Cd. - Abstract: In order to evaluate the spatial distribution and potential ecological risk of Pb, Cu, Zn, Cd, and Hg, the surface sediments were collected from 18 sites in the Shuangtaizi estuary. The concentrations of Pb, Cu, Zn, Cd, and Hg were analyzed by atomic absorption spectrophotometry and atomic fluorescence spectrometry after digestion. The particle sizes of the sediments were analyzed using a laser diffraction particle size analyzer. The results show that the heavy metal contents in the sediments are observed in the following order: Zn (18.25–126.75 mg/kg) > Pb (4.38–9.65 mg/kg) > Cu (1.80–17.68 mg/kg) > Cd (0.241–0.764 mg/kg) > Hg (0.007–0.021 mg/kg). In comparison with the concentrations of heavy metals in other regions, the concentrations of Pb, Cu, and Zn in the Shuangtaizi estuary are generally low, and the Cd concentrations are close to those reported in other regions. Both the potential ecological risk index and the geoaccumulation index reveal that the heavy metal pollution in Shuangtaizi estuary is mainly dominated by Cd

  1. Ocean Ambient Noise Measurement and Theory

    CERN Document Server

    Carey, William M

    2011-01-01

    This book develops the theory of ocean ambient noise mechanisms and measurements, and also describes general noise characteristics and computational methods.  It concisely summarizes the vast ambient noise literature using theory combined with key representative results.  The air-sea boundary interaction zone is described in terms of non-dimensional variables requisite for future experiments.  Noise field coherency, rare directional measurements, and unique basin scale computations and methods are presented.  The use of satellite measurements in these basin scale models is demonstrated.  Finally, this book provides a series of appendices giving in-depth mathematical treatments.  With its complete and careful discussions of both theory and experimental results, this book will be of the greatest interest to graduate students and active researchers working in fields related to ambient noise in the ocean.

  2. MUVA: a MUltimodal Visceral design Ambient device

    DEFF Research Database (Denmark)

    Kivac, Robert; Øllgaard Klem, Sune; Béneé Olsen, Sophus;

    2016-01-01

    work schedule. MUVA differs from the other ambient devices, because it is targeted to children, and it adopts a visceral design approach in order to be appealing to its users. It is a raindrop-shaped lamp, which features audio playing, while its light color is affected by the audio playing. MUVA can be......This paper presents MUVA (MUltimodal Visceral design Ambient device), a prototype for a storytelling light- and sound-based ambient device. The aim of this device is to encourage social interaction and expand the emotional closeness in families with children where at least one parent has irregular...... used by parents to store pre-recorded audio of themselves telling stories, which their children can listen when they are away. In order to investigate if MUVA is appealing to its users and if it creates feelings of closeness between parents and children when the first are absent, we conducted...

  3. Effect of ambient pressure on Leidenfrost temperature

    Science.gov (United States)

    Orejon, Daniel; Sefiane, Khellil; Takata, Yasuyuki

    2014-11-01

    The accurate prediction and control of the interaction of liquids with hot surfaces is paramount in numerous areas, including cooling applications. We present results illustrating the effect of ambient pressure on the temperature required for a droplet to levitate over a hot surface, i.e., the Leidenfrost temperature. In the present study the dependence of wetting and levitating temperatures on ambient pressure in a range of subatmospheric pressures is reported. Experimental data indicate that the Leidenfrost temperature decreases with decreasing pressure at subatmospheric pressures. A physical approach for the dependence of Leidenfrost temperature on ambient pressure, based on an analogy with saturation pressure dependence, is proposed. Furthermore, previous literature data for pressures above atmospheric are also included in the analysis to support and validate the proposed approach. In addition, the effect of substrate material, substrate roughness, and type of fluid on the Leidenfrost temperature is discussed.

  4. La Gestión Ambiental

    OpenAIRE

    Darío Muriel, Rafael

    2006-01-01

    Aquest text tanca la sèrie iniciada amb l'article Orígens de la problemàtica Ambiental, al que l'autor plantejava la problemàtica ambiental des d'una perspectiva de relació entre subsistemes (natural i social). Seguint en la mateixa línia, ara Muriel argumenta que la naturalesa és objecte i els humans objecte-subjecte de la gestió ambiental. És a dir, que de la nostra actuació com a subjectes depèn la sostenibilitat de la naturalesa i de la societat, ambdós objectes de la gestió. El presen...

  5. Ambient Noise Tomography of the British Isles

    Science.gov (United States)

    Nicolson, H. J.; Curtis, A.; Baptie, B.

    2009-12-01

    In recent years, surface wave tomography using empirical Green’s functions computed via the ambient noise interferometry method has become an established approach to lithospheric imaging problems. To date, ambient noise tomography has been successfully applied to seismometer arrays in the United States, Australia, Iceland, China, South Africa, Europe and the Tibetan Plateau. The basis of the ambient seismic interferometry method is that, by cross-correlating noise data between two seismic stations and stacking over a long enough time period, one can approximate the Green’s Function that would have been recorded at one of the stations if the other had actually been a source. Consequently, one of the main advantages of ambient noise interferometry is that traditional seismic sources such as earthquakes or ballistics are not required; therefore it is ideal for application to seismically quiescent areas such as the British Isles. The British Isles are an archipelago located adjacent to the Eurasian continental shelf in a typically intra-plate setting, formed by a complex amalgamation of several terranes. These range from Laurentian north of the Highland Boundary fault to Avalonian south of the Iapetus Suture and evidence of the regions turbulent geological past can be inferred from its lithospheric structure. Previous studies of the structure of the British Isles considered relatively few seismic stations and/or were limited to using offshore shots, quarry blasts or teleseismic earthquakes as seismic energy sources. We have applied the ambient noise tomography method to noise data recorded on approximately 100 broadband and short period seismometers, including many new stations, in the British Isles and mainland Europe. This dense coverage of the British Isles allows us to image the crust and upper mantle velocity structure with a horizontal resolution in the region of 100km across the North Sea and 30km in the mainland United Kingdom. Here we present the first

  6. A Kleene analysis of Mobile Ambients

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Sagiv, M.

    2000-01-01

    We show how a program analysis technique originally developed for C-like pointer structures can be adapted to analyse the hierarchical structure of processes in the ambient calculus. The technique is based on modeling the semantics of the language in a two-valued logic; by reinterpreting the logi......We show how a program analysis technique originally developed for C-like pointer structures can be adapted to analyse the hierarchical structure of processes in the ambient calculus. The technique is based on modeling the semantics of the language in a two-valued logic; by reinterpreting...

  7. A RESPONSABILIDADE CIVIL E O MEIO AMBIENTE

    Directory of Open Access Journals (Sweden)

    DELCYLENE VILLALBA SOARES

    2012-06-01

    Full Text Available RESUMOEste artigo tem por finalidade realizar uma análise sobre a evolução da responsabilidade civil e suas teorias, subjetiva e objetiva aplicadas ao meio ambiente. Dentro desta área, deve-se ressaltar que a responsabilidade civil ao meio ambiente, é um assunto de importante relevância para o efetivo controle da depredação ambiental, permitindo que sejam alcançadas as metas propostas como condição de sobrevivência da espécie humana, ou seja, a conservação do meio ambiente e o desenvolvimento econômico social, visando desta maneira, permitir a qualidade e a continuação da vida. Existe o entendimento, que somente com educação ambiental e normas reguladoras fortes, como a penalidade de ter que indenizar quando praticar algum dano ao meio ambiente conseguirá atingir o objetivo maior de preservação. Necessitam-se além de uma mudança na legislação que responsabilize poluidores do meio ambiente, atribuindo-lhes sanções que inibam a prática de tal conduta ilícita e realizando assim, a aplicabilidade da justiça.Palavras-chave:Responsabilidade Civil; Responsabilidade; Meio Ambiente ABSTRACTThis article have objective to realize a analysis about civil responsibility evolution and your theories, subjective and objective apply environment. Inside this area have to stand out that civil responsibility environment, it is a theme very important relevance for environment depredation control effective, permitting have been obtain proposals target like been human survival condition, therefore, environment conservation and social economic development objective permit quality and continuation of life. There is understanding, that only with environment education and strong regulation principle, like penalty has to indemnify when practice some injury of environment, will obtain more preservation. Demand a change on legislation that responsible environment polluter attribute him inhibit sanctions for practice this illicit conduct and

  8. Hybrid Logical Analyses of the Ambient Calculus

    DEFF Research Database (Denmark)

    Bolander, Thomas; Hansen, Rene Rydhof

    2010-01-01

    In this paper, hybrid logic is used to formulate three control flow analyses for Mobile Ambients, a process calculus designed for modelling mobility. We show that hybrid logic is very well-suited to express the semantic structure of the ambient calculus and how features of hybrid logic can...... be exploited to reduce the "administrative overhead" of the analysis specification and thus simplify it. Finally, we use HyLoTab, a fully automated theorem prover for hybrid logic, both as a convenient platform for a prototype implementation as well as to formally prove the correctness of the analysis. (C...

  9. Ensinar e aprender em ambientes virtuais tridimensionais

    OpenAIRE

    Gonçalves, Vitor

    2012-01-01

    Os mundos virtuais constituem ambientes simulados, normalmente tridimensionais, mediados através de tecnologias de informação e comunicação e que se destinam a ser frequentados por utilizadores que interagem com outros através de avatares. Estes ambientes virtuais tridimensionais (3D) podem ser desenvolvidos recorrendo a software de desenho 3D em versões comerciais e open source ou criados em servidores de mundos virtuais tridimensionais já existentes, tais como o Second Life ou similares. No...

  10. Ambientes virtuales como apoyo al Aprendizaje Colaborativo

    OpenAIRE

    Leguizamón, Guillermo; Chiarani, Marcela Cristina; Lucero, María Margarita; Pianucci, Irma Guadalupe; García, Berta Elena; Ponce, Viviana; Allendes Olave, Paola A.

    2005-01-01

    A partir de las conceptualizaciones sobre Educación a Distancia (EaD); y las Tecnologías disponibles para la EAD; se analizan los Ambientes Virtuales y su relación con el Código Abierto; lo que conlleva a presentar, en forma de grilla, las pautas y alcances de evaluación de plataformas virtuales de OS factibles de ser adaptados hacia la consecución de un Ambiente Virtual como apoyo al Aprendizaje Colaborativo. Con la puesta a punto, aplicación y relevo de esta grilla se estará en condicion...

  11. Medio Ambiente y Sostenibilidad (2012/2013)

    OpenAIRE

    Marzal Doménech, Paula; Gabaldón García, Carmen; Alvarez Hornos, Francisco Javier; Borrás Falomir, Luis

    2012-01-01

    La asignatura Medio Ambiente y Sostenibilidad tiene como objetivo general que los estudiantes adquieran una visión global de la contaminación ambiental atendiendo a sus orígenes y problemática, así como de los principios de la sostenibilidad y de las tecnologías medioambientales y su aplicación.Con esta asignatura se pretende que los estudiantes tomen conciencia de los problemas medioambientales, en particular de los derivados de las actividades industriales, y conozcan las estrategias y form...

  12. ANÁLISIS DE CONFLICTO SOCIO AMBIENTAL

    OpenAIRE

    María Beatriz Eguiguren Riofrío; Arturo Jiménez Lozano

    2011-01-01

    RESUMO El presente artículo hace referencia a las problemáticas socioambientales que han venido surgiendo en la Región Sur del Ecuador, las cuales modifican permanentemente el escenario social, político, económico y ambiental, factores que además se encuentran supeditados a fuerzas externas a nivel regional y mundial. Desde la perspectiva socio ambiental podemos observar algunos cambios jurídico – institucional, que se han dado desde el proceso de reforma de la Constitución 2008, cuyo mayor l...

  13. Human-Centric Interfaces for Ambient Intelligence

    CERN Document Server

    Aghajan, Hamid; Delgado, Ramon Lopez-Cozar

    2009-01-01

    To create truly effective human-centric ambient intelligence systems both engineering and computing methods are needed. This is the first book to bridge data processing and intelligent reasoning methods for the creation of human-centered ambient intelligence systems. Interdisciplinary in nature, the book covers topics such as multi-modal interfaces, human-computer interaction, smart environments and pervasive computing, addressing principles, paradigms, methods and applications. This book will be an ideal reference for university researchers, R&D engineers, computer engineers, and graduate s

  14. The brave new world of ambient intelligence

    Science.gov (United States)

    Ahonen, Pasi; Alahuhta, Petteri; Daskala, Barbara; Delaitre, Sabine; Hert, Paul De; Lindner, Ralf; Maghiros, Ioannis; Moscibroda, Anna; Schreurs, Wim; Verlinden, Michiel

    This chapter provides an overview of ambient intelligence in order to set the stage for the subsequent identification and discussion of threats, vulnerabilities and safeguards In this chapter, we provide a somewhat high-level description of the key technologies that are crucial to the development and deployment of ambient intelligence. The development and deployment of AmI are being propelled by certain visions of the future, which we reference in this chapter. For the most part, the development and deployment are taking place in a rather structured context composed of visions, scenarios, roadmaps, strategic research agendas, platforms and projects. We highlight the most important of these.

  15. Ambient Interstellar Pressure and Superbubble Evolution

    CERN Document Server

    Oey, M S

    2004-01-01

    High ambient interstellar pressure is suggested as a possible factor to explain the ubiquitous observed growth-rate discrepancy for supernova-driven superbubbles and stellar wind bubbles. Pressures of P/k ~ 1e5 cm-3 K are plausible for regions with high star formation rates, and these values are intermediate between the estimated Galactic mid-plane pressure and those observed in starburst galaxies. High-pressure components also are commonly seen in Galactic ISM localizations. We demonstrate the sensitivity of shell growth to the ambient pressure, and suggest that superbubbles ultimately might serve as ISM barometers.

  16. Autotrophic and heterotrophic food sources of copepods in the Scheldt estuary as traced by stable C and N isotopes

    OpenAIRE

    L. De Brabandere

    2005-01-01

    Estuaries draining densely populated watersheds experience significant anthropogenic pressure and sustain large autotrophic and heterotrophic production owing to an increased input of nutrients and organic matter. Polluted estuaries are often net heterotrophic systems. Our objective was to study the relative contributionof autotrophic and heterotrophic food webs in sustaining the high productivity of pelagic estuarine ecosystems along the estuarine gradient of the Scheldt estuary. We concentr...

  17. Estimación de la varianza genética y ambiental en caracteres métricos del esqueleto humano

    Directory of Open Access Journals (Sweden)

    Varela, Héctor Hugo

    2003-01-01

    Full Text Available En la teoría evolutiva de rasgos cuantitativos el conocimiento de la varianza genética (VG es determinante para hacer inferencias acerca del parentesco. En muchos casos no es posible estimar dicha componente sin la información obtenida a partir de la correlación entre parientes o de experimentos de selección. Por esta razón, en ausencia de datos apropiados es posible lograr una aproximación mediante el análisis de la repetibilidad de caracteres cuantitativos. En este trabajo se estima la proporción de la varianza genética máxima (VGmax o repetibilidad de medidas del cráneo y del esqueleto postcraneal, empleando la información obtenida por la Dra. Silvia Quevedo en el grupo prehistórico de Punta Teatinos (Norte Semiárido de Chile. La VG es igual a la varianza fenotípica (VP menos la varianza ambiental (VE. Esta última se puede particionar en una varianza ambiental especial (VEe y en una varianza ambiental general (VEg. Como la VEe se puede conocer por la medición de caracteres simétricos del lado derecho e izquierdo del individuo, entonces es posible calcular la varianza genética máxima de la siguiente manera, VGmax=VP-VEe. La proporción de la VGmax se obtuvo para siete variables del esqueleto postcraneano en individuos femeninos (n=56, masculinos (n=55, de ambos sexos (n=115 e infantiles (n=66, y para nueve mediciones del cráneo en un único grupo (n=54. Los resultados indican que la proporción media de la VGmax es menor en el cráneo que en el esqueleto postcraneal sugiriendo una distribución diferencial del efecto ambiental desde el punto de vista topográfico. Además, dicha cantidad es mayor en individuos infantiles que en masculinos y femeninos posiblemente por la existencia en aquellos de una mayor influencia del efecto ambiental general confundido con la VGmax.

  18. RASGOS CONDUCTALES Y COGNITIVOS DE LOS SÍNDROMES RETT, CRI-DU-CHAT, X-FRÁGIL Y WILLIAMS/ COGNITIVE AND BEHAVIOURAL FEATURES OF THE DESEASES RETT, CRI-DU CHAT, X-FRAGIL AND WILLIAMS

    Directory of Open Access Journals (Sweden)

    Mª Paz Fernández Lozano*

    2010-06-01

    Full Text Available RESUMENEl objetivo del trabajo es analizar las características conductuales y cognitivas de cuatro enfermedades raras (Síndromesde Rett, Cri-du-Chat, Williams y X-Frágil y su impacto en el ámbito educativo y clínico. En cada uno de los síndromes seexamina los rasgos comunes y diferenciados siguiendo un esquema básico: breve historia de la enfermedad, etiología,prevalencia, instrumentos de diagnóstico, pronóstico, genotipo y fenotipo, discapacidades intelectuales-lingüísticaspsicomotorasy su repercusión en el contexto escolar y familiar. Recientemente se constata una gran producción científicade la comunidad médica en relación con el tema; sin embargo, no existe información rigurosa y adaptada para las familias,asociaciones y profesionales que trabajan con estas poblaciones tales como: maestros de educación especial, especialistasde lenguaje, terapeutas ocupacionales y psicólogos, etc. Existe una necesidad sentida entre estos profesionales de traducirlos lenguajes científicos a actividades eficaces de intervención.ABSTRACTThe work aims to analyze the behavioural and cognitive characteristics of four rare diseases (Rett, Cri du Chat, Williamsand X-Fragile syndromes and its impact on education and clinical context. For each of the syndromes we explore commonand distinct traits by following a basic scheme: a brief history of the disease, etiology, prevalence, diagnosis, prognosis,genotype and phenotype, intellectual-linguists-psychomotor disabilities, diagnosis instruments, and their impact withinthe school and family. Recently there is a large scientific production of the medical community related to the subject;however, there is not rigorous and adapted information for families, associations and professionals who work with thesepopulations such as: occupational therapists special education teachers, language therapists, psychologists. There is a feltneed among these professionals to translate scientific languages into

  19. Dissolved inorganic carbon dynamics and CO2 atmospheric exchanges in the inner and outer Scheldt estuary

    OpenAIRE

    Borges, A. V.; Frankignoulle, M.

    2002-01-01

    Since 1992, the Chemical Oceanography Unit of the University of Liège has carried out on a regular basis field cruises in the Scheldt inner estuary and the river plume (outer estuary), during which were measured: pH, total alkalinity, dissolved inorganic carbon, partial pressure of CO2 (pCO2), dissolved oxygen and atmospheric flux of CO2. In the inner Scheldt estuary, pCO2 values in the upper estuary can be as high as 9000 ppm that is about 25 times the value of atmospheric equilibrium (pres...

  20. Decadal morphological evolution of the Yangtze Estuary in response to river input changes and estuarine engineering projects

    Science.gov (United States)

    Luan, Hua Long; Ding, Ping Xing; Wang, Zheng Bing; Ge, Jian Zhong; Yang, Shi Lun

    2016-07-01

    The Yangtze Estuary in China has been intensively influenced by human activities including altered river and sediment discharges in its catchment and local engineering projects in the estuary over the past half century. River sediment discharge has significantly decreased since the 1980s because of upstream dam construction and water-soil conservation. We analyzed bathymetric data from the Yangtze Estuary between 1958 and 2010 and divided the entire estuary into two sections: inner estuary and mouth bar area. The deposition and erosion pattern exhibited strong temporal and spatial variations. The inner estuary and mouth bar area underwent different changes. The inner estuary was altered from sedimentation to erosion primarily at an intermediate depth (5-15 m) along with river sediment decline. In contrast, the mouth bar area showed continued accretion throughout the study period. The frequent river floods during the 1990s and simultaneously decreasing river sediment probably induced the peak erosion of the inner estuary in 1986-1997. We conclude that both sediment discharge and river flood events played important roles in the decadal morphological evolution of the Yangtze Estuary. Regarding the dredged sediment, the highest net accretion rate occurred in the North Passage where jetties and groins were constructed to regulate the navigation channel in 1997-2010. In this period, the jetties induced enhanced deposition at the East Hengsha Mudflat and the high accretion rate within the mouth bar area was maintained. The impacts of estuarine engineering projects on morphological change extended beyond their sites.