WorldWideScience

Sample records for algas problemas emergentes

  1. A obesidade infantil: um problema emergente

    OpenAIRE

    Sousa, Joana; Loureiro, Isabel; Carmo, Isabel do

    2008-01-01

    A obesidade é um dos problemas de saúde mais graves que afecta crianças e adolescentes a nível mundial. As evidências sugerem que o problema está a agravar-se rapidamente. O aumento da prevalência de obesidade infantil pode fazer com que a próxima geração apresente indicadores de obesidade no adulto superiores aos indicadores actuais. Pelo facto de a obesidade estar intimamente associada a diferentes patologias crónicas faz com que estejamos perante um enorme desafio para o sistema de cuidado...

  2. Problemas bioéticos emergentes de la inteligencia artificial

    Directory of Open Access Journals (Sweden)

    Jairo Andrés Villalba Gómez

    2016-01-01

    Full Text Available El presente artículo de revisión, relaciona de forma analítica los conceptos entre bioética e inteligencia artificial, identificando los elementos técnicofilosóficos tales como: transhumanismo, inteligencia artificial y bioética de la tecnología; cuyo orden transdisciplinar, evoluciona en cuestionamientos científicos basados en la evolución de la tecnociencia del siglo XXI. Se identificarán los referentes conceptuales de la relación entre transhumanismo (H+ e inteligencia artificial (IA, su génesis, enfoques, fundamentos disciplinares, así como los elementos básicos que hacen posible la arquitectura en un sistema de inteligencia artificial, precisando así el ambiente prospectivo en el que se consolida una “era” basada en la “singularidad tecnológica”, para finalmente concluir en una descripción de algunos problemas ético-filosóficos que emergen en la evolución de la inteligencia artificial.

  3. Emergentism

    Directory of Open Access Journals (Sweden)

    Carlos Beorlegui

    2015-02-01

    Full Text Available We may wonder if the emergentist model owes too much to the two traditional alternative approaches (first or third person, although it is aware of its weaknesses it fails to complete its interesting contribution with an anthropological approach that may consider mind and mental phenomena as a reality that emerges, matures, develops and expresses itself in its unavoidable interpersonal and social contexts, as is shown by the psychological and anthropological research into the study of the development of human personality. We consider that three complementary elements or dimensions should be taken into account: the evolutionary aspect (the biological maturing process of the brain, which represents the jump from prehuman to human existence; the systemic aspect (the systemic way to understand the mind as the total structure of the brain; and the social aspect (the interpersonal and social dimension as the field where the mind and the person originate. It is only within the context of human society that each personal reality can be shaped as such. Thus, this proposal could be referred to as psycho-social-systemic emergentism.

  4. Síndrome de Sensibilidad Múltiple a sustancias químicas: un problema ambiental emergente

    Directory of Open Access Journals (Sweden)

    E. Ordaz Castillo

    2001-11-01

    Full Text Available El Síndrome de Sensibilidad Múltiple (SSM es un conjunto de múltiples síntomas asociados producidos tras la exposición a agentes químicos a muy bajas concentraciones.Se han propuesto diferentes teorías para explicar sus causas, incluyendo alergia, efectos tóxicos y sensibilización neurobiológica. La evidencia científica es insuficiente para confirmar la relación entre las posibles causas y los síntomas. Los pacientes con SSM presentan depresión, ansiedad y trastornos somatoformes, pero no está clara la relación existente entre este síndrome y los problemas psiquiátricos.El objetivo de esta revisión es presentar de forma resumida el estado actual del conocimiento del tema.

  5. Resistencia emergente a los antibióticos: una amenaza global y un problema crítico en el cuidado de la salud

    Directory of Open Access Journals (Sweden)

    Claudio Rocha

    Full Text Available Después del desarrollo y la comercialización en masa de los antibióticos, las bacterias patógenas y ambientales han desa- rrollado resistencia a los antibióticos desde el siglo pasado, de modo que la infección causada por organismos resistentes a los antibióticos (ORAs podría ser considerada como una infección emergente. Debido a ello, su control debe ser priorizado ya que constituye una amenaza para todas las naciones, sin reparar en su territorio y situación económica. El incremento de la vigilancia en Estados Unidos de América, Europa y Asia Oriental ha ilustrado lo rápido que pueden diseminarse, trayendo como consecuencia un incremento en la carga de infecciones causadas por los ORAs, sin embargo, la información disponible en los países de continuo desarrollo en América Latina es limitada. Esta revisión describe información reciente de estudios de vigilancia de ORAs en América Latina, así como también fuentes comunes de ORAs y posibles estrategias para su control.

  6. Algae

    Czech Academy of Sciences Publication Activity Database

    Raven, John A.; Giordano, Mario

    2014-01-01

    Roč. 24, č. 13 (2014), s. 590-595 ISSN 0960-9822 Institutional support: RVO:61388971 Keywords : algae * life cycle * evolution Subject RIV: EE - Microbiology, Virology Impact factor: 9.571, year: 2014

  7. La competencia informacional desde una perspectiva psicoeducativa: enseñanza basada en la resolución de problemas prototípicos y emergentes

    Directory of Open Access Journals (Sweden)

    Monereo, Carles

    2012-07-01

    Full Text Available This article contributes from a psycho-educational perspective to the definition and characterization of the concept of informational competency in teaching and learning in school-based education and in the training of information professionals. The first section defines a competent person as one who is able to adequately solve a set of typical problems stemming from a particular social or community practice. Based on this definition, the authors then identify and characterize informational problems and the most significant incidents faced by students during their school work, which are grouped into three sections: the demand and the conditions through which it is satisfied; the presence and the activation of beliefs, conceptions and relevant knowledge; and the regulation of decisions, emotions and interactions with others. The text then presents some guidelines for training in information skills, based on authentic tasks. The article concludes by reflecting on the implementation of innovative educational experiences for the development of informational competency in the context of formal education.

    Se realiza una aportación desde un punto de vista psicoeducativo a la definición y caracterización de la noción de competencia informacional, a su enseñanza y aprendizaje en la educación escolar, y a la formación de los profesionales de la información. En el primer apartado, se define una persona competente como aquella que es capaz de resolver adecuadamente un conjunto de problemas característicos de una determinada práctica social y comunitaria. Seguidamente, tomando como base esta definición, se identifican y caracterizan los problemas e incidentes informacionales más significativos que deben afrontar los estudiantes durante sus tareas escolares, agrupados en tres grandes bloques: relativos a la demanda y a las condiciones de su resolución; relacionados con la presencia y la activación de creencias, concepciones y

  8. Seroprevalencia de la hepatitis C en adultos de México: ¿un problema de salud pública emergente? Seroprevalence of hepatitis C among Mexican adults: an emerging public health problem?

    Directory of Open Access Journals (Sweden)

    José Luis Valdespino

    2007-01-01

    Full Text Available OBJETIVO: La infección por virus de la hepatitis (VHC evoluciona hacia la cronicidad en 60 a 85% de los sujetos que la sufren y ocasiona cirrosis hepática y cáncer primario de hígado. El objetivo de este estudio fue notificar la seroprevalencia de infección por VHC en una muestra probabilística de la población en el plano nacional. MATERIAL Y MÉTODOS: Se estudiaron 21 271 sueros seleccionados de manera aleatoria de la Encuesta Nacional de Salud 2000, para anti-VHC y RNA de VHC. El estudio se realizó en el Instituto Nacional de Salud Pública en el año 2005. RESULTADOS: La seroprevalencia de los anticuerpos VHC fue de 1.4% (IC95% 1.1-1.6 y 35.7% tenía infección activa. Los factores de riesgo de infección de VHC detectados son el antecedente de consumo de heroína (RM=9.8, IC: 2.1-41.4, estar separado (RM=2.6, IC: 1.1-5.9 o ser viudo (RM=2.2, IC: 1.1-4.3 y residir en la región norte del país (RM=1.9, IC: 1.1-3.2. CONCLUSIONES: Los datos indican que la hepatitis C es un problema de salud pública emergente en México. Los factores de riesgo de infección indican que la transmisión más frecuente de los infectados ocurre en receptores de sangre y hemoderivados (antes de 1996 y, de manera secundaria, por drogadicción intravenosa y de tipo sexual.OBJECTIVE: Hepatitis C Virus (HCV infection is becoming a chronic disease in 60-85% of individuals and is a cause of hepatic cirrhosis and hepatocellular carcinoma. The objective of this study was to report the seroprevalence of HCV infection in a probabilistic sample of the Mexican population. MATERIAL AND METHODS: This study is based on information obtained from the National Health Survey conducted in 2000. A total of 21 271 sera randomly selected for anti-HCV and RNA of HCV was studied. It was performed at the National Institute of Public Health in 2005. RESULTS: Seroprevalence of HCV antibodies was 1.4% (IC95% 1.1%-1.6%, of which 35.7% had active infection. Risk factors for infection were

  9. Educación-comunicación-tecnología, un campo emergente: retos y problemas en los escenarios epistemológicos y políticos del mundo actual

    Directory of Open Access Journals (Sweden)

    Álvaro Acevedo Tarazona

    2008-01-01

    Full Text Available La historia de la educación es también una forma de abordar el gran campo de la educación si se asume éste como el devenir de aquellas acciones que se dirigen a modificar la conducta humana mediante la enseñanza de lenguajes y la puesta en ejecución de actividades, operaciones concretas, prácticas (didácticas, tanto en los espacios formales como no formales (la escuela, la universidad. La presente reflexión tiene como propósito dirigir la discusión sobre algunos temas considerados hoy fundamentales en la docencia, sobre todo ante a los nuevos retos que entraña los cambios epistemológicos y las prácticas en la educación. Estos temas son: la crisis del proyecto educativo de la modernidad; la educación-comunicación-tecnología, un campo emergente; la inquietante pregunta por la muerte del libro, la mutación de los desarrollos disciplinarios y, por último, el docente como un agente del cambio social.

  10. Geoeconomia dos emergentes

    OpenAIRE

    Pinto, Pedro

    2010-01-01

    Mercados decisivos para a recuperação da economia global, até porque muito mais imunes às consequências da crise fi nanceira, os países emergentes apresentam taxas de crescimento mais altas face aos principais países desenvolvidos e têm desempenhado um papel fundamental na consolidação dos volumes de comércio internacional e de crescimento da economia mundial ao longo desta última década.

  11. La experiencia de los virus emergentes en el Caribe colombiano

    Directory of Open Access Journals (Sweden)

    Salim Máttar V

    2010-04-01

    Full Text Available Existe una interrelación muy estrecha entre el hombre, su ecología y el mundo microbiano, tanto el ser humano como los agentes infecciosos han coevolucionado durante milenios (1. La historia demuestra que ha existido una confluencia de diferentes enfermedades infecciosas y las principales civilizaciones. En los últimos años las enfermedades zoonoticas emergentes han ido cobrando una importancia creciente en el terreno de la salud humana y animal, surgiendo nuevas enfermedades procedentes siempre de lugares insospechados y causantes de graves problemas para el hombre o los animales (2. La mayoría de patógenos involucrados en las enfermedades infecciosas emergentes (EIE son de origen bacteriano o rickettsial (54.3%. En este grupo están incluidos los patógenos bacterianos resistentes a los antibióticos. Los patógenos de origen viral y los priones, constituyen el 25.4% de eventos de las EIE, los protozoarios representan el 10.7%, seguido de los hongos 6.3% y los helmintos en un 3.3%. El 60.3% de las enfermedades infecciosas emergentes son causadas por patógenos zoonoticos (2. El 71.8% de estas zoonosis son causados por patógenos que se originan de la fauna silvestre, como la emergencia del virus de Nipah en Malasia y el síndrome respiratorio agudo severo (SARS en China (3.

  12. una sociedad emergente

    Directory of Open Access Journals (Sweden)

    Derlisiret Rincón M.

    2006-01-01

    Full Text Available Este trabajo busca reflexionar por una parte acerca del papel de la ciencia, la tecnología y la educación, como factores de desarrollo de las naciones e intenta responder la interrogante en torno al cómo estas variables contribuirán a la transformación de la realidad social venezolana. Los planteamientos expuestos en este artículo forman parte de una investigación cualitativa que se sustenta en una revisión teórica cuyos resultados indican que existe la posibilidad cierta de construir y alcanzar una Venezuela virtual en los próximos años; es decir, se vislumbra un país interconectado y funcionando a través de redes cuyos individuos estarían capacitados y entrenados en el uso y usufructo de las nuevas tecnologías. Esta visión de país, se basa en la premisa de que la oportuna implementación de la Planificación de Ciencia y Tecnología resultaría instrumento de vinculación de las variables tecnológicas, educativas y científicas, que permiten obtener conocimientos especializados y orientados a la solución de problemas de creciente dimensión global. Tales conocimientos, pudieran generar los cambios sustanciales necesarios en el contexto nacional, para lograr modificar o disminuir el sentido de crecimiento de la brecha o divisoria digital en este entorno

  13. XAMPP: Problemas

    OpenAIRE

    Luján Mora, Sergio

    2013-01-01

    Dos problemas muy comunes, y sus soluciones, que pueden ocurrir con XAMPP, la plataforma de desarrollo para los sistemas operativos Linux, Windows, MacOS X y Solaris que incluye Apache, MySQL, PHP y Perl.

  14. Justicia Restaurativa: Un paradigma emergente

    OpenAIRE

    García Gumbau, Erica

    2017-01-01

    RESUMEN DE LA TESIS DOCTORAL JUSTICIA RESTAURATIVA: UN PARADIGMA EMERGENTE La tesis profundiza y reflexiona en torno a una nueva concepción de la justicia y su aplicación en la praxis. Actualmente nos encontramos ante una crisis del paradigma retributivo o crisis del modelo de justicia tradicional, dominante hasta ahora en la administración de justicia. Paralelamente, se está empezando a hablar de una nueva filosofía de la administración de justicia. El presente trabajo de i...

  15. The Differences between Emergentism & Skill Acquisition Theory

    Directory of Open Access Journals (Sweden)

    Naeemeh Kharaghani

    2017-01-01

    Full Text Available Although both emergentism and skill acquisition theory developed in the same field (cognitive theories and as an attempt to replace Universal grammar-based approaches, there are some differences between these two theories. The differences lie under their different models of knowledge representation and their diverse degree of emphasis on the role of input. In addition, skill acquisition considers the process of learning while emergentism considers input and output, and what goes on in between has not been considered. Finally it should be mentioned that these two theories take different views towards the learning process. 

  16. The humanist emergentism of Javier Monserrat

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    Carlos Beorlegui

    2016-02-01

    Full Text Available J. Monserrat is the most significant and consistent representative of the emergentist paradigm in our cultural context. He defends a humanist emergentism, which he has deepened from the level of neuronal engrams to later agree with the postulates on quantum neurology by Penrose and Hameroff. This article will present the main arguments supported by J. Monserrat, within the context of the ample paradigm of systemic emergentism. It will show how this paradigm allows him to defend a humanist and believing anthropological model in a more adequate way.

  17. Formas duradouras e formas emergentes de trabalho precário entre os jornalistas brasileiros

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    Jeferson Bertolini

    2015-08-01

    Full Text Available Este artigo busca dimensionar o conceito de trabalho precário entre os jornalistas brasileiros. O texto indica que a categoria sempre esteve exposta a formas precárias de trabalho, mas que o problema se agravou nos últimos 10 anos, com as tecnologias digitais: elas redefiniram o perfil do profissional e reordenaram o modelo de negócio das empresas do setor. O manuscrito, baseado em levantamento bibliográfico e experiência de campo, lista oito formas duradouras e oito formas emergentes de trabalho precário no jornalismo.

  18. PARADIGMAS EMERGENTES, CONHECIMENTO E MEIO AMBIENTE

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    Liane Keitel

    Full Text Available Este artigo tem por objetivo estimular o debate sobre novos modos de se compreender/ tratar o mundo com os recursos científico-epistêmicos. Para tal, o es tudo levanta e analisa novas formas de relacionamento científico com o mundo, com fundamento em paradigmas emergentes em ciências, tais como a teoria dos sistemas de Bertalanfy, a teoria de auto-organização de von Foerster, Ilya Prigogine, Henri Atlan e Edgar Morin, do acaso e necessidade de Monod, de autopoiese de Humberto Maturana e Francisco Varela, com suas emergentes possibilidades epistemológicas e também educacionais. Utiliza-se o método reconstrutivo, ou seja, colocam-se em diálogo teóricos e teorias diferentes que possam fornecer sustentação argumentativa para a tese central defendida.

  19. The Study of Algae

    Science.gov (United States)

    Rushforth, Samuel R.

    1977-01-01

    Included in this introduction to the study of algae are drawings of commonly encountered freshwater algae, a summary of the importance of algae, descriptions of the seven major groups of algae, and techniques for collection and study of algae. (CS)

  20. Soil algae

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Also, the importance of algae in soil formation and soil fertility improvement cannot be over ... The presence of nitrogen fixing microalgae (Nostoc azollae) in the top soil of both vegetable ..... dung, fish food and dirty water from fish ponds on.

  1. Revitalization of Emergentism in SLA: A Panacea!

    Directory of Open Access Journals (Sweden)

    Nima Shakouri Masouleh

    2012-09-01

    Full Text Available Emergentists claim learning takes place by extracting regularities from the input. By the same token, Ellis (1998 disputed the view held by generative linguistics that such a complex phenomenon as language can only be learnt if it is assumed that humans are endowed genetically with a language specific learning device. Emergentists, as O’Grady (2003 reports, claim simple learning mechanisms are sufficient to bring about the emergence of complex language representations. Nevertheless, this perspective toward learning has so far failed to take into account how language competence could emerge (O’Grady, 2003. The following paper is an attempt to elucidate the theoretical assumptions behind emergentism.

  2. Algae Resources

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Algae are highly efficient at producing biomass, and they can be found all over the planet. Many use sunlight and nutrients to create biomass, which contain key components—including lipids, proteins, and carbohydrates— that can be converted and upgraded to a variety of biofuels and products. A functional algal biofuels production system requires resources such as suitable land and climate, sustainable management of water resources, a supplemental carbon dioxide (CO2) supply, and other nutrients (e.g., nitrogen and phosphorus). Algae can be an attractive feedstock for many locations in the United States because their diversity allows for highpotential biomass yields in a variety of climates and environments. Depending on the strain, algae can grow by using fresh, saline, or brackish water from surface water sources, groundwater, or seawater. Additionally, they can grow in water from second-use sources such as treated industrial wastewater; municipal, agricultural, or aquaculture wastewater; or produced water generated from oil and gas drilling operations.

  3. Competencia informacional y brecha digital: preguntas y problemas emergentes derivados de investigación

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    Gloria Patricia Marciales Vivas

    2012-04-01

    Full Text Available El artículo presenta resultados del estudio sobre el análisis de los cambios en las competencias informacionales vinculadas con el tránsito del formato impreso al digital en contextos universitarios. En el estudio fenomenográfico se analizan las trayectorias familiares y escolares y su relación con las prácticas de uso de fuentes de información en los dos formatos. Los resultados dan cuenta de las narraciones construidas por los jóvenes en sus historias familiares y escolares sobre las formas de acceder, evaluar y usar fuentes de información en contextos académicos.

  4. Niños dependientes de tecnología, un problema emergente de salud

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    Gerardo Rogelio Robaina Castellanos

    2012-09-01

    Full Text Available Desde hace varias décadas un número creciente de niños requiere de tecnologías para el mantenimiento de sus vidas. Estos niños dependientes de tecnología a menudo deben recibir cuidados de enfermería en sus propios hogares. El objetivo de este trabajo es realizar una revisión del tema. Se exponen en él algunas definiciones, clasificaciones y principios para la atención en el hogar a niños dependientes de tecnología, así como las habilidades y competencias a desarrollar por el personal de enfermería. Aunque estos niños constituyen un grupo minoritario de pacientes en Cuba, se necesita integrar, en un solo programa, su atención. El cuidado centrado en la familia, la adecuada coordinación entre los diferentes niveles de salud, la continuidad en los cuidados, y la accesibilidad de toda la población, son algunos de los principios básicos para la ejecución de un programa de atención; pero se requiere, además, del apoyo de todos los miembros de la sociedad.

  5. COMPETENCIA INFORMACIONAL Y BRECHA DIGITAL: PREGUNTAS Y PROBLEMAS EMERGENTES DERIVADOS DE INVESTIGACIÓN

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    Gloria Patricia Marciales Vivas

    2012-01-01

    Full Text Available El artículo presenta resultados del estudio sobre el análisis de los cambios en las competencias informacionales vinculadas con el tránsito del formato impreso al digital en contextos universitarios. En el estudio fenomenográfico se analizan las trayectorias familiares y escolares y su relación con las prácticas de uso de fuentes de información en los dos formatos. Los resultados dan cuenta de las narraciones construidas por los jóvenes en sus historias familiares y escolares sobre las formas de acceder, evaluar y usar fuentes de información en contextos académicos.

  6. ENFERMEDADES INFECCIOSAS EMERGENTES: EL TURNO DEL VIRUS DEL ZIKA

    Directory of Open Access Journals (Sweden)

    Carlos Arturo Álvarez Moreno

    2016-04-01

    ó y continúa siendo una causa frecuente de epidemias. En Suramérica, incluyendo Colombia, el último brote fue introducido en 1991.

    Más cerca, en 1918, la pandemia de la influenza (gripa española produjo solo en Estados Unidos 500.000 muertes y mucho más cerca, la pandemia de influenza por la A(H1N1 causó solo en el 2009 cerca de 500.000 muertes y aún sigue circulando, generando muertes adicionales (1. Si a esto le sumamos los casos de otras enfermedades emergentes como síndrome respiratorio agudo severo causados por coronavirus (SARS en el 2003 o MERS actualmente o el brote de fiebre amarilla (enfermedad reemergente ocurrido en el 2003-2004 en nuestro país, se puede decir que las enfermedades infecciosas, tanto las emergentes como las reemergentes, lejos de estar controladas, cada vez son un problema creciente de salud pública.

    1 Miembro Correspondiente. Academia Nacional de Medicina. Profesor Titular, Facultad de Medicina. Universidad Nacional de
    Colombia. Director General, Clínica Universitaria Colombia, Clínicas COLSANITAS S.A...

  7. Un concepto emergente de planeación

    Directory of Open Access Journals (Sweden)

    Jorge Sánchez Buitrago

    2014-01-01

    Full Text Available El propósito de este artículo es sustentar un concepto emergente de planeación derivado del desarrollo de la investigación titulada: “Hacia un paradigma emergente de la planeación: Resignificación desde las instituciones universitarias”. El principal objetivo es el de aportar en el sostenimiento de una racionalidad alternativa de la planeación, a partir de la lectura de algunos de los principales conceptos que están  determinando el salto paradigmático de la ciencia contemporánea. En este sentido se hace una valoración crítica de las actuales tensiones y agotamientos teóricos y prácticos de la planeación, como sustento para el establecimiento de bases conceptuales de nuevos procesos planeación.Generalmente las nuevas propuestas de planeación, en particular las del ámbito educativo y de los escenarios universitarios, se han gestado desde intencionalidades instrumentalistas y materializado en metodologías operativas que poco o nada se ocupan de hacer evidente su fundamentación conceptual; lo que conduce al planificador a un aprisionamiento epistemológico, por cuanto en ausencia de reflexiones teóricas sólidas es difícil superar los modelos de planeación cuando éstos se tornan obsoletos. Se espera que a partir de esta reflexión sobre la naturaleza de la planeación se generen procesos de transformación de prácticas de planeación en las organizaciones educativas, en especial en las universidades.Palabras Clave: Concepto de planeación; problemas de planeación; tipos de planeación; paradigma alternativo de planeación. An emerging concept of planningAbstractThis article briefly describes the discussion of an emerging concept for planning, which is derived from the research entitled “Towards an emerging paradigm in planning: re-conceptualization for higher education institutions. ” The main purpose is to supply the grounds for an alternative rationality in planning, taking into account some of the significant

  8. Tecnologías emergentes, ¿pedagogías emergentes?

    OpenAIRE

    Adell, Jordi; Castañeda Quintero, Linda Johanna

    2012-01-01

    En el presente capítulo intentamos hacer una primera aproximación al actual concepto de pedagogías emergentes y hacer explícitas algunas de sus características –algunas análogas a las de las tecnologías emergentes–, así como delimitar algunos de los principios que actualmente las de!nen en el entorno educativo. Abstract: In the following paper we try to do a !rst approach to the current concept of emergent pedagogies, we try to make explicit some of their characteristics –some of them are ...

  9. Las Enfermedades Infecciosas emergentes y la Salud Pública

    Directory of Open Access Journals (Sweden)

    Fabio Aurelio Rivas Muñoz

    1997-06-01

    Full Text Available

    El optimismo de hace unos años con respecto al control definitivo de las enfermedades infecciosas ha venido diluyéndose poco a poco. Hoy en día, estas entidades nos atacan por múltiples frentes y, en conjunto, representan la principal causa de muerte a escala mundial. En 1995 17 millones de personas, incluidos 9 millones de niños, murieron por infecciones prevenibles como diarreas y neumonías. Los antibióticos, considerados hasta hace poco tiempo la solución al problema de las infecciones, son cada vez menos eficaces en la medida en que se incrementa el número de cepas resistentes y la velocidad con que éstas desarrollan dicha resistencia.

    Si a este hecho agregamos el evidente deterioro de las condiciones de vida de la población y el que ha sufrido la salud pública en particular, a consecuencia del desigual impulso a la más rentable atención de la enfermedad individual, la facilidad y rapidez con que se viaja de uno a otro continente o de una a otra región dentro de un país, la urbanización desordenada e incontrolada de las ciudades, la crisis económica mundial, los daños al ambiente, etc., todas condiciones que, en general, favorecen la aparición de “”nuevas” infecciones, puede entonces comprenderse la magnitud del desafío.

    Algunas de las enfermedades infecciosas emergentes, esto es, aquellas cuya incidencia en el Ser Humano ha aumentado durante los dos últimos decenios o amenaza con aumentar en el futuro próximo, han surgido a consecuencia de la evolución de microorganismos ya existentes como la tuberculosis o el cólera. Otras, quizás las menos, son ocasionadas por agentes hasta hace poco desconocidos (nuevos, varios de gran patogenecidad, como el virus de Ebola o Hantavirus que llevan a severas neumonías con letalidad del 50%.

    En las Américas, entre 1991 y 1995 se notificaron más de 1 millón de casos de cólera y 9 mil muertes. La OPS estima en 10 años y en más de 200.000 millones de

  10. MICROCONTAMINANTES EMERGENTES EN AGUAS: TIPOS Y SISTEMAS DE TRATAMIENTO

    OpenAIRE

    Yolanda Patiño; Eva Díaz; Salvador Ordóñez

    2014-01-01

    En el presente artículo se revisan las distintas clases de contaminantes emergentes, su origen y uso, y su presencia en las cuencas españolas, tanto en aguas superficiales como subterráneas. Los microcontaminantes emergentes son compuestos de distinto origen y naturaleza que hasta ahora habían pasado inadvertidos debido a su baja concentración (en el orden de las ppb) y sobre los que no hay regulación específica. Están divididos en seis grandes grupos y muchos de ellos se comportan como disru...

  11. Un concepto emergente de planeación

    OpenAIRE

    Jorge Sánchez Buitrago

    2014-01-01

    El propósito de este artículo es sustentar un concepto emergente de planeación derivado del desarrollo de la investigación titulada: “Hacia un paradigma emergente de la planeación: Resignificación desde las instituciones universitarias”. El principal objetivo es el de aportar en el sostenimiento de una racionalidad alternativa de la planeación, a partir de la lectura de algunos de los principales conceptos que están  determinando el salto paradigmático de la ciencia contemporánea. En este sen...

  12. Eliminación de contaminantes emergentes presentes en aguas por aplicación de proceso foto-Fenton. Estudio de acoplamiento por depuración biológica

    OpenAIRE

    LORENTE ROSA, LUCÍA

    2018-01-01

    [ES] La escasez del agua de calidad es un problema a nivel mundial que va aumentando a causa de la contaminación que experimenta. Por ello, la depuración y la reutilización de las aguas contaminadas son cada vez más necesarias. La emisión de los denominados contaminantes emergentes (CEs), presenta una gran importancia y son muchas las organizaciones que intentan aportar soluciones al problema. Los CEs son microcontaminantes generalmente de tipo orgánico, que en su mayor parte no ...

  13. Criptosporidiosis: una zoonosis emergente Cryptosporidiosis: an emerging zoonosis

    Directory of Open Access Journals (Sweden)

    V. F. Del Coco

    2009-09-01

    Full Text Available El género Cryptosporidium, responsable de la criptosporidiosis, abarca diversas especies. El ganado vacuno y el hombre constituyen las principales fuentes de infección. Los brotes de criptosporidiosis están asociados al agua de consumo, por ser el ooquiste -la forma infectante del parásito- resistente a los tratamientos convencionales de potabilización. En individuos inmunocompetentes es causa de diarrea aguda, normalmente autolimitada. En pacientes inmunocomprometidos la enfermedad puede adquirir formas graves, potencialmente fatales. Las personas afectadas por el síndrome de inmunodeficiencia adquirida son particularmente propensas a padecer formas graves de criptosporidiosis. En terneros, las infecciones por Cryptosporidium son consideradas un factor de morbimortalidad y conducen a grandes pérdidas económicas. En los últimos años, el incremento del número de pacientes con distintas causas de inmunosupresión ha aumentado la necesidad de encontrar un tratamiento efectivo para la infección por Cryptosporidium. A pesar de los numerosos intentos de la industria farmacéutica de desarrollar un antiparasitario efectivo, la infección gastrointestinal por Cryptosporidium y sus consecuencias clínicas continúan siendo un importante problema en materia de salud pública. En la presente actualización se analiza la taxonomía, la morfología, la biología y el ciclo evolutivo de Cryptosporidium, así como también los aspectos clínicos, inmunológicos, diagnósticos y epidemiológicos de la criptosporidiosis. Se discute el tratamiento y la profilaxis de esta afección y se sugieren pautas tendientes a lograr un control más adecuado de esta parasitosis emergente.The genus Cryptosporidium, responsible for producing cryptosporidiosis, includes several species. Humans and livestock are the main sources of infection. Waterborne cryptosporidiosis outbreaks are associated with drinking water. The infective parasite stage is the oocyst, which is

  14. Magnetic separation of algae

    Science.gov (United States)

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  15. Blue-Green Algae

    Science.gov (United States)

    ... that taking a specific blue-green algae product (Super Blue-Green Algae, Cell Tech, Klamath Falls, OR) ... system. Premenstrual syndrome (PMS). Depression. Digestion. Heart disease. Memory. Wound healing. Other conditions. More evidence is needed ...

  16. Aprendizaje basado en problemas

    OpenAIRE

    Morral, A.; Bou, T.; Cabot, A.; Capitán, A.; Díaz, J.; Fatjó, J.; Macaya, J.L.; Montmany, A.; Romero, D.

    2002-01-01

    Desde el Área de fundamentos de Fisioterapia y con el objetivo de mejorar nuestra calidad docente, iniciamos durante el curso 1999-2000 un conjunto de actividades alrededor de una metodología docente conocida internacionalmente como "problem-based learning". En este articulo explicaremos brevemente en qué consiste el aprendizaje a partir de problemas y cuáles podrían ser las ventajas, desventajas y las posibilidades de implementar este métodos dentro de la Diplomatura de Fisioterapia. T...

  17. Nuestro único problema

    Directory of Open Access Journals (Sweden)

    Héctor Rojas Herazo

    1967-12-01

    Full Text Available Toda vida humana por ser, en profundidad y superficie, una batalla contra la muerte, es un fenómeno epopéyico. Más admirable cuanto más secreta y personal sea esa batalla. Pues no nos enfrentamos a este o aquel obstáculo ni somos atraídos por este o aquel señuelo. Nuestra íntima preocupación, nuestro único problema, nuestro máximo terror es sabernos materia de disolución, míseras astillas para alimentar el insaciable fuego de la muerte.

  18. El riesgo asegurable y los riesgos emergentes de las nuevas tecnologías

    Directory of Open Access Journals (Sweden)

    Hilda Esperanza Zornosa Prieto

    2009-12-01

    Full Text Available Este documento analiza los retos que imponen al sector asegurador tradicional los riesgos emergentes de la era tecnológica, con especial referencia a los daños causados al medio ambiente y los daños ecológicos en general, sobre los que no existe aún, por tratarse de conceptos relativamente nuevos, información estadística que permita la medición de su frecuencia y severidad y, en consecuencia, la determinación del monto de una prima ajustada al riesgo; lo cual se constituye, de hecho, en el factor diferencial entre el concepto general de riesgo asegurable y el concepto que sobre éste se tiene en el seguro de contaminación, pues si bien estos conceptos no difieren en general, es innegable que el último versa sobre un riesgo extraordinario o catastrófico, que conduce a aquella imposibilidad de aplicar técnicas actuariales y mediciones estadísticas; todo lo cual lleva a sostener que el seguro y la responsabilidad civil no pueden, por sí solos, solucionar los problemas que plantean los riesgos de la era tecnológica, lo que hace necesaria la intervención activa del Estado.

  19. PARADIGMA TRADICIONAL E PARADIGMA EMERGENTE: ALGUMAS IMPLICAÇÕES NA EDUCAÇÃO

    Directory of Open Access Journals (Sweden)

    Wallace Carvalho Ribeiro

    Full Text Available É intrínseco ao Homem conhecer os objetos e os fenômenos da realidade que o cerca, por meio de um ponto de vista que, por sinal, se refere a um paradigma que traz consigo uma epistemologia. Nesse con texto, o presente artigo objetiva levantar alguns princípios e pressupostos do Paradigma Tradicional e do Paradigma Emergente, como também visa apresentar algumas implicações desses dois paradigmas na Educação. Esse trabalho foi desenvolvido por meio de pesquisa bibliográfica e faz parte da dissertação de Mestrado, defendida no 1° semestre de 2009, pelo seu primeiro autor no Programa de Pós-Graduação em Educação da PUC Minas. Ao final, constatou-se que se vive hoje um período de mudanças paradigmáticas, embora todos nós ainda temos muito do paradigma cartesiano-newtoniano, mas o surgimento de novos problemas oriundos da dinâmica da realidade nos impõe o desafio da transformação no nosso ser e agir, no intento de (reconstruir um conhecimento mais humano e diversificado.

  20. Infraclases rurales: procesos emergentes de exclusión social en España

    Directory of Open Access Journals (Sweden)

    SIMÓN PEDRO IZCARA PALACIOS

    2002-01-01

    Full Text Available Desde comienzos de los ochenta el discurso sociológico sobre la pobreza ha sufrido un proceso de desruralización, quedando dominado por el concepto de "infraclase". Éste se ha constituido en el término explicativo de un tipo particular de pobreza enraizada en un problema dual de marginalidad económica y aislamiento social en áreas urbanas espacialmente concentradas. En las áreas rurales, este tipo de dislocaciones sociales han permanecido veladas, haciendo que la noción de pobreza rural haya quedado relegada a un segundo plano. Sin embargo, los trazos más destacados de los "infraclase" (desempleo de larga duración, trabajo no cualificado en empleos erráticos, asilamiento social y dependencia de prestaciones sociales son especialmente relevantes para el análisis de los procesos de exclusión social en el medio rural español. Este artículo examina la emergencia de un colectivo "infraclase" en la España rural. Los nuevos procesos emergentes de exclusión social en el medio rural español estarían relacionados con el desempleo agrario en la España meridional y el uso de mano de obra inmigrante ilegal en la agricultura del litoral mediterráneo.

  1. Algoritmos para problemas de empacotamento

    OpenAIRE

    Eduardo Candido Xavier

    2006-01-01

    Resumo: Neste trabalho estudamos diversos problemas de empacotamento considerados NP-difíceis. Assumindo a hipótese de que P ? NP, sabemos que não existem algoritmos eficientes (complexidade de tempo polinomial) exatos para resolver tais problemas. Uma das abordagens consideradas para tratar tais problemas é a de algoritmos de aproximação, que são algoritmos eficientes e que geram soluções com garantia de qualidade. Neste trabalho apresentamos alguns algoritmos aproximados para problemas de e...

  2. La diversidad como problema

    Directory of Open Access Journals (Sweden)

    Jordi Garreta i Bochaca

    2013-05-01

    Full Text Available La diversidad cultural es uno de las trazos definitorios de nuestra socie-dad. En un contexto, en el que la diversidad -resultado de !as migraciones- se va incre-mentando hay que plantearse una serie de adaptaciones mutuas, más allá de la asimila-ción. La escuela, institución reflejo de las ideologías dominantes en este sentido, debería tomar en consideración esta diversidad y convertirla en riqueza más que en un problema. Fijándonos en la experiencia del Quebec y otras sociedades que han recibido durante muchos años inmigrantes, consideramos interesante tener en cuenta su experiencia y, por ejemplo, revisar a fondo el material escolar, desarrollar la figura del mediador (un profe-sional que puede incrementar la comunicación entre centro y familia, relación que se ve influenciada por barreras lingüísticas, socioeconómicas, culturales e institucionales; etc = The cultural diversity is one of the linea of definition of our society. !n a context, in the one that the diversity -for the migrations- it leaves increasing it is necessary to think about mutual adaptations, beyond the assimilation. The school, reflective institu-tian of the dominant ideologies in this sense, it should take in consideration this diversity and to transform it finto wealth more than in a problem. Noticing the experience of the Quebec and other societies that have received during many years immigrants, considera interesting to keep in mind their experience and, for example, to thoroughly revise the school material, to develop the mediator's figure (a professional that it can increase the communication among centre and family, relationship that is influenced by linguistic, socio-economic, cultural and institutional differences; etc

  3. Aprendizaje activo basado en problemas

    OpenAIRE

    Álvarez Martínez, Carlos; Fernández Jiménez, Agustín; Llosa Espuny, José Francisco; Sánchez Carracedo, Fermín

    2013-01-01

    Durante años, los autores del presente trabajo hemos practicado diversos métodos para fomentar el aprendizaje activo de los estudiantes a partir de la resolución de problemas, tanto en clase como fuera de ella. Los últimos cuatro cursos hemos utilizado en clase de problemas de la asignatura una metodología que consiste en encargar a los estudiantes cada semana que resuelvan un pequeño conjunto de problemas que trabajarán en clase la semana siguiente. En clase, los j...

  4. Educabilidad y problemas de aprendizaje

    Directory of Open Access Journals (Sweden)

    Jorge Capella Riera

    1993-12-01

    Full Text Available En el presente artículo voy a intentar responder al pedido de algunos colegas de desarrollar esas ideas a fin de contribuir al estudio de un problema que, por su magnitud y proyección, está causando preocupación entre educadores y psicólogos. Y al hacerlo parto de la idea de que los problemas, no importa de qué índole sean, no pueden resolverse aisladamente. Su interconexión e interdependencia respecto a otros problemas reclaman una visión deconjunto y una gran apertura a la contrastación teórica.

  5. Candida glabrata um patogénio emergente?

    OpenAIRE

    Matilde, Filipa Alexandra Veiga

    2014-01-01

    Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz Nas últimas décadas as infecções fúngicas têm aumentado exponencialmente. Apesar de Candida albicans (C. albicans) continuar a ser a espécie isolada com maior frequência, as espécies não albicans tem vindo a proliferar rapidamente. Candida glabrata (C. glabrata) é uma das espécies emergentes como patogénio oportunista humano, sendo responsável maioritariamente por candidoses invasivas em pacie...

  6. Psicologia do esporte: uma área emergente da psicologia

    OpenAIRE

    Vieira, Lenamar Fiorese; Vissoci, João Ricardo Nickenig; Oliveira, Leonardo Pestillo de; Vieira, José Luiz Lopes

    2010-01-01

    O artigo trata da Psicologia do Esporte, um campo de atuação emergente do psicólogo no Brasil. Faz uma análise sobre o percurso histórico da Psicologia Esportiva apresentando os campos de atuação profissional (pesquisa, ensino e intervenção), o papel do psicólogo esportivo (pesquisador, professor e consultor) e o estado científico atual dessa especialidade psicológica. Mesmo com o vasto campo de trabalho, um elemento interveniente é a diversidade de conhecimentos necessários para esta subdivi...

  7. Algae Derived Biofuel

    Energy Technology Data Exchange (ETDEWEB)

    Jahan, Kauser [Rowan Univ., Glassboro, NJ (United States)

    2015-03-31

    One of the most promising fuel alternatives is algae biodiesel. Algae reproduce quickly, produce oils more efficiently than crop plants, and require relatively few nutrients for growth. These nutrients can potentially be derived from inexpensive waste sources such as flue gas and wastewater, providing a mutual benefit of helping to mitigate carbon dioxide waste. Algae can also be grown on land unsuitable for agricultural purposes, eliminating competition with food sources. This project focused on cultivating select algae species under various environmental conditions to optimize oil yield. Membrane studies were also conducted to transfer carbon di-oxide more efficiently. An LCA study was also conducted to investigate the energy intensive steps in algae cultivation.

  8. FITOTOXICIDADE DE HERBICIDAS PRÉ EMERGENTES EM MUDAS CLONAIS DE EUCALIPTO

    Directory of Open Access Journals (Sweden)

    Ivan da Costa Ilhéu Fontan

    2016-12-01

    Full Text Available O objetivo deste estudo foi avaliar a fitotoxicidade de herbicidas pré emergentes sobre mudas de Eucalyptus urophylla, de modo a subsidiar recomendações de uso em condições de campo. O trabalho foi conduzido em viveiro de eucalipto localizado em Curvelo/MG, utilizando-se os herbicidas pré emergentes isoxaflutole, flumioxazin, sulfentrazone e clomazone + carfentrazone-ethyl, simulando uma taxa de 200 l/ha de calda. O experimento foi estabelecido em um delineamento inteiramente casualizado, com 15 repetições. A sensibilidade dos clones foi avaliada por meio da incidência e da severidade dos sintomas de intoxicação foliar nas mudas, verificadas um, cinco e dez dias após a aplicação. Os herbicidas isoxaflutole e flumioxazin não provocaram reações adversas às mudas, permitindo sua utilização sobre as plantas. Já a pulverização de sulfentrazone e clomazone + carfentrazone-ethyl provocou a manifestação de sintomas de fitotoxicidade (manchas foliares e murcha apical, e desta forma, sua aplicação não é recomendada sobre as mudas, e seu uso deve ser limitado entre as atividades de preparo de solo e plantio.

  9. MICROCONTAMINANTES EMERGENTES EN AGUAS: TIPOS Y SISTEMAS DE TRATAMIENTO

    Directory of Open Access Journals (Sweden)

    Yolanda Patiño

    2014-01-01

    Full Text Available En el presente artículo se revisan las distintas clases de contaminantes emergentes, su origen y uso, y su presencia en las cuencas españolas, tanto en aguas superficiales como subterráneas. Los microcontaminantes emergentes son compuestos de distinto origen y naturaleza que hasta ahora habían pasado inadvertidos debido a su baja concentración (en el orden de las ppb y sobre los que no hay regulación específica. Están divididos en seis grandes grupos y muchos de ellos se comportan como disruptores endocrinos, provocando efectos negativos sobre la salud humana y el medio ambiente. Se encuentran presentes en las aguas ya que las plantas de tratamiento de aguas residuales no están diseñadas para su eliminación, por lo que están siendo vertidos. Se discuten las distintas alternativas para su eliminación – tratamiento físico-químicos, biológicos y tecnologías híbridas - , destacando dentro de los procesos físico-químicos el empleo de procesos avanzados de oxidación (AOPs que están resultando muy prometedores.

  10. Biofuels and algae

    International Nuclear Information System (INIS)

    Anon.

    2011-01-01

    Bio-fuels based on micro-algae are promising, their licensing for being used in plane fuels in a mix containing 50% of fossil kerosene is expected in the coming months. In United-States research on bio-fuels has been made more important since 2006 when 2 policies were launched: 'Advanced energy initiative' and 'Twenty-in-ten', the latter aiming to develop alternative fuels. In Europe less investment has been made concerning micro-algae fuels but research programs were launched in Spain, United-Kingdom and France. In France 3 important projects were launched: SHAMASH (2006-2010) whose aim is to produce lipidic fuels from micro-algae, ALGOHUB (2008-2013) whose aim is to use micro-algae as a raw material for humane and animal food, medicine and cosmetics, SYMBIOSE (2009-2011) whose aim is the optimization of the production of methane through the anaerobic digestion of micro-algae, SALINALGUE (2010-2016) whose aim is to grow micro-algae for the production of bio-energies and bio-products. (A.C.)

  11. Enfermedades emergentes y reemergentes: factores causales y vigilancia

    Directory of Open Access Journals (Sweden)

    Carmen Luisa Suárez Larreinaga

    2000-12-01

    Full Text Available Este artículo tiene como objetivo exponer los conceptos y algunos de los factores causales más importantes en la aparición y diseminación de las enfermedades emergentes y reemergentes, así como presentar brevemente algunas de las actividades de vigilancia epidemiológica y su importancia en la detección y control de estas enfermedadesThe objective of this paper is to expound the concepts and some of the most important causal factors in the appearance and spreading of emergent and reemergent diseases, as well as to make a brief presentation of some of the epidemiological surveillance activities and their importance in the detection and control of these diseases

  12. Canabinoides sintéticos: drogas de abuso emergentes

    Directory of Open Access Journals (Sweden)

    Audrei de Oliveira Alves

    2012-01-01

    Full Text Available CONTEXTO: A Cannabis sativa (cannabis, maconha, marijuana é uma droga de abuso com efeitos psicoativos e potencial terapêutico bastante conhecidos. Um grande número de canabinoides foi sintetizado na tentativa de excluir ou minimizar os efeitos psicotrópicos e mantendo as aplicações terapêuticas. Os canabinoides sintéticos representam o mais recente avanço das designer drugs. OBJETIVOS: Este trabalho busca trazer informações sobre a utilização de canabinoides sintéticos como drogas de abuso emergentes, principalmente sob a forma de spice ou herbal blends. MÉTODOS: Foi realizada uma pesquisa bibliográfica na base de dados PubMed utilizando os descritores de assunto "synthetic cannabinoids", "spice", "legal highs", "herbal blends", "psychosis cannabis" e suas combinações. RESULTADOS: Foram encontrados canabinoides sintéticos nos produtos Spice, confirmando que os incensos herbais realmente surgiram como drogas de abuso emergentes. CONCLUSÃO: Não está claro se a utilização de canabinoides sintéticos e de Spice é uma moda passageira ou se irá se estabelecer em nossa sociedade. No entanto, o fenômeno das designer drugs, especialmente canabinoides sintéticos, representa um desafio presente para o sistemas de saúde no mundo globalizado, tornando-se necessária a pesquisa clínica e forense desses produtos.

  13. Estrategias de aprendizaje emergentes en la modalidad e-learning

    Directory of Open Access Journals (Sweden)

    Luis Demetrio Meza-López

    2016-01-01

    Full Text Available El objetivo de esta investigación fue sistematizar las estrategias de aprendizaje que implementa el alumno de la modalidad e-learning. La problemática fue abordada desde una perspectiva cualitativa utilizando el método de la teoría fundamentada y la técnica de entrevista en profundidad. Se diseñó una plataforma tecnológica propia para realizar el trabajo de campo con entrevistas online, procesando los videos con un software de análisis cualitativo. La validez y confiabilidad de las categorías emergentes fue verificada mediante la saturación de los datos y trianguladas con un constructo teórico propio elaborado con referentes de Weinstein y Meyer (1998, Pintrich, García y Mckeachie (1991 y Tsai (2009. Los resultados muestran que hay una dimensión de estrategias de aprendizaje en la modalidad e-learning en donde el factor de gestión tiene gran influencia para regular el proceso sobre todo en el uso del tiempo y la administración de las estrategias. El factor de autorregulación considerando la metacognición y la adaptabilidad juegan un papel esencial, al igual que el factor sicológico de la motivación y la concentración, aunado al factor de usos de la tecnología en la selección y utilización de los medios tecnológicos. El aporte devela la forma con la que se adaptan estrategias emergentes de aprendizaje en la educación virtual en México y la posibilidad de que se conviertan en líneas de investigación para el contexto de América Latina.

  14. Caracterización genotípica y fenotípica de cepas emergentes de Escherichia coli aisladas de niños con diarrea en Bucaramanga y su área metropolitana, Colombia

    Directory of Open Access Journals (Sweden)

    Monica Yurley Arias Guerrero

    2016-06-01

    Full Text Available Introducción: La enfermedad diarreica aguda (EDA sigue siendo uno de los principales problemas en salud pública en países en desarrollo. Dentro de los agentes infecciosos que causan esta enfermedad se encuentran bacterias, virus y parásitos. Los agentes bacterianos ocupan un segundo lugar destacándose Escherichia coli enteropatógenas entre las más importantes. Actualmente, seis cepas con diferentes mecanismos de patogenicidad están asociados a diarrea  E. coli enteropatógena (ECEP, productora de toxina-shiga (ECTS, enterotoxigénica (ECET, enteroinvasiva (ECEI, enteroagregativa (ECEA y adherente difusa (ECAD, cada una con un set específico de genes de virulencia. No obstante, se han reportado brotes de EDA ocasionados por cepas de E. coli diferentes a los patotipos conocidos, denominadas cepas emergentes. Estos brotes han sido reportados en Alemania, Europa y recientemente en Cartagena Colombia, lo que sugiere que en nuestro medio circulan estas cepas. Por lo cual, es necesario caracterizar estas cepas emergentes. Objetivo: Caracterizar genotípicamente y fenotípicamente dos cepas emergentes de E. coli aisladas de muestras diarreicas en niños menores de cinco años en Bucaramanga, Colombia. Materiales y métodos: De un estudio de casos y controles realizado entre Julio del 2013 y diciembre del 2014 en Bucaramanga y su área metropolitana, Colombia a 860 niños menores de 5 años con diarrea (casos y sin diarrea (controles. Se aislaron a partir de coprocultivos cepas de E. coli mediante pruebas bioquímicas. A estas cepas previamente almacenadas a -80°C se les determino mediante PCR multiplex los patotipos de E. coli, los cuales posteriormente fueron confirmados mediante PCR simple. Muestras positivas para dos patotipos u otra característica fueron clasificadas como cepas emergentes. Finalmente, estas cepas se caracterizaron fenotípica y genotípicamente. Para ello, se llevaron a cabo pruebas como secuenciación de genes de

  15. Movimientos sociales emergentes y nuevas maneras de educar

    Directory of Open Access Journals (Sweden)

    Elsie Rockwell

    2012-09-01

    Full Text Available El objetivo de este artículo es argumentar que los movimientos sociales recientes nos obligan a tomar en serio tanto la profunda desigualdad social, como la diversidad cultural y social generada por recientes cambios en la economía y por proyectos alternativos de vida y formación. Sobre el trasfondo de la formación histórica de la clase trabajadora, un tema recurrente ha sido la esperanza de transformar la sociedad mediante la formación del "hombre nuevo". Sin embargo, la economía capitalista global reciente ha generado una clase trabajadora cada vez más fragmentada y desposeída. En respuesta, se forman nuevos sujetos sociales que retoman recursos y prácticas culturales existentes para fortalecer los movimientos sociales emergentes. Concluyo que el reconocimiento de estos movimientos sociales y procesos de formación ha transformado el pensamiento Iluminista, dando lugar a otras maneras de pensar y actuar en los procesos educativos.

  16. Sociedad y posibilidades tecnológicas emergentes

    Directory of Open Access Journals (Sweden)

    Chaparro Mendivelso Jeffer

    2004-01-01

    Full Text Available Las nuevas tecnologías de la información y la comunicación ”NTIC” están generando cambios trascendentales en la sociedad y el territorio. Se están imbricando diferencialmente en todas las actividades de la vida humana, mediando desde los flujos económicos globales hasta las relaciones personales individuales. Paralelamente se están propiciando profundas alteraciones en términos de la concepción del mundo y del lugar, de lo material y lo inmaterial, de lo real y lo virtual, de lo utópico y lo imaginario, de lo orgánico y lo artificial. Emergen nociones y conceptos diversos perocomplementarios que van desde la idea de ciberespacio hasta la de Internet como un "actante" con propiedades emergentes inquietantes, pasando por la inteligencia colectiva en red y los cyborg como nuevo estadio del devenir humano. Las implicaciones derivadas de las NTIC se perfilan como una línea interesante "y poco exploradas" de trabajo e investigación en geografía ya que, evidentemente, losprocesos y las dinámicas socioterritoriales cada vez se median más por lo digital.

  17. A influência das economias emergentes em assuntos internacionais

    Directory of Open Access Journals (Sweden)

    Nubia Nieto

    2012-08-01

    Full Text Available Este artigo examina o impacto das economias emergentes nos assuntos internacionais. A chegada dos países do Bric (Brasil, Rússia, Índia e China modificou o mapa da ordem mundial e as estratégias para projetar poder hegemônico. O Bric eclipsará o poder econômico dos países mais ricos do mundo? Quais são as principais estratégias do Bric para projetar seu poder no mundo? Essas e outras questões são analisadas no texto, que leva em consideração o novo cenário geopolítico do século XXI.This article explores the impact of emerging economies in international affairs. The arrival of the Bric's countries (Brazil, Russia, India and China has changed the map of the global order and the strategies to project hegemonic power. Could the Bric eclipse the economic power of the richest countries of the world? What are the main strategies of Bric to project its power worldwide? These and other questions are analysed in this text taking into account the new geopolitical scenario of the twenty-first century.

  18. Problemas de matemáticas

    OpenAIRE

    Usunáriz Balanzategui, Ubaldo; Usunáriz Sala, Ignacio

    2012-01-01

    Este libro, Problemas de Matemáticas, junto con otros dos, Problemas de Geometría y Problemas de Geometría Analítica y Diferencial, están dedicados a la presentación y resolución de problemas que se planteaban hace unas décadas, en la preparación para ingreso en las carreras de ingeniería técnica superior. Incluye 1578 problemas, de los que 848 se refieren al Álgebra (operaciones algebraicas, divisibilidad, combinatoria, determinantes, ecuaciones e inecuaciones, fracciones continuas, números ...

  19. Mosquitos Culicidae como vetores emergentes de infecções Culicidae mosquitoes as emerging vectors of diseases

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1998-12-01

    Full Text Available Apresenta-se sucinta revisão do relacionamento entre as chamadas infecções emergentes e o conceito de vetores emergentes. Estes são entendidos não apenas no que concerne aos que são descritos como tais, de forma nova, mas também aqueles com acentuadas mudanças de comportamento. Os fatores específicos que propiciam esse fenômeno identificam-se à poderosa influência humana sobre o ambiente. Assim, aquele construído pelo homem e conhecido como antrópico representa a função de pressão seletiva que induz as populações vetoras a se adaptarem às novas circunstâncias. Nelas inclui-se fatores ecológicos ambientais, ou demográficos, que incrementam o contato com os novos comportamentos vetoriais. Relata-se o encontro de criadouros anômalos de mosquitos Culicidae nas Américas. A interpretação desses encontros é feita visando à vigilância epidemiológica. O significado dessa emergência ou reemergência pode se traduzir no aparecimento de problemas epidemiológicos. Sugere-se que, em sendo assim, a vigilância epidemiológica deva ser feita em grau global.A review is presented of the relationships between the so-called emerging infectious diseases and what may be defined as emerging vectors. These include not only those that have recently appeared but also those that present remarkable behavioral changes. Specific factors leading to that emergence can be associated with the powerful human influence on the environment. So the man-made, i.e. anthropic environment, exercises a selective pressure inducing vector populations to adapt to new circumstances. These may arise from ecological, environmental, or demographic factors that increase contact with the new vector. With this in mind, data on anomalous Culicidae breeding places in the Americas are reported. An interpretation of these findings is offered in the light of epidemiological surveillance. The question is whether vector emergence or re-emergence may constitute an

  20. Genomics of Volvocine Algae

    Science.gov (United States)

    Umen, James G.; Olson, Bradley J.S.C.

    2015-01-01

    Volvocine algae are a group of chlorophytes that together comprise a unique model for evolutionary and developmental biology. The species Chlamydomonas reinhardtii and Volvox carteri represent extremes in morphological diversity within the Volvocine clade. Chlamydomonas is unicellular and reflects the ancestral state of the group, while Volvox is multicellular and has evolved numerous innovations including germ-soma differentiation, sexual dimorphism, and complex morphogenetic patterning. The Chlamydomonas genome sequence has shed light on several areas of eukaryotic cell biology, metabolism and evolution, while the Volvox genome sequence has enabled a comparison with Chlamydomonas that reveals some of the underlying changes that enabled its transition to multicellularity, but also underscores the subtlety of this transition. Many of the tools and resources are in place to further develop Volvocine algae as a model for evolutionary genomics. PMID:25883411

  1. Psycho-physiologic emergentism; four minds in a body

    Directory of Open Access Journals (Sweden)

    David L. Rowland

    2017-10-01

    Full Text Available The mind-body problem represents one of the most debated topics in the neurosciences. From a psychological standpoint, abstract/non-material data are an intrinsic part of the mind, intervening to a large extent in reasoning and decision making processes. Imaging studies also show a strong correlation between higher cognitive functions (such as working memory and specific cerebral brain regions (a fronto-parietal network of interacting left and right brain areas. In contrast, the physical/material brain would be unable to interact with abstract-immaterial data, such that the psychological processing of abstract data (processes such as thinking, reasoning, and judgment is attributed to the mind, with the mind representing a distinct entity interposed between the brain and abstract-immaterial data. Recent data suggest that the mind-body problem may simply be an artifact of human experience/ understanding, as the brain actually represents actually an intrinsic part of the mind. Even if the physical brain is not able to interact with abstract mental data, the brain still could process abstract data through a dynamic association between the abstract data and cerebral stimuli/ impulses. This form of processing without interaction defines the mind as a complex neurobiological structure, with the unconscious part of the mind processing abstract-immaterial data in a conscious/ mental format. In this overview, important concepts of psycho-physiologic emergentism, including internal mental reality, internal mental existence, internal mental interaction, and structural and informational dichotomies of the brain, are iterated. Such concepts/properties represent a neuro-informational support system capable of generating four distinct minds within the single brain. Future studies should further develop the dynamic and immaterial-material nature of the mind, as a possible premise for a scientific definition and understanding of mental events like affectivity

  2. Resolvendo o problema de Bernstein

    Directory of Open Access Journals (Sweden)

    2006-11-01

    Full Text Available O grande problema no controle do movimento diz respeito à redução da redundância do sistema motor, convertendo-o a um sistema controlável. A aprendizagem cerebelar pela realimentação do erro propõe, de forma simples e engenhosa, uma solução biologicamente plausível para este problema, com uma importante característica: é um processo que deve ser aprendido. Importantes aspectos relativos a estas questões são discutidos neste artigo. PALAVRAS-CHAVE: controle motor – aprendizagem motora – aprendizagem cerebelar The great problem about controlling the movement is the reduction of the motor system redundance, converting it into a controlable system. The cerebellar feedback errar learning praposes, by simple and ingenius way, one biologic plausible solution to this problem, with an important feature: it is a process that has to be learnt. Some important aspects about these questions are being discussed in this paper. KEY WORDS: Motor contrai – Motor learning – Cerebellar learning

  3. Efectos de los estrógenos como contaminantes emergentes en la salud y el ambiente

    OpenAIRE

    Ramírez-Sánchez, Irwing M.; Martínez-Austria, Polioptro; Quiroz-Alfaro, Marco A.; Bandala, Erick R.

    2015-01-01

    Los contaminantes emergentes son sustancias que tienen el potencial de dañar al ser humano, flora y fauna, y no están regulados por la legislación. Los estrógenos son parte de esta definición, es decir, contaminantes emergentes, que cuando incrementan su concentración en el ser humano o el ambiente causan daño. Los seres humanos están expuestos a concentraciones altas de estrógenos debido a su uso como parte de terapias de reemplazo hormonal o métodos anticonceptivos. Flora y fauna están expu...

  4. Contaminantes emergentes en aguas subterráneas: origen, presencia y aspectos normativos

    OpenAIRE

    Candela Lledó, Lucila

    2016-01-01

    Una de las amenazas a la calidad de los RRHH es la presencia de múltiples estresores, entre ellos que cabe destacar a los denominados contaminantes emergentes. Con el nombre de contaminantes o compuestos emergentes se define a una serie de compuestos químicos de origen diverso (fármacos, productos de diagnóstico, plaguicidas, detergentes, productos de uso personal, etc.) caracterizados por su continua y creciente producción y consumo. La información existente sobre su presencia en las aguas s...

  5. Modelos de negocio emergentes en la industria del videojuego

    Directory of Open Access Journals (Sweden)

    Milena Trenta

    2013-10-01

    Full Text Available Sylvia Zavala-Trias 12.00 La industria del videojuego está viviendo un proceso de transformación en su manera de crear valor, debido al éxito de los juegos casuales y a la consolidación de nuevas plataformas de juego, cuales las redes sociales, los teléfonos inteligentes, las tabletas y los sitios de juego on line. A consecuencia de estos fenómenos, surgen nuevos modelos de negocio. Posteriormente al estudio del volumen de ingresos generados por los videojuegos distribuidos por canales digitales y de los hábitos de consumo de los usuarios, este trabajo aporta una descripción de los modelos de negocio emergentes en la industria del videojuego. Finalmente, se observa que, frente a la actual situación, las principales compañías del sector diversifican su negocio y las pequeñas empresas aprovechan la multiplicación de los canales de distribución. Mientras que, los usuarios se inclinan por los videojuegos comercializados mediante modelos de negocio que permiten personalizar el consumo y establecer relaciones sociales. Normal 0 21 false false false ES X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-fareast-language:EN-US;}

  6. World Health Day 1997: emerging infectious diseases Día Mundial de la Salud 1997: enfermedades infecciosas emergentes

    Directory of Open Access Journals (Sweden)

    1997-05-01

    Full Text Available Para el Día Mundial de la Salud de 1997, la Organización Mundial de la Salud (OMS ha elegido el tema "Enfermedades infecciosas emergentes; alerta mundial, respuesta mundial" con el fin de llamar la atención hacia la amenaza que representan algunas enfermedades infecciosas recientemente reconocidas en seres humanos y otras que han vuelto a aparecer. En la emergencia y reemergencia de enfermedades infecciosas intervienen factores como el deterioro de la infraestructura de salud pública, la creciente resistencia microbiana a los antibióticos y los cambios sociales y ecológicos asociados con el crecimiento de la población humana. La OMS ha hecho hincapié en la necesidad de que se compromentan a entrar juntos en acción tanto países como organizaciones internacionales, organizaciones no gubernamentales e individuos, con objeto de mejorar la vigilancia de las enfermedades y la capacidad de controlarlas para prevenir y refrenar las epidemias. Por su parte, la OMS está reforzando su sistema de vigilancia mundial tripartito, que consta de los centros de colaboración de la OMS en el área de enfermedades infecciosas, las redes de monitoreo de resistencia antimicrobiana y el Reglamento Sanitario Internacional. Para hacer frente adecuadamente al problema de las enfermedades infecciosas durante el siglo próximo, se necesitarán programas de vigilancia y control; redes mundiales de monitoreo y notificación; rápido intercambio de información por vía electrónica (incluida la World Wide Web; y un estado de preparación efectivo con la capacidad para responder rápidamente a las epidemias y contenerlas.

  7. Problemas de Crecimiento Pondo Estatural

    Directory of Open Access Journals (Sweden)

    Ernesto Plata Rueda

    1979-10-01

    Full Text Available

    Quizás sorprenda un poco que este capítulo no se denomine Desnutrición o Distrofia o Síndrome pluricarencial o Malnutrición proteico calórica o Kwashiorkor o Hambre como preferiría llamarla con no poco sarcasmo el pediatra colombiano Gustavo González Ochoá.

    Al denominarlo por los signos de somatometría (peso y talla queremos proseguir la línea general de este libro de tratar los problemas con base en el motivo de consulta y de este modo, solo por no emplear lenguaje familiar en los títulos de los capítulos, no hicimos como hubiéramos preferido llamarlo: "el niño flaco y pequeño" o algo por el estilo_ Quizás el empleo de terminología científica pero rebuscada o lo que es, como en el caso de Kwashiorkor, referida solo a un signo circunstancial (niño rojo, no frecuente entre nosotros y propio solo de estados muy avanzados de desnutrición, ha contribuído a que los' médicos dejen pasar inadvertidos por su consulta los casos mucho más frecuentes de subalimentación incipiente (desnutrición de primer grado que se manifiestan solo por detención de peso y que en términos de manejo oportuno de los problemas, son en extremo importantes pues como bien lo ha señalado Rafael Ramos Galván (Diagnóstico y Tratamiento de la Desnutrición a nivel individual 'Y colectivo. Impresiones Modernas. México (1.968 p. 39, "en desnutrición el tiempo perdido no se recupera" y las carencias cuando
    ocurren en los períodos de mayor crecimiento y se prolongan, si no matan, dejan una huella imborrable en el individuo, tanto en lo físico (nanismo nutricional como en lo psíquico (retardo psicomotor.

    Con la enumeración de términos hecha al principio no queremos embarcarnos en una discusión por demás bizantina sobre semántica, pero sí queremos señalar un hecho que contrista el ánimo cual es el del muy escaso reconocimiento que de la literatura médica latinoamericana se hace en los medios anglosajones. Durante todo lo que

  8. Habilidades de leitura de pré-escolares deficientes auditivos: letramento emergente

    Directory of Open Access Journals (Sweden)

    Heloísa Helena Motta Bandini

    2006-04-01

    Full Text Available O letramento emergente é um conjunto de comportamentos e conhecimentos sobre leitura e escrita que acontecem no período entre o nascimento e a fase onde a criança torna-se capaz de escrever e ler de maneira convencional. O presente estudo tem como objetivo verificar o desenvolvimento do letramento emergente por meio da escala de letramento emergente em crianças portadoras de deficiência auditiva de grau severo a profundo ou profundo usuárias de LIBRAS (Língua Brasileira de Sinais. O estudo foi dividido em duas avaliações com a aplicação da Escala de Letramento Emergente em momentos diferentes, ao longo de um ano. Fizeram parte desse estudo crianças entre 6.5 anos e 7.3 anos, deficientes auditivas com perda bilateral de grau severo a profundo ou profundo, usuárias de LIBRAS. Os resultados do estudo indicam que o desenvolvimento de habilidades dessa população é semelhante ao de crianças ouvintes.

  9. ESTRATEGIAS Y DESEMPEÑO DE LAS NUEVAS Y EMERGENTES EMPRESAS MULTINACIONALES MEXIANAS

    Directory of Open Access Journals (Sweden)

    José G. Vargas-Hernández

    2010-11-01

    Full Text Available El artículo analiza las nuevas empresas emergentes multinacionales mexicanas (MexEMNEs en el mercado global. Se analizan sus estrategias y desempeño para determinar perfiles y futuros escenarios de desarrollo. Se concluye que la innovación es clave para buscar ventajas y oportunidades en el cambio.

  10. Los Problemas de las Gimnasias

    Directory of Open Access Journals (Sweden)

    Viviana Bulus Rossini

    2011-11-01

    Full Text Available Este artículo se propone sintetizar las principales ideas de las ponencias presentadas en la Mesa de Trabajo "Los problemas de las Gimnasias" que se desarrolló en el marco del 9º Congreso Argentino y 4º Latinoamericano de Educación Física y Ciencias realizado en la Universidad Nacional de La Plata en junio de 2011. Todas ellas coinciden en pensar a la Gimnasia como parte fundamental de una Educación Corporal que se proponga transmitir aquellos saberes corporales culturalmente significativos que sirvan de herramientas para el conocimiento, el cuidado y la autogestión del propio cuerpo. A partir de estos puntos de coincidencia cada ponencia se explaya en su especificidad: ya sea desde la investigación y el análisis de los textos de divulgación y académicos, de los discursos de profesores, alumnos y practicantes; desde el análisis crítico del campo gímnico actual; desde propuestas bien concretas de trabajo de las gimnasias, en este caso la gimnasia aeróbica, la gimnasia funcional, el Método Pilates, o la gimnasia en el Profesorado en Educación Física con proyección en la gimnasia escolar

  11. Algoritmos para problemas de corte e empacotamento

    OpenAIRE

    Thiago Alves de Queiroz

    2010-01-01

    Resumo: Problemas de Corte e Empacotamento são, em sua maioria, NP-difíceis e não existem algoritmos exatos de tempo polinomial para tais se for considerado P ¿ NP. Aplicações práticas envolvendo estes problemas incluem a alocação de recursos para computadores; o corte de chapas de ferro, de madeira, de vidro, de alumínio, peças em couro, etc.; a estocagem de objetos; e, o carregamento de objetos dentro de contêineres ou caminhões-baú. Nesta tese investigamos problemas de Corte e Empacotament...

  12. Shewanella algae in acute gastroenteritis

    Directory of Open Access Journals (Sweden)

    S Dey

    2015-01-01

    Full Text Available Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. Previously reported cases of S. algae have mainly been associated with direct contact with seawater. Here we report the isolation of S. algae as the sole etiological agent from a patient suffering from acute gastroenteritis with bloody diarrhoea. The bacterium was identified by automated identification system and 16S rRNA gene sequence analysis. Our report highlights the importance of looking for the relatively rare aetiological agents in clinical samples that does not yield common pathogens. It also underscores the usefulness of automated systems in identification of rare pathogens.

  13. Transgenic algae engineered for higher performance

    Science.gov (United States)

    Unkefer, Pat J; Anderson, Penelope S; Knight, Thomas J

    2014-10-21

    The present disclosure relates to transgenic algae having increased growth characteristics, and methods of increasing growth characteristics of algae. In particular, the disclosure relates to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and a glutamine synthetase.

  14. Algae biotechnology: products and processes

    National Research Council Canada - National Science Library

    Bux, F; Chisti, Yusuf

    2016-01-01

    This book examines the utilization of algae for the development of useful products and processes with the emphasis towards green technologies and processes, and the requirements to make these viable...

  15. Algae: America's Pathway to Independence

    National Research Council Canada - National Science Library

    Custer, James

    2007-01-01

    .... Oil dependency is an unacceptable risk to U.S. national strategy. This paper advocates independence from foreign oil by converting the national transportation fleet to biodiesel derived from algae...

  16. Scenario studies for algae production

    OpenAIRE

    Slegers, P.M.

    2014-01-01

    Microalgae are a promising biomass for the biobased economy to produce food, feed, fuel, chemicals and materials. So far, large-scale production of algae is limited and as a result estimates on the performance of such large systems are scarce. There is a need to estimate large-scale biomass productivity and energy consumption, while considering the uncertainty and complexity in such large-scale systems. In this thesis frameworks are developed to assess 1) the productivity during algae culti...

  17. Phthalate esters in marine algae

    OpenAIRE

    Gezgin, Tuncay; Güven, Kasim Cemal; Akçin, Göksel

    2001-01-01

    Abstract o-Phthalate esters as diethyl phthalate, dibutyl phthalate, di-isobutyl phthalate and diethylhexyl phthalate were identified at surface and inner part of algae collected in the Bosphorus, as Ulva lactuca, Enteromorpha linza, Cystoseria barbata, Pterocladia capillaceaeand Ceramium rubrum. The same esters were also detected in seawater samples taken from the same area. Thus parallelism in pollution was noted between the algae and the surrounding seawater,

  18. DATURA STRAMONIUM: Toxicología de una droga emergente

    Directory of Open Access Journals (Sweden)

    Soler Carracedo A

    2013-05-01

    Full Text Available El estramonio (Datura stramonium L, al igual que la gran mayoría de las drogas alucinógenas vegetales, ha sido usado a lo largo de los siglos en un contexto místico-religioso chamánico. Sin embargo, fue en el verano de 2011 cuando se detecta su uso como droga de abuso en España tras el fallecimiento de dos jóvenes en una fiesta “rave” en Getafe (Madrid y una intoxicación aguda de un joven en Badajoz, hechos que generaron una gran alarma social. Todo ello pone de manifiesto la constante variabilidad en la familia de las drogas perturbadoras usadas con fines recreativos. La disponibilidad de este vegetal y el desconocimiento sobre los riesgos de su consumo lo convierten en un serio problema de salud pública. El estramonio posee propiedades alucinógenas y anticolinérgicas debido a su contenido en alcaloides tropánicos, entre los que destacan tres: atropina (DL50= 10 mg en humanos, 400 mg/Kg ratón, hiosciamina y escopolamina (DL50= 2-4 mg en humanos, 619 mg/Kg ratón. Entre los efectos psíquicos y orgánicos destacan la alteración del estado mental con alucinaciones y la taquicardia, respectivamente. El tratamiento de las intoxicaciones agudas es sintomatológico y se dispone de un antídoto, la fisostigmina.

  19. EVALUACIÓN DEL APRENDIZAJE EMERGENTE: UNA EXPERIENCIA CON ESTUDIANTES UNIVERSITARIAS DE EDUCACIÓN PREESCOLAR

    Directory of Open Access Journals (Sweden)

    Eleonora Badilla Saxe

    2008-01-01

    Full Text Available Se aborda en este ensayo la necesidad de comprender y evaluar el aprendizaje como un fenómeno emergente, más allá del aprendizaje previsto en los planes de estudio y diseño curricular. Se ejemplifica con la reflexión del propio aprendizaje emergente de la autora en su proceso de dirección de un proyecto de investigación-acción en la Universidad de Costa Rica. En dicha investigación-acción participaron once estudiantes de licenciatura en educación preescolar y veinticinco niños y niñas de 5 y 6 años que contaron con materiales digitales en su ambiente y proceso de aprendizaje.

  20. Emprender en economías emergentes: el entorno institucional y su desarrollo

    Directory of Open Access Journals (Sweden)

    Antonia Mercedes García-Cabrera

    2015-07-01

    Full Text Available Dos motivaciones justifican el presente trabajo: (1 el interés por impulsar la actividad emprendedora como mecanismo de crecimiento en las economías emergentes y (2 la necesidad de desarrollar investigaciones sobre la influencia que las instituciones del entorno ejercen sobre la actividad emprendedora y que se sustenten, más que en un planteamiento de resultados, en el análisis de los procesos, dinámicas e interacciones entre tales elementos para favorecer el emprendimiento. Sobre la base de ellas, se formulan las dos cuestiones de investigación siguientes: ¿cómo interactúan los factores institucionales del entorno para influir en la decisión emprendedora del individuo en una economía emergente?, y ¿qué planteamientos subyacen a los distintos enfoques de actuación que coexisten en la economía institucional para lograr el desarrollo institucional y económico buscado? Las respuestas que ofrecemos a estos interrogantes nos permiten establecer proposiciones de investigación novedosas sobre la particular incidencia que las instituciones ejercen sobre el emprendimiento en las economías emergentes, proporcionando nuevas relaciones que deben ser exploradas empíricamente para mejorar nuestra comprensión del emprendimiento y su promoción efectiva en tales contextos económicos.

  1. Algae-Based Carbon Sequestration

    Science.gov (United States)

    Haoyang, Cai

    2018-03-01

    Our civilization is facing a series of environmental problems, including global warming and climate change, which are caused by the accumulation of green house gases in the atmosphere. This article will briefly analyze the current global warming problem and propose a method that we apply algae cultivation to absorb carbon and use shellfish to sequestrate it. Despite the importance of decreasing CO2 emissions or developing carbon-free energy sources, carbon sequestration should be a key issue, since the amount of carbon dioxide that already exists in the atmosphere is great enough to cause global warming. Algae cultivation would be a good choice because they have high metabolism rates and provides shellfish with abundant food that contains carbon. Shellfish’s shells, which are difficult to be decomposed, are reliable storage of carbon, compared to dead organisms like trees and algae. The amount of carbon that can be sequestrated by shellfish is considerable. However, the sequestrating rate of algae and shellfish is not high enough to affect the global climate. Research on algae and shellfish cultivation, including gene technology that aims to create “super plants” and “super shellfish”, is decisive to the solution. Perhaps the baton of history will shift to gene technology, from nuclear physics that has lost appropriate international environment after the end of the Cold War. Gene technology is vital to human survival.

  2. Problemas de teoria dos números

    OpenAIRE

    Pontes, Dúnia Lisandra Serra Lêdo

    2013-01-01

    Tese de mestrado em Matemática para Professores, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2013 A tese em questão, como o título sugere – Problemas de teoria dos números – propõe-se a estudar problemas relativos a uma das áreas mais antigas e mais ricas da matemática, considerada uma forte influência na evolução de grandes matemáticos. Este trabalho conjuga dois temas deveras importantes para o desenvolvimento da criatividade e do conhecimento matemático: reso...

  3. Algae Bloom in a Lake

    Directory of Open Access Journals (Sweden)

    David Sanabria

    2008-01-01

    Full Text Available The objective of this paper is to determine the likelihood of an algae bloom in a particular lake located in upstate New York. The growth of algae in this lake is caused by a high concentration of phosphorous that diffuses to the surface of the lake. Our calculations, based on Fick's Law, are used to create a mathematical model of the driving force of diffusion for phosphorous. Empirical observations are also used to predict whether the concentration of phosphorous will diffuse to the surface of this lake within a specified time and under specified conditions.

  4. Aislamiento de algas del embalse del Neusa por medio de cultivos In Vitro

    Directory of Open Access Journals (Sweden)

    A. Maldonado

    2000-07-01

    Full Text Available EI cultivo de algas a nivel mundial es un oficio de vieja data, pero en Colombia se encuentra en sus primeras etapas de desarrollo. El presente trabajo desarrollado en el Laboratorio de Bioensayos, Departamento de Biología, Universidad Nacional de Colombia está encaminado a aportar técnicas en el desarrollo del cultivo de algas. En la parte practica del trabajo se utilizaron muestras de agua del embalse del Neusa las cuales se cultivaron en medios líquido y solido. Se observo un mejor crecimiento de cianofíceas filamentosas en medio solido y algas verdes en medio líquido. Las clamidomonas se ven favorecidas en ambos medios, hecho que permitió aislar una sepa pura de este tipo de algas. Las diatorneas por el hecho de crecer en relación con algas verdes generan un problema metodológico para su aislamiento, que aun se encuentra sin resolver.

  5. Formation of algae growth constitutive relations for improved algae modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Gharagozloo, Patricia E.; Drewry, Jessica Louise.

    2013-01-01

    This SAND report summarizes research conducted as a part of a two year Laboratory Directed Research and Development (LDRD) project to improve our abilities to model algal cultivation. Algae-based biofuels have generated much excitement due to their potentially large oil yield from relatively small land use and without interfering with the food or water supply. Algae mitigate atmospheric CO2 through metabolism. Efficient production of algal biofuels could reduce dependence on foreign oil by providing a domestic renewable energy source. Important factors controlling algal productivity include temperature, nutrient concentrations, salinity, pH, and the light-to-biomass conversion rate. Computational models allow for inexpensive predictions of algae growth kinetics in these non-ideal conditions for various bioreactor sizes and geometries without the need for multiple expensive measurement setups. However, these models need to be calibrated for each algal strain. In this work, we conduct a parametric study of key marine algae strains and apply the findings to a computational model.

  6. Indigenous algae: Potential factories for biodiesel production

    CSIR Research Space (South Africa)

    Maharajh, Dheepak M

    2008-11-01

    Full Text Available advantages. Approximately 30% of South African environments favourable for isolating algae have been sampled. Samples were enriched, purified and assessed for lipid content, resulting in a database of indigenous algae. Positive isolates were grown under...

  7. Microscopic Gardens: A Close Look at Algae.

    Science.gov (United States)

    Foote, Mary Ann

    1983-01-01

    Describes classroom activities using algae, including demonstration of eutrophication, examination of mating strains, and activities with Euglena. Includes on algal morphology/physiology, types of algae, and field sources for collecting these organisms. (JN)

  8. O Constitucionalismo entre a Fragmentação e a Privatização: Problemas Evolutivos do Direito e da Política na Era da Governança Global

    Directory of Open Access Journals (Sweden)

    Holmes Pablo

    2014-12-01

    Full Text Available O presente artigo trata do debate em curso na teoria política e teoria constitucional, acerca de problemas de constitucionalização de regimes regulatórios transnacionais e supranacionais desde a perspectiva de uma teoria dos sistemas. Ele se volta aos conhecidos problemas de fragmentação do direito e emergência de novas formas de colisão entre regimes, que alteram os mecanismos de funcionamento e exercício do poder. Nas formas emergentes de administração do direito e do poder regulatório em nível transnacional e supranacional, osmecanismosmodernos de democracia política parecem perder seu poder de vinculação. Isso parece ter consequências drásticas para os imperativos modernos de inclusão social.

  9. Algae. LC Science Tracer Bullet.

    Science.gov (United States)

    Niskern, Diana, Comp.

    The plants and plantlike organisms informally grouped together as algae show great diversity of form and size and occur in a wide variety of habitats. These extremely important photosynthesizers are also economically significant. For example, some species contaminate water supplies; others provide food for aquatic animals and for man; still others…

  10. Scenario studies for algae production

    NARCIS (Netherlands)

    Slegers, P.M.

    2014-01-01

    Microalgae are a promising biomass for the biobased economy to produce food, feed, fuel, chemicals and materials. So far, large-scale production of algae is limited and as a result estimates on the performance of such large systems are scarce. There is a need to estimate large-scale biomass

  11. Banco de sementes e flora emergente de plantas daninhas Seed bank and abovegroud weed

    Directory of Open Access Journals (Sweden)

    R.A. Isaac

    2008-01-01

    Full Text Available Com o objetivo estudar a relação existente entre o banco de sementes e o posterior estabelecimento da flora emergente de plantas daninhas, sob sistema de semeadura direta e convencional, realizou-se uma pesquisa no município de Pedra Preta-MT. O banco de sementes e a flora emergente foram avaliados, em cada sistema de cultivo, em 50 células contíguas de 1 m². O banco de sementes foi determinado a partir de amostras de 2,4% da área de cada célula na profundidade de 0-5 cm, em setembro de 2003, por meio da técnica de flotação. A flora emergente foi avaliada por meio de seis levantamentos sucessivos, até novembro de 2004, realizados na área total de cada célula, com retirada dos indivíduos após cada avaliação. Esses dados foram utilizados para calcular os parâmetros fitossociológicos e também a correlação entre o banco de sementes e a flora emergente. A similaridade entre o banco de sementes e a flora emergente foi baixa tanto no sistema de semeadura direta quanto no convencional. Houve correlação significativa apenas para Amaranthus deflexus e Eleusine indica entre o banco de sementes e a flora emergente. Para A. deflexus a correlação foi significativa nos dois sistemas de semeadura e, para E. indica, somente para semeadura direta.A study was carried out in Pedra Petra-MT aiming to study the relation between seed bank and posterior aboveground weed in annual crop fields under no-till and tillage systems. The seed bank and weed flora were assessed in fifty contiguous 1 m² cells, under both cultivation systems. The seed bank was determined from soil samples from 4% of the area of each cell at 0-5 cm depth using the flotation technique. The aboveground weed vegetation was evaluated by six successive surveys until November 2004, carried out in the total area of each cell, with removal of the individuals from the area after each evaluation. These data were used to calculate the phyto-sociological parameters and the

  12. Estudo dos problemas do carteiro chines e do caixeiro viajante

    OpenAIRE

    Denise Helena Lombardo

    1986-01-01

    Resumo: Esta dissertação envolve o estudo de dois problemas de otimização combinatória: O Problema do Caixeiro Viajante (PCV) e o Problema do Carteiro Chinês (PCC). Dada uma rede (ou grafo), primeiro problema consiste em determinar uma rota circular mínima que passa em cada nó e o segundo em determinar uma rota circular mínima que passa em cada linha da rede. Embora ambos problemas sejam da classe NP-"árduo" (NP- hard ), o problema do Carteiro Chinês é apresentado na literatura como um proble...

  13. Informação: metodologias, temas tradicionais e discussões emergentes

    Directory of Open Access Journals (Sweden)

    Andre Luiz Appel

    2013-08-01

    Full Text Available A AtoZ: novas práticas em informação e conhecimento faz sua estreia no Sistema de Avaliação Qualis-CAPES trazendo novidades em sua interface. Neste novo número a entrevista contempla os principais elementos e desafios da competência informacional, seguida de artigos que abordam a questão da informação no contexto de tecnologias emergentes; ensino de ontologias; enfoques de coleta de dados e legislações voltadas à privacidade de dados pessoais.

  14. Macro algae as substrate for biogas production

    DEFF Research Database (Denmark)

    Møller, Henrik; Sarker, Shiplu; Gautam, Dhan Prasad

    Algae as a substrate for biogas is superior to other crops since it has a much higher yield of biomass per unit area and since algae grows in the seawater there will be no competition with food production on agricultural lands. So far, the progress in treating different groups of algae as a source...... of energy is promising. In this study 5 different algae types were tested for biogas potential and two algae were subsequent used for co-digestion with manure. Green seaweed, Ulva lactuca and brown seaweed Laminaria digitata was co-digested with cattle manure at mesophilic and thermophilic condition...

  15. Analisi matematica del problema dello spazio

    CERN Document Server

    Weyl, Hermann

    1990-01-01

    Al fine di rendere concettualmente evidente il privilegio posseduto dalla metrica pitagorico-riemanniana, e dalle varie metriche riemanniane "indefinite", rispetto alle altre metriche possibili, nel 1921 Weyl, stimolato dagli sviluppi della relatività einsteiniana (sulla quale aveva scritto il mirabile "Raum-Zeit-Materie"), intraprese un profondo studio del problema giovandosi dei metodi della teoria dei gruppi di Lie, studio che egli portò a conclusione con la monografia del 1923 intitolata "Mathematische Analyse des Raumproblems".

  16. Problemas psicosociales en hostelería

    OpenAIRE

    Pérez Martínez, Alberto

    2015-01-01

    Las metas consistirán en: 1- Describir los distintos factores psicosociales que pueden dar lugar a generar estrés en función de las condiciones de trabajo en el que se encuentran la plantilla. 2- Determinar los principales responsables de la existencia de riesgo en los problemas psicosociales. 3- Definir los puntos positivos que permiten unas buenas condiciones de trabajo psicosociales. He trabajado las competencias relativas al estudio que pretende el TFG. Competencias de Psicolo...

  17. Cálculo : problemas y soluciones

    OpenAIRE

    Estela Carbonell, M. Rosa; Cuello Nebot, Eva; Carmona Mejías, Ángeles

    2000-01-01

    Los problemas contenidos en el libro que se presenta son el resultado de cuatro años de docencia en la asignatura Cálcul I de la ETSECCPB. En ellos se desarrolla el cálculo diferencial e integral de una y varias variables, así como una introducción a las sucesiones y series funcionales, con lo que se pretende cubrir cualquier programa de un primer curso de cálculo.

  18. Problemas epistemológicos al historiar

    Directory of Open Access Journals (Sweden)

    Alvar Ezquerra, Alfredo

    1998-09-01

    Full Text Available Not available.Se sintetiza los grandes problemas de la historiografía del XVI y deja al lector la reflexión abierta sobre la situación historiográfica actual. Las similitudes y divergencias entre las angustias y apuestas de aquellos historiadores y los de hoy, esto es, la percepción de la realidad y del pasado por medio de la Historia, ¿son aún iguales?

  19. Juego emergente: ¿Nuevas formas de contar historias en videojuegos?

    Directory of Open Access Journals (Sweden)

    Federico Peinado

    2012-04-01

    Full Text Available Tras treinta años de desarrollo caracterizados por la escalada en rendimiento del hardware, el mercado de los videojuegos está sufriendo una lenta transformación. Los últimos avances tecnológicos en gráficos están empezando a no ser tan decisivos como las mejoras en inteligencia artificial o las nuevas ideas de diseño. Una vez asumido el boom del mercado de los videojuegos y el crecimiento en el espectro social de jugadores, la industria y la comunidad investigadora de reciente creación se están interesando en un nuevo concepto de juego que pone la potencia actual del hardware al servicio del diseño de experiencias interactivas donde el jugador se sienta aún más involucrado. Con este nuevo concepto de juego emergente da comienzo una etapa importante en cuanto a las propiedades narrativas del videojuego: el devenir de los acontecimientos secundarios puede adaptarse al jugador, aunque la historia principal sigue necesitando del autor humano y no puede ser alterada en sus acontecimientos principales. Aún así, el juego emergente representa un esperanzador avance frente a la rígida estructura narrativa con que contaban hasta hace muy poco los videojuegos.

  20. Elementos para uma abordagem das dimensões esquemática e emergente do discurso

    Directory of Open Access Journals (Sweden)

    Gustavo Ximenes Cunha

    2017-07-01

    Full Text Available Este trabalho apresenta apontamentos para uma abordagem que situe, em um quadro teórico unificado, as noções de gêneros do discurso, contexto, tipos de discurso e sequências discursivas. Adotando uma perspectiva sócio-interacionista dos estudos da linguagem e buscando contribuições do Modelo de Análise Modular do Discurso, partimos da hipótese de que, ao longo de uma interação, duas ordens de restrições regulam a maneira como os interactantes elaboram suas produções discursivas. A primeira é de ordem esquemática e diz respeito às expectativas de natureza sócio-histórica que nos fazem saber como agir por meio da linguagem. A segunda ordem de restrições é emergente e corresponde aos parâmetros contextuais que exercem papel sobre as ações linguageiras de fato realizadas. Tomando como base empírica de nossa exposição o tipo narrativo do gênero reportagem e a forma como esse tipo se manifesta em uma sequência narrativa específica, buscamos mostrar que, no curso de uma interação, as dimensões esquemática e emergente do discurso são constante e dinamicamente confrontadas pelos interactantes.

  1. Bioethanol Production from Indigenous Algae

    Directory of Open Access Journals (Sweden)

    Madhuka Roy

    2015-02-01

    Full Text Available Enhanced rate of fossil fuel extraction is likely to deplete limited natural resources over short period of time. So search for alternative fuel is only the way to overcome this problem of upcoming energy crisis. In this aspect biofuel is a sustainable option. Agricultural lands cannot be compromised for biofuel production due to the requirement of food for the increasing population. Certain species of algae can produce ethanol during anaerobic fermentation and thus serve as a direct source for bioethanol production. The high content of complex carbohydrates entrapped in the cell wall of the microalgae makes it essential to incorporate a pre-treatment stage to release and convert these complex carbohydrates into simple sugars prior to the fermentation process. There have been researches on production of bioethanol from a particular species of algae, but this work was an attempt to produce bioethanol from easily available indigenous algae. Acid hydrolysis was carried out as pre-treatment. Gas Chromatographic analysis showed that 5 days’ fermentation by baker’s yeast had yielded 93% pure bioethanol. The fuel characterization of the bioethanol with respect to gasoline showed comparable and quite satisfactory results for its use as an alternative fuel.DOI: http://dx.doi.org/10.3126/ije.v4i1.12182International Journal of Environment Volume-4, Issue-1, Dec-Feb 2014/15, page: 112-120  

  2. Bio diesel production from algae

    International Nuclear Information System (INIS)

    Khola, G.; Ghazala, B.

    2011-01-01

    Algae appear to be an emerging source of biomass for bio diesel that has the potential to completely displace fossil fuel. Two thirds of earth's surface is covered with water, thus alga e would truly be renewable option of great potential for global energy needs. This study discusses specific and comparative bio diesel quantitative potential of Cladophora sp., also highlighting its biomass (after oil extraction), pH and sediments (glycerine, water and pigments) quantitative properties. Comparison of Cladophora sp., with Oedogonium sp., and Spirogyra sp., (Hossain et al., 2008) shows that Cladophora sp., produce higher quantity of bio diesel than Spirogyra sp., whereas biomass and sediments were higher than the both algal specimens in comparison to the results obtained by earlier workers. No prominent difference in pH of bio diesel was found. In Pakistan this is a first step towards bio diesel production from algae. Results indicate that Cladophora sp., provide a reasonable quantity of bio diesel, its greater biomass after oil extraction and sediments make it a better option for bio diesel production than the comparing species. (author)

  3. Método de eliminación de trihalometanos y/o contaminantes emergentes mediante plasma

    OpenAIRE

    Erra Serrabasa, Pilar; Jover Comas, Eric; Molina Mansilla, Ricardo; Bertrán Serra, Enric; Bayona Termens, Josep María; Reyes Contreras, Carolina

    2009-01-01

    Método de eliminación de trihalometanos y/o contaminantes emergentes mediante plasma. Se describe un método de eliminación de trihalometanos y contaminantes refractarios en medios acuosos mediante la aplicación directa de plasma para conseguir la degradación de los compuestos contaminantes presentes en el agua.

  4. Red algae and their use in papermaking.

    Science.gov (United States)

    Seo, Yung-Bum; Lee, Youn-Woo; Lee, Chun-Han; You, Hack-Chul

    2010-04-01

    Gelidialian red algae, that contain rhizoidal filaments, except the family Gelidiellaceae were processed to make bleached pulps, which can be used as raw materials for papermaking. Red algae consist of rhizoidal filaments, cortical cells usually reddish in color, and medullary cells filled with mucilaginous carbohydrates. Red algae pulp consists of mostly rhizoidal filaments. Red algae pulp of high brightness can be produced by extracting mucilaginous carbohydrates after heating the algae in an aqueous medium and subsequently treating the extracted with bleaching chemicals. In this study, we prepared paper samples from bleached pulps obtained from two red algae species (Gelidium amansii and Gelidium corneum) and compared their properties to those of bleached wood chemical pulps. Copyright 2009 Elsevier Ltd. All rights reserved.

  5. Iniciativa europea del radar para riesgos emergentes - ¿una posibilidad a futuro para América Latina?

    Directory of Open Access Journals (Sweden)

    Aleksandar Jovanovic

    2013-04-01

    Full Text Available El proyecto de la Unión Europea (UE: Reconocimiento temprano, monitoreo y gestión integral de riesgos emergentes relacionados con las nuevas tecnologías -iNTeg-Risk ha desarrollado un pragmático e inusual enfoque para un marco integral en la gestión de riesgos emergentes. El principal objetivo de este trabajo fue desarrollar una serie de soluciones específicas e innovadoras aplicando buenos principios de gestión de riesgos y elaborar soluciones más genéricas e integradas, que todas juntas, nos permitan “entender mejor cómo gestionar los riesgos emergentes en un mundo incierto y complejo”El presente artículo presenta una visión general de los diferentes resultados y herramientas desarrolladas a través del proyecto iNTeg-Risk, resaltando algunos logros muy importantes en relación con riesgos emergentes en el área de seguridad de los procesos tales como la regasificación de LNG, operaciones remotas, eventos NaTech, entre otros. Con el fin de asegurar sostenibilidad de los resultados de iNTeg-Risk, el radar europeo de riesgos emergente (E2R2 es una iniciativa prevista como uno de los caminos potenciales para el reconocimiento temprano, monitoreo y gestión de riesgos emergentes.En su fase inicial, los principales componentes de la iniciativa E2R2 son las aplicaciones/herramientas desarrolladas a lo largo del proyecto iNTeg-Risk, tales como RiskAtlas, RiskEars, RiskRadar, RiskClock, RiskTweet, etc. Las entradas multicanales para la iniciativa E2R2 han sido planeadas ser de diferentes fuentes: expertos, proyectos de investigación, publicaciones científicas, aplicaciones web, redes sociales/profesionales y el público en general, por lo tanto, una colaboración posible con interesados latinoamericanos en el futuro seria beneficiosa especialmente para aquellos riesgos emergentes con un carácter más globalizado.

  6. Cellulose powder from Cladophora sp. algae.

    Science.gov (United States)

    Ek, R; Gustafsson, C; Nutt, A; Iversen, T; Nyström, C

    1998-01-01

    The surface are and crystallinity was measured on a cellulose powder made from Cladophora sp. algae. The algae cellulose powder was found to have a very high surface area (63.4 m2/g, N2 gas adsorption) and build up of cellulose with a high crystallinity (approximately 100%, solid state NMR). The high surface area was confirmed by calculations from atomic force microscope imaging of microfibrils from Cladophora sp. algae.

  7. O fluxo de capital para as economias emergentes e o grau de desenvolvimento do sistema financeiro

    Directory of Open Access Journals (Sweden)

    Katia Rocha

    Full Text Available Resumo O presente artigo tem como objetivo analisar o papel do sistema financeiro doméstico como mitigador de eventos de paradas súbitas e condicionante de fluxos de capital de um grupo de 14 economias emergentes no período de 1999-2013, em especial em face de cenários externos desfavoráveis como aumento dos juros internacionais e aversão ao risco global. Os países analisados - Argentina, Brasil, Chile, Colômbia, Indonésia, Malásia, México, Peru, Filipinas, Rússia, África do Sul, Tailândia, Turquia e Ucrânia representavam, em agosto de 2014, aproximadamente 80% do índice EMBIPLUS e 60% do índice EMBIGLOBAL. Procurou-se distinguir o efeito sobre diversos tipos de fluxos de capital: Fluxo de entrada de Investimento Externo Direto, Fluxo de entrada de Investimento em Carteira e Fluxo Líquido, com análise de robustez para período desde 1990 e aumento do número de países emergentes. O principal resultado suporta evidências que o fortalecimento do sistema financeiro doméstico - medido com a capitalização bursátil em proporção do PIB - propicia aumento dos fluxos de entrada de capital de todos os tipos de fluxos em todos os modelos analisados, reduzindo a probabilidade de ocorrência de parada súbita do fluxo de Investimento Externo Direto e em alguns casos do fluxo de Carteira, o que motiva políticas públicas que incentivem o desenvolvimento e fortalecimento deste setor. Estimativas também destacam o papel dos fundamentos domésticos, tão importantes quanto os fatores globais nos condicionantes de fluxo de capital e na ocorrência paradas súbitas. Este fato motiva políticas públicas que incentivem o fortalecimento e desenvolvimento das instituições nos países emergentes, e ressalta o papel dos governos na captação de recursos externos.

  8. Sorção de poluentes orgânicos emergentes em lodo de esgoto

    Directory of Open Access Journals (Sweden)

    Simone Bittencourt

    2016-03-01

    Full Text Available RESUMO O uso de lodo de esgoto na agricultura promove a reciclagem de nutrientes e de matéria orgânica, trazendo benefícios ao desenvolvimento vegetal e à conservação do solo e da água. No entanto, é crescente a preocupação com poluentes orgânicos que possam estar no lodo de esgoto. A presença de medicamentos (antibióticos, tranquilizantes, antiepilépticos, hormônios (naturais e sintéticos, perfumes, bactericidas, entre outros poluentes orgânicos, em diferentes compartimentos ambientais é uma questão emergente, devido à escassez de informações sobre o impacto potencial associado à sua ocorrência, seu destino e efeitos ecotoxicológicos. Esses compostos, denominados poluentes orgânicos emergentes, podem ser removidos durante o tratamento de esgoto por degradação, transformação biológica, volatilização e/ou sorção ao lodo. Esses processos são influenciados pelas propriedades físicas e químicas do poluente e pelas condições de tratamento do esgoto. Informações sobre características físico-químicas, como potencial de acidez e hidrofobicidade, são importantes para compreender os mecanismos de remoção e para adoção de medidas que favoreçam a remoção de tais poluentes, como por exemplo a alteração nas condições operacionais e/ou adoção de tecnologias. A presente revisão bibliográfica apresenta as características físico-químicas de poluentes orgânicos emergentes e seu potencial de sorção em lodo de esgoto.

  9. Biosynthesis of 3-Dimethylsulfoniopropionate in Marine Algae

    National Research Council Canada - National Science Library

    Rhodes, David

    2000-01-01

    ...) in marine algae, including identification of intermediates and enzymes of the pathway in the macroalgae Enteromorpha Intestinalis, and three diverse marine phytoplankton species; Tetraselmis sp...

  10. Algae-production in the desert

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, H.

    1988-11-01

    The company Koor Food Ltd. (Israel) developed in co-operation with the Weizmann-Institute (Israel) a production-plant for the industrial cultivation of algae in the desert area of Elat. For almost a year now, they succeed in harvesting large amounts of algae material with the help of the intensive sun and the Red Sea water. The alga Dunaliella with the natural US -carotine, as well as the alga Spirulina with the high content of protein find their market in the food-, cosmetic- and pharma-industry. This article will give a survey of a yet here unusual project.

  11. El maltrato infantil: un problema mundial

    Directory of Open Access Journals (Sweden)

    SANTANA-TAVIRA ROSALINDA

    1998-01-01

    Full Text Available Al abordar el maltrato infantil se presentan diversos problemas: desconocimiento de la verdadera proporción de dicha problemática; raíces culturales e históricas profundas; diversidad de opiniones en cuanto a su definición y clasificación; dificultades en la investigación y, finalmente, una diversidad de consideraciones sobre sus repercusiones y su manejo terapéutico. En el presente artículo se estudia el maltrato infantil desde sus antecedentes históricos, así como sus clasificaciones, sus definiciones y su epidemiología. Asimismo, se revisan las repercusiones y se plantean las alternativas de tratamiento que en la bibliografía existente se han manejado como fundamentales para enfrentar este fenómeno cada vez más alarmante. Queda subrayada la necesidad de unificar criterios en cuanto a la definición y clasificación de información científica en torno a datos demográficos que, finalmente, hablarán de la realidad del problema, de los avances relacionados con sus causas, su diagnóstico, sus medidas preventivas y su tratamiento. Es fundamental utilizar medidas tendientes a prevenir el maltrato, pues una gran parte de los problemas en el niño se ven reflejados en la vida adulta. Se comparan las distintas clasificaciones en torno al tema, así como las características tanto del agredido como del agresor en los distintos tipos de maltrato.

  12. RETOS DEL APRENDIZAJE BASADO EN PROBLEMAS

    OpenAIRE

    Carlos Antonio Poot-Delgado

    2013-01-01

    Se realiza una breve descripción de la viabilidad y retos de llevar a la práctica docente el aprendizaje basado en problemas, con una estructura organizada, donde se plasman ideas bien fundamentadas con claridad y precisión. Asimismo, se plantean reflexiones pertinentes, mediante ejercicios alusivos y ubicados en la práctica docente. Es decir, una forma de trabajo que puede ser usada por el edu- cador en una parte de su curso, combinado con otras técnicas didácticas y de- limitando los objeti...

  13. Servicio militar un problema de identidades

    OpenAIRE

    Sánchez Navarro, Eulogio

    2005-01-01

    Las diferencias entre la vida civil y la militar han supuesto tradicionalmente lo que podríamos definir como un choque cultural entre aquellos que tuvieron que realizar el servicio militar obligatorio. este choque se vio incrementado en los últimos años de conscripción debido al creciente distanciamiento entre las visiones de mundo de militares y civiles. esta tesis analiza desde la perspectiva de la antropología social los problemas de identidad de los soldados de reemplazo, que habían de...

  14. Anorgasmia femenina como problema de salud

    OpenAIRE

    Farramola Bello, Luis Antonio; Erice Rivero, Teresa Sandra; Frías Alvarez, Yaumara

    2011-01-01

    OBJETIVO: Demostrar que la anorgasmia constituye un problema de salud. MÉTODOS: Se realizó un estudio transversal descriptivo de 227 mujeres que acudieron al Hospital General «Calixto García Iñiguez». Las variables seleccionadas fueron: edad, nivel de escolaridad, edad de inicio de las primeras relaciones sexuales, relación anorgasmia y masturbación femenina. Análisis con porcentajes. RESULTADOS: El mayor porcentaje de anorgasmia coital fue del 35 % y el 40 % eran anorgásmicas fortuitas, toda...

  15. Problemas psiquiátricos em geriatria

    Directory of Open Access Journals (Sweden)

    Marcelo Blaya

    1960-06-01

    Full Text Available Foi apresentado um resumo das idéias comumente aceitas em psiquiatria dinâmica com relação aos problemas emocionais da velhice. A necessidade de uma solução eclética para esta questão de crescente importância na sociedade hodierna não impede que se utilize, com vantagem, uma orientação psicanalítica no tratamento dêsses indivíduos. No caso apresentado acham-se ilustrados alguns pontos de vista do autor.

  16. Problemas de bancarrota multi-escenario.

    Directory of Open Access Journals (Sweden)

    Francisca J. Sánchez

    2004-01-01

    Full Text Available Los problemas de bancarrota representan situaciones donde un número de individuos o entidades acreedoras realizan reclamaciones sobre un cierto bien (estado y el estado total disponible es insuficiente para satisfacer la demanda de todos los acreedores. En este trabajo consideramos el caso en que las reclamaciones de los acreedores dependen de distintos escenarios o que son diferentes bajo distintos estados de la naturaleza. Para obtener repartos del estado disponible en estas situaciones proponemos distintas reglas de división que pueden considerarse racionales independientemente del escenario considerado.

  17. De cómo la realidad puede tomar parte en juegos emergentes

    Directory of Open Access Journals (Sweden)

    Federico Peinado

    2012-04-01

    Full Text Available Este artículo es un estudio del fenómeno de la utilización de elementos reales en aplicaciones software de entretenimiento. De manera más o menos explícita y significativa, este fenómeno se encuentra en la experiencia de juego de numerosos juguetes y experimentos digitales, así como de algunos videojuegos comerciales de gran popularidad; es interesante conocer, por tanto, sus implicaciones estéticas y funcionales a la hora de diseñar interfaces y sistemas de jugabilidad emergente, así como la posible evolución que este fenómeno de la realidad como componente lúdico puede sufrir en los próximos años.

  18. Bioética global y pensamiento complejo. Hacia una emergente manera de ser

    Directory of Open Access Journals (Sweden)

    Sergio Néstor Osorio García

    2008-01-01

    Full Text Available La Bioética global como el pensamiento complejo sólo pueden entenderse en su novedad, si las comprendemos como estrategias emergentes que buscan enfrentar y responder a los desafíos de nuestra era planetaria. Desafíos que retan como nunca nuestra creatividad histórica para habitar la tierra. La consolidación y desarrollo de estas dos importantes estrategias del pensamiento y la acción, nos podrían ayudar en la construcción de un mundo más decente para los humanos y menos destructivo para con los ecosistemas no-humanos.

  19. Cultivation of macroscopic marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J.H.

    1982-11-01

    The red alga Gracilaria tikvahiae may be grown outdoors year-round in central Florida with yields averaging 35.5 g dry wt/m/sup 2/.day, greater than the most productive terrestrial plants. This occurs only when the plants are in a suspended culture, with vigorous aeration and an exchange of 25 or more culture volumes of enriched seawater per day, which is not cost-effective. A culture system was designed in which Gracilaria, stocked at a density of 2 kg wet wt/m/sup 2/, grows to double its biomass in one to two weeks; it is then harvested to its starting density, and anaerobically digested to methane. The biomass is soaked for 6 hours in the digester residue, storing enough nutrients for two weeks' growth in unenriched seawater. The methane is combusted for energy and the waste gas is fed to the culture to provide mixing and CO/sub 2/, eliminating the need for aeration and seawater exchange. The green alga Ulva lactuca, unlike Gracilaria, uses bicarbonate as a photosynthesis carbon source, and can grow at high pH, with little or no free CO/sub 2/. It can therefore produce higher yields than Gracilaria in low water exchange conditions. It is also more efficiently converted to methane than is Gracilaria, but cannot tolerate Florida's summer temperatures so cannot be grown year-round. Attempts are being made to locate or produce a high-temperature tolerant strain.

  20. Modeling and optimization of algae growth

    NARCIS (Netherlands)

    Thornton, Anthony Richard; Weinhart, Thomas; Bokhove, Onno; Zhang, Bowen; van der Sar, Dick M.; Kumar, Kundan; Pisarenco, Maxim; Rudnaya, Maria; Savcenco, Valeriu; Rademacher, Jens; Zijlstra, Julia; Szabelska, Alicja; Zyprych, Joanna; van der Schans, Martin; Timperio, Vincent; Veerman, Frits

    2010-01-01

    The wastewater from greenhouses has a high amount of mineral contamination and an environmentally-friendly method of removal is to use algae to clean this runoff water. The algae consume the minerals as part of their growth process. In addition to cleaning the water, the created algal bio-mass has a

  1. Algae commensal community in Genlisea traps

    Directory of Open Access Journals (Sweden)

    Konrad Wołowski

    2011-01-01

    Full Text Available The community of algae occurring in Genlisea traps and on the external traps surface in laboratory conditions were studied. A total of 29 taxa were found inside the traps, with abundant diatoms, green algae (Chlamydophyceae and four morphotypes of chrysophytes stomatocysts. One morphotype is described as new for science. There are two ways of algae getting into Genlisea traps. The majority of those recorded inside the traps, are mobile; swimming freely by flagella or moving exuding mucilage like diatoms being ablate to colonize the traps themselves. Another possibility is transport of algae by invertebrates such as mites and crustaceans. In any case algae in the Genlisea traps come from the surrounding environment. Two dominant groups of algae (Chladymonas div. and diatoms in the trap environment, show ability to hydrolyze phosphomonoseters. We suggest that algae in carnivorous plant traps can compete with plant (host for organic phosphate (phosphomonoseters. From the spectrum and ecological requirements of algal species found in the traps, environment inside the traps seems to be acidic. However, further studies are needed to test the relations between algae and carnivorous plants both in laboratory conditions and in the natural environment. All the reported taxa are described briefly and documented with 74 LM and SEM micrographs.

  2. Potential biomedical applications of marine algae.

    Science.gov (United States)

    Wang, Hui-Min David; Li, Xiao-Chun; Lee, Duu-Jong; Chang, Jo-Shu

    2017-11-01

    Functional components extracted from algal biomass are widely used as dietary and health supplements with a variety of applications in food science and technology. In contrast, the applications of algae in dermal-related products have received much less attention, despite that algae also possess high potential for the uses in anti-infection, anti-aging, skin-whitening, and skin tumor treatments. This review, therefore, focuses on integrating studies on algae pertinent to human skin care, health and therapy. The active compounds in algae related to human skin treatments are mentioned and the possible mechanisms involved are described. The main purpose of this review is to identify serviceable algae functions in skin treatments to facilitate practical applications in this high-potential area. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Cars will be fed on algae

    International Nuclear Information System (INIS)

    Peltier, G.

    2012-01-01

    The development of the first and second generations of bio-fuels has led to a rise in food prices and the carbon balance sheet is less good than expected. Great hopes have been put on unicellular algae for they can synthesize oils, sugar and even hydrogen and the competition with food production is far less harsh than with actual bio-fuels. Moreover, when you grow micro-algae, the loss of water through evaporation is less important than in the case of intensive farm cultures. In 2009 10.000 tonnes of micro-algae were produced worldwide, they were mainly used for the production of fish food and of complements for humane food (fat acids and antioxidants). Different research programs concern unicellular algae: they aim at modifying micro-algae genetically in order to give them a higher productivity or to make them produce an oil more adapted for motor fuel or more easily recoverable. (A.C.)

  4. Composting of waste algae: a review.

    Science.gov (United States)

    Han, Wei; Clarke, William; Pratt, Steven

    2014-07-01

    Although composting has been successfully used at pilot scale to manage waste algae removed from eutrophied water environments and the compost product applied as a fertiliser, clear guidelines are not available for full scale algae composting. The review reports on the application of composting to stabilize waste algae, which to date has mainly been macro-algae, and identifies the peculiarities of algae as a composting feedstock, these being: relatively low carbon to nitrogen (C/N) ratio, which can result in nitrogen loss as NH3 and even N2O; high moisture content and low porosity, which together make aeration challenging; potentially high salinity, which can have adverse consequence for composting; and potentially have high metals and toxin content, which can affect application of the product as a fertiliser. To overcome the challenges that these peculiarities impose co-compost materials can be employed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Prospects of using algae in biofuel production

    Directory of Open Access Journals (Sweden)

    Y. I. Maltsev

    2017-08-01

    Full Text Available The development of industry, agriculture and the transport sector is associated with the use of various energy sources. Renewable energy sources, including biofuels, are highly promising in this respect. As shown by a number of scientific studies, a promising source for biofuel production that would meet modern requirements may be algal biomass. After activation of the third generation biodiesel production it was assumed that the algae would become the most advantageous source, because it is not only able to accumulate significant amounts of lipids, but could reduce the of agricultural land involved in biofuel production and improve air quality by sequestering CO2. However, a major problem is presented by the cost of algae biomass cultivation and its processing compared to the production of biodiesel from agricultural crops. In this regard, there are several directions of increasing the efficiency of biodiesel production from algae biomass. The first direction is to increase lipid content in algae cells by means of genetic engineering. The second direction is connected with the stimulation of increased accumulation of lipids by stressing algae. The third direction involves the search for new, promising strains of algae that will be characterized by faster biomass accumulation rate, higher content of TAG and the optimal proportions of accumulated saturated and unsaturated fatty acids compared to the already known strains. Recently, a new approach in the search for biotechnologically valuable strains of algae has been formed on the basis of predictions of capacity for sufficient accumulation of lipids by clarifying the evolutionary relationships within the major taxonomic groups of algae. The outcome of these studies is the rapid cost reduction of biofuel production based on algae biomass. All this emphasizes the priority of any research aimed at both improving the process of production of biofuels from algae, and the search for new sources for

  6. Aprendizaje colaborativo a través de problemas

    Directory of Open Access Journals (Sweden)

    María José Labrador Piquer

    2011-01-01

    Full Text Available El objetivo de este taller ha sido acercar a los asistentes al aprendizaje colaborativo a través de problemas en la enseñanza de ELE, para ello, partimos de unas nociones básicas de aprendizaje cooperativo/colaborativo y del análisis de problemas, continuamos con el estudio de problemas y finalizamos con una serie de reflexiones sobre la evaluación. Durante la sesión los asistentes han realizado dos funciones: una, como alumnos analizando y resolviendo los problemas y otra, como profesores reflexionando sobre las destrezas practicadas y sobre la evaluación.

  7. Aprendizaje colaborativo a través de problemas

    Directory of Open Access Journals (Sweden)

    María José Labrador Piquer

    2012-08-01

    Full Text Available El objetivo de este taller ha sido acercar a los asistentes al aprendizaje colaborativo a través de problemas en la enseñanza de ELE, para ello, partimos de unas nociones básicas de aprendizaje cooperativo/colaborativo y del análisis de problemas, continuamos con el estudio de problemas y finalizamos con una serie de reflexiones sobre la evaluación. Durante la sesión los asistentes han realizado dos funciones: una, como alumnos analizando y resolviendo los problemas y otra, como profesores reflexionando sobre las destrezas practicadas y sobre la evaluación.

  8. Contaminación por nitrógeno inorgánico en los ecosistemas acuáticos: problemas medioambientales, criterios de calidad del agua, e implicaciones del cambio climático

    OpenAIRE

    J. A. Camargo; A. Alonso

    2007-01-01

    Los principales problemas medioambientales asociados a la contaminación por nitrógeno inorgánico en los ecosistemas acuáticos son: (1) acidificación de ríos y lagos con baja o reducida alcalinidad; (2) eutrofización de las aguas dulces y marinas (con el problema adicional de las algas tóxicas); y (3) toxicidad directa de los compuestos nitrogenadospara los animales acuáticos. Además, la contaminación por nitrógeno inorgánico podría inducir efectos perjudiciales sobre la salud humana. En b...

  9. Los problemas de las fronteras humanitarias

    Directory of Open Access Journals (Sweden)

    Ticktin, Miriam

    2015-12-01

    Full Text Available This text engages a critical analysis of humanitarian discourses and practices regarding our understanding of migration and the public policies developed in relation to the population movementsacross international borders. It is based on the premise that humanitarianism, even if well intentioned, can have pernicious effects if, eventually, it ends up replacing justice and migrants’ rights. To explore this paradox, the paper sequentially analyzes various problems associated with humanitarian aid: the problem of innocence —the understanding of refugees as victims calls for humanitarian compassion—; the problem with emergency —«rapid response» operations inhibit the contextualized and historical understanding of the root causes of the problems—; and, finally, the problem of compassion —humanitarianism privilegessentiments over rights. The study of these three key features of humanitarianism in Europe and the USA fosters a healthy skepticism of the emerging forms of the legitimation of exclusion. The article also explores alternative political and discursive strategies which allow for new imaginaries to confront migratory processes beyond borders and humanitarianism, breaking up their dynamic of reproduction of social inequalities and placing justice in the horizon of action.Este texto plantea un análisis crítico del papel de los discursos y prácticas humanitaristas en nuestra concepción de la migración y en las políticas públicas desarrolladas en relación a la movilidad poblacional a través de las fronteras internacionales. Se parte de la premisa de que el humanitarismo, aunque fuera bien intencionado, puede tener efectos perniciosos sobre la situación que se vive en las fronteras, especialmente si acaba por sustituir a la justicia y a los derechos que tienen los emigrantes. Para estudiar esta paradoja, el texto analiza, sucesivamente, varios problemas asociados a la acción humanitaria: el problema con la inocencia

  10. Algae biodiesel - a feasibility report

    Science.gov (United States)

    2012-01-01

    Background Algae biofuels have been studied numerous times including the Aquatic Species program in 1978 in the U.S., smaller laboratory research projects and private programs. Results Using Molina Grima 2003 and Department of Energy figures, captial costs and operating costs of the closed systems and open systems were estimated. Cost per gallon of conservative estimates yielded $1,292.05 and $114.94 for closed and open ponds respectively. Contingency scenarios were generated in which cost per gallon of closed system biofuels would reach $17.54 under the generous conditions of 60% yield, 50% reduction in the capital costs and 50% hexane recovery. Price per gallon of open system produced fuel could reach $1.94 under generous assumptions of 30% yield and $0.2/kg CO2. Conclusions Current subsidies could allow biodiesel to be produced economically under the generous conditions specified by the model. PMID:22540986

  11. Algae biodiesel - a feasibility report

    Directory of Open Access Journals (Sweden)

    Gao Yihe

    2012-04-01

    Full Text Available Abstract Background Algae biofuels have been studied numerous times including the Aquatic Species program in 1978 in the U.S., smaller laboratory research projects and private programs. Results Using Molina Grima 2003 and Department of Energy figures, captial costs and operating costs of the closed systems and open systems were estimated. Cost per gallon of conservative estimates yielded $1,292.05 and $114.94 for closed and open ponds respectively. Contingency scenarios were generated in which cost per gallon of closed system biofuels would reach $17.54 under the generous conditions of 60% yield, 50% reduction in the capital costs and 50% hexane recovery. Price per gallon of open system produced fuel could reach $1.94 under generous assumptions of 30% yield and $0.2/kg CO2. Conclusions Current subsidies could allow biodiesel to be produced economically under the generous conditions specified by the model.

  12. Procesos de ozonación fotocatalítica para eliminar contaminantes emergentes de aguas residuales urbanas

    OpenAIRE

    Espejo Morán, María Azahara

    2016-01-01

    En este trabajo se ha estudiado la degradación de distintos contaminantes emergentes (CEs) añadidos a un agua residual urbana mediante procesos químicos integrados secuencialmente como etapa previa o etapa terciaria a un tratamiento biológico aerobio convencional por fangos activos. Los compuestos seleccionados son acetaminofeno, antipirina, bisfenol A, cafeína, carbamazepina, diclofenaco, hidroclorotiazida, ketorolaco, metoprolol, sulfametoxazol y testosterona. Estos CEs se eligieron ya que ...

  13. Control borroso para la valoración del impacto ambiental generado por contaminantes emergentes en aguas residuales hospitalarias

    OpenAIRE

    Leadina Sánchez Barboza

    2015-01-01

    La valoración de impactos ambientales está sujeta a imprecisión, vaguedad y subjetividad. Estas características son extensivas al impacto generado por la presencia de contaminantes emergentes -fármacos- en aguas residuales hospitalarias, por lo que este trabajo propone valorar el impacto de dichos contaminantes mediante un sistema de inferencia borrosa, utilizando el toolbox fuzzy logic de MATLAB®, aplicando el sistema experto Mamdani. Los conjuntos borrosos de entrada se establecieron a part...

  14. Method and apparatus for processing algae

    Science.gov (United States)

    Chew, Geoffrey; Reich, Alton J.; Dykes, Jr., H. Waite; Di Salvo, Roberto

    2012-07-03

    Methods and apparatus for processing algae are described in which a hydrophilic ionic liquid is used to lyse algae cells. The lysate separates into at least two layers including a lipid-containing hydrophobic layer and an ionic liquid-containing hydrophilic layer. A salt or salt solution may be used to remove water from the ionic liquid-containing layer before the ionic liquid is reused. The used salt may also be dried and/or concentrated and reused. The method can operate at relatively low lysis, processing, and recycling temperatures, which minimizes the environmental impact of algae processing while providing reusable biofuels and other useful products.

  15. Errors When Extracting Oil from Algae

    Science.gov (United States)

    Murphy, E.; Treat, R.; Ichiuji, T.

    2014-12-01

    Oil is in popular demand, but the worldwide amount of oil is decreasing and prices for it are steadily increasing. Leading scientists have been working to find a solution of attaining oil in an economically and environmentally friendly way. Researchers at the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) have determined that "a small mixture of algae and water can be turned into crude oil in less than an hour" (Sheehan, Duhahay, Benemann, Poessler). There are various ways of growing the algae, such as closed loop and open loop methods, as well as processes of extracting oil, such as hydrothermal liquefaction and the hexane-solvent method. Our objective was to grow the algae (C. reinhardtii) and extract oil from it using NaOH and HCl, because we had easy access to those specific chemicals. After two trials of attempted algae growth, we discovered that a bacteria was killing off the algae. This led us to further contemplation on how this dead algae and bacteria are affecting our environment, and the organisms within it. Eutrophication occurs when excess nutrients stimulate rapid growth of algae in an aquatic environment. This can clog waterways and create algal blooms in blue-green algae, as well as neurotoxic red tide phytoplankton. These microscopic algae die upon consumption of the nutrients in water and are degraded by bacteria. The bacteria respires and creates an acidic environment with the spontaneous conversion of carbon dioxide to carbonic acid in water. This process of degradation is exactly what occurred in our 250 mL flask. When the phytoplankton attacked our algae, it created a hypoxic environment, which eliminated any remaining amounts of oxygen, carbon dioxide, and nutrients in the water, resulting in a miniature dead zone. These dead zones can occur almost anywhere where there are algae and bacteria, such as the ocean, and make it extremely difficult for any organism to survive. This experiment helped us realize the

  16. Conferencia Argentina de Educación Médica: agendas, aportes y temas Emergentes

    Directory of Open Access Journals (Sweden)

    María Eugenia Brissón

    Full Text Available Propósito: En el presente trabajo se pretende identificar en las Conferencias Argentinas de Educación Médica (CAEMs cuáles son los temas que -en relación a la formación de médicos- se han debatido, los que ocupan la agenda actual y los emergentes, así como establecer algunas relaciones con el movimiento internacional en ese campo, en los últimos veinte años. Material y método: Se trata de un estudio descriptivo del período 1985 - 2003. Se realizaron análisis de programas y resúmenes presentados (CAEMs 1999, 2000, 2001, 2002, 2003, búsquedas no sistemáticas en Internet, revisión documental y consultas a informantes claves. Resultados: Temas en debate: admisión; evaluación y acreditación; cambios curriculares; selección, formación y evaluación del cuerpo docente y evaluación de la calidad de los egresados. Temas emergentes: asuntos de la agenda mundial son apenas incipientes en los debates de las CAEMs. Relaciones con el movimiento internacional: conformación de asociaciones sin fines de lucro para el desarrollo de la educación médica, participación en reuniones internacionales, desarrollo de proyectos de investigaciones, fortalecimiento de la formación de postgrado y legislación de aplicación en el campo de la educación médica. Conclusiones: Existencia de contribuciones mutuas entre el pensamiento latinoamericano en educación médica y el global. En Argentina la expansión de la educación médica ha sido apreciable en los últimos veinte años. Las CAEM han servido como ámbito de convocatoria, discusión y difusión de las cuestiones de la agenda general y de temas particulares del país. Ha dado lugar al establecimiento de líneas de actividades y al inicio de investigaciones. En general, si bien prevalece una discusión basada en opiniones, se advierte, en el transcurso de los años, un mejoramiento de la calidad de las comunicaciones y de los trabajos presentados.

  17. 21 CFR 73.275 - Dried algae meal.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Dried algae meal. 73.275 Section 73.275 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae cells (genus Spongiococcum, separated from its culture broth...

  18. The Biology of blue-green algae

    National Research Council Canada - National Science Library

    Carr, Nicholas G; Whitton, B. A

    1973-01-01

    .... Their important environmental roles, their part in nitrogen fixation and the biochemistry of phototrophic metabolism are some of the attractions of blue-geen algae to an increasing number of biologists...

  19. Diatom algae of the Guni river (Pamir)

    International Nuclear Information System (INIS)

    Kurbonova, P.A.; Hisoriev, H.H.

    2006-01-01

    There are presented the dates of the results of diatom algae (Bacillariophyta) of the Gunt river. There was found 107 species and 9 subspecies which belong to 3 classics, 12 ordos, 13 families and 28 genus

  20. 2011 Biomass Program Platform Peer Review: Algae

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Joyce [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2012-02-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the 2011 U.S. Department of Energy Biomass Program’s Algae Platform Review meeting.

  1. Dipeptides from the red alga Acanthopora spicifera

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; De; Kamat, S.Y.

    An investigation of red alga Acanthophora spicifera afforded the known peptide, aurantiamide acetate and a new diastereoisomer of this dipeptide (dia-aurantiamide acetate). This is a first report of aurantiamide acetate from a marine source...

  2. FUENTES ENERGÉTICAS Y PROBLEMAS AMBIENTALES

    Directory of Open Access Journals (Sweden)

    Antonio Sánchez Ogallar

    2006-12-01

    Full Text Available En esta comunicación se propone una estrategia didáctica organizada en tomo a dos grandes núcleos. El primero, La energía, requiere un planteamiento descriptivo orientado a la obtención de una visión global del problema energético. A continuación se pasa a abordar el otro núcleo: El cambioclimático. Este se enfoca desde un punto de vista más analítico y exige un amplio despliegue metodológico, con actividades de comprensión, de expresión y de valoración. Las actividades son consideradas como pasos previos para continuar un itinerario formativo para que el alumnado realice una construcción personal del entramado conceptual. Para ello se proponen procesos de profundización en aspectos más específicos. Además, se pretende que los alumnos elaboren un criterio propio respecto a las relaciones Humanidad-Naturaleza en general y, muy especialmente, respecto a la incidencia de las actividades humanas sobre el clima.

  3. Historias del cuerpo: Problemas en debate

    Directory of Open Access Journals (Sweden)

    Gerardo Javier Fittipaldi

    2011-11-01

    Full Text Available Los trabajos reunidos en la mesa "Problemas de Historia del Cuerpo", más allá de las diferencias particulares que los separan o los oponen, pueden recorrerse por las siguientes preguntas: ¿cómo asir ese objeto histórico que, perteneciéndole a cada uno, siendo aparentemente lo más propio e irrenunciable, es, sin embargo, blanco de poderes sociales?, ¿por dónde recorrer las huellas que se inscriben en el cuerpo y que éste deja en su paso por la historia? Cuerpo e historia constituyen así un par teórico indisociable: no hay historia sin cuerpo o cuerpo sin historia. Pero, como en toda pareja, ello no implica que siempre haya acuerdos entre sí o que no pueda problematizarse esta relación. Hay conflictos que el cuerpo ha guardado y que los historiadores no han encontrado por dónde buscar; en tanto que hay ideales que se han planteado independientes de todo cuerpo y que los historiadores buscan su encarnación. Quizás podemos encontrar un motivo que anima todos estos trabajos: dejar planteado que la naturaleza del cuerpo es su historia, una historia que hay que contar y que no tiene nada de natural

  4. O problema indígena

    Directory of Open Access Journals (Sweden)

    Egon Schaden

    1960-07-01

    Full Text Available Lembro-me muitas vêzes de uma conversa que, em janeiro de 1949, já lá vão dez anos, tive com o velho General Rondon. Trocávamos idéias sôbre a melhor maneira de se ajudarem os índios brasileiros a se incorporarem à nacionalidade ou, por outra, de se lhes garantir um lugar ao sol. O que mais admiração ,me causava no ancião era a sua juventude de espírito, a sua capacidade de rever e de refazer opiniões defendidas com ardor durante decênios de sua vida. Chegara à convicção de que já não se deveria nacionalizar os índios, o que, afirmava, "cria problemas graves e desajustamentos", mas preservar as culturas tribais, tomando por base os padrões econômicos de cada uma delas, para se fomentar uma atividade de produção que, sem ser revolucionária, lhes proporcionasse os meios necessários para se integrarem à vida econômica das regiões em que vivem.

  5. ALERTA DE TECNOLOGIAS NOVAS E EMERGENTES: O DESAFIO DE INFORMAR A SOCIEDADE

    Directory of Open Access Journals (Sweden)

    Pollyanna Teresa Cirilo Gomes

    2015-10-01

    Full Text Available O monitoramento do Horizonte Tecnológico (MHT é uma etapa específica da Avaliação de Tecnologias em Saúde. Este trabalho teve como objetivo construir um modelo de Alerta de MHT centrado na sociedade, nos gestores e nos profissionais de saúde, a fim de ser utilizado no âmbito do Ministério da Saúde. Para isso, foram pesquisados nos sítios eletrônicos das agências integrantes da EuroScan, informes e alertas de tecnologias em saúde novas e emergentes. A partir dessa busca, levou-se em consideração a relevância da informação, a rapidez na obtenção dos dados e a disponibilidade para a equipe elaboradora. Os Alertas de MHT poderão promover o acesso dos diferentes segmentos da sociedade a informações baseadas na melhor evidência científica disponível, e poderá auxiliar nos processos de tomada decisão em saúde.

  6. Una gramática emergente ¿internet como cultura o artefacto?

    Directory of Open Access Journals (Sweden)

    Mireya Barón Pulido

    2012-12-01

    Full Text Available Nativos digitales, gramáticas emergentes, internet como cultura y como artefacto son referentes marco que dinamizan tanto la emisión como la interpretación de signos en la población universitaria. El artículo muestra los resultados de las tendencias de usos de los lenguajes y mediaciones TICS en jóvenes universitarios de primer semestre del Politécnico Grancolombiano-COLOMBIA a partir del trabajo con grupos focales y aplicación de instrumento, con el propósito de sistematizar la tendencia de esta semiosis y su relación con el escenario pedagógico en la educación superior. Por demás, la investigación logra hacer un estado de arte de los resultados-casos en América Latina y Europa ante la realidad sígnica TICS y actores universitarios.

  7. FRAGILIDADE POTENCIAL E EMERGENTE NA BACIA DO RIO DAS PEDRAS, GUARAPUAVA, PR - BRASIL

    Directory of Open Access Journals (Sweden)

    Paulo Eugênio Pachechenik

    2013-10-01

    Full Text Available O presente trabalho teve por objetivo delimitar a potencialidade do uso do solo para auxiliar no planejamento da exploração dos recursos naturais da bacia do rio das Pedras, situada no município de Guarapuava, Paraná, Brasil. Aplicou-se uma metodologia de análise empírica da fragilidade ambiental, digitalizando a área e rede de drenagem da bacia, e gerando-se, posteriormente, um modelo numérico do terreno, empregando programas especializados. A área da bacia apresenta fragilidade ambiental potencial entre as classes “média” e “alta”, com os usos do solo classificando-a na fragilidade ambiental emergente “muito baixa” e “baixa”. Os limites da potencialidade de uso do solo indicam que a bacia está protegida da erosão e os fatores de forma demonstram, para as atuais condições, que há “pequena” possibilidade de ocorrer enchentes.

  8. LA INFLAMACIÓN COMO FACTOR CAUSAL EMERGENTE DE LA ENFERMEDAD CARDIOVASCULAR

    Directory of Open Access Journals (Sweden)

    T. Fernández-Mora

    2007-06-01

    Full Text Available La ateroesclerosis está involucrada en el desarrollo de la enfermedad cardiovascular, una de las principales enfermedades de morbimortalidad en el mundo. Se han determinado una serie de factores de riesgo, tanto clásicos como emergentes, implicados en el desarrollo de esta enfermedad. Recientes investigaciones han demostrado que la inflamación juega un papel clave en el desarrollo de la ateroesclerosis. Las células del sistema inmune se encuentran presentes en todos los estadios de las lesiones arterioescleróticasy sus moléculas efectoras pueden acelerar la progresión de las lesiones y orquestar los mecanismos de inflamación inducidos en los síndromes coronarios agudos. La evidencia crítica implica a mediadores de la inmunidad tanto innata como adquirida en los diferentes estados de la ateroesclerosis. Dentro de loscomponentes inmunes involucrados en el proceso de la ateroesclerosis se encuentran componentes celulares como macrófagos, linfocitos, células dendríticas, mastocitos, células NK; componentes humoralescomo anticuerpos, citocinas proinflamatorias y moduladoras de la respuesta inmune, complemento, proteínas de fase aguda; y otros componentes como moléculas de adhesión y de choque térmico. A partirdel esclarecimiento del papel del sistema inmune en el desarrollo de la arterioesclerosis, han surgido una serie de perspectivas diagnósticas y terapéuticas para la enfermedad cardiovascular.

  9. Sustainable Algae Biodiesel Production in Cold Climates

    OpenAIRE

    Baliga, Rudras; Powers, Susan E.

    2010-01-01

    This life cycle assessment aims to determine the most suitable operating conditions for algae biodiesel production in cold climates to minimize energy consumption and environmental impacts. Two hypothetical photobioreactor algae production and biodiesel plants located in Upstate New York (USA) are modeled. The photobioreactor is assumed to be housed within a greenhouse that is located adjacent to a fossil fuel or biomass power plant that can supply waste heat and flue gas containing CO2 as a ...

  10. Antioxidant Activity of Hawaiian Marine Algae

    Directory of Open Access Journals (Sweden)

    Anthony D. Wright

    2012-02-01

    Full Text Available Marine algae are known to contain a wide variety of bioactive compounds, many of which have commercial applications in pharmaceutical, medical, cosmetic, nutraceutical, food and agricultural industries. Natural antioxidants, found in many algae, are important bioactive compounds that play an important role against various diseases and ageing processes through protection of cells from oxidative damage. In this respect, relatively little is known about the bioactivity of Hawaiian algae that could be a potential natural source of such antioxidants. The total antioxidant activity of organic extracts of 37 algal samples, comprising of 30 species of Hawaiian algae from 27 different genera was determined. The activity was determined by employing the FRAP (Ferric Reducing Antioxidant Power assays. Of the algae tested, the extract of Turbinaria ornata was found to be the most active. Bioassay-guided fractionation of this extract led to the isolation of a variety of different carotenoids as the active principles. The major bioactive antioxidant compound was identified as the carotenoid fucoxanthin. These results show, for the first time, that numerous Hawaiian algae exhibit significant antioxidant activity, a property that could lead to their application in one of many useful healthcare or related products as well as in chemoprevention of a variety of diseases including cancer.

  11. Hyperspectral imaging of snow algae and green algae from aeroterrestrial habitats.

    Science.gov (United States)

    Holzinger, Andreas; Allen, Michael C; Deheyn, Dimitri D

    2016-09-01

    Snow algae and green algae living in aeroterrestrial habitats are ideal objects to study adaptation to high light irradiation. Here, we used a detailed description of the spectral properties as a proxy for photo-acclimation/protection in snow algae (Chlamydomonas nivalis, Chlainomonas sp. and Chloromonas sp.) and charophyte green algae (Zygnema sp., Zygogonium ericetorum and Klebsormidium crenulatum). The hyperspectral microscopic mapping and imaging technique allowed us to acquire total absorption spectra of these microalgae in the waveband of 400-900nm. Particularly in Chlamydomonas nivalis and Chlainomonas sp., a high absorbance between 400-550nm was observed, due to naturally occurring secondary carotenoids; in Chloromonas sp. and in the charopyhte algae this high absorbance was missing, the latter being close relatives to land plants. To investigate if cellular water loss has an influence on the spectral properties, the cells were plasmolysed in sorbitol or desiccated at ambient air. While in snow algae, these treatments did hardly change the spectral properties, in the charopyhte algae the condensation of the cytoplasm and plastids increased the absorbance in the lower waveband of 400-500nm. These changes might be ecologically relevant and photoprotective, as aeroterrestrial algae are naturally exposed to occasional water limitation, leading to desiccation, which are conditions usually occurring together with higher irradiation. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  12. APLICACIÓN DE ULTRASONIDOS PARA EL CONTROL DE ALGAS EN AGUAS REGENERADAS ALMACENADAS EN BALSAS DE RIEGO

    OpenAIRE

    Maestre Valero, J.F; Pedrero Salcedo, F.; Soto García, M.; Alarcón, J.J

    2015-01-01

    [ES] En las regiones áridas y semiáridas las balsas de riego son infraestructuras que garantizan el suministro de agua a los cultivos. Sin embargo, favorecen la proliferación de algas provocando serios problemas en la calidad del agua que afectan negativamente a los sistemas de riego (filtración, emisores, elementos auxiliares,...). Ante esta problemática, el objetivo de este estudio fue evaluar, a escala real, el efecto de los ultrasonidos sobre parámetros físico-químicos y mi...

  13. Radiation sterilization of harmful algae in water

    International Nuclear Information System (INIS)

    Byung Chull An; Jae-Sung Kim; Seung Sik Lee; Shyamkumar Barampuram; Eun Mi Lee; Byung Yeoup Chung

    2007-01-01

    Complete text of publication follows. Objective: Drinking water, water used in food production and for irrigation, water for fish farming, waste water, surface water, and recreational water have been recently recognized as a vector for the transmission of harmful micro-organisms. The human and animal harmful algae is a waterborne risk to public health and economy because the algae are ubiquitous and persistent in water and wastewater, not completely removed by physical-chemical treatment processes, and relatively resistant to chemical disinfection. Gamma and electron beam radiation technology is of growing in the water industry since it was demonstrated that gamma and electron beam radiation is very effective against harmful algae. Materials and Methods: Harmful algae (Scenedesmus quadricauda(Turpin) Brebisson 1835 (AG10003), Chlorella vulgaris Beijerinck 1896 (AG30007) and Chlamydomonas sp. (AG10061)) were distributed from Korean collection for type cultures (KCTC). Strains were cultured aerobically in Allen's medium at 25□ and 300 umol/m2s for 1 week using bioreactor. We investigated the disinfection efficiency of harmful algae irradiated with gamma (0.05 to 10 kGy for 30 min) and electron beam (1 to 19 kGy for 5 sec) rays. Results and Conclusion: We investigated the disinfection efficiency of harmful algae irradiated with gamma and electron beam rays of 50 to 19000 Gy. We established the optimum sterilization condition which use the gamma and electron beam radiation. Gamma ray disinfected harmful algae at 400 Gy for 30 min. Also, electron beam disinfected at 1000 Gy for 5 sec. This alternative disinfection practice had powerful disinfection efficiency. Hence, the multi-barrier approach for drinking water treatment in which a combination of various disinfectants and filtration technologies are applied for removal and inactivation of different microbial pathogens will guarantee a lower risk of microbial contamination.

  14. Algae production for energy and foddering

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Attila; Jobbagy, Peter; Durko, Emilia [University of Debrecen, Faculty of Applied Economics and Rural Development (UD-FAERD), Centre for Agricultural and Applied Economic Sciences, Debrecen (Hungary)

    2011-09-15

    This study not only presents the results of our own experiments in alga production, but also shows the expected economic results of the various uses of algae (animal feed, direct burning, pelleting, bio-diesel production), the technical characteristics of a new pelleting method based on literature, and also our own recommended alga production technology. In our opinion, the most promising alternative could be the production of alga species with high levels of oil content, which are suitable for utilization as by-products for animal feed and in the production of bio-diesel, as well as for use in waste water management and as a flue gas additive. Based on the data from our laboratory experiments, of the four species we analyzed, Chlorella vulgaris should be considered the most promising species for use in large-scale experiments. Taking expenses into account, our results demonstrate that the use of algae for burning technology purposes results in a significant loss under the current economic conditions; however, the utilization of algae for feeding and bio-diesel purposes - in spite of their innovative nature - is nearing the level needed for competitiveness. By using the alga production technology recommended by us and described in the present study in detail, with an investment of 545 to 727 thousand EUR/ha, this technology should be able to achieve approximately 0-29 thousand EUR/ha net income, depending on size. More favorable values emerge in the case of the 1-ha (larger) size, thanks to the significant savings on fixed costs (depreciation and personnel costs). (orig.)

  15. Psicologia do esporte: uma área emergente da psicologia Psicología del deporte: un area emergente de la psicología Sport psychology: an emergent field in psychology

    OpenAIRE

    Lenamar Fiorese Vieira; João Ricardo Nickenig Vissoci; Leonardo Pestillo de Oliveira; José Luiz Lopes Vieira

    2010-01-01

    O artigo trata da Psicologia do Esporte, um campo de atuação emergente do psicólogo no Brasil. Faz uma análise sobre o percurso histórico da Psicologia Esportiva apresentando os campos de atuação profissional (pesquisa, ensino e intervenção), o papel do psicólogo esportivo (pesquisador, professor e consultor) e o estado científico atual dessa especialidade psicológica. Mesmo com o vasto campo de trabalho, um elemento interveniente é a diversidade de conhecimentos necessários para esta subdivi...

  16. Tecnologías emergentes para la conservación de alimentos sin calor

    Directory of Open Access Journals (Sweden)

    Fernández Molina, Juan José

    2001-01-01

    Full Text Available Not available

    Se han investigado los principios básicos de tres tecnologías emergentes para pasteurizar y esterilizar alimentos sin empleo del calor Mediante numerosos estudios se ha comprobado la efectividad de los campos eléctricos pulsantes de alta intensidad (CEPAI, los pulsos de luz (PL y los campos magnéticos oscilantes (CMO en la destrucción de microorganismos y enzimas de sistemas alimentarios. En la inactivación microbiana por CEPA!, el blanco principal es la membrana celular que, al ser sometida a campos eléctricos de alta intensidad, se hace permeable formando huecos o poros cuyo tamaño se incrementa a medida que aumenta la intensidad del campo eléctrico o el tiempo de tratamiento o se reduce la resistencia iónica del medio de pulsación. Por otra parte, los PL inducen reacciones fotoquímicas y fototérmicas en los alimentos, causando la muerte de gran cantidad de microorganismos, especialmente en productos alimenticios envasados. Los CMO producen simulación o inhibición en el crecimiento y reproducción de los microorganismos, un simple pulso de intensidad de 5-10 teslas y frecuencias de 5-500 kHz es suficiente para reducir el número de microorganismos en un mínimo de 2 ciclos logarítmicos. Se ha comprobado que estas tecnologías alargan la vida de anaquel de diversos productos alimenticios y pueden ser consideradas como sustitutos parciales de los procesos convencionales de pasteurización y esterilización de alimentos por tratamientos térmicos.

  17. Sobre o problema da demarcação

    Directory of Open Access Journals (Sweden)

    Marcos Barbosa de Oliveira

    1982-12-01

    Full Text Available Desde sua publicação, não têm faltado ataques ao critério da refutabilidade - a solução proposta por Popper para seu problema da demarcação. A crítica do presente artigo é mais fundamental: seu alvo é o próprio problema da demarcação. Como preliminar, mostra-se haver na obra de Popper não apenas um, mas dois problemas da demarcação, distintos e incompatíveis. Uma análise do antiessencialismo de Popper é o ponto de partida para a demonstração da tese central do artigo, a saber, a tese de que o problema da demarcação deve ser abandonado, por ser parte de uma abordagem cientificista da questão do valor das ciências.

  18. Effect of ferrate on green algae removal.

    Science.gov (United States)

    Kubiňáková, Emília; Híveš, Ján; Gál, Miroslav; Fašková, Andrea

    2017-09-01

    Green algae Cladophora aegagropila, present in cooling water of thermal power plants, causes many problems and complications, especially during summer. However, algae and its metabolites are rarely eliminated by common removal methods. In this work, the elimination efficiency of electrochemically prepared potassium ferrate(VI) on algae from cooling water was investigated. The influence of experimental parameters, such as Fe(VI) dosage, application time, pH of the system, temperature and hydrodynamics of the solution on removal efficiency, was optimized. This study demonstrates that algae C. aegagropila can be effectively removed from cooling water by ferrate. Application of ferrate(VI) at the optimized dosage and under the suitable conditions (temperature, pH) leads to 100% removal of green algae Cladophora from the system. Environmentally friendly reduction products (Fe(III)) and coagulation properties favour the application of ferrate for the treatment of water contaminated with studied microorganisms compared to other methods such as chlorination and use of permanganate, where harmful products are produced.

  19. Phospholipids of New Zealand Edible Brown Algae.

    Science.gov (United States)

    Vyssotski, Mikhail; Lagutin, Kirill; MacKenzie, Andrew; Mitchell, Kevin; Scott, Dawn

    2017-07-01

    Edible brown algae have attracted interest as a source of beneficial allenic carotenoid fucoxanthin, and glyco- and phospholipids enriched in polyunsaturated fatty acids. Unlike green algae, brown algae contain no or little phosphatidylserine, possessing an unusual aminophospholipid, phosphatidyl-O-[N-(2-hydroxyethyl) glycine], PHEG, instead. When our routinely used technique of 31 P-NMR analysis of phospholipids was applied to the samples of edible New Zealand brown algae, a number of signals corresponding to unidentified phosphorus-containing compounds were observed in total lipids. NI (negative ion) ESI QToF MS spectra confirmed the presence of more familiar phospholipids, and also suggested the presence of PHEG or its isomers. The structure of PHEG was confirmed by comparison with a synthetic standard. An unusual MS fragmentation pattern that was also observed prompted us to synthesise a number of possible candidates, and was found to follow that of phosphatidylhydroxyethyl methylcarbamate, likely an extraction artefact. An unexpected outcome was the finding of ceramidephosphoinositol that has not been reported previously as occurring in brown algae. An uncommon arsenic-containing phospholipid has also been observed and quantified, and its TLC behaviour studied, along with that of the newly synthesised lipids.

  20. Radiation effects on algae and its application

    International Nuclear Information System (INIS)

    Dwivedi, Rakesh Kumar

    2013-01-01

    The effects of radiation on algae have been summarized in this article. Today, algae are being considered to have the great potential to fulfill the demand of food, fodder, fuel and various pharmaceutical products. Red algae are particularly rich in the content of polysaccharides present in their cell wall. For isolation of these polysaccharides, separation of cells cemented together by middle lamella is essential. The gamma rays are known to bring about biochemical changes in the cell wall and cause the breakdown of the middle lamella. These rays ate also known to speed up the starch sugar inter-conversion in the cells which is very useful for the tapping the potential of algae to be used as biofuel as well as in pharmaceutical industries. Cyanobacteria, among algae and other plants are more resistant to the radiation. In some cyanobacteria the radiation treatment is known to enhance the resistance against the antibiotics. Radiation treatment is also known to enhance the diameter of cell and size of the nitrogen fixing heterocyst. (author)

  1. Sustainable Algae Biodiesel Production in Cold Climates

    Directory of Open Access Journals (Sweden)

    Rudras Baliga

    2010-01-01

    Full Text Available This life cycle assessment aims to determine the most suitable operating conditions for algae biodiesel production in cold climates to minimize energy consumption and environmental impacts. Two hypothetical photobioreactor algae production and biodiesel plants located in Upstate New York (USA are modeled. The photobioreactor is assumed to be housed within a greenhouse that is located adjacent to a fossil fuel or biomass power plant that can supply waste heat and flue gas containing CO2 as a primary source of carbon. Model results show that the biodiesel areal productivity is high (19 to 25 L of BD/m2/yr. The total life cycle energy consumption was between 15 and 23 MJ/L of algae BD and 20 MJ/L of soy BD. Energy consumption and air emissions for algae biodiesel are substantially lower than soy biodiesel when waste heat was utilized. Algae's most substantial contribution is a significant decrease in the petroleum consumed to make the fuel.

  2. Biological toxicity of lanthanide elements on algae.

    Science.gov (United States)

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  3. Problemas en la interpretación de la FFT

    OpenAIRE

    Acocella, Emilio Carlos; Tierra, Carlos J.

    1995-01-01

    La Transformada Rápida de Fourier (FFT) es una herramienta muy útil para diversas aplicaciones. Sin embargo, algunos aspectos relativos a la Transformada Discreta de Fourier (DFT) son ignorados, pudiendo en muchas ocasiones llevar a interpretaciones erróneas. El presente estudio trata de los problemas que pueden resultar del hecho que al DFT corresponde al muestreo de la Transformada de Fourier. Se presentan casos típicos en los que ocurre este problema y son propuestas soluciones para evitar...

  4. La Gestión de Tecnologías Emergentes en el Ámbito Universitario

    Directory of Open Access Journals (Sweden)

    Claudia N. Jiménez-Hernández

    2011-06-01

    Full Text Available El carácter emergente de algunas tecnologías hace que tengan un alto grado de incertidumbre, lo que a su vez conlleva particularidades en su manejo respecto a las tecnologías maduras. El objetivo de este artículo es analizar la gestión de tecnologías emergentes en el contexto internacional, con énfasis en el ámbito universitario; para ello, se aplican técnicas cienciométricas a información obtenida de bases de datos de artículos científicos y técnicos. Así mismo, se examina el papel de las universidades, para lo cual se hace un análisis comparativo de algunos casos de reconocido impacto en el nivel mundial. Entre los resultados obtenidos está la identificación de áreas relevantes como la nanotecnología y la telefonía móvil, y la caracterización del manejo de las tecnologías emergentes en las universidades seleccionadas. Esto da la base para plantear algunas conclusiones y consideraciones, como la necesidad de que las universidades colombianas lideren el desarrollo tecnológico en el país promoviendo su impacto en el sector productivo, para lo cual requieren consolidar estructuras y políticas claras en el tema, así como una cultura en propiedad intelectual.

  5. Revisión global de los contaminantes emergentes PBDE y el caso particular de México

    OpenAIRE

    Rocha-Gutiérrez, Beatriz Adriana; Peralta-Pérez, María del Rosario; Zavala-Díaz de la Serna, Francisco Javier

    2015-01-01

    Los éteres de bifenilos polibromados (PBDE, por sus siglas en inglés) son un grupo específico de contaminantes emergentes que se caracterizan por ser lipofílicos, hidrofóbicos, bioacumulables y resistentes a la biodegradación. La familia de PBDE consiste de 209 isómeros o congéneres y su estructura química, persistencia y distribución en el ambiente siguen patrones muy similares a los polibromobifenilos (PBB) y a los policlorobifenilos (PCB). El uso principal de los PBDE es como retardantes d...

  6. Eliminación de contaminantes emergentes mediante adsorción empleando xerogeles de carbón

    OpenAIRE

    Álvarez, Silvia; Ribeiro, Rui; Gomes, Helder; Sotelo, José; Garcia, Juan

    2014-01-01

    En la actualidad el número de sustancias quimicas potencialmente peligrosas que pueden lIegar a alcanzar el medio ambiente es muy amplio, por lo que la atención en la investigación de la contaminación dei agua se ha extendido recientemente a lo que se denomina contaminación emergente; es decir, la contaminación causada por sustancias químicas de origen y propiedades muy diversas, en concentraciones muy bajas, y que persisten en las aguas residuales tras el tratamiento de éstas ...

  7. Pedagogías emergentes en contextos cambiantes: pedagogías en red en la sociedad del conocimiento

    OpenAIRE

    Binod Gurung; Amparo Clavijo Olarte

    2015-01-01

    La noción de pedagogías es un concepto multidimensional emergente construido a partir de la relación entre los componentes pedagógicos (como la tecnología, la pedagogía y el contenido) y los contextos pedagógicos cambiantes de la sociedad, la economía, la educación y la ciencia y tecnología para mencionar algunos. Desafortunadamente, para los marcos teóricos tradicionales existentes no es importante la relación entre los componentes y los contextos pedagógicos cambiantes. Las pedagogías tradi...

  8. Características singulares del comercio exterior de los grandes países emergentes: el caso de Rusia

    OpenAIRE

    Rohr Trushcheleva, Margarita

    2013-01-01

    El proyecto de tesis plantea el objetivo global de arrojar luz sobre la realidad comercial y demográfica de una de las principales potencias emergentes, la Federación de Rusia. La propia importancia del país y el limitado número de estudios existentes hasta el momento al respecto justifican la elección del objeto de estudio. Un segundo objetivo, aportación esencial en este trabajo, es la construcción de series inéditas para la economía rusa, mediante la combinación de múltiples fuentes disper...

  9. Procesos de tratamiento de aguas residuales para la eliminación de contaminantes orgánicos emergentes

    OpenAIRE

    Clemente,Ainhoa Rubio; Chica Arrieta,Edwin Lenin; Peñuela Mesa,Gustavo Antonio

    2013-01-01

    Los contaminantes orgánicos emergentes conforman un grupo de sustancias muy heterogéneas, cuya característica en común es que causan efectos negativos sobre los organismos acuáticos, por lo que deben de ser eliminados del ambiente. Lamentablemente, los procesos convencionales con los que operan las plantas de tratamiento de aguas residuales, especialmente los de tipo biológico, son ineficientes en la remoción de estas sustancias. Por este motivo, se hace necesaria la evaluación y optimización...

  10. Eliminación de contaminantes emergentes en aguas residuales mediante oxidación avanzada con ozono y ultrasonidos

    OpenAIRE

    Abellán Soler, Manuel; Lardín Mifsut, Carlos; Morales Cavero, Eduardo; Pastor Alcañiz, Laura; Martínez Muro, Juan Luis; Santos Asensi, José María; Ibáñez Martínez, María; Hernández Hernández, Félix

    2013-01-01

    Algunos contaminantes emergentes, principalmente fármacos de diferentes clases así como drogas de abuso, pueden estar presentes en las aguas residuales urbanas, no siendo posible su eliminación mediante las técnicas convencionales de depuración. Se ha realizado un estudio en planta piloto en dos estaciones depuradoras de aguas residuales (EDAR), Font de la Pedra (Muro de Alcoy) y Molina de Segura (Murcia), con el fin de determinar la eficacia de eliminación de ciertos ...

  11. Behaviour of technetium in marine algae

    International Nuclear Information System (INIS)

    Bonotto, S.; Kirchmann, R.; Van Baelen, J.; Hurtger, C.; Cogneau, M.; Van der Ben, D.; Verthe, C.; Bouquegneau, J.M.

    1985-01-01

    Uptake and distribution of technetium were studied in several green (Acetabularia acetabulum, Boergesenia forbesii, Ulva lactuca) and brown (Ascophyllum nodosum, Fucus serratus, Fucus spiralis and Fucus vesiculosus) marine algae. Technetium was supplied to the algae as Tc-95m-pertechnetate. Under laboratory conditions, the algae were capable of accumulating technetium, with the exception, however, of Boergesenia, which showed concentration factors (C.F.) comprised between 0.28 and 0.71. The concentration of technetium-99 in Fucus spiralis, collected along the Belgian coast, was measured by a radiochemical procedure. The intracellular distribution of technetium was studied by differential centrifugation in Acetabularia and by the puncturing technique in Boergesenia. The chemical forms of technetium penetrated into the cells were investigated by selective chemical extractions, molecular sieving and thin layer chromatography

  12. Freshwater algae of the Nevada Test Site

    International Nuclear Information System (INIS)

    Taylor, W.D.; Giles, K.R.

    1979-06-01

    Fifty-two species of freshwater algae were identified in samples collected from the eight known natural springs of the Nevada Test Site. Although several species were widespread, 29 species were site specific. Diatoms provided the greatest variety of species at each spring. Three-fifths of all algal species encountered were diatoms. Well-developed mats of filamentous green algae (Chlorophyta) were common in many of the water tanks associated with the springs and accounted for most of the algal biomass. Major nutrients were adequate, if not abundant, in most spring waters - growth being limited primarily by light and physical habitat. There was some evidence of cesium-137 bioconcentration by algae at several of the springs

  13. Behaviour of technetium in marine algae

    International Nuclear Information System (INIS)

    Bonotto, S.; Kirchmann, R.; Baelen, J. van; Hurtgen, C.; Cogneau, M.; Ben, D. van der; Verthe, C.; Bouquegneau, J.M.

    1986-01-01

    Uptake and distribution of technetium were studied in several green (Acetabularia acetabulum, Boergesenia forbesii, Ulva lactuca) and brown (Ascophyllum nodosum, Fucus serratus, Fucus spiralis and Fucus vesiculosus) marine algae. Technetium was supplied to the algae as Tc-95-pertechnetate. Under laboratory conditions, the algae were capable of accumulating technetium, with the exception, however, of Boergesenia, which showed concentration factors (C.F.) comprised between 0.28 and 0.71. The concentration of technetium-99 in Fucus spiralis, collected along the Belgian coast, was measured by a radiochemical procedure. The intracellular distribution of technetium was studied by differential centrifugation in Acetabularia and by the puncturing technique in Boergesenia. The chemical forms of technetium penetrated into the cells were investigated by selective chemical extractions, molecular sieving and thin layer chromatography. (author)

  14. Study of metal bioaccumulation by nuclear microprobe analysis of algae fossils and living algae cells

    International Nuclear Information System (INIS)

    Guo, P.; Wang, J.; Li, X.; Zhu, J.; Reinert, T.; Heitmann, J.; Spemann, D.; Vogt, J.; Flagmeyer, R.-H.; Butz, T.

    2000-01-01

    Microscopic ion-beam analysis of palaeo-algae fossils and living green algae cells have been performed to study the metal bioaccumulation processes. The algae fossils, both single cellular and multicellular, are from the late Neoproterozonic (570 million years ago) ocean and perfectly preserved within a phosphorite formation. The biosorption of the rare earth element ions Nd 3+ by the green algae species euglena gracilis was investigated with a comparison between the normal cells and immobilized ones. The new Leipzig Nanoprobe, LIPSION, was used to produce a proton beam with 2 μm size and 0.5 nA beam current for this study. PIXE and RBS techniques were used for analysis and imaging. The observation of small metal rich spores (<10 μm) surrounding both of the fossils and the living cells proved the existence of some specific receptor sites which bind metal carrier ligands at the microbic surface. The bioaccumulation efficiency of neodymium by the algae cells was 10 times higher for immobilized algae cells. It confirms the fact that the algae immobilization is an useful technique to improve its metal bioaccumulation

  15. Solución al Problema de Secuenciación de Trabajos mediante el Problema del Agente Viajero

    Directory of Open Access Journals (Sweden)

    G.E. Anaya Fuentes

    2016-10-01

    Full Text Available Resumen: En este trabajo se estudia el Problema de Secuenciación de Trabajos codificado como un Problema de Agente Viajero y resuelto mediante Algoritmos Genéticos. Se propone un Algoritmo Genético en donde se comparan dos tipos de selección: por torneo y por ruleta. Se realizan diferentes pruebas para la solución del Problema del Agente Viajero con los dos tipos de selección bajo diferentes parámetros: número de individuos, número de iteraciones, probabilidad de cruce y probabilidad de mutación; a partir de estos se seleccionan los parámetros y el tipo de selección. Posteriormente se codifica al Problema de Secuenciación como un Problema del Agente Viajero. La propuesta se presenta mediante la aplicación a diferentes ejemplos del Problema de Secuenciación de Trabajos y la comparación con los resultados obtenidos en la literatura. Abstract: In this paper we proposed a solution to the Job-Shop Scheduling Problem using the Traveling Salesman Problem solved by Genetic Algorithms. We proposed a genetic algorithm where we compare two types of selection: tournament and roulette. Different tests are performed to solve the Traveling Salesman Problem with the two types of selection under different parameters: number of individuals, number of iterations, crossover probability and mutation probability. Then the best type of selection and the best parameters are used to solve the Job-Shop Scheduling Problem with Genetic Algorithms for the Traveling Salesman Problem. The proposal is presented solving different examples of Job Sequencing Problem and compare them with the results obtained in the literature. Palabras clave: algoritmos eficientes, sistemas industriales de producción, problemas de optimización, problema de agente viajero, Keywords: Efficient algorithms, industrial production systems, optimization problem, traveling salesman problem

  16. Poluentes Orgânicos Emergentes: Impactos e Soluções para a Saúde Humana e o Meio Ambiente

    OpenAIRE

    Nascimento, Lucas X; Trindade Araújo, Reginaldo; Giraldez Alvarez, Lisandro D

    2015-01-01

    Os Poluentes Orgânicos Emergentes (POE) formam um grupo muito heterogêneo de substâncias cuja característica comum é que causam efeitos adversos sobre os organismos aquáticos, e por isso devem ser removidos do ambiente. Esta revisão fornece uma visão geral dos contaminantes emergentes detectados no ambiente aquático, e analisa os trabalhos mais atuais, a fim de refletir sobre as diversas fontes dos contaminantes, os métodos de tratamento e os riscos para a saúde humana e para o meio ambiente,...

  17. Serpins in plants and green algae

    DEFF Research Database (Denmark)

    Roberts, Thomas Hugh; Hejgaard, Jørn

    2008-01-01

    . Serpins have been found in diverse species of the plant kingdom and represent a distinct clade among serpins in multicellular organisms. Serpins are also found in green algae, but the evolutionary relationship between these serpins and those of plants remains unknown. Plant serpins are potent inhibitors...... of mammalian serine proteinases of the chymotrypsin family in vitro but, intriguingly, plants and green algae lack endogenous members of this proteinase family, the most common targets for animal serpins. An Arabidopsis serpin with a conserved reactive centre is now known to be capable of inhibiting...

  18. Biological synthesis of metallic nanoparticles using algae.

    Science.gov (United States)

    Castro, Laura; Blázquez, María Luisa; Muñoz, Jesus Angel; González, Felisa; Ballester, Antonio

    2013-09-01

    The increasing demand and limited natural resources of noble metals make its recovery from dilute industrial wastes attractive, especially when using environmentally friendly methods. Nowadays, the high impact that nanotechnology is having in both science and society offers new research possibilities. Gold and silver nanoparticles were biosynthesised by a simple method using different algae as reducing agent. The authors explored the application of dead algae in an eco-friendly procedure. The nanoparticle formation was followed by UV-vis absorption spectroscopy and transmission electron microscopy. The functional groups involved in the bioreduction were studied by Fourier transform infrared spectroscopy.

  19. P-32 uptake in lentic algae

    International Nuclear Information System (INIS)

    Strange, J.R.; Williamson, G.D.; Fletcher, D.J.

    1975-01-01

    A study of the Flat Creek Embayment of Lake Sidney Lanier near Gainesville, Georgia revealed three genera of algae, Chlorococcum, Fragillaria and Nostoc, to be prominent in this eutrophic region of the lake. The algae was grown in phosphate-rich media and subsequently labelled with P-32. All species incorporated luxury amounts of phosphorus as determined by the uptake of P-32. The results indicate that the P-32 uptake is proportional to the surface-per-volume ratio. The higher surface-per-volume ratio resulted in greater uptake of P-32

  20. Bioremediation of Heavy Metal by Algae

    Directory of Open Access Journals (Sweden)

    Seema Dwivedi

    2012-07-01

    Full Text Available Instead of using mainly bacteria, it is also possible to use mainly algae to clean wastewater because many of the pollutant sources in wastewater are also food sources for algae. Nitrates and phosphates are common components of plant fertilizers for plants. Like plants, algae need large quantities of nitrates and phosphates to support their fast cell cycles. Certain heavy metals are also important for the normal functioning of algae. These include iron (for photosynthesis, and chromium (for metabolism. Because marine environments are normally scarce in these metals, some marine algae especially have developed efficient mechanisms to gather these heavy metals from the environment and take them up. These natural processes can also be used to remove certain heavy metals from the environment. The use of algae has several advantages over normal bacteria-based bioremediation processes. One major advantage in the removal of pollutants is that this is a process that under light conditions does not need oxygen. Instead, as pollutants are taken up and digested, oxygen is added while carbon dioxide is removed. Hence, phytoremediation could potentially be coupled with carbon sequestration. Additionally, because phytoremediation does not rely on fouling processes, odors are much less a problem. Microalgae, in particular, have been recognized as suitable vectors for detoxification and have emerged as a potential low-cost alternative to physicochemical treatments. Uptake of metals by living microalgae occurs in two steps: one takes place rapidly and is essentially independent of cell metabolism – “adsorption” onto the cell surface. The other one is lengthy and relies on cell metabolism – “absorption” or “intracellular uptake.” Nonviable cells have also been successfully used in metal removal from contaminated sites. Some of the technologies in heavy metal removals, such as High Rate Algal Ponds and Algal Turf Scrubber, have been justified for

  1. Algas: cosmética y salud

    OpenAIRE

    Arenas, Patricia Marta; Guayta, Silvina L.

    1998-01-01

    El uso de las algas con fines estéticos y terapéuticos tiene su origen en tiempos muy antiguos. El auge de la utilización de “productos naturales” ha llevado a sobrevalorar las propiedades de los vegetales en general y de las algas en particular. Por tal razón, las mismas gozan de un elevado prestigio, incluso cuando las propiedades reales son en gran medida superadas por las popularmente atribuidas. De allí que surja la necesidad de abordar estudios interdisciplinarios y de naturaleza aplica...

  2. Growth acceleration and photosynthesis of the scenedesmus algae and cocconeis algae in deuterium water

    International Nuclear Information System (INIS)

    Liu Feng; Wang Wenqing

    1998-01-01

    In order to find new way to treat the radioactive tritium waste water, scenedesmus algae and cocconeis algae are cultured in medium which contains 30% (w) deuterium water. During different time, activities of photosymthesis, absorption spectrum, growth rate and low-temperature fluorescence spectrum are measured. Accelerated growth is found in the deuterium water compared to the normal water. Activities of photosynthesis show the similar result (F v /F m ) to the growth data. It is also concluded from low-temperature fluorescence spectra that algae activities in the deuterium water, which are expressed by PS I/PS II, are more sensitive than those in the normal water

  3. WASP7 BENTHIC ALGAE - MODEL THEORY AND USER'S GUIDE

    Science.gov (United States)

    The standard WASP7 eutrophication module includes nitrogen and phosphorus cycling, dissolved oxygen-organic matter interactions, and phytoplankton kinetics. In many shallow streams and rivers, however, the attached algae (benthic algae, or periphyton, attached to submerged substr...

  4. Accumulation of polycyclic arenes in Baltic Sea algae

    Energy Technology Data Exchange (ETDEWEB)

    Veldre, I.A.; Itra, A.R.; Paal' me, L.P.; Kukk, Kh.A.

    1985-01-01

    The paper presents data on the level of benzo(a)pyrene (BP) and some other polycyclic arenes in alga and phanerogam specimens from different gulfs of the Baltic Sea. Algae were shown to absorb BP from sea water. The mean concentration of BP in sea water was under 0.004 microgram/1, while in algae it ranged 0.1-21.2 micrograms/kg dry weight. Algae accumulate BP to a higher degree than phanerogams. The highest concentrations of BP were found in algae Enteromorpha while the lowest ones in Furcellaria. In annual green algae, BP level was higher in autumn, i. e. at the end of vegetation period, than in spring. Brown algae Fucus vesiculosus is recommended for monitoring polycyclic arene pollution in the area from Vormsi Island to Kaesmu and green algae Cladophora or Enteromorpha in the eastern part of the Finnish Gulf.

  5. An Overview of Algae Biofuel Production and Potential Environmental Impact

    Science.gov (United States)

    Algae are among the most potentially significant sources of sustainable biofuels in the future of renewable energy. A feedstock with virtually unlimited applicability, algae can metabolize various waste streams (e.g., municipal wastewater, carbon dioxide from industrial flue gas)...

  6. Association of thraustochytrids and fungi with living marine algae

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Nagarkar, S.; Raghukumar, S.

    only in C. clavulatum, Sargassum cinereum and Padina tetrastromatica whilst mycelial fungi occurred in all. Growth experiments in the laboratory indicated that the growth of thraustochytrids was inhibited on live algae, whereas killed algae supported...

  7. O Problema da mochila compartimentada e aplicações

    Directory of Open Access Journals (Sweden)

    Marques Fabiano do Prado

    2002-01-01

    Full Text Available O Problema da Mochila Compartimentada é uma variação do clássico problema da mochila e pode ser enunciado considerando-se a seguinte situação hipotética: um alpinista deve carregar sua mochila compossíveis itens de seu interesse. A cada item atribui-se o seu peso e um valor de utilidade (até aqui, o problema coincide com o clássico Problema da Mochila. Entretanto, os itens são de agrupamentos distintos (alimentos, medicamentos, utensílios, etc. e devem estar em compartimentos separados na mochila. Os compartimentos da mochila são flexíveis e têm capacidades limitadas. A inclusão de um compartimento tem um custo fixo que depende do agrupamento com que foi preenchido, além de introduzir uma perda da capacidade da mochila. O problema consiste em determinar as capacidades adequadas de cada compartimento e como esses devem ser carregados, maximizando o valor de utilidade total, descontado o custo de incluir compartimentos. Neste trabalho propomos um modelo de otimização não linear inteiro para o problema e algumas heurísticas para sua resolução. Uma aplicação prática de relevância deste problema aparece no corte de bobinas de aço, sujeito à laminação, detalhado em apêndice.

  8. Los países emergentes en el G-20 y la política seguida por Argentina

    Directory of Open Access Journals (Sweden)

    Roberto Miranda

    2017-06-01

    Full Text Available En este artículo se analiza la presencia de los países emergentes en la gobernanza global a través de la participación desplegada por ellos en el G-20, con el fin de identificar la posición de Argentina en este ámbito multilateral, y determinar el uso que hizo de su poder como potencia media. Para cumplir con este objetivo consideramos las cumbres de jefes de Estado y de Gobierno del G-20, desde la primera realizada en Washington, en 2008, hasta la novena llevada a cabo en Brisbane, en 2014. Observamos que más allá de las diferencias y disputa de intereses, países desarrollados y emergentes convergieron en sostener las Viejas instituciones internacionales como el FMI. Argentina, de participación intensa en las cumbres pero sin una estrategia de influencia, quedó fuera de esta coincidencia y perdió poder en las reformas producidas en los medios multilaterales de crédito.

  9. Control borroso para la valoración del impacto ambiental generado por contaminantes emergentes en aguas residuales hospitalarias

    Directory of Open Access Journals (Sweden)

    Leadina Sánchez Barboza

    2015-06-01

    Full Text Available La valoración de impactos ambientales está sujeta a imprecisión, vaguedad y subjetividad. Estas características son extensivas al impacto generado por la presencia de contaminantes emergentes -fármacos- en aguas residuales hospitalarias, por lo que este trabajo propone valorar el impacto de dichos contaminantes mediante un sistema de inferencia borrosa, utilizando el toolbox fuzzy logic de MATLAB®, aplicando el sistema experto Mamdani. Los conjuntos borrosos de entrada se establecieron a partir de las concentraciones de los fármacos mediante variables lingüísticas definidas por medio de funciones de pertenencia trapezoidales, y el conjunto borroso de salida comprende la magnitud del impacto definida a través de una función de pertenencia triangular. Posteriormente, se obtuvo una valoración (en escala de 0 a 100 para concentraciones de fármacos máximas y promedios presentes en el agua residual, y por último, con estos valores se determina la magnitud del impacto ambiental a través del sistema de inferencia borrosa diseñado. El tratamiento borroso es útil para valorar los impactos ambientales en aguas residuales de contaminantes emergentes como los compuestos farmacéuticos.

  10. Novas Tecnologias Educacionais: Uma Cultura Emergente na Formação Docente

    Directory of Open Access Journals (Sweden)

    Maria Augusta Bernardo Marques de Mendon

    2015-12-01

    Full Text Available O objetivo principal desta pesquisa foi analisar a incorporação da cultura emergente na formação docente, ou seja, compreender como as novas tecnologias, recentemente difundidas nos meios educacionais, vêm sendo tratadas pelos processos de formação continuada e incluídas nas práticas pedagógicas. Na delimitação do estudo, procuramos investigar as dificuldades dos professores com a utilização dos novos recursos tecnológicos, considerando-se os fatores internos e externos que possam estar inviabilizando o sucesso da inclusão digital no ambiente escolar da rede pública estadual. Assim, por meio da pesquisa qualitativa e avaliativa propiciada por um projeto de ação, buscamos entender as interferências que ocorrem na prática docente por meio de observações direcionadas ao desempenho dos professores na utilização dos recursos tecnológicos da sala de informática como instrumentos de desenvolvimento do ensino dos conteúdos escolares. Os resultados obtidos no projeto de ação originaram-se de declarações dos sujeitos e de observações estabelecidas nos módulos de capacitação e de aplicação dos planos de aulas. Esses resultados convergem para os fatores desestimulantes como: excesso de movimentações dos docentes entre as escolas; ausência de pessoas credenciadas na própria escola capazes de coordenar as novas tecnologias educacionais e proporcionar segurança aos docentes; falta de capacitações no próprio ambiente escolar; carência de multiplicadores locais; ausência da previsão de tempo da preparação de aulas com os novos recursos tecnológicos na própria carga horária do professor e a inexistência de regulamentação na gestão administrativa que valorize o certificado da formação continuada. Enfim, as informações analisadas nessa pesquisa pelos aspectos positivos e negativos oferecem espaço para novas investigações dessa natureza.

  11. Prototecose: uma doença emergente Protothecosis: an emergent disease

    Directory of Open Access Journals (Sweden)

    Expedito K.A. Camboim

    2010-01-01

    Full Text Available Prototecose, causada por Prototheca zopfii ou P. wickerhamii, é uma doença emergente em animais e humanos. Em bovinos, P. zopfii é uma importante causa de mastite ambiental. Em cães e gatos, a prototecose é causada principalmente por P. zopfii. Em cães, causa infecção cutânea ou uma forma sistêmica envolvendo diversos órgãos. Em gatos, predominam as lesões tegumentares na região da face e plano nasal. No homem, a prototecose, causada principalmente por P. wickerhamii, manifesta-se sob três formas: cutânea, articular com bursite do olécrano e sistêmica. Pode ocorrer em indivíduos imunocompetentes, os quais podem apresentar bursite e/ou infecções cutâneas localizadas, ou em indivíduos imunossuprimidos, nos quais a enfermidade pode ser disseminada e/ou com envolvimento visceral. A prototecose causada por P. wickerhamii foi descrita recentemente em caprinos como causa de rinite afetando o vestíbulo nasal, união mucocutânea, pele da face e orelha. Nesta revisão são abordadas as características microbiologias e susceptibilidade a antimicrobianos do agente, e a epidemiologia, sinais clínicos, patologia, diagnóstico, tratamento e controle da prototecose em animais domésticos e no homem.Protothecosis, caused by Prototheca zopfii or P. wickerhamii, is an emergent disease of human and animals. In cattle, P. zopfii is an important cause of environmental mastitis. In dogs and cats protothecosis is caused mainly by P. zopfii, causing cutaneous infections or a systemic form affecting many organs in dogs, and cutaneous infection affecting mainly the skin of the face and nose in cats. In humans, protothecosis, caused mainly by P. wickerhamii, occurs in three forms: cutaneous; olecran bursitis; and disseminated. The lesion is usually localized in the site of inoculation in immunocompetent individuals; however, in immunocompromised patients, it can become widespread. Protothecosis caused by P. wickerhamii was recently reported in

  12. Web Analytics: Modelos de Métricas de Engajamento em Mídias Emergentes

    Directory of Open Access Journals (Sweden)

    Sionara Ioco Okada

    2012-02-01

    Full Text Available As transformações no comportamento do consumidor inauguraram a “Era da recomendação com a disseminação exponencial de conteúdo relevante, ascensão do prosumerismo e crowdsourcing. A mensuração e o monitoramento contínuo das ações mercadológicas levam ao conhecimento do comportamento do consumidor, não somente nas variáveis como freqüência, recência e valor de compra, mas também nos quesitos engajamento e interação com o produto e/ou marca. O desenvolvimento de métricas para múltiplas mídias elevam a quantidade de informações úteis sobre o perfil de consumo possibilitando a otimização das estratégias digitais à públicos segmentados. Este é um artigo de atualização que tem por objetivo revisar as últimas publicações sobre modelos de métricas - web analytics – WA coadunando estratégias digitais em plataformas e mídias emergentes. Quanto à metodologia utilizada, trata-se de uma investigação secundária, sobretudo bibliográfica visando à atualização e análise comparativa de três modelos web analytics – wa para organizações que atuam no varejo eletrônico, utilizando diferentes canais digitais. O estudo enfoca: i Modelo dos Cinco Estágios de competição analítica, proposto por Davenport; ii Modelo de maturidade em web analytics, proposto por Hammel; iii Modelo Web Analytics Scorecard, proposto por Giuntini & Morier. A expansão do M-commerce e o advento do Social commerce assumem-se como tendências irreversíveis, exigindo das organizações que atuam no varejo eletrônico, métricas e indicadores de desempenho para um monitoramento contínuo do comportamento do consumidor, de modo a consolidar a interação e as métricas de engajamento como principais protagonistas das estratégias digitais contemporâneas. DOI: 10.5585/remark.v10i3.2271

  13. How to Identify and Control Water Weeds and Algae.

    Science.gov (United States)

    Applied Biochemists, Inc., Mequon, WI.

    Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of…

  14. Inventory of North-West European algae initiatives

    NARCIS (Netherlands)

    Spruijt, J.

    2015-01-01

    In 2012 an inventory of North-West European (NWE) algae initiatives was carried out to get an impression of the market and research activities on algae production and refinery, especially for bioenergy purposes. A questionnaire was developed that would provide the EnAlgae project with information on

  15. New methodologies for integrating algae with CO2 capture

    NARCIS (Netherlands)

    Hernandez Mireles, I.; Stel, R.W. van der; Goetheer, E.L.V.

    2014-01-01

    It is generally recognized, that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient

  16. KAROTENOID PADA ALGAE: KAJIAN TENTANG BIOSINTESIS, DISTRIBUSI SERTA FUNGSI KAROTENOID

    OpenAIRE

    Merdekawati, Windu; Karwur, Ferry F.; Susanto, A. B.

    2017-01-01

    ABSTRAK   Karotenoid terdistribusi pada archaea, bakteri, jamur, tumbuhan, hewan serta algae. Karotenoid dihasilkan dari komponen isopentenyl pyrophosphate (IPP) yang mengalami proses secara bertahap untuk membentuk beragam jenis karotenoid. Terdapat dua kelompok karotenoid yaitu karoten dan xantofil dengan berbagai jenis turunannya. Struktur kimia pada karotenoid algae yaitu allene, acetylene serta acetylated carotenoids. Algae mempunyai karotenoid spesifik yang menarik untuk dipe...

  17. Composition of phytoplankton algae in Gubi Reservoir, Bauchi ...

    African Journals Online (AJOL)

    Studies on the distribution, abundance and taxonomic composition of phytoplankton algae in Gubi reservoir were carried out for 12 months (from January to December 1995). Of the 26 algal taxa identified, 14 taxa belonged to the diatoms, 8 taxa were green algae while 4 taxa belonged to the blue-green algae. Higher cell ...

  18. Can the primary algae production be measured precisely?

    International Nuclear Information System (INIS)

    Olesen, M.; Lundsgaard, C.

    1996-01-01

    Algae production in seawater is extremely important as a basic link in marine food chains. Evaluation of the algae quantity is based on 14CO 2 tracer techniques while natural circulation and light absorption in seawater is taken insufficiently into account. Algae production can vary by 500% in similar nourishment conditions, but varying water mixing conditions. (EG)

  19. Agricultural importance of algae | Abdel-Raouf | African Journal of ...

    African Journals Online (AJOL)

    Algae are a large and diverse group of microorganisms that can carry out photosynthesis since they capture energy from sunlight. Algae play an important role in agriculture where they are used as biofertilizer and soil stabilizers. Algae, particularly the seaweeds, are used as fertilizers, resulting in less nitrogen and ...

  20. UV effects on bottom ice algae

    International Nuclear Information System (INIS)

    Ryan, K.; Buckley, B.

    1993-01-01

    Antarctic sea ice can be surprisingly transparent to UV radiation, particularly during spring when ozone depletion reaches a maximum. A 5% reduction in photosynthetic production was observed in laboratory experiments for UVB levels expected under the ice at this time. In situ studies modifying the UVB radiation falling onto algae were inconclusive. (author). 5 refs

  1. Analysis, numerics, and optimization of algae growth

    NARCIS (Netherlands)

    Kumar, K.; Pisarenco, M.; Rudnaya, M.; Savcenco, V.

    2010-01-01

    We extend the mathematical model for algae growth as described in [11] to include new effects. The roles of light, nutrients and acidity of the water body are taken into account. Important properties of the model such as existence and uniqueness of solution, as well as boundedness and positivity are

  2. Isolation of glycoproteins from brown algae

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel process for the isolation of unique anti-oxidative glycoproteins from the pH precipitated fractions of enzymatic extracts of brown algae. Two brown seaweeds viz, Fucus serratus and Fucus vesiculosus were hydrolysed by using 3 enzymes viz, Alcalase, Viscozyme...

  3. Bromophenols in Marine Algae and Their Bioactivities

    DEFF Research Database (Denmark)

    Ming, Liu; Hansen, Poul Erik; Lin, Xiukun

    2011-01-01

    Marine algae contain various bromophenols that have been shown to possess a variety of biological activities, including antioxidant, antimicrobial, anticancer, anti-diabetic, and anti-thrombotic effects. Here, we briefly review the recent progress of these marine algal biomaterials, with respect...

  4. Selenium accumulation and metabolism in algae.

    Science.gov (United States)

    Schiavon, Michela; Ertani, Andrea; Parrasia, Sofia; Vecchia, Francesca Dalla

    2017-08-01

    Selenium (Se) is an intriguing element because it is metabolically required by a variety of organisms, but it may induce toxicity at high doses. Algae primarily absorb selenium in the form of selenate or selenite using mechanisms similar to those reported in plants. However, while Se is needed by several species of microalgae, the essentiality of this element for plants has not been established yet. The study of Se uptake and accumulation strategies in micro- and macro-algae is of pivotal importance, as they represent potential vectors for Se movement in aquatic environments and Se at high levels may affect their growth causing a reduction in primary production. Some microalgae exhibit the capacity of efficiently converting Se to less harmful volatile compounds as a strategy to cope with Se toxicity. Therefore, they play a crucial role in Se-cycling through the ecosystem. On the other side, micro- or macro-algae enriched in Se may be used in Se biofortification programs aimed to improve Se content in human diet via supplementation of valuable food. Indeed, some organic forms of selenium (selenomethionine and methylselenocysteine) are known to act as anticarcinogenic compounds and exert a broad spectrum of beneficial effects in humans and other mammals. Here, we want to give an overview of the developments in the current understanding of Se uptake, accumulation and metabolism in algae, discussing potential ecotoxicological implications and nutritional aspects. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Research for Developing Renewable Biofuels from Algae

    Energy Technology Data Exchange (ETDEWEB)

    Black, Paul N. [Univ. of Nebraska, Lincoln, NE (United States)

    2012-12-15

    Task A. Expansion of knowledge related to lipid production and secretion in algae A.1 Lipid biosynthesis in target algal species; Systems biology approaches are being used in combination with recent advances in Chlorella and Chlamydomonas genomics to address lipid accumulation in response to defined nutrient regimes. The UNL Algal Group continues screening additional species of Chlorella and other naturally occurring algae for those with optimal triglyceride production; Of the strains examined by the DOE's Aquatic Species Program, green algae, several species of Chlorella represent the largest group from which oleaginous candidates have been identified; A.1.1. Lipid profiling; Neutral lipid accumulation is routinely monitored by Nile red and BODIPY staining using high throughput strategies to screen for naturally occurring algae that accumulate triglyceride. These strategies complement those using spectrofluorometry to quantify lipid accumulation; Neutral lipid accumulation is routinely monitored by high performance thin-layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) of lipid extracts in conjunction with; Carbon portioning experiments have been completed and the data currently are being analyzed and prepared for publication; Methods in the Black lab were developed to identify and quantify triacylglycerol (TAG), major membrane lipids [diacylglycerol trimethylhomoserine, phosphatidylethanolamine and chloroplast glycolipids], biosynthetic intermediates such as diacylglycerol, phosphatidic acid and lysophospholipids and different species of acyl-coenzyme A (acyl CoA).

  6. Taxonomic Challenges and Distribution of Gracilarioid Algae ...

    African Journals Online (AJOL)

    This paper reviews the taxonomical literature of the gracilarioid algae from Tanzania, and provides information about their ecology and distribution based on an intensive regime of local collection. Its aim was to provide names, even if on a preliminary basis, for local gracilarioid taxa. Our revision shows that species ...

  7. Washington State University Algae Biofuels Research

    Energy Technology Data Exchange (ETDEWEB)

    chen, Shulin [Washington State Univ., Pullman, WA (United States). Dept. of Biological Systems Engineering; McCormick, Margaret [Targeted Growth, Inc., Seattle, WA (United States); Sutterlin, Rusty [Inventure Renewables, Inc., Gig Harbor, WA (United States)

    2012-12-29

    The goal of this project was to advance algal technologies for the production of biofuels and biochemicals by establishing the Washington State Algae Alliance, a collaboration partnership among two private companies (Targeted Growth, Inc. (TGI), Inventure Chemicals (Inventure) Inc (now Inventure Renewables Inc) and Washington State University (WSU). This project included three major components. The first one was strain development at TGI by genetically engineering cyanobacteria to yield high levels of lipid and other specialty chemicals. The second component was developing an algal culture system at WSU to produce algal biomass as biofuel feedstock year-round in the northern states of the United States. This system included two cultivation modes, the first one was a phototrophic process and the second a heterotrophic process. The phototrophic process would be used for algae production in open ponds during warm seasons; the heterotrophic process would be used in cold seasons so that year-round production of algal lipid would be possible. In warm seasons the heterotrophic process would also produce algal seeds to be used in the phototrophic culture process. Selected strains of green algae and cyanobacteria developed by TGI were tested in the system. The third component was downstream algal biomass processing by Inventure that included efficiently harvesting the usable fuel fractions from the algae mass and effectively isolating and separating the usable components into specific fractions, and converting isolated fractions into green chemicals.

  8. 21 CFR 184.1120 - Brown algae.

    Science.gov (United States)

    2010-04-01

    ... used in food only within the following specific limitations: Category of food Maximum level of use in... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

  9. 21 CFR 184.1121 - Red algae.

    Science.gov (United States)

    2010-04-01

    ... within the following specific limitations: Category of food Maximum level of use in food (as served... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Red algae. 184.1121 Section 184.1121 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

  10. The ice nucleation activity of extremophilic algae

    Czech Academy of Sciences Publication Activity Database

    Kvíderová, Jana; Hájek, J.; Worland, M. R.

    2013-01-01

    Roč. 34, č. 2 (2013), s. 137-148 ISSN 0143-2044 R&D Projects: GA AV ČR KJB601630808; GA AV ČR KJB600050708 Institutional support: RVO:67985939 Keywords : Ice nucleation * snow algae * lichen photobionts Subject RIV: EF - Botanics Impact factor: 0.640, year: 2013

  11. Photoprotection strategies of the alga Nannochloropsis gaditana

    NARCIS (Netherlands)

    Chukhutsina, Volha U.; Fristedt, Rikard; Morosinotto, Tomas; Croce, Roberta

    2017-01-01

    Nannochloropsis spp. are algae with high potential for biotechnological applications due to their capacity to accumulate lipids. However, little is known about their photosynthetic apparatus and acclimation/photoprotective strategies. In this work, we studied the mechanisms of non-photochemical

  12. Usos industriales de las algas diatomeas.

    OpenAIRE

    Illana Esteban, Carlos

    2007-01-01

    Las diatomeas son algas microscópicas que habitan tanto en aguas dulces como marinas. Aparte de su destacado papel en la cadena trófica de los ecosistemas acuáticos, con el tiempo forman depósitos a los que el hombre ha encontrado abundantes aplicaciones prácticas.

  13. Heterotrophic bacteria associated with the green alga

    NARCIS (Netherlands)

    Ismail, A.; Ktari, L.; Ahmed, M.; Bolhuis, H.; Bouhaouala-Zahar, B.; Stal, L.J.; Boudabbous, A.; El Bour, M.

    2018-01-01

    Heterotrophic bacteria associated with the green alga Ulva rigida, collected from the coast of Tunisia, were isolated andsubsequently identified by their 16S rRNA gene sequences and by phylogenetic analysis. The 71 isolates belong to four phyla:Proteobacteria (Alpha-and Gamma- subclasses),

  14. Mecánica de suelos : problemas resueltos

    OpenAIRE

    Olivella Pastallé, Sebastià

    2001-01-01

    Esta publicación contiene una colección de problemas resueltos de mecánica de suelos que ha sido preparada para los estudios de ingeniería técnica de obras públicas que se imparten en la UPC. Se trata de una titulación de primer ciclo, por lo que el enfoque que se da a los problemas se centra en aspectos de concepto y no requiere la realización de desarrollos matemáticos. Incluye problemas relativos a propiedades básicas de los suelos, aspectos básicos de la mecánica de medios porosos indefor...

  15. Um sistema multiagente de apoio à aprendizagem baseada em problema

    Directory of Open Access Journals (Sweden)

    Laysa Mabel Oliveira Fontes

    2011-12-01

    Full Text Available A aprendizagem baseada em problema (Problem-Based Learning - PBL é uma teoria de aprendizagem que enfatiza a colaboração e o trabalho em grupo para resolução de um problema. No entanto, um problema que ocorre com freqüência no processo de aplicação da PBL é a presença de conversações fora do contexto, que é uma situação onde os estudantes perdem o foco das discussões do problema e passam a discutir outros assuntos. Outro aspecto importante é com relação ao processo de formação de grupos na PBL. Pode ser difícil para o facilitador alocar estudantes aos grupos a distância, uma vez que a ausência de um contato presencial dificulta o conhecimento de certas características importantes do perfil dos estudantes envolvidos no processo. Outro aspecto a ser considerado é a ausência de padronização dos conceitos relacionados à PBL, pois isto dificulta a compreensão comum e compartilhada sobre este domínio. Desta forma, este trabalho apresenta um sistema multiagente de apoio à PBL, com o objetivo de detectar e corrigir problemas inerentes à implantação desta teoria de aprendizagem. Para solucionar o problema de padronização dos conceitos relacionados à PBL, é proposta uma ontologia que preenche requisitos de abstração e significação dos conceitos relacionados ao domínio.

  16. La preeclampsia un problema de salud pública mundial

    OpenAIRE

    Vargas H,Víctor Manuel; Acosta A,Gustavo; Moreno E,Mario Adán

    2012-01-01

    La preeclampsia es un problema de salud pública y una de las principales causas de muerte materna. La prevalencia oscila entre 1,8-16,7%. La causa sigue desconocida y se asocia a problemas de salud importantes, existiendo muchos retos para la predicción, prevención y tratamiento. Las medidas profilácticas como dosis baja de aspirina y suplementos de calcio, requieren mayor evidencia para uso rutinario. El control prenatal, diagnóstico oportuno, manejo adecuado, y parto son las medidas más efi...

  17. Boécio e o problema dos futuros contingentes

    Directory of Open Access Journals (Sweden)

    William de Siqueira Piauí

    2010-09-01

    Full Text Available Esse artigo representa nossa crença de que é possível introduzir o pensamento de Boécio a partir de um dos problemas mais recorrentes da filosofia, o problema dos futuros contingentes, explicitando, a partir daquela problemática é claro, quais as ligações mais fundamentais entre três de suas obras, seus dois comentários ao De Interpretatione de Aristóteles e sua Consolaçáo da Filosofia, e, de forma bastante resumida evidentemente, como o alcance do pensamento contido nessas obras chega até pelo menos a filosofia kantiana.

  18. EL PROBLEMA DEL CUMPLEAÑOS, UNA GENERALIZACIÓN

    OpenAIRE

    Aranda, Moisés; Departamento de Matemáticas, Pontificia Universidad Javeriana y Universidad Sergio Arboleda; Molina, Fabio; Departamento de Matemáticas, Pontificia Universidad Javeriana y Universidad Sergio Arboleda; Moreno, Vladimir; Departamento de Matemáticas, Facultad de Ciencias, Pontificia Universidad Javeriana Cra. 7 No 43-82. Bogotá,

    2008-01-01

    El problema del cumpleaños, en el contexto clásico, se resuelve asumiendo una distribución de probabilidades uniforme discreta de los nacimientos. El propósito de este artículo es resolver el mismo problema bajo una distribución de probabilidades discreta arbitraria, y demostrar que bajo la distribución uniforme discreta, la probabilidad de que dos o más personas cumplan años en el mismo día es subestimada. Palabras clave: combinatoria, probabilidad, distribuciones discretas, muestra aleator...

  19. Biofuels from algae for sustainable development

    International Nuclear Information System (INIS)

    Demirbas, M. Fatih

    2011-01-01

    Microalgae are photosynthetic microorganisms that can produce lipids, proteins and carbohydrates in large amounts over short periods of time. These products can be processed into both biofuels and useful chemicals. Two algae samples (Cladophora fracta and Chlorella protothecoid) were studied for biofuel production. Microalgae appear to be the only source of renewable biodiesel that is capable of meeting the global demand for transport fuels. Microalgae can be converted to biodiesel, bioethanol, bio-oil, biohydrogen and biomethane via thermochemical and biochemical methods. Industrial reactors for algal culture are open ponds, photobioreactors and closed systems. Algae can be grown almost anywhere, even on sewage or salt water, and does not require fertile land or food crops, and processing requires less energy than the algae provides. Microalgae have much faster growth-rates than terrestrial crops. the per unit area yield of oil from algae is estimated to be from 20,000 to 80,000 liters per acre, per year; this is 7-31 times greater than the next best crop, palm oil. Algal oil can be used to make biodiesel for cars, trucks, and airplanes. The lipid and fatty acid contents of microalgae vary in accordance with culture conditions. The effect of temperature on the yield of hydrogen from two algae (C. fracta and C. protothecoid) by pyrolysis and steam gasification were investigated in this study. In each run, the main components of the gas phase were CO 2 , CO, H 2 , and CH 4 .The yields of hydrogen by pyrolysis and steam gasification processes of the samples increased with temperature. The yields of gaseous products from the samples of C. fracta and C. protothecoides increased from 8.2% to 39.2% and 9.5% to 40.6% by volume, respectively, while the final pyrolysis temperature was increased from 575 to 925 K. The percent of hydrogen in gaseous products from the samples of C. fracta and C. protothecoides increased from 25.8% to 44.4% and 27.6% to 48.7% by volume

  20. Radiokinetic study in betony marine algae

    International Nuclear Information System (INIS)

    Azevedo Gouvea, V. de.

    1981-01-01

    The influx and outflux kinetics of some radionuclides in algae of the Rio de Janeiro coastline, were studied in order to select bioindicators for radioactive contamination in aquatic media, due to the presence of Nuclear Power Stations. Bioassays of the concentration and loss of radionuclides such as 137 Cs, 51 Cr, 60 Co and 131 I were performed in 1000cm 3 aquarium under controlled laboratory conditions, using a single channel gamma counting system, to study the species of algae most frequently found in the region. The concentration and loss parameters for all the species and radionuclides studied were obtained from the normalized results. The loss parameters were computerwise adjusted using Powell's multiparametric method. (author)

  1. Hyperaccumulation of radioactive isotopes by marine algae

    International Nuclear Information System (INIS)

    Ishii, Toshiaki; Hirano, Shigeki; Watabe, Teruhisa

    2003-01-01

    Hyperaccumlators are effective indicator organisms for monitoring marine pollution by heavy metals and artificial radionuclides. We found a green algae, Bryopsis maxima that hyperaccumulate a stable and radioactive isotopes such as Sr-90, Tc-99, Ba-138, Re-187, and Ra-226. B. maxima showed high concentration factors for heavy alkali earth metals like Ba and Ra, compared with other marine algae in Japan. Furthermore, this species had the highest concentrations for Tc-99 and Re-187. The accumulation and excretion patterns of Sr-85 and Tc-95m were examined by tracer experiments. The chemical states of Sr and Re in living B. maxima were analyzed by HPLC-ICP/MS, LC/MS, and X-ray absorption fine structure analysis using synchrotron radiation. (author)

  2. Um campo emergente: a arqueologia da música e suas interfaces com o patrimônio

    Directory of Open Access Journals (Sweden)

    Fabio Vergara

    2016-07-01

    Full Text Available A presente entrevista com o arqueólogo Fábio Vergara Cerqueira traz informações sobre um campo emergente nos estudos arqueológicos, a assim chamada Arqueologia da Música, que conta, entre suas ramificações, com a especialidade da Arqueoorganologia, que, na sua variante iconográfica, é uma área de atuação deste arqueólogo. Esta nova disciplina se desenvolve em um domínio epistemológico bastante complexo e interdisciplinar e, mais recentemente, como se observa na articulação de programas internacionais de pesquisa, apresenta intensa integração à temática patrimonial, ligada sobretudo ao patrimônio dito imaterial, com forte valorização de saberes musicais de comunidades tradicionais.

  3. CONVERGÊNCIA E TRANSMÍDIA: GALÁXIAS SEMÂNTICAS E NARRATIVAS EMERGENTES EM JORNALISMO

    Directory of Open Access Journals (Sweden)

    Geane Alzamora

    2012-06-01

    Full Text Available Este artigo procura discutir as possibilidades de aplicação no Jornalismo do conceito de narrativa transmidiática, proposto por Henry Jenkins (2003 no âmbito das narrativas ficcionais. Aborda inicialmente as definições de Transmedia Storytelling, investiga as diferenças conceituais entre convergência e transmídia e propõe uma abordagem própria do conceito de transmídia no universo jornalístico, fundada na perspectiva do conhecimento produzido em dimensão transmidiática e nas especificidades informacionais dos formatos. Conclui com uma exploração inicial de exemplos de narrativas emergentes no contexto do jornalismo transmidiático, como o Jornalismo de Imersão e os newsgames, sugerindo que o experimentalismo seja um aspecto marcante da narrativa transmídia.

  4. Algae-Derived Dietary Ingredients Nourish Animals

    Science.gov (United States)

    2015-01-01

    In the 1980s, Columbia, Maryland-based Martek Biosciences Corporation worked with Ames Research Center to pioneer the use of microalgae as a source of essential omega-3 fatty acids, work that led the company to develop its highly successful Formulaid product. Now the Nutritional Products Division of Royal DSM, the company also manufactures DHAgold, a nutritional supplement for pets, livestock and farm-raised fish that uses algae to deliver docosahexaenoic acid (DHA).

  5. Selenium Uptake and Volatilization by Marine Algae

    Science.gov (United States)

    Luxem, Katja E.; Vriens, Bas; Wagner, Bettina; Behra, Renata; Winkel, Lenny H. E.

    2015-04-01

    Selenium (Se) is an essential trace nutrient for humans. An estimated one half to one billion people worldwide suffer from Se deficiency, which is due to low concentrations and bioavailability of Se in soils where crops are grown. It has been hypothesized that more than half of the atmospheric Se deposition to soils is derived from the marine system, where microorganisms methylate and volatilize Se. Based on model results from the late 1980s, the atmospheric flux of these biogenic volatile Se compounds is around 9 Gt/year, with two thirds coming from the marine biosphere. Algae, fungi, and bacteria are known to methylate Se. Although algal Se uptake, metabolism, and methylation influence the speciation and bioavailability of Se in the oceans, these processes have not been quantified under environmentally relevant conditions and are likely to differ among organisms. Therefore, we are investigating the uptake and methylation of the two main inorganic Se species (selenate and selenite) by three globally relevant microalgae: Phaeocystis globosa, the coccolithophorid Emiliania huxleyi, and the diatom Thalassiosira oceanica. Selenium uptake and methylation were quantified in a batch experiment, where parallel gas-tight microcosms in a climate chamber were coupled to a gas-trapping system. For E. huxleyi, selenite uptake was strongly dependent on aqueous phosphate concentrations, which agrees with prior evidence that selenite uptake by phosphate transporters is a significant Se source for marine algae. Selenate uptake was much lower than selenite uptake. The most important volatile Se compounds produced were dimethyl selenide, dimethyl diselenide, and dimethyl selenyl sulfide. Production rates of volatile Se species were larger with increasing intracellular Se concentration and in the decline phase of the alga. Similar experiments are being carried out with P. globosa and T. oceanica. Our results indicate that marine algae are important for the global cycling of Se

  6. Algae as reservoirs for coral pathogens.

    Directory of Open Access Journals (Sweden)

    Michael J Sweet

    Full Text Available Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS in the Indo-Pacific and Yellow Band Disease (YBD in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively. Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is

  7. Antibody Production in Plants and Green Algae.

    Science.gov (United States)

    Yusibov, Vidadi; Kushnir, Natasha; Streatfield, Stephen J

    2016-04-29

    Monoclonal antibodies (mAbs) have a wide range of modern applications, including research, diagnostic, therapeutic, and industrial uses. Market demand for mAbs is high and continues to grow. Although mammalian systems, which currently dominate the biomanufacturing industry, produce effective and safe recombinant mAbs, they have a limited manufacturing capacity and high costs. Bacteria, yeast, and insect cell systems are highly scalable and cost effective but vary in their ability to produce appropriate posttranslationally modified mAbs. Plants and green algae are emerging as promising production platforms because of their time and cost efficiencies, scalability, lack of mammalian pathogens, and eukaryotic posttranslational protein modification machinery. So far, plant- and algae-derived mAbs have been produced predominantly as candidate therapeutics for infectious diseases and cancer. These candidates have been extensively evaluated in animal models, and some have shown efficacy in clinical trials. Here, we review ongoing efforts to advance the production of mAbs in plants and algae.

  8. New records of marine algae in Vietnam

    Science.gov (United States)

    Le Hau, Nhu; Ly, Bui Minh; Van Huynh, Tran; Trung, Vo Thanh

    2015-06-01

    In May, 2013, a scientific expedition was organized by the Vietnam Academy of Science and Technology (VAST) and the Far Eastern Branch of the Russian Academy of Sciences (FEBRAS) through the frame of the VAST-FEBRAS International Collaboration Program. The expedition went along the coast of Vietnam from Quang Ninh to Kien Giang. The objective was to collect natural resources to investigate the biological and biochemical diversity of the territorial waters of Vietnam. Among the collected algae, six taxa are new records for the Vietnam algal flora. They are the red algae Titanophora pikeana (Dickie) Feldmann from Cu Lao Xanh Island, Laurencia natalensis Kylin from Tho Chu Island, Coelothrix irregularis (Harvey) Børgesen from Con Dao Island, the green algae Caulerpa oligophylla Montagne, Caulerpa andamanensis (W.R. Taylor) Draisma, Prudhomme et Sauvage from Phu Quy Island, and Caulerpa falcifolia Harvey & Bailey from Ly Son Island. The seaweed flora of Vietnam now counts 833 marine algal taxa, including 415 Rhodophyta, 147 Phaeophyceae, 183 Chlorophyta, and 88 Cyanobacteria.

  9. Efectos sobre la salud de la contaminación de agua y alimentos por virus emergentes humanos

    Directory of Open Access Journals (Sweden)

    Sílvia Bofill-Mas

    2005-01-01

    Full Text Available El desarrollo de tecnologías moleculares aplicadas a estudios ambientales ha permitido constatar que incluso en países altamente industrializados existe una alta prevalencia de virus en el medio ambiente, lo que causa un importante impacto en la salud pública e importantes pérdidas económicas, principalmente a través de la transmisión de virus por agua y alimentos. Concentraciones significativas de virus son detectadas en las aguas vertidas al ambiente y en los biosólidos generados en plantas de tratamiento de agua residual. En este trabajo se describen las características generales de la contaminaci ón ambiental por virus, principalmente por virus emergentes, analizándose con mayor profundidad los virus de la hepatitis E (VHE y los poliomavirus humanos como los virus contaminantes ambientales de más reciente identificación en países industrializados. Se ha demostrado que existe una elevada prevalencia de los poliomavirus humanos, BK y JC, en agua residual en todos los paí- ses estudiados, lo que implica la potencial transmisión de los virus y de genes potencialmente cancerígenos por vía oral. Estudios recientes demuestran que el patrón epidemiológico de la infección por VHE en países industrializados es complejo y que una gran diversidad de cepas del VHE infecta simultáneamente a la población. El control de la contaminación viral del medio ambiente requiere la estandarización de técnicas moleculares y el desarrollo de un programa de vigilancia que permita valorar parámetros víricos y reducir la diseminación de las enfermedades establecidas y de las infecciones víricas emergentes.

  10. Electro-coagulation-flotation process for algae removal

    International Nuclear Information System (INIS)

    Gao Shanshan; Yang Jixian; Tian Jiayu; Ma Fang; Tu Gang; Du Maoan

    2010-01-01

    Algae in surface water have been a long-term issue all over the world, due to their adverse influence on drinking water treatment process as well as drinking water quality. The algae removal by electro-coagulation-flotation (ECF) technology was investigated in this paper. The results indicated that aluminum was an excellent electrode material for algae removal as compared with iron. The optimal parameters determined were: current density = 1 mA/cm 2 , pH = 4-7, water temperature = 18-36 deg. C, algae density = 0.55 x 10 9 -1.55 x 10 9 cells/L. Under the optimal conditions, 100% of algae removal was achieved with the energy consumption as low as 0.4 kWh/m 3 . The ECF performed well in acid and neutral conditions. At low initial pH of 4-7, the cell density of algae was effectively removed in the ECF, mainly through the charge neutralization mechanism; while the algae removal worsened when the pH increased (7-10), and the main mechanism shifted to sweeping flocculation and enmeshment. The mechanisms for algae removal at different pH were also confirmed by atomic force microscopy (AFM) analysis. Furthermore, initial cell density and water temperature could also influence the algae removal. Overall, the results indicated that the ECF technology was effective for algae removal, from both the technical and economical points of view.

  11. Estudio poliedral y algoritmo branch-and-cut para el problema de coloreo equitativo en grafos

    OpenAIRE

    Severin, Daniel E.

    2012-01-01

    Los problemas de coloreo de grafos constituyen una familia de problemas de una gran relevancia tanto teórica como práctica. Todos ellos son variaciones del problema del coloreo clásico, cuyo estudio se inició en el Siglo XIX. El origen de estas variaciones radica en las restricciones adicionales que imponen las aplicaciones a problemas de la vida real. En esta tesis abordamos en particular el Problema de Coloreo Equitativo en Grafos. Como muchos problemas de Optimización Combinatoria, el Prob...

  12. Brasil, opciones estratégicas de una potencia emergente para afirmar su liderazgo mundial

    Directory of Open Access Journals (Sweden)

    Gisela da Silva Guevara

    2011-11-01

    Full Text Available Desde el siglo XIX Brasil fue adaptando sus estrategias de soft power (poder blando con la meta de afirmar su poderío político y económico en América Latina y en el mundo, en contraposición a otros poderes hegemónicos regionales y mundiales. Sin embargo, sus rivalidades con potencias regionales, como Argentina o Venezuela y, con Estados Unidos, a nivel regional y mundial, nunca llevaron al coloso suramericano a optar por confrontaciones bélicas. Sus estrategias y opciones de política exterior tuvieron siempre en mira la consolidación del país por vía no violenta y a largo plazo. El presente artículo debate la pregunta-problema de si la nación suramericana podrá seguir la línea de poder blando que ha respetado, por siglos, desde su independencia, o será tentada a privilegiar el hard power para lograr, finalmente, ser reconocida como gran potencia en el siglo XXI.

  13. Programa de apoyo al trabajador-cuidador familiar: fenómeno social emergente

    Directory of Open Access Journals (Sweden)

    Luz María Herrera-López

    2014-01-01

    Full Text Available En el contexto demográfico actual de envejecimiento poblacional surge un nuevo rol: el funcionario-cuidador. La persona que trabaja y, además, cuida a un familiar con discapacidad, presenta problemas personales, laborales y menor compromiso con su autocuidado. Entre las intervenciones eficaces se encuentra el mejorar la percepción del apoyo social. Se presenta un programa interdisciplinario, iniciado en el año 2009, de apoyo a trabajadores-cuidadores familiares. Su propósito es promover la salud y prevenir factores de riesgo de enferme- dad a través del fortalecimiento de sus habilidades de autocuidado y el desarrollo de políticas institucionales que faciliten el cumplimiento de ambos roles en forma eficiente y saludable. Como estrategias de promoción en salud se han utilizado: la educación para el autocuidado, el fortalecimiento de redes de apoyo familiar y social, la asesoría profesional y la comunidad de pares. En las últimas tres cohortes anua- les han participado sesenta funcionarios, de los cuales el 83,4 % son mujeres, con un promedio de edad de cincuenta años. El programa ha cumplido con éxito los objetivos propuestos, aumentando la percepción de apoyo social manifestado por los propios participantes.

  14. Algae to Economically Viable Low-Carbon-Footprint Oil.

    Science.gov (United States)

    Bhujade, Ramesh; Chidambaram, Mandan; Kumar, Avnish; Sapre, Ajit

    2017-06-07

    Algal oil as an alternative to fossil fuel has attracted attention since the 1940s, when it was discovered that many microalgae species can produce large amounts of lipids. Economics and energy security were the motivational factors for a spurt in algae research during the 1970s, 1990s, and early 2000s. Whenever crude prices declined, research on algae stopped. The scenario today is different. Even given low and volatile crude prices ($30-$50/barrel), interest in algae continues all over the world. Algae, with their cure-all characteristics, have the potential to provide sustainable solutions to problems in the energy-food-climate nexus. However, after years of effort, there are no signs of algae-to-biofuel technology being commercialized. This article critically reviews past work; summarizes the current status of the technology; and based on the lessons learned, provides a balanced perspective on a potential path toward commercialization of algae-to-oil technology.

  15. Interspecific variation in total phenolic content in temperate brown algae

    Directory of Open Access Journals (Sweden)

    Anna Maria Mannino

    2017-09-01

    Full Text Available Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the sheet-like alga D. polypodioides, living in the upper infralittoral zone, showed the highest concentration of phenolic compounds. These results are in agreement with the hypothesis that total phenolic content in temperate brown algae is influenced by a combination of several factors, such as growth form, depth, and exposition to solar radiation.

  16. Genome Annotation and Transcriptomics of Oil-Producing Algae

    Science.gov (United States)

    2015-03-16

    AFRL-OSR-VA-TR-2015-0103 GENOME ANNOTATION AND TRANSCRIPTOMICS OF OIL-PRODUCING ALGAE Sabeeha Merchant UNIVERSITY OF CALIFORNIA LOS ANGELES Final...2010 To 12-31-2014 4. TITLE AND SUBTITLE GENOME ANNOTATION AND TRANSCRIPTOMICS OF OIL-PRODUCING ALGAE 5a. CONTRACT NUMBER FA9550-10-1-0095 5b...NOTES 14. ABSTRACT Most algae accumulate triacylglycerols (TAGs) when they are starved for essential nutrients like N, S, P (or Si in the case of some

  17. Production and characterization of algae extract from Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Weston Kightlinger

    2014-01-01

    Conclusions: This study showed that algae extract derived from C. reinhardtii is similar, if not superior, to commercially available yeast extract in nutrient content and effects on the growth and metabolism of E. coli and S. cerevisiae. Bacto™ yeast extract is valued at USD $0.15–0.35 per gram, if algae extract was sold at similar prices, it would serve as a high-value co-product in algae-based fuel processes.

  18. Method and apparatus for iterative lysis and extraction of algae

    Science.gov (United States)

    Chew, Geoffrey; Boggs, Tabitha; Dykes, Jr., H. Waite H.; Doherty, Stephen J.

    2015-12-01

    A method and system for processing algae involves the use of an ionic liquid-containing clarified cell lysate to lyse algae cells. The resulting crude cell lysate may be clarified and subsequently used to lyse algae cells. The process may be repeated a number of times before a clarified lysate is separated into lipid and aqueous phases for further processing and/or purification of desired products.

  19. Method and apparatus for lysing and processing algae

    Science.gov (United States)

    Chew, Geoffrey; Reich, Alton J.; Dykes, Jr., H. Waite H.; Di Salvo, Roberto

    2013-03-05

    Methods and apparatus for processing algae are described in which a hydrophilic ionic liquid is used to lyse algae cells at lower temperatures than existing algae processing methods. A salt or salt solution is used as a separation agent and to remove water from the ionic liquid, allowing the ionic liquid to be reused. The used salt may be dried or concentrated and reused. The relatively low lysis temperatures and recycling of the ionic liquid and salt reduce the environmental impact of the algae processing while providing biofuels and other useful products.

  20. Importance of algae oil as a source of biodiesel

    International Nuclear Information System (INIS)

    Demirbas, Ayhan; Fatih Demirbas, M.

    2011-01-01

    Algae are the fastest-growing plants in the world. Industrial reactors for algal culture are open ponds, photobioreactors and closed systems. Algae are very important as a biomass source. Algae will some day be competitive as a source for biofuel. Different species of algae may be better suited for different types of fuel. Algae can be grown almost anywhere, even on sewage or salt water, and does not require fertile land or food crops, and processing requires less energy than the algae provides. Algae can be a replacement for oil based fuels, one that is more effective and has no disadvantages. Algae are among the fastest-growing plants in the world, and about 50% of their weight is oil. This lipid oil can be used to make biodiesel for cars, trucks, and airplanes. Microalgae have much faster growth-rates than terrestrial crops. the per unit area yield of oil from algae is estimated to be from 20,000 to 80,000 l per acre, per year; this is 7-31 times greater than the next best crop, palm oil. The lipid and fatty acid contents of microalgae vary in accordance with culture conditions. Most current research on oil extraction is focused on microalgae to produce biodiesel from algal oil. Algal-oil processes into biodiesel as easily as oil derived from land-based crops.

  1. Accumulation of 210Po by benthic marine algae

    International Nuclear Information System (INIS)

    Gouvea, R.C.; Branco, M.E.C.; Santos, P.L.

    1988-01-01

    The accumulation of polonium 210 Po by various species of benthic marine seaweeds collected from 4 different points on the coast of Rio de Janeiro, showed variations by species and algal groups. The highest value found was in red alga, Plocamium brasiliensis followed by other organisms of the same group. In the group of the brown alga, the specie Sargassum stenophylum was outstanding. The Chlorophyta presented the lowest content of 210 Po. The algae collected in open sea, revealed greater concentration factors of 210 Po than the same species living in bays. The siliceous residue remaining after mineralization of the algae did not interfere with the detection of polonium. (author)

  2. Algae Bioreactor Using Submerged Enclosures with Semi-Permeable Membranes

    Science.gov (United States)

    Trent, Jonathan D (Inventor); Gormly, Sherwin J (Inventor); Embaye, Tsegereda N (Inventor); Delzeit, Lance D (Inventor); Flynn, Michael T (Inventor); Liggett, Travis A (Inventor); Buckwalter, Patrick W (Inventor); Baertsch, Robert (Inventor)

    2013-01-01

    Methods for producing hydrocarbons, including oil, by processing algae and/or other micro-organisms in an aquatic environment. Flexible bags (e.g., plastic) with CO.sub.2/O.sub.2 exchange membranes, suspended at a controllable depth in a first liquid (e.g., seawater), receive a second liquid (e.g., liquid effluent from a "dead zone") containing seeds for algae growth. The algae are cultivated and harvested in the bags, after most of the second liquid is removed by forward osmosis through liquid exchange membranes. The algae are removed and processed, and the bags are cleaned and reused.

  3. Economic evaluation of algae biodiesel based on meta-analyses

    Science.gov (United States)

    Zhang, Yongli; Liu, Xiaowei; White, Mark A.; Colosi, Lisa M.

    2017-08-01

    The objective of this study is to elucidate the economic viability of algae-to-energy systems at a large scale, by developing a meta-analysis of five previously published economic evaluations of systems producing algae biodiesel. Data from original studies were harmonised into a standardised framework using financial and technical assumptions. Results suggest that the selling price of algae biodiesel under the base case would be 5.00-10.31/gal, higher than the selected benchmarks: 3.77/gal for petroleum diesel, and 4.21/gal for commercial biodiesel (B100) from conventional vegetable oil or animal fat. However, the projected selling price of algal biodiesel (2.76-4.92/gal), following anticipated improvements, would be competitive. A scenario-based sensitivity analysis reveals that the price of algae biodiesel is most sensitive to algae biomass productivity, algae oil content, and algae cultivation cost. This indicates that the improvements in the yield, quality, and cost of algae feedstock could be the key factors to make algae-derived biodiesel economically viable.

  4. Modelos matemáticos en un problema de epidemias

    Directory of Open Access Journals (Sweden)

    Anna Vidal

    2016-01-01

    Full Text Available La introducción de conceptos matemáticos a través del desarrollo y estudio de modelos ha sido tratado en numerosos trabajos. La introducción de los modelos suele hacerse básicamente desde el discurso del professor y el trabajo del alumno suele reducirse a la experimentación con el modelo dado. La aproximación a un problema mediante modelos IBM (Individual Based Model resulta más comprensible para el alumno, permite justificar y complementar otras aproximaciones a la solución (modelos diferenciales continuos y/o modelos discretos. En este trabajo se presenta una experiencia docente basada en afrontar un mismo problema mediante enfoques complementarios en base a modelos continuos, discretos e IBM. Finalmente se presenta una propuesta metodológica para ponerla en práctica utilizando el Aprendizaje Cooperativo y el Problem/Project Based Learning.

  5. Aprender con problemas: un enfoque contextualizado y socializado del conocimiento

    Directory of Open Access Journals (Sweden)

    Lola GARCÍA OLALLA

    2008-01-01

    Full Text Available El estudio que presentamos se centra en la utilización del ABP (Aprendizaje Basado en Problemas, que articula dos asignaturas cuatrimestrales: Desarrollo Socioafectivo y Desarrollo Psicomotor. Concluimos que la metodología ABP favorece el aprendizaje significativo, aprender a trabajar en grupo, resolver problemas de forma cooperativa, y la conexión entre la formación teórica y los contextos de actuación profesional. El aprendizaje cooperativo favorece la dinámica de trabajo en equipo, la responsabilidad personal y el desarrollo de estrategias de colaboración, y de competencias sociales como aprender a escuchar, respetar las opiniones de otros, organizar el trabajo, debatir y llegar a consensos, saber expresarse y exponer opiniones, o empatizar.

  6. Saúde mental e trabalho: os problemas que persistem

    Directory of Open Access Journals (Sweden)

    Leny Sato

    Full Text Available Este artigo toma por objeto a Saúde Mental e Trabalho como uma subárea do campo da Saúde do Trabalhador. Parte da constatação de que os problemas de saúde mental e trabalho, já identificados em meados da década de 1980, persistem. Após retomar a taxonomia de tais problemas, busca evidenciar algumas de suas expressões atuais a partir da assistência e da vigilância em saúde do trabalhador, bem como pela perspectiva de alguns sindicatos mais atentos à questão. Para tal, toma como ponto de partida o Centro de Referência em Saúde do Trabalhador (CRST de Campinas. Por fim, pontua algumas características do trabalho no contexto atual para compreender as motivações dessa persistência.

  7. MAPA CONCEPTUAL PARA EL APRENDIZAJE BASADO EN PROBLEMAS

    Directory of Open Access Journals (Sweden)

    YURI GORBANEFF

    2009-01-01

    Full Text Available Se presentan los resultados del experimento sobre el uso de mapas conceptuales en el contexto del aprendizaje basado en problemas (ABP. El experimento fue realizado en la Universidad Javeriana (Bogotá, Colombia en el pregrado de administración. Se encontró que el mapa conceptual mejora el aprendizaje pero no afecta la percepción de los alumnos del método de ABP. Se recomienda incluir mapas conceptuales en los ejercicios de ABP.

  8. Mapa Conceptual Para El Aprendizaje Basado En Problemas

    Directory of Open Access Journals (Sweden)

    Yuri Gorbaneff

    2009-01-01

    Full Text Available Se presentan los resultados del experimento sobre el uso de mapas conceptuales en el contexto del aprendizaje basado en problemas (ABP. El experimento fue realizado en la Universidad Javeriana (Bogotá, Colombia en el pregrado de administración. Se encontró que el mapa conceptual mejora el aprendizaje pero no afecta la percepción de los alumnos del método de ABP. Se recomienda incluir mapas conceptuales en los ejercicios de ABP.

  9. Veridicção: um problema de verdade

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Ortiz Gandin Baldan

    2001-02-01

    Full Text Available

    A teoria semiótica greimasiana provocou, com a definição de veridicção, um avanço considerável rias teorias que tratam do texto. O presente trabalho fornece algumas reflexões, principalmente no sentido de repensar o problema da referencialidade nos discursos através do estatuto cientifico que a teoria greimasiana propõe no seu procedimento descritivo.

  10. LA CUESTIÓN AGRARIA COMO ENFOQUE Y COMO PROBLEMA

    Directory of Open Access Journals (Sweden)

    Carlos Salgado

    2000-01-01

    Full Text Available Este ensayo trata de llamar la atención sobre los problemas del agro hoy, colocando especial énfasis en la disrupción entre las razones tecnológicas -que se asumen como ideológicas-, económicas y políticas que han inspirado el desarrollo del agro, o mejor, sobre las cuales se han basado las políticas de crecimiento agropecuario.

  11. Interactions between arsenic species and marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, J.G.

    1978-01-01

    The arsenic concentration and speciation of marine algae varies widely, from 0.4 to 23 ng.mg/sup -1/, with significant differences in both total arsenic content and arsenic speciation occurring between algal classes. The Phaeophyceae contain more arsenic than other algal classes, and a greater proportion of the arsenic is organic. The concentration of inorganic arsenic is fairly constant in macro-algae, and may indicate a maximum level, with the excess being reduced and methylated. Phytoplankton take up As(V) readily, and incorporate a small percentage of it into the cell. The majority of the As(V) is reduced, methylated, and released to the surrounding media. The arsenic speciation in phytoplankton and Valonia also changes when As(V) is added to cultures. Arsenate and phosphate compete for uptake by algal cells. Arsenate inhibits primary production at concentrations as low as 5 ..mu..g.1/sup -1/ when the phosphate concentration is low. The inhibition is competitive. A phosphate enrichment of > 0.3 ..mu..M alleviates this inhibition; however, the As(V) stress causes an increase in the cell's phosphorus requirement. Arsenite is also toxic to phytoplankton at similar concentrations. Methylated arsenic species did not affect cell productivity, even at concentrations of 25 ..mu..g.1/sup -1/. Thus, the methylation of As(V) by the cell produces a stable, non-reactive compound which is nontoxic. The uptake and subsequent reduction and methylation of As(V) is a significant factor in determining the arsenic biogeochemistry of productive systems, and also the effect that the arsenic may have on algal productivity. Therefore, the role of marine algae in determining the arsenic speciation of marine systems cannot be ignored. (ERB)

  12. Ammonium removal using algae-bacteria consortia: the effect of ammonium concentration, algae biomass, and light.

    Science.gov (United States)

    Jia, Huijun; Yuan, Qiuyan

    2018-04-01

    In this study, the effects of ammonium nitrogen concentration, algae biomass concentration, and light conditions (wavelength and intensity) on the ammonium removal efficiency of algae-bacteria consortia from wastewater were investigated. The results indicated that ammonium concentration and light intensity had a significant impact on nitrification. It was found that the highest ammonia concentration (430 mg N/L) in the influent resulted in the highest ammonia removal rate of 108 ± 3.6 mg N/L/days, which was two times higher than the influent with low ammonia concentration (40 mg N/L). At the lowest light intensity of 1000 Lux, algae biomass concentration, light wavelength, and light cycle did not show a significant effect on the performance of algal-bacterial consortium. Furthermore, the ammonia removal rate was approximately 83 ± 1.0 mg N/L/days, which was up to 40% faster than at the light intensity of 2500 Lux. It was concluded that the algae-bacteria consortia can effectively remove nitrogen from wastewater and the removal performance can be stabilized and enhanced using the low light intensity of 1000 Lux that is also a cost-effective strategy.

  13. Snow algae and lichen algae differ in their resistance to freezing temperature: An ice nucleation study

    Czech Academy of Sciences Publication Activity Database

    Hajek, J.; Kvíderová, Jana; Worland, R.; Barták, M.; Elster, Josef; Vaczi, P.

    2009-01-01

    Roč. 48, č. 4 (2009), s. 37-38 ISSN 0031-8884. [International Phycological Congress /9./. 02.08.2009-08.08.2009, Tokyo] R&D Projects: GA AV ČR IAA600050702; GA AV ČR KJB601630808 Institutional research plan: CEZ:AV0Z60050516 Keywords : ice nucleation * algae * freezing Subject RIV: EF - Botanics

  14. Orden de no reanimar, consideraciones sobre este problema

    Directory of Open Access Journals (Sweden)

    Dr. G. Luis Cereceda

    2011-05-01

    Se analizan los principales problemas, comenzando por las dificultades según los diferentes escenarios (servicio de urgencia, pabellón de maternidad, sala de hospitalizados, unidad de intensivo, pabellones quirúrgicos; se analiza la incertidumbre sobre el pronóstico de cada pacientes y sobre quién(es deben tomar las decisiones sobre el fin de la vida. Idealmente debe ser el paciente autónomo quien tome la decisión, pero en otros casos se requieren alternativas, una de ellas es la Orden Unilateral. Otros problemas son la Validez de las órdenes de no-RCP en los diferentes tiempos evolutivos, el problema de la Futilidad y la Validez de las “Directivas Anticipadas”, en este grupo resalta el enfoque POLST (Physician’s Order for Life Sustaining Treatment como más comprehensivo; como complemento ha surgido también el concepto AND (Allow Natural Death, que podría estar destinado a remplazar la orden de no-RCP (DNR.

  15. Role of marine algae in organic farming

    Digital Repository Service at National Institute of Oceanography (India)

    Pereira, N.; Verlecar, X.N.

    Division of Publication and Information, Indian Council of Medical Research, V. Ramalingaswami Bhawan, Ansari Nagar, New Delhi 110 029, India e - mail: encejain@yahoo.co.in Role of marine algae in organic far m ing As rightly outlined.... The Indi an Ocean, including its adjacent seas, extends over an area of about 73.44 ? 10 6 km 2 and the potential harvest of seaweeds from the Indian Ocean is about 870 thousand tonnes (wet weight) 3 . India could draw benefits from this marine...

  16. Effect of petroleum hydrocarbons on algae

    International Nuclear Information System (INIS)

    Bhadauria, S.; Sengar, R.M.S.; Mittal, S.; Bhattacharjee, S.

    1992-01-01

    Algal species (65) were isolated from oil refinery effluent. Twenty-five of these species were cultured in Benecke's medium in a growth chamber, along with controls. Retardation in algal growth, inhibition in algal photosynthesis, and discoloration was observed in petroleum enriched medium. Few forms, viz. Cyclotella sp., Cosmarium sp., and Merismopedia sp. could not survive. The lag phase lengthened by several days and slope of exponential phase was also depressed. Chlamydomonas sp., Scenedesmus sp., Ankistrodesmus sp., Nitzschia sp. and Navicula sp. were comparatively susceptible to petroleum. Depression in carbon fixation, cell numbers, and total dry algal mass was noticeable, showing toxicity to both diatoms and green algae

  17. Custo de capital próprio em mercados emergentes: uma abordagem empírica no Brasil com o downside risk

    Directory of Open Access Journals (Sweden)

    Graziela Xavier Fortunato

    2010-02-01

    Full Text Available Este artigo visa testar empiricamente a proposta de Estrada (2000 para as empresas que compoem o Ibovespa, avaliando se para mercados emergentes existem outras medidas de risco sistematico diferentes do beta do capital asset pricing model (CAPM. Dessa forma, testou-se o downside risk que capta a parte negativa do retorno. Alem de dados em cross section, utilizaram-se dados em painel, como uma contribuição adicional ao trabalho de Estrada (2000. Os resultados encontrados não confirmam que o downside risk seja uma medida apropriada ao mercado brasileiro. Outras medidas de risco apresentaram melhor correlacao com o retorno, permitindo o calculo do custo de capital com valor diferente daquele obtido pela aplicacao do beta. De acordo com Estrada (2000, os resultados sugerem que os mercados emergentes estao em posicao intermediaria entre os mercados integrados e segmentados, tal como confirmado para o mercado brasileiro.

  18. LA FORMACIÓN DE ESTRATEGIAS DELIBERADAS Y EMERGENTES: UNA PROPUESTA A PARTIR DE DEFINICIONES BÁSICAS DE UNA METODOLOGÍA DE SISTEMAS SUAVES

    Directory of Open Access Journals (Sweden)

    IVÁN ALONSO MONTOYA RESTREPO

    2013-01-01

    Full Text Available La propuesta teórica que se presenta, se relaciona con la formación de la estrategia desde una pers - pectiva evolutiva y con conexiones entre estrategias deliberadas y emergentes, gracias al empleo de definiciones básicas o raíces, empleando la metodología de sistemas suaves SSM propuesta por Checkland & Scholes (1994. Para ello se propone la interacción de entes “autónomos” y semió - ticos (agentes, organizaciones y entorno en los sistemas real y representacional de interacciones. Estas nociones permiten la elaboración de los conceptos de decisión, actuación e intencionalidad. Se reelaboran las nociones de estrategia deliberada y emergente y se detalla un ciclo de operación entre tales tipos de estrategia.

  19. Incursión de tecnologías emergentes en una escuela pública de Negocios de México

    OpenAIRE

    Madrigal Lozano, María Magdalena; Hernández Moreno, Laura Alicia; López Solórzano, Juan Gabriel; Merla González, Alma Elizabeth

    2017-01-01

    En el presente artículo se describen los resultados obtenidos de un estudio exploratorio, descriptivo de alcance transeccional realizado para conocer la realidad del uso, producción e investigación de las tecnologías emergentes MOOC, Gamificación y Realidad Aumentada en los procesos educativos de los programas relacionados con la profesión de negocios. En particular se aplicó un instrumento de medic...

  20. COMPLEJIDAD AMBIENTAL: PROPUESTAS ÉTICAS EMERGENTES DEL PENSAMIENTO AMBIENTAL LATINOAMERICANO

    Directory of Open Access Journals (Sweden)

    Noguera de Echeverri Ana Patricia

    2008-07-01

    Full Text Available En este artículo, se recogen las propuestas ético ambientales más importantes de la Escuela de Pensamiento Ambiental Latinoamericano, que ha ido construyéndose desde hace 30 años. Se destacan autores de primera línea en el campo de la construcción de Pensamiento Ambiental filosófico, como el Filósofo y Pensador Colombiano, de trascendencia latinoamericana, Augusto Ángel Maya, quien plantea la posibilidad de construir una Filosofía Ambiental Ético estética, dado que la Filosofía Moderna ha sido Metafísica, aún en sus corrientes empiristas, positivistas y neopositivistas. Se destaca la obra de Enrique Leff, mexicano, que propone los conceptos de Complejidad y Saber Ambiental, como puntos de partida de una ética en la educación, la ciencia y la tecnología, dentro de unas relaciones sistémicas y holísticas. Igualmente la propuesta ético estética compleja de Julio Carrizoza, colombiano, se hace presente en este ensayo, como una propuesta política fundamental ante problemas colombianos como son la violencia y la exclusión. Las propuestas de Filósofos colombianos de gran importancia en el campo de la Filosofía Política y Moral, que han desembocado en la propuesta de una Ética Ambiental, Pública y Comunicativa, como es el caso de Guillermo Hoyos Vásquez y de otros pensadores tanto de Colombia como de otros países latinoamericanos, se presentan en este espacio, con el fin de recoger de manera crítica nuestras ideas acerca de la posibilidad de una ética ambiental, es decir una ética descentrada, sin sujeto y sin objeto, una ética sistémica, donde los valores se construyen en las relaciones y donde la intricada trama de la vida, que ha venido construyéndose desde hace más de 2.500 millones de años, y de la cual somos meros hilos, pasa de ser objeto a ser valor primero en su más genuino sentido.

  1. Resistencia, cambio y adaptación en las universidades argentinas: problemas conceptuales y tendencias emergentes en el gobierno y la gestión académica

    Directory of Open Access Journals (Sweden)

    Claudio Suasnábar

    2001-01-01

    Full Text Available This article aims to contribute to the theoretical and methodological debate on the most suitable conceptual frameworks for studying the problems of government and management in Argentinian universities. The paper also constitutes a first test of the instruments presented therein. Tensions generated by state policieson academic management are also analysed. The article considers that the emergence of a double line of manegement and condut of the institution of new actors in Argentinian universities constitute the two phenomena which dispute the role historically attributed to academic councils. These tensions, which underlie processes of institutional change the, are the expression of conflicts between new forms of management and the model of cogovernment that established the Argentinian University Reform of 1918.

  2. Doenças infecciosas emergentes no Uruguai: memórias do século 20

    Directory of Open Access Journals (Sweden)

    María Hortal

    2017-02-01

    Full Text Available As doenças emergentes não são novos eventos epidemiológicos: existiram epidemias, mesmo no território uruguaio. A globalização com múltiplos fatores de intervenção acentuou o dinamismo biológico de agentes infecciosos e populações humanas. Considerando que uma doença emergente é causada por um novo agente ou que produz uma série de casos que excedem o número esperado, que invade uma área geográfica diferente ou reaparece após um desaparecimento prolongado, foram feitas tentativas para recuperar memórias de epidemias ocorridas no Uruguai durante o século XX. Também destacou o progresso do conhecimento sobre a biologia dos agentes infecciosos e seu controle. Muitas das doenças epidêmicas endêmicas das primeiras décadas do século, no final deste século foram controladas por vacinas. Há também surtos de outras doenças transmissíveis ou aparecem etiologias desconhecidas. Para obter toda essa informação, foi realizada uma revisão bibliográfica, mas foram encontradas relativamente poucas publicações de epidemias bacterianas ou virais. No entanto, a informação recuperada nos permitiu seguir o comportamento de doenças prevalentes, apreciar ao longo dos anos, a evolução de seus surtos epidêmicos, os sucessos e falhas de recursos para seu controle, bem como a capacidade de subsistência da maioria dos agentes infecciosos. No mundo e no Uruguai, durante o século 20, foi surpreendente expandir o conhecimento que, a partir de uma microbiologia incipiente, atingiu um alto nível científico / técnico que nos permitiu iniciar um novo século com possibilidades auspiciosas para enfrentar desafios persistentes e imprevisíveis.

  3. Algae-based oral recombinant vaccines

    Science.gov (United States)

    Specht, Elizabeth A.; Mayfield, Stephen P.

    2014-01-01

    Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for “molecular pharming” in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae could be poised to become the next candidate in recombinant subunit vaccine production, as they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and systemic immune reactivity. PMID:24596570

  4. Energy from algae using microbial fuel cells

    KAUST Repository

    Velasquez-Orta, Sharon B.

    2009-08-15

    Bioelectricity production froma phytoplankton, Chlorella vulgaris, and a macrophyte, Ulva lactuca was examined in single chamber microbial fuel cells (MFCs). MFCs were fed with the two algae (as powders), obtaining differences in energy recovery, degradation efficiency, and power densities. C. vulgaris produced more energy generation per substrate mass (2.5 kWh/kg), but U. lactuca was degraded more completely over a batch cycle (73±1% COD). Maximum power densities obtained using either single cycle or multiple cycle methods were 0.98 W/m2 (277 W/m3) using C. vulgaris, and 0.76 W/m2 (215 W/m3) using U. lactuca. Polarization curves obtained using a common method of linear sweep voltammetry (LSV) overestimated maximum power densities at a scan rate of 1 mV/s. At 0.1 mV/s, however, the LSV polarization data was in better agreement with single- and multiple-cycle polarization curves. The fingerprints of microbial communities developed in reactors had only 11% similarity to inocula and clustered according to the type of bioprocess used. These results demonstrate that algae can in principle, be used as a renewable source of electricity production in MFCs. © 2009 Wiley Periodicals, Inc.

  5. Energy from algae using microbial fuel cells

    KAUST Repository

    Velasquez-Orta, Sharon B.; Curtis, Tom P.; Logan, Bruce E.

    2009-01-01

    Bioelectricity production froma phytoplankton, Chlorella vulgaris, and a macrophyte, Ulva lactuca was examined in single chamber microbial fuel cells (MFCs). MFCs were fed with the two algae (as powders), obtaining differences in energy recovery, degradation efficiency, and power densities. C. vulgaris produced more energy generation per substrate mass (2.5 kWh/kg), but U. lactuca was degraded more completely over a batch cycle (73±1% COD). Maximum power densities obtained using either single cycle or multiple cycle methods were 0.98 W/m2 (277 W/m3) using C. vulgaris, and 0.76 W/m2 (215 W/m3) using U. lactuca. Polarization curves obtained using a common method of linear sweep voltammetry (LSV) overestimated maximum power densities at a scan rate of 1 mV/s. At 0.1 mV/s, however, the LSV polarization data was in better agreement with single- and multiple-cycle polarization curves. The fingerprints of microbial communities developed in reactors had only 11% similarity to inocula and clustered according to the type of bioprocess used. These results demonstrate that algae can in principle, be used as a renewable source of electricity production in MFCs. © 2009 Wiley Periodicals, Inc.

  6. Algae-based oral recombinant vaccines

    Directory of Open Access Journals (Sweden)

    Elizabeth A Specht

    2014-02-01

    Full Text Available Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for molecular pharming in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae are poised to become the next candidate in recombinant subunit vaccine production, and they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally-delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and system immune reactivity.

  7. Management of autotrophic mass cultures of micro-algae

    CSIR Research Space (South Africa)

    Toerien, DF

    1987-01-01

    Full Text Available Interest in the mass cultivation of micro-algae as feed and foodstuff has existed since the turn of the century (Robinson and Toerien, 1962). Experiments using algae in photosynthetic research (Warburg, 1919) also led to an appreciation...

  8. EnAlgae Decision Support Toolset: model validation

    NARCIS (Netherlands)

    Kenny, Philip; Visser, de Chris; Skarka, Johannes; Sternberg, Kirstin; Schipperus, Roelof; Silkina, Alla; Ginnever, Naomi

    2015-01-01

    One of the drivers behind the EnAlgae project is recognising and addressing the need for increased availability of information about developments in applications of algae biotechnology for energy, particularly in the NW Europe area, where activity has been less intense than in other areas of the

  9. Evaluation of the activated carbon prepared from the algae ...

    African Journals Online (AJOL)

    Evaluation of the activated carbon prepared from the algae Gracilaria for the biosorption of Cu(II) from aqueous solutions. ... African Journal of Biotechnology ... This study shows the benefit of using activated carbon from marine red algae as a low cost sorbent for the removal of copper from aqueous solution wastewater.

  10. Rare species of fungi parasiting on algae. III.

    Directory of Open Access Journals (Sweden)

    Joanna Z. Kadłubowska

    2014-08-01

    Full Text Available The investigations csrried out on algae revealed the following species of fungi from the order of Chytridialis Hawksworth et al. (1995 parasitizing on algae: Rhizophydium subgulosum, R. ganlosporum, R. planctonicum, Entophlyctis rhizina and Harpochytrium hedinii. These species arc new to Poland. The figure of resting spore of Entophlyctis rhizina is the fint graphic documentation of this species.

  11. Rare species of fungi parasiting on algae. III.

    OpenAIRE

    Joanna Z. Kadłubowska

    2014-01-01

    The investigations csrried out on algae revealed the following species of fungi from the order of Chytridialis Hawksworth et al. (1995) parasitizing on algae: Rhizophydium subgulosum, R. ganlosporum, R. planctonicum, Entophlyctis rhizina and Harpochytrium hedinii. These species arc new to Poland. The figure of resting spore of Entophlyctis rhizina is the fint graphic documentation of this species.

  12. Persistence and proliferation of some unicellular algae in drinking ...

    African Journals Online (AJOL)

    Drinking water systems have a complex structure and are characterised by the absence of light, the presence of disinfectants and by low levels of nutrients. Several kinds of bacteria, protozoa, algae and fungi can be found in tap water. Little is known about the ecology of algae in drinking water systems, although their ...

  13. Isolation and Characterization of Blue Green Algae from Egyptian ...

    African Journals Online (AJOL)

    meldemellawy

    2014-02-20

    Feb 20, 2014 ... aminotransferase (AMT) domains of the mycE and ndaF genes (Jungblut et al., 2006) allowing detection of microcystin and nodularin-producing cyanobacteria. MATERIALS AND METHODS. Isolation and cultivation of blue green algae. Blue green algae had been isolated from soil of Rice field in river.

  14. 21 CFR 73.185 - Haematococcus algae meal.

    Science.gov (United States)

    2010-04-01

    ... stabilized color additive mixture. Color additive mixtures for fish feed use made with haematococcus algae... in color additive mixtures for coloring foods. (b) Specifications. Haematococcus algae meal shall... salmonid fish in accordance with the following prescribed conditions: (1) The color additive is used to...

  15. Study on the effect of irradiation on algae by proteomics

    International Nuclear Information System (INIS)

    Choi, Jong Il; Yoon, Yo Han; Kim, Jae Hun

    2010-06-01

    Algae has been utilized as food material from long time ago, and recently newly recognized as functional materials and the source of bio-fuel. But, the study on the algae is just beginning and the study on protein expression and growth by the change of condition was not reported. In this study, the effect of radiation on the protein expression was investigated for the protection mechanisms and new genome source and furthermore, isolation of new mutant strains. To monitor the growth of algae, absorbance and FDA staining methods were developed and the content of lipid of algae species were measured. With these methods, the radiation sensitivity of algae species was determined. To investigate the proteome of algae, 2D-electrophoresis methods was applied. From the comparison of proteomes, the radiation specific expressed protein was identified as thioredoxin-h and its nucleotide sequences was defined. The expression of thioredoxin-h was further defined on the mRNA level. Also, the extract of algae species was analyzed for its antioxidant activity and polyphenolic content. The changes in antioxidant activity of extract by radiation was investigated. From the radiation experiments, mutant Spirogyra species having higher resistant against radical stress was obtained. The mutant strain has higher antioxidant activity. This results can provide the proteome date and mutation technology of algae and further contribute in the activation of fishery industry and national health enhancement

  16. Algae Cultivation for Carbon Capture and Utilization Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-05-01

    The Algae Cultivation for Carbon Capture and Utilization Workshop Summary Report summarizes a workshop hosted by the U.S. Department of Energy's Bioenergy Technologies Office on May 23–24, 2017, in Orlando, Florida. The event gathered stakeholder input through facilitated discussions focused on innovative technologies and business strategies for growing algae on waste carbon dioxide resources.

  17. Efficiency of using green algae as biological controllers against toxic ...

    African Journals Online (AJOL)

    Efficiency of using green algae as biological controllers against toxic algal taxa in cultured ... of two green algal species as biological control of the growth of toxic blue-green algae. ... African Journal of Aquatic Science 2014, 39(4): 443–450 ...

  18. Recent Advances in Marine Algae Polysaccharides: Isolation, Structure, and Activities.

    Science.gov (United States)

    Xu, Shu-Ying; Huang, Xuesong; Cheong, Kit-Leong

    2017-12-13

    Marine algae have attracted a great deal of interest as excellent sources of nutrients. Polysaccharides are the main components in marine algae, hence a great deal of attention has been directed at isolation and characterization of marine algae polysaccharides because of their numerous health benefits. In this review, extraction and purification approaches and chemico-physical properties of marine algae polysaccharides (MAPs) are summarized. The biological activities, which include immunomodulatory, antitumor, antiviral, antioxidant, and hypolipidemic, are also discussed. Additionally, structure-function relationships are analyzed and summarized. MAPs' biological activities are closely correlated with their monosaccharide composition, molecular weights, linkage types, and chain conformation. In order to promote further exploitation and utilization of polysaccharides from marine algae for functional food and pharmaceutical areas, high efficiency, and low-cost polysaccharide extraction and purification methods, quality control, structure-function activity relationships, and specific mechanisms of MAPs activation need to be extensively investigated.

  19. Uptake of americium-241 by algae and bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Geisy, J P; Paine, D

    1978-01-01

    Algae and bacteria are important factors in the transport and mobilization of elements in the biosphere. These factors may be involved in trophic biomagnification, resulting in a potential human hazard or environmental degradation. Although americium, one of the most toxic elements known, is not required for plant growth, it may be concentrated by algae and bacteria. Therefore, the availability of americium-241 to algae and bacteria was studied to determine their role in the ultimate fate of this element released into the environment. Both algae and bacteria concentrated americium-241 to a high degree, making them important parts of the biomagnification process. The ability to concentrate americium-241 makes algae and bacteria potentially significant factors in cycling this element in the water column. (4 graphs, numerous references, 3 tables)

  20. Problemas de investigación en contabilidad y problemas de la investigación en contabilidad

    Directory of Open Access Journals (Sweden)

    Henry Antonio Romero León

    2015-01-01

    Full Text Available En este escrito se plantean dos problemáticas que padece el mundo contable en su concepción de la investigación y en la ejecución de la misma como proceso dinamizador de la disciplina. Se precisan problemas de investigación y problemas de la investigación contable, que derivan en el diagnóstico y descripción de aspectos generadores de trabas en la investigación. A manera de ejemplo se presentan investigaciones en orden de las grandes temáticas de investigación a través de las revistas académicas más representativas con la intención de evidenciar la investigación contable mundial. La problemática que guía la argumentación es la necesidad de distinguir dos ejes problemáticos en la investigación contable que hacen de este ejercicio una actividad que históricamente marcha a pasos lentos, buscando así comprender que con las aclaraciones conceptuales y analíticas en las concepciones que gobiernan el conocimiento contable, se pueda contribuir al desempantanamiento de este asunto. Se logra establecer que no es lo mismo los problemas como motivadores de la investigación, que los problemas que giran alrededor de la investigación como actividad humana.Palabras Clave: problemas de investigación en contabilidad; problemas de la investigación en contabilidad epistemología contable; ontología contable; investigación; problema; giro epistemológico.Research problems in accounting and problems in accounting research.AbstractThere are two questions being raised here regarding the accounting research and foundational research problems in accounting as a dynamizing agent of the discipline progress. Research problems in accounting and problems in accounting research derived therein have been discussed, through a diagnostic process, including a description of the main issues in these problematic research areas. By way of example, research topics published in the main accounting journals will be presented, with the intent to overview the

  1. Investigation about Role of Algae in Kazeroon Sasan Spring Odor

    Directory of Open Access Journals (Sweden)

    A Hamzeian

    2016-05-01

    Full Text Available Introduction: As odor for potable water is unpleasant for costumers, it needs to do researches for finding the reasons of odorous water. Sasan spring that is located in, near kazeroon city, Fars, Iran, is potable water resource for Kazeroon and Booshehr city and many other villages. Water in Sasan spring has the odor problem. With regards to important   role of algae on ado r problems in this study the role of algae on   odor was investigated. Methods: After regular sampling, the TON (threshold odor number was indicated and algae species was distinguished and the number of total algae and any species  of algae was numbers by microscopic direct numbering method .as the algae mass  is related to nitrogen and phosphor concentration, results of concentration Of nitrogen and phosphor in this spring that was examined regularity by water company was investigated and compared to concentration of these component that are need for algae growing.   Results: results shows that TON was in range  of 4.477 to 6.2 that indicated  oderous limit . Regression and diagram between TON and number of total algae showed the linear relationship. The concentration of nitrogen and phosphor, showed adequate condition for algal grow. Result of determination of algae species showed high population of Oscilatoria and Microcystis species, which are known as essential case of mold odor in water resources. Investigation on geological maps in the region around the Sasan spring, show alluvium source and is effected by surface part of it’s around land. Conclusion: because of the algae was determined as the essential cause of odor   in the spring, and algal growth is related to nutrients, and because of the surface pollution can penetrate in the alluvium lands around the spring, and effect the water in spring, so nutrient control and management is the essential way for odor control in the spring.

  2. Violencia intrafamiliar en estudiantes de primer año de la Escuela Emergente de Enfermería

    Directory of Open Access Journals (Sweden)

    Margarita Díaz Lemus

    Full Text Available Introducción: la familia como célula fundamental de la sociedad, tiene entre sus funciones la educación de las nuevas generaciones. En ella pueden aparecer episodios de violencia intrafamiliar que resultan difíciles de identificar y de afrontar por los adolescentes. Objetivos: identificar la presencia de violencia en las familias de los estudiantes de enfermería de primer año de la Escuela de Formación Emergente de Enfermería, así como determinar la relación entre el agresor y los tipos de violencia intrafamiliar. Métodos: se realizó una investigación descriptiva de corte transversal. El universo estuvo constituido por 101 estudiantes de la sede del municipio Cotorro. La muestra fue de 72 estudiantes que reconocieron la presencia de violencia intrafamiliar en sus hogares. Se utilizaron métodos teóricos de revisión documental y métodos empíricos de grupos focales y encuesta. Resultados: existe violencia intrafamiliar en la mayoría de los hogares de los estudiantes estudiados, donde los padres y las madres son los agresores fundamentales. Conclusiones: las manifestaciones de violencia intrafamiliar más representadas fueron el abuso emocional y la agresión física.

  3. Relaciones diferenciales entre experiencias de alfabetización y habilidades de alfabetización emergente

    Directory of Open Access Journals (Sweden)

    Liliana Salazar-Reyes

    2013-08-01

    Full Text Available El objetivo del estudio fue investigar si las experiencias de alfabetización que los padres brindan se relacionan diferencialmente con la alfabetización de los niños. A partir de una muestra intencional, se seleccionaron treinta y cuatro diadas madre-hijo al inicio de preescolar, procedentes de una escuela particular del Estado de México. Se presenta evidencia que considera en un mismo estudio el análisis de las experiencias explícitas e implícitas observadas en una sesión de interacción madre-hijo, haciendo uso de diferentes materiales, y otro tipo de experiencias de alfabetización reportadas por las madres. Ambos resultados se complementaron para comparar los puntajes obtenidos por los niños en las pruebas de alfabetización emergente. Se constataron diferencias significativas en la alfabetización debidas a la escolaridad del padre t(11 = 2,78, p = 0,019; el acercamiento a los libros t(12 = 3,90, p = 0,001, y la frecuencia de lectura de cuentos t(12 = 4,31, p = 0,002. A partir de los resultados se concluye que algunos niños tienen habilidades de alfabetización desde muy temprana edad como resultado de las experiencias que sus padres les proporcionan.

  4. PRÁCTICAS DE CUIDADO Y MODELOS EMERGENTES EN LAS RELACIONES DE GENERO. LA EXPERIENCIA DE ALGUNOS VARONES MEXICANOS

    Directory of Open Access Journals (Sweden)

    Juan Guillermo Figueroa Perea

    2012-01-01

    Full Text Available El propósito de este artículo es reflexionar en torno a las prácticas de cuidado cuando éstas son realizadas por varones en el espacio familiar. En un primer momento se presentan algunos conceptos básicos sobre la manera en que estamos conceptualizando el cuidado, y sobre la forma en que éste organiza y da lugar a ciertas relaciones sociales en las que se concretan vínculos y antagonismos por género y clase. Posteriormente, presentamos la evidencia empírica de un grupo de varones que realizan actividades de cuidado al interior de sus familias, debido a reacomodos asociados a separación, viudez o bien a que la pareja hace el trabajo extradoméstico. Nos centramos en la categoría de modelos emergentes y consideramos las dimensiones de motivos, emergencia de nuevas relaciones sociales, cambios o permanencias en la división sexual del trabajo y percepciones de oposición, valoración y aceptación. Concluimos con propuestas para seguir investigando sobre el tema.

  5. Saúde e ambiente: as doenças emergentes no Brasil Health and environment: emergent diseases in Brazil

    Directory of Open Access Journals (Sweden)

    Marta G. Pignatti

    2004-06-01

    Full Text Available Este artigo faz uma revisão das principais abordagens teóricas da área da Saúde em relação ao estudo das doenças resultantes das mudanças ambientais e a ocorrência de doenças emergentes no Brasil. Apresenta, de forma geral, a dinâmica de transmissão de doenças como a dengue, as leishmanioses, a febre maculosa, a cólera, a malária. Aponta para a necessidade de estudos interdisciplinares e estratégias políticas integradas.This article is a critical review on the main Health theories concerned with diseases resulting from environmental changes and the occurrence of some infectious diseases in Brazil. It addresses the relationship between urbanization, human migration, life quality, institutional intervention policy and the emergence of dengue, cholera, malaria, spot fever, and leishmaniasis. In conclusion, it points out the necessity of carrying out interdisciplinary studies and integrated political strategies.

  6. Um problema de corte com padrões compartimentados

    Directory of Open Access Journals (Sweden)

    Robinson Hoto

    2003-01-01

    Full Text Available Neste artigo apresentaremos a aplicação do Problema da Mochila Compartimentada (PMC no Problema de Corte de Bobinas de Aço (PCBA, que é um problema de corte em duas etapas com restrições especiais de agrupamento dos itens. O PMC consiste em construir compartimentos de capacidades desconhecidas em uma mochila de capacidade conhecida, tendo em vista que os itens de interesse estão agrupados em subconjuntos, de modo que, itens de um agrupamento não podem ser combinados com itens de outro. Para entender melhor o PMC admita que a mochila de um alpinista deve ser composta por um número ideal de compartimentos com itens de quatro categorias (remédios, alimentos, ferramentas, roupas, porém, itens de categorias distintas não podem ser combinados para formar um mesmo compartimento, além do mais, são desconhecidas as capacidades ideais de cada compartimento da mochila.In this paper we will present the application of the Compartmented Knapsack Problem (CKP in the Cut Problem of Steel Rolls (CPSR, that it is a problem of cut in two stages with restrictions special of grouping of items. The CKP consists of constructing compartments of unknown capacities in a knapsack of known capacity, in view of that items of interest is grouped in subgroups, in mode that, items of a grouping cannot be matched with items of another one. To understand the CKP more good it admits that the knapsack of a alpinist must be composite for an ideal number of compartments with items of four categories (remedies, foods, tools, clothes, however, items of distinct categories cannot be matched to form one same compartment, in addition, is unknown the ideal capacities of each compartment of the knapsack.

  7. Teoría redox mediante aprendizaje basado en problemas

    OpenAIRE

    Pérez Lemus, Nereida

    2016-01-01

    La ciencia (en nuestro caso, la Química) tiene una valoración positiva por parte de la sociedad pero los estudiantes muestran poco interés por las materias de carácter científico. Ante esta situación, la metodología tradicional (clase magistral) está siendo sustituida por otros métodos, entre ellos, el aprendizaje basado en problemas, para conseguir aumentar el interés y la motivación de los alumnos por estas materias. El objetivo consiste en que sean capaces de alcanzar las competencias clav...

  8. INAPLICABILIDAD Y VICIOS DE FORMA: ¿UN PROBLEMA RESUELTO?

    OpenAIRE

    Verdugo Ramírez, Sergio

    2010-01-01

    La discusión acerca de la idoneidad de la acción de inaplicabilidad para revisar los vicios de forma de las leyes generados en el proceso legislativo, que existía cuando esta acción era de competencia de la Corte Suprema, aún tiene asidero. El autor, luego de revisar la reacción de la doctrina a la reforma constitucional de 2005, de la cual se muestra crítico, detecta incoherencias en las sentencias del actual Tribunal Constitucional. Luego propone un marco para solucionar el problema, el que...

  9. Violencia sexual: la punta del iceberg de un problema invisible

    OpenAIRE

    López Rojas, Lara

    2017-01-01

    La violencia de género y la violencia sexual son problemas muy graves y generalizados en todo el mundo. Los tipos de violencia sexual, entre los que se encuentran la agresión sexual, la mutilación genital femenina y la trata de mujeres con fines de explotación sexual, afectan a una proporción considerable de la población, constituyen una violación de los derechos humanos, y deterioran profundamente el bienestar físico, sexual, reproductivo, psíquico y social de las mujeres y de sus familias. ...

  10. Clases de cachorros y problemas de comportamiento en perros

    OpenAIRE

    González Alonso, Almudena

    2017-01-01

    Traballo Fin de Grao en Veterinaria. Curso 2016-2017 [ES] Los perros que son debidamente socializados durante las primeras semanas de vida son menos propensos a la aparición de problemas de comportamiento, que pueden deteriorar el vínculo propietario-animal y provocar el abandono y eutanasia de las mascotas. La evidencia de los beneficios de las clases de cachorros no está tan clara, algunos estudios muestran que las clases impactan positivamente en el comportamiento de los adultos, reduci...

  11. La agricultura peruana: problemas, potencialidades y políticas

    OpenAIRE

    Adolfo Figueroa

    1986-01-01

    El presente trabajo tiene por objeto presentar, primero, los problemas estructurales de la agricultura peruana, luego sus potencialidades y, finalmente, los elementos para el diseño de políticas económicas. Debo admitir que este objetivo es muy ambicioso para ser desarrollado en un artículo y por un investigador individual. Por ello espero que el artículo logre, más bien, ordenar los elementos básicos para la discusión de la política económica dirigida al desarrollo agrícola del Perú....

  12. Donar: ¿Un problema bioético?

    OpenAIRE

    Ángel Alonso Salas

    2017-01-01

    El filósofo australiano, Peter Singer escribió un texto que se titula Salvar una vida. Cómo terminar con la pobreza que hace referencia a los motivos que se tienen para que las personas efectúen donaciones y el deber que el ser humano tiene para ayudar a los más necesitados. En este sentido, el presente texto tiene como finalidad, preguntarse acerca del problema bioético que supone el que un sujeto o una institución otorguen algún tipo de donación, bajo el supuesto de ¿cuáles son los motivos ...

  13. Trabajo infantil y problemas del comportamiento en menores trabajadores

    OpenAIRE

    Cardenas Ramirez, Luz Stella

    2016-01-01

    Objetivo: Identificar la relación de los factores de riesgo ocupacional del trabajo infantil con los problemas de comportamiento en menores de edad trabajadores de una plaza de mercado en Colombia Materiales y métodos: Se realizó un estudio de corte transversal con 100 niños trabajadores de la plaza de Mercaneiva. Se aplicó un cuestionario para evaluar los factores ocupacionales en la población, evaluando aspectos sociodemográficos y condiciones laborales; para establecer la prevalencia d...

  14. Phycobiliproteins: A Novel Green Tool from Marine Origin Blue-Green Algae and Red Algae.

    Science.gov (United States)

    Chandra, Rashmi; Parra, Roberto; Iqbal, Hafiz M N

    2017-01-01

    Marine species are comprising about a half of the whole global biodiversity; the sea offers an enormous resource for novel bioactive compounds. Several of the marine origin species show multifunctional bioactivities and characteristics that are useful for a discovery and/or reinvention of biologically active compounds. For millennia, marine species that includes cyanobacteria (blue-green algae) and red algae have been targeted to explore their enormous potential candidature status along with a wider spectrum of novel applications in bio- and non-bio sectors of the modern world. Among them, cyanobacteria are photosynthetic prokaryotes, phylogenetically a primitive group of Gramnegative prokaryotes, ranging from Arctic to Antarctic regions, capable of carrying out photosynthesis and nitrogen fixation. In the recent decade, a great deal of research attention has been paid on the pronouncement of bio-functional proteins along with novel peptides, vitamins, fine chemicals, renewable fuel and bioactive compounds, e.g., phycobiliproteins from marine species, cyanobacteria and red algae. Interestingly, they are extensively commercialized for natural colorants in food and cosmetics, antimicrobial, antioxidant, anti-inflammatory, neuroprotective, hepatoprotective agents and fluorescent neo-glycoproteins as probes for single particle fluorescence imaging fluorescent applications in clinical and immunological analysis. However, a comprehensive knowledge and technological base for augmenting their commercial utilities are lacking. Therefore, this paper will provide an overview of the phycobiliproteins-based research literature from marine cyanobacteria and red algae. This review is also focused towards analyzing global and commercial activities with application oriented-based research. Towards the end, the information is also given on the potential biotechnological and biomedical applications of phycobiliproteins. Copyright© Bentham Science Publishers; For any queries, please

  15. Antibiotic Algae by Chemical Surface Engineering.

    Science.gov (United States)

    Kerschgens, Isabel P; Gademann, Karl

    2018-03-02

    Chemical cell-surface engineering is a tool for modifying and altering cellular functions. Herein, we report the introduction of an antibiotic phenotype to the green alga Chlamydomonas reinhardtii by chemically modifying its cell surface. Flow cytometry and confocal microscopy studies demonstrated that a hybrid of the antibiotic vancomycin and a 4-hydroxyproline oligomer binds reversibly to the cell wall without affecting the viability or motility of the cells. The modified cells were used to inhibit bacterial growth of Gram-positive Bacillus subtilis cultures. Delivery of the antibiotic from the microalgae to the bacterial cells was verified by microscopy. Our studies provide compelling evidence that 1) chemical surface engineering constitutes a useful tool for the introduction of new, previously unknown functionality, and 2) living microalgae can serve as new platforms for drug delivery. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The economics of producing biodiesel from algae

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, Brian J. [Ecotonics Environmental Scientists, 1801 Century Park East, Suite 2400, Los Angeles, CA 90067 (United States)

    2011-01-15

    Biodiesel is an alternative fuel for conventional diesel that is made from natural plant oils, animal fats, and waste cooking oils. This paper discusses the economics of producing biodiesel fuel from algae grown in open ponds. There is potential for large-scale production of biodiesel from algal farms on non-arable land; however, previous studies have failed to demonstrate an economically viable process that could be scalable to a commercialized industry. The problems include inconsistent and insufficient algal productivities, uncertain capital and operating costs, volatile market prices and unknown levels of government support. Although intensive work is being done on many technological issues, the economic studies and data are incomplete and out of date. This paper presents an updated financial analysis of the production and economic conditions that could have a profound effect on the success of this important alternative fuel production process. (author)

  17. The economics of producing biodiesel from algae

    International Nuclear Information System (INIS)

    Gallagher, Brian J.

    2011-01-01

    Biodiesel is an alternative fuel for conventional diesel that is made from natural plant oils, animal fats, and waste cooking oils. This paper discusses the economics of producing biodiesel fuel from algae grown in open ponds. There is potential for large-scale production of biodiesel from algal farms on non-arable land; however, previous studies have failed to demonstrate an economically viable process that could be scalable to a commercialized industry. The problems include inconsistent and insufficient algal productivities, uncertain capital and operating costs, volatile market prices and unknown levels of government support. Although intensive work is being done on many technological issues, the economic studies and data are incomplete and out of date. This paper presents an updated financial analysis of the production and economic conditions that could have a profound effect on the success of this important alternative fuel production process. (author)

  18. El cooperativismo de ayuda mutua en el Uruguay: una alternativa popular y autogestionaria de solución al problema de la vivienda

    Directory of Open Access Journals (Sweden)

    Nahoum, Benjamín

    1984-07-01

    Full Text Available This work attempts to describe the characteristics of the system of building houses by Mutual Assistance Cooperatives, which was introduced in Uruguay in 1968. Its advantages are analyzed with respect to other systems in countries with a capitalist economy, dependent in economic and urban aspects on adapting to the needs of those it is designed for and, in particular, with reference to the profound social and community meaning contained in these experiments. This aspect, which reaffirms values of solidarity deeply-rooted in the sectors of society organized into Cooperatives, subsequently leads the groups to also face colectively other social problems they come up against, which arise from the conditions of under-development and dependence pertaining to Latin American countries: in short, the substantive feature of this type of experience, more than its unquestionable validity, is rather the idea of housing cooperativism as a solution to the habitation problem.El presente trabajo procura describir las características del sistema de construcción de viviendas por Cooperativas de Ayuda Mutua, implantado en el Uruguay, en 1968. Se analizan sus ventajas respecto de otros sistemas en países de economía capitalista dependiente en aspectos económicos, urbanísticos, en la adaptación a las necesidades de los destinatarios y, sobre todo, en lo referente al profundo sentido social y comunitario que estas experiencias contienen. Este aspecto, que reafirma valores solidarios arraigados en los sectores populares organizados en las Cooperativas, conduce posteriormente a los grupos a encarar, también colectivamente, otros problemas sociales que ellos enfrentan, emergentes de las condiciones de subdesarrollo y dependencia de los países latinoamericanos; éste es, en definitiva, más allá de la indiscutible validez, el cooperativismo de vivienda como solución a la problemática habitacional, el rasgo sustantivo de este tipo de experiencias.

  19. A screening method for cardiovascular active compounds in marine algae.

    Science.gov (United States)

    Agatonovic-Kustrin, S; Kustrin, E; Angove, M J; Morton, D W

    2018-05-18

    The interaction of bioactive compounds from ethanolic extracts of selected marine algae samples, separated on chromatographic plates, with nitric/nitrous acid was investigated. The nature of bioactive compounds in the marine algae extracts was characterised using UV absorption spectra before and after reaction with diluted nitric acid, and from the characteristic colour reaction after derivatization with anisaldehyde. It was found that diterpenes from Dictyota dichotoma, an edible brown algae, and sterols from green algae Caulerpa brachypus, bind nitric oxide and may act as a nitric oxide carrier. Although the carotenoid fucoxanthin, found in all brown marine algae also binds nitric oxide, the bonds between nitrogen and the fucoxanthin molecule are much stronger. Further studies are required to evaluate the effects of diterpenes from Dictyota dichotoma and sterols from green algae Caulerpa brachypus to see if they have beneficial cardiovascular effects. The method reported here should prove useful in screening large numbers of algae species for compounds with cardiovascular activity. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Isoprenoid biosynthesis in eukaryotic phototrophs: A spotlight on algae

    Energy Technology Data Exchange (ETDEWEB)

    Lohr M.; Schwender J.; Polle, J. E. W.

    2012-04-01

    Isoprenoids are one of the largest groups of natural compounds and have a variety of important functions in the primary metabolism of land plants and algae. In recent years, our understanding of the numerous facets of isoprenoid metabolism in land plants has been rapidly increasing, while knowledge on the metabolic network of isoprenoids in algae still lags behind. Here, current views on the biochemistry and genetics of the core isoprenoid metabolism in land plants and in the major algal phyla are compared and some of the most pressing open questions are highlighted. Based on the different evolutionary histories of the various groups of eukaryotic phototrophs, we discuss the distribution and regulation of the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathways in land plants and algae and the potential consequences of the loss of the MVA pathway in groups such as the green algae. For the prenyltransferases, serving as gatekeepers to the various branches of terpenoid biosynthesis in land plants and algae, we explore the minimal inventory necessary for the formation of primary isoprenoids and present a preliminary analysis of their occurrence and phylogeny in algae with primary and secondary plastids. The review concludes with some perspectives on genetic engineering of the isoprenoid metabolism in algae.

  1. Aprendizaje basado en problemas en ingeniería

    DEFF Research Database (Denmark)

    es una colección de artículos publicados, recogiendo las principales consideraciones para diseñar e implementar PBL. Los editores seleccionaron artículos originales en inglés para presentar una visión general de la teoría y la práctica del PBL. Se cubren tópicos como: Principios del trabajo en...... problemas y proyectos Modelos de PBL Trabajo en grupos y facilitación Desarrollo de competencias y habilidades Formulación de problemas en PBL Gestión de proyectos Implementación de cambio PBL en para aprendizaje en línea y tecnologías de la información El diseño de un modelo de PBL utiliza teorías de...... aprendizaje con diferentes necesidades sociales y culturales. Este libro será una lectura clave para los académicos e investigadores que diseñan, implementan y ponen en práctica el PBL en cualquier sistema educativo. Descargar libro electrónico aquí...

  2. La comunicación corno quehacer y como problema

    Directory of Open Access Journals (Sweden)

    Javier Luis Mier

    2015-01-01

    Full Text Available Este número aborda la comunicación desde las tres interpretaciones más importantes: la tradicionalista, la militar y mercantilista y el arte popular tan inestable, cuestionado y cambiante. Canclini cuestiona la compartamentalización de cultura: popular y de medios y esboza los problemas que plantea la tradicional miopía de no reconocer la universalización y ubicuidad de la cultura de masas. Se agregan otros temas como: ¿Re-intelección de los medios? apuntes sobre un libro de los Mattelart, ¿"Ética" o "Deontología"?, El lenguaje del vestido y de la fiesta,Talleres de cultura Popular en Santiago de Chile, El dilema del arte popular en Bolivia,¿Sobrevivirán las artesanías aborígenes argentinas?, Los tejedores de El Tintorero, Tecnologías de computación y Tercer Mundo, La cobertura del terremoto en México, La comunicación como quehacer y como problema, la comunicación planificada sirve al desarrollo

  3. Photophysiology and cellular composition of sea ice algae

    International Nuclear Information System (INIS)

    Lizotte, M.P.

    1989-01-01

    The productivity of sea ice algae depends on their physiological capabilities and the environmental conditions within various microhabitats. Pack ice is the dominant form of sea ice, but the photosynthetic activity of associated algae has rarely been studied. Biomass and photosynthetic rates of ice algae of the Weddell-Scotia Sea were investigated during autumn and winter, the period when ice cover grows from its minimum to maximum. Biomass-specific photosynthetic rates typically ranged from 0.3 to 3.0 μg C · μg chl -1 · h -1 higher than land-fast ice algae but similar to Antarctic phytoplankton. Primary production in the pack ice during winter may be minor compared to annual phytoplankton production, but could represent a vital seasonal contribution to the Antarctic ecosystem. Nutrient supply may limit the productivity of ice algae. In McMurdo Sound, congelation ice algae appeared to be more nutrient deficient than underlying platelet ice algae based on: lower nitrogen:carbon, chlorophyll:carbon, and protein:carbohydrate; and 14 C-photosynthate distribution to proteins and phospholipids was lower, while distribution to polysaccharides and neutral lipids was higher. Depletion of nitrate led to decreased nitrogen:carbon, chlorophyll:carbon, protein:carbohydrate, and 14 C-photosynthate to proteins. Studied were conducted during the spring bloom; therefore, nutrient limitation may only apply to dense ice algal communities. Growth limiting conditions may be alleviated when algae are released into seawater during the seasonal recession of the ice cover. To continue growth, algae must adapt to the variable light field encountered in a mixed water column. Photoadaptation was studied in surface ice communities and in bottom ice communities

  4. Psicologia do esporte: uma área emergente da psicologia Psicología del deporte: un area emergente de la psicología Sport psychology: an emergent field in psychology

    Directory of Open Access Journals (Sweden)

    Lenamar Fiorese Vieira

    2010-06-01

    Full Text Available O artigo trata da Psicologia do Esporte, um campo de atuação emergente do psicólogo no Brasil. Faz uma análise sobre o percurso histórico da Psicologia Esportiva apresentando os campos de atuação profissional (pesquisa, ensino e intervenção, o papel do psicólogo esportivo (pesquisador, professor e consultor e o estado científico atual dessa especialidade psicológica. Mesmo com o vasto campo de trabalho, um elemento interveniente é a diversidade de conhecimentos necessários para esta subdivisão da Psicologia, fazendo com que a formação profissional seja insuficiente e a atuação profissional dividida em duas especialidades, a Psicologia Clínica e a Psicologia Educacional aplicada ao esporte. Finalizando, destaca-se a emergência da compreensão destes aspectos, fornecendo subsídios para o entendimento da importância da qualificação de profissionais da área da Psicologia para o contexto do esporte e do exercício físico.El artículo presenta el área de la psicología del deporte como un campo de actuación emergente del psicólogo en Brasil. Hace un análisis del recorrido histórico de la Psicología Deportiva presentando las áreas de actuación profesional (pesquisa, enseñanza e intervención, el papel del psicólogo deportivo (investigador, profesor y consultor y el estado científico actual del área. Mismo con el vasto campo de trabajo, un elemento interventor es la diversidad de conocimientos necesarios para esta subdivisión de la psicología, haciendo con que la formación profesional sea insuficiente y la actuación profesional sea dividida en dos especialidades, la Psicología Clínica y la Psicología Educacional aplicada al deporte. Finalizando, se destaca la emergencia de la comprensión de estos aspectos, proporcionando subsidios para o entendimiento de la importancia de la calificación del profesional del área de la Psicología para el contexto del deporte y del ejercicio.This manuscript presents the

  5. Photobiological hydrogen production with switchable photosystem-II designer algae

    Science.gov (United States)

    Lee, James Weifu

    2014-02-18

    A process for enhanced photobiological H.sub.2 production using transgenic alga. The process includes inducing exogenous genes in a transgenic alga by manipulating selected environmental factors. In one embodiment inducing production of an exogenous gene uncouples H.sub.2 production from existing mechanisms that would downregulate H.sub.2 production in the absence of the exogenous gene. In other embodiments inducing an exogenous gene triggers a cascade of metabolic changes that increase H.sub.2 production. In some embodiments the transgenic alga are rendered non-regenerative by inducing exogenous transgenes for proton channel polypeptides that are targeted to specific algal membranes.

  6. Dinitrogen fixation by blue-green algae from paddy fields

    International Nuclear Information System (INIS)

    Thomas, Joseph

    1977-01-01

    Recent work using radioactive nitrogen on the blue-green algae of paddy fields has been reviewed. These algae fix dinitrogen and photoassimilate carbon evolving oxygen, thereby augmenting nitrogen and carbon status of the soil and also providing oxygen to the water-logged rice paddies. Further studies using radioactive isotopes 13 N, 24 Na and 22 Na on their nitrogen fixation, nitrogen assimilation pathways; regulation of nitrogenase, heterocysts production and sporulation and sodium transport and metabolism have been carried out and reported. The field application of blue green algae for N 2 fixation was found to increase the status of soil nitrogen and yield of paddy. (M.G.B.)

  7. Macro-economics of algae products : Output WP2A7.02

    NARCIS (Netherlands)

    Voort, van der M.P.J.; Vulsteke, E.; Visser, de C.L.M.

    2015-01-01

    This report is part of the EnAlgae Workpackage 2, Action 7, directed at the economics of algae production. The goal of this report is to highlight potential markets for algae. Per type of algae market the market size, product alternatives, constraints and prices are highlighted. Based on these

  8. Teoría emergente en la construcción del saber pedagógico

    Directory of Open Access Journals (Sweden)

    Víctor Díaz Quero

    2004-05-01

    Full Text Available Explicar la construcción y reconstrucción del saber pedagógico de los docentes, desde las perspectivas de su formación y experiencia constituyó el propósito de este trabajo. La naturaleza de la investigación refiere la subjetividad como fuente de conocimiento y componente dimensional de lo humano. El método tilizado fue la etnometodología para evidenciar la acción del hombre y de los significados que da a su propia actividad. Se seleccionaron (6 seis docentes de manera intencional, quienes participaron como sujetos que construyen y reconstruyen sus prácticas como instancia de la construcción de su saber. Los datos fueron obtenidos a través de la entrevista semiestructurada, con base en tres criterios: (a grado de apertura. (b grado de socialización y (c área de interés. El análisis de esta información, permitió su organización en una red conceptual constituida por unidades de información, categorías, tipologías y conceptos integradores que logran configurar la teoría emergente a partir de la reflexión del docente, sobre y desde sus prácticas. Los resultados obtenidos revelan como uno de los principales hallazgos, la existencia en los docentes de un pensamiento disociado entre teoría y práctica y una teoría que define epistemológicamente al saber pedagógico como un proceso complejo y permanente.

  9. Helicobacter pylori y dispepsia, un problema de salud comunitario

    Directory of Open Access Journals (Sweden)

    Miguel González-Carbajal Pascual

    2002-06-01

    Full Text Available Mientras la relación causal entre el Helicobacter pylori y la gastritis crónica, así como la importante conexión entre esta infección, la úlcera gastroduodenal y el cáncer gástrico han sido bien establecidas, la asociación entre la infección por Helicobacter pylori y la dispepsia "no ulcerosa" es un problema que dista mucho de estar esclarecido. Hay autores que no dudan en utilizar tratamiento de erradicación en la dispepsia "no ulcerosa" con Helicobacter pylori, pero existen enfoques alternativos a este problema. La realización de tratamiento de erradicación en los pacientes con dispepsia "no ulcerosa" pudiera beneficiar o no a los enfermos y a la comunidad, pero seguramente no puede dejar de beneficiar a las transnacionales productoras de medicamentos que cosechan cuantiosas ganancias con la comercialización de los bloqueadores de la bomba de protones y los antibióticos que se incluyen en cualquier esquema de terapia erradicadora de la infección por Helicobacter pylori. El alivio de los síntomas dispépticos como consecuencia del tratamiento de erradicación del Helicobacter pylori no ha sido comprobado. El problema de realizar tratamiento de erradicación de la infección a los pacientes con dispepsia "no ulcerosa" continúa siendo un dilema y, por tanto, no debe indicarse sistemáticamente.Although the causative relationship between Helicobacter pylori and chronic gastritis as well as the important connection of this infection with gastric-duodenal ulcer and gastric cancer are well established, the association of Helicobacter pylori infection and non-ulcer dispepsia is a problem that is still unclear. Some authors do not hesitate in using Helicobacter pylori eradication treatment in cases of non-ulcer dispepsia but there are other alternative approaches to this problem. The eradication treatment in patients with non-ulcer dispepsia may or may not benefit patients and the community, but will benefit for sure the big drug

  10. Scenario analysis of large scale algae production in tubular photobioreactors

    NARCIS (Netherlands)

    Slegers, P.M.; Beveren, van P.J.M.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2013-01-01

    Microalgae productivity in tubular photobioreactors depends on algae species, location, tube diameter, biomass concentration, distance between tubes and for vertically stacked systems, the number of horizontal tubes per stack. A simulation model for horizontal and vertically stacked horizontal

  11. Kalaärimeeste kohus algas venitamisega / Hindrek Riikoja

    Index Scriptorium Estoniae

    Riikoja, Hindrek

    2007-01-01

    Harju maakohtus algas kohtuprotsess veterinaar- ja toiduameti endise asejuhi Vladimir Razumovski väidetava altkäemaksuvõtmise üle, kus on süüdistavaid eraisikuid ja ettevõtjaid. Lisa: Kes on kohtu all?

  12. The role of algae in agriculture: a mathematical study.

    Science.gov (United States)

    Tiwari, P K; Misra, A K; Venturino, Ezio

    2017-06-01

    Synthetic fertilizers and livestock manure are nowadays widely used in agriculture to improve crop yield but nitrogen and phosphorous runoff resulting from their use compromises water quality and contributes to eutrophication phenomena in waterbeds within the countryside and ultimately in the ocean. Alternatively, algae could play an important role in agriculture where they can be used as biofertilizers and soil stabilizers. To examine the possible reuse of the detritus generated by dead algae as fertilizer for crops, we develop three mathematical models building upon each other. A system is proposed in which algae recover waste nutrients (nitrogen and phosphorus) for reuse in agricultural production. The results of our study show that in so doing, the crop yield may be increased and simultaneously the density of algae in the lake may be reduced. This could be a way to mitigate and possibly solve the environmental and economic issues nowadays facing agriculture.

  13. Modelization of tritium transfer into the organic compartments of algae

    International Nuclear Information System (INIS)

    Bonotto, S.; Gerber, G.B.; Arapis, G.; Kirchmann, R.

    1982-01-01

    Uptake of tritium oxide and its conversion into organic tritium was studied in four different types of algae with widely varying size and growth characteristics (Acetabularia acetabulum, Boergesenia forbesii, two strains of Chlamydomonas and Dunaliella bioculata). Water in the cell and the vacuales equilibrates rapidly with external tritium water. Tritium is actively incorporated into organically bound form as the organisms grow. During the stationary phase, incorporation of tritium is slow. There exists a discrimination against the incorporation of tritium into organically bound form. A model has been elaborated taking in account these different factors. It appears that transfer of organic tritium by algae growing near the sites of release would be significant only for actively growing algae. Algae growing slowly may, however, be useful as cumulative indicators of discontinuous tritium release. (author)

  14. Studies on allergenic algae of Delhi area: botanical aspects.

    Science.gov (United States)

    Mittal, A; Agarwal, M K; Shivpuri, D N

    1979-04-01

    To study distribution of algae in and around Delhi aerobiological surveys were undertaken for two consecutive years (September, 1972, to August, 1974). The surveys were accomplished by (a) slide exposure method and (b) culture plate exposure method. A total of 850 slides were exposed using Durham's gravity sampling device. Of these, 560 slides were exposed during 1973 (272 slides at two meter and 288 at ten meter height) and the rest (290 slides) were exposed during 1974 at ten meter height. A total of 858 culture plates were exposed (276 for one hour and 282 for two hours) during 1973 and the rest (300 culture plates) were exposed during 1974 at ten meter height for two hours duration only. Air was found to be rich in algae flora during the months of September to November. The dominant forms of algae present were all blue greens. This might be due to the relative greater resistance of blue green algae to unfavorable conditions.

  15. Extreme Low Light Requirement for Algae Growth Underneath Sea Ice

    DEFF Research Database (Denmark)

    Hancke, Kasper; Lund-Hansen, Lars C.; Lamare, Maxim L.

    2018-01-01

    Microalgae colonizing the underside of sea ice in spring are a key component of the Arctic foodweb as they drive early primary production and transport of carbon from the atmosphere to the ocean interior. Onset of the spring bloom of ice algae is typically limited by the availability of light......, and the current consensus is that a few tens-of-centimeters of snow is enough to prevent sufficient solar radiation to reach underneath the sea ice. We challenge this consensus, and investigated the onset and the light requirement of an ice algae spring bloom, and the importance of snow optical properties...... for light penetration. Colonization by ice algae began in May under >1 m of first-year sea ice with approximate to 1 m thick snow cover on top, in NE Greenland. The initial growth of ice algae began at extremely low irradiance (...

  16. Composition, Occurrences and Checklist of Periphyton Algae of ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    The periphyton is also an important indicator of water quality (Azim et al, 2006). Attached algae are primitive plants that get their nutrients from water passing over them. ... rung in the aquatic food chain depend directly ... influence of sea water.

  17. Planktonic algae and cyanoprokaryotes as indicators of ecosystem ...

    African Journals Online (AJOL)

    Planktonic algae and cyanoprokaryotes as indicators of ecosystem quality in the Mooi River system in the North-West Province, South Africa. ... is important for maintaining the quality of potable water of Potchefstroom and surrounding areas.

  18. Chemical examination of the brown alga Stoechospermum marginatum (C. Agardh)

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; DeSouza, L.; Kamat, S.Y.

    The crude methalonic extract of marine algae Stoechospermum marginatum from west coast of India was found to have spasmolytic activity. Search for the pharmacologically active compounds led to the isolation of steroids, fatty acids and an ester...

  19. The Belmont Valley integrated algae pond system in retrospect

    African Journals Online (AJOL)

    2013-03-26

    Mar 26, 2013 ... ness amongst all stakeholders including the public at large, the three spheres of ...... (2011) Algae biofuel from wastewater treatment high rate algal ponds. .... and OELMÜLLER R (2002) Photosynthetic electron transport.

  20. Causalidade entre os retornos de mercados de capitais emergentes e desenvolvidos Causality between stock return rates: emerging versus developed capital markets

    Directory of Open Access Journals (Sweden)

    Wagner Moura Lamounier

    2007-04-01

    Full Text Available Utilizando-se de instrumentais estatísticos para a análise de séries temporais, procurou-se verificar as relações entre os retornos dos principais mercados de capitais emergentes e dos principais mercados desenvolvidos. A amostra foi divida em dois períodos: entre 1995-2002 e entre 2003-2005, tendo em vista os momentos distintos dos mercados quanto à vulnerabilidade externa. No primeiro momento, apesar das diversas crises econômicas, verificou-se que apenas o retorno do mercado emergente da Rússia sofreu grandes impactos ante os choques dos retornos dos outros mercados. Entre 2003-2005, no entanto, os retornos de outros mercados emergentes, como o do Brasil e o do México, responderam de forma significativa aos choques nos retornos dos demais mercados analisados.Using statistical instruments for the analysis of time series, - this work aims to verify the relation of returns of stock investments between the main emerging and the developed capital markets. The sample was divided in two periods: 1995-2002 and 2003-2005, in view of their different external vulnerability moments. At the beginning, - in spite of - several economic crises, only Russia’s stock market returns - suffered great impacts, compared with those at other markets’. Between 2003-2005, however, the returns of other emerging markets, as Brazil’s and Mexico’s, answered in a more significant form to the shocks in the returns of other markets.

  1. Principales problemas de traducción en el doblaje italiano-español

    OpenAIRE

    Ortega Paredes, Laura

    2015-01-01

    La traducción para doblaje resulta especialmente complicada debido a las restricciones causadas por la cohesión entre el texto y la imagen. En el presente trabajo trataremos ciertos problemas generales de traducción cuya dificultad se ve acentuada en el caso del doblaje y también otros problemas propios de este tipo de traducción. Trabajaremos con la combinación italiano-español, por lo que algunos de los problemas a tratar serán problemas específicos de esta lengua La traducció pel doblat...

  2. Diterpenes from the Marine Algae of the Genus Dictyota.

    Science.gov (United States)

    Chen, Jiayun; Li, Hong; Zhao, Zishuo; Xia, Xue; Li, Bo; Zhang, Jinrong; Yan, Xiaojun

    2018-05-11

    Species of the brown algae of the genus Dictyota are rich sources of bioactive secondary metabolites with diverse structural features. Excellent progress has been made in the discovery of diterpenes possessing broad chemical defensive activities from this genus. Most of these diterpenes exhibit significant biological activities, such as antiviral, cytotoxic and chemical defensive activities. In the present review, we summarized diterpenes isolated from the brown algae of the genus.

  3. Algae Reefs in Shark Bay, Western Australia, Australia

    Science.gov (United States)

    1990-01-01

    Numerous algae reefs are seen in Shark Bay, Western Australia, Australia (26.0S, 113.5E) especially in the southern portions of the bay. The south end is more saline because tidal flow in and out of the bay is restricted by sediment deposited at the north and central end of the bay opposite the mouth of the Wooramel River. This extremely arid region produces little sediment runoff so that the waters are very clear, saline and rich in algae.

  4. Thermal algae in certain radioactive springs in Japan, (3)

    International Nuclear Information System (INIS)

    Mifune, Masaaki; Hirose, Hiroyuki.

    1982-01-01

    Shikano Hot Springs are located at five km to the south of Hamamura Station on the Sanin Line in Tottori Prefecture. The water temperature and the pH of the springs are 40.2 - 61.2 0 C, and 7.5 - 7.8, respectively. They belong to simple thermals. Hamamura Hot Springs are located in the neighbourhood of Hamamura Station. The highest radon content of the hot springs is 175.1 x 10 -10 Ci/l, and the great part of the springs belong to radioactive ones. From the viewpoint of the major ionic constituents, they are also classified under weak salt springs, sulfated salt springs, and simple thermals. Regarding the habitates of the algal flora, the water temperature and the pH of the springs are 28.0 - 68.0 0 C, and 6.8 - 7.4, respectively. The thermal algae found by Ikoma and Doi at Hamamura Hot Springs were two species of Cyanophyceae. By the authors, nine species and one variety of Cyanophyceae including Ikoma and Doi's two species were newly found at Shikano and Hamamura Hot Springs. Chlorophyceous alga was not found. The dominant thermal algae of these hot springs were Mastigocladus laminosus, and the other algae which mainly consist of Oscillatoriaceous algae. From these points, it seems that the thermal algae of Shikano and Hamamura Hot Springs belong to the normal type of thermal algae, and they are different from the thermal algae of Ikeda Mineral Springs and Masutomi Hot Springs which belong to strongly radioactive springs. (author)

  5. Using the marine unicellular algae in biological monitoring

    OpenAIRE

    Kapkov V. I.; Shoshina E. V.; Belenikina O. A.

    2017-01-01

    The possibility of using marine unicellular algae from natural plankton community in biomonitoring of pollution by heavy metals has been investigated. Algae of different taxa from the Mediterranean Sea have been allocated to culture. In the laboratory the culture conditions – i. e. growth medium, temperature, photoperiod, level of artificial light and initial density – have been selected for every species. The impact of heavy metals (Hg, Cd, Cu, Pb) in the form of chloride salts on the growth...

  6. Problemas éticos al final de la vida

    Directory of Open Access Journals (Sweden)

    Maria Graciela De Ortuzar

    2014-06-01

    Full Text Available El presente informe trata sobre el análisis filosófico de un tema complejo y controvertido, como lo es la ?definición de muerte?. Por ello, es importante subrayar que no desarrollaré aquí los aspectos antropológicos, sicológicos, médicos y técnicos de la muerte. Sólo me centraré en las teorías filosóficas principales que justifican diferentes definiciones de muerte (esencialista vs. biológica y sus consecuentes problemas prácticos. La necesidad de realizar esta investigación surge a partir del reconocimiento de confusiones conceptuales y contradicciones cuando se comunica ?la muerte? (falta de concordancia entre la definición filosófica, criterios y tests; contradicciones reflejadas cotidianamente en el lenguaje y en las actitudes del personal médico y de enfermería de nuestras Unidades de Terapia Intensiva (UTIs. Hablar de paciente al referirse a un cadáver al que se le ha diagnosticado la muerte encefálica; hablar de muerte cuando se produce el paro cardiorespitariaco (¿dos muertes?; hablar de eutanasia cuando se retira el respirador al individuo muerto cuyos órganos están siendo mantenidos artificialmente; éstas situaciones -entre otras- reflejan conflictos y falta de claridad conceptual sobre los conceptos básicos de muerte y eutanasia. Dichos conflictos constituyen problemas éticos claves al final de la vida, los cuáles nacen a partir del reciente cambio en el criterio de muerte en un contexto de acelerada ?tecnologización? de la salud. He aquí la necesidad del análisis crítico sobre el marco teórico-conceptual requerido en UTIs y su confrontación aplicada, con el fin de esclarecer los citados problemas. Para ello, estudiaré la teoría moral unificada de Bernard Gert, examinando su justificación teórica y su aplicabilidad práctica, como así también las posiciones alternativas a la misma (Wikler. En términos generales, considero que la defensa de la coherencia, sistematicidad y aplicabilidad de las

  7. La violencia familiar, ¿un problema de salud?

    Directory of Open Access Journals (Sweden)

    Mario C. Muñiz Ferrer

    Full Text Available Con el objetivo de profundizar en el estudio de la violencia intrafamiliar y para su mejor conocimiento y enfrentamiento en el área de salud, se realiza un estudio descriptivo de los resultados obtenidos al aplicar el test proyectivo "Lo que no me gusta en mi familia" y una entrevista a 147 niños de 5to. y 6to. grados de la Escuela "Roberto Poland" del Reparto "Antonio Maceo", del municipio Cerro; donde se clasifican las variedades de violencia intrafamiliar y se agrupan éstas por orden de frecuencia. También se calcula la prevalencia de violencia intrafamiliar y se explora la posible relación de la violencia con la ingestión de bebidas alcohólicas. Los resultados obtenidos permiten plantear que la violencia intrafamiliar constituye un problema de salud y que existe relación entre ésta y el consumo de alcohol

  8. DESARROLLO PROFESIONAL Y PROFESIONALIZACIÓN DOCENTE. PERSPECTIVAS Y PROBLEMAS

    Directory of Open Access Journals (Sweden)

    Raúl Eirín Nemiña

    2009-01-01

    Full Text Available Con este trabajo pretendemos compartir algunas reflexiones sobre las relaciones entre la formación de profesores, su desarrollo profesional y la profesionalización docente. Forman parte de una investigación más amplia (Eirín, 2005 en la que hemos indagado sobre el recorrido profesional de un grupo de maestros especialistas en Educación Física. Este escenario nos ha ayudado a situar teóricamente los problemas y expectativas que caracterizan las vidas profesionales de profesores y profesoras, a través del diálogo con los significados atribuidos por aquellos autores con los que hemos ido construyendo este trabajo. Esperamos que este esfuerzo pueda ser de utilidad para aquellos que, como nosotros, están embarcados en la travesía por el desarrollo profesional de los docentes.

  9. A verdade como um problema epistemológico

    Directory of Open Access Journals (Sweden)

    Geilson Fernandes de Oliveira

    2016-07-01

    Full Text Available O presente ensaio é fruto das discussões realizadas durante a disciplina de mestrado Epistemologia das Ciências Sociais e Humanas. Aqui, objetivamos discutir sobre a verdade como um problema epistemológico. Assim, a partir do conceitual teórico utilizado durante a disciplina, entre os quais destacamos Michel Foucault, Norbert Elias, Friedrich Nietzsche e Pierre Bourdieu, tecemos considerações sobre as concepções de verdade no pensamento social contemporâneo, bem como no que diz respeito as rupturas que favoreceram a emergência de seu estado corrente – concepção da verdade como produção social e histórica. Consonante a esta discussão, realizamos ainda uma breve discussão sobre as relações de poder e saber que favorecem a constituição da verdade.

  10. CIESPAL: progreso y problema del comunicólogo

    Directory of Open Access Journals (Sweden)

    Eduardo Meditsch

    2015-01-01

    Full Text Available La creación del CIESPAL dio impulso y consolidación al área de la comunicación en las Universidades de América Latina, pero generó un problema la concepción del comunicador social. Este profesional polivalente fue luego rechazado por el mercado y la sociedad mas, su fantasma continúa orientando los proyectos pedagógicos y de investigación científica. Perpetuado en una universidad que vive de espaldas a la realidad, elevado de comunicador a comunicólogo, es el gran responsable por la falta de vínculo entre la teoría y la práctica, con graves perjuicios para la formación del profesional.

  11. Problemas de Clasificación en las Plantas Cultivadas

    Directory of Open Access Journals (Sweden)

    Aaberg Ewert

    1949-06-01

    Full Text Available Durante los últimos años, se han recolectado numerosos tipos de plantas cultivadas en varias regiones del mundo. Entre éstos, hay colecciones de granos pequeños, de lino, de fríjoles y guisantes y de otras muchas plantas. En muchos países, las especies y variedades principales de estas colecciones se cultivan para investigaciones en grandes viveros. Los investigadores que se encargan de cultivar estas colecciones confrontan problemas de clasificación y descripción de las colecciones. Han encontrado una continua variación, tanto dentro como entre las especies y, por consecuencia, han hallado inadecuados muchos de 105 sistemas de clasificación. La continua variación en el material ha causado una nueva ola de discusión relativa al concepto de especie y a su definición.

  12. La innovación en Uruguay. Problemas, instituciones, perspectivas

    Directory of Open Access Journals (Sweden)

    Judith Sutz

    1995-12-01

    Full Text Available En este trabajo se aborda la innovación en Uruguay desde dos puntos de vista: por una parte, se plantea la innovación como problema; por otra, se analiza el tejido institucional en el cual se desarrollan los procesos innovativos. La necesidad de esfuerzos en el marco del desarrollo científico-tecnológico mundial, la especificidad de un país pequeño, la inadecuación de las formas canónicas de la evaluación académica, el desconocimiento de los actores productivos acerca de la oferta local de soluciones, y la innovación como cuestión de Estado, constituyen el primer abordaje. El segundo presenta un mapa sintético de las diversas instituciones -incluyendo empresas- involucradas en procesos de innovación, señalando sus logros y limitaciones.

  13. Costo de servir como variable de decisión estratégica en el diseño de estrategias de atención a canales de mercados emergentes

    Directory of Open Access Journals (Sweden)

    Christopher Mejía Argueta

    2015-01-01

    Full Text Available Este artículo tiene como objetivo documentar diferentes enfoques tradicionales sobre el análisis de costos para mercados emergentes a fin de hallar brechas y áreas de oportunidad relacionadas con la temática del costo de servir. El artículo encuentra que no existe una metodología adaptada para mercados emergentes que permita analizar detalladamente la rentabilidad en canales, clientes y productos para crear estrategias de atención acordes con las necesidades que estos grupos expresan. Al final de la revisión y contraste de metodologías, se explica una tabla con los procedimientos analizados y las áreas de oportunidad más importantes que servirán de base para la creación de una metodología de costo de servir para mercados emergentes.

  14. Incursión de tecnologías emergentes en una escuela pública de negocios de México

    OpenAIRE

    María Magdalena Madrigal Lozano; Laura Alicia Hernández Moreno; Juan Gabriel López Solórzano; Alma Elizabeth Merla González

    2017-01-01

    En el presente artículo se describen los resultados obtenidos de un estudio exploratorio, descriptivo de alcance transeccional realizado para conocer la realidad del uso, producción e investigación de las tecnologías emergentes MOOC, Gamificación y Realidad Aumentada en los procesos educativos de los programas relacionados con la profesión de negocios. En particular se aplicó un instrumento de medición a los docentes de los programas académicos de la modalidad mixta en la escuela de negocios ...

  15. O Discurso do Sujeito Coletivo Emergente de Médicos em Relação a Cuidados Paliativos/ The Collective Subject Discourse Emerging Physicians Regarding palliative Care

    OpenAIRE

    Katrine de Freitas Valeriano; Thais de Paiva Guimarães Barreiro; José Vitor da Silva; Jorge Leonardo Narcy; Maria Tereza de Jesus Pereira

    2013-01-01

    Objetivos: conhecer os significados e os sentimentos emergentes dos médicos em relação aos cuidados paliativos, bem como identificar a atuação desses profissionais frente aos pacientes com necessidades de cuidados paliativos numa instituição hospitalar da cidade de Pouso Alegre-MG. Materiais e métodos: o presente trabalho foi de abordagem qualitativa, do tipo exploratório e transversal. A amostra foi de 25 médicos atuantes no Hospital Universitário Samuel Libânio, Pouso Alegre, MG. A amostra...

  16. Estrategias funcionales emergentes de promoción por parte de los ejecutivos del negocio bancario: Estudio preliminar a la Banca en Maracaibo

    OpenAIRE

    Emmanuel Borgucci; Roberto Cubillán

    2003-01-01

    En esta investigación de carácter preliminar, se trata de demostrar la existencia de estrategias funcionales emergentes por parte de los ejecutivos de negocios bancarios. Se diseñó una investigación de tipo descriptivo y se aplicó un cuestionario semiestructurado y validado con el procedimiento del pretest-test a 16 ejecutivos del área petrolera pertenecientes a 10 bancos ubicados en Maracaibo (Venezuela). Se concluye que sobre la base de una serie de habilidades personales y oper...

  17. Estudio comparativo entre aislados clínicos y no clínicos de S. cerevisiae y su papel como patógeno emergente.

    OpenAIRE

    Llanos Frutos, Rosa de

    2007-01-01

    RESUMEN La levadura Saccharomyces cerevisiae es la especie más utilizada desde un punto de vista biotecnológico. En la industria agroalimentaria interviene en la elaboración de pan y bebidas alcohólicas como el vino y la cerveza, además se emplea como suplemento dietético y como agente probiótico bajo el nombre de S. cerevisiae var. boulardii. A pesar de sus propiedades beneficiosas, S. cerevisiae se considera actualmente una levadura patógena oportunista emergente de baja virulencia, capa...

  18. Turismo literario como tipología emergente del turismo cultural : Caso: la ciudad de La Plata y una novela de Bioy Casares

    OpenAIRE

    Corrado, Melina Denise

    2015-01-01

    El presente trabajo pretende aportar a la conceptualización teórica del turismo literario como tipología emergente del turismo cultural. A tales fines, se presenta la revisión bibliográfica pertinente sobre el tema, a partir de la cual se sustentan los nuevos aportes. Además, se enumeran en una breve descripción algunas experiencias de turismo literario en el mundo. Seguidamente, se explicita la caracterización del perfil del turista literario – real y potencial - que se suscita sobre las ...

  19. Ocorrência de compostos de interesse emergente no aquífero Dunas-Barreiras e nos esgotos de Natal/RN

    OpenAIRE

    Silva, Francisco Francimar da Fonseca

    2015-01-01

    A detecção de microcontaminantes de interesse emergente em amostras ambientais de águas superficiais, águas subterrâneas, água potável, águas residuárias e efluentes de estações de tratamento de água e esgoto (ETAs e ETEs), em vários países, indica que esses poluentes encontram-se disseminados pelo meio ambiente, principalmente em regiões urbanizadas. Isto é motivo de grande preocupação, pois muitos desses compostos são potencialmente prejudiciais aos seres humanos e a outro...

  20. Determinação de contaminantes emergentes em mananciais de água bruta e na água para consumo humano do Distrito Federal

    OpenAIRE

    Santana, Joyce da Silva

    2013-01-01

    Contaminantes emergentes referem-se às substâncias químicas cujo interesse por estudos associados à ocorrência e efeitos no ambiente é recente. Ainda há uma escassez de dados relacionados à ocorrência destes contaminantes no Brasil, o que motivou a realização do presente trabalho. Foram selecionadas amostras de águas superficiais do Lago Paranoá e de dois mananciais de água do Distrito Federal (DF): Rio Descoberto e Córrego Cabeça de Veado. Também foram analisadas ...

  1. Regime cambial para países emergentes: uma proposição a partir de Keynes Exchange rate regime for emergent countries: a Keynesian proposal

    Directory of Open Access Journals (Sweden)

    Fernando Ferrari Filho

    2008-04-01

    Full Text Available O objetivo do presente artigo consiste em apresentar, tendo como referência a análise de Keynes, uma proposição de regime cambial para países emergentes que seja capaz de assegurar condições para a estabilização macroeconômica, entendida como o binômio estabilidade de preços e pleno-emprego.The article presents, in a Keynesian perspective, a proposal of exchange rate regime for emerging countries to assure macroeconomic stabilization, that is, price stability and full employment.

  2. Avaliação e tratamento dos contaminantes emergentes ( Ácido Acetilsalicílico, Diclofenaco e Paracetamol ) utilizando processos oxidativos avançados

    OpenAIRE

    NAPOLEÃO, Daniella Carla

    2011-01-01

    O interesse da comunidade científica no estudo de micropoluentes é muito recente e tem aumentado a cada dia, uma vez que estas substâncias vêm causando alterações importantes no meio ambiente, interferindo no sistema endócrino de animais e de seres humanos. Logo, foi necessário classificar essas substâncias que receberam o nome de contaminantes emergentes, dentre os quais estão os fármacos de diferentes classes como: analgésicos, antiinflamatórios, drogas psiquiátricas, antilip...

  3. Micro-algae: French players discuss the matter

    International Nuclear Information System (INIS)

    Bouveret, T.

    2013-01-01

    About 75000 species of algae have been reported so far, the domains of application are huge and investment are increasing all around the world. One of the difficulties is to find the most appropriate algae to a specific application. Some development programs have failed scientifically or economically for instance the production of protein for animal food from the chlorella algae or the production of bio-fuel from C14-C18 chains, from zeaxanthine and from phycoerytrine. On the other side some research programs have led to promising industrial applications such as the production of food for fish and farm animals. Some research fields are completely innovative such as the use of micro-algae for the construction of bio-walls for buildings. Micro-algae are diverse and fragile. Photo-bioreactors have been designed to breed fragile algae like some types of chlorophycees used in bio-fuel and in cosmetics, a prototype has been tested for 15 months and its production is about 2 kg of dry matter a day. (A.C.)

  4. Radionuclides and trace metals in eastern Mediterranean Sea algae

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Mamish, S.; Budier, Y.

    2003-01-01

    Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that 137 Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg -1 dry weight) while the levels of naturally occurring radionuclides, such as 210 Po and 210 Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg -1 dry weight) for 210 Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate 210 Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br

  5. Combining of radionuclides with constituent materials of marine algae

    International Nuclear Information System (INIS)

    Nakamura, Ryoichi; Nakahara, Motokazu; Ishii, Toshiaki; Ueda, Taishi; Shimizu, Chiaki.

    1979-01-01

    The relations between the accumulation-elimination of radionuclides and the constituent materials of marine algae were studied to determine more precisely the mechanism of the radioactive contamination of marine organisms. This will increase the information about the behavior of radionuclides in marine organisms in relation to the environmental conditions (temperature, physico-chemical state of radioisotope, and so on) and the biological conditions (feeding habits, species, and so on). Eisenia contaminated by 137 Cs and 106 Ru- 106 Rh was fractionated by solvent extraction into 6 fractions. The largest portion of 137 Cs was in the boiling water fraction; 106 Ru- 106 Rh was most extracted by 24% KOH solution. Elution patterns by Sephadex G-100 gel-filtration of samples differed largely from each other, both among the 3 kinds of radionuclides and between the 2 species of the algae. Therefore, the accumulation of the radionuclides by the marine algae was proved to be not only due to a physical absorption to the surface of the algae but also to the biological combining of the radionuclides with the constituents of the algae. Furthermore, it was found that radionuclides which combine with a few constituents of alga are not eliminated equally. This is considered to be useful for the physiological analysis of elimination curves. (author)

  6. Algae as a Biofuel: Renewable Source for Liquid Fuel

    Directory of Open Access Journals (Sweden)

    Vijay Kant Pandey

    2016-09-01

    Full Text Available Biofuels produced by algae may provide a feasible alternative to fossil fuels like petroleum sourced fuels. However, looking to limited fossil fuel associated with problems, intensive efforts have been given to search for alternative biofuels like biodiesel. Algae are ubiquitous on earth, have potential to produce biofuel. However, technology of biofuel from algae facing a number of hurdles before it can compete in the fuel market and be broadly organized. Different challenges include strain identification and improvement of algal biomass, both in terms of biofuel productivity and the production of other products to improve the economics of the entire system. Algal biofuels could be made more cost effective by extracting other valuable products from algae and algal strains. Algal oil can be prepared by culture of algae on municipal and industrial wastewaters. Photobioreactors methods provide a controlled environment that can be tailored to the specific demands of high production of algae to attain a consistently good yield of biofuel. The algal biomass has been reported to yield high oil contents and have good amount of the biodiesel production capacity. In this article, it has been attempted to review to elucidate the approaches for making algal biodiesel economically competitive with respect to petrodiesel. Consequently, R & D work has been carried out for the growth, harvesting, oil extraction and conversion to biodiesel from algal sources.

  7. Biodiesel Production From Algae to Overcome the Energy Crisis

    Directory of Open Access Journals (Sweden)

    Suliman Khan

    2017-10-01

    Full Text Available The use of energy sources has reached at the level that whole world is relying on it. Being the major source of energy, fuels are considered the most important. The fear of diminishing the available sources thirst towards biofuel production has increased during last decades. Considering the food problems, algae gain the most attention to be used as biofuel producers. The use of crop and food-producing plants will never be a best fit into the priorities for biofuel production as they will disturb the food needs. Different types of algae having the different production abilities. Normally algae have 20%–80% oil contents that could be converted into different types of fuels such as kerosene oil and biodiesel. The diesel production from algae is economical and easy. Different species such as tribonema, ulothrix and euglena have good potential for biodiesel production. Gene technology can be used to enhance the production of oil and biodiesel contents and stability of algae. By increasing the genetic expressions, we can find the ways to achieve the required biofuel amounts easily and continuously to overcome the fuels deficiency. The present review article focusses on the role of algae as a possible substitute for fossil fuel as an ideal biofuel reactant.

  8. Development of Green Fuels From Algae - The University of Tulsa

    Energy Technology Data Exchange (ETDEWEB)

    Crunkleton, Daniel; Price, Geoffrey; Johannes, Tyler; Cremaschi, Selen

    2012-12-03

    The general public has become increasingly aware of the pitfalls encountered with the continued reliance on fossil fuels in the industrialized world. In response, the scientific community is in the process of developing non-fossil fuel technologies that can supply adequate energy while also being environmentally friendly. In this project, we concentrate on green fuels which we define as those capable of being produced from renewable and sustainable resources in a way that is compatible with the current transportation fuel infrastructure. One route to green fuels that has received relatively little attention begins with algae as a feedstock. Algae are a diverse group of aquatic, photosynthetic organisms, generally categorized as either macroalgae (i.e. seaweed) or microalgae. Microalgae constitute a spectacularly diverse group of prokaryotic and eukaryotic unicellular organisms and account for approximately 50% of global organic carbon fixation. The PI's have subdivided the proposed research program into three main research areas, all of which are essential to the development of commercially viable algae fuels compatible with current energy infrastructure. In the fuel development focus, catalytic cracking reactions of algae oils is optimized. In the species development project, genetic engineering is used to create microalgae strains that are capable of high-level hydrocarbon production. For the modeling effort, the construction of multi-scaled models of algae production was prioritized, including integrating small-scale hydrodynamic models of algae production and reactor design and large-scale design optimization models.

  9. Is the Future Really in Algae?

    Science.gov (United States)

    Trent, Jonathan

    2011-01-01

    Having just emerged from the warmest decade on record and watching as the oceans acidify, global resources peak, the world's population continues to climb, and nearly half of all known species face extinction by the end of the century. We stand on the threshold of one of the most important transition in human history-the transition from hunting-and-gathering our energy to cultivating sustainable, carbon-neutral, environmentally-friendly energy supplies. Can we "cultivate" enerm without competing with agriculture for land, freshwater, or fertilizer? Can we develop an "ecology of technology" that optimizes our use of limited resources? Is human activity compatible with improved conditions in the world's oceans? Will our ingenuity prevail in time to make a difference for our children and the children of all species? With support from NASA ARMD and the California Energy Commission, a group of dedicated scientists and engineers are working on a project called OMEGA (Offshore Membrane Enclosures for Growing Algae), to provide practical answers to these critical questions and to leave a legacy of hope for the oceans and for the future.

  10. Detection of Cyanotoxins in Algae Dietary Supplements.

    Science.gov (United States)

    Roy-Lachapelle, Audrey; Solliec, Morgan; Bouchard, Maryse F; Sauvé, Sébastien

    2017-02-25

    Algae dietary supplements are marketed worldwide as natural health products. Although their proprieties have been claimed as beneficial to improve overall health, there have been several previous reports of contamination by cyanotoxins. These products generally contain non-toxic cyanobacteria, but the methods of cultivation in natural waters without appropriate quality controls allow contamination by toxin producer species present in the natural environment. In this study, we investigated the presence of total microcystins, seven individual microcystins (RR, YR, LR, LA, LY, LW, LF), anatoxin-a, dihydroanatoxin-a, epoxyanatoxin-a, cylindrospermopsin, saxitoxin, and β-methylamino-l-alanine in 18 different commercially available products containing Spirulina or Aphanizomenon flos-aquae . Total microcystins analysis was accomplished using a Lemieux oxidation and a chemical derivatization using dansyl chloride was needed for the simultaneous analysis of cylindrospermopsin, saxitoxin, and β-methylamino-l-alanine. Moreover, the use of laser diode thermal desorption (LDTD) and ultra-high performance liquid chromatography (UHPLC) both coupled to high resolution mass spectrometry (HRMS) enabled high performance detection and quantitation. Out of the 18 products analyzed, 8 contained some cyanotoxins at levels exceeding the tolerable daily intake values. The presence of cyanotoxins in these algal dietary supplements reinforces the need for a better quality control as well as consumer's awareness on the potential risks associated with the consumption of these supplements.

  11. Detection of Cyanotoxins in Algae Dietary Supplements

    Directory of Open Access Journals (Sweden)

    Audrey Roy-Lachapelle

    2017-02-01

    Full Text Available Algae dietary supplements are marketed worldwide as natural health products. Although their proprieties have been claimed as beneficial to improve overall health, there have been several previous reports of contamination by cyanotoxins. These products generally contain non-toxic cyanobacteria, but the methods of cultivation in natural waters without appropriate quality controls allow contamination by toxin producer species present in the natural environment. In this study, we investigated the presence of total microcystins, seven individual microcystins (RR, YR, LR, LA, LY, LW, LF, anatoxin-a, dihydroanatoxin-a, epoxyanatoxin-a, cylindrospermopsin, saxitoxin, and β-methylamino-l-alanine in 18 different commercially available products containing Spirulina or Aphanizomenon flos-aquae. Total microcystins analysis was accomplished using a Lemieux oxidation and a chemical derivatization using dansyl chloride was needed for the simultaneous analysis of cylindrospermopsin, saxitoxin, and β-methylamino-l-alanine. Moreover, the use of laser diode thermal desorption (LDTD and ultra-high performance liquid chromatography (UHPLC both coupled to high resolution mass spectrometry (HRMS enabled high performance detection and quantitation. Out of the 18 products analyzed, 8 contained some cyanotoxins at levels exceeding the tolerable daily intake values. The presence of cyanotoxins in these algal dietary supplements reinforces the need for a better quality control as well as consumer’s awareness on the potential risks associated with the consumption of these supplements.

  12. [The effects of blue algae on health].

    Science.gov (United States)

    van Riel, A J H P; Schets, F M; Meulenbelt, J

    2007-08-04

    Cyanobacteria (blue algae) regularly cause recreational waters to become murky and smelly. Skin irritation and mild gastrointestinal disorders have regularly been reported following recreational activities in water suspected of being contaminated with cyanobacteria. The exact cause of these effects on health is not clear. Severe effects are not to be expected from recreational exposure to water contaminated with cyanobacteria. Cyanobacteria can produce hepatotoxins, neurotoxins, cytotoxins and irritants. In Brazil lethal intoxications have occurred due to the occurrence of toxins in drinking water and in dialysis fluid. The Dutch policy is based on the Commissie Integraal Waterbeheer (Commission Integral Water Management) guidelines for recreational waters. It is not clear to what extent the other cyanotoxins occur in the Netherlands. However, several genera ofcyanobacteria capable of producing these other cyanotoxins have been found in the Netherlands. For a good risk assessment in the Netherlands, more information is needed on the effects on health of cyanobacteria. There is also a need for more data on the prevalence of different cyanobacteria and toxins in Dutch recreational waters.

  13. Tecnologías emergentes en la educación: una experiencia de formación de docentes que fomenta el diseño de ambientes de aprendizaje

    OpenAIRE

    Boude Figueredo, Oscar Rafael

    2013-01-01

    Este texto describe los resultados obtenidos en una experiencia de formación de docentes, que son estudiantes de la Maestría en Informática Educativa de la Universidad de La Sabana, dentro de la asignatura electiva Tecnologías Emergentes en la Educación, que cuyo objetivo es: "ofrecer al estudiante un espacio de reflexión y conceptualización sobre las principales tecnologías emergentes (TE) y sus usos en la educación". Entre los principales resultados, se encuentra que los estudiantes analiza...

  14. Lipid oxidation in base algae oil and water-in-algae oil emulsion: Impact of natural antioxidants and emulsifiers.

    Science.gov (United States)

    Chen, Bingcan; Rao, Jiajia; Ding, Yangping; McClements, David Julian; Decker, Eric Andrew

    2016-07-01

    The impact of natural hydrophilic antioxidants, metal chelators, and hydrophilic antioxidant/metal chelator mixture on the oxidative stability of base algae oil and water-in-algae oil emulsion was investigated. The results showed that green tea extract and ascorbic acid had greatest protective effect against algae oil oxidation and generated four day lag phase, whereas rosmarinic acid, grape seed extract, grape seed extract polymer, deferoxamine (DFO), and ethylenediaminetetraacetic acid (EDTA) had no significant protective effect. Besides, there was no synergistic effect observed between natural antioxidants and ascorbic acid. The emulsifiers are critical to the physicochemical stability of water-in-algae oil emulsions. Polyglycerol polyricinoleate (PGPR) promoted the oxidation of emulsion. Conversely, the protective effect on algae oil oxidation was appreciated when defatted soybean lecithin (PC 75) or defatted lyso-lecithin (Lyso-PC) was added. The role of hydrophilic antioxidants in emulsion was similar to that in algae oil except EDTA which demonstrated strong antioxidative effect in emulsion. The results could provide information to build up stable food products containing polyunsaturated fatty acids (PUFA). Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. SOIL ALGAE OF BLADE OF COIL IN DONETSK REGION

    Directory of Open Access Journals (Sweden)

    Maltseva I.A.

    2011-12-01

    Full Text Available On territory of Donbass for more than 200 years the underground coal mining has produced, accompanied by the formation of the mine dumps. Finding ways to reduce their negative impact on the environment should be based on their comprehensive study. The soil algae are active participants in the syngenetic processes in industrial dumps of different origin. The purpose of this paper is to identify the species composition and dominant algae groups in dump mine SH/U5 “Western” in the western part of Donetsk.The test blade is covered with vegetation to the middle from all sides, and on the north side of 20-25 m to the top. The vegetation cover of the lower and middle tiers of all the exposures range in 70-80%. Projective vegetation cover of upper tiers of the northern, north-eastern and north-western exposures are in the range of 20-40%, other – 5-10%. We revealed some 38 algae species as a result of our research in southern, northern, western, and eastern slopes of the blade “Western”. The highest species diversity has Chlorophyta - 14 species (36.8% of the total number of species, then Cyanophyta - 9 (23,7%, Bacillariophyta - 7 (18,4%, Xantophyta - 5 (13.2%, and Eustigmatophyta - 3 (7.9%. The dominants are represented by Hantzschia amphyoxys (Ehrenberg Grunow in Cleve et Grunow, Bracteacoccus aerius, Klebsormidium flaccidum (Kützing Silva et al., Phormidium autumnale, Pinnularia borealis Ehrenberg, Planothidium lanceolatum (Brebisson in Kützing Bukhtiyarova, Xanthonema exile (Klebs Silva.It should be noted that the species composition of algae groups in different slopes of the blade was significantly different. Jacquard coefficient was calculated for algae communities varied in the range of 15,4-39,1%. The smallest number of algae species was observed on the southern slope of the blade (14 species, maximum was registered in the areas of north and west slopes. Differences in the species composition of algae were also observed in three

  16. Levantamento de problemas comportamentais/emocionais em um ambulatório para adolescentes

    Directory of Open Access Journals (Sweden)

    Benedita Salete Costa Lima Valverde

    2012-12-01

    Full Text Available Este estudo teve como objetivo identificar os principais problemas comportamentais e emocionais percebidos por adolescentes que frequentam um ambulatório de saúde. Participaram 320 adolescentes que não estavam em atendimento psicoterápico e que responderam, na sala de espera de um ambulatório, o Youth Self Report. O principal problema relatado foi Ansiedade/Depressão. Os meninos obtiveram escores mais altos em Problemas Sociais e mais baixos em Comportamento Delinquente; as meninas apresentaram-se com menos problemas no agrupamento Problemas Somáticos e com mais problemas em Ansiedade/Depressão. Quanto à faixa etária, observou-se que Problemas Sociais esteve associado ao início da adolescência. Quanto à incidência, menos de um quarto dos adolescentes apresentaram-se com problemas, sugerindo que a adolescência não é um período de turbulência. Observou-se que alguns adolescentes necessitam de uma avaliação mais detalhada, pois relataram comportamentos indicativos de transtornos mentais. Conclui-se a necessidade de profissionais de saúde mental integrarem a equipe de saúde que atende adolescentes.

  17. Bacterial community changes in an industrial algae production system.

    Science.gov (United States)

    Fulbright, Scott P; Robbins-Pianka, Adam; Berg-Lyons, Donna; Knight, Rob; Reardon, Kenneth F; Chisholm, Stephen T

    2018-04-01

    While microalgae are a promising feedstock for production of fuels and other chemicals, a challenge for the algal bioproducts industry is obtaining consistent, robust algae growth. Algal cultures include complex bacterial communities and can be difficult to manage because specific bacteria can promote or reduce algae growth. To overcome bacterial contamination, algae growers may use closed photobioreactors designed to reduce the number of contaminant organisms. Even with closed systems, bacteria are known to enter and cohabitate, but little is known about these communities. Therefore, the richness, structure, and composition of bacterial communities were characterized in closed photobioreactor cultivations of Nannochloropsis salina in F/2 medium at different scales, across nine months spanning late summer-early spring, and during a sequence of serially inoculated cultivations. Using 16S rRNA sequence data from 275 samples, bacterial communities in small, medium, and large cultures were shown to be significantly different. Larger systems contained richer bacterial communities compared to smaller systems. Relationships between bacterial communities and algae growth were complex. On one hand, blooms of a specific bacterial type were observed in three abnormal, poorly performing replicate cultivations, while on the other, notable changes in the bacterial community structures were observed in a series of serial large-scale batch cultivations that had similar growth rates. Bacteria common to the majority of samples were identified, including a single OTU within the class Saprospirae that was found in all samples. This study contributes important information for crop protection in algae systems, and demonstrates the complex ecosystems that need to be understood for consistent, successful industrial algae cultivation. This is the first study to profile bacterial communities during the scale-up process of industrial algae systems.

  18. Two-step evolution of endosymbiosis between hydra and algae.

    Science.gov (United States)

    Ishikawa, Masakazu; Shimizu, Hiroshi; Nozawa, Masafumi; Ikeo, Kazuho; Gojobori, Takashi

    2016-10-01

    In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor algae remains unknown. The endosymbiotic potential of non-symbiotic strains that can harbor algae may have been acquired before or during divergence of the strains. With the aim of understanding the evolutionary process of endosymbiosis in the H. vulgaris group, we examined the endosymbiotic potential of non-symbiotic strains of the H. vulgaris group by artificially introducing endosymbiotic algae. We found that 12 of the 23 non-symbiotic strains were able to harbor the algae until reaching the grand-offspring through the asexual reproduction by budding. Moreover, a phylogenetic analysis of mitochondrial genome sequences showed that all the strains with endosymbiotic potential grouped into a single cluster (cluster γ). This cluster contained two strains (J7 and J10) that currently harbor algae; however, these strains were not the closest relatives. These results suggest that evolution of endosymbiosis occurred in two steps; first, endosymbiotic potential was gained once in the ancestor of the cluster γ lineage; second, strains J7 and J10 obtained algae independently after the divergence of the strains. By demonstrating the evolution of the endosymbiotic potential in non-symbiotic H. vulgaris group strains, we have clearly distinguished two evolutionary steps. The step-by-step evolutionary process provides significant insight into the evolution of endosymbiosis in cnidarians. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Two-Step Evolution of Endosymbiosis between Hydra and Algae

    KAUST Repository

    Ishikawa, Masakazu

    2016-07-09

    In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor algae remains unknown. The endosymbiotic potential of non-symbiotic strains that can harbor algae may have been acquired before or during divergence of the strains. With the aim of understanding the evolutionary process of endosymbiosis in the H. vulgaris group, we examined the endosymbiotic potential of non-symbiotic strains of the H. vulgaris group by artificially introducing endosymbiotic algae. We found that 12 of the 23 non-symbiotic strains were able to harbor the algae until reaching the grand-offspring through the asexual reproduction by budding. Moreover, a phylogenetic analysis of mitochondrial genome sequences showed that all the strains with endosymbiotic potential grouped into a single cluster (cluster γ). This cluster contained two strains (J7 and J10) that currently harbor algae; however, these strains were not the closest relatives. These results suggest that evolution of endosymbiosis occurred in two steps; first, endosymbiotic potential was gained once in the ancestor of the cluster γ lineage; second, strains J7 and J10 obtained algae independently after the divergence of the strains. By demonstrating the evolution of the endosymbiotic potential in non-symbiotic H. vulgaris group strains, we have clearly distinguished two evolutionary steps. The step-by-step evolutionary process provides significant insight into the evolution of endosymbiosis in cnidarians.

  20. DISTRIBUTIONAND DIVERSITY OF MACRO ALGAE COMMUNITIES IN THE AMBON BAY

    Directory of Open Access Journals (Sweden)

    Christina Litaay

    2014-11-01

    Full Text Available Water conditions affected by natural and anthropogenic parameters such as sedimentation and solid waste disposal can influence the growth and distribution of macro algae. Sustainable management efforts can reduce damage on the Gulf coast of Ambon due to human activities and land clearing. This study was conducted in October 2008 using the transect method with 3 replicates in five locations i.e., Tantui, Air Salobar, Hative Besar, Halong, and Lateri. The interior and exterior waters of Ambon Bay contained different habitat conditions due to  sedimentation processes. The purpose of this study was to determine the distribution and diversity of macro algae communities in the Ambon Bay. The results found 21 species of macro- algae consisting of 10 species of Rhodhophyceae, 6 species of Chlorophyceae, and 5 species of Phaeophyceae. The highest density value of seaweed in Tantui was 389.0 g/m² of Chlorophyceae of Halimeda genus. In Air Salobar and Halong, the highest density value was Rhodophyceae of Gracilaria genus of 172.0 g/m² and 155.0 g/m², respectively. For the other genus in the Tantui and Lateri regions were dominated by Ulva at 92.10 gr/m2 and Padina of 20.0 gr/m2, respectively. The highest dominance of macro algae in the Hative Besar was found Chlorophyceae of Halimeda genus of 2.93 %, in the Air Salobar of Phaeophyceae of Turbinaria genus of 1.43 %. The difference values in density and the dominance of macro algae indicated an influence of habitat and environment due to seasons, sediment, and solid waste disposal to the diversity of macro algae. Keywords: Diversity, macro algae, Ambon Bay.

  1. Evaluación del aprendizaje emergente: una experiencia con estudiantes universitarias de Educación Preescolar / Evaluating emergent learning: an experience with university preschool education students

    Directory of Open Access Journals (Sweden)

    Badilla Saxe, Eleonora

    2008-12-01

    Full Text Available Resumen: Se aborda en este ensayo la necesidad de comprender y evaluar el aprendizaje como un fenómeno emergente, más allá del aprendizaje previsto en los planes de estudio y diseño curricular. Se ejemplifica con la reflexión del propio aprendizaje emergente de la autora en su proceso de dirección de un proyecto de investigación-acción en la Universidad de Costa Rica. En dicha investigación-acción participaron once estudiantes de licenciatura en educación preescolar y veinticinco niños y niñas de 5 y 6 años que contaron con materiales digitales en su ambiente y proceso de aprendizaje.Abstract:This essay discusses the need to understand and evaluate learning as an emergent phenomenon that transcends what has been foreseen in the curriculum. It includes reflections of the author as Director of a Reflective-Research Project at the University of Costa Rica UCR about her own emergent learning about evaluating emergent learning. The Research project was developed by eleven university students at the School of Education at UCR and twenty five preschool children using digital technologies in their learning process and environment.

  2. Tecnologías y modelos de aprendizaje emergentes en educación superior. Propuestas y difusión de innovaciones

    Directory of Open Access Journals (Sweden)

    Natália FERNANDES GOMES

    2015-01-01

    Full Text Available El avance de la tecnología, la existencia de nuevos tipos de redes colaborativas y la conectividad global permiten y requieren urgentemente que las instituciones de Educación Superior desarrollen nuevos, innovadores y creativos modelos de enseñanza y aprendizaje. En este trabajo se presentan, primero, algunos de los actuales modelos emergentes de aprendizaje para la Educación Superior, mediados a través del uso de las tecnologías, de acuerdo a diferentes informes internacionales. En la segunda parte se presentan los resultados de un estudio de revisión sistemática que nos permite comprender el grado de difusión de la innovación educativa que subyace a los diferentes modelos de aprendizaje (flipped learning, personal learning environments, mobile learning, massive open online courses. Los resultados indican que el modelo mobile learning es el más productivo con una tendencia en aumento. Finalmente se exponen conclusiones respecto a la importancia de la difusión de innovación y los obstáculos en la traducción de los modelos emergentes a los contextos de aula.

  3. TEORIAS DE INTERNACIONALIZAÇÃO E APLICAÇÃO EM PAÍSES EMERGENTES: UMA ANÁLISE CRÍTICA

    Directory of Open Access Journals (Sweden)

    WALTER F. ARAUJO DE MORAES

    2006-01-01

    Full Text Available Neste artigo são apresentadas e discutidas sete teorias de internacionalização, a saber: oModelo do Ciclo de Vida do Produto, Uppsala – Escola Nórdica de Negócios Internacionais,Relacionado à Inovação, Escolha Adaptativa, Paradigma Eclético de Internalização (OLI,Modelo de Internacionalização Baseado em Recursos (RBV e o Modelo Diamante. Oobjetivo é analisar criticamente estas teorias, propondo uma união entre alguns de seusconceitos-chave para um melhor entendimento do processo de internacionalização incluindo acontexto dos países emergentes. Ademais, questiona-se a aplicação destes modelos, elaboradosem países desenvolvidos, em países emergentes sem uma análise crítica, buscando-se aconvergência sem a percepção dos diferentes contextos e timing de internacionalização, já queo protecionismo instaurado tornou tardia a entrada destes países no mercado internacional.

  4. The effects of mutagens on some algae

    International Nuclear Information System (INIS)

    Aranez, A.T.

    1984-01-01

    Pure cultures of Scenedesmus quadricauda (Turp.) Breb. and chlorella pyrenoidosa Chick were subjected to 0.5, 3, 6, 9 and 12 Kr gamma radiation ( 60 Co source) from the Philippine Atomic Energy Commission. Untreated cells were used as control. Dose of 0.5 Kr increased the growth rate of Scenedesmus by 3.12%, 15.27% and 20.48% during the first, third and fourth week respectively. Doses of 6, 9 and 12 decreased the growth rate by 86.33%, 70.7% and 58.2% respectively during the first week. The stimulating effect of low dose (0.5 Kr) was recovered after the fourth week while the inhibiting effect on growth by higher doses was recovered after the first week. Gamma radiation produced morphological changes in the Scenedesmus in the form of enlarged cells, cells with kidney-shape chloroplast, cells in chain, and coenobia with cells that were not in perfect alignment with each other. In chlorella, gamma radiation produced enlarged cells, cells with wrinkled surface and cells that were colourless. Ethyl methanesulfate of 0.1%, 0.4%, 0.8% and 1.25% in phosphate buffer solution was another mutagen used. Algae in distilled water and phosphate buffer were used as control. Treatment with EMS produced coenobia of Scenedesmus with cells that were twice and thrice the normal cells, cells that were rounded or oval in outline, with wavy instead of smooth margin, cells with pseudopodia-like protrusions and coenobia with abnormal number of cells. In Chlorella, EMS produced cells that were twice the size of the normal size of the normal ones, cells that were wavy in outline, abnormal in shape, and cells with no chlorophyll. Scenedesmus was more sensitive to gamma radiation and EMS than chlorella. Of the morphological changes observed, only Scenedesmus with cells around twice the size of the normal ones produced by treatment with either gamma radiation of EMS were successfully propagated. (author)

  5. El problema de la verdad y la alhqeia

    Directory of Open Access Journals (Sweden)

    Roberto Estrada Olguín

    2009-01-01

    Full Text Available The claim of this work is to expose my vision to near problematic of the truth in the scope of the philosophy. For it we will distinguish the two general orientations in whose direction the problem of the truth in the philosophical scope has been boarded: 1 justificationist and 2 ontological. The criterion that allows us to make this distinction is the “attitude and the answer” that have been adopted as opposed to the skepticism. Therefore, in which it follows we will develop the theoretical origins, basic premises and consequences of two attitudes and two answers corresponding to these attitudes as opposed to the skepticism. In the direction which we denominated justificationist we included the “theories of the truth” that in these times have proliferated, because of them have adopted the same “attitude” and have provided the same “answer” in face of skepticism. For the ontological perspective we will expose the thought of Heidegger on the subject of the truth, because there we find the exposition of the subject adopting a “attitude” and providing a “answer” that is not directed to the search of a justification. These two directions, in my opinion, provide sufficient a minimum sketch of the problem of the truth. Keywords: truth, objectivity, skepticism, justificationism, alhqeia. La pretensión de este trabajo es exponer mi visión acerca de la problemática de la verdad en el ámbito de la filosofía. Para ello distinguiremos las dos orientaciones generales en cuya dirección se ha abordado el problema de la verdad en el ámbito filosófico: 1 la justificacionista y 2 la ontológica. El criterio que nos permite hacer esta distinción es la “actitud y la respuesta” que se han adoptado frente al escepticismo. Por lo tanto, en lo que sigue desarrollaremos los orígenes teoréticos, presupuestos y consecuencias de dos actitudes y dos respuestas correspondientes a estas actitudes frente al escepticismo. En la orientaci

  6. Contabilidad de Costos I. - Problemas sobre contabilización de las actividades relacionadas con los materiales

    OpenAIRE

    Morillo Moreno, Marysela C.

    2008-01-01

    ÍNDICE Introducción Problemas sobre terminología básica Problemas básicos sobre el Ciclo de la Contabilidad de Costos Problemas sobre contabilización de las actividades relacionadas con los materiales Problemas sobre la contabilización de las actividades relacionadas con la mano de obra Problemas sobre la contabilización de las actividades relacionadas con los costos indirectos de fabricación Problemas sobre el Ciclo de la Contabilida...

  7. Contabilidad de Costos I. - Problemas sobre la contabilización de las actividades relacionadas con la mano de obra

    OpenAIRE

    Morillo Moreno, Marysela C.

    2008-01-01

    ÍNDICE Introducción Problemas sobre terminología básica Problemas básicos sobre el Ciclo de la Contabilidad de Costos Problemas sobre contabilización de las actividades relacionadas con los materiales Problemas sobre la contabilización de las actividades relacionadas con la mano de obra Problemas sobre la contabilización de las actividades relacionadas con los costos indirectos de fabricación Problemas sobre el Ciclo de la Contabilida...

  8. Estructura orbital en el Problema Restringido Rectilíneo Isósceles

    Science.gov (United States)

    Orellana, R. B.

    Para definir problemas en Mecánica Celeste se utilizan diferentes parámetros. El conocimiento de la dinámica del problema para valores particulares de estos parámetros nos permite entender el comportamiento en casos más generales. El Problema Restringido Rectilíneo Isósceles puede ser considerado como el caso límite del Problema de Sitnikov cuando la excentricidad tiende a uno o como el Problema Isósceles cuando la masa central tiende a cero. Se ha compactificado el espacio de fases y analizado la dinámica en el límite. Esto ha permitido separar el espacio de fases en diferentes regiones dependiendo de las clases de órbitas.

  9. Method and apparatus using an active ionic liquid for algae biofuel harvest and extraction

    Science.gov (United States)

    Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.; Teixeira, Rodrigo

    2012-11-06

    The invention relates to use of an active ionic liquid to dissolve algae cell walls. The ionic liquid is used to, in an energy efficient manner, dissolve and/or lyse an algae cell walls, which releases algae constituents used in the creation of energy, fuel, and/or cosmetic components. The ionic liquids include ionic salts having multiple charge centers, low, very low, and ultra low melting point ionic liquids, and combinations of ionic liquids. An algae treatment system is described, which processes wet algae in a lysing reactor, separates out algae constituent products, and optionally recovers the ionic liquid in an energy efficient manner.

  10. Optimal control of algae growth by controlling CO 2 and nutrition flow using Pontryagin Maximum Principle

    Science.gov (United States)

    Mardlijah; Jamil, Ahmad; Hanafi, Lukman; Sanjaya, Suharmadi

    2017-09-01

    There are so many benefit of algae. One of them is using for renewable energy and sustainable in the future. The greater growth of algae will increasing biodiesel production and the increase of algae growth is influenced by glucose, nutrients and photosynthesis process. In this paper, the optimal control problem of the growth of algae is discussed. The objective function is to maximize the concentration of dry algae while the control is the flow of carbon dioxide and the nutrition. The solution is obtained by applying the Pontryagin Maximum Principle. and the result show that the concentration of algae increased more than 15 %.

  11. Influence of Algae Age and Population on the Response to TiO2 Nanoparticles

    OpenAIRE

    David M. Metzler; Ayca Erdem; Chin Pao Huang

    2018-01-01

    This work shows the influence of algae age (at the time of the exposure) and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO2 NPs). The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3−4.2 × 106 ...

  12. Radionuclides in macro algae at Monaco following the Chernobyl accident

    International Nuclear Information System (INIS)

    Holm, E.; Ballestra, S.; Lopez, J.J.; Bulos, A.; Whitehead, N.E.; Barci-Funel, G.; Ardisson, G.

    1994-01-01

    Samples of macro algae, Codmium tomentosum (green), Corallina mediterranea (red), Sphaerococcus coronopifolius (red) and Dictyota dichotoma (brown), were collected off Monaco during 1984 and 1988 and analysed for gamma-emitting radionuclides and transuranium elements. Due to the Chernobyl accident, increased radioactivity in the atmosphere at Monaco was recorded on 30 April 1986 with maximal activity concentrations on 2-3 May. The maximal activity concentrations in sea water occurred on 5-6 May and in the algae on 11 May. The decrease of activity concentrations can be described after May 11 as a single exponential relationship, where elimination rates for different radionuclides and different species specific to the environment can be calculated. The elimination rates thus observed correspond to mean residence times between 70 and 370 days corrected for physical decay. The concentration factors were also estimated and the highest values were found for 131 I, 129 Te m , and 110 Ag m and lowest for radiocesium and 140 Ba. The red algae Sphaerococcus coronopifoius showed generally higher concentration factors than green and brown algae. Regarding transuranium elements, a theoretical contribution from the Chernobyl accident can be made but only 242 Cm was detected in the algae above previous levels before the accident, due to the relatively small fallout of transuranics. (author) 23 refs.; 9 figs.; 4 tabs

  13. Acute toxicity and associated mechanisms of four strobilurins in algae.

    Science.gov (United States)

    Liu, Xiaoxu; Wang, Yu; Chen, Hao; Zhang, Junli; Wang, Chengju; Li, Xuefeng; Pang, Sen

    2018-04-03

    Strobilurins have been reported highly toxic to non-target aquatic organisms but few illustrated how they cause toxic effects on algae. This study investigated the acute toxicity of Kresoxim-methy (KRE), Pyraclostrobin (PYR), Trifloxystrobin (TRI) and Picoxystrobin (PIC) on two algae and their toxicity mechanisms. Four strobilurins showed lower toxic effects on Chlorella pyrenoidsa but higher on Chlorella vulgaris. bc1 complex activities in C. vulgaris were significantly inhibited by all strobilurins, suggesting bc 1 complex might be the target of strobilurin toxicity in algae. Moreover, SOD, CAT and POD activities were significantly up-regulated by all doses of KRE, PYR and PIC. In contrast, low concentrations of TRI stimulated SOD and POD activities but highest concentration significantly inhibited those activities. Comet assays showed damaged DNA in C. vulgaris by four strobulirins, suggesting their potential genotoxic threats to algae. The results illustrated acute toxicity by strobulirins on algae and their possible toxicity mechanisms. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Algae Production from Wastewater Resources: An Engineering and Cost Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schoenung, Susan [Longitude 122 West, Inc.; Efroymson, Rebecca Ann [ORNL

    2018-03-01

    Co-locating algae cultivation ponds near municipal wastewater (MWW) facilities provides the opportunity to make use of the nitrogen and phosphorus compounds in the wastewater as nutrient sources for the algae. This use benefits MWW facilities, the algae biomass and biofuel or bioproduct industry, and the users of streams where treated or untreated waste would be discharged. Nutrient compounds can lead to eutrophication, hypoxia, and adverse effects to some organisms if released downstream. This analysis presents an estimate of the cost savings made possible to cultivation facilities by using the nutrients from wastewater for algae growth rather than purchase of the nutrients. The analysis takes into consideration the cost of pipe transport from the wastewater facility to the algae ponds, a cost factor that has not been publicly documented in the past. The results show that the savings in nutrient costs can support a wastewater transport distance up to 10 miles for a 1000-acre-pond facility, with potential adjustments for different operating assumptions.

  15. Anti-Phytopathogenic Activities of Macro-Algae Extracts

    Directory of Open Access Journals (Sweden)

    Ingrid Ramírez

    2011-05-01

    Full Text Available Aqueous and ethanolic extracts obtained from nine Chilean marine macro-algae collected at different seasons were examined in vitro and in vivo for properties that reduce the growth of plant pathogens or decrease the injury severity of plant foliar tissues following pathogen infection. Particular crude aqueous or organic extracts showed effects on the growth of pathogenic bacteria whereas others displayed important effects against pathogenic fungi or viruses, either by inhibiting fungal mycelia growth or by reducing the disease symptoms in leaves caused by pathogen challenge. Organic extracts obtained from the brown-alga Lessonia trabeculata inhibited bacterial growth and reduced both the number and size of the necrotic lesion in tomato leaves following infection with Botrytis cinerea. Aqueous and ethanolic extracts from the red-alga Gracillaria chilensis prevent the growth of Phytophthora cinnamomi, showing a response which depends on doses and collecting-time. Similarly, aqueous and ethanolic extracts from the brown-alga Durvillaea antarctica were able to diminish the damage caused by tobacco mosaic virus (TMV in tobacco leaves, and the aqueous procedure is, in addition, more effective and seasonally independent. These results suggest that macro-algae contain compounds with different chemical properties which could be considered for controlling specific plant pathogens.

  16. Algae-bacteria interactions: Evolution, ecology and emerging applications.

    Science.gov (United States)

    Ramanan, Rishiram; Kim, Byung-Hyuk; Cho, Dae-Hyun; Oh, Hee-Mock; Kim, Hee-Sik

    2016-01-01

    Algae and bacteria have coexisted ever since the early stages of evolution. This coevolution has revolutionized life on earth in many aspects. Algae and bacteria together influence ecosystems as varied as deep seas to lichens and represent all conceivable modes of interactions - from mutualism to parasitism. Several studies have shown that algae and bacteria synergistically affect each other's physiology and metabolism, a classic case being algae-roseobacter interaction. These interactions are ubiquitous and define the primary productivity in most ecosystems. In recent years, algae have received much attention for industrial exploitation but their interaction with bacteria is often considered a contamination during commercialization. A few recent studies have shown that bacteria not only enhance algal growth but also help in flocculation, both essential processes in algal biotechnology. Hence, there is a need to understand these interactions from an evolutionary and ecological standpoint, and integrate this understanding for industrial use. Here we reflect on the diversity of such relationships and their associated mechanisms, as well as the habitats that they mutually influence. This review also outlines the role of these interactions in key evolutionary events such as endosymbiosis, besides their ecological role in biogeochemical cycles. Finally, we focus on extending such studies on algal-bacterial interactions to various environmental and bio-technological applications. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Mg-lattice associations in red coralline algae

    Science.gov (United States)

    Kamenos, N. A.; Cusack, M.; Huthwelker, T.; Lagarde, P.; Scheibling, R. E.

    2009-04-01

    Recent investigations have shown red coralline algae to record ambient temperature in their calcite skeletons. Temperature recorded by variation in Mg concentrations within algal growth bands has sub-annual resolution and high accuracy. The conversion of Mg concentration to temperature is based on the assumption of Ca replacement by Mg within the algal calcite skeleton at higher temperatures. While Mg-temperature relationships in coralline algae have been calibrated for some species, the location of Mg within the calcite lattice remains unknown. Critically, if Mg is not a lattice component but associated with organic components this could lead to erroneous temperature records. Before coralline algae are used in large scale climate reconstructions it is therefore important to determine the location of Mg. Synchrotron Mg-X-ray absorbance near edge structure (XANES) indicates that Mg is associated with the calcite lattice in Lithothamnion glaciale (contemporary free-living, contemporary encrusting and sub-fossil free-living) and Phymatolithon calcareum (contemporary free-living) coralline algae. Mg is deposited within the calcite lattice in all seasons ( L. glaciale & P. calcareum) and thallus areas ( P. calcareum). These results suggest L. glaciale and P. calcareum are robust Mg-palaeotemperature proxies. We suggest that similar confirmation be obtained for Mg associations in other species of red coralline algae aiding our understanding of their role in climate reconstruction at large spatial scales.

  18. El problema del mal y la violencia en Colombia

    Directory of Open Access Journals (Sweden)

    Victor Eligio Espinosa Galán

    2015-09-01

    Full Text Available La historia de la humanidad está marcada por conflictos de distinta naturaleza: religiosos, ideológicos, raciales, etc., expresados en guerras, ataques terroristas, masacres, entre muchas otras situaciones de crueldad que muestran maldad y sevicia ejercida sobre seres humanos. Ante estos acontecimientos que nos enfrentan a la pregunta: ¿qué es aquello que nos hace humanos?, parece, en un contexto como el colombiano, que se asiste a formas oficiales de una agencia de maldad como posibilidad de un ethos cultural que hace plausibles las acciones más perversas en una desoladora minimización de responsabilidad moral, necesaria para construcción de una sociedad justa y en paz. Este escrito es un esfuerzo por pensar el problema del mal en el contexto de la violencia en Colombia y dar cuenta de algunos aspectos de la reflexión filosófica sobre el mal, el sufrimiento y el sentido de la vida; se toma como contexto el conflicto armado en Colombia y las narraciones de sus protagonistas.

  19. ARQUEOLOGIA E TURISMO NA AMAZÔNIA: PROBLEMAS E PERSPECTIVAS

    Directory of Open Access Journals (Sweden)

    Edithe Pereira

    2012-09-01

    Full Text Available RESUMO: O artigo apresenta os problemas decorrentes da prática do turismo sem controle que vem acontecendo em sítios arqueológicos na Amazônia. Apresenta-se a situação atual de alguns sítios localizados em três regiões distintas no Pará e propõem-se recomendações básicas para uso turístico de sítios arqueológicos. PALAVRAS-CHAVE: Patrimônio arqueológico; turismo; Amazônia.ABSTRACT:This article discusses the main problems that have affected Amazonian archaeological sites as a consequence of unsupervised tourist practices. The current state of sites located in three different regions of Pará are examined, while some basic procedures for the touristic access to archaeological sites are recommended.KEY-WORKS: Archaeological heritage; tourism; Amazon Region.

  20. Nietzsche y Freud ante el problema de la verdad

    Directory of Open Access Journals (Sweden)

    Leandro Drivet

    2016-01-01

    Full Text Available Este trabajo se propone reflexionar acerca del problema de la verdad en las obras de Friedrich Nietzsche y Sigmund Freud, a las que se considera estrechamente vinculadas. Esta perspectiva permitirá identificar el carácter específico de la “verdad”, cuyos vestigios detectaron ambos “psicólogos” transvaloradores; apreciar la doble valoración nietzscheana de la verdad, usualmente reducida a un rechazo unilateral; y repensar la pretensión de cientificidad del psicoanálisis, actualmente despreciada en nombre de una sospechosa reivindicación anticientífica. Se concluye con el postulado de que Nietzsche y Freud conciben a la verdad como una lucha contra las resistencias, lo que les conduce a fundar una nueva escucha.

  1. El suicidio en los adolescentes: Un problema en crecimiento

    Directory of Open Access Journals (Sweden)

    Wendy Cervantes P.

    2014-06-01

    Full Text Available ResumenEl suicidio es un fenómeno humano universal que ha estado presente en todas las épocas históricas. Por lo tanto este artículo solo pretende ser una revisión teórica sobre lo que hasta la fecha se conoce sobre los factores implicados en el suicidio en población adolescente. En el intervienen múltiples factores, entre los cuales se pueden citar: nivel socioeconómico de los padres, entorno familiar en el que se vive, las relaciones sexuales y la aceptación del género, padecer una enfermedad mental, nivel de estudios alcanzado, tener problemas en el colegio, con la justicia, entre otros. (Duazary 2008; 148-154AbstractSuicide is a universal human phenomenon that has been present throughout history. Therefore, this article, only wants to check what is known to date about the imply factors in suicides in adolescents. This is about something complicated, because of the many factors imply: social-professional level of the parents, sex, having any mental illness, Level of study, having problems in school, weather where they live, among others.Key Words: Consummated suicide; adolescents; protective factors; risk factors.

  2. Una solución al problema inverso en geomagnetismo

    Directory of Open Access Journals (Sweden)

    Díaz Ramiro L.

    1992-10-01

    Full Text Available

    Un tema importante en geofísica, es el problema inverso en geomagnetismo. En este trabajo se propone un método para resolverlo, que consiste en hallar la solución de un sistema móvil de ecuaciones no lineales a lo largo de un perfil magnético. Conociendo los datos de anomalías magnéticas y por medio de un programa que ejecuta un proceso iterativo eficiente, se determina la estructura bidimensional bajo el perfil muestreado.

    An interesting aspect in Geophysics is the inverse problem in Geomagnetism. This paper proposes a method for solving it. So, the objective is to solve a mobil system of non linear equations along a magnetic profile. From knowed magnetic anomalies and using an efficient iterative process, it is possible to find a bidimensional structure below a sample profile.

  3. Daniel Link y la clase: problemas de convivencia

    Directory of Open Access Journals (Sweden)

    Mariana Catalin

    2016-12-01

    Full Text Available El presente trabajo busca realizar un acercamiento a los modos de la producción ensayística de Daniel Link a partir de un interrogante que cruza toda su producción: la pregunta por cómo vivir juntos. Para esto, en una primera instancia, se realiza un análisis de la aparición explícita del interrogante en una serie de textos del blog del autor (linkillo.blogspot.com, para observar qué problemas se condensan en torno al mismo. A partir de este contexto, en un segundo momento, se abre un recorrido por dos de sus más recientes libros de ensayos, Clases. Literatura y disidencia (2005 y Fantasmas. Imaginación y sociedad (2009. Allí, además de los usos que se articulan a partir de su aparición explícita, el interrogante permite pensar la relación entre clasificación y cualificación, dos conceptos centrales en la producción de Link.

  4. El problema de vivienda de los "con techo"

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    Alfredo Rodríguez

    2004-12-01

    Full Text Available La política de vivienda social en Chile es considerada un éxito. En los últimos quince años la producción masiva de viviendas ha logrado reducir el déficit habitacional, y muchos gobiernos de América Latina están imitando su modelo de financiamiento. Sin embargo, esta política exitosa ha terminado creando nuevos problemas urbanos y sociales: segregación, fragmentación, inseguridad, hacinamiento. En consecuencia, se plantea que una política de vivienda social sensata debe hoy incorporar nuevos criterios, relacionados fundamentalmente con la calidad de viviendas, la localización de los conjuntos construidos y la movilidad residencial de los beneficiarios.Chilen social housing policy is considered a success. During the last fifteen years the massive housing production has managed to reduce housing deficit, and many Latin American governments are imitating it financing model. However, this succesfull policy has ended up by creating new urban and social problems: segregation, fragmentation, insecurity, overcrowding. Consequently, it is pointed that a proper housing policy must currently include new criteria, mainly related to the quality of the product, the locating of the built neighborhoods and beneficiaries residential mobility.

  5. APRENDIZAJE BASADO EN PROBLEMAS (ABP: UNA EXPERIENCIA PEDAGOGICA EN MEDICINA

    Directory of Open Access Journals (Sweden)

    Claudio Lermanda S.

    2007-01-01

    Full Text Available La enseñanza tradicional de la Medicina ha sido cuestionada por el avance tecnológico y el exponencial aumento de información médica accesible, obligando a reformular los curricula médicos bajo la mirada de las reformas educacionales que a escala global vienen desarrollándose desde el Proceso de Bolonia. Una propuesta curricular nueva señalada por Harden (1984 y conocida como modelo SPICES permite incorporar una metodología didáctica más apropiada para el proceso de enseñanza - aprendizaje formativo e integrador que demanda la sociedad actual. En este nuevo escenario, muchas Facultades de Medicina han incorporado el Aprendizaje Basado en Problemas (ABP como herramienta de aproximación al modelo señalado, por su carácter integrador de conocimientos, destrezas y actitudes que facilitan la adquisición de las competencias clínicas necesarias para el ejercicio profesional futuro. Este trabajo resume las consideraciones y sugerencias relativas al modelo y a la metodología tras una experiencia de dos años de ABP en la Facultad de Medicina de la Universidad Católica de la Santísima Concepción.

  6. Lugar de la ciencia, la tecnología y la religión en la cultura emergente

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    Juan Antonio Estrada

    2015-01-01

    Full Text Available No hay duda sobre el actual cambio de época. Se traduce en nombres como postmodernidad, tardo-modernidad y globalización, para designar la nueva fase histórica que hemos iniciado. Desde otra perspectiva podemos hablar de la tercera revolución industrial, que pone el énfasis en la ciencia y en la tecnología como motores del progreso y de la evolución social. Se trata de una auténtica revolución en la que surge un nuevo paradigma de comprensión del ser humano y del mundo. La sociedad como un todo está influida por el cambio científico técnico, con lo que ya no hay áreas exentas y la ciencia plantea problemas en todos los ámbitos culturales, incluida la religión.

  7. Los problemas de la Educación Ambiental: ¿es posible una Educación Ambiental integradora?

    OpenAIRE

    García, J. Eduardo

    2002-01-01

    En este trabajo se presentan diferentes problemas y carencias de la Educación Ambiental. Para el tratamiento de estos problemas se plantea una perspectiva integradora que supere los reduccionismos actualmente existentes

  8. Designer proton-channel transgenic algae for photobiological hydrogen production

    Science.gov (United States)

    Lee, James Weifu [Knoxville, TN

    2011-04-26

    A designer proton-channel transgenic alga for photobiological hydrogen production that is specifically designed for production of molecular hydrogen (H.sub.2) through photosynthetic water splitting. The designer transgenic alga includes proton-conductive channels that are expressed to produce such uncoupler proteins in an amount sufficient to increase the algal H.sub.2 productivity. In one embodiment the designer proton-channel transgene is a nucleic acid construct (300) including a PCR forward primer (302), an externally inducible promoter (304), a transit targeting sequence (306), a designer proton-channel encoding sequence (308), a transcription and translation terminator (310), and a PCR reverse primer (312). In various embodiments, the designer proton-channel transgenic algae are used with a gas-separation system (500) and a gas-products-separation and utilization system (600) for photobiological H.sub.2 production.

  9. Algae from the arid southwestern United States: an annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, W.H.; Gaines, S.R.

    1983-06-01

    Desert algae are attractive biomass producers for capturing solar energy through photosynthesis of organic matter. They are probably capable of higher yields and efficiencies of light utilization than higher plants, and are already adapted to extremes of sunlight intensity, salinity and temperature such as are found in the desert. This report consists of an annotated bibliography of the literature on algae from the arid southwestern United States. It was prepared in anticipation of efforts to isolate desert algae and study their yields in the laboratory. These steps are necessary prior to setting up outdoor algal culture ponds. Desert areas are attractive for such applications because land, sunlight, and, to some extent, water resources are abundant there. References are sorted by state.

  10. Are anti-fouling effects in coralline algae species specific?

    Directory of Open Access Journals (Sweden)

    Alexandre Bigio Villas Bôas

    2004-03-01

    Full Text Available The crustose coralline algae are susceptible to be covered by other algae, which in turn can be affected by anti-fouling effects. In this study the hypothesis tested was that these algae can inhibit the growth of epiphytes in a species specific way. In the laboratory, propagules of Sargassum furcatum and Ulva fasciata were liberated and cultivated on pieces of coralline algae and slide covers (controls and their survival and growth were compared. Spongites and Hydrolithon significantly inhibited the growth of U. fasciata but not Sargassum. In the field, pieces of three species of live and dead coralline algae and their copies in epoxy putty discs were fixed on the rock. After one month epiphytic algae were identified and their dry mass quantified. Lithophyllum did not affect the epiphyte growth. In contrast Spongites and an unidentified coralline significantly inhibited the growth of Enteromorpha spp., Ulva fasciata and Hincksia mitchelliae. Colpomenia sinuosa was absent on all living crusts, but present on controls. Results show that the epiphyte-host relation depends on the species that are interacting. The sloughing of superficial cells of coralline crusts points to the possible action of physical anti-fouling effect, though a chemical one is not rejected.As algas calcárias crostosas são susceptíveis ao recobrimento por outras algas, entretanto, estas podem ser afetadas por efeitos anti-incrustantes. Neste estudo foi testada a hipótese de que estas algas possam inibir o crescimento somente de algumas espécies de epífitas. No laboratório, propágulos de Sargassum furcatum e Ulva fasciata foram liberados e cultivados sobre pedaços de algas calcárias e lamínulas de microscopia (controle e as suas sobrevivência e crescimento comparadas. Spongites e Hydrolithon inibiram significativamente o crescimento de U. fasciata, mas não de Sargassum. No campo, pedaços de três espécies de algas calcárias vivas, mortas e cópias destas em

  11. Stream Level Stabilization by Algae of the Genus Cladophora

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    Zeman J.

    2018-03-01

    Full Text Available Investigations in the Pryský brook experimental catchment revealed that the vegetation of the stream channel stabilizes water level depth in the measured profile. The explored brook has been heavily overgrown by algae of the genus Cladophora due to a strong pollution by nitrates. It seems that if the algae average length exceeds the midsize of the stones paving the bed (ca. 30 ± 7 cm in diameter, escribed circle to pentagon or heptagon, the water level stagnates in the flowrate range of 60–180 l s−1. This totally blocks the streamflow daily oscillation (in summer months in a purely stone bed reaching up to 15%, along with tidal phenomena. The article analyzes one of possible explanations of this effect due to the dependence of the algae thickness layer modifying the channel bed cross-section on the speed of flowing water.

  12. Cycloartane triterpenes from marine green alga Cladophora fascicularis

    Science.gov (United States)

    Huang, Xinping; Zhu, Xiaobin; Deng, Liping; Deng, Zhiwei; Lin, Wenhan

    2006-12-01

    Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structures were elucidated as (1). 24-hydroperoxycycloart-25- en-3β-ol; (2). cycloart-25-en-3β 24-diol; (3). 25-hydroperoxycycloart-23-en-3β-ol; (4). cycloart-23-en-3β, 25-diol; (5). cycloart-23, 25-dien-3β-ol; and (6). cycloart-24-en-3β-ol by spectroscopic (MS, ID and 2D NMR) data analysis. Cycloartane derivatives are widely distributed in terrestrial plants, but only few were obtained in the alga. All these compounds that have been isolated from terrestrial plants, were found in the marine alga for the first time.

  13. Mucormicosis: Una micosis emergente

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    Iris Tiraboschi

    2012-02-01

    Full Text Available El objetivo de este trabajo es presentar la incidencia, frecuencia, características clínicas y evolución de los pacientes con mucormicosis atendidos en el Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, entre los años 1982 y 2010. Durante ese período se diagnosticaron 10 casos de mucormicosis. Los tres primeros entre 1982 y 2004 y los últimos 7 entre 2005 y 2010. La incidencia y frecuencia de esta enfermedad, para el período 1980-2004 fue 0.13 pacientes/año y 0.1 casos/10 000 egresos (IC 95%: 0.00 a 0.3 respectivamente. En el período 2005-2010 la incidencia fue 0.86 pacientes/año y la frecuencia de 1.1 casos/10 000 egresos (IC 95%: 0.5 a 2.4. Hubo nueve casos de mucormicosis rinosinuso-orbitaria, siete en pacientes con diabetes mellitus, uno en una paciente con una hemopatía maligna y neutropenia, y el restante en un paciente con HIV/sida que además estaba neutropénico y con un síndrome hemofagocítico. En una paciente se realizó el diagnóstico post mortem de mucormicosis pulmonar. El diagnóstico se efectuó por la observación de filamentos cenocíticos en los diez casos. Hubo desarrollo de mucorales en los cultivos de 8/9 pacientes; cinco Rhizopus spp y tres Mucor spp. Todos los pacientes recibieron un tratamiento inicial con anfotericina B deoxicolato, que en tres de ellos fue continuado con anfotericina B liposomal, y cirugía. Tres enfermos recibieron además un tratamiento adyuvante con oxigeno hiperbárico. La mortalidad fue 30%.

  14. Characteristics of Red Algae Bioplastics/Latex Blends under Tension

    Directory of Open Access Journals (Sweden)

    M. Nizar Machmud

    2013-10-01

    Full Text Available Cassava, corn, sago and the other food crops have been commonly used as raw materials to produce green plastics. However, plastics produced from such crops cannot be tailored to fit a particular requirement due to their poor water resistance and mechanical properties. Nowadays, researchers are hence looking to get alternative raw materials from the other sustainable resources to produce plastics. Their recent published studies have reported that marine red algae, that has been already widely used as a raw material for producing biofuels, is one of the potential algae crops that can be turned into plastics. In this work, Eucheuma Cottonii, that is one of the red alga crops, was used as raw material to produce plastics by using a filtration technique. Selected latex of Artocarpus altilis and Calostropis gigantea was separately then blended with bioplastics derived from the red algae, to replace use of glycerol as plasticizer. Role of the glycerol and the selected latex on physical and mechanical properties of the red algae bioplastics obtained under a tensile test performed at room temperature are discussed. Tensile strength of some starch-based plastics collected from some recent references is also presented in this paperDoi: 10.12777/ijse.5.2.81-88 [How to cite this article: Machmud, M.N., Fahmi, R.,  Abdullah, R., and Kokarkin, C.  (2013. Characteristics of Red Algae Bioplastics/Latex Blends under Tension. International Journal of Science and Engineering, 5(2,81-88. Doi: 10.12777/ijse.5.2.81-88

  15. Inorganic carbon addition stimulates snow algae primary productivity

    Science.gov (United States)

    Hamilton, T. L.; Havig, J. R.

    2017-12-01

    Earth has experienced glacial/interglacial oscillations throughout its history. Today over 15 million square kilometers (5.8 million square miles) of Earth's land surface is covered in ice including glaciers, ice caps, and the ice sheets of Greenland and Antarctica, most of which are retreating as a consequence of increased atmospheric CO2. Glaciers are teeming with life and supraglacial snow and ice surfaces are often red due to blooms of photoautotrophic algae. Recent evidence suggests the red pigmentation, secondary carotenoids produced in part to thrive under high irradiation, lowers albedo and accelerates melt. However, there are relatively few studies that report the productivity of snow algae communities and the parameters that constrain their growth on snow and ice surfaces. Here, we demonstrate that snow algae primary productivity can be stimulated by the addition of inorganic carbon. We found an increase in light-dependent carbon assimilation in snow algae microcosms amended with increasing amounts of inorganic carbon. Our snow algae communities were dominated by typical cosmopolitan snow algae species recovered from Alpine and Arctic environments. The climate feedbacks necessary to enter and exit glacial/interglacial oscillations are poorly understood. Evidence and models agree that global Snowball events are accompanied by changes in atmospheric CO2 with increasing CO2 necessary for entering periods of interglacial time. Our results demonstrate a positive feedback between increased CO2 and snow algal productivity and presumably growth. With the recent call for bio-albedo effects to be considered in climate models, our results underscore the need for robust climate models to include feedbacks between supraglacial primary productivity, albedo, and atmospheric CO2.

  16. Using the marine unicellular algae in biological monitoring

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    Kapkov V. I.

    2017-06-01

    Full Text Available The possibility of using marine unicellular algae from natural plankton community in biomonitoring of pollution by heavy metals has been investigated. Algae of different taxa from the Mediterranean Sea have been allocated to culture. In the laboratory the culture conditions – i. e. growth medium, temperature, photoperiod, level of artificial light and initial density – have been selected for every species. The impact of heavy metals (Hg, Cd, Cu, Pb in the form of chloride salts on the growth of axenic algae culture has been studied in the modelling experiments. The unicellular marine algae have a very short life cycle, therefore it is possible to use them in the experiments of studying the effect of anthropogenic factors at cellular and population levels on the test-object. With biomonitoring pollution of marine environment by heavy metals and others dangerous toxicants, the major indicators of algae community condition are the cellular cycle and the condition of the photosynthetic apparatus of the cell. The subsequent lysis of cells under the influence of heavy metals leads to the excretion of secondary metabolites which can essentially affect the metal toxicity. The established scales of threshold and lethal concentration of heavy metals for algae of different taxon make it possible to use the ratio of sensitive and resistant species to heavy metals as biological markers when forecasting ecological consequences of pollution of the marine environment by heavy metals. Distinctions in the resistance of different taxon to heavy metals can result in implementing the strategy of selection of test-objects depending on the purposes of the research.

  17. Algoritmos multirecombinativos aplicados al problema de ruteo de vehículos

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    Renzo Ramon Miño

    2014-06-01

    Full Text Available El diseño de algoritmos eficientes para resolver problemas complejos ha sido tradicionalmente uno de los aspectos más importantes en la investigación en el campo de la informática. El objetivo perseguido en este campo es fundamentalmente el desarrollo de nuevos métodos capaces de resolver problemas complejos con el menor esfuerzo computacional posible, mejorando así a los algoritmos existentes. En consecuencia, esto no sólo permite afrontar los problemas de forma más eficiente, sino afrontar tareas vedadas en el pasado debido a su alto costo computacional. Las metaheurísticas son métodos que integran procedimientos de mejora local y estrategias de alto nivel para realizar una búsqueda robusta en el espacio-problema. El problema de ruteo de vehículos es un problema de optimización combinatoria de gran importancia en diferentes entornos logísticos debido a su dificultad (NP-duros y a sus múltiples aplicaciones industriales. Se han propuestos varias soluciones a este problema haciendo uso de heurísticas y metaheurísticas. En este trabajo proponemos dos algoritmos para resolver el problema de ruteo de vehículos con capacidad limitada, utilizando como base un Algoritmo Evolutivo conocido como MCMP-SRI (Stud and Random Inmigrants combinados con Hill- Climbing. Detalles de los algoritmos y los resultados de los experimentos muestran un promisorio comportamiento para resolver el problema.

  18. Uptake of americium-241 by algae and bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Giesy, Jr, J P; Paine, D [Savannah River Ecology Lab., Aiken, S.C. (USA)

    1978-01-01

    The uptake of americium by three algae, Scenedesmus obliguus, Selenastrum capricomutum and Chlorella pyrenosdosa and a bacterium Aeromonas hydrophila was studied. Live and fixed cells of each algal species and live bacterial cells were used. It is shown that algae and bacteria concentrate americium 241 to a high degree which makes them important links in the biomagnification phenomenon which may ultimately lead to a human hazard and be potentially important in recycling Am /sup 241/ in the water column and mobilization from sediments. Chemical fixation of algal cells caused increased uptake which indicated that uptake is by passive diffusion and probably due to chemical alteration of surface binding sites.

  19. The attached algae community near Pickering GS: III

    International Nuclear Information System (INIS)

    McKinley, S.R.

    1982-01-01

    The relationship between attached algae and macro-invertebrates in the nearshore zone of Lake Ontario was investigated in the vicinity of the Pickering 'A' NGS. Measures of faunal density, richness, evenness, and biomass were generally higher from areas which supported attached algae. Gammarus fasciatus, Cricotopus bicinctus, Dicrotendipes spp., Orthocladius obumbratus, Cladotanytarsus spp., Orthocladius spp., and Parakiefferiella spp., were significantly correlated with algal standing crop. All of the above dominant invertebrates ingested epiphytes associated with Cladophora glomerata. Attempts to explain the distribution of the zoobenthic assemblages using the physical/biological characteristics of the study area indicated algal cover, substrate size, wind velocity and water temperature were most important

  20. El problema del control de la Tuberculosis en Colombia

    Directory of Open Access Journals (Sweden)

    Gilberto Rueda P.

    1979-10-01

    Full Text Available

    Bogotá, Noviembre de 1.978
    Señor Presidente de la Academia
    Doctor CésarAugusto Pantoja
    E. S. D.
    Señor Presidente:


    La Comisión con la cual Ud. ha tenido a bien honrarnos, ha analizado el problema del control de la Tuberculosis en Colombia en la siguiente forma:
    Resúmen: La TBC en Colombia como en todos, los países del tercer mundo constituye problema prioritario de salud pública.
    Los datos oficiales colombianos determinan 50.000 pacientes activos en tratamiento y 12.000 casos nuevos bacteriólogicamente diagnosticados por año.
    Se han denunciado numerosos casos de TBC exrrapulmonar no diagnosticables bacteriológicamente.
    La vacunación BCC, de acuerdo con cifras oficiales, cubre el 780/0 de la población infantil globalmente, pero solamente el 300/0 de los menores de 1 año y el 430/0 de los menores de 4 años, lo cual es claramente insuficiente.
    El descubrimiento de casos a base únicamente del recurso bacteriológico debe ser basado en una infraestructura humana y técnica prácticamente perfecta para que éste recurso cumpla un efecto que no sea contraproducente.
    El tratamiento utilizado en Colombia, recomendado por la OMS se hace a base de drogas bacteriostáticas de bajo costo, utilizadas por períodos prolongados que van de 1 año a 18 meses y que provocan un abandono del 230/0 según cifras oficiales.

    La Unión Internacional contra la Tuberculosis con la aquiescencia de la OMS ha estudiado esquemas modernos de tratamiento con las llamadas "drogas esenciales" bacteriolíticas que, en períodos breves (6 a 9 meses curan más del 950/0 de los pacientes. El Seminario Nacional de TBC (Bogotá - abril/78 recomendó la introducción de estas drogas para uso general en el país.
    Se hace un resumen de los principales esquemas recomendados.


  1. PERCEPCIÓN DEL MUNDO: MAPAS MENTALES Y PROBLEMAS SOCIOAMBIENTALES

    Directory of Open Access Journals (Sweden)

    Antonio José Morales Hernández

    Full Text Available Resumen:Las personas construyen su imagen del mundo en relación con relatos que oyen de familiares y amigos, de noticias que observan en los medios de comunicación de masas... También es relevante la influencia del medio escolar, en especial desde materias como la Geografía, que les presenta no sólo hechos y datos del mundo, sino también una representación del planeta en un mapa. En este artículo queremos ofrecer una experiencia empírica sobre la construcción mental del mapamundi por parte de alumnos de Magisterio de Valencia. Con ello queremos mostrar la necesidad de trabajar este contenido de habilidades cartográficas para evitar la deformación de la explicación del planeta Tierra y sus problemas. Palabras ClaveMapas mentales, percepción de los problemas sociambientales, educación en valores. AbstractPeople build their own image of the world in relation to stories they hear from family and friends, news that they observed in the mass media... It is also relevant the influence of school environment, especially from the subject of Geography, which not only presents facts of the world, it is also a representation of the planet on a map.In this paper we want to provide of an empirical experience of the mental construction of the world map made by students that will be primary teachers in Valencia. With all we explained, we want to show the need of working this contents of cartographic skills to prevent deformation of the explanation of planet Earth and its problems.Key WordsMind mapping, perception of socio-environmental issues, education in valuesRésuméLes personnes construissent leur image du monde en rapport avec les récits qu’ils écoutent à d’autres membres de la famille et les amis, les nouvelles qu’ils observent aux mass media... Il est aussi remarquable l’influence du moyen scolaire, spécialement depuis des matières comme la Géographie, qui ne présente que des faits et des renseignements sur le monde, mais

  2. Onicomicoses por fungos emergentes: análise clínica, diagnóstico laboratorial e revisão

    Directory of Open Access Journals (Sweden)

    Araújo Adauto José Gonçalves de

    2003-01-01

    Full Text Available FUNDAMENTOS: As dermatomicoses causadas por fungos emergentes são entidades clínicas raras, à exceção das onicomicoses. Como certos fungos e leveduras podem residir na pele, a positividade em culturas de escamas ungueais deve ser interpretada obrigatoriamente em concordância com os respectivos dados clínicos, exames diretos das amostras, quantificação das colônias isoladas em relação aos pontos de inoculação e, principalmente, deve a positividade ser mantida após a repetição dos cultivos. A invasão da unha por fungos não dermatofíticos (nondermatophytic molds, NDM em diferentes estudos varia de 1,45% a 17,6%. OBJETIVOS: Os objetivos do trabalho são mostrar a ocorrência e realçar a importância dos fungos emergentes como causadores de onicomicose. MÉTODOS: As unhas dos pacientes atendidos nos consultórios dos dermatologistas foram examinadas, e, caso houvesse suspeita clínica de onicomicose, coletavam-se amostras que eram enviadas para exame micológico no laboratório. RESULTADOS: Neste estudo, foram avaliados 2.271 pacientes e diagnosticada onicomicose em 400 deles, sendo 264 com acometimento das unhas do pé, e 136 das unhas da mão. O agente etiológico foi confirmado pelo exame micológico direto e crescimento em cultura. A onicomicose por fungos emergentes representou 4,5% de todas as infecções de unha. Foram detectadas as leveduras do gênero Candida (49% como agentes etiológicos mais freqüentes de onicomicoses nas unhas das mãos e em mulheres. Em contraste, os dermatófitos foram os mais freqüentes de todas as onicomicoses dos pés, no total de 186 (46,5%. CONCLUSÃO: Ao contrário da rotina diagnóstica hoje utilizada, concluiu-se que o diagnóstico correto do agente etiológico da onicomicose não dermatofítica deve obedecer a determinados critérios, dos quais se destaca o conjunto formado pela positividade no exame direto, na cultura, com comprovação na repetição do exame.

  3. Potências médias emergentes e reforma da arquitetura financeira mundial?: Uma análise do BRICS no G20

    Directory of Open Access Journals (Sweden)

    Leonardo Ramos

    2014-06-01

    Full Text Available A partir de 2000, na cúpula de Okinawa, o sistema G7/8 começou um movimento de outreach, ou seja, tanto de "alcançar" aqueles que se encontravam fora quanto de "expandir" o sistema G7/8. Neste sentido, pela primeira vez países não-participantes do G8 foram envolvidos tanto em encontros do G8 quanto em consultas pré-cúpula. Neste processo a cúpula de Gleneagles, em 2005, foi um marco, pois nesta pela primeira vez há um documento conjunto emitido por Brasil, Índia, China, África do Sul e México (BICSAM - Outreach Five ou Grupo dos Cinco (+5. Tal articulação entre tais países tendo como foco o sistema G7/8 vai ocorrer até a cúpula de L’Aquila, em 2009. Não obstante, como desde 2008 o G20 vem lidando com tais questões como um fórum de líderes e a partir de 2009 o BRIC passa a se reunir como coalizão, tal articulação paralela ao G8 perde sua relevância. Neste contexto, uma questão que surge diz respeito à relação entre BRICS e G20. Como se dá a ação de tal bloco emergente neste fórum? Qual seu impacto para as decisões tomadas no âmbito de tal fórum? Qual a importância da China neste processo? Questões deste tipo são relevantes uma vez que muitas abordagens sobre o G20 e sobre as potências médias emergentes falam a respeito da legitimidade e da representatividade do G20 sem, contudo, dar a devida atenção às potências médias emergentes, suas coalizões e formas de engajamento e articulação no âmbito do G20, e é neste contexto que se insere o presente artigo, que busca analisar a inserção e articulação do BRICS no âmbito do G20, suas potencialidades e limites.

  4. La violencia familiar, ¿un problema de salud?

    Directory of Open Access Journals (Sweden)

    Mario C. Muñiz Ferrer

    1998-12-01

    Full Text Available Con el objetivo de profundizar en el estudio de la violencia intrafamiliar y para su mejor conocimiento y enfrentamiento en el área de salud, se realiza un estudio descriptivo de los resultados obtenidos al aplicar el test proyectivo "Lo que no me gusta en mi familia" y una entrevista a 147 niños de 5to. y 6to. grados de la Escuela "Roberto Poland" del Reparto "Antonio Maceo", del municipio Cerro; donde se clasifican las variedades de violencia intrafamiliar y se agrupan éstas por orden de frecuencia. También se calcula la prevalencia de violencia intrafamiliar y se explora la posible relación de la violencia con la ingestión de bebidas alcohólicas. Los resultados obtenidos permiten plantear que la violencia intrafamiliar constituye un problema de salud y que existe relación entre ésta y el consumo de alcoholIn order to deepen into the study of intrafamily violence and to know it and face it better in the health area, it was conducted a descriptive study of the results obtained through the application of a projective test called «What I don’t like about my family» and an interview made to 147 5th and 6th grade children from the «Robert Poland» School in the «Antonio Maceo» District, Cerro municipality. The variaties of intrafamily violence were classified and grouped according to frequency. The prevalence of intrafamily violence was also calculated and the possible relationship existing between violence and the ingestion of alcoholic beverages was explored. According to the results it was concluded that intrafamily violence is a health problem and that it is associated with drinking

  5. Historiografía comparada: problemas y perspectivas

    Directory of Open Access Journals (Sweden)

    Chris Lorenz

    2005-12-01

    Full Text Available In this text contributions related are abridged - direct or indirectly - with the historiography of world war two. The comparative historiography is placed as a gender related to a typology that classified historiography theories over an extended sequence from the general and philosophical to the particular and empirical. Resides, it also places the recent debates on the “fragmentation " of the historiography in a comparative perspective. Due that historiography is the history of the written history -and therefore a reconstruction of reconstructions- we find the problem of comparison in historiography twice. The historiographer is not alone confronting with relative comparative judgments of the historic reconstructions themselves but also related to the historiography reconstructions of those historic reconstructions.//En este texto se compendian contribuciones relacionadas - directa o indirectamente - con la historiografía de la segunda guerra mundial. Se ubica a la historiografía comparada como un género en relación a una tipología que clasifica teorías de historiografía sobre una secuencia extendida de lo general y filosófico a lo particular y empírico. Además, coloca los recientes debates sobre la "fragmentación" de la historiografía en una perspectiva comparada. Debido a que la historiografía es la historia de la historia escrita - y por lo tanto una reconstrucción de reconstrucciones - encontramos el problema de la comparación en historiografía dos veces. El historiógrafo no sólo está confrontado con los juicios comparados relativos a las reconstrucciones históricas mismas, sino también relativas a las reconstrucciones historiográficas de aquellas reconstrucciones históricas.

  6. ANTROPOLOGIA EN LA EMPRESA: ESTRATEGIAS Y PROBLEMAS EN LA INTERVENCION

    Directory of Open Access Journals (Sweden)

    Esteban Ruiz Ballesteros

    2003-08-01

    Full Text Available Entre 1995 y 1 998, el autor ha formado parte del organigrama de una empresa minera implementando diferentes proyectos de intervención como asesor-investigador. La conformación de dicha empresa a mediados de 1995 como sociedad laboral (propiedad de sus trabajadores demandaba un profundo cambio cultural. En concreto, la organización como tal precisaba una remodelación no tanto de la propia estructura de la plantilla, sino más bien de las percepciones y representaciones de lo socio laboral y de las actitudes en tomo al trabajo. En definitiva la plantilla tenía que empezar a ver las mismas cosas de otra manera. Este documento profundiza en los problemas y diferentes estrategias que han surgido después de tres años de trabajo continuado, cuestiones en definitiva que probablemente sean extrapolables a otras experiencias antropológicas más allá de la academia. Y no sólo porque el contexto de la intervención sea una empresa, sino también porque esta forma parte de la Economía Social y contribuye al desarrollo endógeno de una zona sumida en una profunda crisis socioeconómica desde los años ochenta. Se trata, por tanto, de una intervención antropológica en relación al sector privado y al desarrollo local.

  7. El problema social del sida en España

    Directory of Open Access Journals (Sweden)

    JESÚS M. DE MIGUEL

    1991-01-01

    Full Text Available A principios de la década de los noventa, España tiene ya más de siete mil casos de sida, convirtiéndose en el tercer país de Europa con más casos. En la década pasa luego a ser el segundo país europeo. La peculiaridad española es que la mayoría de los casos son drogadictos/as que se inyectan heroína, y no tanto homosexuales. Hay también más casos de mujeres y niños/as que en otros países. Se observa una asociación entre sida y desarrollo: los casos se concentran en las zonas más desarrolladas (País Vasco, Cataluña, Madrid, aunque ataca a personas marginadas. Dado que actualmente no existe cura (ni vacuna, la lucha contra el sida se centra en medidas de prevención, análisis epidemiológico, y estudio de los factores sociales. El análisis sociológico del sida es, pues, imprescindible. El presente artículo define las variables básicas, ofrece un análisis de los datos conocidos durante la primera década (de los ochenta, señala los problemas sociales creados por el sida, y formula las cuestiones que son importantes desde la Sociología.

  8. Problema de la agencia y la cultura corporativa estalinista

    Directory of Open Access Journals (Sweden)

    Yurí Gorbaneff

    2004-12-01

    Full Text Available El problema de la agencia es de los obstáculos para la eficiencia de las organizaciones. A partir de Alchian y Demsetz (1972.la teoría sugiere dos soluciones: la propiedad privada y la cultura corporativa. Sin embargo, aislar el efecto de la cultura sobre las organizaciones no es fácil. La "ingeniería social" estalinista ofrece un material interesante para evaluar los efectos de la cultura corporativa sobre el sistema económico. Acá se sostiene la hipótesis de que los dirigentes soviéticos, al enfrentar los crecientes costos de la agencia tuvieron que inventar otra método, que no fuera la propiedad privada ni el control democrático directo sobre el aparato productivo, para controlar la pérdida de la agencia. Ellos recurrieron a la implantación de la cultura corporativa heroica a nivel nacional. Este trabajo muestra que la propaganda política, el arte, la literatura, los movimientos populares y el culto a la personalidad de Stalin fueran las herramientas gerenciales clave para implantar la cultura corporativa heroica, indispensable en la economía planificada. Su aplicación fue exitosa y generó las condiciones necesarias para la industrialización entre 1920 y 1930 y para el alto desempeño de la economía soviética durante la Segunda Guerra Mundial. La segunda hipótesis consiste en que el fantasma de la agencia, ahuyentado entre 1920 y 1950 por la cultura heroica estalinista, terminó devorando la economía planificada.

  9. Donar: ¿Un problema bioético?

    Directory of Open Access Journals (Sweden)

    Ángel Alonso Salas

    2017-06-01

    Full Text Available El filósofo australiano, Peter Singer escribió un texto que se titula Salvar una vida. Cómo terminar con la pobreza que hace referencia a los motivos que se tienen para que las personas efectúen donaciones y el deber que el ser humano tiene para ayudar a los más necesitados. En este sentido, el presente texto tiene como finalidad, preguntarse acerca del problema bioético que supone el que un sujeto o una institución otorguen algún tipo de donación, bajo el supuesto de ¿cuáles son los motivos éticos que a manera de imperativo categórico subyacen en el donativo? ¿Por qué ante la abismal brecha entre ricos y pobres el donativo se convierte en un paliativo de equidad social? Y ¿cuáles son las desgracias o hechos que obligan a compartir lo poco o mucho que se tiene? Para lograr esto, el texto se dividirá en dos partes, en primer lugar el presentar algunas objeciones que Singer tendría hacia la “Cruzada Nacional contra el Hambre” que se ha impuesto como meta el Gobierno Federal en México en el presente sexenio y, en segundo lugar, lo acontecido hace algunos meses en territorio nacional con la ayuda que miles de personas brindaron a los daminificados por el huracán Ingrid y la tormenta tropical Manuel, en septiembre del 2013, en especial, brindando su solidaridad al pueblo de Guerrero.

  10. Synthetic algae and cyanobacteria: Great potential but what is the exposure risk?

    Science.gov (United States)

    Green algae and cyanobacteria (hereafter, algae) have the attractive properties of relatively simple genomes, rapid growth rates, and an ability to synthesize useful compounds using solar energy and carbon dioxide. They are attractive targets for applications of synthetic biology...

  11. Bioecology of an articulated coralline alga Amphiroa fragilissima from Anjuna, Goa, Central Western Coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ambiye, V.; Untawale, A.G

    An articulated coralline alga Amphiroa fragilissima L. Lam. was found to exhibit spasmogenic and hypotensive activities due to the presence of a biogenic amine. This biologically active alga was studied for its bioecology. Its thallus is multiaxial...

  12. A Adoção da Inovação Aberta Dentro da Estratégia de Internacionalização de Empresas Multinacionais de Economias Emergentes

    Directory of Open Access Journals (Sweden)

    Franciane Freitas Silveira

    2013-01-01

    Full Text Available Com o aumento da relevância dos países emergentes na economia global, acelerou-se o processo de internacionalização das empresas oriundas desses países. Isso pode ser constatado pelo aumento do fluxo de IDE (Investimento Direto Estrangeiro provenientes de empresas de mercados emergentes. Apesar das similaridades com as empresas tradicionais, a literatura indica que as multinacionais emergentes lançam mão de estratégias diferenciadas para traçar sua trajetória de atuação além fronteiras. A partir dessa perspectiva, este estudo exploratório analisa o processo de verticalização e desverticalização das empresas enfocando, sobretudo, a mudança atual do paradigma de inovação, conhecida como inovação aberta. Com base nesse panorama, avaliam-se as estratégias das multinacionais emergentes e o papel de suas subsidiárias, com o intuito compreender como se dá o processo de dispersão das atividades de pesquisa e desenvolvimento (P&D ao longo do processo de internacionalização dessas empresas, e mais particularmente as empresas brasileiras. O estudo mostra, por meio de comparação de estudos teóricos, que o paradigma da inovação aberta traz vantagens para as corporações multinacionais emergentes que o adotam em seus processos de internacionalização das atividades de P&D, mas que as empresas brasileiras não parecem estar se aproveitando em toda sua potencialidade.DOI:10.5585/gep.v3i3.126

  13. Resolución algebraica de problemas estequiométricos

    OpenAIRE

    Reza García, J.

    2009-01-01

    La resolución de problemas, entendida como la metodología para enfrentar situaciones nuevas que impliquen un reto personal, es una estrategia didáctica eficaz que permite generar, consolidar e integrar conocimientos. La resolución de un problema típico en ciencias parte de la comprensión de su enunciado, constituido por un texto corto escrito en lenguaje natural; la traducción de dicha situación al lenguaje matemático constituye un obstáculo en el proceso de resolución de problemas con estruc...

  14. EL ÁLGEBRA LINEAL Y EL PROBLEMA DE MÁXIMOS Y MÍNIMOS

    Directory of Open Access Journals (Sweden)

    Santiago Relos Paco

    2004-01-01

    Full Text Available En este artículo se presenta una aplicación del álgebra lineal al problema de máximos y mínimos de funciones a varias variables. Se considera una función , U abierto y f dos veces diferenciable, se toma un punto tal que , se plantea el problema de determinar si en este punto existe un máximo, mínimo o ninguna de estas situaciones. Se calcula , como se sabe esta segunda derivada es una matriz simétrica en , dependiendo de la signatura de se dará una respuesta al problema planteado.

  15. Algoritmos y complejidad para algunos problemas de dominación

    OpenAIRE

    Mizrahi, Michel Jonathan

    2014-01-01

    Los problemas de dominación forman un área de investigación en crecimiento, debido a la cantidad de aplicaciones que pueden modelar, entre las cuales podemos nombrar redes sociales, sistemas distribuidos, redes biológicas, problemas de localización de instalaciones, etc. En esta tesis estudiamos los siguientes problemas de dominación (i) el conjunto dominante mínimo, (ii) dominación romana, (iii) dominación eficiente por vértices, (iv) dominación eficiente por aristas (también conocida como m...

  16. Controle pós-emergente de plantas daninhas em cenoura Post-emergence weed control in carrot crop

    Directory of Open Access Journals (Sweden)

    Jeferson Zagonel

    1999-03-01

    Full Text Available O experimento foi conduzido em Piraí do Sul-PR no ano de 1995 em solo de textura argilo arenosa, tendo como objetivo avaliar a eficiência e a seletividade do herbicida propaquizafop no controle pós-emergente de plantas daninhas na cultura da cenoura. O delineamento experimental utilizado foi de blocos ao acaso com seis tratamentos e quatro repetições, quais sejam: propaquizafop (100, 125 e 150 g i.a./ha; fluazifop-p-butil (188 g i.a./ha; testemunha capinada e testemunha sem capina. A cultivar de cenoura utilizada foi Nantes Tim Tom semeada em 15 de junho, com espaçamento de 0,25 x 0,05 m, em parcelas com área útil de 5,00 x 1,00 m. As plantas daninhas predominantes foram Brachiaria plantaginea (capim-papuã, Digitaria horizontalis (capim-milhã e Eleusine indica (capim pé-de-galinha. As avaliações foram efetuadas aos 15, 30 e 45 dias após a aplicação dos tratamentos. Observou-se que o herbicida propaquizafop, nas doses de 100, 125 e 150 g i.a./ha foi eficiente no controle sobre capim-papuã, capim-milhã e capim pé-de-galinha. O controle de plantas daninhas realizado através de herbicidas proporcionou a mesma produção obtida com o controle manual. A perda na produção ocasionada pela presença de plantas daninhas foi da ordem de 76,4%. Não foram observados efeitos fitotóxicos nas plantas de cenoura que pudessem ser atribuídos aos produtos utilizados.The presented field trial was conducted in 1995 in Piraí do Sul, Paraná State, Brazil, on a sand-clay texture soil, to evaluate the efficiency and selectivity of propaquizafop on carrot crop weed control. The experiment was laid out in a randomized block design with six treatments and four replications, and 5.00 x 1.00 m plots. The treatmens were: propaquizafop (100, 125 and 150 g a.i/ha; fluazifop-p-butil (188 g a.i/ha; control with weeding and control without weeding. The carrot cultivar Nantes Tim Tom was sown on June 15 with plants spaced 0.25 x 0.05 m. The prevalent weeds

  17. Cultivation Strategy for Freshwater Macro- and Micro-Algae as Biomass Stock for Lipid Production

    OpenAIRE

    Verawaty, Marieska; Melwita, Elda; Apsari, Putri; Mayumi, Mayumi

    2017-01-01

    In this research, an algae cultivation strategy was studied. Integrating algae cultivation with wastewater treatment is currently seen as one of the most economical ways of producing algae biomass. A combination of an anaerobic baffled reactor (ABR) and a constructed wetland (CW) was applied for treating domestic wastewater with an additional collection tank for improving effluent quality. The effluent produced from the three stages was used as algae cultivation media and suplemented with 10%...

  18. New methodologies for the integration of power plants with algae ponds

    NARCIS (Netherlands)

    Schipper, K.; Gijp, S. van der; Stel, R.W van der; Goetheer, E.L.V.

    2013-01-01

    It is generally recognized that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient

  19. Treatment Failure Due to Emergence of Resistance to Carbapenem during Therapy for Shewanella algae Bacteremia

    OpenAIRE

    Kim, Dong-Min; Kang, Cheol-In; Lee, Chang Seop; Kim, Hong-Bin; Kim, Eui-Chong; Kim, Nam Joong; Oh, Myoung-don; Choe, Kang-Won

    2006-01-01

    We describe a case of bacteremia due to imipenem-susceptible Shewanella algae. Despite treatment with imipenem, the patient developed a spinal epidural abscess, from which imipenem-resistant S. algae was isolated. The development of resistance should be monitored when S. algae infection is treated with imipenem, even though the strain is initially susceptible to imipenem.

  20. A review of the taxonomical and ecological studies on Netherlands’ Algae

    NARCIS (Netherlands)

    Koster, Joséphine Th.

    1939-01-01

    The earliest account of the Netherlands’ Algae appeared in 1781 in D. de Gorter, Flora VII Prov. Belgii foederati indigen. Here, however, in the Algae lichens and liverworts have been incorporated. The true Algae, of which 35 are enumerated, are principally marine, though also aërophytical and

  1. Distribution and biomass estimation of shell-boring algae in the intertidal area at Goa India

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Sharma, S.; Lande, V.

    The distribution and frequency of shell-boring green and blue-green algae in the intertidal at Goa, India were studied. The green alga Gomontia sp. and the blue green algae Hyella caespitosa Bornet et Flahault, H. gigas Lucas et Golubic...

  2. Transformações globais, potências emergentes e Cooperação Sul-Sul: desafios para a cooperação europeia

    OpenAIRE

    Pino, Bruno Ayllón

    2012-01-01

    A União Europeia (UE) e seus Estados Membros enfrentam o desafio de adaptar sua política de cooperação para o desenvolvimento a um mundo marcado por rápidas mudanças na criação e distribuição da riqueza e na difusão do poder. A ascensão dos países emergentes, o auge da Cooperação Sul-Sul (CSS), os avanços na luta contra a pobreza em Países de Renda Média (PRM), ou o impacto traumático da crise nos países da Organização para a Cooperação e o Desenvolvimento Econômico (OCDE), são fatores que or...

  3. Tecnologías y pedagogías emergentes instrumentadas en un Mooc en la Universidad Técnica Particular de Loja (UTPL)

    OpenAIRE

    Jara Roa, Dunia I.; Ramírez Montoya, María S.; Cabezas González, Marcos

    2015-01-01

    En esta comunicación se presenta la forma en que se utilizaron  las tecnologías y  las pedagogías emergentes para la educación abierta y masiva,  en la Universidad Técnica Particular de Loja (UTPL).  Se inicia con  la definición conceptual de los términos citados  y luego se presenta la forma en que fueron implementados en un Mooc, tratando de despejar la siguiente inquietud ¿en un Mooc es posible ejecutar el trabajo colaborativo teniendo una población participante heterogénea y geográficamen...

  4. Convergência e transmídia: galáxias semânticas e narrativas emergentes em jornalismo

    Directory of Open Access Journals (Sweden)

    Geane Alzamora

    2012-06-01

    Full Text Available Este artigo procura discutir as possibilidades de aplicação no Jornalismo do conceito de narrativa transmidiática, proposto por Henry Jenkins (2003 no âmbito das narrativas ficcionais. Aborda inicialmente as definições de Transmedia Storytelling, investiga as diferenças conceituais entre convergência e transmídia e propõe uma abordagem própria do conceito de transmídia no universo jornalístico, fundada na perspectiva do conhecimento produzido em dimensão transmidiática e nas especificidades informacionais dos formatos. Conclui com uma exploração inicial de exemplos de narrativas emergentes no contexto do jornalismo transmidiático, como o Jornalismo de Imersão e os newsgames, sugerindo que o experimentalismo seja um aspecto marcante da narrativa transmídia.

  5. La influencia de las TIC en la construcción del mestizaje cultural: el otakismo como un fenómeno emergente de la sociedad en red

    Directory of Open Access Journals (Sweden)

    Verónica Paulina Proaño Vallejo

    2015-12-01

    Full Text Available La complejidad de las relaciones contemporáneas dificulta enormemente la clasificación del locus y la visibilización de los significados imperantes en los imaginarios. En el siglo XXI cobra especial relevancia la ciberesfera, un paradigma emergente que estimula el surgimiento de culturas gestionadas desde el campo virtual, como la del otakismo. Con este ensayo, describimos las principales características de un tipo de cultura que continúa los esfuerzos iniciados durante los siglos XIX y XX y que tiene una vigorosa presencia tanto dentro de la llamada sociedad de consumo como de la sociedad en red. El resultado de la interrelación de estos vectores enunciados produce una integración simbólica identificada por el mestizaje de algunos valores locales japoneses con el lenguaje audiovisual y la tecnología.

  6. Algunas relaciones entre algoritmos y resolución de problemas

    Directory of Open Access Journals (Sweden)

    Jaime Fonseca González

    2012-04-01

    Full Text Available Como parte del estudio realizado en la tesis de maestría “Uso de algoritmos en la resolución de problemas sobre isometrías del plano. Un estudio de caso”, se han identificado diversas formas en que se relacionan los algoritmos con la resolución de problemas, no sólo como procesos mecánicos, sino como fuente de información en el planteamiento de estrategias al resolver un problema, de modo que surgen algunas maneras en que se da esta relación, ejemplificando cada una de ellas con problemas cuyo objeto matemático central son las isometrías del plano.

  7. Biological removal of algae in an integrated pond system

    CSIR Research Space (South Africa)

    Meiring, PGJ

    1995-01-01

    Full Text Available A system of oxidation ponds in series with a biological trickling filter is described. It was known that this arrangement was incapable of reducing effectively the levels of algae present in the pond liquid even though nitrification was effected...

  8. The alga Trachydiscus minutus (Pseudostaurastrum minutum): growth and composition

    Czech Academy of Sciences Publication Activity Database

    Iliev, I.; Petkov, G.; Lukavský, Jaromír; Furnadzhieva, S.; Andreeva, R.; Bankova, V.

    2011-01-01

    Roč. 36, 3-4 (2011), 222-231 ISSN 1312-8183 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516 Keywords : algae, * fatty acids * pilot plant cultivation Subject RIV: EF - Botanics

  9. Algas vene kirjanduse nädal / Raimu Hanson

    Index Scriptorium Estoniae

    Hanson, Raimu, 1957-

    2008-01-01

    22. septembril algas Tartu Linnaraamatukogus vene kirjanduse nädal Inga Ivanova raamatu "Kadunud koerte saladus" esitlusega; 24. sept. toimub Igor Kotjuhi autoriõhtu; 26.-28. toimub Tartu Ülikoolis vene kirjandusele pühendatud rahvusvaheline teaduskonverents. Raamatukogust saab osta ka venekeelseid raamatuid

  10. Evaluation of the activated carbon prepared from the algae ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... algae Gracilaria for the biosorption of Cu(II) from aqueous ... adsorbent dose, and metal ions concentration, were considered. ... precipitation, membrane separation, adsorption and ion exchange processes which are being used to remove copper ... Copper solutions of different concentration (50-180 ppm).

  11. Lab on a chip technologies for algae detection : a review

    NARCIS (Netherlands)

    Schaap, A.M.; Rohrlack, T.; Bellouard, Y.J.

    2012-01-01

    Over the last few decades, lab on a chip technologies have emerged as powerful tools for high-accuracy diagnosis with minute quantities of liquid and as tools for exploring cell properties in general. In this paper, we present a review of the current status of this technology in the context of algae

  12. Experimental analysis of the competition between algae and duckweed

    NARCIS (Netherlands)

    Roijackers, R.M.M.; Szabo, S.; Scheffer, M.

    2004-01-01

    We performed indoor competition experiments between algae and Lemna gibba L. in order to unravel mechanisms of competition. To separate effects of shading and physical interference from nutrient competition we grew the two groups physically separated while sharing the same water. A multifactorial

  13. Switchable photosystem-II designer algae for photobiological hydrogen production

    Science.gov (United States)

    Lee, James Weifu

    2010-01-05

    A switchable photosystem-II designer algae for photobiological hydrogen production. The designer transgenic algae includes at least two transgenes for enhanced photobiological H.sub.2 production wherein a first transgene serves as a genetic switch that can controls photosystem II (PSII) oxygen evolution and a second transgene encodes for creation of free proton channels in the algal photosynthetic membrane. In one embodiment, the algae includes a DNA construct having polymerase chain reaction forward primer (302), a inducible promoter (304), a PSII-iRNA sequence (306), a terminator (308), and a PCR reverse primer (310). In other embodiments, the PSII-iRNA sequence (306) is replaced with a CF.sub.1-iRNA sequence (312), a streptomycin-production gene (314), a targeting sequence (316) followed by a proton-channel producing gene (318), or a PSII-producing gene (320). In one embodiment, a photo-bioreactor and gas-product separation and utilization system produce photobiological H.sub.2 from the switchable PSII designer alga.

  14. Rainfall changes affect the algae dominance in tank bromeliad ecosystems

    Science.gov (United States)

    Pires, Aliny Patricia Flauzino; Leal, Juliana da Silva; Peeters, Edwin T. H. M.

    2017-01-01

    Climate change and biodiversity loss have been reported as major disturbances in the biosphere which can trigger changes in the structure and functioning of natural ecosystems. Nonetheless, empirical studies demonstrating how both factors interact to affect shifts in aquatic ecosystems are still unexplored. Here, we experimentally test how changes in rainfall distribution and litter diversity affect the occurrence of the algae-dominated condition in tank bromeliad ecosystems. Tank bromeliads are miniature aquatic ecosystems shaped by the rainwater and allochthonous detritus accumulated in the bases of their leaves. Here, we demonstrated that changes in the rainfall distribution were able to reduce the chlorophyll-a concentration in the water of bromeliad tanks affecting significantly the occurrence of algae-dominated conditions. On the other hand, litter diversity did not affect the algae dominance irrespective to the rainfall scenario. We suggest that rainfall changes may compromise important self-reinforcing mechanisms responsible for maintaining high levels of algae on tank bromeliads ecosystems. We summarized these results into a theoretical model which suggests that tank bromeliads may show two different regimes, determined by the bromeliad ability in taking up nutrients from the water and by the total amount of light entering the tank. We concluded that predicted climate changes might promote regime shifts in tropical aquatic ecosystems by shaping their structure and the relative importance of other regulating factors. PMID:28422988

  15. New bromotriterpene polyethers from the Indian alga Chondria armata

    Digital Repository Service at National Institute of Oceanography (India)

    Ciavatta, M.L.; Wahidullah, S.; DeSouza, L.; Scognamiglio, G.; Cimino, G.

    Six new bromotriterpene polyethers, armatol A-F (1-6), with a rearranged carbon skeleton, were isolated from the Indian Ocean red alga Chondria armata. The structures were characterized by spectroscopic techniques, in particular 1D- and 2D-NMR...

  16. Meteorological effects on variation of airborne algae in Mexico

    Science.gov (United States)

    Rosas, Irma; Roy-Ocotla, Guadalupe; Mosiño, Pedro

    1989-09-01

    Sixteen species of algae were collected from 73.8 m3 of air. Eleven were obtained in Minatitlán and eleven in México City. The data show that similar diversity occurred between the two localities, in spite of the difference in altitude. This suggests that cosmopolitan airborne microorganisms might have been released from different sources. Three major algal divisions (Chlorophyta, Cyanophyta and Chrysophyta) formed the airborne algal group. Also, a large concentration of 2220 algae m-3 was found near sea-level, while lower amounts were recorded at the high altitude of México City. The genera Scenedesmus, Chlorella and Chlorococcum dominated. Striking relationships were noted between the concentration of airborne green and blue-green algae, and meteorological conditions such as rain, vapour pressure, temperature and winds for different altitudes. In Minatitlán a linear relationship was established between concentration of algae and both vapour pressure (mbar) and temperature (° C), while in México City the wind (m s-1) was associated with variations in the algal count.

  17. EFFECT OF BLUE GREEN ALGAE ON SOIL NITROGEN

    African Journals Online (AJOL)

    Yagya Prasad Paudel

    2012-07-31

    Jul 31, 2012 ... associated with soil dessication at the end of the cultivation cycle and algal growth ... blue-green algae (BGA) on soil nitrogen was carried out from June to December 2005. .... Nitrogen fixation by free living Micro-organisms.

  18. Fatty acid amides from freshwater green alga Rhizoclonium hieroglyphicum.

    Science.gov (United States)

    Dembitsky, V M; Shkrob, I; Rozentsvet, O A

    2000-08-01

    Freshwater green algae Rhizoclonium hieroglyphicum growing in the Ural Mountains were examined for their fatty acid amides using capillary gas chromatography-mass spectrometry (GC-MS). Eight fatty acid amides were identified by GC-MS. (Z)-9-octadecenamide was found to be the major component (2.26%).

  19. Enhanced high energy efficient steam drying of algae

    International Nuclear Information System (INIS)

    Aziz, Muhammad; Oda, Takuya; Kashiwagi, Takao

    2013-01-01

    Highlights: • Brown algae drying processes based on heat circulation technology (HC) were proposed. • HC was developed on exergy recovery through exergy elevation and heat pairing. • The energy efficiency of the proposed drying processes was evaluated. • Significant reduction of energy input and CO 2 emission in drying is readily achieved. - Abstract: State-of-the-art brown algae drying processes based on heat circulation technology were proposed, and their performance with respect to energy consumption was evaluated. Heat circulation technology was developed using the principle of exergy recovery performed through exergy elevation and effective heat pairing for both sensible and latent heat. Two steam drying processes based on heat circulation technology for algae drying were proposed, involving heat circulation with or without steam recirculation. The proposed processes were compared with the conventional heat recovery system employing heat cascade technology. Brown algae Laminaria japonica was selected as the test sample. From the results, it is very clear that both proposed drying processes can reduce the required drying energy significantly by up to 90% of that required in conventional heat recovery drying. Furthermore, the temperature–enthalpy diagram for each process shows that in heat circulation technology based drying, the curves of both hot and cold streams are almost parallel, resulting in the minimization of exergy losses

  20. Uptake of tritiated lysine by fresh water alga, Scenedesmus obliquus

    International Nuclear Information System (INIS)

    Gogate, S.S.; Krishnamoorthy, T.M.

    1983-01-01

    Tritium uptake by fresh water alga. S.obliquus was studied using tritium labelled lysine, and a sequential solvent extraction procedure was used to study the distribution of tritium in different organic constituents of the algal cells. The accumulation of tritium in the algal cells was found to be 3-4 orders of magnitude more than that obtained for tritiated water. (author)

  1. Seasonal abundance of epipelic algae and sediment parameters of ...

    African Journals Online (AJOL)

    Amadi-Ama creek is located close to sources of wastes which are introduced into the creek thus altering the physico-chemical parameters and the aquatic biota of the creek due to variation in nutrient load of the water. The seasonal abundance of epipelic algae and sediment parameters of Amadi-Ama Creek were ...

  2. Evaluation of Algae from the effluent of Dandot cement company ...

    African Journals Online (AJOL)

    Twenty genera and fifty species of algae have been reported from the effluent water of Dandot Cement Company. They include thirteen genera and thirty five species from Chlorophyceae; three genera and six species from Cyanophyceae and four genera and nine species from Bacillariophyceae. Camera Lucida drawings ...

  3. Preliminary Studies on the Occurrence of Freshwater Epipelic Algae ...

    African Journals Online (AJOL)

    The occurrence and composition of the freshwater algae in the epipelon were determined at three sites, namely Machigeni, Manhean and Weija, located in the coastal savanna thicket and grassland vegetation zone of the River Densu basin in southern Ghana. Samples of sediments from the water-substratum interface ...

  4. Prospective effect of red algae, Actinotrichia fragilis, against some ...

    African Journals Online (AJOL)

    Most of the current treatment strategies for OA are effective for symptoms relief but are accompanied with adverse side effect. Thus, the present investigation aims to evaluate the potential influence of red algae, Actinotrichia fragilis, in the dry powder form (AFP) or gel form (AFG) on some relevant factors of OA progression as ...

  5. Effects of UV-B irradiated algae on zooplankton grazing

    NARCIS (Netherlands)

    Lange, de H.J.; Lürling, M.F.L.L.W.

    2003-01-01

    We tested the effects of UV-B stressed algae on grazing rates of zooplankton. Four algal species ( Chlamydomonas reinhardtii, Cryptomonas sp., Scenedesmus obliquus and Microcystis aeruginosa) were used as food and fed to three zooplankton species ( Daphnia galeata, Bosmina longirostris and

  6. Epiphytic Algae study from pool of Ammiq (Bekaa, Lebanon)

    International Nuclear Information System (INIS)

    SLIM, K.

    1984-01-01

    In this particular place which constitutes the pool of Ammiq, 104 species and varieties have been collected. The diatoms constitute in themselves 85% of the algae population. This is an epiphytic microflora which is attached to the immerged macrophytics on this above mentioned place . (author)

  7. The occurrence of hormesis in plants and algae

    DEFF Research Database (Denmark)

    Cedergreen, Nina; Streibig, Jens Carl; Kudsk, Per

    2007-01-01

    This paper evaluated the frequency, magnitude and dose/concentration range of hormesis in four species: The aquatic plant Lemna minor, the micro-alga Pseudokirchneriella subcapitata and the two terrestrial plants Tripleurospermum inodorum and Stellaria media exposed to nine herbicides and one...

  8. Chemical constituents of the red alga @iAcanthophora spicifera@@

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; DeSouza, L.; Kamat, S.Y.

    Analysis of the petroleum-wither and chloroform extracts of the marine red alga @iAcanthophora spicifera@@ led to the isolation of a sterol, cholesterol, fatty acids, stearic, palmitic, behenic (C@d22@@) and arachidic acids (C@d20@@) and a fatty...

  9. Decreased abundance of crustose coralline algae due to ocean acidification

    Science.gov (United States)

    Kuffner, Ilsa B.; Andersson, Andreas J; Jokiel, Paul L.; Rodgers, Ku'ulei S.; Mackenzie, Fred T.

    2008-01-01

    Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios1. Because the ocean absorbs carbon dioxide from the atmosphere2, 3, 4, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states2, 5. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates6, 7, with potentially severe implications for marine ecosystems, including coral reefs6, 8, 9, 10, 11. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallow-water habitats12, 13, 14. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

  10. Bioremediation of acid mine drainage using algae strains: A review

    Directory of Open Access Journals (Sweden)

    J.K. Bwapwa

    2017-12-01

    Full Text Available Acid mine drainage (AMD causes massive environmental concerns worldwide. It is highly acidic and contains high levels of heavy metals causing environmental damage. Conventional treatment methods may not be effective for AMD. The need for environmental remediation requires cost effective technologies for efficient removal of heavy metals. In this study, algae based systems were reviewed and analyzed to point out the potentials and gaps for future studies. Algae strains such as Spirulina sp., Chlorella, Scenedesmus, Cladophora, Oscillatoria, Anabaena, Phaeodactylum tricornutum have showed the capacity to remove a considerable volume of heavy metals from AMD. They act as “hyper-accumulators” and “hyper-adsorbents” with a high selectivity for different elements. In addition, they generate high alkalinity which is essential for precipitation of heavy metals during treatment. However, algae based methods of abating AMD are not the ultimate solution to the problem and there is room for more studies. : The bioremediation of acid mine drainage is achievable with the use of microalgae. Keywords: Acid mine drainage, Algae strains, Contamination, Heavy metals, Bioremediation

  11. Exchange of certain radionuclides between environment and freshwater algae

    International Nuclear Information System (INIS)

    Marchyulenene, E. D.P.

    1978-01-01

    Data on the dynamics and levels of accumulation of strontium, cesium, cerium and ruthenium radionuclides by Charophyta and Cladophora fresh-water algae are presented. An attempt has been made to investigate some processes that accompany the accumulation of radionuclides by plants. Under experimental conditions, the intensity and levels of radionuclide accumulation can be presented in the following order: 144 Ce> 106 Ru> 90 Sr> 137 Cs. The dynamics of radionuclide accumulation varied greatly with the radionuclide and the algae species studied. The 144 Ce accumulation coefficients (AC) in the course of experiment (from 3 hours to 16 days) increased 8-, 9-, 23.4-, 27-, 14.3- and 20.4-fold for Cladophora glomerata, Nitella syncarpa, Nitellopsis obtusa, Chara vulgaris, Ch. rudis, and Ch. aspera, respectively. In the case of 106 Ru, AC for C.glomerata, N. syncarapa, Ch. vulgaris and Ch. rudis increased 34-, 18-,24- and 23-fold, respectively. In all algae species studied the equilibrium of radionuclide accumulation was attained after 2-4 days of experiment. Levels of accumulated 90 Sr and 137 Cs in most species depended on the season while that of 144 Cs and 106 Ru remained constant throughout the vegetation period. The levels of radionuclide elimination, like the accumulation levels, are shown to depend on both isotopes and algae species

  12. Biochar production from freshwater algae by slow pyrolysis

    Directory of Open Access Journals (Sweden)

    Tanongkiat Kiatsiriroat

    2012-05-01

    Full Text Available A study on the feasibility of biochar production from 3 kinds of freshwateralgae, viz. Spirulina, Spirogyra and Cladophora, was undertaken. Using a slow pyrolysis process in a specially designed reactor, biochar could be generated at 550oC under nitrogen atmosphere. The yields of biochar were between 28-31% of the dry algae.

  13. Homogeneity of Danish environmental and clinical isolates of Shewanella algae

    DEFF Research Database (Denmark)

    Vogel, Birte Fonnesbech; Holt, H.M.; Gerner-Smidt, P.

    2000-01-01

    amplified polymorphic DNA analysis, no clonal relationship between infective strains was found. From several patients, clonally identical strains of S. algae were reisolated up to 8 months after the primary isolation, indicating that the same strain may be able to maintain the infection....

  14. Two-Step Evolution of Endosymbiosis between Hydra and Algae

    KAUST Repository

    Ishikawa, Masakazu; Shimizu, Hiroshi; Nozawa, Masafumi; Ikeo, Kazuho; Gojobori, Takashi

    2016-01-01

    In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor

  15. Phytotoxicity, bioaccumulation and degradation of isoproturon in green algae.

    Science.gov (United States)

    Bi, Yan Fang; Miao, Shan Shan; Lu, Yi Chen; Qiu, Chong Bin; Zhou, You; Yang, Hong

    2012-12-01

    Isoproturon (IPU) is a pesticide used for protection of land crops from weed or pathogen attack. Recent survey shows that IPU has been detected as a contaminant in aquatic systems and may have negative impact on aquatic organisms. To understand the phytotoxicity and potential accumulation and degradation of IPU in algae, a comprehensive study was performed with the green alga Chlamydomonas reinhardtii. Algae exposed to 5-50 μg L(-1) IPU for 3d displayed progressive inhibition of cell growth and reduced chlorophyll fluorescence. Time-course experiments with 25 μg L(-1) IPU for 6d showed similar growth responses. The 72 h EC50 value for IPU was 43.25 μg L(-1), NOEC was 5 μg L(-1) and LOEC was 15 μg L(-1). Treatment with IPU induced oxidative stress. This was validated by a group of antioxidant enzymes, whose activities were promoted by IPU exposure. The up-regulation of several genes coding for the enzymes confirmed the observation. IPU was shown to be readily accumulated by C. reinhardtii. However, the alga showed a weak ability to degrade IPU accumulated in its cells, which was best presented at the lower concentration (5 μg L(-1)) of IPU in the medium. The imbalance of accumulation and degradation of IPU may be the cause that resulted in the detrimental growth and cellular damage. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Potential of wastewater grown algae for biodiesel production and CO

    African Journals Online (AJOL)

    Algae have been proposed as a potential renewable fuel source. Photosynthetic CO2 fixation to substrates that can be converted to biodiesel by microalgae is thought to be a feasible technology with energy-saving and environment-friendly approach. In the present study, potential of microalgae, from wastewater ...

  17. Evaluation of filamentous green algae as feedstocks for biofuel production.

    Science.gov (United States)

    Zhang, Wei; Zhao, Yonggang; Cui, Binjie; Wang, Hui; Liu, Tianzhong

    2016-11-01

    Compared with unicellular microalgae, filamentous algae have high resistance to grazer-predation and low-cost recovery in large-scale production. Green algae, as the most diverse group of algae, included numerous filamentous genera and species. In this study, records of filamentous genera and species in green algae were firstly censused and classified. Then, seven filamentous strains subordinated in different genera were cultivated in bubbled-column to investigate their growth rate and energy molecular (lipid and starch) capacity. Four strains including Stigeoclonium sp., Oedogonium nodulosum, Hormidium sp. and Zygnema extenue were screened out due to their robust growth. And they all could accumulate triacylglycerols and starch in their biomass, but with different capacity. After nitrogen starvation, Hormidium sp. and Oedogonium nodulosum respectively exhibited high capacity of lipid (45.38% in dry weight) and starch (46.19% in dry weight) accumulation, which could be of high potential as feedstocks for biodiesel and bioethanol production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Carbon Partitioning in Green Algae (Chlorophyta and the Enolase Enzyme

    Directory of Open Access Journals (Sweden)

    Jürgen E. W. Polle

    2014-08-01

    Full Text Available The exact mechanisms underlying the distribution of fixed carbon within photoautotrophic cells, also referred to as carbon partitioning, and the subcellular localization of many enzymes involved in carbon metabolism are still unknown. In contrast to the majority of investigated green algae, higher plants have multiple isoforms of the glycolytic enolase enzyme, which are differentially regulated in higher plants. Here we report on the number of gene copies coding for the enolase in several genomes of species spanning the major classes of green algae. Our genomic analysis of several green algae revealed the presence of only one gene coding for a glycolytic enolase [EC 4.2.1.11]. Our predicted cytosolic localization would require export of organic carbon from the plastid to provide substrate for the enolase and subsequent re-import of organic carbon back into the plastids. Further, our comparative sequence study of the enolase and its 3D-structure prediction may suggest that the N-terminal extension found in green algal enolases could be involved in regulation of the enolase activity. In summary, we propose that the enolase represents one of the crucial regulatory bottlenecks in carbon partitioning in green algae.

  19. Oxytocic principle of red alga @iAmphiroa fragilissima@@

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; De; Das, B.; Patnaik, G.K.

    The crude aqueous methanolic extract of the marine red alga @iAmphiroa fragilissima@@ has been reported as exhibiting oxytocic and spasmogenic activity at a dose of 50 ~kg/ml. The activity is located in the water soluble fraction and has been found...

  20. Halogenated terpenoids from the brown alga Padina tetrastromatica (HAUCK)

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Bhat, K.L.; Das, B.; Kamat, S.Y.; Harnos, S.

    ranging from 14:0 to 22:0 with palmitic acid (16:0, 67.4%) and oleic acid (18:1, 17.1%) being the major constituents, have been isolated from the pet, ether soluble fraction of the methanol extract of the brown alga Padina tetrastromatica...

  1. Ontem, hoje e amanhã: sobre a web e as ferramentas colaborativas emergentes para o professor de língua estrangeira

    Directory of Open Access Journals (Sweden)

    Alan Ricardo Costa

    2016-12-01

    Full Text Available Considerando que “[...] só é possível prever o futuro quando se olha para o passado” (LEFFA, 2012, p.404, se faz necessário investigar o passado e o presente da web, das Tecnologias de Informação e Comunicação (TIC e das tecnologias educacionais para o ensino e a aprendizagem de Línguas Estrangeira (LE, para especular sobre o futuro, por mais incerto que este seja. Assim, o objetivo deste trabalho é apresentar e discutir as mudanças nas TIC e ferramentas educacionais, do passado para o presente, para apontar perspectivas emergentes ao alcance do professor de LE. Os resultados - que partem de observações sobre alguns recursos e ferramentas digitais disponíveis no Repositório Acción E/LE (Espanhol como Língua Estrangeira - indicam que: (1 recursos online e TIC em geral não tendem a negar o antigo, mas sim incorporá-lo ao novo, fazendo com que tais recursos estejam em contínua evolução; (2 esta evolução, consequentemente, acontece de forma gradual e complexa: nem todas as TIC e tecnologias educacionais mudam ao mesmo tempo ou na mesma medida; (3 a tendência mais visível e emergente é, possivelmente, a colaboração em massa subjacente às ferramentas e seus usos, o que explica o surgimento dos Recursos Educacionais Abertos (REA, por exemplo.

  2. QR académico: una propuesta didáctica emergente con apropiación de la cultura juvenil

    Directory of Open Access Journals (Sweden)

    Flora Arteaga Bustos

    2016-08-01

    Full Text Available Presentar una propuesta didáctica emergente para el uso del celular dentro del aula mediante la utilización de códigos QR (quick response- respuesta rápida- rige el objetivo del artículo. Se basa en la sistematización de teorías previas, identificadas en la búsqueda por difundir las nuevas estrategias educativas tecnológicas que se desarrollan en el ámbito venezolano. Su fundamentación se basa en la promoción de competencias digitales cónsonas a la cultura juvenil, la mejora de la calidad educativa y la optimización del desempeño estudiantil, aspectos fundamentales de las metas educativas de la CEPAL, de la OEI y de la UNESCO. El método utilizado es cuali-cuantitativo, para la técnica se diseñó una entrevista realizada al docente y un cuestionario dirigido a 20 de sus estudiantes. Los resultados indican mayor motivación e interés de los alumnos por la lectura y la investigación, así como un notable desarrollo del trabajo cooperativo-participativo. Se considera el establecer una mayor apropiación de las actividades en el aula consolidando la cultura juvenil, por lo que se demuestra el potencial de los códigos QR como herramienta educativa emergente. Como obstáculo evidenciado con el uso de la aplicación se menciona la deficiente interconectividad a la Internet. Se recomiendan procesos de difusión sobre nuevas experiencias docentes, como propuestas significativas de transposición didáctica tecnológica.

  3. Las TIC en educación: metaanálisis sobre investigación y líneas emergentes en México

    Directory of Open Access Journals (Sweden)

    Karen Michelle Olivares Carmona

    2016-10-01

    Full Text Available El estudio que aquí presentamos tiene el objetivo de comentar, analizar y categorizar de manera descriptiva las líneas de generación y aplicación del conocimiento (LGAC de diversos productos de investigación científica relacionados con la integración de las tecnologías de la información y la comunicación (TIC al proceso educativo en México. Los objetivos específicos consisten en identificar la población a la que se orientan las investigaciones; comparar los tipos de población con mayor y menor número de investigaciones; comparar las LGAC que cuentan con más y menos estudios; y reconocer líneas emergentes de investigación. La metodología consideró criterios de inclusión para seleccionar repositorios y tipos de documentos a analizar (se eligieron 470 documentos; también se precisaron las LGAC sobre las cuales realizamos el análisis. Entre los resultados, encontramos que los niveles educativos con mayor y menor número de investigaciones son la educación superior y el preescolar, respectivamente. Los principales vacíos de conocimiento se localizaron en áreas de gestión y calidad de programas educativos y de políticas educativas en relación con las TIC. Las líneas emergentes de investigación estuvieron vinculadas a la educación de adultos tardíos, población indígena y estudiantes con necesidades educativas especiales.

  4. ALGUNAS CONSIDERACIONES SOBRE EL PROBLEMA DE LA "MUERTE CEREBRAL"

    Directory of Open Access Journals (Sweden)

    Juan Mendoza Vega

    1978-10-01

    Full Text Available

    La muerte, ese momento final y hasta ahora inevitable que señala el término de la existencia terrestre de los seres, ha causado al hombre desde la más remota antigüedad una explicable angustia. No solo como protagonista -jamás mejor aplicado el término- sino en cuanto espectador conmovido por la desaparición de seres que le son queridos.

    Tal angustia ha movido los esfuerzos, cada vez más exitosos y complejos, para luchar contra las causas de la muerte; y ha desembocado, al acercarse el fin de otro milenio, en una situación, que parece absurdamente paradójica: la de una humanidad que, teniendo cada vez más y mejores medios para sostener las funciones corporales que aún persistimos en llamar "vitales" (reemplazando o estimulando una y otra vez en su función a los órganos que la han perdido empieza a preguntarse si es lícito y hasta cuándo el usar de tales medios, en presencia de un ser que ya no tiene las funciones superiores de su sistema nervioso ni la posibilidad razonable de recuperarlos.

    Este trabajo pretende dar una visión sintética del problema, con especial interés por la realidad colombiana y terminando con algunas propuestas acordes con esa realidad.


    Aspecto fisiológico de la muerte.
    Se aceptó durante siglos como definición de "muerte" la que vincula este fenómeno a la cesación de los ritmos respiratorios y cardíaco. Pero la aparición y perfeccionamiento de los aparatos y técnicas de respiración asistida o controlada, los desfibriladores cardíacos, las drogas capaces de modificar el ritmo del corazón, la presión arterial y otros parámetros, la creación de las "Unidades de Cuidados Intensivos", han forzado a poner en discusión tal concepto y buscar en cambio definiciones más acordes con el estado actual de nuestra ciencia y arte...

  5. Algunas consideraciones sobre el problema de la prostitución en Colombia

    Directory of Open Access Journals (Sweden)

    Víctor J. Piñeros Piñeros

    1935-01-01

    Full Text Available El problema de la prostitución es en todas partes y más entre nosotros, un problema muy complejo, que importa desentrañar y estudiar en sus principales aspectos: así, hay que considerar la prostitución en sí, y luégo en sus relaciones con la sociedad y sobre todo en su aspecto sanitario.

  6. Algunas consideraciones sobre el problema de la prostitución en colombia

    OpenAIRE

    Piñeros Piñeros, Víctor J.

    2011-01-01

    El problema de la prostitución es en todas partes y más entre nosotros, un problema muy complejo, que importa desentrañar y estudiar en sus principales aspectos: así, hay que considerar la prostitución en sí, y luégo en sus relaciones con la sociedad y sobre todo en su aspecto sanitario.

  7. Los problemas de esbeltez en el diseño de columnas de concreto

    Directory of Open Access Journals (Sweden)

    Luis Guillermo Aycardi

    1981-07-01

    Full Text Available EI presente es el primero de una serie de artículos en los cuales se pretende estudiar los problemas de segundo orden en el diseño de columnas, la razón de las expresiones que proponen los reglamentos, y  de paso los problemas de inestabilidad estructural de pórticos y estructuras elementales.

  8. Problemas actuales del automóvil y el futuro del mismo

    OpenAIRE

    Gómez San Martín, María Begoña

    2011-01-01

    315 p. El automóvil es un elemento indispensable en la sociedad actual a nivel mundial. Pero presenta serios problemas no resueltos al día de hoy, ocasionados principalmente por el combustible universalmente utilizado: el petróleo. Estos problemas plantean serias preocupaciones cara al futuro. En esta Tesis realizamos una investigación y una prospección sobre los posibles elementos energéticos sustitutivos del petróleo.

  9. El papel de los esquemas en la resolución de problemas de enunciado verbal

    OpenAIRE

    Nesher, Pearla

    1999-01-01

    En el artículo se pretende demostrar que la capacidad para resolver problemas de matemáticas depende de los niveles de esquemas y en las estructuras que tienen los chicos y chicas. Se sugiere que si los profesores son conscientes de los esquemas necesarios para asentar cada nivel de aprendizaje y presentan los problemas de los alumnos de la forma más general posible, eso facilitar la resolución.

  10. Hipertensão arterial - um problema de saúde pública

    Directory of Open Access Journals (Sweden)

    Zélia Maria de Sousa Araújo Santos

    2011-12-01

    Full Text Available Hipertensão Arterial Sistêmica (HAS é considerada um dos grandesproblemas para a saúde pública no Brasil, agravada por sua prevalência e detecção quase sempre tardia, além de constituir um dos principais fatores de risco para as doenças cardiovasculares e cerebrovasculares.A HAS, considerada “assassina silenciosa”, é o maior problema social dos países desenvolvidos e em muitos dos emergentes. Mesmo sendo conhecida a eficácia e efetividade de várias das medidas preventivas e de controle disponíveis, sejam ou não farmacológicas, a HAS continuará, por décadas, representando um dos maiores desafios em saúde e um dos maiores ônus para a pessoa hipertensa e para asociedade. Se o controle de casos existentes, assim como o controle e prevenção dos fatores de risco desta doença não forem implementadas, esta problemática irá afetar grande proporção da população em nosso país, a qual, em 2020, terá um aumento significativo de pessoas com mais de 60 anos.A HAS é uma síndrome multifatorial, multicausal e multisistêmica. Seuaparecimento está relacionado ao estilo de vida inadequado, considerando também os fatores constitucionais, como: sexo, idade, raça/cor e história familiar; e os ambientais, como: sedentarismo, estresse, tabagismo, alcoolismo, alimentação insalubre e obesidade. Mediante ao seu curso silencioso (assintomatologia, a pessoa poderá ser surpreendida por suas complicações, sendo necessário aprendera conviver com a cronicidade no seu cotidiano. Entretanto, este tipo de agravo é influenciado por vários determinantes, incluindo características da personalidade, mecanismos de enfrentamento utilizados, autoconceito e autoimagem, experiênciacom este agravo e atitudes dos cuidadores da área de saúde.Uma das dificuldades encontradas no atendimento às pessoas hipertensas é a falta de adesão ao tratamento, pois 50% dos hipertensos conhecidos não fazem nenhum tratamento e dentre aqueles que o

  11. MORPHOLOGICAL ANATOMICAL AND PHITOCHEMICAL CHARACTERISTICS OF SOME ALGAE

    Directory of Open Access Journals (Sweden)

    N. S. Kaysheva

    2014-01-01

    Full Text Available Morphological and anatomical features of thalluses of brown (Laminaria saccharina, Fucus vesiculosus and red (Ahnfeltia plicata algae, procured at a coastal strip of the Northern basin in gulfs of Ura-Guba and Palkina-Guba at different depths. Compliance of Fucus and Ahnfeltia with pharmacopoeial norms and merchandising indices for Laminaria was established, except for high concentration of sand in Ahnfeltia thalluses. The identity of algae between each other was shown based on the results of qualitative analysis on polysaccharides, alginic acids, reducing sugars, iodine, mannitol, amino acids presence. Quantitative content of polysaccharides, alginic acids, reducing sugars, pentosans, iodine, cellulose, mannitol, proteins, lipids, agar was determined. In comparison with Fucus and Ahnfeltia higher concentration of the following content was noted in Laminaria: alginic acids (1.4 and 5.75 times higher, polysaccharides (1.3 and 1.4 times, iodine (4.5 and 1.8 times, mannatol (1.5 and 2.5 times (data received is statistically reliable. Impropriety of storm algae for processing was shown as law quality raw material. The highest concentration of active substances was revealed in Laminaria thalluses which were procured at the depth of 10 m in a period from September to October. Active accumulation of sodium, potassium, calcium, iron, magnesium, manganese corresponding to similar sea water composition was established in algae. Mathematical equations of regression between protein and manganese, protein and iron content in algae were deduced. Under proper conditions of drying and storage high quality of the materials can be preserved during 3 years. Based on the findings of photochemical researches, taking into account squares of plantations and possible exploitation stocks, the possibility and prospectivity of industrial processing of Fucus vesiculosus and Ahnfeltia plicata together with Laminaria saccharina as plant sources of polysaccharides (mainly

  12. Biodegradation of an oily bilge waste using algae

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.J.

    1987-01-01

    A mixed community of microogranisms was collected from the harbor at the North Island Navy Base and was monitored in a test ecosystem containing an oily bilge waste obtained from off-loading ships. Cultures were examined in the presence and absence of the algae. It was thought that the algae might enhance the degradation of the oil waste by providing oxygen and possibly a nutrient source from dying phytoplankton for the bacterial community. The change in community structure was monitored by isolating the various groups of organisms and determining the biomass change over time for the algae, bacteria and yeasts/fungi subjected to the bilge waste. The biomass (i.e., colony forming units) of the yeasts and fungi increased 100 fold in a 6 week test period. The community containing only the bacteria and fungi/yeasts lost the fungal component of the population, although active bacteria biomass increased more than 10 fold during exposure to the waste. The test ecosystem was subjected to a radiolabeled compound (/sup 14/C-phenol) and bilge waste mixture to ascertain the ability of the communities to mineralize the phenol and/or assimilate the labeled hydrocarbon. The community containing the algae started mineralizing the phenol (measure by /sup 14/CO/sub 2/ production) 24 hours after exposure to the waste/phenol mixture. The bacteria/yeast-fungi community had a lag period of 384 hours before extensive catabolism of the labeled compound occurred. Current data indicate algae may enhance the biodegradation rate of oil bilge waste in a mixed microbial community.

  13. Algae viability over time in a ballast water sample

    Science.gov (United States)

    Gollasch, Stephan; David, Matej

    2018-03-01

    The biology of vessels' ballast water needs to be analysed for several reasons, one of these being performance tests of ballast water management systems. This analysis includes a viability assessment of phytoplankton. To overcome logistical problems to get algae sample processing gear on board of a vessel to document algae viability, samples may be transported to land-based laboratories. Concerns were raised how the storage conditions of the sample may impact algae viability over time and what the most appropriate storage conditions were. Here we answer these questions with a long-term algae viability study with daily sample analysis using Pulse-Amplitude Modulated (PAM) fluorometry. The sample was analysed over 79 days. We tested different storage conditions: fridge and room temperature with and without light. It seems that during the first two weeks of the experiment the viability remains almost unchanged with a slight downwards trend. In the continuing period, before the sample was split, a slightly stronger downwards viability trend was observed, which occurred at a similar rate towards the end of the experiment. After the sample was split, the strongest viability reduction was measured for the sample stored without light at room temperature. We concluded that the storage conditions, especially regarding temperature and light exposure, have a stronger impact on algae viability compared to the storage duration and that inappropriate storage conditions reduce algal viability. A sample storage time of up to two weeks in a dark and cool environment has little influence on the organism viability. This indicates that a two week time duration between sample taking on board a vessel and the viability measurement in a land-based laboratory may not be very critical.

  14. Los nuevos problemas de la infancia, propuestas de solución

    Directory of Open Access Journals (Sweden)

    María Eugenia Mansilla

    1992-12-01

    Full Text Available En este trabajo se analizan los problemas que viven los niños de los sectores populares del Perú, haciendo algunos alcances con la realidad de otros países latinoamericanos. El enfoque del análisis es que el origen de tales problemas se encuentra en la forma que hemos organizado la sociedad, de ahí que se plantee que corresponden a una sociedad del horno sapiens y que "la mayoría de los problemas no son nuevos, (sino que lo nuevo es la forma en que se expresan y la manera en la que los vernos". La revisión de los problemas se inicia con el concepto niño discutiendo el enfoque tradicional con una propuesta alternativa que considera al niño un ser humano en desarrollo; se revisan algunos problemas que son productos de la urbanización y del actual modelo económico y la vigencia de algunos problemas viejos corno la discriminación y el trabajo infantil; se analizan brevemente las políticas sociales y se plantean algunas alternativas dirigidas a superarlos y avanzar en la construcción de una sociedad humana.

  15. Study on the concentration and seasonal variation of inorganic elements in 35 species of marine algae

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Yan, X.J.

    1998-01-01

    The concentrations of five major and 28 trace elements in 35 marine algae collected along the coast of China were determined by instrumental neutron activation analysis. The concentrations of halogens, rare earth elements and many transition metal elements in marine algae are remarkably higher than...... those in terrestrial plants. The concentration factors for 31 elements in all collected algae were calculated, those for tri- and tetra-valent elements were higher than those of the mono- and di-valent elements in marine algae. The biogeochemical characteristics of inorganic elements in marine algae...

  16. An Artificial Neural Network Based Short-term Dynamic Prediction of Algae Bloom

    Directory of Open Access Journals (Sweden)

    Yao Junyang

    2014-06-01

    Full Text Available This paper proposes a method of short-term prediction of algae bloom based on artificial neural network. Firstly, principal component analysis is applied to water environmental factors in algae bloom raceway ponds to get main factors that influence the formation of algae blooms. Then, a model of short-term dynamic prediction based on neural network is built with the current chlorophyll_a values as input and the chlorophyll_a values in the next moment as output to realize short-term dynamic prediction of algae bloom. Simulation results show that the model can realize short-term prediction of algae bloom effectively.

  17. The effects of ProAlgaZyme novel algae infusion on metabolic syndrome and markers of cardiovascular health

    Directory of Open Access Journals (Sweden)

    Hildreth DeWall J

    2007-09-01

    Full Text Available Abstract Background Metabolic Syndrome, or Syndrome X, is characterized by a set of metabolic and lipid imbalances that greatly increases the risk of developing diabetes and cardiovascular disease. The syndrome is highly prevalent in the United States and worldwide, and treatments are in high demand. ProAlgaZyme, a novel and proprietary freshwater algae infusion in purified water, has been the subject of several animal studies and has demonstrated low toxicity even with chronic administration at elevated doses. The infusion has been used historically for the treatment of several inflammatory and immune disorders in humans and is considered well-tolerated. Here, the infusion is evaluated for its effects on the cardiovascular risk factors present in metabolic syndrome in a randomized double-blind placebo-controlled study involving 60 overweight and obese persons, ages 25–60. All participants received four daily oral doses (1 fl oz of ProAlgaZyme (N = 22 or water placebo (N = 30 for a total of 10 weeks, and were encouraged to maintain their normal levels of physical activity. Blood sampling and anthropometric measurements were taken at the beginning of the study period and after 4, 8 and 10 weeks of treatment. Eight participants did not complete the study. Results ProAlgaZyme brought about statistically significant (p Conclusion ProAlgaZyme (4 fl oz daily consumption resulted in significant reductions in weight and blood glucose levels, while significantly improving serum lipid profiles and reducing markers of inflammation, thus improving cardiovascular risk factors in overweight and obese subjects over a course of 10 weeks with an absence of adverse side effects. Trial Registration US ClinicalTrials.gov NCT00489333

  18. Photoreduction of chromium(VI) in the presence of algae, Chlorella vulgaris

    International Nuclear Information System (INIS)

    Deng Lin; Wang Hongli; Deng Nansheng

    2006-01-01

    In this thesis, the photochemical reduction of hexavalent chromium Cr(VI) in the presence of algae, Chlorella vulgaris, was investigated under the irradiation of metal halide lamps (λ=365nm, 250W). The affecting factors of photochemical reduction were studied in detail, such as exposure time, initial Cr(VI) concentration, initial algae concentration and pH. The rate of Cr(VI) photochemical reduction increased with algae concentration increasing, exposure time increasing, initial Cr(VI) concentration decreasing and the decrease of pH. When pH increased to 6, the rate of Cr(VI) photochemical reduction nearly vanished. When initial Cr(VI) concentration ranged from 0.4 to 1.0mgL -1 and initial algae concentration ranged from ABS algae (the absorbency of algae)=0.025 to ABS algae =0.180, According to the results of kinetic analyses, the kinetic equation of Cr(VI) photochemical reduction in aqueous solution with algae under 250W metal halide lamps was V 0 =kC 0 0.1718 A algae 0.5235 (C 0 was initial concentration of Cr(VI); A algae was initial concentration of algae) under the condition of pH 4

  19. Influence of Algae Age and Population on the Response to TiO₂ Nanoparticles.

    Science.gov (United States)

    Metzler, David M; Erdem, Ayca; Huang, Chin Pao

    2018-03-25

    This work shows the influence of algae age (at the time of the exposure) and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO₂ NPs). The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3-4.2 × 10⁶ cells/mL) at a constant NP concentration (100 mg/L) caused a decline in the growth of algae. With increased initial algae population, the lipid peroxidation and chlorophyll both initially decreased and then increased. Lipid peroxidation had 4× the amount of the control at high and low initial population but, at mid-ranged initial population, had approximately half the control value. Chlorophyll a results also showed a similar trend. These results indicate that the physiological state of the algae is important for the toxicological effect of TiO₂ NPs. The condition of algae and exposure regime must be considered in detail when assessing the toxicological response of NPs to algae.

  20. Photoreduction of chromium(VI) in the presence of algae, Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Deng Lin [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China); Wang Hongli [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China); Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China)]. E-mail: nsdengwhu@163.com

    2006-11-16

    In this thesis, the photochemical reduction of hexavalent chromium Cr(VI) in the presence of algae, Chlorella vulgaris, was investigated under the irradiation of metal halide lamps ({lambda}=365nm, 250W). The affecting factors of photochemical reduction were studied in detail, such as exposure time, initial Cr(VI) concentration, initial algae concentration and pH. The rate of Cr(VI) photochemical reduction increased with algae concentration increasing, exposure time increasing, initial Cr(VI) concentration decreasing and the decrease of pH. When pH increased to 6, the rate of Cr(VI) photochemical reduction nearly vanished. When initial Cr(VI) concentration ranged from 0.4 to 1.0mgL{sup -1} and initial algae concentration ranged from ABS{sub algae} (the absorbency of algae)=0.025 to ABS{sub algae}=0.180, According to the results of kinetic analyses, the kinetic equation of Cr(VI) photochemical reduction in aqueous solution with algae under 250W metal halide lamps was V{sub 0}=kC{sub 0}{sup 0.1718}A{sub algae}{sup 0.5235} (C{sub 0} was initial concentration of Cr(VI); A{sub algae} was initial concentration of algae) under the condition of pH 4.

  1. Influence of Algae Age and Population on the Response to TiO2 Nanoparticles

    Directory of Open Access Journals (Sweden)

    David M. Metzler

    2018-03-01

    Full Text Available This work shows the influence of algae age (at the time of the exposure and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO2 NPs. The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3−4.2 × 106 cells/mL at a constant NP concentration (100 mg/L caused a decline in the growth of algae. With increased initial algae population, the lipid peroxidation and chlorophyll both initially decreased and then increased. Lipid peroxidation had 4× the amount of the control at high and low initial population but, at mid-ranged initial population, had approximately half the control value. Chlorophyll a results also showed a similar trend. These results indicate that the physiological state of the algae is important for the toxicological effect of TiO2 NPs. The condition of algae and exposure regime must be considered in detail when assessing the toxicological response of NPs to algae.

  2. Influence of Algae Age and Population on the Response to TiO2 Nanoparticles

    Science.gov (United States)

    Metzler, David M.; Erdem, Ayca; Huang, Chin Pao

    2018-01-01

    This work shows the influence of algae age (at the time of the exposure) and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO2 NPs). The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3−4.2 × 106 cells/mL) at a constant NP concentration (100 mg/L) caused a decline in the growth of algae. With increased initial algae population, the lipid peroxidation and chlorophyll both initially decreased and then increased. Lipid peroxidation had 4× the amount of the control at high and low initial population but, at mid-ranged initial population, had approximately half the control value. Chlorophyll a results also showed a similar trend. These results indicate that the physiological state of the algae is important for the toxicological effect of TiO2 NPs. The condition of algae and exposure regime must be considered in detail when assessing the toxicological response of NPs to algae. PMID:29587381

  3. Cultivation Strategy for Freshwater Macro- and Micro-Algae as Biomass Stock for Lipid Production

    Directory of Open Access Journals (Sweden)

    Marieska Verawaty

    2017-07-01

    Full Text Available In this research, an algae cultivation strategy was studied. Integrating algae cultivation with wastewater treatment is currently seen as one of the most economical ways of producing algae biomass. A combination of an anaerobic baffled reactor (ABR and a constructed wetland (CW was applied for treating domestic wastewater with an additional collection tank for improving effluent quality. The effluent produced from the three stages was used as algae cultivation media and suplemented with 10% bold basal medium (BBM. The results showed both micro- and macro-algae growth and their lipid contents were higher when they were grown in effluent-BBM (9:1 v/v media. The lipid content of the micro-algae mixed culture was 16.5% while for macro-algae Oedogonium sp and Cladophora sp it was 6.90% and 6.75% respectively.

  4. Notas sobre el problema habitacional en 'El otro sendero'

    Directory of Open Access Journals (Sweden)

    1988-01-01

    Full Text Available L'article réunit des notes de lecture sur le livre 'El Otro Sendero', à propos de la construction de logements pour les secteurs à bas revenus. L'importance de ce livre pour le public national est reconnue au départ et l'on tente d'étudier ses propositions en ce qui concerne le logement (chapitre 2. Après avoir examiné les propositions du texte, on commente quelques erreurs dans l'analyse des faits. Le commentaire final dit: La profusion d'analyses erronées qui visent à mettre en évidence la 'longue marche vers la propriété privée', comme le manque d'analyses spécifiques sur le problème du logement et sur celui de la ville -qui constituent le contexte des informels dans les barriadas-, nous font penser que nous sommes confrontés à un schéma idéologique a priori plus qu'à une étude de la réalité urbaine. El artículo proporciona notas de lectura del libro 'El Otro Sendero' referentes a la producción de vivienda para los sectores de bajos ingresos. Se parte de reconocer la importancia que ha tenido este libro en la audiencia nacional y se intenta estudiar sus proposiciones sobre la vivienda (capítulo 2. Luego de examinar las propuestas presentes en el texto, se comentan algunas incorrecciones en el análisis de los hechos. El comentario final dice: La profusión de análisis erróneos que apuntan a destacar la 'larga marcha hacia la propiedad privada', así como la falta de análisis específicos sobre el problema de la vivienda y el de la ciudad -que constituyen el contexto de los informales en las barriadas-, nos hacen pensar que estamos frente a un esquema ideológico a priori más que frente a un estudio de la realidad urbana. The article consists of interpretative notes on the book 'El Otro Sendero', which refer to the production of housing for low-income sectors. It begins by recognizing the importance this book has had for the national audience, and proposes to examine its propositions about housing (chapter 2. An

  5. Estratégia Educacional Baseada em Problemas para Grandes Grupos: Relato de Experiência

    Directory of Open Access Journals (Sweden)

    Sonia Leite da Silva

    Full Text Available RESUMO Nos últimos anos, o olhar sobre a formação dos profissionais de saúde tem se intensificado, particularmente sobre aquela que possa impactar a resolução dos problemas de saúde da população. Um dos aspectos para o alcance desta demanda refere-se a uma formação que incorpore metodologias ativas no processo ensino-aprendizagem de estudantes da saúde. Neste entendimento, tomando como referência metodologias de aprendizagem baseada em problemas, as quais utilizam certos passos para a resolução de problemas, e diante dos desafios de trabalhar com grandes grupos, desenvolveu-se a estratégia educacional denominada Ciclo de Discussão de Problemas (CDP. Este artigo tem por objetivo descrever o CDP como uma estratégia educacional utilizada em grandes grupos no ensino da graduação em saúde. Esta estratégia ancora-se nos princípios de metodologia ativa, pois utiliza problemas com temáticas comuns aos cursos da área da saúde, para desenvolver nos alunos o aprendizado autodirigido, a habilidade de solucionar problemas, o pensamento crítico e o estudo colaborativo, além da visão integrada das ciências básicas. Esta estratégia envolve dois momentos em sala de aula para cada problema: análise e resolução, englobando 12 passos.

  6. Acerca del cáncer cervicouterino como un importante problema de salud pública About uterocervical cancer as an important public health problem

    Directory of Open Access Journals (Sweden)

    Julio César Espín Falcón

    2012-12-01

    Full Text Available El cáncer se presenta como un importante problema de salud, dada la alta morbilidad y mortalidad que produce. Es uno de los procesos más complejos de la naturaleza y resulta el más complicado en la esfera de la medicina por su origen multicausal, la complejidad de sus mecanismos patogénicos y la variedad de formas y tipos que pueden originarse en el ser vivo. El objetivo de este trabajo es ofrecer información útil y actualizada acerca del cáncer cervicouterino. Esta enfermedad es prevenible y curable y se relaciona con la aparición del cáncer en vagina, cuello uterino, vulva y ano; en las mujeres se ha demostrado que la infección por el virus del papiloma humano es un factor de riesgo para su desarrollo. En la actualidad existen y se comercializan en el mundo dos tipos de vacuna, lo que se considera uno de los mayores avances en la medicina preventiva moderna. La aplicación de estas vacunas profilácticas contra el virus del papiloma humano podría reducir la incidencia y mortalidad por cáncer cervicouterino. Esta enfermedad constituye una de las entidades con más impacto y repercusión sobre la salud femenina, particularmente en las mujeres jóvenes. Está considerada una enfermedad emergente desde hace escasos años y sus consecuencias sociales, humanas y económicas lo convierten en un problema importante de salud pública y de la humanidad.Cancer represents an important health problem due to its high morbidity and mortality. It is one of the most complex processes of nature and the most complicated in medicine because of its multiple cause origin, the complexity of its pathogenic mechanisms and the variety of forms and types that may adopt in the subject alive. The objective of this paper was to provide useful and updated information on the uterocervical cancer. This disease is preventable and curable; it is related to the occurrence of cancer in the vagina, the uterine neck, the vulva and the anus. It has been proved that human

  7. Effect of algae and water on water color shift

    Science.gov (United States)

    Yang, Shengguang; Xia, Daying; Yang, Xiaolong; Zhao, Jun

    1991-03-01

    This study showed that the combined effect of absorption of planktonic algae and water on water color shift can be simulated approximately by the exponential function: Log( E {100cm/ W }+ E {100cm/ Xch1})=0.002λ-2.5 where E {100/cm W }, E {100cm/ Xchl} are, respectively, extinction coefficients of seawater and chlorophyll—a (concentration is equal to X mg/m3), and λ (nm) is wavelength. This empirical regression equation is very useful for forecasting the relation between water color and biomass in water not affected by terrigenous material. The main factor affecting water color shift in the ocean should be the absorption of blue light by planktonic algae.

  8. Green Algae as Model Organisms for Biological Fluid Dynamics

    Science.gov (United States)

    Goldstein, Raymond E.

    2015-01-01

    In the past decade, the volvocine green algae, spanning from the unicellular Chlamydomonas to multicellular Volvox, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 μm to several millimeters), their geometric regularity, the ease with which they can be cultured, and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms.

  9. Accumulation and loss of technetium by macrophytic algae

    International Nuclear Information System (INIS)

    Benco, C.; Cannarsa, S.; Ceppodomo, I.; Zattera, A.

    1986-01-01

    Preliminary results are presented of a study of the accumulation of Tc by four species of brown algae (Sargassum vulgare, Cystoseira complexa, Dictyopteris membranacea, Dictyota dichotama implexa) and one species of green algae (Chlorophyta, Ulva rigida). With the exception of Cystoseira complexa, the accumulation was very rapid, and concentration factors decreased from Sargassum vulgare to Ulva rigida. Young stipes of Cystoseira complexa concentrated twice as much more Tc than cylindrical main axes. Attempts were made to understand the mechanism of Tc accumulation by brown seaweed. Fucoidan, a pool of high molecular weight polysaccharides extracted from Fucus sp. was put with sup(95m)Tc in seawater for 48 h and then dialysed, but no activity was retained by Fucoidan. (UK)

  10. Algae as nutritional and functional food sources: revisiting our understanding

    OpenAIRE

    Wells, Mark L.; Potin, Philippe; Craigie, James S.; Raven, John A.; Merchant, Sabeeha S.; Helliwell, Katherine E.; Smith, Alison G.; Camire, Mary Ellen; Brawley, Susan H.

    2016-01-01

    Global demand for macroalgal and microalgal foods is growing, and algae are increasingly being consumed for functional benefits beyond the traditional considerations of nutrition and health. There is substantial evidence for the health benefits of algal-derived food products, but there remain considerable challenges in quantifying these benefits, as well as possible adverse effects. First, there is a limited understanding of nutritional composition across algal species, geographical regions, ...

  11. Rare species of fungi parasitizing on algae. IV

    Directory of Open Access Journals (Sweden)

    Joanna Z. Kadłubowska

    2014-08-01

    Full Text Available The following parasites of the genera Spirogyra Link, Mougeotia Agardh and Oedogonium Link are desribed: Myzocyutium irregulare, Woroninu glomerata, Harpochytrium tenuissimum, Woronina polycystis, Chytridium acuminatu, Myzocytium irregulare and Chytridumm acuminatum are new to Poland. Also, the first information on Woronina polycystis as a parasite on algae is presented. The figure of cystosori in a cell of Mougeotia mysorensis is the first graphic documentation of this species.

  12. Use of Unicellular Algae for Evaluation of Potential Aquatic Contaminants

    Science.gov (United States)

    1981-05-01

    well as long term effects on specific water bodies such as lakes and groundwater basins. Both the hydrazine propellants and the alternative jet fuels... freshwater bioassays was S. capricornutum. Initial investigations of marine waters used Dunaliella tertiolecta as the test organism but the differences in...AFAMRL-TR-80-85 USE OF UNICELLUAR ALGAE FOR EVALUATION OF POTENTIAL AQUATIC CONTAMINANTS JAN SCHERFIG PETER S. DIXON CAROL A. JUSTICE ALBERTO ACEVEDO

  13. DNA barcode of coastal alga ( Chlorella sorokiniana ) from Ago ...

    African Journals Online (AJOL)

    Five different loci 18S, UPA, rbcl, ITS and tufA were tested for their use as deoxyribonucleic acid (DNA) barcode in this study. Although the UPA primers were designed to amplify all phototrophic algae and cyanobacteria, UPA and 18S did not amplified at all for the genus Chlorella while ITS1, ITS2 rDNA and rbcL markers ...

  14. Adsorption of copper onto char derived macro alga, Undaria pinnatifida

    International Nuclear Information System (INIS)

    Cho, Hye Jung; Ko, Jeong Huy; Heo, Hyeon Su; Park, Hye Jin; BAe, Yoon Ju; Kim, Jung Hwan; Park, Young-Kwon

    2010-01-01

    Full text: A release of heavy metals into the environment by industrial activities raises much environmental problems because they tend to remain indefinitely, circulating and eventually accumulating throughout the food chain. Copper is essential to human life and health but, like all heavy metals, is potentially toxic as well. The excessive intakes of copper result in its accumulation in the liver and produce gastrointestinal problems, kidney damage, anemia, and continued inhalation of copper-containing sprays is linked with an increase in lung cancer among exposed people. Consequently, we need to eliminate the copper in drinking water. Also, growth rates of marine macro algae far exceed those of terrestrial biomass, without water limitations, so annual primary production rates are higher for the major marine macro algae than for most terrestrial biomass. According to these reasons, we try to use the macro alga, Undaria pinnatifida. Adsorption of heavy metals is one of the possible technologies involved in the removal of toxic metals from industrial waste streams and mining waste water using low-cost adsorbents. In recent years, many low-cost adsorbents such as seaweeds, activated carbon, etc. have been investigated, but the char by macro alga, Undaria pinnatifida, have not proven to be the most effective and promising substrates. The aim of this study is to remove copper from its aqueous solution by Undaria pinnatifida char for various parameters like pH, contact time, and Cu(II) concentration. The adsorption capacity of Cu(II) by Undaria pinnatifida char was investigated as a function of pH, contact time, and Cu(II) concentration at room temperature. And it was verified using equilibrium studies. (author)

  15. Evidence of ancient genome reduction in red algae (Rhodophyta).

    Science.gov (United States)

    Qiu, Huan; Price, Dana C; Yang, Eun Chan; Yoon, Hwan Su; Bhattacharya, Debashish

    2015-08-01

    Red algae (Rhodophyta) comprise a monophyletic eukaryotic lineage of ~6,500 species with a fossil record that extends back 1.2 billion years. A surprising aspect of red algal evolution is that sequenced genomes encode a relatively limited gene inventory (~5-10 thousand genes) when compared with other free-living algae or to other eukaryotes. This suggests that the common ancestor of red algae may have undergone extensive genome reduction, which can result from lineage specialization to a symbiotic or parasitic lifestyle or adaptation to an extreme or oligotrophic environment. We gathered genome and transcriptome data from a total of 14 red algal genera that represent the major branches of this phylum to study genome evolution in Rhodophyta. Analysis of orthologous gene gains and losses identifies two putative major phases of genome reduction: (i) in the stem lineage leading to all red algae resulting in the loss of major functions such as flagellae and basal bodies, the glycosyl-phosphatidylinositol anchor biosynthesis pathway, and the autophagy regulation pathway; and (ii) in the common ancestor of the extremophilic Cyanidiophytina. Red algal genomes are also characterized by the recruitment of hundreds of bacterial genes through horizontal gene transfer that have taken on multiple functions in shared pathways and have replaced eukaryotic gene homologs. Our results suggest that Rhodophyta may trace their origin to a gene depauperate ancestor. Unlike plants, it appears that a limited gene inventory is sufficient to support the diversification of a major eukaryote lineage that possesses sophisticated multicellular reproductive structures and an elaborate triphasic sexual cycle. © 2015 Phycological Society of America.

  16. Techno-Economic Assessment of Micro-Algae Production Systems

    OpenAIRE

    Hoffman, Justin

    2016-01-01

    Global oil consumption is rising at an unprecedented rate renewing interest in alternative fuels. Micro-algae represents a promising feedstock due to inherent advantages such as high solar energy efficiencies, large lipid fractions, and utilization of various waste streams including industrial flue gas. Current technological challenges have limited the commercial viability of microalgae based biofuel production systems. This study directly evaluates and compares the economic viability of biom...

  17. Nitrogen and sulfur assimilation in plants and algae

    Czech Academy of Sciences Publication Activity Database

    Giordano, Mario; Raven, John A.

    2014-01-01

    Roč. 118, č. 2 (2014), s. 45-61 ISSN 0304-3770 Grant - others:University of Dundee(GB) SC 015096; Italian Ministry for Agriculture(IT) MIPAF, Bioforme project; Italian Ministry of Foreign Affairs(IT) MAE. Joint Italian-Israel Cooperation Program Institutional support: RVO:61388971 Keywords : nitrogen * sulfur * assimilation * algae Subject RIV: EE - Microbiology, Virology Impact factor: 1.608, year: 2014

  18. Distributionand Diversity of Macro Algae Communities in the Ambon Bay

    OpenAIRE

    Litaay, Christina

    2014-01-01

    Water conditions affected by natural and anthropogenic parameters such as sedimentation and solid waste disposal can influence the growth and distribution of macro algae. Sustainable management efforts can reduce damage on the Gulf coast of Ambon due to human activities and land clearing. This study was conducted in October 2008 using the transect method with 3 replicates in five locations i.e., Tantui, Air Salobar, Hative Besar, Halong, and Lateri. The interior and exterior waters of Ambon B...

  19. Variantes del problema del cartero mixto que se pueden resolver usando programación lineal

    Directory of Open Access Journals (Sweden)

    Francisco Javier Zaragoza Martínez

    2012-07-01

    Full Text Available Dada una gráfica mixta y conexa con costos en sus aristas y arcos, el problema del cartero mixto consiste en encontrar un circuito cerrado de la gráfica mixta que recorra sus aristas y arcos a costo mínimo. Se sabe que este problema es NP-duro. Sin embargo, bajo ciertas condiciones adicionales, el problema se puede resolver en tiempo polinomial usando programación lineal, en otras palabras, los poliedros correspondientes son enteros. Algunas de estas condiciones son: la gráfica mixta es serie paralelo o la gráfica mixta tiene grado total par en todos sus vértices. Además, mostramos que si agregamos la restricción adicional de que cada arista se recorra exactamente una vez entonces el problema se puede resolver en tiempo polinomial si el conjunto de arcos forma un bosque. Palabras clave: Gráfica mixta, problema de cartero, programación lineal. Mathematics Subject Classification: 05C45, 90C35.

  20. Niveles de verbalización y resolución colaborativa de problemas poco estructurados

    Directory of Open Access Journals (Sweden)

    José D. Chávez

    2015-01-01

    Full Text Available Se describieron las verbalizaciones de seis estudian - tes universitarios que resolvieron colaborativamen - te un problema poco estructurado. Partiendo de que aportaban información sobre la regulación metacog - nitiva y la solución de problemas, las verbalizacio - nes fueron categorizadas en niveles. Se utilizaron matrices espacio estado para interpretar los niveles de verbalización y los procesos de resolución de problemas poco estructurados. Se evidenció el predo - minio de verbalizaciones no reguladas, la ausencia de verbalizaciones relacionadas a la elaboración de justificaciones y la superficialidad del monitoreo y la evaluación. La evidencia apoya la idea de que la interacción entre pares no mejora por sí misma la solución de problemas. Los resultados invitan al diseño de situaciones de resolución de problemas que efectivamente promuevan la regulación meta - cognitiva entre pares.