WorldWideScience

Sample records for aspen sociedad americana

  1. Muhammad Ali, um outsider na sociedade americana?

    Directory of Open Access Journals (Sweden)

    Flávio Py Mariante Neto

    2010-12-01

    Full Text Available O estudo analisa a carreira do boxeador Muhammad Ali segundo as formulações sobre as relações de poder em configurações apresentadas por Norbert Elias. O propósito foi compreender como um atleta que foi contra questões tão profundas da sociedade estabelecida obteve sucesso profissional. Tratou-se de um estudo documental, tendo como fonte livros, artigos e reportagens publicadas sobre a trajetória do lutador. Concluiu-se que apesar de Ali ter se posicionado contra padrões estabelecidos de sua época em questões como a religião, o racismo e o patriotismo, a sua habilidade técnica acima da média, o seu poder de autopromoção e a sua capacidade de participar do jogo no contexto configuracional de que fazia parte, lhe deram condições de sobrevivência no mundo do boxe e conseqüente sucesso profissional.

  2. Mito e sociedade na literatura latino-americana: Neruda, Carpentier, Bolaño

    Directory of Open Access Journals (Sweden)

    Pedro Dolabela Chagas

    2013-09-01

    Full Text Available Resumo: Discussão sobre a problemática identitária na literatura latino-americana: a sua associação oitocentista à representação da natureza e da paisagem social; a sua longa duração entre os séculos XIX e XX; a sua politização pela dicotomia entre a América Latina e o Centro representado pela Europa e pelos EUA. A construção da identidade como produção de mitos: como construção de passados úteis, valoração positiva ou negativa do presente, projeção de futuros possíveis. A presença do mito em Canto geral, de Pablo Neruda; a sua recusa em 2666, de Roberto Bolaño; discussão sobre as razões desta recusa: a concentração no presente em detrimento da projeção do futuro. Localização de um tensionamento embrionário do mito identitário em Os passos perdidos, de Alejo Carpentier: discussão sobre os termos de orientação deste tensionamento e a diferença que ele produzia em relação à história anterior do romance latino-americano. Sugestão do fechamento recente da época histórica dominada pela problemática identitária na narrativa latino-americana.Palavras-chave: Pablo Neruda; Alejo Carpentier; Roberto Bolaño; romance latino-americano; mito e identidade. Abstract: The problematic of identity representation in Latin- American literature: its 19th Century association to the representation of nature and the social landscape; its long duration in the 19th and 20th Centuries; its politicization through the dichotomy between Latin America and a Center represented by Europe and the USA. Identity construction as a production of myths: as a construction of usable pasts, as a positive or negative evaluation of the present, as a projection of possible futures. The presence of myth in Pablo Neruda’s Canto general; its rejection in Roberto Bolaño’s 2666; the possible reasons of this rejection: a concentration in the present in detriment of the future. Location of an embrionary tensioning of the identity myths

  3. Aspen Delineation - Aspen Delineation Project [ds362

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands, where aspen assessment data was gathered. Aspen assessment information corresponding to this polygon layer can...

  4. Sociedad digital, sociedad dual

    OpenAIRE

    Gustavo Cimadevilla

    2009-01-01

    Lejos de las luchas obreras y campesinas contra el maquinismo, más cerca de las preocupaciones y debates interminables de los años ochenta del siglo xx, centrados en la revolución microelectrónica y la telemática; pero dentro de una sociedad que procura seducirse y seducirnos por el crecimiento de las tecnologías digitales y los dispositivos inteligentes, es oportuno repasar las caras y contracaras de lo que puede denominarse dualismo digital, un estado de realidad altamente cargado de noveda...

  5. Sociedad digital, sociedad dual

    Directory of Open Access Journals (Sweden)

    Gustavo Cimadevilla

    2009-01-01

    Full Text Available Lejos de las luchas obreras y campesinas contra el maquinismo, más cerca de las preocupaciones y debates interminables de los años ochenta del siglo xx, centrados en la revolución microelectrónica y la telemática; pero dentro de una sociedad que procura seducirse y seducirnos por el crecimiento de las tecnologías digitales y los dispositivos inteligentes, es oportuno repasar las caras y contracaras de lo que puede denominarse dualismo digital, un estado de realidad altamente cargado de novedades, estadísticas y tendencias que auguran cierto optimismo tecnológico. El trabajo plantea interrogantes y explora líneas de discusión que procuran apartarse de la tecnofobia y la tecnofilia, que han caracterizado a muchos de los debates del campo.

  6. Assessing aspen using remote sensing

    Science.gov (United States)

    Randy Hamilton; Kevin Megown; Jeff DiBenedetto; Dale Bartos; Anne Mileck

    2009-01-01

    Large areas of aspen (Populus tremuloides) have disappeared and continue to disappear from western forests due to successional decline and sudden aspen decline (SAD). This loss of aspen ecosystems negatively impacts watersheds, wildlife, plants, and recreation. Much can still be done to restore aspen if timely and appropriate action is taken. However, land managers...

  7. La imagen del ‘sueño americano’: estética y modelos de belleza de la sociedad americana a través de ‘Mad Men'

    Directory of Open Access Journals (Sweden)

    Francisco Cabezuelo Lorenzo

    2012-04-01

    Full Text Available El presente artículo pretende desgranar la fórmula con la que una serie actual puede desarrollar herramientas para reproducir los modelos de belleza típicamente americanos de los años cincuenta y sesenta, un período histórico que supone para Occidente el nacimiento de la actual sociedad de consumo. Este trabajo analiza la primera temporada de la serie de televisión ‘Mad Men’ ambientada en Nueva York y que cuenta la vida de la agencia de publicidad ficticia ‘Sterling Cooper’ situada en Madison Avenue. A través de sugerentes pinceladas fílmicas, la serie es un retrato de la sociedad y cultura de los primeros años sesenta, haciendo hincapié en problemas sociales, éticos y estéticos como las conductas sexuales, el alcohol, el tabaco, el adulterio, la homofobia, el antisemitismo, o el racismo, de modo que muestra crueles ejemplos de la sociedad del momento. Pero, al mismo tiempo mira con nostalgia al pasado. A su vez, se hace eco de los problemas sociales del momento. Por estos motivos, puede ser considerada una serie que refleja y reproduce la estética de aquellos años que marcaron el nacimiento del ‘sueño americano’ tan ligado a la Publicidad y la Comunicación de Masas.

  8. ASPEN Version 3.0

    Science.gov (United States)

    Rabideau, Gregg; Chien, Steve; Knight, Russell; Schaffer, Steven; Tran, Daniel; Cichy, Benjamin; Sherwood, Robert

    2006-01-01

    The Automated Scheduling and Planning Environment (ASPEN) computer program has been updated to version 3.0. ASPEN is a modular, reconfigurable, application software framework for solving batch problems that involve reasoning about time, activities, states, and resources. Applications of ASPEN can include planning spacecraft missions, scheduling of personnel, and managing supply chains, inventories, and production lines. ASPEN 3.0 can be customized for a wide range of applications and for a variety of computing environments that include various central processing units and random access memories.

  9. Aspen Delineation - Inyo National Forest [ds366

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of known aspen stands where aspen assessments were collected in the Inyo National Forest, Inyo County, California. The Inyo...

  10. Aspen Delineation - Klamath National Forest [ds370

    Data.gov (United States)

    California Natural Resource Agency — The database represents polygons of aspen stands in the Klamath National Forest, Siskiyou County, California. The Klamath National Forest Region 5 Vegetation aspen...

  11. Manipulations to regenerate aspen ecosystems

    Science.gov (United States)

    Wayne D. Shepperd

    2001-01-01

    Vegetative regeneration of aspen can be initiated through manipulations that provide hormonal stimulation, proper growth environment, and sucker protection - the three elements of the aspen regeneration triangle. The correct course of action depends upon a careful evaluation of the size, vigor, age, and successional status of the existing clone. Soils and site...

  12. Repeated Prescribed Burning in Aspen

    Science.gov (United States)

    Donald A. Perala

    1974-01-01

    Infrequent burning weather, low flammability of the aspen-hardwood association, and prolific sprouting and seeding of shrubs and hardwoods made repeated dormant season burning a poor tool to convert good site aspen to conifers. Repeat fall burns for wildlife habitat maintenance is workable if species composition changes are not important.

  13. Decay of aspen in Colorado

    Science.gov (United States)

    Ross W. Davidson; Thomas E. Hinds; Frank G. Hawksworth

    1959-01-01

    Quaking aspen (Populus tremuloides Michx.) stands are extensive in the central Rocky Mountains. The species reaches its maximum development in the mountains and high mesas west of the Continental Divide in Colorado (Baker, 1925). On the better sites aspen yields a greater volume of wood in a shorter period than most of the conifers growing at comparable elevations. The...

  14. Landscape dynamics of aspen and conifer forests

    Science.gov (United States)

    Dale L. Bartos

    2001-01-01

    Quaking aspen (Populus tremuloides Michx.) is widely dispersed across the landscape of North America. Seventy-five percent of the aspen in the western United States occurs in the states of Colorado (50%) and Utah (25%). Reproduction in aspen is primarily by asexual means, e.g., root sprouts that are generally referred to as suckers. An aspen clone consists of numerous...

  15. Agave Americana Leaf Fibers

    Directory of Open Access Journals (Sweden)

    Ashish Hulle

    2015-02-01

    Full Text Available The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.

  16. Aspen Delineation - Sierra State Parks [ds380

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (SIERRA_SP_PTS) collected in aspen stands on lands administered by the...

  17. Aspen Delineation - Lassen National Forest [ds372

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (LASSEN_NF_EAGLELAKE_PTS) collected in aspen stands in the in the Eagle...

  18. Aspen Delineation - Sequoia National Forest [ds378

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (SEQUOIA_NF_PTS) collected in aspen stands in the Cannell Meadows Ranger...

  19. ASPEN simulation of cogeneration plants

    Energy Technology Data Exchange (ETDEWEB)

    Ligang Zheng [CANMET Energy Technology Center, Natural Resources Canada, Nepean, ONT (Canada); Furimsky, E. [IMAG Group, Ottawa, ONT (Canada)

    2003-07-01

    A detailed flow sheet of the combined cycle cogeneration plant fuelled by natural gas was prepared. The model for simulation of this plant was developed using the ASPEN PLUS software. The results generated using this model were compared with the operating data of the commercial plant generating about 43.6 MW of electricity by gas turbine and 28.6 MW of electricity by steam turbine. The electricity is supplied to the grid, whereas the low pressure steam is utilised locally for heating purposes. The key data generated using the ASPEN model are in good agreement with the operating data. (author)

  20. ASPEN simulation of cogeneration plants

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Ligang E-mail: lzheng@nrcan.gc.ca; Furimsky, Edward

    2003-07-01

    A detailed flow sheet of the combined cycle cogeneration plant fuelled by natural gas was prepared. The model for simulation of this plant was developed using the ASPEN PLUS software. The results generated using this model were compared with the operating data of the commercial plant generating about 43.6 MW of electricity by gas turbine and 28.6 MW of electricity by steam turbine. The electricity is supplied to the grid, whereas the low pressure steam is utilised locally for heating purposes. The key data generated using the ASPEN model are in good agreement with the operating data.

  1. ASPEN simulation of cogeneration plants

    International Nuclear Information System (INIS)

    Zheng Ligang; Furimsky, Edward

    2003-01-01

    A detailed flow sheet of the combined cycle cogeneration plant fuelled by natural gas was prepared. The model for simulation of this plant was developed using the ASPEN PLUS software. The results generated using this model were compared with the operating data of the commercial plant generating about 43.6 MW of electricity by gas turbine and 28.6 MW of electricity by steam turbine. The electricity is supplied to the grid, whereas the low pressure steam is utilised locally for heating purposes. The key data generated using the ASPEN model are in good agreement with the operating data

  2. CARACTERIZACIÓN Y ACTIVIDAD ANTIOXIDANTE DEL ACEITE DE LA SEMILLA DE PALTA Persea americana MILL.

    OpenAIRE

    Rengifo, Pedro G.; Carhuapoma, Mario; Artica, Luis; Castro, Américo J.; López, Sofía

    2017-01-01

    La semilla de palta es una parte del fruto descartada en la obtención industrial del aceite de pulpa y podría ser una fuente de ácidos grasos esenciales y otros fitoconstituyentes. El presente trabajo de investigación tuvo como objetivo caracterizar al aceite de la semilla de Persea americana Mill. Var. Hass Fuerte y su actividad antioxidante. Al aceite obtenido por el método de Soxhlet, se le hizo la caracterización fisicoquímica siguiendo las normas AOCS (Sociedad Americana de la Química de...

  3. Can aspen persist in conifer dominated forests?

    Science.gov (United States)

    Douglas H. Page; John D. Shaw

    2016-01-01

    In 1998 we measured a large, old aspen in a mixed spruce-fir-aspen forest on the Utah State University T.W. Daniel Experimental Forest in northern Utah. The tree was 297 years old - about the same age as the oldest spruce in the stand. A search of the forestry literature revealed that the oldest published age for an aspen came from a tree in the Sierra Nevada Range in...

  4. Aspen Characteristics - Klamath National Forest [ds369

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected with known aspen stands in the Klamath National Forest, Siskiyou County,...

  5. Aspen Characteristics - Plumas National Forest [ds373

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Beckwourth Ranger District...

  6. Aspen Characteristics - Sequoia National Forest [ds377

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected within aspen stands in the Cannell Meadows Ranger District, Sequoia National...

  7. Aspen Delineation - Klamath National Forest, EUI [ds368

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of known aspen stands where aspen assessments were collected in the Klamath National Forest, Siskiyou County, California. The...

  8. Derecho y Sociedad

    Directory of Open Access Journals (Sweden)

    ASOCIACION CIVIL DERECHO Y SOCIEDAD FACULTAD DE DERECHO

    2010-12-01

    Full Text Available Reseña de actividades desarrolladas por la Asociación Civil Derecho y Sociedad, a lo largo de su permanencia-dentro de la Facultad de Derecho de la Pontificia Universidad Católica del Perú vinculadas a la sociedad en general, algunas ligadas al campo jurídico, mientras que otras tuvieron un sentido altruista.

  9. A influência da cultura Otaku na sociedade ocidental

    OpenAIRE

    Barros, Carlos

    2016-01-01

    Com este artigo pretende-se contar a história e o impacto da cultura otaku (cultura pop japonesa) na sociedade ocidental, com principal ênfase nas relações Japão-Estados Unidos da América e ainda com uma pequena ênfase no efeito desta subcultura em Portugal. Durante o artigo abordar-se-ão temas históricos e actuais sobre o que levou ao desenvolvimento desta subcultura, como a história Japonesa, o desenvolvimento pós-guerra do Japão, a influência americana no anime japonês e posterior influênc...

  10. Implementing ASPEN on the CRAY computer

    International Nuclear Information System (INIS)

    Duerre, K.H.; Bumb, A.C.

    1981-01-01

    This paper describes our experience in converting the ASPEN program for use on our CRAY computers at the Los Alamos National Laboratory. The CRAY computer is two-to-five times faster than a CDC-7600 for scalar operations, is equipped with up to two million words of high-speed storage, and has vector processing capability. Thus, the CRAY is a natural candidate for programs that are the size and complexity of ASPEN. Our approach to converting ASPEN and the conversion problems are discussed, including our plans for optimizing the program. Comparisons of run times for test problems between the CRAY and IBM 370 computer versions are presented

  11. Liquefaction of aspen poplar wood

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Mathews, J F; Pepper, J M

    1982-01-01

    Dried and green aspen poplar wood suspended in water containing alkali catalysts was converted completely to an oil, water-soluble chemical, and gases by heating for 1 hour in the presence of CO in a rocking batch reactor. Within the ranges of parameters studied: temperature of 593-633 K; nominal reaction times of less than or equal to 1 hour; water-to-wood ratio of 0.5:1-5:1; Na/sub 2/CO/sub 3/, K/sub 2/CO/sub 3/, and NaOH catalysts; amount of catalyst 7.0-12.5%; and initial H-CO ratios of 2:1-0:1, the water-to-wood ratio was most important. Oil yields of approximately 50% with a C plus H content of approximately 80% and representing a C recovery of approximately 66% were obtained. The higher heats of combustion were 32.2-36.0 MJ/kg.

  12. Biomass of Sacrificed Spruce/Aspen (SNF)

    Data.gov (United States)

    National Aeronautics and Space Administration — Dimension analysis (diameter at breast high, tree height, depth of crown), estimated leaf area, and total aboveground biomass for sacrificed spruce and aspens in...

  13. Aspen Characteristics - Lassen National Forest [ds371

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected in aspen stands in the in the Eagle Lake Ranger District, Lassen National...

  14. amylase from cockroach, Periplaneta americana

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

    Aug 4, 2008 ... The enzyme was stable up to 55°C and its pH stability was in range of 5.6 - 6.6. .... acrylamide gel and by gel filtration chromatography. Gel filtration .... Activity at 55 °C. Figure 8. Thermic inactivation at 37°C and 55°C of Periplaneta americana α-amylase. Thermal stability of the enzyme was followed for 1 h.

  15. Genipa americana L.: technological prospecting

    Directory of Open Access Journals (Sweden)

    Selma Maria Santos Moura

    2016-10-01

    Full Text Available Genipap is a tall tree (10 to 15 meters, found in humid tropical regions, common in brazilian northeastern. Its scientific name is Genipa americana L., jenipapo comes from the Tupi-Guarani jandipap, which means fruit that serves to paint. It features straight stem, dark green leaves, golden-yellow flowers and fruit in the form of ovoid berry, has light brown pulp surrounding seeds in the center. In food, its fruit is edible natural and in the preparation of sweets, soft drinks and wine. It is rich in iron, vitamins B1, B2, B5 and C, calcium and carbohydrates. In popular culture have medicinal indications for the treatment of diseases. When green, the fruit provides a blue juice widely used as a colorant, transparent at first, which becomes black when oxidized, has consistency of ink and body in contact with the skin, it leaves stains that disappear after a week or more spontaneously. The objective of this research was to carry out technology foresight regarding Genipa americana L., to present an overview of the technologies developed related to the theme. For that held a patent search on the basis of the European Patent Office, World Intellectual Property Organization, United States Patent and Trademark Office and the National Institute of Industrial Property. Using the Genipa americana L. keyword were registered 88 patents, when added the word dye 5 patent were found and no request when the search was conducted using Genipa americana L. and cell. Brazil recorded a lower number of patents found in the USA and Japan, with the years 2010, 2011 and 2015, which showed a higher number. Integrated actions should be taken to encourage development institutions to research in order to enable an environment conducive to the generation of innovations, making Brazil a more competitive country in the technological point of view.

  16. Hacia una sociedad hipertextual

    Directory of Open Access Journals (Sweden)

    Mireya Barón Pulido

    2013-03-01

    Full Text Available El presente artículo de revisión analiza y relaciona los resultados de varias investigaciones que toman como objeto de estudio los elementos que incursionan en el contexto de la comunicación desde la red: hiperdocumento, macronavegación y micronavegación. Dimensiones y procesos que afectan y transforman los mismos niveles de interacción al interior de las sociedades; hoy día reco- nocidas como sociedades digitales. El lector encontrará referencia a algunos estudios locales e internacionales haciendo referencia a corpus multimediáticos del periodismo y de la publicidad que permiten evidenciar dichos elementos y que sugieren la transformación y, en algunos casos, la construcción de nuevos patrones de interacción social entre lectores y perceptores.

  17. A sociedade dos vivos

    Directory of Open Access Journals (Sweden)

    Leis Héctor Ricardo

    2003-01-01

    Full Text Available A pergunta: qual é o significado da experiência da morte na sociedade contemporânea? A hipótese: que existe uma faceta sombria e degradante da condição humana, associada à privatização institucional ou "pacificação" da morte que estamos assistindo em nossa época. Muitos teóricos sociais contemporâneos apostam em estratégias como a reflexividade para reconstruir a fragmentação do ser humano, porém essa reconstrução mal poderia vir sem procurar apoio em aspectos chaves da condição humana. Apontar alguns dos déficits da teoria social contemporânea e assinalar alguns caminhos para superar impasses da sociedade contemporânea resume a tentativa deste trabalho.

  18. La sociedad participativa

    Directory of Open Access Journals (Sweden)

    Juan Díaz Bordenave

    2015-01-01

    Full Text Available El autor presenta dos artículos que se complementan: El primero analiza los factores que hacen a una nueva sociedad participativa. Presenta a la situación actual como la expansión del consumo, la violencia política y social, la deuda externa, la aceleración del deterioro del medio ambiente rural y urbano. Planea el que la comunicación y la participación deben considerarse como partes orgánicas de un proceso: la histórica construcción colectiva de una sociedad participativa centrada en tres herramientas: la organización de la economía autogestionaria, el papel de la educación y las funciones de la comunicación.El segundo artículo intenta definir el perfil de un comunicador social al servicio de la sociedad, parte fundamental para lograr un mundo más justo.

  19. ENVELHECIMENTO, CULTURA E SOCIEDADE

    Directory of Open Access Journals (Sweden)

    Andréa Viude

    2010-01-01

    Full Text Available Este artigo discute a participação do eixo envelhecimento, cultura e sociedade no projeto político-pedagógico do Curso de Gerontologia da Escola de Artes, Ciências e Humanidades da Universidade de São Paulo – EACH/USP. O envelhecimento é discutido à luz do pensamento complexo. A heterogeneidade da velhice encontra-se presente ao longo de toda a discussão, com ênfase nos aspectos socioculturais do envelhecimento. Palavras-chave: envelhecimento; aspectos socioculturais; complexidade.

  20. Ewingella Americana: An Emerging True Pathogen

    Directory of Open Access Journals (Sweden)

    Syed Hassan

    2012-01-01

    Full Text Available Infections caused by Ewingella americana have been rarely reported in the literature. Most of the cases that have been reported were among the immunocompromised patients. We report a case of E. americana causing osteomyelitis and septic arthritis of the shoulder joint in a previous intravenous drug abuser. The causative pathogen was identified by synovial fluid analysis and culture.

  1. Aspen Delineation - Plumas National Forest, FRRD [ds376

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (PLUMAS_NF_FEATHERRIVER_PTS) collected in aspen stands in the Plumas...

  2. Fire regimes of quaking aspen in the Mountain West

    Science.gov (United States)

    Shinneman, Douglas J.; Baker, William L.; Rogers, Paul C.; Kulakowski, Dominik

    2013-01-01

    Quaking aspen (Populus tremuloides Michx.) is the most widespread tree species in North America, and it is found throughout much of the Mountain West (MW) across a broad range of bioclimatic regions. Aspen typically regenerates asexually and prolifically after fire, and due to its seral status in many western conifer forests, aspen is often considered dependent upon disturbance for persistence. In many landscapes, historical evidence for post-fire aspen establishment is clear, and following extended fire-free periods senescing or declining aspen overstories sometimes lack adequate regeneration and are succeeding to conifers. However, aspen also forms relatively stable stands that contain little or no evidence of historical fire. In fact, aspen woodlands range from highly fire-dependent, seral communities to relatively stable, self-replacing, non-seral communities that do not require fire for persistence. Given the broad geographic distribution of aspen, fire regimes in these forests likely co-vary spatially with changing community composition, landscape setting, and climate, and temporally with land use and climate – but relatively few studies have explicitly focused on these important spatiotemporal variations. Here we reviewed the literature to summarize aspen fire regimes in the western US and highlight knowledge gaps. We found that only about one-fourth of the 46 research papers assessed for this review could be considered fire history studies (in which mean fire intervals were calculated), and all but one of these were based primarily on data from fire-scarred conifers. Nearly half of the studies reported at least some evidence of persistent aspen in the absence of fire. We also found that large portions of the MW have had little or no aspen fire history research. As a result of this review, we put forth a classification framework for aspen that is defined by key fire regime parameters (fire severity and probability), and that reflects underlying biophysical

  3. de la sociedad argentina

    Directory of Open Access Journals (Sweden)

    Diego Galeano

    2007-01-01

    Full Text Available Este artículo trata sobre un período de la historia argentina en el cual la "mirada médica", a través de un grupo de prestigiosos intelectuales, se convirtió en una clave de interpretación de la sociedad argentina. El análisis gira en torno a la obra de uno de los médicos higienistas más influyentes, José María Ramos Mejía, deteniéndose especialmente en su libro más famoso: Las multitudes argentinas (1899. La hipótesis principal que recorre el texto es la siguiente: la medicalización de la sociedad, acentuada luego de las epidemias de cólera y fiebre amarilla de mediados del siglo XIX, ofreció a las elites públicas la posibilidad de construir dominios legítimos de intervención estatal. Intromisiones del Estado en la vida privada que, además de ser algo resistidas por la población, entraban en tensión con los principios teóricos del liberalismo que los propios miembros de la elite defendían.

  4. de la sociedad actual

    Directory of Open Access Journals (Sweden)

    René Alejandro Jiménez Ornelas

    2005-01-01

    Full Text Available La violencia no es producida aleatoriamente, sino que parte de una cultura de conflictos familiares, sociales, económicos y políticos, y en general, del sistema globalizado que a su vez permea las diferentes formas de vida en la sociedad, donde los estilos de vida de los jóvenes son catalogados como formas de delincuencia. El objetivo de esos estilos de vida, sin embargo, sólo consiste en distanciarse culturalmente de una sociedad que los jóvenes no han fabricado. Víctimas de la discriminación social y excluidos de las decisiones importantes, muchos jóvenes carecen de planes o proyectos de vida, y son considerados incapaces de adaptarse al medio social, por lo cual toman la delincuencia como alternativa de sobrevivencia. El fácil acceso a las drogas, la falta de oportunidades de empleo, salud, educación y espacios para la cultura y el deporte, la desintegración familiar, la impunidad, entre otros factores, componen el contexto en el que nace y crece la juventud mexicana del siglo XXI.

  5. Aspen biology, community classification, and management in the Blue Mountains

    Science.gov (United States)

    David K. Swanson; Craig L. Schmitt; Diane M. Shirley; Vicky Erickson; Kenneth J. Schuetz; Michael L. Tatum; David C. Powell

    2010-01-01

    Quaking aspen (Populus tremuloides Michx.) is a valuable species that is declining in the Blue Mountains of northeastern Oregon. This publication is a compilation of over 20 years of aspen management experience by USDA Forest Service workers in the Blue Mountains. It includes a summary of aspen biology and occurrence in the Blue Mountains, and a...

  6. Evaluation of burned aspen communities in Jackson Hole, Wyoming

    Science.gov (United States)

    Charles E. Kay

    2001-01-01

    Aspen has been declining in Jackson Hole for many years, a condition generally attributed to the fact that lightning fires have been aggressively suppressed since the early 1900s. It is also believed that burning will successfully regenerate aspen stands despite high elk numbers. To test this hypothesis, I evaluated 467 burned and 495 adjacent, unburned aspen stands at...

  7. Aspen: A microsimulation model of the economy

    Energy Technology Data Exchange (ETDEWEB)

    Basu, N.; Pryor, R.J.; Quint, T.; Arnold, T.

    1996-10-01

    This report presents, Aspen. Sandia National Laboratories is developing this new agent-based microeconomic simulation model of the U.S. economy. The model is notable because it allows a large number of individual economic agents to be modeled at a high level of detail and with a great degree of freedom. Some features of Aspen are (a) a sophisticated message-passing system that allows individual pairs of agents to communicate, (b) the use of genetic algorithms to simulate the learning of certain agents, and (c) a detailed financial sector that includes a banking system and a bond market. Results from runs of the model are also presented.

  8. Antioxidant neolignans from Cordia americana.

    Science.gov (United States)

    Fernández, Lucía R; Cirigliano, Adriana; Fabani, María P; Lima, Beatriz; Alberti, Sebastián; Kramer, Fernando; Tapia, Alejandro A; Cabrera, Gabriela; Palermo, Jorge A; Sánchez, Marianela

    2013-12-01

    Five new neolignans with a bicyclo[2.2.2]octene framework were isolated from an ethanolic extract of the bark of Cordia americana. The structures and relative configurations of the compounds were elucidated by a combination of spectroscopic methods. All the isolated compounds showed good antioxidant activities in the DPPH radical scavenging (0.5-100 µg/mL) and Ferric-reducing antioxidant power (FRAP, 1-100 µg/mL) assays. One of the compounds displayed mild fungistatic activity at 0.1 µmol/spot against Fusarium virguliforme while, at the same time, all compounds were inactive against several strains of Gram (+) and Gram (-) bacteria at all assayed concentrations (10-1,000 µg/mL). Georg Thieme Verlag KG Stuttgart · New York.

  9. Aspen Winter Conferences on High Energy

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2011-02-12

    The 2011 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 12 to February 18, 2011. Ninety-four participants from ten countries, and several universities and national labs attended the workshop titled, "New Data From the Energy Frontier." There were 54 formal talks, and a considerable number of informal discussions held during the week. The week's events included a public lecture ("The Hunt for the Elusive Higgs Boson" given by Ben Kilminster from Ohio State University) and attended by 119 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists. The 2011 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was "Indirect and Direct Detection of Dark Matter." It was held from February 6 to February 12, 2011. The 70 participants came from 7 countries and attended 53 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists from other institutions and countries or due to incipient collaborations. In addition, Blas Cabrera of Stanford University gave a public lecture titled "What Makes Up Dark Matter." There were 183 members of the general public in attendance. Before the lecture, 45 people attended the physics cafe to discuss dark matter. This report provides the attendee lists, programs, and announcement posters for each event.

  10. Estimating white trunk rot in aspen stands

    Science.gov (United States)

    Alan C. Jones; Michael E. Ostry

    1998-01-01

    Advanced decay caused by Phellinus tremulae was estimated in 295 trembling aspen on 30 plots in 2 Minnesota counties using existing inventory guides, and then measured by felling and sectioning the trees. In standing trees, decay volume was underestimated by 38% compared to measured decay volume in felled trees. The most reliable external indicator...

  11. Multi-drug resistant Ewingella Americana

    International Nuclear Information System (INIS)

    Bukhari, Syed Z.; Ashshi, Ahmad M.; Hussain, Waleed M.; Fatani, Mohammad I.

    2008-01-01

    We report a case of pneumonia due to multi-drug resistant Ewingella Americana in a young patient admitted in the Intensive Care Unit of Hera General Hospital, Makkah, Saudi Arabia with severe head injury in a road traffic accident. He was an Indonesian pilgrim who had traveled to the Kingdom of Saudi Arabia to perform Hajj in December 2007. Ewingella Americana was identified to be the pathogen of pneumonia with clinical signs and symptoms along with positive radiological findings. (author)

  12. Violencia, Sociedad y Salud

    Directory of Open Access Journals (Sweden)

    Gustavo Malagón Londoño

    1995-04-01

    Full Text Available

    Promovida por la Organización Panamericana de la Salud, con el auspicio de la Organización de los Estados Americanos y del Banco Interamericano de Desarrollo, se celebró el pasado mes en Washington, la Primera Conferencia Interamericana sobre Violencia, Sociedad y Salud.

    Quienes tuvimos la oportunidad de asistir como delegados, participamos en un certamen sin precedentes para el cual se dieron cita los representantes de todos los países de América y el Caribe, con la presencia del Director de la Organización Panamericana de la Salud, el Secretario de la OEA, el Presidente del Banco Interamericano de Desarrollo, de la Directora Regional para América Latina y el Caribe del Fondo de las Naciones Unidas para la Infancia, del Director General para América Latina y el Caribe del Programa de las Naciones Unidas para el Desarrollo, del Secretario del Departamento de Salud y Servicios Humanos de los Estados Unidos de América, además de Ministros de Salud, Justicia y del Interior de los países de la región.

    El temario desarrollado no podía ser de mayor importancia y más relievante actualidad. A través de las varias disertaciones muy bien documentadas nos colocamos en la realidad que consume a la mayoría de los países, con el nuestro a la cabeza, de la más cruel violencia, con cifras escalofriantes no sólo por el crecido número de víctimas, sino por los altos costos que ésta está presentando, además de las implicciones de todo orden que en forma bien clara viene significando. En el año de 1993 ocurrieron en América Latina y el Caribe un total de 456.000 muertes violentas, lo que significa 1.250 por día.

    Las lesiones y discapacidades superan los dos millones de casos. En Colombia ocurrieron 174.000 asesinatos en los últimos cuatro años, 30.000 en lo que va corrido del presente año. Las discapacidades y lesiones presumiblemente exceden en el cuatrienio, de un millón y medio.

    En los Estados Unidos

  13. Aspen Characteristics - Plumas National Forest, FRRD [ds375

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Feather River Ranger...

  14. Iridoids from leaf extract of Genipa americana

    Directory of Open Access Journals (Sweden)

    Jovelina S.F. Alves

    Full Text Available Abstract Genipa americana L., Rubiaceae, is a plant native from Brazil popularly known as “jenipapo”. Two iridoids, 1-hydroxy-7-(hydroxymethyl-1,4aH,5H,7aH-cyclopenta[c]pyran-4-carbaldehyde (1, and iridoid 7-(hydroxymethyl-1-methoxy-1H,4aH,5H,7aH-cyclopenta[c]pyran-4-carbaldehyde (2 were isolated and identified in the leaf extract of G. americana. Compounds 1 and 2 were identified for the first time in G. americana, and 1 has not been yet described in literature. These substances were analyzed by spectroscopic techniques such as infrared, high resolution mass spectrometry, 1H and 13C 1D; as well as 2D nuclear magnetic resonance. Moreover, the presence of flavonoids was detected by a preliminary analysis by Thin Layer Chromatography.

  15. Mycorrhizal fungi of aspen forests: Natural occurrence and potential applications

    Science.gov (United States)

    Cathy L. Cripps

    2001-01-01

    Native mycorrhizal fungi associated with aspen were surveyed on three soil types in the north-central Rocky Mountains. Selected isolates were tested for the ability to enhance aspen seedling growth in vitro. Over 50 species of ectomycorrhizal fungi occur with Populus tremuloides in this region, primarily basidiomycete fungi in the Agaricales. Almost one-third (30%)...

  16. Molecular tools and aspen management: A primer and prospectus

    Science.gov (United States)

    Karen E. Mock; Bryce A. Richardson; Paul G. Wolf

    2013-01-01

    Aspen (Populus tremuloides) isaniconic species in North American landscapes, highly valued for recreation, fiber, wildlife and livestock forage, carbon sequestration, biodiversity, and as a fuelbreak. However, there are rising concerns about the ability of aspen to persist in portions of its range, based on bioclimatic modeling, physiological thresholds and mortality...

  17. Stand development of trembling aspen in Canaan Valley, West Virginia

    Science.gov (United States)

    James S. Rentch; James T. Anderson

    2008-01-01

    In wetlands of Canaan Valley, West Virginia, trembling aspen occurs as a disjunct population well south of its primary natural range. Based on sample data from 15 stands, we found that aspen occurs as nearly monospecific stands or clones. Eight stands had median ages between 30 and 40 yrs, and we suggest that stand initiation was related to changes in land use after...

  18. Iterative Repair Planning for Spacecraft Operations Using the Aspen System

    Science.gov (United States)

    Rabideau, G.; Knight, R.; Chien, S.; Fukunaga, A.; Govindjee, A.

    2000-01-01

    This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflicts) and attempts to repair each by performing a planning or scheduling operation. It must reason about which conflict to resolve first and what repair method to try for the given conflict. ASPEN is currently being utilized in the development of automated planner/scheduler systems for several spacecraft, including the UFO-1 naval communications satellite and the Citizen Explorer (CX1) satellite, as well as for planetary rover operations and antenna ground systems automation. This paper focuses on the algorithm and search strategies employed by ASPEN to resolve spacecraft operations constraints, as well as the data structures for representing these constraints.

  19. Physicochemical Properties of Avocado Pear (Persea americana ...

    African Journals Online (AJOL)

    The oil from edible avocado pear (Persea americana) was extracted using the Soxhlet extraction method and characterized for specific gravity, refractive index, free fatty acids, saponification value, iodine value, acid value and biofuel potential using standard methods. The percent oil content in the fruit pulp was determined.

  20. AspenTech shows specific tools for refiners; AspenTech deploie des outils specifiques pour les raffineurs

    Energy Technology Data Exchange (ETDEWEB)

    Legros, E

    2003-10-01

    The supplier of integrated softwares AspenTech has organized last May, the 7 in Gelsenkirchen, on the site of the Veba Oel refinery, a seminar 'refining' intended to show the specificities of its products: Hysys, Aspen Utilities, Icarus...About fifty German engineers and responsible persons coming from refining and engineering firms have participated to this studies day. (O.M.)

  1. Biologi Perbungaan Tanaman Avokad (Persea Americana Mill.)

    OpenAIRE

    SUKAMTO, L. AGUS

    1985-01-01

    L. AGUS SUKAMTO 1985.The flowering biology of avocado (Persea americana Mill.). Berita Biologi 3 (1) 8 - H.- A study on the flowering biology of avocado available at Bogor Botanic Garden was made.The observation was conducted in respects to the opening and closing of the flowers, the versality of the pollen grains which are then related to the fruit production.The climatic condition as well as pollination agents which may affect on the vertilization in avocado are also discussed.

  2. As empresas em sociedades contemporâneas: a responsabilidade social no Norte e no Sul

    Directory of Open Access Journals (Sweden)

    Paola Cappellin

    Full Text Available Neste artigo a difusão do lema da responsabilidade social é resgatada pela analise de três percursos internacionais: EUA, Brasil e União Européia. No primeiro caso, a vasta literatura sociológica americana relata as preocupações e as pressões de diferentes atores sociais dirigidas às empresas americanas, ao longo dos anos 1960. No Brasil, as primeiras elaborações provêm de associações empresariais nos meados dos anos 60 e se ampliam justo quando a sociedade, no fim dos anos 1990, demanda prosseguir na direção a integrar o compromisso da aplicação das normas e direitos do trabalho. Na União Européia, o lema da responsabilidade social é introduzido nos finais dos anos 1990 envolvendo o compromisso de fazer retroagir a alta taxa de desemprego estrutural. Na última seção, a análise comparativa internacional sugere recompor o quadro dos diversos conteúdos da responsabilidade social a partir da grande questão que está em debate nas sociedades: recompor o compromisso de fortalecimento do vínculo de emprego como fonte de cidadania social.

  3. DE LA SOCIEDAD DEL CONOCIMIENTO A LA SOCIEDAD DEL RIESGO

    OpenAIRE

    Abdala Cardona, Alejandro

    2013-01-01

    El tiempo en el que vivimos: el siglo XXI, presenta a la vez, retos y exigencias al conjunto global de los habitantes del mundo, puesto que, no solo se nos presenta la actualidad como aquella coyuntura histórica en los que el cambio de los acontecimientos gira en torno al rol central del conocimiento, sino también, en torno al potencial que dicho conocimiento trae tras de sí; es decir, el presente siglo impone al conjunto de personas el rótulo de "sociedad del conocimiento" donde se puede enc...

  4. Aspen Grupp võitis RKASi / Lemmi Kann

    Index Scriptorium Estoniae

    Kann, Lemmi

    2008-01-01

    Ehitusfirma Aspen Grupp OÜ võitis Tallinna ringkonnakohtus Riigi Kinnisvara AS-i, kes diskvalifitseeris ehitusfirma riigihankelt seaduses olnud maksevõlgnevuse keelu tõttu. Vt. samas: Lahendust ootavad veel kaks kohtuasja

  5. Aspen Forest Cover by Stratum/Plot (SNF)

    Data.gov (United States)

    National Aeronautics and Space Administration — Average percent coverage and standard deviation of each canopy stratum from subplots at each aspen site during the SNF study in the Superior National Forest, Minnesota

  6. Do Pine Trees in Aspen Stands Increase Bird Diversity

    OpenAIRE

    Rumble, Mark A; Mills, Todd R; Dystra, Brian L; Flake, Lester D

    2001-01-01

    In the Black Hills of South Dakota, quaking aspen (Populus tremuloides) is being replaced by conifers through fire suppression and successional processes. Al- though the Black Hills National forest is removing conifers (primarily ponderosa pine [Pinus ponderosa])toincreasetheaspencommunitiesinsomemixedstands,ForestPlan guidelines allow four conifers per hectare to remain to increase diversity in the remaining aspen stand. We compared bird species richness in pure ponderosa pine, mixed stands ...

  7. Long-term monitoring of western aspen--lessons learned.

    Science.gov (United States)

    Strand, E K; Bunting, S C; Starcevich, L A; Nahorniak, M T; Dicus, G; Garrett, L K

    2015-08-01

    Aspen woodland is an important ecosystem in the western United States. Aspen is currently declining in western mountains; stressors include conifer expansion due to fire suppression, drought, disease, heavy wildlife and livestock use, and human development. Forecasting of tree species distributions under future climate scenarios predicts severe losses of western aspen within the next 50 years. As a result, aspen has been selected as one of 14 vital signs for long-term monitoring by the National Park Service Upper Columbia Basin Network. This article describes the development of a monitoring protocol for aspen including inventory mapping, selection of sampling locations, statistical considerations, a method for accounting for spatial dependence, field sampling strategies, and data management. We emphasize the importance of collecting pilot data for use in statistical power analysis and semi-variogram analysis prior to protocol implementation. Given the spatial and temporal variability within aspen stem size classes, we recommend implementing permanent plots that are distributed spatially within and among stands. Because of our careful statistical design, we were able to detect change between sampling periods with desired confidence and power. Engaging a protocol development and implementation team with necessary and complementary knowledge and skills is critical for success. Besides the project leader, we engaged field sampling personnel, GIS specialists, statisticians, and a data management specialist. We underline the importance of frequent communication with park personnel and network coordinators.

  8. Aspen HYSYS process simulation and Aspen ICARUS cost estimation of CO2 removal plant

    OpenAIRE

    Vozniuk, Ievgeniia Oleksandrivna

    2010-01-01

    An Aspen HYSYS model of CO2 removal was developed and modified with a split-stream configuration in order to reduce energy consumption in the reboiler. The model has been calculated with variation of parameters to optimize the process and find an optimum solution. For the selected base cases the heat exchanger minimum temperature difference was specified to 10K and the removal efficiency was 85%. The reboiler duty of 3.8 MJ/kg CO2 removed for the standard process without split-stream was ...

  9. Culturas orais em sociedades letradas

    Directory of Open Access Journals (Sweden)

    Geraldi João Wanderley

    2000-01-01

    Full Text Available Na relação entre linguagem e cultura, um aspecto essencial diz respeito às diferentes funções da escrita e às formas de sua apropriação social em sociedades letradas. Tomando como inspiração a forma de um uso específico da escrita pelo povo indígena Jarawara e narrativas de ribeirinhos do rio Madeira do mito amazônico Cobra Norato, são discutidas as diferentes relações entre oralidade e escrita que, atravessadas pelas relações de poder, transformam o alfabeto, de artefato histórico construído para o registro da oralidade, em espaço social de construção de distinções, clivagens e exclusões.

  10. Aspen Global Change Institute Summer Science Sessions

    Energy Technology Data Exchange (ETDEWEB)

    Katzenberger, John; Kaye, Jack A

    2006-10-01

    The Aspen Global Change Institute (AGCI) successfully organized and convened six interdisciplinary meetings over the course of award NNG04GA21G. The topics of the meetings were consistent with a range of issues, goals and objectives as described within the NASA Earth Science Enterprise Strategic Plan and more broadly by the US Global Change Research Program/Our Changing Planet, the more recent Climate Change Program Strategic Plan and the NSF Pathways report. The meetings were chaired by two or more leaders from within the disciplinary focus of each session. 222 scholars for a total of 1097 participants-days were convened under the auspices of this award. The overall goal of each AGCI session is to further the understanding of Earth system science and global environmental change through interdisciplinary dialog. The format and structure of the meetings allows for presentation by each participant, in-depth discussion by the whole group, and smaller working group and synthesis activities. The size of the group is important in terms of the group dynamics and interaction, and the ability for each participant's work to be adequately presented and discussed within the duration of the meeting, while still allowing time for synthesis

  11. Chemical studies on oils derived from aspen poplar wood, cellulose, and an isolated aspen poplar lignin

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Pepper, J M; Roy, J C; Mathews, J F

    1983-01-01

    An initial study has been made of the chemical nature of the oil phase resulting from the conversion of aspen poplar wood, cellulose, and an isolated lignin from the aspen poplar as a result of their interactions with water and carbon monoxide in the presence of sodium carbonate at 360 degrees C. Gas chromatographic analysis of the sodium hydroxide soluble fractions from each substrate revealed similar spectra of alkyl-substituted phenols. The relative abundance of identified low molecular weight phenolic compounds decreased from lignin to wood to cellulose. This was in agreement with the known phenolic nature of lignin. As well, it confirmed the synthesis during reaction of such compounds from a carbohydrate substrate. Gas chromatographic analysis of the whole oils also revealed the presence in each case of several alkyl-substituted cyclopentanones whose relative abundance decreased from cellulose to wood to lignin. Silica gel column separation of the oils, after a charcoal treatment, followed by capillary gas chromatographic - mass spectrometric analyses of the resulting fraction indicated the presence of other higher molecular weight phenols, napthols, cycloalkanols, and polycyclic and long chain alkanes and alkenes.

  12. Aspen in the Sierra Nevada: Regional conservation of a continental species

    Science.gov (United States)

    Paul C. Rogers; Wayne D. Shepperd; Dale L. Bartos

    2007-01-01

    Quaking aspen (Populus tremuloides Michx.) a common species in North America, is a minor species in the Sierra Nevada of California. However, the limited coverage of aspen in this area appears to carry a disproportionate biodiversity load: numerous species are dependent on the unique components of aspen forests habitat. Land managers in the region...

  13. Trembling aspen response to a mixed-severity wildfire in the Black Hills, South Dakota, USA

    Science.gov (United States)

    Tara L. Keyser; Frederick W. Smith; Wayne D. Shepperd

    2005-01-01

    Trembling aspen (Populus tremuloides Michx.) regeneration dynamics including sprout production, growth, and clone size were measured to determine the effects of fire on small aspen clone persistence following a mixedseverity wildfire in the Black Hills, South Dakota. Four years postfire, 10 small, isolated aspen clones per low and high fire severity...

  14. Characteristics of aspen infected with heartrot: Implications for cavity-nesting birds

    Science.gov (United States)

    Chris Witt

    2010-01-01

    Phellinus tremulae is an important fungal decay agent common to aspen and a critical component to the cavity-nesting bird complex found in western aspen stands. Little information exists on the conditions that facilitate infection and spread of P. tremulae in aspen forests. I used Forest Inventory and Analysis (FIA) data to explore the relationships of several tree and...

  15. Simulation of quaking aspen potential fire behavior in Northern Utah, USA

    Science.gov (United States)

    R. Justin DeRose; A. Joshua Leffler

    2014-01-01

    Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and...

  16. Lichen community change in response to succession in aspen forests of the southern Rocky Mountains

    Science.gov (United States)

    Paul C. Rogers; Ronald J. Ryel

    2008-01-01

    In western North America, quaking aspen (Populus tremuloides) is the most common hardwood in montane landscapes. Fire suppression, grazing and wildlife management practices, and climate patterns of the past century are all potential threats to aspen coverage in this region. If aspen-dependent species are losing habitat, this raises concerns about...

  17. Sociedades fantasma y Derecho Internacional Privado

    Directory of Open Access Journals (Sweden)

    Javier Carrascosa González

    2014-06-01

    Full Text Available Las conocidas como "sociedades fantasma" son una realidad en el escenario de la economía mundial del siglo XXI. Se trata de entes jurídicos constituidos en ciertos Estados, en los que poseen su sede social, pero en los que no realizan actividad económica o societaria alguna. El presente estudio analiza el régimen jurídico de estas sociedades fantasma en Derecho internacional privado europeo y español. Se aborda la cuestión de la determinación de la Ley reguladora de las sociedades fantasma, la reacción legal contra las pseudo-foreign corporations, la libertad de establecimiento de sociedades fantasma en la UE y la responsabilidad patrimonial de estas sociedades y de sus administradores, en especial, cuando se emplean testaferros. Por último, se presta una especial atención a régimen jurídico de la insolvencia internacional de la sociedad fantasma, lo que comporta el análisis del "centro de intereses principales" de la sociedad fantasma como deudor insolvente, así como del traslado internacional de la sede social de la sociedad fantasma

  18. Evaluation to the aspen for the air pollution monitoring

    International Nuclear Information System (INIS)

    De La Rosa, D.; Lima, L.; Santana, J.L.; Olivares, S.; Martin, R.; Garcia, M.

    2003-01-01

    Aspen is not often used in bio monitoring programs, but when it is, several interacting and confounding variables have to be considered. Biomass of leaves, and height changes are not easy linked with air pollution, whereas dry weight and leaf abscission are. Visible injury diagnosis and crown thinning are useful records for bio monitoring programs to consider, but skill and understanding of air pollution effects versus seasonal effects are very important. Understanding of actual air pollution symptoms and elemental ratios are especially important. Clonal response and heritability is discuses below, and has to be considered in any bio monitoring program. Above all, integration of aspen response with other key variables is key

  19. PERACETIC ACID PRETREATMENT OF ALFALFA STEM AND ASPEN BIOMASS

    OpenAIRE

    Lei Xu,; Ulrike W. Tschirner

    2011-01-01

    Alfalfa stems and ground aspen were exposed to peracetic acid (0.5 to 9% on biomass) at temperatures ranging from 40 to 100° C and reaction times from 1 to 5 hours. Glucose release as a percentage of total cellulose content was determined using subsequent standard enzymatic hydrolysis. Statistical analysis confirmed that aspen showed a strong response to peracetic acid addition rate. 9% peracetic acid removed 14% of the original lignin and increased the rate of glucose release from 23% to 44%...

  20. Pronghorn (Antilocapra americana) Reintroduction and Management Plan [DRAFT

    Data.gov (United States)

    Department of the Interior — Pronghorn (Antilocapra americana) have been a component of North America’s grasslands for millions of years and have thus created a niche for themselves in remaining...

  1. Widespread triploidy in Western North American aspen (Populus tremuloides.

    Directory of Open Access Journals (Sweden)

    Karen E Mock

    Full Text Available We document high rates of triploidy in aspen (Populus tremuloides across the western USA (up to 69% of genets, and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species, climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a low incidence of undetected aneuploidy, tetraploidy or duplicated loci, our evidence suggests that these phenomena are unlikely to be significant contributors to our observed patterns. We suggest that the distribution of triploid aspen is due to a positive synergy between triploidy and ecological factors driving clonality. Although triploids are expected to have low fertility, they are hypothesized to be an evolutionary link to sexual tetraploidy. Thus, interactions between clonality and polyploidy may be a broadly important component of geographic speciation patterns in perennial plants. Further, cytotypes are expected to show physiological and structural differences which may influence susceptibility to ecological factors such as drought, and we suggest that cytotype may be a significant and previously overlooked factor in recent patterns of high aspen mortality in the southwestern portion of the species range. Finally, triploidy should be carefully considered as a source of variance in genomic and ecological studies of aspen, particularly in western U.S. landscapes.

  2. The 2013 Aspen Prize for Community College Excellence

    Science.gov (United States)

    Perlstein, Linda

    2013-01-01

    For millions of Americans, community colleges provide an essential pathway to well-paying jobs and continuing higher education. The Aspen Prize for Community College Excellence honors those institutions that strive for and achieve exceptional levels of success for all students, while they are in college and after they graduate. Community colleges…

  3. Defining Excellence: Lessons from the 2013 Aspen Prize Finalists

    Science.gov (United States)

    Aspen Institute, 2013

    2013-01-01

    In many respects, one couldn't find a group of 10 schools more diverse than the finalists for the 2013 Aspen Prize for Community College Excellence. One community college serves 1,500 students, another 56,000. There are institutions devoted primarily--even solely--to technical degrees, and ones devoted mainly to preparing students for further…

  4. Historical patterns in lichen communities of montane quaking aspen forests

    Science.gov (United States)

    Paul C. Rogers; Dale L. Bartos; Ronald J. Ryel

    2011-01-01

    Climate shifts and resource exploitation in Rocky Mountain forests have caused profound changes in quaking aspen (Populus tremuloides Michx.) structure and function since Euro-American settlement. It therefore seems likely that commensurate shifts in dependent epiphytes would follow major ecological transitions. In the current study, we merge several lines of inquiry...

  5. The Fate of Aspen in a World with Diminishing Snowpacks

    Science.gov (United States)

    Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Kemp, K. B.

    2010-12-01

    Aspen (Populus tremuloides) productivity is tightly coupled with soil moisture. In the mountainous regions of the western USA, annual replenishment of soil moisture commonly occurs during snowmelt. Therefore, snow pack depth and duration can play an important role in sustaining aspen productivity. The presence of almost 50 years of detailed climate data across an elevational transect in the Reynolds Creek Experimental Watershed (RCEW) in southwestern Idaho offers a novel opportunity to better understand the role of shifting precipitation patterns on aspen productivity. Over the past 50 years, the proportion of the precipitation falling in the form of snow decreased by almost a factor of 2 at mid to low elevations in the RCEW, coupled with a roughly four week advance of snow ablation, and decline of large snow drifts that release moisture into the early summer. Results from growth ring increment, stable isotope analysis, sapflux and a process model (Biome BGC), will be used to determine the impact of shifting precipitation patterns on tree productivity along this transect over the past 50 years. Aspen trees located on moist microsites continue to transpire water and maintain high stomatal conductance 21 days later in the growing season relative to individuals on drier microsites. Predictions of net primary productivity (NPP) in aspen are very sensitive to precipitation patterns. NPP becomes negative as early as day 183 (90 days post budbreak) for years with little winter and spring precipitation whereas, in years with ample winter and spring precipitation, NPP remains positive until day 260 when leaf fall occurs. These results give unique insight into the conditions that deciduous tree species will encounter in a warming climate where snow water equivalent continues to diminish and soil moisture declines soon after budbreak occurs.

  6. Orbital Express mission operations planning and resource management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Daniel

    2008-04-01

    As satellite equipment and mission operations become more costly, the drive to keep working equipment running with less labor-power rises. Demonstrating the feasibility of autonomous satellite servicing was the main goal behind the Orbital Express (OE) mission. Like a tow-truck delivering gas to a car on the road, the "servicing" satellite of OE had to find the "client" from several kilometers away, connect directly to the client, and transfer fluid (or a battery) autonomously, while on earth-orbit. The mission met 100% of its success criteria, and proved that autonomous satellite servicing is now a reality for space operations. Planning the satellite mission operations for OE required the ability to create a plan which could be executed autonomously over variable conditions. As the constraints for execution could change weekly, daily, and even hourly, the tools used create the mission execution plans needed to be flexible and adaptable to many different kinds of changes. At the same time, the hard constraints of the plans needed to be maintained and satisfied. The Automated Scheduling and Planning Environment (ASPEN) tool, developed at the Jet Propulsion Laboratory, was used to create the schedule of events in each daily plan for the two satellites of the OE mission. This paper presents an introduction to the ASPEN tool, an overview of the constraints of the OE domain, the variable conditions that were presented within the mission, and the solution to operations that ASPEN provided. ASPEN has been used in several other domains, including research rovers, Deep Space Network scheduling research, and in flight operations for the NASA's Earth Observing One mission's EO1 satellite. Related work is discussed, as are the future of ASPEN and the future of autonomous satellite servicing.

  7. A sociedade cibernética

    Directory of Open Access Journals (Sweden)

    Euripedes Falcão Vieira

    Full Text Available O artigo analisa as mudanças ocorridas na sociedade na transposição de uma época, a modernidade industrial, à outra, a modernidade cibernética. São épocas marcadas por acontecimentos diferenciados no campo da tecnologia, do conhecimento e da informação. Nas duas últimas décadas, particularmente, a mudança em todos os segmentos da sociedade produziu transformações de escala no arcabouço cognitivo, alterando comportamentos e modos de ação e reação ante a nova realidade. Claramente, a nova realidade se impôs e avançou como sociedade cibernética, a sociedade do ciberespaço-tempo com suas narrativas, ainda curtas, dos eventos econômicos, sociais e culturais.

  8. Effects of genotype, elevated CO2 and elevated O3 on aspen phytochemistry and aspen leaf beetle Chrysomela crotchi performance

    Science.gov (United States)

    Leanne M. Vigue; Richard L. Lindroth

    2010-01-01

    Trembling aspen Populus tremuloides Michaux is an important forest species in the Great Lakes region and displays tremendous genetic variation in foliar chemistry. Elevated carbon dioxide (CO2) and ozone (O3) may also influence phytochemistry and thereby alter the performance of insect herbivores such as...

  9. Governo das sociedades, custos de agência e crise financeira: que relação?

    Directory of Open Access Journals (Sweden)

    Catarina Alexandra Alves Fernandes

    2014-03-01

    Full Text Available O debate sobre o governo das sociedades tem ganhado crescente relevo nos meios acadêmico e empresarial desde o fim da década de 1980. Esse maior destaque foi originado por diversos fatores, dos quais se salientam a crise na Ásia, os escândalos financeiros que assolaram grandes empresas cotadas norte-americanas e algumas empresas de auditoria e, mais recentemente, a crise financeira mundial. Embora há muito defendida a necessidade de aperfeiçoar os instrumentos existentes e de descobrir novos mecanismos, de modo a encontrar um sistema de governo das sociedades que minimize os custos de agência, a crise financeira mundial com origem nos EUA veio dar-lhe novo “fôlego”. E, agora, com especial ênfase na banca. Falhas no governo das sociedades, em particular no setor bancário, têm sido apontadas como culpadas pela crise financeira global iniciada em 2007, só comparável à Grande Depressão. Assim, este artigo pretende, em primeiro lugar, apresentar uma caracterização genérica dos mecanismos de governo das sociedades, integrando no estudo os denominados custos de agência e, em seguida, analisar tais mecanismos no setor bancário, estabelecendo uma relação entre eles e a crise financeira. A pesquisa efetuada permite demonstrar a importância dos instrumentos de governo das sociedades na minimização dos custos de agência, nomeadamente no contexto da crise financeira. Ainda que o setor bancário tenha as suas especificidades, a investigação feita indica que existe uma relação entre aqueles instrumentos e a performance dos bancos e que fragilidades no governo das sociedades determinaram em larga medida a crise financeira. 

  10. Assimilate partitioning in avocado, Persea americana

    Energy Technology Data Exchange (ETDEWEB)

    Finazzo, S.; Davenport, T.L.

    1986-04-01

    Assimilate partitioning is being studied in avocado, Persea americana cv. Millborrow in relation to fruit set. Single leaves on girdled branches of 10 year old trees were radiolabeled for 1 hr with 13..mu..Ci of /sup 14/CO/sub 2/. The source leaves were sampled during the experiment to measure translocation rates. At harvest the sink tissues were dissected and the incorporated radioactivity was measured. The translocation of /sup 14/C-labelled compounds to other leaves was minimal. Incorporation of label into fruitlets varied with the tissue and the stage of development. Sink (fruitlets) nearest to the labelled leaf and sharing the same phyllotaxy incorporated the most /sup 14/C. Source leaves for single non-abscising fruitlets retained 3X more /sup 14/C-labelled compounds than did source leaves for 2 or more fruitlets at 31 hrs. post-labelling. Export of label decreased appreciably when fruitlets abscised. If fruitlets abscised within 4 days of labeling then the translocation pattern was similar to the pattern for single fruitlets. If the fruitlet abscised later, the translocation pattern was intermediate between the single and double fruitlet pattern.

  11. Assimilate partitioning in avocado, Persea americana

    International Nuclear Information System (INIS)

    Finazzo, S.; Davenport, T.L.

    1986-01-01

    Assimilate partitioning is being studied in avocado, Persea americana cv. Millborrow in relation to fruit set. Single leaves on girdled branches of 10 year old trees were radiolabeled for 1 hr with 13μCi of 14 CO 2 . The source leaves were sampled during the experiment to measure translocation rates. At harvest the sink tissues were dissected and the incorporated radioactivity was measured. The translocation of 14 C-labelled compounds to other leaves was minimal. Incorporation of label into fruitlets varied with the tissue and the stage of development. Sink (fruitlets) nearest to the labelled leaf and sharing the same phyllotaxy incorporated the most 14 C. Source leaves for single non-abscising fruitlets retained 3X more 14 C-labelled compounds than did source leaves for 2 or more fruitlets at 31 hrs. post-labelling. Export of label decreased appreciably when fruitlets abscised. If fruitlets abscised within 4 days of labeling then the translocation pattern was similar to the pattern for single fruitlets. If the fruitlet abscised later, the translocation pattern was intermediate between the single and double fruitlet pattern

  12. A Rússia Americana The American Russia

    Directory of Open Access Journals (Sweden)

    João Marcelo Ehlert Maia

    2005-08-01

    Full Text Available Este artigo procura analisar interpretações do Brasil assentadas na idéia de que seríamos uma "Rússia Americana". Para tanto, analiso as contribuições de Gilberto Freyre, Otávio Velho e Vicente Licínio Cardoso, e apresento brevemente o caso russo, a partir das obras clássicas de Franco Venturi e Isaiah Berlin. Argumento ao longo do texto que essa percepção de que o Brasil teria uma geografia social "russa" implica a produção de um americanismo específico, que encontra sua maior expressão no pensamento de Vicente Licínio Cardoso e em suas idéias que conjugam fordismo e arielismo.This article seeks to analyse Brazil's interpretations founded on the idea that we would be an "American Russia". in order to do so, I analyse the contributions of Gilberto Freyre, Otávio Velho and Vicente Licínio Cardoso, and I briefly present the russian case, using the works of Franco Venturi and Isaiah Berlin. I suggest that this perception implies the production of an especific type of americanism, wich finds its greater expression on the unusual combination between fordism and arielism made by Vicente Licínio.

  13. Elevated Rocky Mountain elk numbers prevent positive effects of fire on quaking aspen (Populus tremuloides) recruitment

    Science.gov (United States)

    Smith, David Solance; Fettig, Stephen M.; Bowker, Matthew A.

    2016-01-01

    Quaking aspen (Populus tremuloides) is the most widespread tree species in North America and has supported a unique ecosystem for tens of thousands of years, yet is currently threatened by dramatic loss and possible local extinctions. While multiple factors such as climate change and fire suppression are thought to contribute to aspen’s decline, increased browsing by elk (Cervus elaphus), which have experienced dramatic population increases in the last ∼80 years, may severely inhibit aspen growth and regeneration. Fires are known to favor aspen recovery, but in the last several decades the spatial scale and intensity of wildfires has greatly increased, with poorly understood ramifications for aspen growth. Here, focusing on the 2000 Cerro Grande fire in central New Mexico – one of the earliest fires described as a “mega-fire” - we use three methods to examine the impact of elk browsing on aspen regeneration after a mega-fire. First, we use an exclosure experiment to show that aspen growing in the absence of elk were 3× taller than trees growing in the presence of elk. Further, aspen that were both protected from elk and experienced burning were 8.5× taller than unburned trees growing in the presence of elk, suggesting that the combination of release from herbivores and stimulation from fire creates the largest aspen growth rates. Second, using surveys at the landscape level, we found a correlation between elk browsing intensity and aspen height, such that where elk browsing was highest, aspen were shortest. This relationship between elk browsing intensity and aspen height was stronger in burned (r = −0.53) compared to unburned (r = −0.24) areas. Third, in conjunction with the landscape-level surveys, we identified possible natural refugia, microsites containing downed logs, shrubs etc. that may inhibit elk browsing by physically blocking aspen from elk or by impeding elk’s ability to move through the forest patch. We did not find any

  14. Experimental Study of Impregnation Birch and Aspen Samples

    Directory of Open Access Journals (Sweden)

    Igor Vladislavovich Grigorev

    2014-10-01

    Full Text Available An experimental study of wood impregnation was implemented by applying centrifugal methods. The impregnants were a 10% aqueous solution of potassium chloride and a 2% aqueous solution of borax. Birch (Betula pendula and aspen (Populus tremula wood samples in different moisture content were tested. The impregnation time in the centrifugal device were 30 seconds repeated 21 times, and the samples were measured after every 30 seconds. The experimental results were fitted to a nonlinear filtration law, which indicated that the centrifugal wood impregnation was dependent on wood species, wood moisture, rotational speed, and radius. Determination of rotational speed and centrifuge radius for impregnating aspen and birch at varying lengths and humidity under conditions of the nonlinear impregnant filtration law can be done using the example charts that were developed and presented in this study.

  15. Historia de la Tripanosomiasis Americana en Colombia

    Directory of Open Access Journals (Sweden)

    Fernando Serpa Florez

    2000-08-01

    Full Text Available

    La Academia Nacional de Medicina de Colombia rinde homenaje a Carlos Chagas, opónimo médico brasileño, nacido en Oliveira en 1879 y fallecido en Río de Janeiro en 1934, con motivo del nonagésimo aniversario del descubrimiento realizado por él del Trypanosoma cruzi, hazaña científica que bautizó en memoria de su maestro Osvaldo Cruz (1872 – 1917, fundador del Instituto de Manquinhos que hoy lleva el nombre de este sanitarista. (1

    Carlos Chagas fue miembro correspondiente de nuestra Corporación, elegido hace ochenta años, durante la presidencia del profesor Miguel Rueda Acosta, lo que hace que celebremos el triunfo de quien, honrosamente, podemos considerar como uno de los nuestros. (2 Chagas encontró en 1909 la relación existente entre la Tripanosomiasis Americana y el agente de esta dolencia descubierto por él, que por ello hoy se llama Enfermedad de Chagas.

    La tripanosomiasis americana o enfermedad de Chagas, es una entidad autóctona de nuestro continente que, como tantas otras, en un principio fue una zoonosis (enfermedad de los animales que se transmite al hombre tal cual la hidrofobia o rabia, la fiebre amarilla, la encefalitis equina, el carbón bacteridiano, la enfermedad de Lyme… para citar unas cuantas.

    La dolencia se extendió a la especie humana cuando ésta irrumpió en la hábitat del huésped intermedio del mal y se ha hecho cada vez más aparente con el aumento de la población y el desequilibrio ecológico que se presenta con la deforestación.

    Recordemos que sus reservorios (es decir los hospederos que le sirven de depósito, son algunos animales domésticos como el perro, el cerdo o el cobayo y peridomésticos y silvestres como las ratas, los murciélagos, los armadillos, monos y zarigüeyas. Al hombre, desde luego, podemos considerarlo como reservorio de esta dolencia. En Colombia los primeros informes científi-cos sobre animales domésticos y silvestres reservorios del Trypanosoma

  16. Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

    Science.gov (United States)

    Joshi, D. M.; Patel, H. K.

    2015-10-01

    Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant.

  17. Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

    International Nuclear Information System (INIS)

    Joshi, D.M.; Patel, H.K.

    2015-01-01

    Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant

  18. Adverse Influence of Radio Frequency Background on Trembling Aspen Seedlings: Preliminary Observations

    Directory of Open Access Journals (Sweden)

    Katie Haggerty

    2010-01-01

    Full Text Available Numerous incidents of aspen decline have been recorded in North America over the past half century, and incidents of very rapid mortality of aspen clones have been observed in Colorado since 2004. The radio frequency (RF environment of the earth has undergone major changes in the past two centuries due to the development and use of electricity in power and communications applications, and the anthropogenic RF background continues to increase in intensity and complexity. This study suggests that the RF background may have strong adverse effects on growth rate and fall anthocyanin production in aspen, and may be an underlying factor in aspen decline.

  19. Using Aspen plus in thermodynamics instruction a step-by-step guide

    CERN Document Server

    Sandler, Stanley I

    2015-01-01

    A step-by-step guide for students (and faculty) on the use of Aspen in teaching thermodynamics Used for a wide variety of important engineering tasks, Aspen Plus software is a modeling tool used for conceptual design, optimization, and performance monitoring of chemical processes. After more than twenty years, it remains one of the most popular and powerful chemical engineering simulation programs used both industrially and academically. Using Aspen Plus in Thermodynamics Instruction: A Step by Step Guide introduces the reader to the use of Aspen Plus in courses in thermodynamics. It prov

  20. Evaluation of Treatments to Reduce Hardness of Agave americana Core

    Directory of Open Access Journals (Sweden)

    José A. Ramírez

    2006-01-01

    Full Text Available Agave americana contains inulin as storage carbohydrate. Therefore, agave is interesting to be used for the extraction of inulin by pressing. The yield of the process is low due to the high hardness of the core. The objective of this work was to evaluate pretreatments to reduce the hardness in the process of obtaining inulin by pressing. Treatments with water, sulphuric acid 1 % (by mass or sodium hydroxide 1 % (by mass were tested and optimized. The pretreatment of the core of A. americana with sulphuric acid 1 % allowed the reduction of hardness from 30 000 g to 2000 g of breaking force. The mathematical model obtained predicts an optimum processing at 84 °C during 75 min. The treatment with sulphuric acid 1 % also allows white core of A. americana to be obtained, while the other treatments provide yellow core. These results open a good alternative to obtain value added products from this resource.

  1. 2012 Aspen Winter Conferences on High Energy and Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Olivier, Dore [California Inst. of Technology (CalTech), Pasadena, CA (United States); Fox, Patrick [Aspen Center for Physics, CO (United States); Furic, Ivan [Univ. of Florida, Gainesville, FL (United States); Halkiadakis, Eva [Rutgers Univ., Piscataway, NJ (United States); Schmidt, Fabian [California Inst. of Technology (CalTech), Pasadena, CA (United States); Senatore, Leonardo [Stanford Univ., CA (United States); Smith, Kendrick M. [Princeton Univ., NJ (United States); Whiteson, Daniel [Univ. of California, Irvine, CA (United States)

    2012-05-01

    Aspen Center for Physics Project Summary DE-SC0007313 Budget Period: 1/1/2012 to 12/31/2012 The Hunt for New Particles, from the Alps to the Plains to the Rockies The 2012 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 11 to February 17, 2012. Sixty-seven participants from nine countries, and several universities and national labs attended the workshop titled, The Hunt for New Particles, from the Alps to the Plains to the Rockies. There were 53 formal talks, and a considerable number of informal discussions held during the week. The weeks events included a public lecture-Hunting the Dark Universe given by Neal Weiner from New York University) and attended by 237 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists conducted by Spencer Chang (University of Oregon), Matthew Reece (Harvard University) and Julia Shelton (Yale University) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by John Campbell (Fermilab), Patrick Fox (Fermilab), Ivan Furic (University of Florida), Eva Halkiadakis (Rutgers University) and Daniel Whiteson (University of California Irvine). Additional information is available at http://indico.cern.ch/conferenceDisplay.py?confId=143360. Inflationary Theory and its Confrontation with Data in the Planck Era The 2012 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was Inflationary Theory and its Confrontation with Data in the Planck Era. It was held from January 30 to February 4, 2012. The 62 participants came from 7 countries and attended 43 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists

  2. Simulating the Dependence of Aspen on Redistributed Snow

    Science.gov (United States)

    Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Winstral, A. H.

    2013-12-01

    In mountainous regions across the western USA, the distribution of aspen (Populus tremuloides) is often directly related to heterogeneous soil moisture subsidies resulting from redistributed snow. With decades of climate and precipitation data across elevational and precipitation gradients, the Reynolds Creek Experimental Watershed (RCEW) in southwest Idaho provides a unique opportunity to study the relationship between aspen and redistributed snow. Within the RCEW, the total amount of precipitation has not changed in the past 50 years, but there are sharp declines in the percentage of the precipitation falling as snow. As shifts in the distribution of available moisture continue, future trends in aspen net primary productivity (NPP) remain uncertain. In order to assess the importance of snowdrift subsidies, NPP of three aspen stands was simulated at sites spanning elevational and precipitation gradients using the biogeochemical process model BIOME-BGC. At the aspen site experiencing the driest climate and lowest amount of precipitation from snow, approximately 400 mm of total precipitation was measured from November to March of 2008. However, peak measured snow water equivalent (SWE) held in drifts directly upslope of this stand was approximately 2100 mm, 5 times more moisture than the uniform winter precipitation layer initially assumed by BIOME-BGC. BIOME-BGC simulations in dry years forced by adjusted precipitation data resulted in NPP values approximately 30% higher than simulations assuming a uniform precipitation layer. Using BIOME-BGC and climate data from 1985-2011, the relationship between simulated NPP and measured basal area increments (BAI) improved after accounting for redistributed snow, indicating increased simulation representation. In addition to improved simulation capabilities, soil moisture data, diurnal branch water potential, and stomatal conductance observations at each site detail the use of soil moisture in the rooting zone and the onset

  3. Design and simulation of heat exchangers using Aspen HYSYS, and Aspen exchanger design and rating for paddy drying application

    Science.gov (United States)

    Janaun, J.; Kamin, N. H.; Wong, K. H.; Tham, H. J.; Kong, V. V.; Farajpourlar, M.

    2016-06-01

    Air heating unit is one of the most important parts in paddy drying to ensure the efficiency of a drying process. In addition, an optimized air heating unit does not only promise a good paddy quality, but also save more for the operating cost. This study determined the suitable and best specifications heating unit to heat air for paddy drying in the LAMB dryer. In this study, Aspen HYSYS v7.3 was used to obtain the minimum flow rate of hot water needed. The resulting data obtained from Aspen HYSYS v7.3 were used in Aspen Exchanger Design and Rating (EDR) to generate heat exchanger design and costs. The designs include shell and tubes and plate heat exchanger. The heat exchanger was designed in order to produce various drying temperatures of 40, 50, 60 and 70°C of air with different flow rate, 300, 2500 and 5000 LPM. The optimum condition for the heat exchanger were found to be plate heat exchanger with 0.6 mm plate thickness, 198.75 mm plate width, 554.8 mm plate length and 11 numbers of plates operating at 5000 LPM air flow rate.

  4. Sociedad y Salud. Curso 2010-2011

    OpenAIRE

    Ruiz Callado, Raúl; Fabregat Cabrera, María Elena

    2011-01-01

    Sociología de la salud. Determinantes sociales de la salud y la enfermedad. Desigualdades sociales en salud. Las organizaciones como sistemas. Estilos de vida y conductas de salud. Impacto de sociedad de consumo, la ciencia y la tecnología en la salud. Métodos de investigación social aplicados al ámbito de la salud.

  5. En Otras Palabras... (Grupo Mujer Y Sociedad)

    OpenAIRE

    Herminia Gonzálvez Torralbo

    2006-01-01

    En otras palabras.... nace en Colombia en 1996 como una publicación especializada editada por el Grupo Mujer y Sociedad, Escuela de Estudios de Género de la Universidad Nacional de Colombia y la Corporación Casa de la Mujer de Bogotá.

  6. Tratamento da leishmaniose tegumentar americana pelo niridazol

    Directory of Open Access Journals (Sweden)

    Miroslau Constante Baranski

    1970-08-01

    Full Text Available Foi empregue o niridazol um derivado do nitrotiazol, em doze pacientes com leishmaniose tegumentar americana. Em todos êles, o diagnóstico clínico da doença foi confirmado pela biópsia das lesões e em oito dêles também pela positividade da intradetermorreação de Montenegro. Oito pacientes tinham lesões mucosas metastáticas em atividade e lesões cutâneas iniciais cicatrizadas há tempo mais ou menos longo. Dois apresentavam concomitância de lesões cutâneas e mucosas em atividade, e dois tinham lesões cutâneas exclusivas. A duração da doença variou de 2 meses a 32 anos. A posologia diária do niridazol foi uniformememente de 25 mg/kg de pêso corpóreo. O medicamento foi administrado por via oral, em duas tomadas diárias, sempre com o doente internado em hospital. Quando a tolerância o permitia, o paciente recebia cinco séries de tratamento de 10 dias de duração cada, intercaladas por períodos áe suspensão da droga de 10 dias entre uma série e outra. Isso foi possível em 10 dos 12 pacientes. O tratamento foi bem tolerado em 5 doentes e de tolerância regular em 4. Mal tolerado em um paciente pela ocorrência de alucinações e excitação mental e interrompido pela péssima tolerância em dois doentes devido ao aparecimento de convulsões generalizadas com perda da consciência. O tratamento acompanhou-se de grande incidência, de efeitos colaterais. A ocorrência de para-efeitos mais intensos não foi devida às más condições hepáticas. Provas de função hepática. hemogramas, estudos bioquímicos do sangue e exames de urina, realizados antes, durante e após o tratamento, não revelaram alterações significativas. Biópsias hepáticas por punção com agulha em dez doentes, prévias e posteriores ao tratamento, não detectaram lesões hepáticas que pudessem ser atribuídas à medicação. O seguimento dos doentes prolongou-se pelo prazo de dois a 36 meses apos o tratamento. Alterações eletrocardiogr

  7. Agrobacterium-mediated genetic transformation of Fraxinus americana hypocotyls

    Science.gov (United States)

    Kaitlin J. Palla; Paula M. Pijut

    2015-01-01

    An Agrobacterium tumefaciens-mediated genetic transformation system was successfully developed for white ash (Fraxinus americana) using hypocotyls as the initial explants. Hypocotyls isolated from mature embryos germinated on Murashige and Skoog (MS) medium supplemented with 22.2 µM 6-benzyladenine (BA) and 0.5 µM...

  8. Memory Consolidation and Gene Expression in "Periplaneta Americana"

    Science.gov (United States)

    Strausfeld, Nicholas J.; Pinter, Marianna; Lent, David D.

    2005-01-01

    A unique behavioral paradigm has been developed for "Periplaneta americana" that assesses the timing and success of memory consolidation leading to long-term memory of visual-olfactory associations. The brains of trained and control animals, removed at the critical consolidation period, were screened by two-directional suppression subtractive…

  9. Drug interaction studies of Ximenia americana and Pavetta ...

    African Journals Online (AJOL)

    The therapeutic efficacy of single or multicomponent herbs is thought to reside in synergistic interactions between the bioactive constituents. The methanol extracts of X. americana and P. crassipes were initially screened against Gram positive and negative organisms as well as against Mycobacterium tuberculosis H37Rv ...

  10. Genetic characterisation of avocado ( Persea americana Mill.) in two ...

    African Journals Online (AJOL)

    Avocado (Persea americana Mill.) is a nutritious and economic tree crop with cultivations scattered all over Ghana. Although, there have been some genetic diversity research on this crop in some parts of the world, rather limited research has been done on avocado in Ghana. A study was therefore conducted to assess its ...

  11. Analgesic effect of the aqueous seed extract of Persea Americana ...

    African Journals Online (AJOL)

    Persea americana, Mill (Lauraceae) is one of the medicinal plants used in Nigeria for pain relief. Based on its ethnomedicinal use in pain management, the seed of the plant was extracted with distilled water and screened for analgesic activity. The analgesic screening was done in mice using four models: acetic ...

  12. Hybrid Aspen Response to Shearing in Minnesota: Implications for Biomass Production

    Science.gov (United States)

    Grant M. Domke; Andrew J. David; Anthony W. D' Amato; Alan R. Ek; Gary W. Wycoff

    2011-01-01

    There is great potential for the production of woody biomass feedstocks from hybrid aspen stands; however, little is known about the response of these systems to silvicultural treatments, such as shearing. We sought to address this need by integrating results from more than 20 years of individual tree and yield measurements in hybrid aspen (Populus tremuloides Mich. ×...

  13. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Darbah, Joseph N.T., E-mail: darbah@ohio.ed [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States); Department of Environmental and Plant Biology, Ohio University, 315 Porter Hall, Athens, OH 45701 (United States); Sharkey, Thomas D. [Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 (United States); Calfapietra, Carlo [Institute of Agro-Environmental and Forest Biology (IBAF), National Research Council (CNR), Via Salaria km 29300, 00016 Monterotondo Scalo, Roma (Italy); Karnosky, David F. [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States)

    2010-04-15

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO{sub 2} and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO{sub 2} protected photosynthesis of both species against moderate heat stress. Elevated CO{sub 2} increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO{sub 2} treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO{sub 2} were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO{sub 2}. Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO{sub 2} confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  14. Nest-site selection and nest survival of Lewis's woodpecker in aspen riparian woodlands

    Science.gov (United States)

    Karen R. Newlon; Victoria A. Saab

    2011-01-01

    Riparian woodlands of aspen (Populus tremuloides) provide valuable breeding habitat for several cavity-nesting birds. Although anecdotal information for this habitat is available for Lewis's Woodpecker (Melanerpes lewis), no study has previously examined the importance of aspen woodlands to this species' breeding biology. From 2002 to 2004, we monitored 76...

  15. Synergetic hydrothermal co-liquefaction of crude glycerol and aspen wood

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Jasiunas, Lukas; Casamassima, Luca

    2015-01-01

    quality were all invariant to the reaction temperature. By increasing the crude glycerol to aspen wood mass ratio from 0:1 to 3:1, char yield was decreased from 18.3% (only aspen wood) to 3.4%. Furthermore, the biocrude quality in terms of the effective hydrogen-to-carbon ratio (H/Ceff) was significantly...

  16. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    International Nuclear Information System (INIS)

    Darbah, Joseph N.T.; Sharkey, Thomas D.; Calfapietra, Carlo; Karnosky, David F.

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO 2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO 2 protected photosynthesis of both species against moderate heat stress. Elevated CO 2 increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO 2 treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO 2 were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO 2 . Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO 2 confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  17. The aspen mortality summit; December 18 and 19, 2006; Salt Lake City, UT

    Science.gov (United States)

    Dale L. Bartos; Wayne D. Shepperd

    2010-01-01

    The USDA Forest Service Rocky Mountain Research Station sponsored an aspen summit meeting in Salt Lake City, Utah, on December 18 and19, 2006, to discuss the rapidly increasing mortality of aspen (Populus tremuloides) throughout the western United States. Selected scientists, university faculty, and managers from Federal, State, and non-profit agencies with experience...

  18. Differential response of Aspen and Birch trees to heat stress under elevated carbon dioxide

    Science.gov (United States)

    Joseph N.T. Darbah; Thomas D. Sharkey; Carlo Calfapietra; David F. Karnosky

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO2 protected photosynthesis of both species against moderate heat stress. Elevated CO...

  19. Aspen increase soil moisture, nutrients, organic matter and respiration in Rocky Mountain forest communities.

    Science.gov (United States)

    Buck, Joshua R; St Clair, Samuel B

    2012-01-01

    Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO(3) and NH(4) were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development.

  20. Factors influencing epiphytic lichen communities in aspen-associated forests of the Bear River Range, Idaho and Utah

    Science.gov (United States)

    Paul C. Rogers

    2007-01-01

    In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing...

  1. 76 FR 69279 - Notice of Intent to Prepare an Environmental Impact Statement for the Quaking Aspen Wind Energy...

    Science.gov (United States)

    2011-11-08

    ... Intent to Prepare an Environmental Impact Statement for the Quaking Aspen Wind Energy Project, Wyoming... Statement (EIS) for the Quaking Aspen Wind Energy Project (Quaking Aspen). By this notice, BLM is: (1..._Wind_Energy[email protected] ; or Mail: 280 Highway 191 N., Rock Springs, WY 82901. Documents pertinent to...

  2. Allozyme and microsatellite data reveal small clone size and high genetic diversity in aspen in the southern Cascade Mountains

    Science.gov (United States)

    Jennifer DeWoody; Thomas H. Rickman; Bobette E. Jones; Valerie D. Hipkins

    2009-01-01

    The most widely distributed tree in North America, quaking aspen (Populus tremuloides, Michx.), reproduces sexually via seed and clonally via suckers. The size of aspen clones varies geographically, generally smaller in the east and large in the arid Intermountain West. In order to describe clone size and genetic structure of aspen in the southern Cascade...

  3. Habitone analysis of quaking aspen in the Utah Book Cliffs: Effects of site water demand and conifer cover

    Science.gov (United States)

    Joseph O. Sexton; R. Douglas Ramsey; Dale L. Bartos

    2006-01-01

    Quaking aspen (Populus tremuloides Michx.) is the most widely distributed tree species in North America, but its presence is declining across much of the Western United States. Aspen decline is complex, but results largely from two factors widely divergent in temporal scale: (1) Holocene climatic drying of the region has led to water limitation of aspen seedling...

  4. O direito dos povos: uma proposta de sociedade bem ordenada

    Directory of Open Access Journals (Sweden)

    Jéssica de Farias Mesquita

    2017-02-01

    Full Text Available O presente texto tem como objetivo examinar a visão de John Rawls acerca das sociedades bem ordenadas na obra O Direito dos Povos, bem como o significado destas para o desenvolvimento da proposta de sociedade democrática liberal. Rawls, na primeira parte da obra, que trata sobre a teoria ideal, refere-se à ideia geral de contrato social nas Sociedades dos Povos democráticos liberais. O autor prossegue com a mesma ideia, na segunda parte da obra quando trata da teoria não-ideal, referindo-se aos povos decentes. Uma sociedade dos povos decentes, segundo Rawls, é uma sociedade cujas características são aceitáveis como membro de uma Sociedade dos Povos razoável, embora não seja uma sociedade democrática liberal. Ambas as sociedades, seja ela democrática liberal ou decente, fazem parte de uma sociedade bem ordenada por obedecerem aos critérios estabelecidos pela Sociedade dos Povos. Para a garantia de uma sociedade bem ordenada, Rawls expõe uma série de condições para que esse tipo de sociedade seja possível, uma dessas condições é o modo como essas sociedades se encontram reguladas.

  5. Enfermedad de Chagas o Tripanosomiasis Americana.

    Directory of Open Access Journals (Sweden)

    Felipe Guhl

    2000-08-01

    Full Text Available

    Situación Actual de Colombia.

    La enfermedad de Chagas o tripanosomiasis americana es una enfermedad parasitaria crónica causada por un protozoario flagelado el Trypanosoma cruzi, descrito por primera vez por Carlos Chagas, médico brasileño, a comienzos de este siglo y en su honor se denominó la enfermedad que lleva su nombre.

    Este parásito normalmente se transmite al ser humano a través de insectos triatomíneos estrictamente hematófagos de la familia Reduviidae, en el momento en que perforan la piel para succionar la sangre que los alimenta.

    Sin embargo, no se inocula directamente por intermedio de las estructuras bucales del insecto en el momento de la picadura como en el caso de las tripanosomiasis africanas, si no que se deposita pasivamente en la piel a través de las heces del insecto, penetrando en el cuerpo por la herida que causa la picadura u otras abrasiones de la piel o de la mucosa. El T. cruzi, también puede transmitirse por infección congénita, por transfusión de sangre contaminada o por el transplante de órganos contaminados. El ciclo vital del parásito es largo y complejo y su desarrollo tiene varias etapas, tanto en el vector triatomineo como en el huésped vertebrado .

    La Enfermedad de Chagas constituye una amenaza permanente para casi la cuarta parte de toda la población de América Latina. Si bien la enfermedad se encuentra presente en toda América Central y del Sur, sus manifestaciones y características epidemiológicas son altamente variables entre una y otra zona endémica. Existe una gran diversidad en las tasas de prevalencia, formas de transmisión, características parasitarias, patología clínica, vectores y reservorios.

    Más que cualquier otra enfermedad parasitaria, la enfermedad de Chagas se relaciona con el desarrollo económico y social de la población: los insectos triatomineos y las enfermedades que ellos transmiten existirán mientras en

  6. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu

    2013-12-01

    Full Text Available In this paper gas engine model was developed in Aspen HYSYS V7.3 and validated with Waukesha 16V275GL+ gas engine. Fuel flexibility, fuel types and part load performance of the gas engine were investigated. The design variability revealed that the gas engine can operate on poor fuel with low lower heating value (LHV such as landfill gas, sewage gas and biogas with biogas offering potential integration with bottoming cycles when compared to natural gas. The result of the gas engine simulation gave an efficiency 40.7% and power output of 3592kW.

  7. Recovering aspen follow changing elk dynamics in Yellowstone: evidence of a trophic cascade?

    Science.gov (United States)

    Painter, Luke E; Beschta, Robert L; Larsen, Eric J; Ripple, William J

    2015-01-01

    To investigate the extent and causes of recent quaking aspen (Populus tremuloides) recruitment in northern Yellowstone National Park, we measured browsing intensity and height of young aspen in 87 randomly selected aspen stands in 2012, and compared our results to similar data collected in 1997-1998. We also examined the relationship between aspen recovery and the distribution of Rocky Mountain elk (Cervus elaphus) and bison (Bison bison) on the Yellowstone northern ungulate winter range, using ungulate fecal pile densities and annual elk count data. In 1998, 90% of young aspen were browsed and none were taller-than 200 cm, the height at which aspen begin to escape from elk browsing. In 2012, only 37% in the east and 63% in the west portions of the winter range were browsed, and 65% of stands in the east had young aspen taller than 200 cm. Heights of young aspen were inversely related to browsing intensity, with the least browsing and greatest heights in the eastern portion of the range, corresponding with recent changes in elk density and distribution. In contrast with historical elk distribution (1930s-1990s), the greatest densities of elk recently (2006-2012) have been north of the park boundary (approximately 5 elk/km2), and in the western part of the range (2-4 elk/km2), with relatively few elk in the eastern portion of the range (wolves (Canis lupius) in 1995-1996 played a role in these changing elk population dynamics, interacting with other influences including increased predation by bears (Ursus spp.), competition with an expanding bison population, and shifting patterns of human land use and hunting outside the park. The resulting new aspen recruitment is evidence of a landscape-scale trophic cascade in which a resurgent large carnivore community, combined with other ecological changes, has benefited aspen through effects on ungulate prey.

  8. de la sociedad de la ubicuidad

    Directory of Open Access Journals (Sweden)

    Jose Octavio Islas-Carmona

    2008-01-01

    Full Text Available En el imaginario de la sociedad de la ubicuidad, en el cual las comunicaciones digitales inciden de forma categórica en el desarrollo y la evolución de los nuevos ambientes comunicativos, las figuras de "emisor" y "receptor", así como los modelos que ayer permitían explicar el proceso comunicativo, hoy exhiben evidentes limitaciones en sus capacidades explicativas. La realidad los ha desbordado. En el desarrollo histórico de los medios de comunicación es posible advertir cómo éstos resienten determinadas remediaciones. Desde la perspectiva de la ecología de medios, Internet -el medio de comunicación inteligente-, admite ser comprendido como lógica extensión del telégrafo. El telégrafo representó la primera exteriorización de nuestro sistema nervioso. El desarrollo de las comunicaciones digitales móviles nos desplaza hacia un nuevo ambiente mediático: la "sociedad de la ubicuidad". De acuerdo con Neil Postman, detrás de toda tecnología subyace una filosofía, y los principios comunicativos de la "sociedad de la ubicuidad": comunicación para todos, en cualquier momento, en cualquier lugar, desplazan consigo la necesidad de producir los dispositivos de comunicaciones digitales móviles idóneos para responder a las exigencias del ambiente comunicativo que supone dicha sociedad. El desarrollo de la web 2.0 admite ser considerado como un auténtico parteaguas histórico en la evolución de Internet; éste impuso importantes cambios tanto en el comportamiento como en los hábitos de consumo cultural de los cibernautas. El cibernauta accedió a la condición de prosumidor. Debemos reconocer a los prosumidores como los actores comunicativos de la sociedad de la ubicuidad. El papel de los prosumidores resultará definitivo en las siguientes remediaciones que experimentará Internet, medio que definitivamente admite ser comprendido como lógica extensión de la inteligencia humana.

  9. La inscripción de las sociedades profesionales en el Registro mercantil y en el de Sociedades profesionales

    OpenAIRE

    García Presas, Inmaculada

    2008-01-01

    La Ley 2/2007, de 15 de marzo, de Sociedades Profesionales considera, entre otras cuestiones, la inscripción de las Sociedades profesionales en el Registro mercantil y en el de las Sociedades profesionales. En este sentido se valora, entre otros contenidos de dicha Ley, su artículo 8, incidiéndose en el grado de exigencia de la inscripción de las Sociedades profesionales en el Registro Civil.

  10. La sociedad de la información. Tecnología, cultura, sociedad

    Directory of Open Access Journals (Sweden)

    EDUARDO BERICAT ALASTUEY

    1996-01-01

    Full Text Available En este artículo se precisa conceptualmente, desde la sociología, lo que puede entenderse por sociedad de la información. Con este objeto se avanzan algunas tesis sobre la naturaleza de los vectores tecnológico, cultural y relacional que subyacen al advenimiento de esta nueva sociedad. El paradigma tecnológico constituye el principio activo o motor de los cambios. Así, definimos la sociedad de la información como aquella sociedad que utilice tanto intensiva como extensivamente el paradigma de ordenadores en red, ahora bien, el vector tecnológico modifica radicalmente el vector cultural en sus dos componentes básicos, el cognitivo y el expresivo. Una nueva cultura del conocimiento y de la expresión esta surgiendo, cultura de la inteligencia artificial y de la realidad virtual. Todavía no podemos concebir cientificamente la naturaleza de la sociedad de la infocomunicación. Frente a la poco rigurosa imaginación de mundos o sociedades digitales, el autor propone el desarrollo de una teoría social de la infocomunicación, todavía hoy inexistente. Para tal empeño, tienen especial interés las obras elaboradas por dos teóricos sociales de excepción ; Niklas Luhmann y Jürgen Habermas. Información y comunicación, infocomunicación, en la trama y en la urdimbre de las futuras estructuras sociales.

  11. Notas sobre la sociedad en la (prehistoria

    Directory of Open Access Journals (Sweden)

    A. GÓMEZ FUENTES

    2010-02-01

    Full Text Available Las relaciones sociales responden a la pregunta de cómo se sitúan los hombres en el proceso de la producción si atendemos a quién o quiénes son los propietarios o los poseedores de los útiles. Para el paleolítico —inferior, medio y superior— y aún después, claramente se ve que no se puede hablar de clasese sociales si éstas se definen a partir del concepto de propiedad o de posesión. ¿Qué se entiende por propiedad en la sociedad primitiva? Podríamos definir la propiedad como una posesión reconocida por los miembros de la sociedad, garantizada por las normas de vida de la comunidad, admitidas por tal sociedad y protegida por la costumbre o por la ley. Esta definición para época paleolítica no sirve. Decir que propiedad es una posesión es no intentar resolver el problema, porque tendríamos que preguntarnos inmediatamente qué se entiende por posesión en una época que grosso modo abarca desde 5,5 millones de años al 9000 a. n. e. Si examinamos la definición donde se habla de que la posesión está garantizada por las normas de vida en común y protegida por la costumbre o por la ley ¿cómo podemos investigar la norma, la costumbre o la ley durante el paleolítico inferior, medio o superior?

  12. Inventory of aspen trees in spruce dominated stands in conservation area

    Directory of Open Access Journals (Sweden)

    Matti Maltamo

    2015-05-01

    Full Text Available Background The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of aspens is challenging. Methods We characterized aspen populations in a boreal nature reserve using diameter distribution, spatial pattern, and forest attributes: volume, number of aspens, number of large aspen stems and basal area median diameter. The data were collected from three separate forest stands in Koli National Park, eastern Finland. At each site, we measured breast height diameter and coordinates of each aspen. The comparison of inventory methods of aspens within the three stands was based on simulations with mapped field data. We mimicked stand level inventory by locating varying numbers of fixed area circular plots both systematically and randomly within the stands. Additionally, we also tested if the use of airborne laser scanning (ALS data as auxiliary information would improve the accuracy of the stand level inventory by applying the probability proportional to size sampling to assist the selection of field plot locations. Results The results showed that aspens were always clustered, and the diameter distributions indicated different stand structures in the three investigated forest stands. The reliability of the volume and number of large aspen trees varied from relative root mean square error figures above 50% with fewer sample plots (5–10 to values of 25%–50% with 10 or more sample plots. Stand level inventory estimates were also able to detect spatial pattern and the shape of the diameter distribution. In addition, ALS-based auxiliary information could be useful in guiding the inventories, but caution should be used when applying the ALS-supported inventory technique. Conclusions This study characterized European aspen populations for the purposes of monitoring and management of boreal conservation areas. Our

  13. Redes sociales y sociedad del conocimiento

    OpenAIRE

    Vélez Cuartas, Gabriel Jaime

    2009-01-01

    Esta segunda edición de Innovación RICEC integra 5 de los artículos presentados en la mesa "Redes Sociales y Sociedad del Conocimiento" del "4to Congreso de Sistemas de Innovación para la Competitividad 2009: SINNCO" realizado por el CONCYTEG (Consejo de Ciencia y Tecnología de Guanajuato - México). Dos artículos sobre avances de investigación cercanas al concepto de controversia de Callon y por tanto al de teoría del actor red; y finalmente una reseña de la escuela de verano de la red intern...

  14. Relaciones de poder en la sociedad patriarcal

    Directory of Open Access Journals (Sweden)

    Villarreal Montoya, Ana Lucía

    2001-06-01

    Full Text Available Cotidianamente escuchamos y hablamos de relaciones de poder, pero cuando se trata de profundizar en el concepto en realidad es poco lo que se ha estudiado, por lo cual en este artículo se hace una revisión, desde lo macro - vida pública- a lo micro - vida privada -, con el propósito de elaborar una propuesta de cómo se puede entender este concepto. Se analizan varias propuestas, como las planteadas por los teóricos del intercambio, así como la de Clara Coria de que en la sociedad patriarcal las mujeres ejercen el poder oculto, el cual es la otra cara de la moneda del poder legítimo, que ejercen los hombres. Específicamente se trata de abrir un sendero que permita analizar dichas relaciones desde la teoría feminista, de la construcción de una sociedad en la cual las personas, sin importar su sexo/género, tengan la oportunidad de construir su proyecto de vida con libertad, sin prejuicios y estereotipos que les limiten campos de realización.

  15. Sociedad del aprendizaje y tercera edad

    Directory of Open Access Journals (Sweden)

    Agustín REQUEJO OSORIO

    2009-11-01

    Full Text Available RESUMEN: Desde hace tiempo se vienen analizando los fenómenos que acontecen en la denominada «sociedad cognitiva». Particularmente en Europa el tema cobra mayor interés a partir de la publicación: «Enseñary aprender: hacia la sociedad cognitiva».El presente artículo tiene como objetivo básico exponer los rasgos más importantes y las demandas de esta sociedad en relación con el grupo de personas cada vez más numeroso: las personas mayores o también denominadas de la «Tercera Edad».En este contexto se estudian las relaciones entre sociedad cognitiva y fenómeno demográfico que nos muestran un número cada vez más importante de personas mayores. Junto a este hecho sociológico se debate el problema de su formación a partir de los presupuestos de una educación permanente de carácter humanista y democrático frente a la visión neoliberal centrada en la propuesta unilateral del capital humano.Desde esta propuesta educativa se comentan los diversos programas que hoy existen para los mayores haciendo tanto un breve recorrido histórico de las distintas ofertas como un estudio de las más actuales que se realizan por parte de las universidades: universidades de la Tercera Edad, universidades de la Experiencia, «Cuartos Ciclos» universitarios para personas mayores.ABSTRACT: Analysis of the phenomena which occur in the so-called «cognitive society» has been going for a long time in education. Particulary in Europe, the issue of the «cognitive society» has gained interest since the publication of «Enseñar y aprender: hacia la sociedad cognitiva (Teaching and Learning: Aiming at the Cognitivy Society.The main purpose of this paper is to show the most relevant features and demands of this kind of society in relation to a group of people that is steadily growing in number: senior citizens (also named as the «Third Age».Within this context, we having studied the relations between the cognitive society and the demography, it can

  16. Orbital Express Mission Operations Planning and Resource Management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Danny

    2008-01-01

    The Orbital Express satellite servicing demonstrator program is a DARPA program aimed at developing "a safe and cost-effective approach to autonomously service satellites in orbit". The system consists of: a) the Autonomous Space Transport Robotic Operations (ASTRO) vehicle, under development by Boeing Integrated Defense Systems, and b) a prototype modular next-generation serviceable satellite, NEXTSat, being developed by Ball Aerospace. Flexibility of ASPEN: a) Accommodate changes to procedures; b) Accommodate changes to daily losses and gains; c) Responsive re-planning; and d) Critical to success of mission planning Auto-Generation of activity models: a) Created plans quickly; b) Repetition/Re-use of models each day; and c) Guarantees the AML syntax. One SRP per day vs. Tactical team

  17. Elevated CO2 response of photosynthesis depends on ozone concentration in aspen

    Science.gov (United States)

    Asko Noormets; Olevi Kull; Anu Sober; Mark E. Kubiske; David F. Karnosky

    2010-01-01

    The effect of elevated CO2 and O3 on apparent quantum yield (ø), maximum photosynthesis (Pmax), carboxylation efficiency (Vcmax) and electron transport capacity (Jmax) at different canopy locations was studied in two aspen (Populus...

  18. Effects of elevated CO2 and ozone on phenolic glycosides of trembling aspen

    Science.gov (United States)

    James K. Nitao; Muraleedharan G. Nair; William J. Mattson; Daniel A. Herms; Bruce A. Birr; Mark D. Coleman; Terry M. Trier; J. G. Isebrands

    1996-01-01

    We tested the effects of elevated CO2 and ozone on concentrations of the phenolic glycosides salicortin and tremulacin in immature and mature foliage of the trembling aspen (Populus tremuloides) clones 216, 259, and 271.

  19. 77 FR 60373 - Monroe Mountain Aspen Ecosystems Restoration Project Fishlake National Forest; Sevier and Piute...

    Science.gov (United States)

    2012-10-03

    ....u s. In addition, an Open House will be held at the Sevier County Administrative Building in... continual maintenance, fencing is not a long term sustainable response option for protecting aspen sprouts...

  20. Using Aspen simulation package to determine solubility of mixed salts in TRU waste evaporator bottoms

    Energy Technology Data Exchange (ETDEWEB)

    Hatchell, J.L.

    1998-03-01

    Nitric acid from plutonium process waste is a candidate for waste minimization by recycling. Process simulation software packages, such as Aspen, are valuable tools to estimate how effective recovery processes can be, however, constants in equations of state for many ionic components are not in their data libraries. One option is to combine single salt solubility`s in the Aspen model for mixed salt system. Single salt solubilities were regressed in Aspen within 0.82 weight percent of literature values. These were combined into a single Aspen model and used in the mixed salt studies. A simulated nitric acid waste containing mixed aluminum, calcium, iron, magnesium and sodium nitrate was tested to determine points of solubility between 25 and 100 C. Only four of the modeled experimental conditions, at 50 C and 75 C, produced a saturated solution. While experimental results indicate that sodium nitrate is the first salt to crystallize out, the Aspen computer model shows that the most insoluble salt, magnesium nitrate, the first salt to crystallize. Possible double salt formation is actually taking place under experimental conditions, which is not captured by the Aspen model.

  1. Genetic Variation in Functional Traits Influences Arthropod Community Composition in Aspen (Populus tremula L.)

    Science.gov (United States)

    Robinson, Kathryn M.; Ingvarsson, Pär K.; Jansson, Stefan; Albrectsen, Benedicte R.

    2012-01-01

    We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores. PMID:22662190

  2. Genetic variation in functional traits influences arthropod community composition in aspen (Populus tremula L..

    Directory of Open Access Journals (Sweden)

    Kathryn M Robinson

    Full Text Available We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores.

  3. Lo sagrado en las sociedades secularizadas

    Directory of Open Access Journals (Sweden)

    González Noriega, Santiago

    1993-10-01

    Full Text Available Not available.

    La potencia tutelar burocrática asume la custodia de una masa amorfa. Frente a ella ha de afirmarse una sociedad civil a partir de núcleos de ciudadanos activos. El motor de esta ciudadanía es la formación de un núcleo básico de creencias -«lo sagrados-e- que desempeña un papel comparable, en cuanto a capacidad de movilización, al de las viejas religiones. Lo sagrado «laico» o «filosófico» apunta a aquello que el hombre puede considerar perdurable y conferir sentido a su existencia.

  4. El destino de la sociedad conyugal

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    María Paz Gatica R.

    2011-11-01

    Full Text Available El régimen chileno de sociedad conyugal establece distinciones legales que resultan discriminatorias para ambos cónyuges. En el caso de la mujer, al impedir que pueda ser administradora ordinaria de los bienes sociales y privarla de la administración de sus bienes propios, y en el del marido, a través de la institución del patrimonio reservado. En este artículo se revisan los problemas recientes que dicho régimen ha generado para el Estado de Chile en el contexto internacional y se analizan algunas de las propuestas de reforma legislativa desde la perspectiva de su cumplimiento con los estándares de derechos fundamentales.

  5. Predation risk, elk, and aspen: tests of a behaviorally mediated trophic cascade in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Winnie, John A

    2012-12-01

    Aspen in the Greater Yellowstone Ecosystem are hypothesized to be recovering from decades of heavy browsing by elk due to a behaviorally mediated trophic cascade (BMTC). Several authors have suggested that wolves interact with certain terrain features, creating places of high predation risk at fine spatial scales, and that elk avoid these places, which creates refugia for plants. This hypothesized BMTC could release aspen from elk browsing pressure, leading to a patchy recovery in places of high risk. I tested whether four specific, hypothesized fine-scale risk factors are correlated with changes in current elk browsing pressure on aspen, or with aspen recruitment since wolf reintroduction, in the Daly Creek drainage in Yellowstone National Park, and near two aspen enclosures outside of the park boundary. Aspen were not responding to hypothesized fine-scale risk factors in ways consistent with the current BMTC hypothesis.

  6. American wild celery (Vallisneria americana): Ecological considerations for restoration

    Science.gov (United States)

    Korschgen, C.E.; Green, W.L.

    1988-01-01

    The success of vegetation management programs for waterfowl is dependent on knowing the physical and physiological requirements of target species. Lakes and riverine impoundments that contain an abundance of the American wildcelery (Vallisneria americana ) have traditionally been favored by canvasbacks (Aythya valisineria ) and other waterfowl as feeding areas during migration. Information on the ecology of American wildcelery is summarized to serve as a guide for potential wetland restoration projects. Techniques are described for transplanting winter buds. Management programs that employ these techniques should define objectives clearly and evaluate the water regime carefully before initiating major restoration.

  7. Distribution and characterization of Heterobilharzia americana in dogs in Texas.

    Science.gov (United States)

    Rodriguez, J Y; Lewis, B C; Snowden, K F

    2014-06-16

    Heterobilharzia americana is a trematode parasite (family Schistosomatidae) that infects a wide range of wild mammalian hosts. Canine cases have been reported in the Gulf coast and south Atlantic states, Kansas, and Oklahoma. A total of 238 canine H. americana cases in Texas were retrospectively collected for a period of approximately 22 years from case records at the Texas Veterinary Medical Diagnostic Laboratory and the Veterinary Medical Teaching Hospital pathology service, diagnostic parasitology service, and Gastrointestinal Laboratory at Texas A&M University College of Veterinary Medicine. Of these cases, 26 patients had 1-2 repeat positive tests for a total of 268 positive tests (26 biopsies, 39 necropsies, 160 fecal examinations, and 43 PCR). Multiple dogs were infected in 12 households. Cases were distributed primarily in the eastern region of Texas in 42 of 254 counties. Cases were seen as far west as Kerr county and in counties bordering Oklahoma, Louisiana, Mexico, and the Gulf of Mexico. The median dog age was 5.6 years (2.7 months to 17.2 years) and the median weight was 20.5 kg (1-61.6 kg). All American Kennel Club (AKC) breed groups were represented (n=186): crossbred (20%), herding (17.8%), sporting (16.1%), toy (10.8%), hounds (10.8%), working (10.1%), terrier (8.5%), non-sporting (4.9%), and miscellaneous (1%). No seasonal pattern of diagnosis was apparent. Clinical signs reported (n=90) were diarrhea (67%), weight loss (38%), anorexia/hyporexia (27%), vomiting (22%), hematochezia (20%), lethargy (17%), polyuria/polydipsia (6%), and collapse (3%). In 39 necropsy cases, trematode eggs were identified by histopathology in the small intestine (84%), liver (84%), large intestine (39%), pancreas (35%), lung (9%), lymph node (8%), spleen (4%), and stomach (3%). Adult parasites were identified histologically in four cases. Granulomatous inflammation associated with the eggs was the most commonly reported histopathologic change. Other changes reported

  8. Establishing of Agave Americana industry in South Africa

    CSIR Research Space (South Africa)

    Boguslavsky, A

    2007-09-01

    Full Text Available of the sisal decorticator was therefore modified to make it more suitable for the processing of Agave Americana leaves. Steel side plates were attached to the rotor to prevent the blockage of the machine. The feeding tray and beater bars were modified... to accommodate the side plates of the enlarged rotor. For added operator safety, a “tunnel” guard was also added the feeding tray through which the leaves are fed. The size of this was such that the Agave leaf could fit into it but without any space...

  9. Bases legales para la transformación de Sociedades Civiles en Sociedades Cooperativas

    Directory of Open Access Journals (Sweden)

    Javier Divar Garteiz-Aurrecoa

    2013-12-01

    Full Text Available El Derecho interno vigente permite abiertamente la transformación de Sociedades Civiles con personalidad jurídica, Asociaciones y Fundaciones, en Cooperativas. Ello está además integrado en las propuestas del Parlamento Europeo en beneficio del empleo, la lucha contra la exclusión en la UE y el mantenimiento del bienestar social en la Unión.Recibido: 11.12.2012Aceptado: 20.04.2013

  10. Discapacidad y sociedad democrática

    Directory of Open Access Journals (Sweden)

    Mario Andrés Ospina Ramírez

    2010-07-01

    Full Text Available La eficacia de los derechos y libertades de las personas con discapacidad son pretensiones morales perfectamente compatibles con los anhelos de una sociedad pluralista y democrática. La inclusión de la No-discriminación como elemento de transversalidad dentro de las políticas públicas del Estado pone de relieve la existencia de una aceptación generalizada por parte de la comunidad de la situación de marginalidad a la que han sido sometidos tradicionalmente este colectivo de personas. De ahí la importancia de adoptar medidas de acción afirmativa a fin de promover el disfrute efectivo de los derechos fundamentales. Y es que el tema de la discapacidad no siempre ha hecho parte del discurso de los derechos humanos. Esto explica el por qué en diferentes contextos históricos el uso de métodos y procedimientos degradantes e inhumanos para el tratamiento de la discapacidad no sólo se constituía –y se constituye aún– en una práctica habitual sino que además es un hecho que con el tiempo alcanza a adquirir plena legitimidad. En el mejor de los casos a la personas con discapacidad se les considera “enfermos” y su proyecto de vida sólo tiene sentido en la medida que logren salir de esa situación “de anormalidad”. Incluso hoy en día persiste la idea de que la discapacidad es una cuestión que se circunscribe exclusivamente en el ámbito de la medicina y de la seguridad social (modelo médico-rehabilitador. Sin embargo, en los últimos años ha venido tomando fuerza una nueva forma de abordar esta cuestión y que supone un cambio de paradigma a propósito del esquema tradicional de la discapacidad. A partir de este nuevo enfoque (modelo social de la discapacidad, se concibe que la limitación infundada del ejercicio de los derechos de las personas que poseen alguna deficiencia no se produce por circunstancias “invalidantes” individuales sino que procede de la construcción unidireccional y excluyente de la sociedad. En suma

  11. Discapacidad y sociedad democrática

    Directory of Open Access Journals (Sweden)

    Mario Andrés Ospina Ramírez

    2010-06-01

    Full Text Available La eficacia de los derechos y libertades de las personas con discapacidad son pretensiones morales perfectamente compatibles con los anhelos de una sociedad pluralista y democrática. La inclusión de la No-discriminación como elemento de transversalidad dentro de las políticas públicas del Estado pone de relieve la existencia de una aceptación generalizada por parte de la comunidad de la situación de marginalidad a la que han sido sometidos tradicionalmente este colectivo de personas. De ahí la importancia de adoptar medidas de acción afirmativa a fin de promover el disfrute efectivo de los derechos fundamentales. Y es que el tema de la discapacidad no siempre ha hecho parte del discurso de los derechos humanos. Esto explica el por qué en diferentes contextos históricos el uso de métodos y procedimientos degradantes e inhumanos para el tratamiento de la discapacidad no sólo se constituía –y se constituye aún– en una práctica habitual sino que además es un hecho que con el tiempo alcanza a adquirir plena legitimidad. En el mejor de los casos a la personas con discapacidad se les considera “enfermos” y su proyecto de vida sólo tiene sentido en la medida que logren salir de esa situación “de anormalidad”. Incluso hoy en día persiste la idea de que la discapacidad es una cuestión que se circunscribe exclusivamente en el ámbito de la medicina y de la seguridad social (modelo médico-rehabilitador. Sin embargo, en los últimos años ha venido tomando fuerza una nueva forma de abordar esta cuestión y que supone un cambio de paradigma a propósito del esquema tradicional de la discapacidad. A partir de este nuevo enfoque (modelo social de la discapacidad, se concibe que la limitación infundada del ejercicio de los derechos de las personas que poseen alguna deficiencia no se produce por circunstancias “invalidantes” individuales sino que procede de la construcción unidireccional y excluyente de la sociedad. En suma

  12. Are wolves saving Yellowstone's aspen? A landscape-level test of a behaviorally mediated trophic cascade.

    Science.gov (United States)

    Kauffman, Matthew J; Brodie, Jedediah F; Jules, Erik S

    2010-09-01

    Behaviorally mediated trophic cascades (BMTCs) occur when the fear of predation among herbivores enhances plant productivity. Based primarily on systems involving small-bodied predators, BMTCs have been proposed as both strong and ubiquitous in natural ecosystems. Recently, however, synthetic work has suggested that the existence of BMTCs may be mediated by predator hunting mode, whereby passive (sit-and-wait) predators have much stronger effects than active (coursing) predators. One BMTC that has been proposed for a wide-ranging active predator system involves the reintroduction of wolves (Canis lupus) to Yellowstone National Park, USA, which is thought to be leading to a recovery of trembling aspen (Populus tremuloides) by causing elk (Cervus elaphus) to avoid foraging in risky areas. Although this BMTC has been generally accepted and highly popularized, it has never been adequately tested. We assessed whether wolves influence aspen by obtaining detailed demographic data on aspen Stands using tree rings and by monitoring browsing levels in experimental elk exclosures arrayed across a gradient of predation risk for three years. Our study demonstrates that the historical failure of aspen to regenerate varied widely among stands (last recruitment year ranged from 1892 to 1956), and our data do not indicate an abrupt cessation of recruitment. This pattern of recruitment failure appears more consistent with a gradual increase in elk numbers rather than a rapid behavioral shift in elk foraging following wolf extirpation. In addition, our estimates of relative survivorship of young browsable aspen indicate that aspen are not currently recovering in Yellowstone, even in the presence of a large wolf population. Finally, in an experimental test of the BMTC hypothesis we found that the impacts of elk browsing on aspen demography are not diminished in sites where elk are at higher risk of predation by wolves. These findings suggest the need to further evaluate how trophic

  13. American Narcissus: Lacanian Reflections on DeLillo’s Americana

    Directory of Open Access Journals (Sweden)

    Graley Herren

    2016-05-01

    Full Text Available Don DeLillo’s first novel, 'Americana' (1971, is assembled from a toolkit of psychological tropes. Critics have long recognized the novel’s debts to (and parodies of Sigmund Freud, leading one critic to dub protagonist David Bell as “the American Oedipus.” The present article reconsiders the novel from the perspective of Jacques Lacan’s psychoanalytic theories. Several of Lacan’s key concepts—including his seminal articulation of the Mirror Stage, his revisions to Freud’s Oedipus Complex, his emphasis on lack as the engine of desire, as well as his reflections on dreams, fantasies, and the gaze—help shed new light on DeLillo’s splintered portrait of postmodern subjectivity in 'Americana'. The article uses Lacan to explain how and why each of David Bell’s attempts at indulging his incestuous maternal desires ends in disappointment, with particular emphasis on his three failed attempts at restaging the primal scene. Lacanian psychology provides a conceptual framework and useful taxonomy for understanding the shifting desires, misrecognitions, obfuscations, deflections, projections, and self-reflections of the American Narcissus, David Bell.

  14. Las lenguas en las sociedades del conocimiento

    Directory of Open Access Journals (Sweden)

    Álvarez, J. Francisco

    2008-12-01

    Full Text Available Languages become a strategic resource for information and knowledge societies. By expressing and sharing knowledge by means of languages, every culture generates deposits of knowledge, which can be transferred and exchanged among different epistemic communities. The contemporary technologies of information and communication have changed the structure of knowledge flows. Globalization of knowledge poses a great challenge to every language, including the Spanish one. In order to survive in the digital world, they should develop technolanguages. The lemma “Thinking in Spanish” implies a new model of governance for the Ibero-American knowledge communities.En las sociedades de la información y el conocimiento las lenguas se convierten en un recurso estratégico. Al expresar y compartir conocimiento por medio de los idiomas, las culturas generan yacimientos de conocimiento, que pueden ser transferidos e intercambiados entre comunidades epistémicas diferentes. Las actuales tecnologías de la información y la comunicación han cambiado la estructura de los flujos de conocimiento. La globalización del conocimiento plantea un gran desafío a todas las lenguas, incluyendo la española. Para sobrevivir en el mundo digital, los lenguajes han de convertirse en tecnolenguajes. El lema “Pensar en español” aporta un nuevo modelo de gobernanza para las comunidades iberoamericanas del conocimiento.

  15. Relacione de poder en la sociedad red

    Directory of Open Access Journals (Sweden)

    Miguel-Héctor Fernández-Carrión

    2010-12-01

    Full Text Available La segunda mitad del siglo XX ha estado caracterizada por a imposición económica de algunas multinacionales, sobre las políticas nacionales de unos países (los menos sobre otros (los más, y la política de dos superpotencias (EEUU y URSS que terminan al inicio de la era digital (1992 en una única (Estados Unidos sobre el resto del mundo. Asimismo, desde el último tercio de siglo veinte la sociedad del conocimiento y la globalización define un nuevo estado mundial cibernético global, en el que destaca la comunicación interpersonal, la propaganda política digital y el comercio por internet "en tiempo real", junto a la decadencia del Estado-nación moderno, caída de los patrones sociales del patriarcado y la emancipación de la mujer, que la caracteriza.

  16. El turismo y la sociedad de consumo

    Directory of Open Access Journals (Sweden)

    Alfredo Argentino César Dachary

    2013-12-01

    Full Text Available El objetivo de este ensayo es aportar una lectura desde la perspectiva de definir a la actividad turística como un modelo al interior del capitalismo, que ha nacido, crecido y adecuado a las transformaciones de éste, pasando de la periferia al centro mismo hasta confundirse con el gran espectro de oportunidades que plantea hoy la sociedad de consumo. Para ello intentaremos una lectura desde el origen, desarrollo y el papel que cumple en el proceso de ocupación territorial del planeta durante la última colonización, la de fines del XIX y el proceso de descolonización de la segunda parte del siglo XX, cuando emerge el denominado turismo de masas. Se dará prioridad a la periferia de los países desarrollados, ya que el papel que juega esta actividad en la misma es diferente aunque complementario al que se presenta en los países centrales.

  17. El turismo y la sociedad de consumo

    Directory of Open Access Journals (Sweden)

    Alfredo Argentino César Dachary

    2013-11-01

    Full Text Available El objetivo de este ensayo es aportar una lectura desde la perspectiva de definir a la actividad turística como un modelo al interior del capitalismo, que ha nacido, crecido y adecuado a las transformaciones de éste, pasando de la periferia al centro mismo hasta confundirse con el gran espectro de oportunidades que plantea hoy la sociedad de consumo. Para ello intentaremos una lectura desde el origen, desarrollo y el papel que cumple en el proceso de ocupación territorial del planeta durante la última colonización, la de fines del XIX y el proceso de descolonización de la segunda parte del siglo XX, cuando emerge el denominado turismo de masas. Se dará prioridad a la periferia de los países desarrollados, ya que el papel que juega esta actividad en la misma es diferente aunque complementario al que se presenta en los países centrales.

  18. Nivel operacional de la sociedad civil

    Directory of Open Access Journals (Sweden)

    Zoraida Mendiwelso Bendek

    2012-03-01

    Full Text Available Michael Walzer (2002 afirma que las organizaciones de la sociedad civil se generan en procesos de auto organización pero que existen algunas organizaciones con mayor capacidad que otras para organizarse y que también es necesario que el estado provea la asistencia que requiere la vida en asociación en donde primero que todo se debe proteger a los más débiles. En este artículo, desde una visión sistémica, se intenta reflexionar sobre las competencias requeridas para un efectivo proceso de auto-organización en la construcción de lo público. Se sostiene que esto hace necesario observar las estructuras que apoyan el aprendizaje y participación ciudadana.Michael Walzer (2002 claims that self-organization underpins the emergence of civil society organizations and that some of these organizations have more opportunities than others to be effective, suggesting that it is necessary for the State to support those associations that operate in weaker contexts. In this paper, from a systemic perspective, the author reflects upon the required competencies to enable effective self-organizing processes in the construction of the public sphere, in particular she advocates the need to observe the emerging organization structures supporting citizens' learning and participation.

  19. Simulation of SOFCs based power generation system using Aspen

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2017-12-01

    Full Text Available This study presents a thermodynamic Aspen simulation model for Solid Oxide Fuel Cells, SOFCs, based power generation system. In the first step, a steady-state SOFCs system model was developed. The model includes the electrochemistry and the diffusion phenomena. The electrochemical model gives good agreement with experimental data in a wide operating range. Then, a parametric study has been conducted to estimate effects of the oxygen to carbon ratio, O/C, on reformer temperature, fuel cell temperature, fuel utilization, overall fuel cell performance, and the results are discussed in this paper. In the second step, a dynamic analysis of SOFCs characteristic has been developed. The aim of dynamic modelling was to find the response of the system against the fuel utilization and the O/C ratio variations. From the simulations, it was concluded that both developed models in the steady and dynamic state were reasonably accurate and can be used for system level optimization studies of the SOFC based power generation system.

  20. Aspen Simulation of Diesel-Biodiesel Blends Combustion

    Directory of Open Access Journals (Sweden)

    Pérez-Sánchez Armando

    2015-01-01

    Full Text Available Biodiesel is a fuel produced by transesterification of vegetable oils or animal fats, which currently is gaining attention as a diesel substitute. It represents an opportunity to reduce CO2, SO2, CO, HC, PAH and PM emissions and contributes to the diversification of fuels in Mexico's energetic matrix. The results of the simulation of the combustion process are presented in this paper with reference to an engine specification KUBOTA D600-B, operated with diesel-biodiesel blends. The physicochemical properties of the compounds and the operating conditions of equipment were developed using the simulator Aspen® and supplementary information. The main aspects of the engine working conditions were considered such as diesel-biodiesel ratio, air/fuel mixture, temperature of the combustion gases and heat load. Diesel physicochemical specifications were taken from reports of PEMEX and SENER. Methyl esters corresponding to the transesterification of fatty acids that comprise castor oil were regarded as representative molecules of biodiesel obtained from chromatographic analysis. The results include CO2, water vapor, combustion efficiency, power and lower calorific value of fuels.

  1. Forest stand structure, productivity, and age mediate climatic effects on aspen decline

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2014-01-01

    Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand-scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing-season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.

  2. The yield of natural trembling aspen (populus tremula L.) stands (northern and eastern anatolia)

    International Nuclear Information System (INIS)

    Misir, M.; Misir, N.

    2013-01-01

    Trembling aspen (Populus tremula L.) is one of the most resistant to cold natural species in Turkey. In spite of its importance, there is no research on the yield. Hence, site productivity was determined and yield Table for undisturbed natural trembling aspen stands in Turkey was developed. Data were obtained from a total of 46 plots ranging in age from 17 to 82 years. Yield Table indicates that trembling aspen is very slow growing in young and middle age and Current Annual Increment (CAI) and Mean Annual Increment (MAI) values do not reach its maximum value, even at age 70. This is a proof that trembling aspen is not a fast growing species as expected. The reason for its slow growth is attributed to very short period of growth at very high altitudes. However, in the event of 50 years rotation age, mean annual volume increments of 8.0, 3.6 and 1.1 m3 are estimated for trembling aspen for site classes I, II and III, respectively. At extended rotations, trees of pole sizes could be obtained on all site classes. (author)

  3. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL

    2008-10-01

    Lack of aspen (Populus tremuloides) recruitment and canopy replacement of aspen stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado has been a cause of concern for more than 70 years (Packard, 1942; Olmsted, 1979; Stevens, 1980; Hess, 1993; R.J. Monello, T.L. Johnson, and R.G. Wright, Rocky Mountain National Park, 2006, written commun.). These aspen stands are a significant resource since they are located close to the park's road system and thus are highly visible to park visitors. Aspen communities are integral to the ecological structure of montane and subalpine landscapes because they contain high native species richness of plants, birds, and butterflies (Chong and others, 2001; Simonson and others, 2001; Chong and Stohlgren, 2007). These low-elevation, winter range stands also represent a unique component of the park's plant community diversity since most (more than 95 percent) of the park's aspen stands grow in coniferous forest, often on sheltered slopes and at higher elevations, while these winter range stands are situated on the low-elevation ecotone between the winter range grasslands and some of the park's drier coniferous forests.

  4. Bioenergy harvest impacts to biodiversity and resilience vary across aspen-dominated forest ecosystems in the Lake States region, USA

    Science.gov (United States)

    Miranda T. Curzon; Anthony W. D' Amato; Brian J. Palik; Kris Verheyen

    2016-01-01

    Questions: Does the increase in disturbance associated with removing harvest residues negatively impact biodiversity and resilience in aspen-dominated forest ecosystems? How do responses of functional diversity measures relate to community recovery and standing biomass? Location: Aspen (Populus tremuloides, Michx.) mixedwood forests in Minnesota...

  5. Summary and abstracts from Sudden Aspen Decline (SAD) Meeting; Fort Collins, Colorado, February 12-13, 2008

    Science.gov (United States)

    Paul C. Rogers

    2008-01-01

    In recent years the aspen research and management community has witnessed increasing accounts of unexplained aspen die-offs across the Rocky Mountain region. In response, two meetings were held to address the issue; this paper summarizes the most recent gathering, a symposium held in Fort Collins at the USDA Forest Service, Rocky Mountain Research Station, on February...

  6. Moderate-scale mapping methods of aspen stand types: a case study for Cedar Mountain in southern Utah

    Science.gov (United States)

    Chad M. Oukrop; David M. Evans; Dale L. Bartos; R. Douglas Ramsey; Ronald J. Ryel

    2011-01-01

    Quaking aspen (Populus tremuloides Michx.) are the most widely distributed tree species across North America, but its dominance is declining in many areas of the western United States, with certain areas experiencing rapid mortality events over the past decade. The loss of aspen from western landscapes will continue to profoundly impact biological, commercial, and...

  7. Earthworms, arthropods and plant litter decomposition in aspen (Populus tremuloides) and lodgepole pine(Pinus contorta) forests in Colorado, USA

    Science.gov (United States)

    Grizelle Gonzalez; Timothy R. Seastedt; Zugeily Donato

    2003-01-01

    We compared the abundance and community composition of earthworms, soil macroarthropods, and litter microarthropods to test faunal effects on plant litter decomposition rates in two forests in the subalpine in Colorado, USA. Litterbags containing recently senesced litter of Populus tremuloides (aspen) and Pinus contorta (lodgepole pine) were placed in aspen and pine...

  8. Heterobilharzia americana infection and congestive heart failure in a llama (Lama glama).

    Science.gov (United States)

    Corapi, W V; Eden, K B; Edwards, J F; Snowden, K F

    2015-05-01

    The schistosome Heterobilharzia americana infects several mammalian species in the southeastern United States, including horses, but infections have not been reported in camelids. This is a report of H. americana infection in a 6-year-old llama with extensive cardiac pathology and congestive heart failure. Parasite-induced granulomas were widely disseminated and included overwhelming involvement of the lungs and liver. Microscopic lesions in the heart included myofiber degeneration and necrosis, with extensive replacement fibrosis. Polymerase chain reaction amplification and sequencing confirmed the presence of H. americana in the lungs. © The Author(s) 2014.

  9. Scale dependence of disease impacts on quaking aspen (Populus tremuloides) mortality in the southwestern United States

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2015-01-01

    Depending on how disease impacts tree exposure to risk, both the prevalence of disease and disease effects on survival may contribute to patterns of mortality risk across a species' range. Disease may accelerate tree species' declines in response to global change factors, such as drought, biotic interactions, such as competition, or functional traits, such as allometry. To assess the role of disease in mediating mortality risk in quaking aspen (Populus tremuloides), we developed hierarchical Bayesian models for both disease prevalence in live aspen stems and the resulting survival rates of healthy and diseased aspen near the species' southern range limit using 5088 individual trees on 281 United States Forest Service Forest Inventory and Analysis plots in the southwestern United States.

  10. Fibrillation of Aspen by Alkaline Cold Pre-treatment and Vibration Milling

    Directory of Open Access Journals (Sweden)

    Kärt KÄRNER

    2016-09-01

    Full Text Available In this article an attempt to fibrillate aspen bleached chemi-thermo mechanical pulp (BCTMP fibre in an environmentally friendly way is reported. The effects of various NaOH, KOH, urea and ethanol aqueous solutions at lowered temperature were tested for pre-treatment. The pre-treatment was followed by vibration milling aiming to peel off outer cell wall layers and to fibrillate S2 layer of the aspen wood fibre. The effects of the treatments were evaluated by scanning electron microscopy (SEM. The results show that it is possible to fibrillate BCTMP aspen fibres by using alkaline aqueous solutions at low temperatures followed by a mechanical treatment. A strong dependence on fibrillation of cellulose on temperature, time and alkali concentration was established.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7412

  11. Sociedad civil: una concepción radical

    OpenAIRE

    García Marzá, Vicente Domingo

    2008-01-01

    El presente trabajo1 tiene como objetivos presentar un concepto de sociedad civil desde una perspectiva crítica, una perspectiva que pueda dar razón del potencial de cambio y transformación social que encierra este ámbito de la interacción social. Con este fin, se adentra en primer lugar en la difícil relación entre democracia y sociedad civil, analizándola desde el paso de las democracias participativas a las democracias deliberativas. El caràcter global de la sociedad civil y los problemas ...

  12. Evolución legislativa de las sociedades laborales

    OpenAIRE

    Toribio Cara, Miguel

    2018-01-01

    Mediante este resumen o trabajo he pretendido realizar un estudio más o menos completo sobre las sociedades laborales en nuestro país. Previo a ello decir que las Sociedades Laborales constituyen una figura del Derecho de Sociedades español que cumple con su regulación en la propia Constitución Española en su artículo 129.2 que otorga a los poderes públicos para promover la participación en la empresa de los trabajadores y su acceso a la propiedad de los medios de producción. ...

  13. Componentes volátiles de mamey (mammea americana L.

    Directory of Open Access Journals (Sweden)

    Alicia Lucía Morales

    2010-07-01

    Full Text Available Los componentes volátiles del aroma de mamey (Mammea americana L, fueron extraídos utilizando el método de destilación por arrastre con vapor-extracción simultánea con solvente orgánico. El extracto fue prefraccionado por cromatografía en columna en silica gel con gradiente discontinuo Pentano: Éter etílico para obtener tres fracciones que fueron analizadas por CGAR y CGAR-EM. Se detectaron 34 compuestos, de los cuales fueron identificados 22, siendo los componentes mayoritarios: Furfural (7281 ^ig/kg y E-Famesol (2145 ng/kg

  14. Distribution of 137Cs in the American Coot (Fulica americana)

    International Nuclear Information System (INIS)

    Potter, C.M.; Brisbin, I.L. Jr.; McDowell, S.G.; Whicker, F.W.

    1989-01-01

    Caesium-137 concentrations were determined for major tissue and organ components of Americal Coots (Fulica americana) wintering on two contaminated reactor cooling reservoirs on the US Department of Energy's Savannah River Plant. Concentrations reflected the relative contamination levels of the two reservoirs. A low ratio of 137 Cs in gut contents to that in muscle indicated that the coots used in the study were established winter residents and tissue 137 Cs had probably reached equilibrium with intake. The contributions of each component to the whole body weight and total 137 Cs body burden were calculated. Skeletal muscle exhibited the highest 137 Cs concentrations and comprised 35% of the total 137 Cs body burden. Gut contents represented 17% of the total body burden. Various other organs were intermediate and bone exhibited the lowest 137 Cs concentrations. Linear regressions were determined for 137 Cs concentrations in skeletal muscle, liver, kidney, gastrointestinal (GI) tract tissue and gut contents, as functions of whole-body concentrations. (author)

  15. Volumetry of Genipa americana in homogeneous plantation in Southwest Bahia

    Directory of Open Access Journals (Sweden)

    Mislene Barbosa Rocha

    2015-12-01

    Full Text Available This research aim to evaluate the volumetric estimates obtaining for Genipa americana, commonly known as jenipapeiro, in pure plantation in the municipality of Vitória da Conquista, Bahia State, Brazil. To determine individual volume, 100 standing trees were rigorously cubed. Ten volumetric models were adjusted. The best models were selected based on the selection criteria of weighted value of statistical parameters scores and residues distribution. Volume estimates were obtained by form factor and by adjusted equations. To validate the estimates, the calculate volumes were compared to measured data. Among the used methods to predict wood volume, the adjusted volumetric equations are recommended. Spurr (Log model present the best performance to estimate total wood volume.

  16. Defensive effects of extrafloral nectaries in quaking aspen differ with scale.

    Science.gov (United States)

    Mortensen, Brent; Wagner, Diane; Doak, Patricia

    2011-04-01

    The effects of plant defenses on herbivory can differ among spatial scales. This may be particularly common with indirect defenses, such as extrafloral nectaries (EFNs), that attract predatory arthropods and are dependent on predator distribution, abundance, and behavior. We tested the defensive effects of EFNs in quaking aspen (Populus tremuloides Michx.) against damage by a specialist herbivore, the aspen leaf miner (Phyllocnistis populiella Cham.), at the scale of individual leaves and entire ramets (i.e., stems). Experiments excluding crawling arthropods revealed that the effects of aspen EFNs differed at the leaf and ramet scales. Crawling predators caused similar reductions in the percent leaf area mined on individual leaves with and without EFNs. However, the extent to which crawling predators increased leaf miner mortality and, consequently, reduced mining damage increased with EFN expression at the ramet scale. Thus, aspen EFNs provided a diffuse defense, reducing damage to leaves across a ramet regardless of leaf-scale EFN expression. We detected lower leaf miner damage and survival unassociated with crawling predators on EFN-bearing leaves, suggesting that direct defenses (e.g., chemical defenses) were stronger on leaves with than without EFNs. Greater direct defenses on EFN-bearing leaves may reduce the probability of losing these leaves and thus weakening ramet-scale EFN defense. Aspen growth was not related to EFN expression or the presence of crawling predators over the course of a single season. Different effects of aspen EFNs at the leaf and ramet scales suggest that future studies may benefit from examining indirect defenses simultaneously at multiple scales.

  17. Morfoanatomia de folha e caule de Genipa americana L., Rubiaceae

    Directory of Open Access Journals (Sweden)

    Marianna Erbano

    2010-10-01

    Full Text Available Genipa americana L., conhecida como jenipapo, é uma Rubiaceae nativa do Brasil e as suas folhas são utilizadas pela população como antidiarreico e febrífugo, e o caule como anti-hemorrágico, contra luxações e contusões. Com o objetivo de caracterizar macro e microscopicamente folhas adultas e caules jovens para o controle de qualidade farmacognóstico, essa planta medicinal foi analisada segundo a metodologia clássica de morfoanatomia vegetal. Genipa americana apresenta folhas simples, opostas, de formato obovado a oblanceolado e pecíolos curtos. A epiderme foliar é uniestratificada e revestida por cutícula delgada e levemente estriada. Os estômatos são paracíticos e restritos à superfície abaxial. Há tricomas tectores uni e pluricelulares predominantemente na superfície abaxial. O mesofilo é dorsiventral. Em secção transversal, a nervura central é plano-convexa e o pecíolo é circular, ambos apresentando um feixe vascular colateral em disposição cilíndrica e outros menores. O caule possui felogênio localizado nas camadas subepidérmicas, colênquima anelar e um cilindro floemático externo ao de xilema, sendo ambos percorridos por raios parenquimáticos estreitos. Ocorrem idioblastos contendo compostos fenólicos, areia cristalina e drusas de oxalato de cálcio na folha e no caule.

  18. Physical property parameter set for modeling ICPP aqueous wastes with ASPEN electrolyte NRTL model

    International Nuclear Information System (INIS)

    Schindler, R.E.

    1996-09-01

    The aqueous waste evaporators at the Idaho Chemical Processing Plant (ICPP) are being modeled using ASPEN software. The ASPEN software calculates chemical and vapor-liquid equilibria with activity coefficients calculated using the electrolyte Non-Random Two Liquid (NRTL) model for local excess Gibbs free energies of interactions between ions and molecules in solution. The use of the electrolyte NRTL model requires the determination of empirical parameters for the excess Gibbs free energies of the interactions between species in solution. This report covers the development of a set parameters, from literature data, for the use of the electrolyte NRTL model with the major solutes in the ICPP aqueous wastes

  19. Mujer, sociedad y comunicación

    Directory of Open Access Journals (Sweden)

    Cumandá Gamboa de Zelaya

    2015-01-01

    Full Text Available La desigualdad ante la ley y en la acción, entre el hombre y la mujer, se registra, como su inicio, en la etapa histórica de la esclavitud, con el surgimiento de la propiedad privada y el establecimiento entre otras Instituciones, la del matrimonio monogámico. El hombre necesitaba estar seguro de la paternidad de sus descendientes a quienes debía legar sus dominios; para lograrlo tenía que poseer una mujer que únicamente lo tuviese a él por esposo. Esa pertenencia de la mujer entre sus otros bienes, el hombre la consagraba no solo con la marca de su apellido adherido al nombre de la esposa sino asignándole un papel específico en la Sociedad: ocuparse de cuestiones domésticas, vigilar y cuidar del crecimiento de los niños, bordar, es decir toda clase de tareas a realizar en casa, dando esta última condición asidero a expresiones como "la señora de la casa" , status que fue consignándose en las normas jurídicas que iban surgiendo conforme el hombre obtenía conquistas para sí, de las cuales quedaba excluida la "Reina del Hogar", membrete bajo el cual se anuncian electrodomésticos en los Medios de Comunicación, en el "Día de la Madre".  Las mujeres que se apartaban de ese esquema, eran consideradas de "mal vivir", "libertinas", etc. Más adelante, con el desarrollo del comercio, que para abrir mercados va rompiendo con tradiciones, modificando costumbres, el sometimiento de la mujer al hombre y la dependencia al hogar, va disminuyendo, en un proceso que se cuenta en siglos. La expansión del comercio influye también en el advenimiento y desarrollo tecnológico de los Medios de Comunicación. Ambas actividades se nutren y se sustentan mutuamente.

  20. Swimming black-crowned night-herons (Nycticorax nycticorax) Kleptoparasitize American coots (Fulica americana)

    DEFF Research Database (Denmark)

    Graves, Gary R.

    2015-01-01

    I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid.......I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid....

  1. A entrada de franquias americanas no Brasil: uma estratégia diferente

    OpenAIRE

    Gurtner, Werner Frank

    2010-01-01

    Escrita para o público americano, destaca peculiaridades administrativas e culturais do mercado brasileiro de fast food. Usa exemplos dos procedimentos de entrada de algumas franquias americanas e seus consequentes sucessos e fracassos. Concentra-se, particularnente, no desempenho administrativo destas franquias no Brasil. Discute estratégias alternativas para a expansão internacional futura das franquias americanas. Written for an American audience, highli...

  2. A Case of Ventilator-Associated Pneumonia Caused by Ewingella americana : First Report from Turkey

    Directory of Open Access Journals (Sweden)

    Kenan Ecemiş

    2014-09-01

    Full Text Available Ewingella americana is a very rare cause of serious infections, especially in immunocompromised patients. We report a case of ventilator-associated pneumonia (VAP in an intensive care unit patient, who was treated successfully with ceftriaxone. To the best of our knowledge, this is the first case of VAP due to Ewingella americana in the English literature.J Microbiol Infect Dis 2014; 4(3: 118-120

  3. La sociedad de ensueño del turismo

    Directory of Open Access Journals (Sweden)

    Ruth Arroyo

    2011-11-01

    Full Text Available Este artículo proclama el nacimiento de una nueva sociedad denominada la sociedad deensueño. Se presenta como un tema fascinante sobre la demanda futura de bienes y servicios, que predice que la sociedad actual, basada en la información, se convertirá en una sociedad que valora las historias detrás de los productos y servicios. Estas historias se construyen a partir de la necesidad de riqueza emocional, que la riqueza material ha convertido en algo común. La demanda de productos, a su vez aumentará la demanda de contadores de historias imaginativas que artísticamente pueden dirigir las emociones de los consumidores de una diversificada cultura global, donde imaginar, crear, divertir y fascinar puede resultar un duro trabajo para nuestros conceptos actuales. El resultado de la sociedad de ensueño es que los consumidores no compran productos sino estilos de vida e “historias”, experiencias, emociones y elementos que transmiten un sentido o un significado. En el artículo se menciona cómo los negocios de la industria turística se están transformando, y también se habla de los cambios en otros ámbitos de la sociedad como: el lugar de trabajo, la casa, las relaciones entre las personas y las naciones. Este tema es recomendado para el sector académico y empresarial.

  4. La sociedad de ensueño del turismo

    Directory of Open Access Journals (Sweden)

    Ruth Arroyo

    2011-11-01

    Full Text Available Este artículo proclama el nacimiento de una nueva sociedad denominada la sociedad de ensueño. Se presenta como un tema fascinante sobre la demanda futura de bienes y servicios, que predice que la sociedad actual, basada en la información, se convertirá en una sociedad que valora las historias detrás de los productos y servicios. Estas historias se construyen a partir de la necesidad de riqueza emocional, que la riqueza material ha convertido en algo común. La demanda de productos, a su vez aumentará la demanda de contadores de historias imaginativas que artísticamente pueden dirigir las emociones de los consumidores de una diversificada cultura global, donde imaginar, crear, divertir y fascinar puede resultar un duro trabajo para nuestros conceptos actuales. El resultado de la sociedad de ensueño es que los consumidores no compran productos sino estilos de vida e “historias”, experiencias, emociones y elementos que transmiten un sentido o un significado. En el artículo se menciona cómo los negocios de la industria turística se están transformando, y también se habla de los cambios en otros ámbitos de la sociedad como: el lugar de trabajo, la casa, las relaciones entre las personas y las naciones. Este tema es recomendado para el sector académico y empresarial.

  5. Da sociedade de sociedades à insularidade do estado entre medievo e idade moderna

    Directory of Open Access Journals (Sweden)

    Paolo Grossi

    2007-12-01

    Full Text Available O presente artigo tem por objetivo exploraras descontinuidades entre os universos medievale moderno, enfocando, para tanto, as diferentesformas de a dimensão jurídica relacionar-secom a dimensão política e social, que, sobre basesantropológicas profundamente distintas (primeirocomunitária e, depois, individualista, identificama contraposição entre a “sociedade de sociedades”de origem medieval, e a insularidade doEstado, caracteristicamente moderna.This article has by purpose to explorethe discontinuities between the middle-aged andmodern universes, focusing, so for, the differentways to the juridical dimension to relate with thepolitical and social dimension, that, overanthropological bases deeply distint (firstcommunitarian and then individualist, identify thecounterposition between the “society of societies”from middle-aged source,and the State insularity,characteristicly modern.

  6. Using user models in Matlab® within the Aspen Plus® interface with an Excel® link

    Directory of Open Access Journals (Sweden)

    Javier Fontalvo Alzate

    2014-05-01

    Full Text Available Process intensification and new technologies require tools for process design that can be integrated into well-known simulation software, such as Aspen Plus®. Thus, unit operations that are not included in traditional Aspen Plus software packages can be simulated with Matlab® and integrated within the Aspen Plus interface. In this way, the user can take advantage of all of the tools of Aspen Plus, such as optimization, sensitivity analysis and cost estimation. This paper gives a detailed description of how to implement this integration. The interface between Matlab and Aspen Plus is accomplished by sending the relevant information from Aspen Plus to Excel, which feeds the information to a Matlab routine. Once the Matlab routine processes the information, it is returned to Excel and to Aspen Plus. This paper includes the Excel and Matlab template files so the reader can implement their own simulations. By applying the protocol described here, a hybrid distillation-vapor permeation system has been simulated as an example of the applications that can be implemented. For the hybrid system, the effect of membrane selectivity on membrane area and reboiler duty for the partial dehydration of ethanol is studied. Very high selectivities are not necessarily required for an optimum hybrid distillation and vapor permeation system.

  7. Using Aspen to Teach Chromatographic Bioprocessing: A Case Study in Weak Partitioning Chromatography for Biotechnology Applications

    Science.gov (United States)

    Evans, Steven T.; Huang, Xinqun; Cramer, Steven M.

    2010-01-01

    The commercial simulator Aspen Chromatography was employed to study and optimize an important new industrial separation process, weak partitioning chromatography. This case study on antibody purification was implemented in a chromatographic separations course. Parametric simulations were performed to investigate the effect of operating parameters…

  8. Polypropylene /Aspen/ liquid polybutadienes composites: maximization of impact strength, tensile and modulus by statistical experimental design

    Czech Academy of Sciences Publication Activity Database

    Kokta, B. V.; Fortelný, Ivan; Kruliš, Zdeněk; Horák, Zdeněk; Michálková, Danuše

    2005-01-01

    Roč. 99, - (2005), s. 10-11 ISSN 0009-2770. [International Conference on Polymeric Materials in Automotive , Slovak Rubber Conference /17./. 10.5.2005-12.5.2005, Bratislava] Institutional research plan: CEZ:AV0Z40500505 Keywords : polypropylene * Aspen-PP composite Subject RIV: CD - Macromolecular Chemistry

  9. Phosphate removal by refined aspen wood fiber treated with carboxymethyl cellulose and ferrous chloride

    Science.gov (United States)

    Thomas L. Eberhardt; Soo-Hong Min; James S. Han

    2006-01-01

    Biomass-based filtration media are of interest as an economical means to remove pollutants and nutrients found in stormwater runoff. Refined aspen wood fiber samples treated with iron salt solutions demonstrated limited capacities to remove (ortho)phosphate from test solutions. To provide additional sites for iron complex formation, and thereby impart a greater...

  10. Effect of citric acid modification of aspen wood on sorption of copper ion

    Science.gov (United States)

    James D. McSweeny; Roger M. Rowell; Soo Hong Min

    2006-01-01

    Milled aspen wood was thermochemically modified with citric acid for the purpose of improving the copper (Cu2+) ion sorption capacity of the wood when tested in 24-hour equilibrium batch tests. The wood-citric acid adducts provided additional carboxyl groups to those in the native wood and substantially increased Cu2+ ion uptake of the modified wood compared with that...

  11. Variable performance of outbreak defoliators on aspen clones exposed to elevated CO2 and O3

    Science.gov (United States)

    Daniel A. Herms; William J. Mattson; David N. Karowe; Mark D. Coleman; Terry M. Trier; Bruce A. Birr; J. G. Isebrands

    1996-01-01

    Increasing atmospheric concentrations of ozone and CO2 affect many aspects of tree physiology. However, their effects on tree resistance to insects have received relatively little attention. The objectives of this study were to test the effects of elevated CO2 and ozone on the resistance of three quaking aspen (...

  12. Soil properties and aspen development five years after compaction and forest floor removal

    Science.gov (United States)

    Douglas M. Stone; John D. Elioff

    1998-01-01

    Forest management activities that decrease soil porosity and remove organic matter have been associated with declines in site productivity. In the northern Lake States region, research is in progress in the aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forest type to determine effects of soil compaction and organic...

  13. Continental-scale assessment of genetic diversity and population structure in quaking aspen (Populus tremuloides)

    Science.gov (United States)

    Colin M. Callahan; Carol A. Rowe; Ronald J. Ryel; John D. Shaw; Michael D. Madritch; Karen E. Mock

    2013-01-01

    Aspen populations in the south-western portion of the range are consistent with expectations for a historically stable edge, with low within-population diversity, significant geographical population structuring, and little evidence of northward expansion. Structuring within the southwestern cluster may result from distinct gene pools separated during the Pleistocene...

  14. ASPEN+ and economic modeling of equine waste utilization for localized hot water heating via fast pyrolysis

    Science.gov (United States)

    ASPEN Plus based simulation models have been developed to design a pyrolysis process for the on-site production and utilization of pyrolysis oil from equine waste at the Equine Rehabilitation Center at Morrisville State College (MSC). The results indicate that utilization of all available Equine Reh...

  15. Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mark E. Kubiske

    2013-04-15

    The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

  16. Is the wide distribution of aspen a result of its stress tolerance?

    Science.gov (United States)

    V. J. Lieffers; S. M. Landhausser; E. H. Hogg

    2001-01-01

    Populus tremuloides is distributed from drought-prone fringes of the Great Plains to extremely cold sites at arctic treeline. To occupy these conditions aspen appears to be more tolerant of stress than the other North American species of the genus Populus. Cold winters, cold soil conditions during the growing season, periodic drought, insect defoliation, and...

  17. Increased saccharification yields from aspen biomass upon treatment with enzymatically generated peracetic acid.

    Science.gov (United States)

    Duncan, Shona; Jing, Qing; Katona, Adrian; Kazlauskas, Romas J; Schilling, Jonathan; Tschirner, Ulrike; Aldajani, Waleed Wafa

    2010-03-01

    The recalcitrance of lignocellulosic biomass to enzymatic release of sugars (saccharification) currently limits its use as feedstock for biofuels. Enzymatic hydrolysis of untreated aspen wood releases only 21.8% of the available sugars due primarily to the lignin barrier. Nature uses oxidative enzymes to selectively degrade lignin in lignocellulosic biomass, but thus far, natural enzymes have been too slow for industrial use. In this study, oxidative pretreatment with commercial peracetic acid (470 mM) removed 40% of the lignin (from 19.9 to 12.0 wt.% lignin) from aspen and enhanced the sugar yields in subsequent enzymatic hydrolysis to about 90%. Increasing the amount of lignin removed correlated with increasing yields of sugar release. Unfortunately, peracetic acid is expensive, and concentrated forms can be hazardous. To reduce costs and hazards associated with using commercial peracetic acid, we used a hydrolase to catalyze the perhydrolysis of ethyl acetate generating 60-70 mM peracetic acid in situ as a pretreatment to remove lignin from aspen wood. A single pretreatment was insufficient, but multiple cycles (up to eight) removed up to 61.7% of the lignin enabling release of >90% of the sugars during saccharification. This value corresponds to a predicted 581 g of fermentable sugars from 1 kg of aspen wood. Improvements in the enzyme stability are needed before the enzymatically generated peracetic acid is a commercially viable alternative.

  18. Modeling of existing cooling towers in ASPEN PLUS using an equilibrium stage method

    International Nuclear Information System (INIS)

    Queiroz, João A.; Rodrigues, Vitor M.S.; Matos, Henrique A.; Martins, F.G.

    2012-01-01

    Highlights: ► Simulation of cooling tower performance under different operating conditions. ► Cooling tower performance is simulated using ASPEN PLUS. ► Levenberg–Marquardt method used to adjust model parameters. ► Air and water outlet temperatures are in good accordance with experimental data. - Abstract: Simulation of cooling tower performance considering operating conditions away from design is typically based on the geometrical parameters provided by the cooling tower vendor, which are often unavailable or outdated. In this paper a different approach for cooling tower modeling based on equilibrium stages and Murphree efficiencies to describe heat and mass transfer is presented. This approach is validated with published data and with data collected from an industrial application. Cooling tower performance is simulated using ASPEN PLUS. Murphree stage efficiency values for the process simulator model were optimized by minimizing the squared difference between the experimental and calculated data using the Levenberg–Marquardt method. The minimization algorithm was implemented in Microsoft Excel with Visual Basic for Applications, integrated with the process simulator (ASPEN PLUS) using Aspen Simulation Workbook. The simulated cooling tower air and water outlet temperatures are in good accordance with experimental data when applying only the outlet water temperature to calibrate the model. The methodology is accurate for simulating cooling towers at different operational conditions.

  19. Prehydrolysis of aspen wood with water and with dilute aqueous sulfuric acid

    Science.gov (United States)

    Edward L. Springer; John F. Harris

    1982-01-01

    Water prehydrolysis of aspen wood was compared with 0.40% sulfuric acid prehydrolysis at a reaction temperature of 170°C. Acid prehydrolysis gave much higher yields of total anhydroxylose units in the prehydrolyzate and removed significantly less anhydroglucose from the wood than did the water treatment. At maximum yields of total anhydroxylose units in the...

  20. Genetic, morphological, and spectral characterization of relictual Niobrara River hybrid aspens (Populus × smithii).

    Science.gov (United States)

    Deacon, Nicholas John; Grossman, Jake Joseph; Schweiger, Anna Katharina; Armour, Isabella; Cavender-Bares, Jeannine

    2017-12-01

    Aspen groves along the Niobrara River in Nebraska have long been a biogeographic curiosity due to morphological differences from nearby remnant Populus tremuloides populations. Pleistocene hybridization between P. tremuloides and P. grandidentata has been proposed, but the nearest P. grandidentata populations are currently several hundred kilometers east. We tested the hybrid-origin hypothesis using genetic data and characterized putative hybrids phenotypically. We compared nuclear microsatellite loci and chloroplast sequences of Niobrara River aspens to their putative parental species. Parental species and putative hybrids were also grown in a common garden for phenotypic comparison. On the common garden plants, we measured leaf morphological traits and leaf-level spectral reflectance profiles, from which chemical traits were derived. The genetic composition of the three unique Niobrara aspen genotypes is consistent with the hybridization hypothesis and with maternal chloroplast inheritance from P. grandidentata . Leaf margin dentition and abaxial pubescence differentiated taxa, with the hybrids showing intermediate values. Spectral profiles allowed statistical separation of taxa in short-wave infrared wavelengths, with hybrids showing intermediate values, indicating that traits associated with internal structure of leaves and water absorption may vary among taxa. However, reflectance values in the visible region did not differentiate taxa, indicating that traits related to pigments are not differentiated. Both genetic and phenotypic results support the hypothesis of a hybrid origin for these genetically unique aspens. However, low genetic diversity and ongoing ecological and climatic threats to the hybrid taxon present a challenge for conservation of these relictual boreal communities. © 2017 Botanical Society of America.

  1. Root growth and physiology of potted and field-grown trembling aspen exposed to tropospheric ozone

    Science.gov (United States)

    M.D. Coleman; R.E. Dickson; J.G. Isebrands; D.F. Karnosky

    1996-01-01

    We studied root growth and respiration of potted plants and field-grown aspen trees (Populus tremuloides Michx.) exposed to ambient or twice-ambient ozone. Root dry weight of potted plants decreased up to 45% after 12 weeks of ozone treatment, and root system respiration decreased by 27%. The ozone-induced decrease in root system respiration of...

  2. La cultura del horror en las sociedades avanzadas: de la sociedad centrípeta a la sociedad centrífuga.

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    EDUARDO BERICAT ALASTUEY

    2005-01-01

    Full Text Available El presente artículo expone los principales resultados de una investigación realizada con el objeto de analizar el papel que cumplen las emociones colectivas en el mantenimiento del orden social. En concreto, trata de explicar el hecho de que las noticias más importantes que aparecen en los medios de comunicación sean noticias de horror, es decir, noticias en las que la muerte siempre aparece en el primer plano de la escena. Los informativos de los medios de comunicación expresan y fomentan la cultura del horror característica de nuestras sociedades avanzadas. Ahora bien, para entender esta cultura es preciso determinar previamente la naturaleza emocional del horror, así como establecer una definición sociológica de este sentimiento. El horror es una emoción compleja compuesta por sentimientos de terror, de asco y de conmoción. El horror, sociológicamente, puede entenderse como "la emoción mediante la que un orden social señala sus límites más extremos". El estudio concluye señalando que existen dos modos alternativos de mantener el orden y la cohesión en el seno de un sistema social. El primer modo de legitimación, característico de las sociedades centrípetas, funciona mediante la gran potencia atractiva que ejerce sobre el campo social un núcleo central de valores sociales positivos. El segundo, característico de las sociedades centrífugas, funciona mediante la gran potencia repulsiva que ejercen sobre el campo social las transgresiones flagrantes del orden moral. El modo típico en el que las sociedades centrífugas regulan el orden social explica la cultura del horror característica de nuestras sociedades avanzadas.

  3. Gibberellins inhibit adventitious rooting in hybrid aspen and Arabidopsis by affecting auxin transport.

    Science.gov (United States)

    Mauriat, Mélanie; Petterle, Anna; Bellini, Catherine; Moritz, Thomas

    2014-05-01

    Knowledge of processes involved in adventitious rooting is important to improve both fundamental understanding of plant physiology and the propagation of numerous plants. Hybrid aspen (Populus tremula × tremuloïdes) plants overexpressing a key gibberellin (GA) biosynthesis gene (AtGA20ox1) grow rapidly but have poor rooting efficiency, which restricts their clonal propagation. Therefore, we investigated the molecular basis of adventitious rooting in Populus and the model plant Arabidopsis. The production of adventitious roots (ARs) in tree cuttings is initiated from the basal stem region, and involves the interplay of several endogenous and exogenous factors. The roles of several hormones in this process have been characterized, but the effects of GAs have not been fully investigated. Here, we show that a GA treatment negatively affects the numbers of ARs produced by wild-type hybrid aspen cuttings. Furthermore, both hybrid aspen plants and intact Arabidopsis seedlings overexpressing AtGA20ox1, PttGID1.1 or PttGID1.3 genes (with a 35S promoter) produce few ARs, although ARs develop from the basal stem region of hybrid aspen and the hypocotyl of Arabidopsis. In Arabidopsis, auxin and strigolactones are known to affect AR formation. Our data show that the inhibitory effect of GA treatment on adventitious rooting is not mediated by perturbation of the auxin signalling pathway, or of the strigolactone biosynthetic and signalling pathways. Instead, GAs appear to act by perturbing polar auxin transport, in particular auxin efflux in hybrid aspen, and both efflux and influx in Arabidopsis. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  4. Vertical and horizontal root distribution of mature aspen clones: mechanisms for resource acquisition

    Science.gov (United States)

    Landhäusser, S. M.; Snedden, J.; Silins, U.; Devito, K. J.

    2012-04-01

    Spatial root distribution, root morphology, and intra- and inter-clonal connections of mature boreal trembling aspen clones (Populus tremuloides Michx.) were explored to shed light on the functional relationships between vertical and horizontal distribution of roots and the variation in soil water availability along hill slopes. Root systems of mature aspen were hydraulically excavated in large plots (6 m wide and 12 m long) and to a depth of 30 cm. Most aspen roots were located in the upper 20 cm of the soil and fine and coarse root occupancy was highest in the lower slope positions and lowest towards the upper hill slope position likely because of soil moisture availability. Observation of the root system distribution along the hill slope correlated well with the observation of greater leaf area carried by trees growing at the lower portion of the hill slope. Interestingly, trees growing at the bottom of the slope required also less sapwood area to support the same amount of leaf area of trees growing at the top of a slope. These observations appear to be closely related to soil moisture availability and with that greater productivity at the bottom of the slope. However, trees growing on the upper slope tended to have long lateral roots extending downslope, which suggests long distance water transport through these lateral feeder roots. Genetic analysis indicated that both intra- and inter-clonal root connections occur in aspen, which can play a role in the sharing of resources along moisture gradients. Root systems of boreal aspen growing on upper slope positions exhibited a combination of three attributes (1) asymmetric lateral root systems, that are skewed downslope, (2) deeper taproots, and (3) intra and inter-clonal root connections, which can all be considered adaptive strategies to avoid drought stress in upper slope positions.

  5. As bibliotecas nacionais latino americanas e o capital social

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    Deborah Medeiros

    2017-01-01

    Full Text Available Resumo Estudo que pretende analisar o uso da web social nos serviços das bibliotecas nacionais latino americanas e as formas de fomentar Capital Social em sua comunidade. Buscou-se verificar quais mídias sociais as bibliotecas nacionais usam, avaliando como adaptam aos serviços das bibliotecas e como as utilizam para fomentar o Capital Social, adotando-se para isso a teoria do fator whuffie. Utilizou-se a coleta e mapeamento de mídias sociais e observação não participante para a análise dos websites das Bibliotecas Nacionais analisadas. Como resultado, a pesquisa constatou que as Bibliotecas Nacionais em sua grande maioria utilizam seus sites e bibliotecas digitais para oferecer serviços e fomentar Capital Social entre seus interagentes. Por fim, conclui-se que as bibliotecas analisadas ainda utilizam suas mídias sociais na internet para fins administrativos e de divulgação, e observa-se que, através de algumas práticas identificadas nas bibliotecas analisadas nesta pesquisa, as demais bibliotecas podem buscar novas formas e possibilidades de interação dos seus serviços com seus interagentes por meio dessas mídias e de seus websites.

  6. Paul Strand y las paradojas de la modernidad americana

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    Vicente Sánchez Biosca

    2010-06-01

    Full Text Available As contribuições de Strand para o cinema estão estreitamente relacionadas com seus trabalhos fotográficos da época e mesmo com um olhar que, apesar de suas múltiplas diferenças, possui muitos pontos em comum. Se em Manhatta (1920, Strand (em colaboração com Sheeler oferece uma síntese da natureza e da modernidade, em Redes (1934 o que predomina, em contrapartida, é a experiência da arte muralista mexicana e a influência de Eisenstein (em suas andanças por México são os fatores que determinam seus esforços na construção de uma épica dos operários. Mas sem dúvida, o projeto mais ambicioso de Strand (ao mando da produtora Frontier Films foi Native Land, o filme que atendeu às demandas do American Popular Front e as moldou nas palavras dos fundadores da pátria americana.

  7. Avocado (Persea americana) seed as a source of bioactive phytochemicals.

    Science.gov (United States)

    Dabas, Deepti; Shegog, Rachel M; Ziegler, Gregory R; Lambert, Joshua D

    2013-01-01

    The pulp of avocado (Persea americana, Lauraceae) has been reported to have beneficial cardiovascular health effects. Avocado oil is used for dermatological applications and its unsaponifiable portion is reported to have beneficial effects against osteoarthritis. Although the seed represents a considerable percentage of the total fruit, scientific research on the phytochemistry and biological effects of avocado seeds is in the nascent stages,. Currently, the seed represents an under-utilized resource and a waste issue for avocado processors. There is ethno-pharmacological information on the use of seeds for the treatment of health-related conditions, especially in South American countries where avocados are endemic and currently grown on a large scale. Current research has shown that avocado seeds may improve hypercholesterolemia, and be useful in the treatment of hypertension, inflammatory conditions and diabetes. Seeds have also been found to possess insecticidal, fungicidal, and anti-microbial activities. The avocado seeds and rich in phenolic compounds, and these may play a role in the putative health effects. Historically, extracts of avocado seeds were also used as ink for writing and research in our laboratory has explored the potential colorant properties of a polyphenol oxidase-produced colored avocado seed extract. Here, we review the currently-available data on the bioactivity and other functional properties of avocado seeds. We discuss the strength of the available data, the putative active compounds, and potential directions for future studies.

  8. Sociedad civil / sociedad informacional: redes sociales basadas en tic en argentina

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    Susana Finquelievich

    2011-01-01

    Full Text Available Este trabajo es una contribución al estudio sobre las redes sociales sustentadas por Tecnologías de Información y Comunicación (TICs, en relación con el proceso de apropiación social de las TICs como instrumentos de comunicación y organización social para el desarrollo local. Definimos este desarrollo como el empoderamiento de organizaciones intermedias y de base, movimientos y movilizaciones populares y, en general, de entidades y organizaciones comprometidas con el apoyo popular a nivel local, y sus interacciones con otros actores sociales, como el sector público, el privado y el académico, para el progreso económico y social de la comunidad en su conjunto. A fin de ilustrar las consecuencias y desarrollos de esta perspectiva, se estudia la evolución del uso de TIC en las organizaciones de la sociedad civil en Argentina y específicamente, aquellas con sede en la ciudad de Buenos Aires.

  9. De la sociedad de trabajo a la sociedad tecnológica

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    JOSÉ ENRIQUE RODRÍGUEZ IBÁÑEZ

    1989-01-01

    Full Text Available En la sociedad actual, caracterizada por la revolución tecnoproductiva (el crecimiento y la difusión acelerados de industrias de alta tecnología, como, por ejemplo, el tratamiento de la información, las comunicaciones avanzadas, y la biotecnología y por un cambio en la mentalidad del "estado de bienestar" en lo que concierne a las preocupaciones por la calidad de vida y la intimidad, es recomendable que los valores tradicionales rígidos con respecto al trabajo, sean reestructurados según los nuevos criterios sociales y económicos. Los problemas sociales actuales - por ejemplo, el alto desempleo y las injusticias sociales entre aquéllos incluidos en la jerarquía de la alta tecnología y aquéllos que son excluidos a causa de unas habilidades y una educación obsoletas - se podrían mejorar por medio de una mayor preocupación por el capital humano, la desburocratización, y a través de iniciativas sociales. Se detallan las estrategias específicas para tales cambios, como por ejemplo aquellas propuestas por A. Gorz ("El que no trabaje, comerá", Letra Internacional, 1986, 3.

  10. Emoções e guerras: da Micronésia às bases militares americanas

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    Clara Saraiva

    2007-11-01

    Full Text Available Catherine Lutz tem um PhD em antropologia cultural da Universidade de Harvard, é professora do Departamento de Antropologia da Brown University, e investigadora do Watson Institute for International Studies da mesma universidade. Os seus temas de pesquisa debruçam-se sobre a antropologia das emoções, construção do género e da noção de raça, teoria crítica, mudanças na democracia e, mais recentemente, guerra, grupos militares e sociedade, nomeadamente através do estudo de bases militares americanas e do retorno de militares americanos dissidentes da guerra do Iraque. Lutz conduziu igualmente pesquisa para organizações activistas e todas estas temáticas se relacionam com a vontade de compreender as articulações socais e culturais das construções de poder e de desigualdade. Algumas das suas obras, influentes no campo da antropologia das emoções, da antropologia cognitiva e da história política são Unnatural Emotions: Everyday Sentiments on a Micronesian Atoll and their Challenge to Western Theory; Language and the Politics of Emotion(com Abu-Lughod; Reading National Geographic; Homefront: a Military City and the American 20th Century; Local Democracy under Siege: Activism, Public Interests, and Private Politics; The Bases of the Empire. The Struggle against US Military Posts, além de vários artigos como "Empire is in the details" e "Making war at home in the United States: militarization and the current crisis". Nesta entrevista Lutz fala sobre o que tem sido o seu trabalho e as suas preocupações académicas mas também sociais e interventivas.

  11. La educación en la sociedad del conocimiento

    OpenAIRE

    Paur, Alicia Beatriz; Rosanigo, Zulema Beatriz; Bramati, Pedro

    2006-01-01

    En este artículo analizamos el impacto de las TICs en la sociedad y en la educación, resaltando la importancia de adoptar una postura crítica frente a la cantidad de información que nos llega a través de las nuevas tecnologías. La educación es el eje vertebral y director que nos permitirá avanzar desde la llamada sociedad de la información hacia una sociedad del conocimiento más justa y democrática; de ahí que la formación permanente y el logro de la independencia cognoscitiva debieran est...

  12. Optimization of composition and technology for tablets containing aspen bark extract

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    O. I. Onуshkiv

    2015-04-01

    Full Text Available Summary. Influence of quantitativefactorsof basic quality parameters has been investigated for tabletscontainingextractofaspenbark, receivedbydirect pressingmethodand mathematicalplanningof experiment.To set the optimal composition of tablets containingaspen bark extract the proportion ofProsolv 90, Ludiflash and Polyplasdone XL 10 has been studied. The relationship between the studied factors and parameters of tablets’ regression models has been described. As a result tablets containing aspen bark extractwith mentioned above formula match necessary pharmaco-technological parameters of State Pharmacopoeia of Ukraine. Introduction.Peptic and duodenal ulcer are serious problems in modern medicine. According to statistics this disease is found in 12,83 % of the adult population in Ukraine [1]. Among the remedies for treatment and prevention of peptic ulcers we can find herbal medicines that may be used in the treatment of pre-peptic conditions and during an acute period as a means of adjuvant therapy in combination with strong remedies [2]. An antacid, cytoprotective, anti-inflammatory and reparative actions of aspen bark extract were proved by the researches of domestic and foreign scientists [3, 4]. Previously, we researched the mutual influence of excipients on the main indicators of quality of aspen bark extract tablets obtained by direct compression method. Due to these researches the best excipientshave been selected. It is necessary to establish the optimal quantitative proportion of excipients in order to obtain the tablets with suitable parameters that satisfy the requirements of the State Pharmacopoeia of Ukraine (SPU [5, 6]. Rational selection of excipients requires wide range of studies to obtain the optimal composition of the tablets containing aspen bark extract. Using mathematical planning of the experiment gives the possibility to reduce the number of experiments and to obtain the most detailed results of researches about effects

  13. IMPACTO DE LAS CATÁSTROFES NATURALES EN SOCIEDADES COLONIALES

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    Margarita Gascón

    2005-01-01

    Full Text Available En este trabajo resaltamos la relación entre la dinámica de una sociedad y los cambios operados por catástrofes masivas, tanto en lo material como en la economía, la política y las ideas y valores religiosos. Examinamos casos coloniales, como la erupción del volcán Villarrica (1640 en el sur de Chile y otros terremotos destructivos del siglo XVII. Adoptaremos una perspectiva comparativa para mostrar cómo las catástrofes modifican las condiciones locales y provocan cambios en la vida de las sociedades coloniales.

  14. Beneficios fiscales de las sociedades cooperativas en Venezuela

    OpenAIRE

    Ramírez A., Héctor M.

    2013-01-01

    En la última década (período 2000-2010) en Venezuela, el número de sociedades cooperativas ha aumentado notablemente. Esto debido al énfasis por parte del Estado en promover la creación de estas asociaciones inmersas en la economía social, otorgando a las mismas diversos beneficios fiscales. La presente investigación tiene como objetivo, analizar los beneficios fiscales de las sociedades cooperativas en Venezuela. Se concluye, que las cooperativas poseen varios beneficios fi...

  15. Psiquismo y sociedad de la información

    OpenAIRE

    Robles Rodríguez, Francisco José; Caballero de la Torre, Vicente

    2009-01-01

    Se quiere mostrar la figura psíquica que podría explicar el entretejimiento entre las nociones de psiquismo y sociedad de la información; tal figura vendría a ser la de una suerte de individuo desfondado que se mostraría como el precipitado del psiquismo telemático característico de la sociedad de la información. A su vez, el desfondamiento inherente a tal forma de individualidad actuaría según una particular y evanescente lógica interna que cabría denominar mentalismo mágico.

  16. Dispersal of invasive Phytolacca americana seeds by birds in an urban garden in China.

    Science.gov (United States)

    Li, Ning; Yang, Wen; Fang, Shubo; Li, Xinhai; Liu, Zhanchen; Leng, Xin; An, Shuqing

    2017-01-01

    Although seed dispersal is a key process determining the regeneration and spread of invasive plant populations, few studies have explicitly addressed the link between dispersal vector behavior and seedling recruitment to gain insight into the invasion process within an urban garden context. We evaluated the role of bird vectors in the dispersal of pokeweed (Phytolacca americana), a North American herb that is invasive in urban gardens in China. Fruiting P. americana attracted both generalist and specialist bird species that fed on and dispersed its seeds. The generalist species Pycnonotus sinensis and Urocissa erythrorhyncha were the most frequent dispersers. Seedling numbers of P. americana were strongly associated with the perching behavior of frugivorous birds. If newly recruited bird species use seedling-safe perching sites, the P. americana will regenerate faster, which would enhance its invasive potential. Based on our observations, we conclude that the 2 main bird vectors, P. sinensis and U. erythrorhyncha, provide potential effective dispersal agents for P. americana. Our results highlight the role of native birds in seed dispersal of invasive plants in urban gardens. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  17. Antidiabetic potential of methanol extracts from leaves of Piper umbellatum L. and Persea americana Mill.

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    Guy Sedar Singor Njateng

    2018-01-01

    Full Text Available Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P. americana (traditionally used in Cameroon against diabetes on α -glucosidase, β -glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results: The tested extracts strongly inhibited α -glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC50 ranging from (1.07 ± 0.03 to (31.77 ± 1.17 μg/mL. Among the tested extracts, P. americana was the most active against sensitive enzymes (IC50 of 1.07 ± 0.03 to 15.63 ± 1.23. But, none of the extracts showed interesting inhibitory effect against β -glucosidase as their percentage inhibitions were less than 16%. From gas chromatography-mass spectrum analysis, 10 and 8 compounds were identified in Piper umbellatum and P. americana extracts respectively, using NIST library 2014. Conclusions: Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes.

  18. Susceptibility of Porphyromonas gingivalis and Streptococcus mutans to Antibacterial Effect from Mammea americana

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    Alejandra Herrera Herrera

    2014-01-01

    Full Text Available The development of periodontal disease and dental caries is influenced by several factors, such as microorganisms of bacterial biofilm or commensal bacteria in the mouth. These microorganisms trigger inflammatory and immune responses in the host. Currently, medicinal plants are treatment options for these oral diseases. Mammea americana extracts have reported antimicrobial effects against several microorganisms. Nevertheless, this effect is unknown against oral bacteria. Therefore, the aim of this study was to evaluate the antibacterial effect of M. americana extract against Porphyromonas gingivalis and Streptococcus mutans. For this, an experimental study was conducted. Ethanolic extract was obtained from seeds of M. americana (one oil phase and one ethanolic phase. The strains of Porphyromonas gingivalis ATCC 33277 and Streptococcus mutans ATCC 25175 were exposed to this extract to evaluate its antibacterial effect. Antibacterial activity was observed with the two phases of M. americana extract on P. gingivalis and S. mutans with lower MICs (minimum inhibitory concentration. Also, bactericidal and bacteriostatic activity was detected against S. mutans, depending on the concentration of the extract, while on M. americana extract presented only bacteriostatic activity against P. gingivalis. These findings provide important and promising information allowing for further exploration in the future.

  19. Neuropharmacological and neuroprotective activities of some metabolites produced by cell suspension culture of Waltheria americana Linn.

    Science.gov (United States)

    Mundo, Jorge; Villeda-Hernández, Juana; Herrera-Ruiz, Maribel; Gutiérrez, María Del Carmen; Arellano-García, Jesús; León-Rivera, Ismael; Perea-Arango, Irene

    2017-10-01

    Waltheria americana is a plant used in Mexican traditional medicine to treat some nervous system disorders. The aims of the present study were to isolate and determine the neuropharmacological and neurprotective activities of metabolites produced by a cell suspension culture of Waltheria americana. Submerged cultivation of W. americana cells provided biomass. A methanol-soluble extract (WAsc) was obtained from biomass. WAsc was fractionated yielding the chromatographic fractions 4WAsc-H 2 O and WAsc-CH 2 Cl 2 . For the determination of anticonvulsant activity in vivo, seizures were induced in mice by pentylenetetrazol (PTZ). Neuropharmacological activities (release of gamma amino butyric acid (GABA) and neuroprotection) of chromatographic fractions were determined by in vitro histological analysis of brain sections of mice post mortem. Fraction 4WAsc-H 2 O (containing saccharides) did not produce neuronal damage, neurodegeneration, interstitial tissue edema, astrocytic activation, nor cell death. Pretreatment of animals with 4WAsc-H 2 O and WAsc-CH 2 Cl 2 from W. americana cell suspensions induced an increase in: GABA release, seizure latency, survival time, neuroprotection, and a decrease in the degree of severity of tonic/tonic-clonic convulsions, preventing PTZ-induced death of up to 100% of animals of study. Bioactive compounds produced in suspension cell culture of W. americana produce neuroprotective and neuropharmacological activities associated with the GABAergic neurotransmission system. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Preparation of Eleutherine americana-Alginate Complex Microcapsules and Application in Bifidobacterium longum

    Science.gov (United States)

    Phoem, Atchara N; Chanthachum, Suphitchaya; Voravuthikunchai, Supayang P

    2015-01-01

    Microencapsulation using extrusion and emulsion techniques was prepared for Bifidobacterium longum protection against sequential exposure to simulated gastric and intestinal juices, refrigeration storage and heat treatment. Eleutherine americana was used as the co-encapsulating agent. Hydrolysis of E. americana by gastric and intestinal juices was also determined. E. americana and its oligosaccharide extract demonstrated their resistance to low pH and partial tolerance to human α-amylase. Microencapsulated B. longum with E. americana and oligosaccharide extract prepared by the extrusion technique survived better than that by the emulsion technique under adverse conditions. Survival of microencapsulated cells after exposure to the juices and refrigeration storage was higher than free cells at Weeks 2 and 4. In addition, the viability of microencapsulated cells was better than free cells at 65 °C for 15 min. This work suggested that microencapsulated B. longum with E. americana offers the effective delivery of probiotics to colon and maintains their survival in food products. PMID:25629556

  1. Transcriptome responses to aluminum stress in roots of aspen (Populus tremula

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    Grisel Nadine

    2010-08-01

    Full Text Available Abstract Background Ionic aluminum (mainly Al3+ is rhizotoxic and can be present in acid soils at concentrations high enough to inhibit root growth. Many forest tree species grow naturally in acid soils and often tolerate high concentrations of Al. Previously, we have shown that aspen (Populus tremula releases citrate and oxalate from roots in response to Al exposure. To obtain further insights into the root responses of aspen to Al, we investigated root gene expression at Al conditions that inhibit root growth. Results Treatment of the aspen roots with 500 μM Al induced a strong inhibition of root growth within 6 h of exposure time. The root growth subsequently recovered, reaching growth rates comparable to that of control plants. Changes in gene expression were determined after 6 h, 2 d, and 10 d of Al exposure. Replicated transcriptome analyses using the Affymetrix poplar genome array revealed a total of 175 significantly up-regulated and 69 down-regulated genes, of which 70% could be annotated based on Arabidopsis genome resources. Between 6 h and 2 d, the number of responsive genes strongly decreased from 202 to 26, and then the number of changes remained low. The responses after 6 h were characterized by genes involved in cell wall modification, ion transport, and oxidative stress. Two genes with prolonged induction were closely related to the Arabidopsis Al tolerance genes ALS3 (for Al sensitive 3 and MATE (for multidrug and toxin efflux protein, mediating citrate efflux. Patterns of expression in different plant organs and in response to Al indicated that the two aspen genes are homologs of the Arabidopsis ALS3 and MATE. Conclusion Exposure of aspen roots to Al results in a rapid inhibition of root growth and a large change in root gene expression. The subsequent root growth recovery and the concomitant reduction in the number of responsive genes presumably reflect the success of the roots in activating Al tolerance mechanisms. The

  2. Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

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    Teresa A. Newsome

    2012-01-01

    Full Text Available Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximized R2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. Maximum R2 values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.

  3. Sociedad y medio ambiente. Ciudadanos y científicos ante la reforma medioambiental de la sociedad

    OpenAIRE

    Oltra Algado, Cristian

    2006-01-01

    El objetivo de la presente investigación es analizar el papel de los ciudadanos y los científicos en la reforma medioambiental de la sociedad, a partir del estudio de los valores y actitudes que estos dos actores sociales poseen ante la solución de los problemas medioambientales. El argumento esencial que se desarrolla en la investigación es que los factores culturales juegan un papel esencial en el proceso por el que las sociedades avanzadas hacen frente a los problemas medioambientales e in...

  4. Orchidaceae Americanae Orchidaceae Americanae

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    Jones H. G.

    1970-09-01

    Full Text Available The following paper continues the series of nomenclatural notes and adjustments commenced under the title "Studies in Neotropical Orchidology" in Acta Botanica Academiae Scientiarum Hungaricae, Vol. 14: pp. 63-70 (1968. As in the previous contribution, the genera considered in the present study are Brassavola R. Br., Schomburgkia Lindl, and HoffmannseggellaH. G. Jones. The notes which comprise this series of studieshave been accumulated during the course of collecting materials for a taxonomic revision of the three genera concerned.The following paper continues the series of nomenclatural notes and adjustments commenced under the title "Studies in Neotropical Orchidology" in Acta Botanica Academiae Scientiarum Hungaricae, Vol. 14: pp. 63-70 (1968. As in the previous contribution, the genera considered in the present study are Brassavola R. Br., Schomburgkia Lindl, and HoffmannseggellaH. G. Jones. The notes which comprise this series of studieshave been accumulated during the course of collecting materials for a taxonomic revision of the three genera concerned.

  5. Antinomias y paradojas de la sociedad civil global

    Directory of Open Access Journals (Sweden)

    Edwin Cruz Rodríguez

    2012-01-01

    Full Text Available ¿Qué podemos entender por sociedad civil global y cuáles son sus implicaciones sobre el ejercicio del poder a nivel mundial? El presente trabajo examina este problema. Primero, analiza las antinomias del concepto de sociedad civil global desde una perspectiva analítica. Segundo, estudia sus contenidos normativos en relación con la democratización y el poder a escala global. Existen tres antinomias cuando se trata de precisar el concepto de sociedad civil global como categoría analítica: no puede concebirse por referencia a un Estado o comunidad política global, pues este es inexistente; no se erige en un ámbito de civilidad que excluya la violencia; y no es posible definirla desde una perspectiva objetiva, porque la disputa por su significado hace parte de sí misma. En términos normativos, existe una paradoja pues la sociedad civil global no representa ciudadanos o intereses generales sino cuerpos con intereses particulares vinculados a la necesidad de gobierno o gobernanza global. Sin embargo, ha generado un cambio en las concepciones y las condiciones de ejercicio del poder en el escenario global, que potencialmente contribuye a la democratización de la política mundial.

  6. ¿Catastrofe o Nueva Sociedad? Modelo Mundial Latinoamericano

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... necesaria el favorecer la recuperación de esta parte de la memoria en la construcción de un conjunto de ... La capacidad de las sociedades de pensar a largo plazo, revisando la evidencia existente ..... Plazo más corto (menos de 20 años).

  7. Sociedade e Sustentabilidade: qual o lugar do conhecimento?

    Directory of Open Access Journals (Sweden)

    Maíra Baumgarten

    2014-12-01

    Full Text Available O texto aporta algumas considerações histórico-teóricas sobre as relações entre sociedade, conhecimento e sustentabilidade, buscando as intersecções desse debate com a problemática do desenvolvimento no mundo contemporâneo. A seguir são apresentados os artigos que integram o dossiê Sociedade, Conhecimentos e Sustentabilidade. Esses artigos têm em comum o enlace entre sociedade, ciência e sustentabilidade, ora trazendo controvérsias teóricas e colocando em discussão o próprio fazer científico e sua crítica, ora apresentando a temática da produção científica sobre sustentabilidade, observando arranjos conceituais, abordagens das interfaces entre humanos e não humanos, hibridismos, disciplinaridade e interdisciplinaridade. As tecnologias da informação e suas aplicações e repercussões sociais também estão presentes nas análises apresentadas, que abordam, de um lado, interações mediadas pela internet e sua capacidade para a criação de apoio social e, de outro lado, o aumento de desigualdades sociais no acesso a bens e a recursos característicos de uma sociedade com uso mais intensificado de tecnologias de informação e comunicação.

  8. La sociedad civil en el proceso de toma de decisiones

    Directory of Open Access Journals (Sweden)

    Margarita Marín Aranguren

    2006-01-01

    Full Text Available ¿Qué es la sociedad civil? Es la pregunta más recurrente cuando se intentan explicar sus objetivos, alcances, impacto y fines. En este documento se recogen las distintas definiciones que en la teoría política se han dado acerca de la sociedad civil. Luego, se intenta demostrar la necesidad e importancia de las dinámicas efectivas que ejerce la sociedad civil sobre la gestión pública y su incidencia para el engrosamiento del capital social y el desarrollo democrático. Finalmente se propone que, posteriormente, desde la academia, se hagan análisis más precisos alrededor de las organizaciones no gubernamentales con posibles temas aún no investigados en Colombia como por ejemplo: la responsabilidad y la democratización; la tercerización de la sociedad civil, los pros y contras del marketing social, las ventajas y desventajas al hablar de ciudadanía corporativa, entre otros problemas que involucran a este actor

  9. La sociedad civil en el proceso de toma de decisiones

    Directory of Open Access Journals (Sweden)

    Margarita Marín Aranguren

    2006-11-01

    Full Text Available ¿Qué es la sociedad civil? Es la pregunta más recurrente cuando se intentan explicar sus objetivos, alcances, impacto y fines. En este documento se recogen las distintas definiciones que en la teoría política se han dado acerca de la sociedad civil. Luego, se intenta demostrar la necesidad e importancia de las dinámicas efectivas que ejerce la sociedad civil sobre la gestión pública y su incidencia para el engrosamiento del capital social y el desarrollo democrático. Finalmente se propone que, posteriormente, desde la academia, se hagan análisis más precisos alrededor de las organizaciones no gubernamentales con posibles temas aún no investigados en Colombia como por ejemplo: la responsabilidad y la democratización; la tercerización de la sociedad civil, los pros y contras del marketing social, las ventajas y desventajas al hablar de ciudadanía corporativa, entre otros problemas que involucran a este actor.

  10. Enhanced model for integrated simulation of an entrained bed gasifier implemented as Aspen Hysys extension

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M; Bojarski, A; Ferrer-Nadal, S; Kopanos, G; Mitta, N; Pinilla, C A; Nougues, J M; Velo, E; Puigjaner, L [Universitat Politecnica de Catalunya, Barcelona (Spain). Dept. of Chemical Engineering-CEPIMA

    2007-07-01

    In this work an enhanced mathematical model of an entrained bed gasifier has been developed for improved synthesis gas production. The gasification model considers five stages: pyrolysis, volatiles combustion, char combustion, gasification and a final gas equilibrium zone. Mathematical simulations are carried out to help finding out feasible operating conditions of the process to achieve improved process performance. Visual Basic (VB) is tested as tool for modelling, by using the Aspen Hysys Extension (AHE) interface standards. This standard provides a suitable environment for this purpose, since it allows the creation of completely custom modules which are easy to plug and use thus facilitating the handling of complex models ready to interact with commercial simulation platforms. In this work, integration of different models is accomplished in Aspen Hysys (AH), which provides the basic connectivity within models components, and the thermodynamic framework needed. The integrated modules simulation environment platform uses data from ELCOGAS for validation purposes with excellent preliminary results. 9 refs., 2 figs.

  11. Standardized Competencies for Parenteral Nutrition Order Review and Parenteral Nutrition Preparation, Including Compounding: The ASPEN Model.

    Science.gov (United States)

    Boullata, Joseph I; Holcombe, Beverly; Sacks, Gordon; Gervasio, Jane; Adams, Stephen C; Christensen, Michael; Durfee, Sharon; Ayers, Phil; Marshall, Neil; Guenter, Peggi

    2016-08-01

    Parenteral nutrition (PN) is a high-alert medication with a complex drug use process. Key steps in the process include the review of each PN prescription followed by the preparation of the formulation. The preparation step includes compounding the PN or activating a standardized commercially available PN product. The verification and review, as well as preparation of this complex therapy, require competency that may be determined by using a standardized process for pharmacists and for pharmacy technicians involved with PN. An American Society for Parenteral and Enteral Nutrition (ASPEN) standardized model for PN order review and PN preparation competencies is proposed based on a competency framework, the ASPEN-published interdisciplinary core competencies, safe practice recommendations, and clinical guidelines, and is intended for institutions and agencies to use with their staff. © 2016 American Society for Parenteral and Enteral Nutrition.

  12. Identification of rosmarinic acid as the major active constituent in Cordia americana.

    Science.gov (United States)

    Geller, F; Schmidt, C; Göttert, M; Fronza, M; Schattel, V; Heinzmann, B; Werz, O; Flores, E M M; Merfort, I; Laufer, S

    2010-04-21

    Preparation from leaves of Cordia americana have been widely used in traditional medicine in South Brazil to treat wounds and various inflammations. The objective of this work was to identify the effective compounds in the ethanolic extract prepared from the leaves of Cordia americana, which is used in traditional South Brazilian medicine as anti-inflammatory and wound healing remedy. Isolation and structure elucidation techniques were performed in order to identify the compounds of Cordia americana and HPLC analysis was used for the quantification. The major constituent and the ethanolic extract were investigated for inhibition of 5-lipoxygenase, p38alpha MAPK, TNFalpha release and NF-kappaB as well as in the fibroblast scratch assay. Rosmarinic acid (1) was identified as the major compound with an amount of 8.44% in the ethanolic extract of the leaves of Cordia americana. The ethanolic extract as well as (1) exhibited the highest inhibitory effects on 5-lipoxygenase (IC(50)=0.69 and 0.97microg/mL, resp., IC50 of BWA4C as reference: 0.3microM) and p38alpha (IC50=3.25 and 1.16microg/mL, resp., IC50 of SB203580 as reference: 0.046microM) and moderate inhibitory effects on TNFalpha release. Slight effects were observed in the fibroblast scratch assay. This study increases our knowledge on the effective compound in Cordia americana and supports its use in traditional medicine. We demonstrated for the first time pharmacological effects of Cordia americana and we provide evidences for a crucial role of rosmarinic acid as the major key player. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  13. Aquatic ecosystem response to timber harvesting for the purpose of restoring aspen.

    Directory of Open Access Journals (Sweden)

    Bobette E Jones

    Full Text Available The removal of conifers through commercial timber harvesting has been successful in restoring aspen, however many aspen stands are located near streams, and there are concerns about potential aquatic ecosystem impairment. We examined the effects of management-scale conifer removal from aspen stands located adjacent to streams on water quality, solar radiation, canopy cover, temperature, aquatic macroinvertebrates, and soil moisture. This 8-year study (2003-2010 involved two projects located in Lassen National Forest. The Pine-Bogard Project consisted of three treatments adjacent to Pine and Bogard Creeks: (i Phase 1 in January 2004, (ii Phase 2 in August 2005, and (iii Phase 3 in January 2008. The Bailey Project consisted of one treatment adjacent to Bailey Creek in September 2006. Treatments involved whole tree removal using track-laying harvesters and rubber tire skidders. More than 80% of all samples analyzed for NO₃-N, NH₄-N, and PO₄-P at Pine, Bogard, and Bailey Creeks were below the detection limit, with the exception of naturally elevated PO₄-P in Bogard Creek. All nutrient concentrations (NO₃-N, NH₄-N, PO₄-P, K, and SO₄-S showed little variation within streams and across years. Turbidity and TSS exhibited annual variation, but there was no significant increase in the difference between upstream and downstream turbidity and TSS levels. There was a significant decrease in stream canopy cover and increase in the potential fraction of solar radiation reaching the streams in response to the Pine-Bogard Phase 3 and Bailey treatments; however, there was no corresponding increase in stream temperatures. Macroinvertebrate metrics indicated healthy aquatic ecosystem conditions throughout the course of the study. Lastly, the removal of vegetation significantly increased soil moisture in treated stands relative to untreated stands. These results indicate that, with careful planning and implementation of site-specific best management

  14. Can Carbon Fluxes Explain Differences in Soil Organic Carbon Storage under Aspen and Conifer Forest Overstories?

    Directory of Open Access Journals (Sweden)

    Antra Boča

    2017-04-01

    Full Text Available Climate- and management-induced changes in tree species distributions are raising questions regarding tree species-specific effects on soil organic carbon (SOC storage and stability. Quaking aspen (Populus tremuloides Michx. is the most widespread tree species in North America, but fire exclusion often promotes the succession to conifer dominated forests. Aspen in the Western US have been found to store more SOC in the mineral soil than nearby conifers, but we do not yet fully understand the source of this differential SOC accumulation. We measured total SOC storage (0–50 cm, characterized stable and labile SOC pools, and quantified above- and belowground litter inputs and dissolved organic carbon (DOC fluxes during snowmelt in plots located in N and S Utah, to elucidate the role of foliage vs. root detritus in SOC storage and stabilization in both ecosystems. While leaf litterfall was twice as high under aspen as under conifers, input of litter-derived DOC with snowmelt water was consistently higher under conifers. Fine root (<2 mm biomass, estimated root detritus input, and root-derived DOC fluxes were also higher under conifers. A strong positive relationship between root and light fraction C content suggests that root detritus mostly fueled the labile fraction of SOC. Overall, neither differences in above- and belowground detritus C inputs nor in detritus-derived DOC fluxes could explain the higher and more stable SOC pools under aspen. We hypothesize that root–microbe–soil interactions in the rhizosphere are more likely to drive these SOC pool differences.

  15. Effect of steam treatment on the hydrolysis of aspen by commerical enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, D G; Mathews, J F

    1979-06-01

    Steam treatment renders aspen wood more susceptible to hydrolysis by commerical enzyme preparations such as the Onozuka variety. The main products of enzymatic hydrolysis are glucose, xylose, and xylobiose. Cellobiose may have been another product but it could not be measured due to interference by lactose, a sugar found in the enzyme. The hemicellulose fraction of the wood is relatively more rapidly hydrolyzed by the enzymes than the cellulose fraction.

  16. The Impact of Nitrogen Limitation and Mycorrhizal Symbiosis on Aspen Tree Growth and Development

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Bich Thi Ngoc [Univ. of Alabama, Huntsville, AL (United States)

    2014-08-18

    Nitrogen deficiency is the most common and widespread nutritional deficiency affecting plants worldwide. Ectromycorrhizal symbiosis involves the beneficial interaction of plants with soil fungi and plays a critical role in nutrient cycling, including the uptake of nitrogen from the environment. The main goal of this study is to understand how limiting nitrogen in the presence or absence of an ectomycorrhizal fungi, Laccaria bicolor, affects the health of aspen trees, Populus temuloides.

  17. Figured grain in aspen is heritable and not affected by graft-transmissible signals

    Science.gov (United States)

    Youran Fan; Kendal Rupert; Alex C. Wiedenhoeft; Keith Woeste; Christian Lexer; Richard. Meilan

    2013-01-01

    Figure can add value to wood products, but its occurrence is unpredictable. A first step in reliably producing figured wood is determining whether it is faithfully transmitted to progeny via sexual and asexual reproduction. We describe a 26-year-old male aspen genotype, designated ‘Curly Poplar’, which was shown to be a Populus × canescens hybrid using microsatellite...

  18. Genetic Augmentation of Syringyl Lignin in Low-lignin Aspen Trees, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chung-Jui Tsai; Mark F. Davis; Vincent L. Chiang

    2004-11-10

    As a polysaccharide-encrusting component, lignin is critical to cell wall integrity and plant growth but also hinders recovery of cellulose fibers during the wood pulping process. To improve pulping efficiency, it is highly desirable to genetically modify lignin content and/or structure in pulpwood species to maximize pulp yields with minimal energy consumption and environmental impact. This project aimed to genetically augment the syringyl-to-guaiacyl lignin ratio in low-lignin transgenic aspen in order to produce trees with reduced lignin content, more reactive lignin structures and increased cellulose content. Transgenic aspen trees with reduced lignin content have already been achieved, prior to the start of this project, by antisense downregulation of a 4-coumarate:coenzyme A ligase gene (Hu et al., 1999 Nature Biotechnol 17: 808- 812). The primary objective of this study was to genetically augment syringyl lignin biosynthesis in these low-lignin trees in order to enhance lignin reactivity during chemical pulping. To accomplish this, both aspen and sweetgum genes encoding coniferaldehyde 5-hydroxylase (Osakabe et al., 1999 PNAS 96: 8955-8960) were targeted for over-expression in wildtype or low-lignin aspen under control of either a constitutive or a xylem-specific promoter. A second objective for this project was to develop reliable and cost-effective methods, such as pyrolysis Molecular Beam Mass Spectrometry and NMR, for rapid evaluation of cell wall chemical components of transgenic wood samples. With these high-throughput techniques, we observed increased syringyl-to-guaiacyl lignin ratios in the transgenic wood samples, regardless of the promoter used or gene origin. Our results confirmed that the coniferaldehyde 5-hydroxylase gene is key to syringyl lignin biosynthesis. The outcomes of this research should be readily applicable to other pulpwood species, and promise to bring direct economic and environmental benefits to the pulp and paper industry.

  19. A system for predicting the amount of Phellinus (Fomes) igniarius rot in trembling aspen stands

    Science.gov (United States)

    Robert L. Anderson; Arthur L. Jr. Schipper

    1978-01-01

    The occurrence of Phellinus (Fomes) igniarius white trunk rot in 45- to 50-year-old trembling aspen stands can be predicted by applying a constant to the stand basal area with P. igniarius conks to estimate the total basal area with P. igniarius rot. Future decay projections can be made by reapplying the basal area of hidden decay for each 6 years projected. This paper...

  20. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Science.gov (United States)

    Oldén, Anna; Ovaskainen, Otso; Kotiaho, Janne S; Laaka-Lindberg, Sanna; Halme, Panu

    2014-01-01

    Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L.) retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered) and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old-growth forests.

  1. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Directory of Open Access Journals (Sweden)

    Anna Oldén

    Full Text Available Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L. retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old

  2. A REPRESENTAÇÃO DA MULHER LATINO-AMERICANA: DA LITERATURA PARA O CINEMA

    OpenAIRE

    de Amorim, Maria Inês Freitas; Universidade do Estado do Rio de Janeiro

    2015-01-01

    As obras do escritor colombiano Gabriel García Márquez são reconhecidas pela presença de personagens femininas fortes e pela representação de elementos da cultura latino-americana. Já a indústria cinematográfica de Hollywood costuma representar a mulher latino-americana a partir de estereótipos, sobretudo relacionados à sensualidade e submissas às vontades da voz masculina. O romance de García Márquez El amor en los tiempos del cólera foi adaptado para o cinema pela industria estadunidense, ...

  3. Acute Toxicity and Genotoxic Activity of Avocado Seed Extract (Persea americana Mill., c.v. Hass

    Directory of Open Access Journals (Sweden)

    Eduardo Padilla-Camberos

    2013-01-01

    Full Text Available The use of vegetal extracts requires toxicological and genotoxic evaluations to establish and verify safety before being added to human cosmetic, pharmaceutical medicine, or alimentary products. Persea americana seeds have been used in traditional medicine as treatment for several diseases. In this work, the ethanolic seed extract of Persea americana was evaluated with respect to its genotoxic potential through micronucleus assay in rodents. The frequency of micronuclei in groups of animals treated with avocado seed extract showed no differences compared to the negative control (vehicle; therefore, it is considered that the avocado seed extract showed no genotoxic activity in the micronucleus test.

  4. Acute toxicity and genotoxic activity of avocado seed extract (Persea americana Mill., c.v. Hass).

    Science.gov (United States)

    Padilla-Camberos, Eduardo; Martínez-Velázquez, Moisés; Flores-Fernández, José Miguel; Villanueva-Rodríguez, Socorro

    2013-01-01

    The use of vegetal extracts requires toxicological and genotoxic evaluations to establish and verify safety before being added to human cosmetic, pharmaceutical medicine, or alimentary products. Persea americana seeds have been used in traditional medicine as treatment for several diseases. In this work, the ethanolic seed extract of Persea americana was evaluated with respect to its genotoxic potential through micronucleus assay in rodents. The frequency of micronuclei in groups of animals treated with avocado seed extract showed no differences compared to the negative control (vehicle); therefore, it is considered that the avocado seed extract showed no genotoxic activity in the micronucleus test.

  5. Quantitative Evaluation of Hybrid Aspen Xylem and Immunolabeling Patterns Using Image Analysis and Multivariate Statistics

    Directory of Open Access Journals (Sweden)

    David Sandquist

    2015-06-01

    Full Text Available A new method is presented for quantitative evaluation of hybrid aspen genotype xylem morphology and immunolabeling micro-distribution. This method can be used as an aid in assessing differences in genotypes from classic tree breeding studies, as well as genetically engineered plants. The method is based on image analysis, multivariate statistical evaluation of light, and immunofluorescence microscopy images of wood xylem cross sections. The selected immunolabeling antibodies targeted five different epitopes present in aspen xylem cell walls. Twelve down-regulated hybrid aspen genotypes were included in the method development. The 12 knock-down genotypes were selected based on pre-screening by pyrolysis-IR of global chemical content. The multivariate statistical evaluations successfully identified comparative trends for modifications in the down-regulated genotypes compared to the unmodified control, even when no definitive conclusions could be drawn from individual studied variables alone. Of the 12 genotypes analyzed, three genotypes showed significant trends for modifications in both morphology and immunolabeling. Six genotypes showed significant trends for modifications in either morphology or immunocoverage. The remaining three genotypes did not show any significant trends for modification.

  6. Effect of Auxins and Associated Metabolic Changes on Cuttings of Hybrid Aspen

    Directory of Open Access Journals (Sweden)

    Shao Peng Yan

    2017-04-01

    Full Text Available In the present study, an attempt was made to induce rooting from single-node cuttings of hybrid aspen (Populus tremula L. × P. tremuloides Michx. with different concentrations of Indole-3-acetic acid (IAA, Indole-3-Butytric acid (IBA and 1-Naphthylacetic acid (NAA. Among the three auxins used, 0.54 mM NAA showed more effective induction on rooting as compared to IAA and IBA at the whole level. Thereafter, 0.54 mM NAA was used further for the anatomical and biochemical investigation. The results showed that it took 12 days from the differentiation of primordium to the appearance of young adventitious roots under NAA application. It was found that endogenous IAA, Zeatin riboside (ZR and Gibberellic Acid (GA3 levels increased, but Abscisic acid (ABA decreased in cuttings with NAA treatment. In contrast to the endogenous IAA level, NAA resulted in a decrease in IAA-oxidase (IAAO activity. Similarly, the decreased peroxidase (POD activity, consistent with down-regulation of expressed levels of POD1 and POD2, was observed in NAA-treated cuttings. Moreover, NAA resulted in a higher activity in polyphenol oxidase (PPO compared with control cuttings. Collectively, the study highlighted that 0.54 mM NAA is efficient on rooting in hybrid aspen, and its effect on metabolic changes during rooting was discussed, which can provide valuable information for propagating hybrid aspen.

  7. Modeling the Removal of Xenon from Lithium Hydrate with Aspen HYSYS

    Science.gov (United States)

    Efthimion, Phillip; Gentile, Charles

    2011-10-01

    The Laser Inertial Fusion Engine (LIFE) project mission is to provide a long-term, carbon-free source of sustainable energy, in the form of electricity. A conceptual xenon removal system has been modeled with the aid of Aspen HYSYS, a chemical process simulator. Aspen HYSYS provides excellent capability to model chemical flow processes, which generates outputs which includes specific variables such as temperature, pressure, and molar flow. The system is designed to strip out hydrogen isotopes deuterium and tritium. The base design bubbles plasma exhaust laden with x filled with liquid helium. The system separates the xenon from the hydrogen, deuterium, and tritium with a lithium hydrate and a lithium bubbler. After the removal of the hydrogen and its isotopes, the xenon is then purified by way of the process of cryogenic distillation. The pure hydrogen, deuterium, and tritium are then sent to the isotope separation system (ISS). The removal of xenon is an integral part of the laser inertial fusion engine and Aspen HYSYS is an excellent tool to calculate how to create pure xenon.

  8. Testing Transgenic Aspen Plants with bar Gene for Herbicide Resistance under Semi-natural Conditions.

    Science.gov (United States)

    Lebedev, V G; Faskhiev, V N; Kovalenko, N P; Shestibratov, K A; Miroshnikov, A I

    2016-01-01

    Obtaining herbicide resistant plants is an important task in the genetic engineering of forest trees. Transgenic European aspen plants (Populus tremula L.) expressing the bar gene for phosphinothricin resistance have been produced using Agrobacterium tumefaciens-mediated transformation. Successful genetic transformation was confirmed by PCR analysis for thirteen lines derived from two elite genotypes. In 2014-2015, six lines were evaluated for resistance to herbicide treatment under semi-natural conditions. All selected transgenic lines were resistant to the herbicide Basta at doses equivalent to 10 l/ha (twofold normal field dosage) whereas the control plants died at 2.5 l/ha. Foliar NH4-N concentrations in transgenic plants did not change after treatment. Extremely low temperatures in the third ten-day period of October 2014 revealed differences in freeze tolerance between the lines obtained from Pt of f2 aspen genotypes. Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. On the basis of the tests, four transgenic aspen lines were selected. The bar gene could be used for retransformation of transgenic forest trees expressing valuable traits, such as increased productivity.

  9. New exposure-based metric approach for evaluating O3 risk to North American aspen forests

    International Nuclear Information System (INIS)

    Percy, K.E.; Nosal, M.; Heilman, W.; Dann, T.; Sober, J.; Legge, A.H.; Karnosky, D.F.

    2007-01-01

    The United States and Canada currently use exposure-based metrics to protect vegetation from O 3 . Using 5 years (1999-2003) of co-measured O 3 , meteorology and growth response, we have developed exposure-based regression models that predict Populus tremuloides growth change within the North American ambient air quality context. The models comprised growing season fourth-highest daily maximum 8-h average O 3 concentration, growing degree days, and wind speed. They had high statistical significance, high goodness of fit, include 95% confidence intervals for tree growth change, and are simple to use. Averaged across a wide range of clonal sensitivity, historical 2001-2003 growth change over most of the 26 M ha P. tremuloides distribution was estimated to have ranged from no impact (0%) to strong negative impacts (-31%). With four aspen clones responding negatively (one responded positively) to O 3 , the growing season fourth-highest daily maximum 8-h average O 3 concentration performed much better than growing season SUM06, AOT40 or maximum 1 h average O 3 concentration metrics as a single indicator of aspen stem cross-sectional area growth. - A new exposure-based metric approach to predict O 3 risk to North American aspen forests has been developed

  10. El "sistema de guerra" de la sociedad industrial

    Directory of Open Access Journals (Sweden)

    JORGE VERSTRYNGE ROJAS

    1978-01-01

    Full Text Available Se presenta una tipología de la guerra, la cual es definida como una "empresa organizada de destrucción", y se examina el proceso implicado en el desarrollo de un "combate totalmente industrializado". Se analizan varias guerras, entre las cuales figuran la revolución Francesa, la guerra civil Americana, la guerra austro-prusiana de 1866, etc. La I Guerra Mundial es considerada la primera "guerra total" de la era paleotécnica; la II Guerra Mundial fue la culminación de la era neotécnica. La "guerra total", sea esta limitada o ilimitada, viene marcada por un gran incremento en la competición por la innovación militar. Se destaca la concepción prusiana del hombre militar en tanto que criatura disciplinada y mecanizada dedicada al proceso de intensificación de la guerra.

  11. Polysaccharide rich fractions from barks of Ximenia americana inhibit peripheral inflammatory nociception in mice Antinociceptive effect of Ximenia americana polysaccharide rich fractions

    Directory of Open Access Journals (Sweden)

    Kaira E.S. da Silva-Leite

    Full Text Available Abstract Ximenia americana L., Olacaceae, barks are utilized in folk medicine as analgesic and anti-inflammatory. The objective was to evaluate the toxicity and antinociceptive effect of polysaccharides rich fractions from X. americana barks. The fractions were obtained by extraction with NaOH, followed by precipitation with ethanol and fractionation by ion exchange chromatography. They were administered i.v. or p.o. before nociception tests (writhing, formalin, carragenan-induced hypernociception, hot plate, or during 14 days for toxicity assay. The total polysaccharides fraction (TPL-Xa: 8.1% yield presented 43% carbohydrate (21% uronic acid and resulted in two main fractions after chromatography (FI: 12%, FII: 22% yield. FII showed better homogeneity/purity, content of 44% carbohydrate, including 39% uronic acid, arabinose and galactose as major monosaccharides, and infrared spectra with peaks in carbohydrate range for COO- groups of uronic acid. TPL-Xa (10 mg/kg and FII (0.1 and 1 mg/kg presented inhibitory effect in behavior tests that evaluate nociception induced by chemical and mechanical, but not thermal stimuli. TPL-Xa did not alter parameters of systemic toxicity. In conclusion, polysaccharides rich fractions of X. americana barks inhibit peripheral inflammatory nociception, being well tolerated by animals.

  12. La infancia en riesgo social desde la sociedad del bienestar

    Directory of Open Access Journals (Sweden)

    M. Ángeles BALSELLS

    2016-04-01

    Full Text Available El artículo plantea la necesidad de redefinir el concepto de infancia en situación de riesgo social, dado que las avanzadas sociedades del bienestar están siendo escenario de nuevos fenómenos sociales que provocan a su vez la aparición de nuevos colectivos infanto-juveniles en riesgo. Se conoce el maltrato infantil familiar como una causa clara del riesgo social pero, ¿existen otras situaciones, fuera de la familia, que provocan la aparición de poblaciones infantiles en situación de riesgo social?, ¿se puede hablar de infancia en situación de riesgo social cuando no existen maltratos o negligencia en la familia? En definitiva, ¿las sociedades desarrolladas y avanzadas son el escenario de nuevos grupos de riesgo social? Estos son los interrogantes que pretende responder el presente artículo.

  13. La sociedad colombiana de fomento: empresarios bogotanos en 1920

    Directory of Open Access Journals (Sweden)

    Javier Montes Calderón

    2015-02-01

    La información que se encuentra en los archivos notariales es de gran importancia para conocer los antecedentes, el capital y la organización inicial de las sociedades empresariales. Tal es el caso de LA SOCIEDAD COLOMBIANA DE FOMENTO, una empresa conformada por un grupo selecto de empresarios nacionales cuyos objetivos eran buscar la rentabilidad y el dasarrollo del país. En este sentido la empresa se propuso diferentes frentes de trabajo tanto en la industria como en los servicios. Si bien conocer el desarrollo de la misma hubiera sido lo más deseable, esto no se pudo lograr pues la información se quemó en el holocausto de la toma del palacio de Justicia en 1989...

  14. La relación administrador-sociedad

    Directory of Open Access Journals (Sweden)

    Luis Fernando Sabogal Bernal

    2010-07-01

    Full Text Available En este trabajo se aborda el tema de la naturaleza jurídica de la relación administrador – sociedad con el fin de dar una mayor claridad sobre el cuerpo de normas y principios jurídicos que definen la posición, facultades y poderes de los administradores de sociedades. En la primera parte se hace una síntesis de las principales doctrinas que explican esta relación en el derecho continental europeo y angloamericano; en la segunda se organizan y concretizan las diferentes soluciones al problema por parte de la legislación, la jurisprudencia y la doctrina nacional colombiana; y finalmente, en la tercera se propone una aproximación interpretativa propia del autor, intentando conciliar las posiciones extranjeras y nacionales de conformidad con la jurisprudencia y la legislación colombianas.

  15. White ash (Fraxinus americana) decline and mortality: the role of site nutrition and stress history

    Science.gov (United States)

    Alejandro A. Royo; Kathleen S. Knight

    2012-01-01

    Over the past century, white ash (Fraxinus americana) populations throughout its range have deteriorated as a result of declining tree health and increased mortality rates. Although co-occurring factors including site nutritional deficiencies and punctuated stress events (e.g., defoliations, drought) are hypothesized to trigger white ash decline,...

  16. Effects of Persea americana leaf extracts on body weight and liver ...

    African Journals Online (AJOL)

    GREGO

    2007-04-16

    Apr 16, 2007 ... weight of either aqueous or methanolic extract of P. americana leaf daily for 8 weeks. There were no significant differences (p>0.05) in the overall body weight gain of the hyperlipidaemic rats compared to normal control. However, the administration of the aqueous and methanolic extracts provoked 14 and.

  17. Description of a new coccid (Hemiptera, Coccidae on avocado (Persea americana Mill. from Colombia, South America

    Directory of Open Access Journals (Sweden)

    Takumasa Kondo

    2010-04-01

    Full Text Available A new soft scale insect, Bombacoccus aguacatae Kondo, gen. n. and sp. n. (Hemiptera: Coccidae collected on the branches and twigs of avocado, Persea americana Mill. (Lauraceae in Colombia, is described and illustrated based on the adult female. An updated taxonomic key to closely related genera of the Toumeyella-group is provided.

  18. Multi scale habitat relationships of Martes americana in northern Idaho, U.S.A.

    Science.gov (United States)

    Tzeidle N. Wasserman; Samuel A. Cushman; David O. Wallin; Jim Hayden

    2012-01-01

    We used bivariate scaling and logistic regression to investigate multiple-scale habitat selection by American marten (Martes americana). Bivariate scaling reveals dramatic differences in the apparent nature and strength of relationships between marten occupancy and a number of habitat variables across a range of spatial scales. These differences include reversals in...

  19. Race, Interracial Admixture and Genetic Differentiation of Avocado (Persea americana Mill)

    Science.gov (United States)

    Avocado (Persea americana Mill.) is a major tropical fruit crop native to Mesoamerica and domesticated around 8000 to 7000 BC. It is a member of the Laureace family and currently classified into three subspecies or races: Guatemalan (G), Mexican (M) and West Indian (WI) according to their ecological...

  20. Delineation of a New Species of the Borrelia burgdorferi Sensu Lato Complex, Borrelia americana sp. nov

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Lin, T.; Gao, L.; Grubhoffer, Libor; Oliver, J. H., Jr.

    2009-01-01

    Roč. 47, č. 12 (2009), s. 3875-3880 ISSN 0095-1137 R&D Projects: GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : multilocus sequence analysis * B. burgdorferi sl complex * new borrelia species * Borrelia americana Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.162, year: 2009

  1. The Scirtothrips perseae species-group (Thysanoptera), with one new species from avocado, Persea americana.

    Science.gov (United States)

    Mound, Laurence A; Hoddle, Mark S

    2016-02-12

    Following recent molecular studies on avocado thrips, a new species is described from Costa Rica, Ecuador, and Colombia from the young leaves of avocado, Persea americana. Scirtothrips hansoni sp.n. is closely related to the Californian pest, S. perseae, and also to S. astrictus from Costa Rica that remains known from a single female. An illustrated key to these three species is provided.

  2. SOCIEDAD, PAZ Y GUERRA EN SAN AGUSTÍN

    Directory of Open Access Journals (Sweden)

    MIGUEL VERGARA VILLALOBOS

    2017-12-01

    Full Text Available Este trabajo analiza las nociones de sociedad, paz y guerra, en La ciudad de Dios, de San Agustín, a la que nos referimos principalmente según la edición bilingüe preparada por José Morán (1965. En una primera parte, a modo de introducción, se expone el argumento general del libro y se explica la teoría de las dos ciudades, la terrena y la de Dios. Enseguida se analiza la noción de sociedad, que se fundamenta en la justicia y en el interés común como camino para alcanzar la paz. Esto nos lleva a examinar la justicia, que para San Agustín es un concepto fundamental tanto en la ciudad terrena como en la ciudad de Dios. Teniendo este marco conceptual en cuanto la sociedad y la autoridad, se entra a discutir la paz, que representa uno de los aspectos centrales de la obra que comentamos. En contraste y como oposición a la paz se analiza la guerra; para nalizar con un tema cuyo origen clásicamente se atribuye a San Agustín, cual es la guerra justa.

  3. UNA TEORÍA RETÓRICA DE LA SOCIEDAD

    Directory of Open Access Journals (Sweden)

    Javier Hernández García

    2005-08-01

    Full Text Available Se plantea en este artículo la tesis de que la estrategia discursiva de Miguel Antonio Caro de integrar en una misma dinámica constituyente de la civilización a la Lengua y al ordenamiento social (como Autoridad, rinde jugosos frutos conceptuales. Al hacer posible la postulación de una correspondencia sustantiva entre una gramática de la lengua y una gramática de la sociedad (entendida como civilización, y partiendo de la elaboración de postulados histórico sociales entresacados de las ciencias del lenguaje de la época, por los que se establecen, entre otras cosas, diferencias sustantivas entre lenguas complejamente desarrolladas y lenguas de menor complejidad, se extrapola un modelo de jerarquización de las sociedades humanas y de los hombres que las hablan y desarrollan que naturaliza, retorizándolas, las gradaciones, contraposiciones, junturas y distanciamientos constitutivos de la vida social. Teniendo en cuenta que para Caro el lenguaje es el primero y necesario elemento de sociabilidad, éste se autoconstituye en el mismo juego de vectores que se entrecruzan y combinan, avanzan y retroceden configurando la sociedad-civilización en la que el lenguaje se despliega y encarna, en un compartido camino que integra tradición y progreso, superioridad e inferioridad, hegemonía y subordinación.

  4. Comunidades virtuais gerando identidades na sociedade em rede

    Directory of Open Access Journals (Sweden)

    Cynthia Harumy Watanabe Corrêa

    2011-01-01

    Full Text Available

    A revolução tecnológica concentrada nas Tecnologias da Informação e da Comunicação (TICs, que possibilita a conexão mundial via redes de computadores, promove alterações significativas na base material da sociedade, ao estabelecer uma interdependência global entre os países e modificar as relações entre economia, Estado-nação e sociedade.  O uso crescente de redes como a Internet resultou na criação de um novo tipo de organização social, a sociedade em rede, que permite a formação de comunidades virtuais, grupos humanos constituídos pela identificação de interesses comuns.  Neste artigo, elaborado a partir de revisão teórica, abordaremos a formação dessas comunidades como uma estratégia do indivíduo para adquirir uma nova identidade, uma vez que as identidades culturais estão se fragmentando em conseqüência do processo de globalização, que é inerente à modernidade.

  5. Developmental ecdysteroid titers and DNA puffs in larvae of two sciarid species, Rhynchosciara americana and Rhynchosciara milleri (Diptera: Sciaridae).

    Science.gov (United States)

    Soares, M A M; Hartfelder, K; Tesserolli de Souza, J M; Stocker, A J

    2015-10-01

    Ecdysteroid titers, developmental landmarks and the presence of prominent amplifying regions (DNA puffs) have been compared during late larval to pupal development in four groups of Rhynchosciara americana larvae and in R. americana and Rhynchosciara milleri. Three prominent DNA puffs (B2, C3 and C8) expand and regress sequentially on the rising phase of the 20-hydroxyecdysone (20E) titer in R. americana as a firm, cellular cocoon is being constructed. A sharp rise in 20E coincides with the regression of these puffs. The shape of the 20E curve is similar in R. milleri, a species that does not construct a massive cocoon, but the behavior of certain DNA puffs and their temporal relationship to the curve differs. Regions corresponding to B2 and C3 can be identified in R. milleri by banding pattern similarity with R. americana chromosomes and, in the case of B2, by hybridization to an R. americana probe. A B2 puff appears in R. milleri as the 20E titer rises but remains small in all gland regions. A puff similar to the R. americana C3 puff occurs in posterior gland cells of R. milleri (C3(Rm)) after the B2 puff, but this site did not hybridize to R. americana C3 probes. C3(Rm) incorporated (3)H-thymidine above background, but showed less post-puff DNA accumulation than C3 of R. americana. R. americana C8 probes hybridized to a more distal region of the R. milleri C chromosome that did not appear to amplify or form a large puff. These differences can be related to developmental differences, in particular differences in cocoon construction between the two species.

  6. Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae against Periplaneta americana(L.

    Directory of Open Access Journals (Sweden)

    I Ling A

    2009-12-01

    Full Text Available Background: The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory.Methods: The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme.Results: Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same con­centrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cock­roaches. Treatment with Resigen (R at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the fe­males, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach.Conclusion: Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peri­patetic americana.

  7. Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae) against Periplaneta americana (L.).

    Science.gov (United States)

    Ling A, I; Sulaiman, S; Othman, H

    2009-01-01

    The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory. The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R) 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme. Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same concentrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cockroaches. Treatment with Resigen (R) at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the females, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach. Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peripatetic americana.

  8. Growing Season Conditions Mediate the Dependence of Aspen on Redistributed Snow Under Climate Change.

    Science.gov (United States)

    Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Strand, E. K.

    2016-12-01

    Precipitation regimes in many semiarid ecosystems are becoming increasingly dominated by winter rainfall as a result of climate change. Across these regions, snowpack plays a vital role in the distribution and timing of soil moisture availability. Rising temperatures will result in a more uniform distribution of soil moisture, advanced spring phenology, and prolonged growing seasons. Productive and wide ranging tree species like aspen, Populus tremuloides, may experience increased vulnerability to drought and mortality resulting from both reduced snowpack and increased evaporative demand during the growing season. We simulated the net primary production (NPP) of aspen stands spanning the rain:snow transition zone in the Reynolds Creek Critical Zone Observatory (RCCZO) in southwest Idaho, USA. Within the RCCZO, the total amount of precipitation has remained unchanged over the past 50 years, however the percentage of the precipitation falling as snow has declined by approximately 4% per decade at mid-elevation sites. The biogeochemical process model Biome-BGC was used to simulate aspen NPP at three stands located directly below snowdrifts that provide melt water late into the spring. After adjusting precipitation inputs to account for the redistribution of snow, we assessed climate change impacts on future aspen productivity. Mid-century (2046-2065) aspen NPP was simulated using temperature projections from a multi-model average under high emission conditions using the Multivariate Adaptive Constructed Analogs (MACA) data set. While climate change simulations indicated over a 20% decrease in annual NPP for some years, NPP rates for other mid-century years remained relatively unchanged due to variations in growing season conditions. Mid-century years with the largest decreases in NPP typically showed increased spring transpiration rates resulting from earlier leaf flush combined with warmer spring conditions. During these years, the onset of drought stress occurred

  9. La sociedad civil como base de la educación y la educación como base de la sociedad civil

    OpenAIRE

    Alvira, Rafael

    2013-01-01

    La tesis fundamental del trabajo está expresada en el título: la sociedad civil es condición indispensable para que se pueda realizar una tarea educativa de altura y, a su vez, sin una educación bien hecha la sociedad civil sería imposible. Como sucede siempre, se puede comenzar por intentar mejorar las estructuras de la sociedad civil, o por potenciar la educación, pero en realidad la clave ahora está en cambiar la concepción tanto de la sociedad civil como de la educación. Para ello, result...

  10. Ozone-induced H2O2 accumulation in field-grown aspen and birch is linked to foliar ultrastructure and peroxisomal activity

    Science.gov (United States)

    E. Oksanen; E. Häikiö; J. Sober; D.F. Karnosky

    2003-01-01

    Saplings of three aspen (Populus tremuloides) genotypes and seedlings of paper birch (Betula papyrifera) were exposed to elevated ozone (1.5x ambient) and 560 p.p.m. CO2, singly and in combination, from 1998 at the Aspen-FACE (free-air CO2 enrichment) site (Rhinelander, USA).

  11. Detection of Aspens Using High Resolution Aerial Laser Scanning Data and Digital Aerial Images

    Directory of Open Access Journals (Sweden)

    Kalle Eerikäinen

    2008-08-01

    Full Text Available The aim was to use high resolution Aerial Laser Scanning (ALS data and aerial images to detect European aspen (Populus tremula L. from among other deciduous trees. The field data consisted of 14 sample plots of 30 m × 30 m size located in the Koli National Park in the North Karelia, Eastern Finland. A Canopy Height Model (CHM was interpolated from the ALS data with a pulse density of 3.86/m2, low-pass filtered using Height-Based Filtering (HBF and binarized to create the mask needed to separate the ground pixels from the canopy pixels within individual areas. Watershed segmentation was applied to the low-pass filtered CHM in order to create preliminary canopy segments, from which the non-canopy elements were extracted to obtain the final canopy segmentation, i.e. the ground mask was analysed against the canopy mask. A manual classification of aerial images was employed to separate the canopy segments of deciduous trees from those of coniferous trees. Finally, linear discriminant analysis was applied to the correctly classified canopy segments of deciduous trees to classify them into segments belonging to aspen and those belonging to other deciduous trees. The independent variables used in the classification were obtained from the first pulse ALS point data. The accuracy of discrimination between aspen and other deciduous trees was 78.6%. The independent variables in the classification function were the proportion of vegetation hits, the standard deviation of in pulse heights, accumulated intensity at the 90th percentile and the proportion of laser points reflected at the 60th height percentile. The accuracy of classification corresponded to the validation results of earlier ALS-based studies on the classification of individual deciduous trees to tree species.

  12. Development and validation of the activity significance personal evaluation (ASPEn) scale.

    Science.gov (United States)

    Mallinson, Trudy; Schepens Niemiec, Stacey L; Carlson, Mike; Leland, Natalie; Vigen, Cheryl; Blanchard, Jeanine; Clark, Florence

    2014-12-01

    Engagement in desired occupations can promote health and wellbeing in older adults. Assessments of engagement often measure frequency, amount or importance of specific activities. This study aimed to develop a scale to measure older adults' evaluation of the extent to which their everyday activities are contributing to their health and wellness. Eighteen items, each scored with a seven-point rating scale, were initially developed by content experts, covering perceptions of how daily activities contribute to physical and mental health, as well as satisfaction and activity participation in the last six months. Rasch analysis methods were used to refine the scale using the pencil and paper responses of 460 community-living older adults. Initial Rasch analysis indicated three unlabelled rating scale categories were seldom used, reducing measurement precision. Five items were conceptually different by misfit statistics and principal component analysis. Subsequently, those items were removed and the number of rating scale steps reduced to 4. The remaining 13-item, 4-step scale, termed the Activity Significance Personal Evaluation (ASPEn), formed a unidimensional hierarchy with good fit statistics and targeting. Person separation reliability (2.7) and internal consistency (.91) indicated the tool is appropriate for individual person measurement. Relative validity indicated equivalence between Rasch measures and total raw scores. ASPEn is a brief, easily administered assessment of older adults' perception of the contribution of everyday activities to personal health and wellness. ASPEn may facilitate occupational therapy practice by enabling clinicians to assess change in meaning of an older adult's activity over time. © 2014 Occupational Therapy Australia.

  13. Fast growing aspens in the development of a plant micropropagation system based on plant-produced ethylene action

    International Nuclear Information System (INIS)

    Žiauka, Jonas; Kuusienė, Sigutė; Šilininkas, Mindaugas

    2013-01-01

    Representatives of the genus Populus (poplars), such as Populus tremula L. (European aspen) and its fast-growing hybrids, are recognized as being among the most suitable tree species for short rotation coppicing in Northern Europe. Several technologies have been developed for fast propagation of selected aspen genotypes, including laboratory (in vitro) micropropagation, which is usually based on the action of exogenous plant hormones. Seeking to minimize the use of the latter, the present study was designed to test if the conditions suitable for increased accumulation of plant-produced gas, including the gaseous plant hormone ethylene, inside a culture vessel could contribute to commercially desirable changes in aspen development. Shoot cultures of several European and hybrid (Populus tremuloides Michx. × P. tremula) aspen genotypes were studied using two different types of culture vessels: tightly sealed Petri dishes (15 × 54 mm) designed to provide restricted gas exchange (RGE) conditions, and capped (but not sealed) test tubes (150 × 18 mm) providing control conditions. Under RGE conditions, not only the positive impact of the ethylene precursors 1-aminocyclopropane-1-carboxylic-acid (ACC) and ethephon on shoot proliferation was demonstrated but also a several-fold increase, compared to the control conditions, in the mean shoot number per explant was recorded even on the hormone-free nutrient medium. Moreover, the shoots developed under RGE conditions were distinguished by superior rooting ability in the subsequent culture. These results suggest that a plant micropropagation system based on the action of plant-produced ethylene rather than of exogenous hormones is possible. -- Highlights: ► Aspen in vitro cultures were grown in different vessels. ► Small-volume vessels were used for restriction of gas exchange. ► Aspen explants produced most shoots in small-volume vessels. ► Shoot proliferation was increased due to explant response to ethylene.

  14. Heavy metals uptake by the hybrid aspen and rowan-tree clones

    Czech Academy of Sciences Publication Activity Database

    Malá, J.; Máchová, P.; Cvrčková, H.; Vaněk, Tomáš

    2007-01-01

    Roč. 53, č. 11 (2007), s. 491-497 ISSN 1212-4834 R&D Projects: GA ČR GA526/04/0135; GA MŠk 2B06187 Grant - others:Výzkumný ústav lesního hospodářství a myslivosti, v.v (CZ) OC 118 Institutional research plan: CEZ:AV0Z50380511 Source of funding: V - iné verejné zdroje ; V - iné verejné zdroje Keywords : phytoremediation * heavy metals * hybrid aspen Subject RIV: EB - Genetics ; Molecular Biology http://journals.uzpi.cz:8050/uniqueFiles/00437.pdf

  15. A simulation study of Solid Oxide fuel cell for IGCC power generation using Aspen Plus

    DEFF Research Database (Denmark)

    Rudra, Souman; Kim, Hyung Taek

    2010-01-01

    operating conditions and using diverse fuels. The SOFC stack model developed using the chemical process flow sheet simulator Aspen Plus which is of equilibrium type and is based on Gibbs free energy minimization. The SOFC model performs heat and mass balances and considers the ohmic, activation...... with respect to a variety of SOFC inputs. SOFC stack operation on syn-gas is compared to operation on different coal properties and as expected there is a drop in performance, which is attributed to increased input fuel and air flow due to the lower quality of the fuel gas....

  16. Elevated [CO2] magnifies isoprene emissions under heat and improves thermal resistance in hybrid aspen

    OpenAIRE

    Sun, Zhihong; H?ve, Katja; Vislap, Vivian; Niinemets, ?lo

    2013-01-01

    Isoprene emissions importantly protect plants from heat stress, but the emissions become inhibited by instantaneous increase of [CO2], and it is currently unclear how isoprene-emitting plants cope with future more frequent and severe heat episodes under high [CO2]. Hybrid aspen (Populus tremula x Populus tremuloides) saplings grown under ambient [CO2] of 380 ?mol mol?1 and elevated [CO2] of 780 ?mol mol?1 were used to test the hypothesis that acclimation to elevated [CO2] reduces the inhibito...

  17. Estimation of Physical Properties for Hydrogen Isotopes Using Aspen Plus Simulator

    International Nuclear Information System (INIS)

    Cho, Jung Ho; Yun, Sei Hun; Cho, Seung Yon; Chang, Min Ho; Kang, Hyun Goo; Jung, Ki Jung; Kim, Dong Min

    2009-01-01

    Hydrogen isotopes are H 2 , HD, D 2 , H 2 , HD, D 2 , HT, DT and T 2 . Among the hydrogen isotopes, the physical properties of H2, HD and D+2 are included in the Aspen Plus, however HT, D T and T 2 are not included. In this study, various thermodynamic properties were estimated for six components of isotopes by use of the fixed properties and temperature-dependent properties. To estimate thermodynamic properties, Soave modified Redlich-Kwong equation of state and Aspenplus simulator was used. The results were verified and compared with by PRO/II with PROVISION of Invensys

  18. Utilization of steam- and explosion-decompressed aspen wood by some anaerobes

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A W; Asther, M; Giuliano, C

    1984-01-01

    Tests made to study the suitability of using steam- and explosion-decompressed aspen wood as a substrate in anaerobic fermentations indicated that after washing with dilute NaOH it becomes less than 80% accessible to both mesophilic and thermophilic cellulolytic anaerobes and cellulases, compared with delignified, ball-milled pulp. After washing, this material was also suitable for the single-step conversion of cellulose to EtOH using cocultures consisting of cellulolytic and EtOH-producing saccharolytic anaerobes; and without and after washing by the use of cellulolytic enzymes and ethanologenic anaerobes.

  19. Microscale Ocean Biophysics, Aspen Center for Physics: January 11-16 2015

    Science.gov (United States)

    2017-04-19

    dissolved   organic  matter  persist  in  the  deep  ocean:  Is  the  solution   dilution ?”     8.45  –  Kwangmin  Son...AUTHORS 7. PERFORMING ORGANIZATION NAMES AND ADDRESSES 15. SUBJECT TERMS b. ABSTRACT 2. REPORT TYPE 17. LIMITATION OF ABSTRACT 15. NUMBER OF PAGES...Microscale Ocean Biophysics, Aspen Center for Physics, January 11-16, 2015 Microscopic organisms control ocean processes at global scales. However

  20. Sociedad civil: una interpretación y una trayectoria

    Directory of Open Access Journals (Sweden)

    Pérez-Díaz, Víctor

    1996-04-01

    Full Text Available Not available.

    El lector me permitirá quizá que le explique de entrada el propósito y el alcance de este brevísimo ensayo, anticipándole los temas de las tres partes que lo componen. Primero, explico lo que quiero decir con la expresión «sociedad civil». Con este fin, describo un tipo o carácter ideal de sociedad civil, en torno al cual he organizado un esquema conceptual que utilizo desde hace años en un amplio programa de investigación en ciencia social; y esbozo las líneas de demarcación entre mi uso de esa expresión y otros usos que se han hecho y se hacen tic ella. Segundo, reelaboro el proceso por el que comencé a utilizar este concepto a mediados de los años setenta. Se trata de un esbozo de reconstrucción, hipotético y fragmentario, del contexto de descubrimiento de aquel esquema conceptual. Es un flash back que me lleva de los primeros sesenta (podría haberme llevado más atrás a mi libro Estado, burocracia y sociedad civil, que escribí en 1976 (Pérez- Díaz, 1978. Tercero, tomo nota de los cambios en mi posición a lo largo de estos años, y me interrogo sobre algunos de los problemas que me han llevado de la concepción de 1976 a la que expongo en La primacía de la sociedad civil de 1993 (Pérez- Díaz, 1993, y en mis trabajos ulteriores, donde hay un desplazamiento sistemático del énfasis de mi trabajo desde lo que Hamo (en la Primada «sociedad civil sensu stricto» hacia la «sociedad civil sensu lato». La explicación podría radicar en la necesidad de revisar, ampliar y formalizar el esquema «acomodándolo»: uno, al proceso en curso de mis trabajos de investigación empírica, y a la importancia creciente en esos trabajos de los temas de autoridad pública, esfera pública y política pública; dos, al horizonte histórico del whithcring away del totalitarismo comunista; y tres, a mi interés creciente en los temas de tradición, instituciones y retórica. Aunque los

  1. Sociedad civil: una concepción radical

    Directory of Open Access Journals (Sweden)

    Domingo García Marzá

    2012-02-01

    Full Text Available El presente trabajo tiene como objetivos presentar un concepto de sociedad civil desde una perspectiva crítica, una perspectiva que pueda dar razón del potencial de cambio y transformación social que encierra este ámbito de la interacción social. Con este fin, se adentra en primer lugar en la difícil relación entre democracia y sociedad civil, analizándola desde el paso de las democracias participativas a las democracias deliberativas. El carácter global de la sociedad civil y los problemas de realización práctica nos conducen, en segundo lugar, a la discusión de la propuesta de autores como J. Habermas y M. Kaldor, destacando las insuficiencias de sus respectivos enfoques. A continuación, y en discusión con los trabajos de J. Keane, se presenta una propuesta de definición y fundamentación del concepto de sociedad civil apoyado en una hermenéutica crítica, capaz de justificar su núcleo moral como ética de la sociedad civil y, al mismo tiempo, de sus posibilidades reales de aplicación. Por último, se propone el concepto de recursos morales para reconstruir las características básicas que definen a los recursos propios de la sociedad civil.The objective of this paper is to present a concept of civil society from a critical perspective that can explain the potential for change and social transformation encompassed within this sphere of social interaction. To this end, we first explore the difficult relationship between democracy and civil society, through an analysis of the shift from participative to deliberative democracy. The global character of civil society and the problems of its practical achievement lead us, in a second stage, to discuss proposals from authors such as J. Habermas and M. Kaldor, and to uncover the inadequacies of their respective approaches. This is followed by a proposal, arising from debate on the works of J. Keane, in which the concept of civil society is defined and grounded

  2. A study of polymerization of aspen (Populus) wood lipophilic extractives by SEC and Py-GC/MS

    CSIR Research Space (South Africa)

    Sithole, Bruce

    2013-03-01

    Full Text Available ) Orig inal manuscript received 13 June 2012, revision accepted 31 October 2012 Vol 66 No 1 January - March 2013 1 PEER REVIEWED A study of polymerization of aspen (Populus) wood lipophilic extractives by SEC and Py-GC/MS BRUCE SITHOLE1*, LUC... of polymerized wood resin that will be difficult to remove if present in pulp and paper products. On the other hand, these problems may be minor compared to using unseasoned wood. KEYWORDS: Aspen, extractives, polymerization, size exclusion chromatography, Py...

  3. Impacts of climate and insect defoliators on productivity and function of trembling aspen (Populus tremuloides) in Alaskan boreal forests

    Science.gov (United States)

    Boyd, M. A.; Walker, X. J.; Rogers, B. M.; Goetz, S. J.; Wagner, D.; Mack, M. C.

    2017-12-01

    Climate change has increased tree mortality and growth decline in forested ecosystems worldwide. In response to warming and drying of the boreal forest, trembling aspen (Populus tremuloides) has experienced recent large-scale productivity declines. Although declines in productivity are thought to be primarily a result of moistures stress, infestation is another major driver of aspen decline and may interact strongly with climate. Throughout interior Alaska widespread and consistent foliar damage by the aspen epidermal leaf miner Phyllocnistis populiella has been observed concurrent with some of the warmest and driest growing seasons on record. Here we use tree ring measurements and remote sensing indices of vegetation productivity (NDVI) to study the influence of leaf miner and climate on aspen productivity and physiology in the Alaskan boreal forest, and assess if NDVI reflects variations in these ground-based measurements. We assessed ring width and tree ring stable carbon isotope (d13C) response of aspen to infestation and a climate moisture index (CMI) from 2004 - 2014. We found that when growth was negatively correlated to infestation, then it was no longer positively influenced by moisture availability during the growing season. Regardless of the radial growth response to leaf mining, tree ring d13C decreased with increasing infestation. We also found that NDVI was influenced by leaf mining and showed a positive correlation with tree ring d13C, which suggests that NDVI is reflective of changes in tree characteristics under leaf mining that influence tree ring d13C. This finding also reveals the prospect of using satellite data to monitor fluctuations in tree physiology during leaf miner infestation. Our results indicate that aspen productivity will be severely hindered during leaf miner infestation, and that infestation will inhibit the ability of aspen to respond to favorable climate conditions by increasing growth and potentially photosynthesis. This

  4. Contemporaneidade: uma psicopatia americana? Contemporaneidad: ¿una psicopatía americana? Contemporaneity: an american psychopathy?

    Directory of Open Access Journals (Sweden)

    Simone Martins

    2008-03-01

    Full Text Available A herança recebida pela contemporaneidade inclui, entre outras características, a racionalidade, as normatizações, a influência da ciência, certa busca por legitimações e uma valorização das permanências. O objetivo deste artigo é questionar alguns desses conceitos tão arraigados no Ocidente utilizando recortes do livro "O psicopata americano", de Bret Easton Ellis, como ilustração e ponto de partida para refletir acerca de alguns aspectos. A tendência a diagnósticos individuais e a busca por anomalias que sejam respostas a questionamentos de uma sociedade que não se responsabiliza pelas margens que estipula, demonstram a compreensão de que o mal pode e deve ser controlado em favor da cidadania dos considerados normais. Questionar, refletir e se responsabilizar é princípio de mudanças sociais para além da simples repressão do diferente; e perceber que há um pouco deste diferente em cada um é repensar os papéis determinados socialmente.La herencia recibida por la contemporaneidad incluye, entre otras características, la racionalidad, las normatizaciones, la influencia de la ciencia, la búsqueda por la legitimación y la valorización de las permanencias. El objetivo de este artículo es cuestionar algunos de esos conceptos tan arraigados en el Occidente, utilizando partes del libro "O psicopata americano" de Bret Easton Ellis, como ilustración y punto de partida para reflexionar sobre algunos aspectos. La tendencia a diagnósticos individuales y la búsqueda por anomalías que respondan a cuestiones de una sociedad que no asume la responsabilidad por las márgenes que determina, demuestran la comprensión de que el malo puede y debe ser controlado en favor de la ciudadanía de los considerados normales. Cuestionar, reflexionar y responsabilizarse es principio de transformaciones sociales más allá de la simple represión de lo diferente. Y percibir que existe un poco de este diferente en cada uno es repensar los

  5. Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae against Periplaneta americana(L.

    Directory of Open Access Journals (Sweden)

    I Ling A

    2009-12-01

    Full Text Available Background: The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory."nMethods: The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme."nResults: Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same con­centrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cock­roaches. Treatment with Resigen (R at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the fe­males, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach."nConclusion: Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peri­patetic americana. "nKeywords: Piper aduncum essential oil, Periplaneta americana, Adults, Nymphs

  6. Universidad, sociedad y conocimiento: reflexiones para el debate

    Directory of Open Access Journals (Sweden)

    Norberto Fernández Lamarra

    2014-11-01

    Full Text Available El artículo presenta algunas reflexiones sobre la relación actual entre universidad, sociedad y políticas del conocimiento en Latinoamérica. Para ello, parte de considerar la situación pasada y presente de la educación superior en la región pero a la vez plantea sus interrogantes mirando hacia el futuro de los niños y jóvenes que hoy transitan las aulas de los sistemas educativos. Se consideran 4 ejes de análisis: "la Universidad que América Latina hubiese tenido", "la Universidad que tenemos", "Universidad y sociedad: su democratización" y "Universidad y conocimiento: la innovación". A través de ellos, y partiendo de un diagnóstico de la situación actual de los sistemas educativos en la región, sus mandatos fundacionales y sus promesas aún no cumplidas, se postula la necesidad de innovar. A modo de ejemplo, se plantea una reflexión a partir de los primeros resultados de una investigación desarrollada por el NIFEDE (UNTREF sobre la innovación en las universidades públicas en Argentina. El artículo concluye con algunas propuestas para una nueva Universidad en América Latina que se plantean en dos dimensiones. En primer lugar, una serie de desafíos que deben enfrentar las políticas para la educación superior en la región y en segundo lugar los desafíos que deben enfrentar las propias instituciones de nivel superior para que esas políticas logren los resultados que la Sociedad del Conocimiento hoy demanda a la Universidad.

  7. La Sociedad del Conocimiento y el Fin de la Escuela

    OpenAIRE

    Rodríguez Rojas, Pedro

    2004-01-01

    Educere:Una Brizna de Aliento en el Tiempo Rivas, Pedro El Paradigma Reinante y su Paideia Alonso, Leonor La Experiencia Contemporánea como Expresión del Fin de una ÉticaAlgunas Ideas desde la Postmodernidad para Releer el Dato Educativo Perdomo, José Camilo La Sociedad del Conocimiento y el Fin de la Escuela Rodríguez Rojas, Pedro Escuela, Alteridad y Experiencia de SíLa Producción Pedagógica del Sujeto Valera Villegas, G...

  8. Responsabilidad de directores de sociedades en Estados Unidos. Aspectos procesales

    Directory of Open Access Journals (Sweden)

    Héctor José Miguens

    2015-01-01

    El objeto de este artículo es describir este régimen en su totalidad y realizar un juicio crítico de las normas que rigen las acciones procesales de la responsabilidad de los directores de sociedades comerciales en el derecho societario en Estados Unidos. La metodología utilizada en este trabajo responde a la sistemática de los autores norteamericanos citados, que se caracteriza por centrarse en los aspectos prácticos, la solución de problemas particulares y el comentario crítico de la jurisprudencia aplicable a la cuestión.

  9. México hacia una sociedad del conocimiento

    OpenAIRE

    Héctor Carreón Mendoza; Ricardo Melgoza Ramos

    2012-01-01

    Es importante para México convertirse en una sociedad del conocimiento, con una clara estrategia en su plan de desarrollo con respecto a la inversión en: transferencia tecnológica, incremento del capital intelectual, mayor vinculación de los sectores nacionales que generan ciencia y la generación de políticas públicas que incentiven la innovación en ciencia y tecnología y la protección de la propiedad intelectual.

  10. IMPACTO DE LAS CATÁSTROFES NATURALES EN SOCIEDADES COLONIALES

    OpenAIRE

    Margarita Gascón

    2005-01-01

    En este trabajo resaltamos la relación entre la dinámica de una sociedad y los cambios operados por catástrofes masivas, tanto en lo material como en la economía, la política y las ideas y valores religiosos. Examinamos casos coloniales, como la erupción del volcán Villarrica (1640) en el sur de Chile y otros terremotos destructivos del siglo XVII. Adoptaremos una perspectiva comparativa para mostrar cómo las catástrofes modifican las condiciones locales y provocan cambios en la vida de las s...

  11. De la accion comunicativa a la sociedad democratica

    Directory of Open Access Journals (Sweden)

    J. Félix Ángulo Rasco

    1998-08-01

    Full Text Available Defendendo uma ética da comunicação como condição da construção de uma sociedade democrática de indivíduos emancipados, o texto traz uma reflexão sobre os fundamentos da ética comunicativa de Habermas, a partir da distinção entre dois campos de desenvolvimento discursivo: o discurso teórico e o discurso prático.

  12. A UNIVERSIDADE E A "SOCIEDADE DA INFORMAÇÃO" LA UNIVERSIDAD Y LA "SOCIEDAD DE LA INFORMACIÓNS

    Directory of Open Access Journals (Sweden)

    Maria Nélida González de Gómez

    2011-07-01

    Full Text Available Podemos dizer que a Sociedade da Informação ocupa o lugar e assume as expectativas que outrora eram projetadas na Modernidade. Para Habermas, o entendimento do presente passa por pensar no avançar desde e além da modernidade parcial, não já como superada (como quando se fala da pós-modernidade, nem como uma ficção a ser simplesmente negada (como quando se afirma que jamais fomos modernos. Trata-se de pensar, com esses pontos de partida, se estamos hoje a buscar soluções vicariantes ao déficit sistêmico daquela modernidade incompleta, ou se, superando uma modernização periférica ou tardia, empreendemos caminhos auto-reflexivos e inovadores para definir e construir novas configurações do conhecimento, da comunicação e da informação. Como resposta às demandas das quais a Sociedade da Informação é ao mesmo tempo sintoma, apelação e desafio, as Universidades do Brasil e da América Latina tem em suas mãos o poder e a dívida de nutrir as variáveis epistêmicas de processos e práticas auto-reflexivos, gerando novas formas de um diálogo polifônico entre as esferas quase-públicas das Ciências, as plurais redes das tradições locais e os dilemas universais, que colocam hoje um novo cosmopolitismo informacional à luz de um repensar geral do devir da humanidade. Palavras-chave Sociedade da informação; Universidade; Bibliotecas universitárias Resumen Podemos decir que la sociedad de la información ocupa el lugar y asume las expectativas que ya fueran proyectadas sobre la Modernidad. Para Habermas, entender el presente es pensar en avanzar desde y mas allá de una modernidad parcial, ni superada(como cuando se habla de la pós-modernidad, ni puramente una ficción a se negada (diciendo que nunca fuimos modernos. Se piensa, con esos puntos de partida, si hoy buscamos soluciones vicarias del déficit sistémico de aquella modernidad incompleta, o si, superando una modernización periférica o tardía, iniciamos caminos

  13. Preparation of Highly Porous Binderless Active Carbon Monoliths from Waste Aspen Sawdust

    Directory of Open Access Journals (Sweden)

    Dawei Li

    2014-01-01

    Full Text Available Waste aspen sawdust was used as a precursor to prepare binderless active carbon monoliths (ACMs with high porosities. The ACMs were prepared by activation with H3PO4 at different activation temperatures (500 to 700 °C and retention times (1 to 3 h. Their morphologies, yields, textural properties, and microcrystalline structures were investigated using scanning electron microscopy (SEM, an analytical balance, N2 adsorption/desorption techniques, and X-ray diffraction (XRD. The results indicated that waste aspen sawdust could be successfully converted into highly porous binderless ACMs. The apparent specific surface area (SSA and yield of ACMs were in the range of 688 to 951 m2/g and 26.6 to 36.2%, respectively. Highly microporous ACMs with a micropore percentage of 91.1%, apparent specific surface area of 951 m2/g, pore volume of 0.481 mL/g, and bulk density of 0.56 g/mL could be produced by activation at 700 °C for 1 h. Increasing the activation temperature or retention time increased the specific surface area, pore volume, and turbostratic degree, but decreased the yield.

  14. Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification.

    Science.gov (United States)

    Pawar, Prashant Mohan-Anupama; Ratke, Christine; Balasubramanian, Vimal K; Chong, Sun-Li; Gandla, Madhavi Latha; Adriasola, Mathilda; Sparrman, Tobias; Hedenström, Mattias; Szwaj, Klaudia; Derba-Maceluch, Marta; Gaertner, Cyril; Mouille, Gregory; Ezcurra, Ines; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J

    2017-06-01

    High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter::GUS lines in hybrid aspen (Populus tremula × tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  15. Vegetation of birch and aspen forests in the Pinega State Reserve

    Directory of Open Access Journals (Sweden)

    Sergey Yu. Popov

    2017-05-01

    Full Text Available The Pinega State Nature Reserve (Russia is located in the Arkhangelsk region in the northern taiga subzone. Together with spruce forests and mires, birch forests represent one of the most wide-spread plant communities of its territory. Birch forests cover 24.6% of the Reserve's area. Aspen forests are rare plant communities in the Pinega Reserve. These forests cover only 0.9% of the whole Reserve's area. The birch and aspen forests vegetation has been classified based on 82 relevès. Eleven associations could be distinguished, which represent six groups of associations. Detailed characteristics of these syntaxa are provided including their biodiversity analysis. The analysis allowed establishing that the revealed syntaxa differ in relation to habitat environmental conditions: e.g., soil moisture, trophicity, nitrogen saturation and soil acidity. Sphagnum and blueberry birch forests proved to be the poorest in nitrogen, in contrast to the richest humidoherbaceous and broad-grassed groups of birch forest associations. Broad-grassed birch forests in the Pinega Reserve inhabit the most drained locations, while humidoherbaceous and Sphagnum forests occur in lesser drained locations.

  16. Urbanization-related changes in European aspen (Populus tremula L.): Leaf traits and litter decomposition

    International Nuclear Information System (INIS)

    Nikula, Suvi; Vapaavuori, Elina; Manninen, Sirkku

    2010-01-01

    We investigated foliar and litter responses of European aspen (Populus tremula L.) to urbanization, including factors such as increased temperature, moisture stress and nitrogen (N) deposition. Leaf samples were collected in 2006-2008 from three urban and three rural forest stands in the Helsinki Metropolitan Area, southern Finland, and reciprocal litter transplantations were established between urban and rural sites. Urban leaves exhibited a higher amount of epicuticular waxes and N concentration, and a lower C:N ratio than rural ones, but there was no difference in specific leaf area. Urban litter had a slightly higher N concentration, lower concentrations of lignin and total phenolics, and was more palatable to a macrofaunal decomposer. Moreover, litter decay was faster at the urban site and for urban litter. Urbanization thus resulted in foliar acclimatization in terms of increased amount of epicuticular waxes, as well as in accelerated decomposition of the N-richer leaf litter. - Urbanization can modify leaf traits of aspen and accelerate litter decomposition through changes in litter traits as well as in environmental conditions at the decomposition site.

  17. UN HELICTERES NUEVO DE MEXICO, NEXO ENTRE LAS ESPECIES ASIATICAS y AMERICANAS

    Directory of Open Access Journals (Sweden)

    Carmen L. Cristóbal

    1987-01-01

    Full Text Available Una nueva especie, Helicteres vegae (Sterculiaceae, de Sinaloa, México es descripta e ilustrada. Se encontró el número de cromosomas 2n = 18. H. vegae se compara con el resto de las especies mexicanas y se proporciona una clave. Su afinidad con la de Asia y las especies americanas es discutida. H. vegae junto con H. Rekoí y H.carthagenensis se consideran las más diferenciadas de las especies americanas. Se propone una posible área de origen de América para Helicteres , incluido en esta área se encuentran los otros dos nuevos géneros mundiales de la tribu Helictereae.

  18. Applications of Microencapsulated Bifidobacterium Longum with Eleutherine Americana in Fresh Milk Tofu and Pineapple Juice

    Science.gov (United States)

    Phoem, Atchara N.; Chanthachum, Suphitchaya; Voravuthikunchai, Supayang P.

    2015-01-01

    Bifidobacterium longum was microencapsulated by extrusion technique and added in fresh milk tofu and pineapple juice. Microencapsulation of B. longum with Eleutherine americana extract, oligosaccharides extract, and commercial fructo-oligosaccharides was assessed for the bacterial survival after sequential exposure to simulated gastric and intestinal juices, and refrigeration storage. Microencapsulated B. longum with the extract and oligosaccharides extract in the food products showed better survival than free cells under adverse conditions. Sensory analysis demonstrated that the products containing co-encapsulated bacterial cells were more acceptable by consumers than free cells. Pineapple juice prepared with co-encapsulated cells had lower values for over acidification, compared with the juice with free cells added. This work suggested that microencapsulated B. longum with E. americana could enhance functional properties of fresh milk tofu and pineapple juice. PMID:25854832

  19. Applications of Microencapsulated Bifidobacterium Longum with Eleutherine Americana in Fresh Milk Tofu and Pineapple Juice

    Directory of Open Access Journals (Sweden)

    Atchara N. Phoem

    2015-04-01

    Full Text Available Bifidobacterium longum was microencapsulated by extrusion technique and added in fresh milk tofu and pineapple juice. Microencapsulation of B. longum with Eleutherine americana extract, oligosaccharides extract, and commercial fructo-oligosaccharides was assessed for the bacterial survival after sequential exposure to simulated gastric and intestinal juices, and refrigeration storage. Microencapsulated B. longum with the extract and oligosaccharides extract in the food products showed better survival than free cells under adverse conditions. Sensory analysis demonstrated that the products containing co-encapsulated bacterial cells were more acceptable by consumers than free cells. Pineapple juice prepared with co-encapsulated cells had lower values for over acidification, compared with the juice with free cells added. This work suggested that microencapsulated B. longum with E. americana could enhance functional properties of fresh milk tofu and pineapple juice.

  20. Pathogenicity of Aspergillus westerdijkiae to females and oothecae of Periplaneta Americana

    Directory of Open Access Journals (Sweden)

    Mariah Valente Baggio

    2016-01-01

    Full Text Available ABSTRACT: Cockroach control is performed by the application of chemical insecticides which exert high selective pressure on populations and introduces synthetic substances in the environment, motivating the search for other methods of control such as entomopathogenic fungi. The objectives of this study were to investigate the pathogenicity of the JAB 42 Aspergillus westerdijkiae to females and oothecae of Periplaneta americana and to demonstrate its mechanism of action on oothecae. Suspensions containing 106 to 108 conidia/ml were used to infect females and oothecae. Mortality and other variables such as scanning electron microscopy were used to demonstrate the mechanism of action of the fungus. The isolated JAB 42 A. westerdijkiae is pathogenic to oothecae of P. americana, with low capacity to kill females. Adhesion, germination, penetration and extrusion of the fungus on the cockroach oothecae were observed.

  1. Manganese uptake and interactions with cadmium in the hyperaccumulator-Phytolacca Americana L

    Energy Technology Data Exchange (ETDEWEB)

    Peng Kejian [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Hunan Research Academy of Environmental Sciences Changsha 410004 (China); Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); You Wuxin [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Lian Chunlan [Asian Natural Environmental Science Center, University of Tokyo, 1-1-8 Midori-cho, Nishitokyo, Tokyo 188-0002 (Japan); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Shen Zhenguo [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China)], E-mail: zgshen@njau.edu.cn

    2008-06-15

    In the present study, the accumulation of Mn and other metals by Phytolacca Americana L. from contaminated soils in Hunan Province, South China, was investigated. Results showed that the average concentrations of Mn in the leaves and roots reached 2198 and 80.4 mg kg{sup -1} (dry weight), respectively, with a maximum 13,400 mg kg{sup -1} in the leaves. A significant correlation was found between Mn concentrations in the plant leaves and those in the corresponding soils. Hydroponic experiments were also conducted to study the Cd uptake ability and interactions between Mn and Cd in the plant. It was found that P. americana hyperaccumulated not only Mn, but also Cd in the leaves. In the presence of Cd, adding Mn to the solution significantly improved the plant growth and reduced the concentrations of Cd in all organs of the plant.

  2. La educación comparada en una sociedad global

    Directory of Open Access Journals (Sweden)

    José Luis García Garrido

    1997-01-01

    Full Text Available Intenta el autor ofrecer un cuadro de referencia de 10 que va a suponer, para la educacion comparada en cuanto disciplina cientifica y academica, el advenimiento del siglo XXI y, con él,el de una sociedad humana globalizada. Se refiere en concreto a los nuevos desafios presentes ya hoy, particularmente los derivados de la globalizacion económica, cultural y social, asi como a los nuevos recursos con que puede y podra contarse, sobre todo los relativos a la tecnologia de la comunicación. Exarnina, a modo de ejemplo, dos enfoques metodológicos defendidos recientemente como especialmente adecuados a las necesidades del momento, estableciendo sus pros y contras. Y finaliza con una llamada de atención hacia la necesidad de que la educacion comparada, en la sociedad giobalizada del siglo XXI, profundice sus planteamientos epistemológicos por la via de una mayor ret1exion histórica, cultural y filosofica de los sistemas educacionales

  3. Hume, Smith e as etapas da sociedade comercial

    Directory of Open Access Journals (Sweden)

    Rogério Arthmar

    Full Text Available Resumo O artigo trata das concepções de David Hume e de Adam Smith sobre o ressurgimento da sociedade comercial na Europa após o feudalismo. Parte-se de breve exposição dos princípios filosóficos de Hume a fim de se apresentar suas teses referentes ao assunto na obra History of England. Mostra-se como ele associa o movimento parlamentar pela liberdade na Inglaterra com o progresso do comércio ocasionado pelo consumo de luxo da nobreza. Posteriormente, revisa-se a posição de Smith sobre os obstáculos à riqueza, bem como sua explicação para a decadência das civilizações grega e romana. Evidencia-se ainda como a interpretação smithiana do advento da sociedade comercial moderna apoia-se na versão antecipada por Hume. Por fim, destacam-se as implicações do conflito central entre predação e produção presente nas teorias do desenvolvimento de longo prazo da humanidade elaboradas por ambos os autores.

  4. Sociedad y naturaleza en la mitología Muisca

    Directory of Open Access Journals (Sweden)

    François Correa Rubio

    2005-01-01

    Full Text Available Analizando la mitología de los muiscas ilustraré cómo se trata de un discurso que puede guiar el comportamiento social porque esta constituido por un conjunto de abstracciones que, en el lenguaje simbólico, expresan el conocimiento de la sociedad sobre sus propias relaciones y de estas con la naturaleza. El análisis evidencia cómo el sol y la luna eran los símbolos dominantes no sólo por su importancia en el ordenamiento del tiempo y espacio del universo y, en consecuencia, en las tareas cotidianas, sino cómo su comportamiento pretendía ser explicado a semejanza de la estabilidad y variabilidad de las relaciones sociales. Argumentaré que esta analogía entre el comportamiento de los astros y las gentes constituye un operador lógico en el que descansa la simbología. Los mitos no son, pues, fantasía, ni en ellos «todo puede suceder». Son construcciones culturales que expresan en un discurso codificado, conocimientos de la experiencia que la sociedad debe seguir para garantizar su propia reproducción social.

  5. Educación compleja: Indisciplinar la sociedad

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Maldonado

    2017-07-01

    Full Text Available Este artículo de investigación es eminentemente crítico y propositivo. Se plantea aquí la tesis de una educación modo complejo, la cual consiste, específicamente, en una indisciplinarización del conocimiento, de la sociedad y de las instituciones. Se aportan, por consiguiente, los argumentos que hacen posible comprender esta tesis. En primer lugar, se muestra qué y cómo la historia de Occidente ha sido la historia de la disciplinarización de la sociedad. Sobre esta base, el segundo argumento establece lo que puede ser considerado como el estado del arte de la indisciplinariedad. Seguidamente, se justifica por qué razón tiene sentido afirmar aquí la indisciplinarización del conocimiento. El cuarto argumento se concentra entonces en una educación modo complejo (que es mucho mejor que hablar de una educación compleja. Al final se extraen algunas conclusiones.

  6. Deporte y modernidad: caso Colombia. Del deporte en sociedad a la deportivización de la sociedad

    OpenAIRE

    David Leonardo Quitián Roldán

    2013-01-01

    El deporte es, quizá, la expresión más potente de la modernidad: surge con la industrialización y la urbanización, teniendo como epicentro los clubes londinenses. Sin embargo, su difusión desde la metrópoli victoriana y la apropiación de los principios morales que encarnaba en cada sociedad merece un escrutinio detallado, considerando escenarios de lucha, como su popularización a través de expresiones como el fútbol y el ciclismo. El presente artículo pretende realizar un recorrido analítico ...

  7. Effects of long-term (10 years) exposure to elevated CO2 and O3 on trembling Aspen carbon and nitrogen metabolism at the aspen FACE (Free-Air Carbon Dioxide Enrichment) study site

    Science.gov (United States)

    Rakesh Minocha; Stephanie Long; Subhash Minocha; Paula Marquardt; Neil Nelson; Mark. Kubiske

    2010-01-01

    This study was conducted at the Aspen Free-Air Carbon Dioxide Enrichment (FACE) experimental site, Rhinelander, WI, (USA). Since 1998, 12 experimental rings planted in 1997 underwent four different treatments: control; elevated CO2 (560 ppm); elevated O3 (1.5X ambient) and elevated CO2 (560 ppm) + O...

  8. The Future of Community and Personal Identity in the Coming Electronic Culture. A Report of the Annual Aspen Institute Roundtable on Information Technology (3rd, Aspen, Colorado, August 18-21, 1994).

    Science.gov (United States)

    Bollier, David

    The 1994 Aspen Institute Roundtable on Information Technology began as a look at the changing nature of the home. In building scenarios of the "new home," the participants expressed many significant insights into issues of personal identity, community-building, and setting boundaries in our lives and environments. This report captures…

  9. Identification of Heterobilharzia americana infection in a dog residing in Indiana with no history of travel.

    Science.gov (United States)

    Rodriguez, Jessica Y; Camp, Joseph W; Lenz, Stephen D; Kazacos, Kevin R; Snowden, Karen F

    2016-04-01

    A 1-year-old castrated male dog residing in Indiana was examined because of intermittent vomiting of 4 months' duration. The dog's condition did not resolve with medication. Diagnostic imaging revealed a possible partial obstruction at the ileocecal junction. An exploratory laparotomy was performed. The jejunum contained diffusely distributed, nodular, intramural lesions; 2 biopsy specimens were collected from representative lesions. The pancreas was grossly swollen, and pancreatitis was presumed present. No other abnormalities were observed in the abdomen. Histologic examination of the submitted biopsy specimens revealed infection with Heterobilharzia americana. After diagnosis, the dog was treated with fenbendazole suspension (48 mg/kg [21.8 mg/lb], PO, q 24 h) for 10 days. This treatment was subsequently repeated 11 and 80 days later. One week after the end of the last fenbendazole treatment, several H americana eggs were detected in a fecal sample via saline sedimentation, and the dog was given praziquantel (25 mg/kg [11.4 mg/lb], PO, q 8 h) for 2 days. No gastrointestinal signs were evident 4 months after that treatment. The dog described in this report was the first autochthonous canine case of H americana infection in Indiana, to the authors' knowledge; this case has confirmed that the distribution of this parasite in the Midwestern United States is broader than previously known. Increased awareness of the distribution of H americana should aid veterinarians in early, noninvasive diagnosis and appropriate treatment of affected animals. Repeated treatments and recheck fecal examinations may be necessary when managing these cases.

  10. Pistil Starch Reserves at Anthesis Correlate with Final Flower Fate in Avocado (Persea americana)

    OpenAIRE

    Alcaraz, Mar?a Librada; Hormaza, Jos? Ignacio; Rodrigo, Javier

    2013-01-01

    A common observation in different plant species is a massive abscission of flowers and fruitlets even after adequate pollination, but little is known as to the reason for this drop. Previous research has shown the importance of nutritive reserves accumulated in the flower on fertilization success and initial fruit development but direct evidence has been elusive. Avocado (Persea americana) is an extreme case of a species with a very low fruit to flower ratio. In this work, the implications of...

  11. One pot phytosynthesis of gold nanoparticles using Genipa americana fruit extract and its biological applications

    International Nuclear Information System (INIS)

    Kumar, Brajesh; Smita, Kumari; Cumbal, Luis; Camacho, Javier; Hernández-Gallegos, Elisabeth; Guadalupe Chávez-López, María de; Grijalva, Marcelo; Andrade, Kleber

    2016-01-01

    In this article, rapid one pot synthesis of gold nanoparticles (GNPs) using an eco-friendly extract of Genipa americana L. fruit is described. Electrospray ionization mass spectrometry (ESI-MS) and Fourier transform infrared (FTIR) spectroscopic studies demonstrated that small molecules such as genipin, genipaol, geniposide and ranolazine can act as reducer as well as stabilizers. The monodispersed, spherical GNPs were further characterized by UV–vis spectroscopy at λ max = 535 nm, transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray diffraction (XRD) analysis. This synthetic approach offers a greener and alternate route to the preparation of GNPs free from toxic chemical components and stable for 6–7 months under room temperature. The green synthesized GNPs showed weak antioxidant efficacy against 1,1-diphenyl-2-picrylhydrazyl and no cytotoxicity against A-549 and HeLa human cancer cell lines, from lung and cervix. This study opens a new industrial scope of G. americana fruit in nanoscience and as surface modified GNPs can be developed into a successful drug carrier for future pharmaceutical products. - Highlights: • Gold nanoparticles can be synthesized by Genipa americana fruit extract. • TEM-DLS analysis confirmed that the average particle size is 30.4 ± 14.9 nm. • Nanoparticles showed weak antioxidant and no cytotoxicity activity.

  12. One pot phytosynthesis of gold nanoparticles using Genipa americana fruit extract and its biological applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Brajesh, E-mail: krmbraj@gmail.com [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador); Smita, Kumari; Cumbal, Luis [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador); Camacho, Javier [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador); Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Departamento de Farmacología, C.P. 07360 Mexico City (Mexico); Hernández-Gallegos, Elisabeth; Guadalupe Chávez-López, María de [Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Departamento de Farmacología, C.P. 07360 Mexico City (Mexico); Grijalva, Marcelo; Andrade, Kleber [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador)

    2016-05-01

    In this article, rapid one pot synthesis of gold nanoparticles (GNPs) using an eco-friendly extract of Genipa americana L. fruit is described. Electrospray ionization mass spectrometry (ESI-MS) and Fourier transform infrared (FTIR) spectroscopic studies demonstrated that small molecules such as genipin, genipaol, geniposide and ranolazine can act as reducer as well as stabilizers. The monodispersed, spherical GNPs were further characterized by UV–vis spectroscopy at λ{sub max} = 535 nm, transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray diffraction (XRD) analysis. This synthetic approach offers a greener and alternate route to the preparation of GNPs free from toxic chemical components and stable for 6–7 months under room temperature. The green synthesized GNPs showed weak antioxidant efficacy against 1,1-diphenyl-2-picrylhydrazyl and no cytotoxicity against A-549 and HeLa human cancer cell lines, from lung and cervix. This study opens a new industrial scope of G. americana fruit in nanoscience and as surface modified GNPs can be developed into a successful drug carrier for future pharmaceutical products. - Highlights: • Gold nanoparticles can be synthesized by Genipa americana fruit extract. • TEM-DLS analysis confirmed that the average particle size is 30.4 ± 14.9 nm. • Nanoparticles showed weak antioxidant and no cytotoxicity activity.

  13. La empresa familiar y su organización en forma de sociedad mercantil, con especial referencia a la sociedad de responsabilidad limitada

    Directory of Open Access Journals (Sweden)

    María Angustias Díaz Gómez

    2011-06-01

    Full Text Available En este trabajo, tras unas consideraciones generales sobre la Empresa Familiar, analizamos, en primer lugar, los tipos sociales mercantiles que puede adoptar en España la Sociedad Familiar, haciendo un repaso de las formas sociales típicas reconocidas por el legislador, reflexionando sobre sus ventajas e inconvenientes. En segundo lugar, nos centramos en el estudio del régimen jurídico de las dos Sociedades Capitalistas más representativas, la Sociedad Anónima y la Sociedad de Responsabilidad Limitada, analizando sus rasgos comunes, todo ello con el fin de dilucidar cuál se adapta mejor a las particularidades de la Sociedad Familiar. En tercer lugar, considerando que la Sociedad de Responsabilidad Limitada es la forma jurídica de creación de Sociedades Familiares más utilizada, se le dedica especial atención, destacando las divergencias fundamentales de regulación entre esta sociedad y la Sociedad Anónima. Asimismo se estudia la Sociedad Limitada Nueva Empresa, como subtipo de la Sociedad de Responsabilidad Limitada. Como conclusión, se trata de arrojar luz sobre la elección preferente de la Sociedad de Responsabilidad Limitada como forma jurídica de constitución de la Sociedad Familiar y, al mismo tiempo, de examinar, desde una perspectiva crítica, la normativa que le resulta aplicable.In this work, after a few general considerations on the Family enterprise, we analyze, first, the types of mercantile companies that the Familiar Company can adopt in Spain, doing a revision of the social typical forms recognized by the legislator, thinking about his advantages and disadvantages. Secondly, we centre on the study of the juridical regime of both most representative Capitalist Companies, the public limited liability company and the Private limited company, analyzing his common features, all this in order to explain which one adapts better to the particularities of the Familiar Company. Thirdly, considering that the Private limited

  14. Effects of elevated atmospheric CO2 and/or O3 on intra- and interspecific competitive ability of aspen

    Science.gov (United States)

    M. E. Kubiske; V. S. Quinn; P. E. Marquardt; D. F. Karnosky

    2007-01-01

    Three model communities of trembling aspen (monoculture, and mixed with either paper birch or sugar maple) were grown for seven years in elevated atmospheric CO2 and O3 using Free Air CO2 Enrichment (FACE) technology. We utilized trends in species' importance, calculated as an index of volume...

  15. Wood-inhabiting, polyporoid fungi in aspen-dominated forests managed for biomass in the U.S. Lake States

    Science.gov (United States)

    Nicholas J. Brazee; Daniel L. Lindner; Shawn Fraver; Anthony W. D' Amato; Amy M. Milo

    2012-01-01

    To better understand the potential long-term effects of biomass harvesting on biodiversity, the polyporoid fungi community was characterized from 120 plots in four aspen-dominated forests in Minnesota. Four deadwood variables (substratum species, substratum type, decay class and diameter class) were recorded for each polyporoid species occurrence. A total of 2358...

  16. Converting partially-stocked aspen stands to fully-stocked stands in the Lake States: an economic analysis.

    Science.gov (United States)

    Jeffrey T. Olson; Allen L. Lundgren

    1978-01-01

    The 1968 Wisconsin Forest Survey showed large areas of aspen type that are not considered fully stocked. The economic feasibility of converting partially-stocked stands to full stocking is examined, and a rule presented for determining when a partially-stocked stand should be harvested to maximize its present value.

  17. Ectopic expression of a horseradish peroxidase enhances growth rate and increases oxidative stress resistance in hybrid aspen.

    Science.gov (United States)

    Kawaoka, Akiyoshi; Matsunaga, Etsuko; Endo, Saori; Kondo, Shinkichi; Yoshida, Kazuya; Shinmyo, Atsuhiko; Ebinuma, Hiroyasu

    2003-07-01

    We previously demonstrated that overexpression of the horseradish (Armoracia rusticana) peroxidase prxC1a gene stimulated the growth rate of tobacco (Nicotiana tabacum) plants. Here, the cauliflower mosaic virus 35S::prxC1a construct was introduced into hybrid aspen (Populus sieboldii x Populus grandidentata). The growth rate of these transformed hybrid aspen plants was substantially increased under greenhouse conditions. The average stem length of transformed plants was 25% greater than that of control plants. There was no other obvious phenotypic difference between the transformed and control plants. Fast-growing transformed hybrid aspen showed high levels of expression of prxC1a and had elevated peroxidase activities toward guaiacol and ascorbate. However, there was no increase of the endogenous class I ascorbate peroxidase activities in the transformed plants by separate assay and activity staining of native polyacrylamide gel electrophoresis. Furthermore, calli derived from the transformed hybrid aspen grew faster than those from control plants and were resistant to the oxidative stress imposed by hydrogen peroxide. Therefore, enhanced peroxidase activity affects plant growth rate and oxidative stress resistance.

  18. Climatic Sensitivity of a Mixed Forest Association of White Spruce and Trembling Aspen at Their Southern Range Limit

    Directory of Open Access Journals (Sweden)

    Sophan Chhin

    2016-10-01

    Full Text Available Climatic sensitivity of white spruce (Picea glauca (Moench Voss was examined growing in association with trembling aspen (Populus tremuloides Michx. at their southern limit of distribution in a transitional ecotone between the southern boreal forest and northern prairie region. The study was carried out in the Spruce Woods Provincial Park (SWPP located in southwestern Manitoba, Canada. The dry regional climate restricted trembling aspen growth during the growing season via moisture deficiency and temperature induced drought stress. Warm, mild winters also negatively affected radial growth of trembling aspen. Growth of white spruce was moderated by conditions within the aspen stands as radial growth patterns showed low variability from year to year, a low common growth signal, and a stronger response to temperature than to precipitation. Nonetheless, the dry regional climate still restricted growth of white spruce during the growing season via temperature induced drought stress. The findings of the study for white spruce support the stress gradient hypothesis in which facilitative interactions between tree species are expected under harsher environmental conditions.

  19. Moderation of [CO2]-induced gas exchange responses by elevated tropospheric O3 in trembling aspen and sugar maple

    Science.gov (United States)

    Pooja Sharma; Anu Sober; Jaak Sober; Gopi P. Podila; Mark E. Kubiske; William J. Mattson; Judson G. Isebrands; David F. Karnosky

    2003-01-01

    The greenhouse gases CO2 and 03 are increasing in the earth's atmosphere. Little is known about long-term impacts of these two co-occurring gases on forest trees. We have been examining the impacts of these two gases on the physiology and growth of trembling aspen (Populus tremuloides) and sugar...

  20. Using aspen for artist stretcher frames: adding value through quality service, direct marketing, and careful material selection

    Science.gov (United States)

    Chris Polson

    2001-01-01

    Aspen wood, when carefully selected and kiln dried, makes excellent stock for artist stretcher frames. Direct marketing techniques including the Internet and word of mouth give access to national markets, providing a more diverse and stable customer base for operations from a rural area. High-quality service, as shown by product performance and rapid order fulfillment...

  1. Semi-Interpenetrating polymer network hydrogels based on aspen hemicellulose and chitosan: Effect of crosslinking sequence on hydrogel properties

    Science.gov (United States)

    Muzaffer Ahmet Karaaslan; Mandla A. Tshabalala; Gisela Buschle-Diller

    2012-01-01

    Semi-interpenetrating network hydrogel films were prepared using hemicellulose and chemically crosslinked chitosan. Hemicellulose was extracted from aspen by using a novel alkaline treatment and characterized by HPSEC, and consisted of a mixture of high and low molecular weight polymeric fractions. HPLC analysis of the acid hydrolysate of the hemicellulose showed that...

  2. Acute O3 damage on first year coppice sprouts of aspen and maple sprouts in an open-air experiment

    Science.gov (United States)

    Joseph N.T. Darbah; Wendy S. Jones; Andrew J. Burton; John Nagy; Mark E. Kubiske

    2011-01-01

    We studied the effect of high ozone (O3) concentration (110-490 nmol mol-1) on regenerating aspen (Populus tremuloides) and maple (Acer saccharum) trees at an open-air O3 pollution experiment near Rhinelander WI USA. This study is the first of its kind to examine...

  3. O corpo colonial e as políticas e poéticas da diáspora para compreender as mobilizações afro-latino-americanas

    Directory of Open Access Journals (Sweden)

    Laura Cecilia López

    2015-06-01

    Full Text Available ResumoO artigo tece uma relação entre corpo colonial e diáspora como dimensões relevantes para compreender as mobilizações afro-latino-americanas, particularmente no Brasil. A partir de dados etnográficos e produções discursivas de intelectuais e militantes negros, analiso a relação entre corpo e poder em diferentes dimensões da luta antirracista. Abordarei dois cenários diferenciados para analisar como a diáspora aparece nas narrativas de sujeitos negros como dimensão disruptiva da colonialidade, provocando a possibilidade de corpos/sujeitos decoloniais que demandam justiça racial. Enfatizarei a dimensão diaspórica como força desse deslocamento nas mobilizações negras: como ela se vincula às políticas e poéticas do corpo/espaço/tempo. Indagarei também na visibilização do corpo colonial na crítica das feministas negras, ao considerar raça e gênero como opressões entrelaçadas. Propõem-se contribuições para uma antropologia política do corpo ao levar a sério perspectivas diaspóricas afro-latino-americanas que focam o corpo como centro das disputas políticas, no sentido de desracializar e pluralizar nossas sociedades.

  4. Assessing Hydraulic Modifications on Vallisneria americana in Peoria Lake, Illinois. A Pilot Study Using Data Sharing Protocols to Integrate Legacy Models

    National Research Council Canada - National Science Library

    Black, Patrick

    2003-01-01

    .... The modeling was directed toward an investigation of potential population increase of the submersed macrophyte Vallisneila americana as a consequence of the construction of a hypothetical levee...

  5. Response Surface Methodology and Aspen Plus Integration for the Simulation of the Catalytic Steam Reforming of Ethanol

    Directory of Open Access Journals (Sweden)

    Bernay Cifuentes

    2017-01-01

    Full Text Available The steam reforming of ethanol (SRE on a bimetallic RhPt/CeO2 catalyst was evaluated by the integration of Response Surface Methodology (RSM and Aspen Plus (version 9.0, Aspen Tech, Burlington, MA, USA, 2016. First, the effect of the Rh–Pt weight ratio (1:0, 3:1, 1:1, 1:3, and 0:1 on the performance of SRE on RhPt/CeO2 was assessed between 400 to 700 °C with a stoichiometric steam/ethanol molar ratio of 3. RSM enabled modeling of the system and identification of a maximum of 4.2 mol H2/mol EtOH (700 °C with the Rh0.4Pt0.4/CeO2 catalyst. The mathematical models were integrated into Aspen Plus through Excel in order to simulate a process involving SRE, H2 purification, and electricity production in a fuel cell (FC. An energy sensitivity analysis of the process was performed in Aspen Plus, and the information obtained was used to generate new response surfaces. The response surfaces demonstrated that an increase in H2 production requires more energy consumption in the steam reforming of ethanol. However, increasing H2 production rebounds in more energy production in the fuel cell, which increases the overall efficiency of the system. The minimum H2 yield needed to make the system energetically sustainable was identified as 1.2 mol H2/mol EtOH. According to the results of the integration of RSM models into Aspen Plus, the system using Rh0.4Pt0.4/CeO2 can produce a maximum net energy of 742 kJ/mol H2, of which 40% could be converted into electricity in the FC (297 kJ/mol H2 produced. The remaining energy can be recovered as heat.

  6. The potential of aspen clonal forestry in Alberta: breeding regions and estimates of genetic gain from selection.

    Directory of Open Access Journals (Sweden)

    Tim Gylander

    Full Text Available BACKGROUND: Aspen naturally grows in large, single-species, even-aged stands that regenerate clonally after fire disturbance. This offers an opportunity for an intensive clonal forestry system that closely emulates the natural life history of the species. In this paper, we assess the potential of genetic tree improvement and clonal deployment to enhance the productivity of aspen forests in Alberta. We further investigate geographic patterns of genetic variation in aspen and infer forest management strategies under uncertain future climates. METHODOLOGY/PRINCIPAL FINDINGS: Genetic variation among 242 clones from Alberta was evaluated in 13 common garden trials after 5-8 growing seasons in the field. Broad-sense heritabilities for height and diameter at breast height (DBH ranged from 0.36 to 0.64, allowing 5-15% genetic gains in height and 9-34% genetic gains in DBH. Geographic partitioning of genetic variance revealed predominant latitudinal genetic differentiation. We further observed that northward movement of clones almost always resulted in increased growth relative to local planting material, while southward movement had a strong opposite effect. CONCLUSION/SIGNIFICANCE: Aspen forests are an important natural resource in western Canada that is used for pulp and oriented strandboard production, accounting for ~40% of the total forest harvest. Moderate to high broad-sense heritabilities in growth traits suggest good potential for a genetic tree improvement program with aspen. Significant productivity gains appear possible through clonal selection from existing trials. We propose two breeding regions for Alberta, and suggest that well-tested southern clones may be used in the northern breeding region, accounting for a general warming trend observed over the last several decades in Alberta.

  7. The Potential of Aspen Clonal Forestry in Alberta: Breeding Regions and Estimates of Genetic Gain from Selection

    Science.gov (United States)

    Gylander, Tim; Hamann, Andreas; Brouard, Jean S.; Thomas, Barb R.

    2012-01-01

    Background Aspen naturally grows in large, single-species, even-aged stands that regenerate clonally after fire disturbance. This offers an opportunity for an intensive clonal forestry system that closely emulates the natural life history of the species. In this paper, we assess the potential of genetic tree improvement and clonal deployment to enhance the productivity of aspen forests in Alberta. We further investigate geographic patterns of genetic variation in aspen and infer forest management strategies under uncertain future climates. Methodology/Principal Findings Genetic variation among 242 clones from Alberta was evaluated in 13 common garden trials after 5–8 growing seasons in the field. Broad-sense heritabilities for height and diameter at breast height (DBH) ranged from 0.36 to 0.64, allowing 5–15% genetic gains in height and 9–34% genetic gains in DBH. Geographic partitioning of genetic variance revealed predominant latitudinal genetic differentiation. We further observed that northward movement of clones almost always resulted in increased growth relative to local planting material, while southward movement had a strong opposite effect. Conclusion/Significance Aspen forests are an important natural resource in western Canada that is used for pulp and oriented strandboard production, accounting for ∼40% of the total forest harvest. Moderate to high broad-sense heritabilities in growth traits suggest good potential for a genetic tree improvement program with aspen. Significant productivity gains appear possible through clonal selection from existing trials. We propose two breeding regions for Alberta, and suggest that well-tested southern clones may be used in the northern breeding region, accounting for a general warming trend observed over the last several decades in Alberta. PMID:22957006

  8. Práxis educativa: tempo, pensamento e sociedade

    Directory of Open Access Journals (Sweden)

    Wilson Correia

    2012-01-01

    Full Text Available El tema de este trabajo es la praxis educativa, concebida por la articulación de los conceptos de tiempo, pensamiento y sociedad. Se llevó a cabo a la luz de las directivas de la investigación conceptual. Defiende la preocupación con la educación del presente para el hombre y de la mujer en realidad, no idealmente diseñados. El trabajo analiza los modelos corporativos capitalistas y socialistas y preconiza enfrentar al reto de crear un modelo corporativo y un estilo existencial basados en los valores de la justicia y de la libertad, qué son las justificaciones últimas para que el maestro e la maestra puedan movilizar los conocimientos que poseen en situaciones reales de enseñanza y aprendizaje.

  9. Futebol, identidade e media na sociedade em rede

    OpenAIRE

    Cardoso, G.; Xavier, D.; Cardoso, T.

    2007-01-01

    Este artigo lida com um dos fenómenos mediáticos de maior abrangência nas sociedades contemporâneas: o futebol. Partindo do pressuposto de que o futebol é também um elemento de construção de comunidades de pertença, sejam elas nacionais, regionais ou de menor dimensão geográfica, procura-se através da análise das respostas a um inquérito representativo da população portuguesa compreender que factores diferenciam identitariamente os adeptos dos três maiores clubes portugueses: Benfica, Porto e...

  10. DERECHOS HUMANOS, SOCIEDAD DE LA INFORMACIÓN Y SOCIEDAD DE RIESGO DIREITOS HUMANOS, SOCIEDADE DA INFORMAÇÃO E SOCIEDADE DE RISCO HUMAN RIGHTS, INFORMATION SOCIETY AND RISK SOCIETY

    Directory of Open Access Journals (Sweden)

    María Lucrecia Rovaletti

    Full Text Available La irrupción de la informática obliga a replantear el derecho a la intimidad, dada la organización de grandes bancos de datos de carácter personal. Debe añadirse además que la posibilidad del entrecruzamiento de la información contenida en los mismos puede facilitar el control y la manipulación de información sensible. Estas nuevas tecnologías de información y comunicación (TIC, en continuo desarrollo, se han expandido también a los distintos dominios de salud, incidiendo en todos los actores, tanto usuarios como profesionales, poderes públicos y organismos de seguridad social. Dada la particular estigmatización que conlleva el complejo VIH/SIDA, es preciso exigir severas restricciones en el acceso a estos bancos, pero también normativas internacionales acordes, para que con la "sociedad de la información" no se agudice aún más la "sociedad de riesgo".A irrupção da informática obriga a reconsiderar o direito à intimidade, dada a organização de grandes bancos de dados de caráter pessoal. Deve-se acrescentar, ademais, que a possibilidade do entrecruzamento da informação contida nestes bancos pode facilitar o controle e a manipulação de informação sensível. Estas novas tecnologias de informação e comunicação (TIC, em contínuo desenvolvimento, têm se expandido também aos diferentes domínios da saúde, incidindo em todos os atores, seja de usuários e profissionais, poderes públicos e organismos de segurança social. Dada a particular estigmatização que implica o complexo HIV/AIDS, é preciso exigir severas restrições no acesso a estes bancos, ademais de normativas internacionais acordes, para que a "sociedade da informação" não agudize ainda mais a "sociedade de risco".Online bursting obliges to rethink the right to privacy, given the organization of huge databases of personal character. Furthermore, it must be added that the possibility of intercrossing information content may facilitate the control

  11. A cultura material no estudo das sociedades antigas

    Directory of Open Access Journals (Sweden)

    Ulpiano Toledo Bezerra Meneses

    1983-12-01

    Full Text Available (primeiro parágrafo do artigo Embora o título desta exposição privilegie o campo da História Antiga, o problema a que se refere permeia todos os domínios da História. Certamente, no caso da Antiguidade, ele é crucial, pela raridade e fragmentação das fontes escritas. Meu propósito aqui, porém, não é montar uma apologia da cultura material, mas lançar algumas pistas para refletir sobre o alcance de um tipo de documento, as coisas físicas, como campo de fenômenos históricos, sem o qual a compreensão de uma sociedade se vê comprometida. Esta reflexão é tanto mais necessária quanto se verifica, ainda, o descaso habitual dos historiadores a respeito.

  12. LA PARTICIPACION EN LA SOCIEDAD COMO BASE DEL DESARROLLO

    Directory of Open Access Journals (Sweden)

    María Cecilia Múnera López

    2012-11-01

    Full Text Available A explicação dela participação na sociedade como a base para o desenvolvimento é o resultado dum processo longo de pesquisa, que no âmbito da teoria fundamentada, tem chegado a aspetos essenciais de ordem conceitual e metodológica, que sustentam o desenvolvimento e a participação. Assim, este artigo apresenta o desenvolvimento desde uma perspectiva resignificada, entendida como uma construção sociocultural múltipla, histórica e territorialmente determinada. De acordo com tal renovação teórica, se apresenta uma forma tipológica de participação, chamada "participação sinérgica", como uma opção plausível para impactar positivamente o desenvolvimento.

  13. El capital social en las sociedades cooperativas. Las Normas sobre los aspectos contables de las sociedades cooperativas a la luz de los principios cooperativos

    OpenAIRE

    Pilar Gómez Aparicio

    2003-01-01

    Los principios cooperativos tienen un alto contenido económico y marcan particularidades en la estructura financiera y en la generación y reparto del excedente. La diferencia concreta en España entre sociedades cooperativas y de capitales procede de la diferente normativa y las distintas leyes que han influido en el régimen económico de estas sociedades. La aparición de las Normas sobre los aspectos contables de las sociedades cooperativas tienen incidencia directa sobre régimen económico ...

  14. Morfoanatomia de folha e caule de Genipa americana L., Rubiaceae Leaf and stem morpho-anatomy of Genipa americana L., Rubiaceae

    Directory of Open Access Journals (Sweden)

    Marianna Erbano

    2010-12-01

    Full Text Available Genipa americana L., conhecida como jenipapo, é uma Rubiaceae nativa do Brasil e as suas folhas são utilizadas pela população como antidiarreico e febrífugo, e o caule como anti-hemorrágico, contra luxações e contusões. Com o objetivo de caracterizar macro e microscopicamente folhas adultas e caules jovens para o controle de qualidade farmacognóstico, essa planta medicinal foi analisada segundo a metodologia clássica de morfoanatomia vegetal. Genipa americana apresenta folhas simples, opostas, de formato obovado a oblanceolado e pecíolos curtos. A epiderme foliar é uniestratificada e revestida por cutícula delgada e levemente estriada. Os estômatos são paracíticos e restritos à superfície abaxial. Há tricomas tectores uni e pluricelulares predominantemente na superfície abaxial. O mesofilo é dorsiventral. Em secção transversal, a nervura central é plano-convexa e o pecíolo é circular, ambos apresentando um feixe vascular colateral em disposição cilíndrica e outros menores. O caule possui felogênio localizado nas camadas subepidérmicas, colênquima anelar e um cilindro floemático externo ao de xilema, sendo ambos percorridos por raios parenquimáticos estreitos. Ocorrem idioblastos contendo compostos fenólicos, areia cristalina e drusas de oxalato de cálcio na folha e no caule.Genipa americana L., known as jenipapo, is a Rubiaceae species native to Brazil. Its leaves are used by the population as anti-diarrheic and febrifuge, and its stem as anti-hemorrhagic and for trauma injuries. Aiming to identify macro and microscopically mature leaves and young stems for the pharmacognostic quality control, this medicinal plant was investigated according to standard morpho-anatomical techniques. The leaves are simple, opposite, obovate-oblanceolate, presenting short petiole. The epidermis is uniseriate and coated with thin and slightly striate cuticle. The stomata are paracytic and restricted to the abaxial surface. It

  15. Herança e ligação em locos de isoenzimas em Genipa americana L. Inheritance and linkage in isozymes loci of Genipa americana L.

    Directory of Open Access Journals (Sweden)

    Alexandre Magno SEBBENN

    2004-06-01

    Full Text Available A herança e a ligação foram estudadasem quatro locos polimórficos (6pghd-1, Pgi-2,Mdh-1 e Mdh-2 de três sistemas isoenzimáticos deGenipa americana, analisados por eletroforesehorizontal em gel de amido, usando tecidoscoletados de quinze progênies de polinização aberta,procedentes de Moji-Guaçu, Estado de São Paulo.Esses locos segregaram de dois a três alelos.A segregação nesses locos foi homogênea entreárvores. Contudo, existem desvios significativos dasegregação esperada 1:1 para algumas árvores emalguns locos. Desvios significativos da razão desegregação esperada 1:1 foram detectados noslocos Mdh-2 e 6pgdh-1. Não foram detectadasevidências de ligação entre nenhum dos pares delocos avaliados em G. americana e esses podemser utilizados sem restrição para estudos do sistemade reprodução, diversidade e estrutura genética depopulações da espécie.Inheritance and linkage for fourpolymorphic loci (6pghd-1, Pgi-2, Mdh-1 andMdh-2 from three enzyme systems in Genipaamericana were analyzed by horizontal starch gelelectrophoresis using tissues collected from fiftyopen-pollinated families in Moji-Guaçu, São PauloState. These allozyme loci have segregated fromtwo to four alleles per polymorphic locus. Genesegregation on those loci was homogeneous amongtrees. However, there were significant deviationsfrom the expected segregation ratios on some lociand some individual trees. In addition, Mdh-2 and6pgdh-1 loci have shown significant deviationsfrom the 1:1 expected segregation ratio. Linkagedisequilibrium evidences were not detected betweenany two pairs of loci from G. americana and thosecan be used with no restriction to study the matingsystem, genetic diversity, and genetic structure onthe species.

  16. Simulation and validation of chemical-looping combustion using ASPEN plus

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ling [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States); Zhang, Zheming; Agarwal, Ramesh K. [Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States)

    2013-07-01

    Laboratory-scale experimental studies have demonstrated that Chemical-Looping Combustion (CLC) is an advanced technology which holds great potential for high-efficiency low-cost carbon capture. The generated syngas in CLC is subsequently oxidized to CO2 and H2O by reaction with an oxygen carrier. In this paper, process-level models of CLC are established in ASPEN Plus code for detailed simulations. The entire CLC process, from the beginning of coal gasification to reduction and oxidation of the oxygen carrier is modeled. The heat content of each major component such as fuel and air reactors and air/flue gas heat exchangers is carefully examined. Large amount of energy is produced in the fuel reactor, but energy needs to be supplied to the air reactor. The overall performance and efficiency of the modeled CLC systems are also evaluated.

  17. Simple Y-autosomal incompatibilities cause hybrid male sterility in reciprocal crosses between Drosophila virilis and D. americana.

    Science.gov (United States)

    Sweigart, Andrea L

    2010-03-01

    Postzygotic reproductive isolation evolves when hybrid incompatibilities accumulate between diverging populations. Here, I examine the genetic basis of hybrid male sterility between two species of Drosophila, Drosophila virilis and D. americana. From these analyses, I reach several conclusions. First, neither species carries any autosomal dominant hybrid male sterility alleles: reciprocal F(1) hybrid males are perfectly fertile. Second, later generation (backcross and F(2)) hybrid male sterility between D. virilis and D. americana is not polygenic. In fact, I identified only three genetically independent incompatibilities that cause hybrid male sterility. Remarkably, each of these incompatibilities involves the Y chromosome. In one direction of the cross, the D. americana Y is incompatible with recessive D. virilis alleles at loci on chromosomes 2 and 5. In the other direction, the D. virilis Y chromosome causes hybrid male sterility in combination with recessive D. americana alleles at a single QTL on chromosome 5. Finally, in contrast with findings from other Drosophila species pairs, the X chromosome has only a modest effect on hybrid male sterility between D. virilis and D. americana.

  18. Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

    International Nuclear Information System (INIS)

    Bassyouni, M.; Waheed ul Hasan, Syed; Abdel-Aziz, M.H.; Abdel-hamid, S.M.-S.; Naveed, Shahid; Hussain, Ahmed; Ani, Farid Nasir

    2014-01-01

    Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO 2 and CH 4 in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H 2 = 56.27%, CO = 21.71%, CO 2 = 18.24%, CH 4 = 3.78%). Increasing steam to biomass ratio increases CO 2 and H 2 at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas

  19. Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

    Energy Technology Data Exchange (ETDEWEB)

    Bassyouni, M. [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Department of Chemical Engineering, Higher Technological Institute, Tenth of Ramdan City (Egypt); Waheed ul Hasan, Syed [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Abdel-Aziz, M.H., E-mail: helmy2002@gmail.com [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria (Egypt); Abdel-hamid, S. M.-S. [Department of Chemical Engineering, Higher Technological Institute, Tenth of Ramdan City (Egypt); Naveed, Shahid [Punjab Institute of Contemporary Sciences, 5.5 KM Raiwind Road, Lahore (Pakistan); Hussain, Ahmed [Department of Nuclear Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ani, Farid Nasir [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, UTM 81310 Johor Bahru (Malaysia)

    2014-12-15

    Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO{sub 2} and CH{sub 4} in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H{sub 2} = 56.27%, CO = 21.71%, CO{sub 2} = 18.24%, CH{sub 4} = 3.78%). Increasing steam to biomass ratio increases CO{sub 2} and H{sub 2} at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas.

  20. Periods and dry environments in the seeds quality of Genipa americana L.Períodos e ambientes de secagem na qualidade de sementes de Genipa americana L.

    Directory of Open Access Journals (Sweden)

    Riselane de Lucena Alcântara Bruno

    2011-07-01

    Full Text Available Genipa americana L. is a tropical tree belonging to Rubiaceae family, providing fruit that are consumed in natura and is being increasingly explored as raw material to liquor, wine, soft drink and also the use of white wood for making various products. The seeds drying this species can be made using natural and or artificial methods. Thus, this study aimed to evaluate the effects of natural drying, in different periods and ambient, in the physiological quality of Genipa americana seeds. Seeds were submitted to the determination of moisture content after processing and drying of each period (0, 24, 48, 72, 96, 120, 144 and 168 hours. To evaluate the effects of ambient (laboratory and greenhouse and drying periods were performed the following tests: emergence in greenhouse, emergence speed index, seedling length and dry weight. Drying seed genipa can be done in a greenhouse (temperature of 33°C with relative humidity of 70% for 24 hours or laboratory environment (temperature of 28°C with relative humidity of 75% for 48 hours without compromising the physiological quality.Genipa americana L. é uma árvore tropical, pertencente à família Rubiaceae, fornece frutos que são consumidos in natura e vem sendo explorada cada vez mais como matéria-prima de licor, vinho, refresco e também o uso da madeira branca para confecção de vários produtos. A secagem de sementes dessa espécie pode ser feita pelo método natural e/ou artificial. Dessa forma, este trabalho teve por objetivo avaliar o efeito da secagem natural, em diferentes ambientes e períodos, na qualidade fisiológica das sementes de Genipa americana. As sementes foram submetidas à determinação do teor de água após o beneficiamento em cada período de secagem (0, 24, 48, 72, 96, 120, 144 e 168 horas. Para a avaliação do efeito dos ambientes (laboratório e ambiente telado e períodos de secagem foram realizados os seguintes testes: emergência em ambiente telado, índice de

  1. Tree age-dependent changes in photosynthetic and respiratory CO2 exchange in leaves of micropropagated diploid, triploid and hybrid aspen.

    Science.gov (United States)

    Pärnik, Tiit; Ivanova, Hiie; Keerberg, Olav; Vardja, Rael; Niinemets, Ulo

    2014-06-01

    The growth rate of triploid European aspen (Populus tremula L.) and hybrid aspen (P. tremula × Populus tremuloides Michx.) significantly exceeds that of diploid aspen, but the underlying physiological controls of the superior growth rates of these genotypes are not known. We tested the hypothesis that the superior growth rate of triploid and hybrid aspen reflects their greater net photosynthesis rate. Micropropagated clonal plants varying in age from 2.5 to 19 months were used to investigate the ploidy and plant age interaction. The quantum yield of net CO2 fixation (Φ) in leaves of young 2.5-month-old hybrid aspen was lower than that of diploid and triploid trees. However, Φ in 19-month-old hybrid aspen was equal to that in triploid aspen and higher than that in diploid aspen. Φ and the rate of light-saturated net photosynthesis (ANS) increased with plant age, largely due to higher leaf dry mass per unit area in older plants. ANS in leaves of 19-month-old trees was highest in hybrid, medium in triploid and lowest in diploid aspen. Light-saturated photosynthesis had a broad temperature optimum between 20 and 35 °C. Rate of respiration in the dark (RDS) did not vary among the genotypes in 2.5-month-old plants, and the shape of the temperature response was also similar. RDS increased with plant age, but RDS was still not significantly different among the leaves of 19-month-old diploid and triploid aspen, but it was significantly lower in leaves of 19-month-old hybrid plants. The initial differences in the growth of plants with different ploidy were minor up to the age of 19 months, but during the next 2 years, the growth rate of hybrid aspen exceeded that of triploid plants by 2.7 times and of diploid plants by five times, in line with differences in ANS of 19-month-old plants of these species. It is suggested that differences in photosynthesis and growth became more pronounced with tree aging, indicating that ontogeny plays a key role in the expression of

  2. Cloning of a chitinase gene from Ewingella americana, a pathogen of the cultivated mushroom, Agaricus bisporus

    Directory of Open Access Journals (Sweden)

    P.W. Inglis

    2000-09-01

    Full Text Available We have isolated a gene encoding a chitinase (EC 3.2.1.14 from Ewingella americana, a recently described pathogen of the mushroom Agaricus bisporus. This gene, designated chiA (EMBL/Genbank/DDBJ accession number X90562, was cloned by expression screening of a plasmid-based E. americana HindIII genomic library in Escherichia coli using remazol brilliant violet-stained carboxymethylated chitin incorporated into selective medium. The chiA gene has a 918-bp ORF, terminated by a TAA codon, with a calculated polypeptide size of 33.2 kDa, likely corresponding to a previously purified and characterised 33-kDa endochitinase from E. americana. The deduced amino acid sequence shares 33% identity with chitinase II from Aeromonas sp. No. 10S-24 and 7.8% identity with a chitinase from Saccharopolyspora erythraeus. Homology to other chitinase sequences was otherwise low. The peptide sequence deduced from chiA lacks a typical N-terminal signal sequence and also lacks the chitin binding and type III fibronectin homology units common to many bacterial chitinases. The possibility that this chitinase is not primarily adapted for the environmental mineralisation of pre-formed chitin, but rather for the breakdown of nascent chitin, is discussed in the context of mushroom disease.O gene que codifica uma quitinase (EC 3.2.1.14 foi isolado de Ewingella americana, recentemente descrita como patógeno do cogumelo Agaricus bisporus. Este gene, denominado chiA (EMBL/Genebank/DDBJ número de acesso X9061, foi clonado e selecionado a partir de livraria genômica construída por digestão do DNA de E. americana com HindIII e ligação em plasmídio de expressão em E. coli, utilizando meio seletivo contendo quitina carboximetilada, corada com "remazol brilliant violet'' para seleção de clones. O gene chiA apresenta uma ORF de 918 bp, código terminador TAA, tendo o tamanho do polipeptídeo sido calculado como 33,2 kDa, o qual corresponde ao tamanho de 33 kDa da endoquitinase

  3. TÉCNICA, AMBIENTE Y SOCIEDAD DEL RIESGO

    Directory of Open Access Journals (Sweden)

    GÓMEZ G LUIS JAIR

    2010-05-01

    Full Text Available En la Modernidad, el hombre pasa de sentirse sojuzgado por la naturaleza a sentirse dominador de ella, para lo cual se erige el «racionalismo», consustancial al desarrollo de la ciencia y la técnica modernas, como la expresión más destacada del «progreso»; pero además, unida a esta característica del hombre moderno, surge el «individuo» que reclama la libertad individual y establece la competencia entre individuos. En el entorno social de esa época, se configura el Estado- Nación y con él, la Economía Política y la propiedad privada, que toman la forma de Capitalismo, cuyo objetivo central es la acumulación individual. Esta nueva forma de ordenamiento social favorece el crecimiento poblacional - en el año 1500, hay 500 millones de habitantes; en el 2000,6000 millones -; el desarrollo industrial que implica demandas crecientes de energía fósil principalmente; un intenso comercio que estimula el intercambio entre regiones y, en consecuencia, el transporte a distancia que requiere también altos consumos energéticos. La industria y el comercio hacen surgir la ciudad moderna con todas sus exigencias: una explotación intensiva de recursos naturales que conduce a una recarga de tos ciclos naturales y una desmesurada recarga de los sumideros para descargar Ice deseches sólidos, líquidos y gaseosos, lo que provoca un preocupante deterioro ecológico que condujo a una «crisis civilizatoria» que se configura en la llamada «sociedad del riesgo». Este impresionante deterioro reclama un replanteamiento de la forma analítica de la ciencia para adoptar una visión sistémica que coloque en el centro a la complejidad de la naturaleza como manera de pensar la manera de compensar el malogrado equilibrio operativo de la biosfera y de la relación sociedad/naturaleza. Se hace también necesario incorporar a los grupos sociales afectados a construir con los técnicos las soluciones más viables, es lo que hemos denominado la t

  4. LAS DIMENSIONES DEL OCIO EN LAS SOCIEDADES RURALES

    Directory of Open Access Journals (Sweden)

    S. Rebollo

    2010-09-01

    Full Text Available

     

     

    RESUMEN

    El presente artículo es un análisis sobre el Ocio en la sociedad rural. El medio rural se ha estudiado desde el punto de vista económico, político y social y sin duda ha despertado un gran interés. Numerosos son los problemas que arrastran estas sociedades a lo largo de la historia. Problemas que han dado lugar a una situación de subdesarrollo y marginalidad. Hoy día indicadores de desarrollo y calidad de vida de una población pueden ser las actividades de ocio realizadas. El nivel de práctica deportiva y el empleo del tiempo libre como actividades de ocio son fenómenos que despiertan gran interés desde el mundo académico. En esta investigación se evalúa estos parámetros y se da información sobre las necesidades de sus habitantes en materia de tiempo libre, actividades de ocio y de forma concreta actividades deportivas.
    PALABRAS CLAVE: Ocio, Tiempo libre, Deporte, Rural.

     

    ABSTRACT

    The present article is an analysis of leisure in rural society. Rural areas have been studied from economic, political and social points of view and without a doubt there is heightened interest in these areas. Numerous problems have plagued these societies throughout history, and consequently led to underdevelopment and marginality. Nowadays leisure activities indicate development and quality of life in given populations. The level of sport practice and the use of the free time to do leisure activities are phenomena that interest the academic world. This investigation evaluated these parameters and information on the necessities of its inhabitants in the matter of free time, leisure activities and specifically sport activities.
    KEY WORDS: Leisure, free Time, Sport, Rural.

  5. Violencia, Sociedad y Salud. Foro del 11 de Mayo

    Directory of Open Access Journals (Sweden)

    Academia Nacional de Medicina

    1995-12-01

    Full Text Available

    Introducción

    La Academia Nacional de Medicina, consciente de su alta responsabilidad social y del deber moral que tiene, como máximo organismo asesor del Gobierno en lo relacionado con la salud, consideró necesario e inaplazable promover un estudio a fondo sobre el problema de la violencia en Colombia, ante el notable recrudecimiento de este preocupante flagelo, que la coloca entre los países más violentos del mundo, y frente a las circunstancias manifiestas de progresiva agresividad que afecta a la familia, al individuo, al funcionario público, a la autoridad, y que ha convertido al delincuente común, al guerrillero y al narcotraficante en crueles destructores de la tranquilidad ciudadana.

    Las graves implicaciones de la violencia sobre la salud del individuo y de la comunidad, no sólo desde el punto de vista psicológico y físico, sino de las consecuencias notables sobre los pre-supuestos del sector y sobre el desarrollo y la economía nacionales, además de la mala imagen internacional, exigen una acción frontal contra este flagelo, de todos los estamentos gubernamentales y privados y los esfuerzos decisivos de la universidad, de las organizaciones gremiales y científicas, en una palabra de todos los conglomerados representativos, entre los cuales la Academia juega papel de liderazgo.

    Organismos Internacionales, liderados por la Organización Panamericana de la Salud, convocaron a fines del año pasado a representantes de los países Americanos para tratar el tema de la violencia y sus implicaciones sobre la sociedad, en particular sobre la salud. En la importante Conferencia Interamericana celebrada en Washington, revisaron a profundidad aspectos como el de la violencia como problema de salud pública, la democracia sin violencia, la cultura de paz para el siglo XXI, la economía política de la no violencia, la construcción de las relaciones sociales no violentas.

    La trascendental reuni

  6. Competencias docentes para enfrentar la sociedad del conocimiento

    Directory of Open Access Journals (Sweden)

    Yajaira del Carmen Oviedo G.

    2009-10-01

    Full Text Available Los avances científicos y la nueva economía global gestan la necesidad de adquirir nuevas competencias, en particular personales y profesionales, en los futuros ciudadanos y ciudadanas. Ante ello, es urgente la formación de actitudes, conocimientos y habilidades en el docente para afrontar exigencias y requerimientos de una sociedad del conocimiento que otorga un valor distinto a la información más allá de la mera transmisión. Esta reflexión de naturaleza documental hace un aporte a las instituciones formadoras del docente en este siglo XXI, ante el apremio de hacer frente a nuevos retos; asimismo, es viable como una alternativa al requisito de diseñar un perfil complejo que parta de la construcción, manejo y difusión de saberes y haceres vinculados al uso de las TIC. Desde este ámbito, el propósito es generar una visión holística de las perspectivas que constituyen la formación de este profesional (constructiva, reflexiva y humana para dar respuesta a los requerimientos de una sociedad que se transforma en todos los órdenes y, por ende, demanda nuevas formas de pensamiento para manejar el cúmulo de información a la cual está expuesta; implica el manejo y posicionamiento de estrategias y herramientas para mediar entre la tecnología y el estudiante. Estos aportes brindarán espacios para generar aproximaciones a un perfil del docente venezolano desde una dimensión ética, participativa, comprometida y consustanciada con su quehacer pedagógico mediado por las TIC. Se requiere una formación en las dimensiones del ser y el convivir, en las cuales la formación de principios como autonomía, libertad, respeto, responsabilidad, tolerancia, equidad, compromiso y solidaridad con sus pares, sean considerados rasgos fundamentales. Dejar de lado al profesional de la docencia desde concepciones mecanicistas, para entenderlo a partir de una visión integradora.

  7. Macropropagation of Erythrina americana in a greenhouse: a potential tool for seasonally dry tropical forest restoration

    Directory of Open Access Journals (Sweden)

    Tara C. Fehling-Fraser

    2015-01-01

    Full Text Available L a deforestación en México ha hecho que la restauración sea una necesidad urgente. Erythrina americana es un árbol multipropósito, útil para la restauración de bosques tropicales estacionalmente secos (BTES, pero es poco estudiado. La macropropagación de esta especie es ventajosa comparada con la reproducción sexual que requiere de semillas escarificadas para germinar. En este estudio se evaluaron los efectos de la aplicación exógena de la fitohormona ácido indol-3-butírico en esquejes y del fertilizante fosfatado de liberación lenta (FLL en el sustrato, sobre el crecimiento de E. americana en invernadero. El experimento tuvo un diseño de cuatro bloques al azar. Diez esquejes se cosecharon por tratamiento después de 36, 66, 96 y 126 días de crecimiento. La sobrevivencia, biomasa seca total (BST, tasa de crecimiento relativo (TCR y la asignación de recursos (AR se evaluaron. La sobrevivencia promedio de los esquejes fue alta (95 %. Los tratamientos no afectaron la BST, TCR y AR; sin embargo, la aplicación de FLL en el sustrato mostró valores significativamente (P < 0.05 mayores de biomasa seca radical. Los periodos de crecimiento afectaron la TCR y AR. La macropropagación de E. americana fue exitosa y no requirió cuidados intensivos, por lo que esta técnica puede ser una alternativa viable para proyectos de restauración, principalmente en comunidades con bajos recursos.

  8. Technical approaches of a natural dye extracted from Phytolacca americana L.-berries with chemical mordants.

    Science.gov (United States)

    Park, Su-Youn; Jung, Suk-Yul

    2014-01-01

    Phytolacca americana L. is a large semi-succulent herbaceous plant which reaches three meters in height. It is native to eastern North America, the Midwest, and the Gulf Coast, with more scattered populations in the far West. It is imported into Korea and has been frequently used as a traditional natural drug for diseases such as systemic edema and nephritis. Its berries, that is, fruits are shiny dark purple held in racemous clusters on pink pedicels with a pink peduncle. They are round with a flat indented top and bottom. Immature berries are green, maturing into white and then blackish purple. It is not well known how the berries are used for a natural staining yet. In this study, using Phytolacca americana L.-berries, a natural staining was analyzed. Moreover, due to the broad use of chemical mordants, five different mordants including copper acetate, aluminum potassium sulfate, sodium tartrate plus citric acid, Iron II sulfate and potassium dichromate were combined. Extracted dye from the berries stained silk fabrics with ivory. The original purple color from the berries disappeared and transformed into ivory. Although the silk fabrics were differentially stained by the berries that were combined with mordants of aluminum potassium sulfate, sodium tartrate plus citric acid and potassium dichromate, only differences in lightness and darkness were observed. Interestingly, the combination of the dye from the berries with a mordant of copper acetate and Iron II sulfate induced the staining of the silk fabrics into khaki and dark khaki, respectively. This study is the first systemic report on staining silk fabrics with Phytolacca americana L.-berries and chemical mordants and suggests application of natural products to the fiber industry.

  9. Vascular riffle flora of Appalachian streams: the ecology and effects of acid mine drainage on Justificia americana (L. ) Vahl

    Energy Technology Data Exchange (ETDEWEB)

    Koryak, M.; Reilly, R.J.

    1984-06-01

    Justicia americana is a stout-based colonial plant, abundant in most of the larger, low to moderate gradient streams of the upper Ohio River basin. The distribution of J. americana is related to acid drainage from bituminous coal mining operations in the upper Ohio River drainage basin. Possible fluvial and biological consequences of the colonization or absence of Justicia are considered. Luxuriant growths were noted on gravel bars and riffles of larger, unpolluted streams in the basin. Acid mine drainage severely depresses the growth of the plant, leaving gravel shoals and riffles in the acid streams either barren or dominated by other emergent species. Particular among these new species is Elecocharis acicularis. The elimination of J. americana from suitable habitat adversely affects channel morphology, substrate composition, general aesthetic quality and aquatic stream life in the region. 16 references, 2 figures, 3 tables.

  10. Consideraciones sobre el cultivo del aguacate Persea Americana Mill. en Atlixco, Puebla

    Directory of Open Access Journals (Sweden)

    Teresa Reyna Trujillo

    1983-01-01

    Full Text Available The production of avocado Persea americana Mill in our country has been intensified the last years, particularly in some states such as Michoacán, Puebla, Veracruz and others. Specifically in Puebla, there are some counties "municipios", Atlixco among others, where its exploitation represents an important economical fact. Because of this, it is being pretended to increase the surface occupied with that fruit tree. However, its growth and cultivation, has been exposed to a great number of problems, such as the ecologic ones (inadecuate soils, for example and fitopathologic ones mainly, reasons enough to consider the increase of its growth as inadecuate.

  11. Preliminar toxicological assesement of Ruta graveolens, Origanum vulgare and Persea americana on the preimplantational mouse embryos

    Directory of Open Access Journals (Sweden)

    V. Benavides

    2014-06-01

    Full Text Available The growing interest in natural medicine makes it necessary to study plant properties as well as their possible secondary effects. In recent years the toxic effects of many medicinal plants on the preimplantational mouse embryo development have been studied. Many of them produce malformations and alterations in the embryonic development. Ruta graveolens "ruda", Origanum vulgare "oregano" and Persea americana "palta" are used in rural areas to menstrual colic and to provoke abortion (estrella, 1995. This study is aimed at assessing "in vivd'the effect of extracts of "oregano", "ruda" and "palta" to 20% on the morphology and growth of preimplantational mouse embryos.

  12. Thermal effects on growth and respiration rates of the mayfly, Dolania americana (ephemeroptera)

    International Nuclear Information System (INIS)

    Harvey, R.S.

    1975-01-01

    The mayfly Dolania Americana, common in the sand of Upper Three Runs Creek, Savannah River Plant, was studied to determine the effects of seasonal changes in temperature on population growth rates and to determine the effects of slight elevations in water temperature on respiration rates of this benthic species. Growth of the population increased with stream temperature until peak emergence of adults in June and July. There was a strong inverse correlation between body weight and respiration rates of immature nymphs. Respiration rates at 2.5, 5, and 10 0 C above ambient creekwater temperatures were not significantly higher than those measured at ambient creekwater temperatures. (auth)

  13. Reflexões sobre as Independências Ibero-americanas

    Directory of Open Access Journals (Sweden)

    Manuel Chust

    2008-12-01

    Full Text Available O objetivo deste artigo é refletir acerca do tema das independências iberoamericanas do século XIX como objeto historiográfico, considerando-o em tempos e espaços amplos, gerais e de dimensões européias e americanas. Resgatando algumas das principais teses a respeito formuladas nas últimas quatro décadas, pretende-se examinar algumas posições em voga no momento, considerando-se a efervescência historiográfica anunciada pelas comemorações dos bicentenários no mundo ibérico.

  14. Antioxidant activity of hydroalcoholic leaf extracts of Psidium guajava and Persea Americana, an invitro study

    International Nuclear Information System (INIS)

    Kumar, Amith; Kumarachandra, Reshma; Rai, Rajalakshmi; Rao, Satish; Suchetha Kumari; Joshi, Manjunath

    2013-01-01

    Ionizing radiation produce deleterious effects in the living organisms. Rapid technological advancement has increased human exposure to ionizing radiations enormously. Several plants have been screened for their radio protective ability and the hunt for identifying many more safe, nontoxic and effective ones is in progress. The aim of the present study was to evaluate the antioxidant activity in hydro alcoholic leaf extract of Psidium guajava (guava) and Persea americana (avocado). The antioxidant assay such as 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) free radical scavenging assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, chelation of iron by plant extract, hydroxyl radical scavenging assay, ferric reducing antioxidant potential (FRAP), and total antioxidant activity of extract was analyzed using spectrophotometer. Phytochemical screening and HPLC analysis of leaf extracts were also performed. The results indicated that the IC50 value of hydro alcoholic leaf extract of P.guajava and P. americana were 14 μg/ml and 15 μg/ml in ABTS free radical scavenging assay, 4 μg/ml and 2.5 μg/ml in DPPH free radical scavenging assay, 7.2 μg/ml and 8.4 μg/ml in chelation of iron by plant extract, 2 μg/ml and, 4.3 μg/ml in hydroxyl radical scavenging assay and effective concentration(EC50) was 57.80 μg/ml and 87.56 μg/ml in FRAP assay respectively. The results for total antioxidant activity indicated that 242.3 μg/ml of P.guajava and 432.7 μg/ml of P.americana extract was equivalent to 100 μg/ml of standard qurecetin respectively. Qualitative analysis of hydroalcoholic leaf extracts revealed the presence of flavonoids, tannins, saponions, terpenoids, and glycosides. HPLC analysis confirmed the presence of flavonoids qurecetin and rutin in leaf extracts on comparison with standard compounds. Our study showed that hydro alcoholic leaf extracts of Psidium guajava and Persea americana act as strong antioxidant and free

  15. Hongos Fitopatógenos asociados a semillas de palto (Persea Americana mill.)

    OpenAIRE

    Leon Ttacca, Betsabe; Mattos Calderon, Leonor

    2016-01-01

    Una serie de enfermedades severas de origen fungoso son diseminadas por semillas de palto, y pueden causar una disminución de la producción en aproximadamente el 14 % y una reducción de calidad en un 10 %. El presente trabajo consistió en aislar e identificar hongos fitopatógenos presentes en las semillas de palto (Persea americana Mill.) raza mexicana utilizadas para patrón. A partir del embrión y cotiledón de 200 semillas de palto, se aislo los hongos fotopatogenos en medio de cultivo Papa ...

  16. Effects of ripening on rheological properties of avocado pulp (Persea americana mill. Cv. Hass)

    Science.gov (United States)

    Osorio, F.; Roman, A.; Ortiz, J.

    2015-04-01

    Avocado (Persea americana Mill) Hass variety is the most planted in Chile with a greater trade prospect. The aim of this study was to investigate the effect of maturity on rheological properties of Chilean Avocado Hass pulp. Fresh unripe avocados were washed and peeled, cut and stored at 3 different times; a portion was treated at 5°C and the other was treated at 20°C until it reached 2 lb puncture pressure. During maturation changes would develop due to temperature and time, with internal cellular structure changes. Preliminary results of the rheological characteristics of avocado puree show a Bingham plastic behavior.

  17. Effects of simulated acid rain on leaf anatomy and micromorphology of Genipa americana L. (Rubiaceae

    Directory of Open Access Journals (Sweden)

    Bruno Francisco Sant'Anna-Santos

    2006-03-01

    Full Text Available Experiments were conducted in order to characterize the injuries on leaf structure and micromorphology of G. americana and evaluate the degree of susceptibility of this species to simulated acid rain. Plants were exposed to acid rain (pH 3.0 for ten consecutive days. Control plants were submitted only to distilled water (pH 6.0. Leaf tissue was sampled and fixed for light and scanning electron microscopy. Necrotic interveinal spots on the leaf blade occurred. Epidermis and mesophyll cells collapse, hypertrophy of spongy parenchyma cells, accumulation of phenolic compounds and starch grains were observed in leaves exposed to acid rain. The micromorphological analysis showed, in necrotic areas, plasmolized guard cells and cuticle rupture. Epidermal and mesophyll cells alterations occurred before symptoms were visualized in the leaves. These results showed the importance of anatomical data for precocious diagnosis injury and to determine the sensitivity of G. americana to acid rain.Experimentos foram conduzidos para avaliar o grau de susceptibilidade e determinar as injúrias causadas pela chuva ácida simulada na anatomia e micromorfologia foliar de Genipa americana. Plantas foram expostas à chuva com pH 3,0 durante 10 dias consecutivos. No tratamento controle utilizou-se apenas água destilada (pH 6,0. Amostras foliares foram coletadas e fixadas para microscopia de luz e eletrônica de varredura. Foram observados nas folhas expostas à chuva ácida: necroses pontuais intervenais, colapso das células do mesofilo e da epiderme; hipertrofia do parênquima lacunoso e acúmulo de compostos fenólicos e grãos de amido. A análise micromorfológica evidenciou, nas áreas necrosadas, plasmólise das células-guarda e ruptura da cutícula e da crista estomática. Alterações anatômicas ocorreram antes que sintomas visuais fossem observados nas folhas. Estes resultados comprovam a importância de dados anatômicos na diagnose precoce da injúria e na

  18. Genipa americana: prospecção tecnológica

    Directory of Open Access Journals (Sweden)

    Selma Maria Santos Moura

    2016-10-01

    Full Text Available O jenipapo é uma árvore alta (10 a 15 metros, encontrada em regiões de clima tropical úmido, comum no nordeste brasileiro. Seu nome científico é Genipa americana L., jenipapo vem do Tupi-guarani jandipap, que significa fruto que serve para pintar. Apresenta caule reto, folhas verde-escuras, flores amarelo-ouro e o fruto na forma de baga ovoide, possui polpa marrom clara que envolve sementes no centro. Na alimentação humana, seu fruto é comestível ao natural e no preparo de doces, refrescos e vinho. É rico em ferro, vitaminas B1, B2, B5 e C, cálcio e hidratos de carbono. Na cultura popular têm indicações medicinais para o tratamento de afecções. Quando verde, o fruto fornece um suco azul muito utilizado como corante, transparente a princípio, o qual torna-se preto quando oxida, apresenta consistência do nanquim e no corpo, em contato com a pele, deixa manchas que desaparecem após uma semana ou mais, espontaneamente. O objetivo desta pesquisa foi realizar a prospecção tecnológica com relação à Genipa americana L., para apresentar uma visão geral sobre as tecnologias desenvolvidas relacionadas ao tema. Para isso realizou-se uma busca de patentes nas bases do European Patent Office, World Intellectual Property Organization, United States Patent and Trademark Office e no Instituto Nacional de Propriedade Industrial. Utilizando a palavra-chave Genipa americana L. foram registradas 88 patentes, quando acrescido à especificação corante encontrou-se 5 e nenhuma quando utilizou-se Genipa americana L. e célula. O Brasil registrou um número de patentes inferior ao encontrado nos USA e no Japão, sendo os anos de 2010, 2011 e 2015 os que apresentaram maior número. Ações integradas devem ser realizadas para estimular as instituições de fomento à pesquisa no intuito de viabilizar um ambiente propício à geração de inovações, fazendo do Brasil um país mais competitivo do ponto de vista tecnológico.  

  19. Democracia y sociedad de la información

    Directory of Open Access Journals (Sweden)

    Echeverría Ezponda, Javier

    2000-09-01

    Full Text Available Not Available

    Las nuevas tecnologías de la información y las telecomunicaciones (NTIT están suscitando profundos cambios en las sociedades avanzadas y plantean dilemas estratégicos a los países en vías de desarrollo. La rápida difusión de la red Internet es uno de los fenómenos más destacados de la década final del siglo XX, pero la transformación proviene de otras muchas tecnologías: informática, bases de datos, teléfonos móviles, satélites de telecomunicaciones, televisión digital, realidad virtual, tecnologías multimedia, etc. En conjunto, las redes telemáticas están modificando profundamente la guerra, las finanzas, la organización y actividades empresariales, el trabajo, el comercio, la administración, la enseñanza, la medicina, el ocio, el arte y la cultura. Por ello cabe afirmar que las NTIT están posibilitando un profundo cambio, que afecta a casi todas las actividades sociales, incluida la vida cotidiana. En esta conferencia me ocuparé de su influencia sobre la política y la democracia.

  20. 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.

  1. La funcionalidad de los medios rurales en las sociedades urbanas

    Directory of Open Access Journals (Sweden)

    Enrique Moltó Mantero

    2004-01-01

    Full Text Available Los medios rurales en los países desarrollados han experimentado notables cambios en las funciones que desempeñan desde mediados de la década de los cincuenta del siglo veinte. Frente a unos ámbitos donde dominaban las actividades y modos de vida rurales, en las últimas décadas se observa la progresiva aparición de nuevos usos y actividades vinculados a su terciarización. La homogeneización de las pautas de comportamiento y de los modos de vida hace difícil disociar la sociedad urbana de la rural. Este artículo reflexiona sobre los diferentes procesos (éxodo rural, políticas de desarrollo rural, medios de comunicación, etc. que han intervenido en estas transformaciones y han favorecido los procesos de homogeneización de los medios rurales, sin embargo, es necesario insistir que uno de los rasgos de numerosos medios rurales es su diversidad. Esta heterogeneidad condiciona, no solo su evolución, sino también su grado de adaptación a las nuevas funciones que se les asignan. Este artículo pretende realizar una reflexión acerca de las posibles disfuncionalidades que la aplicación de políticas homogéneas está generando en ámbitos contrastados.

  2. Maltrato al anciano: "una realidad oculta en nuestra sociedad"

    Directory of Open Access Journals (Sweden)

    Rodríguez H. Shirley Catherine

    1996-06-01

    Full Text Available

    El maltrato al anciano es un hecho cotidiano, no reconocido socialmente como tal, por el contrario, el maltrato es considerado un cuento normal al que se ve expuesto un gran número de personas; que afecta el sistema familiar y a cada uno de sus miembros. Conscientes de la importancia del reconocimiento, identificación, manejo oportuno y adecuado y la intervención que enfermería realice en la situación del maltrato al anciano, se podrá forjar un camino hacia el cambio. La concepción de envejecimiento que tiene la sociedad favorece el maltrato al anciano, situación tan común como el maltrato de esposas y niños. Sumado a ello, los casos de maltrato al anciano son poco reconocidos y denunciados; las situaciones que evidencian el maltrato son negadas o justificadas por la familia, lo cual dificulta el reconocimiento de este hecho.


  3. Obesidade em adultos de segmentos pauperizados da sociedade

    Directory of Open Access Journals (Sweden)

    Marinho Sheila Pita

    2003-01-01

    Full Text Available O aumento da incidência de obesidade em segmentos pauperizados da sociedade levanta a questão sobre sua etiologia. Este trabalho pretende caracterizar a prevalência de sobrepeso e obesidade nestas populações. Participaram da pesquisa 390 famílias, incluindo 782 indivíduos com idades iguais ou maiores de 19 anos, dos quais 360 (46,0% eram homens e 422 (54,0% mulheres. As prevalências de obesidade entre os homens das zonas urbana e rural foram de 5,6% e 5,8%, respectivamente. Em relação ao sobrepeso, esta incidência foi de cerca de 25% em ambas as regiões, evidenciando-se aumento com a idade. As prevalências de obesidade entre homens e mulheres foram, respectivamente, de 5,6% e 21,6% (p<0,05. Entre as mulheres a ocorrência de obesidade aumentou discretamente com a idade, com prevalências padronizadas de 19,8% na zona urbana e 23,4% na rural. Considerando tratar-se de uma população pauperizada, o excesso de peso, que atinge principalmente as mulheres, tem etiologia complexa e precisa ser melhor estudado.

  4. Desarrollo de Competencias Investigadoras en la Sociedad Red

    Directory of Open Access Journals (Sweden)

    Marta Mena

    2013-01-01

    Full Text Available La labor de investigación científica y tecnológica en el siglo XXI requiere del desarrollo de competencias multidisciplinares que van más allá de los conocimientos disciplinares específicos o de las bases metodológicas. El investigador en la sociedad del conocimiento necesita utilizar eficazmente herramientas que le permitan relacionarse con colegas en el mismo campo del conocimiento, recurrir a bases bibliográficas y journals específicos, acceder a bases de datos investigaciones y journals relevantes y actualizados, y en la muchos casos trabajar en conjunto con colegas que pueden estar a miles de kilómetros de distancia. El presente trabajo presenta el Programa de Formación Virtual de Investigadores de la Universidad Tecnológica Nacional, en Argentina, como modelo de desarrollo de esas competencias a través de una red de campus virtuales que incluye 32 nodos y una red de servicios que estimulan la generación proyectos inclusivosde innovación productiva.

  5. Mechanistic simulation of batch acetone-butanol-ethanol (ABE) fermentation with in situ gas stripping using Aspen Plus™.

    Science.gov (United States)

    Darkwah, Kwabena; Nokes, Sue E; Seay, Jeffrey R; Knutson, Barbara L

    2018-05-22

    Process simulations of batch fermentations with in situ product separation traditionally decouple these interdependent steps by simulating a separate "steady state" continuous fermentation and separation units. In this study, an integrated batch fermentation and separation process was simulated for a model system of acetone-butanol-ethanol (ABE) fermentation with in situ gas stripping, such that the fermentation kinetics are linked in real-time to the gas stripping process. A time-dependent cell growth, substrate utilization, and product production is translated to an Aspen Plus batch reactor. This approach capitalizes on the phase equilibria calculations of Aspen Plus to predict the effect of stripping on the ABE fermentation kinetics. The product profiles of the integrated fermentation and separation are shown to be sensitive to gas flow rate, unlike separate steady state fermentation and separation simulations. This study demonstrates the importance of coupled fermentation and separation simulation approaches for the systematic analyses of unsteady state processes.

  6. Organo-mineral interactions promote greater soil organic carbon stability under aspen in semi-arid montane forests in Utah

    Science.gov (United States)

    Van Miegroet, H.; Roman Dobarco, M.

    2014-12-01

    Forest species influence soil organic carbon (SOC) storage through litter input, which in interaction with soil microclimate, texture and mineralogy, lead to different SOC stabilization and storage patterns. We sampled mineral soil (0-15 cm) across the ecotone between aspen (Populus tremuloides) and mixed conifers stands (Abies lasiocarpa and Pseudotsuga menziesii) in semi-arid montane forests from Utah, to investigate the influence of vegetation vs. site characteristics on SOC stabilization, storage and chemistry. SOC was divided into light fraction (LF), mineral-associated SOC in the silt and clay fraction (MoM), and a dense subfraction > 53 μm (SMoM) using wet sieving and electrostatic attraction. SOC decomposability and solubility was derived from long term laboratory incubations and hot water extractions (HWE). Fourier transform infrared spectroscopy (FTIR) was used to study differences in chemical functional groups in LF and MoM. Vegetation cover did not affect SOC storage (47.0 ± 16.5 Mg C ha-1), SOC decomposability (cumulative CO2-C release of 93.2 ± 65.4 g C g-1 C), or SOC solubility (9.8 ± 7.2 mg C g-1 C), but MoM content increased with presence of aspen [pure aspen (31.2 ± 15.1 Mg C ha-1) > mixed (25.7 ± 8.8 Mg C ha-1) > conifer (22.8 ± 9.0 Mg C ha-1)]. Organo-mineral complexes reduced biological availability of SOC, indicated by the negative correlation between silt+clay (%) and decomposable SOC per gram of C (r = -0.48, p = 0.001) or soluble SOC (r = -0.59, p plant or microbial origin. FTIR spectra clustered by sites with similar parent material rather than by vegetation cover. This suggests that initial differences in litter chemistry between aspen and conifers converged into similar MoM chemistry within sites.

  7. Simulation of a tubular solid oxide fuel cell stack using AspenPlusTM unit operation models

    International Nuclear Information System (INIS)

    Zhang, W.; Croiset, E.; Douglas, P.L.; Fowler, M.W.; Entchev, E.

    2005-01-01

    The design of a fuel cell system involves both optimization of the fuel cell stack and the balance of plant with respect to efficiency and economics. Many commercially available process simulators, such as AspenPlus TM , can facilitate the analysis of a solid oxide fuel cell (SOFC) system. A SOFC system may include fuel pre-processors, heat exchangers, turbines, bottoming cycles, etc., all of which can be very effectively modelled in process simulation software. The current challenge is that AspenPlus TM or any other commercial process simulators do not have a model of a basic SOFC stack. Therefore, to enable performing SOFC system simulation using one of these simulators, one must construct an SOFC stack model that can be implemented in them. The most common approach is to develop a complete SOFC model in a programming language, such as Fortran, Visual Basic or C++, first and then link it to a commercial process simulator as a user defined model or subroutine. This paper introduces a different approach to the development of a SOFC model by utilizing existing AspenPlus TM functions and existing unit operation modules. The developed ''AspenPlus TM SOFC'' model is able to provide detailed thermodynamic and parametric analyses of the SOFC operation and can easily be extended to study the entire power plant consisting of the SOFC and the balance of plant without the requirement for linking with other software. Validation of this model is performed by comparison to a Siemens-Westinghouse 100 kW class tubular SOFC stack. Sensitivity analyses of major operating parameters, such as utilization factor (U f ), current density (I c ) and steam-carbon ratio (S/C), were performed using the developed model, and the results are discussed in this paper

  8. Factors affecting fall down rates of dead aspen (Populus tremuloides) biomass following severe drought in west-central Canada.

    Science.gov (United States)

    Ted Hogg, Edward H; Michaelian, Michael

    2015-05-01

    Increases in mortality of trembling aspen (Populus tremuloides Michx.) have been recorded across large areas of western North America following recent periods of exceptionally severe drought. The resultant increase in standing, dead tree biomass represents a significant potential source of carbon emissions to the atmosphere, but the timing of emissions is partially driven by dead-wood dynamics which include the fall down and breakage of dead aspen stems. The rate at which dead trees fall to the ground also strongly influences the period over which forest dieback episodes can be detected by aerial surveys or satellite remote sensing observations. Over a 12-year period (2000-2012), we monitored the annual status of 1010 aspen trees that died during and following a severe regional drought within 25 study areas across west-central Canada. Observations of stem fall down and breakage (snapping) were used to estimate woody biomass transfer from standing to downed dead wood as a function of years since tree death. For the region as a whole, we estimated that >80% of standing dead aspen biomass had fallen after 10 years. Overall, the rate of fall down was minimal during the year following stem death, but thereafter fall rates followed a negative exponential equation with k = 0.20 per year. However, there was high between-site variation in the rate of fall down (k = 0.08-0.37 per year). The analysis showed that fall down rates were positively correlated with stand age, site windiness, and the incidence of decay fungi (Phellinus tremulae (Bond.) Bond. and Boris.) and wood-boring insects. These factors are thus likely to influence the rate of carbon emissions from dead trees following periods of climate-related forest die-off episodes. © 2014 Her Majesty the Queen in Right of Canada Global Change Biology © 2014 John Wiley & Sons Ltd Reproduced with the permission of the Minister of Natural Resources Canada.

  9. Factors Influencing the Tissue Culture and the Agrobacterium tumefaciens-Mediated Transformation of Hybrid Aspen and Poplar Clones.

    Science.gov (United States)

    De Block, M

    1990-07-01

    Tissue culture conditions and transformation have been established for both aspen and poplar. The use of previously described culture conditions resulted in shoot tip necrosis in the shoot cultures and necrosis of stem and leaf explants. Shoot tip necrosis could be overcome by buffering the medium with 2-(N-morpholino)ethanesulfonic acid and Ca-gluconate and by growing the shoots below 25 degrees C. Necrosis of the explants was probably due to an accumulation of ammonium in the explants and could be overcome by adapting the NO(3) (-)/NH(4) (+) ratio of the media. Stem explants of established shoot cultures of the aspen hybrid Populus alba x P. tremula and of the poplar hybrid Populus trichocarpa x P. deltoides were cocultivated with Agrobacterium strains having chimeric bar and neo genes on their disarmed tDNAs. Transformed aspen shoots were obtained from 30 to 40% of the explants, while transformed poplar shoots were obtained from 10% of the explants. Extracts from the transformed trees contained high phosphinotricin acetyltransferase and neomycin phosphotransferase activities, and the trees contained one to three copies of the chimeric genes. The transformed trees were completely resistant to the commercial preparations of the herbicide phosphinotricin (glufosinate), while control trees were not.

  10. Bioconcentration of zinc and cadmium in ectomycorrhizal fungi and associated aspen trees as affected by level of pollution

    International Nuclear Information System (INIS)

    Krpata, Doris; Fitz, Walter; Peintner, Ursula; Langer, Ingrid; Schweiger, Peter

    2009-01-01

    Concentrations of Zn and Cd were measured in fruitbodies of ectomycorrhizal (ECM) fungi and leaves of co-occurring accumulator aspen. Samples were taken on three metal-polluted sites and one control site. Fungal bioconcentration factors (BCF = fruitbody concentration: soil concentration) were calculated on the basis of total metal concentrations in surface soil horizons (BCF tot ) and NH 4 NO 3 -extractable metal concentrations in mineral soil (BCF lab ). When plotted on log-log scale, values of BCF decreased linearly with increasing soil metal concentrations. BCF lab for both Zn and Cd described the data more closely than BCF tot . Fungal genera differed in ZnBCF but not in CdBCF. The information on differences between fungi with respect to their predominant occurrence in different soil horizons did not improve relations of BCF with soil metal concentrations. Aspen trees accumulated Zn and Cd to similar concentrations as the ECM fungi. Apparently, the fungi did not act as an effective barrier against aspen metal uptake by retaining the metals. - Populus tremula and associated ectomycorrhizal fungi accumulate zinc and cadmium to similar concentrations

  11. Growth, leaf traits and litter decomposition of roadside hybrid aspen (Populus tremula L. x P. tremuloides Michx.) clones

    International Nuclear Information System (INIS)

    Nikula, Suvi; Manninen, Sirkku; Vapaavuori, Elina; Pulkkinen, Pertti

    2011-01-01

    Road traffic contributes considerably to ground-level air pollution and is therefore likely to affect roadside ecosystems. Differences in growth and leaf traits among 13 hybrid aspen (Populus tremula x P. tremuloides) clones were studied in relation to distance from a motorway. The trees sampled were growing 15 and 30 m from a motorway and at a background rural site in southern Finland. Litter decomposition was also measured at both the roadside and rural sites. Height and diameter growth rate and specific leaf area were lowest, and epicuticular wax amount highest in trees growing 15 m from the motorway. Although no significant distance x clone interactions were detected, clone-based analyses indicated differences in genotypic responses to motorway proximity. Leaf N concentration did not differ with distance from the motorway for any of the clones. Leaf litter decomposition was only temporarily retarded in the roadside environment, suggesting minor effects on nutrient cycling. - Highlights: → Roadside hybrid aspen displayed xeromorphic leaf traits and reduction in growth rate. → These responses were limited to trees close to the motorway and only to some clones. → Leaf litter decomposition was only temporarily retarded in the roadside environment. - Hybrid aspen had more xeromorphic leaves, displayed reduced growth, and showed retarded litter decomposition at an early stage in the roadside environment.

  12. Effect of Agave americana and Agave salmiana Ripeness on Saponin Content from Aguamiel (Agave Sap).

    Science.gov (United States)

    Leal-Díaz, Ana María; Santos-Zea, Liliana; Martínez-Escobedo, Hilda Cecilia; Guajardo-Flores, Daniel; Gutiérrez-Uribe, Janet Alejandra; Serna-Saldivar, Sergio Othón

    2015-04-22

    Steroidal saponins have shown beneficial health effects. Agave spp. leaves and rhizomes are sources of these compounds, but their presence has not been reported in the aguamiel. Aguamiel is the sweet edible sap from mature agave, and its quality is influenced by the plant ripening stage. The purpose of this research was to identify and quantitate saponins in aguamiel from Agave americana and Agave salmiana at two ripening stages. Saponins and sapogenins were identified with HPLC/ESI-MS/TOF and quantitated with HPLC/ELSD. Results proved the presence of saponins derived from kammogenin, manogenin, gentrogenin, and hecogenin. The saponin content in aguamiel from immature A. salmiana was 2-fold higher (478.3 protodioscin equivalents (PE) μg/g aguamiel (DM)) compared with A. americana (179.0 PE μg/g aguamiel (DM)). In both species, saponin content decreased when plants reached sexual maturity. This should be considered before evaluating the effects of Agave spp. as a source of bioactive saponins.

  13. Evaluation of in vitro antioxidant and anti-inflmmatory activities of Ximenia americana extracts

    Directory of Open Access Journals (Sweden)

    Arun Kashivishwanath Shettar

    2015-11-01

    Full Text Available Objective: To evaluate in vitro antioxidant and anti-inflammatory activity of Ximenia americana extracts. Methods: Herbal extraction was done by Soxhlet extraction method with increasing polarity of solvents viz., chloroform, ethyl acetate, methanol, ethanol and water. Phytochemical analysis was done using different biochemical tests. Antioxidant potential of plant extracts were analyzed by ferric ion reducing antioxidant power, phosphomolybdenum and 2,2-diphenyl-1- picrylhydrazyl, and anti-inflammatory activity by using protein denaturation in vitro bioassay. Total phenolic content of each extract was also determined to assess their corresponding effect on antioxidant capacity of plant. Results: Phytochemical analysis showed that each solvent extract contained broad spectrum of secondary metabolites, phenolic compounds, flavonoids, tannins and glycosides, whereas compared to other solvent extracts, chloroform extract showed negative result for phenolic compounds whereas aqueous extract exhibited the highest phenolic content and the significant antioxidant capacity based on the test performed. Out of all extracts, methanol extract showed high anti-inflammatory activity. Conclusions: The present study revealed that different solvent extracts of Ximenia americana leaves contain broad spectrum of bioactive compounds. Results confirm that aqueous extract exhibited high antioxidant activity and methanol extract exhibited high antiinflammatory activity. Further study requires purification, characterization and structural elucidation of phenolic compounds in both extracts that may help in the development of new phytopharmaceuticals.

  14. ETIQUETAS DE SECUENCIAS EXPRESADAS DIFERENCIALES DE FRUTOS DE AGUACATE RAZA MEXICANA (Persea americana Mill. var. drymifolia

    Directory of Open Access Journals (Sweden)

    Enrique Ignacio Sánchez-González

    2018-02-01

    Full Text Available RESUMEN En este estudio se desarrollaron e identificaron etiquetas de secuencias expresadas diferencialmente (ESTs de frutos inmaduros de Persea americana Mill. var. drymifolia del estado de Nuevo León, México. Diez genotipos con frutos de forma y tamaño diferentes fueron seleccionados para generar ESTs por la técnica de despliegue diferencial.Se obtuvieron en total 393 fragmentos diferenciales amplificados, 82 fragmentos diferenciales fueron secuenciados y editados para identificación y comparación en las bases de datos para nucleótidos y proteínas del NCBI. Cuarenta secuencias mostraron similitud significativa con secuencias de ARNm y/o secuencias de proteínas hipotéticas o predichas pertenecientes a P. americana y/o a otros géneros. Algunas secuencias estuvieron relacionadas a enzimas como flavanona-3-hidroxilasa (F3H, lecitina-colesterol aciltransferasa, glutatión-S-transferasamicrosomal y proteína pleiotrópica de resistencia a drogas. Con la información de la composición nucleotídica de las ESTs se podrán diseñar iniciadores para cuantificar niveles de expresión por RT-PCR en tiempo real de los genes, en diferentes etapas fenológicas del fruto y hacer comparaciones entre los genotipos que permitan determinar usos alternos de sus frutos.

  15. Transplantation immunity in the American cockroach, Periplaneta americana: the rejection of integumentary grafts from Blatta orientalis.

    Science.gov (United States)

    Karp, R D; Meade, C C

    1993-01-01

    The results from several previous studies have indicated that the American cockroach is able to respond to integumentary xenografts, but doubt remained as to whether cockroaches could effectively discriminate between self and allogeneic differences. This was emphasized by the fact that while one study reported that Periplaneta americana responded to grafts donated by the closely related genus Blatta orientalis, the data reported elsewhere, using a different assay system, found no such reactivity. Since we have subsequently reported, using a direct histological assay, that Periplaneta can in fact recognize and destroy integumentary allografts, we initiated a study to hopefully sort out the enigma presented by previous data using Blatta as a transplant donor. Integument from Blatta orientalis was transplanted orthotopically onto Periplaneta americana, and at various time points post-transplant, scored histologically for the survival of the subcuticular epidermal layer. The results clearly demonstrated that Periplaneta reacted to the Blatta tissue, because approximately 82% of the grafts had the epidermal layer destroyed by day 7 posttransplant. The kinetics of the response to Blatta was more in line with our allograft data, which would be in agreement with other work indicating that the closer the donor and recipient are on the phylogenetic tree, the less intense the reactivity to the foreign transplant.

  16. Characterization of an Invertebrate-Type Dopamine Receptor of the American Cockroach, Periplaneta americana

    Directory of Open Access Journals (Sweden)

    Britta Troppmann

    2014-01-01

    Full Text Available We have isolated a cDNA coding for a putative invertebrate-type dopamine receptor (Peadop2 from P. americana brain by using a PCR-based strategy. The mRNA is present in samples from brain and salivary glands. We analyzed the distribution of the PeaDOP2 receptor protein with specific affinity-purified polyclonal antibodies. On Western blots, PeaDOP2 was detected in protein samples from brain, subesophageal ganglion, thoracic ganglia, and salivary glands. In immunocytochemical experiments, we detected PeaDOP2 in neurons with their somata being located at the anterior edge of the medulla bilaterally innervating the optic lobes and projecting to the ventro-lateral protocerebrum. In order to determine the functional and pharmacological properties of the cloned receptor, we generated a cell line constitutively expressing PeaDOP2. Activation of PeaDOP2-expressing cells with dopamine induced an increase in intracellular cAMP. In contrast, a C-terminally truncated splice variant of this receptor did not exhibit any functional property by itself. The molecular and pharmacological characterization of the first dopamine receptor from P. americana provides the basis for forthcoming studies focusing on the significance of the dopaminergic system in cockroach behavior and physiology.

  17. Characterization of an invertebrate-type dopamine receptor of the American cockroach, Periplaneta americana.

    Science.gov (United States)

    Troppmann, Britta; Balfanz, Sabine; Krach, Christian; Baumann, Arnd; Blenau, Wolfgang

    2014-01-06

    We have isolated a cDNA coding for a putative invertebrate-type dopamine receptor (Peadop2) from P. americana brain by using a PCR-based strategy. The mRNA is present in samples from brain and salivary glands. We analyzed the distribution of the PeaDOP2 receptor protein with specific affinity-purified polyclonal antibodies. On Western blots, PeaDOP2 was detected in protein samples from brain, subesophageal ganglion, thoracic ganglia, and salivary glands. In immunocytochemical experiments, we detected PeaDOP2 in neurons with their somata being located at the anterior edge of the medulla bilaterally innervating the optic lobes and projecting to the ventro-lateral protocerebrum. In order to determine the functional and pharmacological properties of the cloned receptor, we generated a cell line constitutively expressing PeaDOP2. Activation of PeaDOP2-expressing cells with dopamine induced an increase in intracellular cAMP. In contrast, a C-terminally truncated splice variant of this receptor did not exhibit any functional property by itself. The molecular and pharmacological characterization of the first dopamine receptor from P. americana provides the basis for forthcoming studies focusing on the significance of the dopaminergic system in cockroach behavior and physiology.

  18. Isolasi Senyawa Aktif Ekstrak Etanol Biji Alpukat (Persea americana dan Uji Toksisitas Terhadap Artemia Salina Leach

    Directory of Open Access Journals (Sweden)

    Andi Nur Fitriani Abubakar

    2014-07-01

    Full Text Available Avocado seed (Persea americana is recognized as one of medicinal plants. It contains several secondary metabolites, which have toxic activity. However, efforts to identify active compounds from avocado seeds (Persea americana are still relatively rare. Therefore, isolation and toxicity assay have been conducted foward the active compound of avocado seed. Maceration one kilogram of seed dried powder by ethanol obtained 49,7464 gram extract. Separation of etanol extract by column chromatography generated 0,0698 grams of pure white needle crytal, which is positively triterpenoid based on Lieberman-Buchard test. In addition, infrared spectrum showed the existence of OH, C=C, C-C, C=O, -C-H, -CH3,-CH2 and C-O stretch, which support the presumed compound. The result of toxicity test on Artemia salina Leach showed that the extract, fraction and pure isolates of the etanol extract are toxic with LC50 values 13,274 g/mL; 9,528 g/mL and 8,128 g/mL, respectively.

  19. Pro-apoptotic effect of Persea americana var. Hass (avocado) on Jurkat lymphoblastic leukemia cells.

    Science.gov (United States)

    Bonilla-Porras, Angelica R; Salazar-Ospina, Andrea; Jimenez-Del-Rio, Marlene; Pereañez-Jimenez, Andres; Velez-Pardo, Carlos

    2013-11-05

    Abstract Context: Therapy for leukemia has a limited efficacy. There is a need to search for alternative anti-leukemia therapies. Persea americana Mill var. Hass (Lauraceae) is a tropical fruit (avocado) that might be used against cancer. Objective: To investigate whether P. americana induces death in Jurkat lymphoblastic leukemia cells. Materials and methods: Four ethanol extracts (0.1, 0.5, 1, 2 and 5 mg/mL) from avocado fruit (endocarp, whole seed, seed and leaves) were analyzed against Jurkat cells. Hydrogen peroxide generation by oxidation of 2',7'-dichlorodihydrofluorescein diacetate to the fluorescent compound 2',7'-dichlorfluorescein assay, acridine orange/ethidium bromide staining, flow cytometry analysis of annexin-V/7-amino-actinomycin, mitochondrial membrane potential and immunocytochemistry detection of transcription factor p53, caspase-3 and apoptosis-inducing factor (AIF) were evaluated. Results: Endocarp, seed, whole seed, and leaf (0.1 mg/mL) extracts induced significant apoptosis in Jurkat cells (p avocado and its therapeutic action on leukemia.

  20. ECOPHYSIOLOGICAL ANALYSIS OF GENIPA AMERICANA L. SEEDS IN AN INDUCED SOIL SEED BANK

    Directory of Open Access Journals (Sweden)

    Francesca Salla

    2016-03-01

    Full Text Available This work studied the behavior of G. americana L. (Rubiaceae seeds in an induced soil seed bank. This study was conducted in Lavras-MG in a seasonal semideciduous forest of the Federal University of Lavras. Seeds collected in the area were cleaned and analyzed (water content, viability and desiccation tolerance. Soil banks were installed in two distinct areas (top of hill and riparian forest located in the understory of the forest. Seeds were placed in nylon nets and covered with a thin litter layer that was previously removed for this purpose. Monthly assessment of germination, seedling emergence, seed and soil water content, and the characterization of the initial seedling growth was performed. It was observed that G. americana seeds forms a transitory seed bank, with maintenance of its viability until the fourth month after disposal in natural environment. In general, the seed bank located in the riparian forest area showed the best potential for seedling establishment in a natural environment, which supports the ecological behavior of this species.

  1. La sociedad de la información como una sociedad en transición: Caracterización, tendencias y paradojas

    Directory of Open Access Journals (Sweden)

    Migdalia Pineda

    2003-01-01

    Full Text Available En este artículo se presentan los principales rasgos que caracterizan a la sociedad de la información como una sociedad en transición y se asoman algunas de sus tendencias futuras. Los planteamientos realizados forman parte de una investigación cualitativa que se sustenta en un análisis crítico de lo señalado por diversos autores sobre la sociedad de la información y el conjunto de cambios que las tecnologías de la información y la comunicación producen en diversos órdenes de la vida social (cultural, económico, laboral, comunicacional y de conocimiento, insistiendo en sus posibilidades y contradicciones. Se considera la premisa que, en ese conjunto de cambios, el ser humano es quien adquiere jerarquía por encima de la tecnología y que la sociedad de la información debe ser vista como una oportunidad para rescatar las diferencias, la diversidad y para avanzar hacia una sociedad que, ayudada por las TIC, potencie el conocimiento y el ingenio humano para resolver problemas del entorno.

  2. La economía en una sociedad violenta

    Directory of Open Access Journals (Sweden)

    Mauricio Rubio

    1998-08-01

    Full Text Available Este artículo indaga porte contribución de la economía, como disciplina que aporta al conocimiento de una realidad social, en la comprensión de la relación entre el crimen, la violencia y el desarrollo en Colombia. Para ello y luego de reconocer que la violencia constituye el problema económico más grave que afronta el país, se examinan críticamente los conocimientos existentes sobre la violencia y su impacto en la sociedad colombiana. A continuación se analizan los vacíos en el diagnóstico de este fenómeno y se muestran las limitaciones de la disciplina económica en la comprensión del crimen y la violencia. Finalmente, el artículo discute acerca del papel que puede jugar la, economía en el diseño y evaluación de las políticas contra la violencia, para concluir; acerca de las redefiniciones necesarias en la medición de las variables de la violencia y en el acopio de información para un mejor diseño y aplicación; de políticas, recurriendo incluso a metodologías extrañas a la disciplina como los testimonios, los estudios de caso y las historias de vida, sin rechazar el papel de la teoría y la estadística.

  3. Colaboración educativa en la sociedad del conocimiento

    Directory of Open Access Journals (Sweden)

    Ángela Martín Gutiérrez

    2013-04-01

    Full Text Available El mundo globalizado en el estamos inmersos plantea retos y exigencias a los centros educativos. La participación y la colaboración surgen como desafíos cada vez más acuciantes en la sociedad actual, y el futuro de la educación pública está orientado a la implicación de los centros educativos en sus comunidades socioculturales. En la Ley Orgánica de Educación (LOE, 2006 se habla de la participación como principio constitucional y la necesidad de colaborar y trabajar en equipo de manera interna y externa al centro. Ante estos supuestos teóricos, planteamos la necesidad de conocer las relaciones de colaboración que los centros educativos de secundaria mantienen con el entorno y si para ello cuentan con el apoyo de las tecnologías. Entre los resultados y conclusiones de este estudio, podemos destacar que las relaciones más habituales son las efectuadas con otros centros educativos y con las instituciones locales. Para establecerlas, más de la mitad de los docentes andaluces de secundaria no cuentan con las tecnologías, aunque más de 60% estarían interesados en encontrarse inmersos en redes educativas, profesionales y sociales. Los resultados reflejan que debemos potenciar las redes y comunidades virtuales como puentes para crear relaciones de colaboración, estables y fuertes, que promuevan mejoras y cambios significativos en los centros educativos.

  4. Simulation of the gasification of animal wastes in a dual gasifier using Aspen Plus®

    International Nuclear Information System (INIS)

    Fernandez-Lopez, M.; Pedroche, J.; Valverde, J.L.; Sanchez-Silva, L.

    2017-01-01

    Highlights: • The gasification of manure was evaluated using the software Aspen Plus®. • Composition and LHV of the obtained syngas depends on the operating conditions. • CO 2 net emissions for the steam and CO 2 gasification processes were calculated. • Manure steam gasification can be used as feedstock for Fischer-Tropsch. • Manure CO 2 gasification lead to a syngas suitable for energy production. - Abstract: The gasification of an animal waste biomass (manure) in a dual gasifier was studied using the software Aspen Plus®. For this purpose, a model based on a Gibbs free energy reactor was considered. Effects of the gasification temperature, the gasifying/biomass ratio and the use of steam and CO 2 as the gasifying agents on the composition and the low heating value (LHV) of the produced syngas were evaluated. In this sense, the H 2 /CO ratio and the LHV were the parameters calculated to stablish the best operating conditions for the production of either hydrocarbons via Fischer-Tropsch or energy. Furthermore, the CO 2 net emissions generated by the gasification process were also important in the selection of the best operating conditions from an environmental point of view. The obtained results showed that for both gasifying agents the H 2 and CO production was favoured at high temperatures whereas the production of CH 4 and CO 2 was favoured at low ones. On the other hand, the H 2 production was higher when steam was used as the gasifying agent and the formation of CO was enhanced when CO 2 was considered as gasification agent. An increase of the gasifying agent/biomass ratio had a negatively influence on the production of CH 4 , leading to a decrease of the LHV. Therefore, steam as the gasifying agent and high temperatures favoured the obtaining of a syngas suitable for the Fischer-Tropsch process whereas CO 2 and low gasification temperatures enhanced a syngas with a high LHV which could be used for energy production. Finally, the net CO 2

  5. Changes in avian and plant communities of aspen woodlands over 12 years after livestock removal in the northwestern Great Basin

    Science.gov (United States)

    Earnst, Susan L.; Dobkin, David S.; Ballard, Jennifer A.

    2012-01-01

    Riparian and quaking aspen (Populus tremuloides) woodlands are centers of avian abundance and diversity in the western United States, but they have been affected adversely by land use practices, particularly livestock grazing. In 1990, cattle were removed from a 112,500-ha national wildlife refuge in southeastern Oregon. Thereafter, we monitored changes in vegetation and bird abundance in years 1–3 (phase 1) and 10–12 (phase 2) in 17 riparian and 9 snow-pocket aspen plots. On each 1.5-ha plot, we sampled vegetation in 6 transects. Three times during each breeding season, observers recorded all birds 50 m to each side of the plot's 150-m centerline for 25 minutes. We analyzed data with multivariate analysis of variance and paired t tests with p values adjusted for multiple comparisons. In both periods, riparian and snow-pocket aspen produced extensive regeneration of new shoots (x̄ = 2646 stems/ha and 7079 stems/ha, respectively). By phase 2, a 64% increase in medium-diameter trees in riparian stands indicated successful recruitment into the overstory, but this pattern was not seen in snow-pocket stands, where the density of trees was over 2 times greater. By phase 2 in riparian and snow-pocket stands, native forb cover had increased by 68% and 57%, respectively, mesic shrub cover had increased by 29% and 58%, and sagebrush cover had decreased by 24% and 31%. Total avian abundance increased by 33% and 39% in riparian and snow-pocket aspen, respectively, ground or understory nesters increased by 133% and 67% and overstory nesters increased by 34% and 33%. Similarly, ground or understory foragers increased by 25% and 32%, aerial foragers by 55% and 57%, and overstory foragers by 66% and 43%. We interpreted the substantial regeneration of aspen shoots, increased densities of riparian forbs and shrubs, and increased avian abundances as a multitrophic-level response to the total removal of livestock and as substantial movement toward recovery of biological integrity.

  6. The effect of warming and enhanced ultraviolet radiation on gender-specific emissions of volatile organic compounds from European aspen

    Energy Technology Data Exchange (ETDEWEB)

    Maja, Mengistu M., E-mail: mengistu.maja@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland); Kasurinen, Anne; Holopainen, Toini [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland); Julkunen-Tiitto, Riitta [University of Eastern Finland, Department of Biology, P.O. Box 111, 80101 Joensuu (Finland); Holopainen, Jarmo K. [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland)

    2016-03-15

    Different environmental stress factors often occur together but their combined effects on plant secondary metabolism are seldom considered. We studied the effect of enhanced ultraviolet (UV-B) (31% increase) radiation and temperature (ambient + 2 °C) singly and in combination on gender-specific emissions of volatile organic compounds (VOCs) from 2-year-old clones of European aspen (Populus tremula L.). Plants grew in 36 experimental plots (6 replicates for Control, UV-A, UV-B, T, UV-A + T and UV-B + T treatments), in an experimental field. VOCs emitted from shoots were sampled from two (1 male and 1 female) randomly selected saplings (total of 72 saplings), per plot on two sampling occasions (June and July) in 2014. There was a significant UV-B × temperature interaction effect on emission rates of different VOCs. Isoprene emission rate was increased due to warming, but warming also modified VOC responses to both UV-A and UV-B radiation. Thus, UV-A increased isoprene emissions without warming, whereas UV-B increased emissions only in combination with warming. Warming-modified UV-A and UV-B responses were also seen in monoterpenes (MTs), sesquiterpenes (SQTs) and green leaf volatiles (GLVs). MTs showed also a UV × gender interaction effect as females had higher emission rates under UV-A and UV-B than males. UV × gender and T × gender interactions caused significant differences in VOC blend as there was more variation (more GLVs and trans-β-caryophyllene) in VOCs from female saplings compared to male saplings. VOCs from the rhizosphere were also collected from each plot in two exposure seasons, but no significant treatment effects were observed. Our results suggest that simultaneous warming and elevated-UV-radiation increase the emission of VOCs from aspen. Thus the contribution of combined environmental factors on VOC emissions may have a greater impact to the photochemical reactions in the atmosphere compared to the impact of individual factors acting alone

  7. The effect of warming and enhanced ultraviolet radiation on gender-specific emissions of volatile organic compounds from European aspen

    International Nuclear Information System (INIS)

    Maja, Mengistu M.; Kasurinen, Anne; Holopainen, Toini; Julkunen-Tiitto, Riitta; Holopainen, Jarmo K.

    2016-01-01

    Different environmental stress factors often occur together but their combined effects on plant secondary metabolism are seldom considered. We studied the effect of enhanced ultraviolet (UV-B) (31% increase) radiation and temperature (ambient + 2 °C) singly and in combination on gender-specific emissions of volatile organic compounds (VOCs) from 2-year-old clones of European aspen (Populus tremula L.). Plants grew in 36 experimental plots (6 replicates for Control, UV-A, UV-B, T, UV-A + T and UV-B + T treatments), in an experimental field. VOCs emitted from shoots were sampled from two (1 male and 1 female) randomly selected saplings (total of 72 saplings), per plot on two sampling occasions (June and July) in 2014. There was a significant UV-B × temperature interaction effect on emission rates of different VOCs. Isoprene emission rate was increased due to warming, but warming also modified VOC responses to both UV-A and UV-B radiation. Thus, UV-A increased isoprene emissions without warming, whereas UV-B increased emissions only in combination with warming. Warming-modified UV-A and UV-B responses were also seen in monoterpenes (MTs), sesquiterpenes (SQTs) and green leaf volatiles (GLVs). MTs showed also a UV × gender interaction effect as females had higher emission rates under UV-A and UV-B than males. UV × gender and T × gender interactions caused significant differences in VOC blend as there was more variation (more GLVs and trans-β-caryophyllene) in VOCs from female saplings compared to male saplings. VOCs from the rhizosphere were also collected from each plot in two exposure seasons, but no significant treatment effects were observed. Our results suggest that simultaneous warming and elevated-UV-radiation increase the emission of VOCs from aspen. Thus the contribution of combined environmental factors on VOC emissions may have a greater impact to the photochemical reactions in the atmosphere compared to the impact of individual factors acting alone

  8. El modelo de gobierno corporativo de una sociedad depende de su estructura legal -Diferencias entre sociedades anónimas y/o limitadas-

    Directory of Open Access Journals (Sweden)

    Elizabeth Prada

    2009-12-01

    Full Text Available El presente documento tiene como finalidad comprobar que a pesar de existir unos temas comunes a analizar en el gobierno corporativo de cualquier compañía, el mismo dependerá de su estructura legal societaria, entendiendo por esta las diferentes clases de sociedades que existen en Colombia. De acuerdo con los resultados financieros obtenidos y la identificación de las dos sociedades predominantes en la mayoría de los niveles financieros a los que hace referencia el documento, se hacen unas recomendaciones sobre los principios y medidas que pueden ser tomados como referencia al momento de crear un modelo de gobierno corporativo acorde con la realidad y necesidades de las sociedades anónimas y las limitadas.

  9. Comunicação e culturas regionais e a sociedade digital no Brasil

    Directory of Open Access Journals (Sweden)

    Doris Fagundes Haussen

    2010-11-01

    Full Text Available A globalização da economia e a evolução tecnológica têm provocado significativas alterações na sociedade. As fronteiras geográficas são atravessadas por referentes virtuais que incidem diretamente sobre acomunicação e a cultura. Este artigo propõe-se, assim, a analisar o fenômeno, procurando identificar a sua influência sobre a sociedade brasileira, sua cultura e identidade. Estuda, também, a inserção do País na sociedade digital.

  10. El ahorro fiscal de las cooperativas en el impuesto sobre Sociedades en España

    OpenAIRE

    Herrero Blasco, Aurelio

    2015-01-01

    [ES] El objeto de este artículo es medir el ahorro fiscal que procede del Impuesto sobre Sociedades de las cooperativas en España para el período 1999-2009. La metodología utilizada ha sido un estudio longitudinal en el cual se ha analizado la recaudación total en España por tipos impositivos. Se ha analizado el Impuesto sobre Sociedades en general y posteriormente el Tipo Impositivo Efectivo (TIE) de las Sociedades Cooperativas. Los resultados más importantes son la constatación de diferenc...

  11. Simulating the effects of climate change on population connectivity of American marten (Martes americana) in the northern Rocky Mountains, USA

    Science.gov (United States)

    T. N. Wasserman; S. A. Cushman; A. S. Shirk; E. L. Landguth; J. S. Littell

    2012-01-01

    We utilize empirically derived estimates of landscape resistance to assess current landscape connectivity of American marten (Martes americana) in the northern Rocky Mountains, USA, and project how a warming climate may affect landscape resistance and population connectivity in the future. We evaluate the influences of five potential future temperature scenarios...

  12. Use of culture filtrates of Ceratocystis ulmi as a bioassay to screen for disease tolerant Ulmus americana

    Science.gov (United States)

    Paula M. Pijut; Subash C. Domir; R. Daniel Lineberger; Lawrence R. Schreiber

    1990-01-01

    Callus cultures of elm (Ulmus americana L.) derived from Dutch elm disease susceptible, intermediate-resistant, and resistant genotypes were exposed to the culture filtrates of three pathogenic isolates of Ceratocystis ulmi, the causal agent of Dutch elm disease. Callus fresh weights, cell viability, and reactions of stem cuttings...

  13. The Complex of Scolytinae Inhabiting Persea borbonia and Persea americana in Florida: Possible Interactions with Other Species

    Science.gov (United States)

    A diverse number of Scolytinae (Coleoptera: Curculionidae) have been found inhabiting Persea borbonia and P. americana in Florida during 2009 and 2010. They include the exotic redbay ambrosia beetle, Xyleborus glabratus, vector of Raffaelea lauricola, X. volvulus, X. ferrugineus, Xylosandrus crassiu...

  14. Seed rescue from photoperiod sensitive American Joint Vetch (Aeschynomene americana L.) accessions using hydroponic cloning and aeroponics

    Science.gov (United States)

    American joint vetch, Aeschynomene Americana L. is a self-pollinated tropical pasture legume and the USDA, ARS, PGRCU curates 137 accessions from the United States, S. America, Mexico, Central America, and Zambia. Many accessions in this collection are photoperiod sensitive due to their typical flow...

  15. The Core Gut Microbiome of the American Cockroach, Periplaneta americana, Is Stable and Resilient to Dietary Shifts.

    Science.gov (United States)

    Tinker, Kara A; Ottesen, Elizabeth A

    2016-11-15

    The omnivorous cockroach Periplaneta americana hosts a diverse hindgut microbiota encompassing hundreds of microbial species. In this study, we used 16S rRNA gene sequencing to examine the effect of diet on the composition of the P. americana hindgut microbial community. Results show that the hindgut microbiota of P. americana exhibit a highly stable core microbial community with low variance in compositions between individuals and minimal community change in response to dietary shifts. This core hindgut microbiome is shared between laboratory-hosted and wild-caught individuals, although wild-caught specimens exhibited a higher diversity of low-abundance microbes that were lost following extended cultivation under laboratory conditions. This taxonomic stability strongly contrasts with observations of the gut microbiota of mammals, which have been shown to be highly responsive to dietary change. A comparison of P. americana hindgut samples with human fecal samples indicated that the cockroach hindgut community exhibited higher alpha diversity but a substantially lower beta diversity than the human gut microbiome. This suggests that cockroaches have evolved unique mechanisms for establishing and maintaining a diverse and stable core microbiome. The gut microbiome plays an important role in the overall health of its host. A healthy gut microbiota typically assists with defense against pathogens and the digestion and absorption of nutrients from food, while dysbiosis of the gut microbiota has been associated with reduced health. In this study, we examined the composition and stability of the gut microbiota from the omnivorous cockroach Periplaneta americana. We found that P. americana hosts a diverse core gut microbiome that remains stable after drastic long-term changes in diet. While other insects, notably ant and bee species, have evolved mechanisms for maintaining a stable association with specific gut microbiota, these insects typically host low-diversity gut

  16. Studies on the products resulting from the conversion of aspen poplar to an oil

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Mathews, J F; Pepper, J M; Zohdi, H

    1981-01-01

    The reactions involved in the conversion of aspen poplar into a variety of chemical products as a result of its interaction with CO and H/sub 2/O in the presence of Na/sub 2/CO/sub 3/ at elevated temperatures and pressures are considered. The original C content of the wood is distributed between an oil phase, a complex mixture of highly oxygenated H/sub 2/O-soluble products many of which were identified as low-molecular-weight aliphatic alcohols, ketones, and acids, and a gaseous phase consisting of mainly H and CO/sub 2/. Using model substances (cellulose, cellobiose, -D-glucose, D-fructose, D-xylose, sorbitol, glycerol, and an isolated lignin) information was obtained on the origin of the oil and of the H/sub 2/O-soluble products. Studies at 160 degrees - 360 degrees revealed a marked exothermic reaction occurring at 200-240 degrees for wood and cellulose, which was reflected in the nature of the resulting product. With increasing temperature an increase in the yields of the H/sub 2/O-souluble derivatives and also a change in their relative abundance was observed.

  17. Dying piece by piece: carbohydrate dynamics in aspen (Populus tremuloides) seedlings under severe carbon stress.

    Science.gov (United States)

    Wiley, Erin; Hoch, Günter; Landhäusser, Simon M

    2017-11-02

    Carbon starvation as a mechanism of tree mortality is poorly understood. We exposed seedlings of aspen (Populus tremuloides) to complete darkness at 20 or 28 °C to identify minimum non-structural carbohydrate (NSC) concentrations at which trees die and to see if these levels vary between organs or with environmental conditions. We also first grew seedlings under different shade levels to determine if size affects survival time under darkness due to changes in initial NSC concentration and pool size and/or respiration rates. Darkness treatments caused a gradual dieback of tissues. Even after half the stem had died, substantial starch reserves were still present in the roots (1.3-3% dry weight), indicating limitations to carbohydrate remobilization and/or transport during starvation in the absence of water stress. Survival time decreased with increased temperature and with increasing initial shade level, which was associated with smaller biomass, higher respiration rates, and initially smaller NSC pool size. Dead tissues generally contained no starch, but sugar concentrations were substantially above zero and differed between organs (~2% in stems up to ~7.5% in leaves) and, at times, between temperature treatments and initial, pre-darkness shade treatments. Minimum root NSC concentrations were difficult to determine because dead roots quickly began to decompose, but we identify 5-6% sugar as a potential threshold for living roots. This variability may complicate efforts to identify critical NSC thresholds below which trees starve. © Society for Experimental Biology 2017.

  18. Elevated CO2 response of photosynthesis depends on ozone concentration in aspen

    International Nuclear Information System (INIS)

    Noormets, Asko; Kull, Olevi; Sober, Anu; Kubiske, Mark E.; Karnosky, David F.

    2010-01-01

    The effect of elevated CO 2 and O 3 on apparent quantum yield (φ), maximum photosynthesis (P max ), carboxylation efficiency (V cmax ) and electron transport capacity (J max ) at different canopy locations was studied in two aspen (Populus tremuloides) clones of contrasting O 3 tolerance. Local light climate at every leaf was characterized as fraction of above-canopy photosynthetic photon flux density (%PPFD). Elevated CO 2 alone did not affect φ or P max , and increased J max in the O 3 -sensitive, but not in the O 3 -tolerant clone. Elevated O 3 decreased leaf chlorophyll content and all photosynthetic parameters, particularly in the lower canopy, and the negative impact of O 3 increased through time. Significant interaction effect, whereby the negative impact of elevated O 3 was exaggerated by elevated CO 2 was seen in Chl, N and J max , and occurred in both O 3 -tolerant and O 3 -sensitive clones. The clonal differences in the level of CO 2 x O 3 interaction suggest a relationship between photosynthetic acclimation and background O 3 concentration. - Photosynthetic acclimation to elevated CO 2 depends on the background oxidant levels.

  19. Dual RBFNNs-Based Model-Free Adaptive Control With Aspen HYSYS Simulation.

    Science.gov (United States)

    Zhu, Yuanming; Hou, Zhongsheng; Qian, Feng; Du, Wenli

    2017-03-01

    In this brief, we propose a new data-driven model-free adaptive control (MFAC) method with dual radial basis function neural networks (RBFNNs) for a class of discrete-time nonlinear systems. The main novelty lies in that it provides a systematic design method for controller structure by the direct usage of I/O data, rather than using the first-principle model or offline identified plant model. The controller structure is determined by equivalent-dynamic-linearization representation of the ideal nonlinear controller, and the controller parameters are tuned by the pseudogradient information extracted from the I/O data of the plant, which can deal with the unknown nonlinear system. The stability of the closed-loop control system and the stability of the training process for RBFNNs are guaranteed by rigorous theoretical analysis. Meanwhile, the effectiveness and the applicability of the proposed method are further demonstrated by the numerical example and Aspen HYSYS simulation of distillation column in crude styrene produce process.

  20. Full employment and competition in the Aspen economic model: implications for modeling acts of terrorism.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.; Ehlen, Mark Andrew

    2004-11-01

    Acts of terrorism could have a range of broad impacts on an economy, including changes in consumer (or demand) confidence and the ability of productive sectors to respond to changes. As a first step toward a model of terrorism-based impacts, we develop here a model of production and employment that characterizes dynamics in ways useful toward understanding how terrorism-based shocks could propagate through the economy; subsequent models will introduce the role of savings and investment into the economy. We use Aspen, a powerful economic modeling tool developed at Sandia, to demonstrate for validation purposes that a single-firm economy converges to the known monopoly equilibrium price, output, and employment levels, while multiple-firm economies converge toward the competitive equilibria typified by lower prices and higher output and employment. However, we find that competition also leads to churn by consumers seeking lower prices, making it difficult for firms to optimize with respect to wages, prices, and employment levels. Thus, competitive firms generate market ''noise'' in the steady state as they search for prices and employment levels that will maximize profits. In the context of this model, not only could terrorism depress overall consumer confidence and economic activity but terrorist acts could also cause normal short-run dynamics to be misinterpreted by consumers as a faltering economy.

  1. Volatile-Mediated within-Plant Signaling in Hybrid Aspen: Required for Systemic Responses.

    Science.gov (United States)

    Li, Tao; Blande, James D

    2017-04-01

    Plant volatiles play crucial roles in signaling between plants and their associated community members, but their role in within-plant signaling remains largely unexplored, particularly under field conditions. Using a system comprising the hybrid aspen (Populus tremula x tremuloides) and the specialized herbivorous leaf beetle (Phratora laticollis) and, combining field, greenhouse and laboratory experiments, we examined whether local damage triggered systemic responses in undamaged branches that lack vascular connection to the damaged branches, and to what extent this was caused by airborne volatile signals versus internal signals. An experiment tracing dye through the vasculature of saplings revealed no downward movement of the dye from upper to lower branches, suggesting a lack of vascular connectivity among branches. However, we found under both field and laboratory conditions that herbivore feeding on upper branches elicited volatile emissions by undamaged lower branches. Greenhouse experiments manipulating air contact between damaged and undamaged branches showed that systemic induction of volatiles was almost eliminated when air contact was interrupted. Our findings clearly demonstrate that herbivore-induced volatiles overcome vascular constraints and mediate within-plant signaling. Further, we found that volatile signaling led to induction of different classes of volatiles under field and environment controlled conditions, with a weaker response observed in the field. This difference not only reflects the dose- and time-dependent nature of volatile signaling, but also points out that future studies should focus more on field observations to better understand the ecological role of volatile-mediated within-plant signaling.

  2. ASPEN: A fully kinetic, reduced-description particle-in-cell model for simulating parametric instabilities

    International Nuclear Information System (INIS)

    Vu, H.X.; Bezzerides, B.; DuBois, D.F.

    1999-01-01

    A fully kinetic, reduced-description particle-in-cell (RPIC) model is presented in which deviations from quasineutrality, electron and ion kinetic effects, and nonlinear interactions between low-frequency and high-frequency parametric instabilities are modeled correctly. The model is based on a reduced description where the electromagnetic field is represented by three separate temporal envelopes in order to model parametric instabilities with low-frequency and high-frequency daughter waves. Because temporal envelope approximations are invoked, the simulation can be performed on the electron time scale instead of the time scale of the light waves. The electrons and ions are represented by discrete finite-size particles, permitting electron and ion kinetic effects to be modeled properly. The Poisson equation is utilized to ensure that space-charge effects are included. The RPIC model is fully three dimensional and has been implemented in two dimensions on the Accelerated Strategic Computing Initiative (ASCI) parallel computer at Los Alamos National Laboratory, and the resulting simulation code has been named ASPEN. The authors believe this code is the first particle-in-cell code capable of simulating the interaction between low-frequency and high-frequency parametric instabilities in multiple dimensions. Test simulations of stimulated Raman scattering, stimulated Brillouin scattering, and Langmuir decay instability are presented

  3. Thermochemical Equilibrium Model of Synthetic Natural Gas Production from Coal Gasification Using Aspen Plus

    Directory of Open Access Journals (Sweden)

    Rolando Barrera

    2014-01-01

    Full Text Available The production of synthetic or substitute natural gas (SNG from coal is a process of interest in Colombia where the reserves-to-production ratio (R/P for natural gas is expected to be between 7 and 10 years, while the R/P for coal is forecasted to be around 90 years. In this work, the process to produce SNG by means of coal-entrained flow gasifiers is modeled under thermochemical equilibrium with the Gibbs free energy approach. The model was developed using a complete and comprehensive Aspen Plus model. Two typical technologies used in entrained flow gasifiers such as coal dry and coal slurry are modeled and simulated. Emphasis is put on interactions between the fuel feeding technology and selected energy output parameters of coal-SNG process, that is, energy efficiencies, power, and SNG quality. It was found that coal rank does not significantly affect energy indicators such as cold gas, process, and global efficiencies. However, feeding technology clearly has an effect on the process due to the gasifying agent. Simulations results are compared against available technical data with good accuracy. Thus, the proposed model is considered as a versatile and useful computational tool to study and optimize the coal to SNG process.

  4. Aspen SUCROSE TRANSPORTER3 Allocates Carbon into Wood Fibers1[C][W

    Science.gov (United States)

    Mahboubi, Amir; Ratke, Christine; Gorzsás, András; Kumar, Manoj; Mellerowicz, Ewa J.; Niittylä, Totte

    2013-01-01

    Wood formation in trees requires carbon import from the photosynthetic tissues. In several tree species, including Populus species, the majority of this carbon is derived from sucrose (Suc) transported in the phloem. The mechanism of radial Suc transport from phloem to developing wood is not well understood. We investigated the role of active Suc transport during secondary cell wall formation in hybrid aspen (Populus tremula × Populus tremuloides). We show that RNA interference-mediated reduction of PttSUT3 (for Suc/H+ symporter) during secondary cell wall formation in developing wood caused thinner wood fiber walls accompanied by a reduction in cellulose and an increase in lignin. Suc content in the phloem and developing wood was not significantly changed. However, after 13CO2 assimilation, the SUT3RNAi lines contained more 13C than the wild type in the Suc-containing extract of developing wood. Hence, Suc was transported into developing wood, but the Suc-derived carbon was not efficiently incorporated to wood fiber walls. A yellow fluorescent protein:PttSUT3 fusion localized to plasma membrane, suggesting that reduced Suc import into developing wood fibers was the cause of the observed cell wall phenotype. The results show the importance of active Suc transport for wood formation in a symplasmically phloem-loading tree species and identify PttSUT3 as a principal transporter for carbon delivery into secondary cell wall-forming wood fibers. PMID:24170204

  5. Antiviral effect of compounds derived from the seeds of Mammea americana and Tabernaemontana cymosa on Dengue and Chikungunya virus infections.

    Science.gov (United States)

    Gómez-Calderón, Cecilia; Mesa-Castro, Carol; Robledo, Sara; Gómez, Sergio; Bolivar-Avila, Santiago; Diaz-Castillo, Fredyc; Martínez-Gutierrez, Marlen

    2017-01-18

    The transmission of Dengue virus (DENV) and Chikungunya virus (CHIKV) has increased worldwide, due in part to the lack of a specific antiviral treatment. For this reason, the search for compounds with antiviral potential, either as licensed drugs or in natural products, is a research priority. The objective of this study was to identify some of the compounds that are present in Mammea americana (M. americana) and Tabernaemontana cymosa (T. cymosa) plants and, subsequently, to evaluate their cytotoxicity in VERO cells and their potential antiviral effects on DENV and CHIKV infections in those same cells. Dry ethanolic extracts of M. americana and T. cymosa seeds were subjected to open column chromatographic fractionation, leading to the identification of four compounds: two coumarins, derived from M. americana; and lupeol acetate and voacangine derived from T. cymosa.. The cytotoxicity of each compound was subsequently assessed by the MTT method (at concentrations from 400 to 6.25 μg/mL). Pre- and post-treatment antiviral assays were performed at non-toxic concentrations; the resulting DENV inhibition was evaluated by Real-Time PCR, and the CHIKV inhibition was tested by the plating method. The results were analyzed by means of statistical analysis. The compounds showed low toxicity at concentrations ≤ 200 μg/mL. The compounds coumarin A and coumarin B, which are derived from the M. americana plant, significantly inhibited infection with both viruses during the implementation of the two experimental strategies employed here (post-treatment with inhibition percentages greater than 50%, p treatment with percentages of inhibition greater than 40%, p treatment strategy (at inhibition percentages greater than 70%, p treating Dengue and Chikungunya fever. Additionally, lupeol acetate and voacangine efficiently inhibit infection with DENV, also turning them into promising antivirals for Dengue fever.

  6. Sociedade cabocla: participação e diversidade na Amazônia

    Directory of Open Access Journals (Sweden)

    Raquel Caribé Grando

    2011-07-01

    Full Text Available ADAMS, Cristina; MURRIETA, Rui; NEVES, Walter (Eds.. Sociedades caboclas amazônicas: modernidade e invisibilidade. São Paulo: Annablume, 2006. 364 p.; 16 X 23 cm. ISBN 85-7419-644-4.

  7. Sociedade justa: palco para o progresso moral do homem em Kant

    Directory of Open Access Journals (Sweden)

    Celso de Moraes Pinheiro

    2004-01-01

    Full Text Available A tarefa fundamental deste texto é explorar a relação entre a finalidade moral e a finalidade política nos textos de Kant. Buscaremos mostrar que a fundação de uma sociedade justa aproxima- se da efetivação possível de um reino dos fins na terra, desde que a finalidade política da sociedade encontre-se de acordo com a finalidade moral de cada indivíduo membro da sociedade. O pleno desenvolvimento moral, requerido por Kant, apenas poderá ser atingido em uma sociedade politicamente justa, com leis orientadas pela idéia de moralidade.

  8. El desafío cultural en las sociedades del conocimiento

    Directory of Open Access Journals (Sweden)

    Carmen Rodríguez Martínez

    2017-01-01

    Full Text Available Los cambios producidos por la revolución tecnológica y la globalización tienen una influencia decisiva en la formación de las nuevas sociedades del conocimiento, con un desafío cultural importante para la sociedad y las instituciones educativas. Para la educación implica desarrollar dos horizontes pedagógicos: una pedagogía de la consciencia y una pedagogía comunitaria.

  9. La sociedad del conocimiento: inclusión o exclusión

    Directory of Open Access Journals (Sweden)

    Herminia Moreno Ríos

    2012-01-01

    Full Text Available En la historia de todas las sociedades, el conocimiento ha sido monopolizado por una élite, que lo utiliza para conservar el poder, se crearon limitantes para excluir a la masa de los saberes relevantes que otorgan la supremacía a unos y confinan a la mayoría a un trabajo físico o menos remunerado. En la actualidad surge el término Sociedad del Conocimiento para designar a nuestra sociedad, denominación que pareciera poner al alcance de todos tan preciado saber, con este trabajo pretendemos analizar si este beneficio es para todos, o es una forma disfrazada para continuar excluyendo y marginando a una gran parte de la sociedad, ya que la realidad muestra solo a una humanidad que tiene mayor acceso a la información, por la tecnología de la comunicación y el Internet, pero esa información aún debe transformarse en conocimiento utilitario, lo que en realidad existe es una sociedad de la información, que realmente no asegura que se pueda compartir con todos, los beneficios que brinda el conocimiento conductor de las sociedades, únicamente ofrece los saberes necesarios para competir en un mundo globalizado en donde cada individuo, según sus capacidades y competencias, debe encontrar su lugar.

  10. Reunión y escritura femeninas en los contextos de las independencias americanas

    Directory of Open Access Journals (Sweden)

    Patricia Martínez i Álvarez

    2010-10-01

    Full Text Available En los ámbitos de las relaciones de género y la representación de la diferencia sexual femenina, las mujeres –en el contexto de los procesos de emancipación y de construcción de los nuevos Estados en América Latina en el siglo XIX– llevaron a cabo proyectos propios de significación, al margen de los proyectos políticos que había en el escenario. El objetivo de la investigación que sustenta el artículo, es dar lectura, a la luz de los sentidos que las mujeres les dieron, a textos y contextos de aquel momento. Se recurre a fragmentos de dos de las obras literarias más importantes de finales del siglo XIX, para afirmar una historia de las mujeres que invita al final de la colonialidad americana.

  11. Reunión y escritura femeninas en los contextos de las independencias americanas

    Directory of Open Access Journals (Sweden)

    Patricia Martínez i Álvarez

    2010-01-01

    Full Text Available En los ámbitos de las relaciones de género y la representación de la diferencia sexual femenina, las mujeres en el contexto de los procesos de emancipación y de construcción de los nuevos Estados en América Latina en el siglo XIX llevaron a cabo proyectos propios de significación, al margen de los proyectos políticos que había en el escenario. El objetivo de la investigación que sustenta el artículo, es dar lectura, a la luz de los sentidos que las mujeres les dieron, a textos y contextos de aquel momento. Se recurre a fragmentos de dos de las obras literarias más importantes de finales del siglo XIX, para afirmar una historia de las mujeres que invita al final de la colonialidad americana.

  12. Cloning and characterization of the adipokinetic hormone receptor from the cockroach Periplaneta americana

    DEFF Research Database (Denmark)

    Hansen, Karina K; Hauser, Frank; Cazzamali, Giuseppe

    2006-01-01

    Cockroaches have long been used as insect models to investigate the actions of biologically active neuropeptides. Here, we describe the cloning and functional expression in Chinese hamster ovary cells of an adipokinetic hormone (AKH) G protein-coupled receptor from the cockroach Periplaneta...... americana. This receptor is only activated by various insect AKHs (we tested eight) and not by a library of 29 other insect or invertebrate neuropeptides and nine biogenic amines. Periplaneta has two intrinsic AKHs, Pea-AKH-1, and Pea-AKH-2. The Periplaneta AKH receptor is activated by low concentrations...... of both Pea-AKH-1 (EC50, 5 x 10(-9)M), and Pea-AKH-2 (EC50, 2 x 10(-9)M). Insects can be subdivided into two evolutionary lineages, holometabola (insects with a complete metamorphosis during development) and hemimetabola (incomplete metamorphosis). This paper describes the first AKH receptor from...

  13. FORMULASI NANOPARTIKEL EKSTRAK BAWANG DAYAK (Eleutherine americana (Aubl Merr DENGAN VARIASI KONSENTRASI KITOSAN-TRIPOLIFOSFAT (TPP

    Directory of Open Access Journals (Sweden)

    Ermina Pakki

    2016-12-01

    Full Text Available Ekstrak etanol Bawang dayak (Eleutherine americana (Aubl Merr. diketahui memiliki aktivitas antioksidan yang kuat sehingga berpotensi untuk dikembangkan menjadi sistem penghantaran nanopartikel. Penelitian ini bertujuan untuk mengetahui pengaruh variasi konsentrasi kitosan – tripolifosfat (TPP terhadap karakteristik fisik dari nanopartikel. Ekstrak bawang dayak diformulasi dalam bentuk nanopartikel dengan metode gelasi ionik dengan variasi konsentrasi polimer kitosan : tripolifosfat yaitu 0,5% : 0,5% (F1, 0,75% : 0,5% (F2, dan 1% : 0,5% (F3. Parameter pengujian meliputi penentuan ukuran dan indeks polidispersitas nanopartikel menggunakan particle size analyzer, pengamatan morfologi menggunakan scanning electron microscopy, pengukuran efisiensi penjerapan, dan disolusi in vitro. Hasil penelitian menunjukkan bahwa nanopartikel F1, F2, dan F3 memiliki ukuran masing-masing sebesar 256,30 nm, 376,28 nm dan 419,18 nm dengan distribusi ukuran yang relatif homogen dan efisiensi penjerapan masing-masing sebesar 69,54%, 77,51% dan 79,79%. Pengamatan morfologi dari nanopartikel menunjukkan bentuk partikel yang mendekati spheris (bulat dengan permukaan yang kasar. Profil pelepasan obat dari nanopartikel F1, F2, dan F3 pada jam ke-8 masing-masing sebesar 71,19 % (F1, 74,97% (F2 dan 80,55% (F3. Berdasarkan hasil penelitian yang telah dilakukan, dapat disimpulkan bahwa ekstrak bawang dayak dapat diformulasi dalam ukuran nanopartikel dengan karakteristik fisik yang bervariasi tergantung pada konsentrasi kitosan dan tripolifosfat yang digunakan. Kata Kunci:   Bawang dayak (Eleutherine americana (Aubl Merr., antioksidan, nanopartikel, kitosan, tripolifosfat, gelasi ionik. ABSTRACT Bawang dayak (Eleutherine americana (Aubl Merr. ethanol extract had been known to have excellent antioxidant activity that has the potential to be developed into a nanoparticle delivery systems. This study aims to determine the effect of varying concentrations of chitosan

  14. A Revista Ibero-Americana De Estratégia Em 2016 E 2017

    Directory of Open Access Journals (Sweden)

    Fernando Antonio Ribeiro Serra

    2018-04-01

    Full Text Available Nestes últimos dois anos a Revista Ibero-Americana de Estratégia (RIAE – Iberoamerican Journal of Strategic Management (IJSM tem procurado aprimorar e consolidar as mudanças realizadas desde 2014. Este movimento não poderia acontecer sem que os autores, a quem agradecemos, apesar das diversas alternativas de periódicos onde submeter os seus trabalhos, tenham escolhido a RIAE/IJSM. Também não seria possível sem o esforço e dedicação dos revisores. Agradecemos aos nossos revisores, não só pela dedicação, mas pelo esforço que têm feito em melhorar a qualidade das revisões e apontar possibilidades de melhoria, mesmo para os artigos que por ventura não sejam aceitos.

  15. Diversity and genetic structure of jenipapo (Genipa americana L. Brazilian accessions

    Directory of Open Access Journals (Sweden)

    Ana Veruska Cruz da Silva

    2014-10-01

    Full Text Available Usually known as jenipapo, Genipa americana L. is a Rubiaceae Brazilian native species. It is an important species in the restoration of Brazilian riparian forests and is one of the most promising fruit trees for sustainable harvesting programs. In this study we provide the first data on the genetic diversity and structure of a Jenipapo Germplasm Bank using inter simple sequence repeat (ISSR markers. We evaluated 160 accessions from wild populations, and the data generated from 12 ISSR primers were used to determine genetic variability via a model-based Bayesian procedure (Structure and molecular variance analysis. In addition, Shannon index, genetic diversity and Jaccard coefficients were estimated. A total of 12 primers were used, which generated 123 polymorphic fragments. Four groups were formed from the analysis of the fragments, and the CR1-2 genotype was isolated, being more divergent than the other genotypes.

  16. Morfologia das células do sangue periférico em emas (Rhea americana

    Directory of Open Access Journals (Sweden)

    Eunice Anita de Moura Fortes

    2009-06-01

    Full Text Available The rhea (Rhea americana is a South American bird of the ratite group and of the Rheiformes order. It has been exploited for economical purposes, as cattle alternative in European and South American countries. In Brazil, the State of Rio Grande do Sul is outstanding, in rhea rearing and it is in the process of implantation in the Country Northeasty Region. This work aims to describe the morphology of the blood cells in rheas. In this work ten rheas were used, regardless age and sex. Two ml of peripheral blood were collected by puncture of the brachial vein with disposable syringe. The samples here partially used to make extensions with Leishman stain. Seven types of nucleate cells have been observed through morphologic analysis on the light microscope. The erythrocyte revealed an elliptical form, with condensed nucleus of elliptical form; acidophilic cytoplasm. The thrombocyte revealed an elliptical form, with nucleus located in one of the polar regions; pale cytoplasm. As to the round-shaped leukocytes, within the granulocytes, the heterophils presented excentric, condensed, and lobulated nucleus; cytoplasm rich in fusiform salmon-colored granules. The eosinophils distinguish from the heterophils due to the round eosinophilic granules. The basophils stand out from the other granulocytes due to its large and central nucleus with round specific cytoplasmic and highly basophilic granules. Within the agranulocytes, the monocytes presented reniform nucleus, which is frequently central, with slack chromatin, with small areas of condensation; cytoplasm lightly basophilic and with vacuoles. The lymphocytes presented varies forms and sizes; large nucleus with slack chromatin with some nucleoli; scarce and basophilic cytoplasm. The cells of the peripheral blood of Rhea americana present on the light microscope morphology similar to the other birds which have already been studied.

  17. Monitoramento de fitoplâncton e microcistina no reservatório da UHE Americana Monitoring phytoplankton and microcistyn at the Americana reservoir

    Directory of Open Access Journals (Sweden)

    R.A.R. Ferreira

    2005-06-01

    Full Text Available Este trabalho foi realizado na UHE Americana, pertencente à Companhia Paulista de Força e Luz, e faz parte de um projeto de pesquisa e desenvolvimento realizado em conjunto com a Faculdade de Ciências Agronômicas - UNESP, de Botucatu. As amostragens de água foram realizadas nos meses de fevereiro, abril, junho e outubro de 2004. As características analisadas foram: temperatura da água, pH, oxigênio dissolvido, condutividade, nitrogênio total, nitrito, nitrato, amônia, fósforo total, fosfato, fosfato inorgânico, juntamente com análise qualitativa e quantitativa da comunidade fitoplanctônica e a toxicidade. O reservatório apresentou valores elevados de fósforo total, variando de 18 a 509 µg L-1; fosfato, de 4 a 463 µg L-1; nitrogênio total, de 0,99 a 17,25 mg L-1; e nitrato, de 0,26 a 15,29 mg L-1. Para a comunidade fitoplanctônica foram encontrados 103 táxons em todo o período amostrado; a maior riqueza foi encontrada no ponto P06, e a maior pobreza de táxons, nos pontos localizadas no corpo central do reservatório (P02, P03, P04 e P05. A maior concentração de cianofícea ocorreu em abril de 2004: 5.375.175 ind. L-1. As espécies que apresentaram as maiores densidades foram Microcystis aeruginosa, Anabaena spiroides, Microcystis sp. e Pseudoanabaena mucicola; a maior densidade foi apresentada por Anabaena spiroides, com 4.178.084 ind. L-1. Nos meses de junho e outubro a classe Cryptophyceae teve uma grande contribuição para a densidade total. Apesar da grande densidade de cianobactérias, os valores de toxicidade ficaram abaixo do limite permitido pela Portaria nº 1.469.This work was carried out at the Americana Reservoir, owned by Companhia Paulista de Força e Luz, and was part of a joint R&D project with Faculdade de Ciências Agronômicas - Botucatu - São Paulo - Brazil. Water sampling was collected in February, April, June and October 2004. The following characteristics were analyzed: water temperature, p

  18. Quality of fresh-cut avocado (Persea americana Mill. stored under different temperatures Qualidade de abacates (Persea americana Mill. minimally processados armazenados sob diferentes temperaturas

    Directory of Open Access Journals (Sweden)

    Ana Carla Marques Pinheiro

    2009-08-01

    Full Text Available The goal of this work was to evaluate the effect of different storage temperatures on the quality maintenance of fresh-cut 'Fortuna' avocado (Persea americana Mill.. The fruit was selected, washed and sanitized with sodium hypochlorite solution (190 ppm total residual chlorinee for 15 minutes. After that, the tip was cut and the fruit was also cut in halves, peeled and the pit removed, manually. Then the halves were immersed in 0.5% calcium chlorite + 0.5% cysteine solution for 2 minutes, to avoid darkening and packed in rigid plastic covered with 20 micrometer thick plastic wrap (PVC film with a permeability to O2, CO2 and water vapor of 15,000, 80,000 and 390 cm³/m²/day, respectively. The product was stored under 3 different temperatures 0, 5, 10ºC and evaluated at 5 different storege periods of 0, 2, 3, 5 and 6 days, in a randomized design in a 3x5 factorial. The storage of fresh-cut avocado at 5ºC is the best alternative because it determines better maintenance of quality of the avocado. These presented lower darkening of pulp, better scores for appearance and acceptability, lower softening and polyphenoloxidase activity, in comparison to those stored at 0 and 10ºC. The fresh-cut avocados stored at 5ºC presented a shelf life of 5 days, based, mainly on, appearance, score 7.3, sited between the concepts "like moderately" and "like very much" on a hedonic scale of 9 points and 86% of acceptability, at the end of 5 days of storage.Objetivou-se avaliar o efeito de diferentes temperaturas de armazenamento na manutenção da qualidade de abacates 'Fortuna' (Persea americana Mill. minimally processados. Os frutos foram lavados e sanificados em solução de hipoclorito de sódio (190 ppm de cloro residual total por 15 minutos. Posteriormente, efetuou-se a retirada da extremidade onde se insere o pedúnculo, o corte em metades, retirada do caroço e casca, manualmente. Em seguida, as metades foram imersas em solução com cloreto de cálcio 0

  19. 2012 Aspen Winter Conference New Paradigms for Low-Dimensional Electronic Materials, February 5-10, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Joel; Rabe, Karin; Nayak, Chetan; Troyer, Matthias

    2012-05-01

    Aspen Center for Physics Project Summary DOE Budget Period: 10/1/2011 to 9/30/2012 Contract # DE-SC0007479 New Paradigms for Low-Dimensional Electronic Materials The 2012 Aspen Winter Conference on Condensed Matter Physics was held at the Aspen Center for Physics from February 5 to 10, 2012. Seventy-four participants from seven countries, and several universities and national labs attended the workshop titled, New Paradigms for Low-Dimensional Electronic Materials. There were 34 formal talks, and a number of informal discussions held during the week. Talks covered a variety of topics related to DOE BES priorities, including, for example, advanced photon techniques (Hasan, Abbamonte, Orenstein, Shen, Ghosh) and predictive theoretical modeling of materials properties (Rappe, Pickett, Balents, Zhang, Vanderbilt); the full conference schedule is provided with this report. The week's events included a public lecture (Quantum Matters given by Chetan Nayak from Microsoft Research) and attended by 234 members of the public, and a physics caf© geared for high schoolers that is a discussion with physicists conducted by Kathryn Moler (Stanford University) and Andrew M. Rappe (University of Pennsylvania) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by Joel Moore (University of California Berkeley), Chetan Nayak (Microsoft Research), Karin Rabe (Rutgers University), and Matthias Troyer (ETH Zurich). Two organizers who did not attend the conference were Gabriel Aeppli (University College London & London Centre for Nanotechnology) and Andrea Cavalleri (Oxford University & Max Planck Hamburg).

  20. Soil Organic Carbon Storage and Stability in the Aspen-Conifer Ecotone in Montane Forests in Utah, USA

    Directory of Open Access Journals (Sweden)

    Mercedes Román Dobarco

    2014-04-01

    Full Text Available To assess the potential impact of conifer encroachment on soil organic carbon (SOC dynamics and storage in montane aspen-conifer forests from the interior western US, we sampled mineral soils (0–15 cm across the aspen-conifer ecotones in southern and northern Utah and quantified total SOC stocks, stable SOC (i.e., mineral-associated SOC (MoM, labile SOC (i.e., light fraction (LF, decomposable (CO2 release during long-term aerobic incubations and soluble SOC (hot water extractable organic carbon (HWEOC. Total SOC storage (47.0 ± 16.5 Mg C ha−1 and labile SOC as LF (14.0 ± 7.10 Mg C ha−1, SOC decomposability (cumulative released CO2-C of 5.6 ± 3.8 g C g−1 soil or HWEOC (0.6 ± 0.6 mg C g−1 soil did not differ substantially with vegetation type, although a slight increase in HWEOC was observed with increasing conifer in the overstory. There were statistically significant differences (p = 0.035 in stable MoM storage, which was higher under aspen (31.2 ± 15.1 Mg C ha−1 than under conifer (22.8 ± 9.0 Mg C ha−1, with intermediate values under mixed (25.7 ± 8.8 Mg C ha−1. Texture had the greatest impact on SOC distribution among labile and stable fractions, with increasing stabilization in MoM and decreasing bio-availability of SOC with increasing silt + clay content. Only at lower silt + clay contents (40%–70% could we discern the influence of vegetation on MoM content. This highlights the importance of chemical protection mechanisms for long-term C sequestration.

  1. Thomas Jefferson, I dilemmi della democrazia americana, translated and edited by Alberto Giordano, with a preface by Dino Cofrancesco (Novi Ligure: Città del Silenzio, 2007

    Directory of Open Access Journals (Sweden)

    Pierluigi Chiassoni

    2010-03-01

    Full Text Available A review of Thomas Jefferson, I dilemmi della democrazia americana, translated and edited by Alberto Giordano, with a preface by Dino Cofrancesco (Novi Ligure: Città del Silenzio, 2007

  2. Proconsuls and CINCs from the Roman Republic to the Republic of the United States of America: Lessons for the Pax Americana

    National Research Council Canada - National Science Library

    Bradford, Jeffrey

    2001-01-01

    Political and media pundits have labeled the current period of post Cold-War world order the Pax Americana, reminiscent of the Pax Romana that occurred from 27 to 180 AD, during the zenith of the Roman Empire...

  3. How light, temperature, and measurement and growth [CO2] interactively control isoprene emission in hybrid aspen.

    Science.gov (United States)

    Niinemets, Ülo; Sun, Zhihong

    2015-02-01

    Plant isoprene emissions have been modelled assuming independent controls by light, temperature and atmospheric [CO2]. However, the isoprene emission rate is ultimately controlled by the pool size of its immediate substrate, dimethylallyl diphosphate (DMADP), and isoprene synthase activity, implying that the environmental controls might interact. In addition, acclimation to growth [CO2] can shift the share of the control by DMADP pool size and isoprene synthase activity, and thereby alter the environmental sensitivity. Environmental controls of isoprene emission were studied in hybrid aspen (Populus tremula × Populus tremuloides) saplings acclimated either to ambient [CO2] of 380 μmol mol(-1) or elevated [CO2] of 780 μmol mol(-1). The data demonstrated strong interactive effects of environmental drivers and growth [CO2] on isoprene emissions. Light enhancement of isoprene emission was the greatest at intermediate temperatures and was greater in elevated-[CO2]-grown plants, indicating greater enhancement of the DMADP supply. The optimum temperature for isoprene emission was higher at lower light, suggesting activation of alternative DMADP sinks at higher light. In addition, [CO2] inhibition of isoprene emission was lost at a higher temperature with particularly strong effects in elevated-[CO2]-grown plants. Nevertheless, DMADP pool size was still predicted to more strongly control isoprene emission at higher temperatures in elevated-[CO2]-grown plants. We argue that interactive environmental controls and acclimation to growth [CO2] should be incorporated in future isoprene emission models at the level of DMADP pool size. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  4. Circadian patterns of xylem sap properties and their covariation with plant hydraulic traits in hybrid aspen.

    Science.gov (United States)

    Meitern, Annika; Õunapuu-Pikas, Eele; Sellin, Arne

    2017-06-01

    Physiological processes taking place in plants are subject to diverse circadian patterns but some of them are poorly documented in natural conditions. The daily dynamics of physico-chemical properties of xylem sap and their covariation with tree hydraulic traits were investigated in hybrid aspen (Populus tremula L.×P. tremuloides Michx) in field conditions in order to clarify which environmental drivers govern the daily variation in these parameters. K + concentration ([K + ]), electrical conductivity (σ sap ), osmolality (Osm) and pH of the xylem sap, as well as branch hydraulic traits, were measured in the field over 24-h cycles. All studied xylem sap properties and hydraulic characteristics including whole-branch (K wb ), leaf blade (K lb ) and petiole hydraulic conductances (K P ) showed clear daily dynamics. Air temperature (T A ) and photosynthetic photon flux density (PPFD), but also water vapour pressure deficit (VPD) and relative humidity (RH), had significant impacts on K wb K lb , K P , [K + ] and σ sap . Osm varied only with light intensity, while K B varied depending on atmospheric evaporative demand expressed as T A , VPD or RH. Xylem sap pH depended inversely on soil water potential (Ψ S ) and during daylight also on VPD. Although soil water content was close to saturation during the study period, Ψ S influenced also [K + ] and σ sap . The present study presents evidence of coupling between circadian patterns of xylem sap properties and plant hydraulic conductance providing adequate water supply to foliage under environmental conditions characterised by diurnal variation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  5. Estimation of Power Production Potential from Natural Gas Pressure Reduction Stations in Pakistan Using ASPEN HYSYS

    Directory of Open Access Journals (Sweden)

    Imran Nazir Unar

    2015-07-01

    Full Text Available Pakistan is a gas rich but power poor country. It consumes approximately 1, 559 Billion cubic feet of natural gas annually. Gas is transported around the country in a system of pressurized transmission pipelines under a pressure range of 600-1000 psig exclusively operated by two state owned companies i.e. SNGPL (Sui Northern Gas Pipelines Limited and SSGCL (Sui Southern Gas Company Limited. The gas is distributed by reducing from the transmission pressure into distribution pressure up to maximum level of 150 psig at the city gate stations normally called SMS (Sales Metering Station. As a normal practice gas pressure reduction at those SMSs is accomplished in pressure regulators (PCVs or in throttle valves where isenthalpic expansion takes place without producing any energy. Pressure potential of natural gas is an untapped energy resource which is currently wasted by its throttling. This pressure reduction at SMS (pressure drop through SMS may also be achieved by expansion of natural gas in TE, which converts its pressure into the mechanical energy, which can be transmitted any loading device for example electric generator. The aim of present paper is to explore the expected power production potential of various Sales Metering Stations of SSGCL company in Pakistan. The model of sales metering station was developed in a standard flow sheeting software Aspen HYSYS®7.1 to calculate power and study other parameters when an expansion turbine is used instead of throttling valves. It was observed from the simulation results that a significant power (more than 140 KW can be produced at pressure reducing stations of SSGC network with gas flows more than 2.2 MMSCFD and pressure ration more than 1.3.

  6. Estimation of power production potential from natural gas pressure reduction stations in pakistan using aspen hysys

    International Nuclear Information System (INIS)

    Unar, I.N.; Aftab, A.

    2015-01-01

    Pakistan is a gas rich but power poor country. It consumes approximately 1, 559 Billion cubic feet of natural gas annually. Gas is transported around the country in a system of pressurized transmission pipelines under a pressure-range of 600-1 000 psig exclusively operated by two state owned companies i.e. SNGPL (Sui Northern Gas Pipelines Limited) and SSGCL (Sui Southern Gas Company Limited). The gas is distributed by reducing from the transmission pressure into distribution pressure up to maximum level of 150 psig at the city gate stations normally called SMS (Sales Metering Station). As a normal practice gas pressure reduction at those SMSs is accomplished in pressure regulators (PCVs or in of natural gas is an untapped energy resource which is currently wasted by its throttling. This pressure reduction at SMS (pressure drop through SMS) may also be achieved by expansion of natural gas in TE, which converts its pressure into the mechanical energy, which can be transmitted any loading device for example electric generator. The aim of present paper is to explore the expected power production potential of various Sales Metering Stations of SSGCL company in Pakistan. The model of sales metering station was developed in a standard flow sheeting software Aspen HYSYS at the rate 7.1 to calculate power and study other parameters when an expansion turbine is used instead of throttling valves. It was observed from the simulation results that a significant power (more than 140 KW) can be produced at pressure reducing stations of SSGC network with gas flows more than 2.2 MMSCFD and pressure ration more than 1.3. (author)

  7. Aspen Plus simulation of biomass integrated gasification combined cycle systems at corn ethanol plants

    International Nuclear Information System (INIS)

    Zheng, Huixiao; Kaliyan, Nalladurai; Morey, R. Vance

    2013-01-01

    Biomass integrated gasification combined cycle (BIGCC) systems and natural gas combined cycle (NGCC) systems are employed to provide heat and electricity to a 0.19 hm 3 y −1 (50 million gallon per year) corn ethanol plant using different fuels (syrup and corn stover, corn stover alone, and natural gas). Aspen Plus simulations of BIGCC/NGCC systems are performed to study effects of different fuels, gas turbine compression pressure, dryers (steam tube or superheated steam) for biomass fuels and ethanol co-products, and steam tube dryer exhaust treatment methods. The goal is to maximize electricity generation while meeting process heat needs of the plant. At fuel input rates of 110 MW, BIGCC systems with steam tube dryers provide 20–25 MW of power to the grid with system thermal efficiencies (net power generated plus process heat rate divided by fuel input rate) of 69–74%. NGCC systems with steam tube dryers provide 26–30 MW of power to the grid with system thermal efficiencies of 74–78%. BIGCC systems with superheated steam dryers provide 20–22 MW of power to the grid with system thermal efficiencies of 53–56%. The life-cycle greenhouse gas (GHG) emission reduction for conventional corn ethanol compared to gasoline is 39% for process heat with natural gas (grid electricity), 117% for BIGCC with syrup and corn stover fuel, 124% for BIGCC with corn stover fuel, and 93% for NGCC with natural gas fuel. These GHG emission estimates do not include indirect land use change effects. -- Highlights: •BIGCC and natural gas combined cycle systems at corn ethanol plants are simulated. •The best performance results in 25–30 MW power to grid. •The best performance results in 74–78% system thermal efficiencies. •GHG reduction for corn ethanol with BIGCC systems compared to gasoline is over 100%

  8. Experimental Investigation and Aspen Plus Simulation of the MSW Pyrolysis Process

    Science.gov (United States)

    Ansah, Emmanuel

    Municipal solid waste (MSW) is a potential feedstock for producing transportation fuels because it is readily available using an existing collection/transportation infrastructure and fees are provided by the suppliers or government agencies to treat MSW. North Carolina with a population of 9.4 millions generates 3.629 million metric tons of MSW each year, which contains about 113,396,356 TJs of energy. The average moisture content of MSW samples is 44.3% on a wet basis. About 77% of the dry MSW mass is combustible components including paper, organics, textile and plastics. The average heating values of MSW were 9.7, 17.5, and 22.7 MJ/kg on a wet basis, dry basis and dry combustible basis, respectively. The MSW generated in North Carolina can produce 7.619 million barrels of crude bio-oil or around 4% of total petroleum consumption in North Carolina. MSW can be thermally pyrolyzed into bio-oil in the absence of oxygen or air at a temperature of 500°C or above. As bio-oil can be easily stored and transported, compared to bulky MSW, landfill gas and electricity, pyrolysis offers significant logistical and economic advantages over landfilling and other thermal conversion processes such as combustion and gasification. Crude bio-oils produced from the pyrolysis of MSW can be further refined to transportation fuels in existing petroleum refinery facilities. The objective of this research is to analyze the technical and economic feasibility of pyrolyzing MSW into liquid transportation fuels. A combined thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC) instrument, which can serve as a micro-scale pyrolysis reactor, was used to simultaneously determine the degradation characteristics of MSW during pyrolysis. An ASPEN Plus-based mathematical model was further developed to analyze the technical and economic feasibility of pyrolysing of MSW into liquid transportation fuels in fixed bed reactors at varying operating conditions

  9. ASPEN Plus simulation of coal integrated gasification combined blast furnace slag waste heat recovery system

    International Nuclear Information System (INIS)

    Duan, Wenjun; Yu, Qingbo; Wang, Kun; Qin, Qin; Hou, Limin; Yao, Xin; Wu, Tianwei

    2015-01-01

    Highlights: • An integrated system of coal gasification with slag waste heat recovery was proposed. • The goal of BF slag heat saving and emission reduction was achieved by this system. • The optimal parameters were obtained and the waste heat recovery rate reached 83.08%. • About 6.64 kmol/min syngas was produced when using one ton BF slag to provide energy. - Abstract: This article presented a model for the system of coal gasification with steam and blast furnace slag waste heat recovery by using the ASPEN Plus as the simulating and modeling tool. Constrained by mass and energy balance for the entire system, the model included the gasifier used to product syngas at the chemical equilibrium based on the Gibbs free energy minimization approach and the boiler used to recover the heat of the blast furnace slag (BF slag) and syngas. Two parameters of temperature and steam to coal ratio (S/C) were considered to account for their impacts on the Datong coal (DT coal) gasification process. The carbon gasification efficiency (CE), cold gasification efficiency (CGE), syngas product efficiency (PE) and the heating value of syngas produced by 1 kg pulverized coal (HV) were adopted as the indicators to examine the gasification performance. The optimal operating temperature and S/C were 800 °C and 1.5, respectively. At this condition, CE reached above 90% and the maximum values of the CGE, PE and HV were all obtained. Under the optimal operating conditions, 1000 kg/min BF slag, about 40.41 kg/min DT pulverized coal and 77.94 kg/min steam were fed into the gasifier and approximate 6.64 kmol/min syngas could be generated. Overall, the coal was converted to clean syngas by gasification reaction and the BF slag waste heat was also recovered effectively (reached up to 83.08%) in this system, achieving the objective of energy saving and emission reduction

  10. Simulation of the SSC refrigeration system using the ASPEN/SP process simulator

    International Nuclear Information System (INIS)

    Rasson, J.; Dweck, J.

    1990-01-01

    The SSC Magnet must be maintained at a superconducting temperature of 4 K. The proposed refrigeration cooling processes consist of fairly simple closed cycles which take advantage of the Joule-Thompson effect via a series of expansions and compressions of helium gas which has been precooled by liquid nitrogen. The processes currently under consideration consist of three cycles, the 20 K shield cooling, the 4.0 K helium refrigerator and the helium liquefier. The process units which are to be employed are compressors, turbines, expanders, mixers, flashes, two stream heat exchangers and multiple stream heat exchangers. The cycles are to be operated at or near steady state. Due to the large number of competing cooling sector designs to be considered and the high capital and operating costs of the proposed processes, the SSC Laboratory requires a software tool for the validation and optimization of the individual designs and for the performance of cost-benefit analyses among competing designs. Since these processes are steady state flow processes involving primarily standard unit operations, a decision was made to investigate the application of a commercial process simulator to the task. Several months of internal evaluations by the SSC Laboratory revealed that while the overall structure and calculation approach of a number of the commercial simulators were appropriate for this task, all were lacking essential capabilities in the areas of thermodynamic property calculations for cryogenic systems and modeling of complex, multiple stream heat exchangers. An acceptable thermodynamic model was provided and a series of simple, but three software vendors. Based on the results of the benchmark tests, the ASPEN/SP process simulator was selected for future modeling work. 2 refs., 4 figs

  11. A kinetic reaction model for biomass pyrolysis processes in Aspen Plus

    International Nuclear Information System (INIS)

    Peters, Jens F.; Banks, Scott W.; Bridgwater, Anthony V.; Dufour, Javier

    2017-01-01

    Highlights: • Predictive kinetic reaction model applicable to any lignocellulosic feedstock. • Calculates pyrolysis yields and product composition as function of reactor conditions. • Detailed modelling of product composition (33 model compounds for the bio-oil). • Good agreement with literature regarding yield curves and product composition. • Successful validation with pyrolysis experiments in bench scale fast pyrolysis rig. - Abstract: This paper presents a novel kinetic reaction model for biomass pyrolysis processes. The model is based on the three main building blocks of lignocellulosic biomass, cellulose, hemicellulose and lignin and can be readily implemented in Aspen Plus and easily adapted to other process simulation software packages. It uses a set of 149 individual reactions that represent the volatilization, decomposition and recomposition processes of biomass pyrolysis. A linear regression algorithm accounts for the secondary pyrolysis reactions, thus allowing the calculation of slow and intermediate pyrolysis reactions. The bio-oil is modelled with a high level of detail, using up to 33 model compounds, which allows for a comprehensive estimation of the properties of the bio-oil and the prediction of further upgrading reactions. After showing good agreement with existing literature data, our own pyrolysis experiments are reported for validating the reaction model. A beech wood feedstock is subjected to pyrolysis under well-defined conditions at different temperatures and the product yields and compositions are determined. Reproducing the experimental pyrolysis runs with the simulation model, a high coincidence is found for the obtained fraction yields (bio-oil, char and gas), for the water content and for the elemental composition of the pyrolysis products. The kinetic reaction model is found to be suited for predicting pyrolysis yields and product composition for any lignocellulosic biomass feedstock under typical pyrolysis conditions

  12. Simulation of the SSC [Superconducting Super Collider] refrigeration system using the ASPEN/SP process simulator

    International Nuclear Information System (INIS)

    Rasson, J.; Dweck, J.

    1990-08-01

    The SSC Magnet must maintain at a super conducting temperature of 4 K. The proposed refrigeration cooling processes consist of fairly simple closed cycles which take advantage of the Joule-Thompson effect via a series of expansions and compressions of helium gas which has been precooled by liquid nitrogen. The processes currently under consideration consist of three cycles, the 20 K shield cooling, the 45 K helium refrigerator and the helium liquefier. The process units which are to be employed are compressors, turbines, expanders, mixers, flashes, two stream heat exchangers and multiple stream heat exchangers. The cycles are to be operated at or near steady state. Due to the large number of competing cooling sector designs to be considered and the high capital and operating costs of the proposed processes, the SSC Laboratory requires a software tool for the validation and optimization of the individual designs and for the performance of cost-benefit analyses among competing designs. Since these processes are steady state flow processes involving primarily standard unit operations, a decision was made to investigate the application of a commercial process simulator to the task. Several months of internal evaluations by the SSC Laboratory revealed that while the overall structure and calculation approach of number of the commercial simulators were appropriate for this task, all were lacking essential capabilities in the areas of thermodynamic property calculations for cryogenic systems and modeling of complex, multiple stream heat exchangers. An acceptable thermodynamics model was provided and a series of simple, but representative benchmark problems developed. The model and problems were provided to three software vendors. Based on the results of the benchmark test, the ASPEN/SP process simulator was selected for future modeling work

  13. Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration

    International Nuclear Information System (INIS)

    McGrath, Justin M.; Karnosky, David F.; Ainsworth, Elizabeth A.

    2010-01-01

    Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO 2 ]) and elevated ozone concentration ([O 3 ]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO 2 ] and [O 3 ] predicted for ∼2050. The responses of two clones were compared during the first month of spring leaf out when CO 2 fumigation had begun, but O 3 fumigation had not. Trees in elevated [CO 2 ] plots showed a stimulation of leaf area index (36%), while trees in elevated [O 3 ] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO 2 ], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO 2 ]; however, the two clones responded differently to long-term growth at elevated [O 3 ]. The O 3 -sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O 3 ] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O 3 ] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O 3 ], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions. - Spring leaf flush is stimulated by elevated [CO 2 ] and suppressed by elevated [O 3 ] in aspen (Populus tremuloides).

  14. Utilization of steam- and explosion-decompressed aspen wood by some anaerobes. [Acetivibrio cellulolyticus, Clostridium saccharolyticum, Zymomonas anaerobia

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A W; Asther, M; Giuliano, C

    1984-01-01

    Tests made to study the suitability of using steam- and explosion-decompressed aspen wood as substrate in anaerobic fermentations indicated that after washing with dilute NaOH it becomes over 80% accessible to both mesophilic and thermophilic cellulolytic anaerobes and cellulases, compared with delignified, ball-milled pulp. After washing, this material was also found to be suitable for the single-step conversion of cellulose to ethanol using cocultures consisting of cellylolytic and ethanol-producing saccharolytic anaerobes; and without and after washing by the use of cellulolytic enzymes and ethanologenic anaerobes. 16 references, 3 tables.

  15. Movimiento estudiantil, sociedad civil, democracia y gobernabilidad en Venezuela: 2000-2010

    Directory of Open Access Journals (Sweden)

    Egda Ortiz

    2013-01-01

    Full Text Available Este artículo tiene como objetivo explicar la relación entre movimiento estudiantil, sociedad civil, democracia y gobernabilidad en Venezuela. Se adelanta una revisión conceptual y teórica respecto a los aspectos mencionados para el período seleccionado. La gobernabilidad para este período se explica al encontrarse una interrelación histórica entre democracia, movimiento estudiantil y sociedad civil venezolana. La democracia es la construcción de consensos y mayorías políticas para realizar los. PNUD-OEA (2010. En el caso venezolano, los distintos actores políticos y sociales que conforman la sociedad civil han expresado la defensa de los valores democráticos desde las dictaduras del siglo pasado hasta la actualidad. Son las sociedades civiles las que amplían el espacio público de los derechos yde la conciencia social sobre éstos. Grzybowski (2004. Se concluye que la construcción democrática requiere de la participación de distintos actores políticos y sociales que intercambien valores, procesos e ideas en el seno de la sociedad civil venezolana; y en este proceso complejo de la última década el movimiento estudiantil y los ciudadanos en general han destacado en el rescate de la gobernabilidad y la democracia en el país

  16. Movimiento estudiantil, sociedad civil, democracia y gobernabilidad en Venezuela: 2000-2010

    Directory of Open Access Journals (Sweden)

    Egda Ortiz

    2013-09-01

    Full Text Available Este artículo tiene como objetivo explicar la relación entre movimiento estudiantil, sociedad civil, democracia y gobernabilidad en Venezuela. Se adelanta una revisión conceptual y teórica respecto a los aspectos mencionados para el período seleccionado. La gobernabilidad para este período se explica al encontrarse una interrelación histórica entre democracia, movimiento estudiantil y sociedad civil venezolana. La democracia es la construcción de consensos y mayorías políticas para realizarlos. PNUD-OEA (2010. En el caso venezolano, los distintos actores políticos y sociales que conforman la sociedad civil han expresado la defensa de los valores democráticos desde las dictaduras del siglo pasado hasta la actualidad. Son las sociedades civiles las que amplían el espacio público de los derechos y de la conciencia social sobre éstos. Grzybowski (2004. Se concluye que la construcción democrática requiere de la participación de distintos actores políticos y sociales que intercambien valores, procesos e ideas en el seno de la sociedad civil venezolana; y en este proceso complejo de la última década el movimiento estudiantil y los ciudadanos en general han destacado en el rescate de la gobernabilidad y la democracia en el país.

  17. Las Sociedades que Utilizan las NIC/NIIF ya no Tienen que Reconciliar las Cifras Contables a US GAAP. ¿Está Justificada

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    Juan Palomares Laguna

    2009-06-01

    Full Text Available Nuestro trabajo tiene como objetivo contrastar si la decisión de la SEC en base a la cual se permite no reconciliar el Patrimonio Neto (PN y el Resultado neto (RN, a las normas americanas, exclusivamente a las sociedades que utilizan las NIC/NIIF en sus estados primarios, está justificada o no. Nuestro estudio está referido al sector de las telecomunicaciones por lo que otros trabajos deberán en su caso contrastar si los resultados aquí obtenidos son extrapolables a otros sectores. Utilizando una muestra de sociedades pertenecientes al sector de las telecomunicaciones, analizaremos si las distancias con los US GAAP se reducen o no, una vez que éstas han migrado a las NIC/NIIF y si éstas diferencias son significativas. Podemos afirmar, de forma general, en base a los resultados obtenidos, que la migración a la normativa internacional ha supuesto un acercamiento con los US GAAP y que las diferencias no son significativas, aunque sí existen tipos de ajustes, como las combinaciones de negocios, que de por si solos introducen impactos significativos. Sin embargo, de forma transitoria, las sociedades recién migradas muestran una menor homogeneidad en el RN con los US GAAP.Por todo ello, consideramos acertada la decisión de la SEC, aunque futuras investigaciones deberán confirmar que las diferencias tienden a reducirse una vez que los efectos de la NIIF 1 se difuminan y que los avances previstos en la armonización de iure se trasladan a la armonización de facto.The aim of this paper is to test whether, the SEC’s decision to allow only companies using IFRS not to reconcile their Equity (E and Net Profit (NP to US GAAP is justified. Ourresearch is restricted to the telecommunications sector, and therefore, further research is needed to test whether our result are similar for other sectors. Using a sample of companies belonging to the telecommunications sector, we investigate whether the differences to US GAAP have been reduced after

  18. Antibacterial effect of crude extract and metabolites of Phytolacca americana on pathogens responsible for periodontal inflammatory diseases and dental caries.

    Science.gov (United States)

    Patra, Jayanta Kumar; Kim, Eun Sil; Oh, Kyounghee; Kim, Hyeon-Jeong; Kim, Yangseon; Baek, Kwang-Hyun

    2014-09-20

    The oral cavity is the store house of different species of microorganisms that are continuously engaged in causing diseases in the mouth. The present study was conducted to evaluate the antibacterial potential of crude extracts of the aerial parts of Phytolacca americana and its natural compounds against two oral pathogens, Porphyromonas gingivalis and Streptococcus mutans, which are primarily responsible for periodontal inflammatory diseases and dental caries, as well as a nonpathogenic Escherichia coli. Crude extract and fractions from the aerial parts of P. americana (0.008-1.8 mg/mL) were evaluated for their potential antibacterial activity against two oral disease causing microorganisms by micro-assays. The standard natural compounds present in P. americana, kaempferol, quercetin, quercetin 3-glucoside, isoqueritrin and ferulic acid, were also tested for their antibacterial activity against the pathogens at 1-8 μg/mL. The crude extract was highly active against P. gingivalis (100% growth inhibition) and moderately active against S. mutans (44% growth inhibition) at 1.8 mg/mL. The chloroform and hexane fraction controlled the growth of P. gingivalis with 91% and 92% growth inhibition at a concentration of 0.2 mg/mL, respectively. Kaempferol exerted antibacterial activity against both the pathogens, whereas quercetin showed potent growth inhibition activity against only S. mutans in a concentration dependent manner. The crude extract, chloroform fraction, and hexane fraction of P. americana possesses active natural compounds that can inhibit the growth of oral disease causing bacteria. Thus, these extracts have the potential for use in the preparation of toothpaste and other drugs related to various oral diseases.

  19. Studies on the Paint Forming Properties of Avocado(Persea Americana) and African Pear (Dacryodes Edulis) Seed Oils.

    OpenAIRE

    Otaigbe, J.O.E; Oriji, O.G; Ekerenam, G.E

    2016-01-01

    Avocado(Persea Americana) and African Pear (Dacryodes edulis) seed oils were investigated for their suitability as base materials for oil paint production. Soxhlet extraction of the oils from the powdered seeds using n-hexane gave 3.63% and 10.40% yields for Avocado and African Pear respectively. Proximate analysis and chemical characterization of the seed oils were carried out using standard procedures according to the American Oil Chemist Society (AOCS) and the American Society for Testing ...

  20. Simple Y-Autosomal Incompatibilities Cause Hybrid Male Sterility in Reciprocal Crosses Between Drosophila virilis and D. americana

    OpenAIRE

    Sweigart, Andrea L.

    2010-01-01

    Postzygotic reproductive isolation evolves when hybrid incompatibilities accumulate between diverging populations. Here, I examine the genetic basis of hybrid male sterility between two species of Drosophila, Drosophila virilis and D. americana. From these analyses, I reach several conclusions. First, neither species carries any autosomal dominant hybrid male sterility alleles: reciprocal F1 hybrid males are perfectly fertile. Second, later generation (backcross and F2) hybrid male sterility ...

  1. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    Science.gov (United States)

    Huang, Jian-Guo; Stadt, Kenneth J; Dawson, Andria; Comeau, Philip G

    2013-01-01

    We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA), the sum of stem diameter at breast height (SDBH), and density (N) for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR), were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2)>0.67) to represent this complex variation in growth as a function of site, size and competition.

  2. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    Directory of Open Access Journals (Sweden)

    Jian-Guo Huang

    Full Text Available We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA, the sum of stem diameter at breast height (SDBH, and density (N for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR, were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2>0.67 to represent this complex variation in growth as a function of site, size and competition.

  3. "Bases legales para la transformación de Sociedades Civiles en Sociedades Cooperativas" (Legal bases for the transformation of Civil Societies into Cooperative Societies

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    Enrique Gadea Soler

    2013-01-01

    Full Text Available El Derecho interno vigente permite abiertamente la transformaciónde Sociedades Civiles con personalidad jurídica, Asociaciones y Fundaciones,en Cooperativas. Ello está además integrado en las propuestas del ParlamentoEuropeo en beneficio del empleo, la lucha contra la exclusión en la UEy el mantenimiento del bienestar social en la Unión.

  4. Survival and weight change among adult individuals of Periplaneta americana (Linnaeus, 1758 (Blattaria, Blattidae subject to various stress conditions

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    Jucelio Peter Duarte

    2015-05-01

    Full Text Available Periplaneta americana is a species of great importance to public health, since it can act as a vector of many pathogens and it reaches large populations in urban environments. This is probably due to its ability to resist starvation and desiccation. This study aimed to evaluate the effects of absence of water and food on survival and weight change among adult P. americana individuals and check whether the initial weight of individuals influences on their survival. Four groups having twenty P. americana couples were formed and subject to: I no water or food; II no food; III no water; and IV control group. Insects were isolated according to the groups, which were weighed at the beginning and end of the stress conditions. They remained under these conditions until all individuals in each test group were dead. Stress conditions caused reduction in survival time when compared to the control group. Adults with higher body mass survived longer when deprived only of food, while among those lacking water, weight had no influence on survival. Total weight loss was greater among individuals deprived of water than those deprived only of food.

  5. Survival and weight change among adult individuals of Periplaneta americana (Linnaeus, 1758 (Blattaria, Blattidae subject to various stress conditions

    Directory of Open Access Journals (Sweden)

    Jucelio Peter Duarte

    2015-03-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n2p103 Periplaneta americana is a species of great importance to public health, since it can act as a vector of many pathogens and it reaches large populations in urban environments. This is probably due to its ability to resist starvation and desiccation. This study aimed to evaluate the effects of absence of water and food on survival and weight change among adult P. americana individuals and check whether the initial weight of individuals influences on their survival. Four groups having twenty P. americana couples were formed and subject to: I no water or food; II no food; III no water; and IV control group. Insects were isolated according to the groups, which were weighed at the beginning and end of the stress conditions. They remained under these conditions until all individuals in each test group were dead. Stress conditions caused reduction in survival time when compared to the control group. Adults with higher body mass survived longer when deprived only of food, while among those lacking water, weight had no influence on survival. Total weight loss was greater among individuals deprived of water than those deprived only of food.

  6. IN VITRO CYTOTOXICITY STUDY OF AGAVE AMERICANA, STRYCHNOS NUX-VOMICA AND ARECA CATECHU EXTRACTS USING MCF-7 CELL LINE

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    Anajwala Chetan C.

    2010-06-01

    Full Text Available Research is focusing on the search for new types of natural chemotherapeutic agent that is plant based medicines which are proving to be excellent sources of new compounds. In present research study, an attempt was made to prove cytotoxicity activity of various parts of medicinal plants such as Agave americana, Strychnos nux-vomica and Areca catechu using MCF-7 and Vero cell line. Various parts of the medicinal plants were extracted by soxhlet apparatus using solvents likes methanol and water. By trypan blue dye exclusion method, Viability of MCF-7 and Vero cell lines were 85.50 and 81.13%, respectively. IC50 value of methanol extract of Agave americana leaves and aqueous extract of Areca catechu fruits were found to be 545.9 & 826.1 µg/ml by SRB assay and 775.1 & 1461µg/ml by MTT assay, respectively, against MCF-7 cell line. From cytotoxicity study data by SRB and MTT assay, it revealed that methanol extract of Agave americana and aqueous extract of Areca catechu are potent cytotoxic.

  7. Phylogenomic analysis of Odyssella thessalonicensis fortifies the common origin of Rickettsiales, Pelagibacter ubique and Reclimonas americana mitochondrion.

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    Kalliopi Georgiades

    Full Text Available BACKGROUND: The evolution of the Alphaproteobacteria and origin of the mitochondria are topics of considerable debate. Most studies have placed the mitochondria ancestor within the Rickettsiales order. Ten years ago, the bacterium Odyssella thessalonicensis was isolated from Acanthamoeba spp., and the 16S rDNA phylogeny placed it within the Rickettsiales. Recently, the whole genome of O. thessalonicensis has been sequenced, and 16S rDNA phylogeny and more robust and accurate phylogenomic analyses have been performed with 65 highly conserved proteins. METHODOLOGY/PRINCIPAL FINDINGS: The results suggested that the O. thessalonicensis emerged between the Rickettsiales and other Alphaproteobacteria. The mitochondrial proteins of the Reclinomonas americana have been used to locate the phylogenetic position of the mitochondrion ancestor within the Alphaproteobacteria tree. Using the K tree score method, nine mitochondrion-encoded proteins, whose phylogenies were congruent with the Alphaproteobacteria phylogenomic tree, have been selected and concatenated for Bayesian and Maximum Likelihood phylogenies. The Reclinomonas americana mitochondrion is a sister taxon to the free-living bacteria Candidatus Pelagibacter ubique, and together, they form a clade that is deeply rooted in the Rickettsiales clade. CONCLUSIONS/SIGNIFICANCE: The Reclinomonas americana mitochondrion phylogenomic study confirmed that mitochondria emerged deeply in the Rickettsiales clade and that they are closely related to Candidatus Pelagibacter ubique.

  8. Antimicrobial activity of crude epicarp and seed extracts from mature avocado fruit (Persea americana) of three cultivars.

    Science.gov (United States)

    Raymond Chia, Teck Wah; Dykes, Gary A

    2010-07-01

    The epicarp and seed of Persea Americana Mill. var. Hass (Lauraceae), Persea Americana Mill. var. Shepard, and Persea americana Mill. var Fuerte cultivars of mature avocados (n = 3) were ground separately and extracted with both absolute ethanol and distilled water. Extracts were analyzed for antimicrobial activity using the microtiter broth microdilution assay against four Gram-positive bacteria, six Gram-negative bacteria, and one yeast. Antimicrobial activity against two molds was determined by the hole plate method. The ethanol extracts showed antimicrobial activity (104.2-416.7 microg/mL) toward both Gram-positive and Gram-negative bacteria (except Escherichia coli), while inhibition of the water extracts was only observed for Listeria monocytogenes (93.8-375.0 microg/mL) and Staphylococcus epidermidis (354.2 microg/mL). The minimum concentration required to inhibit Zygosaccharomyces bailii was 500 microg/mL for the ethanol extracts, while no inhibition was observed for the water extracts. No inhibition by either ethanol or water extracts was observed against Penicillium spp. and Aspergillus flavus.

  9. Biochemical and molecular modulation of CCl4-induced peripheral and central damage by Tilia americana var. mexicanaextracts.

    Science.gov (United States)

    Coballase-Urrutia, Elvia; Cárdenas-Rodríguez, Noemí; González-García, María Carolina; Núñez-Ramírez, Eithan; Floriano-Sánchez, Esaú; González-Trujano, María Eva; Fernández-Rojas, Berenice; Pedraza-Chaverrí, José; Montesinos-Correa, Hortencia; Rivera-Espinosa, Liliana; Sampieri, Aristides Iii; Carmona-Aparicio, Liliana

    2017-03-01

    Around the world, species from the genus Tilia are commonly used because of their peripheral and central medicinal effects; they are prepared as teas and used as tranquilizing, anticonvulsant, and analgesic agents. In this study, we provide evidence of the protective effects of organic and aqueous extracts (100 mg/kg, i.p.) obtained from the leaves of Tilia americana var. mexicana on CCl 4 -induced liver and brain damage in the rat. Protection was observed in the liver and brain (cerebellum, cortex and cerebral hemispheres) by measuring the activity of antioxidant enzymes and levels of malondialdehyde (MDA) using spectrophotometric methods. Biochemical parameters were also assessed in serum samples from the CCl 4 -treated rats. The T. americana var. mexicana leaf extracts provided significant protection against CCl 4 -induced peripheral and central damage by increasing the activity of antioxidant enzymes, diminishing lipid peroxidation, and preventing alterations in biochemical serum parameters, such as the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-globulin (γ-GLOB), serum albumin (ALB), total bilirubin (BB), creatinine (CREA) and creatine kinase (CK), relative to the control group. Additionally, we correlated gene expression with antioxidant activity in the experimental groups treated with the organic and aqueous Tilia extracts and observed a non-statistically significant positive correlation. Our results provide evidence of the underlying biomedical properties of T. americana var. mexicana that confer its neuro- and hepatoprotective effects.

  10. Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

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    Neyser De La Torre-Ruiz

    Full Text Available ABSTRACT The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene showed that strains ACO-34A, ACO-40 and ACO-140 were Rhizobium daejeonense, Acinetobacter calcoaceticus and Pseudomonas mosselii, respectively. All of the strains were able to synthesize indole-3-acetic acid (IAA, solubilize phosphate, and had nitrogenase activity. Inoculation using the plant growth-promoting bacteria strains had a significant effect (p < 0.05 on plant growth and the sugar content of A. americana, showing that these native plant growth-promoting bacteria are a practical, simple, and efficient alternative to promote the growth of agave plants with proper biological characteristics for agroindustrial and biotechnological use and to increase the sugar content in this agave species.

  11. SCAI Expert consensus statement: Evaluation, management, and special considerations of cardio-oncology patients in the cardiac catheterization laboratory (endorsed by the cardiological society of india, and sociedad Latino Americana de Cardiologıa intervencionista).

    Science.gov (United States)

    Iliescu, Cezar A; Grines, Cindy L; Herrmann, Joerg; Yang, Eric H; Cilingiroglu, Mehmet; Charitakis, Konstantinos; Hakeem, Abdul; Toutouzas, Konstantinos P; Leesar, Massoud A; Marmagkiolis, Konstantinos

    2016-04-01

    In the United States alone, there are currently approximately 14.5 million cancer survivors, and this number is expected to increase to 20 million by 2020. Cancer therapies can cause significant injury to the vasculature, resulting in angina, acute coronary syndromes (ACS), stroke, critical limb ischemia, arrhythmias, and heart failure, independently from the direct myocardial or pericardial damage from the malignancy itself. Consequently, the need for invasive evaluation and management in the cardiac catheterization laboratory (CCL) for such patients has been increasing. In recognition of the need for a document on special considerations for cancer patients in the CCL, the Society for Cardiovascular Angiography and Interventions (SCAI) commissioned a consensus group to provide recommendations based on the published medical literature and on the expertise of operators with accumulated experience in the cardiac catheterization of cancer patients. © 2016 Wiley Periodicals, Inc.

  12. Um olhar sistêmico sobre a crise norte-americana

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    CHRISTIAN CARVALHO GANZERT

    Full Text Available RESUMO No contexto contemporâneo, a economia global pode ser descrita como um sistema baseado em agentes que, quando associados, manifestam seus próprios meios e fins. A crise das hipotecas subprime nos Estados Unidos é um bom exemplo das implicações desse tipo de relacionamento. Ela está diretamente relacionada a poderosos laços de realimentação, compostos por uma série de variáveis que amplificaram o fato de as famílias americanas terem se endividado em ritmo maior do que a sua distribuição de riqueza, prejudicada pela externalização da produção. Há atualmente uma nova estrutura na economia internacional, em que as ex-nações subdesenvolvidas estão mais bem posicionadas no cenário macroeconômico e têm maior poder do que antes - uma consequência do necessário rearranjo sistêmico. Diante dessa complexa dinâmica, a função de inteligência que deveria controlar e garantir a estabilidade sistêmica falhou em perceber a dinâmica e os impactos da nova cultura atrelada ao comportamento do capital contemporâneo, para evitar a perda da hegemonia. Observando-se ex post facto, por meio de um enfoque sistêmico, a crise econômica americana pode ser definida como tendo suas raízes nas premissas de todo o arcabouço cultural da globalização que acabou por conduzir à externalização da produção. Assim, o contexto sistêmico desta análise aponta que a cultura, como importante gerador e amplificador, deve ser o principal foco dos intentos de análise do atual contexto socioeconômico global.

  13. Effect of an admixture from Agave americana on the physical and mechanical properties of plaster

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    Ochoa, J. C.

    2013-03-01

    Full Text Available Physical and mechanical properties of a plaster paste added with an organic admixture, of the leaves of Agave americana, were studied. Plastic consistency behavior was evaluated and the water/gypsum(w/g ratio was determined for each dosage of the admixture. Admixtur eeffect on setting was evaluated too. The chemical transformation of the hemihydrated form to gypsum (dihydrated form was studied using a novel technique based on a moisture analyzer by halogen light. Flexural and compressive strengths were measured. The results show that ,for the same consistency, accordingly mechanical strengths were improved too. The setting times were increased which would enhance the application time of plaster and would reduce plastic shrinkage, common problems in this type of material. The changes in these physical properties not substantially affect the final mechanical strengths.

    Se estudiaron algunas propiedades físicas y mecánicas de pastas de yeso de construcción adicionadas con un aditivo de origen orgánico, producto de las hojas de la planta Agave americana. Se evaluó el comportamiento plástico de la pasta mediante ensayos de consistencia y se determinó, para cada dosificación, su relación agua/ yeso (a/y. Se evaluó la incidencia del aditivo en los tiempos de fraguado. La transformación química del hemihidrato a yeso dihidrato se estudió mediante una novedosa técnica basada en un analizador de humedad por luz halógena. Se midieron las resistencias mecánicas a flexo-tracción y a compresión. Los resultados del estudio muestran que, para una misma consistencia, se mejoran las resistencias mecánicas. Los tiempos de fraguado de la pasta se aumentaron lo que ayudaría mejorar los tiempos de aplicación del yeso y a disminuir las retracciones plásticas. Las modificaciones de estas propiedades físicas no afectan considerablemente las resistencias mecánicas finales.

  14. Nucleolar organizer regions and a new chromosome number for Rhea americana (Aves: Rheiformes

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    Ricardo José Gunski

    1998-06-01

    Full Text Available Sequential banding analysis (Giemsa-C-banding-Ag NOR of chromosomes of the common rhea (Rhea americana was performed. Metaphases were obtained by peripheral blood lymphocyte culture and monolayer embryo cell culture. The diploid chromosome number was 80, different from the 2n = 82 in previous reports. Macrochromosome pairs 1, 2 and 5 were submetacentric and pair 3, subacrocentric. The 4th pair was acrocentric and all of the microchromosomes appeared to be acrocentric, with the exception of a clearly metacentric pair which was fully heterochromatic. The Z was slightly larger than the W, both being acrocentric and C-band negative. Nucleolar organizer regions were observed in the secondary constriction of a microchromosome pair. Correct identification of the NOR-bearing pair was possible only by sequential analyses, Giemsa staining followed by the Ag-NOR technique.Foram efetuadas análises seqüenciais de bandeamento cromossômico (Giemsa-banda-C-AgNOR em material da espécie Rhea americana (ema com o objetivo de identificar os cromossomos portadores de regiões organizadoras de nucléolos e confirmar o cariótipo desta espécie. As metáfases foram obtidas de culturas de leucócitos e de células de embrião. O número diplóide de cromossomos, determinado pela análise de metáfases oriundas de 19 espécimes, foi de 80 (2n = 80, NF = 95, o que difere da literatura. Os pares de macrocromossomos números 1, 2 e 5 eram submetacêntricos e o par 3 era sub-acrocêntrico, confirmado pelo bandeamento C. O par 4 era acrocêntrico, bem como todos os microcromossomos, com exceção de um metacêntrico inteiramente heterocromático. O cromossomo Z era ligeiramente maior que o W, sendo ambos acrocêntricos e banda-C negativos. A região organizadora de nucléolos foi observada na constrição secundária de um par de microcromossomos. A correta identificação do par portador da NOR só foi possível com a utilização da análise seqüencial de colora

  15. Cinética de secagem e difusividade efetiva em folhas de jenipapo (Genipa americana L.

    Directory of Open Access Journals (Sweden)

    L.A. SILVA

    2015-01-01

    Full Text Available RESUMO O jenipapo (Genipa americana L. é uma espécie nativa com importância medicinal, sendo amplamente utilizada no Brasil. Em função da necessidade de conhecimento à cerca do pré-processamento desta espécie, este trabalho foi desenvolvido com o objetivo de avaliar a cinética de secagem de folhas de jenipapo (G. americana L., bem como determinar a difusividade efetiva da água durante o processo. As folhas foram coletadas com teor de água inicial de 2,30±0,05 (decimal b.s., e submetidas à secagem em três condições de temperatura do ar (35,3; 46,0 e 65,0°C até atingirem o teor de água de equilíbrio. Aos dados experimentais, ajustaram-se doze modelos matemáticos, recomendados para representar o processo de secagem de produtos agrícolas. As magnitudes do coeficiente de determinação (R2, do erro médio relativo (P, do erro médio estimado (SE e do teste do qui-quadrado (χ2, foram utilizadas para verificar o grau de ajuste dos modelos. Os modelos de Henderson e Pabis modificado e Midilli apresentaram ajustes adequados aos dados experimentais, sendo o modelo de Midilli, em função de sua simplicidade, escolhido para representar a cinética de secagem das folhas de jenipapo. Aumentando a temperatura do ar de secagem de 35,3 para 46,0 e 65,0ºC houve redução no tempo de secagem das folhas de jenipapo de 91,1 para 62,5 e 24,2 horas, respectivamente. O coeficiente de difusão efetivo aumenta com a elevação da temperatura, e esta relação é descrita pela equação de Arrhenius, que apresenta energia de ativação para a difusão líquida de 33,9 kJ mol-1.

  16. Dying piece by piece: carbohydrate dynamics in aspen seedlings under severe carbon stress and starvation

    Science.gov (United States)

    Wiley, Erin; Chow, Pak; Landhäusser, Simon

    2016-04-01

    Carbon stress and starvation remain poorly understood in trees, despite their potential role in mortality from a variety of agents. To explore the effects of carbon stress on nonstructural carbohydrate (NSC) dynamics and recovery potential and to examine the process of starvation, we grew aspen seedlings under one of three levels of shade: 40% (light shade), 8% (medium shade), and 4% (dark shade) of full sunlight. We then exposed seedlings to 24 hours darkness at either 20° or 28° C until trees had died. Periodically, seedlings were harvested for NSC analysis and to measure stem and root respiration. In addition, some seedlings were moved back into the light to determine if recovery was possible at certain points during starvation. Specifically, we sought to address the following questions: 1) Do NSC concentrations or mass influence tree survival under carbon stress? 2) At what carbohydrate levels do trees fail to recover and starve? 3) Does temperature affect the NSC level at which trees starve? Increasing shade reduced growth, but surprisingly did not reduce NSC levels, except in a portion of deep shade seedlings that experienced dieback. Once in darkness, leaves died first, with final NSC levels ranging from ~4% (Medium shade, 28 degrees) to 7.5% (Light shade). Stem death generally occurred gradually down the stem. Stem tissues retained ~1-2% NSC when dead. Recovery was still possible when only the upper half of the stem had died; at this point, seedlings had relatively high root NSC levels in their remaining roots (7-10%), with 1-3% starch. No trees recovered after the whole stem had died, at which point, some trees root systems were completely dead. However, most retained substantial amounts of live roots, averaging 5-6% NSC, with 0.25-1.5% starch. Despite the initially similar NSC concentrations, light shade seedlings took longer to reach half stem and whole stem death than seedlings from medium and dark shade. Longer survival times were associated with

  17. Energy from poultry waste: An Aspen Plus-based approach to the thermo-chemical processes.

    Science.gov (United States)

    Cavalaglio, Gianluca; Coccia, Valentina; Cotana, Franco; Gelosia, Mattia; Nicolini, Andrea; Petrozzi, Alessandro

    2018-03-01

    A particular approach to the task of energy conversion of a residual waste material was properly experienced during the implementation of the national funded Enerpoll project. This project is a case study developed in the estate of a poultry farm that is located in a rural area of central Italy (Umbria Region); such a farm was chosen for the research project since it is almost representative of many similar small-sized breeding realties of the Italian regional context. The purpose of the case study was the disposal of a waste material (i.e. poultry manure) and its energy recovery; this task is in agreement with the main objectives of the new Energy Union policy. Considering this background, an innovative gasification plant (300KW thermal power) was chosen and installed for the experimentation. The novelty of the investigated technology is the possibility to achieve the production of thermal energy burning just the produced syngas and not directly the solid residues. This aspect allows to reduce the quantity of nitrogen released in the atmosphere by the exhaust flue gases and conveying it into the solid residues (ashes). A critical aspect of the research program was the optimization of the pretreatment (reduction of the water content) and the dimensional homogenization of the poultry waste before its energy recovery. This physical pretreatment allowed the reduction of the complexity of the matrix to be energy enhanced. Further to the real scale plant monitoring, a complete Aspen Plus v.8.0 model was also elaborated for the prediction of the quality of the produced synthesis gas as a function of both the gasification temperature and the equivalence ratio (ER). The model is an ideal flowchart using as input material just the homogenized and dried material. On the basis of the real monitored thermal power (equal to about 200kW average value in an hour) the model was used for the estimation of the syngas energy content (i.e. LHV) that resulted in the range of 3-5MJ/m 3

  18. O conhecimento e as tecnologias na sociedade da informação

    Directory of Open Access Journals (Sweden)

    Alzira Karla Araújo da Silva

    2010-01-01

    Full Text Available Artículo de reflexión en torno a la sociedad de la información, la sociedad del conocimiento, el paradigma de la cibercultura y el papel de las tecnologías de la información y la comunicación en el progreso social. Se resaltan los factores de inclusión y exclusión sociales que se producen en la sociedad de la información, y se señalan las acciones, intenciones y necesidades que le son propias. La reflexión contribuye a caracterizar la sociedad de la información en tanto busca entenderla desde perspectivas sociales, culturales, económicas y de búsqueda de la ciudadanía. En especial, se analizan los nuevos entornos originados por la revolución tecnológica y su impacto en la información y el conocimiento en un mundo globalizado. Se reconoce que la educación es uno de los pilares de construcción de esa sociedad y se pone como ejemplo el caso de Brasil, donde hay un círculo virtuoso de avances en el uso intensivo de las tecnologias informativas en las escuelas y en la enseñanza superior, gracias a la creación de nuevos espacios públicos, políticas educacionales y el desarrollo tecnológico. Se concluye que la inclusión y democratización de la información son inseparables y determinates para la consolidación de la sociedad de la información.

  19. Sociedad de la información: ¿utopía o panóptico?

    Directory of Open Access Journals (Sweden)

    Octavio Islas

    2015-01-01

    Full Text Available Inicia con los conceptos de Sociedad de la Información. Evoca a estas como el tipo de sociedades deseables a las que nos conducirá la globalización. Hace una evaluación de los resultados de la Cumbre de la Sociedad de la Información, convocada por las Naciones Unidas en Suiza y se adentra en nuevas formas de informar y comunicar: los weblogs o bitácoras del Internet.

  20. Virtude, trabalho e riqueza: a concepção de sociedade civil em Benjamin Franklin

    OpenAIRE

    Ana Maria Brito Sanches

    2006-01-01

    Neste trabalho examinamos a concepção de sociedade civil no pensamento social e político de Benjamin Franklin, cujas idéias exerceram grande influência na formação da mentalidade do homem do Novo Mundo. Essa mentalidade inaugura um novo modo de conceber a vida em sociedade, exaltando tudo o que se opõe aos valores da velha ordem. Contra o princípio da honra, os títulos de nobreza e a posição social dos indivíduos, ela exalta a virtude republicana, celebra o trabalho e reclama o respeito à dig...

  1. Sociedad civil: democracia monitorizada y medios de comunicación en John Keane

    OpenAIRE

    Feenstra, Ramón Andrés

    2010-01-01

    El objetivo de esta tesis doctoral consiste en analizar de manera exhaustiva el concepto de sociedad civil en la obra de Keane. Un estudio que pretende mostrar la potencialidad de la propuesta de sociedad civil de este autor que, ampliamente entendida en la definición de su espacio y de sus actores, ha destacado el papel central de los medios de comunicación en el modelo de democracia monitorizada. Un modelo democrático que se constituye fruto del creciente contrapoder adquirido por una socie...

  2. La calidad y salud del suelo influyen sobre la naturaleza y la sociedad

    Directory of Open Access Journals (Sweden)

    Hernán Burbano Orjuela

    2017-02-01

    Full Text Available La preservación del suelo resulta prioritaria para todos los sectores de la sociedad, porque su deterioro repercute adversamente sobre otros componentes de la naturaleza y sobre los grupos sociales que necesitan del suelo. Por eso, es importante mantener la calidad y salud del suelo, para que la sociedad pueda garantizar su seguridad alimentaria y disfrutar de los servicios ecosistémicos que presta este recurso natural. En este artículo se revisan los conceptos centrales que buscan explicar las relaciones del suelo con la naturaleza y con las personas.

  3. Impacto de las catástrofes naturales en sociedades coloniales

    Directory of Open Access Journals (Sweden)

    Margarita Gascón

    2005-04-01

    Full Text Available En este trabajo resaltamos la relación entre la dinámica de una sociedad y los cambios operados por catástrofes masivas, tanto en lo material como en la economía, la política y las ideas y valores religiosos. Examinamos casos coloniales, como la erupción del volcán Villarrica (1640 en el sur de Chile y otros terremotos destructivos del siglo XVII. Adoptaremos una perspectiva comparativa para mostrar cómo las catástrofes modifican las condiciones locales y provocan cambios en la vida de las sociedades coloniales.

  4. La representación social de las familias diversas: Ley de Sociedades de Convivencia

    OpenAIRE

    María de Jesús González Pérez

    2007-01-01

    La familia es un pilar fundamental que se relaciona determinantemente con las demás estructuras de un sistema social; en el caso de nuestra sociedad, esta institución se encuentra en el más alto rango del orden moral, sancionando desde una perspectiva heterosexista la presencia de nuevas familias que alteran el modelo tradicional, por lo que la Ley de Sociedades de Convivencia reforma al Código Civil del Distrito Federal, y trae consigo la posibilidad de resguardar jurídica e institucionalmen...

  5. La gerencia pública en la sociedad post-industrial

    OpenAIRE

    Guerrero, Omar

    2005-01-01

    Hoy en día la sociedad postindustrial se manifiesta en cinco dimensiones: un sector económico; una distribución ocupacional; la centralidad del conocimiento teórico; una orientación del futuro con base en el control de la tecnología y una hechura de decisiones orientadas por la nueva tecnología intelectual. De ahí nace la motivación del presente trabajo, el cual consiste en analizar la gerencia pública en la sociedad postindustrial, a través del análisis documental. Así, en consonancia con la...

  6. La gerencia pública en la sociedad post-industrial

    OpenAIRE

    Omar Guerrero

    2005-01-01

    Hoy en día la sociedad postindustrial se manifiesta en cinco dimensiones: un sector económico; una distribución ocupacional; la centralidad del conocimiento teórico; una orientación del futuro con base en el control de la tecnología y una hechura de decisiones orientadas por la nueva tecnología intelectual. De ahí nace la motivación del presente trabajo, el cual consiste en analizar la gerencia pública en la sociedad postindustrial, a través del análisis documental. Así, en conson...

  7. Educación mediática en la sociedad actual

    Directory of Open Access Journals (Sweden)

    Rosa García Ruíz

    2013-07-01

    Full Text Available La influencia de los medios de comunicación en la sociedad actual conlleva un cambio de actitud por parte de todos los ciudadanos, instituciones y organismos. De este modo, emana una incesante búsqueda de recursos, propuestas, investigaciones, iniciativas innovadoras y estrategias, relacionadas con la alfabetización mediática, que garantice la participación activa y responsable de la ciudadanía en la sociedad de las múltiples pantallas, como un derecho básico.

  8. Oportunidades y desarrollo en las sociedades científicas estudiantiles

    Directory of Open Access Journals (Sweden)

    Álvaro Mondragón-Cardona

    2013-01-01

    Full Text Available La formación en investigación desde el pregrado como competencia básica y parte fundamental de la educación médica continua y la formación integral, ha sido el punto de encuentro para las diferentes sociedades científicas de estudiantes de medicina de Latinoamérica, convirtiéndose así en el fundamento de la Federación Latinoamericana de Sociedades Científicas de Estudiantes de Medicina FELSOCEM

  9. UNIVERSIDAD Y SOCIEDAD: LA UNIVERSIDAD COMO PALANCA DE TRANSFORMACIÓN SOCIAL

    OpenAIRE

    CULLEN, PATRICIO ALBERTO

    2011-01-01

    Es esencial instalar en la agenda de Gestión Universitaria la discusión política acerca de cuál debe ser hoy el rol de la Universidad en la sociedad. Se postula que no se ejerce el rol de mejora social que es competencia nata de la universidad, como agente principal de producción y distribución del conocimiento. Se ha configurado una deserción que es preciso revertir para transformar la universidad en palanca para sacudir y empezar a cambiar la sociedad. La universidad debe ser un agente d...

  10. La disolución de las Sociedades Mercantiles: Causa ex voluntate

    OpenAIRE

    Huertas López, Josefa

    2014-01-01

    Estudiando el Derecho Mercantil, se encuentra todo lo referente a las sociedades mercantiles, empezando por su constitución, transformación, fusión, escisión hasta de su extinción. Este estudio pese a la complejidad de su título, se centra en la disolución de las sociedades mercantiles y en concreto en la disolución por “CAUSA EX VOLUNTATE”. Diversos son los criterios que han utilizado los distintos autores a lo largo del tiempo para agruparlas, centrándose en las causas de disolución (arts. ...

  11. Dotaciones para la recuperación de activos revertibles como deducibles del impuesto sobre sociedades

    OpenAIRE

    Duplá Marín, María José

    2001-01-01

    El objetivo final que nos propusimos con este trabajo de investigación fue profundizar en el estudio jurídico-tributario de las dotaciones al fondo de reversión como gasto deducible para determinar la base imponible del impuesto sobre sociedades, en aquellas sociedades concesionarias de servicios públicos con cláusula de reversión de activos, partiendo de su realidad contable.En consecuencia el trabajo se ciñe al estudio crítico de la regulación jurídica del fondo de reversión como gasto fisc...

  12. Effects of Tropospheric O3 on Trembling Aspen and Interaction with CO2: Results From An O3-Gradient and a Face Experiment

    Science.gov (United States)

    D.F. Karnosky; B. Mankovska; K. Percy; R.E. Dickson; G.K. Podila; J. Sober; A. Noormets; G. Hendrey; Mark D. Coleman; M. Kubiske; K.S. Pregitzer; J.G. Isebrands

    1999-01-01

    Abstract. Over the years, a series of trembling aspen (Populus tremuloides Michx.) clones differing in O3 sensitivity have been identified from OTC studies. Three clones (216 and 271[(O3 tolerant] and 259 [O3 sensitive]) have been characterized for O3...

  13. Information Literacy: Advancing Opportunities for Learning in the Digital Age. A Report of The Aspen Institute Forum on Communications and Society.

    Science.gov (United States)

    Adler, Richard P.; Breivik, Patricia Senn

    This report is an informed observer's interpretation of the discussions that took place at the 1998 annual meeting of the Aspen Institute's Forum on Communications and Society (FOCAS). It summarizes the inquiry made by FOCAS members into the many issues surrounding information literacy, including what information literacy is, why we need an…

  14. Comparative analysis of the effect of pretreating aspen wood with aqueous and aqueous-organic solutions of sulfuric and nitric acid on its reactivity during enzymatic hydrolysis

    DEFF Research Database (Denmark)

    Dotsenko, Gleb; Osipov, D. O.; Zorov, I. N.

    2016-01-01

    The effect of aspen wood pretreatment methods with the use of both aqueous solutions of sulfuric and nitric acids and aqueous-organic solutions (ethanol, butanol) of sulfuric acid (organosolv) on the limiting degree of conversion of this type of raw material into simple sugars during enzymatic...

  15. Effects of freezing on white perch Morone americana (Gmelin, 1789): Implications for multivariate morphometrics

    Science.gov (United States)

    Kocovsky, Patrick

    2016-01-01

    This study tested the hypothesis that duration of freezing differentially affects whole-body morphometrics of a derived teleost. Whole-body morphometrics are frequently analyzed to test hypotheses of different species, or stocks within a species, of fishes. Specimens used for morphometric analyses are typically fixed or preserved prior to analysis, yet little research has been done on how fixation or preservation methods or duration of preservation of specimens might affect outcomes of multivariate statistical analyses of differences in shape. To determine whether whole-body morphometrics changed as a result of freezing, 23 whole-body morphometrics of age-1 white perch (Morone americana) from western Lake Erie (n = 211) were analyzed immediately after capture, after being held on ice overnight, and after freezing for 100 or 200 days. Discriminant function analysis revealed that all four groups differed significantly from one another (P time to avoid biases related to the length of time they were frozen. Similar experiments should be conducted on other species and also using formalin- and alcohol-preserved specimens.

  16. Comparison of Serum Protein Electrophoresis Values in Wild and Captive Whooping Cranes ( Grus americana ).

    Science.gov (United States)

    Hausmann, Jennifer C; Cray, Carolyn; Hartup, Barry K

    2015-09-01

    Protein electrophoresis of serum samples from endangered, wild whooping cranes ( Grus americana ) was performed to help assess the health of the only self-sustaining, migratory population in North America. Serum samples from wild adult cranes (n = 22) were taken at Aransas National Wildlife Refuge, Texas, USA during winter. Wild juvenile cranes (n = 26) were sampled at Wood Buffalo National Park, Northwest Territories, Canada, in midsummer. All captive crane samples were acquired from the International Crane Foundation, Baraboo, WI, USA. Captive adult cranes (n = 30) were sampled during annual examinations, and archived serum samples from captive juvenile cranes (n = 19) were selected to match the estimated age of wild juveniles. Wild juveniles had significantly lower concentrations of all protein fractions than wild adults, except for prealbumin and γ globulins. All protein fraction concentrations for wild juveniles were significantly lower compared with captive juveniles, except for prealbumin and γ globulins, which were higher. Wild adults had significantly greater γ globulin concentrations than captive adults. Captive juveniles had significantly lower prealbumin and albumin concentrations and albumin : globulin ratios than captive adults. The higher γ globulin concentrations in wild versus captive cranes are likely because of increased antigenic exposure and immune stimulation. Protein fraction concentrations vary significantly with age and natural history in this species. Reference intervals for serum protein electrophoresis results from captive adult whooping cranes are provided in this study.

  17. Potential risk to wood storks (Mycteria americana) from mercury in Carolina Bay fish

    International Nuclear Information System (INIS)

    Brant, H.A.; Jagoe, C.H.; Snodgrass, J.W.; Bryan, A.L.; Gariboldi, J.C.

    2002-01-01

    Fish mercury levels from some Carolina bays pose risk to wood stork. - Carolina bays are freshwater wetlands that serve as important feeding habitats for the endangered wood stork (Mycteria americana). Water levels in these bays fluctuate greatly and tend to be acidic and rich in dissolved organic carbon (DOC), factors that favor mercury (Hg) methylation and bioaccumulation in fish. To assess potential risks to wood storks consuming mercury contaminated fish in bays, we sampled fish from 10 bays on the Savannah River Site (SRS), South Carolina, an area with documented use by wood storks. Whole body mercury concentrations in 258 fishes of three species (Erimyzon sucetta, Acantharchus pomotis and Esox americanus) commonly consumed by wood storks were determined. Risk factors for nestlings and free-ranging adults were calculated using published no and lowest observable adverse effect concentration (NOAEC and LOAEC) values for birds. Fish from higher trophic levels and those from wetlands with relatively shallow maximum depths and fluctuating water levels were more likely to exceed NOAEC and LOAEC values. Calculation of exposure rates of nestling wood storks indicated they are at highest risk during the first 10 days of the nestling period. These calculations suggest that there is potential concern for wood storks foraging in relatively shallow bays with fluctuating water levels, even though there is no obvious local source of mercury to these wetlands

  18. Seasonal movements and multiscale habitat selection of Whooping Crane (Grus americana) in natural and agricultural wetlands

    Science.gov (United States)

    Pickens, Bradley A.; King, Sammy L.; Vasseur, Phillip L.; Zimorski, Sara E.; Selman, Will

    2017-01-01

    Eleven of 15 species of cranes (family: Gruidae) are considered vulnerable or endangered, and the increase of agriculture and aquaculture at the expense of natural wetlands and grasslands is a threat to Gruidae worldwide. A reintroduced population of Whooping Crane (Grus americana) was studied in coastal and agricultural wetlands of Louisiana and Texas, USA. The objectives were to compare Whooping Crane movements across seasons, quantify multiscale habitat selection, and identify seasonal shifts in selection. Whooping Cranes (n = 53) were tracked with satellite transmitters to estimate seasonal core-use areas (50% home range contours) via Brownian bridge movement models and assess habitat selection. Whooping Crane core-use areas (n = 283) ranged from 4.7 to 438.0 km2, and habitat selection changed seasonally as shallow water availability varied. Whooping Crane core-use areas were composed of more fresh marsh in spring/summer, but shifted towards rice and crawfish (Procambarus spp.) aquaculture in the fall/winter. Within core-use areas, aquaculture was most strongly selected, particularly in fall when fresh marsh became unsuitable. Overall, the shifting of Whooping Crane habitat selection over seasons is likely to require large, heterogeneous areas. Whooping Crane use of agricultural and natural wetlands may depend on spatio-temporal dynamics of water depth.

  19. Plantio direto de alface americana sobre plantas de cobertura dessecadas ou roçadas

    Directory of Open Access Journals (Sweden)

    Andréia Cristina Silva Hirata

    2014-06-01

    Full Text Available O objetivo deste trabalho foi avaliar o plantio direto de alface americana no verão sobre plantas de cobertura dessecadas ou roçadas em cultivos sucessivos. O trabalho foi desenvolvido no município de Álvares Machado, São Paulo, Brasil. O delineamento experimental foi em blocos ao acaso, dispostos em parcelas subdivididas, com quatro repetições. O fator da parcela principal foram dois manejos das plantas de cobertura (dessecadas com herbicida ou roçadas e as subparcelas, seis espécies de plantas de cobertura (Cajanus cajan cv. IAPAR 43, Crotalaria spectabilis, Crotalaria juncea, Mucuna pruriens, Pennisetum glaucum e vegetação natural, além da testemunha sem plantas de cobertura. O manejo roçado apresentou desempenho inferior no primeiro cultivo da alface, todavia não diferiu do manejo químico no segundo cultivo. A cobertura do solo com mucuna apresentou maior produtividade da alface no primeiro cultivo devido ao excesso de palha das demais coberturas, o qual prejudicou o estabelecimento da alface. No segundo cultivo não houve diferenças entre as coberturas. A roçagem de plantas de cobertura é uma opção viável para plantio direto de alface sem herbicidas.

  20. Los aportes de una antropología americana en el pensamiento de Rodolfo Kusch

    Directory of Open Access Journals (Sweden)

    Dina Picotti

    2010-01-01

    Full Text Available El presente texto versa sobre la propuesta de Rodolfo Kusch en torno a una antropología del hombre americano a partir de un recorrido por algunas obras insignes de su pensamiento antropológico. El trabajo parte de la pro - blematización de la categoría de situación. A partir de ciertas distinciones filosóficas establecidas entre ser y estar , la autora aborda la cuestión de la identidad americana como pueblo , para indicar la manera en que el habla popular, en su nombrar y callar, es la base de lo que pueda ser el hombre ame - ricano. Después de la descripción de la consolidación del hombre americano tras el dualismo mito-razón y la formulación de la inconmensurabilidad del hombre americano ante criterios que resultan discordes, se sugiere otro modo de pensar, en este caso, de concebir una antropología, otra línea de encarar lo humano en relación con el orden vigente. De esta manera, se postula la idea de que el problema de América es el de recuperar toda la potencialidad del pensar y saber apostar al futuro, lo cual se realiza a partir de la revisión de los niveles económicos, educativos y artísticos del hombre americano.

  1. Utilization of modified starch from avocado (Persea americana Mill.) seed in cream soup production

    Science.gov (United States)

    Cornelia, M.; Christianti, A.

    2018-01-01

    Avocado (Persea americana Mill.) seed was often seen as waste and underutilized resources, especially in the food industry. The aim of this research was to modify the structure of avocado seed starch using the cross-linking method, to improve the viscosity stability in the cream soup. In the preliminary research, starch was isolated from the seed and modified by STPP (sodium tripolyphosphate) with 2%, 4%, and 6% concentration and were reacted for 1, 2, and 3 hours. Starches were analyzed for moisture and ash content, paste clarity, gel strength, swelling power, solubility, yield, and degree of whiteness. Based on the analysis results, the best reaction time and STPP concentration was 6% at 1 hour reaction time. Native starch and the best-modified starch were applied in the cream soup and compared with commercial cream soup. Cream soups were analyzed for viscosity stability using viscometer in 0, 1, 3, and 5 hours after storage in room temperature. The result showed that cream soup using modified starch has better viscosity stability than native starch and commercial cream soup after 5 hours storage, which was 181.7 ± 4.85 cP. Sensory analysis showed that cream soup using modified starch was more acceptable than the others. Avocado seed modified starch has phosphate group that strengthen the starch chain to prevent viscosity breakdown.

  2. Transcriptome analysis of Phytolacca americana L. in response to cadmium stress.

    Directory of Open Access Journals (Sweden)

    Yongkun Chen

    Full Text Available Phytolacca americana L. (pokeweed has metal phytoremediation potential, but little is known about its metal accumulation-related genes. In this study, the de novo sequencing of total RNA produced 53.15 million reads covering 10.63 gigabases of transcriptome raw data in cadmium (Cd-treated and untreated pokeweed. Of the 97,502 assembled unigenes, 42,197 had significant matches in a public database and were annotated accordingly. An expression level comparison between the samples revealed 1515 differentially expressed genes (DEGs, 923 down- and 592 up-regulated under Cd treatment. A KEGG pathway enrichment analysis of DEGs revealed that they were involved in 72 metabolism pathways, with photosynthesis, phenylalanine metabolism, ribosome, phenylpropanoid biosynthesis, flavonoid biosynthesis and carbon fixation in photosynthetic organisms containing 24, 18, 72, 14, 7 and 15 genes, respectively. Genes related to heavy metal tolerance, absorption, transport and accumulation were also identified, including 11 expansins, 8 nicotianamine synthases, 6 aquaporins, 4 ZRT/IRT-like proteins, 3 ABC transporters and 3 metallothioneins. The gene expression results of 12 randomly selected DEGs were validated using quantitative real-time PCR, and showed different response patterns to Cd in their roots, stems and leaves. These results may be helpful in increasing our understanding of heavy metal hyperaccumulators and in future phytoremediation applications.

  3. Effects of Persea americana Mill. seed extracts on the postembryonic development of Musca domestica (Diptera: Muscoide

    Directory of Open Access Journals (Sweden)

    Silvia del C. Molina Bertrán

    2018-04-01

    Full Text Available Context: The synthetic insecticides used to control Diptera are harmful to the environment and humans. Extracts and compounds from plants are a more sustainable source for the development of bio-insecticides. Aims: To evaluate the efficacy of a hydroalcoholic extract of Persea americana Mill seeds as an alternative control of the species Musca domestica. Methods: The extracts were obtained by two methods, the Shaker (S and the Soxhlet extraction (SE method, using 94% ethanol as the solvent. Also, the qualitative chemical composition was determined by phytochemical screening. The effect of the two extracts on the post-embryonic development of the fly as well as the adulticidal effect was evaluated. Results: Phytochemical analysis revealed the presence of metabolites such as alkaloids, coumarins, tannins, flavonoids, sugars and amino acids. The influence on the post-embryonic development of M. domestica was demonstrated, especially on the viability of larvae and neolarvae to adults; however, the effect on the weight and duration of each period was low. The adulticidal effects of the extracts were determined by the lethal concentration 50(LC50 of 2.910 mg/100 mL and 3.944 mg/100 mL for the S and SE extracts, respectively. Conclusions: Both extracts showed their insecticidal effects against Musca domestica, but the extract elaborated by S method showed greater influence diminishing viability and better adulticidal effect.

  4. GENETIC VARIABILITY WITHIN MEXICAN RACE AVOCADO (Persea americana Mill. GERMPLASM COLLECTIONS DETERMINED BY ISSRs

    Directory of Open Access Journals (Sweden)

    H. Cuiris-Pérez

    2009-01-01

    Full Text Available El presente estudio se efectuó para determinar la existencia de diversidad genética dentro de una colección de germoplasma de aguacate (Persea americana Mill. perteneciente al Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP, Campo Experimental Uruapan (CEFAP-Uruapan. Se investigó la relación parental entre 77 accesiones (231 plantas de la raza Mexicana con el uso de siete ISSRs (Inter Simple Sequence Repeat microsatellites, en inglés. En total se detectaron 154 loci. El porcentaje de polimorfismo varió de 82.3 a 95.4, con un número de bandas entre 17 y 25 dentro de las accesiones. El análisis de similitud genética reveló la formación de dos grupos principales, uno con once subgrupos y el otro con tres subgrupos. La similitud genética fue más alta entre las accesiones 237 (Atlixco, Puebla y XTC01 (Uruapan, Michoacán, mientras que las accesiones 532 (Atlixco, Puebla y 369 (Chilchota, Michoacán fueron las más disímiles. No se encontraron duplicados en los genotipos analizados. En general, el presente estudio demostró la utilidad del análisis mediante ISSRs para la determinación de diversidad genética en aguacate.

  5. Estudios sobre Trypanosomiasis americana en el Perú. Observaciones en el departamento de Ica

    Directory of Open Access Journals (Sweden)

    Víctor M Ayulo Robles

    1946-01-01

    Full Text Available Hemos comprobado la presencia de Triatomas en las ciudades de Ica y Nazca. Los Triatomas encontrados en esas localidades son de la especie del Triatoma Infestans. Las observaciones del contenido intestinal de los Triatomas capturados en ambas ciudades reveló que ellos no se encuentran infestados; lo que hace sospechar que estos insectos procedan de la Ciudad de Arequipa. Los exámenes de sangre en fresco, gota gruesa y frotis coloreados por el método de Giemsa en 174 personas y 32 animales, así como las pruebas de Desviación del Complemento (Reacción de GUERREIRO Y MACHADO e intradermo-reacción en las 174 personas, fueron negativas; lo que demuestra que actualmente no existe la Enfermedad de Chagas en el Departamento de Ica. Dada la presencia de Triatomas en Ica y Nazca y la existencia de la Enfermedad de Chagas en Vitor, Sihuas y Quishuarani del Departamento de Arequipa no se excluye la posibilidad de que posteriormente se haga presente la Trypanosomiasis americana, también, en esas zonas.

  6. “Ser devorado no duele”. Th. W. Adorno y la experiencia americana

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    Maiso, Jordi

    2009-10-01

    Full Text Available The present text aims to fathom Theodor W. Adorno’s american experience as a deciding learning process in the development of his Critical Theory. As a consequence of his New York exile years and his participance on the Princeton Radio Research Project, Adorno not only gets in touch with the proceeding of the culture industry and sets down a resolute theoretical approach to radio music, but also realizes a shift has taken place on the social function of theory which enables him a poignant self-reflection on the situation of the emigrated intellectual.El presente texto pretende desentrañar la experiencia americana de Theodor W. Adorno como un proceso de aprendizaje decisivo en la formulación de su Teoría Crítica. A partir de su exilio en Nueva York y de su participación en el Princeton Radio Research Project, Adorno no sólo adquiere un conocimiento directo del funcionamiento de la industria de la cultura y formula una decisiva aproximación teórica a la música radiofónica, sino que también toma conciencia de un cambio en la función social de la teoría que le permite llevar a cabo una aguda autorreflexión sobre la situación del intelectual emigrado.

  7. Isolation and Purification of an Antibacterial Protein from Immune Induced Haemolymph of American Cockroach, Periplaneta americana

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    Hamid Reza Basseri

    2016-10-01

    Full Text Available Background: Antimicrobial peptides play a role as effectors substances in the immunity of vertebrate and inverte­brate hosts. In the current study, antimicrobial peptide was isolated from the haemolymph of the American cock­roach, Periplaneta americana.Methods: Micrococcus luteus as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria were candi­date for injection. Induction was done by injecting both bacteria into the abdominal cavity of two groups of cock­roaches separately. The haemolymphs were collected 24 hours after post injection and initially tested against both bacteria. Subsequently, the immune induced haemolymph was purified by high performance liquid chromatography (HPLC to separate the proteins responsible for the antibacterial activity.Results: The non-induced haemolymph did not show any activity against both bacteria whereas induced haemo­lymph exhibited high activity against M. luteus but did less against E. coli. Two fractions showed antibacterial activ­ity against M. luteus. Finally the molecular weight of the isolated antibacterial proteins were determined as 72 kDa and 62 kDa using SDS-PAGE.Conclusion: Induced haemolymph of American cockroaches has the ability to produce peptides to combat against Gram-positive bacteria when an immune challenge is mounted. Further work has to be done to sequence of the pro­tein, which it would be advantageous.

  8. De la independencia a la natural barbarie americana. Una lectura del Facundo de Domingo F. Sarmiento

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    Maura Brighenti

    2010-01-01

    Full Text Available Se presenta una lectura del "Facundo" de Domingo F. Sarmiento y, en particular, de su más general visión de la historia y de la realidad argentina y latinoamericana a partir del esquema dicotómico de civilización y barbarie que tendrá mucha suerte en las narraciones de los procesos del modernización latinoamericanos por lo menos hasta la segunda mitad del siglo XX. A través del análisis de algunos entre los múltiples niveles narrativos del "Facundo" se quiere mostrar como tal imagen dicotómica se va cristalizando en el texto. Partiendo del espacio infinito y vacío de la pampa y pasando por una antropología del gaucho - de su manera de vivir y de conducir la guerra - Sarmiento conduce el lector hasta la forma típicamente americana de despotismo, el caudillismo, llegado en Argentina a su epopeya final con el régimen de Juan M. de Rosas. En la última parte se intenta injertar el esquema dicotómico del Facundo al interior de la más general reflexión del Occidente sobre la modernidad y sus alteridades, a través por un lado del prisma orientalista y por el otro de las mismas fuentes del pensamiento moderno europeo y en particular de Locke y Hobbes.

  9. Subcellular distribution and chemical forms of cadmium in Phytolacca americana L

    Energy Technology Data Exchange (ETDEWEB)

    Fu Xiaoping; Dou Changming [Ministry of Agriculture Key Laboratory of Non-point Source Pollution Control, Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China); Chen Yingxu, E-mail: yingxu_chen@hotmail.com [Ministry of Agriculture Key Laboratory of Non-point Source Pollution Control, Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China); Chen Xincai; Shi Jiyan; Yu Mingge; Xu Jie [Ministry of Agriculture Key Laboratory of Non-point Source Pollution Control, Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China)

    2011-02-15

    Phytolacca americana L. (pokeweed) is a promising species for Cd phytoextraction with large biomass and fast growth rate. To further understand the mechanisms involved in Cd tolerance and detoxification, the present study investigated subcellular distribution and chemical forms of Cd in pokeweed. Subcellular fractionation of Cd-containing tissues indicated that both in root and leaves, the majority of the element was located in soluble fraction and cell walls. Meanwhile, Cd taken up by pokeweed existed in different chemical forms. Results showed that the greatest amount of Cd was found in the extraction of 80% ethanol in roots, followed by 1 M NaCl, d-H{sub 2}O and 2% HAc, while in leaves and stems, most of the Cd was extracted by 1 M NaCl, and the subdominant amount of Cd was extracted by 80% ethanol. It could be suggested that Cd compartmentation with organo-ligands in vacuole or integrated with pectates and proteins in cell wall might be responsible for the adaptation of pokeweed to Cd stress.

  10. Food habits of stunted and non-stunted white perch (Morone americana)

    Science.gov (United States)

    Gosch, N.J.C.; Stittie, J.R.; Pope, K.L.

    2010-01-01

    We studied food habits of white perch (Morone americana) from two populations with different stable states (stunted [Branched Oak Lake, Nebraska] and nonstunted [Pawnee Lake, Nebraska]) to determine if change in food habits of white perch is likely to occur in situations where a stunted white perch population is altered to a nonstunted state and vice versa. Three approaches were used to quantitatively describe seasonal (spring = March-May, summer = June-August, autumn = September-November) diets of white perch - 1) frequency of occurrence, 2) percentage of composition by volume, and 3) mean stomach fullness. White perch diets were dominated by cladocerans and dipterans in both reservoirs during all seasons. Fish egg predation was similar between reservoirs, and white perch rarely consumed fishes in either the stunted or the non-stunted population. Shifting a white perch population between stunted and non-stunted states will likely cause little or no change in food habits; fish in both states will primarily consume invertebrates.

  11. Microsatellite markers in avocado (Persea americana Mill.): genealogical relationships among cultivated avocado genotypes.

    Science.gov (United States)

    Ashworth, V E T M; Clegg, M T

    2003-01-01

    Twenty-five microsatellite markers uniquely differentiated 35 avocado cultivars and two wild relatives. Average heterozygosity was high (60.7%), ranging from 32% in P. steyermarkii to 84% in Fuerte and Bacon. In a subset of 15 cultivars, heterozygosity averaged 63.5% for microsatellites, compared to 41.8% for restriction fragment length polymorphisms (RFLPs). A neighbor-joining tree, according to average shared allele distances, consisted of three clusters likely corresponding to the botanical races of avocado and intermediate clusters uniting genotypes of presumably racially hybrid origin. Several results were at odds with existing botanical assignments that are sometimes rendered difficult by incomplete pedigree information, the complexity of the hybrid status (multiple backcrossing), or both. For example, cv. Harvest clustered with the Guatemalan race cultivars, yet it is derived from the Guatemalan x Mexican hybrid cv. Gwen. Persea schiedeana grouped with cv. Bacon. The rootstock G875 emerged as the most divergent genotype in our data set. Considerable diversity was found particularly among accessions from Guatemala, including G810 (West Indian race), G6 (Mexican race), G755A (hybrid Guatemalan x P. schiedeana), and G875 (probably not P. americana). Low bootstrap support, even upon exclusion of (known) hybrid genotypes from the data matrix, suggests the existence of ancient hybridization or that the botanical races originated more recently than previously thought.

  12. Fast and Powerful: Biomechanics and Bite Forces of the Mandibles in the American Cockroach Periplaneta americana.

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    Tom Weihmann

    Full Text Available Knowing the functionality and capabilities of masticatory apparatuses is essential for the ecological classification of jawed organisms. Nevertheless insects, especially with their outstanding high species number providing an overwhelming morphological diversity, are notoriously underexplored with respect to maximum bite forces and their dependency on the mandible opening angles. Aiming for a general understanding of insect biting, we examined the generalist feeding cockroach Periplaneta americana, characterized by its primitive chewing mouth parts. We measured active isometric bite forces and passive forces caused by joint resistance over the entire mandibular range with a custom-built 2D force transducer. The opening angle of the mandibles was quantified by using a video system. With respect to the effective mechanical advantage of the mandibles and the cross-section areas, we calculated the forces exerted by the mandible closer muscles and the corresponding muscle stress values. Comparisons with the scarce data available revealed close similarities of the cockroaches' mandible closer stress values (58 N/cm2 to that of smaller specialist carnivorous ground beetles, but strikingly higher values than in larger stag beetles. In contrast to available datasets our results imply the activity of faster and slower muscle fibres, with the latter becoming active only when the animals chew on tough material which requires repetitive, hard biting. Under such circumstances the coactivity of fast and slow fibres provides a force boost which is not available during short-term activities, since long latencies prevent a specific effective employment of the slow fibres in this case.

  13. Morphogenesis of the rhea (Rhea americana respiratory system in different embryonic and foetal stages

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    Renata P. Sousa

    Full Text Available ABSTRACT: The rhea (Rhea americana is an important wild species that has been highlighted in national and international livestock. This research aims to analyse embryo-foetal development in different phases of the respiratory system of rheas. Twenty-three embryos and foetuses were euthanized, fixed and dissected. Fragments of the respiratory system, including the nasal cavity, larynx, trachea, syrinx, bronchi and lungs, were collected and processed for studies using light and scanning electron microscopy. The nasal cavity presented cubic epithelium in the early stages of development. The larynx exhibited typical respiratory epithelium between 27 and 31 days. The trachea showed early formation of hyaline cartilage after 15 days. Syrinx in the mucous membrane of 18-day foetuses consisted of ciliated epithelium in the bronchial region. The main bronchi had ciliated epithelium with goblet cells in the syringeal region. In the lung, the parabronchial stage presented numerous parabronchi between 15 and 21 days. This study allowed the identification of normal events that occur during the development of the rhea respiratory system, an important model that has not previously been described. The information generated here will be useful for the diagnosis of pathologies that affect this organic system, aimed at improving captive production systems.

  14. Molecular characterization and localization of the first tyramine receptor of the American cockroach (Periplaneta americana).

    Science.gov (United States)

    Rotte, C; Krach, C; Balfanz, S; Baumann, A; Walz, B; Blenau, W

    2009-09-15

    The phenolamines octopamine and tyramine control, regulate, and modulate many physiological and behavioral processes in invertebrates. Vertebrates possess only small amounts of both substances, and thus, octopamine and tyramine, together with other biogenic amines, are referred to as "trace amines." Biogenic amines evoke cellular responses by activating G-protein-coupled receptors. We have isolated a complementary DNA (cDNA) that encodes a biogenic amine receptor from the American cockroach Periplaneta americana, viz., Peatyr1, which shares high sequence similarity to members of the invertebrate tyramine-receptor family. The PeaTYR1 receptor was stably expressed in human embryonic kidney (HEK) 293 cells, and its ligand response has been examined. Receptor activation with tyramine reduces adenylyl cyclase activity in a dose-dependent manner (EC(50) approximately 350 nM). The inhibitory effect of tyramine is abolished by co-incubation with either yohimbine or chlorpromazine. Receptor expression has been investigated by reverse transcription polymerase chain reaction and immunocytochemistry. The mRNA is present in various tissues including brain, salivary glands, midgut, Malpighian tubules, and leg muscles. The effect of tyramine on salivary gland acinar cells has been investigated by intracellular recordings, which have revealed excitatory presynaptic actions of tyramine. This study marks the first comprehensive molecular, pharmacological, and functional characterization of a tyramine receptor in the cockroach.

  15. The role of gut microbiota in the regulation of standard metabolic rate in female Periplaneta americana

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    Paul A. Ayayee

    2018-05-01

    Full Text Available Insect gut microbiota contribute significantly to host nutritional ecology. Disrupting insect gut microbial assemblages impacts nutrient provisioning functions, and can potentially affect host standard metabolic rate (SMR, a measure of host energy balance. In this study, we evaluated the effect of disrupting gut microbial assemblages on the SMR of female Periplaneta americana cockroaches fed dog food (DF, high protein/carbohydrate (p/c ratio, and cellulose-amended dog food (CADF, 30% dog food, 70% cellulose, low p/c ratio diets, supplemented with none, low, or high antibiotic doses. Bacterial loads decreased significantly between diet types (P = 0.04 and across antibiotic doses (P = 0.04. There was a significant diet type x antibiotic dose interaction on SMR of females on both diets (P = 0.05 by the end of the seven-day experimental period. In CADF-fed females, SMR decreased linearly with decreasing bacterial load. However, SMR of DF-fed females on the low dose was significantly higher than those in the control and high dose groups. This is interpreted as a diet-dependent response by low dose DF-fed females to the loss of nutritional services provided by gut bacteria. Severe reductions in bacterial load at high doses reduced SMR of females on both diet types. This study provides insights into the potential role of gut bacteria as modulators of host energy expenditure under varying dietary conditions.

  16. Anti Lithiasis Activity of Avocado (Persea americana Mill Leaves Extract in White Male Rats

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    IETJE WIENTARSIH

    2012-03-01

    Full Text Available In Indonesia, avocado leaves have been used as traditional medicines for diureticum to cure urolithiasis. This research was to determine anti lithiasis activity of avocado leaves (Persea americana Mill extract on white male rats nefrolithiasis model induced by ethylene glycol. Ethanol extraction method was used to get extract of avogadro leaves. Twenty adult male white rats were divided into 4 different induction treatments i.e. aquadest, ethylene glycol 0.75% and ammonium chloride 2%, and extract of avocado leaves with different levels of 100 and 300 mg/kg bw respectively. Their body weight was measured daily to determine their growth ratio. And at the end of the trial, the kidney was analyzed its calcium level and inhibitory activity to formation of calcium oxalate crystals. The results showed that the amount of calcium level in the kidney of rats treated with extract of avogadro leaves was significantly decreased than that of rats treated with ethylene glycol 0.75% and ammonium chloride 2% (P < 0.05. The extract avocado leaves as a herbal remedy can be recommended as a phytotherapeutic agent especially for preventive action for urolithiasis diseases.

  17. Transcriptional signatures of ancient floral developmental genetics in avocado (Persea americana; Lauraceae).

    Science.gov (United States)

    Chanderbali, André S; Albert, Victor A; Leebens-Mack, Jim; Altman, Naomi S; Soltis, Douglas E; Soltis, Pamela S

    2009-06-02

    The debate on the origin and evolution of flowers has recently entered the field of developmental genetics, with focus on the design of the ancestral floral regulatory program. Flowers can differ dramatically among angiosperm lineages, but in general, male and female reproductive organs surrounded by a sterile perianth of sepals and petals constitute the basic floral structure. However, the basal angiosperm lineages exhibit spectacular diversity in the number, arrangement, and structure of floral organs, whereas the evolutionarily derived monocot and eudicot lineages share a far more uniform floral ground plan. Here we show that broadly overlapping transcriptional programs characterize the floral transcriptome of the basal angiosperm Persea americana (avocado), whereas floral gene expression domains are considerably more organ specific in the model eudicot Arabidopsis thaliana. Our findings therefore support the "fading borders" model for organ identity determination in basal angiosperm flowers and extend it from the action of regulatory genes to downstream transcriptional programs. Furthermore, the declining expression of components of the staminal transcriptome in central and peripheral regions of Persea flowers concurs with elements of a previous hypothesis for developmental regulation in a gymnosperm "floral progenitor." Accordingly, in contrast to the canalized organ-specific regulatory apparatus of Arabidopsis, floral development may have been originally regulated by overlapping transcriptional cascades with fading gradients of influence from focal to bordering organs.

  18. Purification and characterization of peroxidase from avocado (Persea americana Mill, cv. Hass).

    Science.gov (United States)

    Rojas-Reyes, José O; Robles-Olvera, Victor; Carvajal-Zarrabal, Octavio; Castro Matinez, Claudia; Waliszewski, Krzysztof N; Aguilar-Uscanga, María Guadalupe

    2014-07-01

    Avocado (Persea americana Mill, cv. Hass) fruit ranks tenth in terms of the most important products for Mexico. Avocado products are quite unstable due to the presence of oxidative enzymes such as polyphenol oxidase and peroxidase. The present study is to characterize the activity of purified avocado peroxidase from avocado in order to ascertain the biochemical and kinetic properties and their inhibition conditions. Purification was performed by Sephacryl S 200 HR gel filtration chromatography and its estimated molecular weight was 40 kDa. The zymogram showed an isoelectric point of 4.7. Six substrates were tested in order to ascertain the affinity of the enzyme for these substrates. The purified peroxidase was found to have low Km (0.296 mM) and high catalytic efficiency (2688 mM(-1) s(-1)) using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), optimum activity being reached at 51°C, pH 3.8. The addition of dithiothreitol, β-mercaptoethanol, ascorbic acid, sodium azide, L-cysteine and Tween-20 had high inhibitory effects, while metals ions such as Cu(+), Fe(2+) and Mn(2+) had weak inhibitory activity on purified avocado peroxidase. The purified avocado peroxidase exhibits high inhibition (Ki = 0.37 µM) with 1.97 µM n-propyl gallate using ABTS as substrate at 51°C, pH 3.8 for 10 min. © 2013 Society of Chemical Industry.

  19. Transcriptomic Analysis of Avocado Hass (Persea americana Mill) in the Interaction System Fruit-Chitosan-Colletotrichum.

    Science.gov (United States)

    Xoca-Orozco, Luis-Ángel; Cuellar-Torres, Esther Angélica; González-Morales, Sandra; Gutiérrez-Martínez, Porfirio; López-García, Ulises; Herrera-Estrella, Luis; Vega-Arreguín, Julio; Chacón-López, Alejandra

    2017-01-01

    Avocado ( Persea americana ) is one of the most important crops in Mexico as it is the main producer, consumer, and exporter of avocado fruit in the world. However, successful avocado commercialization is often reduced by large postharvest losses due to Colletotrichum sp., the causal agent of anthracnose. Chitosan is known to have a direct antifungal effect and acts also as an elicitor capable of stimulating a defense response in plants. However, there is little information regarding the genes that are either activated or repressed in fruits treated with chitosan. The aim of this study was to identify by RNA-seq the genes differentially regulated by the action of low molecular weight chitosan in the avocado-chitosan- Colletotrichum interaction system. The samples for RNA-seq were obtained from fruits treated with chitosan, fruits inoculated with Colletotrichum and fruits both treated with chitosan and inoculated with the fungus. Non-treated and non-inoculated fruits were also analyzed. Expression profiles showed that in short times, the fruit-chitosan system presented a greater number of differentially expressed genes, compared to the fruit-pathogen system. Gene Ontology analysis of differentially expressed genes showed a large number of metabolic processes regulated by chitosan, including those preventing the spread of Colletotrichum . It was also found that there is a high correlation between the expression of genes in silico and qPCR of several genes involved in different metabolic pathways.

  20. Persea americana (avocado): bringing ancient flowers to fruit in the genomics era.

    Science.gov (United States)

    Chanderbali, André S; Albert, Victor A; Ashworth, Vanessa E T M; Clegg, Michael T; Litz, Richard E; Soltis, Douglas E; Soltis, Pamela S

    2008-04-01

    The avocado (Persea americana) is a major crop commodity worldwide. Moreover, avocado, a paleopolyploid, is an evolutionary "outpost" among flowering plants, representing a basal lineage (the magnoliid clade) near the origin of the flowering plants themselves. Following centuries of selective breeding, avocado germplasm has been characterized at the level of microsatellite and RFLP markers. Nonetheless, little is known beyond these general diversity estimates, and much work remains to be done to develop avocado as a major subtropical-zone crop. Among the goals of avocado improvement are to develop varieties with fruit that will "store" better on the tree, show uniform ripening and have better post-harvest storage. Avocado transcriptome sequencing, genome mapping and partial genomic sequencing will represent a major step toward the goal of sequencing the entire avocado genome, which is expected to aid in improving avocado varieties and production, as well as understanding the evolution of flowers from non-flowering seed plants (gymnosperms). Additionally, continued evolutionary and other comparative studies of flower and fruit development in different avocado strains can be accomplished at the gene expression level, including in comparison with avocado relatives, and these should provide important insights into the genetic regulation of fruit development in basal angiosperms.