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  1. Mismi y Huarancante: nevados sagrados del Valle de Colca.

    OpenAIRE

    Ceruti, María Constanza

    2013-01-01

    El presente trabajo hace referencia a ascensiones efectuadas por la autora a las cimas de los montes Mismi (5596 m) y Huarancante (5360 m), en el sur de Perú. Ambas montañas ostentan evidencias de sitios rituales de altura de probable filiación Inca en avanzado estado de destrucción por eventos de huaqueo que se remontan a fines de la década del setenta. Al igual que otros nevados que flanquean al valle de Colca, el Huarancante y el Mismi siguen ...

  2. Volcanic hazard maps of the Nevado del Ruiz volcano, Colombia

    Science.gov (United States)

    Parra, Eduardo; Cepeda, Hector

    1990-07-01

    Although the potential hazards associated with an eruption of Nevado del Ruiz volcano were known to civil authorities before the catastrophic eruption there in November 1985, their low perception of risk and the long quiescent period since the last eruption (140 years), caused them to wait for stronger activity before developing an eruption alert system. Unfortunately, the eruption occurred suddenly after a period of relative quiet, and as a result more than 25,000 people were killed. Although it was accurate and reasonably comprehensive, the hazard map that existed before the eruption was poorly understood by the authorities and even less so by the general population, because the scientific terminology and probabilistic approach to natural hazards were unfamiliar to many of them. This confusion was shared by the communication media, which at critical times placed undue emphasis on the possibility of lava flows rather than on the more imminent threat from mudflows, in keeping with the popular but often inaccurate perception of volcanic eruptions. This work presents an updated hazard map of Nevado del Ruiz that combines information on various hazardous phenomena with their relative probability of occurrence in order to depict numerical "hazard levels" that are easily comprehensible to nonspecialists and therefore less susceptible to misinterpretation. The scale of relative risk is arbitrary, ranging from five to one, and is intended to provide an intuitive indication of danger to people, property and crops. The map is meant to facilitate emergency preparedness and management by political and civil authorities, to educate the public concerning volcanic hazards and to assist in land-use planning decisions.

  3. Elementos geomorfológico-cuantitativos del piedemonte nororiental del volcán Nevado de Toluca

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    Luis Miguel Espinosa Rodríguez

    2003-01-01

    Full Text Available A partir de un análisis cuantitativo y morfométrico, se determina la geodinámica del piedemonte nororiental del volcán Nevado de Toluca. Se destaca la relación entre el material, las formas heredadas y la energía que dinamiza el noreste del volcán.

  4. The 1985 Nevado del Ruiz volcano catastrophe: anatomy and retrospection

    Science.gov (United States)

    Voight, Barry

    1990-12-01

    This paper seeks to analyze in an objective way the circumstances and events that contributed to the 1985 Nevado del Ruiz catastrophe, in order to provide useful guidelines for future emergencies. The paper is organized into two principal parts. In the first part, an Anatomy of the catastrophe is developed as a step-by-step chronicle of events and actions taken by individuals and organizations during the period November 1984 through November 1985. This chronicle provides the essential background for the crucial events of November 13. This year-long period is broken down further to emphasize important chapters: the gradual awareness of the awakening of the volcano; a long period of institutional skepticism reflecting an absence of credibility; the closure of the credibility gap with the September 11 phreatic eruption, followed by an intensive effort to gird for the worst; and a detailed account of the day of reckoning. The second part of the paper, Retrospection, examines the numerous complicated factors that influenced the catastrophic outcome, and attempts to cull a few "lessons from Armero" in order to avoid similar occurrences in the future. In a nutshell, the government on the whole acted responsibly but was not willing to bear the economic or political costs of early evacuation or a false alarm. Science accurately foresaw the hazards but was insufficiently precise to render reliable warning of the crucial event at the last possible minute. Catastrophe was therefore a calculated risk, and this combination - the limitations of prediction/detection, the refusal to bear a false alarm and the lack of will to act on the uncertain information available - provided its immediate and most obvious causes. But because the crucial event occurred just two days before the Armero emergency management plan was to be critically examined and improved, the numerous circumstances which delayed progress of emergency management over the previous year also may be said to have

  5. SIMPOSIO "ASPECTOS MÉDICOS DE LA ERUPCIÓN DEL NEVADO DEL RUIZ". CONCLUSIONES PRELIMINARES

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    Academia Nacional de Medicina

    1986-12-01

    Full Text Available

    El Comité Organizador del Simposio "' Aspéctos Medicos de la Erupción Volcanica del Nevado del Ruiz". confor­mado por los doctores Pablo Gomez Martinez, Jose Felix Patino, Valentin Malagón, German Fernandez. Ivan Munera y Luis Jorge Perez, se permite informar a la opinion publica, las conclusiones preliminares a las que ha llegado despues de haber analizado todas las ponencias presentadas por las personas y entidades que atendieron sobrevivientes de la catastrofe de noviembre de 1985.

    1. Aspectos geológicos

    Colombia está situada en el area denominada Cinturón de Fuego, que envuelve el Oceano Pacifico y en su conformación geográfica se encuentran 30 volcanes, situados en su mayorla en la Cordillera Central. De estos, 11 están en mayor o menor actividad y 7 tienen historia de erupciones. Las capas geol6ógicas sobre las cuales se extiende el pals presentan zonas de elevada sismicidad

    Las caracterlsticas de la erupción del Nevado del Ruiz permiten clasificarlo como un volcan de tipo "'Pliniano- explosivo". que puede emitir enorme cantidad de gases y fragmentos sólidos a grandes velocidades y altas tempe­raturas, como tambien lodo caliente, con deshielo de las nieves perpetuas cuyo resultado es Ia formación del "lahar" que sepultó las poblaciones y cubrió extensas zonas de terreno. Estas erupciones se presentan de manera intermitente y su comportamiento es impredecible. Existe siempre la posibilidad de erupciones late­rales que aumentan su peligro y radio de acción.

    El "lahar" fue una avalancha de lodo que cubrió a la poblacion de Armero; lo componían materiales inorgánicos provenientes del volcan, mezclados con los materiales orgánicos presentes en las tierras fertiles dedicadas a la agricultura y la ganadería. Estudios microbiológicos demostraron la presencia de una rica flora bacteriana y de hongos...

  6. ESTUDIO EPIDEMIOLÓGICO DEL CONEJO SILVESTRE Sylvilagus brasiliensis EN EL PARQUE NACIONAL NATURAL LOS NEVADOS

    OpenAIRE

    Insuasty Osorio, Julián Alejandro; Ramírez Benavides, Ginés Fernando; Mejía Morales, Luis Miguel

    2008-01-01

    Este estudio epidemiológico se realizó con el objeto de identificar los agentes etiológicos responsables de las afecciones presentes en las poblaciones de conejo silvestre Sylvilagus brasiliensis, en la zona amortiguadora del Parque Nacional Natural Los Nevados. Con un enfoque en Medicina de la Conservación, bajo el concepto "Triada Ecológica de la Enfermedad" y por medio del análisis multivariado "Análisis Factorial de Correspondencias Múltiples" con el programa "SPAD-WIN"; se determinó y an...

  7. Fluid inclusions study in thermal gradient wells, Nevado del Ruiz Volcano

    International Nuclear Information System (INIS)

    Uruena Suarez, Cindy L; Zuluaga, Carlos A; Molano, Juan Carlos

    2012-01-01

    A fluid inclusions study in the Nevado del Ruiz volcano hydrothermal system allowed to characterize fluids involved in the evolution of the geothermal system. Fluid inclusions hosted in quartz, plagioclase and carbonate from samples of the deepest parts of three thermal gradient wells were analyzed to understand fluid-rock interaction. Fluid inclusions hosted in carbonate veins with coloform microestructure represent hydrothermal fluids with temperatures higher than 250 Celsius degrade. This interpretation is supported by microprobe and cathodoluminescence analysis that also indicate a hydrothermal origin for the veins. Fluid inclusions hosted in quartz (mylonite) were originated by metamorphic fluids and fluid inclusions hosted in plagioclase (andesitic lavas) are considered to be originated from magmatic fluids (H 2 O + CO 2 system).

  8. STRUCTURAL CHARACTERIZATION OF VOLCANIC ASH OF THE NEVADO DEL RUIZ: ZEOLITE PHASE IDENTIFICATION

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    Heiddy P. Quiroz

    2014-08-01

    Full Text Available This paper presents a study of the structural properties obtained from volcanic ash from Nevado del Ruiz located in the Central Range of Andes - Colombia. The volcanic ash samples were subjected to hydration processes and heat treatments in situ during characterization stage material. During the hydration process, which consisted of introducing 2.4875 ± 0.0002g of volcanic ash in 20ml of water for 48 hours, the organic fraction present was removed from the particulate suspension in the aqueous medium. From measurements of X-ray diffraction (XRD, it was observed, that the temperature variations between 323 and 673 K influence the phase formation of zeolite with structures Heulandite -Ca, Stellerita and gmelinite. XRD measurements were performed in vacuum and atmospheric pressure. X'pert Highscore Plus program and simulation Rietveld refinement were used for to obtain the structures of each of the phases. It was found, using the Scherrer equation, that crystallite sizes (Δ (2θ are influenced by changes crystal-chemical caused by hydration, heat treatment and pressure conditions during the characterization. A variation of Δ ( 2θ between 37 and 106.9 nm from XRD measurements was found. It was determined that from 423K in the sample of un-hydrated volcanic ash, the formation of zeolite Stellerita presents with a stable phase up to 673 K.

  9. Structural analysis of the northeast nevado del Ruiz volcano area, Colombia - a contribution to geothermal exploration

    International Nuclear Information System (INIS)

    Mejia, Eliana L; Velandia, Francisco; Zuluaga, Carlos A; Lopez, Julian A; Cramer, Thomas

    2012-01-01

    The structural geology studies around the Nevado del Ruiz Volcano (NRV), based on aerial photographs and digital terrene models interpretation, in conjunction with analysis of morphological, tectonic features, striated fault planes data and stress field calculation allow to propose a structural scheme that explains the pattern of location of hot springs and fluid released in the western part of the NRV. Structures and kinematics in the region are closely related to the dominant tectonic features of the NVR, nominally longitudinal NE-SW and N-S faults (Palestina, Santa Rosa and San Jeronimo) and a transverse NW-SE to E-W system (Villamaria-Termales,Campoalegrito, San Ramon faults). Quaternary stress tensor was obtained with a WSW-ENE direction of contraction, and dextral strike slip deformation by simple shear along main longitudinal faults, while left lateral displacement is transmitted to most of the NW transverse structures. A WSW-ENE direction of compression was also calculated from striated planes of Cretaceous-Paleocene and older rocks, meaning previous right lateral displacements along longitudinal faults (i.e. Palestina or San Jeronimo).

  10. El impacto del cambio climático en los glaciares del complejo volcánico Nevado Coropuna, (Cordillera Occidental de los Andes Centrales)

    OpenAIRE

    Ubeda Palenque, José

    2010-01-01

    El objetivo de la investigación ha sido evaluar el impacto del cambio climático en los glaciares del Nevado Coropuna, que en la actualidad recubren el área de cumbres de ese complejo de edificios volcánicos alcanzando una superficie de casi medio centenar de km2. El interés del trabajo de investigación se debe a tres razones principales: 1) De esas masas de hielo depende el abastecimiento de varias decenas de miles de personas; 2) El escenario de riesgo que se deduce de la localización vulner...

  11. Pago por servicios ambientales hidrológicos: caso de estudio Parque Nacional del Nevado de Toluca, México

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    Edgar Brunett

    2011-01-01

    Full Text Available El potencial hídrico que representa el Parque Nacional Nevado de Toluca se ha visto disminuido por numerosos impactos antrópicos, lo que exige crear estrategias para su conservación. Este estudio tiene como objetivo estimar la disposición a pagar haciendo una encuesta en una muestra de usuarios del Valle de Toluca en el marco de un programa de Pago por Servicios Ambientales Hidrológicos. Los resultados muestran que los usuarios dispuestos a pagar rebasan el 50%, con cantidades que oscilan entre 30 y 80 pesos mensuales, sin embargo hay un sector de los encuestados que no estarían dispuestos a contribuir, pero realizarían acciones enfocadas al cuidado del medio ambiente.

  12. Pago por servicios ambientales hidrológicos: caso de estudio Parque Nacional del Nevado de Toluca, México

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    Edgar Brunett

    2010-01-01

    Full Text Available El potencial hídrico que representa el Parque Nacional Nevado de Toluca se ha visto disminuido por numerosos impactos antrópicos, lo que exige crear estrategias para su conservación. Este estudio tiene como objetivo estimar la disposición a pagar haciendo una encuesta en una muestra de usuarios del Valle de Toluca en el marco de un programa de Pago por Servicios Ambientales Hidrológicos. Los resultados muestran que los usuarios dispuestos a pagar rebasan el 50%, con cantidades que oscilan entre 30 y 80 pesos mensuales, sin embargo hay un sector de los encuestados que no estarían dispuestos a contribuir, pero realizarían acciones enfocadas al cuidado del medio ambiente.

  13. Records of new or poorly known migratory birds from Laguna del Otun, Los Nevados National Natural Park, Risaralda, Colombia

    International Nuclear Information System (INIS)

    Acevedo Charry, Orlando; Matta Camacho, Nubia E; Moncada Alvarez, Ligia Ines

    2013-01-01

    Colombia is important for migratory birds. Despite this, we do not know where they are during their crossing or residency in the country, and which species use paramo. We registered new migratory bird species for Laguna Del Otun, immersed in a complex of wetlands declared a Ramsar site since 2008. The lagoon is located in the Los Nevados National Natural Park at 3932 m asl, in paramo ecosystems of the Central Andes of Colombia. During five field trips between 2010-2012 we recorded four new migratory bird species for the park: Anas acuta, Pandion haliaetus, Riparia riparia, and Dendroica petechia. We also registered an altitudinal range extension for two additional migratory species which had only been recorded below 3500 m: Tringa flavipes and Hirundo rustica. These findings suggest these species could tolerate high mountain conditions and use the paramo. It's needed inquiry about migratory dynamics and high mountain habitat use by migratory birds.

  14. Riqueza específica de vertebrados en un bosque reforestado del Parque Nacional Nevado de Toluca, México Species richness of vertebrates in a reforested woodland of the Nevado de Toluca National Park, Mexico

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    Jessica Mariana Sánchez-Jasso

    2013-03-01

    Full Text Available Este trabajo documenta la riqueza específica de vertebrados de un bosque reforestado del Parque Nacional Nevado de Toluca (PNNT Estado de México, México. Se identificaron 85 especies totales, de las cuales 24 especies son endémicas de México, 14 especies se encuentran en alguna categoría de riesgo de acuerdo con la NOM-059 (SEMARNAT, 2010 y 3 especies en la lista roja de la UICN. Aun cuando la zona de estudio representa apenas el 0.42% de la superficie total del PNNT, la riqueza de vertebrados encontrada constituye el 11.37% de la riqueza total en el Estado de México, lo cual destaca la importancia de este espacio y una urgente necesidad de establecer estrategias de manejo que garanticen la conservación de las especies y su hábitat.This paper documents the richness of vertebrates in reforested woodlands inside the Nevado de Toluca National Park, State of Mexico, Mexico. A total of 85 species were identified, of which 24 species are endemic to Mexico, 14 species are in some risk category according to NOM-059-SEMARNAT-2010 and 3 species in the IUCN Red List. Even though the study area accounts for 0.42% of the total area of the Nevado de Toluca National Park, the richness of vertebrates in this area includes 11.37% of the total richness in the State of Mexico, highlighting the importance of the area and an urgent need to establish management strategies for its conservation.

  15. Deterioro y conservación de los bosques del Nevado de Toluca y el rol de los actores locales

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    Ángel Rolando Endara Agramont

    2016-01-01

    Full Text Available El Área de Protección de Flora y Fauna Nevado de Toluca presenta una constante fragmentación de sus bosques. El objetivo de la investigación fue identificar los procesos de deterioro de sus bosques y el rol de los actores locales en su conservación. Se utilizaron los sistemas de información geográfica como base para la generación de mapas temáticos, además de la aplicación de un diagrama de flujo que define los problemas del bosque y otro que los describe y analiza para la búsqueda de soluciones. Los resultados muestran que los principales factores que inciden en el deterioro son incendios forestales, tala inmoderada, plagas y enfermedades. Finalmente se plantean estrategias y escenarios de manejo de los bosques a partir de la articulación de los actores locales.

  16. ACTIVITY AND Vp/Vs RATIO OF VOLCANO-TECTONIC SEISMIC SWARM ZONES AT NEVADO DEL RUIZ VOLCANO, COLOMBIA

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    Londoño B. John Makario

    2010-06-01

    Full Text Available An analysis of the seismic activity for volcano-tectonic earthquake (VT swarms zones at Nevado del Ruiz Volcano (NRV was carried out for the interval 1985- 2002, which is the most seismic active period at NRV until now (2010. The swarm-like seismicity of NRV was frequently concentrated in very well defined clusters around the volcano. The seismic swarm zone located at the active crater was the most active during the entire time. The seismic swarm zone located to the west of the volcano suggested some relationship with the volcanic crises. It was active before and after the two eruptions occurred in November 1985 and September 1989. It is believed that this seismic activity may be used as a monitoring tool of volcanic activity. For each seismic swarm zone the Vp/Vs ratio was also calculated by grouping of earthquakes and stations. It was found that each seismic swarm zone had a distinct Vp/Vs ratio with respect to the others, except for the crater and west swarm zones, which had the same value. The average Vp/Vs ratios for the seismic swarm zones located at the active crater and to the west of the volcano are about 6-7% lower than that for the north swarm zone, and about 3% lower than that for the south swarm zone. We suggest that the reduction of the Vp/Vs ratio is due to degassing phenomena inside the central and western earthquake swarm zones, or due to the presence of microcracks inside the volcano. This supposition is in agreement with other studies of geophysics, geochemistry and drilling surveys carried out at NRV.

  17. Cambios en las propiedades del suelo, posteriores a un incendio en el Parque Nacional Natural de Los Nevados, Colombia

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    Camargo García Juan Carlos

    2012-11-01

    Full Text Available

    En 2006 ocurrió un incendio en el Parque Nacional Natural de Los Nevados, Colombia, que afectó aproximadamente 2400 ha de ecosistema de páramo de sectores aledaños a la laguna del Otún (4 º

    46' 58.4'' N y 75º 24' 26.8'' O. Teniendo en cuenta la posible afectación de algunos servicios ecosis- témicos proveídos por el suelo y la necesidad de encontrar variables que puedan ser utilizadas como indicadores del estado de este recurso, se realizó una evaluación de las propiedades físicas y químicas de los suelos en áreas afectadas (AA y no afectadas (NA por el incendio. Las evaluaciones se tuvieron inmediatamente después del evento (2006, dos años (2008 y tres años (2009 después. Se incluyeron áreas donde se implementaron estrategias de restauración y dos posiciones en el relieve: valle (turbe- ras y laderas. Para identificar diferencias en las caracterIsticas del suelo evaluadas entre sitios afec- tados y no-afectados, posiciones topogrãficas y los tratamientos de restauración, se hizo una prueba no-paramétrica de Kruskall-%allis. Posteriormente, para verificar relaciones entre variables, se realizó un anãlisis de correlación usando el coeficiente de Sperman. En general, la posición de valle mostró los cambios más drásticos en el suelo a través del tiempo de evaluación. Allí, más del 50% de la mate- ria orgánica se perdió, generando cambios también en algunas propiedades físicas como la densidad aparente y la estabilidad estructural, que después de tres años, y a pesar de las actividades de restau- ración, muestran evidentes problemas de degradación. Con los resultados obtenidos ha sido posible definir variables indicadoras de las condiciones del suelo, /ue podrIan ser usadas en programas de monitoreo de este recurso. Así mismo, se evidencia que los procesos de restauración en este ecosiste- ma son lentos y se requiere un tiempo prolongado para generar cambios positivos en las

  18. Cambios en las propiedades del suelo, posteriores a un incendio en el Parque Nacional Natural de Los Nevados, Colombia

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    Juan Carlos Camargo-García

    2012-04-01

    Full Text Available En 2006 ocurrió un incendio en el Parque Nacional Natural de Los Nevados, Colombia, que afectó aproximadamente 2400 ha de ecosistema de páramo de sectores aledaños a la laguna del Otún (4 ° 46' 58.4" N y 75° 24' 26.8" O. Teniendo en cuenta la posible afectación de algunos servicios ecosistémicos proveídos por el suelo y la necesidad de encontrar variables que puedan ser utilizadas como indicadores del estado de este recurso, se realizó una evaluación de las propiedades físicas y químicas de los suelos en áreas afectadas (AA y no afectadas (NA por el incendio. Las evaluaciones se tuvieron inmediatamente después del evento (2006, dos años (2008 y tres años (2009 después. Se incluyeron áreas donde se implementaron estrategias de restauración y dos posiciones en el relieve: valle (turberas y laderas. Para identificar diferencias en las características del suelo evaluadas entre sitios afectados y no-afectados, posiciones topográficas y los tratamientos de restauración, se hizo una prueba no-paramétrica de Kruskall-Wallis. Posteriormente, para verificar relaciones entre variables, se realizó un análisis de correlación usando el coeficiente de Sperman. En general, la posición de valle mostró los cambios más drásticos en el suelo a través del tiempo de evaluación. Allí, más del 50% de la materia orgánica se perdió, generando cambios también en algunas propiedades físicas como la densidad aparente y la estabilidad estructural, que después de tres años, y a pesar de las actividades de restauración, muestran evidentes problemas de degradación. Con los resultados obtenidos ha sido posible definir variables indicadoras de las condiciones del suelo, que podrían ser usadas en programas de monitoreo de este recurso. Así mismo, se evidencia que los procesos de restauración en este ecosistema son lentos y se requiere un tiempo prolongado para generar cambios positivos en las propiedades de los suelos afectados, que

  19. El visitante del Parque Nacional Nevado de Toluca, México. Análisis del comportamiento en un área natural protegida

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    Maribel Osorio García

    2012-02-01

    Full Text Available El artículo expone los resultados de una investigación realizada sobre los visitantes que llegan al Parque Nacional Nevado de Toluca (PNNT ubicado en la región central de México. El estudio resulta novedoso porque se retoman las variables demográficas y psicográficas del análisis de mercado turístico para identificar los perfiles de visitantes de esta área natural. De esta manera, se realiza un análisis estadístico y cartográfico de los datos obtenidos mediante la aplicación de una encuesta estratificada que implicó hacer cruce de variables y el cálculo de desviaciones estándar para algunas de ellas. Finalmente, los resultados se confrontan a partir de los hallazgos de la aún limitada literatura científica producida en torno al visitante del turismo de naturaleza.

  20. Prototipo de vivienda de adobe con energías renovables: caso de estudio localidad de Raíces, Área Natural Protegida del Parque Nacional del Nevado de Toluca, Estado de México

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    Mercedes Ramírez Rodríguez

    2013-01-01

    Full Text Available Como una alternativa a la construcción de la vivienda, este artículo introduce una nueva tecnología para edificar un prototipo de casa de adobe con energías renovables. Se muestrauna metodología para su diseño que se establece a partir de las características de las viviendas de la localidad de Raíces, ubicada en el municipio de Zinacantepec, dentro del territorio del Parque Nacional del Nevado de Toluca, espacio natural protegido por Decreto en 1936.

  1. Prototipo de vivienda de adobe con energías renovables: caso de estudio localidad de Raíces, Área Natural Protegida del Parque Nacional del Nevado de Toluca, Estado de México

    OpenAIRE

    Mercedes Ramírez Rodríguez

    2013-01-01

    Como una alternativa a la construcción de la vivienda, este artículo introduce una nueva tecnología para edificar un prototipo de casa de adobe con energías renovables. Se muestrauna metodología para su diseño que se establece a partir de las características de las viviendas de la localidad de Raíces, ubicada en el municipio de Zinacantepec, dentro del territorio del Parque Nacional del Nevado de Toluca, espacio natural protegido por Decreto en 1936.

  2. Nivel de adecuación del territorio para el desarrollo de especies agrícolas y forestales en el Parque Nacional Nevado de Toluca

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    HÉCTOR HUGO REGIL-GARCÍA

    2009-01-01

    Full Text Available El Parque Nacional Nevado de Toluca es una importante reserva de recursos naturales del Estado de México. En la recuperación de los ecosistemas forestales se planteó como objetivo determinar el grado de adecuación para el desarrollo de especies forestales nativas y cultivos en la zona. En este trabajo se presenta una metodología basada en la aplicación de sistemas de información geográfica (SIG para evaluar algunos requerimientos de las especies (climáticos, fisiográficos y edáficos y generar mapas criterios de adecuación. El análisis permitió obtener la ocupación óptima del suelo de cuatro especies forestales y dos especies agrícolas.

  3. Cambio de uso del suelo y vegetación en el Parque Nacional Nevado de Toluca, México, en el periodo 1972-2000

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    Sergio Franco Maass

    2012-02-01

    Full Text Available Para conocer el estado de conservación del Parque Nacional Nevado de Toluca (PNNT, se analizaron los cambios en el uso del suelo y vegetación ocurridos entre 1972 y el 2000. Para ello fue preciso obtener cartografía digital mediante procesos de digitalización y fotointerpretación. Los mapas obtenidos se basaron en el sistema de clasificación del INEGI, serie 1. La aplicación de un sistema de información geográfica (SIG permitió obtener la densidad de la cobertura forestal y analizar el cambio de uso de suelo y vegetación, identificando los procesos de disminución y/o incremento en la densidad de las zonas forestales. En el periodo estudiado, poco más de 9 700 ha de bosques de pino, latifoliadas u oyamel, sufrieron pérdidas de densidad, esto representó 20% de la superficie del área natural protegida. Las zonas boscosas que mostraron incrementos apenas alcanzaron 4 800 ha. El enfoque metodológico adoptado resultó especialmente válido para obtener información detallada y con un alto nivel de precisión. Dicha información constituye un punto de partida para estudios a profundidad del parque nacional.

  4. Cambios en las propiedades del suelo, posteriores a un incendio en el Parque Nacional Natural de Los Nevados, Colombia Soil changes after a fire event in a páramo ecosystem: Los Nevados Natural National Park, Colombia

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    Juan Carlos Camargo-García

    2012-04-01

    Full Text Available En 2006 ocurrió un incendio en el Parque Nacional Natural de Los Nevados, Colombia, que afectó aproximadamente 2400 ha de ecosistema de páramo de sectores aledaños a la laguna del Otún (4 ° 46' 58.4" N y 75° 24' 26.8" O. Teniendo en cuenta la posible afectación de algunos servicios ecosistémicos proveídos por el suelo y la necesidad de encontrar variables que puedan ser utilizadas como indicadores del estado de este recurso, se realizó una evaluación de las propiedades físicas y químicas de los suelos en áreas afectadas (AA y no afectadas (NA por el incendio. Las evaluaciones se tuvieron inmediatamente después del evento (2006, dos años (2008 y tres años (2009 después. Se incluyeron áreas donde se implementaron estrategias de restauración y dos posiciones en el relieve: valle (turberas y laderas. Para identificar diferencias en las características del suelo evaluadas entre sitios afectados y no-afectados, posiciones topográficas y los tratamientos de restauración, se hizo una prueba no-paramétrica de Kruskall-Wallis. Posteriormente, para verificar relaciones entre variables, se realizó un análisis de correlación usando el coeficiente de Sperman. En general, la posición de valle mostró los cambios más drásticos en el suelo a través del tiempo de evaluación. Allí, más del 50% de la materia orgánica se perdió, generando cambios también en algunas propiedades físicas como la densidad aparente y la estabilidad estructural, que después de tres años, y a pesar de las actividades de restauración, muestran evidentes problemas de degradación. Con los resultados obtenidos ha sido posible definir variables indicadoras de las condiciones del suelo, que podrían ser usadas en programas de monitoreo de este recurso. Así mismo, se evidencia que los procesos de restauración en este ecosistema son lentos y se requiere un tiempo prolongado para generar cambios positivos en las propiedades de los suelos afectados, que

  5. Geothermal potential assessment of the Nevado del Ruiz volcano based on rock thermal conductivity measurements and numerical modeling of heat transfer

    Science.gov (United States)

    Vélez, Maria Isabel; Blessent, Daniela; Córdoba, Sebastián; López-Sánchez, Jacqueline; Raymond, Jasmin; Parra-Palacio, Eduardo

    2018-01-01

    This work presents an estimation of the geothermal potential of the Nevado del Ruiz (NDR) volcano, bridging the knowledge gap to develop geothermal energy in Colombia and improve resource estimates in South America. Field work, laboratory measurements, geological interpretations, 2D numerical modeling, and uncertainty analysis were conducted to the northwest of the NDR to assess temperature at depth and define thermal energy content. About 60 rock samples were collected at outcrops to measure thermal conductivity with a needle probe. A 2D numerical model, built from an inferred geological cross-section, was developed with the software OpenGeoSys to simulate the underground temperature distribution and then estimate the geothermal potential of a 1 km2 area with sufficient temperature, assuming a recovery factor equal to 2.4% and a 30 years exploitation time. Coupled groundwater flow and heat transfer were simulated in steady-state considering two different thermal conductivity scenarios. Results show that the average estimated potential is 1.5 × 10-2 MWt m-1 of the reservoir thickness, considering temperatures greater than 150 °C located at a depth of approximately 2 km, in a selected area situated outside of the Los Nevados National Natural Park (NNP), to avoid any direct intervention on this protected area. According to a Monte Carlo analysis considering pessimist and optimist scenarios of thermal conductivity, the estimated geothermal power was 1.54 × 10-2 MW m-1 (σ = 2.91 × 10-3 MW m-1) and 1.88 × 10-2 MW/m (σ = 2.91 × 10-3 MW m-1) for the two modeling scenario considered.

  6. Perturbation and melting of snow and ice by the 13 November 1985 eruption of Nevado del Ruiz, Colombia, and consequent mobilization, flow and deposition of lahars

    Science.gov (United States)

    Pierson, T.C.; Janda, R.J.; Thouret, J.-C.; Borrero, C.A.

    1990-01-01

    A complex sequence of pyroclastic flows and surges erupted by Nevado del Ruiz volcano on 13 November 1985 interacted with snow and ice on the summit ice cap to trigger catastrophic lahars (volcanic debris flows), which killed more than 23,000 people living at or beyond the base of the volcano. The rapid transfer of heat from the hot eruptive products to about 10 km2 of the snowpack, combined with seismic shaking, produced large volumes of meltwater that flowed downslope, liquefied some of the new volcanic deposits, and generated avalanches of saturated snow, ice and rock debris within minutes of the 21:08 (local time) eruption. About 2 ?? 107 m3 of water was discharged into the upper reaches of the Molinos, Nereidas, Guali, Azufrado and Lagunillas valleys, where rapid entrainment of valley-fill sediment transformed the dilute flows and avalanches to debris flows. Computed mean velocities of the lahars at peak flow ranged up to 17 m s-1. Flows were rapid in the steep, narrow upper canyons and slowed with distance away from the volcano as flow depth and channel slope diminished. Computed peak discharges ranged up to 48,000 m3 s-1 and were greatest in reaches 10 to 20 km downstream from the summit. A total of about 9 ?? 107 m3 of lahar slurry was transported to depositional areas up to 104 km from the source area. Initial volumes of individual lahars increased up to 4 times with distance away from the summit. The sedimentology and stratigraphy of the lahar deposits provide compelling evidence that: (1) multiple initial meltwater pulses tended to coalesce into single flood waves; (2) lahars remained fully developed debris flows until they reached confluences with major rivers; and (3) debris-flow slurry composition and rheology varied to produce gradationally density-stratified flows. Key lessons and reminders from the 1985 Nevado del Ruiz volcanic eruption are: (1) catastrophic lahars can be generated on ice- and snow-capped volcanoes by relatively small eruptions; (2

  7. Destrucción de tierras en el flanco oriental del Nevado de Toluca, el caso de la cuenca del arroyo El Zaguán

    Directory of Open Access Journals (Sweden)

    José Luis Palacio-Prieto

    1988-01-01

    Full Text Available Changes in landuse and the presence of an erodible lithology (pumice lapilli are the main factors controlling the accelerated erosion in the eastern slope of the Nevado de Toluca volcano, state of Mexico. A detailed geomorphological study of a small catchment allowed the recognition of several unstable sectors along the catchment, requiring prior attention in order to avoid problems due to silting in dams, roads and towns. Among the uns­table sectors, first order streams and external portions in mean­ders developed in pumice lahars and tephra ace included.

  8. Efectos de la erupción del volcán nevado del Ruiz, ocurrida el 13-noviembre-1985, sobre la atmósfera en Colombia. Caso: humedad

    Directory of Open Access Journals (Sweden)

    Eslava Ramírez Jesús Antonio

    1995-10-01

    Full Text Available

    Este es el tercer artículo en el que se analiza el electo de la erupción del volcán Nevado del Ruiz del 13-11-85, sobre las diferentes propiedades atmosféricas. En trabajos anteriores se analizaron los cambios temporales ocasionados en la Insolación (horas de brillo solar y la temperatura del aire. Acá se muestran los efectos que se ocasionaron en la humedad del aire, los cuales comenzaron desde el día anterior por los gases y cenizas emitidas con anterioridad y que por efecto de los movimientos locales y generales del aire se habían acumulado en sectores ubicados al W y NW del volcán.

    Effects on the different atmospheric properties due to Volcano Nevado del Ruiz activity on Nov.13.85, are shows here as a continuation of several publish previous works, were has been analyzed, air temperature, and sunshine changes. This article shows the air humidity effects, starting one day before, due to the action of the previous volcanic gases and ashes emitted which were located and accumulated to Wand NW of the volcano by action of the local and general movements.

     

  9. Vapour discharges on Nevado del Ruiz during the recent activity: Clues on the composition of the deep hydrothermal system and its effects on thermal springs

    Science.gov (United States)

    Federico, Cinzia; Inguaggiato, Salvatore; Chacón, Zoraida; Londoño, John Makario; Gil, Edwing; Alzate, Diego

    2017-10-01

    The Nevado del Ruiz volcano is considered one of the most active volcanoes in Colombia, which can potentially threaten approximately 600,000 inhabitants. The existence of a glacier and several streams channelling in some main rivers, flowing downslope, increases the risk for the population living on the flank of the volcano in case of unrest, because of the generation of lahars and mudflows. Indeed, during the November 1985 subplinian eruption, a lahar generated by the sudden melting of the glacier killed twenty thousand people in the town of Armero. Moreover, the involvement of the local hydrothermal system has produced in the past phreatic and phreatomagmatic activity, as occurred in 1989. Therefore, the physico-chemical conditions of the hydrothermal system as well as its contribution to the shallow thermal groundwater and freshwater in terms of enthalpy and chemicals require a close monitoring. The phase of unrest occurred since 2010 and culminated with an eruption in 2012, after several years of relative stability, still maintains a moderate alert, as required by the high seismicity and SO2 degassing. In October 2013, a sampling campaign has been performed on thermal springs and stream water, located at 2600-5000 m of elevation on the slope of Nevado del Ruiz, analyzed for water chemistry and stable isotopes. Some of these waters are typically steam-heated (low pH and high sulfate content) by the vapour probably separating from a zoned hydrothermal system. By applying a model of steam-heating, based on mass and enthalpy balances, we have estimated the mass rate of hydrothermal steam discharging in the different springs. The composition of the hottest thermal spring (Botero Londono) is probably representative of a marginal part of the hydrothermal system, having a temperature of 250 °C and low salinity (Cl 1500 mg/l), which suggest, along with the retrieved isotope composition, a chiefly meteoric origin. The vapour discharged at the steam vent "Nereidas" (3600

  10. Las comunidades vegetales del Zacatonal Alpino de los volcanes Popocatépetl y Nevado de Toluca, Región Central de México.

    NARCIS (Netherlands)

    Almeida-Lenero, L.; Gimenez de Azcarate, J.; Cleef, A.M.; Gonzales Trapaga, A.

    2004-01-01

    This study of the zacatonal alpino zone of the volcanoes Popocatepetl (5452 in) and Nevado de Toluca (4690 m) in the central region of the Transmexican Volcanic Belt, is a follow-up of the study of ALMEIDA et al. (1994). This tropical alpine zacatonal represents the potential vegetation of the

  11. Field guides for excursions to the Nevado del Ruiz Volcano and to the Romeral Fault System (Colombia, in the frame of the Neotectonics of arc-continent collision concepts

    Directory of Open Access Journals (Sweden)

    Borrero Carlos

    2011-06-01

    Full Text Available Central Cordillera of Colombia near to the Nevado del Ruiz volcano, is a seismically active area above the subducting slab of the Nazca plate and deforming upper crust of the Andes. Buildings in the region require strengthening against the effects of both types of hazards: earthquakes and volcanoes. During these trips, we will discuss the 13
    November, 1985, Nevado del Ruiz Volcano eruption that destroyed the Armero city with about 22,000 deceases, as well the 25 January, 1999, Armenia earthquake (M 6.2 that killed about 2000 people and injured 4000 largely as the result of older, poorly 3 constructed buildings. The economic impact of the quake on the region was significant with about 8000 coffee farms either completely or partially destroyed and over 13,000 structures either partially damaged or completely destroyed.
    Both phenomena are associated to a large-transversal structure termed Caldas tear, which is controlling strong motion earthquakes and the Quaternary volcanism of the northern Andes.

  12. Vapor Discharges On Nevado Del Ruiz During The Recent Activity: Clues On The Composition Of The Deep Hydrothermal System And Its Effects On Thermal Springs

    Science.gov (United States)

    Inguaggiato, S.; Federico, C.; Chacon, Z.; Londono, J. M.; Alzate, D. M.; Gil, E.

    2015-12-01

    The Nevado del ruiz volcano (NdR, 5321m asl), one of the most active in Colombia, threatens about 600,000 people. The existence of an ice cap and several streams channeling in some main rivers increase the risk of lahars and mudflows in case of unrest, as occurred during the November 1985 eruption, which caused 20,000 casualties. The involvement of the local hydrothermal system has also produced in the past phreatic and phreatomagmatic activity, as in 1985 and 1989. After more than 7 years of relative stability, since 2010, the still ongoing phase of unrest has produced two small eruption in 2012, and still maintains in high levels of seismicity and SO2 degassing. In October 2013, a sampling campaign has been performed on thermal springs and streamwater, located at 2600-5000 m asl, analyzed for water chemistry and stable isotopes. By applying a model of steam-heating, based on mass and enthalpy balances, we have estimated the mass rate of steam discharging in the different steam-heated springs. The composition of the hottest thermal spring (Botero Londoño) is probably representative of a marginal part of the hydrothermal system, having a temperature of 250°C and low salinity (Cl ~1500 mg/l), which suggest a chiefly meteoric origin, as also confirmed by the isotope composition retrieved for the hydrothermal water. The vapour discharged at the steam vent "Nereidas" (3600 m asl) is hypothesised to be separated from a high-temperature hyrothermal system. Based on its composition and on literature data on fluid inclusions, we have retrieved the P-T-X conditions of the deep hydrothermal system, as well as its pH and fO2. The vapour feeding Nereidas would separate from a byphasic hydrothermal system characterised by the follow parameters: t= 315°C, P=19 MPa, NaCl= 15 %, CO2 = 9%, and similar proportion between liquid and vapour. Considering also the equilibria involving S-bearing gases and HCl, we obtain pH=2, fO2 fixed by FeO-Fe2O3 buffer, and [Cl]=12000 mg/l. Changes

  13. LA SUCESIÓN VEGETAL EN LOS LODOS FLUVIOVOLCÁNICOS DE ARMERO-TOLIMA-COLOMBIA 30 AÑOS DESPUÉS DE LA ERUPCIÓN DEL VOLCÁN ARENAS DEL NEVADO DEL RUIZ

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    Héctor Eduardo Esquivel

    2016-01-01

    Full Text Available Se estudió la dinámica sucesional y la evolución edafológica de una zona de bosque seco tropical afectada por lodos de la erupción volcánica del nevado del Ruiz el 13 de noviembre de 1985. La zona de estudio está ubicada en el municipio de Armero con una extensión de 3500 hectáreas a 450 msnm. Se levantaron 10 parcelas de muestreo de 10 x 20 m, acorde con las consociaciones establecidas por el IGAC. En total los cuatro estudios florísticos reportan 565 especies distribuidas en 72 familias, de las cuales sobresalen la familia Asteraceae, Malvaceae, Fabaceae, Euphorbiaceae y Poaceae. El número de especies ha variado significativamente, para el primer estudio 294 distribuidas en 66 familias, para el segundo 332 especies, para el tercer estudio 284 especies y para el cuarto estudio un total de 217. Al comienzo se confirma lo que Braun Blanquet planteó según la Fitosociología, que en áreas fuertemente disturbadas la vegetación inicialmente se establece en montículos; cinco años después el segundo estudio mostró la formación de asociaciones así: Rhynchelytretum, por estar dominada por el pasto Rhynchelytrum repens (Will Hubb., la asociación Indigoferetum por la alta presencia de Indigofera hirsuta Jacq., Panicetum, por el dominio de Panicum maximum Jacq. y la asociación Ficetum, por la presencia de varias especies de cauchos. La vegetación ha presentado un recambio constante y se reconoce actualmente una formación sucesional avanzada donde domina el hábito de crecimiento arbóreo, conformando relictos de bosque. El pH del suelo ha variado de 3.2 a 6.5, como también varios de los elementos evaluados.

  14. Las cuencas cenozoicas y su control en el volcanismo de los Complejos Nevados de Chillan y Copahue-Callaqui (Andes del Sur, 36-39°S Cenozoic basins and their control on volcanism of Nevados de Chillan and Copahue-Callaqui complexes (36-39°S, Southern Andes

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    Juan Pablo Radic

    2010-01-01

    Full Text Available La Cordillera Principal de los Andes entre los 36° y 39°S constituye un excelente lugar para el estudio de la relación entre volcanismo y tectónica. Por medio del análisis tectonoestratigráfico de las cuencas cenozoicas se ha podido reconocer una clara coincidencia espacial entre estructuras de primer orden pertenecientes a estas cuencas y la distribución del volcanismo plio-pleistocénico. Las cuencas cenozoicas comenzaron su desarrollo durante el Oligoceno-Mioceno como depresiones extensionales, conformando un sistema de al menos tres subcuencas orientadas N-S y conectadas por dos zonas de acomodación estructural. Posteriormente este sistema de cuencas fue tectónicamente invertido hacia finales del Mioceno y los antiguos depocentros fueron deformados y exhumados, reutilizando las fallas originalmente extensionales. Las zonas de acomodación estructural permanecieron como estructuras de primer orden a escala de cuenca y constituyeron zonas de debilidad que favorecieron el posterior desarrollo del volcanismo y magma-tismo en los complejos volcánicos Nevados de Chillan y Copahue-Callaqui. Cada uno de estos complejos volcánicos se caracteriza por una orientación de sus centros de emisión, morfología y depósitos volcánicos en forma subparalela a la orientación de las zonas de acomodación estructural inmediatamente por debajo.The Cordillera Principal at 36° to 39°S is an excellent place to address the relationship between tectonics and volcanism. Based on tectonostratigraphic analysis of the Cenozoic basins it has been possible to recognize a clear spatial coincidence between first order basin scale structures and Plio-Pleistocene volcanism. Cenozoic basins started in the Oligocene-Miocene as extensional depocenters, characterized by at least three north-south oriented sub-basins connected by two structural accommodation zones. Towards the Late Miocene this extensional system was tectonically inverted deforming and uplifting the

  15. Microorganismos asociados al ciclo del nitrógeno en suelos bajo tres sistemas de uso: cultivo de papa, ganadería y páramo, en el Parque Los Nevados, Colombia

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    Roger Guillermo Cañón-Cortázar

    2012-12-01

    Full Text Available En la vereda El Bosque del Parque Nacional Natural de Los Nevados (PNNN, Colombia, se estimó la densidad poblacional de microorganismos asociados con el metabolismo de nitrógeno (N en suelos bajo tres sistemas de uso: cultivo de papa, ganadería y zonas poco intervenidas (páramo. Indirectamente se cuantificaron microorganismos amonificantes (AMO, proteolíticos (PRO, oxidantes del amonio (BOA, oxidantes del nitrito (BON y denitrificantes (DEN en suelos de tres fincas ubicadas a diferente altitud y en épocas seca y lluviosa. Se realizó la prueba no-paramétrica de Kruskal-Wallis por pares, con un nivel de significancia P < 0.05, para detectar diferencias estadísticamente significativas entre las diferentes abundancias de grupos funcionales de microorganismos. Luego, se realizó análisis de componentes principales (ACP para evaluar las relaciones entre las diferentes variables estudiadas. Los resultados mostraron diferencias para los grupos evaluados, siendo menor la densidad de microorganismos en suelos de páramo. Los PRO fueron más abundantes en todos los tipos de suelos, seguido de los DEN con mayor densidad en el ecosistema páramo. La densidad poblacional microbiana no fue afectada por la altitud, sin embargo se presentaron algunas diferencias que no mostraron un patrón único de comportamiento. Se observaron diferencias como resultado de la época climática, siendo mayor en la época seca para los grupos PRO, AMO, BOA y BON, y en época de lluvias para los DEN. Este estudio contribuye al conocimiento de las relaciones que existen entre el uso del suelo y la presencia de los microorganismos asociados con el ciclo de nitrógeno.

  16. Evaluación del uso agrícola y forestal del suelo en la cuenca del río Temascaltepec, Nevado de Toluca, México

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    Lourdes Villers Ruiz

    1995-06-01

    Full Text Available Characteristics of relief, vegetation, farmland, and forest exploitations were obtained of the Temascaltepec River Basin, in the western and southwestern slopes of the Nevado de Toluca Vulcano, in Central Mexico. The main crops were characterized for each of the 15 communities of the basin. A percentage of the land covered with forest was established for each of the 148 areas considered for forest exploitation. The majority of the forests localized between 2 000 and 3 000 m, have less than 60% of their area covered by woods. Larger cover of forests areas are constituted by Pinus and Abies–Pinus communities. The average slope dominant of the croplands is 11º and its limits are from 4.7º to 11.4 º. The main crops at regional level are corn, oat and potato. The processing and information analysis were done in a GIS PC–based software.

  17. La fuerza del espíritu (fe en el camino (ancestral indígena

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    Paola Andrea Pérez Gil

    2016-01-01

    Full Text Available El mundo de hoy se encuentra encerrado en la visión reduccionista y enajenada que ha sido imperante a lo largo de la historia, el valor del consumo, la ambición y el individualismo han enterrado los valores fundantes de sencillez, humildad y honestidad. La profunda necesidad de volver la mirada al conocimiento y psicología propios, ha hecho que retornemos a la sabiduría de las plantas, los abuelos, lugares sagrados, costumbres y mitos para abandonar la ilusión racionalista que todo lo divide, todo lo niega y nada lo contempla. El camino recorrido en el fuego, la montaña, Sie, el chunsúa, las cansamarias, permite mirar, recordar y recuperar lo fundamental en la existencia humana: su propia fuerza, la fe. Esa que sostiene la vida, que va más allá de verificación o comprobación alguna, que es cultivada en la palabra dulce, el tejido sentido y la esencia misma. Conectando al humano en sus diferentes niveles, a su psiquismo, conectándolo al amor. Por ello, la importancia de vivenciar a Sue, Chía, en y con la Hytcha Guaia, vivenciar al Espíritu en su expresión más latente, aceptar al ego como uno de los maestros para comprender el ser, integrar la materia y lo trascendente, entregarse a la ley de los abuelos, a lo sagrado propio, a la conciencia profunda, al guerrero interno, a la vida misma.

  18. Dinámica y condiciones de vida de la población del Parque Nacional Nevado de Toluca (pnnt en la generación de presión a los ecosistemas circundantes y de impactos ambientales a través de un sistema de información geográfica

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    Rafael Candeau Dufat

    2012-02-01

    Full Text Available Este trabajo tiene como objetivo conocer como influye la dinámica y condiciones de vida de la población de las localidades dentro del Parque Nacional Nevado de Toluca y de su área de influencia inmediata, en la presión a los ecosistemas circundantes y en la generación de impactos ambientales, que propician una mala calidad del bosque y el cambio de uso del suelo, de forestal a agropecuario, urbano o industrial. Para ello se aplicó una novedosa metodología que permitió evaluar la relación entre estos factores socioeconómicos y el grado de deterioro ambiental dado en los geosistemas, estableciéndose en qué regiones se concentra la mayor influencia directa y en qué magnitud lo hacen y, del mismo modo, cuáles son las localidades en donde el impacto se deriva de factores externos.

  19. Determinación de peligros volcánicos aplicando técnicas de evaluación multicriterio y SIG en el área del Nevado de Toluca, centro de México

    OpenAIRE

    Aceves-Quesada, Fernando; López-Blanco, Jorge; Martin del Pozzo, Ana Lillian

    2006-01-01

    Los estudios de peligros volcánicos a corto y largo plazo mediante la utilización de tecnologías geográficas generan un conocimiento útil para el análisis, planeación y manejo de las crisis volcánicas. El Nevado de Toluca es un estratovolcán que a lo largo de su historia geológica ha tenido erupciones violentas acompañadas de flujos piroclásticos, lahares, avalanchas, caída de cenizas y pómez. Durante los últimos 50,000 años, este volcán ha presentado al menos ocho erupciones vesuvianas, cuat...

  20. A common ancestral origin of the frequent and widespread 2299delG USH2A mutation.

    NARCIS (Netherlands)

    Dreyer, B.; Tranebjaerg, L.; Brox, V.; Rosenberg, T.; Moller, C.G.; Beneyto, M.; Weston, M.D.; Kimberling, W.J.; Cremers, C.W.R.J.; Liu, X.Z.; Nilssen, O.

    2001-01-01

    Usher syndrome type IIa is an autosomal recessive disorder characterized by mild-to-severe hearing loss and progressive visual loss due to retinitis pigmentosa. The mutation that most commonly causes Usher syndrome type IIa is a 1-bp deletion, described as "2299delG," in the USH2A gene. The mutation

  1. Evolución del cuidado desde una práctica ancestral hasta ser la esencia del profesional de enfermería

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    Mirith Vásquez Munive

    2013-10-01

    Full Text Available Cuidar ha sido desde tiempos inmemoriales una capacidad inherente e identificativa del sexo femenino, que se extendió al generó masculino en el momento de la división sexual del trabajo; en este punto nació una forma de cuidar diferente, de acuerdo a las capacidades físicas de cada cual, y a las labores que hasta ese momento habían sido la responsabilidad de hombres por un lado y mujeres por el otro. Significa esto que hay varias formas de cuidar, cada una dependiendo de las características individuales de la vida de cada ser humano, pero todos, absolutamente todos tenemos la capacidad de cuidar. Luego, cuando fue necesario, que una persona se encargara de preservar la salud de los individuos de la comunidad, y adoptara medidas curativas, apareció la mujer como cuidadora, por la sapiencia acumulada a través de la observación de la naturaleza, que la dotó de un bagaje de conocimientos que no poseía ningún otro ser diferente a ella. Aquí surgió la mujer como cuidadora natural, empírica, y pragmática, y con el paso del tiempo llegó a la mujer preparada académicamente, para brindar un cuidado, organizado de acuerdo al conocimiento científico, es decir hasta la enfermera del día de hoy, ampliamente preparada para brindar cuidado de calidad. (Duazary 2006; 1: 76 - 80.

  2. Balance enérgetico neto (2012-2014) y evolución temporal del nevado Quisoquipina en la región de Cusco (1990-2010)

    OpenAIRE

    Suarez, Wilson; Macedo, Nicolás; Montoya, Nilton; Arias, Santos; Schauwecker, Simone; Huggel, Christian; Rohrer, Mario; Condom, Thomas

    2015-01-01

    En el Perú se ubican cerca del 71% de los glaciares tropicales del planeta, y los glaciares de la Cordillera Blanca (norte de Lima) son los más estudiados; del resto de los glaciares se tiene un limitado conocimiento basado en la información que proporcionan las imágenes de satélite. Ante esta situación el Proyecto de Adaptación al Retroceso Acelerado de los Glaciares en el año 2010 adquirió dos estaciones meteorológicas para el monitoreo del entorno de los glaciares en el centro y sur del Pe...

  3. Impactos de las actividades antrópicas en el nevado Huaytapallana

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    Jacinto Arroyo Aliaga

    2012-06-01

    Full Text Available Objetivos: Explicar la influencia de las actividades antrópicas en la variación de las capas de acumulación de nieve en los glaciares de la vertiente sur-occidental del nevado Huaytapallana de los Andes Centrales del Perú, en el ciclo hidrológico 2011-2012. Métodos: Se utilizó el método general hipotético – deductivo como guía en la investigación cuantitativa; el método del Thornthwaite para realizar el análisis hidrológico y clasificación climática de la zona; y el balance de masas como método para estimar la carga o descarga de nieve acumulado mediante balizas. Resultados: Se ha encontrado que las actividades antrópicas de turismo vivencial es una de las actividades principales que afectan al glaciar con el 60% de impacto. Las actividades de reforestación constituyen el 20% de impacto y el 10% la actividad de pastoreo. También los impactos de las actividades antrópicas a altitudes bajas en el glaciar son negativas, mientras que a altitudes superiores a los 5 000 msnm se registran menores impactos negativos. De igual manera se encontró una relación directa (coeficiente r= 0,97 entre el impacto a bajas altitudes de las masas glaciares. Conclusiones: La actividad de turismo vivencial que se realiza en varios sectores del nevado Huaytapallana, es una de las principales actividades antrópicas que está generando impactos negativos en el sistema glaciar al acelerar la pérdida de masa de nieve acumulado durante un ciclo hidrológico.

  4. Haplotype Diversity and Reconstruction of Ancestral Haplotype Associated with the c.35delG Mutation in the GJB2 (Cx26) Gene among the Volgo-Ural Populations of Russia.

    Science.gov (United States)

    Dzhemileva, L U; Posukh, O L; Barashkov, N A; Fedorova, S A; Teryutin, F M; Akhmetova, V L; Khidiyatova, I M; Khusainova, R I; Lobov, S L; Khusnutdinova, E K

    2011-07-01

    The mutations in theGJB2(Сх26) gene make the biggest contribution to hereditary hearing loss. The spectrum and prevalence of theGJB2gene mutations are specific to populations of different ethnic origins. For severalGJB2 mutations, their origin from appropriate ancestral founder chromosome was shown, approximate estimations of "age" obtained, and presumable regions of their origin outlined. This work presents the results of the carrier frequencies' analysis of the major (for European countries) mutation c.35delG (GJB2gene) among 2,308 healthy individuals from 18 Eurasian populations of different ethnic origins: Bashkirs, Tatars, Chuvashs, Udmurts, Komi-Permyaks, Mordvins, and Russians (the Volga-Ural region of Russia); Byelorussians, Ukrainians (Eastern Europe); Abkhazians, Avars, Cherkessians, and Ingushes (Caucasus); Kazakhs, Uzbeks, Uighurs (Central Asia); and Yakuts, and Altaians (Siberia). The prevalence of the c.35delG mutation in the studied ethnic groups may act as additional evidence for a prospective role of the founder effect in the origin and distribution of this mutation in various populations worldwide. The haplotype analysis of chromosomes with the c.35delG mutation in patients with nonsyndromic sensorineural hearing loss (N=112) and in population samples (N =358) permitted the reconstruction of an ancestral haplotype with this mutation, established the common origin of the majority of the studied mutant chromosomes, and provided the estimated time of the c.35delG mutation carriers expansion (11,800 years) on the territory of the Volga-Ural region.

  5. Cambios en el régimen hídrico de la laguna Lasuntay y Chuspicocha por variaciones en el Nevado Huaytapallana

    OpenAIRE

    Jacinto Arroyo Aliaga; Pedro Gurmendi Párraga

    2011-01-01

    Objetivos: Estimar los efectos de las variaciones de torrentes de agua de los glaciares del Nevado Huaytapallana que emanan al sistema hídrico de las lagunas de Lasuntay y Chuspicocha. Métodos: Se utilizó el método general teórico deductivo de nivel explicativo, con un diseño no experimental del tipo transversal en el tratamiento de información; como método específico se ha utilizado el balance de masa del glaciar para el cálculo de volúmenes de agua de los torrentes a partir de la instalació...

  6. Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia

    OpenAIRE

    Avellaneda-Torres,Lizeth Manuela; Pulido,Claudia Patricia Guevara; Rojas,Esperanza Torres

    2014-01-01

    A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP), Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as ...

  7. Dimorfismo sexual en tamaño y marca frontal en el chorlo nevado (Charadrius nivosus

    Directory of Open Access Journals (Sweden)

    Salvador Gómez del Ángel

    2015-01-01

    Full Text Available El dimorfismo sexual en aves se expresa de diferentes formas, entre ellas está el tamaño o la coloración del plumaje. En aves playeras las marcas melánicas son distintas entre sexos y muy variables; se cree que cumplen una función disruptiva con el paisaje. Analizamos el dimorfismo sexual en tamaño corporal y en la estructura de la barra frontal del chorlo nevado (Charadrius nivosus y encontramos que el tarso, la cuerda alar y que tanto la longitud como la amplitud de la barra frontal son de mayores dimensiones en los machos. Además, describimos por primera vez un ornamento con forma de “cuernos” en la frente, exclusivo de los machos. Aunque otros autores han revisado la variabilidad de estas marcas, su valor adaptativo es poco conocido. Consideramos que el dimorfismo en la estructura de la barra frontal es importante dentro y entre sexos durante la temporada reproductora, ya que cumple un papel clave durante los despliegues de cortejo y en la competencia entre machos, donde son exhibidas las plumas del pecho que contrastan con esta marca. Además, las medidas morfométricas mayores en los machos son consistentes con la poliandria y la competitividad intensa entre los machos.

  8. Are palaeoscolecids ancestral ecdysozoans?

    Science.gov (United States)

    Harvey, Thomas H P; Dong, Xiping; Donoghue, Philip C J

    2010-01-01

    The reconstruction of ancestors is a central aim of comparative anatomy and evolutionary developmental biology, not least in attempts to understand the relationship between developmental and organismal evolution. Inferences based on living taxa can and should be tested against the fossil record, which provides an independent and direct view onto historical character combinations. Here, we consider the nature of the last common ancestor of living ecdysozoans through a detailed analysis of palaeoscolecids, an early and extinct group of introvert-bearing worms that have been proposed to be ancestral ecdysozoans. In a review of palaeoscolecid anatomy, including newly resolved details of the internal and external cuticle structure, we identify specific characters shared with various living nematoid and scalidophoran worms, but not with panarthropods. Considered within a formal cladistic context, these characters provide most overall support for a stem-priapulid affinity, meaning that palaeoscolecids are far-removed from the ecdysozoan ancestor. We conclude that previous interpretations in which palaeoscolecids occupy a deeper position in the ecdysozoan tree lack particular morphological support and rely instead on a paucity of preserved characters. This bears out a more general point that fossil taxa may appear plesiomorphic merely because they preserve only plesiomorphies, rather than the mélange of primitive and derived characters anticipated of organisms properly allocated to a position deep within animal phylogeny.

  9. Abdias do Nascimento y Manuel Zapata Olivella: intelectuales del siglo XX en el sendero de la discursividad ancestral yoruba y bantú

    Directory of Open Access Journals (Sweden)

    Denilson Lima Santos

    2014-01-01

    Full Text Available En este ensayo planteamos el texto literario como un espacio de re - escritura de las tradiciones yoruba s y bantúes como fuerza motriz creadora de un discurso literario. Las voces africanas en las Américas aparecen recuperadas en un modelo estético diferente del hegemónico. Como ejemplo de eso, se propone describir las obras: Sortilégio II: mistério negro de Zumbi redivivo (1979, de Abdias do Nascimento (1914 - 2011, y Changó, el gran putas (1983, de Manuel Zapata Olivella (1920 - 2004. Los autores de estas obras, como intelectuales, se posicionan como insurrectos, como conscientes de las voces heterogéneas q ue habitan el mundo afrolatino y ponen esas voces como parte de la estética de sus textos. Así, los intelectuales afrolatinos proponen una escritura de la ancestralidad afro con propósitos estéticos y políticos en la tradición literaria latinoamericana.

  10. Cambios en el régimen hídrico de la laguna Lasuntay y Chuspicocha por variaciones en el Nevado Huaytapallana

    Directory of Open Access Journals (Sweden)

    Jacinto Arroyo Aliaga

    2011-12-01

    Full Text Available Objetivos: Estimar los efectos de las variaciones de torrentes de agua de los glaciares del Nevado Huaytapallana que emanan al sistema hídrico de las lagunas de Lasuntay y Chuspicocha. Métodos: Se utilizó el método general teórico deductivo de nivel explicativo, con un diseño no experimental del tipo transversal en el tratamiento de información; como método específico se ha utilizado el balance de masa del glaciar para el cálculo de volúmenes de agua de los torrentes a partir de la instalación de una red de balizas en la mayor parte del glaciar y en la zona de acumulación y ablación se excavaron pozos mediante perforaciones para medir directamente la cantidad de nieve acumulada entre el inicio y el fin del año hidrológico. Resultados: Se ha estimado los torrentes de caudal de agua que emanan del nevado Huaytapallana a las lagunas de Lasuntay y Chuspicocha en 1 226 700 m3 en la estación de verano; y de 245 340 m3 en la estación de primavera. Conclusiones: El volumen máximo de acumulación en ambas lagunas fue en el verano y el volumen mínimo en la estación de primavera, debido a las variaciones en el régimen hídrico del sistema de acumulación y ablación que afectan la disponibilidad de agua.

  11. Integrating Principles Underlying Ancestral Spirits Belief in ...

    African Journals Online (AJOL)

    , associated with ancestral spirits and its use as powerful therapeutic agent for influencing behavior or lifestyle changes. Explanatory models of attachment to ancestral spirits by living descendants are first discussed, followed by a discussion ...

  12. Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia.

    Science.gov (United States)

    Avellaneda-Torres, Lizeth Manuela; Pulido, Claudia Patricia Guevara; Rojas, Esperanza Torres

    2014-01-01

    A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP), Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS) of ribosomal DNA for fungi. Multivariate statistical analysis (MVA) was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.

  13. Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia

    Directory of Open Access Journals (Sweden)

    Lizeth Manuela Avellaneda-Torres

    2014-12-01

    Full Text Available A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP, Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS of ribosomal DNA for fungi. Multivariate statistical analysis (MVA was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.

  14. Miocene to Recent structural evolution of the Nevado de Toluca volcano region, Central Mexico

    Science.gov (United States)

    García-Palomo, A.; Macías, J. L.; Garduño, V. H.

    2000-03-01

    Based on aerial photography, satellite imagery, and detailed field work, a geological and structural model of Nevado de Toluca and its surroundings is presented. The Nevado de Toluca volcano is built upon the intersection of three complex fault systems of different age, orientation, and kinematics. These systems from the older to the younger are: (a) The Taxco-Querétaro Fault System (NNW-SSE) with clear expression south of the volcano; (b) The San Antonio Fault System (NE-SW) that runs between the San Antonio and Nevado de Toluca volcanoes; and (c) The Tenango Fault System (E-W) located to the east of Nevado de Toluca volcano. Our field data, supported by previous studies, suggest that these systems have coexisted since the late Miocene. In addition, the stratigraphy, chronology, and kinematics of fault planes point to the existence of at least three main deformation events that have affected the region since the late Miocene. During the early Miocene, an extensional phase with the same deformation style as the Basin and Range tectonics of northern Mexico caused the formation of horsts and grabens south of Nevado de Toluca and allowed the intrusion of sub-vertical dikes oriented NW-SE and NNW-SSE. During the middle Miocene, a transcurrent episode generated NE-SW faults that presented two main motions: the first movement was left-lateral with a σ3 oriented NW-SE and later turned into normal through a counter-clockwise rotation of σ3 up to a N-S position. The latest deformation phase started during the late Pliocene and produced oblique extension ( σ3 oriented NE-SW) along E-W-trending faults that later changed to pure extension by shifting of σ3 to a N-S orientation. These faults appear to control the late Pleistocene to Holocene monogenetic volcanism, the flank collapses of Nevado de Toluca volcano and the seismic activity of the region.

  15. Energy and Mass Balance At Gran Campo Nevado, Patagonia, Chile

    Science.gov (United States)

    Schneider, C.; Kilian, R.; Casassa, G.

    The Gran Campo Nevado (GCN) Ice Cap on Peninsula Muñoz Gamero, Chile, is lo- cated in the southernmost part of the Patagonian Andes at 53S. It comprises an ice cap and numerous outlet glaciers which mostly end in proglacial lakes at sea level. The total ice covered area sums up to approximately 250 km2. GCN forms the only major ice body between the Southern Patagonian Icefield and the Street of Magallan. Its almost unique location in the zone of the all-year westerlies makes it a region of key interest in terms of glacier and climate change studies of the westwind zone of the Southern Hemisphere. Mean annual temperature of approximately +5C at sea level and high precipitation of about 8.000 mm per year lead to an extreme turn-over of ice mass from the accumulation area of the GCN Ice Cap to the ablation areas of the outlet glaciers. Since October 1999 an automated weather station (AWS) is run continuously in the area at Bahia Bahamondes for monitoring climate parameters. From February to April 2000 an additional AWS was operated on Glaciar Lengua a small outlet glacier of GCN to the north-west. Ablation has been measured at stakes during the same pe- riod. The aim of this study, was to obtain point energy and mass balance on Glaciar Lengua. The work was conducted as part of the international and interdisciplinary working group SGran Campo NevadoT and supported by the German Research Foun- & cedil;dation (DFG). Energy balance was calculated using the bulk approach formulas and calibrated to the measured ablation. It turns out, that sensible heat transfer is the major contribution to the energy balance. Since high cloud cover rates prevail, air tempera- ture is the key factor for the energy balance of the glacier. Despite high rain fall rates, energy input from rain fall is of only minor importance to the overall energy balance. From the energy balance computed, it was possible to derive summer-time degree-day factors for Glaciar Lengua. With data from the nearby

  16. REGEN: Ancestral Genome Reconstruction for Bacteria

    OpenAIRE

    Yang, Kuan; Heath, Lenwood S.; Setubal, João C.

    2012-01-01

    Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deleti...

  17. The Quaternary history of effusive volcanism of the Nevado de Toluca area, Central Mexico

    Science.gov (United States)

    Torres-Orozco, R.; Arce, J. L.; Layer, P. W.; Benowitz, J. A.

    2017-11-01

    Andesite and dacite lava flows and domes, and intermediate-mafic cones from the Nevado de Toluca area were classified into five groups using field data and 40Ar/39Ar geochronology constraints. Thirty-four lava units of diverse mineralogy and whole-rock major-element geochemistry, distributed between the groups, were identified. These effusive products were produced between ∼1.5 and ∼0.05 Ma, indicating a mid-Pleistocene older-age for Nevado de Toluca volcano, coexisting with explosive products that suggest a complex history for this volcano. A ∼0.96 Ma pyroclastic deposit attests for the co-existence of effusive and explosive episodes in the mid-Pleistocene history. Nevado de Toluca initiated as a composite volcano with multiple vents until ∼1.0 Ma, when the activity began to centralize in an area close to the present-day crater. The modern main edifice reached its maximum height at ca. 50 ka after bulky, spiny domes erupted in the current summit of the crater. Distribution and geochemical behavior in major elements of lavas indicate a co-magmatic relationship between different andesite and dacite domes and flows, although unrelated to the magmatism of the monogenetic volcanism. Mafic-intermediate magma likely replenished the system at Nevado de Toluca since ca. ∼1.0 Ma and contributed to the eruption of new domes, cones, as well as effusive-explosive activity. Altogether, field and laboratory data suggest that a large volume of magma was ejected around 1 Ma in and around the Nevado de Toluca.

  18. Late Pleistocene-Holocene cataclysmic eruptions at Nevado de Toluca and Jocotitlan volcanoes, central Mexico

    Science.gov (United States)

    Macias, J.L.; Garcia, P.A.; Arce, J.L.; Siebe, C.; Espindola, J.M.; Komorowski, J.C.; Scott, K.

    1997-01-01

    This field guide describes a five day trip to examine deposits of Late Pleistocene-Holocene cataclysmic eruptions at Nevado de Toluca and Jocotitlan volcanoes in central Mexico. We will discuss the stratigraphy, petrology, and sedimentological characteristics of these deposits which provide insights into the eruptive history, type of volcanic activity, and transport and emplacement mechanisms of pyroclastic materials. These parameters will allow us to discuss the kinds of hazards and the risk that they pose to populations around these volcanoes. The area to be visited is tectonically complex thus we will also discuss the location of the volcanoes with respect to the tectonic environment. The first four days of the field trip will be dedicated to Nevado de Toluca Volcano (19 degrees 09'N; 99 degrees 45'W) located at 23 km. southwest of the City of Toluca, and is the fourth highest peak in the country, reaching an elevation of 4,680 meters above sea level (m.a.s.l.). Nevado de Toluca is an andesitic-dacitic stratovolcano, composed of a central vent excavated upon the remains of older craters destroyed by former events. Bloomfield and Valastro, (1974, 1977) concluded that the last cycle of activity occurred nearly equal 11,600 yr. ago. For this reason Nevado de Toluca has been considered an extinct volcano. Our studies, however, indicate that Nevado de Toluca has had at least two episodes of cone destruction by sector collapse as well as several explosive episodes including plinian eruptions and dome-destruction events. These eruptions occurred during the Pleistocene but a very young eruption characterized by surge and ash flows occurred ca. 3,300 yr. BP. This new knowledge of the volcano's eruptive history makes the evaluation of its present state of activity and the geological hazards necessary. This is important because the area is densely populated and large cities such as Toluca and Mexico are located in its proximity.

  19. Ancestral sequence reconstruction with Maximum Parsimony

    OpenAIRE

    Herbst, Lina; Fischer, Mareike

    2017-01-01

    One of the main aims in phylogenetics is the estimation of ancestral sequences based on present-day data like, for instance, DNA alignments. One way to estimate the data of the last common ancestor of a given set of species is to first reconstruct a phylogenetic tree with some tree inference method and then to use some method of ancestral state inference based on that tree. One of the best-known methods both for tree inference as well as for ancestral sequence inference is Maximum Parsimony (...

  20. Chemical characteristics of the crater lakes of Popocatetetl, El Chichon, and Nevado de Toluca volcanoes, Mexico

    Science.gov (United States)

    Armienta, M. A.; De la Cruz-Reyna, S.; Macías, J. L.

    2000-04-01

    Three crater lakes from Mexican volcanoes were sampled and analyzed at various dates to determine their chemical characteristics. Strong differences were observed in the chemistry among the three lakes: Nevado de Toluca, considered as dormant, El Chichón at a post-eruptive stage, and Popocatépetl at a pre-eruptive stage. Not surprisingly, no influence of volcanic activity was found at the Nevado de Toluca volcano, while the other volcanoes showed a correlation between the changing level of activity and the evolution of chemical trends. Low pHs (Nevado de Toluca Sun lake. Changes with time were observed at Popocatépetl and El Chichón. Concentrations of volcanic-gas derived species like Cl-, SO42- and F- decreased irregularly at El Chichón from 1983 until 1997. Major cations concentrations also diminished at El Chichón. A 100% increase in the SO42- content was measured at Popocatépetl between 1985 and 1994. An increase in the Mg/Cl ratio between 1992 (Mg/Cl=0.085) and 1994 (Mg/Cl=0.177) was observed at Popocatépetl, before the disappearance of the crater lake in 1994. It is concluded that chemical analysis of crater lakes may provide a useful additional tool for active-volcano monitoring.

  1. Ancestral sequence alignment under optimal conditions

    Directory of Open Access Journals (Sweden)

    Brown Daniel G

    2005-11-01

    Full Text Available Abstract Background Multiple genome alignment is an important problem in bioinformatics. An important subproblem used by many multiple alignment approaches is that of aligning two multiple alignments. Many popular alignment algorithms for DNA use the sum-of-pairs heuristic, where the score of a multiple alignment is the sum of its induced pairwise alignment scores. However, the biological meaning of the sum-of-pairs of pairs heuristic is not obvious. Additionally, many algorithms based on the sum-of-pairs heuristic are complicated and slow, compared to pairwise alignment algorithms. An alternative approach to aligning alignments is to first infer ancestral sequences for each alignment, and then align the two ancestral sequences. In addition to being fast, this method has a clear biological basis that takes into account the evolution implied by an underlying phylogenetic tree. In this study we explore the accuracy of aligning alignments by ancestral sequence alignment. We examine the use of both maximum likelihood and parsimony to infer ancestral sequences. Additionally, we investigate the effect on accuracy of allowing ambiguity in our ancestral sequences. Results We use synthetic sequence data that we generate by simulating evolution on a phylogenetic tree. We use two different types of phylogenetic trees: trees with a period of rapid growth followed by a period of slow growth, and trees with a period of slow growth followed by a period of rapid growth. We examine the alignment accuracy of four ancestral sequence reconstruction and alignment methods: parsimony, maximum likelihood, ambiguous parsimony, and ambiguous maximum likelihood. Additionally, we compare against the alignment accuracy of two sum-of-pairs algorithms: ClustalW and the heuristic of Ma, Zhang, and Wang. Conclusion We find that allowing ambiguity in ancestral sequences does not lead to better multiple alignments. Regardless of whether we use parsimony or maximum likelihood, the

  2. REGEN: Ancestral Genome Reconstruction for Bacteria

    Directory of Open Access Journals (Sweden)

    João C. Setubal

    2012-07-01

    Full Text Available Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  3. REGEN: Ancestral Genome Reconstruction for Bacteria.

    Science.gov (United States)

    Yang, Kuan; Heath, Lenwood S; Setubal, João C

    2012-07-18

    Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  4. Resolution effects in reconstructing ancestral genomes.

    Science.gov (United States)

    Zheng, Chunfang; Jeong, Yuji; Turcotte, Madisyn Gabrielle; Sankoff, David

    2018-05-09

    The reconstruction of ancestral genomes must deal with the problem of resolution, necessarily involving a trade-off between trying to identify genomic details and being overwhelmed by noise at higher resolutions. We use the median reconstruction at the synteny block level, of the ancestral genome of the order Gentianales, based on coffee, Rhazya stricta and grape, to exemplify the effects of resolution (granularity) on comparative genomic analyses. We show how decreased resolution blurs the differences between evolving genomes, with respect to rate, mutational process and other characteristics.

  5. Coccidia in passerines from the Nevado de Toluca National Park, Mexico.

    Science.gov (United States)

    Medina, Juan P; Salgado-Miranda, Celene; García-Conejo, Michele; Galindo-Sánchez, Karla P; Mejía-García, Cristian J; Janczur, Mariusz K; Gomes Lopes, Carlos W; Berto, Bruno P; Soriano-Vargas, Edgardo

    2014-03-01

    In this study, we found unsporulated coccidia oocysts in passerines from the Nevado de Toluca National Park, Mexico. We captured birds and took samples of their droppings during three field visits. We examined a total of 72 fecal samples and found unsporulated coccidia oocysts in 10 samples from five passerine species: Atlapetes pileatus (3), Cardelina ruber (1), Mniotilta varia (1), Oreothlypis celata (2) and Regulus calendula (3). This appears to be the first recorded study of unsporulated coccidia oocysts in passerine species from Mexico.

  6. Ancestral Sequence Reconstruction with Maximum Parsimony.

    Science.gov (United States)

    Herbst, Lina; Fischer, Mareike

    2017-12-01

    One of the main aims in phylogenetics is the estimation of ancestral sequences based on present-day data like, for instance, DNA alignments. One way to estimate the data of the last common ancestor of a given set of species is to first reconstruct a phylogenetic tree with some tree inference method and then to use some method of ancestral state inference based on that tree. One of the best-known methods both for tree inference and for ancestral sequence inference is Maximum Parsimony (MP). In this manuscript, we focus on this method and on ancestral state inference for fully bifurcating trees. In particular, we investigate a conjecture published by Charleston and Steel in 1995 concerning the number of species which need to have a particular state, say a, at a particular site in order for MP to unambiguously return a as an estimate for the state of the last common ancestor. We prove the conjecture for all even numbers of character states, which is the most relevant case in biology. We also show that the conjecture does not hold in general for odd numbers of character states, but also present some positive results for this case.

  7. Volcanic hazard zonation of the Nevado de Toluca volcano, México

    Science.gov (United States)

    Capra, L.; Norini, G.; Groppelli, G.; Macías, J. L.; Arce, J. L.

    2008-10-01

    The Nevado de Toluca is a quiescent volcano located 20 km southwest of the City of Toluca and 70 km west of Mexico City. It has been quiescent since its last eruptive activity, dated at ˜ 3.3 ka BP. During the Pleistocene and Holocene, it experienced several eruptive phases, including five dome collapses with the emplacement of block-and-ash flows and four Plinian eruptions, including the 10.5 ka BP Plinian eruption that deposited more than 10 cm of sand-sized pumice in the area occupied today by Mexico City. A detailed geological map coupled with computer simulations (FLOW3D, TITAN2D, LAHARZ and HAZMAP softwares) were used to produce the volcanic hazard assessment. Based on the final hazard zonation the northern and eastern sectors of Nevado de Toluca would be affected by a greater number of phenomena in case of reappraisal activity. Block-and-ash flows will affect deep ravines up to a distance of 15 km and associated ash clouds could blanket the Toluca basin, whereas ash falls from Plinian events will have catastrophic effects for populated areas within a radius of 70 km, including the Mexico City Metropolitan area, inhabited by more than 20 million people. Independently of the activity of the volcano, lahars occur every year, affecting small villages settled down flow from main ravines.

  8. Assessing the Accuracy of Ancestral Protein Reconstruction Methods

    OpenAIRE

    Williams, Paul D; Pollock, David D; Blackburne, Benjamin P; Goldstein, Richard A

    2006-01-01

    The phylogenetic inference of ancestral protein sequences is a powerful technique for the study of molecular evolution, but any conclusions drawn from such studies are only as good as the accuracy of the reconstruction method. Every inference method leads to errors in the ancestral protein sequence, resulting in potentially misleading estimates of the ancestral protein's properties. To assess the accuracy of ancestral protein reconstruction methods, we performed computational population evolu...

  9. Animal regeneration: ancestral character or evolutionary novelty?

    Science.gov (United States)

    Slack, Jonathan Mw

    2017-09-01

    An old question about regeneration is whether it is an ancestral character which is a general property of living matter, or whether it represents a set of specific adaptations to the different circumstances faced by different types of animal. In this review, some recent results on regeneration are assessed to see if they can throw any new light on this question. Evidence in favour of an ancestral character comes from the role of Wnt and bone morphogenetic protein signalling in controlling the pattern of whole-body regeneration in acoels, which are a basal group of bilaterian animals. On the other hand, there is some evidence for adaptive acquisition or maintenance of the regeneration of appendages based on the occurrence of severe non-lethal predation, the existence of some novel genes in regenerating organisms, and differences at the molecular level between apparently similar forms of regeneration. It is tentatively concluded that whole-body regeneration is an ancestral character although has been lost from most animal lineages. Appendage regeneration is more likely to represent a derived character resulting from many specific adaptations. © 2017 The Author.

  10. Long term storage of explosively erupted magma at Nevado de Toluca volcano, Mexico

    Science.gov (United States)

    Arce, J. L.; Gardner, J.; Macias, J. L.

    2007-12-01

    Dacitic magmas production is common in subduction-related volcanoes, occurring in those with a long period of activity as a result of the magmatic evolution. However, in this evolution many factors (i.e. crystal fractionation, assimilation, magma mixing) can interact to produce dacites. Nevado de Toluca volcano (4,680 masl; 19°09'N; 99°45'W) Central Mexico has recorded a long period of time producing dacites explosively, at least during 42 ka of activity, involving several km3 of magma, with two important Plinian-type eruptions occurred at ~21.7 ka (Lower Toluca Pumice) and ~10.5 ka (Upper Toluca Pumice). Questions like, what was the mechanism responsible to produce voluminous dacitic magma and how the volatiles and pressure changed in the Nevado de Toluca system, remain without answers. Dacites from the Lower Toluca Pumice (LTP) contain plagioclase, amphibole, iron-titanium oxides, and minor resorbed biotite, set in a glassy-vesicular matrix and the Upper Toluca Pumice (UTP) dacites contain the same mineral phases plus orthopyroxene. Ilmenite- ulvospinel geothermometry yielded a temperature of ~860°C for the LTP dacite, a little hotter than the UTP (~ 840°C). Based on hydrothermal experiments data, amphibole is stable above 100 MPa under 900°C, while plagioclase crystallizes up to 250-100 MPa at temperatures of 850-900°C. Pyroxene occurs only at pressures of 200-100 MPa with its respective temperatures of 825-900°C. Water contents in the LTP magma (2-3.5 wt %) are similar to that calculated for the UTP magma (1.3-3.6 wt %). So, there are only small changes in temperature and pressure from ~21.7 ka to 10.5 ka. It is noteworthy that orthopyroxene is absent in the LTP, however reaction-rimmed biotite (probably xenocrystic) is commonly observed in all dacites. Hence, almost all dacitic magmas seem to be stored at relatively similar pressures, water contents, and temperatures. All of these data could suggest repetitive basic magma injections producing the

  11. ALTERATION RELATED TO HYDROTHERMAL ACTIVITY OF THE NEVADO DEL RUIZ VOLCANO (NRV), COLOMBIA

    OpenAIRE

    Forero, Jhon; Zuluaga, Carlos; Mojica, Jaime

    2011-01-01

    The hydrothermal activity in the NRV generates alteration characterized by mineral associations depending on a number of physic-chemical factors of the hydrothermal system. Petrography of unaltered rocks was used to establish the mineral assemblage prior to rock-fluid interaction. XRD was used in altered rocks, where it was not possible to recognize the alteration products. The observed mineral assemblages indicate advanced and intermediate argillic alterations, this and the observation of ve...

  12. Alteration related to hydrothermal activity of the Nevado del Ruiz volcano (NRV), Colombia

    International Nuclear Information System (INIS)

    Forero, Jhon; Zuluaga, Carlos; Mojica, Jaime

    2011-01-01

    The hydrothermal activity in the NRV generates alteration characterized by mineral associations depending one number of physic-chemical factors of the hydrothermal system. Petrography of unaltered rocks was used to establish the mineral assemblage prior to rock-fluid interaction. XRD was used in altered rocks, where it was not possible to recognize the alteration products. the observed mineral assemblages indicate advanced and intermediate argillic alterations, this and the observation of very low modal proportion of sulphates, sulphides and native sulphur in some areas could point to a low sulphidation zone. However, the proximity to the volcano and the presence of acid thermal waters and steam pose an apparent contradiction with an expected high sulphidation zone which is explained by climatic conditions, where excess water has dissolved and leached sulfides, sulphur and sulphates close to the volcano. fault zones serve as conducts for fluid transport and have acid-sulphate mineral associations produced by atmospheric oxidation at the water table in a steam-heated environment of H 2 S released by deeper, boiling fluids or by the disproportionation of magmatic SO 2 to H 2 S and H 2 SO 4 during condensation of magmatic vapor plume at intermedia depths in magmatic hydrothermal environment in andesitic volcanic terrain characteristic of high sulphidation zones.

  13. Environmental records from temperate glacier ice on Nevado Coropuna saddle, southern Peru

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    J. Herreros

    2009-10-01

    Full Text Available We investigated past climate variability and the zonal short and long-range transport of air masses in tropical South America using chemical, isotopic and palynological signals from a 42 m-long ice core recovered in 2003 from the saddle of the Nevado Coropuna, southern Peru (72°39´ W; 15°32´ S; 6080 m a.s.l.. We found that precipitation at this site depends mainly on the easterly circulation of air masses originated from the tropical Atlantic Ocean. Nevertheless, sporadic Pacific air masses arrivals, and strong cold waves coming from southern South America reach this altitude site. In spite of post-depositional effects, we were able to identify two strong ENSO (El Niño-Southern Oscillation event signatures (1982–1983 and 1992 and the eruptive activity of the nearby Sabancaya volcano (1994.

  14. Numerical modeling of debris avalanches at Nevado de Toluca (Mexico): implications for hazard evaluation and mapping

    Science.gov (United States)

    Grieco, F.; Capra, L.; Groppelli, G.; Norini, G.

    2007-05-01

    The present study concerns the numerical modeling of debris avalanches on the Nevado de Toluca Volcano (Mexico) using TITAN2D simulation software, and its application to create hazard maps. Nevado de Toluca is an andesitic to dacitic stratovolcano of Late Pliocene-Holocene age, located in central México near to the cities of Toluca and México City; its past activity has endangered an area with more than 25 million inhabitants today. The present work is based upon the data collected during extensive field work finalized to the realization of the geological map of Nevado de Toluca at 1:25,000 scale. The activity of the volcano has developed from 2.6 Ma until 10.5 ka with both effusive and explosive events; the Nevado de Toluca has presented long phases of inactivity characterized by erosion and emplacement of debris flow and debris avalanche deposits on its flanks. The largest epiclastic events in the history of the volcano are wide debris flows and debris avalanches, occurred between 1 Ma and 50 ka, during a prolonged hiatus in eruptive activity. Other minor events happened mainly during the most recent volcanic activity (less than 50 ka), characterized by magmatic and tectonic-induced instability of the summit dome complex. According to the most recent tectonic analysis, the active transtensive kinematics of the E-W Tenango Fault System had a strong influence on the preferential directions of the last three documented lateral collapses, which generated the Arroyo Grande and Zaguàn debris avalanche deposits towards E and Nopal debris avalanche deposit towards W. The analysis of the data collected during the field work permitted to create a detailed GIS database of the spatial and temporal distribution of debris avalanche deposits on the volcano. Flow models, that have been performed with the software TITAN2D, developed by GMFG at Buffalo, were entirely based upon the information stored in the geological database. The modeling software is built upon equations

  15. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  16. Robustness of ancestral sequence reconstruction to phylogenetic uncertainty.

    Science.gov (United States)

    Hanson-Smith, Victor; Kolaczkowski, Bryan; Thornton, Joseph W

    2010-09-01

    Ancestral sequence reconstruction (ASR) is widely used to formulate and test hypotheses about the sequences, functions, and structures of ancient genes. Ancestral sequences are usually inferred from an alignment of extant sequences using a maximum likelihood (ML) phylogenetic algorithm, which calculates the most likely ancestral sequence assuming a probabilistic model of sequence evolution and a specific phylogeny--typically the tree with the ML. The true phylogeny is seldom known with certainty, however. ML methods ignore this uncertainty, whereas Bayesian methods incorporate it by integrating the likelihood of each ancestral state over a distribution of possible trees. It is not known whether Bayesian approaches to phylogenetic uncertainty improve the accuracy of inferred ancestral sequences. Here, we use simulation-based experiments under both simplified and empirically derived conditions to compare the accuracy of ASR carried out using ML and Bayesian approaches. We show that incorporating phylogenetic uncertainty by integrating over topologies very rarely changes the inferred ancestral state and does not improve the accuracy of the reconstructed ancestral sequence. Ancestral state reconstructions are robust to uncertainty about the underlying tree because the conditions that produce phylogenetic uncertainty also make the ancestral state identical across plausible trees; conversely, the conditions under which different phylogenies yield different inferred ancestral states produce little or no ambiguity about the true phylogeny. Our results suggest that ML can produce accurate ASRs, even in the face of phylogenetic uncertainty. Using Bayesian integration to incorporate this uncertainty is neither necessary nor beneficial.

  17. EVALUATION OF PRIMARY PRODUCTIVITY AT THE WILDLIFE PROTECTED AREA, "NEVADO DE TOLUCA" MEXICO, DURING THE DRY SEASON

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    J. Martínez-Hernández

    2014-08-01

    Full Text Available This is the first report on grassland primary productivity for the wildlife protected area Nevado de Toluca (APFF Nevado de Toluca. We evaluated three communities in this area during dry season: Loma Alta, La Peñuela y Agua Blanca. Following Hodgson (1994, for this study we used exclusion cages. Vegetation was cut every 28 days during a five months sampling period. A randomized block design was used, where the blocks represented the grassland communities and the different months constituted treatments. The month of September showed the higher production (610.3 kg/ha DM. No significant differences were observed among communities (P >0.05. In conclusion, these communities have similar low primary productivity through the evaluation dry season months, which in addition was found lower in comparison to other areas, therefore livestock grazing in this region should be limited this season.

  18. Ancestral Relationships Using Metafounders: Finite Ancestral Populations and Across Population Relationships.

    Science.gov (United States)

    Legarra, Andres; Christensen, Ole F; Vitezica, Zulma G; Aguilar, Ignacio; Misztal, Ignacy

    2015-06-01

    Recent use of genomic (marker-based) relationships shows that relationships exist within and across base population (breeds or lines). However, current treatment of pedigree relationships is unable to consider relationships within or across base populations, although such relationships must exist due to finite size of the ancestral population and connections between populations. This complicates the conciliation of both approaches and, in particular, combining pedigree with genomic relationships. We present a coherent theoretical framework to consider base population in pedigree relationships. We suggest a conceptual framework that considers each ancestral population as a finite-sized pool of gametes. This generates across-individual relationships and contrasts with the classical view which each population is considered as an infinite, unrelated pool. Several ancestral populations may be connected and therefore related. Each ancestral population can be represented as a "metafounder," a pseudo-individual included as founder of the pedigree and similar to an "unknown parent group." Metafounders have self- and across relationships according to a set of parameters, which measure ancestral relationships, i.e., homozygozities within populations and relationships across populations. These parameters can be estimated from existing pedigree and marker genotypes using maximum likelihood or a method based on summary statistics, for arbitrarily complex pedigrees. Equivalences of genetic variance and variance components between the classical and this new parameterization are shown. Segregation variance on crosses of populations is modeled. Efficient algorithms for computation of relationship matrices, their inverses, and inbreeding coefficients are presented. Use of metafounders leads to compatibility of genomic and pedigree relationship matrices and to simple computing algorithms. Examples and code are given. Copyright © 2015 by the Genetics Society of America.

  19. Equilibrium Line Altitude Fluctuation on the South West Slope of Nevado Coropuna Since The Last Glacial Maximum (Cordillera Ampato, Perú

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    Campos, Néstor

    2015-12-01

    Full Text Available The main aim of this research was to reconstruct the LLGM (local last glacial maximum, 1955 and 2007 glacial phases on the South West slope of Nevado Coropuna to obtain valuable information on the changes that have occurred and analyze the glacier evolution. For this purpose the ELA (Equilibrium Line Altitude indicator has been used as a reference, with the AABR (Area x Altitude Balance Ratio method, based on the principle of weighting the mass balance according to the distance above or below the ELA of that area. An ELA of 4762 m was obtained for the LLGM, 5779 m for 1955 and 5850 m for 2007, implying a vertical shift of 1088 m from the LLGM to 2007 and of 71 m from 1955 to 2007. The total glaciated surface was reduced by 21.5% between 1955 and 2007 and the temperature shift from LLGM to 2007 was 9.13 ºC (0.0091ºC/m. The ice of glaciers makes them valuable for climate research, this method offers quantitative information and the analysis of this data may contribute to research into climate change and climatic trends for future predictions.El principal objetivo de esta investigación es reconstruir las fases glaciares del Último Máximo Glaciar Local (LLGM, 1955 y 2007 en la vertiente Suroeste del Nevado Coropuna para obtener información sobre los cambios ocurridos y analizar la evolución glaciar. Para este propósito el indicador de la altitud de la línea de equilibrio glaciar (ELA ha sido utilizado como referencia, calculado con el método AABR (Area x Altitude Balance Ratio, basado en el principio de ponderación del balance de masa en función de la distancia por encima o debajo de la ELA de esa área. Se obtuvo una ELA de 4762 m para el LLGM, 5779 m para 1955 y 5850 m para 2007, lo que implica una variación de 1088 m desde el LLGM hasta el 2007 y 71 m desde 1955 hasta 2007. La superficie total glaciada se redujo un 21,5% entre 1955 y 2007 y la variación de temperatura desde el LLGM hasta 2007 fue de 9,13 ºC (0,0091ºC/m. El hielo

  20. Assessing the accuracy of ancestral protein reconstruction methods.

    Directory of Open Access Journals (Sweden)

    Paul D Williams

    2006-06-01

    Full Text Available The phylogenetic inference of ancestral protein sequences is a powerful technique for the study of molecular evolution, but any conclusions drawn from such studies are only as good as the accuracy of the reconstruction method. Every inference method leads to errors in the ancestral protein sequence, resulting in potentially misleading estimates of the ancestral protein's properties. To assess the accuracy of ancestral protein reconstruction methods, we performed computational population evolution simulations featuring near-neutral evolution under purifying selection, speciation, and divergence using an off-lattice protein model where fitness depends on the ability to be stable in a specified target structure. We were thus able to compare the thermodynamic properties of the true ancestral sequences with the properties of "ancestral sequences" inferred by maximum parsimony, maximum likelihood, and Bayesian methods. Surprisingly, we found that methods such as maximum parsimony and maximum likelihood that reconstruct a "best guess" amino acid at each position overestimate thermostability, while a Bayesian method that sometimes chooses less-probable residues from the posterior probability distribution does not. Maximum likelihood and maximum parsimony apparently tend to eliminate variants at a position that are slightly detrimental to structural stability simply because such detrimental variants are less frequent. Other properties of ancestral proteins might be similarly overestimated. This suggests that ancestral reconstruction studies require greater care to come to credible conclusions regarding functional evolution. Inferred functional patterns that mimic reconstruction bias should be reevaluated.

  1. Assessing the accuracy of ancestral protein reconstruction methods.

    Science.gov (United States)

    Williams, Paul D; Pollock, David D; Blackburne, Benjamin P; Goldstein, Richard A

    2006-06-23

    The phylogenetic inference of ancestral protein sequences is a powerful technique for the study of molecular evolution, but any conclusions drawn from such studies are only as good as the accuracy of the reconstruction method. Every inference method leads to errors in the ancestral protein sequence, resulting in potentially misleading estimates of the ancestral protein's properties. To assess the accuracy of ancestral protein reconstruction methods, we performed computational population evolution simulations featuring near-neutral evolution under purifying selection, speciation, and divergence using an off-lattice protein model where fitness depends on the ability to be stable in a specified target structure. We were thus able to compare the thermodynamic properties of the true ancestral sequences with the properties of "ancestral sequences" inferred by maximum parsimony, maximum likelihood, and Bayesian methods. Surprisingly, we found that methods such as maximum parsimony and maximum likelihood that reconstruct a "best guess" amino acid at each position overestimate thermostability, while a Bayesian method that sometimes chooses less-probable residues from the posterior probability distribution does not. Maximum likelihood and maximum parsimony apparently tend to eliminate variants at a position that are slightly detrimental to structural stability simply because such detrimental variants are less frequent. Other properties of ancestral proteins might be similarly overestimated. This suggests that ancestral reconstruction studies require greater care to come to credible conclusions regarding functional evolution. Inferred functional patterns that mimic reconstruction bias should be reevaluated.

  2. Using Automated Point Dendrometers to Analyze Tropical Treeline Stem Growth at Nevado de Colima, Mexico

    Directory of Open Access Journals (Sweden)

    Franco Biondi

    2010-06-01

    Full Text Available The relationship between wood growth and environmental variability at the tropical treeline of North America was investigated using automated, solar-powered sensors (a meteorological station and two dendrometer clusters installed on Nevado de Colima, Mexico (19° 35’ N, 103° 37’ W, 3,760 m a.s.l.. Pure stands of Pinus hartwegii Lindl. (Mexican mountain pine were targeted because of their suitability for tree-ring analysis in low-latitude, high-elevation, North American Monsoon environments. Stem size and hydroclimatic variables recorded at half-hour intervals were summarized on a daily timescale. Power outages, insect outbreaks, and sensor failures limited the analysis to non-consecutive months during 2001–2003 at one dendrometer site, and during 2002–2005 at the other. Combined data from the two sites showed that maximum radial growth rates occur in late spring (May, as soil temperature increases, and incoming short-wave radiation reaches its highest values. Early season (April–May radial increment correlated directly with temperature, especially of the soil, and with solar radiation. Stem expansion at the start of the summer monsoon (June–July was mostly influenced by moisture, and revealed a drought signal, while late season relationships were more varied.

  3. Using automated point dendrometers to analyze tropical treeline stem growth at Nevado de Colima, Mexico.

    Science.gov (United States)

    Biondi, Franco; Hartsough, Peter

    2010-01-01

    The relationship between wood growth and environmental variability at the tropical treeline of North America was investigated using automated, solar-powered sensors (a meteorological station and two dendrometer clusters) installed on Nevado de Colima, Mexico (19° 35' N, 103° 37' W, 3,760 m a.s.l.). Pure stands of Pinus hartwegii Lindl. (Mexican mountain pine) were targeted because of their suitability for tree-ring analysis in low-latitude, high-elevation, North American Monsoon environments. Stem size and hydroclimatic variables recorded at half-hour intervals were summarized on a daily timescale. Power outages, insect outbreaks, and sensor failures limited the analysis to non-consecutive months during 2001-2003 at one dendrometer site, and during 2002-2005 at the other. Combined data from the two sites showed that maximum radial growth rates occur in late spring (May), as soil temperature increases, and incoming short-wave radiation reaches its highest values. Early season (April-May) radial increment correlated directly with temperature, especially of the soil, and with solar radiation. Stem expansion at the start of the summer monsoon (June-July) was mostly influenced by moisture, and revealed a drought signal, while late season relationships were more varied.

  4. Development of green tea scented with organic roses "Vitality" from Nevado Ecuador

    Directory of Open Access Journals (Sweden)

    Elena Beltrán

    2014-12-01

    Full Text Available (Received: 2014/11/03 - Accepted: 2014/12/15The aim of this study was to obtain a flavored green tea with organic rose petals "Vitality" from Nevado Ecuador. Green tea, purchased from a private company, it was subjected to analysis to verify compliance with the requirements of standard INEN 2381: 2005. The Characterization of fresh rose petals was to made and for the dehydration was used two temperatures and two geometries. Analysis of total polyphenol content (Folin-Ciocalteu and antioxidant capacity (TEACmethod were performed. The dried petals, with a higher content of polyphenols and antioxidant capacity, were used in the preparation to flavored tea. Three formulations with different amounts of dried rose petals (10, 17.5 and 25% were tested sensorially by 100 judges to determine the aroma rose in the tea. The final product was analyzed to determine compliance of the requirements of the standard INEN of the tea. Finally acceptability and purchase intention of the product is evaluated. The values of content total polyphenol in the extracts of rose petals were superior to fruits such as blackberries, and strawberries.

  5. Pleistocene cohesive debris flows at Nevado de Toluca Volcano, central Mexico

    Science.gov (United States)

    Capra, L.; Macías, J. L.

    2000-10-01

    During the Pleistocene, intense hydrothermal alteration promoted a flank failure of the southern portion of Nevado de Toluca volcano. This event produced a debris avalanche that transformed into a cohesive debris flow (Pilcaya deposit) owing to water saturation and weakness of the altered pre-avalanche rocks. The Pilcaya debris flow traveled along a narrow tectonic depression up to a distance of 40 km and then spread over a flat plain reaching up to 55 km from the volcano summit. This transition zone corresponds with a sudden break in slope from 5 to 0.5° that caused a rapid reduction in velocity and thickening of the flow that consequently reduced its competence to transport large particles. The resulting deposit thickens from 15 to 40 m, and contains boulders up to 15 m in diameter that form hummocky morphology close to the transitional zone. Sometime after the emplacement of the Pilcaya debris flow, heavy rains and superficial drainage contributed to remobilize the upper portions of the deposit causing two secondary lahars. These debris flows called El Mogote, traveled up to 75 km from the volcano. The edifice collapse generated lahars with a total volume of 2.8 km3 that devastated an approximate area of 250 km2. The area versus volume plot for both deposits shows that the magnitude of the event is comparable to other cohesive debris flows such as the Teteltzingo lahar (Pico de Orizaba, Mexico) and the Osceola mudflow (Mount Rainier, Wa). The Pilcaya debris flow represents additional evidence of debris flow transformed from a flank failure, a potentially devastating phenomenon that could threaten distant areas from the volcano previously considered without risk.

  6. Magma fluxes and recurreance rate of eruptions at Nevado de Toluca volcano (Mexico)

    Science.gov (United States)

    Weber, Gregor; Probst, Line; Arce, José L.; Caricchi, Luca

    2017-04-01

    Forecasting the frequency and size of volcanic eruptions is a long-term goal for hazard mitigation. The frequency at which a given crustal magmatic system is driven towards a critical state and the magnitude of the resulting volcanic events are linked to the supply rate of fresh magma, crustal properties, and tectonic setting. Our ability to forecast the recurrence rate of eruptions is hampered by the lack of data on key variables such as the average magma flux locally and globally. The aim of this project is to identify the average magma supply rate and injection frequency for eruptions of different magnitude and eruptive style. We centred our study at Nevado de Toluca in Mexico, a subduction-related volcano with an eruptive history spanning about 1.5 million years of comparatively well documented effusive and explosive eruptions dominantly of dacitic composition. We carry out in-situ high precision zircon geochronology for a sequence of eruptions of different magnitude to obtain a distribution of crystal ages from which average crustal magma fluxes can be calculated. Eruptive fluxes will be constrained by extracting lava flow volumes from a digital elevation model. A combination of whole rock and mineral chemistry will provide quantitative insights on petrogenetic processes and on the frequency at which intensive parameters changed within the magma reservoir before the eruptions. Our results will be integrated in a global database including other volcanic systems and literature data to attempt to identify similarities and differences between magmatic reservoirs feeding volcanic eruptions of different magnitude. The final target of this project is to identify the physical factors controlling the recurrence rate of volcanic eruptions at regional and global scale.

  7. Why Meillassoux’s Speculative Materialism Struggles with Ancestrality

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    Ciprian Jeler

    2014-12-01

    Full Text Available This paper shows that Quentin Meillassoux’s speculative materialism doesn’t offer us the means to account for the ancestral statements that the modern sciences produce, i.e. for the scientific statements about events preceding all forms of life. An analysis of the reasons why Meillassoux thinks that the problem of ancestrality problematizes the contemporary self-evidence of correlationism is first offered. The results of this analysis are then applied to speculative materialism itself and the consequences are not very promising: very much like correlationism, speculative materialism explicitly denies what I call the “generalized version of the realistic assumption of science” and, in so doing, renders scientific ancestral statements de jure unverifiable. Therefore, if correlationism is rendered suspicious by the issue of ancestrality, the same can be said of speculative materialism.

  8. WARACS: Wrappers to Automate the Reconstruction of Ancestral Character States.

    Science.gov (United States)

    Gruenstaeudl, Michael

    2016-02-01

    Reconstructions of ancestral character states are among the most widely used analyses for evaluating the morphological, cytological, or ecological evolution of an organismic lineage. The software application Mesquite remains the most popular application for such reconstructions among plant scientists, even though its support for automating complex analyses is limited. A software tool is needed that automates the reconstruction and visualization of ancestral character states with Mesquite and similar applications. A set of command line-based Python scripts was developed that (a) communicates standardized input to and output from the software applications Mesquite, BayesTraits, and TreeGraph2; (b) automates the process of ancestral character state reconstruction; and (c) facilitates the visualization of reconstruction results. WARACS provides a simple tool that streamlines the reconstruction and visualization of ancestral character states over a wide array of parameters, including tree distribution, character state, and optimality criterion.

  9. Why Meillassoux’s Speculative Materialism Struggles with Ancestrality

    OpenAIRE

    Ciprian Jeler

    2014-01-01

    This paper shows that Quentin Meillassoux’s speculative materialism doesn’t offer us the means to account for the ancestral statements that the modern sciences produce, i.e. for the scientific statements about events preceding all forms of life. An analysis of the reasons why Meillassoux thinks that the problem of ancestrality problematizes the contemporary self-evidence of correlationism is first offered. The results of this analysis are then applied to speculative materialism itself and the...

  10. Estudio del impacto de los fluidos volcánicos en el recurso hídrico de la cuenca del río Chinchiná

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    Denis Evelin Erazo Chamorro

    2015-07-01

    Full Text Available La corriente superficial del río Rioclaro constituye uno de los principales tributarios del río Chinchiná y nace en la zona de influencia del volcán Nevado del Ruiz en el municipio de Villamaría, departamento de Caldas (Colombia. Teniendo en cuenta que el impacto de la actividad volcánica puede generar cambios en las condiciones ambientales, la geomorfología de la región y la calidad de elementos vitales como el agua, aire y suelo, en este estudio se busca analizar la variación de parámetros físico-químicos mediante una caracterización del agua a lo largo de la subcuenca de Rioclaro, mediante campañas de monitoreo en los puntos más representativos, seleccionados por la posible influencia volcánica, facilidad de acceso y las condiciones de seguridad de la zona. Los resultados que se obtienen permiten generar una mayor comprensión sobre el posible impacto derivado de los flujos del volcán Nevado del Ruiz y la influencia de fuentes termales sobre el recurso hídrico. Los resultados obtenidos de los análisis fisicoquímicos confirman la influencia del volcán Nevado del Ruiz en las corrientes de agua de la subcuenca de Rioclaro y se evidencia una variación en los valores comunes de las concentraciones de los compuestos analizados para la mayoría de corrientes superficiales de agua dulce.

  11. Founder haplotype analysis of Fanconi anemia in the Korean population finds common ancestral haplotypes for a FANCG variant.

    Science.gov (United States)

    Park, Joonhong; Kim, Myungshin; Jang, Woori; Chae, Hyojin; Kim, Yonggoo; Chung, Nack-Gyun; Lee, Jae-Wook; Cho, Bin; Jeong, Dae-Chul; Park, In Yang; Park, Mi Sun

    2015-05-01

    A common ancestral haplotype is strongly suggested in the Korean and Japanese patients with Fanconi anemia (FA), because common mutations have been frequently found: c.2546delC and c.3720_3724delAAACA of FANCA; c.307+1G>C, c.1066C>T, and c.1589_1591delATA of FANCG. Our aim in this study was to investigate the origin of these common mutations of FANCA and FANCG. We genotyped 13 FA patients consisting of five FA-A patients and eight FA-G patients from the Korean FA population. Microsatellite markers used for haplotype analysis included four CA repeat markers which are closely linked with FANCA and eight CA repeat markers which are contiguous with FANCG. As a result, Korean FA-A patients carrying c.2546delC or c.3720_3724delAAACA did not share the same haplotypes. However, three unique haplotypes carrying c.307+1G>C, c.1066C > T, or c.1589_1591delATA, that consisted of eight polymorphic loci covering a flanking region were strongly associated with Korean FA-G, consistent with founder haplotypes reported previously in the Japanese FA-G population. Our finding confirmed the common ancestral haplotypes on the origins of the East Asian FA-G patients, which will improve our understanding of the molecular population genetics of FA-G. To the best of our knowledge, this is the first report on the association between disease-linked mutations and common ancestral haplotypes in the Korean FA population. © 2015 John Wiley & Sons Ltd/University College London.

  12. Novel ancestral Dysferlin splicing mutation which migrated from the Iberian peninsula to South America.

    Science.gov (United States)

    Vernengo, Luis; Oliveira, Jorge; Krahn, Martin; Vieira, Emilia; Santos, Rosário; Carrasco, Luisa; Negrão, Luís; Panuncio, Ana; Leturcq, France; Labelle, Veronique; Bronze-da-Rocha, Elsa; Mesa, Rosario; Pizzarossa, Carlos; Lévy, Nicolas; Rodriguez, Maria-Mirta

    2011-05-01

    Primary dysferlinopathies are a group of recessive heterogeneous muscular dystrophies. The most common clinical presentations are Miyoshi myopathy and LGMD2B. Additional presentations range from isolated hyperCKemia to severe functional disability. Symptomatology begins in the posterior muscle compartment of the calf and its clinical course progresses slowly in Miyoshi myopathy whereas LGMD2B involves predominantly the proximal muscles of the lower limbs. The age of onset ranges from 13 to 60years in Caucasians. We present five patients that carry a novel mutation in the exon12/intron12 boundary: c.1180_1180+7delAGTGCGTG (r.1054_1284del). We provide evidence of a founder effect due to a common ancestral origin of this mutation, detected in heterozygosity in four patients and in homozygosity in one patient. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Ancestral Rocky Mountian Tectonics: A Sedimentary Record of Ancestral Front Range and Uncompahgre Exhumation

    Science.gov (United States)

    Smith, T. M.; Saylor, J. E.; Lapen, T. J.

    2015-12-01

    The Ancestral Rocky Mountains (ARM) encompass multiple crustal provinces with characteristic crystallization ages across the central and western US. Two driving mechanisms have been proposed to explain ARM deformation. (1) Ouachita-Marathon collision SE of the ARM uplifts has been linked to an E-to-W sequence of uplift and is consistent with proposed disruption of a larger Paradox-Central Colorado Trough Basin by exhumation of the Uncompahgre Uplift. Initial exhumation of the Amarillo-Wichita Uplift to the east would provide a unique ~530 Ma signal absent from source areas to the SW, and result in initial exhumation of the Ancestral Front Range. (2) Alternatively, deformation due to flat slab subduction along a hypothesized plate boundary to the SW suggests a SW-to-NE younging of exhumation. This hypothesis suggests a SW-derived Grenville signature, and would trigger uplift of the Uncompahgre first. We analyzed depositional environments, sediment dispersal patterns, and sediment and basement zircon U-Pb and (U-Th)/He ages in 3 locations in the Paradox Basin and Central Colorado Trough (CCT). The Paradox Basin exhibits an up-section transition in fluvial style that suggests a decrease in overbank stability and increased lateral migration. Similarly, the CCT records a long-term progradation of depositional environments from marginal marine to fluvial, indicating that sediment supply in both basins outpaced accommodation. Preliminary provenance results indicate little to no input from the Amarillo-Wichita uplift in either basin despite uniformly westward sediment dispersal systems in both basins. Results also show that the Uncompahgre Uplift was the source for sediment throughout Paradox Basin deposition. These observations are inconsistent with the predictions of scenario 1 above. Rather, they suggest either a synchronous response to tectonic stress across the ARM provinces or an SW-to-NE pattern of deformation.

  14. Ancestrality and evolution of trait syndromes in finches (Fringillidae).

    Science.gov (United States)

    Ponge, Jean-François; Zuccon, Dario; Elias, Marianne; Pavoine, Sandrine; Henry, Pierre-Yves; Théry, Marc; Guilbert, Éric

    2017-12-01

    Species traits have been hypothesized by one of us (Ponge, 2013) to evolve in a correlated manner as species colonize stable, undisturbed habitats, shifting from "ancestral" to "derived" strategies. We predicted that generalism, r-selection, sexual monomorphism, and migration/gregariousness are the ancestral states (collectively called strategy A) and evolved correlatively toward specialism, K-selection, sexual dimorphism, and residence/territoriality as habitat stabilized (collectively called B strategy). We analyzed the correlated evolution of four syndromes, summarizing the covariation between 53 traits, respectively, involved in ecological specialization, r-K gradient, sexual selection, and dispersal/social behaviors in 81 species representative of Fringillidae, a bird family with available natural history information and that shows variability for all these traits. The ancestrality of strategy A was supported for three of the four syndromes, the ancestrality of generalism having a weaker support, except for the core group Carduelinae (69 species). It appeared that two different B-strategies evolved from the ancestral state A, both associated with highly predictable environments: one in poorly seasonal environments, called B1, with species living permanently in lowland tropics, with "slow pace of life" and weak sexual dimorphism, and one in highly seasonal environments, called B2, with species breeding out-of-the-tropics, migratory, with a "fast pace of life" and high sexual dimorphism.

  15. Reproductive function in mice exposed to ancestral and direct irradiation

    International Nuclear Information System (INIS)

    Nash, D.J.; Sprackling, L.S.

    1978-01-01

    Reproduction was studied in 13 inbred strains of mice that had been exposed continuously to 60 Co gamma radiation for varying numbers of generations. At weaning the mice were removed from the irradiation chamber and were tested for reproductive performance. Ancestral and direct levels of irradiation were determined for each animal. Each irradiated or control female was scored as fertile or sterile, and in utero litter counts were made in pregnant females that were dissected past the 10th day of pregnancy. The number of resorptions, dead embryos, and live embryos were counted, and the ratio of living embryos to the total number of embryos was determined for each litter. The overall fertility curves were sigmoid in the range of doses below those which caused complete sterility, which indicated some sort of cumulative damage. In 11 of the 13 strains studied, an increase in ancestral and/or direct irradiation led to significant decreases in fertility. The means of the number alive in the litters for the control and irradiated mice in each strain showed a definite trend toward fewer live mice in utero after irradiation. Least-squares analyses of variance were made to detect possible effects of any of six irradiation variables (ancestral linear, ancestral quadratic, ancestral cubic, direct linear, direct quadratic, or direct cubic) or of strain differences on total litter size and on ratio. Strain effects were significant in each instance. Litter size was more likely to be affected by radiation variables than ratios were

  16. Enzyme functional evolution through improved catalysis of ancestrally nonpreferred substrates

    Science.gov (United States)

    Huang, Ruiqi; Hippauf, Frank; Rohrbeck, Diana; Haustein, Maria; Wenke, Katrin; Feike, Janie; Sorrelle, Noah; Piechulla, Birgit; Barkman, Todd J.

    2012-01-01

    In this study, we investigated the role for ancestral functional variation that may be selected upon to generate protein functional shifts using ancestral protein resurrection, statistical tests for positive selection, forward and reverse evolutionary genetics, and enzyme functional assays. Data are presented for three instances of protein functional change in the salicylic acid/benzoic acid/theobromine (SABATH) lineage of plant secondary metabolite-producing enzymes. In each case, we demonstrate that ancestral nonpreferred activities were improved upon in a daughter enzyme after gene duplication, and that these functional shifts were likely coincident with positive selection. Both forward and reverse mutagenesis studies validate the impact of one or a few sites toward increasing activity with ancestrally nonpreferred substrates. In one case, we document the occurrence of an evolutionary reversal of an active site residue that reversed enzyme properties. Furthermore, these studies show that functionally important amino acid replacements result in substrate discrimination as reflected in evolutionary changes in the specificity constant (kcat/KM) for competing substrates, even though adaptive substitutions may affect KM and kcat separately. In total, these results indicate that nonpreferred, or even latent, ancestral protein activities may be coopted at later times to become the primary or preferred protein activities. PMID:22315396

  17. Initial Time Of Two High Altitude Crater Lakes (Nevado De Toluca, Central Mexico Recorded In Subfossil Cladocera

    Directory of Open Access Journals (Sweden)

    Szeroczyńska Krystyna

    2015-12-01

    Full Text Available The objective of this study was the recognition and reconstruction of the origin of two high altitude lakes and the ecological conditions of their early existence based on subfossil Cladocera and chemical analyses. The study focused on the oldest lacustrine sediments from Lake Sol and Lake Luna, located in the crater of Volcano Nevado de Toluca (Central Mexico. The Nevado de Toluca crater developed approximately 12 ka yr BP. According to the literature, the volcano was last active approximately 3.3 ka yr BP, and the lakes developed after that eruption. The remains of nine Cladocera species were found in the bottom sediments of both lakes. The most dominant taxa were two endemic littoral species: Alona manueli and Iliocryptus nevadensis. The total frequency of Cladocera specimens in both of the sediment cores was very low. No Cladocera remains were recorded in the sediment layer at depths between 123–103 m from Lake Luna. The results of the lithological and geochemical analyses showed that this sediment layer was composed of allochthonous material, probably originating from slid down from the volcanic cone. This was suggested by the content of silica (up to 13%, iron (up to 12%, and titanium (up to 4%. The Cladocera remains recorded in the bottom sediments suggested that both reservoirs developed as freshwater lakes at the beginning of the sedimentation. The calibrated radiocarbon dates obtained for the bottom samples were 4040 to 3990 yr BP for Lake Luna (129 cm and 4485 to 4485 yr BP for Lake Sol (89 cm. The obtained ages were older than the dates of the last eruption, which occurred approximately 3300 yr BP. This result was likely related to the type of radiocarbon dated materials (charcoals.

  18. Peruvian Tropical Glacier May Survive Longer Than Previously Thought: Landsat Image Analysis of Nevado Coropuna Ice Cap, Peru

    Science.gov (United States)

    Kochtitzky, W. H.; Edwards, B. R.; Marino, J.; Manrique, N.

    2015-12-01

    Nevado Coropuna is a large volcanic complex in southern Peru (15.56°S, 72.62°N; 6,425 m). The complex is approximately 12 km east-west and 8 km north-south with elevation from ~4,500 m at the base to over 6,000 m at the highest points. This ice cap is the largest hosted by a volcano in the tropics, and one of the ten biggest ice masses in the tropics. Previous workers have predicted that the Coropuna ice cap will completely melt by 2050. We present a new analysis of historic satellite imagery to test this hypothesis. In this study, ice and snow are classified based on unique spectral signatures including spectral band thresholds, Normalized Difference Snow Index, and Band 4/5 ratio. Landsat scenes (L2, 4, 5, 7, and 8) from 1975 to present in addition to one SPOT scene (2013) are used. Previous workers used images from June and July, which are peak snow periods in southern Peru, leading to overestimates of ice area. This study uses November and December images when snow is at an annual minimum. Annual equilibrium line altitudes are calculated for each end of year image (November/December). The glaciers of Nevado Coropuna were found to be shrinking at ~0.5 km2/yr, which is ~1/3 the rate previously published. In this study, SPOT (1.5 m resolution) and Landsat 7 ETM scenes from November 23 and 26, 2013 respectively were used to calibrate the spectral band threshold classification. While this study suggests that the ice cap of Coropuna will persist until 2100 given current rates, water quantity and security remains a concern for Peruvian agriculture. Coropuna is an active volcano, so it poses great risk to surrounding inhabitants from lahars, flooding, and debris avalanches. Our new data suggest that these will continue to be risks late into this century.

  19. Isolation of Ancestral Sylvatic Dengue Virus Type 1, Malaysia

    Science.gov (United States)

    Teoh, Boon-Teong; Sam, Sing-Sin; Abd-Jamil, Juraina

    2010-01-01

    Ancestral sylvatic dengue virus type 1, which was isolated from a monkey in 1972, was isolated from a patient with dengue fever in Malaysia. The virus is neutralized by serum of patients with endemic DENV-1 infection. Rare isolation of this virus suggests a limited spillover infection from an otherwise restricted sylvatic cycle. PMID:21029545

  20. An Epistemological Analysis of the African Ontology of `Ancestral ...

    African Journals Online (AJOL)

    The paper explores the contemporary debate surrounding the idea of ancestral reincarnation in African society and philosophy. It analyzes various problem areas having to do with the physical and spiritual status of ancestors, their relationship with their societies of orientation, the philosophical contexts of their existence, ...

  1. Musculature in sipunculan worms: ontogeny and ancestral states.

    Science.gov (United States)

    Schulze, Anja; Rice, Mary E

    2009-01-01

    Molecular phylogenetics suggests that the Sipuncula fall into the Annelida, although they are morphologically very distinct and lack segmentation. To understand the evolutionary transformations from the annelid to the sipunculan body plan, it is important to reconstruct the ancestral states within the respective clades at all life history stages. Here we reconstruct the ancestral states for the head/introvert retractor muscles and the body wall musculature in the Sipuncula using Bayesian statistics. In addition, we describe the ontogenetic transformations of the two muscle systems in four sipunculan species with different developmental modes, using F-actin staining with fluorescent-labeled phalloidin in conjunction with confocal laser scanning microscopy. All four species, which have smooth body wall musculature and less than the full set of four introvert retractor muscles as adults, go through developmental stages with four retractor muscles that are eventually reduced to a lower number in the adult. The circular and sometimes the longitudinal body wall musculature are split into bands that later transform into a smooth sheath. Our ancestral state reconstructions suggest with nearly 100% probability that the ancestral sipunculan had four introvert retractor muscles, longitudinal body wall musculature in bands and circular body wall musculature arranged as a smooth sheath. Species with crawling larvae have more strongly developed body wall musculature than those with swimming larvae. To interpret our findings in the context of annelid evolution, a more solid phylogenetic framework is needed for the entire group and more data on ontogenetic transformations of annelid musculature are desirable.

  2. A comparison of ancestral state reconstruction methods for quantitative characters.

    Science.gov (United States)

    Royer-Carenzi, Manuela; Didier, Gilles

    2016-09-07

    Choosing an ancestral state reconstruction method among the alternatives available for quantitative characters may be puzzling. We present here a comparison of seven of them, namely the maximum likelihood, restricted maximum likelihood, generalized least squares under Brownian, Brownian-with-trend and Ornstein-Uhlenbeck models, phylogenetic independent contrasts and squared parsimony methods. A review of the relations between these methods shows that the maximum likelihood, the restricted maximum likelihood and the generalized least squares under Brownian model infer the same ancestral states and can only be distinguished by the distributions accounting for the reconstruction uncertainty which they provide. The respective accuracy of the methods is assessed over character evolution simulated under a Brownian motion with (and without) directional or stabilizing selection. We give the general form of ancestral state distributions conditioned on leaf states under the simulation models. Ancestral distributions are used first, to give a theoretical lower bound of the expected reconstruction error, and second, to develop an original evaluation scheme which is more efficient than comparing the reconstructed and the simulated states. Our simulations show that: (i) the distributions of the reconstruction uncertainty provided by the methods generally make sense (some more than others); (ii) it is essential to detect the presence of an evolutionary trend and to choose a reconstruction method accordingly; (iii) all the methods show good performances on characters under stabilizing selection; (iv) without trend or stabilizing selection, the maximum likelihood method is generally the most accurate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Modeling X-linked ancestral origins in multiparental populations

    NARCIS (Netherlands)

    Zheng, Chaozhi

    2015-01-01

    The models for the mosaic structure of an individual's genome from multiparental populations have been developed primarily for autosomes, whereas X chromosomes receive very little attention. In this paper, we extend our previous approach to model ancestral origin processes along two X chromosomes

  4. Les grandes étapes d'évolution d'un volcan andésitique composite: Exemple du Nevado de Toluca (Méxique)

    Science.gov (United States)

    Cantagrel, J. M.; Robin, C.; Vincent, P.

    1981-06-01

    The Nevado de Toluca, in the middle of the Mexican volcanic belt, has been built by two very dissimilar phases. The first one that lasted more than one million years is mainly andesitic. Numerous massive and autobrecciated lava flows of this phase pass outwards into thick conglomeratic formations. The volume of this primitive volcano represents the essential part of the Nevado. After an intense periode of erosion, the second phase is of very short duration (about 100.000 years) and is dacitic in nature. Three main episode can be distinguished: 1. Eruption of important ash and pumice pyroclastic flows related to caldera collapse above a shallow magmatic reservoir. 2. Extrusions of several dacitic domes within and outside the caldera with numerous associated «nuées ardentes» surrounding the volcano. 3. Plinian eruption leading to widespread pumiceous air-fall and to the opening of the present crater inside the caldera. Extrusion of a new small dacitic dome and late phreatic explosions. This second sequence of events can be interpreted as the progressive emptying of the crustal magmatic chamber without refilling by a new magma supply. The most recent activity in the area is represented by monogenic cones and flows of basic andesites outside the central vent system of the Nevado.

  5. Historian: accurate reconstruction of ancestral sequences and evolutionary rates.

    Science.gov (United States)

    Holmes, Ian H

    2017-04-15

    Reconstruction of ancestral sequence histories, and estimation of parameters like indel rates, are improved by using explicit evolutionary models and summing over uncertain alignments. The previous best tool for this purpose (according to simulation benchmarks) was ProtPal, but this tool was too slow for practical use. Historian combines an efficient reimplementation of the ProtPal algorithm with performance-improving heuristics from other alignment tools. Simulation results on fidelity of rate estimation via ancestral reconstruction, along with evaluations on the structurally informed alignment dataset BAliBase 3.0, recommend Historian over other alignment tools for evolutionary applications. Historian is available at https://github.com/evoldoers/historian under the Creative Commons Attribution 3.0 US license. ihholmes+historian@gmail.com. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  6. Using Resurrected Ancestral Proviral Proteins to Engineer Virus Resistance

    Directory of Open Access Journals (Sweden)

    Asunción Delgado

    2017-05-01

    Full Text Available Proviral factors are host proteins hijacked by viruses for processes essential for virus propagation such as cellular entry and replication. Pathogens and their hosts co-evolve. It follows that replacing a proviral factor with a functional ancestral form of the same protein could prevent viral propagation without fatally compromising organismal fitness. Here, we provide proof of concept of this notion. Thioredoxins serve as general oxidoreductases in all known cells. We report that several laboratory resurrections of Precambrian thioredoxins display substantial levels of functionality within Escherichia coli. Unlike E. coli thioredoxin, however, these ancestral thioredoxins are not efficiently recruited by the bacteriophage T7 for its replisome and therefore prevent phage propagation in E. coli. These results suggest an approach to the engineering of virus resistance. Diseases caused by viruses may have a devastating effect in agriculture. We discuss how the suggested approach could be applied to the engineering of plant virus resistance.

  7. Perianth evolution in Ranunculaceae: are petals ancestral in the family?

    Directory of Open Access Journals (Sweden)

    Sophie Nadot

    2016-04-01

    Full Text Available Progress has been made recently towards the elucidation of phylogenetic relationships among subfamilies and tribes of the Ranunculaceae – the most recent hypothesis was published in 2016 by our team. Although relationships among the 10 tribes of the subfamily Ranunculoideae remain incompletely supported, this hypothesis provides an interesting framework to address the key issue of the ancestral vs. derived nature of a differentiated perianth within the family, and at the level of Ranunculales as a whole. Here, we present ancestral state reconstructions for several perianth characters, such as differentiation into sepals and petals, shape of petals, presence/absence of nectaries, and petaloid or sepaloid aspect of sepals. Characters were scored using the PROTEUS database and optimized on the most recent phylogeny of Ranunculaceae using parsimony and maximum likelihood methods. The results are discussed with regard to recent evo-devo studies focused on identifying genes involved in floral organs identity (the so-called ABC model in Ranunculales.

  8. The ancestral selection graph under strong directional selection.

    Science.gov (United States)

    Pokalyuk, Cornelia; Pfaffelhuber, Peter

    2013-08-01

    The ancestral selection graph (ASG) was introduced by  Neuhauser and Krone (1997) in order to study populations of constant size which evolve under selection. Coalescence events, which occur at rate 1 for every pair of lines, lead to joint ancestry. In addition, splitting events in the ASG at rate α, the scaled selection coefficient, produce possible ancestors, such that the real ancestor depends on the ancestral alleles. Here, we use the ASG in the case without mutation in order to study fixation of a beneficial mutant. Using our main tool, a reversibility property of the ASG, we provide a new proof of the fact that a beneficial allele fixes roughly in time (2logα)/α if α is large. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Identificación de áreas críticas de erosión en el Curso Alto del Río Lerma

    Directory of Open Access Journals (Sweden)

    Marivel Hernández Téllez

    2009-01-01

    los municipios más afectados con el fin de instarles a tomar medidas preventivas. Estos municipios corresponden a Santiago Tianguistenco, Lerma y Ocoyoacac que juntos representan 60% de las zonas con grado de erosión extrema. En índices de erosión alta a los anteriores se le suman Otzolotepec, Temoaya, Xalatlaco, Toluca en las faldas del Nevado y Zinacantepec.

  10. Glacial and volcanic evolution on Nevado Coropuna (Tropical Andes) based on cosmogenic 36Cl surface exposure dating

    Science.gov (United States)

    Úbeda, J.; Palacios, D.; Vázquez-Selém, L.

    2012-04-01

    We have reconstructed the evolution of the paleo-glaciers of the volcanic complex Nevado Coropuna (15°S, 72°W; 6377 m asl) through the interpretation and dating of geomorphological evidences. Surface exposure dating (SED) based on the accumulation of 36Cl on the surface of moraine boulders, polished bedrock and lava flows allowed: 1) to confirm that the presence of ice masses in the region dates back to >80ka; 2) to produce chronologies of glacial and volcanic phases for the last ~21 ka; and 3) to obtain evidences of the reactivation of volcanic activity after the Last Glacial Maximum. Bromley et al. (2009) presented 3He SED ages of 21 ka for moraine boulders on the Mapa Mayo valley, to the North of Nevado Coropuna. Our 36Cl SED SED for moraine boulders from the valleys on the NE sector of the volcanic complex suggest a maximum initial advance between 20 and 16 ka, followed by another expansion of similar extent at 12-11 ka. On the Southern slope of Nevado Coropuna, the 36Cl ages show a maximum initial advance that reaches to the level of the Altiplano at 14 ka, and a re-advance at ~10-9 ka BP. Other data show minor re-advances at 9 ka on the Northern slope and at 6 ka to the South of the volcanic complex. These minor positive pulses interrupted a fast deglaciation process during the Holocene as shown by two series of 36Cl SED from polished rock surfaces on successively higher altitudes along the valleys of rivers Blanco and Cospanja, to the SW and SE. Despite the global warming occuring since 20 ka, deduced from the record of sea surface paleo-temperature of the Galapago Islands (Lea et al, 2006), the evolution of the fresh-water plankton from Lake Titicaca (Fritz et al, 2007) is consistent with sustained glacial conditions until 10-9 ka as suggested by the present work. Exposure ages of three lava flows indicate a reactivation of the magmatic system as the paleo-glaciers abandonned the slopes. The eruptive activity migrated from the West, where we found a lava

  11. Prenatal effects of ancestral irradiation in inbred mice

    International Nuclear Information System (INIS)

    Sprackling, L.E.S.

    1975-01-01

    Mice from 13 inbred strains (S, Z, E, Bab, BaB, BrR, C, K, N, Q, G, CFW, CF1) received continuous cobalt 60 irradiation at low dose rates for varying numbers of consecutive generations. Some Bab and BaB mice had received continuous irradiation for from 24 to 31 generations and the other mice had up to six generations of continuous irradiation in their ancestry. At weaning, the mice were removed from the irradiation room and were mated within strains either to sibs or nonsibs. Ancestral and direct irradiation doses were calculated. The ancestral dose was the effective accumulated dose to the progeny of the mated mice. The direct dose was the amount of irradiation received by any mated female from her conception to her weaning. Each irradiated or control female was scored as fertile or sterile and in utero litter counts were made in pregnant females that were dissected past the tenth day of pregnancy; the sum of moles, dead embryos, and live embryos was the total in utero litter size. A ratio of the living embryos to the total number of embryos in utero was determined for each litter. An increase in ancestral or direct irradiation dose significantly decreased fertility in 11 of the 13 strains. The fertility curves for the pooled data were sigmoid in the area of the doses below those that caused complete sterility. Among the controls, there were significant strain differences in total litter size and in the ratio. Strain X--Y plots, with ancestral or direct doses plotted against total litter size or ratio, revealed the tendency for litter size to decrease as dose increased. The only trend shown for ratio was for the litters with ratios of 0.50 or less to appear more frequently among the irradiated mice. The few corpora lutea counts revealed nothing of significance. Generally, there was a definite trend toward fewer mice alive in utero among the irradiated mice

  12. Ancestrality and evolution of trait syndromes in finches (Fringillidae)

    OpenAIRE

    Ponge, Jean‐François; Zuccon, Dario; Elias, Marianne; Pavoine, Sandrine; Henry, Pierre‐Yves; Théry, Marc; Guilbert, Éric

    2017-01-01

    International audience; Species traits have been hypothesized by one of us (Ponge, 2013) to evolve in a correlated manner as species colonize stable, undisturbed habitats, shifting from “ancestral” to “derived” strategies. We predicted that generalism, r-selection, sexual monomorphism, and migration/gregariousness are the ancestral states (collectively called strategy A) and evolved correlatively toward specialism, K-selection, sexual dimorphism, and residence/territoriality as habitat stabil...

  13. Reconstruction of ancestral RNA sequences under multiple structural constraints

    OpenAIRE

    Tremblay-Savard, Olivier; Reinharz, Vladimir; Waldisp?hl, J?r?me

    2016-01-01

    Background Secondary structures form the scaffold of multiple sequence alignment of non-coding RNA (ncRNA) families. An accurate reconstruction of ancestral ncRNAs must use this structural signal. However, the inference of ancestors of a single ncRNA family with a single consensus structure may bias the results towards sequences with high affinity to this structure, which are far from the true ancestors. Methods In this paper, we introduce achARNement, a maximum parsimony approach that, given...

  14. Infant and juvenile growth in ancestral Pueblo Indians.

    Science.gov (United States)

    Schillaci, Michael A; Nikitovic, Dejana; Akins, Nancy J; Tripp, Lianne; Palkovich, Ann M

    2011-06-01

    The present study examines patterns of infant and juvenile growth in a diachronic sample of ancestral Pueblo Indians (AD 1300-1680) from the American Southwest. An assessment of growth patterns is accompanied by an evaluation of pathological conditions often considered to be indicators of nutritional deficiencies and/or gastrointestinal infections. Growth patterns and the distribution of pathological conditions are interpreted relative to culturally relevant age categories defined by Puebloan rites of passage described in the ethnographic literature. A visual comparison of growth distance curves revealed that relative to a modern comparative group our sample of ancestral Pueblo infant and juveniles exhibited faltering growth beginning soon after birth to about 5 years of age. A comparison of curves describing growth relative to adult femoral length, however, indicated reduced growth occurring later, by around 2 years of age. Similar to previous studies, we observed a high proportion of nonsurvivors exhibiting porotic cranial lesions during the first 2 years of life. Contrary to expectations, infants and juveniles without evidence of porotic cranial lesions exhibited a higher degree of stunting. Our study is generally consistent with previous research reporting poor health and high mortality for ancestral Pueblo Indian infants and juveniles. Through use of a culturally relevant context defining childhood, we argue that the observed poor health and high mortality in our sample occur before the important transition from young to older child and the concomitant initial incorporation into tribal ritual organization. Copyright © 2011 Wiley-Liss, Inc.

  15. Cases in which ancestral maximum likelihood will be confusingly misleading.

    Science.gov (United States)

    Handelman, Tomer; Chor, Benny

    2017-05-07

    Ancestral maximum likelihood (AML) is a phylogenetic tree reconstruction criteria that "lies between" maximum parsimony (MP) and maximum likelihood (ML). ML has long been known to be statistically consistent. On the other hand, Felsenstein (1978) showed that MP is statistically inconsistent, and even positively misleading: There are cases where the parsimony criteria, applied to data generated according to one tree topology, will be optimized on a different tree topology. The question of weather AML is statistically consistent or not has been open for a long time. Mossel et al. (2009) have shown that AML can "shrink" short tree edges, resulting in a star tree with no internal resolution, which yields a better AML score than the original (resolved) model. This result implies that AML is statistically inconsistent, but not that it is positively misleading, because the star tree is compatible with any other topology. We show that AML is confusingly misleading: For some simple, four taxa (resolved) tree, the ancestral likelihood optimization criteria is maximized on an incorrect (resolved) tree topology, as well as on a star tree (both with specific edge lengths), while the tree with the original, correct topology, has strictly lower ancestral likelihood. Interestingly, the two short edges in the incorrect, resolved tree topology are of length zero, and are not adjacent, so this resolved tree is in fact a simple path. While for MP, the underlying phenomenon can be described as long edge attraction, it turns out that here we have long edge repulsion. Copyright © 2017. Published by Elsevier Ltd.

  16. Choosing the best ancestral character state reconstruction method.

    Science.gov (United States)

    Royer-Carenzi, Manuela; Pontarotti, Pierre; Didier, Gilles

    2013-03-01

    Despite its intrinsic difficulty, ancestral character state reconstruction is an essential tool for testing evolutionary hypothesis. Two major classes of approaches to this question can be distinguished: parsimony- or likelihood-based approaches. We focus here on the second class of methods, more specifically on approaches based on continuous-time Markov modeling of character evolution. Among them, we consider the most-likely-ancestor reconstruction, the posterior-probability reconstruction, the likelihood-ratio method, and the Bayesian approach. We discuss and compare the above-mentioned methods over several phylogenetic trees, adding the maximum-parsimony method performance in the comparison. Under the assumption that the character evolves according a continuous-time Markov process, we compute and compare the expectations of success of each method for a broad range of model parameter values. Moreover, we show how the knowledge of the evolution model parameters allows to compute upper bounds of reconstruction performances, which are provided as references. The results of all these reconstruction methods are quite close one to another, and the expectations of success are not so far from their theoretical upper bounds. But the performance ranking heavily depends on the topology of the studied tree, on the ancestral node that is to be inferred and on the parameter values. Consequently, we propose a protocol providing for each parameter value the best method in terms of expectation of success, with regard to the phylogenetic tree and the ancestral node to infer. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Cosmogenic 10Be Dating of Early and Latest Holocene Moraines on Nevado Salcantay in the Southern Peruvian Andes

    Science.gov (United States)

    Licciardi, J. M.; Schaefer, J. M.; Lund, D. C.

    2007-12-01

    A two-fold sequence of nested lateral and end moraines was mapped in a glacial trough emanating from the southwest flank of Nevado Salcantay (6271 m; ~13°S latitude), the highest peak in the Cordillera Vilcabamba of southern Peru. The field area is situated 25 km due south of the archaeological site of Machu Picchu. Outer and inner moraines in the sequence were deposited by valley glaciers that terminated ~5 km and ~3 km, respectively, from their headwall on the Salcantay summit massif. Cosmogenic 10Be surface exposure dating of granitic boulders sampled on the Salcantay moraines is underway and has provided the first numerical ages for these deposits. Initial results indicate ages of 8.1 ± 0.1 10Be ka for the outer moraine and 200 ± 20 10Be years for the sharp-crested inner moraine. These ages are derived using the CRONUS-Earth 10Be exposure age calculator (version 2.0) and expressed with respect to the Lal- Stone production rate scaling scheme using the standard atmosphere. The outer and inner moraine ages correspond to glacial events during the early and latest Holocene, respectively. Further 10Be dating of the mapped moraines and similar deposits observed in adjacent drainages on Nevado Salcantay is anticipated to yield a high-resolution chronology of valley glaciation in this segment of the southern Peruvian Andes. The new results bridge an important gap between existing Andean glacier records to the north and south, and complement available ice core and lacustrine paleoclimate records in the vicinity, thereby expanding spatial and temporal coverage for identifying patterns of Holocene climate change in the tropical Andes. Notably, the inner moraine age correlates with the timing of the Little Ice Age as defined in northern mid- and high latitude glacier records, and suggests considerable expansion of valley glaciers in the southern Peruvian Andes during this climatic minimum. Apart from their paleoclimatic significance, the initial results also demonstrate

  18. The 12.1 ka Middle Toluca Pumice: A dacitic Plinian subplinian eruption of Nevado de Toluca in Central Mexico

    Science.gov (United States)

    Arce, J. L.; Cervantes, K. E.; Macías, J. L.; Mora, J. C.

    2005-10-01

    The Nevado de Toluca volcano erupted explosively approximately 12.1 ka ago, producing a Plinian-subplinian eruption that deposited the Middle Toluca Pumice (MTP). The MTP consists of white and gray juvenile pumice, gray dense juvenile lapilli, and red altered lithic lapilli. The pumice is dacitic (63.54-65.06 wt.% SiO 2) with phenocrysts of plagioclase > orthopyroxene > hornblende ± ilmenite and titanomagnetite, and biotite xenocrysts set in a groundmass of rhyolitic glass (70-71 wt.% SiO 2). The MTP has a dispersal axis to the ESE covering an area of 92 km 2, with a minimum volume of 1.8 km 3 (DRE). Stratigraphic relations, grain size, componentry, and vesicularity analyses suggest that the eruption occurred in five major phases: (1) an opening magmatic phase that generated a 20-km-high Plinian column dispersed to the SE; (2) a hydromagmatic explosion followed with the establishment of a subplinian eruptive column (18-19 km high) dispersed tephra to the SE and gradually waned; (3) hydromagmatic explosions emplaced dilute pyroclastic density currents followed by the formation of an eruptive column of unknown height; (4) immediately after, a new magmatic explosion established another eruptive column; and (5) the collapse of the latter column generated two pumiceous pyroclastic density currents that were fully dilute proximally, but transformed into two granular-fluid pyroclastic currents that traveled 19 km from the source.

  19. Buried palaeosols of the Nevado de Toluca: an alternative record of Late Quaternary environmental change in central Mexico

    Science.gov (United States)

    Sedov, Sergey; Solleiro-Rebolledo, Elizabeth; Gama-Castro, Jorge E.; Vallejo-Gómez, Ernestina; González-Velázquez, Arelia

    2001-05-01

    Buried palaeosols of central Mexico, not previously analysed from a palaeopedological standpoint, have helped to develop a reliable regional model of Late Quaternary climatic change. This paper focuses upon morphological and micromorphological properties, particle-size distribution, and extractable Fe, Al and Si of seven palaeosols (named PT1-PT7) in the vicinity of the Nevado de Toluca volcano. The characteristics of Andic Cambisol PT1, similar to those of modern soils in semi-arid environments, indicate a drier climate in the first half of the Holocene. Humic Andosols PT2-PT4 are analogous to modern volcanic soils of humid forest environments. They show evidence that a moist palaeoclimate prevailed during marine oxygen isotope stages (OIS) 2 and 3. Luvisols PT5 and PT6, which are assumed to have formed at the end of marine OIS 5 to marine OIS 4, also indicate humid conditions. We attribute the differences between Andosols PT2-PT4 and Luvisols PT5-PT7 to variations in the duration in the pedogenesis rather than to changes in palaeoclimate. Micromorphological features of Andosol to Luvisol transition confirm that these soils form an evolutionary sequence. Being for the most part consistent with lacustrine records, the palaeosol properties do not reflect the episodes of drier climate during the Last Glacial Maximum, however, as shown by diatom and palynological data from lake sediments. Mesoclimate variations and/or incompleteness of soil memory, reflecting mostly periods of humid pedogenesis, probably provide the reason for this disagreement.

  20. Diet of larval Ambystoma rivulare (Caudata: Ambystomatidae, a threatened salamander from the Volcán Nevado de Toluca, Mexico

    Directory of Open Access Journals (Sweden)

    Julio A. Lemos-Espinal

    2015-06-01

    Full Text Available Several species of salamander in the genus Ambystoma occur in the mountains surrounding Mexico City and are considered at risk of extinction. However, little is known about their ecology and natural history. The Toluca Stream Siredon (Ambystoma rivulare is classified as “Data Deficient” by the IUCN, and considered “Threatened” under Mexican law. From October 2013 to September 2014, we examined the diet of larval A. rivulare from a stream on the Volcán Nevado de Toluca in Mexico to provide insight into the suitability of the habitat to support this population of salamanders. Ostracods accounted for approximately 90% of all prey items consumed by larval A. rivulare. The number of ostracods found in stomachs increased with individual body size, but the proportion of ostracods in stomachs did not vary with body size. Nematodes were observed in approximately one third of the stomachs we examined. The diversity of prey in the diet of A. rivulare in the stream we studied is low and dominated by a single prey taxon, ostracods. Our results suggest that if environmental conditions in the stream change such that ostracods are negatively affected then the long-term persistence of this population of A. rivulare might be in jeopardy.

  1. Visual system evolution and the nature of the ancestral snake.

    Science.gov (United States)

    Simões, B F; Sampaio, F L; Jared, C; Antoniazzi, M M; Loew, E R; Bowmaker, J K; Rodriguez, A; Hart, N S; Hunt, D M; Partridge, J C; Gower, D J

    2015-07-01

    The dominant hypothesis for the evolutionary origin of snakes from 'lizards' (non-snake squamates) is that stem snakes acquired many snake features while passing through a profound burrowing (fossorial) phase. To investigate this, we examined the visual pigments and their encoding opsin genes in a range of squamate reptiles, focusing on fossorial lizards and snakes. We sequenced opsin transcripts isolated from retinal cDNA and used microspectrophotometry to measure directly the spectral absorbance of the photoreceptor visual pigments in a subset of samples. In snakes, but not lizards, dedicated fossoriality (as in Scolecophidia and the alethinophidian Anilius scytale) corresponds with loss of all visual opsins other than RH1 (λmax 490-497 nm); all other snakes (including less dedicated burrowers) also have functional sws1 and lws opsin genes. In contrast, the retinas of all lizards sampled, even highly fossorial amphisbaenians with reduced eyes, express functional lws, sws1, sws2 and rh1 genes, and most also express rh2 (i.e. they express all five of the visual opsin genes present in the ancestral vertebrate). Our evidence of visual pigment complements suggests that the visual system of stem snakes was partly reduced, with two (RH2 and SWS2) of the ancestral vertebrate visual pigments being eliminated, but that this did not extend to the extreme additional loss of SWS1 and LWS that subsequently occurred (probably independently) in highly fossorial extant scolecophidians and A. scytale. We therefore consider it unlikely that the ancestral snake was as fossorial as extant scolecophidians, whether or not the latter are para- or monophyletic. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  2. Ancestral Variations in the Shape and Size of the Zygoma.

    Science.gov (United States)

    Oettlé, Anna C; Demeter, Fabrice P; L'abbé, Ericka N

    2017-01-01

    The variable development of the zygoma, dictating its shape and size variations among ancestral groups, has important clinical implications and valuable anthropological and evolutionary inferences. The purpose of the study was to review the literature regarding the variations in the zygoma with ancestry. Ancestral variation in the zygoma reflects genetic variations because of genetic drift as well as natural selection and epigenetic changes to adapt to diet and climate variations with possible intensification by isolation. Prominence of the zygoma, zygomaxillary tuberosity, and malar tubercle have been associated with Eastern Asian populations in whom these features intensified. Prominence of the zygoma is also associated with groups from Eastern Europe and the rest of Asia. Diffusion of these traits occurred across the Behring Sea to the Arctic areas and to North and South America. The greatest zygomatic projections are exhibited in Arctic groups as an adaptation to extreme cold conditions, while Native South American groups also present with other features of facial robusticity. Groups from Australia, Malaysia, and Oceania show prominence of the zygoma to a certain extent, possibly because of archaic occupations by undifferentiated Southeast Asian populations. More recent interactions with Chinese groups might explain the prominent cheekbones noted in certain South African groups. Many deductions regarding evolutionary processes and diversifications of early groups have been made. Cognisance of these ancestral variations also have implications for forensic anthropological assessments as well as plastic and reconstructive surgery. More studies are needed to improve accuracy of forensic anthropological identification techniques. Anat Rec, 300:196-208, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Glacier melting during lava dome growth at Nevado de Toluca volcano (Mexico): Evidences of a major threat before main eruptive phases at ice-caped volcanoes

    Science.gov (United States)

    Capra, L.; Roverato, M.; Groppelli, G.; Caballero, L.; Sulpizio, R.; Norini, G.

    2015-03-01

    Nevado de Toluca volcano is one of the largest stratovolcanoes in the Trans-Mexican Volcanic Belt. During Late Pleistocene its activity was characterized by large dome growth and subsequent collapse emplacing large block and ash flow deposits, intercalated by Plinian eruptions. Morphological and paleoclimate studies at Nevado de Toluca and the surrounding area evidenced that the volcano was affected by extensive glaciation during Late Pleistocene and Holocene. During the older recognized glacial period (27-60 ka, MIS 3), the glacier was disturbed by the intense magmatic and hydrothermal activity related to two dome extrusion episodes (at 37 ka and 28 ka). Glacier reconstruction indicates maximum ice thickness of 90 m along main valleys, as at the Cano ravines, the major glacial valley on the northern slope of the volcano. Along this ravine, both 37 and 28 ka block-and-ash deposits are exposed, and they directly overlay a fluviatile sequence, up to 40 m-thick, which 14C ages clearly indicate that their emplacement occurred just before the dome collapsed. These evidences point to a clear interaction between the growing dome and its hydrothermal system with the glacier. During dome growth, a large amount of melting water was released along major glacial valleys forming thick fluvioglacial sequences that were subsequently covered by the block-and-ash flow deposits generated by the collapse of the growing dome. Even though this scenario is no longer possible at the Nevado de Toluca volcano, the data presented here indicate that special attention should be paid to the possible inundation areas from fluviatile/lahar activity prior to the main magmatic eruption at ice-capped volcanoes.

  4. Evaluación hidrológica de la subcuenca alta del río Chinchiná

    OpenAIRE

    Franco Villegas, Ana María

    2001-01-01

    La subcuenca alta del Río Chinchiná es una de las de mayor importancia en el Departamento de Caldas, por pertenecer a una región que se define como ecosistema estratégico productor de recursos naturales, como es el Parque Nacional Natural de Los Nevados, y además por contribuir a soportar la mayor población a escala regional establecida sobre la Cuenca del Río Chinchiná. El presente estudio incluye un aporte al conocimiento de las características físicas territoriales de la región, y en d...

  5. Using Resurrected Ancestral Proviral Proteins to Engineer Virus Resistance.

    Science.gov (United States)

    Delgado, Asunción; Arco, Rocio; Ibarra-Molero, Beatriz; Sanchez-Ruiz, Jose M

    2017-05-09

    Proviral factors are host proteins hijacked by viruses for processes essential for virus propagation such as cellular entry and replication. Pathogens and their hosts co-evolve. It follows that replacing a proviral factor with a functional ancestral form of the same protein could prevent viral propagation without fatally compromising organismal fitness. Here, we provide proof of concept of this notion. Thioredoxins serve as general oxidoreductases in all known cells. We report that several laboratory resurrections of Precambrian thioredoxins display substantial levels of functionality within Escherichia coli. Unlike E. coli thioredoxin, however, these ancestral thioredoxins are not efficiently recruited by the bacteriophage T7 for its replisome and therefore prevent phage propagation in E. coli. These results suggest an approach to the engineering of virus resistance. Diseases caused by viruses may have a devastating effect in agriculture. We discuss how the suggested approach could be applied to the engineering of plant virus resistance. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. Reconstruction of ancestral RNA sequences under multiple structural constraints

    Directory of Open Access Journals (Sweden)

    Olivier Tremblay-Savard

    2016-11-01

    Full Text Available Abstract Background Secondary structures form the scaffold of multiple sequence alignment of non-coding RNA (ncRNA families. An accurate reconstruction of ancestral ncRNAs must use this structural signal. However, the inference of ancestors of a single ncRNA family with a single consensus structure may bias the results towards sequences with high affinity to this structure, which are far from the true ancestors. Methods In this paper, we introduce achARNement, a maximum parsimony approach that, given two alignments of homologous ncRNA families with consensus secondary structures and a phylogenetic tree, simultaneously calculates ancestral RNA sequences for these two families. Results We test our methodology on simulated data sets, and show that achARNement outperforms classical maximum parsimony approaches in terms of accuracy, but also reduces by several orders of magnitude the number of candidate sequences. To conclude this study, we apply our algorithms on the Glm clan and the FinP-traJ clan from the Rfam database. Conclusions Our results show that our methods reconstruct small sets of high-quality candidate ancestors with better agreement to the two target structures than with classical approaches. Our program is freely available at: http://csb.cs.mcgill.ca/acharnement .

  7. Reconstruction of ancestral RNA sequences under multiple structural constraints.

    Science.gov (United States)

    Tremblay-Savard, Olivier; Reinharz, Vladimir; Waldispühl, Jérôme

    2016-11-11

    Secondary structures form the scaffold of multiple sequence alignment of non-coding RNA (ncRNA) families. An accurate reconstruction of ancestral ncRNAs must use this structural signal. However, the inference of ancestors of a single ncRNA family with a single consensus structure may bias the results towards sequences with high affinity to this structure, which are far from the true ancestors. In this paper, we introduce achARNement, a maximum parsimony approach that, given two alignments of homologous ncRNA families with consensus secondary structures and a phylogenetic tree, simultaneously calculates ancestral RNA sequences for these two families. We test our methodology on simulated data sets, and show that achARNement outperforms classical maximum parsimony approaches in terms of accuracy, but also reduces by several orders of magnitude the number of candidate sequences. To conclude this study, we apply our algorithms on the Glm clan and the FinP-traJ clan from the Rfam database. Our results show that our methods reconstruct small sets of high-quality candidate ancestors with better agreement to the two target structures than with classical approaches. Our program is freely available at: http://csb.cs.mcgill.ca/acharnement .

  8. Evaluación de los bosques templados en México: una aplicación en el Parque Nacional Nevado de Toluca

    OpenAIRE

    Lourdes Villers Ruíz; Laura García del Valle; Jorge López Blanco

    1998-01-01

    Con base en un análisis de fotointerpretación y de evaluación botánica de sitios, se propone una metodología expedita que permita conocer las características generales de los bosques templados en México. La metodología fue aplicada en el parque nacional Nevado de Toluca. Se determinaron tres comunidades de bosque: a) de Pinus hartwegu. b) de Abies religiosa y c) mixto Abies religiosa. Alnas jorullensis, P pseudostrobus y P hartwegii Para cada comunidad se definieron por fotointerpretación tre...

  9. Comments on cladocerans of crater lakes of the Nevado de Toluca Volcano (Central Mexico), with the description of a new species, Alona manueli sp. nov.

    Science.gov (United States)

    Sinev, Artem Y; Zawisza, Edyta

    2013-01-01

    Cladoceran communities of two lakes of Nevado de Toluca Volcano, Central Mexico, were studied. A new species of Aloninae, Alona manueli sp. nov., is described. It was previously confused with Palearctic Alona intermedia Sars, 1862, but clearly differs from it in the morphology of postabdomen, head shield and head pores, and thoracic limbs. Position of Alona manueli sp. nov. within the genus is unclear, it did not belong to any species-group within Alona s. lato. Other species recorded in the studied lakes are Alona ossiani Sinev, 1998, Alonella pulchella Herrick, 1884, Chydorus belonging to sphaericus-group, Eurycercus longirostris Hann, 1982 and Pleuroxus cf. denticulatus Birge, 1879.

  10. Tectonic evolution of the central-eastern sector of Trans Mexican Volcanic Belt and its influence on the eruptive history of the Nevado de Toluca volcano (Mexico)

    Science.gov (United States)

    Bellotti, F.; Capra, L.; Groppelli, G.; Norini, G.

    2006-11-01

    The Nevado de Toluca is an andesitic to dacitic stratovolcano of Late Pliocene-Holocene age located within the central and eastern sectors of the Trans Mexican Volcanic Belt. Morphostructural analysis, aerial photograph and satellite image interpretation, structural analysis and geological fieldwork were methods used to investigate the relationship between the evolution of the volcano and the tectonic framework of its basement. The study revealed that the area of Nevado de Toluca is affected by three main fault systems that intersect close to the volcanic edifice. These are from oldest to youngest, the Taxco-Querétaro, San Antonio and Tenango fault systems. The NNW-SSE Taxco-Querétaro fault system was active in the area since Early Miocene, and is characterized by right-lateral transtensive movement. Its reactivation during Early to Middle Pleistocene was responsible for the emplacement of andesitic to dacitic lava flows and domes of La Cieneguilla Supersynthem. The NE-SW San Antonio fault system was active during Late Pliocene, before the reactivation of the Taxco-Querétaro fault system, and is characterized by extensional left-lateral oblique-slip kinematics. The youngest is the E-W Tenango fault system that has been active since Late Pleistocene. This fault system is characterized by transtensive left-lateral strike-slip movement, and partly coeval with the youngest eruptive phase, the Nevado Supersynthem, which formed the present summit cone of the Nevado de Toluca volcano. The stress re-orientation from the Taxco-Querétaro to the Tenango fault system during Late Pleistocene is responsible for the ˜ 1 Ma hiatus in the magmatic activity between 1.15 Ma and 42 ka. After this period of repose, the eruptive style drastically changed from effusive to explosive with the emission of dacitic products. The methodology presented here furnish new data that can be used to better assess the complex structural evolution of this sector of the Trans Mexican Volcanic Belt

  11. Geostatistics and multivariate analysis as a tool to characterize volcaniclastic deposits: Application to Nevado de Toluca volcano, Mexico

    Science.gov (United States)

    Bellotti, F.; Capra, L.; Sarocchi, D.; D'Antonio, M.

    2010-03-01

    Grain size analysis of volcaniclastic deposits is mainly used to study flow transport and depositional processes, in most cases by comparing some statistical parameters and how they change with distance from the source. In this work the geospatial and multivariate analyses are presented as a strong adaptable geostatistical tool applied to volcaniclastic deposits in order to provide an effective and relatively simple methodology for texture description, deposit discrimination and interpretation of depositional processes. We choose the case of Nevado de Toluca volcano (Mexico) due to existing knowledge of its geological evolution, stratigraphic succession and spatial distribution of volcaniclastic units. Grain size analyses and frequency distribution curves have been carried out to characterize and compare the 28-ka block-and-ash flow deposit associated to a dome destruction episode, and the El Morral debris avalanche deposit originated from the collapse of the south-eastern sector of the volcano. The geostatistical interpolation of sedimentological data allows to realize bidimensional maps draped over the volcano topography, showing the granulometric distribution, sorting and fine material concentration into the whole deposit with respect to topographic changes. In this way, it is possible to analyze a continuous surface of the grain size distribution of volcaniclastic deposits and better understand flow transport processes. The application of multivariate statistic analysis (discriminant function) indicates that this methodology could be useful in discriminating deposits with different origin or different depositional lithofacies within the same deposit. The proposed methodology could be an interesting approach to sustain more classical analysis of volcaniclastic deposits, especially where a clear field classification appears problematic because of a homogeneous texture of the deposits or their scarce and discontinuous outcrops. Our study is an example of the

  12. The 13 ka Pelée-Type Dome Collapse at Nevado de Toluca Volcano, México.

    Science.gov (United States)

    D'Antonio, M.; Capra, L.; Sarocchi, D.; Bellotti, F.

    2007-05-01

    The Nevado de Toluca is an active volcano located in the central sector of the Trans-Mexican Volcanic Belt, 80 km southwest of Mexico City. Activity at this andesitic to dacitic stratovolcano began ca. 2.6 Ma ago. During the last 42 ka, the volcano has been characterized by different eruptive styles, including five dome collapses dated at 37, 32, 28, 26, and 13 ka and five Plinian eruptions at 42 ka, 36 ka, 21.7 ka, 12.1 ka and 10.5 ka. The 13 ka dome collapse is the youngest event of this type, and originated a 0.11 km3 block-and-ash flow deposit on the north-eastern sector of the volcano. The deposit consists of two facies: channel-like, 10 m thick, monolitologic, that is composed of up to five units, with decimetric dacitic clasts set in a sandy matrix; and a lateral facies that consists of a gray, sandy horizon, up to 4 m thick, with a 30 cm-thick surge layer at the base. The main component is a dacitic lava, with different degree of vesciculation, with mineral association of Pl-Hbl-Opx. Plagioclases show two different textures: in equilibrium, with normal zoning (core = An37-64.3, rim = An30.7-45.8) or with spongy cellular texture with inverse zoning (core = An38-43.5, rim = An45-51.2). Hornblende is normally light green, barren of oxidation. The rock matrix contains up to 53 perc. of glass with abundant microlites, indicating over-pressure on the crystallizing magma and a rapid expulsion. All these stratigraphic and petrographic features indicate that the dome was quickly extruded on the summit of the volcano, probably triggered by a magma mixing process, and its collapse was accompanied by an explosive component, being classified as a Pelée-type event.

  13. Resurrecting ancestral genes in bacteria to interpret ancient biosignatures

    Science.gov (United States)

    Kacar, Betul; Guy, Lionel; Smith, Eric; Baross, John

    2017-11-01

    Two datasets, the geologic record and the genetic content of extant organisms, provide complementary insights into the history of how key molecular components have shaped or driven global environmental and macroevolutionary trends. Changes in global physico-chemical modes over time are thought to be a consistent feature of this relationship between Earth and life, as life is thought to have been optimizing protein functions for the entirety of its approximately 3.8 billion years of history on the Earth. Organismal survival depends on how well critical genetic and metabolic components can adapt to their environments, reflecting an ability to optimize efficiently to changing conditions. The geologic record provides an array of biologically independent indicators of macroscale atmospheric and oceanic composition, but provides little in the way of the exact behaviour of the molecular components that influenced the compositions of these reservoirs. By reconstructing sequences of proteins that might have been present in ancient organisms, we can downselect to a subset of possible sequences that may have been optimized to these ancient environmental conditions. How can one use modern life to reconstruct ancestral behaviours? Configurations of ancient sequences can be inferred from the diversity of extant sequences, and then resurrected in the laboratory to ascertain their biochemical attributes. One way to augment sequence-based, single-gene methods to obtain a richer and more reliable picture of the deep past, is to resurrect inferred ancestral protein sequences in living organisms, where their phenotypes can be exposed in a complex molecular-systems context, and then to link consequences of those phenotypes to biosignatures that were preserved in the independent historical repository of the geological record. As a first step beyond single-molecule reconstruction to the study of functional molecular systems, we present here the ancestral sequence reconstruction of the

  14. Computational analysis and functional expression of ancestral copepod luciferase.

    Science.gov (United States)

    Takenaka, Yasuhiro; Noda-Ogura, Akiko; Imanishi, Tadashi; Yamaguchi, Atsushi; Gojobori, Takashi; Shigeri, Yasushi

    2013-10-10

    We recently reported the cDNA sequences of 11 copepod luciferases from the superfamily Augaptiloidea in the order Calanoida. They were classified into two groups, Metridinidae and Heterorhabdidae/Lucicutiidae families, by phylogenetic analyses. To elucidate the evolutionary processes, we have now further isolated 12 copepod luciferases from Augaptiloidea species (Metridia asymmetrica, Metridia curticauda, Pleuromamma scutullata, Pleuromamma xiphias, Lucicutia ovaliformis and Heterorhabdus tanneri). Codon-based synonymous/nonsynonymous tests of positive selection for 25 identified copepod luciferases suggested that positive Darwinian selection operated in the evolution of Heterorhabdidae luciferases, whereas two types of Metridinidae luciferases had diversified via neutral mechanism. By in silico analysis of the decoded amino acid sequences of 25 copepod luciferases, we inferred two protein sequences as ancestral copepod luciferases. They were expressed in HEK293 cells where they exhibited notable luciferase activity both in intracellular lysates and cultured media, indicating that the luciferase activity was established before evolutionary diversification of these copepod species. © 2013.

  15. Morphological analysis of Nevado de Toluca volcano (Mexico): new insights into the structure and evolution of an andesitic to dacitic stratovolcano

    Science.gov (United States)

    Norini, Gianluca; Groppelli, Gianluca; Capra, Lucia; De Beni, Emanuela

    2004-09-01

    We present a morphological analysis of Nevado de Toluca volcano located 80 km WSW of Mexico City based on digital elevation model study, where slope and aspect maps have been generated and analysed. Aerial photograph and satellite image observations improve the morphological analysis. The synoptic view which is offered by this analysis allowed for recognition and localization of the main volcanic and tectonic features of the area. On the basis of digital elevation model value distribution and surface textures, five morphological domains were defined. The most interesting domain, south of the crater, reflects the occurrence of an ancient complex volcano distinct from the adjacent areas. Interaction between the volcanic and volcano-tectonic evolution and the basement produced the other domains. Single volcanic edifices, like lava domes and scoria cones, and eruptive fractures were recognized. Finally, flank collapse scarps opened to the east and to the north were identified and four relevant morphostructural lineaments and their possible role in the Nevado de Toluca geological and structural evolution are discussed.

  16. Ancestral dichlorodiphenyltrichloroethane (DDT) exposure promotes epigenetic transgenerational inheritance of obesity

    Science.gov (United States)

    2013-01-01

    Background Ancestral environmental exposures to a variety of environmental factors and toxicants have been shown to promote the epigenetic transgenerational inheritance of adult onset disease. The present work examined the potential transgenerational actions of the insecticide dichlorodiphenyltrichloroethane (DDT) on obesity and associated disease. Methods Outbred gestating female rats were transiently exposed to a vehicle control or DDT and the F1 generation offspring bred to generate the F2 generation and F2 generation bred to generate the F3 generation. The F1 and F3 generation control and DDT lineage rats were aged and various pathologies investigated. The F3 generation male sperm were collected to investigate methylation between the control and DDT lineage male sperm. Results The F1 generation offspring (directly exposed as a fetus) derived from the F0 generation exposed gestating female rats were not found to develop obesity. The F1 generation DDT lineage animals did develop kidney disease, prostate disease, ovary disease and tumor development as adults. Interestingly, the F3 generation (great grand-offspring) had over 50% of males and females develop obesity. Several transgenerational diseases previously shown to be associated with metabolic syndrome and obesity were observed in the testis, ovary and kidney. The transgenerational transmission of disease was through both female (egg) and male (sperm) germlines. F3 generation sperm epimutations, differential DNA methylation regions (DMR), induced by DDT were identified. A number of the genes associated with the DMR have previously been shown to be associated with obesity. Conclusions Observations indicate ancestral exposure to DDT can promote obesity and associated disease transgenerationally. The etiology of disease such as obesity may be in part due to environmentally induced epigenetic transgenerational inheritance. PMID:24228800

  17. Palaeohistological Evidence for Ancestral High Metabolic Rate in Archosaurs.

    Science.gov (United States)

    Legendre, Lucas J; Guénard, Guillaume; Botha-Brink, Jennifer; Cubo, Jorge

    2016-11-01

    Metabolic heat production in archosaurs has played an important role in their evolutionary radiation during the Mesozoic, and their ancestral metabolic condition has long been a matter of debate in systematics and palaeontology. The study of fossil bone histology provides crucial information on bone growth rate, which has been used to indirectly investigate the evolution of thermometabolism in archosaurs. However, no quantitative estimation of metabolic rate has ever been performed on fossils using bone histological features. Moreover, to date, no inference model has included phylogenetic information in the form of predictive variables. Here we performed statistical predictive modeling using the new method of phylogenetic eigenvector maps on a set of bone histological features for a sample of extant and extinct vertebrates, to estimate metabolic rates of fossil archosauromorphs. This modeling procedure serves as a case study for eigenvector-based predictive modeling in a phylogenetic context, as well as an investigation of the poorly known evolutionary patterns of metabolic rate in archosaurs. Our results show that Mesozoic theropod dinosaurs exhibit metabolic rates very close to those found in modern birds, that archosaurs share a higher ancestral metabolic rate than that of extant ectotherms, and that this derived high metabolic rate was acquired at a much more inclusive level of the phylogenetic tree, among non-archosaurian archosauromorphs. These results also highlight the difficulties of assigning a given heat production strategy (i.e., endothermy, ectothermy) to an estimated metabolic rate value, and confirm findings of previous studies that the definition of the endotherm/ectotherm dichotomy may be ambiguous. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. PRÁCTICAS SOSTENIBLES BASADAS EN EL CONOCIMIENTO ANCESTRAL Y LA TECNOLOGÍA. APLICACIÓN EN EL CULTIVO DE MAÍZ

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    Tony JinsopYangüés Pappa

    2012-11-01

    Full Text Available Este trabajo fue desarrollado en la microcuenca Membrillo del cantón Bolívar, provincia de Manabí, su objetivo fue incrementar la productividad del cultivo de maíz aplicando prácticas sostenibles basadas en el conocimiento ancestral y la tecnología. Para lograr el objetivo propuesto se realizó un Diagnóstico Rural Participativo (DRP y se aplicaron las Metodologías de Escuelas de Aprendizaje (ERAs. Entre los principales resultados obtenidos se destacan el incremento de la productividad promedio del cultivo del maíz a 120 qq/ha con prácticas alternativas sostenibles basadas en el conocimiento ancestral y la tecnología en las comunidades donde se aplicaron las experiencias, alcanzando estas mayores ingresos que satisfacen las necesidades de los productores y consecuentemente se logró reducir la presión hacia los bosques por la producción intensiva alcanzada. Se capacitaron a los agricultores involucrados en técnicas de elaboración de bioinsumos que se utilizaron para la producción de maíz, alternativas para el manejo técnico sostenible y amigable con el ambiente en este cultivo. También se demostró que las prácticas implementadas en el desarrollo de este trabajo contribuyen al desarrollo sostenible de la Microcuenca Membrillo.

  19. COMPONENTES NUTRICIONALES Y ANTIOXIDANTES DE DOS ESPECIES DE GUAJE (Leucaena spp.: UN RECURSO ANCESTRAL SUBUTILIZADO

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    Nallely Román-Cortés

    2014-01-01

    Full Text Available El guaje ( Leucaena spp. es una planta de vaina y semillas comestibles, un recurso ancestral subutilizado por los pueblos mesoamericanos. El valor nutricional y nutracéutico del guaje se desconoce pese a su consumo vigente en las poblaciones rurales. El objetivo de este trabajo fue evaluar el contenido de minerales, compo - nentes nutricionales y antioxidantes para contribuir a la revalorización alimentaria del guaje rojo ( L. esculenta Benth. y verde ( L. leucocephala Lam.. Los contenidos de antocianinas, flavonoides, fenoles totales, taninos y actividad antioxidante se cuantificaron, así como la composición proximal y mineral. Las semillas de guaje rojo superaron a las de guaje verde en los contenidos de N, Mg, Mn, P y Zn; en contraste, las semillas de guaje verde presentaron niveles mayores de Na y de Fe. El contenido de fibra cruda fue 10.55 y 10.07 % en guaje rojo y verde, respectivamente, mientras que el de proteína fue 33.12 % en guaje rojo y 31.7 % en el verde. El alto contenido de compuestos fenólicos fue mayor en las semillas frescas de guaje rojo (1,088.70 mg equivalentes de ácido gálico [EAG]·100 g -1 p. f. que en las verdes (969.09 mg EAG·100 g -1 p. f., pero las últimas presen - taron mayor cantidad de taninos. La elevada actividad secuestradora de radicales libres (97.22 a 98.11 % obtenida por el método ABTS ( á cido 2,2’-azino-bis(3-etilben-zotiazolin-6-sulfónico, puede estar asociada al contenido de compuestos fenólicos. En conclusión, las semillas de guaje podrían considerarse un alimento funcional, principalmente las de guaje rojo debido a su calidad nutricional y mayor actividad antioxidante.

  20. Estimation of the ancestral effective population sizes of African great apes under different selection regimes.

    Science.gov (United States)

    Schrago, Carlos G

    2014-08-01

    Reliable estimates of ancestral effective population sizes are necessary to unveil the population-level phenomena that shaped the phylogeny and molecular evolution of the African great apes. Although several methods have previously been applied to infer ancestral effective population sizes, an analysis of the influence of the selective regime on the estimates of ancestral demography has not been thoroughly conducted. In this study, three independent data sets under different selective regimes were used were composed to tackle this issue. The results showed that selection had a significant impact on the estimates of ancestral effective population sizes of the African great apes. The inference of the ancestral demography of African great apes was affected by the selection regime. The effects, however, were not homogeneous along the ancestral populations of great apes. The effective population size of the ancestor of humans and chimpanzees was more impacted by the selection regime when compared to the same parameter in the ancestor of humans, chimpanzees and gorillas. Because the selection regime influenced the estimates of ancestral effective population size, it is reasonable to assume that a portion of the discrepancy found in previous studies that inferred the ancestral effective population size may be attributable to the differential action of selection on the genes sampled.

  1. The rain-triggered Atenquique volcaniclastic debris flow of October 16, 1955 at Nevado de Colima Volcano, Mexico

    Science.gov (United States)

    Saucedo, R.; Macías, J. L.; Sarocchi, D.; Bursik, M.; Rupp, B.

    2008-06-01

    On October 16, 1955, at 10:45 a.m. (local time), after three days of intense rain (140 mm) that was twice the monthly average precipitation, a devastating flood surge formed a volcaniclastic debris flow on the eastern slopes of Nevado de Colima Volcano. Nearly simultaneous flood surges formed in the Arroyo Seco, Los Platanos, and Dos Volcanes ravines that coalesced with the larger flow in the Atenquique ravine. At each confluence with a tributary, the flow was diluted. The texture and structure of the preserved 1955 deposits near high water marks indicate that the downstream flow was mainly in the lower range of debris flow concentration (60% sediment concentration by weight). Downstream the tributaries, the flood encountered a ˜ 0.06 × 10 6 m 3 water reservoir that failed, significantly increasing the surge volume. Additional entrained sediment also increased the flow volume. Downstream, the flood wave reached the town of Atenquique as an 8-9 m catastrophic wave causing the death of more than 23 people, the partial destruction of the town, and losses of ˜ 13,000,000 pesos (˜ 1 million US dollars today) to a paper mill and company facilities. According to eyewitness accounts the flood wave had a peak discharge that lasted ca. 10 to 15 minutes at Atenquique. Deposits at the site and the high-water marks observed from photographs of the town's church indicate that sediment concentration was ca. 60 wt.%. The flood continued for about 1 km to its junction with the Tuxpan River where it was diluted by mixing with normal flood flow. The deposits covered an area of ˜ 1.2 km 2 and had a minimum volume of ˜ 3.2 × 10 6 m 3. The main deposit consists of a single unit, averaging 4 m in thickness, with weak textural variations that suggest surging within the flood wave. The deposit is heterolithologic and consists of boulders set in a matrix of sand-size sediment, with polymodal or bimodal distributions and normal grading varying with distance from source. The town of

  2. Inference of Ancestral Recombination Graphs through Topological Data Analysis

    Science.gov (United States)

    Cámara, Pablo G.; Levine, Arnold J.; Rabadán, Raúl

    2016-01-01

    The recent explosion of genomic data has underscored the need for interpretable and comprehensive analyses that can capture complex phylogenetic relationships within and across species. Recombination, reassortment and horizontal gene transfer constitute examples of pervasive biological phenomena that cannot be captured by tree-like representations. Starting from hundreds of genomes, we are interested in the reconstruction of potential evolutionary histories leading to the observed data. Ancestral recombination graphs represent potential histories that explicitly accommodate recombination and mutation events across orthologous genomes. However, they are computationally costly to reconstruct, usually being infeasible for more than few tens of genomes. Recently, Topological Data Analysis (TDA) methods have been proposed as robust and scalable methods that can capture the genetic scale and frequency of recombination. We build upon previous TDA developments for detecting and quantifying recombination, and present a novel framework that can be applied to hundreds of genomes and can be interpreted in terms of minimal histories of mutation and recombination events, quantifying the scales and identifying the genomic locations of recombinations. We implement this framework in a software package, called TARGet, and apply it to several examples, including small migration between different populations, human recombination, and horizontal evolution in finches inhabiting the Galápagos Islands. PMID:27532298

  3. Mitochondrial introgression suggests extensive ancestral hybridization events among Saccharomyces species.

    Science.gov (United States)

    Peris, David; Arias, Armando; Orlić, Sandi; Belloch, Carmela; Pérez-Través, Laura; Querol, Amparo; Barrio, Eladio

    2017-03-01

    Horizontal gene transfer (HGT) in eukaryotic plastids and mitochondrial genomes is common, and plays an important role in organism evolution. In yeasts, recent mitochondrial HGT has been suggested between S. cerevisiae and S. paradoxus. However, few strains have been explored given the lack of accurate mitochondrial genome annotations. Mitochondrial genome sequences are important to understand how frequent these introgressions occur, and their role in cytonuclear incompatibilities and fitness. Indeed, most of the Bateson-Dobzhansky-Muller genetic incompatibilities described in yeasts are driven by cytonuclear incompatibilities. We herein explored the mitochondrial inheritance of several worldwide distributed wild Saccharomyces species and their hybrids isolated from different sources and geographic origins. We demonstrated the existence of several recombination points in mitochondrial region COX2-ORF1, likely mediated by either the activity of the protein encoded by the ORF1 (F-SceIII) gene, a free-standing homing endonuclease, or mostly facilitated by A+T tandem repeats and regions of integration of GC clusters. These introgressions were shown to occur among strains of the same species and among strains of different species, which suggests a complex model of Saccharomyces evolution that involves several ancestral hybridization events in wild environments. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Time-Dependent-Asymmetric-Linear-Parsimonious Ancestral State Reconstruction.

    Science.gov (United States)

    Didier, Gilles

    2017-10-01

    The time-dependent-asymmetric-linear parsimony is an ancestral state reconstruction method which extends the standard linear parsimony (a.k.a. Wagner parsimony) approach by taking into account both branch lengths and asymmetric evolutionary costs for reconstructing quantitative characters (asymmetric costs amount to assuming an evolutionary trend toward the direction with the lowest cost). A formal study of the influence of the asymmetry parameter shows that the time-dependent-asymmetric-linear parsimony infers states which are all taken among the known states, except for some degenerate cases corresponding to special values of the asymmetry parameter. This remarkable property holds in particular for the Wagner parsimony. This study leads to a polynomial algorithm which determines, and provides a compact representation of, the parametric reconstruction of a phylogenetic tree, that is for all the unknown nodes, the set of all the possible reconstructed states associated with the asymmetry parameters leading to them. The time-dependent-asymmetric-linear parsimony is finally illustrated with the parametric reconstruction of the body size of cetaceans.

  5. Ancestral gene reconstruction and synthesis of ancient rhodopsins in the laboratory.

    Science.gov (United States)

    Chang, Belinda S W

    2003-08-01

    Laboratory synthesis of ancestral proteins offers an intriguing opportunity to study the past directly. The development of Bayesian methods to infer ancestral sequences, combined with advances in models of molecular evolution, and synthetic gene technology make this an increasingly promising approach in evolutionary studies of molecular function. Visual pigments form the first step in the biochemical cascade of events in the retina in all animals known to possess visual capabilities. In vertebrates, the necessity of spanning a dynamic range of light intensities of many orders of magnitude has given rise to two different types of photoreceptors, rods specialized for dim-light conditions, and cones for daylight and color vision. These photoreceptors contain different types of visual pigment genes. Reviewed here are methods of inferring ancestral sequences, chemical synthesis of artificial ancestral genes in the laboratory, and applications to the evolution of vertebrate visual systems and the experimental recreation of an archosaur rod visual pigment. The ancestral archosaurs gave rise to several notable lineages of diapsid reptiles, including the birds and the dinosaurs, and would have existed over 200 MYA. What little is known of their physiology comes from fossil remains, and inference based on the biology of their living descendants. Despite its age, an ancestral archosaur pigment was successfully recreated in the lab, and showed interesting properties of its wavelength sensitivity that may have implications for the visual capabilities of the ancestral archosaurs in dim light.

  6. Characterization of Reconstructed Ancestral Proteins Suggests a Change in Temperature of the Ancient Biosphere.

    Science.gov (United States)

    Akanuma, Satoshi

    2017-08-06

    Understanding the evolution of ancestral life, and especially the ability of some organisms to flourish in the variable environments experienced in Earth's early biosphere, requires knowledge of the characteristics and the environment of these ancestral organisms. Information about early life and environmental conditions has been obtained from fossil records and geological surveys. Recent advances in phylogenetic analysis, and an increasing number of protein sequences available in public databases, have made it possible to infer ancestral protein sequences possessed by ancient organisms. However, the in silico studies that assess the ancestral base content of ribosomal RNAs, the frequency of each amino acid in ancestral proteins, and estimate the environmental temperatures of ancient organisms, show conflicting results. The characterization of ancestral proteins reconstructed in vitro suggests that ancient organisms had very thermally stable proteins, and therefore were thermophilic or hyperthermophilic. Experimental data supports the idea that only thermophilic ancestors survived the catastrophic increase in temperature of the biosphere that was likely associated with meteorite impacts during the early history of Earth. In addition, by expanding the timescale and including more ancestral proteins for reconstruction, it appears as though the Earth's surface temperature gradually decreased over time, from Archean to present.

  7. Evaluación de los bosques templados en México: una aplicación en el Parque Nacional Nevado de Toluca

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    Lourdes Villers Ruíz

    1998-01-01

    Full Text Available Based on In a photonterpretation and fieldwork analysis a méthodologie procedure to characterize the temperate forests in Mexico is proposed The methodology was applied in the Nevado de Toluca National Park, Three forest communities were determined; a Pinus hartwegii. b Abies religiosa and ci mixed: Abies religiosa, Alnus jorullensis. P pseudostrobus and P. hartwegii. For each community three types of covering density were delineated. Remarkable differences between number of trees, height and cover, with regard to the different density types and the three forest types were found. From dominant species analysis, subdominants species and covering percentage of the fieldwork sampling sites suggested more richness in the Abies and mixed forests than in the Pmus forests. Several impact levels caused by human activities exist: logging (mainly in Abies forest, in Pinus forests deliberately fires for grass-induced. The presence of Lipmus montanus and Penstemon gentienoides can be used as disturbed indicators.

  8. The nevado-filábride complex in the western part of Sierra de los Filabres (Betic Internal Zone), structure and lithologic succession

    Energy Technology Data Exchange (ETDEWEB)

    Sanz de Galdeano, C.; López Garrido, A.

    2016-07-01

    In the western part of Sierra de los Filabres (in the Nevado-Filábride Complex, within the Betic Internal Zone) several tectonic units have been described, in varying numbers depending on the author describing them. However, new cartographical data show that the limits of these units pass through the lithological formations without displacing them. Moreover, the rocks belonging to some units that are supposedly situated in a lower tectonic position really belong to higher formations. From bottom to top, these lithological formations are the following: (1) dark schists and quartzites; (2) quartzites, sandstones, sands, lutites, schists, and mica schists; (3) schists; (4) marbles, schists, and mica schists. High-angle reverse faults are associated with the great E-W anticline of Sierra de los Filabres. The existence of sands and apparent lutites visibly interlayered between rocks, such as schists and mica schists with garnets, poses a metamorphic problem that has not as yet been addressed. (Author)

  9. Reconstruction of Equilibrium Line Altitudes of Nevado Coropuna Glaciers (Southern Peru) from the Late Pleistocene to the present

    Science.gov (United States)

    Úbeda, J.; Palacios, D.; Vázquez, L.

    2009-04-01

    The Nevado Coropuna (15°31'S-72°39'W) is a volcanic complex located 200 km NE of the city of Arequipa, in the Southern Peruvian Andes. The summit area in the complex is covered with a glacier system formed by dozens of branches descending in all directions totaling many km2 in surface area. The study of the volcanic complex and its glaciers is of great interest because it is the main water reserve for tens of thousands of people, because of the risk scenario created by the presence of ice masses on a volcano with relatively recent activity, and because it constitutes an excellent geoindicator of the effects of climate change on ice masses in the western mountain chain of the Central Andes. This research aims to analyze glacier evolution using as geoindicators variations in glacier surface and equilibrium line altitudes (ELAs), defining deglaciation rates based on those variations and preparing forecasts with them on when the ice masses might disappear if the same rates were to occur in the future. In addition, a first estimation is attempted of the chronologies of the last phase of volcanic activity and the last phase of maximum glacier advance that can be attributed to the Late Glacial or Last Glacial Maximum periods. To achieve these aims, digital topography with 50m contour interval, two orthophotos of the central section of the Coropuna complex (15-6-1955 and 21-10-1986), an ASTER satellite image (12-11-2007) and geomorphological mapping of the volcanic complex created in a previous phase of the research (Ubeda, 2007) were integrated into a Geographical Information System (GIS). The GIS was used to determine the global extent of the glacier system, and in more detail, that of two groups (NE and SE) in 1955, 1986 and 2007. Using the geomorphological cartography as a basis, the extent of the glaciers during their last advance in the Little Ice Age (LIA) and their last maximum advance were calculated. Next, surface areas for all phases were calculated using

  10. The 21,700 yr b.p. Lower Toluca Pumice Plinian Eruption of Nevado de Toluca Volcano (Mexico): Evidences of Magma Mixing Process as Triggering Mechanism.

    Science.gov (United States)

    Capra, L.; Arce, J.; Macias, J.

    2006-05-01

    Approximately 21,700 yr B.P., after a period of quiescence of 4800 yr, Nevado de Toluca volcano erupted, producing the Lower Toluca Pumice deposit. The activity generated a 24-km-high Plinian column that lasted ~11 h and dispersed 2.3 km3 (0.8 km3 dense rock equivalent) of tephra toward the NE, blanketing the Lerma basin, an area occupied today by the city of Toluca, with up to 5 cm of ash. Subsequent eruptive pulses were sub-Plinian in style, accompanied by phreatomagmatic explosions that emplaced surge deposits. Finally, the column collapsed toward the NE with the emplacement of a pumice flow deposit. The high vesicularity of the pumice from the basal Plinian layer, up to 83% by volume, indicates that exsolution was dominantly magmatic, and that pressurization of the magma chamber was probably due to a magma mixing process. Evidence for this includes the compositional range of juvenile products (from 55 to 65 wt% SiO2), as well as the presence of two types of plagioclase, one in equilibrium and the other one with disequilibrium textures and reverse zoning. This suggests input of an andesitic liquid into the dacitic magma chamber. Based on the eruptive record, the most likely future eruptive activity at Nevado de Toluca volcano will be Plinian. Although quiet for more than 3250 yr, Plinian activity could occur after a long period of quiescence, and it could represent a hazard for the entire Toluca basin, where more than one million people live today.

  11. The Microcephalin Ancestral Allele in a Neanderthal Individual

    Science.gov (United States)

    Lari, Martina; Rizzi, Ermanno; Milani, Lucio; Corti, Giorgio; Balsamo, Carlotta; Vai, Stefania; Catalano, Giulio; Pilli, Elena; Longo, Laura; Condemi, Silvana; Giunti, Paolo; Hänni, Catherine; De Bellis, Gianluca; Orlando, Ludovic; Barbujani, Guido; Caramelli, David

    2010-01-01

    Background The high frequency (around 0.70 worlwide) and the relatively young age (between 14,000 and 62,000 years) of a derived group of haplotypes, haplogroup D, at the microcephalin (MCPH1) locus led to the proposal that haplogroup D originated in a human lineage that separated from modern humans >1 million years ago, evolved under strong positive selection, and passed into the human gene pool by an episode of admixture circa 37,000 years ago. The geographic distribution of haplogroup D, with marked differences between Africa and Eurasia, suggested that the archaic human form admixing with anatomically modern humans might have been Neanderthal. Methodology/Principal Findings Here we report the first PCR amplification and high- throughput sequencing of nuclear DNA at the microcephalin (MCPH1) locus from Neanderthal individual from Mezzena Rockshelter (Monti Lessini, Italy). We show that a well-preserved Neanderthal fossil dated at approximately 50,000 years B.P., was homozygous for the ancestral, non-D, allele. The high yield of Neanderthal mtDNA sequences of the studied specimen, the pattern of nucleotide misincorporation among sequences consistent with post-mortem DNA damage and an accurate control of the MCPH1 alleles in all personnel that manipulated the sample, make it extremely unlikely that this result might reflect modern DNA contamination. Conclusions/Significance The MCPH1 genotype of the Monti Lessini (MLS) Neanderthal does not prove that there was no interbreeding between anatomically archaic and modern humans in Europe, but certainly shows that speculations on a possible Neanderthal origin of what is now the most common MCPH1 haplogroup are not supported by empirical evidence from ancient DNA. PMID:20498832

  12. Genetic Diversity, Population Structure and Ancestral Origin of Australian Wheat

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    Reem Joukhadar

    2017-12-01

    Full Text Available Since the introduction of wheat into Australia by the First Fleet settlers, germplasm from different geographical origins has been used to adapt wheat to the Australian climate through selection and breeding. In this paper, we used 482 cultivars, representing the breeding history of bread wheat in Australia since 1840, to characterize their diversity and population structure and to define the geographical ancestral background of Australian wheat germplasm. This was achieved by comparing them to a global wheat collection using in-silico chromosome painting based on SNP genotyping. The global collection involved 2,335 wheat accessions which was divided into 23 different geographical subpopulations. However, the whole set was reduced to 1,544 accessions to increase the differentiation and decrease the admixture among different global subpopulations to increase the power of the painting analysis. Our analysis revealed that the structure of Australian wheat germplasm and its geographic ancestors have changed significantly through time, especially after the Green Revolution. Before 1920, breeders used cultivars from around the world, but mainly Europe and Africa, to select potential cultivars that could tolerate Australian growing conditions. Between 1921 and 1970, a dependence on African wheat germplasm became more prevalent. Since 1970, a heavy reliance on International Maize and Wheat Improvement Center (CIMMYT germplasm has persisted. Combining the results from linkage disequilibrium, population structure and in-silico painting revealed that the dependence on CIMMYT materials has varied among different Australian States, has shrunken the germplasm effective population size and produced larger linkage disequilibrium blocks. This study documents the evolutionary history of wheat breeding in Australia and provides an understanding for how the wheat genome has been adapted to local growing conditions. This information provides a guide for industry to

  13. Genetic Diversity, Population Structure and Ancestral Origin of Australian Wheat.

    Science.gov (United States)

    Joukhadar, Reem; Daetwyler, Hans D; Bansal, Urmil K; Gendall, Anthony R; Hayden, Matthew J

    2017-01-01

    Since the introduction of wheat into Australia by the First Fleet settlers, germplasm from different geographical origins has been used to adapt wheat to the Australian climate through selection and breeding. In this paper, we used 482 cultivars, representing the breeding history of bread wheat in Australia since 1840, to characterize their diversity and population structure and to define the geographical ancestral background of Australian wheat germplasm. This was achieved by comparing them to a global wheat collection using in-silico chromosome painting based on SNP genotyping. The global collection involved 2,335 wheat accessions which was divided into 23 different geographical subpopulations. However, the whole set was reduced to 1,544 accessions to increase the differentiation and decrease the admixture among different global subpopulations to increase the power of the painting analysis. Our analysis revealed that the structure of Australian wheat germplasm and its geographic ancestors have changed significantly through time, especially after the Green Revolution. Before 1920, breeders used cultivars from around the world, but mainly Europe and Africa, to select potential cultivars that could tolerate Australian growing conditions. Between 1921 and 1970, a dependence on African wheat germplasm became more prevalent. Since 1970, a heavy reliance on International Maize and Wheat Improvement Center (CIMMYT) germplasm has persisted. Combining the results from linkage disequilibrium, population structure and in-silico painting revealed that the dependence on CIMMYT materials has varied among different Australian States, has shrunken the germplasm effective population size and produced larger linkage disequilibrium blocks. This study documents the evolutionary history of wheat breeding in Australia and provides an understanding for how the wheat genome has been adapted to local growing conditions. This information provides a guide for industry to assist with

  14. The Korarchaeota: Archaeal orphans representing an ancestral lineage of life

    Energy Technology Data Exchange (ETDEWEB)

    Elkins, James G.; Kunin, Victor; Anderson, Iain; Barry, Kerrie; Goltsman, Eugene; Lapidus, Alla; Hedlund, Brian; Hugenholtz, Phil; Kyrpides, Nikos; Graham, David; Keller, Martin; Wanner, Gerhard; Richardson, Paul; Stetter, Karl O.

    2007-05-01

    Based on conserved cellular properties, all life on Earth can be grouped into different phyla which belong to the primary domains Bacteria, Archaea, and Eukarya. However, tracing back their evolutionary relationships has been impeded by horizontal gene transfer and gene loss. Within the Archaea, the kingdoms Crenarchaeota and Euryarchaeota exhibit a profound divergence. In order to elucidate the evolution of these two major kingdoms, representatives of more deeply diverged lineages would be required. Based on their environmental small subunit ribosomal (ss RNA) sequences, the Korarchaeota had been originally suggested to have an ancestral relationship to all known Archaea although this assessment has been refuted. Here we describe the cultivation and initial characterization of the first member of the Korarchaeota, highly unusual, ultrathin filamentous cells about 0.16 {micro}m in diameter. A complete genome sequence obtained from enrichment cultures revealed an unprecedented combination of signature genes which were thought to be characteristic of either the Crenarchaeota, Euryarchaeota, or Eukarya. Cell division appears to be mediated through a FtsZ-dependent mechanism which is highly conserved throughout the Bacteria and Euryarchaeota. An rpb8 subunit of the DNA-dependent RNA polymerase was identified which is absent from other Archaea and has been described as a eukaryotic signature gene. In addition, the representative organism possesses a ribosome structure typical for members of the Crenarchaeota. Based on its gene complement, this lineage likely diverged near the separation of the two major kingdoms of Archaea. Further investigations of these unique organisms may shed additional light onto the evolution of extant life.

  15. The microcephalin ancestral allele in a Neanderthal individual.

    Directory of Open Access Journals (Sweden)

    Martina Lari

    Full Text Available BACKGROUND: The high frequency (around 0.70 worldwide and the relatively young age (between 14,000 and 62,000 years of a derived group of haplotypes, haplogroup D, at the microcephalin (MCPH1 locus led to the proposal that haplogroup D originated in a human lineage that separated from modern humans >1 million years ago, evolved under strong positive selection, and passed into the human gene pool by an episode of admixture circa 37,000 years ago. The geographic distribution of haplogroup D, with marked differences between Africa and Eurasia, suggested that the archaic human form admixing with anatomically modern humans might have been Neanderthal. METHODOLOGY/PRINCIPAL FINDINGS: Here we report the first PCR amplification and high-throughput sequencing of nuclear DNA at the microcephalin (MCPH1 locus from Neanderthal individual from Mezzena Rockshelter (Monti Lessini, Italy. We show that a well-preserved Neanderthal fossil dated at approximately 50,000 years B.P., was homozygous for the ancestral, non-D, allele. The high yield of Neanderthal mtDNA sequences of the studied specimen, the pattern of nucleotide misincorporation among sequences consistent with post-mortem DNA damage and an accurate control of the MCPH1 alleles in all personnel that manipulated the sample, make it extremely unlikely that this result might reflect modern DNA contamination. CONCLUSIONS/SIGNIFICANCE: The MCPH1 genotype of the Monti Lessini (MLS Neanderthal does not prove that there was no interbreeding between anatomically archaic and modern humans in Europe, but certainly shows that speculations on a possible Neanderthal origin of what is now the most common MCPH1 haplogroup are not supported by empirical evidence from ancient DNA.

  16. CHAAJ (JUEGO DE PELOTA MESOAMERICANO: UN jUEGO ANCESTRAL ENTRE EMERGENCIAS CULTURALES

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    Jairzinho Francisco Panqueba Cifuentes

    2012-06-01

    Full Text Available Los juegos de pelota mesoamericanos son manifestaciones corporales que han sido exploradasprincipalmente desde perspectivas arqueológicas e históricas, pero también han sido retomadosdesde distintas iniciativas para ponerlos en práctica. Desde la frontera entre Estados Unidos conMéxico, pasando por distintos Estados del país “azteca”, son practicadas diferentes modalidades deeste juego. Sin embargo, decir que el chaaj en Mesoamérica es hoy en día una alternativa recreativay deportiva, es quedarse corto respecto a su ya demostrado potencial. La sacralidad manifestada através de los movimientos corporales está ofreciendo opciones de innovación en varios espacios de lassociedades actuales. En su dimensión ceremonial, revela una comunicación ancestral muy actual. Allíse ponen en juego los códices, las interpretaciones arqueológicas y los conocimientos territoriales depersonas sabedoras de las comunidades. En su dimensión lúdica, el juego reúne elementos culturales,deportivos y pedagógicos. Ha sido una práctica corporal, técnica y motora ejecutada constantementeen algunas regiones mexicanas y guatemaltecas. No obstante su antigüedad, en los últimos años seviene registrando una promoción inusitada, en medio de los actuales tiempos de cambio que fueronanunciados desde tiempos inmemoriales por los sabedores y las sabedoras mayas.

  17. Análisis del efecto antimicrobiano de doce plantas medicinales de uso ancestral en Ecuador

    Directory of Open Access Journals (Sweden)

    Azuero, Andrea

    2016-09-01

    Full Text Available The specimens of plant species Lippia citriodora K (cedrón, Ambrosia artemisifolia L (altamisa, Taraxacum officinale Weber (diente de león, Ageratum conyzoides L (mastrante, Piper carpunya Ruiz & Pav (guaviduca, Borago officinalis L (borraja, Coriandrum sativum L (cilantro,Melissa officinalis L (toronjil, Cymbopogon citratus S (hierba luisa, Artemisia absinthium L (ajenjo, Momordica charantia L (achochilla y Moringa oleífera Lam (moringa were collected randomly in the towns of Santa Rosa and Machala, Ecuador. The leaves were washed, dried, ground and extracted by maceration with methanol; the filtrates concentrated by evaporation under reduced pressure. A diffusion technique in agar was used to determine the antimicrobial activity of the obtained methanolic extracts, by which they were tested against strains of Gram-positive (Staphylococcus aureus and Gram negative bacteria (Escherichia coli and Paeruginosa, and a strain of fungus (Candida albicans. All extracts analyzed, except for those of Lcitriodora and A. conyzoides showed a bactericidal action against all bacterial strains tested, reflecting the importance of these species in the production of herbal medicines antibiotics. T. officinale and Pcarpunya showed a high antibacterial effect against E. coli; however, S. aureus did not show sensitivity to P. carpunya and L. citriodora extracts. The antifungal activity bioassay conducted to studied extracts against C. albicans, showed that all have high fungicidal action, except for T. officinale with less inhibitory effect of fungal growth. It can be inferred that these plants are a promising source of antimicrobial components of high pharmacological value.

  18. WARACS: Wrappers to Automate the Reconstruction of Ancestral Character States1

    Science.gov (United States)

    Gruenstaeudl, Michael

    2016-01-01

    Premise of the study: Reconstructions of ancestral character states are among the most widely used analyses for evaluating the morphological, cytological, or ecological evolution of an organismic lineage. The software application Mesquite remains the most popular application for such reconstructions among plant scientists, even though its support for automating complex analyses is limited. A software tool is needed that automates the reconstruction and visualization of ancestral character states with Mesquite and similar applications. Methods and Results: A set of command line–based Python scripts was developed that (a) communicates standardized input to and output from the software applications Mesquite, BayesTraits, and TreeGraph2; (b) automates the process of ancestral character state reconstruction; and (c) facilitates the visualization of reconstruction results. Conclusions: WARACS provides a simple tool that streamlines the reconstruction and visualization of ancestral character states over a wide array of parameters, including tree distribution, character state, and optimality criterion. PMID:26949580

  19. Rapid maximum likelihood ancestral state reconstruction of continuous characters: A rerooting-free algorithm.

    Science.gov (United States)

    Goolsby, Eric W

    2017-04-01

    Ancestral state reconstruction is a method used to study the evolutionary trajectories of quantitative characters on phylogenies. Although efficient methods for univariate ancestral state reconstruction under a Brownian motion model have been described for at least 25 years, to date no generalization has been described to allow more complex evolutionary models, such as multivariate trait evolution, non-Brownian models, missing data, and within-species variation. Furthermore, even for simple univariate Brownian motion models, most phylogenetic comparative R packages compute ancestral states via inefficient tree rerooting and full tree traversals at each tree node, making ancestral state reconstruction extremely time-consuming for large phylogenies. Here, a computationally efficient method for fast maximum likelihood ancestral state reconstruction of continuous characters is described. The algorithm has linear complexity relative to the number of species and outperforms the fastest existing R implementations by several orders of magnitude. The described algorithm is capable of performing ancestral state reconstruction on a 1,000,000-species phylogeny in fewer than 2 s using a standard laptop, whereas the next fastest R implementation would take several days to complete. The method is generalizable to more complex evolutionary models, such as phylogenetic regression, within-species variation, non-Brownian evolutionary models, and multivariate trait evolution. Because this method enables fast repeated computations on phylogenies of virtually any size, implementation of the described algorithm can drastically alleviate the computational burden of many otherwise prohibitively time-consuming tasks requiring reconstruction of ancestral states, such as phylogenetic imputation of missing data, bootstrapping procedures, Expectation-Maximization algorithms, and Bayesian estimation. The described ancestral state reconstruction algorithm is implemented in the Rphylopars

  20. Mutismo ancestral: a sorte dos índios

    Directory of Open Access Journals (Sweden)

    Luis Adriano de Souza Cezar

    2014-12-01

    Full Text Available Milton Hatoum es uno de los autores más relevantes de la literatura brasileña contemporánea. En 1989, realizó su debut en el universo literario con la aclamada novela Relato de um certo Oriente. Resultado de una alta sofisticación estética y de una intrincada disposición narrativa, esa obra se distingue no solo por la fuerza de su enredo, sino también, sobre todo, porque incorpora, como elemento constituyente de los personajes y sus conflictos, el discurso histórico de una Manaus en crisis económica y cultural, después del decaimiento del Ciclo da Borracha. De tal manera, este trabajo presenta un análisis del romance, cuya referencia es la sociedad amazónica (y brasileña a lo largo del siglo XX. Milton Hatoum é um dos autores mais relevantes da literatura brasileira contemporânea. Em 1989, realizou sua estreia no universo literário com o aclamado romance Relato de um certo Oriente. Resultado de um alto refinamento estético e de um intricado arranjo narrativo, essa obra se distingue não só pela força de seu enredo, mas, sobretudo, porque incorpora, como elemento constituinte das personagens e seus conflitos, o discurso histórico de uma Manaus em crise econômica e cultural, após a decadência do Ciclo da Borracha. Dessa maneira, este trabalho apresenta uma análise do romance, cuja referência é a sociedade amazônica (e brasileira ao longo do século XX. Milton Hatoum is one of the most important authors of contemporary Brazilian literature. He made his debut in the literary world in 1989 with the acclaimed novel Relato de um Certo Oriente. This work, the result of high aesthetic refinement and an intricate narrative arrangement, is distinguished not only by the strength of its plot, but above all because it incorporates, as a constituent element of the characters and their conflicts, the historic discourse of Manaus during an economic and cultural crisis subsequent to the decline in the Rubber Boom. This paper therefore

  1. Ancestral sequence reconstruction in primate mitochondrial DNA: compositional bias and effect on functional inference.

    Science.gov (United States)

    Krishnan, Neeraja M; Seligmann, Hervé; Stewart, Caro-Beth; De Koning, A P Jason; Pollock, David D

    2004-10-01

    Reconstruction of ancestral DNA and amino acid sequences is an important means of inferring information about past evolutionary events. Such reconstructions suggest changes in molecular function and evolutionary processes over the course of evolution and are used to infer adaptation and convergence. Maximum likelihood (ML) is generally thought to provide relatively accurate reconstructed sequences compared to parsimony, but both methods lead to the inference of multiple directional changes in nucleotide frequencies in primate mitochondrial DNA (mtDNA). To better understand this surprising result, as well as to better understand how parsimony and ML differ, we constructed a series of computationally simple "conditional pathway" methods that differed in the number of substitutions allowed per site along each branch, and we also evaluated the entire Bayesian posterior frequency distribution of reconstructed ancestral states. We analyzed primate mitochondrial cytochrome b (Cyt-b) and cytochrome oxidase subunit I (COI) genes and found that ML reconstructs ancestral frequencies that are often more different from tip sequences than are parsimony reconstructions. In contrast, frequency reconstructions based on the posterior ensemble more closely resemble extant nucleotide frequencies. Simulations indicate that these differences in ancestral sequence inference are probably due to deterministic bias caused by high uncertainty in the optimization-based ancestral reconstruction methods (parsimony, ML, Bayesian maximum a posteriori). In contrast, ancestral nucleotide frequencies based on an average of the Bayesian set of credible ancestral sequences are much less biased. The methods involving simpler conditional pathway calculations have slightly reduced likelihood values compared to full likelihood calculations, but they can provide fairly unbiased nucleotide reconstructions and may be useful in more complex phylogenetic analyses than considered here due to their speed and

  2. A 17-year Record of Meteorological Observations Across the Gran Campo Nevado Ice Cap in Southern Patagonia, Chile, Related to Synoptic Weather Types and Climate Modes

    Directory of Open Access Journals (Sweden)

    Stephanie S. Weidemann

    2018-05-01

    Full Text Available The network of long-term meteorological observations in Southernmost Patagonia is still sparse but crucial to improve our understanding of climatic variability, in particular in the more elevated and partially glaciated Southernmost Andes. Here we present a unique 17-year meteorological record (2000–2016 of four automatic weather stations (AWS across the Gran Campo Nevado Ice Cap (53°S in the Southernmost Andes (Chile and the conventional weather station Jorge Schythe of the Instituto de la Patagonia in Punta Arenas for comparison. We revisit the relationship between in situ observations and large-scale climate models as well as mesoscale weather patterns. For this purpose, a 37-year record of ERA Interim Reanalysis data has been used to compute a weather type classification based on a hierarchical correlation-based leader algorithm. The orographic perturbation on the predominantly westerly airflow determines the hydroclimatic response across the mountain range, leading to significant west-east gradients of precipitation, air temperature and humidity. Annual precipitation sums heavily drop within only tens of kilometers from ~7,500 mm a−1 to less than 800 mm a−1. The occurrence of high precipitation events of up to 620 mm in 5 days and wet spells of up to 61 consecutive days underscore the year-around wet conditions in the Southernmost Andes. Given the strong link between large-scale circulation and orographically controlled precipitation, the synoptic-scale weather conditions largely determine the precipitation and temperature variability on all time scales. Major synoptic weather types with distinct low-pressure cells in the Weddell Sea or Bellingshausen Sea, causing a prevailing southwesterly, northwesterly or westerly airflow, determine the weather conditions in Southernmost Patagonia during 68% of the year. At Gran Campo Nevado, more than 80% of extreme precipitation events occur during the persistence of these weather types. The

  3. Ancestral effect on HOMA-IR levels quantitated in an American population of Mexican origin.

    Science.gov (United States)

    Qu, Hui-Qi; Li, Quan; Lu, Yang; Hanis, Craig L; Fisher-Hoch, Susan P; McCormick, Joseph B

    2012-12-01

    An elevated insulin resistance index (homeostasis model assessment of insulin resistance [HOMA-IR]) is more commonly seen in the Mexican American population than in European populations. We report quantitative ancestral effects within a Mexican American population, and we correlate ancestral components with HOMA-IR. We performed ancestral analysis in 1,551 participants of the Cameron County Hispanic Cohort by genotyping 103 ancestry-informative markers (AIMs). These AIMs allow determination of the percentage (0-100%) ancestry from three major continental populations, i.e., European, African, and Amerindian. We observed that predominantly Amerindian ancestral components were associated with increased HOMA-IR (β = 0.124, P = 1.64 × 10(-7)). The correlation was more significant in males (Amerindian β = 0.165, P = 5.08 × 10(-7)) than in females (Amerindian β = 0.079, P = 0.019). This unique study design demonstrates how genomic markers for quantitative ancestral information can be used in admixed populations to predict phenotypic traits such as insulin resistance.

  4. Social capital and health: evidence that ancestral trust promotes health among children of immigrants.

    Science.gov (United States)

    Ljunge, Martin

    2014-12-01

    This paper presents evidence that generalized trust promotes health. Children of immigrants in a broad set of European countries with ancestry from across the world are studied. Individuals are examined within country of residence using variation in trust across countries of ancestry. The approach addresses reverse causality and concerns that the trust measure picks up institutional factors in the individual's contextual setting. There is a significant positive estimate of ancestral trust in explaining self-assessed health. The finding is robust to accounting for individual, parental, and extensive ancestral country characteristics. Individuals with higher ancestral trust are also less likely to be hampered by health problems in their daily life, providing evidence of trust influencing real life outcomes. Individuals with high trust feel and act healthier, enabling a more productive life.

  5. On the Accuracy of Ancestral Sequence Reconstruction for Ultrametric Trees with Parsimony.

    Science.gov (United States)

    Herbst, Lina; Fischer, Mareike

    2018-04-01

    We examine a mathematical question concerning the reconstruction accuracy of the Fitch algorithm for reconstructing the ancestral sequence of the most recent common ancestor given a phylogenetic tree and sequence data for all taxa under consideration. In particular, for the symmetric four-state substitution model which is also known as Jukes-Cantor model, we answer affirmatively a conjecture of Li, Steel and Zhang which states that for any ultrametric phylogenetic tree and a symmetric model, the Fitch parsimony method using all terminal taxa is more accurate, or at least as accurate, for ancestral state reconstruction than using any particular terminal taxon or any particular pair of taxa. This conjecture had so far only been answered for two-state data by Fischer and Thatte. Here, we focus on answering the biologically more relevant case with four states, which corresponds to ancestral sequence reconstruction from DNA or RNA data.

  6. Ancestral TCDD exposure promotes epigenetic transgenerational inheritance of imprinted gene Igf2: Methylation status and DNMTs

    International Nuclear Information System (INIS)

    Ma, Jing; Chen, Xi; Liu, Yanan; Xie, Qunhui; Sun, Yawen; Chen, Jingshan; Leng, Ling; Yan, Huan; Zhao, Bin; Tang, Naijun

    2015-01-01

    Ancestral TCDD exposure could induce epigenetic transgenerational phenotypes, which may be mediated in part by imprinted gene inheritance. The aim of our study was to evaluate the transgenerational effects of ancestral TCDD exposure on the imprinted gene insulin-like growth factor-2 (Igf2) in rat somatic tissue. TCDD was administered daily by oral gavage to groups of F0 pregnant SD rats at dose levels of 0 (control), 200 or 800 ng/kg bw during gestation day 8–14. Animal transgenerational model of ancestral exposure to TCDD was carefully built, avoiding sibling inbreeding. Hepatic Igf2 expression of the TCDD male progeny was decreased concomitantly with hepatic damage and increased activities of serum hepatic enzymes both in the F1 and F3 generation. Imprinted Control Region (ICR) of Igf2 manifested a hypermethylated pattern, whereas methylation status in the Differentially Methylated Region 2 (DMR2) showed a hypomethylated manner in the F1 generation. These epigenetic alterations in these two regions maintained similar trends in the F3 generation. Meanwhile, the expressions of DNA methyltransferases (DNMT1, DNMT3A and DNMT3B) changed in a non-monotonic manner both in the F1 and F3 generation. This study provides evidence that ancestral TCDD exposure may promote epigenetic transgenerational alterations of imprinted gene Igf2 in adult somatic tissue. - Highlights: • Ancestral TCDD exposure induces epigenetic transgenerational inheritance. • Ancestral TCDD exposure affects methylation status in ICR and DMR2 region of Igf2. • DNMTs play a role in TCDD induced epigenetic transgenerational changes of Igf2.

  7. Reconstructed Ancestral Enzymes Impose a Fitness Cost upon Modern Bacteria Despite Exhibiting Favourable Biochemical Properties.

    Science.gov (United States)

    Hobbs, Joanne K; Prentice, Erica J; Groussin, Mathieu; Arcus, Vickery L

    2015-10-01

    Ancestral sequence reconstruction has been widely used to study historical enzyme evolution, both from biochemical and cellular perspectives. Two properties of reconstructed ancestral proteins/enzymes are commonly reported--high thermostability and high catalytic activity--compared with their contemporaries. Increased protein stability is associated with lower aggregation rates, higher soluble protein abundance and a greater capacity to evolve, and therefore, these proteins could be considered "superior" to their contemporary counterparts. In this study, we investigate the relationship between the favourable in vitro biochemical properties of reconstructed ancestral enzymes and the organismal fitness they confer in vivo. We have previously reconstructed several ancestors of the enzyme LeuB, which is essential for leucine biosynthesis. Our initial fitness experiments revealed that overexpression of ANC4, a reconstructed LeuB that exhibits high stability and activity, was only able to partially rescue the growth of a ΔleuB strain, and that a strain complemented with this enzyme was outcompeted by strains carrying one of its descendants. When we expanded our study to include five reconstructed LeuBs and one contemporary, we found that neither in vitro protein stability nor the catalytic rate was correlated with fitness. Instead, fitness showed a strong, negative correlation with estimated evolutionary age (based on phylogenetic relationships). Our findings suggest that, for reconstructed ancestral enzymes, superior in vitro properties do not translate into organismal fitness in vivo. The molecular basis of the relationship between fitness and the inferred age of ancestral LeuB enzymes is unknown, but may be related to the reconstruction process. We also hypothesise that the ancestral enzymes may be incompatible with the other, contemporary enzymes of the metabolic network.

  8. Asymptotic distributions of coalescence times and ancestral lineage numbers for populations with temporally varying size.

    Science.gov (United States)

    Chen, Hua; Chen, Kun

    2013-07-01

    The distributions of coalescence times and ancestral lineage numbers play an essential role in coalescent modeling and ancestral inference. Both exact distributions of coalescence times and ancestral lineage numbers are expressed as the sum of alternating series, and the terms in the series become numerically intractable for large samples. More computationally attractive are their asymptotic distributions, which were derived in Griffiths (1984) for populations with constant size. In this article, we derive the asymptotic distributions of coalescence times and ancestral lineage numbers for populations with temporally varying size. For a sample of size n, denote by Tm the mth coalescent time, when m + 1 lineages coalesce into m lineages, and An(t) the number of ancestral lineages at time t back from the current generation. Similar to the results in Griffiths (1984), the number of ancestral lineages, An(t), and the coalescence times, Tm, are asymptotically normal, with the mean and variance of these distributions depending on the population size function, N(t). At the very early stage of the coalescent, when t → 0, the number of coalesced lineages n - An(t) follows a Poisson distribution, and as m → n, $$n\\left(n-1\\right){T}_{m}/2N\\left(0\\right)$$ follows a gamma distribution. We demonstrate the accuracy of the asymptotic approximations by comparing to both exact distributions and coalescent simulations. Several applications of the theoretical results are also shown: deriving statistics related to the properties of gene genealogies, such as the time to the most recent common ancestor (TMRCA) and the total branch length (TBL) of the genealogy, and deriving the allele frequency spectrum for large genealogies. With the advent of genomic-level sequencing data for large samples, the asymptotic distributions are expected to have wide applications in theoretical and methodological development for population genetic inference.

  9. Environmental enrichment mitigates the impact of ancestral stress on motor skill and corticospinal tract plasticity.

    Science.gov (United States)

    McCreary, J Keiko; Erickson, Zachary T; Metz, Gerlinde A S

    2016-10-06

    An adverse fetal environment in utero has been associated with long-term alterations in brain structure and function, and a higher risk of neurological disorders in later life. A common consequence of early adverse experience is impaired motor system function. A causal relationship for stress-associated impairments and a suitable therapy, however, have not been determined yet. To investigate the impact of ancestral stress on corticospinal tract (CST) morphology and fine motor performance in rats, and to determine if adverse programming by ancestral stress can be mitigated by environmental enrichment therapy in rats. The study examined F3 offspring generated by three lineages; one with prenatal stress only in the F1 generation, one with compounding effects of multigenerational prenatal stress, and a non-stress control lineage. F3 offspring from each lineage were injected with biotinylated dextran amine (BDA) into the motor cortex for anterograde tracing of the CST. Examination of the CST revealed reduced axonal density in the ancestrally stressed lineages. These anatomical changes were associated with significant impairments in skilled walking, as indicated by reduced foot placement accuracy and disturbed inter-limb coordination. Therapeutic intervention by environmental enrichment reduced the neuromorphological consequences of ancestral stress and restored skilled walking ability. The data suggest a causal relationship between stress-induced abnormal CST function and loss of fine motor performance. Thus, ancestral stress may be a determinant of motor system development and motor skill. Environmental enrichment may represent an effective intervention for the adverse programming by ancestral stress and trauma. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Ancestral TCDD exposure promotes epigenetic transgenerational inheritance of imprinted gene Igf2: Methylation status and DNMTs

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jing; Chen, Xi; Liu, Yanan [Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin 300070 (China); Xie, Qunhui [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Sun, Yawen; Chen, Jingshan; Leng, Ling; Yan, Huan [Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin 300070 (China); Zhao, Bin, E-mail: binzhao@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Tang, Naijun, E-mail: tangnaijun@tijmu.edu.cn [Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin 300070 (China)

    2015-12-01

    Ancestral TCDD exposure could induce epigenetic transgenerational phenotypes, which may be mediated in part by imprinted gene inheritance. The aim of our study was to evaluate the transgenerational effects of ancestral TCDD exposure on the imprinted gene insulin-like growth factor-2 (Igf2) in rat somatic tissue. TCDD was administered daily by oral gavage to groups of F0 pregnant SD rats at dose levels of 0 (control), 200 or 800 ng/kg bw during gestation day 8–14. Animal transgenerational model of ancestral exposure to TCDD was carefully built, avoiding sibling inbreeding. Hepatic Igf2 expression of the TCDD male progeny was decreased concomitantly with hepatic damage and increased activities of serum hepatic enzymes both in the F1 and F3 generation. Imprinted Control Region (ICR) of Igf2 manifested a hypermethylated pattern, whereas methylation status in the Differentially Methylated Region 2 (DMR2) showed a hypomethylated manner in the F1 generation. These epigenetic alterations in these two regions maintained similar trends in the F3 generation. Meanwhile, the expressions of DNA methyltransferases (DNMT1, DNMT3A and DNMT3B) changed in a non-monotonic manner both in the F1 and F3 generation. This study provides evidence that ancestral TCDD exposure may promote epigenetic transgenerational alterations of imprinted gene Igf2 in adult somatic tissue. - Highlights: • Ancestral TCDD exposure induces epigenetic transgenerational inheritance. • Ancestral TCDD exposure affects methylation status in ICR and DMR2 region of Igf2. • DNMTs play a role in TCDD induced epigenetic transgenerational changes of Igf2.

  11. Textural analysis of particles from El Zaguán debris avalanche deposit, Nevado de Toluca volcano, Mexico: Evidence of flow behavior during emplacement

    Science.gov (United States)

    Caballero, Lizeth; Capra, Lucia

    2011-02-01

    El Zaguán deposit originated at 28,000 yrs. B.P. from the flank collapse of Nevado de Toluca, a dacitic stratovolcano of the Transmexican Volcanic Belt. Scanning Electron Microprobe analyses (SEM) were performed on some particles from this deposit to observe microtextures produced during transport and emplacement of the debris avalanche flow. Particles from 2ϕ (250 μm), 0ϕ (1 mm) and - 2ϕ (4 mm) granulometric classes were randomly selected at different outcrops, and their surface textures were described. The observed textures are divided in two groups, Basal and Upper textures, each one indicating different clast interactions. Basal textures are observed predominantly in the lower part of the deposit and consist of parallel ridges, parallel grooves, scratches and lips. Upper textures are mainly present in the upper part of the deposit and consisted of fractures, percussion marks, and broken or grinded crystals. These characteristics, coupled with field observations such as the presence of clastic dikes and deformed lacustrine mega-blocks, indicate that the basal part of the debris avalanche was moving in a partially liquefied state. By contrast, the particles in the upper part were able to move freely, interacting by collision. These microscopic textures are in agreement with previously described emplacement behaviors in debris avalanches of volcanic origin, suggesting a stratified flow dominated by different transport and depositional mechanisms depending upon flow depth and possible fluid content at their base.

  12. Sr, Nd and Pb isotope and geochemical data from the Quaternary Nevado de Toluca volcano, a source of recent adakitic magmatism, and the Tenango Volcanic Field, Mexico

    Science.gov (United States)

    Martínez-Serrano, Raymundo G.; Schaaf, Peter; Solís-Pichardo, Gabriela; Hernández-Bernal, Ma. del Sol; Hernández-Treviño, Teodoro; Julio Morales-Contreras, Juan; Macías, José Luis

    2004-11-01

    Volcanic activity at Nevado de Toluca (NT) volcano began 2.6 Ma ago with the emission of andesitic lavas, but over the past 40 ka, eruptions have produced mainly lava flows and pyroclastic deposits of predominantly orthopyroxene-hornblende dacitic composition. In the nearby Tenango Volcanic Field (TVF) pyroclastic products and lava flows ranging in composition from basaltic andesite to andesite were erupted at most of 40 monogenetic volcanic centers and were coeval with the last stages of NT. All volcanic rocks in the study area are characterized by a calc-alkaline affinity that is consistent with a subduction setting. Relatively high concentrations of Sr (>460 ppm) coupled with low Y (45 km) that underlies the volcanoes of the study area, the geochemical and isotopic patterns of these rocks indicate low interaction with this crust. NT volcano was constructed at the intersection of three fault systems, and it seems that the Plio-Quaternary E-W system played an important role in the ascent and storage of magmas during the recent volcanic activity in the two regions. Chemical and textural features of orthopyroxene, amphibole and Fe-Ti oxides from NT suggest that crystallization of magmas occurred at polybaric conditions, confirming the rapid upwelling of magmas.

  13. Sem Analysis of particles from the 28, 000 B.P El Zaguan debris avalanche deposit, Nevado de Toluca volcano, Central Mexico: evidences of flow behavior during emplacement

    Science.gov (United States)

    Caballero, L.; Capra, L.

    2008-12-01

    The Zaguan deposit originated at 28, 000 yr. B.P from the flank collapse of the Nevado de Toluca volcano, a dacitic stratovolcano of the Transmexican Volcanic Belt. A Scanning Electron Microprobe analysis (SEM) was made to some clasts of this deposit to observe microtextures produced during transport and emplacement of the debris avalanche flow. Particles from 2, 0 and -2 Φ granulometric classes were randomly selected and their surface textures were described. The textures observed were divided in two groups, collision and shear structures indicating different clast interaction. Shear textures were observed predominantly on the basal part of the deposit and consisted of parallel ridges, parallel grooves, scratches and lips. Collision textures were mainly present in the upper part of the deposit and consisted of fractures, percussion marks, and broken or grinded crystals. These characteristics, coupled with field observation, like the presence of clast dikes and deformed lacustrine megaclasts, indicate that the basal part of the debris avalanche was moving in a partially liquefied state, were particles were not able to move freely because of the confinement exerted by the upper part of the flow, so shear stresses dominated. On the contrary, the particles in the upper part were able to move freely so the principal mechanism of interaction between particles was collision. These microscopic textures are in agreement with previously described behavior of emplacement of debris avalanches of volcanic origin, that suggest a stratified flow dominated by different transport and depositional mechanism depending on flow depth and possible fluid content at their base.

  14. Which came first: The lizard or the egg? Robustness in phylogenetic reconstruction of ancestral states.

    Science.gov (United States)

    Wright, April M; Lyons, Kathleen M; Brandley, Matthew C; Hillis, David M

    2015-09-01

    Changes in parity mode between egg-laying (oviparity) and live-bearing (viviparity) have occurred repeatedly throughout vertebrate evolution. Oviparity is the ancestral amniote state, and viviparity has evolved many times independently within amniotes (especially in lizards and snakes), with possibly a few reversions to oviparity. In amniotes, the shelled egg is considered a complex structure that is unlikely to re-evolve if lost (i.e., it is an example of Dollo's Principle). However, a recent ancestral state reconstruction analysis concluded that viviparity was the ancestral state of squamate reptiles (lizards and snakes), and that oviparity re-evolved from viviparity many times throughout the evolutionary history of squamates. Here, we re-evaluate support for this provocative conclusion by testing the sensitivity of the analysis to model assumptions and estimates of squamate phylogeny. We found that the models and methods used for parity mode reconstruction are highly sensitive to the specific estimate of phylogeny used, and that the point estimate of phylogeny used to suggest that viviparity is the root state of the squamate tree is far from an optimal phylogenetic solution. The ancestral state reconstructions are also highly sensitive to model choice and specific values of model parameters. A method that is designed to account for biases in taxon sampling actually accentuates, rather than lessens, those biases with respect to ancestral state reconstructions. In contrast to recent conclusions from the same data set, we find that ancestral state reconstruction analyses provide highly equivocal support for the number and direction of transitions between oviparity and viviparity in squamates. Moreover, the reconstructions of ancestral parity state are highly dependent on the assumptions of each model. We conclude that the common ancestor of squamates was oviparous, and subsequent evolutionary transitions to viviparity were common, but reversals to oviparity were

  15. ¿Con o sin ancestros?: vigencia de lo ancestral en la Amazonía peruana

    Directory of Open Access Journals (Sweden)

    Thomas Mouriès

    2014-06-01

    Full Text Available La existencia o no de ancestros en la Amazonía indígena ha sido objeto de importantes debates. Sin embargo, los líderes de la región no dudan en llamar ‘ancestrales’ sus saberes, normas o territorios, en un sentido que, desde un punto de vista académico, puede parecer enigmático. «Ancestrales, pero… ¿con o sin ancestros?», preguntaría entonces, confuso, el antropólogo. En este artículo propongo aportar elementos de respuesta a esta pregunta a través del caso peruano. Primero analizo cómo los líderes indígenas amazónicos, conectándose al circuito del derecho internacional, adoptan la noción jurídica de ‘posesión ancestral’ del territorio para adaptarla al ámbito político. Este planteamiento rinde cuenta de la generalización y uniformización reciente del vocablo ‘ancestral’ pero deja pendiente el problema de su eventual articulación con las cosmologías indígenas que pretende reflejar. Por eso, en la segunda parte, intento sondear sobre la pertinencia de la categoría de ‘ancestro’ en la Amazonía indígena, recordando brevemente el debate académico para ir definiendo en qué medida esta categoría puede cobrar sentido. A partir del testimonio de un experimentado líder awajún, la tercera parte permite, entonces, volver más explícitos los diferentes sentidos y planos referenciales que despliega la referencia a lo ancestral, mostrando cómo los indígenas amazónicos no solo adoptan elementos conceptuales y discursivos externos, sino que al mismo tiempo los transforman a partir de sus propias singularidades cosmológicas y perspectivas políticas.

  16. A skull might lie: modelling ancestral ranges and diet from genes and shape of tree squirrels

    Czech Academy of Sciences Publication Activity Database

    Pečnerová, Patrícia; Moravec, Jiří C.; Martínková, Natália

    2015-01-01

    Roč. 64, č. 6 (2015), s. 1074-1088 ISSN 1063-5157 EU Projects: European Commission(XE) CZ.1.07/2.4.00/17.0138 Institutional support: RVO:68081766 Keywords : Sciurini * multilocus phylogeny * geometric morphometry * speciation * ancestral range reconstruction * diet modelling Subject RIV: EG - Zoology Impact factor: 8.225, year: 2015

  17. Language Shift and Maintenance in Multilingual Mauritius: The Case of Indian Ancestral Languages

    Science.gov (United States)

    Bissoonauth, Anu

    2011-01-01

    This paper reports on a research study conducted in Mauritius between June and July 2009. The aim of this research was to investigate the use of Indian ancestral languages in the domestic domain by the younger generations. The data were collected in the field by means of a questionnaire and interviews from a quota sample of secondary school…

  18. Inferring ancestral distribution area and survival vegetation of Caragana (Fabaceae) in Tertiary

    Science.gov (United States)

    Mingli Zhang; Juanjuan Xue; Qiang Zhang; Stewart C. Sanderson

    2015-01-01

    Caragana, a leguminous genus mainly restricted to temperate Central and East Asia, occurs in arid, semiarid, and humid belts, and has forest, grassland, and desert ecotypes. Based on the previous molecular phylogenetic tree and dating, biogeographical analyses of extant species area and ecotype were conducted by means of four ancestral optimization approaches: S-DIVA,...

  19. The structured ancestral selection graph and the many-demes limit.

    Science.gov (United States)

    Slade, Paul F; Wakeley, John

    2005-02-01

    We show that the unstructured ancestral selection graph applies to part of the history of a sample from a population structured by restricted migration among subpopulations, or demes. The result holds in the limit as the number of demes tends to infinity with proportionately weak selection, and we have also made the assumptions of island-type migration and that demes are equivalent in size. After an instantaneous sample-size adjustment, this structured ancestral selection graph converges to an unstructured ancestral selection graph with a mutation parameter that depends inversely on the migration rate. In contrast, the selection parameter for the population is independent of the migration rate and is identical to the selection parameter in an unstructured population. We show analytically that estimators of the migration rate, based on pairwise sequence differences, derived under the assumption of neutrality should perform equally well in the presence of weak selection. We also modify an algorithm for simulating genealogies conditional on the frequencies of two selected alleles in a sample. This permits efficient simulation of stronger selection than was previously possible. Using this new algorithm, we simulate gene genealogies under the many-demes ancestral selection graph and identify some situations in which migration has a strong effect on the time to the most recent common ancestor of the sample. We find that a similar effect also increases the sensitivity of the genealogy to selection.

  20. Indigenous ancestral sayings contribute to modern conservation partnerships: examples using Phormium tenax.

    Science.gov (United States)

    Wehi, Priscilla M

    2009-01-01

    Traditional ecological knowledge (TEK) is central to indigenous worldviews and practices and is one of the most important contributions that indigenous people can bring to conservation management partnerships. However, researchers and managers may have difficulty accessing such knowledge, particularly where knowledge transmission has been damaged. A new methodological approach analyzes ancestral sayings from Maori oral traditions for ecological information about Phormium tenax, a plant with high cultural value that is a dominant component in many threatened wetland systems, and frequently used in restoration plantings in New Zealand. Maori ancestral sayings record an association with nectar-feeding native parrots that has only rarely been reported, as well as indications of important environmental parameters (rainfall and drought) for this species. These sayings provide evidence of indigenous management that has not been reported from interviews with elders, including evidence of fire use to create Phormium cultivations. TEK in Maori ancestral sayings imply landscape-scale processes in comparison to intensive, small-scale management methods often reported in interviews. TEK in ancestral sayings can be used to generate new scientific hypotheses, negotiate collaborative pathways, and identify ecological management strategies that support biodiversity retention. TEK can inform restoration ecology, historical ecology, and conservation management of species and ecosystems, especially where data from pollen records and archaeological artifacts are incomplete.

  1. Invasion of Ancestral Mammals into Dim-light Environments Inferred from Adaptive Evolution of the Phototransduction Genes.

    Science.gov (United States)

    Wu, Yonghua; Wang, Haifeng; Hadly, Elizabeth A

    2017-04-20

    Nocturnality is a key evolutionary innovation of mammals that enables mammals to occupy relatively empty nocturnal niches. Invasion of ancestral mammals into nocturnality has long been inferred from the phylogenetic relationships of crown Mammalia, which is primarily nocturnal, and crown Reptilia, which is primarily diurnal, although molecular evidence for this is lacking. Here we used phylogenetic analyses of the vision genes involved in the phototransduction pathway to predict the diel activity patterns of ancestral mammals and reptiles. Our results demonstrated that the common ancestor of the extant Mammalia was dominated by positive selection for dim-light vision, supporting the predominate nocturnality of the ancestral mammals. Further analyses showed that the nocturnality of the ancestral mammals was probably derived from the predominate diurnality of the ancestral amniotes, which featured strong positive selection for bright-light vision. Like the ancestral amniotes, the common ancestor of the extant reptiles and various taxa in Squamata, one of the main competitors of the temporal niches of the ancestral mammals, were found to be predominate diurnality as well. Despite this relatively apparent temporal niche partitioning between ancestral mammals and the relevant reptiles, our results suggested partial overlap of their temporal niches during crepuscular periods.

  2. Reconstruction of Ancestral Genomes in Presence of Gene Gain and Loss.

    Science.gov (United States)

    Avdeyev, Pavel; Jiang, Shuai; Aganezov, Sergey; Hu, Fei; Alekseyev, Max A

    2016-03-01

    Since most dramatic genomic changes are caused by genome rearrangements as well as gene duplications and gain/loss events, it becomes crucial to understand their mechanisms and reconstruct ancestral genomes of the given genomes. This problem was shown to be NP-complete even in the "simplest" case of three genomes, thus calling for heuristic rather than exact algorithmic solutions. At the same time, a larger number of input genomes may actually simplify the problem in practice as it was earlier illustrated with MGRA, a state-of-the-art software tool for reconstruction of ancestral genomes of multiple genomes. One of the key obstacles for MGRA and other similar tools is presence of breakpoint reuses when the same breakpoint region is broken by several different genome rearrangements in the course of evolution. Furthermore, such tools are often limited to genomes composed of the same genes with each gene present in a single copy in every genome. This limitation makes these tools inapplicable for many biological datasets and degrades the resolution of ancestral reconstructions in diverse datasets. We address these deficiencies by extending the MGRA algorithm to genomes with unequal gene contents. The developed next-generation tool MGRA2 can handle gene gain/loss events and shares the ability of MGRA to reconstruct ancestral genomes uniquely in the case of limited breakpoint reuse. Furthermore, MGRA2 employs a number of novel heuristics to cope with higher breakpoint reuse and process datasets inaccessible for MGRA. In practical experiments, MGRA2 shows superior performance for simulated and real genomes as compared to other ancestral genome reconstruction tools.

  3. The Upper Toluca Pumice (10.5 kyr): Product of the last major Plinian eruption of Nevado de Toluca volcano, Central Mexico

    Science.gov (United States)

    Arce, J. L.; Macias, J. L.

    2001-12-01

    The last Plinian eruption at Nevado de Toluca volcano occurred 10.5 kyr ago producing the Upper Toluca Pumice (UTP). The UTP consists of four widespread fallout layers, interbedded with pyroclastic flow and surge deposits. The UTP event occurred under open vent conditions starting with hydromagmatic explosions that emplaced a hot pyroclastic flow (F0) on the east and northern flanks of the volcano. This explosion decompressed the magmatic system allowing almost immediately the formation of a 21 km high Plinian column that was dispersed by predominant winds 5o to the NE (PC0), which waned after some time. The eruption recommenced with the establishment of three Plinian columns that were dispersed in a NE-E direction, reaching heights of 39, 42, and 28 km, and deposited fall layers (PC1, PC2, and PC3) respectively. These Plinian columns were interrupted several times by phreatomagmatic and collapse events that emplaced pyroclastic flows (F1, F2, and F3) and surges (S1, and S2), mainly on the eastern and northern flanks of the volcano. The juvenile components of the UTP sequence are white, gray and banded pumice and gray juvenile lithic clasts both of dacitic composition (63-66wt% SiO2), and minor accidental lithics. The fallout deposits (PC1 and PC2) covered a minimum area of 2000 km2 with a total volume of 14 km3 (ca. 6 km3 D.R.E.); a mass eruption rate ranging from 3\\times107 to 5\\times108 kg/s and a total mass of 1.2\\times1013 kg. The UTP emplaced 1.5 m of gravel-sized pumice in the modern City of Toluca region and ca. 20 cm of fine sand in the Mexico City region. A future event of this magnitude might represent a major catastrophe to the 30 million people living in these cities and their surroundings.

  4. Pre-eruptive conditions of dacitic magma erupted during the 21.7 ka Plinian event at Nevado de Toluca volcano, Central Mexico

    Science.gov (United States)

    Arce, J. L.; Gardner, J. E.; Macías, J. L.

    2013-01-01

    The Nevado de Toluca volcano in Central Mexico has been active over the last ca. 42 ka, during which tens of km3 of pyroclastic material were erupted and two important Plinian-type eruptions occurred at ca. 21.7 ka (Lower Toluca Pumice: LTP) and ca. 10.5 ka (Upper Toluca Pumice: UTP). Samples from both the LTP and UTP contain plagioclase, amphibole, iron-titanium oxides, and minor anhedral biotite, set in a vesicular, rhyolitic, glassy matrix. In addition, UTP dacites contain orthopyroxene. Analysis of melt inclusions in plagioclase phenocrysts yields H2O contents of 2-3.5 wt.% for LTP and 1.3-3.6 wt.% for UTP samples. Ilmenite-ulvospinel geothermometry yields an average temperature of ~ 868 °C for the LTP magma (hotter than the UTP magma, ~ 842 °C; Arce et al., 2006), whereas amphibole-plagioclase geothermometry yields a temperature of 825-859 °C for the LTP magma. Water-saturated experiments using LTP dacite suggest that: (i) amphibole is stable above 100 MPa and below 900 °C; (ii) plagioclase crystallizes below 250-100 MPa at temperatures of 850-900 °C; and (iii) pyroxene is stable only below pressures of 200-100 MPa and temperatures of 825-900 °C. Comparison of natural and experimental data suggests that the LTP dacitic magma was stored at 150-200 MPa (5.8-7.7 km below the volcano summit). No differences in pressure found between 21.7 ka and 10.5 ka suggest that these two magmas were stored at similar depths. Orthopyroxene produced in lower temperature LTP experiments is compositionally different to those found in UTP natural samples, suggesting that they originated in two different magma batches. Whole-rock chemistry, petrographic features, and mineral compositions suggest that magma mixing was responsible for the generation of the dacitic Plinian LTP eruption.

  5. Metamorphic brines and no surficial fluids trapped in the detachment footwall of a Metamorphic Core Complex (Nevado-Filábride units, Betics, Spain)

    Science.gov (United States)

    Dyja-Person, Vanessa; Tarantola, Alexandre; Richard, Antonin; Hibsch, Christian; Siebenaller, Luc; Boiron, Marie-Christine; Cathelineau, Michel; Boulvais, Philippe

    2018-03-01

    The ductile-brittle transition zone in extensional regimes can play the role of a hydrogeological barrier. Quartz veins developed within an orthogneiss body located in the detachment footwall of a Metamorphic Core Complex (MCC) in the Nevado-Filábride units (Betics, Spain). The detachment footwall is composed mainly of gneisses, schists and metacarbonates from the Bédar-Macael sub-unit. Schist and metacarbonate bodies show evidence of ductile deformation at the time the gneiss was already undergoing brittle deformation and vein opening during exhumation. The vein system provides the opportunity to investigate the origin, composition and PVTX conditions of the fluids that circulated in the detachment footwall while the footwall units were crossing the ductile-brittle transition. The analysis of fluid inclusions reveals the presence of a single type of fluid: 30-40 mass% NaCl > KCl > CaCl2 > MgCl2 brines, with trace amounts of CO2 and N2 and tens to thousands of ppm of metals such as Fe, Sr, Li, Zn, Ba, Pb and Cu. δDfluid values between -39.8 and -16.7‰ and δ18Ofluid values between 4.4 and 11.7 ± 0.5‰ show that the brines have undergone protracted interaction with the host orthogneissic body. Coupled salinity and Cl/Br ratios (200 to 4400) indicate that the brines originate from dissolution of Triassic metaevaporites by metamorphic fluids variably enriched in Br by interaction with graphitic schists. This study highlights the absence of any record of surficial fluids within the veins, despite the brittle deformation conditions prevailing in this orthogneiss body. The fact that fluids from the detachment footwall were isolated from surficial fluid reservoirs may result from the presence of overlying schists and metacarbonates that continued to be affected by ductile deformation during vein formation in the gneiss, preventing downward circulation of surface-derived fluids.

  6. FUNCIONES ORTOGONALES EMPÍRICAS (EOF APLICADAS A LAS CUENCAS OCEÁNICAS TROPICALES INDO-PACÍFICA Y ATLÁNTICA: CONTRIBUCIONES AL ANÁLISIS DE LAS CONDICIONES DE COBERTURA DE NUBES EN EL PARQUE NACIONAL NATURAL LOS NEVADOS FUNÇÕES ORTOGONAIS EMPÍRICAS (EOF APLICADAS ÀS BACIAS OCEÂNICAS TROPICAIS INDO-PACÍFICA E ATLÂNTICA: CONTRIBUIÇÕES PARA A ANÁLISE DAS CONDIÇÕES DA COBERTURA DE NUVENS NO PARQUE NACIONAL NATURAL LOS NEVADOS INDO-PACIFIC AND TROPICAL ATLANTIC EOF MODES: CONTRIBUTIONS TO THE ANALYSES OF CLOUD COVER CONDITIONS IN THE LOS NEVADOS NATURAL PARK

    Directory of Open Access Journals (Sweden)

    DANIEL RUIZ CARRASCAL

    2010-12-01

    Full Text Available Los páramos colombianos están experimentando un aumento en su estrés climático. Uno de los factores clave detrás de esto es el cambio en las condiciones de cobertura de nubes, que dependen de procesos regionales y locales. Este trabajo busca explorar el grado de asociación entre la variabilidad año a año de las temperaturas superficiales del mar (TSM observadas en las zonas tropicales de los océanos Índico-Pacífico y Atlántico y los cambios de año a año en las condiciones de cobertura regional de nubes imperantes en la cordillera Central de Colombia, pero enfocándose en el píxel de la retícula satelital donde se encuentran el macizo volcánico Ruiz-Tolima, el Parque Nacional Natural Los Nevados y sus alrededores. Los registros analizados incluyen valores promedio mensuales de TSM observados en la región Niño 3.4 del Pacífico ecuatorial, anomalías de las TSM observadas en las cuencas tropicales del Índico-Pacífico y el Atlántico, así como la cobertura de nubes de todo tipo y la presión atmosférica en su capa alta observadas sobre los Andes septentrionales. Aunque se procesan los datos de cuatro meses "secos", la discusión se centra en las condiciones de enero, cuando las zonas de alta montaña de la cordillera Central de Colombia están expuestas a máximos de brillo solar. Los análisis de funciones ortogonales empíricas (EOF / componentes principales (PC se llevan a cabo para identificar los principales modos de variabilidad de las TSM, tales como El Niño-Oscilación del Sur (ENOS. Los primeros modos de EOF en las anomalías de las TSM observadas en enero en las regiones 30°S a 30°N y 15°S a 15°N del Índico-Pacífico representan, en particular, la fase madura del ENOS y explican el 30,7 % y 44,3 %, respectivamente, de la variabilidad espacio-temporal de las anomalías de las TSM en enero. El primer modo de EOF de anomalías de las TSM observadas en enero en las latitudes 19°S a 29°N del Atlántico tropical

  7. Expression, purification and crystallization of the ancestral androgen receptor-DHT complex.

    Science.gov (United States)

    Colucci, Jennifer K; Ortlund, Eric A

    2013-09-01

    Steroid receptors (SRs) are a closely related family of ligand-dependent nuclear receptors that mediate the transcription of genes critical for development, reproduction and immunity. SR dysregulation has been implicated in cancer, inflammatory diseases and metabolic disorders. SRs bind their cognate hormone ligand with exquisite specificity, offering a unique system to study the evolution of molecular recognition. The SR family evolved from an estrogen-sensitive ancestor and diverged to become sensitive to progestagens, corticoids and, most recently, androgens. To understand the structural mechanisms driving the evolution of androgen responsiveness, the ancestral androgen receptor (ancAR1) was crystallized in complex with 5α-dihydrotestosterone (DHT) and a fragment of the transcriptional mediator/intermediary factor 2 (Tif2). Crystals diffracted to 2.1 Å resolution and the resulting structure will permit a direct comparison with its progestagen-sensitive ancestor, ancestral steroid receptor 2 (AncSR2).

  8. Inference of the ancestral vertebrate phenotype through vestiges of the whole-genome duplications.

    Science.gov (United States)

    Onimaru, Koh; Kuraku, Shigehiro

    2018-03-16

    Inferring the phenotype of the last common ancestor of living vertebrates is a challenging problem because of several unresolvable factors. They include the lack of reliable out-groups of living vertebrates, poor information about less fossilizable organs and specialized traits of phylogenetically important species, such as lampreys and hagfishes (e.g. secondary loss of vertebrae in adult hagfishes). These factors undermine the reliability of ancestral reconstruction by traditional character mapping approaches based on maximum parsimony. In this article, we formulate an approach to hypothesizing ancestral vertebrate phenotypes using information from the phylogenetic and functional properties of genes duplicated by genome expansions in early vertebrate evolution. We named the conjecture as 'chronological reconstruction of ohnolog functions (CHROF)'. This CHROF conjecture raises the possibility that the last common ancestor of living vertebrates may have had more complex traits than currently thought.

  9. Ancestral genes can control the ability of horizontally acquired loci to confer new traits.

    Directory of Open Access Journals (Sweden)

    H Deborah Chen

    2011-07-01

    Full Text Available Horizontally acquired genes typically function as autonomous units conferring new abilities when introduced into different species. However, we reasoned that proteins preexisting in an organism might constrain the functionality of a horizontally acquired gene product if it operates on an ancestral pathway. Here, we determine how the horizontally acquired pmrD gene product activates the ancestral PmrA/PmrB two-component system in Salmonella enterica but not in the closely related bacterium Escherichia coli. The Salmonella PmrD protein binds to the phosphorylated PmrA protein (PmrA-P, protecting it from dephosphorylation by the PmrB protein. This results in transcription of PmrA-dependent genes, including those conferring polymyxin B resistance. We now report that the E. coli PmrD protein can activate the PmrA/PmrB system in Salmonella even though it cannot do it in E. coli, suggesting that these two species differ in an additional component controlling PmrA-P levels. We establish that the E. coli PmrB displays higher phosphatase activity towards PmrA-P than the Salmonella PmrB, and we identified a PmrB subdomain responsible for this property. Replacement of the E. coli pmrB gene with the Salmonella homolog was sufficient to render E. coli resistant to polymyxin B under PmrD-inducing conditions. Our findings provide a singular example whereby quantitative differences in the biochemical activities of orthologous ancestral proteins dictate the ability of a horizontally acquired gene product to confer species-specific traits. And they suggest that horizontally acquired genes can potentiate selection at ancestral loci.

  10. Temperature-dependent respiration-growth relations in ancestral maize cultivars

    Science.gov (United States)

    Bruce N. Smith; Jillian L. Walker; Rebekka L. Stone; Angela R. Jones; Lee D. Hansen

    2001-01-01

    Shoots from 4- to 6-day old seedlings of seven ancestral or old cultivars of Zea mays L. were placed in a calorimeter. Dark metabolic heat rate (q) and CO2 production rate (RCO2) were measured at nine temperatures (5, 10, 15, 20, 25, 30, 35, 40, and 45 °C). Temperature dependencies of q and RCO2 were used to model response of both growth and substrate carbon conversion...

  11. Ancestral diet leads to dynamic transgenerational plasticity for five generations in Drosophila melanogaster

    OpenAIRE

    Mikheyev, Alexander; Emborski, Carmen

    2018-01-01

    Ancestral exposures can influence phenotypic expression in subsequent generations, which influence diverse biological processes ranging from phenotypic plasticity to obesity. Currently, most transgenerational studies work under the assumption of transgenerational response stability and reproducibility through time and across exposure differences, relying on short-term (i.e. 2-3 generations) single-exposure experiments. Yet, little evidence exists in the literature to validate this assumption,...

  12. Perianth evolution in Ranunculaceae: are petals ancestral in the family?

    OpenAIRE

    Nadot S.; Sauquet H.; Damerval C.; Jabbour F.; Domenech B.

    2016-01-01

    Progress has been made recently towards the elucidation of phylogenetic relationships among subfamilies and tribes of the Ranunculaceae – the most recent hypothesis was published in 2016 by our team. Although relationships among the 10 tribes of the subfamily Ranunculoideae remain incompletely supported, this hypothesis provides an interesting framework to address the key issue of the ancestral vs. derived nature of a differentiated perianth within the family, and at the level of Ranunculales...

  13. Lack of Social Support Raises Stress Vulnerability in Rats with a History of Ancestral Stress.

    Science.gov (United States)

    Faraji, Jamshid; Soltanpour, Nabiollah; Lotfi, Hamid; Moeeini, Reza; Moharreri, Ali-Reza; Roudaki, Shabnam; Hosseini, S Abedin; Olson, David M; Abdollahi, Ali-Akbar; Soltanpour, Nasrin; Mohajerani, Majid H; Metz, Gerlinde A S

    2017-07-13

    Stress is a primary risk factor for psychiatric disorders. However, it is not fully understood why some stressed individuals are more vulnerable to psychiatric disorders than others. Here, we investigated whether multigenerational ancestral stress produces phenotypes that are sensitive to depression-like symptoms in rats. We also examined whether social isolation reveals potentially latent sensitivity to depression-like behaviours. F4 female rats born to a lineage of stressed mothers (F0-F3) received stress in adulthood while housed in pairs or alone. Social isolation during stress induced cognitive and psychomotor retardation only in rats exposed to ancestral stress. Social isolation also hampered the resilience of the hypothalamic-pituitary-adrenal axis to chronic stress and reduced hippocampal volume and brain-derived neurotrophic factor (BDNF) expression. Thus, synergy between social isolation and stress may unmask a latent history of ancestral stress, and raises vulnerability to mental health conditions. The findings support the notion that social support critically promotes stress coping and resilience.

  14. Ancestral state reconstruction, rate heterogeneity, and the evolution of reptile viviparity.

    Science.gov (United States)

    King, Benedict; Lee, Michael S Y

    2015-05-01

    Virtually all models for reconstructing ancestral states for discrete characters make the crucial assumption that the trait of interest evolves at a uniform rate across the entire tree. However, this assumption is unlikely to hold in many situations, particularly as ancestral state reconstructions are being performed on increasingly large phylogenies. Here, we show how failure to account for such variable evolutionary rates can cause highly anomalous (and likely incorrect) results, while three methods that accommodate rate variability yield the opposite, more plausible, and more robust reconstructions. The random local clock method, implemented in BEAST, estimates the position and magnitude of rate changes on the tree; split BiSSE estimates separate rate parameters for pre-specified clades; and the hidden rates model partitions each character state into a number of rate categories. Simulations show the inadequacy of traditional models when characters evolve with both asymmetry (different rates of change between states within a character) and heterotachy (different rates of character evolution across different clades). The importance of accounting for rate heterogeneity in ancestral state reconstruction is highlighted empirically with a new analysis of the evolution of viviparity in squamate reptiles, which reveal a predominance of forward (oviparous-viviparous) transitions and very few reversals. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Preliminary appraisal of ground water in and near the ancestral Missouri River Valley, northeastern Montana

    Science.gov (United States)

    Levings, G.W.

    1986-01-01

    A preliminary appraisal was conducted in and near the ancestral Missouri River valley in northeastern Montana to describe the groundwater resources and to establish a data base for the area. The data base then could be used for future evaluation of possible changes in water levels or water quality. In this area, consolidated aquifers are the Upper Cretaceous Fox Hills-lower Hell Creek aquifer and the overlying Paleocene Fort Union Formation. Unconsolidated aquifers are Pleistocene terrace gravel and glacial deposits and Holocene alluvial deposits. Aquifers are recharged by precipitation, infiltration of streamflow, and possibly leakage from lakes and potholes. Groundwater moves from topographically higher areas to the ancestral valley, then along the ancestral valley to the southwest. Water is discharged from aquifers by evapotranspiration, springs and seeps, movement directly into streams and lakes, and from pumping wells. Average well yields are greatest for irrigation wells completed in outwash gravel (886 gallons/min). Eighteen wells were completed in various aquifers to monitor potential long-term changes in water levels and water quality. Measured water levels declined about 2 ft. or less during the study (1982-85). Chemical analysis of groundwater samples indicated that concentrations of some dissolved constituents exceeded U.S. Environmental Protection Agency standards for drinking water. (USGS)

  16. An allele of an ancestral transcription factor dependent on a horizontally acquired gene product.

    Science.gov (United States)

    Chen, H Deborah; Jewett, Mollie W; Groisman, Eduardo A

    2012-01-01

    Changes in gene regulatory circuits often give rise to phenotypic differences among closely related organisms. In bacteria, these changes can result from alterations in the ancestral genome and/or be brought about by genes acquired by horizontal transfer. Here, we identify an allele of the ancestral transcription factor PmrA that requires the horizontally acquired pmrD gene product to promote gene expression. We determined that a single amino acid difference between the PmrA proteins from the human adapted Salmonella enterica serovar Paratyphi B and the broad host range S. enterica serovar Typhimurium rendered transcription of PmrA-activated genes dependent on the PmrD protein in the former but not the latter serovar. Bacteria harboring the serovar Typhimurium allele exhibited polymyxin B resistance under PmrA- or under PmrA- and PmrD-inducing conditions. By contrast, isogenic strains with the serovar Paratyphi B allele displayed PmrA-regulated polymyxin B resistance only when experiencing activating conditions for both PmrA and PmrD. We establish that the two PmrA orthologs display quantitative differences in several biochemical properties. Strains harboring the serovar Paratyphi B allele showed enhanced biofilm formation, a property that might promote serovar Paratyphi B's chronic infection of the gallbladder. Our findings illustrate how subtle differences in ancestral genes can impact the ability of horizontally acquired genes to confer new properties.

  17. Distinct actions of ancestral vinclozolin and juvenile stress on neural gene expression in the male rat

    Directory of Open Access Journals (Sweden)

    Ross eGillette

    2015-03-01

    Full Text Available Exposure to the endocrine disrupting chemical vinclozolin during gestation of an F0 generation and/or chronic restraint stress during adolescence of the F3 descendants affects behavior, physiology, and gene expression in the brain. Genes related to the networks of growth factors, signaling peptides and receptors, steroid hormone receptors and enzymes, and epigenetic related factors were measured using quantitative polymerase chain reaction via Taqman low density arrays targeting 48 genes in the central amygdaloid nucleus, medial amygdaloid nucleus, medial preoptic area, lateral hypothalamus, and the ventromedial nucleus of the hypothalamus. We found that growth factors are particularly vulnerable to ancestral exposure in the central and medial amygdala; restraint stress during adolescence affected neural growth factors in the medial amygdala. Signaling peptides were affected by both ancestral exposure and stress during adolescence primarily in hypothalamic nuclei. Steroid hormone receptors and enzymes were strongly affected by restraint stress in the medial preoptic area. Epigenetic related genes were affected by stress in the ventromedial hypothalamus and by both ancestral exposure and stress during adolescence independently in the central amygdala. It is noteworthy that the lateral hypothalamus showed no effects of either manipulation. Gene expression is discussed in the context of behavioral and physiological measures previously published.

  18. Distinct actions of ancestral vinclozolin and juvenile stress on neural gene expression in the male rat.

    Science.gov (United States)

    Gillette, Ross; Miller-Crews, Isaac; Skinner, Michael K; Crews, David

    2015-01-01

    Exposure to the endocrine disrupting chemical vinclozolin during gestation of an F0 generation and/or chronic restraint stress during adolescence of the F3 descendants affects behavior, physiology, and gene expression in the brain. Genes related to the networks of growth factors, signaling peptides, and receptors, steroid hormone receptors and enzymes, and epigenetic related factors were measured using quantitative polymerase chain reaction via Taqman low density arrays targeting 48 genes in the central amygdaloid nucleus, medial amygdaloid nucleus, medial preoptic area (mPOA), lateral hypothalamus (LH), and the ventromedial nucleus of the hypothalamus. We found that growth factors are particularly vulnerable to ancestral exposure in the central and medial amygdala; restraint stress during adolescence affected neural growth factors in the medial amygdala. Signaling peptides were affected by both ancestral exposure and stress during adolescence primarily in hypothalamic nuclei. Steroid hormone receptors and enzymes were strongly affected by restraint stress in the mPOA. Epigenetic related genes were affected by stress in the ventromedial nucleus and by both ancestral exposure and stress during adolescence independently in the central amygdala. It is noteworthy that the LH showed no effects of either manipulation. Gene expression is discussed in the context of behavioral and physiological measures previously published.

  19. Ancestral informative marker selection and population structure visualization using sparse Laplacian eigenfunctions.

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    Jun Zhang

    Full Text Available Identification of a small panel of population structure informative markers can reduce genotyping cost and is useful in various applications, such as ancestry inference in association mapping, forensics and evolutionary theory in population genetics. Traditional methods to ascertain ancestral informative markers usually require the prior knowledge of individual ancestry and have difficulty for admixed populations. Recently Principal Components Analysis (PCA has been employed with success to select SNPs which are highly correlated with top significant principal components (PCs without use of individual ancestral information. The approach is also applicable to admixed populations. Here we propose a novel approach based on our recent result on summarizing population structure by graph laplacian eigenfunctions, which differs from PCA in that it is geometric and robust to outliers. Our approach also takes advantage of the priori sparseness of informative markers in the genome. Through simulation of a ring population and the real global population sample HGDP of 650K SNPs genotyped in 940 unrelated individuals, we validate the proposed algorithm at selecting most informative markers, a small fraction of which can recover the similar underlying population structure efficiently. Employing a standard Support Vector Machine (SVM to predict individuals' continental memberships on HGDP dataset of seven continents, we demonstrate that the selected SNPs by our method are more informative but less redundant than those selected by PCA. Our algorithm is a promising tool in genome-wide association studies and population genetics, facilitating the selection of structure informative markers, efficient detection of population substructure and ancestral inference.

  20. Pollination and reproduction of an invasive plant inside and outside its ancestral range

    Science.gov (United States)

    Petanidou, Theodora; Price, Mary V.; Bronstein, Judith L.; Kantsa, Aphrodite; Tscheulin, Thomas; Kariyat, Rupesh; Krigas, Nikos; Mescher, Mark C.; De Moraes, Consuelo M.; Waser, Nickolas M.

    2018-05-01

    Comparing traits of invasive species within and beyond their ancestral range may improve our understanding of processes that promote aggressive spread. Solanum elaeagnifolium (silverleaf nightshade) is a noxious weed in its ancestral range in North America and is invasive on other continents. We compared investment in flowers and ovules, pollination success, and fruit and seed set in populations from Arizona, USA ("AZ") and Greece ("GR"). In both countries, the populations we sampled varied in size and types of present-day disturbance. Stature of plants increased with population size in AZ samples whereas GR plants were uniformly tall. Taller plants produced more flowers, and GR plants produced more flowers for a given stature and allocated more ovules per flower. Similar functional groups of native bees pollinated in AZ and GR populations, but visits to flowers decreased with population size and we observed no visits in the largest GR populations. As a result, plants in large GR populations were pollen-limited, and estimates of fecundity were lower on average in GR populations despite the larger allocation to flowers and ovules. These differences between plants in our AZ and GR populations suggest promising directions for further study. It would be useful to sample S. elaeagnifolium in Mediterranean climates within the ancestral range (e.g., in California, USA), to study asexual spread via rhizomes, and to use common gardens and genetic studies to explore the basis of variation in allocation patterns and of relationships between visitation and fruit set.

  1. Geomorphological Characterization of Atenquique Basin in the Eastern Sector of the Volcan-Nevado-Colima, Jalisco, Mexico, As an Input to the Risk Assessment of Debris Flows.

    Science.gov (United States)

    Flores-Pena, S.; Suarez-Plascencia, C.

    2014-12-01

    The Atenquique river basin drains the eastern sector of the Volcanic Complex (VC) Volcan-Nevado de Colima, located on the border of the states of Jalisco and Colima. To use the digital geomorphological analysis 1:50000 scale mapping provided by INEGI and Landsat images, manipulating it in ArcGIS 10.2 developing the DEM that was the basis for morphometric characterization. The results show that the basin is divided into five sub-basins, with the main Atenquique (SAT) and Arroyo Seco (SAS), calculating the compactness coefficient (Kc) and the coefficient of sinuosity indicate that SAT is the most prone to floods due to straight and slightly sinuous channels. However, the density of dissection shows a more developed drainage network on the SAT, with slopes up to 84° and 600 m deep. The drainage basin has its source at an altitude of 4260 m and its mouth is in the Tuxpan River at 1040 m, which has a relative height of 2800 m; has a funnel-shaped elongated west-east, its outstanding average in the sector are Mountain 44° and 10° the piedmont. The SAT has a total area of 81.8 km2, with a dendritic river network, where the first order streams reach an 82.99%, and second order streams are the 13.4% of the total, these values show that most of the slopes of the basin have incipient development valleys and steep slopes. The basin has had 3 debris flows in recent 58 years; these are formed by large volumes of rock and mud that covered the town of Atenquique and paper mill located at the mouth of the Tuxpan River, caused deaths and significant economic damage. Its genesis is associated with the end of the summer rainy season, so he also worked in the hydrological analysis in order to determine the volume of runoff in the basin. The results of this work are used as input for the determining the risk levels in the study area, and may also be used by the municipality of Tuxpan, in order to define policies to manage risk and reduce future risks to the industrial town of

  2. The ancestral chromosomes of Dromiciops gliroides (Microbiotheridae), and its bearings on the karyotypic evolution of American marsupials

    OpenAIRE

    Su?rez-Villota, Elkin Y.; Haro, Ronie E.; Vargas, Rodrigo A.; Gallardo, Milton H.

    2016-01-01

    Background The low-numbered 14-chromosome karyotype of marsupials has falsified the fusion hypothesis claiming ancestrality from a 22-chromosome karyotype. Since the 14-chromosome condition of the relict Dromiciops gliroides is reminecent of ancestrality, its interstitial traces of past putative fusions and heterochromatin banding patterns were studied and added to available marsupials? cytogenetic data. Fluorescent in situ hybridization (FISH) and self-genomic in situ hybridization (self-GIS...

  3. Evidence that the ancestral haplotype in Australian hemochromatosis patients may be associated with a common mutation in the gene.

    OpenAIRE

    Crawford, D H; Powell, L W; Leggett, B A; Francis, J S; Fletcher, L M; Webb, S I; Halliday, J W; Jazwinska, E C

    1995-01-01

    Hemochromatosis (HC) is a common inherited disorder of iron metabolism for which neither the gene nor biochemical defect have yet been identified. The aim of this study was to look for clinical evidence that the predominant ancestral haplotype in Australian patients is associated with a common mutation in the gene. We compared indices of iron metabolism and storage in three groups of HC patients categorized according to the presence of the ancestral haplotype (i.e., patients with two copies, ...

  4. Evidence that the ancestral haplotype in Australian hemochromatosis patients may be associated with a common mutation in the gene

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, D.H.G.; Powell, L.W.; Leggett, B.A. [Univ. of Queensland (Australia)] [and others

    1995-08-01

    Hemochromatosis (HC) is a common inherited disorder of iron metabolism for which neither the gene nor biochemical defect have yet been identified. The aim of this study was to look for clinical evidence that the predominant ancestral haplotype in Australian patients is associated with a common mutation in the gene. We compared indices of iron metabolism and storage in three groups of HC patients categorized according to the presence of the ancestral haplotype (i.e., patients with two copies, one copy, and no copies of the ancestral haplotype). We also examined iron indices in two groups of HC heterozygotes (those with the ancestral haplotype and those without) and in age-matched controls. These analyses indicate that (i) HC patients with two copies of the ancestral haplotype show significantly more severe expression of the disorder than those with one copy or those without, (ii) HC heterozygotes have partial clinical expression, which may be influenced by the presence of the ancestral haplotype in females but not in males, and (iii) the high population frequency of the HC gene may be the result of the selective advantage conferred by protecting heterozygotes against iron deficiency. 18 refs., 3 tabs.

  5. Evolution of sexes from an ancestral mating-type specification pathway.

    Directory of Open Access Journals (Sweden)

    Sa Geng

    2014-07-01

    Full Text Available Male and female sexes have evolved repeatedly in eukaryotes but the origins of dimorphic sexes and their relationship to mating types in unicellular species are not understood. Volvocine algae include isogamous species such as Chlamydomonas reinhardtii, with two equal-sized mating types, and oogamous multicellular species such as Volvox carteri with sperm-producing males and egg-producing females. Theoretical work predicts genetic linkage of a gamete cell-size regulatory gene(s to an ancestral mating-type locus as a possible step in the evolution of dimorphic gametes, but this idea has not been tested. Here we show that, contrary to predictions, a single conserved mating locus (MT gene in volvocine algae-MID, which encodes a RWP-RK domain transcription factor-evolved from its ancestral role in C. reinhardtii as a mating-type specifier, to become a determinant of sperm and egg development in V. carteri. Transgenic female V. carteri expressing male MID produced functional sperm packets during sexual development. Transgenic male V. carteri with RNA interference (RNAi-mediated knockdowns of VcMID produced functional eggs, or self-fertile hermaphrodites. Post-transcriptional controls were found to regulate cell-type-limited expression and nuclear localization of VcMid protein that restricted its activity to nuclei of developing male germ cells and sperm. Crosses with sex-reversed strains uncoupled sex determination from sex chromosome identity and revealed gender-specific roles for male and female mating locus genes in sexual development, gamete fitness and reproductive success. Our data show genetic continuity between the mating-type specification and sex determination pathways of volvocine algae, and reveal evidence for gender-specific adaptations in the male and female mating locus haplotypes of Volvox. These findings will enable a deeper understanding of how a master regulator of mating-type determination in an ancestral unicellular species was

  6. What was the ancestral sex-determining mechanism in amniote vertebrates?

    Science.gov (United States)

    Johnson Pokorná, Martina; Kratochvíl, Lukáš

    2016-02-01

    Amniote vertebrates, the group consisting of mammals and reptiles including birds, possess various mechanisms of sex determination. Under environmental sex determination (ESD), the sex of individuals depends on the environmental conditions occurring during their development and therefore there are no sexual differences present in their genotypes. Alternatively, through the mode of genotypic sex determination (GSD), sex is determined by a sex-specific genotype, i.e. by the combination of sex chromosomes at various stages of differentiation at conception. As well as influencing sex determination, sex-specific parts of genomes may, and often do, develop specific reproductive or ecological roles in their bearers. Accordingly, an individual with a mismatch between phenotypic (gonadal) and genotypic sex, for example an individual sex-reversed by environmental effects, should have a lower fitness due to the lack of specialized, sex-specific parts of their genome. In this case, evolutionary transitions from GSD to ESD should be less likely than transitions in the opposite direction. This prediction contrasts with the view that GSD was the ancestral sex-determining mechanism for amniote vertebrates. Ancestral GSD would require several transitions from GSD to ESD associated with an independent dedifferentiation of sex chromosomes, at least in the ancestors of crocodiles, turtles, and lepidosaurs (tuataras and squamate reptiles). In this review, we argue that the alternative theory postulating ESD as ancestral in amniotes is more parsimonious and is largely concordant with the theoretical expectations and current knowledge of the phylogenetic distribution and homology of sex-determining mechanisms. © 2014 Cambridge Philosophical Society.

  7. Analysis of ancestral and functionally relevant CD5 variants in systemic lupus erythematosus patients.

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    Maria Carmen Cenit

    Full Text Available CD5 plays a crucial role in autoimmunity and is a well-established genetic risk factor of developing RA. Recently, evidence of positive selection has been provided for the CD5 Pro224-Val471 haplotype in East Asian populations. The aim of the present work was to further analyze the functional relevance of non-synonymous CD5 polymorphisms conforming the ancestral and the newly derived haplotypes (Pro224-Ala471 and Pro224-Val471, respectively as well as to investigate the potential role of CD5 on the development of SLE and/or SLE nephritis.The CD5 SNPs rs2241002 (C/T; Pro224Leu and rs2229177 (C/T; Ala471Val were genotyped using TaqMan allelic discrimination assays in a total of 1,324 controls and 681 SLE patients of Spanish origin. In vitro analysis of CD3-mediated T cell proliferative and cytokine response profiles of healthy volunteers homozygous for the above mentioned CD5 haplotypes were also analyzed.T-cell proliferation and cytokine release were significantly increased showing a bias towards to a Th2 profile after CD3 cross-linking of peripheral mononuclear cells from healthy individuals homozygous for the ancestral Pro224-Ala471 (CC haplotype, compared to the more recently derived Pro224-Val471 (CT. The same allelic combination was statistically associated with Lupus nephritis.The ancestral Ala471 CD5 allele confers lymphocyte hyper-responsiveness to TCR/CD3 cross-linking and is associated with nephritis in SLE patients.

  8. Do Père David's deer lose memories of their ancestral predators?

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    Chunwang Li

    Full Text Available Whether prey retains antipredator behavior after a long period of predator relaxation is an important question in predator-prey evolution. Père David's deer have been raised in enclosures for more than 1200 years and this isolation provides an opportunity to study whether Père David's deer still respond to the cues of their ancestral predators or to novel predators. We played back the sounds of crows (familiar sound and domestic dogs (familiar non-predators, of tigers and wolves (ancestral predators, and of lions (potential naïve predator to Père David's deer in paddocks, and blank sounds to the control group, and videoed the behavior of the deer during the experiment. We also showed life-size photo models of dog, leopard, bear, tiger, wolf, and lion to the deer and video taped their responses after seeing these models. Père David's deer stared at and approached the hidden loudspeaker when they heard the roars of tiger or lion. The deer listened to tiger roars longer, approached to tiger roars more and spent more time staring at the tiger model. The stags were also found to forage less in the trials of tiger roars than that of other sound playbacks. Additionally, it took longer for the deer to restore their normal behavior after they heard tiger roars, which was longer than that after the trial of other sound playbacks. Moreover, the deer were only found to walk away after hearing the sounds of tiger and wolf. Therefore, the tiger was probably the main predator for Père David's deer in ancient time. Our study implies that Père David's deer still retain the memories of the acoustic and visual cues of their ancestral predators in spite of the long term isolation from natural habitat.

  9. The mammary gland-specific marsupial ELP and eutherian CTI share a common ancestral gene.

    Science.gov (United States)

    Pharo, Elizabeth A; De Leo, Alison A; Renfree, Marilyn B; Thomson, Peter C; Lefèvre, Christophe M; Nicholas, Kevin R

    2012-06-08

    The marsupial early lactation protein (ELP) gene is expressed in the mammary gland and the protein is secreted into milk during early lactation (Phase 2A). Mature ELP shares approximately 55.4% similarity with the colostrum-specific bovine colostrum trypsin inhibitor (CTI) protein. Although ELP and CTI both have a single bovine pancreatic trypsin inhibitor (BPTI)-Kunitz domain and are secreted only during the early lactation phases, their evolutionary history is yet to be investigated. Tammar ELP was isolated from a genomic library and the fat-tailed dunnart and Southern koala ELP genes cloned from genomic DNA. The tammar ELP gene was expressed only in the mammary gland during late pregnancy (Phase 1) and early lactation (Phase 2A). The opossum and fat-tailed dunnart ELP and cow CTI transcripts were cloned from RNA isolated from the mammary gland and dog CTI from cells in colostrum. The putative mature ELP and CTI peptides shared 44.6%-62.2% similarity. In silico analyses identified the ELP and CTI genes in the other species examined and provided compelling evidence that they evolved from a common ancestral gene. In addition, whilst the eutherian CTI gene was conserved in the Laurasiatherian orders Carnivora and Cetartiodactyla, it had become a pseudogene in others. These data suggest that bovine CTI may be the ancestral gene of the Artiodactyla-specific, rapidly evolving chromosome 13 pancreatic trypsin inhibitor (PTI), spleen trypsin inhibitor (STI) and the five placenta-specific trophoblast Kunitz domain protein (TKDP1-5) genes. Marsupial ELP and eutherian CTI evolved from an ancestral therian mammal gene before the divergence of marsupials and eutherians between 130 and 160 million years ago. The retention of the ELP gene in marsupials suggests that this early lactation-specific milk protein may have an important role in the immunologically naïve young of these species.

  10. The mammary gland-specific marsupial ELP and eutherian CTI share a common ancestral gene

    Directory of Open Access Journals (Sweden)

    Pharo Elizabeth A

    2012-06-01

    Full Text Available Abstract Background The marsupial early lactation protein (ELP gene is expressed in the mammary gland and the protein is secreted into milk during early lactation (Phase 2A. Mature ELP shares approximately 55.4% similarity with the colostrum-specific bovine colostrum trypsin inhibitor (CTI protein. Although ELP and CTI both have a single bovine pancreatic trypsin inhibitor (BPTI-Kunitz domain and are secreted only during the early lactation phases, their evolutionary history is yet to be investigated. Results Tammar ELP was isolated from a genomic library and the fat-tailed dunnart and Southern koala ELP genes cloned from genomic DNA. The tammar ELP gene was expressed only in the mammary gland during late pregnancy (Phase 1 and early lactation (Phase 2A. The opossum and fat-tailed dunnart ELP and cow CTI transcripts were cloned from RNA isolated from the mammary gland and dog CTI from cells in colostrum. The putative mature ELP and CTI peptides shared 44.6%-62.2% similarity. In silico analyses identified the ELP and CTI genes in the other species examined and provided compelling evidence that they evolved from a common ancestral gene. In addition, whilst the eutherian CTI gene was conserved in the Laurasiatherian orders Carnivora and Cetartiodactyla, it had become a pseudogene in others. These data suggest that bovine CTI may be the ancestral gene of the Artiodactyla-specific, rapidly evolving chromosome 13 pancreatic trypsin inhibitor (PTI, spleen trypsin inhibitor (STI and the five placenta-specific trophoblast Kunitz domain protein (TKDP1-5 genes. Conclusions Marsupial ELP and eutherian CTI evolved from an ancestral therian mammal gene before the divergence of marsupials and eutherians between 130 and 160 million years ago. The retention of the ELP gene in marsupials suggests that this early lactation-specific milk protein may have an important role in the immunologically naïve young of these species.

  11. Sustainability of ancestral methods of agricultural production in Perú: ¿keep or replace?

    Directory of Open Access Journals (Sweden)

    Dani Eduardo Vargas Huanca

    2016-09-01

    Full Text Available Based on the success of some Andean products such as quinoa, potatoes or maca in international food trade and the growing environmental degradation facing developing countries, resulting from intensive exploitation activities; Our research seeks to show the trend that is assumed from the academic / scientific community and public officials in the food sector in Peru, against the need to maintain sustainable various ancestral modes of agricultural production (case quinoa, for it analyze quantitative and qualitative obtained from public institutions and Peruvian universities.

  12. Comparative analysis of rosaceous genomes and the reconstruction of a putative ancestral genome for the family.

    Science.gov (United States)

    Illa, Eudald; Sargent, Daniel J; Lopez Girona, Elena; Bushakra, Jill; Cestaro, Alessandro; Crowhurst, Ross; Pindo, Massimo; Cabrera, Antonio; van der Knaap, Esther; Iezzoni, Amy; Gardiner, Susan; Velasco, Riccardo; Arús, Pere; Chagné, David; Troggio, Michela

    2011-01-12

    Comparative genome mapping studies in Rosaceae have been conducted until now by aligning genetic maps within the same genus, or closely related genera and using a limited number of common markers. The growing body of genomics resources and sequence data for both Prunus and Fragaria permits detailed comparisons between these genera and the recently released Malus × domestica genome sequence. We generated a comparative analysis using 806 molecular markers that are anchored genetically to the Prunus and/or Fragaria reference maps, and physically to the Malus genome sequence. Markers in common for Malus and Prunus, and Malus and Fragaria, respectively were 784 and 148. The correspondence between marker positions was high and conserved syntenic blocks were identified among the three genera in the Rosaceae. We reconstructed a proposed ancestral genome for the Rosaceae. A genome containing nine chromosomes is the most likely candidate for the ancestral Rosaceae progenitor. The number of chromosomal translocations observed between the three genera investigated was low. However, the number of inversions identified among Malus and Prunus was much higher than any reported genome comparisons in plants, suggesting that small inversions have played an important role in the evolution of these two genera or of the Rosaceae.

  13. Comparative analysis of rosaceous genomes and the reconstruction of a putative ancestral genome for the family

    Directory of Open Access Journals (Sweden)

    Velasco Riccardo

    2011-01-01

    Full Text Available Abstract Background Comparative genome mapping studies in Rosaceae have been conducted until now by aligning genetic maps within the same genus, or closely related genera and using a limited number of common markers. The growing body of genomics resources and sequence data for both Prunus and Fragaria permits detailed comparisons between these genera and the recently released Malus × domestica genome sequence. Results We generated a comparative analysis using 806 molecular markers that are anchored genetically to the Prunus and/or Fragaria reference maps, and physically to the Malus genome sequence. Markers in common for Malus and Prunus, and Malus and Fragaria, respectively were 784 and 148. The correspondence between marker positions was high and conserved syntenic blocks were identified among the three genera in the Rosaceae. We reconstructed a proposed ancestral genome for the Rosaceae. Conclusions A genome containing nine chromosomes is the most likely candidate for the ancestral Rosaceae progenitor. The number of chromosomal translocations observed between the three genera investigated was low. However, the number of inversions identified among Malus and Prunus was much higher than any reported genome comparisons in plants, suggesting that small inversions have played an important role in the evolution of these two genera or of the Rosaceae.

  14. Ancestral state reconstruction infers phytopathogenic origins of sooty blotch and flyspeck fungi on apple.

    Science.gov (United States)

    Ismail, Siti Izera; Batzer, Jean Carlson; Harrington, Thomas C; Crous, Pedro W; Lavrov, Dennis V; Li, Huanyu; Gleason, Mark L

    2016-01-01

    Members of the sooty blotch and flyspeck (SBFS) complex are epiphytic fungi in the Ascomycota that cause economically damaging blemishes of apples worldwide. SBFS fungi are polyphyletic, but approx. 96% of SBFS species are in the Capnodiales. Evolutionary origins of SBFS fungi remain unclear, so we attempted to infer their origins by means of ancestral state reconstruction on a phylogenetic tree built utilizing genes for the nuc 28S rDNA (approx. 830 bp from near the 59 end) and the second largest subunit of RNA polymerase II (RPB2). The analyzed taxa included the well-known genera of SBFS as well as non-SBFS fungi from seven families within the Capnodiales. The non-SBFS taxa were selected based on their distinct ecological niches, including plant-parasitic and saprophytic species. The phylogenetic analyses revealed that most SBFS species in the Capnodiales are closely related to plant-parasitic fungi. Ancestral state reconstruction provided strong evidence that plant-parasitic fungi were the ancestors of the major SBFS lineages. Knowledge gained from this study may help to better understand the ecology and evolution of epiphytic fungi. © 2016 by The Mycological Society of America.

  15. Reconstructing an ancestral mammalian immune supercomplex from a marsupial major histocompatibility complex.

    Directory of Open Access Journals (Sweden)

    Katherine Belov

    2006-03-01

    Full Text Available The first sequenced marsupial genome promises to reveal unparalleled insights into mammalian evolution. We have used the Monodelphis domestica (gray short-tailed opossum sequence to construct the first map of a marsupial major histocompatibility complex (MHC. The MHC is the most gene-dense region of the mammalian genome and is critical to immunity and reproductive success. The marsupial MHC bridges the phylogenetic gap between the complex MHC of eutherian mammals and the minimal essential MHC of birds. Here we show that the opossum MHC is gene dense and complex, as in humans, but shares more organizational features with non-mammals. The Class I genes have amplified within the Class II region, resulting in a unique Class I/II region. We present a model of the organization of the MHC in ancestral mammals and its elaboration during mammalian evolution. The opossum genome, together with other extant genomes, reveals the existence of an ancestral "immune supercomplex" that contained genes of both types of natural killer receptors together with antigen processing genes and MHC genes.

  16. Evidence for Ancestral Programming of Resilience in a Two-Hit Stress Model

    Directory of Open Access Journals (Sweden)

    Jamshid Faraji

    2017-05-01

    Full Text Available In a continuously stressful environment, the effects of recurrent prenatal stress (PS may accumulate across generations and alter stress vulnerability and resilience. Here, we report in female rats that a family history of recurrent ancestral PS facilitates certain aspects of movement performance, and that these benefits are abolished by the experience of a second hit, induced by a silent ischemia during adulthood. Female F4-generation rats with and without a family history of cumulative multigenerational PS (MPS were tested for skilled motor function before and after the induction of a minor ischemic insult by endothelin-1 infusion into the primary motor cortex. MPS resulted in improved skilled motor abilities and blunted hypothalamic-pituitary-adrenal (HPA axis function compared to non-stressed rats. Deep sequencing revealed downregulation of miR-708 in MPS rats along with upregulation of its predicted target genes Mapk10 and Rasd2. Through miR-708 stress may regulate mitogen-activated protein kinase (MAPK pathway activity. Hair trace elemental analysis revealed an increased Na/K ratio, which suggests a chronic shift in adrenal gland function. The ischemic lesion activated the HPA axis in MPS rats only; the lesion, however, abolished the advantage of MPS in skilled reaching. The findings indicate that MPS generates adaptive flexibility in movement, which is challenged by a second stressor, such as a neuropathological condition. Thus, a second “hit” by a stressor may limit behavioral flexibility and neural plasticity associated with ancestral stress.

  17. Bearing the unbearable: ancestral transmission through dreams and moving metaphors in the analtyic field.

    Science.gov (United States)

    Pickering, Judith

    2012-11-01

    This paper explores how untold and unresolved intergenerational trauma may be transmitted through unconscious channels of communication, manifesting in the dreams of descendants. Unwitting carriers for that which was too horrific for their ancestors to bear, descendants may enter analysis through an unconscious need to uncover past secrets, piece together ancestral histories before the keys to comprehending their terrible inheritance die with their forebears. They seek the relational containment of the analytic relationship to provide psychological conditions to bear the unbearable, know the unknowable, speak the unspeakable and redeem the unredeemable. In the case of 'Rachael', initial dreams gave rise to what Hobson (1984) called 'moving metaphors of self' in the analytic field. Dream imagery, projective and introjective processes in the transference-countertransference dynamics gradually revealed an unknown ancestral history. I clarify the back and forth process from dream to waking dream thoughts to moving metaphors and differentiate the moving metaphor from a living symbol. I argue that the containment of the analytic relationship nested within the security of the analytic space is a necessary precondition for such healing processes to occur. © 2012, The Society of Analytical Psychology.

  18. Sexually dimorphic effects of ancestral exposure to vinclozolin on stress reactivity in rats.

    Science.gov (United States)

    Gillette, Ross; Miller-Crews, Isaac; Nilsson, Eric E; Skinner, Michael K; Gore, Andrea C; Crews, David

    2014-10-01

    How an individual responds to the environment depends upon both personal life history as well as inherited genetic and epigenetic factors from ancestors. Using a 2-hit, 3 generations apart model, we tested how F3 descendants of rats given in utero exposure to the environmental endocrine-disrupting chemical (EDC) vinclozolin reacted to stress during adolescence in their own lives, focusing on sexually dimorphic phenotypic outcomes. In adulthood, male and female F3 vinclozolin- or vehicle-lineage rats, stressed or nonstressed, were behaviorally characterized on a battery of tests and then euthanized. Serum was used for hormone assays, and brains were used for quantitative PCR and transcriptome analyses. Results showed that the effects of ancestral exposure to vinclozolin converged with stress experienced during adolescence in a sexually dimorphic manner. Debilitating effects were seen at all levels of the phenotype, including physiology, behavior, brain metabolism, gene expression, and genome-wide transcriptome modifications in specific brain nuclei. Additionally, females were significantly more vulnerable than males to transgenerational effects of vinclozolin on anxiety but not sociality tests. This fundamental transformation occurs in a manner not predicted by the ancestral exposure or the proximate effects of stress during adolescence, an interaction we refer to as synchronicity.

  19. Phylogenetic signal from rearrangements in 18 Anopheles species by joint scaffolding extant and ancestral genomes.

    Science.gov (United States)

    Anselmetti, Yoann; Duchemin, Wandrille; Tannier, Eric; Chauve, Cedric; Bérard, Sèverine

    2018-05-09

    Genomes rearrangements carry valuable information for phylogenetic inference or the elucidation of molecular mechanisms of adaptation. However, the detection of genome rearrangements is often hampered by current deficiencies in data and methods: Genomes obtained from short sequence reads have generally very fragmented assemblies, and comparing multiple gene orders generally leads to computationally intractable algorithmic questions. We present a computational method, ADSEQ, which, by combining ancestral gene order reconstruction, comparative scaffolding and de novo scaffolding methods, overcomes these two caveats. ADSEQ provides simultaneously improved assemblies and ancestral genomes, with statistical supports on all local features. Compared to previous comparative methods, it runs in polynomial time, it samples solutions in a probabilistic space, and it can handle a significantly larger gene complement from the considered extant genomes, with complex histories including gene duplications and losses. We use ADSEQ to provide improved assemblies and a genome history made of duplications, losses, gene translocations, rearrangements, of 18 complete Anopheles genomes, including several important malaria vectors. We also provide additional support for a differentiated mode of evolution of the sex chromosome and of the autosomes in these mosquito genomes. We demonstrate the method's ability to improve extant assemblies accurately through a procedure simulating realistic assembly fragmentation. We study a debated issue regarding the phylogeny of the Gambiae complex group of Anopheles genomes in the light of the evolution of chromosomal rearrangements, suggesting that the phylogenetic signal they carry can differ from the phylogenetic signal carried by gene sequences, more prone to introgression.

  20. A branch-heterogeneous model of protein evolution for efficient inference of ancestral sequences.

    Science.gov (United States)

    Groussin, M; Boussau, B; Gouy, M

    2013-07-01

    Most models of nucleotide or amino acid substitution used in phylogenetic studies assume that the evolutionary process has been homogeneous across lineages and that composition of nucleotides or amino acids has remained the same throughout the tree. These oversimplified assumptions are refuted by the observation that compositional variability characterizes extant biological sequences. Branch-heterogeneous models of protein evolution that account for compositional variability have been developed, but are not yet in common use because of the large number of parameters required, leading to high computational costs and potential overparameterization. Here, we present a new branch-nonhomogeneous and nonstationary model of protein evolution that captures more accurately the high complexity of sequence evolution. This model, henceforth called Correspondence and likelihood analysis (COaLA), makes use of a correspondence analysis to reduce the number of parameters to be optimized through maximum likelihood, focusing on most of the compositional variation observed in the data. The model was thoroughly tested on both simulated and biological data sets to show its high performance in terms of data fitting and CPU time. COaLA efficiently estimates ancestral amino acid frequencies and sequences, making it relevant for studies aiming at reconstructing and resurrecting ancestral amino acid sequences. Finally, we applied COaLA on a concatenate of universal amino acid sequences to confirm previous results obtained with a nonhomogeneous Bayesian model regarding the early pattern of adaptation to optimal growth temperature, supporting the mesophilic nature of the Last Universal Common Ancestor.

  1. A phylogenetic Kalman filter for ancestral trait reconstruction using molecular data.

    Science.gov (United States)

    Lartillot, Nicolas

    2014-02-15

    Correlation between life history or ecological traits and genomic features such as nucleotide or amino acid composition can be used for reconstructing the evolutionary history of the traits of interest along phylogenies. Thus far, however, such ancestral reconstructions have been done using simple linear regression approaches that do not account for phylogenetic inertia. These reconstructions could instead be seen as a genuine comparative regression problem, such as formalized by classical generalized least-square comparative methods, in which the trait of interest and the molecular predictor are represented as correlated Brownian characters coevolving along the phylogeny. Here, a Bayesian sampler is introduced, representing an alternative and more efficient algorithmic solution to this comparative regression problem, compared with currently existing generalized least-square approaches. Technically, ancestral trait reconstruction based on a molecular predictor is shown to be formally equivalent to a phylogenetic Kalman filter problem, for which backward and forward recursions are developed and implemented in the context of a Markov chain Monte Carlo sampler. The comparative regression method results in more accurate reconstructions and a more faithful representation of uncertainty, compared with simple linear regression. Application to the reconstruction of the evolution of optimal growth temperature in Archaea, using GC composition in ribosomal RNA stems and amino acid composition of a sample of protein-coding genes, confirms previous findings, in particular, pointing to a hyperthermophilic ancestor for the kingdom. The program is freely available at www.phylobayes.org.

  2. Trace elements in South America aerosol during 20th century inferred from a Nevado Illimani ice core, Eastern Bolivian Andes (6350 m asl

    Directory of Open Access Journals (Sweden)

    A. Correia

    2003-01-01

    Full Text Available A 137 m ice core drilled in 1999 from Eastern Bolivian Andes at the summit of Nevado Illimani (16º 37' S, 67º 46' W, 6350 m asl was analyzed at high temporal resolution, allowing a characterization of trace elements in Andean aerosol trapped in the ice during the 20th century. The upper 50 m of the ice core were dated by multi-proxy analysis of stable isotopes (d18O and d2H, 137Cs and Ca+2 content, electrical conductivity, and insoluble microparticle content, together with reference historical horizons from atmospheric nuclear tests and known volcanic eruptions. This 50 m section corresponds to a record of environmental variations spanning about 80 years from 1919 to 1999. It was cut in 744 sub-samples under laminar flow in a clean bench, which were analyzed by Ion Chromatography for major ionic concentration, by a particle counter for insoluble aerosol content, and by Inductively Coupled Plasma Mass Spectrometry (ICP-MS for the concentration of 45 chemical species from Li to U. This paper focuses on results of trace element concentrations measured by ICP-MS. The high temporal resolution used in the analyses allowed classifying samples as belonging to dry or wet seasons. During wet season elemental concentrations are low and samples show high crustal enrichment factors. During dry seasons the situation is opposite, with high elemental concentrations and low crustal enrichments. For example, with salt lakes as main sources in the region, average Li concentration during the 20th century is 0.035 and 0.90 ng g-1 for wet and dry seasons, respectively. Illimani average seasonal concentration ranges cover the spectrum of elemental concentration measurements at another Andean ice core site (Sajama for most soil-related elements. Regional crustal dust load in the deposits was found to be overwhelming during dry season, obfuscating the contribution of biomass burning material. Marked temporal trends from the onset of 20th century to more recent years

  3. Thermotolerant Yeast Strains Adapted by Laboratory Evolution Show Trade-Off at Ancestral Temperatures and Preadaptation to Other Stresses

    DEFF Research Database (Denmark)

    Caspeta, Luis; Nielsen, Jens

    2015-01-01

    adaptive laboratory evolution, we previously isolated seven Saccharomyces cerevisiae strains with improved growth at 40°C. Here, we show that genetic adaptations to high temperature caused a growth trade-off at ancestral temperatures, reduced cellular functions, and improved tolerance of other stresses...... in the ancestral strain. The latter is an advantageous attribute for acquiring thermotolerance and correlates with the reduction of yeast functions associated with loss of respiration capacity. This trait caused glycerol overproduction that was associated with the growth trade-off at ancestral temperatures....... In combination with altered sterol composition of cellular membranes, glycerol overproduction was also associated with yeast osmotolerance and improved tolerance of high concentrations of glucose and ethanol. Our study shows that thermal adaptation of yeast is suitable for improving yeast resistance...

  4. Estimating Divergence Time and Ancestral Effective Population Size of Bornean and Sumatran Orangutan Subspecies Using a Coalescent Hidden Markov Model

    DEFF Research Database (Denmark)

    Mailund, Thomas; Dutheil, Julien; Hobolth, Asger

    2011-01-01

    event has occurred to split them apart. The size of these segments of constant divergence depends on the recombination rate, but also on the speciation time, the effective population size of the ancestral population, as well as demographic effects and selection. Thus, inference of these parameters may......, and the ancestral effective population size. The model is efficient enough to allow inference on whole-genome data sets. We first investigate the power and consistency of the model with coalescent simulations and then apply it to the whole-genome sequences of the two orangutan sub-species, Bornean (P. p. pygmaeus......) and Sumatran (P. p. abelii) orangutans from the Orangutan Genome Project. We estimate the speciation time between the two sub-species to be thousand years ago and the effective population size of the ancestral orangutan species to be , consistent with recent results based on smaller data sets. We also report...

  5. Peces del Noroeste del Ecuador

    OpenAIRE

    Barriga, Ramiro

    1994-01-01

    La ictiofauna del occidente del Ecuador es poco conocida. Los peces del noroccidente son diferentes a los del suroccidente del Ecuador. 34 familias y 82 especies fueron colectadas que equivale al 11 % de las especies de peces continentales registradas en el Ecuador. Icteogeográficamente se sabe que la costa ecuatoriana posee dos provincias: la del Pacifico Norte y la del Guayas, se determinó que el límite de las dos provincias es el río Santiago ya que las especies del mencionado río so...

  6. Effects of ancestral x irradiation followed by random mating on body weight of rats

    International Nuclear Information System (INIS)

    Gianola, D.; Chapman, A.B.; Rutledge, J.J.

    1977-01-01

    Effects of nine generations of 450R per generation of ancestral spermatogonial x irradiation of inbred rats on body weight were examined. After six generations of random mating (avoiding inbreeding) following the termination of irradiation, descendants of irradiated males (R) were significantly lighter than their controls (C) at 3 and 6 weeks, but not at 10 weeks of age. However, differences in growth between R and C populations were small. Among-litter and within-litter variance estimates were generally larger in the R lines than in the C lines, suggesting that selection responses would be greater in R than in C lines. In conjunction with previous evidence--obtained during the irradiation phase of the experiment--this suggested that more rapid response to selection for 6-week body weight, in particular, might accrue in the R lines

  7. Where did the chili get its spice? Biogeography of capsaicinoid production in ancestral wild chili species.

    Science.gov (United States)

    Tewksbury, Joshua J; Manchego, Carlos; Haak, David C; Levey, Douglas J

    2006-03-01

    The biogeography of pungency in three species of wild chili in the chaco and surrounding highland habitats of southeastern Bolivia is described. We report that Capsicum chacoense, C. baccatum, and C. eximium are polymorphic for production of capsaicin and its analogs, such that completely pungent and completely nonpungent individuals co-occur in some populations. In C. chacoense, the density of plants and the proportion of pungent plants increased with elevation. Above 900 m, all individuals in all populations except two were pungent; nonpungent individuals in at least one of the two polymorphic populations were likely a result of spreading by humans. The occurrence of pungent and nonpungent individuals in three species of ancestral Capsicum and the geographic variation of pungency within species suggest that production of capsaicin and its analogs entails both costs and benefits, which shift from one locality to another. Determining the selection pressures behind such shifts is necessary to understand the evolution of pungency in chilies.

  8. Loop Replacement Enhances the Ancestral Antibacterial Function of a Bifunctional Scorpion Toxin

    Directory of Open Access Journals (Sweden)

    Shangfei Zhang

    2018-06-01

    Full Text Available On the basis of the evolutionary relationship between scorpion toxins targeting K+ channels (KTxs and antibacterial defensins (Zhu S., Peigneur S., Gao B., Umetsu Y., Ohki S., Tytgat J. Experimental conversion of a defensin into a neurotoxin: Implications for origin of toxic function. Mol. Biol. Evol. 2014, 31, 546–559, we performed protein engineering experiments to modify a bifunctional KTx (i.e., weak inhibitory activities on both K+ channels and bacteria via substituting its carboxyl loop with the structurally equivalent loop of contemporary defensins. As expected, the engineered peptide (named MeuTXKα3-KFGGI remarkably improved the antibacterial activity, particularly on some Gram-positive bacteria, including several antibiotic-resistant opportunistic pathogens. Compared with the unmodified toxin, its antibacterial spectrum also enlarged. Our work provides a new method to enhance the antibacterial activity of bifunctional scorpion venom peptides, which might be useful in engineering other proteins with an ancestral activity.

  9. Did warfare among ancestral hunter-gatherers affect the evolution of human social behaviors?

    Science.gov (United States)

    Bowles, Samuel

    2009-06-05

    Since Darwin, intergroup hostilities have figured prominently in explanations of the evolution of human social behavior. Yet whether ancestral humans were largely "peaceful" or "warlike" remains controversial. I ask a more precise question: If more cooperative groups were more likely to prevail in conflicts with other groups, was the level of intergroup violence sufficient to influence the evolution of human social behavior? Using a model of the evolutionary impact of between-group competition and a new data set that combines archaeological evidence on causes of death during the Late Pleistocene and early Holocene with ethnographic and historical reports on hunter-gatherer populations, I find that the estimated level of mortality in intergroup conflicts would have had substantial effects, allowing the proliferation of group-beneficial behaviors that were quite costly to the individual altruist.

  10. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor

    Science.gov (United States)

    Baldwin, Maude W.; Toda, Yasuka; Nakagita, Tomoya; O'Connell, Mary J.; Klasing, Kirk C.; Misaka, Takumi; Edwards, Scott V.; Liberles, Stephen D.

    2015-01-01

    Sensory systems define an animal's capacity for perception and can evolve to promote survival in new environmental niches. We have uncovered a noncanonical mechanism for sweet taste perception that evolved in hummingbirds since their divergence from insectivorous swifts, their closest relatives. We observed the widespread absence in birds of an essential subunit (T1R2) of the only known vertebrate sweet receptor, raising questions about how specialized nectar feeders such as hummingbirds sense sugars. Receptor expression studies revealed that the ancestral umami receptor (the T1R1-T1R3 heterodimer) was repurposed in hummingbirds to function as a carbohydrate receptor. Furthermore, the molecular recognition properties of T1R1-T1R3 guided taste behavior in captive and wild hummingbirds. We propose that changing taste receptor function enabled hummingbirds to perceive and use nectar, facilitating the massive radiation of hummingbird species. PMID:25146290

  11. Sensory biology. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor.

    Science.gov (United States)

    Baldwin, Maude W; Toda, Yasuka; Nakagita, Tomoya; O'Connell, Mary J; Klasing, Kirk C; Misaka, Takumi; Edwards, Scott V; Liberles, Stephen D

    2014-08-22

    Sensory systems define an animal's capacity for perception and can evolve to promote survival in new environmental niches. We have uncovered a noncanonical mechanism for sweet taste perception that evolved in hummingbirds since their divergence from insectivorous swifts, their closest relatives. We observed the widespread absence in birds of an essential subunit (T1R2) of the only known vertebrate sweet receptor, raising questions about how specialized nectar feeders such as hummingbirds sense sugars. Receptor expression studies revealed that the ancestral umami receptor (the T1R1-T1R3 heterodimer) was repurposed in hummingbirds to function as a carbohydrate receptor. Furthermore, the molecular recognition properties of T1R1-T1R3 guided taste behavior in captive and wild hummingbirds. We propose that changing taste receptor function enabled hummingbirds to perceive and use nectar, facilitating the massive radiation of hummingbird species. Copyright © 2014, American Association for the Advancement of Science.

  12. Treinta años después de la erupción del volcán Nevado del Ruiz: memorias, voces, reparación y escenarios de participación

    Directory of Open Access Journals (Sweden)

    Viviana Ramírez Loaiza

    2017-01-01

    Se concluye, que las personas sobrevivientes, participantes de la investigación, muestran una tendencia ante la memoria, conminada por el recuerdo, el dolor y la confusión, tanto en lo individual, como en lo colectivo e institucional. De igual forma los hallazgos develaron escenarios de participación política que aportan al fortalecimiento de las estrategias de afrontamiento individual y a la construcción de ejercicios de ciudadanía activa que, para el caso de Villamaría (Caldas, empieza a permear modos de vida de los habitantes en zona de alto riesgo.

  13. Wiring a periscope--ocelli, retinula axons, visual neuropils and the ancestrality of sea spiders.

    Science.gov (United States)

    Lehmann, Tobias; Hess, Martin; Melzer, Roland R

    2012-01-01

    The Pycnogonida or sea spiders are cryptic, eight-legged arthropods with four median ocelli in a 'periscope' or eye tubercle. In older attempts at reconstructing phylogeny they were Arthropoda incertae sedis, but recent molecular trees placed them as the sister group either to all other euchelicerates or even to all euarthropods. Thus, pycnogonids are among the oldest extant arthropods and hold a key position for the understanding of arthropod evolution. This has stimulated studies of new sets of characters conductive to cladistic analyses, e.g. of the chelifores and of the hox gene expression pattern. In contrast knowledge of the architecture of the visual system is cursory. A few studies have analysed the ocelli and the uncommon "pseudoinverted" retinula cells. Moreover, analyses of visual neuropils are still at the stage of Hanström's early comprehensive works. We have therefore used various techniques to analyse the visual fibre pathways and the structure of their interrelated neuropils in several species. We found that pycnogonid ocelli are innervated to first and second visual neuropils in close vicinity to an unpaired midline neuropil, i.e. possibly the arcuate body, in a way very similar to ancestral euarthropods like Euperipatoides rowelli (Onychophora) and Limulus polyphemus (Xiphosura). This supports the ancestrality of pycnogonids and sheds light on what eyes in the pycnogonid ground plan might have 'looked' like. Recently it was suggested that arthropod eyes originated from simple ocelli similar to larval eyes. Hence, pycnogonid eyes would be one of the early offshoots among the wealth of more sophisticated arthropod eyes.

  14. Wiring a periscope--ocelli, retinula axons, visual neuropils and the ancestrality of sea spiders.

    Directory of Open Access Journals (Sweden)

    Tobias Lehmann

    Full Text Available The Pycnogonida or sea spiders are cryptic, eight-legged arthropods with four median ocelli in a 'periscope' or eye tubercle. In older attempts at reconstructing phylogeny they were Arthropoda incertae sedis, but recent molecular trees placed them as the sister group either to all other euchelicerates or even to all euarthropods. Thus, pycnogonids are among the oldest extant arthropods and hold a key position for the understanding of arthropod evolution. This has stimulated studies of new sets of characters conductive to cladistic analyses, e.g. of the chelifores and of the hox gene expression pattern. In contrast knowledge of the architecture of the visual system is cursory. A few studies have analysed the ocelli and the uncommon "pseudoinverted" retinula cells. Moreover, analyses of visual neuropils are still at the stage of Hanström's early comprehensive works. We have therefore used various techniques to analyse the visual fibre pathways and the structure of their interrelated neuropils in several species. We found that pycnogonid ocelli are innervated to first and second visual neuropils in close vicinity to an unpaired midline neuropil, i.e. possibly the arcuate body, in a way very similar to ancestral euarthropods like Euperipatoides rowelli (Onychophora and Limulus polyphemus (Xiphosura. This supports the ancestrality of pycnogonids and sheds light on what eyes in the pycnogonid ground plan might have 'looked' like. Recently it was suggested that arthropod eyes originated from simple ocelli similar to larval eyes. Hence, pycnogonid eyes would be one of the early offshoots among the wealth of more sophisticated arthropod eyes.

  15. Wiring a Periscope – Ocelli, Retinula Axons, Visual Neuropils and the Ancestrality of Sea Spiders

    Science.gov (United States)

    Lehmann, Tobias; Heß, Martin; Melzer, Roland R.

    2012-01-01

    The Pycnogonida or sea spiders are cryptic, eight-legged arthropods with four median ocelli in a ‘periscope’ or eye tubercle. In older attempts at reconstructing phylogeny they were Arthropoda incertae sedis, but recent molecular trees placed them as the sister group either to all other euchelicerates or even to all euarthropods. Thus, pycnogonids are among the oldest extant arthropods and hold a key position for the understanding of arthropod evolution. This has stimulated studies of new sets of characters conductive to cladistic analyses, e.g. of the chelifores and of the hox gene expression pattern. In contrast knowledge of the architecture of the visual system is cursory. A few studies have analysed the ocelli and the uncommon “pseudoinverted” retinula cells. Moreover, analyses of visual neuropils are still at the stage of Hanström's early comprehensive works. We have therefore used various techniques to analyse the visual fibre pathways and the structure of their interrelated neuropils in several species. We found that pycnogonid ocelli are innervated to first and second visual neuropils in close vicinity to an unpaired midline neuropil, i.e. possibly the arcuate body, in a way very similar to ancestral euarthropods like Euperipatoides rowelli (Onychophora) and Limulus polyphemus (Xiphosura). This supports the ancestrality of pycnogonids and sheds light on what eyes in the pycnogonid ground plan might have ‘looked’ like. Recently it was suggested that arthropod eyes originated from simple ocelli similar to larval eyes. Hence, pycnogonid eyes would be one of the early offshoots among the wealth of more sophisticated arthropod eyes. PMID:22279594

  16. Genes Suggest Ancestral Colour Polymorphisms Are Shared across Morphologically Cryptic Species in Arctic Bumblebees.

    Directory of Open Access Journals (Sweden)

    Paul H Williams

    Full Text Available Our grasp of biodiversity is fine-tuned through the process of revisionary taxonomy. If species do exist in nature and can be discovered with available techniques, then we expect these revisions to converge on broadly shared interpretations of species. But for the primarily arctic bumblebees of the subgenus Alpinobombus of the genus Bombus, revisions by some of the most experienced specialists are unusual for bumblebees in that they have all reached different conclusions on the number of species present. Recent revisions based on skeletal morphology have concluded that there are from four to six species, while variation in colour pattern of the hair raised questions as to whether at least seven species might be present. Even more species are supported if we accept the recent move away from viewing species as morphotypes to viewing them instead as evolutionarily independent lineages (EILs using data from genes. EILs are recognised here in practice from the gene coalescents that provide direct evidence for their evolutionary independence. We show from fitting both general mixed Yule/coalescent (GMYC models and Poisson-tree-process (PTP models to data for the mitochondrial COI gene that there is support for nine species in the subgenus Alpinobombus. Examination of the more slowly evolving nuclear PEPCK gene shows further support for a previously unrecognised taxon as a new species in northwestern North America. The three pairs of the most morphologically similar sister species are separated allopatrically and prevented from interbreeding by oceans. We also find that most of the species show multiple shared colour patterns, giving the appearance of mimicry among parts of the different species. However, reconstructing ancestral colour-pattern states shows that speciation is likely to have cut across widespread ancestral polymorphisms, without or largely without convergence. In the particular case of Alpinobombus, morphological, colour-pattern, and

  17. Characterisation of monotreme caseins reveals lineage-specific expansion of an ancestral casein locus in mammals.

    Science.gov (United States)

    Lefèvre, Christophe M; Sharp, Julie A; Nicholas, Kevin R

    2009-01-01

    Using a milk-cell cDNA sequencing approach we characterised milk-protein sequences from two monotreme species, platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus) and found a full set of caseins and casein variants. The genomic organisation of the platypus casein locus is compared with other mammalian genomes, including the marsupial opossum and several eutherians. Physical linkage of casein genes has been seen in the casein loci of all mammalian genomes examined and we confirm that this is also observed in platypus. However, we show that a recent duplication of beta-casein occurred in the monotreme lineage, as opposed to more ancient duplications of alpha-casein in the eutherian lineage, while marsupials possess only single copies of alpha- and beta-caseins. Despite this variability, the close proximity of the main alpha- and beta-casein genes in an inverted tail-tail orientation and the relative orientation of the more distant kappa-casein genes are similar in all mammalian genome sequences so far available. Overall, the conservation of the genomic organisation of the caseins indicates the early, pre-monotreme development of the fundamental role of caseins during lactation. In contrast, the lineage-specific gene duplications that have occurred within the casein locus of monotremes and eutherians but not marsupials, which may have lost part of the ancestral casein locus, emphasises the independent selection on milk provision strategies to the young, most likely linked to different developmental strategies. The monotremes therefore provide insight into the ancestral drivers for lactation and how these have adapted in different lineages.

  18. Origin of amphibian and avian chromosomes by fission, fusion, and retention of ancestral chromosomes

    Science.gov (United States)

    Voss, Stephen R.; Kump, D. Kevin; Putta, Srikrishna; Pauly, Nathan; Reynolds, Anna; Henry, Rema J.; Basa, Saritha; Walker, John A.; Smith, Jeramiah J.

    2011-01-01

    Amphibian genomes differ greatly in DNA content and chromosome size, morphology, and number. Investigations of this diversity are needed to identify mechanisms that have shaped the evolution of vertebrate genomes. We used comparative mapping to investigate the organization of genes in the Mexican axolotl (Ambystoma mexicanum), a species that presents relatively few chromosomes (n = 14) and a gigantic genome (>20 pg/N). We show extensive conservation of synteny between Ambystoma, chicken, and human, and a positive correlation between the length of conserved segments and genome size. Ambystoma segments are estimated to be four to 51 times longer than homologous human and chicken segments. Strikingly, genes demarking the structures of 28 chicken chromosomes are ordered among linkage groups defining the Ambystoma genome, and we show that these same chromosomal segments are also conserved in a distantly related anuran amphibian (Xenopus tropicalis). Using linkage relationships from the amphibian maps, we predict that three chicken chromosomes originated by fusion, nine to 14 originated by fission, and 12–17 evolved directly from ancestral tetrapod chromosomes. We further show that some ancestral segments were fused prior to the divergence of salamanders and anurans, while others fused independently and randomly as chromosome numbers were reduced in lineages leading to Ambystoma and Xenopus. The maintenance of gene order relationships between chromosomal segments that have greatly expanded and contracted in salamander and chicken genomes, respectively, suggests selection to maintain synteny relationships and/or extremely low rates of chromosomal rearrangement. Overall, the results demonstrate the value of data from diverse, amphibian genomes in studies of vertebrate genome evolution. PMID:21482624

  19. Ancestral Variations of the PCDHG Gene Cluster Predispose to Dyslexia in a Multiplex Family

    Directory of Open Access Journals (Sweden)

    Teesta Naskar

    2018-02-01

    Full Text Available Dyslexia is a heritable neurodevelopmental disorder characterized by difficulties in reading and writing. In this study, we describe the identification of a set of 17 polymorphisms located across 1.9 Mb region on chromosome 5q31.3, encompassing genes of the PCDHG cluster, TAF7, PCDH1 and ARHGAP26, dominantly inherited with dyslexia in a multi-incident family. Strikingly, the non-risk form of seven variations of the PCDHG cluster, are preponderant in the human lineage, while risk alleles are ancestral and conserved across Neanderthals to non-human primates. Four of these seven ancestral variations (c.460A > C [p.Ile154Leu], c.541G > A [p.Ala181Thr], c.2036G > C [p.Arg679Pro] and c.2059A > G [p.Lys687Glu] result in amino acid alterations. p.Ile154Leu and p.Ala181Thr are present at EC2: EC3 interacting interface of γA3-PCDH and γA4-PCDH respectively might affect trans-homophilic interaction and hence neuronal connectivity. p.Arg679Pro and p.Lys687Glu are present within the linker region connecting trans-membrane to extracellular domain. Sequence analysis indicated the importance of p.Ile154, p.Arg679 and p.Lys687 in maintaining class specificity. Thus the observed association of PCDHG genes encoding neural adhesion proteins reinforces the hypothesis of aberrant neuronal connectivity in the pathophysiology of dyslexia. Additionally, the striking conservation of the identified variants indicates a role of PCDHG in the evolution of highly specialized cognitive skills critical to reading.

  20. Metamorphosis Is Ancestral for Crown Euarthropods, and Evolved in the Cambrian or Earlier.

    Science.gov (United States)

    Wolfe, Joanna M

    2017-09-01

    Macroevolutionary developmental biology employs fossilized ontogenetic data and phylogenetic comparative methods to probe the evolution of development at ancient nodes. Despite the prevalence of ecologically differentiated larval forms in marine invertebrates, it has been frequently presumed that the ancestors of arthropods were direct developers, and that metamorphosis may not have evolved until the Ordovician or later. Using fossils and new dated phylogenies, I infer that metamorphosis was likely ancestral for crown arthropods, contradicting this assumption. Based on a published morphological dataset encompassing 217 exceptionally preserved fossil and 96 extant taxa, fossils were directly incorporated into both the topology and age estimates, as in "tip dating" analyses. Using data from post-embryonic fossils representing 25 species throughout stem and crown arthropod lineages (as well as most of the 96 extant taxa), characters for metamorphosis were assigned based on inferred ecological changes in development (e.g., changes in habitat and adaptive landscape). Under all phylogenetic hypotheses, metamorphosis was supported as most likely ancestral to both ecdysozoans and euarthropods. Care must be taken to account for potential drastic post-embryonic morphological changes in evolutionary analyses. Many stem group euarthrpods may have had ecologically differentiated larval stages that did not preserve in the fossil record. Moreover, a complex life cycle and planktonic ecology may have evolved in the Ediacaran or earlier, and may have typified the pre-Cambrian explosion "wormworld" prior to the origin of crown group euarthropods. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  1. Inferring genome-wide patterns of admixture in Qataris using fifty-five ancestral populations

    Directory of Open Access Journals (Sweden)

    Omberg Larsson

    2012-06-01

    Full Text Available Abstract Background Populations of the Arabian Peninsula have a complex genetic structure that reflects waves of migrations including the earliest human migrations from Africa and eastern Asia, migrations along ancient civilization trading routes and colonization history of recent centuries. Results Here, we present a study of genome-wide admixture in this region, using 156 genotyped individuals from Qatar, a country located at the crossroads of these migration patterns. Since haplotypes of these individuals could have originated from many different populations across the world, we have developed a machine learning method "SupportMix" to infer loci-specific genomic ancestry when simultaneously analyzing many possible ancestral populations. Simulations show that SupportMix is not only more accurate than other popular admixture discovery tools but is the first admixture inference method that can efficiently scale for simultaneous analysis of 50-100 putative ancestral populations while being independent of prior demographic information. Conclusions By simultaneously using the 55 world populations from the Human Genome Diversity Panel, SupportMix was able to extract the fine-scale ancestry of the Qatar population, providing many new observations concerning the ancestry of the region. For example, as well as recapitulating the three major sub-populations in Qatar, composed of mainly Arabic, Persian, and African ancestry, SupportMix additionally identifies the specific ancestry of the Persian group to populations sampled in Greater Persia rather than from China and the ancestry of the African group to sub-Saharan origin and not Southern African Bantu origin as previously thought.

  2. Magmatism and Epithermal Gold-Silver Deposits of the Southern Ancestral Cascade Arc, Western Nevada and Eastern California

    Science.gov (United States)

    John, David A.; du Bray, Edward A.; Henry, Christopher D.; Vikre, Peter

    2015-01-01

    Many epithermal gold-silver deposits are temporally and spatially associated with late Oligocene to Pliocene magmatism of the southern ancestral Cascade arc in western Nevada and eastern California. These deposits, which include both quartz-adularia (low- and intermediate-sulfidation; Comstock Lode, Tonopah, Bodie) and quartz-alunite (high-sulfidation; Goldfield, Paradise Peak) types, were major producers of gold and silver. Ancestral Cascade arc magmatism preceded that of the modern High Cascades arc and reflects subduction of the Farallon plate beneath North America. Ancestral arc magmatism began about 45 Ma, continued until about 3 Ma, and extended from near the Canada-United States border in Washington southward to about 250 km southeast of Reno, Nevada. The ancestral arc was split into northern and southern segments across an inferred tear in the subducting slab between Mount Shasta and Lassen Peak in northern California. The southern segment extends between 42°N in northern California and 37°N in western Nevada and was active from about 30 to 3 Ma. It is bounded on the east by the northeast edge of the Walker Lane. Ancestral arc volcanism represents an abrupt change in composition and style of magmatism relative to that in central Nevada. Large volume, caldera-forming, silicic ignimbrites associated with the 37 to 19 Ma ignimbrite flareup are dominant in central Nevada, whereas volcanic centers of the ancestral arc in western Nevada consist of andesitic stratovolcanoes and dacitic to rhyolitic lava domes that mostly formed between 25 and 4 Ma. Both ancestral arc and ignimbrite flareup magmatism resulted from rollback of the shallowly dipping slab that began about 45 Ma in northeast Nevada and migrated south-southwest with time. Most southern segment ancestral arc rocks have oxidized, high potassium, calc-alkaline compositions with silica contents ranging continuously from about 55 to 77 wt%. Most lavas are porphyritic and contain coarse plagioclase

  3. The mechanistic basis of hemoglobin adaptation in the high-flying barheaded goose: insights from ancestral protein resurrection

    DEFF Research Database (Denmark)

    Natarajan, Chandrasekhar; Kumar, Amit; Moriyama, Hideaki

    2016-01-01

    the functional effects of causative mutations on the genetic background in which they actually occurred during evolution (i.e., in the BHG ancestor). An alternative ‘vertical’ approach is to reconstruct and resurrect ancestral proteins to test the effects of historical mutations on the genetic background...

  4. ReAS: Recovery of ancestral sequences for transposable elements from the unassembled reads of a whole genome shotgun

    DEFF Research Database (Denmark)

    Li, Ruiqiang; Ye, Jia; Li, Songgang

    2005-01-01

    in comparison to their ancestral sequences. Tested on the japonica rice genome, ReAS was able to reconstruct all of the high copy sequences in the Repbase repository of known TEs, and increase the effectiveness of RepeatMasker in identifying TEs from genome sequences. Udgivelsesdato: 2005-Sep...

  5. Chromosome evolution in kangaroos (Marsupialia: Macropodidae): cross species chromosome painting between the tammar wallaby and rock wallaby spp. with the 2n = 22 ancestral macropodid karyotype.

    Science.gov (United States)

    O'Neill, R J; Eldridge, M D; Toder, R; Ferguson-Smith, M A; O'Brien, P C; Graves, J A

    1999-06-01

    Marsupial mammals show extraordinary karyotype stability, with 2n = 14 considered ancestral. However, macropodid marsupials (kangaroos and wallabies) exhibit a considerable variety of karyotypes, with a hypothesised ancestral karyotype of 2n = 22. Speciation and karyotypic diversity in rock wallabies (Petrogale) is exceptional. We used cross species chromosome painting to examine the chromosome evolution between the tammar wallaby (2n = 16) and three 2n = 22 rock wallaby species groups with the putative ancestral karyotype. Hybridization of chromosome paints prepared from flow sorted chromosomes of the tammar wallaby to Petrogale spp., showed that this ancestral karyotype is largely conserved among 2n = 22 rock wallaby species, and confirmed the identity of ancestral chromosomes which fused to produce the bi-armed chromosomes of the 2n = 16 tammar wallaby. These results illustrate the fission-fusion process of karyotype evolution characteristic of the kangaroo group.

  6. Creation of Functional Viruses from Non-Functional cDNA Clones Obtained from an RNA Virus Population by the Use of Ancestral Reconstruction

    DEFF Research Database (Denmark)

    Fahnøe, Ulrik; Pedersen, Anders Gorm; Dräger, Carolin

    2015-01-01

    necessarily be the descendant of a functional ancestor, we hypothesized that it should be possible to produce functional clones by reconstructing ancestral sequences. To test this we used phylogenetic methods to infer two ancestral sequences, which were then reconstructed as cDNA clones. Viruses rescued from...... the reconstructed cDNAs were tested in cell culture and pigs. Both reconstructed ancestral genomes proved functional, and displayed distinct phenotypes in vitro and in vivo. We suggest that reconstruction of ancestral viruses is a useful tool for experimental and computational investigations of virulence and viral...... evolution. Importantly, ancestral reconstruction can be done even on the basis of a set of sequences that all correspond to non-functional variants....

  7. Analysis on the reconstruction accuracy of the Fitch method for inferring ancestral states

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    Grünewald Stefan

    2011-01-01

    Full Text Available Abstract Background As one of the most widely used parsimony methods for ancestral reconstruction, the Fitch method minimizes the total number of hypothetical substitutions along all branches of a tree to explain the evolution of a character. Due to the extensive usage of this method, it has become a scientific endeavor in recent years to study the reconstruction accuracies of the Fitch method. However, most studies are restricted to 2-state evolutionary models and a study for higher-state models is needed since DNA sequences take the format of 4-state series and protein sequences even have 20 states. Results In this paper, the ambiguous and unambiguous reconstruction accuracy of the Fitch method are studied for N-state evolutionary models. Given an arbitrary phylogenetic tree, a recurrence system is first presented to calculate iteratively the two accuracies. As complete binary tree and comb-shaped tree are the two extremal evolutionary tree topologies according to balance, we focus on the reconstruction accuracies on these two topologies and analyze their asymptotic properties. Then, 1000 Yule trees with 1024 leaves are generated and analyzed to simulate real evolutionary scenarios. It is known that more taxa not necessarily increase the reconstruction accuracies under 2-state models. The result under N-state models is also tested. Conclusions In a large tree with many leaves, the reconstruction accuracies of using all taxa are sometimes less than those of using a leaf subset under N-state models. For complete binary trees, there always exists an equilibrium interval [a, b] of conservation probability, in which the limiting ambiguous reconstruction accuracy equals to the probability of randomly picking a state. The value b decreases with the increase of the number of states, and it seems to converge. When the conservation probability is greater than b, the reconstruction accuracies of the Fitch method increase rapidly. The reconstruction

  8. El sentido cultural del cuidado en casa del enfermo

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    Marina Sánches-Sanabria

    2008-12-01

    Full Text Available Esta investigación tiene un diseño cualitativo descriptivo, transversal para comprender las diferencias existentes en los conocimientos, actitudes y prácticas influidas por la percepción o sentido cultural de cuidar del cuidador primario, como elemento básico para caracterizar elementos culturales presentes en el ambiente de cuidado al enfermo o discapacitado que está en casa a través de la indagación profunda de la percepción y sentimientos que tiene tanto el cuidador primario como el ser cuidado en casa. Se realizó con los usuarios inscritos del Programa de Promoción y Prevención de la indagación profunda de la percepción y sentimientos Universidad Popular del Cesar (IPS-UPC de los enfermos crónicos y discapacitados a nivel comunitario del grupo extramural de la comuna cinco y del Hospital Eduardo Arredondo Daza de la ciudad de Valledupar, Colombia. El valor de realizar este proyecto, está en desocultar los múltiples significados que en la realidad vivida por los seres cuidadores primarios y en los seres cuidados; son esas distintas formas de percibir la existencia, influido por el conocimiento de lo ancestral, los sentimientos y la sabiduría de la cultura que cada uno posee para expresarse en las múltiples formas que el cuidado lo acontece y lo requiere para dar el sentido cultural característico y diferenciado que se percibe en el modo de cuidar y la satisfacción de quien lo recibe y lo ofrece. Este aspecto fue valioso para la comunidad académica del programa de enfermería, porque ubicó epistémicamente la transculturalidad del cuidado como una mirada y forma de enseñar transdisciplinariamente, enseñando y ofreciendo el cuidado desde la cultura, sentimientos y pensamientos del ser cuidado para el mantenimiento de la vida y la salud, en la que estudiantes de enfermeria desde sus primeras experiencias formativas deben incursionar en la intervención holística que se requiere en el cuidado de la salud y de la vida.

  9. The evolution of brachiation in ateline primates, ancestral character states and history.

    Science.gov (United States)

    Jones, Andrea L

    2008-10-01

    This study examines how brachiation locomotion evolved in ateline primates using recently-developed molecular phylogenies and character reconstruction algorithms, and a newly-collected dataset including the fossils Protopithecus, Caipora, and Cebupithecia. Fossils are added to two platyrrhine molecular phylogenies to create several phylogenetic scenarios. A generalized least squares algorithm reconstructs ateline and atelin ancestral character states for 17 characters that differentiate between ateline brachiators and nonbrachiators. Histories of these characters are mapped out on these phylogenies, producing two scenarios of ateline brachiation evolution that have four commonalities: First, many characters change towards the Ateles condition on the ateline stem lineage before Alouatta splits off from the atelins, suggesting that an ateline energy-maximizing strategy began before the atelines diversified. Second, the ateline last common ancestor is always reconstructed as an agile quadruped, usually with suspensory abilities. It is never exactly like Alouatta and many characters reverse and change towards the Alouatta condition after Alouatta separates from the atelins. Third, most characters undergo homoplastic change in all ateline lineages, especially on the Ateles and Brachyteles terminal branches. Fourth, ateline character evolution probably went through a hindlimb suspension with tail-bracing phase. The atelines most likely diversified via a quick adaptive radiation, with bursts of punctuated change occurring in their postcranial skeletons, due to changing climatic conditions, which may have caused competition among the atelines and between atelines and pitheciines.

  10. An ancestral role for the mitochondrial pyruvate carrier in glucose-stimulated insulin secretion

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    Kyle S. McCommis

    2016-08-01

    Full Text Available Objective: Transport of pyruvate into the mitochondrial matrix by the Mitochondrial Pyruvate Carrier (MPC is an important and rate-limiting step in its metabolism. In pancreatic β-cells, mitochondrial pyruvate metabolism is thought to be important for glucose sensing and glucose-stimulated insulin secretion. Methods: To evaluate the role that the MPC plays in maintaining systemic glucose homeostasis, we used genetically-engineered Drosophila and mice with loss of MPC activity in insulin-producing cells. Results: In both species, MPC deficiency results in elevated blood sugar concentrations and glucose intolerance accompanied by impaired glucose-stimulated insulin secretion. In mouse islets, β-cell MPC-deficiency resulted in decreased respiration with glucose, ATP-sensitive potassium (KATP channel hyperactivity, and impaired insulin release. Moreover, treatment of pancreas-specific MPC knockout mice with glibenclamide, a sulfonylurea KATP channel inhibitor, improved defects in islet insulin secretion and abnormalities in glucose homeostasis in vivo. Finally, using a recently-developed biosensor for MPC activity, we show that the MPC is rapidly stimulated by glucose treatment in INS-1 insulinoma cells suggesting that glucose sensing is coupled to mitochondrial pyruvate carrier activity. Conclusions: Altogether, these studies suggest that the MPC plays an important and ancestral role in insulin-secreting cells in mediating glucose sensing, regulating insulin secretion, and controlling systemic glycemia. Keywords: Stimulus-coupled secretion, Insulin, β-Cell, Diabetes, Pyruvate, Mitochondria, Drosophila

  11. Mitogenomics and phylogenomics reveal priapulid worms as extant models of the ancestral Ecdysozoan.

    Science.gov (United States)

    Webster, Bonnie L; Copley, Richard R; Jenner, Ronald A; Mackenzie-Dodds, Jacqueline A; Bourlat, Sarah J; Rota-Stabelli, Omar; Littlewood, D T J; Telford, Maximilian J

    2006-01-01

    Research into arthropod evolution is hampered by the derived nature and rapid evolution of the best-studied out-group: the nematodes. We consider priapulids as an alternative out-group. Priapulids are a small phylum of bottom-dwelling marine worms; their tubular body with spiny proboscis or introvert has changed little over 520 million years and recognizable priapulids are common among exceptionally preserved Cambrian fossils. Using the complete mitochondrial genome and 42 nuclear genes from Priapulus caudatus, we show that priapulids are slowly evolving ecdysozoans; almost all these priapulid genes have evolved more slowly than nematode orthologs and the priapulid mitochondrial gene order may be unchanged since the Cambrian. Considering their primitive bodyplan and embryology and the great conservation of both nuclear and mitochondrial genomes, priapulids may deserve the popular epithet of "living fossil." Their study is likely to yield significant new insights into the early evolution of the Ecdysozoa and the origins of the arthropods and their kin as well as aiding inference of the morphology of ancestral Ecdysozoa and Bilateria and their genomes.

  12. Multiple chromosomal rearrangements structured the ancestral vertebrate Hox-bearing protochromosomes.

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    Vincent J Lynch

    2009-01-01

    Full Text Available While the proposal that large-scale genome expansions occurred early in vertebrate evolution is widely accepted, the exact mechanisms of the expansion--such as a single or multiple rounds of whole genome duplication, bloc chromosome duplications, large-scale individual gene duplications, or some combination of these--is unclear. Gene families with a single invertebrate member but four vertebrate members, such as the Hox clusters, provided early support for Ohno's hypothesis that two rounds of genome duplication (the 2R-model occurred in the stem lineage of extant vertebrates. However, despite extensive study, the duplication history of the Hox clusters has remained unclear, calling into question its usefulness in resolving the role of large-scale gene or genome duplications in early vertebrates. Here, we present a phylogenetic analysis of the vertebrate Hox clusters and several linked genes (the Hox "paralogon" and show that different phylogenies are obtained for Dlx and Col genes than for Hox and ErbB genes. We show that these results are robust to errors in phylogenetic inference and suggest that these competing phylogenies can be resolved if two chromosomal crossover events occurred in the ancestral vertebrate. These results resolve conflicting data on the order of Hox gene duplications and the role of genome duplication in vertebrate evolution and suggest that a period of genome reorganization occurred after genome duplications in early vertebrates.

  13. Detection of Weakly Conserved Ancestral Mammalian RegulatorySequences by Primate Comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qian-fei; Prabhakar, Shyam; Chanan, Sumita; Cheng,Jan-Fang; Rubin, Edward M.; Boffelli, Dario

    2006-06-01

    Genomic comparisons between human and distant, non-primatemammals are commonly used to identify cis-regulatory elements based onconstrained sequence evolution. However, these methods fail to detectcryptic functional elements, which are too weakly conserved among mammalsto distinguish from nonfunctional DNA. To address this problem, weexplored the potential of deep intra-primate sequence comparisons. Wesequenced the orthologs of 558 kb of human genomic sequence, coveringmultiple loci involved in cholesterol homeostasis, in 6 nonhumanprimates. Our analysis identified 6 noncoding DNA elements displayingsignificant conservation among primates, but undetectable in more distantcomparisons. In vitro and in vivo tests revealed that at least three ofthese 6 elements have regulatory function. Notably, the mouse orthologsof these three functional human sequences had regulatory activity despitetheir lack of significant sequence conservation, indicating that they arecryptic ancestral cis-regulatory elements. These regulatory elementscould still be detected in a smaller set of three primate speciesincluding human, rhesus and marmoset. Since the human and rhesus genomesequences are already available, and the marmoset genome is activelybeing sequenced, the primate-specific conservation analysis describedhere can be applied in the near future on a whole-genome scale, tocomplement the annotation provided by more distant speciescomparisons.

  14. Anomalously high variation in postnatal development is ancestral for dinosaurs but lost in birds

    Science.gov (United States)

    Griffin, Christopher T.; Nesbitt, Sterling J.

    2016-12-01

    Compared with all other living reptiles, birds grow extremely fast and possess unusually low levels of intraspecific variation during postnatal development. It is now clear that birds inherited their high rates of growth from their dinosaurian ancestors, but the origin of the avian condition of low variation during development is poorly constrained. The most well-understood growth trajectories of later Mesozoic theropods (e.g., Tyrannosaurus, Allosaurus) show similarly low variation to birds, contrasting with higher variation in extant crocodylians. Here, we show that deep within Dinosauria, among the earliest-diverging dinosaurs, anomalously high intraspecific variation is widespread but then is lost in more derived theropods. This style of development is ancestral for dinosaurs and their closest relatives, and, surprisingly, this level of variation is far higher than in living crocodylians. Among early dinosaurs, this variation is widespread across Pangaea in the Triassic and Early Jurassic, and among early-diverging theropods (ceratosaurs), this variation is maintained for 165 million years to the end of the Cretaceous. Because the Late Triassic environment across Pangaea was volatile and heterogeneous, this variation may have contributed to the rise of dinosaurian dominance through the end of the Triassic Period.

  15. Fixation Probability in a Two-Locus Model by the Ancestral Recombination–Selection Graph

    Science.gov (United States)

    Lessard, Sabin; Kermany, Amir R.

    2012-01-01

    We use the ancestral influence graph (AIG) for a two-locus, two-allele selection model in the limit of a large population size to obtain an analytic approximation for the probability of ultimate fixation of a single mutant allele A. We assume that this new mutant is introduced at a given locus into a finite population in which a previous mutant allele B is already segregating with a wild type at another linked locus. We deduce that the fixation probability increases as the recombination rate increases if allele A is either in positive epistatic interaction with B and allele B is beneficial or in no epistatic interaction with B and then allele A itself is beneficial. This holds at least as long as the recombination fraction and the selection intensity are small enough and the population size is large enough. In particular this confirms the Hill–Robertson effect, which predicts that recombination renders more likely the ultimate fixation of beneficial mutants at different loci in a population in the presence of random genetic drift even in the absence of epistasis. More importantly, we show that this is true from weak negative epistasis to positive epistasis, at least under weak selection. In the case of deleterious mutants, the fixation probability decreases as the recombination rate increases. This supports Muller’s ratchet mechanism to explain the accumulation of deleterious mutants in a population lacking recombination. PMID:22095080

  16. Comparative Genomics of Facultative Bacterial Symbionts Isolated from European Orius Species Reveals an Ancestral Symbiotic Association

    Directory of Open Access Journals (Sweden)

    Xiaorui Chen

    2017-10-01

    Full Text Available Pest control in agriculture employs diverse strategies, among which the use of predatory insects has steadily increased. The use of several species within the genus Orius in pest control is widely spread, particularly in Mediterranean Europe. Commercial mass rearing of predatory insects is costly, and research efforts have concentrated on diet manipulation and selective breeding to reduce costs and improve efficacy. The characterisation and contribution of microbial symbionts to Orius sp. fitness, behaviour, and potential impact on human health has been neglected. This paper provides the first genome sequence level description of the predominant culturable facultative bacterial symbionts associated with five Orius species (O. laevigatus, O. niger, O. pallidicornis, O. majusculus, and O. albidipennis from several geographical locations. Two types of symbionts were broadly classified as members of the genera Serratia and Leucobacter, while a third constitutes a new genus within the Erwiniaceae. These symbionts were found to colonise all the insect specimens tested, which evidenced an ancestral symbiotic association between these bacteria and the genus Orius. Pangenome analyses of the Serratia sp. isolates offered clues linking Type VI secretion system effector–immunity proteins from the Tai4 sub-family to the symbiotic lifestyle.

  17. Comparative Genomics of Facultative Bacterial Symbionts Isolated from European Orius Species Reveals an Ancestral Symbiotic Association

    Science.gov (United States)

    Chen, Xiaorui; Hitchings, Matthew D.; Mendoza, José E.; Balanza, Virginia; Facey, Paul D.; Dyson, Paul J.; Bielza, Pablo; Del Sol, Ricardo

    2017-01-01

    Pest control in agriculture employs diverse strategies, among which the use of predatory insects has steadily increased. The use of several species within the genus Orius in pest control is widely spread, particularly in Mediterranean Europe. Commercial mass rearing of predatory insects is costly, and research efforts have concentrated on diet manipulation and selective breeding to reduce costs and improve efficacy. The characterisation and contribution of microbial symbionts to Orius sp. fitness, behaviour, and potential impact on human health has been neglected. This paper provides the first genome sequence level description of the predominant culturable facultative bacterial symbionts associated with five Orius species (O. laevigatus, O. niger, O. pallidicornis, O. majusculus, and O. albidipennis) from several geographical locations. Two types of symbionts were broadly classified as members of the genera Serratia and Leucobacter, while a third constitutes a new genus within the Erwiniaceae. These symbionts were found to colonise all the insect specimens tested, which evidenced an ancestral symbiotic association between these bacteria and the genus Orius. Pangenome analyses of the Serratia sp. isolates offered clues linking Type VI secretion system effector–immunity proteins from the Tai4 sub-family to the symbiotic lifestyle. PMID:29067021

  18. Phylogenetic uncertainty can bias the number of evolutionary transitions estimated from ancestral state reconstruction methods.

    Science.gov (United States)

    Duchêne, Sebastian; Lanfear, Robert

    2015-09-01

    Ancestral state reconstruction (ASR) is a popular method for exploring the evolutionary history of traits that leave little or no trace in the fossil record. For example, it has been used to test hypotheses about the number of evolutionary origins of key life-history traits such as oviparity, or key morphological structures such as wings. Many studies that use ASR have suggested that the number of evolutionary origins of such traits is higher than was previously thought. The scope of such inferences is increasing rapidly, facilitated by the construction of very large phylogenies and life-history databases. In this paper, we use simulations to show that the number of evolutionary origins of a trait tends to be overestimated when the phylogeny is not perfect. In some cases, the estimated number of transitions can be several fold higher than the true value. Furthermore, we show that the bias is not always corrected by standard approaches to account for phylogenetic uncertainty, such as repeating the analysis on a large collection of possible trees. These findings have important implications for studies that seek to estimate the number of origins of a trait, particularly those that use large phylogenies that are associated with considerable uncertainty. We discuss the implications of this bias, and methods to ameliorate it. © 2015 Wiley Periodicals, Inc.

  19. Reconstruction of chromosome rearrangements between the two most ancestral duckweed species Spirodela polyrhiza and S. intermedia.

    Science.gov (United States)

    Hoang, Phuong T N; Schubert, Ingo

    2017-12-01

    The monophyletic duckweeds comprising five genera within the monocot order Alismatales are neotenic, free-floating, aquatic organisms with fast vegetative propagation. Some species are considered for efficient biomass production, for life stock feeding, and for (simultaneous) wastewater phytoremediation. The ancestral genus Spirodela consists of only two species, Spirodela polyrhiza and Spirodela intermedia, both with a similar small genome (~160 Mbp/1C). Reference genome drafts and a physical map of 96 BACs on the 20 chromosome pairs of S. polyrhiza strain 7498 are available and provide useful tools for further evolutionary studies within and between duckweed genera. Here we applied sequential comparative multicolor fluorescence in situ hybridization (mcFISH) to address homeologous chromosomes in S. intermedia (2n = 36), to detect chromosome rearrangements between both species and to elucidate the mechanisms which may have led to the chromosome number alteration after their evolutionary separation. Ten chromosome pairs proved to be conserved between S. polyrhiza and S. intermedia, the remaining ones experienced, depending on the assumed direction of evolution, translocations, inversion, and fissions, respectively. These results represent a first step to unravel karyotype evolution among duckweeds and are anchor points for future genome assembly of S. intermedia.

  20. Convergent evolution of caffeine in plants by co-option of exapted ancestral enzymes.

    Science.gov (United States)

    Huang, Ruiqi; O'Donnell, Andrew J; Barboline, Jessica J; Barkman, Todd J

    2016-09-20

    Convergent evolution is a process that has occurred throughout the tree of life, but the historical genetic and biochemical context promoting the repeated independent origins of a trait is rarely understood. The well-known stimulant caffeine, and its xanthine alkaloid precursors, has evolved multiple times in flowering plant history for various roles in plant defense and pollination. We have shown that convergent caffeine production, surprisingly, has evolved by two previously unknown biochemical pathways in chocolate, citrus, and guaraná plants using either caffeine synthase- or xanthine methyltransferase-like enzymes. However, the pathway and enzyme lineage used by any given plant species is not predictable from phylogenetic relatedness alone. Ancestral sequence resurrection reveals that this convergence was facilitated by co-option of genes maintained over 100 million y for alternative biochemical roles. The ancient enzymes of the Citrus lineage were exapted for reactions currently used for various steps of caffeine biosynthesis and required very few mutations to acquire modern-day enzymatic characteristics, allowing for the evolution of a complete pathway. Future studies aimed at manipulating caffeine content of plants will require the use of different approaches given the metabolic and genetic diversity revealed by this study.

  1. Reinterpretation of Halokinetic Features in the Ancestral Rocky Mountains Paradox Salt Basin, Utah and Colorado

    Science.gov (United States)

    Thompson, J. A.; Giles, K. A.; Rowan, M. G.; Hearon, T. E., IV

    2016-12-01

    The Paradox Basin in southeastern Utah and southwestern Colorado is a foreland basin formed in response to flexural loading by the Pennsylvanian-aged Uncompaghre uplift during the Ancestral Rocky Mountain orogen. Thick sequences of evaporites (Paradox Formation) were deposited within the foreland basin, which interfinger with clastic sediments in the foredeep and carbonates around the basin margin. Differential loading of the Pennsylvanian-Jurassic sediments onto the evaporites drove synsedimentary halokinesis, creating a series of salt walls and adjacent minibasins within the larger foreland basin. The growing salt walls within the basin influenced patterns of sediment deposition from the Pennsylvanian through the Cretaceous. By integrating previously published mapping with recent field observations, mapping, and subsurface interpretations of well logs and 2D seismic lines, we present interpretations of the timing, geometry, and nature of halokinesis within the Paradox Basin, which record the complex salt tectonic history in the basin. Furthermore, we present recent work on the relationships between the local passive salt history and the formation of syndepositional counter-regional extensional fault systems within the foreland. These results will be integrated into a new regional salt-tectonic and stratigraphic framework of the Paradox Basin, and have broader implications for interpreting sedimentary records in other basins with a mobile substrate.

  2. Accuracy of Genomic Prediction in Synthetic Populations Depending on the Number of Parents, Relatedness, and Ancestral Linkage Disequilibrium.

    Science.gov (United States)

    Schopp, Pascal; Müller, Dominik; Technow, Frank; Melchinger, Albrecht E

    2017-01-01

    Synthetics play an important role in quantitative genetic research and plant breeding, but few studies have investigated the application of genomic prediction (GP) to these populations. Synthetics are generated by intermating a small number of parents ([Formula: see text] and thereby possess unique genetic properties, which make them especially suited for systematic investigations of factors contributing to the accuracy of GP. We generated synthetics in silico from [Formula: see text]2 to 32 maize (Zea mays L.) lines taken from an ancestral population with either short- or long-range linkage disequilibrium (LD). In eight scenarios differing in relatedness of the training and prediction sets and in the types of data used to calculate the relationship matrix (QTL, SNPs, tag markers, and pedigree), we investigated the prediction accuracy (PA) of Genomic best linear unbiased prediction (GBLUP) and analyzed contributions from pedigree relationships captured by SNP markers, as well as from cosegregation and ancestral LD between QTL and SNPs. The effects of training set size [Formula: see text] and marker density were also studied. Sampling few parents ([Formula: see text]) generates substantial sample LD that carries over into synthetics through cosegregation of alleles at linked loci. For fixed [Formula: see text], [Formula: see text] influences PA most strongly. If the training and prediction set are related, using [Formula: see text] parents yields high PA regardless of ancestral LD because SNPs capture pedigree relationships and Mendelian sampling through cosegregation. As [Formula: see text] increases, ancestral LD contributes more information, while other factors contribute less due to lower frequencies of closely related individuals. For unrelated prediction sets, only ancestral LD contributes information and accuracies were poor and highly variable for [Formula: see text] due to large sample LD. For large [Formula: see text], achieving moderate accuracy requires

  3. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Rapacz, J.; Hasler-Rapacz, J.O. (Univ. of Wisconsin, Madison (United States)); Chen, L.; Wu, Mingjiuan; Schumaker, V.N. (Univ. of California, Los Angeles (United States)); Butler-Brunner, E.; Butler, R. (Swiss Red Cross Blood Transfusion Service, Bern (Switzerland))

    1991-02-15

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes.

  4. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific

    International Nuclear Information System (INIS)

    Rapacz, J.; Hasler-Rapacz, J.O.; Chen, L.; Wu, Mingjiuan; Schumaker, V.N.; Butler-Brunner, E.; Butler, R.

    1991-01-01

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes

  5. Effect of the assignment of ancestral CpG state on the estimation of nucleotide substitution rates in mammals

    Directory of Open Access Journals (Sweden)

    Keightley Peter D

    2008-09-01

    Full Text Available Abstract Background Molecular evolutionary studies in mammals often estimate nucleotide substitution rates within and outside CpG dinucleotides separately. Frequently, in alignments of two sequences, the division of sites into CpG and non-CpG classes is based simply on the presence or absence of a CpG dinucleotide in either sequence, a procedure that we refer to as CpG/non-CpG assignment. Although it likely that this procedure is biased, it is generally assumed that the bias is negligible if species are very closely related. Results Using simulations of DNA sequence evolution we show that assignment of the ancestral CpG state based on the simple presence/absence of the CpG dinucleotide can seriously bias estimates of the substitution rate, because many true non-CpG changes are misassigned as CpG. Paradoxically, this bias is most severe between closely related species, because a minimum of two substitutions are required to misassign a true ancestral CpG site as non-CpG whereas only a single substitution is required to misassign a true ancestral non-CpG site as CpG in a two branch tree. We also show that CpG misassignment bias differentially affects fourfold degenerate and noncoding sites due to differences in base composition such that fourfold degenerate sites can appear to be evolving more slowly than noncoding sites. We demonstrate that the effects predicted by our simulations occur in a real evolutionary setting by comparing substitution rates estimated from human-chimp coding and intronic sequence using CpG/non-CpG assignment with estimates derived from a method that is largely free from bias. Conclusion Our study demonstrates that a common method of assigning sites into CpG and non CpG classes in pairwise alignments is seriously biased and recommends against the adoption of ad hoc methods of ancestral state assignment.

  6. Effectiveness of ancestral irradiation on the direct and correlated responses to selection for body weight in rats

    International Nuclear Information System (INIS)

    Gianola, D.

    1975-01-01

    The effects of ancestral irradiation of rat spermatogonia (a cumulative total of 4050 r of x-rays) were studied in a highly inbred line of rats to explore the feasibility of using irradiation to enhance the effectiveness of selection. Six generations after irradiation was terminated, a selection experiment for body weight at six weeks of age was started in both ancestrally irradiated and non-irradiated populations. There were two non-contemporaneous replicates in each of the populations. Within each of the ancestral treatment-replicate combinations one line was selected for high, one for low body weight at six weeks of age, and a third line was maintained by random selection. In each line, avoidance of mating of animals with grandparents in common was attempted. Data on the first ten progeny generations of selection were included in this study. Five types of covariances among relatives were used to estimate causal components of variance for five different genetic models within the ''non-irradiated'' and ''irradiated'' randomly selected models. The parameters in the genetic models were estimated by generalized least-squares. This analysis suggested that a genetic model including direct genetic and maternal genetic effects was adequate to describe the body weights at 3, 6 and 10 weeks of age and the weight gains between these ages. Ancestral irradiation seemed to have enhanced the maternal genetic variance and the covariance between the direct genetic and the maternal genetic effects. On the basis of the above analysis, it was deduced that mass selection should have been more effective in the descendants of irradiated males than in those of the non-irradiated males as a consequence of greater phenotypic variability in their progeny and an enhancement in the regression of the genetic value on the selection criterion

  7. Genotype-based ancestral background consistently predicts efficacy and side effects across treatments in CATIE and STAR*D.

    Directory of Open Access Journals (Sweden)

    Daniel E Adkins

    Full Text Available Only a subset of patients will typically respond to any given prescribed drug. The time it takes clinicians to declare a treatment ineffective leaves the patient in an impaired state and at unnecessary risk for adverse drug effects. Thus, diagnostic tests robustly predicting the most effective and safe medication for each patient prior to starting pharmacotherapy would have tremendous clinical value. In this article, we evaluated the use of genetic markers to estimate ancestry as a predictive component of such diagnostic tests. We first estimated each patient's unique mosaic of ancestral backgrounds using genome-wide SNP data collected in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE (n = 765 and the Sequenced Treatment Alternatives to Relieve Depression (STAR*D (n = 1892. Next, we performed multiple regression analyses to estimate the predictive power of these ancestral dimensions. For 136/89 treatment-outcome combinations tested in CATIE/STAR*D, results indicated 1.67/1.84 times higher median test statistics than expected under the null hypothesis assuming no predictive power (p<0.01, both samples. Thus, ancestry showed robust and pervasive correlations with drug efficacy and side effects in both CATIE and STAR*D. Comparison of the marginal predictive power of MDS ancestral dimensions and self-reported race indicated significant improvements to model fit with the inclusion of MDS dimensions, but mixed evidence for self-reported race. Knowledge of each patient's unique mosaic of ancestral backgrounds provides a potent immediate starting point for developing algorithms identifying the most effective and safe medication for a wide variety of drug-treatment response combinations. As relatively few new psychiatric drugs are currently under development, such personalized medicine offers a promising approach toward optimizing pharmacotherapy for psychiatric conditions.

  8. Effects of ancestral populations on entrepreneurial founding and failure: private liquor stores in Alberta, 1994--2003

    OpenAIRE

    Glen Dowell; Robert J. David

    2011-01-01

    Until 1993, all liquor stores in the Canadian province of Alberta were government owned and run. In the fall of 1993, the provincial government exited liquor retailing, all government stores were shut down, and entrepreneurs were allowed to open private liquor stores. In this article, we take advantage of this abrupt regulatory change in the Alberta liquor-retailing industry to address two related issues that have received little empirical attention. First, we investigate how an ancestral pop...

  9. Ancestral origins and invasion pathways in a globally invasive bird correlate with climate and influences from bird trade.

    Science.gov (United States)

    Jackson, Hazel; Strubbe, Diederik; Tollington, Simon; Prys-Jones, Robert; Matthysen, Erik; Groombridge, Jim J

    2015-08-01

    Invasive species present a major threat to global biodiversity. Understanding genetic patterns and evolutionary processes that reinforce successful establishment is paramount for elucidating mechanisms underlying biological invasions. Among birds, the ring-necked parakeet (Psittacula krameri) is one of the most successful invasive species, established in over 35 countries. However, little is known about the evolutionary genetic origins of this species and what population genetic signatures tell us about patterns of invasion. We reveal the ancestral origins of populations across the invasive range and explore the potential influence of climate and propagule pressure from the pet trade on observed genetic patterns. Ring-necked parakeet samples representing the ancestral native range (n = 96) were collected from museum specimens, and modern samples from the invasive range (n = 855) were gathered from across Europe, Mauritius and Seychelles, and sequenced for two mitochondrial DNA markers comprising 868 bp of cytochrome b and control region, and genotyped at 10 microsatellite loci. Invasive populations comprise birds that originate predominantly from Pakistan and northern areas of India. Haplotypes associated with more northerly distribution limits in the ancestral native range were more prevalent in invasive populations in Europe, and the predominance of Asian haplotypes in Europe is consistent with the higher number of Asian birds transported by the pet trade outside the native range. Successful establishment of invasive species is likely to be underpinned by a combination of environmental and anthropogenic influences. © 2015 John Wiley & Sons Ltd.

  10. The ancestral chromosomes of Dromiciops gliroides (Microbiotheridae), and its bearings on the karyotypic evolution of American marsupials.

    Science.gov (United States)

    Suárez-Villota, Elkin Y; Haro, Ronie E; Vargas, Rodrigo A; Gallardo, Milton H

    2016-01-01

    The low-numbered 14-chromosome karyotype of marsupials has falsified the fusion hypothesis claiming ancestrality from a 22-chromosome karyotype. Since the 14-chromosome condition of the relict Dromiciops gliroides is reminecent of ancestrality, its interstitial traces of past putative fusions and heterochromatin banding patterns were studied and added to available marsupials' cytogenetic data. Fluorescent in situ hybridization (FISH) and self-genomic in situ hybridization (self-GISH) were used to detect telomeric and repetitive sequences, respectively. These were complemented with C-, fluorescent banding, and centromere immunodetection over mitotic spreads. The presence of interstitial telomeric sequences (ITS) and diploid numbers were reconstructed and mapped onto the marsupial phylogenetic tree. No interstitial, fluorescent signals, but clearly stained telomeric regions were detected by FISH and self-GISH. Heterochromatin distribution was sparse in the telomeric/subtelomeric regions of large submetacentric chromosomes. Large AT-rich blocks were detected in the long arm of four submetacentrics and CG-rich block in the telomeric regions of all chromosomes. The ancestral reconstructions both ITS presence and diploid numbers suggested that ITS are unrelated to fusion events. Although the lack of interstitial signals in D. gliroides' karyotype does not prove absence of past fusions, our data suggests its non-rearranged plesiomorphic condition.

  11. Emergence, Retention and Selection: A Trilogy of Origination for Functional De Novo Proteins from Ancestral LncRNAs in Primates.

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    Jia-Yu Chen

    2015-07-01

    Full Text Available While some human-specific protein-coding genes have been proposed to originate from ancestral lncRNAs, the transition process remains poorly understood. Here we identified 64 hominoid-specific de novo genes and report a mechanism for the origination of functional de novo proteins from ancestral lncRNAs with precise splicing structures and specific tissue expression profiles. Whole-genome sequencing of dozens of rhesus macaque animals revealed that these lncRNAs are generally not more selectively constrained than other lncRNA loci. The existence of these newly-originated de novo proteins is also not beyond anticipation under neutral expectation, as they generally have longer theoretical lifespan than their current age, due to their GC-rich sequence property enabling stable ORFs with lower chance of non-sense mutations. Interestingly, although the emergence and retention of these de novo genes are likely driven by neutral forces, population genetics study in 67 human individuals and 82 macaque animals revealed signatures of purifying selection on these genes specifically in human population, indicating a proportion of these newly-originated proteins are already functional in human. We thus propose a mechanism for creation of functional de novo proteins from ancestral lncRNAs during the primate evolution, which may contribute to human-specific genetic novelties by taking advantage of existed genomic contexts.

  12. When ancestral heritage is a source of discomfort: culture, pre-object relatedness, and self-alienation.

    Science.gov (United States)

    Kradin, Richard L

    2012-04-01

    The ancestral claims on an individual can evoke mental conflict when they involve separating from an ethnic group whose beliefs and customs are devalued by the dominant culture. However, these claims are engraved on the psyche early in development by caretakers to the level of pre-object relatedness, where contents and affect tones are implicit and may be unavailable for later psychoanalytical interventions. In addition, as the anthropologist Clifford Geertz notes, one's culture of origin precedes the development of psyche and creates its own set of claims that must be renegotiated when one encounters a different domain of cultural symbols, a confrontation that can produce psychological dissonance and self-alienation. In this paper, three cases are examined in which mental conflicts were evoked by attempts at divesting ancestral claims in response to conscious efforts to assimilate into the dominant culture. These patients suffered from separation guilt and unstable self-esteem and reported dream imagery suggesting psychological imbalance. The requirement to carefully delineate the ancestral claims on psyche as well as those contents and affects that may not be accessible to therapeutic intervention is emphasized, and the importance of compromise and acceptance with respect to the psychological demands of the unconscious are considered. 2012, The Society of Analytical Psychology.

  13. Are Hox genes ancestrally involved in axial patterning? Evidence from the hydrozoan Clytia hemisphaerica (Cnidaria.

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    Roxane Chiori

    Full Text Available BACKGROUND: The early evolution and diversification of Hox-related genes in eumetazoans has been the subject of conflicting hypotheses concerning the evolutionary conservation of their role in axial patterning and the pre-bilaterian origin of the Hox and ParaHox clusters. The diversification of Hox/ParaHox genes clearly predates the origin of bilaterians. However, the existence of a "Hox code" predating the cnidarian-bilaterian ancestor and supporting the deep homology of axes is more controversial. This assumption was mainly based on the interpretation of Hox expression data from the sea anemone, but growing evidence from other cnidarian taxa puts into question this hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: Hox, ParaHox and Hox-related genes have been investigated here by phylogenetic analysis and in situ hybridisation in Clytia hemisphaerica, an hydrozoan species with medusa and polyp stages alternating in the life cycle. Our phylogenetic analyses do not support an origin of ParaHox and Hox genes by duplication of an ancestral ProtoHox cluster, and reveal a diversification of the cnidarian HOX9-14 genes into three groups called A, B, C. Among the 7 examined genes, only those belonging to the HOX9-14 and the CDX groups exhibit a restricted expression along the oral-aboral axis during development and in the planula larva, while the others are expressed in very specialised areas at the medusa stage. CONCLUSIONS/SIGNIFICANCE: Cross species comparison reveals a strong variability of gene expression along the oral-aboral axis and during the life cycle among cnidarian lineages. The most parsimonious interpretation is that the Hox code, collinearity and conservative role along the antero-posterior axis are bilaterian innovations.

  14. Toxic and nontoxic components of botulinum neurotoxin complex are evolved from a common ancestral zinc protein

    International Nuclear Information System (INIS)

    Inui, Ken; Sagane, Yoshimasa; Miyata, Keita; Miyashita, Shin-Ichiro; Suzuki, Tomonori; Shikamori, Yasuyuki; Ohyama, Tohru; Niwa, Koichi; Watanabe, Toshihiro

    2012-01-01

    Highlights: ► BoNT and NTNHA proteins share a similar protein architecture. ► NTNHA and BoNT were both identified as zinc-binding proteins. ► NTNHA does not have a classical HEXXH zinc-coordinating motif similar to that found in all serotypes of BoNT. ► Homology modeling implied probable key residues involved in zinc coordination. -- Abstract: Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structure classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X 35 -D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.

  15. Allelic lineages of the ficolin genes (FCNs are passed from ancestral to descendant primates.

    Directory of Open Access Journals (Sweden)

    Tina Hummelshøj

    Full Text Available The ficolins recognize carbohydrates and acetylated compounds on microorganisms and dying host cells and are able to activate the lectin pathway of the complement system. In humans, three ficolin genes have been identified: FCN1, FCN2 and FCN3, which encode ficolin-1, ficolin-2 and ficolin-3, respectively. Rodents have only two ficolins designated ficolin-A and ficolin-B that are closely related to human ficolin-1, while the rodent FCN3 orthologue is a pseudogene. Ficolin-2 and ficolin-3 have so far only been observed in humans. Thus, we performed a systematic investigation of the FCN genes in non-human primates. The exons and intron-exon boundaries of the FCN1-3 genes were sequenced in the following primate species: chimpanzee, gorilla, orangutan, rhesus macaque, cynomolgus macaque, baboon and common marmoset. We found that the exon organisation of the FCN genes was very similar between all the non-human primates and the human FCN genes. Several variations in the FCN genes were found in more than one primate specie suggesting that they were carried from one species to another including humans. The amino acid diversity of the ficolins among human and non-human primate species was estimated by calculating the Shannon entropy revealing that all three proteins are generally highly conserved. Ficolin-1 and ficolin-2 showed the highest diversity, whereas ficolin-3 was more conserved. Ficolin-2 and ficolin-3 were present in non-human primate sera with the same characteristic oligomeric structures as seen in human serum. Taken together all the FCN genes show the same characteristics in lower and higher primates. The existence of trans-species polymorphisms suggests that different FCN allelic lineages may be passed from ancestral to descendant species.

  16. Evolutionary history of Lissotriton helveticus: multilocus assessment of ancestral vs. recent colonization of the Iberian Peninsula.

    Science.gov (United States)

    Recuero, Ernesto; García-París, Mario

    2011-07-01

    The Pleistocene was characterized by climatic changes that greatly altered the distribution of organisms. Population extinctions, bottlenecks, isolation, range expansions and contractions were often associated with glaciations, leaving signatures in the spatial patterns of genetic diversity across species. Lissotriton helveticus belongs to a Pan-European lineage of newts that were strongly affected by glaciations and represent an excellent model to analyse the effect of generalized climatic changes in phylogeographic patterns. We studied the genetic diversity of the species using data from two mitochondrial and three nuclear genes analyzed in a Bayesian phylogenetic framework to investigate the historical processes shaping spatial patterns of genetic diversity. Mitochondrial haplotypes cluster in four different groups present in the Iberian Peninsula and of Pleistocene origin, probably by allopatric fragmentation. Nuclear genes present no obvious geographic structure patterns, suggesting gene flow and generalized incomplete lineage sorting. Populations north of the Pyrenees are closely related to those from northeastern Iberia, suggesting recent range expansion from this region. Historical demographic analyses indicate a demographic expansion starting about 100,000years ago and more recent population declines. Compared to other Lissotriton species, L. helveticus includes only relatively young genetic lineages, suggesting a Central European pre-Pleistocene distribution followed by complete extirpation of the species during glaciations in that area. Historical demographic trends in the Iberian Peninsula are reversed with respect to the more Mediterranean species Lissotriton boscai, indicating different responses of both species to climate changes. Diversity patterns among Lissotriton species seem to be defined by four main factors: ancestral distributions, colonization capabilities, interactions with other species and effective population sizes. Differences in these

  17. Evolution of neural crest and placodes: amphioxus as a model for the ancestral vertebrate?

    Science.gov (United States)

    Holland, L. Z.; Holland, N. D.

    2001-01-01

    Recent studies of protochordates (ascidian tunicates and amphioxus) have given insights into possible ancestors of 2 of the characteristic features of the vertebrate head: neural crest and placodes. The neural crest probably evolved from cells on either side of the neural plate-epidermis boundary in a protochordate ancestral to the vertebrates. In amphioxus, homologues of several vertebrate neural crest marker genes (BMP2/4, Pax3/7, Msx, Dll and Snail) are expressed at the edges of the neural plate and/or adjacent nonneural ectoderm. Some of these markers are also similarly expressed in tunicates. In protochordates, however, these cells, unlike vertebrate neural crest, neither migrate as individuals through embryonic tissues nor differentiate into a wide spectrum of cell types. Therefore, while the protochordate ancestor of the vertebrates probably had the beginnings of a genetic programme for neural crest formation, this programme was augmented in the earliest vertebrates to attain definitive neural crest. Clear homologues of vertebrate placodes are lacking in protochordates. However, both amphioxus and tunicates have ectodermal sensory cells. In tunicates these are all primary neurons, sending axons to the central nervous system, while in amphioxus, the ectodermal sensory cells include both primary neurons and secondary neurons lacking axons. Comparisons of developmental gene expression suggest that the anterior ectoderm in amphioxus may be homologous to the vertebrate olfactory placode, the only vertebrate placode with primary, not secondary, neurons. Similarly, biochemical, morphological and gene expression data suggest that amphioxus and tunicates also have homologues of the adenohypophysis, one of the few vertebrate structures derived from nonneurogenic placodes. In contrast, the origin of the other vertebrate placodes is very uncertain.

  18. Functions of two distinct prolactin-releasing peptides evolved from a common ancestral gene

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    Tetsuya eTachibana

    2014-11-01

    Full Text Available Prolactin-releasing peptide (PrRP is one of the RF-amide peptides and was originally identified in the bovine hypothalamus as a stimulator of prolactin (PRL release. Independently, another RF-amide peptide was found in Japanese crucian carp and named Carassius RFa (C-RFa, which shows high homology to PrRP and stimulates PRL secretion in teleost fish. Therefore, C-RFa has been recognized as fish PrRP. However, recent work has revealed that PrRP and C-RFa in non-mammalian vertebrates are encoded by separate genes originated through duplication of an ancestral gene. Indeed, both PrRP and C-RFa are suggested to exist in teleost, amphibian, reptile, and avian species. Therefore, we propose that non-mammalian PrRP (C-RFa be renamed PrRP2. Despite a common evolutionary origin, PrRP2 appears to be a physiological regulator of PRL, whereas this is not a consistent role for PrRP itself. Further work revealed that the biological functions of PrRP and PrRP2 are not limited solely to PRL release, because they are also neuromodulators of several hypothalamus-pituitary axes and are involved in some brain circuits related to the regulation of food intake, stress, and cardiovascular functions. However, these actions appear to be different among vertebrates. For example, central injection of PrRP inhibits feeding behavior in rodents and teleosts while it stimulates it in chicks. Therefore, both PrRP and PrRP2 have acquired diverse actions through evolution. In this review, we integrate the burgeoning information of structures, expression profiles, and multiple biological actions of PrRP in higher vertebrates, as well as those of PrRP2 in non-mammals.

  19. Toxic and nontoxic components of botulinum neurotoxin complex are evolved from a common ancestral zinc protein

    Energy Technology Data Exchange (ETDEWEB)

    Inui, Ken [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472 (Japan); Sagane, Yoshimasa [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Miyata, Keita [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472 (Japan); Miyashita, Shin-Ichiro [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Suzuki, Tomonori [Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558 (Japan); Shikamori, Yasuyuki [Agilent Technologies International Japan, Ltd. Takaura-cho 9-1, Hachioji-shi, Tokyo 192-0033 (Japan); Ohyama, Tohru; Niwa, Koichi [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Watanabe, Toshihiro, E-mail: t-watana@bioindustry.nodai.ac.jp [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan)

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer BoNT and NTNHA proteins share a similar protein architecture. Black-Right-Pointing-Pointer NTNHA and BoNT were both identified as zinc-binding proteins. Black-Right-Pointing-Pointer NTNHA does not have a classical HEXXH zinc-coordinating motif similar to that found in all serotypes of BoNT. Black-Right-Pointing-Pointer Homology modeling implied probable key residues involved in zinc coordination. -- Abstract: Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structure classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X{sub 35}-D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.

  20. The vomeronasal complex of nocturnal strepsirhines and implications for the ancestral condition in primates.

    Science.gov (United States)

    Garrett, Eva C; Dennis, John C; Bhatnagar, Kunwar P; Durham, Emily L; Burrows, Anne M; Bonar, Christopher J; Steckler, Natalie K; Morrison, Edward E; Smith, Timothy D

    2013-12-01

    This study investigates the vomeronasal organ in extant nocturnal strepsirhines as a model for ancestral primates. Cadaveric samples from 10 strepsirhine species, ranging from fetal to adult ages, were studied histologically. Dimensions of structures in the vomeronasal complex, such as the vomeronasal neuroepithelium (VNNE) and vomeronasal cartilage (VNC) were measured in serial sections and selected specimens were studied immunohistochemically to determine physiological aspects of the vomeronasal sensory neurons (VSNs). Osteological features corresponding to vomeronasal structures were studied histologically and related to 3-D CT reconstructions. The VNC consistently rests in a depression on the palatal portion of the maxilla, which we refer to as the vomeronasal groove (VNG). Most age comparisons indicate that in adults VNNE is about twice the length compared with perinatal animals. In VNNE volume, adults are 2- to 3-fold larger compared with perinatal specimens. Across ages, a strong linear relationship exists between VNNE dimensions and body length, mass, and midfacial length. Results indicate that the VNNE of nocturnal strepsirhines is neurogenic postnatally based on GAP43 expression. In addition, based on Olfactory Marker Protein expression, terminally differentiated VSNs are present in the VNNE. Therefore, nocturnal strepsirhines have basic similarities to rodents in growth and maturational characteristics of VSNs. These results indicate that a functional vomeronasal system is likely present in all nocturnal strepsirhines. Finally, given that osteological features such as the VNG are visible on midfacial bones, primate fossils can be assessed to determine whether primate ancestors possessed a vomeronasal complex morphologically similar to that of modern nocturnal strepsirhines. Copyright © 2013 Wiley Periodicals, Inc.

  1. Estudio de dos materiales volcánicos y efecto del tipo de molienda en su reactividad

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    Diana M Burgos

    2014-08-01

    Full Text Available En este estudio se presenta la caracterización y evaluación de la actividad puzolánica de dos materiales volcánicos procedentes de dos depósitos volcánicos Colombianos (Volcán Puracé y Nevado del Tolima. Estos materiales fueron analizados mediante diversas técnicas de caracterización, la aptitud de los materiales volcánicos como puzolanas y el efecto de la molienda en su reactividad, se evaluó por medio del índice de Actividad Puzolánica (iaP, ensayo de Frattini. Los resultados indican que el MVP presenta un iaP de 77,51% y se ubica en la zona reactiva de la curva de Frattini, características que permiten clasificar este material como una puzolana natural. En cuanto al MVT los resultados indicaron que químicamente no reaccionó, pero generó un índice de resistencia de 92,36% respecto a la muestra patrón, características de un material inerte que por efecto filler permite el desarrollo de resistencias mecánicas. Por otra parte, también se evidenció que no existe un efecto significativo del proceso de molienda en la reactividad de estos materiales.

  2. Complete tribal sampling reveals basal split in Muscidae (Diptera), confirms saprophagy as ancestral feeding mode, and reveals an evolutionary correlation between instar numbers and carnivory

    DEFF Research Database (Denmark)

    Kutty, Sujatha Narayanan; Pont, Adrian C.; Meier, Rudolf

    2014-01-01

    split within this family. The ancestral larval feeding habit is reconstructed to be saprophagy with more specialised coprophagous saprophagy, phytophagy, and carnivory evolving multiple times from saprophagous ancestors. The origins of carnivory in larvae are significantly correlated with a reduction...

  3. Reconstructed ancestral Myo-inositol-3-phosphate synthases indicate that ancestors of the Thermococcales and Thermotoga species were more thermophilic than their descendants.

    Science.gov (United States)

    Butzin, Nicholas C; Lapierre, Pascal; Green, Anna G; Swithers, Kristen S; Gogarten, J Peter; Noll, Kenneth M

    2013-01-01

    The bacterial genomes of Thermotoga species show evidence of significant interdomain horizontal gene transfer from the Archaea. Members of this genus acquired many genes from the Thermococcales, which grow at higher temperatures than Thermotoga species. In order to study the functional history of an interdomain horizontally acquired gene we used ancestral sequence reconstruction to examine the thermal characteristics of reconstructed ancestral proteins of the Thermotoga lineage and its archaeal donors. Several ancestral sequence reconstruction methods were used to determine the possible sequences of the ancestral Thermotoga and Archaea myo-inositol-3-phosphate synthase (MIPS). These sequences were predicted to be more thermostable than the extant proteins using an established sequence composition method. We verified these computational predictions by measuring the activities and thermostabilities of purified proteins from the Thermotoga and the Thermococcales species, and eight ancestral reconstructed proteins. We found that the ancestral proteins from both the archaeal donor and the Thermotoga most recent common ancestor recipient were more thermostable than their descendants. We show that there is a correlation between the thermostability of MIPS protein and the optimal growth temperature (OGT) of its host, which suggests that the OGT of the ancestors of these species of Archaea and the Thermotoga grew at higher OGTs than their descendants.

  4. Reconstructed ancestral Myo-inositol-3-phosphate synthases indicate that ancestors of the Thermococcales and Thermotoga species were more thermophilic than their descendants.

    Directory of Open Access Journals (Sweden)

    Nicholas C Butzin

    Full Text Available The bacterial genomes of Thermotoga species show evidence of significant interdomain horizontal gene transfer from the Archaea. Members of this genus acquired many genes from the Thermococcales, which grow at higher temperatures than Thermotoga species. In order to study the functional history of an interdomain horizontally acquired gene we used ancestral sequence reconstruction to examine the thermal characteristics of reconstructed ancestral proteins of the Thermotoga lineage and its archaeal donors. Several ancestral sequence reconstruction methods were used to determine the possible sequences of the ancestral Thermotoga and Archaea myo-inositol-3-phosphate synthase (MIPS. These sequences were predicted to be more thermostable than the extant proteins using an established sequence composition method. We verified these computational predictions by measuring the activities and thermostabilities of purified proteins from the Thermotoga and the Thermococcales species, and eight ancestral reconstructed proteins. We found that the ancestral proteins from both the archaeal donor and the Thermotoga most recent common ancestor recipient were more thermostable than their descendants. We show that there is a correlation between the thermostability of MIPS protein and the optimal growth temperature (OGT of its host, which suggests that the OGT of the ancestors of these species of Archaea and the Thermotoga grew at higher OGTs than their descendants.

  5. A Common Ancestral Mutation in CRYBB3 Identified in Multiple Consanguineous Families with Congenital Cataracts.

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    Xiaodong Jiao

    report a common ancestral mutation in CRYBB3 associated with autosomal recessive congenital cataracts identified in four familial cases of Pakistani origin.

  6. Del discurso del desarrollo al buen vivir: una aproximación con enfoque étnico diferencial a la intervención megaminera en el Alto Putumayo

    OpenAIRE

    Pardo Quintero, Andrés Felipe

    2015-01-01

    Este estudio de caso aborda el tema de las alternativas al desarrollo convencional, concretamente el concepto de Buen Vivir- Sumak Kawsay, a la luz de la descripción y el análisis de los impactos del auge minero en la región del Alto Putumayo, territorio ancestral de los pueblos indígenas Inga y Camëntsá. Este trabajo quiere mostrar que la apuesta por un modelo económico extractivista, está inspirado en un plan de dominación global de recursos naturales por parte del algunas potencias, que a ...

  7. Reestablishment of the Ancestral Cascades Arc in Western Nevada and Eastern California by Rollback of the Shallow Farallon Slab

    Science.gov (United States)

    Henry, C. D.; Cousens, B.; John, D. A.; Colgan, J. P.

    2009-12-01

    The character and even existence of an ancestral Tertiary Cascades arc in western Nevada and eastern California south of the modern arc are controversial. Based on extensive published and new data on the regional distribution, timing, style, and composition of magmatism, we conclude that an ancestral arc was established by WSW migration of magmatism into western NV and the northeastern Sierra Nevada in the Oligocene and Miocene as a result of progressive rollback of the shallow subducted slab. Magma migration started with the well-known southward sweep through NE NV and NW UT between ~46 and 36 Ma. By ~30 Ma, migration of the leading edge and central belt of activity was much more WSW, especially after removing younger ~E-W extension. Locally sourced, initially dispersed and small volume, intermediate to mafic lavas erupted in western NV and northeastern CA by ~30 Ma and the eastern Sierra Nevada by ~28 Ma, contemporaneous with the much more voluminous ignimbrite flare-up in central NV. As migration continued, the ignimbrite flare-up tapered off. A voluminous, NNW-trending, dominantly effusive volcanic belt developed by ~22-18 Ma in western NV and was continuous from the Bodie Hills (CA/NV) to the Warner Range (northeast CA) by ~16-15 Ma. The volcanic belt was dominated by intermediate to mafic magmas compositionally similar to those of the modern south Cascades arc but reflecting melting of an old, subduction-modified lithosphere (Cousens et al. 2008; Geosphere). Extensive middle Miocene bimodal rocks related to the Yellowstone hotspot cover these rocks in NW NV, NE CA, and SE OR, but 30-23 Ma, intermediate to mafic and lesser silicic rocks are voluminous wherever older rocks are exposed below the middle Miocene rocks. Between ~25 Ma and the present, magmatism migrated WSW at an average rate of ~8 km/Ma but was at least partly stepwise, as exemplified by an ~50 km westward step at 2 Ma in the Lassen area (Guffanti et al. 1990, JGR). The magmatic belt was as much

  8. Human Genetic Ancestral Composition Correlates with the Origin of Mycobacterium leprae Strains in a Leprosy Endemic Population.

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    Nora Cardona-Castro

    Full Text Available Recent reports have suggested that leprosy originated in Africa, extended to Asia and Europe, and arrived in the Americas during European colonization and the African slave trade. Due to colonization, the contemporary Colombian population is an admixture of Native-American, European and African ancestries. Because microorganisms are known to accompany humans during migrations, patterns of human migration can be traced by examining genomic changes in associated microbes. The current study analyzed 118 leprosy cases and 116 unrelated controls from two Colombian regions endemic for leprosy (Atlantic and Andean in order to determine possible associations of leprosy with patient ancestral background (determined using 36 ancestry informative markers, Mycobacterium leprae genotype and/or patient geographical origin. We found significant differences between ancestral genetic composition. European components were predominant in Andean populations. In contrast, African components were higher in the Atlantic region. M. leprae genotypes were then analyzed for cluster associations and compared with the ancestral composition of leprosy patients. Two M. leprae principal clusters were found: haplotypes C54 and T45. Haplotype C54 associated with African origin and was more frequent in patients from the Atlantic region with a high African component. In contrast, haplotype T45 associated with European origin and was more frequent in Andean patients with a higher European component. These results suggest that the human and M. leprae genomes have co-existed since the African and European origins of the disease, with leprosy ultimately arriving in Colombia during colonization. Distinct M. leprae strains followed European and African settlement in the country and can be detected in contemporary Colombian populations.

  9. Allo-allo-triploid Sphagnum × falcatulum: single individuals contain most of the Holantarctic diversity for ancestrally indicative markers.

    Science.gov (United States)

    Karlin, Eric F; Smouse, Peter E

    2017-08-01

    Allopolyploids exhibit both different levels and different patterns of genetic variation than are typical of diploids. However, scant attention has been given to the partitioning of allelic information and diversity in allopolyploids, particularly that among homeologous monoploid components of the hologenome. Sphagnum × falcatulum is a double allopolyploid peat moss that spans a considerable portion of the Holantarctic. With monoploid genomes from three ancestral species, this organism exhibits a complex evolutionary history involving serial inter-subgeneric allopolyploidizations. Studying populations from three disjunct regions [South Island (New Zealand); Tierra de Fuego archipelago (Chile, Argentina); Tasmania (Australia)], allelic information for five highly stable microsatellite markers that differed among the three (ancestral) monoploid genomes was examined. Using Shannon information and diversity measures, the holoploid information, as well as the information within and among the three component monoploid genomes, was partitioned into separate components for individuals within and among populations and regions, and those information components were then converted into corresponding diversity measures. The majority (76 %) of alleles detected across these five markers are most likely to have been captured by hybridization, but the information within each of the three monoploid genomes varied, suggesting a history of recurrent allopolyploidization between ancestral species containing different levels of genetic diversity. Information within individuals, equivalent to the information among monoploid genomes (for this dataset), was relatively stable, and represented 83 % of the grand total information across the Holantarctic, with both inter-regional and inter-population diversification each accounting for about 5 % of the total information. Sphagnum × falcatulum probably inherited the great majority of its genetic diversity at these markers by reticulation

  10. Saccharomyces cerevisiae Bat1 and Bat2 aminotransferases have functionally diverged from the ancestral-like Kluyveromyces lactis orthologous enzyme.

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    Maritrini Colón

    Full Text Available BACKGROUND: Gene duplication is a key evolutionary mechanism providing material for the generation of genes with new or modified functions. The fate of duplicated gene copies has been amply discussed and several models have been put forward to account for duplicate conservation. The specialization model considers that duplication of a bifunctional ancestral gene could result in the preservation of both copies through subfunctionalization, resulting in the distribution of the two ancestral functions between the gene duplicates. Here we investigate whether the presumed bifunctional character displayed by the single branched chain amino acid aminotransferase present in K. lactis has been distributed in the two paralogous genes present in S. cerevisiae, and whether this conservation has impacted S. cerevisiae metabolism. PRINCIPAL FINDINGS: Our results show that the KlBat1 orthologous BCAT is a bifunctional enzyme, which participates in the biosynthesis and catabolism of branched chain aminoacids (BCAAs. This dual role has been distributed in S. cerevisiae Bat1 and Bat2 paralogous proteins, supporting the specialization model posed to explain the evolution of gene duplications. BAT1 is highly expressed under biosynthetic conditions, while BAT2 expression is highest under catabolic conditions. Bat1 and Bat2 differential relocalization has favored their physiological function, since biosynthetic precursors are generated in the mitochondria (Bat1, while catabolic substrates are accumulated in the cytosol (Bat2. Under respiratory conditions, in the presence of ammonium and BCAAs the bat1Δ bat2Δ double mutant shows impaired growth, indicating that Bat1 and Bat2 could play redundant roles. In K. lactis wild type growth is independent of BCAA degradation, since a Klbat1Δ mutant grows under this condition. CONCLUSIONS: Our study shows that BAT1 and BAT2 differential expression and subcellular relocalization has resulted in the distribution of the

  11. Human Genetic Ancestral Composition Correlates with the Origin of Mycobacterium leprae Strains in a Leprosy Endemic Population.

    Science.gov (United States)

    Cardona-Castro, Nora; Cortés, Edwin; Beltrán, Camilo; Romero, Marcela; Badel-Mogollón, Jaime E; Bedoya, Gabriel

    2015-01-01

    Recent reports have suggested that leprosy originated in Africa, extended to Asia and Europe, and arrived in the Americas during European colonization and the African slave trade. Due to colonization, the contemporary Colombian population is an admixture of Native-American, European and African ancestries. Because microorganisms are known to accompany humans during migrations, patterns of human migration can be traced by examining genomic changes in associated microbes. The current study analyzed 118 leprosy cases and 116 unrelated controls from two Colombian regions endemic for leprosy (Atlantic and Andean) in order to determine possible associations of leprosy with patient ancestral background (determined using 36 ancestry informative markers), Mycobacterium leprae genotype and/or patient geographical origin. We found significant differences between ancestral genetic composition. European components were predominant in Andean populations. In contrast, African components were higher in the Atlantic region. M. leprae genotypes were then analyzed for cluster associations and compared with the ancestral composition of leprosy patients. Two M. leprae principal clusters were found: haplotypes C54 and T45. Haplotype C54 associated with African origin and was more frequent in patients from the Atlantic region with a high African component. In contrast, haplotype T45 associated with European origin and was more frequent in Andean patients with a higher European component. These results suggest that the human and M. leprae genomes have co-existed since the African and European origins of the disease, with leprosy ultimately arriving in Colombia during colonization. Distinct M. leprae strains followed European and African settlement in the country and can be detected in contemporary Colombian populations.

  12. Reconstructed ancestral enzymes reveal that negative selection drove the evolution of substrate specificity in ADP-dependent kinases.

    Science.gov (United States)

    Castro-Fernandez, Víctor; Herrera-Morande, Alejandra; Zamora, Ricardo; Merino, Felipe; Gonzalez-Ordenes, Felipe; Padilla-Salinas, Felipe; Pereira, Humberto M; Brandão-Neto, Jose; Garratt, Richard C; Guixe, Victoria

    2017-09-22

    One central goal in molecular evolution is to pinpoint the mechanisms and evolutionary forces that cause an enzyme to change its substrate specificity; however, these processes remain largely unexplored. Using the glycolytic ADP-dependent kinases of archaea, including the orders Thermococcales , Methanosarcinales , and Methanococcales , as a model and employing an approach involving paleoenzymology, evolutionary statistics, and protein structural analysis, we could track changes in substrate specificity during ADP-dependent kinase evolution along with the structural determinants of these changes. To do so, we studied five key resurrected ancestral enzymes as well as their extant counterparts. We found that a major shift in function from a bifunctional ancestor that could phosphorylate either glucose or fructose 6-phosphate (fructose-6-P) as a substrate to a fructose 6-P-specific enzyme was started by a single amino acid substitution resulting in negative selection with a ground-state mode against glucose and a subsequent 1,600-fold change in specificity of the ancestral protein. This change rendered the residual phosphorylation of glucose a promiscuous and physiologically irrelevant activity, highlighting how promiscuity may be an evolutionary vestige of ancestral enzyme activities, which have been eliminated over time. We also could reconstruct the evolutionary history of substrate utilization by using an evolutionary model of discrete binary characters, indicating that substrate uses can be discretely lost or acquired during enzyme evolution. These findings exemplify how negative selection and subtle enzyme changes can lead to major evolutionary shifts in function, which can subsequently generate important adaptive advantages, for example, in improving glycolytic efficiency in Thermococcales . © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Estimation of the net acid load of the diet of ancestral preagricultural Homo sapiens and their hominid ancestors.

    Science.gov (United States)

    Sebastian, Anthony; Frassetto, Lynda A; Sellmeyer, Deborah E; Merriam, Renée L; Morris, R Curtis

    2002-12-01

    Natural selection has had diet resulting from the inventions of agriculture and animal husbandry. The objective was to estimate the net systemic load of acid (net endogenous acid production; NEAP) from retrojected ancestral preagricultural diets and to compare it with that of contemporary diets, which are characterized by an imbalance of nutrient precursors of hydrogen and bicarbonate ions that induces a lifelong, low-grade, pathogenically significant systemic metabolic acidosis. Using established computational methods, we computed NEAP for a large number of retrojected ancestral preagricultural diets and compared them with computed and measured values for typical American diets. The mean (+/- SD) NEAP for 159 retrojected preagricultural diets was -88 +/- 82 mEq/d; 87% were net base-producing. The computational model predicted NEAP for the average American diet (as recorded in the third National Health and Nutrition Examination Survey) as 48 mEq/d, within a few percentage points of published measured values for free-living Americans; the model, therefore, was not biased toward generating negative NEAP values. The historical shift from negative to positive NEAP was accounted for by the displacement of high-bicarbonate-yielding plant foods in the ancestral diet by cereal grains and energy-dense, nutrient-poor foods in the contemporary diet-neither of which are net base-producing. The findings suggest that diet-induced metabolic acidosis and its sequelae in humans eating contemporary diets reflect a mismatch between the nutrient composition of the diet and genetically determined nutritional requirements for optimal systemic acid-base status.

  14. Potencial del Agua del suelo

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    Bustamante Heliodoro

    1986-12-01

    Full Text Available La energía potencial del agua presenta diferencias de un punto del suelo a otro; esas diferencias son las que originan el movimiento del agua de acuerdo a la tendencia universal de la materia en el sentido de moverse de donde la energía potencial es mayor a donde dicha energía es menor. En el suelo el agua en consecuencia se mueve hacia donde su energía decrece hasta lograr su estado de equilibrio. Se desprende entonces que la cantidad de energía potencial absoluta contenida en el agua, no es importante por sí misma, sino por su relación con la energía en diferentes lugares dentro del suelo. El concepto Potencial de agua del suelo es un criterio para esta energía.

  15. Thermotolerant Yeast Strains Adapted by Laboratory Evolution Show Trade-Off at Ancestral Temperatures and Preadaptation to Other Stresses.

    Science.gov (United States)

    Caspeta, Luis; Nielsen, Jens

    2015-07-21

    A major challenge for the production of ethanol from biomass-derived feedstocks is to develop yeasts that can sustain growth under the variety of inhibitory conditions present in the production process, e.g., high osmolality, high ethanol titers, and/or elevated temperatures (≥ 40 °C). Using adaptive laboratory evolution, we previously isolated seven Saccharomyces cerevisiae strains with improved growth at 40 °C. Here, we show that genetic adaptations to high temperature caused a growth trade-off at ancestral temperatures, reduced cellular functions, and improved tolerance of other stresses. Thermotolerant yeast strains showed horizontal displacement of their thermal reaction norms to higher temperatures. Hence, their optimal and maximum growth temperatures increased by about 3 °C, whereas they showed a growth trade-off at temperatures below 34 °C. Computational analysis of the physical properties of proteins showed that the lethal temperature for yeast is around 49 °C, as a large fraction of the yeast proteins denature above this temperature. Our analysis also indicated that the number of functions involved in controlling the growth rate decreased in the thermotolerant strains compared with the number in the ancestral strain. The latter is an advantageous attribute for acquiring thermotolerance and correlates with the reduction of yeast functions associated with loss of respiration capacity. This trait caused glycerol overproduction that was associated with the growth trade-off at ancestral temperatures. In combination with altered sterol composition of cellular membranes, glycerol overproduction was also associated with yeast osmotolerance and improved tolerance of high concentrations of glucose and ethanol. Our study shows that thermal adaptation of yeast is suitable for improving yeast resistance to inhibitory conditions found in industrial ethanol production processes. Yeast thermotolerance can significantly reduce the production costs of biomass

  16. Breadth of T cell responses after immunization with adenovirus vectors encoding ancestral antigens or polyvalent papillomavirus antigens

    DEFF Research Database (Denmark)

    Ragonnaud, Emeline; Pedersen, Anders Gorm; Holst, Peter Johannes

    2017-01-01

    to the other PV proteins. The PV sequences were fused to a T cell adjuvant, the murine invariant chain and encoded in a recombinant adenoviral vector which was administered to naïve outbred mice. By measuring T cell responses induced by these different vaccines and towards peptide pools representing 3...... circulating strains and a putative ancestor of oncogenic HPVs, we showed that the ancestral vaccine antigen has to be approximately 90% identical to the circulating PVs before a marked drop of ~90% mean CD8+ T cell responses ensues. Interestingly, the combination of two or three type-specific PV vaccines did...

  17. The Odyssey of the Ancestral Escherich Strain through Culture Collections: an Example of Allopatric Diversification.

    Science.gov (United States)

    Desroches, M; Royer, G; Roche, D; Mercier-Darty, M; Vallenet, D; Médigue, C; Bastard, K; Rodriguez, C; Clermont, O; Denamur, E; Decousser, J-W

    2018-01-01

    More than a century ago, Theodor Escherich isolated the bacterium that was to become Escherichia coli , one of the most studied organisms. Not long after, the strain began an odyssey and landed in many laboratories across the world. As laboratory culture conditions could be responsible for major changes in bacterial strains, we conducted a genome analysis of isolates of this emblematic strain from different culture collections (England, France, the United States, Germany). Strikingly, many discrepancies between the isolates were observed, as revealed by multilocus sequence typing (MLST), the presence of virulence-associated genes, core genome MLST, and single nucleotide polymorphism/indel analyses. These differences are correlated with the phylogeographic history of the strain and were due to an unprecedented number of mutations in coding DNA repair functions such as mismatch repair (MutL) and oxidized guanine nucleotide pool cleaning (MutT), conferring a specific mutational spectrum and leading to a mutator phenotype. The mutator phenotype was probably acquired during subculturing and corresponded to second-order selection. Furthermore, all of the isolates exhibited hypersusceptibility to antibiotics due to mutations in efflux pump- and porin-encoding genes, as well as a specific mutation in the sigma factor-encoding gene rpoS . These defects reflect a self-preservation and nutritional competence tradeoff allowing survival under the starvation conditions imposed by storage. From a clinical point of view, dealing with such mutator strains can lead microbiologists to draw false conclusions about isolate relatedness and may impact therapeutic effectiveness. IMPORTANCE Mutator phenotypes have been described in laboratory-evolved bacteria, as well as in natural isolates. Several genes can be impacted, each of them being associated with a typical mutational spectrum. By studying one of the oldest strains available, the ancestral Escherich strain, we were able to

  18. Evidence for an Ancestral Association of Human Coronavirus 229E with Bats.

    Science.gov (United States)

    Corman, Victor Max; Baldwin, Heather J; Tateno, Adriana Fumie; Zerbinati, Rodrigo Melim; Annan, Augustina; Owusu, Michael; Nkrumah, Evans Ewald; Maganga, Gael Darren; Oppong, Samuel; Adu-Sarkodie, Yaw; Vallo, Peter; da Silva Filho, Luiz Vicente Ribeiro Ferreira; Leroy, Eric M; Thiel, Volker; van der Hoek, Lia; Poon, Leo L M; Tschapka, Marco; Drosten, Christian; Drexler, Jan Felix

    2015-12-01

    We previously showed that close relatives of human coronavirus 229E (HCoV-229E) exist in African bats. The small sample and limited genomic characterizations have prevented further analyses so far. Here, we tested 2,087 fecal specimens from 11 bat species sampled in Ghana for HCoV-229E-related viruses by reverse transcription-PCR (RT-PCR). Only hipposiderid bats tested positive. To compare the genetic diversity of bat viruses and HCoV-229E, we tested historical isolates and diagnostic specimens sampled globally over 10 years. Bat viruses were 5- and 6-fold more diversified than HCoV-229E in the RNA-dependent RNA polymerase (RdRp) and spike genes. In phylogenetic analyses, HCoV-229E strains were monophyletic and not intermixed with animal viruses. Bat viruses formed three large clades in close and more distant sister relationships. A recently described 229E-related alpaca virus occupied an intermediate phylogenetic position between bat and human viruses. According to taxonomic criteria, human, alpaca, and bat viruses form a single CoV species showing evidence for multiple recombination events. HCoV-229E and the alpaca virus showed a major deletion in the spike S1 region compared to all bat viruses. Analyses of four full genomes from 229E-related bat CoVs revealed an eighth open reading frame (ORF8) located at the genomic 3' end. ORF8 also existed in the 229E-related alpaca virus. Reanalysis of HCoV-229E sequences showed a conserved transcription regulatory sequence preceding remnants of this ORF, suggesting its loss after acquisition of a 229E-related CoV by humans. These data suggested an evolutionary origin of 229E-related CoVs in hipposiderid bats, hypothetically with camelids as intermediate hosts preceding the establishment of HCoV-229E. The ancestral origins of major human coronaviruses (HCoVs) likely involve bat hosts. Here, we provide conclusive genetic evidence for an evolutionary origin of the common cold virus HCoV-229E in hipposiderid bats by analyzing a

  19. DISCUSSION OF “CLUSTERING ON DISSIMILARITY REPRESENTATIONS FOR DETECTING MISLABELLED SEISMIC SIGNALS AT NEVADO DEL RUIZ VOLCANO” BY MAURICIO OROZCO-ALZATE, AND CÉSAR GERMÁN CASTELLANOS-DOMÍNGUEZ

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    Rivera Diego

    2008-12-01

    Full Text Available The authors are to be congratulated for a systematic investigationof the accurate and non subjective classifying approach in seismic research. The authors have conducted several clustering algorithms to the seismic event records from Volcanological and SeismologicalObservatory at Manizales. Their objective was to improve the grouping of seismic data (i.e., volcano-tectonic earthquakes, long-period earthquakes and icequakes digitized at 100.16 Hz sampling frequency.Their study seems adding new approach to their previous work of Langer et al. (2006 who applied different classification techniques to seismic data.

  20. Amplification of an ancestral mammalian L1 family of long interspersed repeated DNA occurred just before the murine radiation

    International Nuclear Information System (INIS)

    Pascale, E.; Valle, E.; Furano, A.V.

    1990-01-01

    Each mammalian genus examined so far contains 50,000-100,000 members of an L1 (LINE 1) family of long interspersed repeated DNA elements. Current knowledge on the evolution of L1 families presents a paradox because, although L1 families have been in mammalian genomes since before the mammalian radiation ∼80 million years ago, most members of the L1 families are only a few million years old. Accordingly it has been suggested either that the extensive amplification that characterizes present-day L1 families did not occur in the past or that old members were removed as new one were generated. However, the authors show here that an ancestral rodent L1 family was extensively amplified ∼10 million years ago and that the relics of this amplification have persisted in modern murine genomes. This amplification occurred just before the divergence of modern murine genera from their common ancestor and identifies the murine node in the lineage of modern muroid rodents The results suggest that repeated amplification of L1 elements is a feature of the evaluation of mammalian genomes and that ancestral amplification events could provide a useful tool for determining mammalian lineages

  1. The ghost of Afrikaner identity in Ancestral voices, Leap year and The long silence of Mario Salviati (Etienne van Heerden

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    Mariëtte van Graan

    2017-04-01

    Full Text Available Ghost characters are a characteristic of the novels of Etienne van Heerden, but little research has been done concerning the nature and function of these ghost characters. In this article I discuss Van Heerden’s use of ghost characters diachronically with reference to the novels Ancestral voices (1986, Leap year (1993 and The long silence of Mario Salviati (2000. In order to clarify the nature of these ghosts, I use the so-called science of the paranormal as a framework. The ghosts in the three novels will be classified accordingly, and then discussed within the context of the novels in which they appear. In this way, I shall show how the ghost characters in these novels can be read as a constantly changing embodiment of Afrikaner identity (a central theme in Van Heerden’s oeuvre. Van Heerden’s Afrikaner changes with the times: in Ancestral voices the ghost characters form a collective that represents a fragmented image of the stereotypical, archaic male Afrikaner identity; in Leap year a liminal character is written in a liminal time to embody a liminal Afrikaner identity; and in The long silence of Mario Salviati Van Heerden moves away from the exclusive Afrikaner identity to a broader South African identity by using ghost characters from very different backgrounds and origins. In conclusion I shall compare these identities and the historical contexts of these novels in order to show the function of Van Heerden’s ghost characters as constant rewritings of South African identities.

  2. Racionalidad del terror

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    Sauquillo, Julián

    2012-06-01

    Full Text Available Contemporary terrorism is not an ancestral, irrational, oriental, phenomenon. Nor is it a fanatical reaction of the religions that vindicate a backward society as against the developed societies of the first world. The terrorism of today is a thoroughly modern phenomenon: one of the worst monstrosities of modern society, supplied with rational planning of objectives. A captious interpretation of the Islamic religion endows terrorism with a universal projection among the multitudinous audience of the discontented with the might of that diffuse power that we know as the developed Western world. Al Qaeda does not hesitate to present its war against the West as «a war without quarter» lasting until the infidel Christians are eliminated and the world is subjugated to Islam In the meantime, in a similar conflictive sense, the theoretical campaign of Samuel Huntington across the entire planet responds with a paradigmatic post-cold war, capable of inflaming the international conflict, in a sense no less belligerent with the Anti-Occident than that employed by the radical Imams. As has been pointed out by Amartya Sen, to give priority in this way to the religious identity, the response of the West to international terrorism in calling it «islamic terrorism» is very clumsy, as it magnifies the importance of the religious authorities in detriment to governmental ways and means in the solving of problems.

    El terrorismo contemporáneo no es un fenómeno ancestral, irracional y oriental. Tampoco es una reacción fanática de las religiones que reivindican una sociedad atrasada frente a las sociedades desarrolladas del primer mundo. El terrorismo actual es un fenómeno plenamente moderno: uno de los peores engendros de la sociedad moderna, dotado de una planificación racional de objetivos. Una interpretación capciosa de la religión islámica dota al terrorismo de una proyección universal entre la numerosa audiencia de descontentos con el poder

  3. Anatomía foliar y del pecíolo de cuatro especies de Lupinus (Fabaceae Foliar and petiole anatomy of four species of Lupinus (Fabaceae

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    Juan Francisco Zamora-Natera

    2012-09-01

    Full Text Available Se describe y compara la anatomía foliar y del pecíolo de 4 especies del género Lupinus (L. aschenbornii S.Schauer, L. exaltatus Zucc., L. montanus Kunth y L. reflexus Rose que se distribuyen en un gradiente altitudinal en el Parque Nacional Nevado de Colima. Las hojas se fijaron en campo y se procesaron mediante la técnica de inclusión en parafina. Parte de las láminas se deshidrataron para caracterizar la superficie foliar por medio del microscopio electrónico de barrido. Las especies comparten la epidermis papilosa de paredes anticlinales con diferentes grados de ondulación, estomas anomocíticos, tricomas simples lineares y mesofilo bifacial. Los folíolos de L. montanus son glabros en la superficie abaxial, las estrías cuticulares sobre las células localizadas en la base de los tricomas es un rasgo característico de L. montanus y de L. reflexus. Las diferencias encontradas en espesor de la lámina y del mesofilo así como la abundancia de ceras epicuticulares pueden estar influenciadas por el ambiente. Distintivamente, el número y distribución de haces vasculares en los pecíolos difieren entre las 4 especies y podrían ser de utilidad para diferenciarlas si estos resultados se confirman al estudiar un mayor número de especies de Lupinus.The aims of this study were to describe and compare the foliar and petiole anatomy of 4 species of Lupinus (L. aschenbornii S.Schauer, L. exaltatus Zucc., L. montanus Kunth, and L. reflexus Rose distributed in an elevation gradient at Parque Nacional Nevado de Colima. Leaves were fixed in the field and prepared using the paraffin embedding technique. In addition, part of the blades was dehydrated to describe leaf surface through the scanning electron microscope. The 4 species shared a papillose epidermis with undulated anticlinal walls in different degrees, stomata anomocytic, simple unicellular trichomes, and bifacial mesophyll. Leaflets of L. montanus are glabrous on the abaxial surface

  4. Efectos del contacto piel con piel del recién nacido con su madre

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    Camila Lucchini Raies

    Full Text Available Antecedentes: el contacto piel con piel ha sido una práctica ancestral en toda cultura, que debido a la institucionalización de la atención del parto, disminuyó en occidente. Se retomó en el marco de la atención humanizada del parto. Objetivo principal: determinar los efectos del contacto piel con piel del recién nacido con su madre. Metodología: revisión bibliográfica de 26 estudios. Límites de búsqueda: new borns, humans, clinical trials, de 10 años de publicación, en bases de datos: Pubmed, ProQuest, CINHAL, Lilacs. Resultados principales: Se observaron beneficios en las variables: duración de lactancia materna, comportamiento neurosensorial, regulación de temperatura, como alternativa al cuidado estándar, disminución en días hospitalización y niveles de cortisol, favorecedor de la interacción madre-hijo y desarrollo infantil. Conclusión principal: el contacto piel con piel brinda múltiples beneficios a recién nacidos. Se presenta como alternativa de cuidado segura, factible de implementar.

  5. del alcoholismo

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    Rodrigo Arias Duque

    2005-01-01

    Full Text Available Desde el punto de vista farmacológico, es importante comprender qué es el alcohol y cómo actúa en el organismo. No existe una causa simple, sino una interacción complicada de factores neuroquímicos, fisiológicos, psicológicos y sociales que originan y desarrollan esta grave enfermedad fármaco-dependiente. La acción psicofisiológica y farmacodinámica del alcohol es fundamentalmente depresiva, por la reducción de la transmisión sináptica en el sistema nervioso humano. Es un hecho conocido que el consumo excesivo de alcohol causa una disfunción aguda y crónica del cerebro, produciendo trastornos en el sistema nervioso central, presentando alteraciones en la memoria y en las funciones intelectuales como cálculo, comprensión y aprendizaje. A nivel hepático tiene lugar, en su mayoría, el metabolismo del alcohol, produciéndose un hígado graso alcohólico, aumentando el tamaño, terminando en necrosis e inflamación grave del hígado; esto se llama hepatitis alcohólica, y si se sigue consumiendo alcohol se desarrollará la cirrosis. El alcohol también ha estado relacionado con alteraciones del miocardio; se ha constatado en animales de experimentación sanos que tanto la velocidad de contracción del músculo cardiaco y su máxima tensión disminuyen en presencia del alcohol, como consecuencia, la fuerza de cada contracción y el aumento de presión en el ventrículo izquierdo son menores, perdiendo eficacia el corazón como bomba.

  6. MADS goes genomic in conifers: towards determining the ancestral set of MADS-box genes in seed plants.

    Science.gov (United States)

    Gramzow, Lydia; Weilandt, Lisa; Theißen, Günter

    2014-11-01

    MADS-box genes comprise a gene family coding for transcription factors. This gene family expanded greatly during land plant evolution such that the number of MADS-box genes ranges from one or two in green algae to around 100 in angiosperms. Given the crucial functions of MADS-box genes for nearly all aspects of plant development, the expansion of this gene family probably contributed to the increasing complexity of plants. However, the expansion of MADS-box genes during one important step of land plant evolution, namely the origin of seed plants, remains poorly understood due to the previous lack of whole-genome data for gymnosperms. The newly available genome sequences of Picea abies, Picea glauca and Pinus taeda were used to identify the complete set of MADS-box genes in these conifers. In addition, MADS-box genes were identified in the growing number of transcriptomes available for gymnosperms. With these datasets, phylogenies were constructed to determine the ancestral set of MADS-box genes of seed plants and to infer the ancestral functions of these genes. Type I MADS-box genes are under-represented in gymnosperms and only a minimum of two Type I MADS-box genes have been present in the most recent common ancestor (MRCA) of seed plants. In contrast, a large number of Type II MADS-box genes were found in gymnosperms. The MRCA of extant seed plants probably possessed at least 11-14 Type II MADS-box genes. In gymnosperms two duplications of Type II MADS-box genes were found, such that the MRCA of extant gymnosperms had at least 14-16 Type II MADS-box genes. The implied ancestral set of MADS-box genes for seed plants shows simplicity for Type I MADS-box genes and remarkable complexity for Type II MADS-box genes in terms of phylogeny and putative functions. The analysis of transcriptome data reveals that gymnosperm MADS-box genes are expressed in a great variety of tissues, indicating diverse roles of MADS-box genes for the development of gymnosperms. This study is

  7. Culturas del Mundo

    DEFF Research Database (Denmark)

    Benwell, Ann Fenger; Costa, Alberto; Waehle, Espen

    2006-01-01

    ’Culturas del mundo. Colecciones del Museo Nacional de Dinamarca’ with Ann Fenger Benwell in Culturas del Mundo. Colecciones del Museo Nacional de Dinamarca, ed. Silvia Sauquet, Fundación "la Caixa", Barcelona 2006, pp. 31-39......’Culturas del mundo. Colecciones del Museo Nacional de Dinamarca’ with Ann Fenger Benwell in Culturas del Mundo. Colecciones del Museo Nacional de Dinamarca, ed. Silvia Sauquet, Fundación "la Caixa", Barcelona 2006, pp. 31-39...

  8. Ancestral mutations as a tool for solubilizing proteins: The case of a hydrophobic phosphate-binding protein

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    Daniel Gonzalez

    2014-01-01

    Full Text Available Stable and soluble proteins are ideal candidates for functional and structural studies. Unfortunately, some proteins or enzymes can be difficult to isolate, being sometimes poorly expressed in heterologous systems, insoluble and/or unstable. Numerous methods have been developed to address these issues, from the screening of various expression systems to the modification of the target protein itself. Here we use a hydrophobic, aggregation-prone, phosphate-binding protein (HPBP as a case study. We describe a simple and fast method that selectively uses ancestral mutations to generate a soluble, stable and functional variant of the target protein, here named sHPBP. This variant is highly expressed in Escherichia coli, is easily purified and its structure was solved at much higher resolution than its wild-type progenitor (1.3 versus 1.9 Å, respectively.

  9. EREM: Parameter Estimation and Ancestral Reconstruction by Expectation-Maximization Algorithm for a Probabilistic Model of Genomic Binary Characters Evolution

    Directory of Open Access Journals (Sweden)

    Liran Carmel

    2010-01-01

    Full Text Available Evolutionary binary characters are features of species or genes, indicating the absence (value zero or presence (value one of some property. Examples include eukaryotic gene architecture (the presence or absence of an intron in a particular locus, gene content, and morphological characters. In many studies, the acquisition of such binary characters is assumed to represent a rare evolutionary event, and consequently, their evolution is analyzed using various flavors of parsimony. However, when gain and loss of the character are not rare enough, a probabilistic analysis becomes essential. Here, we present a comprehensive probabilistic model to describe the evolution of binary characters on a bifurcating phylogenetic tree. A fast software tool, EREM, is provided, using maximum likelihood to estimate the parameters of the model and to reconstruct ancestral states (presence and absence in internal nodes and events (gain and loss events along branches.

  10. EREM: Parameter Estimation and Ancestral Reconstruction by Expectation-Maximization Algorithm for a Probabilistic Model of Genomic Binary Characters Evolution.

    Science.gov (United States)

    Carmel, Liran; Wolf, Yuri I; Rogozin, Igor B; Koonin, Eugene V

    2010-01-01

    Evolutionary binary characters are features of species or genes, indicating the absence (value zero) or presence (value one) of some property. Examples include eukaryotic gene architecture (the presence or absence of an intron in a particular locus), gene content, and morphological characters. In many studies, the acquisition of such binary characters is assumed to represent a rare evolutionary event, and consequently, their evolution is analyzed using various flavors of parsimony. However, when gain and loss of the character are not rare enough, a probabilistic analysis becomes essential. Here, we present a comprehensive probabilistic model to describe the evolution of binary characters on a bifurcating phylogenetic tree. A fast software tool, EREM, is provided, using maximum likelihood to estimate the parameters of the model and to reconstruct ancestral states (presence and absence in internal nodes) and events (gain and loss events along branches).

  11. PhyloBot: A Web Portal for Automated Phylogenetics, Ancestral Sequence Reconstruction, and Exploration of Mutational Trajectories.

    Directory of Open Access Journals (Sweden)

    Victor Hanson-Smith

    2016-07-01

    Full Text Available The method of phylogenetic ancestral sequence reconstruction is a powerful approach for studying evolutionary relationships among protein sequence, structure, and function. In particular, this approach allows investigators to (1 reconstruct and "resurrect" (that is, synthesize in vivo or in vitro extinct proteins to study how they differ from modern proteins, (2 identify key amino acid changes that, over evolutionary timescales, have altered the function of the protein, and (3 order historical events in the evolution of protein function. Widespread use of this approach has been slow among molecular biologists, in part because the methods require significant computational expertise. Here we present PhyloBot, a web-based software tool that makes ancestral sequence reconstruction easy. Designed for non-experts, it integrates all the necessary software into a single user interface. Additionally, PhyloBot provides interactive tools to explore evolutionary trajectories between ancestors, enabling the rapid generation of hypotheses that can be tested using genetic or biochemical approaches. Early versions of this software were used in previous studies to discover genetic mechanisms underlying the functions of diverse protein families, including V-ATPase ion pumps, DNA-binding transcription regulators, and serine/threonine protein kinases. PhyloBot runs in a web browser, and is available at the following URL: http://www.phylobot.com. The software is implemented in Python using the Django web framework, and runs on elastic cloud computing resources from Amazon Web Services. Users can create and submit jobs on our free server (at the URL listed above, or use our open-source code to launch their own PhyloBot server.

  12. Centromere Destiny in Dicentric Chromosomes: New Insights from the Evolution of Human Chromosome 2 Ancestral Centromeric Region.

    Science.gov (United States)

    Chiatante, Giorgia; Giannuzzi, Giuliana; Calabrese, Francesco Maria; Eichler, Evan E; Ventura, Mario

    2017-07-01

    Dicentric chromosomes are products of genomic rearrangements that place two centromeres on the same chromosome. Due to the presence of two primary constrictions, they are inherently unstable and overcome their instability by epigenetically inactivating and/or deleting one of the two centromeres, thus resulting in functionally monocentric chromosomes that segregate normally during cell division. Our understanding to date of dicentric chromosome formation, behavior and fate has been largely inferred from observational studies in plants and humans as well as artificially produced de novo dicentrics in yeast and in human cells. We investigate the most recent product of a chromosome fusion event fixed in the human lineage, human chromosome 2, whose stability was acquired by the suppression of one centromere, resulting in a unique difference in chromosome number between humans (46 chromosomes) and our most closely related ape relatives (48 chromosomes). Using molecular cytogenetics, sequencing, and comparative sequence data, we deeply characterize the relicts of the chromosome 2q ancestral centromere and its flanking regions, gaining insight into the ancestral organization that can be easily broadened to all acrocentric chromosome centromeres. Moreover, our analyses offered the opportunity to trace the evolutionary history of rDNA and satellite III sequences among great apes, thus suggesting a new hypothesis for the preferential inactivation of some human centromeres, including IIq. Our results suggest two possible centromere inactivation models to explain the evolutionarily stabilization of human chromosome 2 over the last 5-6 million years. Our results strongly favor centromere excision through a one-step process. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. ¿Con o sin ancestros? Vigencia de lo ancestral en la Amazonía peruana

    Directory of Open Access Journals (Sweden)

    Thomas Mouriès

    2014-07-01

    Full Text Available The existence —or not— of the concept of ancestors in the indigenous Amazon has been the subject of much debate. However, regional leaders do not hesitate to call upon ‘ancestral’ knowledge, customs, or territories in the sense that, from an academic point of view, could appear enigmatic. «Ancestral, but… with or without ancestors?» is the question a confused anthropologist might ask. In this article, I propose to offer elements of a response to this question,based on a case study in Peru. First I analyze how Amazonian indigenous leaders, following international law, have adopted the legal notion of ‘ancestral possession’ of their territory to adapt it to the political sphere. This approach accounts for the recent generalization and uniformization of the term ‘ancestral’, but poses the problem of how it articulates with the indigenous cosmologies that it supposes to reflect. For this reason, I explore in the second section the pertinence of the category of ‘ancestor’ in the indigenous Amazon, briefly drawing upon the academic debate in order to define inwhat way this category takes on meaning. Based on testimony from an experienced Awajún leader, we thus return in the third section more explicitly to the different meanings and planes of reference that unfold when one uses the term ‘ancestral’, showing how Amazonian indigenous people not only adopt external conceptual elements and arguments, but also transform them based on their own cosmological singularities and political perspectives.

  14. Inferred L/M cone opsin polymorphism of ancestral tarsiers sheds dim light on the origin of anthropoid primates.

    Science.gov (United States)

    Melin, Amanda D; Matsushita, Yuka; Moritz, Gillian L; Dominy, Nathaniel J; Kawamura, Shoji

    2013-05-22

    Tarsiers are small nocturnal primates with a long history of fuelling debate on the origin and evolution of anthropoid primates. Recently, the discovery of M and L opsin genes in two sister species, Tarsius bancanus (Bornean tarsier) and Tarsius syrichta (Philippine tarsier), respectively, was interpreted as evidence of an ancestral long-to-middle (L/M) opsin polymorphism, which, in turn, suggested a diurnal or cathemeral (arrhythmic) activity pattern. This view is compatible with the hypothesis that stem tarsiers were diurnal; however, a reversion to nocturnality during the Middle Eocene, as evidenced by hyper-enlarged orbits, predates the divergence of T. bancanus and T. syrichta in the Late Miocene. Taken together, these findings suggest that some nocturnal tarsiers possessed high-acuity trichromatic vision, a concept that challenges prevailing views on the adaptive origins of the anthropoid visual system. It is, therefore, important to explore the plausibility and antiquity of trichromatic vision in the genus Tarsius. Here, we show that Sulawesi tarsiers (Tarsius tarsier), a phylogenetic out-group of Philippine and Bornean tarsiers, have an L opsin gene that is more similar to the L opsin gene of T. syrichta than to the M opsin gene of T. bancanus in non-synonymous nucleotide sequence. This result suggests that an L/M opsin polymorphism is the ancestral character state of crown tarsiers and raises the possibility that many hallmarks of the anthropoid visual system evolved under dim (mesopic) light conditions. This interpretation challenges the persistent nocturnal-diurnal dichotomy that has long informed debate on the origin of anthropoid primates.

  15. Mating animals by minimising the covariance between ancestral contributions generates less inbreeding without compromising genetic gain in breeding schemes with truncation selection

    DEFF Research Database (Denmark)

    Henryon, M; Berg, P; Sørensen, A C

    2009-01-01

    We reasoned that mating animals by minimising the covariance between ancestral contributions (MCAC mating) will generate less inbreeding and at least as much genetic gain as minimum-coancestry mating in breeding schemes where the animals are truncation-selected. We tested this hypothesis by stoch...

  16. Systematics and morphological evolution within the moss family Bryaceae: a comparison between parsimony and Bayesian methods for reconstruction of ancestral character states.

    Science.gov (United States)

    Pedersen, Niklas; Holyoak, David T; Newton, Angela E

    2007-06-01

    The Bryaceae are a large cosmopolitan moss family including genera of significant morphological and taxonomic complexity. Phylogenetic relationships within the Bryaceae were reconstructed based on DNA sequence data from all three genomic compartments. In addition, maximum parsimony and Bayesian inference were employed to reconstruct ancestral character states of 38 morphological plus four habitat characters and eight insertion/deletion events. The recovered phylogenetic patterns are generally in accord with previous phylogenies based on chloroplast DNA sequence data and three major clades are identified. The first clade comprises Bryum bornholmense, B. rubens, B. caespiticium, and Plagiobryum. This corroborates the hypothesis suggested by previous studies that several Bryum species are more closely related to Plagiobryum than to the core Bryum species. The second clade includes Acidodontium, Anomobryum, and Haplodontium, while the third clade contains the core Bryum species plus Imbribryum. Within the latter clade, B. subapiculatum and B. tenuisetum form the sister clade to Imbribryum. Reconstructions of ancestral character states under maximum parsimony and Bayesian inference suggest fourteen morphological synapomorphies for the ingroup and synapomorphies are detected for most clades within the ingroup. Maximum parsimony and Bayesian reconstructions of ancestral character states are mostly congruent although Bayesian inference shows that the posterior probability of ancestral character states may decrease dramatically when node support is taken into account. Bayesian inference also indicates that reconstructions may be ambiguous at internal nodes for highly polymorphic characters.

  17. Ancestral polymorphisms and sex-biased migration shaped the demographic history of brown bears and polar bears.

    Directory of Open Access Journals (Sweden)

    Shigeki Nakagome

    Full Text Available Recent studies have reported discordant gene trees in the evolution of brown bears and polar bears. Genealogical histories are different among independent nuclear loci and between biparentally inherited autosomal DNA (aDNA and matrilineal mitochondrial DNA (mtDNA. Based on multi-locus genomic sequences from aDNA and mtDNA, we inferred the population demography of brown and polar bears and found that brown bears have 6 times (aDNA or more than 14 times (mtDNA larger population sizes than polar bears and that polar bear lineage is derived from within brown bear diversity. In brown bears, the effective population size ratio of mtDNA to aDNA was at least 0.62, which deviated from the expected value of 0.25, suggesting matriarchal population due to female philopatry and male-biased migration. These results emphasize that ancestral polymorphisms and sex-biased migration may have contributed to conflicting branching patterns in brown and polar bears across aDNA genes and mtDNA.

  18. Natural environments, ancestral diets, and microbial ecology: is there a modern "paleo-deficit disorder"? Part II.

    Science.gov (United States)

    Logan, Alan C; Katzman, Martin A; Balanzá-Martínez, Vicent

    2015-03-10

    Famed microbiologist René J. Dubos (1901-1982) was an early pioneer in the developmental origins of health and disease (DOHaD) construct. In the 1960s, he conducted groundbreaking research concerning the ways in which early-life experience with nutrition, microbiota, stress, and other environmental variables could influence later-life health outcomes. He recognized the co-evolutionary relationship between microbiota and the human host. Almost 2 decades before the hygiene hypothesis, he suggested that children in developed nations were becoming too sanitized (vs. our ancestral past) and that scientists should determine whether the childhood environment should be "dirtied up in a controlled manner." He also argued that oft-celebrated growth chart increases via changes in the global food supply and dietary patterns should not be equated to quality of life and mental health. Here in the second part of our review, we reflect the words of Dubos off contemporary research findings in the areas of diet, the gut-brain-axis (microbiota and anxiety and depression) and microbial ecology. Finally, we argue, as Dubos did 40 years ago, that researchers should more closely examine the relevancy of silo-sequestered, reductionist findings in the larger picture of human quality of life. In the context of global climate change and the epidemiological transition, an allergy epidemic and psychosocial stress, our review suggests that discussions of natural environments, urbanization, biodiversity, microbiota, nutrition, and mental health, are often one in the same.

  19. Elucidating the triplicated ancestral genome structure of radish based on chromosome-level comparison with the Brassica genomes.

    Science.gov (United States)

    Jeong, Young-Min; Kim, Namshin; Ahn, Byung Ohg; Oh, Mijin; Chung, Won-Hyong; Chung, Hee; Jeong, Seongmun; Lim, Ki-Byung; Hwang, Yoon-Jung; Kim, Goon-Bo; Baek, Seunghoon; Choi, Sang-Bong; Hyung, Dae-Jin; Lee, Seung-Won; Sohn, Seong-Han; Kwon, Soo-Jin; Jin, Mina; Seol, Young-Joo; Chae, Won Byoung; Choi, Keun Jin; Park, Beom-Seok; Yu, Hee-Ju; Mun, Jeong-Hwan

    2016-07-01

    This study presents a chromosome-scale draft genome sequence of radish that is assembled into nine chromosomal pseudomolecules. A comprehensive comparative genome analysis with the Brassica genomes provides genomic evidences on the evolution of the mesohexaploid radish genome. Radish (Raphanus sativus L.) is an agronomically important root vegetable crop and its origin and phylogenetic position in the tribe Brassiceae is controversial. Here we present a comprehensive analysis of the radish genome based on the chromosome sequences of R. sativus cv. WK10039. The radish genome was sequenced and assembled into 426.2 Mb spanning >98 % of the gene space, of which 344.0 Mb were integrated into nine chromosome pseudomolecules. Approximately 36 % of the genome was repetitive sequences and 46,514 protein-coding genes were predicted and annotated. Comparative mapping of the tPCK-like ancestral genome revealed that the radish genome has intermediate characteristics between the Brassica A/C and B genomes in the triplicated segments, suggesting an internal origin from the genus Brassica. The evolutionary characteristics shared between radish and other Brassica species provided genomic evidences that the current form of nine chromosomes in radish was rearranged from the chromosomes of hexaploid progenitor. Overall, this study provides a chromosome-scale draft genome sequence of radish as well as novel insight into evolution of the mesohexaploid genomes in the tribe Brassiceae.

  20. Research on Non-Destructive Testing Technology in Conservation Repair Project of Ancestral Temple in Mukden Palace

    Science.gov (United States)

    Yang, J.; Fu, M.

    2017-08-01

    Due to the use of wood and other non-permanent materials, traditional Chinese architecture is one of the most fragile constructions in various heritage objects today. With the increasing emphasis on the protection of cultural relics, the repair project of wooden structure has become more and more important. There are various kinds of destructions, which pose a hidden danger to the overall safety of the ancient buildings, caused not only by time and nature, but also by improper repairs in history or nowadays. Today, the use of digital technology is a basic requirement in the conservation of cultural heritage. Detection technology, especially non-destructive testing technology, could provide more accurate records in capturing detailed physical characteristics of structures such as geometric deformation and invisible damage, as well as prevent a man-made destruction in the process of repair project. This paper aims to interpret with a typical example, Ancestral Temple in Mukden Palace, along with a discussion of how to use the non-destructive testing technology with ground penetrating radar, stress wave, resistograph and so on, in addition to find an appropriate protection method in repair project of traditional Chinese wooden architecture.

  1. Ancestral association between HLA and HFE H63D and C282Y gene mutations from northwest Colombia.

    Science.gov (United States)

    Rodriguez, Libia M; Giraldo, Mabel C; Velasquez, Laura I; Alvarez, Cristiam M; Garcia, Luis F; Jimenez-Del-Rio, Marlene; Velez-Pardo, Carlos

    2015-03-01

    A significant association between HFE gene mutations and the HLA-A*03-B*07 and HLA-A*29-B*44 haplotypes has been reported in the Spanish population. It has been proposed that these mutations are probably connected with Celtic and North African ancestry, respectively. We aimed to find the possible ancestral association between HLA alleles and haplotypes associated with the HFE gene (C282Y and H63D) mutations in 214 subjects from Antioquia, Colombia. These were 18 individuals with presumed hereditary hemochromatosis ("HH") and 196 controls. The HLA-B*07 allele was in linkage disequilibrium (LD) with C282Y, while HLA-A*23, A*29, HLA-B*44, and B*49 were in LD with H63D. Altogether, our results show that, although the H63D mutation is more common in the Antioquia population, it is not associated with any particular HLA haplotype, whereas the C282Y mutation is associated with HLA-A*03-B*07, this supporting a northern Spaniard ancestry.

  2. Ancestral association between HLA and HFE H63D and C282Y gene mutations from northwest Colombia

    Directory of Open Access Journals (Sweden)

    Libia M Rodriguez

    2015-03-01

    Full Text Available A significant association between HFE gene mutations and the HLA-A*03-B*07 and HLA-A*29-B*44 haplotypes has been reported in the Spanish population. It has been proposed that these mutations are probably connected with Celtic and North African ancestry, respectively. We aimed to find the possible ancestral association between HLA alleles and haplotypes associated with the HFE gene (C282Y and H63D mutations in 214 subjects from Antioquia, Colombia. These were 18 individuals with presumed hereditary hemochromatosis (“HH” and 196 controls. The HLA-B*07 allele was in linkage disequilibrium (LD with C282Y, while HLA-A*23, A*29, HLA-B*44, and B*49 were in LD with H63D. Altogether, our results show that, although the H63D mutation is more common in the Antioquia population, it is not associated with any particular HLA haplotype, whereas the C282Y mutation is associated with HLA-A*03-B*07, this supporting a northern Spaniard ancestry.

  3. Haplotype Study in SCA10 Families Provides Further Evidence for a Common Ancestral Origin of the Mutation.

    Science.gov (United States)

    Bampi, Giovana B; Bisso-Machado, Rafael; Hünemeier, Tábita; Gheno, Tailise C; Furtado, Gabriel V; Veliz-Otani, Diego; Cornejo-Olivas, Mario; Mazzeti, Pillar; Bortolini, Maria Cátira; Jardim, Laura B; Saraiva-Pereira, Maria Luiza

    2017-12-01

    Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant neurodegenerative disorder characterized by progressive cerebellar ataxia and epilepsy. The disease is caused by a pentanucleotide ATTCT expansion in intron 9 of the ATXN10 gene on chromosome 22q13.3. SCA10 has shown a geographical distribution throughout America with a likely degree of Amerindian ancestry from different countries so far. Currently available data suggest that SCA10 mutation might have spread out early during the peopling of the Americas. However, the ancestral origin of SCA10 mutation remains under speculation. Samples of SCA10 patients from two Latin American countries were analysed, being 16 families from Brazil (29 patients) and 21 families from Peru (27 patients) as well as 49 healthy individuals from Indigenous Quechua population and 51 healthy Brazilian individuals. Four polymorphic markers spanning a region of 5.2 cM harbouring the ATTCT expansion were used to define the haplotypes, which were genotyped by different approaches. Our data have shown that 19-CGGC-14 shared haplotype was found in 47% of Brazilian and in 63% of Peruvian families. Frequencies from both groups are not statistically different from Quechua controls (57%), but they are statistically different from Brazilian controls (12%) (p Quechuas, 19-15-CGGC-14-10, is found in 50% of Brazilian and in 65% of Peruvian patients with SCA10. These findings bring valuable evidence that ATTCT expansion may have arisen in a Native American chromosome.

  4. RESEARCH ON NON-DESTRUCTIVE TESTING TECHNOLOGY IN CONSERVATION REPAIR PROJECT OF ANCESTRAL TEMPLE IN MUKDEN PALACE

    Directory of Open Access Journals (Sweden)

    J. Yang

    2017-08-01

    Full Text Available Due to the use of wood and other non-permanent materials, traditional Chinese architecture is one of the most fragile constructions in various heritage objects today. With the increasing emphasis on the protection of cultural relics, the repair project of wooden structure has become more and more important. There are various kinds of destructions, which pose a hidden danger to the overall safety of the ancient buildings, caused not only by time and nature, but also by improper repairs in history or nowadays. Today, the use of digital technology is a basic requirement in the conservation of cultural heritage. Detection technology, especially non-destructive testing technology, could provide more accurate records in capturing detailed physical characteristics of structures such as geometric deformation and invisible damage, as well as prevent a man-made destruction in the process of repair project. This paper aims to interpret with a typical example, Ancestral Temple in Mukden Palace, along with a discussion of how to use the non-destructive testing technology with ground penetrating radar, stress wave, resistograph and so on, in addition to find an appropriate protection method in repair project of traditional Chinese wooden architecture.

  5. Ancestral polymorphisms and sex-biased migration shaped the demographic history of brown bears and polar bears.

    Science.gov (United States)

    Nakagome, Shigeki; Mano, Shuhei; Hasegawa, Masami

    2013-01-01

    Recent studies have reported discordant gene trees in the evolution of brown bears and polar bears. Genealogical histories are different among independent nuclear loci and between biparentally inherited autosomal DNA (aDNA) and matrilineal mitochondrial DNA (mtDNA). Based on multi-locus genomic sequences from aDNA and mtDNA, we inferred the population demography of brown and polar bears and found that brown bears have 6 times (aDNA) or more than 14 times (mtDNA) larger population sizes than polar bears and that polar bear lineage is derived from within brown bear diversity. In brown bears, the effective population size ratio of mtDNA to aDNA was at least 0.62, which deviated from the expected value of 0.25, suggesting matriarchal population due to female philopatry and male-biased migration. These results emphasize that ancestral polymorphisms and sex-biased migration may have contributed to conflicting branching patterns in brown and polar bears across aDNA genes and mtDNA.

  6. Lower Cretaceous fossils from China shed light on the ancestral body plan of crown softshell turtles (Trionychidae, Cryptodira).

    Science.gov (United States)

    Brinkman, Donald; Rabi, Márton; Zhao, Lijun

    2017-07-27

    Pan-trionychids or softshell turtles are a highly specialized and widespread extant group of aquatic taxa with an evolutionary history that goes back to the Early Cretaceous. The earliest pan-trionychids had already fully developed the "classic" softshell turtle morphology and it has been impossible to resolve whether they are stem members of the family or are within the crown. This has hindered our understanding of the evolution of the two basic body plans of crown-trionychids. Thus it remains unclear whether the more heavily ossified shell of the cyclanorbines or the highly reduced trionychine morphotype is the ancestral condition for softshell turtles. A new pan-trionychid from the Early Cretaceous of Zhejiang, China, Perochelys hengshanensis sp. nov., allows a revision of softshell-turtle phylogeny. Equal character weighting resulted in a topology that is fundamentally inconsistent with molecular divergence date estimates of deeply nested extant species. In contrast, implied weighting retrieved Lower Cretaceous Perochelys spp. and Petrochelys kyrgyzensis as stem trionychids, which is fully consistent with their basal stratigraphic occurrence and an Aptian-Santonian molecular age estimate for crown-trionychids. These results indicate that the primitive morphology for soft-shell turtles is a poorly ossified shell like that of crown-trionychines and that shell re-ossification in cyclanorbines (including re-acquisition of peripheral elements) is secondary.

  7. On the Trails of the Proteasome Fold: Structural and Functional Analysis of the Ancestral β-Subunit Protein Anbu.

    Science.gov (United States)

    Vielberg, Marie-Theres; Bauer, Verena C; Groll, Michael

    2018-03-02

    The 20S proteasome is a key player in eukaryotic and archaeal protein degradation, but its progenitor in eubacteria is unknown. Recently, the ancestral β-subunit protein (Anbu) was predicted to be the evolutionary precursor of the proteasome. We crystallized Anbu from Hyphomicrobium sp. strain MC1 in four different space groups and solved the structures by SAD-phasing and Patterson search calculation techniques. Our data reveal that Anbu adopts the classical fold of Ntn-hydrolases, but its oligomeric state differs from that of barrel-shaped proteases. In contrast to their typical architecture, the Anbu protomer is a tightly interacting dimer that can assemble into a helical superstructure. Although Anbu features a catalytic triad of Thr1O γ , Asp17O δ1 and Lys32N ε , it is unable to hydrolyze standard protease substrates. The lack of activity might be caused by the incapacity of Thr1NH 2 to function as a Brønsted acid during substrate cleavage due to its missing activation via hydrogen bonding. Altogether, we demonstrate that the topology of the proteasomal fold is conserved in Anbu, but whether it acts as a protease still needs to be clarified. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Il dono del racconto

    DEFF Research Database (Denmark)

    Polito, Paola

    1998-01-01

    L'articolo indaga a vari livelli strutturali del romanzo "Il coraggio del pettirosso" (rete metaforica, dialogismo diegetico, dialogismo come fenomeno di voce, strategie discorsive messe in atto dalla voce narrante, stile colloquiale) la complessa realizzazione testuale del genere narrativo...

  9. La búsqueda del espíritu traslativo de la compraventa consensual: un antiguo instrumento en la cultura jurídica latinoamericana para el fomento del comercio común

    Directory of Open Access Journals (Sweden)

    Diego Fernando Monje Mayorca

    2015-06-01

    Full Text Available Este trabajo pretende develar históricamente la característica consensual del contrato de compraventa y su influjo en la forma de concebir teóricamente el fenómeno de la transferencia de la propiedad en el ámbito de la cultura jurídica occidental, con el fin práctico de promocionar la unificación de la técnica del ‘solo consensu’ y la teoría romanista del título y el modo, situación factible que a la postre contribuirá ostensiblemente al mejoramiento de las relaciones comerciales de aquellos países que hoy comparten un ancestral parentesco derivado del derecho romano.

  10. The pig story (tiboi sakkoko Storytelling of kinship, memories of the past, and rights to plots of ancestral land in Mentawai

    Directory of Open Access Journals (Sweden)

    Juniator Tulius

    2016-07-01

    Full Text Available This paper examines some significant elements of the pig story (tiboi sakkoko. This tale contains crucial information about the collective identity, ancestors and historical events affecting particular Mentawai kin-groups. As families do not preserve their culture and traditions in written form, storytellers of kin-groups have narrated the pig story from generation to generation so as to preserve it carefully. In the course of time, storytellers establish particular ways of telling their stories so as to remember the content and plot of the stories easily. Through the pig story, members of kin groups also recollect their ancestral place of origin and plots of ancestral lands. The role of human memory is indispensable to recalling all these important elements. Therefore, this paper analyses memories of the past of different family generations. To achieve its aims, this paper also evaluates the roles of family stories in the culture and traditions of Mentawai society.

  11. Ancestral state reconstructions require biological evidence to test evolutionary hypotheses: A case study examining the evolution of reproductive mode in squamate reptiles.

    Science.gov (United States)

    Griffith, Oliver W; Blackburn, Daniel G; Brandley, Matthew C; Van Dyke, James U; Whittington, Camilla M; Thompson, Michael B

    2015-09-01

    To understand evolutionary transformations it is necessary to identify the character states of extinct ancestors. Ancestral character state reconstruction is inherently difficult because it requires an accurate phylogeny, character state data, and a statistical model of transition rates and is fundamentally constrained by missing data such as extinct taxa. We argue that model based ancestral character state reconstruction should be used to generate hypotheses but should not be considered an analytical endpoint. Using the evolution of viviparity and reversals to oviparity in squamates as a case study, we show how anatomical, physiological, and ecological data can be used to evaluate hypotheses about evolutionary transitions. The evolution of squamate viviparity requires changes to the timing of reproductive events and the successive loss of features responsible for building an eggshell. A reversal to oviparity requires that those lost traits re-evolve. We argue that the re-evolution of oviparity is inherently more difficult than the reverse. We outline how the inviability of intermediate phenotypes might present physiological barriers to reversals from viviparity to oviparity. Finally, we show that ecological data supports an oviparous ancestral state for squamates and multiple transitions to viviparity. In summary, we conclude that the first squamates were oviparous, that frequent transitions to viviparity have occurred, and that reversals to oviparity in viviparous lineages either have not occurred or are exceedingly rare. As this evidence supports conclusions that differ from previous ancestral state reconstructions, our paper highlights the importance of incorporating biological evidence to evaluate model-generated hypotheses. © 2015 Wiley Periodicals, Inc.

  12. Archaeology of the Afro-Ecuadorians in La Concepción, Ancestral Territory of the Chota-Mira Valley (Carchi-Ecuador)

    OpenAIRE

    Balanzategui , Daniela Catalina

    2017-01-01

    Historical Archaeology of the African Diaspora in the Americas urges for interdisciplinary, collaborative, and intercultural approaches to shed light on how the material culture reflects conditions of enslavement and racialization, but also process of resistance and historical reparation. This investigation is organized in five articles connected around the topic of the cultural construction of the African Diaspora identities in the Afro-Ecuadorian Ancestral Territory of the Chota-Mira Valley...

  13. del cambio

    Directory of Open Access Journals (Sweden)

    Alejandro Canales

    2006-01-01

    Full Text Available El artículo analiza las propuestas y los compromisos en materia de cobertura y de financiamiento en el periodo 2000-2006. En particular, revisa las modificaciones y los ajustes de los tres principales documentos en los que se expresaron las iniciativas: el de la Asociación Nacional de Universidades e Instituciones de Educación Superior, el del equipo de la transición y el programa sectorial. Los resultados muestran que las cifras de atención a la demanda educativa e inversión quedaron lejos de las metas autoimpuestas por el gobierno federal y que será necesario realizar mayores esfuerzos para atender tales desafíos.

  14. Presence of a Shared 5'-Leader Sequence in Ancestral Human and Mammalian Retroviruses and Its Transduction into Feline Leukemia Virus.

    Science.gov (United States)

    Kawasaki, Junna; Kawamura, Maki; Ohsato, Yoshiharu; Ito, Jumpei; Nishigaki, Kazuo

    2017-10-15

    Recombination events induce significant genetic changes, and this process can result in virus genetic diversity or in the generation of novel pathogenicity. We discovered a new recombinant feline leukemia virus (FeLV) gag gene harboring an unrelated insertion, termed the X region, which was derived from Felis catus endogenous gammaretrovirus 4 (FcERV-gamma4). The identified FcERV-gamma4 proviruses have lost their coding capabilities, but some can express their viral RNA in feline tissues. Although the X-region-carrying recombinant FeLVs appeared to be replication-defective viruses, they were detected in 6.4% of tested FeLV-infected cats. All isolated recombinant FeLV clones commonly incorporated a middle part of the FcERV-gamma4 5'-leader region as an X region. Surprisingly, a sequence corresponding to the portion contained in all X regions is also present in at least 13 endogenous retroviruses (ERVs) observed in the cat, human, primate, and pig genomes. We termed this shared genetic feature the commonly shared (CS) sequence. Despite our phylogenetic analysis indicating that all CS-sequence-carrying ERVs are classified as gammaretroviruses, no obvious closeness was revealed among these ERVs. However, the Shannon entropy in the CS sequence was lower than that in other parts of the provirus genome. Notably, the CS sequence of human endogenous retrovirus T had 73.8% similarity with that of FcERV-gamma4, and specific signals were detected in the human genome by Southern blot analysis using a probe for the FcERV-gamma4 CS sequence. Our results provide an interesting evolutionary history for CS-sequence circulation among several distinct ancestral viruses and a novel recombined virus over a prolonged period. IMPORTANCE Recombination among ERVs or modern viral genomes causes a rapid evolution of retroviruses, and this phenomenon can result in the serious situation of viral disease reemergence. We identified a novel recombinant FeLV gag gene that contains an unrelated

  15. Cross-species chromosome painting in bats from Madagascar: the contribution of Myzopodidae to revealing ancestral syntenies in Chiroptera.

    Science.gov (United States)

    Richards, Leigh R; Rambau, Ramugondo V; Lamb, Jennifer M; Taylor, Peter J; Yang, Fengtang; Schoeman, M Corrie; Goodman, Steven M

    2010-09-01

    The chiropteran fauna of Madagascar comprises eight of the 19 recognized families of bats, including the endemic Myzopodidae. While recent systematic studies of Malagasy bats have contributed to our understanding of the morphological and genetic diversity of the island's fauna, little is known about their cytosystematics. Here we investigate karyotypic relationships among four species, representing four families of Chiroptera endemic to the Malagasy region using cross-species chromosome painting with painting probes of Myotis myotis: Myzopodidae (Myzopoda aurita, 2n = 26), Molossidae (Mormopterus jugularis, 2n = 48), Miniopteridae (Miniopterus griveaudi, 2n = 46), and Vespertilionidae (Myotis goudoti, 2n = 44). This study represents the first time a member of the family Myzopodidae has been investigated using chromosome painting. Painting probes of M. myotis were used to delimit 29, 24, 23, and 22 homologous chromosomal segments in the genomes of M. aurita, M. jugularis, M. griveaudi, and M. goudoti, respectively. Comparison of GTG-banded homologous chromosomes/chromosomal segments among the four species revealed the genome of M. aurita has been structured through 14 fusions of chromosomes and chromosomal segments of M. myotis chromosomes leading to a karyotype consisting solely of bi-armed chromosomes. In addition, chromosome painting revealed a novel X-autosome translocation in M. aurita. Comparison of our results with published chromosome maps provided further evidence for karyotypic conservatism within the genera Mormopterus, Miniopterus, and Myotis. Mapping of chromosomal rearrangements onto a molecular consensus phylogeny revealed ancestral syntenies shared between Myzopoda and other bat species of the infraorders Pteropodiformes and Vespertilioniformes. Our study provides further evidence for the involvement of Robertsonian (Rb) translocations and fusions/fissions in chromosomal evolution within Chiroptera.

  16. Diversification of a single ancestral gene into a successful toxin superfamily in highly venomous Australian funnel-web spiders.

    Science.gov (United States)

    Pineda, Sandy S; Sollod, Brianna L; Wilson, David; Darling, Aaron; Sunagar, Kartik; Undheim, Eivind A B; Kely, Laurence; Antunes, Agostinho; Fry, Bryan G; King, Glenn F

    2014-03-05

    Spiders have evolved pharmacologically complex venoms that serve to rapidly subdue prey and deter predators. The major toxic factors in most spider venoms are small, disulfide-rich peptides. While there is abundant evidence that snake venoms evolved by recruitment of genes encoding normal body proteins followed by extensive gene duplication accompanied by explosive structural and functional diversification, the evolutionary trajectory of spider-venom peptides is less clear. Here we present evidence of a spider-toxin superfamily encoding a high degree of sequence and functional diversity that has evolved via accelerated duplication and diversification of a single ancestral gene. The peptides within this toxin superfamily are translated as prepropeptides that are posttranslationally processed to yield the mature toxin. The N-terminal signal sequence, as well as the protease recognition site at the junction of the propeptide and mature toxin are conserved, whereas the remainder of the propeptide and mature toxin sequences are variable. All toxin transcripts within this superfamily exhibit a striking cysteine codon bias. We show that different pharmacological classes of toxins within this peptide superfamily evolved under different evolutionary selection pressures. Overall, this study reinforces the hypothesis that spiders use a combinatorial peptide library strategy to evolve a complex cocktail of peptide toxins that target neuronal receptors and ion channels in prey and predators. We show that the ω-hexatoxins that target insect voltage-gated calcium channels evolved under the influence of positive Darwinian selection in an episodic fashion, whereas the κ-hexatoxins that target insect calcium-activated potassium channels appear to be under negative selection. A majority of the diversifying sites in the ω-hexatoxins are concentrated on the molecular surface of the toxins, thereby facilitating neofunctionalisation leading to new toxin pharmacology.

  17. An ancestral haplotype of the human PERIOD2 gene associates with reduced sensitivity to light-induced melatonin suppression.

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    Tokiho Akiyama

    Full Text Available Humans show various responses to the environmental stimulus in individual levels as "physiological variations." However, it has been unclear if these are caused by genetic variations. In this study, we examined the association between the physiological variation of response to light-stimulus and genetic polymorphisms. We collected physiological data from 43 subjects, including light-induced melatonin suppression, and performed haplotype analyses on the clock genes, PER2 and PER3, exhibiting geographical differentiation of allele frequencies. Among the haplotypes of PER3, no significant difference in light sensitivity was found. However, three common haplotypes of PER2 accounted for more than 96% of the chromosomes in subjects, and 1 of those 3 had a significantly low-sensitive response to light-stimulus (P < 0.05. The homozygote of the low-sensitive PER2 haplotype showed significantly lower percentages of melatonin suppression (P < 0.05, and the heterozygotes of the haplotypes varied their ratios, indicating that the physiological variation for light-sensitivity is evidently related to the PER2 polymorphism. Compared with global haplotype frequencies, the haplotype with a low-sensitive response was more frequent in Africans than in non-Africans, and came to the root in the phylogenetic tree, suggesting that the low light-sensitive haplotype is the ancestral type, whereas the other haplotypes with high sensitivity to light are the derived types. Hence, we speculate that the high light-sensitive haplotypes have spread throughout the world after the Out-of-Africa migration of modern humans.

  18. Light from dark: A relictual troglobite reveals a broader ancestral distribution for kimulid harvestmen (Opiliones: Laniatores: Kimulidae) in South America

    Science.gov (United States)

    Ceccarelli, F. Sara; Monte, Bruno G. O.; Proud, Daniel N.; DaSilva, Márcio Bernardino; Bichuette, Maria E.

    2017-01-01

    A new troglobitic harvestman, Relictopiolus galadriel gen. nov et sp. nov., is described from Olhos d’Água cave, Itacarambi, Minas Gerais State, Brazil. Morphological characters, including male genitalia and exomorphology, suggest that this species belongs to the family Kimulidae, and it appears to share the greatest similarities with Tegipiolus pachypus. Bayesian inference analyses of a molecular dataset strongly support the inclusion of this species in Kimulidae and confirm the hypothesized sister-group relationship between R. galadriel and T. pachypus. A time calibrated phylogeny indicates that these sister-taxa diverged from a common ancestor approximately 40 Mya, during the Paleogene. The current range of Kimulidae illustrates a remarkable disjunct distribution, and leads us to hypothesize that the ancestral distribution of Kimulidae was once much more widespread across eastern Brazil. This may be attributed to the Eocene radiation associated with the warming (and humidifying) events in the Cenozoic when the best conditions for evergreen tropical vegetation in South America were established and followed by the extinction of kimulid epigean populations together with the retraction of rain forests during the Oligocene to Miocene cooling. The discovery of this relictual troglobite indicates that the Olhos d’Água cave was a stable refugium for this ancient lineage of kimulids and acted as a "museum" of biodiversity. Our findings, considered collectively with the diverse troglofauna of the Olhos d’Água cave, highlight it as one of the most important hotspots of troglobite diversity and endemism in the Neotropics. Given the ecological stresses on this habitat, the cavernicolous fauna are at risk of extinction and we emphasize the urgent need for appropriate conservation actions. Finally, we propose the transfer of Acanthominua, Euminua, Euminuoides and Pseudominua from Kimulidae to Zalmoxidae, resulting in two new synonymies and 13 new combinations. PMID

  19. Phylogenomic analysis of vertebrate thrombospondins reveals fish-specific paralogues, ancestral gene relationships and a tetrapod innovation

    Directory of Open Access Journals (Sweden)

    Adams Josephine C

    2006-04-01

    Full Text Available Abstract Background Thrombospondins (TSPs are evolutionarily-conserved, extracellular, calcium-binding glycoproteins with important roles in cell-extracellular matrix interactions, angiogenesis, synaptogenesis and connective tissue organisation. Five TSPs, designated TSP-1 through TSP-5, are encoded in the human genome. All but one have known roles in acquired or inherited human diseases. To further understand the roles of TSPs in human physiology and pathology, it would be advantageous to extend the repertoire of relevant vertebrate models. In general the zebrafish is proving an excellent model organism for vertebrate biology, therefore we set out to evaluate the status of TSPs in zebrafish and two species of pufferfish. Results We identified by bioinformatics that three fish species encode larger numbers of TSPs than vertebrates, yet all these sequences group as homologues of TSP-1 to -4. By phylogenomic analysis of neighboring genes, we uncovered that, in fish, a TSP-4-like sequence is encoded from the gene corresponding to the tetrapod TSP-5 gene. Thus, all TSP genes show conservation of synteny between fish and tetrapods. In the human genome, the TSP-1, TSP-3, TSP-4 and TSP-5 genes lie within paralogous regions that provide insight into the ancestral genomic context of vertebrate TSPs. Conclusion A new model for TSP evolution in vertebrates is presented. The TSP-5 protein sequence has evolved rapidly from a TSP-4-like sequence as an innovation in the tetrapod lineage. TSP biology in fish is complicated by the presence of additional lineage- and species-specific TSP paralogues. These novel results give deeper insight into the evolution of TSPs in vertebrates and open new directions for understanding the physiological and pathological roles of TSP-4 and TSP-5 in humans.

  20. Phylogenetic analysis of glycerol 3-phosphate acyltransferases in opisthokonts reveals unexpected ancestral complexity and novel modern biosynthetic components.

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    Heather C Smart

    Full Text Available Glycerolipid synthesis represents a central metabolic process of all forms of life. In the last decade multiple genes coding for enzymes responsible for the first step of the pathway, catalyzed by glycerol 3-phosphate acyltransferase (GPAT, have been described, and characterized primarily in model organisms like Saccharomyces cerevisiae and mice. Notoriously, the fungal enzymes share low sequence identity with their known animal counterparts, and the nature of their homology is unclear. Furthermore, two mitochondrial GPAT isoforms have been described in animal cells, while no such enzymes have been identified in Fungi. In order to determine if the yeast and mammalian GPATs are representative of the set of enzymes present in their respective groups, and to test the hypothesis that metazoan orthologues are indeed absent from the fungal clade, a comparative genomic and phylogenetic analysis was performed including organisms spanning the breadth of the Opisthokonta supergroup. Surprisingly, our study unveiled the presence of 'fungal' orthologs in the basal taxa of the holozoa and 'animal' orthologues in the basal holomycetes. This includes a novel clade of fungal homologues, with putative peroxisomal targeting signals, of the mitochondrial/peroxisomal acyltransferases in Metazoa, thus potentially representing an undescribed metabolic capacity in the Fungi. The overall distribution of GPAT homologues is suggestive of high relative complexity in the ancestors of the opisthokont clade, followed by loss and sculpting of the complement in the descendent lineages. Divergence from a general versatile metabolic model, present in ancestrally deduced GPAT complements, points to distinctive contributions of each GPAT isoform to lipid metabolism and homeostasis in contemporary organisms like humans and their fungal pathogens.

  1. Evolution and functional insights of different ancestral orthologous clades of chitin synthase genes in the fungal tree of life

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    Mu eLi

    2016-02-01

    Full Text Available Chitin synthases (CHSs are key enzymes in the biosynthesis of chitin, an important structural component of fungal cell walls that can trigger innate immune responses in host plants and animals. Members of CHS gene family perform various functions in fungal cellular processes. Previous studies focused primarily on classifying diverse CHSs into different classes, regardless of their functional diversification, or on characterizing their functions in individual fungal species. A complete and systematic comparative analysis of CHS genes based on their orthologous relationships will be valuable for elucidating the evolution and functions of different CHS genes in fungi. Here, we identified and compared members of the CHS gene family across the fungal tree of life, including 18 divergent fungal lineages. Phylogenetic analysis revealed that the fungal CHS gene family is comprised of at least 10 ancestral orthologous clades, which have undergone multiple independent duplications and losses in different fungal lineages during evolution. Interestingly, one of these CHS clades (class III was expanded in plant or animal pathogenic fungi belonging to different fungal lineages. Two clades (classes VIb and VIc identified for the first time in this study occurred mainly in plant pathogenic fungi from Sordariomycetes and Dothideomycetes. Moreover, members of classes III and VIb were specifically up-regulated during plant infection, suggesting important roles in pathogenesis. In addition, CHS-associated networks conserved among plant pathogenic fungi are involved in various biological processes, including sexual reproduction and plant infection. We also identified specificity-determining sites, many of which are located at or adjacent to important structural and functional sites that are potentially responsible for functional divergence of different CHS classes. Overall, our results provide new insights into the evolution and function of members of CHS gene

  2. Ancestral Relationships Using Metafounders

    DEFF Research Database (Denmark)

    Legarra, Andres; Christensen, Ole Fredslund; Vitezica, Zulma G

    2015-01-01

    Recent use of genomic (marker-based) relationships shows that relationships exist within and across base population (breeds or lines). However, current treatment of pedigree relationships is unable to consider relationships within or across base populations, although such relationships must exist...

  3. La superaci??n del modelo del ??ngel del hogar:

    OpenAIRE

    Hurtado Mu??oz, M??nica

    2012-01-01

    La Tesis Doctoral titulada "La superaci??n del modelo del "??ngel del hogar". Recuperaci??n de la escritora Leonor Canalejas y Fustegueras (1869-1945)" aborda, en primer lugar, un an??lisis sociol??gico de las circunstancias que rodearon a la mujer espa??ola en el cambio de siglo en el ??mbito social y educativo, en un intento de esclarecer las caracter??sticas propias del contexto en el que la mujer accede a la intelectualidad en general y a la literatura en particular. Esta parte concluye q...

  4. Relación heterófilo/linfocito, frecuencia espontánea de eritrocitos micronucleados y prolongaciones nucleares en el ganso nevado (Chen caerulescens: Una propuesta como posible biomonitor de estrés y genotóxicos ambientales

    Directory of Open Access Journals (Sweden)

    Martha C. Martínez Quintanilla

    2017-04-01

    Full Text Available Existen organismos silvestres que son altamente vulnerables ante estresores antropogénicos y naturales, estos organismos pueden ser de utilidad para evaluar la salud ambiental mediante diferentes indicadores confiables, sencillos, rápidos, económicos para determinar y si es posible reducir estos efectos negativos. En este estudio proponemos al ganso nevado (Chen caerulescens como posible biomonitor de estrés y genotóxicos ambientales mediante la relación heterófilo/linfocito (H/L, la prueba de micronúcleos (EMN, prolongaciones nucleares en eritrocitos (EPN y eritrocitos policromáticos (EPC. Durante la temporada de caza (2012-2013 en el humedal de Málaga, Durango, México, colectamos 18 organismos. Los eritrocitos fueron las células más abundantes, de núcleo y morfología elípticos, de tamaño 12.68 ± 0.89 µm. Observamos heterófilos (11.07±1.32 µm, eosinófilos (9.67±1.26 µm, basófilos (5.75 ± 0.78 µm, monocitos (10.49±1.36 µm y linfocitos (6.53±1.0 µm. No identificamos alteración en las proporciones ni en la morfología de leucocitos, sin embargo, es necesario un mayor número de organismos para establecer los parámetros sanguíneos de base normal para esta especie. La relación h/l fue de 0.41 ± 0.11 este valor es similar a lo reportado para esta y otras especies de aves consideradas como sanas. Establecimos la frecuencia basal de EMN (2.6±1.45, epn (249.2 ± 89.74 y EPC (156.5 ± 50. El ganso nevado es un organismo que se perfila como buen candidato a biomonitor ambiental debido a la frecuencia basal de su relación H/L, EMN, EPN y EPC, pero debe probarse en condiciones estandarizadas y a través de estudios en zonas con y sin contaminación.

  5. Whirling in the late Permian: ancestral Gyrinidae show early radiation of beetles before Permian-Triassic mass extinction.

    Science.gov (United States)

    Yan, Evgeny V; Beutel, Rolf G; Lawrence, John F

    2018-03-16

    Gyrinidae are a charismatic group of highly specialized beetles, adapted for a unique lifestyle of swimming on the water surface. They prey on drowning insects and other small arthropods caught in the surface film. Studies based on morphological and molecular data suggest that gyrinids were the first branch splitting off in Adephaga, the second largest suborder of beetles. Despite its basal position within this lineage and a very peculiar morphology, earliest Gyrinidae were recorded not earlier than from the Upper Triassic. Tunguskagyrus. with the single species Tunguskagyrus planus is described from Late Permian deposits of the Anakit area in Middle Siberia. The genus is assigned to the stemgroup of Gyrinidae, thus shifting back the minimum age of this taxon considerably: Tunguskagyrus demonstrates 250 million years of evolutionary stability for a very specialized lifestyle, with a number of key apomorphies characteristic for these epineuston predators and scavengers, but also with some preserved ancestral features not found in extant members of the family. It also implies that major splitting events in this suborder and in crown group Coleoptera had already occurred in the Permian. Gyrinidae and especially aquatic groups of Dytiscoidea flourished in the Mesozoic (for example Coptoclavidae and Dytiscidae) and most survive until the present day, despite the dramatic "Great Dying" - Permian-Triassic mass extinction, which took place shortly (in geological terms) after the time when Tunguskagyrus lived. Tunguskagyrus confirms a Permian origin of Adephaga, which was recently suggested by phylogenetic "tip-dating" analysis including both fossil and Recent gyrinids. This also confirms that main splitting events leading to the "modern" lineages of beetles took place before the Permian-Triassic mass extinction. Tunguskagyrus shows that Gyrinidae became adapted to swimming on the water surface long before Mesozoic invasions of the aquatic environment took place

  6. Perfil del visitante de naturaleza en Latinoamérica: prácticas, motivaciones e imaginarios. Estudio comparativo entre México y Ecuador.

    Directory of Open Access Journals (Sweden)

    Maribel Osorio García

    2017-01-01

    Full Text Available El artículo expone los resultados de una investigación interinstitucional realizada sobre el com‑ parativo entre el perfil de los visitantes que llegan al Área de Protección de Flora y Fauna Nevado de Toluca, México y a la Reserva Ecológica Cotacachi Cayapas, Ecuador, ambas áreas naturales protegidas. Se toma como postura teórica que el comportamiento del visitante de naturaleza tiene una explicación no sólo a partir de sus motivaciones e interés ambiental, sino desde sus imaginarios. La metodología aplicada fue de carácter cuan‑ titativo a través de una encuesta realizada en cada sitio, considerando las motivaciones, el comportamiento de viaje, las prácticas ambientales y los imaginarios. Mediante un cruce de variables se caracterizaron cuatro perfiles: el recreativo, el deportivo, el de convivencia y el de contacto, siendo el primero el dominante. En cada caso se identifica el modo de interrelación que se establece con la naturaleza.

  7. Written Exercises: Ancestral Magic and Emergent Intellectuals in Mia Couto, Lhoussain Azergui and Dorota Masłowska

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    Ewa Łukaszyk

    2016-12-01

    Full Text Available Written Exercises: Ancestral Magic and Emergent Intellectuals in Mia Couto, Lhoussain Azergui and Dorota Masłowska The article consists in a comparative reading of three novels: Um rio chamado tempo by Mia Couto, Le pain des corbeaux by Lhoussain Azergui and Paw królowej by Dorota Masłowska. In spite of the difference of the historical circumstances of Mozambique, Morocco and Poland, these three books meet at an intersecting point: the emergence of an intelligentsia that uses literacy and writing as an instrument to deconstruct the post-colonial concept of nation and to operate a trans-colonial renegotiation of identity. By the notion of trans-colonial, I understand the opposition against new kinds of symbolic violence that emerged after the end of the colonial period; here this new form of oppression is related to the concept of national unity – an artificial construct that leaves no place for a dualism or pluralism of cultural reality (two shores of the Zambezi river, Arab and Berber dualism in Morocco, “small homelands” in Poland. The young heroes of the novels grasp the pen in order to break through the falseness or the taboos created by the fathers, establishing, at the same time, the relation of solidarity with the world of the grandfathers. The act of writing becomes an actualization of the ancestral universe of magic. The settlement of accounts with the parental generation concerns the vision of nation built upon the resistance against the colonizer (it also refers to the Polish cultural formation, based on the tradition of uprisings and resistance against the Russians.   Ćwiczenia pisemne: magia przodków i nowi intelektualiści w powieściach Mii Couto, Lhoussaina Azerguiego i Doroty Masłowskiej Na podstawie powieści Um rio chamado tempo, uma casa chamada terra Mii Couto (2002, Le pain des corbeaux Lhoussaina Azerguiego (2012 oraz Paw królowej Doroty Masłowskiej (2005 dokonano analizy zjawiska wyłonienia się nowej

  8. CONDICIONES ACTUALES DE LA MINERIA DEL ORO EN LA ZONA ANDINA DEL DEPARTAMENTO DE NARIÑO

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    Carlos Córdoba Barahona

    2007-07-01

    Full Text Available El artículo analiza las condiciones actuales del oro en la zona andina del departamento de Nariño a partir de sus antecedentes históricos. Se aborda aspectos como costos y beneficios de esta actividad, que permiten sugerir las causas de la escasa inversión por parte de las compañías extranjeras en esta área geográfica, mientras han logrado entrar con éxito a otros departamentos colombianos como Antioquia, Santander, Caldas y que relativamente, dejan a Nariño por fuera de sus intereses. Se hace una propuesta que incluye nuevas estrategias de desarrollo para dinamizar el sector de la minería y se concluye que esta actividad, no obstante ser centenaria, permanece en su ancestral atraso, es decir, entre la subsistencia y la actividad artesanal. Sin embargo, tiene un potencial en recursos de minerales metálicos particularmente del oro, cuyo aporte al PIB podría ser más significativo.

  9. Molecular phylogenetic reconstruction and localization of the (TTAGGn telomeric repeats in the chromosomes of Acromyrmex striatus (Roger, 1863 suggests a lower ancestral karyotype for leafcutter ants (Hymenoptera

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    Tássia Tatiane Pontes Pereira

    2018-01-01

    Full Text Available Chromosome counts and karyotype characterization have proved to be important features of a genome. Chromosome changes during the diversification of ants might play an important role, given the diversity and success of Formicidae. Comparative karyotype analyses on ants have enriched and helped ant systematics. Among leafcutter ants, two major chromosome counts have been described, one frequent in Atta Fabricius, 1804 (2n = 22 in all Atta spp. whose karyotype is known and the other frequent in Acromyrmex Mayr, 1865 (2n = 38 in the majority of species whose karyotype is known. The main exception is Acromyrmex striatus (Roger, 1863, which harbors a diploid chromosome set of 22. Here we describe the use of fluorescence in situ hybridization (FISH with telomeric probes with (TTAGG6 repeats to describe the telomere composition of A. striatus and to recover potential interstitial non-telomeric signals that may reflect fusion events during the evolution of leafcutter lineage from 38 to 22 chromosomes. Further, we reconstruct the ancestral chromosome numbers of the leafcutter clade based on a recently proposed molecular phylogenetic hypothesis and phylogenomic tree. Distinct signals have been observed in both extremities on the telomere chromosomes of A. striatus. Non-telomeric signals have not been retrieved in our analysis. It could be supposed that the low-numbered karyotype indeed represents the ancestral chromosome number of leafcutters. The phylogenetic reconstruction also recovered a low chromosome number from the diverse approaches implemented, suggesting that n = 11 is the most likely ancestral karyotype of the leafcutter ants and is a plesiomorphic feature shared between A. striatus and Atta spp.

  10. Human immunodeficiency virus type 1 subtype B ancestral envelope protein is functional and elicits neutralizing antibodies in rabbits similar to those elicited by a circulating subtype B envelope.

    Science.gov (United States)

    Doria-Rose, N A; Learn, G H; Rodrigo, A G; Nickle, D C; Li, F; Mahalanabis, M; Hensel, M T; McLaughlin, S; Edmonson, P F; Montefiori, D; Barnett, S W; Haigwood, N L; Mullins, J I

    2005-09-01

    Human immunodeficiency virus type 1 (HIV-1) is a difficult target for vaccine development, in part because of its ever-expanding genetic diversity and attendant capacity to escape immunologic recognition. Vaccine efficacy might be improved by maximizing immunogen antigenic similarity to viruses likely to be encountered by vaccinees. To this end, we designed a prototype HIV-1 envelope vaccine using a deduced ancestral state for the env gene. The ancestral state reconstruction method was shown to be >95% accurate by computer simulation and 99.8% accurate when estimating the known inoculum used in an experimental infection study in rhesus macaques. Furthermore, the deduced ancestor gene differed from the set of sequences used to derive the ancestor by an average of 12.3%, while these latter sequences were an average of 17.3% different from each other. A full-length ancestral subtype B HIV-1 env gene was constructed and shown to produce a glycoprotein of 160 kDa that bound and fused with cells expressing the HIV-1 coreceptor CCR5. This Env was also functional in a virus pseudotype assay. When either gp160- or gp140-expressing plasmids and recombinant gp120 were used to immunize rabbits in a DNA prime-protein boost regimen, the artificial gene induced immunoglobulin G antibodies capable of weakly neutralizing heterologous primary HIV-1 strains. The results were similar for rabbits immunized in parallel with a natural isolate, HIV-1 SF162. Further design efforts to better present conserved neutralization determinants are warranted.

  11. Latest Miocene-earliest Pliocene evolution of the ancestral Rio Grande at the Española-San Luis Basin boundary, northern New Mexico

    Science.gov (United States)

    Daniel J. Koning,; Aby, Scott B.; Grauch, V. J.; Matthew J. Zimmerer,

    2016-01-01

    We use stratigraphic relations, paleoflow data, and 40Ar/39Ar dating to interpret net aggradation, punctuated by at least two minor incisional events, along part of the upper ancestral Rio Grande fluvial system between 5.5 and 4.5 Ma (in northern New Mexico). The studied fluvial deposits, which we informally call the Sandlin unit of the Santa Fe Group, overlie a structural high between the San Luis and Española Basins. The Sandlin unit was deposited by two merging, west- to southwest-flowing, ancestral Rio Grande tributaries respectively sourced in the central Taos Mountains and southern Taos Mountains-northeastern Picuris Mountains. The river confluence progressively shifted southwestward (downstream) with time, and the integrated river (ancestral Rio Grande) flowed southwards into the Española Basin to merge with the ancestral Rio Chama. Just prior to the end of the Miocene, this fluvial system was incised in the southern part of the study area (resulting in an approximately 4–7 km wide paleovalley), and had sufficient competency to transport cobbles and boulders. Sometime between emplacement of two basalt flows dated at 5.54± 0.38 Ma and 4.82±0.20 Ma (groundmass 40Ar/39Ar ages), this fluvial system deposited 10–12 m of sandier sediment (lower Sandlin subunit) preserved in the northern part of this paleovalley. The fluvial system widened between 4.82±0.20 and 4.50±0.07 Ma, depositing coarse sand and fine gravel up to 14 km north of the present-day Rio Grande. This 10–25 m-thick sediment package (upper Sandlin unit) buried earlier south- to southeast-trending paleovalleys (500–800 m wide) inferred from aeromagnetic data. Two brief incisional events are recognized. The first was caused by the 4.82±0.20 Ma basalt flow impounding south-flowing paleodrainages, and the second occurred shortly after emplacement of a 4.69±0.09 Ma basalt flow in the northern study area. Drivers responsible for Sandlin unit aggradation may include climate

  12. Acerca del moho

    Science.gov (United States)

    El moho forma parte del medio ambiente natural. Afuera del hogar, el moho juega un papel en la naturaleza al desintegrar materias organicas tales como las hojas que se han caido o los arboles muertos. El moho puede crecer adentro del hogar cuando las espor

  13. Del bit al qubit

    OpenAIRE

    Torras Font, Josep

    2011-01-01

    Aquest document pretén donar una visió del desenvolupament dels computadors electrònics i dels components que els han fet possibles. Dintre de les opcions de futur en computació, també intenta donar una visió de les bases en que es fonamenta la computació quàntica.

  14. [High frequency of ancestral allele of the TJP1 polymorphism rs2291166 in Mexican population, conformational effect and applications in surgery and medicine].

    Science.gov (United States)

    Ramirez-Garcia, Sergio Alberto; Flores-Alvarado, Luis Javier; Topete-González, Luz Rosalba; Charles-Niño, Claudia; Mazariegos-Rubi, Manuel; Dávalos-Rodríguez, Nory Omayra

    2016-01-01

    TJP1 gene encodes a ZO-1 protein that is required for the recruitment of occludins and claudins in tight junction, and is involved in cell polarisation. It has different variations, the frequency of which has been studied in different populations. In Mexico there are no studies of this gene. These are required because their polymorphisms can be used in studies associated with medicine and surgery. Therefore, the aim of this study was to estimate the frequency of alleles and genotypes of rs2291166 gene polymorphism TJP1 in Mexico Mestizos population, and to estimate the conformational effect of an amino acid change. A total of 473 individuals were included. The rs2291166 polymorphism was identified PASA PCR-7% PAGE, and stained with silver nitrate. The conformational effect of amino acid change was performed in silico, and was carried out with servers ProtPraram Tool and Search Database with Fasta. The most frequent allele in the two populations is the ancestral allele (T). A genotype distribution similar to other populations was found. The polymorphism is in Hardy-Weinberg, p>0.05. Changing aspartate to alanine produced a conformational change. The study reveals a high frequency of the ancestral allele at rs2291166 polymorphism in the Mexican population. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  15. Miocene magmatism in the Bodie Hills volcanic field, California and Nevada: A long-lived eruptive center in the southern segment of the ancestral Cascades arc

    Science.gov (United States)

    John, David A.; du Bray, Edward A.; Blakely, Richard J.; Fleck, Robert J.; Vikre, Peter; Box, Stephen E.; Moring, Barry C.

    2012-01-01

    The Middle to Late Miocene Bodie Hills volcanic field is a >700 km2, long-lived (∼9 Ma) but episodic eruptive center in the southern segment of the ancestral Cascades arc north of Mono Lake (California, U.S.). It consists of ∼20 major eruptive units, including 4 trachyandesite stratovolcanoes emplaced along the margins of the field, and numerous, more centrally located silicic trachyandesite to rhyolite flow dome complexes. Bodie Hills volcanism was episodic with two peak periods of eruptive activity: an early period ca. 14.7–12.9 Ma that mostly formed trachyandesite stratovolcanoes and a later period between ca. 9.2 and 8.0 Ma dominated by large trachyandesite-dacite dome fields. A final period of small silicic dome emplacement occurred ca. 6 Ma. Aeromagnetic and gravity data suggest that many of the Miocene volcanoes have shallow plutonic roots that extend to depths ≥1–2 km below the surface, and much of the Bodie Hills may be underlain by low-density plutons presumably related to Miocene volcanism.Compositions of Bodie Hills volcanic rocks vary from ∼50 to 78 wt% SiO2, although rocks with Bodie Hills rocks are porphyritic, commonly containing 15–35 vol% phenocrysts of plagioclase, pyroxene, and hornblende ± biotite. The oldest eruptive units have the most mafic compositions, but volcanic rocks oscillated between mafic and intermediate to felsic compositions through time. Following a 2 Ma hiatus in volcanism, postsubduction rocks of the ca. 3.6–0.1 Ma, bimodal, high-K Aurora volcanic field erupted unconformably onto rocks of the Miocene Bodie Hills volcanic field.At the latitude of the Bodie Hills, subduction of the Farallon plate is inferred to have ended ca. 10 Ma, evolving to a transform plate margin. However, volcanism in the region continued until 8 Ma without an apparent change in rock composition or style of eruption. Equidimensional, polygenetic volcanoes and the absence of dike swarms suggest a low differential horizontal stress regime

  16. Algunas aclaraciones acerca del conocimiento del singular.

    Directory of Open Access Journals (Sweden)

    Carlos Llano Cifuentes

    2013-11-01

    Full Text Available Llano tries to explain the main purpose of El Conocimiento del Singular, showing how the individuals about which the book is concerned are basically human individuals: people as decision makers.

  17. Psicodrama del duelo.

    OpenAIRE

    José Antonio Espina Barrio; Marisol Filgueira Bouza

    1997-01-01

    La pérdida de rituales agrava y alarga la reacción del duelo. Se define el Psicodrama Antropológico y su intervención en el proceso del duelo. El Psicodrama Focal del Duelo es una psicoterapia breve centrada en el proceso de Duelo. Se comentan varios casos y resultados. Se concluye con un programa sencillo para el duelo en Atención Primaria.

  18. Fractura triple del complejo suspensorio del hombro

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    Eraclio Delgado Rifá

    2015-06-01

    Full Text Available El complejo suspensorio del hombro es una estructura sumamente importante, compuesta por un anillo de huesos y tejidos blandos. Las lesiones aisladas de este complejo anatómico son frecuentes y no afectan su estabilidad. La interrupción doble conduce a la inestabilidad de esta estructura y usualmente requiere tratamiento quirúrgico. La triple interrupción, por su parte, es sumamente rara y es encontrada en casos de trauma de alta energía a menudo en asociación con otras lesiones. Se presenta una triple lesión del complejo suspensorio del hombro en un paciente de 46 años de edad, con una fractura de la glenoides, del acromion tipo III de Kuhn y de la coracoides tipo II de Ogawa. En este caso, la fractura del acromion fue tratada con fijación percutánea con alambres de Kirschner, por tener asociado lesiones de partes blandas que contraindicaron la reducción abierta. La fractura de la glenoides y de la apófisis coracoides fueron tratadas conservadoramente. Después de 6 meses de evolución, el paciente tuvo un resultado funcional aceptable, con una abducción de 90 grados, los 30 grados de rotación externa y 70 de rotación interna, además asintomático y consolidación de todas las fracturas. A pesar de ser catalogada de una lesión grave del cinturón escapular y estar asociada a otras lesiones se obtuvo un resultado satisfactorio al final del tratamiento.

  19. Vigencia del Darwinismo

    OpenAIRE

    Lessa, Enrique P

    2009-01-01

    En este ensayo se presenta una revisión histórica del signifcado y legado del darwinismo, con énfasis en el último siglo. La principal conclusión es que la visión darwiniana de la evolución, con las modifcaciones requeridas para dar cuenta de los grandes desarrollos de la disciplina, se ha impuesto y mantiene vigencia en nuestros días. En particular, el papel del azar, la evolución como proceso de “descendencia con modifcación” a lo largo de diversas ramas del árbol de la vida, el pensamiento...

  20. Alcances translocales de cultos ancestrales: El caso de las danzas rituales aztecas (Translocales reaches of ancestral cults: The case of the Aztec ritual dances

    Directory of Open Access Journals (Sweden)

    Renée de la Torre

    2007-03-01

    Full Text Available Este trabajo trata sobre las transformaciones de identidad que se gestan en los grupos de danza conocidos como aztecas o concheros en su intercambio cultural y encuentro con redes espirituales alternativas o conocidas como movimientos de espiritualidad Nueva Era (o New Age. El objetivo de este trabajo es dar cuenta de los procesos a partir de los cuales la tradición dancística conchera o azteca está siendo trasformada por las dinámicas de la globalización cultural, haciendo de esta tradición mexicana y ancestral, un eslabón de una amplia red New Age de alcances planetarios.

  1. A linear mitochondrial genome of Cyclospora cayetanensis (Eimeriidae, Eucoccidiorida, Coccidiasina, Apicomplexa) suggests the ancestral start position within mitochondrial genomes of eimeriid coccidia.

    Science.gov (United States)

    Ogedengbe, Mosun E; Qvarnstrom, Yvonne; da Silva, Alexandre J; Arrowood, Michael J; Barta, John R

    2015-05-01

    The near complete mitochondrial genome for Cyclospora cayetanensis is 6184 bp in length with three protein-coding genes (Cox1, Cox3, CytB) and numerous lsrDNA and ssrDNA fragments. Gene arrangements were conserved with other coccidia in the Eimeriidae, but the C. cayetanensis mitochondrial genome is not circular-mapping. Terminal transferase tailing and nested PCR completed the 5'-terminus of the genome starting with a 21 bp A/T-only region that forms a potential stem-loop. Regions homologous to the C. cayetanensis mitochondrial genome 5'-terminus are found in all eimeriid mitochondrial genomes available and suggest this may be the ancestral start of eimeriid mitochondrial genomes. Copyright © 2015 Australian Society for Parasitology Inc. All rights reserved.

  2. Field-trip guide to subaqueous volcaniclastic facies in the Ancestral Cascades arc in southern Washington State—The Ohanapecosh Formation and Wildcat Creek beds

    Science.gov (United States)

    Jutzeler, Martin; McPhie, Jocelyn

    2017-06-27

    Partly situated in the idyllic Mount Rainier National Park, this field trip visits exceptional examples of Oligocene subaqueous volcaniclastic successions in continental basins adjacent to the Ancestral Cascades arc. The >800-m-thick Ohanapecosh Formation (32–26 Ma) and the >300-m-thick Wildcat Creek (27 Ma) beds record similar sedimentation processes from various volcanic sources. Both show evidence of below-wave-base deposition, and voluminous accumulation of volcaniclastic facies from subaqueous density currents and suspension settling. Eruption-fed facies include deposits from pyroclastic flows that crossed the shoreline, from tephra fallout over water, and from probable Surtseyan eruptions, whereas re-sedimented facies comprise subaqueous density currents and debris flow deposits.

  3. Estudio de Recursos Humanos del Sector Salud en Colombia.

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    Gustavo Malagón Londoño

    1997-12-01

    variables de interés.

    El marco legal vigente en la actualidad para las profesiones de la salud, parte desde el año de 1914, y es de tener en cuenta que muchas leyes reglamentarias de profesiones, tales como las de medicina y odontología datan de 1962.

    Esto trae como consecuencia, que estos marcos legales no se encuentren actualizados a los nuevos esquemas de prestación de servicios planteados y que la norma como tal no pueda ser aplicada en el momento que se requiere.

    Colombia posee una gran tradición en el estudio de sus recursos humanos del sector salud, pero los mismos no han sido utilizados con el impacto que se esperaría. Últimamente el proceso se ha abandonado y no se lo ha incluido dentro de un esquema serio de planeación.

    Hace mucho tiempo se inició el proceso de reglamentación y estudio, siendo posiblemente el más serio y profundo el nevado a cabo entre los años de 1964 y 1967 denominado Estudio de Recursos Humanos para la Salud y la Educación Médica, cuyos resultados fueron expuestos a nivel mundial y colocaron a Colombia a la vanguardia en este tipo de trabajos.

    Este estudio recolectó información con respecto a morbimortalidad, recursos físicos, financieros, cobertura y concentración de servicios médico-asistenciales. En el área de recursos humanos investigó tópicos relativos a la formación y utilización del recurso dentro de los cuales se destacan los siguientes aspectos: mala distribución geográfica, insatisfacción en el trabajo, inadecuación entre tareas asignadas y su formación, subutilización por carencia de personal auxiliar y alto nivel de práctica privada.

    Así mismo estudios correspondientes a profesiones específicas se han adelantado desde 1970 siendo las áreas más exploradas, medicina, odontología, enfermería, nutrición y bacteriología.

    En el año de 1970 se inició el Inventario Nacional de Recursos Humanos para la Salud, tal como lo recomendó el estudio realizado entre

  4. Conserved intron positions in FGFR genes reflect the modular structure of FGFR and reveal stepwise addition of domains to an already complex ancestral FGFR.

    Science.gov (United States)

    Rebscher, Nicole; Deichmann, Christina; Sudhop, Stefanie; Fritzenwanker, Jens Holger; Green, Stephen; Hassel, Monika

    2009-10-01

    We have analyzed the evolution of fibroblast growth factor receptor (FGFR) tyrosine kinase genes throughout a wide range of animal phyla. No evidence for an FGFR gene was found in Porifera, but we tentatively identified an FGFR gene in the placozoan Trichoplax adhaerens. The gene encodes a protein with three immunoglobulin-like domains, a single-pass transmembrane, and a split tyrosine kinase domain. By superimposing intron positions of 20 FGFR genes from Placozoa, Cnidaria, Protostomia, and Deuterostomia over the respective protein domain structure, we identified ten ancestral introns and three conserved intron groups. Our analysis shows (1) that the position of ancestral introns correlates to the modular structure of FGFRs, (2) that the acidic domain very likely evolved in the last common ancestor of triploblasts, (3) that splicing of IgIII was enabled by a triploblast-specific insertion, and (4) that IgI is subject to substantial loss or duplication particularly in quickly evolving genomes. Moreover, intron positions in the catalytic domain of FGFRs map to the borders of protein subdomains highly conserved in other serine/threonine kinases. Nevertheless, these introns were introduced in metazoan receptor tyrosine kinases exclusively. Our data support the view that protein evolution dating back to the Cambrian explosion took place in such a short time window that only subtle changes in the domain structure are detectable in extant representatives of animal phyla. We propose that the first multidomain FGFR originated in the last common ancestor of Placozoa, Cnidaria, and Bilateria. Additional domains were introduced mainly in the ancestor of triploblasts and in the Ecdysozoa.

  5. Bayesian phylogeography of influenza A/H3N2 for the 2014-15 season in the United States using three frameworks of ancestral state reconstruction.

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    Daniel Magee

    2017-02-01

    Full Text Available Ancestral state reconstructions in Bayesian phylogeography of virus pandemics have been improved by utilizing a Bayesian stochastic search variable selection (BSSVS framework. Recently, this framework has been extended to model the transition rate matrix between discrete states as a generalized linear model (GLM of genetic, geographic, demographic, and environmental predictors of interest to the virus and incorporating BSSVS to estimate the posterior inclusion probabilities of each predictor. Although the latter appears to enhance the biological validity of ancestral state reconstruction, there has yet to be a comparison of phylogenies created by the two methods. In this paper, we compare these two methods, while also using a primitive method without BSSVS, and highlight the differences in phylogenies created by each. We test six coalescent priors and six random sequence samples of H3N2 influenza during the 2014-15 flu season in the U.S. We show that the GLMs yield significantly greater root state posterior probabilities than the two alternative methods under five of the six priors, and significantly greater Kullback-Leibler divergence values than the two alternative methods under all priors. Furthermore, the GLMs strongly implicate temperature and precipitation as driving forces of this flu season and nearly unanimously identified a single root state, which exhibits the most tropical climate during a typical flu season in the U.S. The GLM, however, appears to be highly susceptible to sampling bias compared with the other methods, which casts doubt on whether its reconstructions should be favored over those created by alternate methods. We report that a BSSVS approach with a Poisson prior demonstrates less bias toward sample size under certain conditions than the GLMs or primitive models, and believe that the connection between reconstruction method and sampling bias warrants further investigation.

  6. The impact of ancestral heath management on soils and landscapes. A reconstruction based on paleoecological analyses of soil records in the middle and southeast Netherlands.

    Science.gov (United States)

    van Mourik, Jan; Doorenbosch, Marieke

    2016-04-01

    The evolution of heath lands during the Holocene has been registered in various soil records . Paleoecological analyses of these records enable to reconstruct the changing economic and cultural management of heaths and the consequences for landscape and soils. Heaths are characteristic components of cultural landscape mosaics on sandy soils in the Netherlands. The natural habitat of heather species was moorland. At first, natural events like forest fires and storms caused small-scale forest degradation, in addition on the forest degradation accelerated due to cultural activities like forest grazing, wood cutting and shifting cultivation. Heather plants invaded on degraded forest soils and heaths developed. People learned to use the heaths for economic and cultural purposes. The impact of the heath management on landscape and soils was registered in soil records of barrows, drift sand sequences and plaggic Anthrosols. Based on pollen diagrams of such records we could reconstruct that heaths were developed and used for cattle grazing before the Bronze Age. During the Late Neolithic, the Bronze Age and Iron Age, people created the barrow landscape on the ancestral heaths. After the Iron Age people probably continued with cattle grazing on the heaths and plaggic agriculture until the Early Middle Ages. After 1000 AD two events affected the heaths. At first deforestation for the sale of wood resulted in the first regional extension of sand drifting and heath degradation. After that the introduction of the deep stable economy and heath sods digging resulted in acceleration of the rise of plaggic horizons, severe heath degradation and the second extension of sand drifting. At the end of the 19th century the heath lost its economic value due to the introduction of chemical fertilizers. The heaths were transformed into 'new' arable fields and forests and due to deep ploughing most soil archives were destroyed. Since 1980 AD, the remaining relicts of the ancestral heaths are

  7. Clusters of ancestrally related genes that show paralogy in whole or in part are a major feature of the genomes of humans and other species.

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    Michael B Walker

    Full Text Available Arrangements of genes along chromosomes are a product of evolutionary processes, and we can expect that preferable arrangements will prevail over the span of evolutionary time, often being reflected in the non-random clustering of structurally and/or functionally related genes. Such non-random arrangements can arise by two distinct evolutionary processes: duplications of DNA sequences that give rise to clusters of genes sharing both sequence similarity and common sequence features and the migration together of genes related by function, but not by common descent. To provide a background for distinguishing between the two, which is important for future efforts to unravel the evolutionary processes involved, we here provide a description of the extent to which ancestrally related genes are found in proximity.Towards this purpose, we combined information from five genomic datasets, InterPro, SCOP, PANTHER, Ensembl protein families, and Ensembl gene paralogs. The results are provided in publicly available datasets (http://cgd.jax.org/datasets/clustering/paraclustering.shtml describing the extent to which ancestrally related genes are in proximity beyond what is expected by chance (i.e. form paraclusters in the human and nine other vertebrate genomes, as well as the D. melanogaster, C. elegans, A. thaliana, and S. cerevisiae genomes. With the exception of Saccharomyces, paraclusters are a common feature of the genomes we examined. In the human genome they are estimated to include at least 22% of all protein coding genes. Paraclusters are far more prevalent among some gene families than others, are highly species or clade specific and can evolve rapidly, sometimes in response to environmental cues. Altogether, they account for a large portion of the functional clustering previously reported in several genomes.

  8. La luz del origen del universo

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    Casas, Alberto

    2015-10-01

    Full Text Available Penzias and Wilson discovered the cosmic microwave background, a luminous echo of the Big Bang, in 1965. The amount of information encoded in this relic of the early universe is truly extraordinary. At present, the most precise data about the origin and structure of the universe comes from the study of this primordial light, the full potential of which has yet to be explored.En 1965 se descubrió el fondo de radiación de microondas, un eco luminoso de la Gran Explosión (Big Bang. La cantidad de información contenida en esta reliquia del universo primitivo es verdaderamente extraordinaria. En la actualidad los datos más precisos sobre el origen y estructura del universo provienen del estudio de esta luz primigenia, que aún no ha sido explorada en todo su potencial.

  9. Archivo del Duelo

    OpenAIRE

    Ferrera, Tamara

    2010-01-01

    Photos taken from the Archive of Mourning following the March 11 terrorist attacks El Archivo del Duelo. Creación de un archivo etnográfico de los Atentados del 11 de marzo en Madrid. Ministerio de Educación y Ciencia HUM2005-03490.

  10. Displasias del seno

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    Ernesto Andrade Valderrama

    1971-04-01

    Full Text Available En general, las Displasias no se presentan antes de la iniciación del estímulo Gonadal y tienden a desaparecer con el climaterio. Se definen entonces como las afecciones benignas del Seno, de origen endocrino.

  11. Derived (mutated)-types of TRPV6 channels elicit greater Ca²+ influx into the cells than ancestral-types of TRPV6: evidence from Xenopus oocytes and mammalian cell expression system.

    Science.gov (United States)

    Sudo, Yuka; Matsuo, Kiyotaka; Tetsuo, Tomoyuki; Tsutsumi, Satoshi; Ohkura, Masamichi; Nakai, Junichi; Uezono, Yasuhito

    2010-01-01

    The frequency of the allele containing three derived nonsynonymous SNPs (157C, 378M, 681M) of the gene encoding calcium permeable TRPV6 channels expressed in the intestine has been increased by positive selection in non-African populations. To understand the nature of these SNPs, we compared the properties of Ca²+ influx of ancestral (in African populations) and derived-TRPV6 (in non-African populations) channels with electrophysiological, Ca²+-imaging, and morphological methods using both the Xenopus oocyte and mammalian cell expression systems. Functional electrophysiological and Ca²+-imaging analyses indicated that the derived-TRPV6 elicited more Ca²+ influx than the ancestral one in TRPV6-expressing cells where both channels were equally expressed in the cells. Ca²+-inactivation properties in the ancestral- and derived-TRPV6 were almost the same. Furthermore, fluorescence resonance energy transfer (FRET) analysis showed that both channels have similar multimeric formation properties, suggesting that derived-TRPV6 itself could cause higher Ca²+ influx. These findings suggest that populations having derived-TRPV6 in non-African areas may absorb higher Ca²+ from the intestine than ancestral-TRPV6 in the African area.

  12. El swing del soneo del sonero mayor. La improvisación salsera y la memoria del ritmo en el caribe y su diáspora

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    Ángel G. Quintero Rivera

    2008-01-01

    Full Text Available La ponencia examina el arte de la improvisación vocal (o soneo de Ismael Rivera (Maelo, reconocido como “ el Sonero Mayor ” de la música “tropical”. Analiza cómo mucha de la riqueza del soneo de Maelo, más que en la retahíla de palabras que improvisa, se encuentra en el swing de su manera de hilvanar esas improvisaciones, desarrollando modulaciones rítmicas a l a manera del bailador en diálogo con el tambor repicador en la memoria caribeña de sus primeras músicas emergiendo de su herencia cultural africana. Estas primeras músicas partían de una realidad, en medida considerable, “despalabrada”, terrible carimbo de la esclavitud. El análisis del soneo de Maelo es muy importante para comprender la salsa, un movimiento musical liderado por la diáspora caribeña en Nueva York que alcanzó una enorme difusión internacional. Su trayectoria como cantante se ubica en los añ os de transición entre la música afrocaribeña tradicional y las nuevas sonoridades que asume esa música en la expresión salsera. Fue, de hecho, en Nueva York a donde emigró en 1967 y como parte del boom salsero que se iniciaba entonces, que su soneo alca nzó su máximo desarrollo artístico, pero incorporando siempre la memoria ancestral y el hondo sentido comunal de sus inicios sobre todo con el Combo de Cortijo en los barrios populares del Puerto Rico de los años cincuenta. La manera como Maelo “apalabró” su swing le imprimió una gran riqueza libertaria al soneo salsero convirtiéndolo en uno de los nuevos elementos centrales de dicha sonoridad diaspórica.

  13. La crisi del diritto del lavoro

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    Alessandro Garilli

    2012-01-01

    Full Text Available Riassunto - L’Autore ripercorre in chiave critica l’evoluzione delle politiche legislative in materia di lavoro, alla luce dell’attuale fase di crisi economico finanziaria. Nell’esaminare i principali interventi normativi attuati da inizio secolo, l’Autore mette in evidenza le scelte di metodo e gli elementi di continuità che accomunano i vari provvedimenti, individuandoli nell’affannosa ricerca del punto di equilibrio tra flessibilità e garantismo. La riflessione si chiude con alcuni interrogativi sulle ultime linee di riforma del mercato del lavoro e con l’auspicio che, anche al cospetto delle imprescindibili ragioni dell’economia, il diritto del lavoro possa continuare a svolgere il proprio tradizionale ruolo di disciplina di tutela della persona.   Abstract - The author analyzes, with a critically oriented approach, the development of the employment law, in the light of the current economic and financial crisis. In examining the main regulatory measures implemented since the beginning of the century, the author highlights the methodological choices and the elements of continuity that unite the various measures, focusing them in a hard research of a point of balance between flexibility and security. The discussion concludes with some questions about the last lines of the reform of the labor market and with the hope that, even in the face of compelling reasons of economy, labor law can continue to play its traditional role of governing the protection of person.

  14. OBJETIVO DEL DESARROLLO DEL MILENIO 7

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    Margarita M. Pérez O.

    2013-10-01

    Full Text Available Los Objetivos de Desarrollo del Milenio, también conocidos como los Objetivos del Milenio, constituyeron las metas finales que aprobaron los dirigentes mundiales, 189 jefes de estado y de gobierno en la Cumbre del Milenio de las Naciones Unidas celebrada en Nueva York en el año 2000, en la cual los Estados miembros de la organización reafirmaron su compromiso de luchar por un mundo en el que el desarrollo sostenible y la eliminación de la pobreza tuvieran máxima prioridad1 . En la cumbre se definió la Declaración del Milenio, la cual detalla los objetivos, principios, valores, metas y acciones para erradicar la pobreza Mundial hacia el año 2015, todos ellos ratificados con alto interés y acción estratégica de carácter global, como marco para la medición de los progresos en materia de desarrollo.

  15. Elementos del sistema electoral del Congreso Mexicano

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    Aldo Medina García

    2013-08-01

    Full Text Available El presente artículo es un estudio de los componentes del sistema electoral, diseñado por el legislador mexicano para integrar al parlamento federal. Estudio desarrollado a sabiendas de la importancia que reviste el sistema electoral como un medio que permite a los ciudadanos convertir su voto expresado en las urnas en escaños a favor de determinado candidato o partido. En dicho análisis tomamos en cuenta la evolución constitucional del sistema electoral mexicano, la participación de las fuerzas minoritarias en la integración del Senado y de la Cámara de Diputados, la división que se hace del territorio en circunscripciones electorales, la barrera electoral que se fija a los partidos políticos para acceder a la representación en el Parlamento, la fórmula de asignación que se aplica a la votación obtenida, para finalmente concluir que el sistema electoral mexicano es esencialmente mayoritario aun cuando se vista de proporcional.

  16. Investigación, Planificación y Estudio del Potencial Turístico del Parque Nacional Bernardo O’Higgins, Patagonia Chilena.

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    Germaynee Vela-Ruiz Figueroa

    2013-01-01

    Full Text Available El Parque Nacional Bernardo O’Higgins (PNBO, ubicado en el extremo austral de Chile, protege 3,5 millones de hectáreas caracterizadas por una geomorfología de fiordos, archipiélagos, islas y glaciares del Campo de Hielo Sur. Este Parque Nacional resalta además por ser el territorio ancestral de los últimos habitantes que mantienen la lengua y el acervo cultural del pueblo indígena Kawésqar. El presente artículo muestra el proceso de investigación ecológica y cultural realizado en el PNBO, así como el proceso de planificación participativa y la elaboración de una propuesta de potencial turístico de dicho territorio. Proyecto que ha sido innovador en la planificación de áreas protegidas en Chile, ya que ha incorporado directamente a una comunidad kawésqar como equipo técnico del proyecto, así como ha permitido levantar información de base de una zona de relevancia mundial escasamente conocida hasta antes de este estudio.

  17. La Danza del Diablo: Estéticas-rituales-comunitarias en la Mixteca Oaxaqueña

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    David Terrazas Tello

    2014-07-01

    Full Text Available La imagen del diablo que trajeron los evangelizado- res, junto con la espada del conquistador, fue el resulta- do de un largo proceso socio-histórico-político-cultural. La espada y la cruz necesitaban herramientas de control ideológico a través del miedo, la culpa, la amenaza del infierno. Esta imagen fue utilizada por las órdenes mo- násticas para emprender la lucha contra la idolatría, cuya premisa fue la total extirpación del “paganismo”; usan- do como estrategia la satanización de los dioses del Me- soamericanos. El Mal tiene una de tantas encarnaciones dentro del contexto festivo actual en el calendario de la mixteca oaxaqueña, a través de la puesta en escena de la Danza de Diablos. Para el análisis de esta danza se pro- pone la categoría transdisciplinaria de estéticas-ritua- les-comunitarias, la cual muestra como se reproduce lo simbólico en la memoria ancestral de la cultura, y como la figura del mal está presente en las cosmovisiones mix- tecas contemporáneas. AbstractThe image of the devil that brought the evangelizers, along with the sword of the conqueror, was the result of a long process socio-historical-political-cultural. The sword and the cross needed tools of ideological control through fear, the guilt, the threat of hell. This image was used by the monastic orders to take up the fight against the idolatry, whose premise was the complete removal of the “paganism”; using as strategy the demonization of the gods of the Mesoamericans. The evil is one of many incar- nations within the current context in the festive calendar of the Mixteca oaxacan, through the implementation of the dance scene of Devils. For the analysis of this dance it is proposed that the transdisciplinary category of aes- thetic-ritual-community, which shows how symbolic it is reproduced in the ancestral memory of the culture, and as the figure of the evil is present in the Mixtec contem- porary worldviews. 

  18. Castillo del Real. Olocau

    OpenAIRE

    AUÑÓN VALLEJO, JONATAN

    2012-01-01

    El objetivo que se quiere alcanzar con este proyecto es el de realizar un estudio lo más cercano posible del Catillo del Real, de manera que se pueda conocer su origen, su evolución a lo largo de la historia, así como las diferentes técnicas y sistemas constructivos utilizados en su construcción. Auñón Vallejo, J. (2011). Castillo del Real. Olocau. http://hdl.handle.net/10251/14244. Archivo delegado

  19. La Representabilidad del Genocidio

    OpenAIRE

    Cardona González, Lorena

    2012-01-01

    El presente artículo intenta hacer una aproximación histórica y analítica al fenómeno del Genocidio, sus implicaciones sociales y culturales que dieron como resultado la reformulación analítica y conceptual de hechos que hasta entonces superaban el conocimiento y la moral humana. De este modo, se hace un trayecto histórico de la paulatina aparición del asesinato masivo como practica de Estado, enmarcado en las experiencias del genocidio armenio y el alemán. A su vez, se hace una mirada sobre ...

  20. Significado presente del CSIC

    OpenAIRE

    Garrido Gallardo, Miguel Angel

    2000-01-01

    Not available

    Este artículo, elaborado en 1999, ofrece una panorámica de la realidad del Consejo Superior de Investigaciones Científicas en la actualidad. Repasa su organización, su volumen de publicaciones, sus indicadores de productividad, su capacidad de obtener recursos y, en suma, su lugar en el conjunto del sistema español de Ciencia y Tecnología, considerado en sí mismo y en relación con la Universidad. Como conclusión del repaso de datos, se afirma que, aunque la fó...

  1. Tratamiento del pie equino

    OpenAIRE

    Robles, Fernanda

    2012-01-01

    El pie equino varo es una patología frecuente en los pacientes con Encefalopatía crónica no evolutiva (ECNE).Se observó que existe una mayor frecuencia en el sexo masculino. Se realizó un estudio descriptivo, comparativo y secundario, durante el periodo de septiembre del 2006 a septiembre del 2011, con un total de 125 pacientes con Ecne, de los cuales se encontraron 101 con pie equino varo congénito. Objetivo: observar los resultados obtenidos en la rehabilitación del pie equino, en niños de ...

  2. Del Pasadismo al Futurismo

    OpenAIRE

    Agudo-Martínez, M. J.

    2003-01-01

    Uno de los habituales prejuicios a la hora de abordar el análisis del movimiento futurista, al igual que sucede con el constructivismo, es la consideración del contexto político en el que se desarrollaron ambas vanguardias. Sin embargo, y dejando a un lado un enfoque del arte con finalidad política de signo diverso, habría que insistir en el hecho de que posiblemente sean tanto el futurismo italiano como el constructivismo ruso, los movimientos que con mayor entusiasmo se manifestaron, en un ...

  3. Genomes of Helicobacter pylori from native Peruvians suggest admixture of ancestral and modern lineages and reveal a western type cag-pathogenicity island

    Directory of Open Access Journals (Sweden)

    Rahman Syed

    2006-07-01

    Full Text Available Abstract Background Helicobacter pylori is presumed to be co-evolved with its human host and is a highly diverse gastric pathogen at genetic levels. Ancient origins of H. pylori in the New World are still debatable. It is not clear how different waves of human migrations in South America contributed to the evolution of strain diversity of H. pylori. The objective of our 'phylogeographic' study was to gain fresh insights into these issues through mapping genetic origins of H. pylori of native Peruvians (of Amerindian ancestry and their genomic comparison with isolates from Spain, and Japan. Results For this purpose, we attempted to dissect genetic identity of strains by fluorescent amplified fragment length polymorphism (FAFLP analysis, multilocus sequence typing (MLST of the 7 housekeeping genes (atpA, efp, ureI, ppa, mutY, trpC, yphC and the sequence analyses of the babB adhesin and oipA genes. The whole cag pathogenicity-island (cagPAI from these strains was analyzed using PCR and the geographic type of cagA phosphorylation motif EPIYA was determined by gene sequencing. We observed that while European genotype (hp-Europe predominates in native Peruvian strains, approximately 20% of these strains represent a sub-population with an Amerindian ancestry (hsp-Amerind. All of these strains however, irrespective of their ancestral affiliation harbored a complete, 'western' type cagPAI and the motifs surrounding it. This indicates a possible acquisition of cagPAI by the hsp-Amerind strains from the European strains, during decades of co-colonization. Conclusion Our observations suggest presence of ancestral H. pylori (hsp-Amerind in Peruvian Amerindians which possibly managed to survive and compete against the Spanish strains that arrived to the New World about 500 years ago. We suggest that this might have happened after native Peruvian H. pylori strains acquired cagPAI sequences, either by new acquisition in cag-negative strains or by recombination

  4. Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity

    Directory of Open Access Journals (Sweden)

    Spreadbury I

    2012-07-01

    Full Text Available Ian SpreadburyGastrointestinal Diseases Research Unit, Queen's University, Kingston, Ontario, CanadaAbstract: A novel hypothesis of obesity is suggested by consideration of diet-related inflammation and evolutionary medicine. The obese homeostatically guard their elevated weight. In rodent models of high-fat diet-induced obesity, leptin resistance is seen initially at vagal afferents, blunting the actions of satiety mediators, then centrally, with gastrointestinal bacterial-triggered SOCS3 signaling implicated. In humans, dietary fat and fructose elevate systemic lipopolysaccharide, while dietary glucose also strongly activates SOCS3 signaling. Crucially however, in humans, low-carbohydrate diets spontaneously decrease weight in a way that low-fat diets do not. Furthermore, nutrition transition patterns and the health of those still eating diverse ancestral diets with abundant food suggest that neither glycemic index, altered fat, nor carbohydrate intake can be intrinsic causes of obesity, and that human energy homeostasis functions well without Westernized foods containing flours, sugar, and refined fats. Due to being made up of cells, virtually all "ancestral foods" have markedly lower carbohydrate densities than flour- and sugar-containing foods, a property quite independent of glycemic index. Thus the "forgotten organ" of the gastrointestinal microbiota is a prime candidate to be influenced by evolutionarily unprecedented postprandial luminal carbohydrate concentrations. The present hypothesis suggests that in parallel with the bacterial effects of sugars on dental and periodontal health, acellular flours, sugars, and processed foods produce an inflammatory microbiota via the upper gastrointestinal tract, with fat able to effect a "double hit" by increasing systemic absorption of lipopolysaccharide. This model is consistent with a broad spectrum of reported dietary phenomena. A diet of grain-free whole foods with carbohydrate from cellular

  5. The impact of ancestral heath management on soils and landscapes: a reconstruction based on paleoecological analyses of soil records in the central and southeastern Netherlands

    Science.gov (United States)

    Doorenbosch, Marieke; van Mourik, Jan M.

    2016-07-01

    The evolution of heathlands during the Holocene has been registered in various soil records. Paleoecological analyses of these records enable reconstruction of the changing economic and cultural management of heaths and the consequences for landscape and soils. Heaths are characteristic components of cultural landscape mosaics on sandy soils in the Netherlands. The natural habitat of heather species was moorland. At first, natural events like forest fires and storms caused small-scale forest degradation; in addition on that, the forest degradation accelerated due to cultural activities like forest grazing, wood cutting, and shifting cultivation. Heather plants invaded degraded forest soils, and heaths developed. People learned to use the heaths for economic and cultural purposes. The impact of the heath management on landscape and soils was registered in soil records of barrows, drift sand sequences, and plaggic Anthrosols. Based on pollen diagrams of such records we could reconstruct that heaths were developed and used for cattle grazing before the Bronze Age. During the late Neolithic, the Bronze Age, and Iron Age, people created the barrow landscape on the ancestral heaths. After the Iron Age, people probably continued with cattle grazing on the heaths and plaggic agriculture until the early Middle Ages. Severe forest degradation by the production of charcoal for melting iron during the Iron Age till the 6th-7th century and during the 11th-13th century for the trade of wood resulted in extensive sand drifting, a threat to the valuable heaths. The introduction of the deep, stable economy and heath sods digging in the course of the 18th century resulted in acceleration of the rise of plaggic horizons, severe heath degradation, and again extension of sand drifting. At the end of the 19th century heath lost its economic value due to the introduction of chemical fertilizers. The heaths were transformed into "new" arable fields and forests, and due to deep ploughing

  6. Preferencias del Turista

    Directory of Open Access Journals (Sweden)

    Jose Luis Leiva Olivencia

    2015-01-01

    Full Text Available Actualmente existen aplicaciones orientadas al turismo basadas en realidad aumentada, pero no integran técnicas de recomendación. Este articulo describe RAMCAT (Realidad Aumentada Móvil Contextual Aplicada al Turismo un modelo de guía turística, que recomienda puntos de interés, teniendo en cuenta factores como preferencias personales y atributos contextuales. Se presentan los componentes teóricos de la arquitectura propuesta, así como sus características, destacando la integración de diferentes sistemas de recomendación, que permiten añadir nuevos motores en el futuro. El articulo se centra en describir sus funcionalidades y el modulo correspondiente al sistema de recomendación basado en el perfil del turista. Otra característica importante del sistema propuesto es la retroalimentación del mismo mediante calificaciones del turista y su trazabilidad.

  7. Carta del Editor

    Directory of Open Access Journals (Sweden)

    Luis Eladio Proaño

    2015-01-01

    Full Text Available La millonaria contratación del futbolista David Beckham, un fenómeno del mercado, ha provocado cuestionamientos a los que se busca respuesta. Es tema de análisis el por qué el betseller "Harry Potter" ha causado tanta conmoción en la opinión pública. Respecto al periodista cibernético, se señalan los contornos del presente y atisban las posibilidades del futuro de esta nueva profesión. El tratamiento de los mitos de la prensa, los temores de la Ley mordaza venezolana y la brutalidad de los video juegos e Internet son temas de enorme interés. Se comenta las pocas veces que la prensa reflexiona sobre la comunicación corporal y la anorexia.

  8. Los muertos del Floreanismo

    Directory of Open Access Journals (Sweden)

    Enrique Ayala Mora

    2008-06-01

    Full Text Available El artículo analiza el crimen político durante las primeras décadas de vida de la República del Ecuador. Específicamente centra su estudio en el período dominado por la figura de Juan José Flores, primer presidente del Ecuador. La inestabilidad política, la precariedad de las alianzas entre las élites regionales, la crisis económica generada por las guerras de Independencia, las conspiraciones y la violencia que caracterizaron al período de surgimiento de las repúblicas andinas hicieron del crimen político un “vicio de nacimiento”. El asesinato del general Antonio José de Sucre, la muerte de los miembros de la sociedad El Quiteño Libre, el homicidio de Juan Otamendi, entre otros, hicieron patente esta característica.

  9. Niveles del aprendizaje organizacional

    OpenAIRE

    Garzón Castrillón, Manuel Alfonso

    2005-01-01

    En la propuesta de modelo de aprendizaje organizacional (AO), la segunda variable se denomina niveles del aprendizaje organizacional ; los niveles de aprendizaje que contemplamos para nuestra investigación son: individual, de equipo, organizacional e interorganizacional.

  10. La escritura del Yo

    Directory of Open Access Journals (Sweden)

    Patricio Landaeta Mardones

    2013-11-01

    Full Text Available Si la creación de una imagen fidedigna del mundo fue la condición de la conquista cognitiva y económica de la tierra, las imágenes mediáticas circulan hoy en día a la manera de un montaje que organiza los sujetos como elementos de un territorio. En esta presentación abordaremos el cruce entre estos dos hechos, entre la escritura del mundo y la de los sujetos, a partir de la idea de Fabulación para mostrar otra escritura del mundo y del yo, leyendo textos e imágenes de la Primera buena Corónica y Buen Gobierno de Felipe Guaman Poma de Ayala.

  11. Consideraciones alrededor del Libro del Almismo, el Libro del Pensar.

    Directory of Open Access Journals (Sweden)

    MartaLucía Tamayo Fernandez

    1999-12-01

    Full Text Available

    La doctora MarthaLucía Tamayo comparte muchas inquietudes alrededor del Libro del Almismo, el Libro del Pensar; de dónde salió ese nombre; de juntar en medicina y en genética a tres escritores como lo son Jorge Luis Borges, Macedonio Fernández y Julio Cortázar. Su conferencia dice así:

    El término almismo fue ideado por Macedonio Fernández porque defendía mucho el ensimismamiento y el pensamiento hacia el interior, mirar hacia adentro; cada uno somos un “sí mismo” que nos hace diferentes aunque al mismo tiempo podemos ser iguales. Todos tenemos esa parte interior que la medicina debe trabajar y que no puede olvidar.

    “El Libro del Almismo, el libro del pensar” nos lleva a replantear y a repensar un poco la medicina que queremos, una medicina vuelta a pensar.

    Quiero contarles la historia de cómo se llegó a este libro y por qué y para qué se sigue trabajando en estos temas: Después de mi internado y de un trabajo un poco triste de rural, volví al Instituto de Genética y a la Universidad Javeriana en donde encontré al doctor Bernal y un espacio que estaba buscando para esa medicina diferente que quería, con un grupo de personas que me permitía no sólo ver la medicina sino ver muchas otras cosas más; había espacio para la literatura, para Mafalda, para hablar de niños, de locos, había incluso tiempo para hablar de medicina dentro del golf, de carros antiguos y de todo eso fui aprendiendo.

    Eso era lo que estaba buscando. Una medicina que diera espacios diferentes, que fuera más humanizada. Rápidamente me ubiqué y me quedé! No me arrepiento en lo absoluto de haberme quedado porque fue, ha sido y sigue siendo, una experiencia enriquecedora, de muchas vivencias importantes. Sabía exactamente dónde estaba y sabía que había que seguir rápido y había que trabajar muchos aspectos de esa medicina que estábamos buscando y de esa genética especial.

    Rápidamente empezamos a trabajar

  12. Actualidad del relativismo cultural

    OpenAIRE

    Sánchez Durá, Nicolás

    2013-01-01

    Este ensayo tiene tres propósitos. En primer lugar, propone examinar las relaciones entre etnocentrismo y relativismo. El etnocentrismo puede tomar tres formas distintas: a saber, la de una universalidad impostada, la del exotismo y la de un particularismo narcisista exacerbado. El relativismo cultural es una postura que asume la inconmensurabilidad de los conceptos y valores que deben ser considerados como válidos dentro de las imágenes del mundo definidas. En segundo lugar, se argumenta que...

  13. Claves de la pervivencia del mito en los medios de comunicación

    Directory of Open Access Journals (Sweden)

    Antonio Gómez Aguilar

    2007-01-01

    Full Text Available Los relatos míticos ancestrales siguen hoy de plena actualidad. Esto es posible porque el mito ha ido evolucionando de forma paralela al cambio de los contextos culturales, renovando ciertos matices, pero manteniendo intactos los valores en base a los cuales se gestó. Los medios de comunicación recurren a los mitos porque estos responden a las preguntas esenciales del hombre, que siguen sin respuesta.Mythical ancestral stories continue being relevant nowadays. This is possible because myths have evolved in a similar way to the change of cultural contexts; they have renewed certain aspects, but remain intact those values because of which they were created. The media appeals to myths because they give answers to human being´s essential questions, that are still unanswered.

  14. el Valle del Cauca

    Directory of Open Access Journals (Sweden)

    Carlos Humberto Ortiz

    2007-01-01

    Full Text Available Este artículo se enfoca en la identi- ficación de aquellos factores estructurales que explican la pérdida de dinamismo económico de largo plazo en Colombia y, en particular, en el Valle del Cauca. Se examina la competitividad del Valle en relación con Colombia y con el resto del mundo. Se cuestiona la insistencia en una estrategia exportadora como dinamizadora del desarrollo económico. Se identifica que una gran parte de la población está excluida de los beneficios del desarrollo económico. Para construir un modelo de desarrollo que incluya a esta población se recomienda recuperar la senda de la industrialización, invertir en el capital humano (educación de alta calidad, salud, salubridad y nutrición, e invertir en infraestructura. La participación del Estado en estas inversiones sociales es necesaria para disminuir la desigualdad y aumentar el crecimiento económico.

  15. Espectroscopia del Cometa Halley

    Science.gov (United States)

    Naranjo, O.; Fuenmayor, F.; Ferrin, L.; Bulka, P.; Mendoza, C.

    1987-05-01

    Se reportan observaciones espectroscópicas del cometa Halley. Los espectros fueron tomados usando el espectrógrafo del telescopio reflector de 1 metro del Observatorio Nacional de Venezuela. Se utilizó óptica azul, con una red de difracción de 600 lineas/min, obteniéndose una dispersión de 74.2 A/mm y una resolución de 2.5 A, en el rango espectral de 3500 a 6500 A. Seis placas fueron tomadas con emulsión IIa-O y dos con IIa-D. Los tiempos de exposición fueron entre 10 y 150 minutos. El cometa se encontraba entre 0.70 y 1.04 UA del Sol, y entre 1.28 y 0.73 UA de la Tierra. Las emisiones más prominentes en el espectro, son las del CN, C2, y C3. Otras emisiones detectadas corresponden a CH, NH2 y Na. Los espectros muestran un fuerte continuo, indicando un contenido significativo de polvo. Se detectó mayor intensidad del contínuo, en la dirección anti solar, lo cual es evidencia de la cola de polvo.

  16. Inventario nacional del uso actual del agua

    OpenAIRE

    Oficina Nacional de Evaluación de Recursos Naturales

    1984-01-01

    Establece como se emplea el agua en el Perú, teniendo en cuenta el tipo de uso, consuntivo y no consuntivo, discriminando según sea el destino: agrícola, pecuario, poblacional,industrial, minero, energético y pesquero, así como su localización geográfica; ello con la finalidad de que sirva de información básica para la planificación del desarrollo.

  17. Gerencia del cuidado-gerencia del servicio

    Directory of Open Access Journals (Sweden)

    Marta Palmet Jiménez

    2016-01-01

    Full Text Available La gerencia de este siglo debe estar plenamente identificada con la administración para planear, organizar, decidir y obtener resultados definidos, evaluados y alcanzados a través de las personas. Para poder gerenciar el cuidado se debe saber administrar. El objetivo de enfermería es cuidar; el objetivo de la gerencia es la conducción de la producción de bienes o servicios en las organizaciones. La gerencia del cuidado implica: motivación, creatividad, responsabilidad y ética por parte del cuidador y de quien cuida, claridad de actitud frente al ser y al qué hacer por parte del cuidador. Se puede concluir que la gerencia (administración, el cuidado (producto de calidad, el servicio (valor intangible, querer servir son un trinomio que deben ir de la mano de manera integrada para el logro de los objetivos propuestos por la organización de salud y de enfermería.

  18. TM4SF20 Ancestral Deletion and Susceptibility to a Pediatric Disorder of Early Language Delay and Cerebral White Matter Hyperintensities

    Science.gov (United States)

    Wiszniewski, Wojciech; Hunter, Jill V.; Hanchard, Neil A.; Willer, Jason R.; Shaw, Chad; Tian, Qi; Illner, Anna; Wang, Xueqing; Cheung, Sau W.; Patel, Ankita; Campbell, Ian M.; Gelowani, Violet; Hixson, Patricia; Ester, Audrey R.; Azamian, Mahshid S.; Potocki, Lorraine; Zapata, Gladys; Hernandez, Patricia P.; Ramocki, Melissa B.; Santos-Cortez, Regie L.P.; Wang, Gao; York, Michele K.; Justice, Monica J.; Chu, Zili D.; Bader, Patricia I.; Omo-Griffith, Lisa; Madduri, Nirupama S.; Scharer, Gunter; Crawford, Heather P.; Yanatatsaneejit, Pattamawadee; Eifert, Anna; Kerr, Jeffery; Bacino, Carlos A.; Franklin, Adiaha I.A.; Goin-Kochel, Robin P.; Simpson, Gayle; Immken, Ladonna; Haque, Muhammad E.; Stosic, Marija; Williams, Misti D.; Morgan, Thomas M.; Pruthi, Sumit; Omary, Reed; Boyadjiev, Simeon A.; Win, Kay K.; Thida, Aye; Hurles, Matthew; Hibberd, Martin Lloyd; Khor, Chiea Chuen; Van Vinh Chau, Nguyen; Gallagher, Thomas E.; Mutirangura, Apiwat; Stankiewicz, Pawel; Beaudet, Arthur L.; Maletic-Savatic, Mirjana; Rosenfeld, Jill A.; Shaffer, Lisa G.; Davis, Erica E.; Belmont, John W.; Dunstan, Sarah; Simmons, Cameron P.; Bonnen, Penelope E.; Leal, Suzanne M.; Katsanis, Nicholas; Lupski, James R.; Lalani, Seema R.

    2013-01-01

    White matter hyperintensities (WMHs) of the brain are important markers of aging and small-vessel disease. WMHs are rare in healthy children and, when observed, often occur with comorbid neuroinflammatory or vasculitic processes. Here, we describe a complex 4 kb deletion in 2q36.3 that segregates with early childhood communication disorders and WMH in 15 unrelated families predominantly from Southeast Asia. The premature brain aging phenotype with punctate and multifocal WMHs was observed in ∼70% of young carrier parents who underwent brain MRI. The complex deletion removes the penultimate exon 3 of TM4SF20, a gene encoding a transmembrane protein of unknown function. Minigene analysis showed that the resultant net loss of an exon introduces a premature stop codon, which, in turn, leads to the generation of a stable protein that fails to target to the plasma membrane and accumulates in the cytoplasm. Finally, we report this deletion to be enriched in individuals of Vietnamese Kinh descent, with an allele frequency of about 1%, embedded in an ancestral haplotype. Our data point to a constellation of early language delay and WMH phenotypes, driven by a likely toxic mechanism of TM4SF20 truncation, and highlight the importance of understanding and managing population-specific low-frequency pathogenic alleles. PMID:23810381

  19. Genome-wide association study identifies HLA 8.1 ancestral haplotype alleles as major genetic risk factors for myositis phenotypes.

    Science.gov (United States)

    Miller, F W; Chen, W; O'Hanlon, T P; Cooper, R G; Vencovsky, J; Rider, L G; Danko, K; Wedderburn, L R; Lundberg, I E; Pachman, L M; Reed, A M; Ytterberg, S R; Padyukov, L; Selva-O'Callaghan, A; Radstake, T R; Isenberg, D A; Chinoy, H; Ollier, W E R; Scheet, P; Peng, B; Lee, A; Byun, J; Lamb, J A; Gregersen, P K; Amos, C I

    2015-10-01

    Autoimmune muscle diseases (myositis) comprise a group of complex phenotypes influenced by genetic and environmental factors. To identify genetic risk factors in patients of European ancestry, we conducted a genome-wide association study (GWAS) of the major myositis phenotypes in a total of 1710 cases, which included 705 adult dermatomyositis, 473 juvenile dermatomyositis, 532 polymyositis and 202 adult dermatomyositis, juvenile dermatomyositis or polymyositis patients with anti-histidyl-tRNA synthetase (anti-Jo-1) autoantibodies, and compared them with 4724 controls. Single-nucleotide polymorphisms showing strong associations (Pmyositis phenotypes together, as well as for the four clinical and autoantibody phenotypes studied separately. Imputation and regression analyses found that alleles comprising the human leukocyte antigen (HLA) 8.1 ancestral haplotype (AH8.1) defined essentially all the genetic risk in the phenotypes studied. Although the HLA DRB1*03:01 allele showed slightly stronger associations with adult and juvenile dermatomyositis, and HLA B*08:01 with polymyositis and anti-Jo-1 autoantibody-positive myositis, multiple alleles of AH8.1 were required for the full risk effects. Our findings establish that alleles of the AH8.1 comprise the primary genetic risk factors associated with the major myositis phenotypes in geographically diverse Caucasian populations.

  20. The Drosophila genome nexus: a population genomic resource of 623 Drosophila melanogaster genomes, including 197 from a single ancestral range population.

    Science.gov (United States)

    Lack, Justin B; Cardeno, Charis M; Crepeau, Marc W; Taylor, William; Corbett-Detig, Russell B; Stevens, Kristian A; Langley, Charles H; Pool, John E

    2015-04-01

    Hundreds of wild-derived Drosophila melanogaster genomes have been published, but rigorous comparisons across data sets are precluded by differences in alignment methodology. The most common approach to reference-based genome assembly is a single round of alignment followed by quality filtering and variant detection. We evaluated variations and extensions of this approach and settled on an assembly strategy that utilizes two alignment programs and incorporates both substitutions and short indels to construct an updated reference for a second round of mapping prior to final variant detection. Utilizing this approach, we reassembled published D. melanogaster population genomic data sets and added unpublished genomes from several sub-Saharan populations. Most notably, we present aligned data from phase 3 of the Drosophila Population Genomics Project (DPGP3), which provides 197 genomes from a single ancestral range population of D. melanogaster (from Zambia). The large sample size, high genetic diversity, and potentially simpler demographic history of the DPGP3 sample will make this a highly valuable resource for fundamental population genetic research. The complete set of assemblies described here, termed the Drosophila Genome Nexus, presently comprises 623 consistently aligned genomes and is publicly available in multiple formats with supporting documentation and bioinformatic tools. This resource will greatly facilitate population genomic analysis in this model species by reducing the methodological differences between data sets. Copyright © 2015 by the Genetics Society of America.

  1. Travelling in time with networks: Revealing present day hybridization versus ancestral polymorphism between two species of brown algae, Fucus vesiculosus and F. spiralis

    Directory of Open Access Journals (Sweden)

    Pearson Gareth A

    2011-01-01

    Full Text Available Abstract Background Hybridization or divergence between sympatric sister species provides a natural laboratory to study speciation processes. The shared polymorphism in sister species may either be ancestral or derive from hybridization, and the accuracy of analytic methods used thus far to derive convincing evidence for the occurrence of present day hybridization is largely debated. Results Here we propose the application of network analysis to test for the occurrence of present day hybridization between the two species of brown algae Fucus spiralis and F. vesiculosus. Individual-centered networks were analyzed on the basis of microsatellite genotypes from North Africa to the Pacific American coast, through the North Atlantic. Two genetic distances integrating different time steps were used, the Rozenfeld (RD; based on alleles divergence and the Shared Allele (SAD; based on alleles identity distances. A diagnostic level of genotype divergence and clustering of individuals from each species was obtained through RD while screening for exchanges through putative hybridization was facilitated using SAD. Intermediate individuals linking both clusters on the RD network were those sampled at the limits of the sympatric zone in Northwest Iberia. Conclusion These results suggesting rare hybridization were confirmed by simulation of hybrids and F2 with directed backcrosses. Comparison with the Bayesian method STRUCTURE confirmed the usefulness of both approaches and emphasized the reliability of network analysis to unravel and study hybridization

  2. Ancestral knowledge about the use of flora and fauna in the indigenous community Tikuna from Cushillo Cocha, border with Peru-Colombia-Brazil

    Directory of Open Access Journals (Sweden)

    Elsa Rengifo-Salgado

    2017-04-01

    Full Text Available In the present study, ancestral indigenous knowledge (ethno-knowledge of the indigenous community “Tikuna from Cushillo Cocha” is reported. The community is located in the province of Ramón Castilla, northeast of Loreto Region, Peru. Data was collected through participatory workshops, interviews and biological expeditions in order to collect plant species, observe animals and identify them in situ, always accompanied by local people considered them with experience and knowledge of their territory. A total of 247 species of flora and fauna were registered. In ethnobotany, 101 species were identified, grouped in seven categories of assigned uses by locals, being food and medicinal categories the most representative. For the case of ethnozoology, 146 species were identified, which are used in six categories, being food and pet categories the most relevant. It was evidenced that the forest is the main source for food, medical supplies, handicrafts, animals as pets to be sold and plants as ornamental, all these with important acceptance by the indigenous population.

  3. Determinantes del ingreso y del gasto corriente de los hogares

    OpenAIRE

    Muñoz C., Manuel

    2004-01-01

    Este ensayo de investigación empírica analiza los determinantes del ingreso y del gasto en los hogares colombianos. Utilizando un modelo del ciclo de vida con datos de la encuesta de hogares de 1994 y 1995, muestra que el comportamiento del ingreso está afectado principalmente por las características demográficas del hogar y los rasgos socio ocupacionales de sus miembros. El comportamiento del gasto está determinado ante todo por el ingreso y, en menor medida, por las características sociales...

  4. Las fluctuaciones del nivel del mar durante el Cuaternario

    OpenAIRE

    Pousa, Jorge Lorenzo; Isla, Federico Ignacio; Schnack, Enrique Jorge

    2002-01-01

    Los cambios del nivel del mar han ejercido una fuerte influencia en la evolución del planeta y en la historia de la humanidad. En una escala de tiempo geológico, las variaciones de los niveles oceánicos han dejado un registro ampliamente distribuido en la forma de depósitos sedimentarios. El descenso del nivel del mar durante la Ultima Glaciación, que alcanzó unos 120 metros hace 18.000 años, permitió la emergencia del estrecho de Bering y la migración humana desde Eurasia hacia América. Se e...

  5. La imagen del pase.

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    Hernando Bernal.

    1999-11-01

    Full Text Available A partir de un texto del poeta Octavio Paz llamado «La imagen», se busca proseguir la equivalencia entre las imágenes de la poesía y la función que ellas tienen para el poeta, y el fantasma fundamental y su función para el analizante que está en el momento del pase. Se parte de la idea de que la poesía busca entrar en el ser así como el psicoanálisis tiene como finalidad apuntar al corazón del ser del sujeto. Se hace entonces una distinción del concepto de «ser» para el psicoanálisis, haciendo alusión también al discurso de la filosofía. Esclarecido el sentido de lo que es el «ser» para el psicoanálisis, se aborda de lleno – entre otras cosas, relacionadas con la experiencia del pase específicamente- la equivalencia entre la definición que hace Octavio Paz de «La Imagen» y el momento del pase en el análisis de un sujeto, imagen que, al igual que el mito para la filosofía, las leyes para la ciencia y el matema para el psicoanálisis, se constituyen en los instrumentos con los que cada una de estas disciplinas horadan en lo real.

  6. Estructura de la población prehistórica del noroeste argentino (sector septentrional

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    Varela, Héctor Hugo

    2004-01-01

    Full Text Available Se estudió la estructura de la poblaci6n prehistórica del sector septentrional del noroeste argentino mediante el empleo de caracteres no-métricos del cráneo. La muestra está constituida por 673 individuos pertenecientes a las regiones de Puna (111, Quebrada de Humahuaca (269, Selvas Occidentales (50 y Valliserrana (243. Se observaron 33 caracteres y se aplicó un diseño tipo factorial "i" por "j" para tablas de contingencia. Mediante la prueba X2 se analizó la distribuci6n de la muestra por sexo, edad, deformación artificial y región. La estructura de la población se estudió empleando análisis de correspondencia, medida media de divergencia estandarizada (sMMD y análisis de agrupamiento. Se comprobó que seis rasgos están asociados con deformación, cinco con sexo, siete con edad y doce con región. Los resultados multivariados revelaron la existencia de dos componentes biológicos, uno constituido por Quebrada de Humahuaca y la Puna y otro por Valliserrana y Las Pirguas. Es posible que dichos componentes se hayan originado a partir de un mismo grupo ancestral probablemente de origen andino y que luego se diferenciaron por la acción de diferentes factores evolutivos (pautas particulares de apareamiento, deriva y migración.

  7. The complete sequence of marine bacteriophage VpV262 infecting vibrio parahaemolyticus indicates that an ancestral component of a T7 viral supergroup is widespread in the marine environment

    International Nuclear Information System (INIS)

    Hardies, Stephen C.; Comeau, Andre M.; Serwer, Philip; Suttle, Curtis A.

    2003-01-01

    The 46,012-bp sequence of the marine bacteriophage VpV262 infecting the bacterium Vibrio parahaemolyticus is reported. The VpV262 sequence reveals that it is a distant relative of marine Roseophage SIO1, and an even more distant relative of coliphage T7. VpV262 and SIO1 appear to represent a widespread marine phage group that lacks an RNA polymerase gene and is ancestral to the T7-like phages. We propose that this group together with the T7-like phages be designated as the T7 supergroup. The ancestral head structure gene module for the T7 supergroup was reconstructed by using sensitive biased Psi-blast searches supplemented by statistical support derived from gene order. In the early and replicative segments, these phages have participated in extensive interchange with the viral gene pool. VpV262 carries a different replicative module than SIO1 and the T7-like phages

  8. del Estado Aragua

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    Joselys Cintia Zerpa

    2008-01-01

    Full Text Available Diagnostica la situación actual de los bienes que conforman al patrimonio histórico-cultural del Municipio Zamora, Estado Aragua, Venezuela. La Investigación es descriptiva y de campo, comprendió la elaboración de un inventario de los bienes inmuebles, festividades religiosas y manifestaciones artesanales del municipio. Se estudiaron la condición física y uso actual de estos bienes y los planes y proyectos existentes. Analizó el marco normativo que los rige. Se obtuvo la opinión de los representantes de organismos públicos relacionados con la actividad turística del Municipio, de los visitantes, cronistas e historiadores. Aportes: La mayoría de los bienes se encuentran en buen estado de conservación, Las manifestaciones culturales, festividades y la artesanía se desarrollan periódicamente pero no son aprovechadas turísticamente, Se determinó que existe un marco normativo para tales bienes y No existen propuestas actuales referentes a estos bienes. Se reflejó el interés de los sectores institucional y privado para la incorporación de estos bienes a la oferta turística del Municipio y del Estado

  9. APOSTILLAS ACERCA DEL POSTRABAJO

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    Arturo Torrecilla

    2000-01-01

    Full Text Available El más reciente debate en torno al postrabajo transforma la herencia de los dos ciclos que le precedieron desde los años setenta. El primero se correspondía con la crítica de la división social y técnica de labores informada por una filosofía de la alienación o bien por una rectificación de la arquitectónica marxista pero salvaguardando la promesa laborista del buen trabajo. El segundo ciclo hacía eco del rechazo a las cadenas de montaje fordistas y se abría al horizonte de la abolición del trabajo salarial, manteniendo sin embargo el abolengo del sujeto unitario de la historia. La presente escena asume una densidad mayor, producto del encuentro entre las nuevas tecnologías informacionales, las discusiones en el ámbito de la sociología y la antropología, de la tecnología y la ciencia, junto al dueto que inaugura el posmodernismo.

  10. Apostillas acerca del postrabajo

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    Arturo Torrecilla

    2000-04-01

    Full Text Available El más reciente debate en torno al postrabajo transforma la herencia de los dos ciclos que le precedieron desde los años setenta. El primero se correspondía con la crítica de la división social y técnica de labores informada por una filosofía de la alienación o bien por una rectificación de la arquitectónica marxista pero salvaguardando la promesa laborista del buen trabajo. El segundo ciclo hacía eco del rechazo a las cadenas de montaje fordistas y se abría al horizonte de la abolición del trabajo salarial, manteniendo sin embargo el abolengo del sujeto unitario de la historia. La presente escena asume una densidad mayor, producto del encuentro entre las nuevas tecnologías informacionales, las discusiones en el ámbito de la sociología y la antropología, de la tecnología y la ciencia, junto al dueto que inaugura el posmodernismo.

  11. La universidad del futuro

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    FERNANDO SANCÉN CONTRERAS

    2013-01-01

    Full Text Available El trabajo señala la necesidad de reconstruir la Universidad, dado el dinamismo que muestra la ciencia y la sociedad, pues trae consigo cambios sustanciales en la visión del mundo y en el aumento del poder del hombre sobre la naturaleza. Se analizan los supuestos epistemológicos de la universidad tradicional y se propone una nueva explicación del conocimiento humano, enfatizando el conocimiento científico. Postula una docencia fundada en las propiedades de la ciencia, cuyo método inductivo basado en los paradigmas vigentes: analítico, crítico, pragmático, ofrece una herramienta para la docencia, la investigación y la difusión de la cultura. Se propone una educación centrada en el sujeto que se hace a sí mismo (etopoiética y que insiste en el proceso de auto-creación del individuo y de la sociedad.

  12. Significado presente del CSIC

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    Garrido Gallardo, Miguel Angel

    2000-05-01

    Full Text Available Not available

    Este artículo, elaborado en 1999, ofrece una panorámica de la realidad del Consejo Superior de Investigaciones Científicas en la actualidad. Repasa su organización, su volumen de publicaciones, sus indicadores de productividad, su capacidad de obtener recursos y, en suma, su lugar en el conjunto del sistema español de Ciencia y Tecnología, considerado en sí mismo y en relación con la Universidad. Como conclusión del repaso de datos, se afirma que, aunque la fórmula del CSIC, como organismo nacional e interdisciplinario, no es la única posible, la organización del Estado de las Autonomías, así como la evaluación de los datos con que se cuenta, la hacen vivamente recomendable. No hay, pues, sino que seguir con su desarrollo.

  13. Dalt del tren

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    Jaume Subirana

    2001-11-01

    Full Text Available Ens consta que la saviesa popular hi toca més del que a aquest temps d’enquestes, telèfons mòbils i targetes de crèdit li ve de gust admetre, per això em fa gràcia, en veure la pausada però continuada intrusió de la cultura catalana a Internet, recordar les cançons de quan era petit: “Dalt del tren, tots anem-hi dalt del tren, hi ha lloc per tota la gent”, dèiem, i “El tren pinxo de Banyoles és el més bonic que hi ha, ple de llaunes i cassoles i barrets de capellà”. I resulta que per una vegada a la vida hem pujat, efectivament, dalt del tren que passava per l’estació de Catalunya i en cinc anys hem passat de gairebé res a prou pàgines amb un contingut, a més, apreciable i, sobretot, a un petit teixit de persones i institucions que han entès la importància de la revolució comunicativa que Internet representa i que hi teixeixen i projecten webs amb el convenciment dels conversos.

  14. Las carreras del futuro

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    Luis Piscoya Hermoza

    2011-07-01

    Full Text Available La primera década del siglo XXI ha estado signada por un énfasis en los estudiosde prospectiva, los mismos que, a partir de procesos de complejizacióny articulación de la sociedad planetaria como son la digitalización, el progresivodeterioro del medio ambiente, la necesidad del cambio de la matriz energéticay la globalización del mercado, han ensayado hipótesis para identificar lastendencias que se fortalecerán y profundizarán durante las próximas décadas.Desde el punto de vista metodológico, existen muchas maneras de clasificarlaspara conceptualizarlas y entenderlas mejor. Sin embargo, considerando lanaturaleza de esta edición nos proponemos enfocar directamente aquellas queestán estrechamente ligadas a la formación universitaria.Naturalmente, no pensamos que estamos ante tendencias inevitables en lamedida que epistemológicamente la creencia en leyes históricas deterministases insostenible y la práctica social nos muestra que la construcción del futuroes nuestra responsabilidad y siempre rebasa las mejores previsiones.

  15. La transformación del Valle en la literatura del narcotráfico de Rolando Hinojosa

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    María del Carmen García

    2011-12-01

    Full Text Available Esta investigación analiza cómo Rolando Hinojosa, un escritor chicano, explora la transformación socioeconómica en el espacio textual y extratextual de la frontera entre México y los Estados Unidos, específicamente el Valle del Río Grande en Texas. El propósito es estudiar cómo el autor utiliza las convenciones literarias de la novela policíaca para sus fines historiográficos, al explorar en Partners in Crime y Ask a Policeman la transición de una economía local a otra global y basada en el narcotráfico, así como sus implicaciones sociales en un lugar ancestralmente signado por la violencia.This research paper analyzes how Rolando Hinojosa, a Chicano writer, explores the socioeconomic transformation in the textual and extra-textual space on the Mexico-USA border, specifically, the Rio Grande Valley in Texas. It is studied how the autor utilizes the literary conventions of the policial novel for his historiographic purposes, when he explores in Partners in Crime and Ask a Policeman the transition from a local to a globally controlled economy based on narcotraffic and its social implications in a place ancestrally signed by violence.

  16. Un primitivo Notonychopidae (Litopterna del Paleoceno inferior de Punta Peligro, Chubut, Argentina

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    Morales, J.

    1997-12-01

    Full Text Available The discovery of a new ungulate species, Requisia vidmari gen. nov., nov. sp. in the lower Paleocene of Punta Peligro, Chubut (Argentine represents the earliest known record of Litopterna. The dental morphology of this new genus is very similar to that known for Notonychops powelli Soria, 1989, differing mainly by its more primitive M3, which is less elongated and less selenodont. Requisia vidmari, together with Wainka tshotshe Simpson, 1948, can be included in the family Notonychopidae, which appear to represent an ancestral grade in the evolution of Litopterna. Because cladogenesis of South American ungulates clearly took place prior to the Punta Peligro fauna and was apparently rapid, phylogenetic interpretation is difficult.Se comunica un nuevo ungulado con dentición pre-selenodonta del Paleoceno inferior, Peligrense, de Patagonia, Argentina. Su morfología dentaria es muy similar a la de Notonychops powelli Soria, 1989, pero con caracteres más primitivos. La morfología de las cúspides, el tipo de desgaste y los caracteres crescentiformes del M3 indican que Requisia vidmari gen. nov., sp. nov. presenta fuertes evidencias del desarrollo de caracteres selenodontos, por lo que se lo considera como el más primitivo representante del orden Litopterna. Requisia vidmari y probablemente Wainka tshotshe Simpson, 1948, son primitivos en relación a Notonychops, pero su similitud morfológica justificaría su inclusión en la misma familia Notonychopidae. Se considera que la radiación adaptativa de los ungulados paleocenos de América del Sur fue precoz, eventualmente rápida, lo que dificulta encontrar un modelo filogenético suficientemente explicativo.

  17. Componente Cultura del Agua del PMGRH: plan de trabajo

    OpenAIRE

    Autoridad Nacional del Agua; Proyecto de Modernización de la Gestión de Recursos Hídricos

    2012-01-01

    Describe el plan de trabajo del Componente Cultura del Agua del Proyecto de Modernización de la Gestión de Recursos Hídricos (PMGRH) en relacion a dos aspectos estructurales del proyecto: 1. Mejora de la capacidad de la Gestión Integrada de Recursos Hídricos (GIRH) a nivel nacional y 2. Fortalecimiento de las capacidades de GIRH en las cuencas.

  18. En busca del concepto de gerencia del cuidado

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    Ligia Teresa Mora-Delgado

    2005-12-01

    Full Text Available Este articulo, presenta los conceptos de gerencia del cuidado de enfermería, desarrollado por las enfermeras profesionales que laboran en le Empresa social del estado Hospital Universitario Erasmo Meoz de las Ciudad de Cúcuta, desde su desempeño en la asistencia, administración y docencia. Se pretende además precisar los elementos gerenciales, sociales, humanísticos y éticos que deben hacer parte del concepto de gerencia del cuidado.

  19. LA PERSISTENCIA DEL SUBALTERNO

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    John Beverley

    2002-01-01

    Full Text Available Este trabajo es el texto literal de una ponencia presentada en un panel sobre los estudios culturales latinoamericanos en el congreso de LASA en 2001 en Washington DC. Representa la posición desarrollada en el trabajo colectivo del llamado Grupo de Estudios Subalternos Latinoamericano, desde nuestra fundación en 1992 hasta la disolución del grupo en 2001, que sirve como pretexto introductorio para la ponencia. Los otros participantes en el panel eran Walter Mignolo, representando los estudios poscoloniales, Néstor García Canclini y John Kraniauskas, representando los estudios culturales, y Nelly Richard representando la llamada crítica cultural. El trabajo dialoga y debate con cada una de estas posiciones respectivamente desde el punto de vista específico de los estudios subalternos. Concluye con un llamado a una crítica del saber académico en sí.

  20. Acalasia. Controversias del tratamiento

    OpenAIRE

    Restrepo P, Antonio J; Rey T, Mario H; Garzón O, Martín A; Farfán Q, Yesid A; Molano V, Juan C; Marulanda, Juan C; Lizarazo, Jorge I

    2007-01-01

    La acalasia es un desorden motor del esófago caracterizado por pérdida de la peristalsis esofágica con falta en la relajación o relajación incompleta del esfínter esofágico inferior (EEI) (1). La causa exacta de este trastorno es desconocida. Los síntomas más comunes son disfagia, regurgitación, pérdida de peso y dolor torácico (2). La manometría esofágica es el principal método diagnóstico, mostrando aperistalsis del cuerpo esofágico con aumento de la presión, falta de relajación o relajació...

  1. Procedimiento Del Triple Fin

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    Oscar L. Bellido Aguilera

    2008-01-01

    Full Text Available Presenta un procedimiento novedoso basado en un método dialéctico - sistémico - integrador, que facilita la precisión de los fines u objetivos más generales de un proceso de desarrollo comunitario o de otros procesos de cambio deseados (un proyecto sociocultural, una investigación social, un proceso de mejoramiento organizacional, etc.. Su importancia radica en que los fines, según Marx, son una guía que rige como una ley la actuación del hombre y determinarlos es parte esencial del planeamiento del cambio. Se trata de un asunto aparentemente simple, sin embargo, en la práctica es mucho más problemático de lo que comúnmente se cree.

  2. Late Cenozoic Magmatic and Tectonic Evolution of the Ancestral Cascade Arc in the Bodie Hills, California and Nevada: Insights from Integrated Geologic, Geophysical, Geochemical and Geochronologic Studies

    Science.gov (United States)

    John, D. A.; du Bray, E. A.; Box, S. E.; Blakely, R. J.; Fleck, R. J.; Vikre, P. G.; Cousens, B.; Moring, B. C.

    2012-12-01

    Geologic mapping integrated with new geophysical, geochemical, and geochronologic data characterize the evolution of Bodie Hills volcanic field (BHVF), a long-lived eruptive center in the southern part of the ancestral Cascade arc. The ~700 km2 field was a locus of magmatic activity from ~15 to 8 Ma. It includes >25 basaltic andesite to trachyandesite stratovolcanoes and silicic trachyandesite to rhyolite dome complexes. The southeastern part of the BHVF is overlain by the ~3.9 to 0.1 Ma, post-arc Aurora Volcanic Field. Long-lived BHVF magmatism was localized by crustal-scale tectonic features, including the Precambrian continental margin, the Walker Lane, the Basin and Range Province, and the Mina deflection. BHVF eruptive activity occurred primarily during 3 stages: 1) dominantly trachyandesite stratovolcanoes (~15.0 to 12.9 Ma), 2) coalesced trachydacite and rhyolite lava domes and trachyandesite stratovolcanoes (~11.6 to 9.7 Ma), and 3) dominantly silicic trachyandesite to dacite lava dome complexes (~9.2 to 8.0 Ma). Small rhyolite domes were emplaced at ~6 Ma. Relatively mafic stratovolcanoes surrounded by debris flow aprons lie on the margins of the BHVF, whereas more silicic dome fields occupy its center. Detailed gravity and aeromagnetic data suggest the presence of unexposed cogenetic granitic plutons beneath the center of the BHVF. Isotopic compositions of BHVF rocks are generally more radiogenic with decreasing age (e.g., initial Sr isotope values increase from ~0.7049 to 0.7061), which suggests progressively greater magma contamination by crustal components during evolution of the BHVF. Approximately circular, polygenetic volcanoes and scarcity of dikes suggest a low differential horizontal stress field during BHVF formation. Extensive alluvial gravel deposits that grade laterally into fluvial gravels and finer grained lacustrine sediments and the westerly sourced Eureka Valley Tuff (EVT; ~9.4 Ma) blanket large parts of the BHVF. The earliest sediments

  3. Efecto del silicio y plaguicidas en la fertilidad del suelo y rendimiento del arroz

    OpenAIRE

    Furcal-Beriguete, Parménides; Herrera-Barrantes, Alejandra

    2013-01-01

    Efecto del silicio y plaguicidas en la fertilidad del suelo y rendimiento del arroz. El objetivo de este trabajo fue evaluar el efecto del silicio en la fertilidad del suelo, la incidencia de enfermedades y plagas insectiles, el rendimiento y la calidad de granos del cultivo de arroz. El estudio se realizó en La Vega, Florencia, San Carlos, Costa Rica entre mayo y octubre en los años 2010 y 2011, en el mismo lote con la variedad CR 4477. Se establecieron cinco tratamientos: silicio al suelo, ...

  4. The Ancestral Carnivore Karyotype As Substantiated by Comparative Chromosome Painting of Three Pinnipeds, the Walrus, the Steller Sea Lion and the Baikal Seal (Pinnipedia, Carnivora.

    Directory of Open Access Journals (Sweden)

    Violetta R Beklemisheva

    Full Text Available Karyotype evolution in Carnivora is thoroughly studied by classical and molecular cytogenetics and supplemented by reconstructions of Ancestral Carnivora Karyotype (ACK. However chromosome painting information from two pinniped families (Odobenidae and Otariidae is noticeably missing. We report on the construction of the comparative chromosome map for species from each of the three pinniped families: the walrus (Odobenus rosmarus, Odobenidae-monotypic family, near threatened Steller sea lion (Eumetopias jubatus, Otariidae and the endemic Baikal seal (Pusa sibirica, Phocidae using combination of human, domestic dog and stone marten whole-chromosome painting probes. The earliest karyological studies of Pinnipedia showed that pinnipeds were characterized by a pronounced karyological conservatism that is confirmed here with species from Phocidae, Otariidae and Odobenidae sharing same low number of conserved human autosomal segments (32. Chromosome painting in Pinnipedia and comparison with non-pinniped carnivore karyotypes provide strong support for refined structure of ACK with 2n = 38. Constructed comparative chromosome maps show that pinniped karyotype evolution was characterized by few tandem fusions, seemingly absent inversions and slow rate of genome rearrangements (less then one rearrangement per 10 million years. Integrative comparative analyses with published chromosome painting of Phoca vitulina revealed common cytogenetic signature for Phoca/Pusa branch and supports Phocidae and Otaroidea (Otariidae/Odobenidae as sister groups. We revealed rearrangements specific for walrus karyotype and found the chromosomal signature linking together families Otariidae and Odobenidae. The Steller sea lion karyotype is the most conserved among three studied species and differs from the ACK by single fusion. The study underlined the strikingly slow karyotype evolution of the Pinnipedia in general and the Otariidae in particular.

  5. Survival relative to new and ancestral host plants, phytoplasma infection, and genetic constitution in host races of a polyphagous insect disease vector

    Science.gov (United States)

    Maixner, Michael; Albert, Andreas; Johannesen, Jes

    2014-01-01

    Dissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host-race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant-specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentiation between the host races. We used a twice repeated, identical nested experimental design to study survival of the vector on alternative hosts and relative to infection status. Survival was tested with Kaplan–Meier analyses, while genetic differentiation between vector populations was quantified with microsatellite allele frequencies. We found significant direct effects of host plant (reduced survival on wrong hosts) and sex (males survive longer than females) in both host races and relative effects of host (nettle animals more affected than bindweed animals) and sex (males more affected than females). Survival of bindweed animals was significantly higher on symptomatic than nonsymptomatic field bindweed, but in the second experiment only. Infection potentially had a positive effect on survival in nettle animals but due to low infection rates the results remain suggestive. Genetic differentiation was not related to survival. Greater negative plant-transfer effect but no negative effect of stolbur in the derived host race suggests preadaptation to the new pathogen/symbiont strain before strong diversifying selection during the specialization process. Physiological maladaptation or failure to accept the ancestral plant will have similar consequences, namely positive assortative

  6. The Zygosaccharomyces bailii transcription factor Haa1 is required for acetic acid and copper stress responses suggesting subfunctionalization of the ancestral bifunctional protein Haa1/Cup2.

    Science.gov (United States)

    Palma, Margarida; Dias, Paulo Jorge; Roque, Filipa de Canaveira; Luzia, Laura; Guerreiro, Joana Fernandes; Sá-Correia, Isabel

    2017-01-13

    The food spoilage yeast species Zygosaccharomyces bailii exhibits an extraordinary capacity to tolerate weak acids, in particular acetic acid. In Saccharomyces cerevisiae, the transcription factor Haa1 (ScHaa1) is considered the main player in genomic expression reprogramming in response to acetic acid stress, but the role of its homologue in Z. bailii (ZbHaa1) is unknown. In this study it is demonstrated that ZbHaa1 is a ScHaa1 functional homologue by rescuing the acetic acid susceptibility phenotype of S. cerevisiae haa1Δ. The disruption of ZbHAA1 in Z. bailii IST302 and the expression of an extra ZbHAA1 copy confirmed ZbHAA1 as a determinant of acetic acid tolerance. ZbHaa1 was found to be required for acetic acid stress-induced transcriptional activation of Z. bailii genes homologous to ScHaa1-target genes. An evolutionary analysis of the Haa1 homologues identified in 28 Saccharomycetaceae species genome sequences, including Z bailii, was carried out using phylogenetic and gene neighbourhood approaches. Consistent with previous studies, this analysis revealed a group containing pre-whole genome duplication species Haa1/Cup2 single orthologues, including ZbHaa1, and two groups containing either Haa1 or Cup2 orthologues from post-whole genome duplication species. S. cerevisiae Cup2 (alias Ace1) is a transcription factor involved in response and tolerance to copper stress. Taken together, these observations led us to hypothesize and demonstrate that ZbHaa1 is also involved in copper-induced transcriptional regulation and copper tolerance. The transcription factor ZbHaa1 is required for adaptive response and tolerance to both acetic acid and copper stresses. The subfunctionalization of the single ancestral Haa1/Cup2 orthologue that originated Haa1 and Cup2 paralogues after whole genome duplication is proposed.

  7. Storia del pensiero matematico

    CERN Document Server

    Kline, Morris

    1999-01-01

    Costruita con l'intento di presentare le idee oltre ai protagonisti della matematica, questa storia ha il duplice pregio dell'esaustività e della chiarezza. Essa prevede infatti vari livelli di lettura: lo specialista vi trova una messe di dati, fonti e spunti di ricerca, mentre lo studente ha a disposizione un formidabile strumento di consultazione e sintesi. L'arco temporale coperto è vasto: dalla Mesopotamia a Euclide, da Fibonacci all'invenzione del calcolo infinitesimale, da Gauss a Poincare, con un'appendice dedicata agli sviluppi piu recenti scritta appositamente per la prima edizione italiana del 1991, nei «Manuali» Einaudi.

  8. La escritura del quechua

    OpenAIRE

    Authier, Martine du

    2015-01-01

    La mayor fantasía ha acompañado siempre la transcripción del quechua. El primer intento de sistematización fue el sistema de la Paz, en 1953. Sin embargo, no existe en el comercio un diccionario satisfactorio en lo que se refiere al quechua del Cusco y, prácticamente, nada se edita en quechua, fuera de algunos trabajos antropológicos bilingües. Bajo la égida de la UNESCO, la Academia Peruana de la Lengua Quechua, que tiene su sede en el Cusco, ha colaborado en un diccionario de doce de los tr...

  9. El lenguaje del cerebro

    Directory of Open Access Journals (Sweden)

    Antonio Ibáñez Molina

    2011-04-01

    Full Text Available La introducción de nuevas técnicas de análisis de ritmos EEG en estudio de la comprensión del lenguaje permite explorar esta habilidad humana desde una perspectiva de integración de grupos de redes neuronales. Los ritmos de disparo neuronal que generan estos grupos pueden conectarse por sincronía formando unidades funcionales transitorias distribuidas en diversas áreas del cerebro. En esta revisión comentamos algunos de estos ritmos y su relación con el lenguaje.

  10. Plasticidad del sistema nervioso

    Directory of Open Access Journals (Sweden)

    L. M. Garcia-Segura

    1976-06-01

    Full Text Available En este trabajo se revisan los conocimientos más recientes sobre el fenómeno de la plasticidad del sistéma nervioso, tanto a nivel morfológico como a nivel fisiológico y molecular. Se estudian los cambios morfólogicos y fisiológicos de las neuronas frente a la experiencia. Tambien se considera la adaptación molecular del sistéma nervioso a la información que recibe como la base de todo tipo de plasticidad.

  11. Las causas del desempleo

    OpenAIRE

    García Balbás, Salomé

    2014-01-01

    En este documento vamos a tratar de dar respuesta a la siguiente pregunta: ¿cuáles son las causas del desempleo? Para ello realizaremos un repaso de las principales teorías económicas del desempleo llegando a la conclusión de que existe una causa fundamental que lo genera: la rigidez de los salarios a la baja. Consideramos el desempleo como la existencia de un exceso de oferta en el mercado de trabajo y haremos alusión, únicamente, a la existencia de desempleo involuntario. La exposición de l...

  12. Inventario del Archivo del conde de Bornos

    Directory of Open Access Journals (Sweden)

    Pedro Antonio Porras Arboledas

    1995-01-01

    Full Text Available Mi primer contacto con esta Casa se remonta a algunos años atrás, cuando me Mamó la atención un documento muy interesante, publicado a comienzos del presente siglo por el ilustre erudito ubetense don Alfredo Cazaban, por el que los Reyes Católicos hacían merced a su secretario y jefe de la artillería real durante la Guerra contra Granada, Francisco Ramírez de Madrid, personaje madrileño de origen cántabro, de una heredad en término de Jaén —el cortijo de Bornos— por sus grandes esfuerzos en la conquista de las plazas, hasta el momento inexpugnables, de Cambil y Alhabar. Posteriormente, al realizar un estudio sobre el régimen señorial en el Reino de Jaén, intenté localizar los archivos de las diferentes casas nobiliarias asentadas en esta provincia, gracias a lo cual pude saber que la documentación del Condado de Bornos se hallaba en Madrid, bien en la Biblioteca Nacional o en el Archivo Histórico, ya que el actual Conde, el Excmo. Sr. Don Ignacio Ramírez de Haro, así me lo comunicó en marzo de 1983.

  13. Curved canals: Ancestral files revisited

    Directory of Open Access Journals (Sweden)

    Jain Nidhi

    2008-01-01

    Full Text Available The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed ® etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.

  14. Ancestral Genres of Mathematical Graphs

    Science.gov (United States)

    Gerofsky, Susan

    2011-01-01

    Drawing from sources in gesture studies, cognitive science, the anthropology of religion and art/architecture history, this article explores cultural, bodily and cosmological resonances carried (unintentionally) by mathematical graphs on Cartesian coordinates. Concepts of asymmetric bodily spaces, grids, orthogonality, mapping and sacred spaces…

  15. Ancestral susceptibility to colorectal cancer

    Czech Academy of Sciences Publication Activity Database

    Huhn, S.; Pardini, Barbara; Naccarati, Alessio; Vodička, Pavel (ed.); Hemminki, K.; Försti, A.

    2012-01-01

    Roč. 27, č. 2 (2012), s. 197-204 ISSN 0267-8357 R&D Projects: GA ČR GA310/07/1430; GA ČR GAP304/10/1286 Grant - others:EU FP7(XE) HEALTH-F4-2007-200767 Institutional research plan: CEZ:AV0Z50390512 Keywords : cancer susceptibility * molecular epidemiology * genetic susceptibility Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.500, year: 2012

  16. Competencia Desarrollo del Pensamiento Creativo

    OpenAIRE

    Rodríguez, Eric; Miceli, Francisco; Tiburcio, Georgina; Gómez, Orlando

    2012-01-01

    1. ¿Qué significa la competencia Desarrollo del Pensamiento Creativo? 2. ¿Por qué es relevante que adquiera la competencia Desarrollo del Pensamiento Creativo en mi formación? 3. ¿Cómo aprendo la competencia Desarrollo del Pensamiento Creativo? 4. ¿Cómo aplico la competencia Desarrollo del Pensamiento Creativo? 5. ¿Cómo puedo autoevaluar mi competencia (con miras a un constante crecimiento)?

  17. Ruptura del projecte parental i disposició dels preembrions

    OpenAIRE

    Farnós Amorós, Esther

    2010-01-01

    La tesi doctoral "Ruptura del projecte parental i disposició dels preembrions" analitza els efectes del consentiment a les tècniques de reproducció assistida prestat en el marc d'un projecte parental. La tesi ofereix una resposta als conflictes que enfronten exesposos o exconvivents en relació al destí dels preembrions sobrants d'un cicle de fecundació "in vitro" iniciat durant la relació. Aquests conflictes constitueixen un grup de casos al voltant del qual no hi ha solucions legislatives qu...

  18. La equinoterapia en las distintas alteraciones del desarrollo del menor.

    OpenAIRE

    Chamorro González, Mireya

    2015-01-01

    La equinoterapia consiste en la utilización del caballo como un método terapéutico para rehabilitar a personas con discapacidad. Esta terapia es considerada una gran alternativa para aumentar el autoestima de los que sufren algún tipo de discapacidad, también a través de esta terapia se mejora y fortalece el estado emocional, así del mismo modo ayuda a mejorar la manera de desenvolverse en su entorno social. Esta terapia se realiza a través de la trasmisión del calor corporal del caballo, del...

  19. Gestión del riesgo del cambio (segunda parte)

    OpenAIRE

    Zorrilla Salgador, Juan Pablo

    2004-01-01

    Segunda parte del artículo acerca del uso de futuros sobre el tipo de cambio. Esta continuación abarca estrategias, definiciones, metodología y explicaciones sobre todo lo relacionado con el Ratio de cobertura de los futuros y la aparición del riesgo base.Segunda parte del artículo acerca del uso de futuros sobre el tipo de cambio. Esta continuación abarca estrategias, definiciones, metodología y explicaciones sobre todo lo relacionado con el Ratio de cobertura de los futuros y la aparición d...

  20. del's Proof

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 5. Gödel's Proof - Incompleteness Theorems. S M Srivastava. General Article Volume 12 Issue 5 May 2007 pp 71-84. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/012/05/0071-0084. Keywords.

  1. Marketing Mix del Software.

    Directory of Open Access Journals (Sweden)

    Yudith del Carmen Rodríguez Pérez

    2006-03-01

    Por ello, en este trabajo se define el concepto de producto software, se caracteriza al mismo y se exponen sus atributos de calidad. Además, se aborda la mezcla de marketing del software necesaria y diferente a la de otros productos para que este triunfe en el mercado.

  2. Gerencia del servicio

    OpenAIRE

    Nancy Peña Acosta

    1992-01-01

    Estamos en la era de la pirámide invertida donde el cliente es primero por lo que es fundamental incentivar la calidad desde abajo; hacer que el trabajador defina su misión, sienta que es parte de la compañía para que la satisfacción del negocio realizado sea de todos.

  3. El Juego del Juego

    OpenAIRE

    Carvalho, Nazaré Cristina

    2012-01-01

    DUVIGNAUD, Jean. El Juego del Juego. Santafé de Bogotá, Colômbia: Fondo de Cultura Econômica, 1997.The game gameDUVIGNAUD, Jean. The Game Game. Santafé de Bogotá, Colombia: Fondo de Cultura Econômica, 1997

  4. El helor del cuerpo

    OpenAIRE

    Sánchez-Biosca, Vicente

    1992-01-01

    Ensayo sobre las formas clásicas y modernas de la metamorfosis. En esta figura mitológica se advierte de manera privilegiada la entrada del imaginario científico, biológico y genético en el dominio de las construcciones literarias y cinematográficas.

  5. Carta del Editor

    Directory of Open Access Journals (Sweden)

    Luis Eladio Proaño

    2014-12-01

    Full Text Available La publicación se centra en temas como: Procesos electorales en México e Italia, se analizan los procesos comunicacionales y sus efectos; las infiltraciones de las agencias de seguridad en la actividad periodística en Europa; la radio y la televisión pública en los EE.UU. Para conocer cómo la prensa enfrenta los problemas críticos entre países, esta el caso de Uruguay y Argentina (discrepancia por la planta de procesamiento de papel y la contaminación del Río de La Plata. Otro artículo refiere la difícil relación entre los medios de comunicación y el gobierno de Chávez en Venezuela. Se aborda el caso brasileño para entender el crecimiento de los Observatorios de Medios; otro sobre el crecimiento del "periodismo confidencial" en la web y la prensa gratuita. Se estudia el impacto de la telenovela "pasión de gavilanes". Para quienes interese la penetración del Internet está: "Usos y competencias del weblog en las corporaciones" más otro sobre la lucha sorda que mantienen los gigantes de la autopista de la información Google y Yahoo.

  6. Punctualizaciones del CERN

    CERN Multimedia

    2002-01-01

    "Viene de la pagina anterior. Puntualizaciones del CERN. La valoracion que me merece la aprobacion en el Consejo de Ministros el 24 de mayo de un acuerdo de colaboracion entre el MCYT y el CERN para el proyecto de neutrinos al Gran Sasso es positiva" (1 page).

  7. Software del sistema osteomioarticular

    Directory of Open Access Journals (Sweden)

    Dianelys León Medina

    2015-06-01

    Full Text Available Introducción: la aplicación en la enseñanza de las Tecnologías de la Informática y las Comunicaciones, es una de las líneas que ha trazado el sistema de salud cubano en estudiantes de las ciencias médicas. La anatomía es una de las ciencias que integra la disciplina de Morfofisiología y para facilitar su comprensión resulta necesario el empleo de recursos y estrategias, entre los que puede figurar un software educativo. Objetivo: diseñar un software sobre la anatomía del sistema osteomioarticular de cabeza y cuello para los estudiantes de primer año de la carrera de Estomatología de Pinar del Río. Material y método: se realizó un estudio cualitativo. Para obtener los resultados se utilizó el método materialista dialéctico. Para la dialéctica del desarrollo del proceso estudiado se utilizaron los métodos teóricos, empíricos, el estudio profundo del tema, tipo de plataforma a utilizar y criterios de los especialistas. Para su procesamiento se utilizaron técnicas estadísticas descriptivas e inferenciales no paramétricas. Resultados: debido a la necesidad de fortalecer en los estudiantes las habilidades en la utilización de las tecnologías de la informática y las comunicaciones, se elaboró el software de la anatomía del sistema osteomioarticular de cabeza y cuello "Aprendiendo anatomía" mediante imágenes, videos y textos. Conclusiones: el software constituye un aporte al proceso enseñanza aprendizaje, el cual facilita el trabajo independiente y autopreparación mediante la interactividad con el contenido, retroalimentación y evaluación utilizando medios de enseñanza modernos, lo cual tributa al modo de actuación del futuro egresado.

  8. Historia deldel = History of Padel

    Directory of Open Access Journals (Sweden)

    Bernardino Javier Sánchez-Alcaraz Martínez

    2013-10-01

    Full Text Available El presente trabajo resume la historia del deporte deldel. Existen dos versiones sobre el origen deldel. La primera versión relaciona los antecedentes deldel con los de otros deportes de raqueta como el tenis o el bádminton, siendo su origen común el jeu de la paume francés. Posteriormente, surgen variantes en Estados Unidos como el Paddle Tennis y el Platform Tennis, siendo versiones reducidas del tenis, pero con elementos muy comunes al pádel actual. La segunda versión, aprobada por la Federación Internacional de Pádel, afirma que este deporte nació en México, en 1969, a través del empresario Enrique Corcuera.--------------------------------------------------------------------This research summarizes the history of paddle sport. There are two versions about the origin of paddle. The first version relates the history of paddle with other racket sports like tennis or badminton, and its common origin of the Jeu de Paume French. Later, in in the United States, appear two sports called Paddle Tennis and Platform Tennis, which are reduced versions of tennis sport, but these have lot of common characteristics with paddle. The second version, approved by the International Padel Federation, said the sport was born in Mexico in 1969, through the businessman Enrique Corcuera.

  9. Determinantes del ingreso y del gasto corriente de los hogares

    Directory of Open Access Journals (Sweden)

    Muñoz C., Manuel

    2004-06-01

    Full Text Available Este ensayo de investigación empírica analiza los determinantes del ingreso y del gasto en los hogares colombianos. Utilizando un modelo del ciclo de vida con datos de la encuesta de hogares de 1994 y 1995, muestra que el comportamiento del ingreso está afectado principalmente por las características demográficas del hogar y los rasgos socio ocupacionales de sus miembros. El comportamiento del gasto está determinado ante todo por el ingreso y, en menor medida, por las características sociales del hogar y el gasto de otros hogares con características similares. También examina la influencia de la incertidumbre acerca de los ingresos en el gasto de los hogares para comprobar si estos actúan con motivos de precaución.

  10. Estudio del CH interestelar

    Science.gov (United States)

    Olano, C.; Lemarchand, G.; Sanz, A. J.; Bava, J. A.

    El objetivo principal de este proyecto consiste en el estudio de la distribución y abundancia del CH en nubes interestelares a través de la observación de las líneas hiperfinas del CH en 3,3 GHz. El CH es una molécula de amplia distribución en el espacio interestelar y una de las pocas especies que han sido observadas tanto con técnicas de radio como ópticas. Desde el punto de vista tecnológico se ha desarrollado un cabezal de receptor que permitirá la realización de observaciones polarimétricas en la frecuencia de 3,3 GHz, con una temperatura del sistema de 60 K y un ancho de banda de 140 MHz, y que será instalado en el foco primario de la antena parabólica del IAR. El cabezal del receptor es capaz de detectar señales polarizadas, separando las componentes de polarización circular derecha e izquierda. Para tal fin el cabezal consta de dos ramas receptoras que amplificarán la señal y la trasladarán a una frecuencia más baja (frecuencia intermedia), permitiendo de esa forma un mejor transporte de la señal a la sala de control para su posterior procesamiento. El receptor además de tener características polarimétricas, podrá ser usado en el continuo y en la línea, utilizando las ventajas observacionales y de procesamiento de señal que actualmente posee el IAR.

  11. La pluridimensionalidad del rol del docente hospitalario

    Directory of Open Access Journals (Sweden)

    Marian Serradas Fonseca

    2015-07-01

    Full Text Available Este trabajo es el fruto de la observación y la investigación en la trayectoria personal y profesional de la autora dedicada a la educación de niños y niñas en situación de enfermedad u hospitalización. El objetivo de este ensayo es intentar definir de manera específica, el papel, tareas y competencias que el profesional del ámbito educativo tiene en la atención educativa hospitalaria; haciendo especial énfasis en la importancia de la formación de este profesional abogándose por una preparación que permita brindar una atención educativa de calidad a los niños y niñas en situación de enfermedad u hospitalizados.

  12. C1.\taminos del jaguar y el venado. conversación con kuau htli vásquez, médico tradicional mexica

    Directory of Open Access Journals (Sweden)

    Mario Madroñero Morillo

    2013-04-01

    Full Text Available La presente entrevista con Kuahtli Vásquez, médico peyotero de ascendencia mexica, refiere,en primera instancia, las experiencias de aprendizaje del médico tradicional y su relacióncon el contexto político de los indígenas en el norte de México. Luego introduce a otromédico tradicional, esta vez del Putumayo, en busca de la medicina del yagé o ayahuasca,y lo que implica el encuentro entre formas de curación que expresan caminos del saber sinintermediación epistémica, como las prácticas chamánicas del Jaguar y el Venado, o las profecíasdel encuentro entre el Cóndor y el Águila. El propósito final es entrever, entre las palabras delmédico tradicional amerindio, lo que este pensar ancestral puede aportar a los tiempos actuales.

  13. Loop 7 of E2 enzymes: an ancestral conserved functional motif involved in the E2-mediated steps of the ubiquitination cascade.

    Directory of Open Access Journals (Sweden)

    Elena Papaleo

    Full Text Available The ubiquitin (Ub system controls almost every aspect of eukaryotic cell biology. Protein ubiquitination depends on the sequential action of three classes of enzymes (E1, E2 and E3. E2 Ub-conjugating enzymes have a central role in the ubiquitination pathway, interacting with both E1 and E3, and influencing the ultimate fate of the substrates. Several E2s are characterized by an extended acidic insertion in loop 7 (L7, which if mutated is known to impair the proper E2-related functions. In the present contribution, we show that acidic loop is a conserved ancestral motif in E2s, relying on the presence of alternate hydrophobic and acidic residues. Moreover, the dynamic properties of a subset of family 3 E2s, as well as their binary and ternary complexes with Ub and the cognate E3, have been investigated. Here we provide a model of L7 role in the different steps of the ubiquitination cascade of family 3 E2s. The L7 hydrophobic residues turned out to be the main determinant for the stabilization of the E2 inactive conformations by a tight network of interactions in the catalytic cleft. Moreover, phosphorylation is known from previous studies to promote E2 competent conformations for Ub charging, inducing electrostatic repulsion and acting on the L7 acidic residues. Here we show that these active conformations are stabilized by a network of hydrophobic interactions between L7 and L4, the latter being a conserved interface for E3-recruitment in several E2s. In the successive steps, L7 conserved acidic residues also provide an interaction interface for both Ub and the Rbx1 RING subdomain of the cognate E3. Our data therefore suggest a crucial role for L7 of family 3 E2s in all the E2-mediated steps of the ubiquitination cascade. Its different functions are exploited thank to its conserved hydrophobic and acidic residues in a finely orchestrate mechanism.

  14. Serotonin-immunoreactivity in the ventral nerve cord of Pycnogonida--support for individually identifiable neurons as ancestral feature of the arthropod nervous system.

    Science.gov (United States)

    Brenneis, Georg; Scholtz, Gerhard

    2015-07-10

    -immunoreactive neurons in the pycnogonid ventral nerve cord. Accordingly, the validity of this neuroanatomical feature as apomorphy of Mandibulata is questioned and we suggest it to be ancestral for arthropods instead. The pronounced disparities between the segmental pattern in pycnogonids and the one of studied euchelicerates call for denser sampling within the latter taxon. By contrast, overall similarities between the pycnogonid and myriapod patterns may be indicative of single cell homologies in these two taxa. This notion awaits further substantiation from future studies.

  15. ABC del Ajedrez. I

    Directory of Open Access Journals (Sweden)

    Marisel Piñeiro Gomez

    2009-03-01

    Full Text Available La promoción del Ajedrez, su conocimiento y práctica por la población constituye uno de los programas de la Revolución, por tal motivo el presente trabajo está encaminado a proponer un material bibliográfico con variadas posiciones sobre el movimiento-captura de las piezas y los sistemas de notación para los masificadores de Ajedrez del municipio Pinar del Río. En esta investigación se utilizaron variados métodos: teóricos, empíricos y estadísticos, además, como método rector el dialéctico materialista. Constituye una novedad científica porque aporta un material bibliográfico que contiene: la composición,  disposición  e  identificación  del  tablero de  ajedrez;  identificación, colocación, movimiento y captura de las piezas de ajedrez; la promoción del Peón; el valor absoluto de las piezas; los sistemas de notación: descriptivo y algebraico. Se le incluyen más de trescientos gráficos, conceptos que son trabajados de lo simple a lo complejo de manera tal que el masificador de Ajedrez lo utilice en sus clases donde se viabilice el conocimiento gracias a las facilidades que le aporta el material; ofrece algoritmos que le guiarán a elaborar nuevas posiciones, los cuales son inexistentes para este propósito en otras bibliografías; su significación práctica radica en que proporciona, tanto al estudiantado como profesorado, ejercicios de ajedrez sencillos que les permitirá a los primeros para que les sirva en su comportamiento, y a los segundos utilizarlos en su auto preparación; el interés social se halla en que pueden ser utilizados por profesores, personal de apoyo a la docencia,  técnicos  del  INDER,  familiares  de  los  estudiantes  para  ayudarlos;  el interés educativo reside en que a través de esos ejercicios contribuimos al fortalecimiento de valores.

  16. Arco del milenio

    Directory of Open Access Journals (Sweden)

    Adell, Josep Mª

    2005-02-01

    the most significant stages in the erection of the Millennium Arch outside the Palacio de Congresos, venue for the 12th IBMAC.
    These pictures are divided into six chapters: Background, Components, Springline, Piers, Arch, Centring Erection and Removal, and Trimming.

    A lo largo de la historia, el Arco de fábrica ha sido el componente constructivo más característico de la Arquitectura y la Ingeniería desde que después de sus inicios etruscos en la época romana fuera desarrollado adelantándose con ello a la cultura helénica.
    El Arco, desde entonces, viene empleándose como una solución constructiva eficiente para cubrir espacios con materiales que no soportan tracciones. La originalidad técnica del Arco lo ha llevado a imponerse como símbolo de las hazañas bélicas como era el Arco de Triunfo.
    En el cambio de siglo y milenio en el que nos encontramos, un salto técnico fundamental se desvela en este Congreso, el Sistema de Albañilería Integral, que abre la posibilidad de ampliar el campo de aplicación de la albañilería con la incorporación del acero, a través de las perforaciones de las piezas, lográndose por fin armar en las tres direcciones del espacio cualquier muro de fábrica que se desee.
    El Arco del Milenio conmemoró el 12th IBMAC de Madrid, mostrando en él los avances técnicos que el Sistema de Albañilería Integral permite, al tratarse de un arco inclinado en el espacio y, por tanto, el primer arco de fábrica construido fuera de la vertical, mediante fábrica de Ladriflor aparejada a tizón, reforzada con barras y cercos.
    El Arco del Milenio, diseñado por J.M. Adell (Presidente del 12th IBMAC, parte de un cilindro de 14 m de diámetro, inclinado 30º sobre el terreno, y construido con fábrica de ladrillo de un pie de grueso, alternando una hilada de color amarillo de cada seis en rojo. El hueco deja un paso libre de 10 m de lado y 5,5 m de altura. La fábrica está armada regularmente por tendeles con cerchas cada

  17. Determinantes del trabajo infantil y la escolaridad: el caso del Valle del Cauca en Colombia

    Directory of Open Access Journals (Sweden)

    Sebastián Urueña Abadía

    2009-10-01

    Full Text Available Colombia, al igual que la mayoría de países latinoamericanos, consciente de las repercusiones sociales y económicas negativas del trabajo infantil, se ha comprometido en la lucha por la erradicación de este fenómeno. Prueba de ello es la ratificación por parte del gobierno colombiano en el año 2007, del Convenio 182 de la OIT sobre la Prohibición de las Peores Formas de Trabajo Infantil y la Acción Inmediata para su Eliminación. En el plano regional, como parte del Plan de Desarrollo del Departamento del Valle del Cauca 2008-2011, se está implementando actualmente una estrategia territorial de erradicación del trabajo infantil en sus 42 municipios. Considerando este panorama, este trabajo indaga cuáles son los determinantes del trabajo infantil y la escolaridad en el departamento del Valle a partir de los datos de la Encuesta Nacional de Calidad de Vida del año 2003. Para el análisis se emplea un modelo econométrico Probit Bivariado, que permite el estudio conjunto e interrelacionado de decisiones diferentes, en este caso la asistencia escolar y el trabajo.

  18. Andesite Petrogenesis in Nevado de Toluca Stratovolcano, Central Mexico

    Science.gov (United States)

    Gomez-Tuena, A.; Capra, L.; Cai, Y.; Goldstein, S. L.

    2007-05-01

    A popular model for andesite petrogenesis in continental arcs involves a hydrous parental basalt that fractionates and probably assimilates continental crust during ascent. Nevertheless, andesites erupted from polygenetic volcanoes in the Trans-Mexican Volcanic Belt are not entirely consistent with this scenario because: (1) they display a shift to higher SiO2 contents at similar Mg# than true basalts, (2) they trend to lower HREE and HFSE contents with increasing SiO2, and (3) they often show correlated isotopic compositions with proxies for slab inputs but not with fractionation indexes. Young andesites from Toluca stratovolcano (1-0.042 Ma) also display modest adakite-like features (Sr/YToluca rock-suite revealed that some other andesites (2.6-1 Ma) also exhibit very strong negative Ce (Ce/Ce~0.25) anomalies, fractionated HREE patterns (Gd/Yb~4.2), as well as low Zr/Sm (~12.6), and Sr/Y (~12) ratios. These features are not easily explained by low or even high pressure differentiation from a common primitive magma, unless enormous quantities of fractionating accessory minerals are taken into account. And yet these geochemical signals are almost identical to those observed in the pelagic sedimentary horizon of the subducted Cocos plate sampled at DSDP site 487, and thus provide strong evidence for slab-derived sediment contributions to the petrogenesis of Toluca andesites. Since sediment transfer to the Toluca source must have occurred in the form of a silicate melt, the new evidence brings further support to the slab melting hypothesis in the Mexican subduction zone. Interestingly, Ce/Pb ratios of the Toluca rocks display a linear positive correlation with Pb isotopes, that departs from the pelagic sediment values, and extends to the enriched Pb isotopic compositions of intraplate-type volcanic rocks from the Chichinautzin volcanic field. Thus the Toluca rocks likely represent discrete slab-derived melts coming from different portions of the subducted slab that have interacted with the distinctively enriched Mexican mantle wedge.

  19. En defensa del indigenismo

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Huamán

    2011-05-01

    Full Text Available El indigenismo como movimiento literario, cultural, ideológico y políticoconstituye un hito, una referencia obligada de nuestra tradición culturaly literaria nacional. Su debate no se reduce ni limita a las primerasdécadas del siglo XX, etapa privilegiada en forma recurrente en los estudiosiniciales sobre esta corriente. Podemos afirmar, sin temor a equivocarnos,que no hay momento ni periodo, más o menos visible, en elque no se haya evaluado en forma crítica este acontecimiento, el mismoque ha resurgido con otras denominaciones o referencias (regionalismo,andinismo, mariateguismo, humalismo, etc., a lo largo de nuestro procesohistórico, pero imbuidas de la perspectiva inicial. El propósito deeste artículo es hacer una defensa del indigenismo contestando algunasposiciones contrarias como la de Mirko Lauer.

  20. RESPONSABILIDAD DEL ODONTOPEDIATRA

    OpenAIRE

    Guillen B., Celso

    2014-01-01

    La Responsabilidad de la atención del niño, requiere de una formación y preparación universitaria de la Segunda Especialidad en Odontopediatría para manejar organismos en proceso de crecimiento somático y psicológico. Es por eso que con el proceso de la ciencia se ha comprendido la importancia de la atención del niño desde que nace. Es así que se ha creado sistemas integrales de atención odontopediátrica durante los primeros años de vida, debido a la alta vulnerabilidad de contraer las enferm...

  1. Responsabilidad Constitucional del Gobierno

    Directory of Open Access Journals (Sweden)

    Francisco Zúñiga Urbina

    2006-01-01

    Full Text Available El artículo analiza la responsabilidad constitucional del Gobierno y sostiene que es jurídico-política, de lejano cuño penal y administrativo, y el procedimiento empleado para hacerla efectiva es la acusación en juicio político, que es un típico caso de "justicia política". A la responsabilidad constitucional se suman las responsabilidades civil y penal de Derecho Público del Presidente de la República y sus ministrosThis paper analyses constitutional responsibility of the government and sustains that it is political and juridical, of distant penal and administrative inspiration, and that the procedure used for persecution is impeachment in political trials, demonstrating a typical case of "political justice." Added to the constitutional responsibility of the government are the civil and penal responsibilities of the President and minister's public law

  2. Infecciones del tracto urinario

    Directory of Open Access Journals (Sweden)

    K. Andrés Wurgaft, Dr.

    2010-07-01

    Full Text Available La infección del tracto urinario (ITU, con sus múltiples presentaciones clínicas, está entre las enfermedades infecciosas más frecuentes, tanto en pacientes ambulatorios como hospitalizados. El uso del examen de orina completa y de urocultivo debe ser racional. La bacteriuria asintomática no debe ser buscada ni tratada, en parte porque esto favorece el desarrollo de bacterias resistentes a antibióticos. Distintos cuadros clínicos requieren de distintas duraciones de terapia antibiótica, y tanto el exceso de días de tratamiento como su falta deben evitarse. Se requiere investigación en la búsqueda de estrategias más efectivas para prevenir las ITU recurrentes y en el desarrollo de nuevos antibióticos orales para las ITU resistentes.

  3. Las cruces del olvido

    Directory of Open Access Journals (Sweden)

    Carla Fernandes

    2012-08-01

    Full Text Available Les tragiques événements du « mars paraguayen » ont signifié la disparition de l’espoir en la transition démocratique dans laquelle le pays s’était engagé depuis presque une dizaine d’années. Renée Ferrer, poète, dramaturge, auteur de plusieurs recueils de contes et de deux romans, consigne alors le témoignage poétique de ce drame national dans le recueil Las cruces del olvido (2001. Elle a auparavant publié d’autres textes qui peuvent rentrer dans la catégorie de la poésie sociale : c’est le cas en particulier de Viaje a destiempo (1989 dédié aux victimes de la dictature. Las cruces del olvido, dès son paratexte, insiste sur la fonction de témoignage que l’auteur souhaite assigner à ses vers et sur le rôle que ceux-ci peuvent jouer dans la transmission d’une mémoire collective. La voix d’un jeune disparu de ce « mars paraguayen », le dédoublement qu’il subit et travers lequel il évoque son entrée dans la mort et son absence du monde des vivants, rendent possible l’écriture de cette expérience de l’indicible qu’est la disparition.Los trágicos acontecimientos del «marzo paraguayo» significaron la desaparición de la esperanza en la transición democrática que el país está viviendo desde unos diez años. Renée Ferrer, poeta, dramaturga, autora de varios libros de cuentos y de dos novelas, escribe entonces el testimonio poético de ese drama nacional en su poemario Las cruces del olvido (2001. Ya había publicado antes textos que se pueden considerar como poesía social: es el caso de Viaje a destiempo (1989 dedicado a las víctimas de la dictadura. Desde el texto apertural, Las cruces del olvido potencia la función de testimonio que la autora desea conceder a sus versos y el papel que éstos pueden desempeñar en la transmisión de una memoria colectiva. La voz de un joven desaparecido del «marzo paraguayo», el desdoblamiento que sufre y a través del cual evoca su entrada en la

  4. Carta del editor

    Directory of Open Access Journals (Sweden)

    José Sánchez Gutiérrez

    2018-01-01

    Full Text Available La comunicación científica en México vive enormes retos ante la carrera de adaptar sus formas de comunicación a las nuevas tecnologías. No es tarea fácil convencerse de abandonar el papel y la imprenta para apostar por el código abierto. Sin embargo, esto es apremiante debido al retraso que se lleva en comparación con otras regiones.  Un reto muy evidente ha sido comprender el acceso abierto, reconociendo que este permite mayor visibilidad a la ciencia y que ayuda a evitar el plagio.  Razón por la que nos alegra que a partir del número 37, Mercados y Negocios cuenta con el ISSN electrónico, además del impreso

  5. Carta del Editor

    OpenAIRE

    Luis Eladio Proaño

    2015-01-01

    Henos aquí con un nuevo número de RIESED. Después de casi un año de ver la luz, y como lo anticipábamos en la carta del editor que acompañaba al número fundacional, hacer una revista electrónica no ha sido una tarea sencilla. Un año más tarde no podemos sino confirmar esa opinión.Gracias al decidido trabajo de los autores, revisores y miembros del equipo editorial hemos podido hacerlo. El proceso de revisión de los artículos ha merecido un cuidado, dedicación y tiempo especiales, que hicieron...

  6. Sonidos del Silencio

    Directory of Open Access Journals (Sweden)

    Luz Rodríguez Carranza

    2009-12-01

    Full Text Available La novela ha muerto, afirmaba Alberto Moravia, popularizada, anexada y banalizada por el cine, la televisión, la prensa, la sicología y la sociología. Para Carlos Fuentes en cambio - quien cita a Moravia en 1969 – « lo que ha muerto es sólo la forma burguesa de la novela, el realismo » (17. Basta un viaje rápido por la red para verificar, sin embargo, que la víctima goza de buena salud y que no está confinada en la cultura de masas o en las ciencias sociales : el modelo realista del siglo XIX – y particularmente la creación de tipos representativos de una época, sean éstos promediales o excepcionales - constituye aún la principal preocupación de los escritores y críticos literarios del siglo XXI.

  7. del consumidor mexicano

    Directory of Open Access Journals (Sweden)

    Nadia Huitzilin Jiménez Torres

    2013-01-01

    Full Text Available Pese a que el 80% de la población del mundo vive en mercados emergentes y países en desarrollo, como México, la investigación sobre el consumidor de estos países ha sido insuficiente. El objetivo de este estudio es determinar el perfil del consumidor mexicano en función de variables psicosociológicas como el etnocentrismo, la apertura cultural, el patriotismo, el colectivismo y las características demográficas. Con este propósito se recogió la información de una muestra de 274 consumidores, se realizaron un análisis factorial de sus principales componentes y un análisis cluster con el cual se aglomeró a los individuos en tres grupos con diferentes perfiles psicosociológicos y demográficos.

  8. del noroeste murciano

    Directory of Open Access Journals (Sweden)

    Ma. Luz Tudela Serrano

    2006-01-01

    Full Text Available En la Región de Murcia se está realizando un esfuerzo por aumentar la producción de energías renovables en cumplimiento de los objetivos de Kyoto establecidos para España. Paralelamente, la percepción social acerca de las mismas preocupa cada vez más. En este trabajo, los ciudadanos opinan ante la necesidad de promover el uso e implantación de energías renovables en varias poblaciones afectadas del noroeste. Emplazamientos idóneos, la conservación de los valores naturales y paisajísticos del entorno y las necesidades socioeconómicas de la zona se suman a un uso racional de estas energías y un desarrollo tecnológico paralelo para alcanzar un desarrollo sostenible.

  9. Lo siniestro del enigma.

    Directory of Open Access Journals (Sweden)

    Victoria Eugenia Diaz.

    1999-11-01

    Full Text Available En "El nacimiento de la filosofía griega", Giorgio Colli nos muestra una faceta tenebrosa del enigma. El dios Apolo, de naturaleza ilimitada, insondable, caprichosa, plantea al hombre enigmas que lo enfrentan con el sufrimiento y con la muerte. Allí, Edipo se confronta con enigmas enviados por el dios en los que se pone en juego su propia existencia. Tiempo después, en el transcurrir del siglo XX, reaparece una nueva forma de este dios arbitrario y arrogante: el desaparecedor de personas, ese inmoderado que impone moderación, borra con su acto un cuerpo, una imagen, un nombre, y formula un nuevo enigma siniestro que enfrenta otra vez al hombre con el dolor y con la muerte.

  10. Carta del Editor

    Directory of Open Access Journals (Sweden)

    Luis Eladio Proaño

    2015-01-01

    Full Text Available El aparecimiento del periodista digital y la educación superior en su formación, el cine indígena y la resistencia cultural, más los Grammy latinos, son temas protagónicos de este número. Se suman la prensa en el combate de piráticas corruptas, los errores de la comunicación del presidente URIBE en el referendo, el fútbol y las Relaciones Públicas en España, la libertad de prensa encarcelada, el Internet y la sociedad de la Información y México: profesiones emergentes para los comunicadores, completan la edición.

  11. CULTO A LA VIRGEN DEL VALLE COMO CREENCIA AUTÓCTONA EN LAS ISLAS ORIENTALES VENEZOLANAS

    Directory of Open Access Journals (Sweden)

    Natalia Bondarenko

    2016-01-01

    Full Text Available Se analiza el origen del culto a la Virgen del Valle en el estado insular Nueva Esparta (Venezuela y su relación con las creencias autóctonas de los indígenas guaiqueríes, por un lado, y la creencia católica clásica en la Virgen María, por el otro. Luego de describir la religiosidad de los guaiqueríes en la época prehispánica y presentar las características de la creencia en la Virgen María en la España medieval, se argumenta que el culto a la Virgen se inició en Venezuela en el período colonial, cuando algunos guaiqueríes la aceptaron debido a su semejanza con los cemíes y el carácter matriarcal de su sociedad, para luego, en el período republicano, adherirse masiva y definitivamente a la Virgen, incorporándola a su panteón de divinidades a partir de un suceso histórico insólito. Ellos rendían culto a la Virgen a su modo ancestral, por lo cual esta creencia no puede ser considerada como sincrética. Se concluye que en las islas neoespartanas, aunque con el nombre de una Virgen católica, el culto a la Virgen del Valle representa una creencia autóctona guaiquerí que persiste a través del tiempo, desplegando aspectos católicos solo en los rituales formales de la iglesia.

  12. Percepcion multisensorial del sabor

    Directory of Open Access Journals (Sweden)

    Charles Spence

    2010-12-01

    Full Text Available La investigación sobre la integración multisensorial de los estímulos auditivos, visuales y táctiles nos está ayudando a entender el funcionamiento de la percepción del sabor. Este conocimiento está teniendo ya un impacto sobre el diseño de alimentos y bebidas, desde los productos que compramos en un supermercado hasta aquellos que encontramos en los restaurantes con estrellas Michelin.

  13. Estado Nutricional del Yodo.

    Directory of Open Access Journals (Sweden)

    Hernando Vargas Uricoechea

    2015-06-01

    Full Text Available INTRODUCCIÓN: Los Desórdenes por Deficiencia de Yodo son un problema serio de salud pública, con cerca de 2 mil millones de personas a riesgo de padecerlos, pudiendo causar bocio neonatal, cretinismo, retardo mental, hipotiroidismo, entre otros. Estos desórdenes son aún prevalentes, y en algunos casos los esfuerzos para su erradicación se han traducido en aumento del riesgo de exceso poblacional de yodo y autoinmunidad tiroidea. En Colombia, se desconoce el estado real de yodo en la población. OBJETIVOS: Determinar la mediana de la yoduría en población escolar, y de los hábitos del consumo de sal, función y parámetros de autoinmunidad tiroidea, y cociente intelectual. MATERIALES Y MÉTODOS: Estudio basado en la comunidad, de corte transversal. Se evaluaron las variables sociodemográficas, la frecuencia de bocio y los niveles de TSH, anti-TPO, anti-Tg, anti-TSHR, yoduria, test de factor G de Cattell, y hábitos del consumo de sal. RESULTADOS: El consumo de sal promedio persona/día fue de 18,13 g. El 37,9% presentó bocio. 36,1% tenían un valor límite en el cociente intelectual. La mediana de yoduria fue de 510,3 μg/L. El 42,75% tuvo anti-TPO positivos, y el 2,87% anti-Tg positivos. El 10% presentó niveles de TSH elevados. CONCLUSIÓN: En escolares de zona urbana, hay un exceso en la mediana de yoduria, pudiendo explicarse por el alto consumo de sal. La alta prevalencia de autoinmunidad tiroidea y bocio, junto al alto nivel de la TSH, puede ser consecuencia del exceso en la ingesta de sal y de otros factores medioambientales/ hereditarios.

  14. El lenguaje del pensamiento

    Directory of Open Access Journals (Sweden)

    Alberto Andreu Marín

    2017-09-01

    Full Text Available ¿Somos capaces de interpretar las señales eléctricas que genera nuestro cerebro cuando estamos pensando? Lo que a priori parece ciencia ficción comienza a ser factible gracias a los avances recientes en técnicas de registro cerebral y en aprendizaje automático. Nos encontramos en el inicio de una nueva era en lo que al conocimiento del cerebro se refiere.

  15. Fundamentos del saber administrativo

    OpenAIRE

    Paola Podestá Correa; Juan Carlos Jurado Jurado

    2005-01-01

    El presente texto tiene por objetivo delimitar, de manera general, algunos de los conceptos más importantes del saber administrativo; en primera instancia, práctica administrativa y saber administrativo. Estos conceptos están ligados con los que en el texto se denominan fundamentos de la administración, estableciendo consensos sobre algunas expresiones comunes en el lenguaje administrativo, y contribuyendo a la comprensión de estos temas para los estudiantes de los primeros niv...

  16. Carta del Editor

    Directory of Open Access Journals (Sweden)

    Jorge Aguirre

    2015-01-01

    Full Text Available La crisis de la prensa Argentina a efecto del mal manejo de la economía y las finanzas, ocupa el tema central. Pasa revista a tres temas de actualidad: El aumento de cobertura y difusión de la prensa gratuita; los esfuerzos de los "viejos" diarios por cambiar de apariencia y el caso del diario estadounidense TODAY que hace veinte años dio un cambio revolucionario en la forma de hacer periodismo diario. Se analizan también temas como: el "carisma" de los líderes actuales, los acuerdos entre los medios de comunicación y el gobierno de México para la difusión de planes y programas oficiales y el rol de los medios en el proceso de establecimiento del ALCA. Agrega el tema controversial sobre la Ley de radiodifusión privada, vigente desde la época de la dictadura pinochetista. En este mismo campo de la Radio otro artículo señala las normas para "contar las noticias" con impacto e interés.

  17. Carta del Editor

    Directory of Open Access Journals (Sweden)

    Jorge Mantilla Jarrín

    2015-01-01

    Full Text Available En este número, el módulo Dibujos Animados, recoge las experiencias del primer curso realizado por el CIESPAL con apoyo de la UNICEF sobre la producción de programas educativos y culturales que utilizan este recurso como una opción comunicacional. Se trata de nuevas tecnologías aprovechadas en Cuba y que pueden ser aplicadas en nuestros países. El módulo relativo al medio ambiente habla del periodismo ecológico con importante desarrollo en América Latina, tema de actualidad que requiere preocupación por parte de los medios de comunicación. Incluye entrevistas a Gunter Grass y Jesús Polanco. Gabriel Alba adentra a los lectores en una novedosa forma de usar las computadoras. En el módulo Debate se trata la Economía, cultura y comunicación; La publicidad vía televisión, La evolución del merchandising en las novelas brasileñas ¿Exigir Ética solo al periodista?

  18. Los felinos del canciller

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    Marco Palacios

    1988-01-01

    Full Text Available En la introducción a una de las obras más influyentes de la historiografía colombiana de nuestros tiempos, el autor, Luis Ospina Vásquez, advierte ciertas dificultades inherentes al oficio de historiar la economía: "Otros aspectos del tema son difíciles de tratar por otros motivos: no se puede citar, entre las causas del difícil adelanto económico de cierta región nuestra, llamada por la generosidad de la naturaleza a una gran riqueza; el hecho de que en ella la política se haya reducido con frecuencia a una pugna entre grupos de hampones[...] Y en el supuesto de que se pudiera dar tratamiento adecuado a lo que, al fin y al cabo, es cosa tangible, no muy difícil de percibir y de describir, faltaría aun dar entrada a un elemento sumamente importante, pero este sí difícil de captar y de transmitir: la 'atmósfera', las 'atmósferas' sucesivas del país y sus regiones, elemento esencial en la historia de la evolución económica.

  19. El Museo del Oro

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    Efraín Sánchez Cabra

    2003-09-01

    Full Text Available El 22 de diciembre de 1939 el Banco de la República compró un objeto de oro de 777,7 gramos de peso y 23,5 centímetros de altura que dio origen al Museo del Oro. Era un poporo quimbaya, pieza maestra de la orfebrería prehispánica. Un objeto bello bello que levanta su bruñido vientre globular y su cuello coronado por cuatro cuerpos esféricos sobre una exquisita base de filigrana fundida, y parece flotar en un espacio propio. Quien lo contempla no puede menos que asombrarse, deleitarse y sentir admiración por sus artífices. Detrás de la compra del poporo había una clara preocupación oficial por proteger una riqueza que comenzaba a entenderse como parte del patrimonio nacional. Esta motivación se pone de manifiesto en una serie de documentos relativos a su adquisición.

  20. Llanto del adulto

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    Alegría Majluf

    2013-09-01

    Full Text Available Se presentan los resultados de un primer estudio transcultural del llanto del adulto que comprende 30 países, entre los que se encuentra el Perú. Vingerhoets et al. (1997 de la Universidad de Tilburg, Holanda, analizan las causas, tendencia y frecuencia del llanto, emociones y sentimientos que inducen al llanto, diferencias y similitudes entre los países y los sexos. Los autores encuentran que las mujeres tienden a llorar con más frecuencia e intensidad que los varones, advirtiendo que en algunos países las mujeres establecen mayor relación entre la tendencia al llanto y el ciclo menstrual que en otros. The results of a first cross-cultural study on adult crying in 30 countries including Peru are presented. Vingerhoets et al. (1997 from the University of Tilburg have analyzed motives, tendencies and frequency of crying, emotions and feelings that provoke crying, as well as differences and similarities among countries and sexes. Results show that women have a tendency to cry more frequently and intensively than men. It has also been noted that, in certain countries, there is a link between crying in women and their monthly period.

  1. Carta del Editor

    Directory of Open Access Journals (Sweden)

    Luis Eladio Proaño

    2015-01-01

    Full Text Available Artículo de fondo es un ejemplo de una campaña exitosa de Relaciones Públicas realizada para rescatar a Medellín para el turismo, ahora herida de muerte por el narcotráfico. Reinicia el tema sobre el cine, recordando el aniversario del nacimiento de Luis Buñuel. Y sobre el Nuevo Orden Internacional de la Información, Luis Ramiro Beltrán da respuesta a las múltiples interrogantes planteadas en la controversia surgida alrededor del tema. Se da a conocer cómo era el periódico de ayer, de hoy y del futuro frente al desafío de las nuevas tecnologías. Se señala el camino para hacer publicidad en Internet. El Internet y la radio nuevos actores para un mismo mercado. Y para los interesados en la investigación se trata cómo y cuándo hacer sondeos flash y se cierra con el lenguaje periodístico cuándo el dequeísmo es lícito.

  2. comportamiento del consumidor

    Directory of Open Access Journals (Sweden)

    Erico Rentería Pérez

    2006-01-01

    Full Text Available En este artículo se analiza el posicionamiento exitoso de los profesionales, particularmente los jóvenes, a partir de las nuevas realidades del mundo y del mercado laboral, así como la empleabilidad como constructo, estrategias posibles y, finalmente, una discusión sobre falacias y realidades de discursos sobre mercado de trabajo profesional. La reflexión se liga a dos investigaciones, y a redes de discusión en Brasil y Colombia, que reflexionan sobre las implicaciones y requerimientos estratégicos que marcan el ingreso o permanencia en el mercado de trabajo de profesionales jóvenes, y se reconoce que esto afecta a otros tipos de profesionales. La investigación de Rentería (2006ª sobre Empleabilidad arroja información sobre las dos primeras partes. La de Enríquez y Rentería (2006 sobre Estrategias de aprendizaje y empleabilidad informa sobre la tercera. Apoyan la discusión elementos de psicología y comportamiento del consumidor. Se discute la inclusión social y calidad de vida por el trabajo.

  3. Carta del Editor

    Directory of Open Access Journals (Sweden)

    Luis Eladio Proaño

    2015-01-01

    Full Text Available Abre la revista una retrospectiva de la crisis económica, política y social en la que se precipitó Argentina (2001-2002 y el tratamiento que dieron los medios a esta situación. En opinión se describe el significado de los nuevos paradigmas de Internet como: interactividad, personalidad, multimedialidad, hipertextualidad, actualización, abundancia y mediación. Responde a la cuestión de ¿cómo y cuándo en la prensa latinoamericana sigue imperando la prensa amarilla? Recoge en un artículo los factores que más inciden en el éxito o fracaso de una campaña política. Aborda la implantación de una nueva moneda única en la Unión Europea y sus incidencias. Destaca las consecuencias vividas por México tras el ataque terrorista del 11 de septiembre 2001 y analiza el tratamiento que los medios dan a las informaciones procedentes del Tercer Mundo en Europa. Contesta a la pregunta inquietante sobre las posibilidades del liberalismo económico para garantizar o contrarrestar la libertad de prensa y por último se aclara los mitos y realidades que se han tejido alrededor de Windows XP de Microsoft.

  4. Inestabilidad compleja del codo

    Directory of Open Access Journals (Sweden)

    Héctor Gabriel Díaz Carrillo

    2014-08-01

    Full Text Available La inestabilidad compleja del codo es de reciente descripción y controversial en sus resultados; es el estado que se deriva del daño estructural y funcional, producido por la incongruencia de las superficies articulares y las estructuras ligamentosas que estabilizan el codo. Se realizó un estudio descriptivo prospectivo, en el período comprendido entre enero de 2011 y abril de 2013, en una muestra no probabilística de ocho pacientes (diez codos, seleccionados según criterios de inclusión y exclusión. Los objetivos fundamentales del estudio fueron: la actualización de conocimientos para el manejo de la enfermedad y la caracterización de los resultados obtenidos en los afectados por esta dolencia que fueron operados en el Hospital Dr. Ernesto Guevara de la Serna de la provincia de Las Tunas. Se analizaron los datos mediante técnicas estadísticas descriptivas y se realizó la evaluación clínica y radiográfica de los lesionados. El tratamiento se ejecutó según los hallazgos y consistió en: reparación ligamentosa, actuación sobre las partes óseas dañadas y colocación de osteosíntesis diversas. La edad promedio fue de 39,2 años y predominó el sexo masculino. A todos se les practicó reparación ligamentosa, siete cupulectomías y seis aplicaciones de cerclajes anti-distractores. Existieron dos reluxaciones y una sepsis local. La amplitud de movimientos fue aceptable dentro del rango compatible, con una buena función ergonómica; de acuerdo a las comparaciones bibliográficas actualizadas que se realizaron. La fijación y reparación de los estabilizadores del codo brindan buenos resultados funcionales. La sistematización en el manejo de la enfermedad, la detección de complicaciones y el arsenal terapéutico disponible son factores a tener en cuenta

  5. Nuevos usos del cemento

    Directory of Open Access Journals (Sweden)

    Páez Balaca, A.

    1977-04-01

    Full Text Available In this article, the evolution of the different systems of transporting and storing submarine oil and its by-products (petroleum gas and natural gas, is dealt with stressing the importance of the use of concrete boats. Due to the high cost of oil pipelines, we have passed from tanks built on land to prestressed concrete tanks which can be berthed at great depths or anchored to the bottom to keep them afloat, it being possible to unmoor them for transferring them. Transporting and storing liquated gas leads US to see the advantages of prestressed concrete over steel, as the latter becomes brittle at low temperatures, whereas the former's strength increases. The different forms and possible sections are analyzed, stressing the great importance of the solution of the double concrete hull with pearlite insulation. Finally, a study is made of «light concretes », not the classical types used as thermal and acoustic insulation, but the semi-heavy ones made with expanded clay, high quality sand and P-450 cement, which technique is not yet as developed in Spain at might be wished.En este artículo se trata la evolución de los distintos sistemas de transporte y almacenamiento del petróleo submarino y sus derivados (gas de petróleo y gas natural, resaltando la importancia del uso de barcos de hormigón. Debido al gran coste de los oleoductos, se ha pasado de los tanques construidos en tierra firme a los depósitos de hormigón pretensado que pueden estar fondeados a gran profundidad o anclados al fondo para mantenerlos flotantes, existiendo la posibilidad de poder desamarrarlos para su traslado. El transporte y almacenamiento del gas licuado nos hace ver las ventajas del hormigón pretensado sobre el acero, pues éste se vuelve quebradizo a bajas temperaturas, mientras aquél aumenta su resistencia. Se analizan las diferentes formas y secciones posibles, destacando la gran importancia de la solución del doble casco de hormigón con

  6. Enfermedad Diverticular del Colon

    Directory of Open Access Journals (Sweden)

    Gonzalo López Escobar

    1991-06-01

    Full Text Available

    Los divertículos del colon han sido reconocidos por varios observadores desde hace más de un siglo, pero en su mayor parte se trataba de casos aislados, hoy se la considera como la enfermedad del siglo XX, la de la era moderna y de los países industrializados y de avanzada tecnología (5,18,33.

    Según el diccionario de la Real Academia Española (11, divertículo, del latín, diverticulum, quiere decir desviación de un camino; y desde el punto de vista anatómico, apéndice hueco y terminado en fondo de saco. (Gráfica No. 1.

    Goligher (17 lo define como la “posada al borde del camino, probablemente un lugar, a menudo, de mala reputación”.

    Historia

    Según Hackford (18, el proceso fué descrito brevemente por Littre a comienzos del siglo XVIII; pero se le atribuye a Cruveilhier la primera descripción como proceso patológico en 1849, quien, además, mencionó: “encontramos, no rara vez, en el sigmoide, entre las bandas de fibras musculares longitudinales, una serie de pequeños tumores piriformes oscuros, que están formados por hernias de la mucosa a través de brechas en la capa muscular” (17.

    Fleischman en 1815 hizo la primera observación de la enfermedad y empleó el término divertículo (45.

    Rokitansky en 1.849, habló de una enfermedad adquirida y consideró que su causa consistía en la constipación (45.

    Virchowen 1853 describió la perisigmoiditis (45.

    En 1859 Sidney Jones informó de una fístula colo-vesical debida a diverticulitis (5,45.

    Loomis en 1870 describe una peritonitis como resultante de una diverticulitis (45.

    En 1877 Ball describió la anatomía patológica de la enfermedad y presentó dos casos de fístula colovesical debidas a diverticulitis (9. Cripps en 1.888 popularizó la colostomía de desviación como tratamiento para la fístula colovesical(18...

  7. Max Weber o el enigma emocional del origen del capitalismo

    OpenAIRE

    EDUARDO BERICAT ALASTUEY

    2001-01-01

    Se analiza el trabajo clave de Max Weber, La ética protestante y el espíritu del capitalismo, desde la perspectiva de la Sociología de las Emociones. Aunque la inclusión de las emociones de los fenómenos sociales es clave para entender la idea de Weber sobre el dogma de la predestinación, los sociólogos han trivializado el papel de la emoción. Tras detallar la creencia de Weber en que el espíritu del capitalismo parte del conocimiento de que el destino del hombre está predeterminado (la ética...

  8. Sobre el significado del descubrimiento del gen FOXP2

    OpenAIRE

    Longa Martínez, Víctor Manuel

    2006-01-01

    El reciente descubrimiento del gen FOXP2 ha ofrecido la primera evidencia clara de la base genética del lenguaje, mostrando una correlación inequívoca desde la perspectiva genética entre una versión mutada de F0XP2 y los trastornos lingüísticos de diferente tipo sufridos por una familia inglesa, conocida como KE. El objetivo central del presente trabajo es discutir diferentes aspectos relacionados con tal descubrimiento; especialmente, la discusión del significado de FOXP2 con ...

  9. Competitividad sectorial internacional. Caso: sector del cuero y del calzado

    Directory of Open Access Journals (Sweden)

    Diana Carolina Villegas Álvarez

    2007-01-01

    Full Text Available El presente escrito se origina en un trabajo de investigación cuya pretensión fue indagar sobre el nivel de competitividad internacional (C.I, del sector del cuero y del calzado colombiano, mediante la aplicación de indicadores que, a partir de la información estadística de las variables de comercio exterior permiten establecer ciertas relaciones que dan cuenta de la importancia del producto en los mercados de los países de la Comunidad Andina de Naciones (CAN, seleccionados para la comparación.

  10. The mitochondrial genomes of Nuttalliella namaqua (Ixodoidea: Nuttalliellidae and Argas africolumbae (Ixodoidae: Argasidae: estimation of divergence dates for the major tick lineages and reconstruction of ancestral blood-feeding characters.

    Directory of Open Access Journals (Sweden)

    Ben J Mans

    Full Text Available Ixodida are composed of hard (Ixodidae, soft (Argasidae and the monotypic Nuttalliellidae (Nuttalliella namaqua tick families. Nuclear 18S rRNA analysis suggested that N. namaqua was the closest extant relative to the last common ancestral tick lineage. The mitochondrial genomes of N. namaqua and Argas africolumbae were determined using next generation sequencing and de novo assembly to investigate this further. The latter was included since previous estimates on the divergence times of argasids lacked data for this major genus. Mitochondrial gene order for both was identical to that of the Argasidae and Prostriata. Bayesian analysis of the COI, Cytb, ND1, ND2 and ND4 genes confirmed the monophyly of ticks, the basal position of N. namaqua to the other tick families and the accepted systematic relationships of the other tick genera. Molecular clock estimates were derived for the divergence of the major tick lineages and supported previous estimates on the origins of ticks in the Carboniferous. N. namaqua larvae fed successfully on lizards and mice in a prolonged manner similar to many argasids and all ixodids. Excess blood meal-derived water was secreted via the salivary glands, similar to ixodids. We propose that this prolonged larval feeding style eventually gave rise to the long feeding periods that typify the single larval, nymphal and adult stages of ixodid ticks and the associated secretion of water via the salivary glands. Ancestral reconstruction of characters involved in blood-feeding indicates that most of the characteristics unique to either hard or soft tick families were present in the ancestral tick lineage.

  11. Molecular phylogenetic reconstruction and localization of the (TTAGG)n telomeric repeats in the chromosomes of Acromyrmex striatus (Roger, 1863) suggests a lower ancestral karyotype for leafcutter ants (Hymenoptera).

    Science.gov (United States)

    Pereira, Tássia Tatiane Pontes; Dos Reis, Ana Caroline Coelho Corrêa; Cardoso, Danon Clemes; Cristiano, Maykon Passos

    2018-01-01

    Chromosome counts and karyotype characterization have proved to be important features of a genome. Chromosome changes during the diversification of ants might play an important role, given the diversity and success of Formicidae. Comparative karyotype analyses on ants have enriched and helped ant systematics. Among leafcutter ants, two major chromosome counts have been described, one frequent in Atta Fabricius, 1804 (2n = 22 in all Atta spp. whose karyotype is known) and the other frequent in Acromyrmex Mayr, 1865 (2n = 38 in the majority of species whose karyotype is known). The main exception is Acromyrmex striatus (Roger, 1863), which harbors a diploid chromosome set of 22. Here we describe the use of fluorescence in situ hybridization (FISH) with telomeric probes with (TTAGG) 6 repeats to describe the telomere composition of A. striatus and to recover potential interstitial non-telomeric signals that may reflect fusion events during the evolution of leafcutter lineage from 38 to 22 chromosomes. Further, we reconstruct the ancestral chromosome numbers of the leafcutter clade based on a recently proposed molecular phylogenetic hypothesis and phylogenomic tree. Distinct signals have been observed in both extremities on the telomere chromosomes of A. striatus . Non-telomeric signals have not been retrieved in our analysis. It could be supposed that the low-numbered karyotype indeed represents the ancestral chromosome number of leafcutters. The phylogenetic reconstruction also recovered a low chromosome number from the diverse approaches implemented, suggesting that n = 11 is the most likely ancestral karyotype of the leafcutter ants and is a plesiomorphic feature shared between A. striatus and Atta spp.

  12. Aplicación de las pruebas estadísticas de discordancia y significancia en la comparación del vulcanismo dacítico de la parte central de Cinturón Volcánico Mexicano

    Directory of Open Access Journals (Sweden)

    Lorena Díaz-González

    2013-01-01

    Full Text Available Nuestro objetivo es presentar una metodología estadística, junto con dos nuevos programas (DODESSYS y UDASYS. Para esta tarea compilamos una base de datos de 249 muestras de rocas dacitas provenientes de cuatro regiones del cinturón volcánico mexicano (MVB: volcanes monogenéticos de la Sierra de Chichinautzin y el Valle de México, estratovolcán Nevado de Toluca, estratovolcán Iztaccíhuatl y estratovolcán Popocatépetl. Las pruebas estadísticas de discordancia y significancia (ANOVA –ANalysis Of Variance–, F de Fisher y t de Student fueron aplicadas al 99% de nivel de confianza. Se calculó la estadística final para 98 parámetros, incluyendo óxidos mayores, elementos de tierras raras, elementos traza y parámetros adicionales, tales como parámetros de relaciones logarítmicas usados en nuevos diagramas de discriminación tectónica. Estos parámetros fueron tratados como muestras estadísticas univariadas y fueron clasificados en cuatro regiones del MVB. Las pruebas estadísticas de discordancia detectaron datos discordantes en 124 (aproximadamente en el 35% muestras estadísticas univariadas. La prueba ANOVA mostró diferencias significativas entre todos los grupos en 32 parámetros. Las similitudes y diferencias entre los parámetros de relaciones logarítmicas pueden ser útiles en el futuro para proponer diagramas de discriminación tectónica a partir de una base de datos representativa.

  13. Jugadores de pelota maya en tiempos del oxlajuj b’ak’tún

    Directory of Open Access Journals (Sweden)

    Jairzinho Francisco Panqueba Cifuentes

    2012-12-01

    Full Text Available La presente reflexión hace parte de un proceso investigativo cuyo objeto ha sido la práctica contemporánea del juego de pelota maya en Guatemala. Es un acercamiento analítico a los testimonios de vida recabados a través de la metodología de investigación-aprehendizaje compartida con los actores del proceso. Sus trayectorias vitales nos permiten comprender en descripciones y acciones, los detalles contemporáneos de una manifestación cultural, lúdica y recreativa ancestral. Pero también de qué maneras el juego de pelota mesoamericano es fuente de conocimientos de los patrimonios corporales hasta ahora difusos entre discursos relacionados con el folclor, las etnicidades, las artes, el deporte, la cultura, las espiritualidades y en general con ciencias como la historia, la antropología y la arqueología. Las vidas cotidianas de los actuales jugadores de pelota ayudan a comprender una parte de las sabidurías ancestrales mayas. Se integran, por tanto, a los testimonios de las herencias inmateriales arqueológicas representadas en los campos de juego de pelota diseminados por Mesoamérica.

  14. Prevalencia de Caries Dental en una Comunidad Escolar de la Etnia Wayúu, en la Guajira Colombiana y su Manejo con Medicina Ancestral.

    Directory of Open Access Journals (Sweden)

    Hector Ángel Polanco Narvaéz

    2012-03-01

    Full Text Available Objetivo: Establecer la prevalencia de caries dental y su manejo terapéutico tradicional en la población indígena wayuu de la Guajira colombiana. Materiales y métodos: Se realizó un examen oral a 245 niños en edad escolar que asisten a la concentración escolar Camino Verde del Municipio de Manaure en la Guajira Colombiana; mediante entrevistas semiestructuradas con la población, se hizo reconocimiento de las plantas que son utilizadas para tratar los problemas de salud oral. Se analizo e interpretó el concepto de la salud bucal, en una comunidad que resalta la importancia del equilibrio con la naturaleza; los recursos que utilizan para preservar una adecuada higiene oral, la interacción de la naturaleza con su cuerpo para mantener un equilibrio con la vida. Resultados: Los indices Ceo-d y CPO-D en comparacion con el estudio del ENSAB III, mostraron un aumento de la prevalencia de caries; solo los niños de 5 años presentan  un promedio de caries mas bajo en comparacion con los resultados de este estudio. De otra parte, el tratamiento y prevencion de las patologias de cavidad oral siguen siendo tratadas bajo la medicina tradicional indigena, aunque la medicina occidental ya hace parte de la terapeutica de la poblacion. Conclusiones: Los resultados sugieren trabajar mas en la promocion de la salud oral, para asi bajar los indices de caries; Por otro lado, La medicina tradicional indigena aunque importante, no refleja sus efectos, ademas de observar que la medicina occidental ha tenido gran acogida y cada vez su uso es mayor.

  15. Petrological evolution of subducted rodingite from seafloor metamorphism to dehydration of enclosing antigorite-serpentinite (Cerro del Almirez massif, southern Spain)

    Science.gov (United States)

    Laborda-López, Casto; López Sánchez-Vizcaíno, Vicente; Marchesi, Claudio; Gómez-Pugnaire, María Teresa; Garrido, Carlos J.; Jabaloy-Sánchez, Antonio; Padrón-Navarta, José Alberto

    2016-04-01

    . Close to the contact with the blackwall, antigorite-serpentinite is very rich in diopside, olivine and Ti-clinohumite. In this study we present a thermodynamic model of phase relationships in rodingites and transitional blackwalls during their metamorphic history. We mainly aim to establish the evolution of P-T conditions experienced by metarodingites during subduction and the influence of fluids in the formation of mineral assemblages at different metamorphic stages. REFERENCES Padrón-Navarta, J.A., López Sánchez-Vizcaíno, V., Garrido, C.J., Gómez-Pugnaire, M.T., (2011): Metamorphic record of high-pressure dehydration of antigorite serpentinite to chlorite harzburgite in a subduction setting (Cerro Del Almirez, Nevado-Filábride Complex, Southern Spain). Journal of Petrology, 52, 2047-2078.

  16. La impronta del nuevo mundo

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    Rodrigo Lagos Vergara

    1992-05-01

    Full Text Available Cuando nos aprontamos a conmemorar el quinto centenario del Nuevo Mundo, cabe hacer algunas reflexiones acerca de nuestro continente a la luz del lenguaje propio de las artes y la arquitectura a través del tiempo. Hablamos del Nuevo Mundo en la medida que aceptamos, por una parte, la concepción del nuevo espacio generado a partir del encuentro de dos culturas, la precolombina americana y la propiamente europea llegada principalmente a través de España, y, por otra parte, aceptando también que el nuevo continente resulta ser la pieza clave que ayuda definitivamente a configurar un nuevo cosmos que revela al mundo su otro extremo y aquella parte que manifiesta la totalidad en la certeza de que la tierra es un planeta.

  17. Efectos colaterales del voto preferente

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    Luis Diego Brenes Villalobos

    2012-07-01

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

  18. El movimiento del software libre

    OpenAIRE

    Prudencio Óscar Mochi Alemán

    2002-01-01

    El objetivo de este trabajo es describir el surgimiento y desarrollo del movimiento de software libre. Para ello se analizan algunas características importantes que dan cuenta del origen y desarrollo del mismo, así como de sus momentos más críticos y sus tensiones, sus desafíos y sus retos. Otra de las grandes inquietudes de este trabajo, es intentar descifrar cómo el movimiento del software libre y Linux, en su versión más conocida, sobrevivieron y se afirmaron hasta llegar a ...

  19. Analisi del decadimento $W -> \\tau \

    CERN Document Server

    Coscetti, Simone

    Questo lavoro di tesi si e' svolto nell'ambito dell'esperimento CMS a LHC, ed in particolare verte sullo studio delle strategie di identificazione off-line del leptone tau, atteso tra i prodotti di decadimento del bosone di Higgs, cosi' come di altre particelle previste in altri modelli teorici. Il canale utilizzato per testare la procedura di identificazione del tau e' il decadimento semileptonico del bosone vettore W. Infine, sulla base dei risultati ottenuti viene presentata una stima quantitativa della sezione d'urto di produzione pp-> W + X

  20. El pie del adulto mayor