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Sample records for bajas cuboidales utilizando

  1. PLANEAMIENTO DE REDES DE BAJA TENSIÓN, UTILIZANDO UN MODELO TRIFÁSICO

    Directory of Open Access Journals (Sweden)

    Julián Mauricio Londoño Posso

    2011-01-01

    Full Text Available En este artículo, se presenta una metodología para resolver el problema de la expansión del sistema de distribución de baja tensión. Para solucionar este problema, se elabora un modelo trifásico con los diferentes costos operativos y de diseño que incluyen el efecto del desequilibrio, reubicación y repotenciación de elementos existentes, y localización y dimensionamiento de elementos nuevos. Como costos operativos, se consideran las pérdidas de energía en fases y neutros de conductores. Para resolver el modelo, se usa el algoritmo genético de Chu-Beasley. La metodología fue probada, usando un sistema de 54 nodos y 57 líneas propuestas y analizado bajo condiciones de equilibrio y desequilibrio. Los resultados obtenidos son de buena calidad porque presentan un bajo nivel de pérdidas como resultado de una efectiva localización de transformadores, una adecuada selección del calibre de conductores y un buen equilibrio de fases.

  2. Optimization of air conditioning systems utilizing low temperature thermal storage; Optimizacion de sistemas de acondicionamiento de aire utilizando sistemas de almacenamiento termico de baja temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Contreras Ramirez, J.; Dorantes Rodriguez, R. [Departamento de Energia, Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D. F. (Mexico)

    1997-12-31

    sistemas esta relacionado con la variabilidad de la carga termica y las posibilidades de regulacion de la o las maquinas termicas, de tal manera de lograr, a lo largo del dia, un adecuado uso y optimizacion de la carga total instalada, con los mejores beneficios economicos posibles. Entre las estrategias que permiten optimizar la capacidad de la instalacion y la variacion de la carga termica esta el almacenamiento termico de baja temperatura, por ejemplo, el almacenamiento de hielo, el cual se produce y se almacena durante las horas en que normalmente las maquinas de refrigeracion estan paradas, y con el fin de usar esta energia almacenada durante el horario pico y durante las horas de operacion normal del equipo, pero disminuyendo en forma importante la demanda electrica de la instalacion al satisfacer la carga termica con una combinacion almacen termico-maquina de refrigeracion. En este trabajo se presentan algunos antecedentes y tipos de almacenes termicos utilizados comunmente, se discute una metodologia que permite dimensionar un almacen termico, tanto tecnica como economicamente, y se plantean algunos de los problemas en el control y operacion de estos sistemas termicos.

  3. Baja loggerhead

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Pacific Coast of the Baja California Peninsula (BCP), Mexico, is a hotspot for foraging loggerhead turtles Caretta caretta originating from nesting beaches in...

  4. Los vidrios de baja emisividad

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    Olivares Santiago, Manuel

    1994-12-01

    Full Text Available The use of low-emittance coating (low-E glasses in Europe and the United States is not recent (they make use of them long since: 10-15years, nevertheless they are almost unknown in Spain, in all respects, in spite of being commercialized long since by different houses, specialists in these matters. We run into a lack of regulation about the qualities and stipulations these elements must comply with, since the regulations governing the thermal insulation of the buildings (CT-79 refers to the generic and peculiar qualities of the glazed openings, but these regulations do not approach the question of the real behaviour of the glazed openings with low-emittance glasses and other semi-transparent elements. The expenditure of energy and the lighting characteristics of the openings are not yet unforeseen, so far. These properties undergo a variation with regard to the base-glass or the support, due to the low-emittance coating. The article is organized in to three parts. The first part is the analysis of the functional characteristics and the lighting properties of the glasses from a general point of view. The second one explains what low-emittance glasses are, and the way of obtaining them (very briefly; according to the kind of process of obtaining the low-emission coating, the proceedings of low-emission glasses are gradually limited. Finally, the third part deals with the thermic characteristics of whole glazing, and specially with the glazed openings, from the point of view of a functional consistency for both glass and joinery.

    Aunque en Europa y EEUU el uso de los vidrios de baja emisividad no es reciente (se llevan utilizando unos 10-15 años, en España son prácticamente desconocidos desde el punto de vista teórico y práctico, a pesar de estar comercializándose desde hace varios años por las casas especializadas. Nos encontramos con un vacío normativo sobre las condiciones que han de cumplir, ya que la norma de

  5. Compensación de la potencia reactiva en sistemas de baja tensión mediante bancos de capacitores fijos, utilizando algoritmos genéticos; Reactive compensation in low voltaje power systems with fixed capaciyors banks using genetic algorithms

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    Davel Borges Vasconcellos

    2011-05-01

    Full Text Available Una óptima selección de estos, presupone tres aspectos: la selección de la capacidad de los bancos, el tipo de compensador a utilizar, así como la ubicación en el sistema eléctrico de baja tensión Existen referencias de métodos que consideran los tres aspectos de manera conjunta, basados en la programación matemática, pero estos presentan limitantes dado que no pueden representar todos los efectos de la compensación y se basan en técnicas de programación continua, siendo este un problema de optimización complejo de espacio de búsqueda discreto.En tal sentido, hemos desarrollado un método con el empleo de los algoritmos genéticos que posibilita una formulación más exacta del problema. El método ha sido programado con ayuda del MATLAB, versión 7.5 (R2007b, utilizando las estructuras de programación de Genetic Algorithm and Direct Search Toolbox. La efectividad del mismo se muestra en un ejemplo real de aplicación al sistema eléctrico de baja tensión de una instalación hotelera del Grupo Cubanacan de la provincia de Camagüey.  A good selection of these, presupposes three aspects: the selection of the banks capacity, the compensador type to use, as well as the location in the low voltage system.References of methods that consider the three aspects in a same problem are based on the mathematical programming, but these cannot represent all the effects of the compensation and these based in technical of continuous programming, being this a complex optimization problem of discreet search space.In the paper, we have developed a method with the employment of the genetic algorithms, which facilitates a more exact problem formulation. The method has been programmed in MATLAB, version 7.5 (R2007b, using programming structures of Genetic Algorithm and Direct Search Toolbox.The effectiveness is shown in an example of real application to the low voltage system of a hotel installation of the Cubanacan Company in Camagüey.

  6. Measurement of soil aggregate stability using low intensity ultrasonic vibration Medición de la estabilidad de agregados de suelo utilizando vibración ultrasónica de baja intensidad Medição da estabilidade dos agregados do solo por vibração ultrasónica de baixa intensidade

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    Herwig Mayer

    2011-11-01

    del laboreo sobre la estabilidad de los agregados del suelo (soil aggregate stability – SAS utilizando un método de dispersión ultrasónica con diferentes niveles de energía. Se hicieron ensayos con un equipo de dispersión ultrasónica desarrollado en la Universidad de Ciencias de Recursos Naturales y de la Vida (Viena. Este equipo facilita la aplicación de amplitudes de baja vibración, de 0.5 µm, 2 µm y 5 µm. La potencia ultrasónica determinada por un método de balance de energía es de 0.7 W, 8.9 W y 22.3 W para cada amplitud. Se tomaron muestras de agregados de 2 000 a 250 µm, en tres tipos de suelo del este de Austria: un suelo del tipo Chernozem franco limoso degradado, un Cambisol franco arcilloso y un Cambisol franco arenoso, y sometidos a diferentes tipos de laboreo: laboreo convencional (CT – conventional tillage, laboreo con eliminación mecánica de malas hierbas y sin laboreo (NT – no tillage, con siembra intercalada en invierno. Los resultados de la estabilidad de los agregados del suelo obtenidos según la norma DIN (Deutsches Institut für Normung mostraron que la estabilidad disminuía en el siguiente orden: Cambisol franco arcilloso > Cambisol franco arenoso > Chernozem franco limoso. La influencia del tipo de laboreo se observó en el segundo y tercer tipo de los suelos mencionados. La dispersión ultrasónica por amplitudes de baja vibración mostró una estabilidad más alta en suelos del tipo Cambisol. Se observó una influencia significativa del tipo de laboreo sobre la estabilidad de los agregados del suelo (entre 1 y 1.7 J ml-1 en el Cambisol franco arcilloso y el Chernozem degradado, resultando una disminución de la estabilidad de los agregados en el orden siguiente: Cambisol NT > Cambisol CT > Chernozem NT > Chernozem CT. No se observaron diferencias en el Cambisol franco arenoso, porque el nivel de agregación de los macroagregados fue demasiado débil. Este trabajo destaca la importancia de cuantificar la energ

  7. Baja California: literatura y frontera

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    Gabriel Trujillo Muñoz

    2014-06-01

    Baja California is a region that not only has migration problems and criminal violence because of the war of drugs or is a space of border conflicts in close neighborhood with the United States of America. Baja California is too a geographic space of culture and art, of creative writing and struggle to narrate the things and persons that here live, a plain sight, like their house, like their home, like a center of creation. This text give a cultural context of the border literature in the north of Mexico like a phenomenon in notice because his own merits, books and writers.

  8. Determinantes del Embarazo en Adolescentes en la Población Atendida en el Centro de Salud Ancieta Baja, año 2014

    OpenAIRE

    Huaranga Angulo, Lucero

    2015-01-01

    Objetivo: Establecer los determinantes del embarazo en adolescentes atendidas en el Centro de Salud Ancieta Baja, año 2014. Materiales y Métodos: Se realizó un estudio observacional, retrospectivo, de corte transversal con diseño caso-control. Se encuestó a las gestantes adolescentes que acuden para ser atendidas en el Centro de Salud Ancieta Baja. Se empleó la técnica de encuesta validada, luego del cual se recolectaron los datos y fueron procesados utilizando el programa SPSS Versión 22, pr...

  9. California-Baja California border master plan - plan maestro fronterizo California-Baja California : technical appendix.

    Science.gov (United States)

    2008-09-01

    Under the direction of the U.S. / Mexico Joint Working Committee, the California Department of : Transportation (Caltrans) and the State of Baja Californias Secretariat of Infrastructure and Urban : Development (SIDUE) hereby establish the Califor...

  10. Hurricane Linda Off the Baja Coast

    Science.gov (United States)

    1999-01-01

    This Quick Time movie captures Hurricane Linda moving off the Baja California coast in September 1997. The strongest hurricane on record for the eastern Pacific at that time, Hurricane Linda invaded Southern California with winds that had gusted to 105 mph (174 kph). While off the coast of Mexico, her winds gusted up to 220 mph (354 kph). Earth science and weather studies are an important ongoing function of NASA and its affiliates.

  11. Contrasted fossil spreading centers off Baja California

    Science.gov (United States)

    Dyment, J.; Michaud, F.; Royer, J. Y.; Bourgois, J.; Sichler, B.; Bandy, W.; Mortera, C.; Sosson, M.; Pontoise, B.; Calmus, T.

    2003-04-01

    In April 2002, R/V L Atalante collected swath-bathymetry, surface and deep tow magnetic, gravity and seismic data in order to investigate the existence, characteristics and age of the Guadalupe and Magdalena fossil spreading centers that were postulated off Baja California (eastern Pacific Ocean). The new data confirm the existence of these extinct spreading centers and better define the location and orientation of the Magdalena Ridge segments. The two fossil ridges exhibit very different characters. The Guadalupe fossil axis displays a deep N-S axial valley with a 2D geometry, and regular abyssal hills and magnetic anomalies on its flanks. According to surface and deep tow magnetics, seafloor spreading stopped at 12 Ma (anomaly 5A). Conversely, the Magdalena fossil spreading system exhibits a complex bathymetric structure, with a series of ridge segments and conjugate fan-shaped abyssal hills, troughs and volcanic highs, and spreading discontinuities with various orientation. The surface and deep-tow magnetics indicate an age younger than or equal to 12 Ma, 5A being the youngest unambiguously identified magnetic anomaly. The morphological and structural difference between the two fossil spreading centers is striking. We interpret the fan-shaped abyssal hills and the various structural direction of the Magdalena spreading system as the result of a continuous clockwise change in spreading direction of about 18deg./Ma, for a total of 45deg. between anomalies 5B and 5A. Spreading finally ceased when the seafloor spreading direction became parallel to the margin. We believe that then, a new strike-slip plate boundary initiated along the western margin of Baja California. The Guadalupe ridge gradually slowed down with a minor 10deg. reorientation prior to extinction at chron 5A. This observation suggests that a Magdalena plate and a Guadalupe plate started to behave independently at about 14.5 Ma, with the Shirley FZ (27.6N) acting as a plate boundary. Whether there

  12. ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI IMPOR BAJA DI INDONESIA

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    Jhonson Agustinus Pasaribu

    2017-06-01

    Full Text Available Impor baja terus mengalami peningkatan dari tahun 1980-2012, hal ini disebabkan karena tingkat produksi baja tidak mampu mengimbangi dan memenuhi tingkat konsumsi baja. Penelitian ini bertujuan untuk menganalisis faktor-faktor yang mempengaruhi impor baja di Indonesia. Metode analisis yang digunakan adalah Error Corection Model (ECM. Pengujian secara parsial digunakan uji t-statistik dan pengujian secara serempak digunakan uji F-statistik. Hasil penelitian ini menunjukan bahwa Produksi baja berpengaruh negatif dan signifikan terhadap impor baja dalam jangka panjang dan jangka pendek. Konsumsi baja menunjukan pengaruh positif dan signifikan terhadap impor baja dalam jangka panjang dan jangka pendek. Gross Domestic Product (GDP menunjukan pengaruh yang negatif dan tidak signifikan terhadap impor baja dalam jangka panjang dan jangka pendek. Nilai tukar rupiah (Kurs menunjukan pengaruh yang positif dan tidak signifikan terhadap impor baja dalam jangka panjang dan jangka pendek.  The steel import keep having enhancement from 1980 to 2012, it’s because of steel production level can’t fulfill the steel consumption level. If the high level of the steel import volume continues, domestic steel industries will run into a low impact for Indonesian’s economy. The goal of this research analize the affecting factors of steel import in Indonesia. The analytical method use the Error Correction Model (ECM. The partial test use t-statistic and the simultan test use F-statistic. The results showed that the steel production has negative and significant effect on steel import in the long term and short term. The steel consumption has positive and significant effect on steel import in the long term and short term. The Gross Domestic Product (GDP has negative and not significant effect on steel import in the long term and short term. The exchange rate indicates positive and not significant effect on steel import in the long term and short term.

  13. Autónoma de Baja California, México

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    Isaac Cruz Estrada

    2017-01-01

    Full Text Available En la actualidad, la constante evolución de las TIC son un reto para las instituciones universitarias, ya que en su velocidad de cambio se pueden exhibir las dificultades para adaptarse y poder abastecer a los estudiantes del uso adecuado de los dispositivos electrónicos y su entendimiento con el Internet. De este modo, se llevó a cabo un estudio descriptivo para caracterizar la forma en que los universitarios en Turismo están utilizando las tecnologías y conduzca a identificar los elementos y hábitos de estudio que tiene que tomar en cuenta la institución académica, en su papel de contribuir para aprovechar las bondades de los medios electrónicos que están presente en el entorno de los universitarios. Se aplicaron 138 encuestas de 215 estudiantes de la Licenciatura en Gestión Turística de la Facultad de Turismo y Mercadotecnia de la Universidad Autónoma de Baja California, considerando 95% de confianza y 5% de error admitido. De los resultados a destacar se encontró que, los estudiantes están adoptando con frecuencia el uso de dispositivos móviles para tomar notas en las clases, de este modo más del 80% mencionan tener un buen manejo de Internet y las redes sociales, además es frecuente la utilización de la mensajería instantánea para comunicarse. Sin embargo, al usar Internet para buscar información mediante bibliotecas virtuales no se tiene un resultado positivo, lo que conduce a la unidad académica a formar al estudiante en éste y otros aspectos en beneficio del aprovechamiento de los medios digitales, que a su vez conduzca a adaptarse a la modalidad virtual, que pueda satisfacer las necesidades actuales en la educación universitaria.

  14. Learning in Baja California micro-enterprises

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    Michelle Texis Flores

    2011-01-01

    Full Text Available Mexico’s business structure has been characterized by the presence of microenterprises, particularly those averaging two workers, representing 65% of establishments in 2008 and 18% of employment. This makes them important for equity and welfare improvement of their members. This paper analyzes the performance of a group of 227 microenterprises in the state of Baja California, by the use of a practical application of the concept of learning curve arranged to incorporate returns to scale. The results indicate that in 48% of cases there is evidence of learning processes and 58% exhibited increasing returns to scale. This allows evaluating the development potential of these microenterprises and the design and implementation of proactive programs that encourage their learning and consolidation in the market.

  15. Tijuana, Baja California, 1999-2005

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    David F. Fuentes Romero

    2008-01-01

    Full Text Available En este artículo se analiza el perfil de las muertes violentas en las mujeres de Tijuana, Baja California. Los datos provienen de fuentes forense, hemerográfica y del análisis derivado de los expedientes de homicidios dolosos. Se encontró que el rango de edad con mayor frecuencia en los homicidios de mujeres se da entre los 20 y los 34 años (42 por ciento. Sin embargo, en las mujeres el riesgo de morir víctima de un asesinato es más alto en menores de 15 años (20 por ciento. Las formas y medios de mayor frecuencia para asesinar a las mujeres son: heridas por lesiones y golpes (42.3 por ciento, disparo con arma de fuego (28 por ciento, asfixia mecánica y herida por arma blanca (28.8 por ciento.

  16. Evaluación de las propiedades mecánicas en mezclas de Poliestireno/Polietileno de baja densidad reciclado y tamizado

    OpenAIRE

    Franco-Urquiza, E.A.; Maspoch, M.Ll.

    2017-01-01

    En el presente trabajo se prepararon mezclas de poliestireno(PS) con residuo tamizado de Polietileno de baja densidad (LDPE) reciclado de cables eléctricos. Las mezclas se prepararon utilizando una línea de extrusión mono-husillo a nivel planta piloto. Las mezclas, con concentraciones nominales de 5, 7.5,15, 25 y 35 % en peso de residuo, fueron ensayadas bajo las configuraciones a tracción y a flexión. La evaluación mecánica se realizó en función del contenido de residuo y del número de pasos...

  17. Consideraciones sobre el hidrocefalo de baja presion

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    E. Herskovits

    1976-12-01

    Full Text Available Se analizan las condiciones fisiopatológicas del sindrome de hidrocéfalo de presión normal. De un grupo de 21 pacientes con sintomatologia clínica correspondiente a esta entidad, se seleccionan 10 que presentan un diagnóstico clínico, radiológico y cisternográfico indudable de la entidad en estudio. Se observó que, a pesar de esta selección solamente un 50% de ellos se vió beneficiado con la colocación de una válvula de baja presión. Surge entonces la hipotésis de que este cuadro es un sindrome multicausal; que por un proceso fisiopatogenico común produce un cuadro clínico, radiológico y cisternográfico similar y que serían beneficiados únicamente aquellos enfermos en los que se soluciona el problema mecánico.

  18. Bioclimatología de la Coccidioidomicosis en Baja California, México

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    Raúl C, Baptista Rosas

    2010-06-01

    Full Text Available El estudio bioclimático de la Coccidioidomicosis, enfermedad endémica de las zonas áridas de América ocasionada por ascomicetos del género Coccidioides spp., tiene una estrecha relación con dos aspectos: la distribución espacial de la enfermedad asociada a ambientes desérticos, y la correlación entre la incidencia de casos y eventos meteorológicos. A pesar de que el noroeste de México es un área endémica bien conocida, la situación actual de la enfermedad prácticamente está inexplorada. Por tal motivo, en este trabajo se regionalizó la probable área endémica en Baja California, por medio de un sistema de información geográfica (SIG utilizando variables bioclimáticas, y se analizó la relación entre eventos meteorológicos y los casos reportados de la enfermedad durante el periodo de enero de 1988 a diciembre de 1994. Se encontró correlación entre el número de casos reportados de la enfermedad, la precipitación pluvial mensual acumulada (PP y las temperaturas medias máxima y mínima. Existe evidencia a favor de que la región endémica propuesta para Baja California presenta un patrón de lluvias bimodal, en verano y en invierno, característico de zonas bioclimáticas transicionales. Los casos reportados de la enfermedad se registraron principalmente en los meses más secos del año después de las lluvias estacionales. Se concluye que Baja California reúne las condiciones bioclimáticas más favorables para el hábitat de Coccidioides spp. en la transición del bioma mediterráneo al desértico.

  19. Mining activities and arsenic in a Baja California Sur watershed

    Science.gov (United States)

    Alejandro Naranjo-Pulido; Alfredo Ortega-Rubio; Baudillo Acost-Vargas; Lia Rodriguez-Mendez; Marcos Acevedo-Beltran; Cerafina Arguelles-Mendez

    2000-01-01

    Mining is one of the most important sources of income for the Baja California Sur state. This state is the second most important area for mineral (gold, silver, copper) and non-mineral (salt) mining activities in the Mexican Republic. In the San Antonio-El Triunfo region, mineral-mining activities flourished during the 19th century. Tons of debris containing a high...

  20. ANALISIS DAYA SAING INDUSTRI BESI BAJA DALAM RANGKA MENGHADAPI ACFTA

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    Christiana Ari Cahyani

    2014-10-01

    Full Text Available Abstrak ___________________________________________________________________ Industri baja merupakan industri strategis karena merupakan salah satu pendorong utama pembangunan suatu negara. Hasil yang dihasilkan oleh industri baja masih cukup defisit karena ketergantungan yang tinggi terhadap impor baja lebih tinggi dari yang dihasilkan oleh ekspor. Nilai negara ekspor baja Indonesia dari 2008 sampai 2012, mencapai 9129400000000 Euro sedangkan impor negara baja Indonesia mencapai 42.874,70 miliar dolar AS. Metode menggunakan analisis CMS untuk menentukan faktor-faktor apa yang mempengaruhi daya saing, bagaimana pengaruh faktor-faktor tersebut. Dari analisis perhitungan Revealed Comparative Advantage (RCA yang membandingkan negara-negara ACFTA menunjukkan bahwa Indonesia berada di lima besar dengan rata-rata 2.003 hingga tahun 2012 adalah 0,5193. Hasil CMS bahwa efek daya saing sebagian besar pangsa pasar Indonesia diambil alih oleh negara pesaing. Efek distribusi pasar rata-rata selama bertahun-tahun 2003-2012 menghasilkan nilai positif menunjukkan bahwa ketika impor ACFTA pasar meningkat pertumbuhan Indonesia merespon dengan menaikkan volume industri baja Saran yang diberikan kebutuhan untuk perluasan cakupan di pasar dunia, untuk mengurangi ketergantungan pada Indonesia ke negara-negara lainnya yang diimpor. Hal ini ditunjukkan dengan besarnya pengaruh terhadap pertumbuhan distribusi pasar baja komoditas ekspor Indonesia ke negara-negara lain. Konsumsi masyarakat Indonesia terhadap industri baja tinggi perlu diimbangi dengan konsumsi baja nasional dengan kontribusi mampu meningkatkan baja nasional.. Abstract ___________________________________________________________________ Steel industry is a strategic industry because it is one of the main drivers of development of a country. Proceeds generated by the steel industry is still quite a deficit due to the high dependence on imported steel is higher than that generated by exports. State steel

  1. Media and nationalism in Baja California during World War II

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    Víctor M. Gruel Sández

    2013-01-01

    Full Text Available The purpose of this work is to explain some journalistic representations of the Northern Territory of Baja California. The body of documents that pertain this article, will document different versions of the past of the peninsula, from the nature of political discourse. Bajacalifornians will appear represented by journalists, struggling to eliminate an image of an isolated, uninhabited place filled with U.S. citizens. The editorial portrayal of the Tijuana, Mexicali and Mexico City press will be analyzed in context with the regional, national and international conflicts. Public opinion was a ground where the people of Baja California negotiated the nationalism, as the rest of the world collapsed with World War ii.

  2. Densidad de desarrollo alta y baja en Puerto Rico

    Science.gov (United States)

    William A. Gould; Sebastian Martinuzzi; Olga M. Ramos Gonzalez

    2008-01-01

    Este mapa demuestra la distribución de terrenos de alta y baja densidad de desarrollo urbano en Puerto Rico (Martinuzzi et al. 2007). El mapa fue creado mediante el analisis de un mosaico de imagenes de satelite Landsat ETM+ de los años 2000 – 2003. La clasificacion no supervisada ISODATA (“Iterative Self-Organizing Data Analysis Technique”) (ERDAS 2003) fue utilizada...

  3. Miocene detachment faulting predating EPR propagation: Southern Baja California

    Science.gov (United States)

    Bot, Anna; Geoffroy, Laurent; Authemayou, Christine; Bellon, Hervé; Graindorge, David; Pik, Raphaël.

    2016-05-01

    At the southern tip of the Baja California peninsula, we characterize the onshore structures and kinematics associated with crustal necking leading up to the Pliocene breakup and early East Pacific Rise seafloor spreading. From a combination of tectonic field investigations, K-Ar and cosmogenic isotope dating and geomorphology, we propose that the Los Cabos block represents the exhumed footwall of a major detachment fault. This north trending detachment fault is marked by a conspicuous low-dipping brittle-ductile shear zone showing a finite displacement with top to the SE ending to the ESE. This major feature is associated with fluid circulations which led to rejuvenation of the deformed Cretaceous magmatic rocks at a maximum of 17.5 Ma. The detachment footwall displays kilometer-scale corrugations controlling the present-day drainage pattern. This major detachment is synchronous with the development of the San José del Cabo Basin where syntectonic sedimentation took place from the middle Miocene to probably the early Pliocene. We propose that this seaward dipping detachment fault accommodates the proximal crustal necking of the Baja California passive margin, which predates the onset of formation of the East Pacific Rise spreading axis in the Cabo-Puerto Vallarta segment. Our data illustrate an apparent anticlockwise rotation of the stretching direction in Baja California Sur from ~17 Ma to the Pliocene.

  4. Ambientes virtuales de aprendizaje utilizando realidad aumentada

    Directory of Open Access Journals (Sweden)

    Diana Nancy Martínez García

    2018-03-01

    Full Text Available Realidad aumentada o Augmented reality es una nueva tecnología que al combinarla con espacios físicos permite ampliar el espectro de la información relacionada con dichos espacios; esto se hace a través de la superposición de imágenes, información o material audiovisual específico aplicado a cualquier área de conocimiento. Los ambientes virtuales de aprendizaje basados en realidad aumentada prometen innovación debido a que transforman los escenarios de aprendizaje real mediante el uso de nuevas tecnologías aplicadas al ámbito educativo, complementando de esta manera la percepción e interacción con el mundo real; logrando el acceso a nuevos contenidos prescindiendo de recursos físicos. En cuanto al uso de la realidad aumentada aplicada al área de enfermería, existe un sinnúmero de herramientas para complementar una clase magistral y enriquecer el proceso de aprendizaje. Sin embargo, la mayoría de los desarrollos realizados utilizando realidad aumentada proviene de contextos diferentes al nuestro, por lo que resulta importante fomentar el uso de este tipo de herramientas para que suscite el interés de los desarrolladores locales de tecnologías aplicadas al ámbito educativo y más específicamente el de salud. El objetivo de la presente revisión fue fundamentar teóricamente acerca de los ambientes virtuales de aprendizaje utilizando aplicaciones basadas en realidad aumentada.

  5. The economic value chain of wine in Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Salvador González Andrade

    2015-07-01

    Full Text Available Recent economic policy debates have centered on increasing and quantifying the value chain, and the objective of this research is to characterize the value chain of vitiviniculture in Baja California according to organizational subsystems, including management, marketing, quality, productivity and environment. This study presents a comparative analysis between the capabilities of the vitiviniculture industry and sectors within which it participates. The analysis shows that the primary issues are related to sectors that have weak productive infrastructure, marketing problems, product shortages and few local suppliers, and additional problems include insufficient funding, water shortages and high taxes. Moreover, investments in human capital are required to train human resources.

  6. KEKUATAN LEKAT BETON DAN BAJA TULANGAN AKIBAT PEMANASAN

    Directory of Open Access Journals (Sweden)

    Ellen Kumaat

    2003-01-01

    Full Text Available The combination of concrete and steel form economical and efficient composite material by means of the created cooperation through bond stress on the interface of both materials. Heating at varying temperature would result in behaviour change of the composite material, particularly regarding its bond stress performance due to the microstructure change of the concrete and steel. The uniaxial compression test indicated that the value of concrete compression strength on seven days if heated at 2000 C , 5000 C, and 8000 C temperature would decrease, varying from six to 100%, whereas the decrease of concrete compression strength on 28 days varying from ten to 90%. At 2000 C heating, the decrease of bond stress between steel and concrete on 28 days was approximately 30%. Heating at a higher temperature or at 5000 C would lead to 40% to 77% decrease. The decrease of concrete compression and that of bond stress due to heating was presented by a non-linear curve showing that there was a positive correlation between the two characteristics. Abstract in Bahasa Indonesia : Perpaduan antara material beton dan baja tulangan akan membentuk material komposit yang ekonomis serta efisien lewat hasil kerjasama yang tercipta melalui kekuatan lekat pada interface kedua material tersebut. Pemanasan dengan temperatur yang bervariasi akan menyebabkan terjadinya perubahan perilaku material komposit tersebut, khususnya menyangkut kinerja kekuatan lekatnya akibat perubahan mikrostruktur pada material beton dan material baja tulangan. Dari hasil uji tekan uniaksial diperoleh nilai kuat tekan beton umur tujuh hari yang bila dipanaskan dengan temperatur 200oC, 500oC dan 800oC akan mengalami penurunan yang bervariasi antara enam hingga 100%, sedangkan penurunan kuat tekan beton pada umur 28 hari berkisar antara sepuluh hingga 90%. Pada tingkat pemanasan dengan temperatur 200oC, penurunan kekuatan lekat antara baja tulangan dan beton umur 28 hari adalah sekitar 30%, serta

  7. Jack Mosby en la revuelta de 1911 en Baja California

    Directory of Open Access Journals (Sweden)

    Lawrence Douglas Taylor

    2000-01-01

    Full Text Available En el presente artículo se analiza el papel que desempeñó el estadounidense John R. Mosby, conocido popularmente como Jack Mosby, en la revuelta de 1911 en Baja California encabezada por Ricardo Flores Magón y el Partido Liberal Mexicano. Mosby fue uno de los personajes más interesantes y controvertidos de esta campaña. Militar de profesión, también era miembro de los Industrial Workers of the World (Trabajadores Industriales del Mundo , una organización laboral radical de Estados Unidos que contribuyó a la defensa legal de los miembros de la junta dirigente del P L M, acusados por las autoridades estadounidenses de haber violado las leyes de neutralidad. Se examina la postura de Mosby a lo largo de la lucha, incluyendo las raíces de su apoyo entre los hombres de la Segunda División de los grupos armados liberales en la Baja California, su decisión de sostener los principios de Ricardo Flores Magón y del P L M, así como su determinación de continuar la lucha en la región aun cuando la derrota era casi inevitable.

  8. Pengaruh Nitridasi Plasma Terhadap Kekerasan Aisi 304 Dan Baja Karbon Rendah

    OpenAIRE

    Suprapto, Suprapto; Sudjatmoko, Sudjatmoko; Sujitno, Tjipto

    2010-01-01

    PENGARUH NITRIDASI PLASMA TERHADAP KEKERASAN AISI 304 DAN BAJA KARBON RENDAH. Telahdilakukan nitridasi dengan teknik nitridasi plasma/ion untuk perlakuan permukaan AISI 304 dan baja karbon rendahsebagai material komponen mesin. Perlakuan permukaan dimaksudkan untuk meningkatkan kualitas permukaankhususnya kekerasan. Untuk mencapai kondisi optimum dilakukan dengan memvariasi tekanan gas saat prosesnitridasi, sedangkan untuk mengetahui hasilnya dilakukan uji kekerasan, struktur mikro dan kandun...

  9. Crustal thickness estimates for Baja California, Sonora, and Sinaloa, Mexico, using disperse surface waves

    Science.gov (United States)

    López-Pineda, Leobardo; Rebollar, Cecilio J.; Quintanar, Luis

    2007-04-01

    Dispersed surface waves of regional events recorded at Network of Autonomously Recording Seismographs (NARS)-Baja and Red Sísmica de Banda Ancha (RESBAN) networks located over the Baja California Peninsula, Sonora, and Sinaloa, Mexico, were used to estimate shear wave elastic models and crustal thickness. We analyzed fundamental modes of surface waves with period between 10 and 40 s. Multiple filter analysis and the inversion method described by Herrmann and Ammon (2003) was used. Crustal thickness estimates for the Peninsular Ranges of Northern Baja California agree with those obtained by previous studies in the Peninsular Ranges of Northern Baja California. We analyzed dispersion of surface waves with northwest-southeast travel paths along the east and west sides of the Baja California Peninsula as well as a northwest-southeast travel path along the western sides of the Mexican states of Sonora and Sinaloa. It was found that the crustal structure east of the Baja California Peninsula is similar to the structure of Sonora and Sinaloa. The correlation between those two structures suggests dextral offset of the order of 275 ± 25 km if we consider Baja California Peninsula as a rigid body moving toward the northwest relative to the North America plate. This displacement between the structures is in agreement with the displacement determined by the dating of Miocene deposits located in San Felipe on the Baja California Peninsula (Pacific plate), and Isle Tiburon located west of Sonora (North America plate).

  10. Indentación por impacto de baja energía: modelo completo

    Directory of Open Access Journals (Sweden)

    Jiménez, O.

    2004-04-01

    Full Text Available The present work propose is the polymer and composites mechanical proprieties evaluation, using low energy impact techniques in flexure plate configuration hitting by a semi spherical indenters and working with a non linear and non conservative model that involve the permanent deformations due to the impact flexure and indentation. Two systems arrayed in serial configuration, a flexion spring-dashpot and an indentation hertzian spring-dashpot, conform this model. Since this do not have analytical solutions, a 4rd order Runge-Kutta numeric model is used in order to solve it and is compared with experimental results measuring the global energy lost with the restitution coefficient. Different polystyrene (PS matrix composites series with elastomeric and rigid dispersed phases were tested. A satisfactory model approach to the registered experimental curves is showed, allowing the elastic modulus calculus at high impact velocities and also the determination of the energy at the beginning of the specimen damage.

    El objetivo de este trabajo es la evaluación de las propiedades mecánicas de polímeros y composites mediante el uso de técnicas de impacto de baja energía en configuración de flexión, de platos golpeados con cabezales semiesféricos, utilizando para ello un modelo no lineal y no conservativo que involucre el efecto de las deformaciones permanentes inherentes a la flexión y a la indentación presentes en el proceso de impacto. Este modelo esta compuesto por dos sistemas en serie: resorte-amortiguador para la flexión y resorte hertziano-amortiguador para la indentación. Al carecer éste de soluciones analíticas, se resuelve usando el método numérico de Runge-Kutta de cuarto orden, comparándose con resultados experimentales y evaluando, mediante el coeficiente de restitución, las pérdidas globales de energía ocasionadas durante el ensayo. Se realizaron ensayos en varias series de composites de matriz polimérica de

  11. Identifying recharge from tropical cyclonic storms, Baja California Sur, Mexico.

    Science.gov (United States)

    Eastoe, Christopher J; Hess, Greg; Mahieux, Susana

    2015-04-01

    Groundwater in the Todos Santos watershed in southern Baja California, and throughout the peninsula south of latitude 28°N, has values of (δ18 O‰, δD‰) ranging between (-8.3, -57) and (-10.9, -78). Such negative values are uncharacteristic of the site latitude near the sea level. Altitude effects do not explain the isotope data. Tropical depressions originating along the Pacific coast of North America yield rain with isotopic depletion; rain from these weather systems in southern Arizona commonly has δ18O valuestropical depressions bring large rains (>50 mm) at least once every 2 to 3 years, and along the Pacific coast between Jalisco and Oaxaca. © 2014, National Ground Water Association.

  12. Standards establishment within Baja California’s horticultural sector

    Directory of Open Access Journals (Sweden)

    Belem Avendaño Ruiz

    2010-01-01

    Full Text Available The Baja California produce industry is notice by its strong export orientation production. Never less, in the past few years some products have been associated to food safety outbreaks in the United States, its main market, affecting its competitiveness and market share, driven produce growers to the adoption of standards as a mean to stay in the international market. The paper focus in the role of adoption of International standards in the firms as part of a competitive strategy that implies a technological change in order to comply with the certification requirements. A descriptive statistical analysis is conducted as well as a discriminate analysis in order to explain the factors that are involved in the firms that present technical innovation (adoption of standards to achieve competitiveness and those that don’t improve their productive process.

  13. Coastal submarine hydrothermal activity off northern Baja California

    International Nuclear Information System (INIS)

    Vidal, V.M.V.; Vidal, F.V.; Isaacs, J.D.; Young, D.R.

    1978-01-01

    In situ observations of submarine hydrothermal activity have been conducted in Punta Banda. Baja Califronia, Mexico, approximately 400 m from the coast and at a seawater depth of 30 m. The hydrothermal activity occurs within the Agua Blanca Fault, a major transverse structure of Northern Baja California. Hot springwater samples have been collected and analyzed. Marked differences exist between the submarine hot springwater, local land hot springwaters, groundwater, and local seawater. SiO 2 , HCO 3 , Ca, K, Li, B, Ba, Rb, Fe, Mn, As, and Zn are enriched in the submarine hot springwater, while Cl, Na, So 4 2 , Mg, Cu, Ni, Cd, Cr, and perhaps Pb are depleted in relation to average and local seawater values. Very high temperatures, at the hydrothermal vents, have been recorded (102 0 C at 4-atm pressure). Visible gaseous emanations rich in CH 4 and N 2 coexist with the hydrothermal solutions. Metalliferous deposits, pyrite, have been encountered with high concentrations of Fe, S, Si, Al, Mn, Ca, and the volatile elements As, Hg, Sb, and Tl, X ray dispersive spectrometry (1500-ppm detection limit). X ray diffraction, and scanning electron microscopy of the isolated metalliferous precipitates indicate that the principal products of precipitation are pyrite and gypsum accompanied by minor amounts of amorphous material containing Si and Al. Chemical analyses and XRD of the reference control rocks of the locality (volcanics) versus the hydrothermally altered rocks indicate that high-temperature and high-pressure water-rock interactions can in part explain the water chemistry characteristics of the submarine hydrothermal waters. Their long residence time, the occurrence of an extensive marine sedimentary formation, their association with CH 4 and their similarities with connate waters of oil and gas fields suggest that another component of their genesis could be in cation exchange reactions within deeply buried sediments of marine origin

  14. EVALUACIÓN DE LA BIOESTIMULACION (NUTRIENTES EN SUELOS CONTAMINADOS CON HIDROCARBUROS UTILIZANDO RESPIROMETRIA

    Directory of Open Access Journals (Sweden)

    Erika garcia

    2011-01-01

    Full Text Available Se evaluó el proceso de bioestimulación por nutrientes: fertilizantes inorgánicos compuestos (FIC N:P:K 28:12:7 y sales inorgánicas simples (SIS NH4NO3 y K2HPO4 en suelos contaminados con hidrocarburos utilizando respirometría. El suelo fue contaminado con lodos aceitosos a una concentración ~40,000 mgTPH/kgps. Para cuantificar el consumo de oxigeno se utilizaron dos respirómetros de medición manométrica HACH® 2173b y OXITOP® PF600 durante ensayos de trece días. Se evaluaron dos tratamientos (FIC y SIS y tres controles (abiótico, sustrato de referencia y sin nutrientes. Se analizaron parámetros físico-químicos (pH, nutrientes y TPH y microbiológicos (heterótrofos y degradadores al inicio y al final de cada ensayo. SIS y el control sin nutrientes presentaron las mayores tasas de respiración, en el equipo HACH se obtuvieron valores de: 802.28 y 850.72 mgO2kgps-1d-1 respectivamente mientras que en el OXITOP fueron de 936.65 y 502.05 mgO2kgps-1d-1, respectivamente. En ninguno de los equipos se observo un aumento significativo de los degradadores, indicando que la bioestimulación no tuvo un efecto sobre la densidad microbiana. Por otro lado FIC, presentó los recuentos y tasas de respiración más bajas (188.18 y 139.87 mgO2kgps-1d-1 en HACH y OXITOP, respectivamente, esto pudo estar correlacionado a un efecto toxico generado por la acumulación de amoniaco.

  15. Climate change and the northern elephant seal (Mirounga angustirostris population in Baja California, Mexico.

    Directory of Open Access Journals (Sweden)

    María C García-Aguilar

    Full Text Available The Earth's climate is warming, especially in the mid- and high latitudes of the Northern Hemisphere. The northern elephant seal (Mirounga angustirostris breeds and haul-outs on islands and the mainland of Baja California, Mexico, and California, U.S.A. At the beginning of the 21st century, numbers of elephant seals in California are increasing, but the status of Baja California populations is unknown, and some data suggest they may be decreasing. We hypothesize that the elephant seal population of Baja California is experiencing a decline because the animals are not migrating as far south due to warming sea and air temperatures. Here we assessed population trends of the Baja California population, and climate change in the region. The numbers of northern elephant seals in Baja California colonies have been decreasing since the 1990s, and both the surface waters off Baja California and the local air temperatures have warmed during the last three decades. We propose that declining population sizes may be attributable to decreased migration towards the southern portions of the range in response to the observed temperature increases. Further research is needed to confirm our hypothesis; however, if true, it would imply that elephant seal colonies of Baja California and California are not demographically isolated which would pose challenges to environmental and management policies between Mexico and the United States.

  16. Climate change and the northern elephant seal (Mirounga angustirostris) population in Baja California, Mexico.

    Science.gov (United States)

    García-Aguilar, María C; Turrent, Cuauhtémoc; Elorriaga-Verplancken, Fernando R; Arias-Del-Razo, Alejandro; Schramm, Yolanda

    2018-01-01

    The Earth's climate is warming, especially in the mid- and high latitudes of the Northern Hemisphere. The northern elephant seal (Mirounga angustirostris) breeds and haul-outs on islands and the mainland of Baja California, Mexico, and California, U.S.A. At the beginning of the 21st century, numbers of elephant seals in California are increasing, but the status of Baja California populations is unknown, and some data suggest they may be decreasing. We hypothesize that the elephant seal population of Baja California is experiencing a decline because the animals are not migrating as far south due to warming sea and air temperatures. Here we assessed population trends of the Baja California population, and climate change in the region. The numbers of northern elephant seals in Baja California colonies have been decreasing since the 1990s, and both the surface waters off Baja California and the local air temperatures have warmed during the last three decades. We propose that declining population sizes may be attributable to decreased migration towards the southern portions of the range in response to the observed temperature increases. Further research is needed to confirm our hypothesis; however, if true, it would imply that elephant seal colonies of Baja California and California are not demographically isolated which would pose challenges to environmental and management policies between Mexico and the United States.

  17. Economic restructuring plan and emergent regions: Baja California, 1980-1995

    Directory of Open Access Journals (Sweden)

    Arturo Ranfla González

    2000-07-01

    Full Text Available The aim of this essay is to foster a discussion on the political and territorial levels that are involved in the process of economic globalization of the Northern border region of Mexico, and particularly the state of Baja California. For such purpose, an approach is taken on the economic and sectorial conditions of the Baja California economy during the 1981-1994 period. Also, a detailed analysis of the sectorial structure and dynamics of production —during that same period— of the main municipalities is Baja California in order to identify the profiles and hierarchy of each of them is carried out.

  18. Compensación de la potencia reactiva en sistemas de baja tensión mediante bancos de condensadores fijos, utilizando algoritmos genéticos

    Directory of Open Access Journals (Sweden)

    Davel Borges, et al.

    2010-11-01

    Full Text Available The energy efficiency of an electric system depends in great measure of the reactive power compensationthat it is carried out. One of the roads more employees are the use of capacitors banks.A good selection of these, presupposes three aspects: the selection of the banks capacity, thecompensator type to use, as well as the location in the low voltage system.References of methods thatconsider the three aspects in a same problem are based on the mathematical programming, but thesecannot represent all the effects of the compensation and these based in technical of continuousprogramming, being this a complex optimization problem of discreet search space.In the paper, we havedeveloped a method with the employment of the genetic algorithms, which facilitates a more exact problemformulation. The method has been programmed in MATLAB, version 7.5 (R2007b, using programmingstructures of Genetic Algorithm and Direct Search Toolbox.The effectiveness is shown in an example ofreal application to the low voltage system of a hotel installation of the Cubanacan Company in Camagüey.

  19. A Weather Analysis and Forecasting System for Baja California, Mexico

    Science.gov (United States)

    Farfan, L. M.

    2006-05-01

    The weather of the Baja California Peninsula, part of northwestern Mexico, is mild and dry most of the year. However, during the summer, humid air masses associated with tropical cyclones move northward in the eastern Pacific Ocean. Added features that create a unique meteorological situation include mountain ranges along the spine of the peninsula, warm water in the Gulf of California, and the cold California Current in the Pacific. These features interact with the environmental flow to induce conditions that play a role in the occurrence of localized, convective systems during the approach of tropical cyclones. Most of these events occur late in the summer, generating heavy precipitation, strong winds, lightning, and are associated with significant property damage to the local populations. Our goal is to provide information on the characteristics of these weather systems by performing an analysis of observations derived from a regional network. This includes imagery from radar and geostationary satellite, and data from surface stations. A set of real-time products are generated in our research center and are made available to a broad audience (researchers, students, and business employees) by using an internet site. Graphical products are updated anywhere from one to 24 hours and includes predictions from numerical models. Forecasts are derived from an operational model (GFS) and locally generated simulations based on a mesoscale model (MM5). Our analysis and forecasting system has been in operation since the summer of 2005 and was used as a reference for a set of discussions during the development of eastern Pacific tropical cyclones. This basin had 15 named storms and none of them made landfall on the west coast of Mexico; however, four systems were within 800 km from the area of interest, resulting in some convective activity. During the whole season, a group of 30 users from our institution, government offices, and local businesses received daily information

  20. Land use change in the Baja California Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Gerardo Bocco

    2009-10-01

    Full Text Available This work analyzes the land use change in the Baja California Peninsula, at the level of vegetation types. The time period analyzed was 1978 (Serie I de INEGI to 2000 (Inventario Nacional Forestal at 1:250 000 scale. The spatial analyses were carried out in a GIS environment to identify the changes in the period. A transition matrix was elaborated and the changes detected were grouped in three major processes: scrubland depletion (deforestation of woody vegetation, recovery of natural vegetation cover, and urban growth. In the time period analyzed (22 years 7.7 % of the territory underwent land use changes. The deforestation and urbanization processes were more dynamic in the northern part of the peninsula, while recovery was more relevant in the south zone. The deforestation of scrubland for agriculture activities is the main process in the peninsula. The urbanization, in absolute terms, is the least important in the time period analyzed; however, the surface occupied for human settlements increased in almost 270 %.

  1. [Main causes of maternal mortality in Mexicali, Baja California (Mexico)].

    Science.gov (United States)

    Medina-Ramírez', Maria Concepción; Leal-Anaya, Paula; Aguilera-Romero, Tricia Nohemí; Leyva-Quintero, Elizabeth

    2015-11-01

    The objective of this study is to determine the main causes of maternal mortality in the period 2009 to 2013 in Mexicali, Baja California, Mexico. Epidemiological, observational, descriptive, cross-sectional, and retrospective study was conducted with a universe of 30 cases of maternal death. The information was collected from death certificates and records of cases obtained from the Institute of State Public Service Health of University Xochicalco. The average age of patients were 26.6 ± 5.6 years. Educational level and marital status was with junior school 15 (50%) and free union 12 (40%) respectively, 21 (70%) had no prenatal care. The mean gestational age was 28.8 ± 3.72 weeks, there was no difference in the place of residence, urban and rural, 15(50%). The main cause of death was hemorrhage 9(30%). The highest mortality was during the postpartum period 23 (77%). During the study period, the mortality rate was 36.8 x 100,000 live births. The increased frequency of maternal mortality was in young women, 70% had no prenatal care. Bleeding from ectopic pregnancy was the leading cause of death.

  2. Microfossils from Cerro Prieto geothermal wells, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, M.L.; Haar, S.V.

    1982-08-10

    To aid in a paleonenvironmental and age reconstruction of the Cerro Prieto reservoir system, 59 samples of well cuttings were analyzed for microfossils. The cuttings were obtained at depths from 351 to 3495m in 14 geothermal wells in the Cerro Prieto field, Baja California, Mexico. Foraminifera was found in 6 samples, ostracodes in 19 samples and mannoplankton as coccoliths in 24 samples. Other groups, such as molluscus, insects, fish skeletal parts, and plant material were occasionally present. Detailed interpretations at this time cannot be made because of poor preservation of samples. This is primarily due to causes: dissolution by geothermal fluids that reach 350/sup 0/C, and the extensive mixing of filled Cretaceous forms (reworked from the Colorado Plateau region) with Tertiary species during drilling. Further studies of ostracodes and foraminifera from colder portions of the wells are needed. The abundant and well-preserved ostracodes indicate marine to backish water inviroments that correspond in part, to lagoonal or estuarine facies. The presence of the mid-Tertiary (15-m.y.-old) marine foraminifera, Cassigerinela chipolensis, in wells M-11 and M-38, 350 to 500m deep, is perplexing. These are not laboratory contaminates and, as yet have not been found in the drilling mud. If further studies confirm their presence at Cerro Prieto, established ideas about the opening of the Gulf of California and about Pacific Coast mid-Tertiary history will need to be rewritten.

  3. Microfossils from Cerro Prieto geothermal wells, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, M.L.; Vonder Haar, S.

    1980-01-01

    To aid in a paleoenvironmental and age reconstruction of the Cerro Prieto reservoir system, 59 samples of well cuttings were analyzed for microfossils. The cuttings were obtained at depths from 351 to 3495 m in 14 geothermal wells in the Cerro Prieto field, Baja California, Mexico. We found foraminifera in 6 samples, ostracodes in 19 samples, and nannoplankton as coccoliths in 24 samples. Other groups, such as molluscs, insects, fish skeletal parts, and plant material were occasionally present. Detailed interpretations are not possible at this time because of poor preservation of samples. This is primarily due to causes: dissolution by geothermal fluids that reach 350{sup 0}C, and the extensive mixing of filled Cretaceous forms (reworked from the Colorado Plateau region) with Tertiary species during drilling. Further studies of ostracodes and foraminifera from colder portions of the wells are needed. The abundant and well-preserved ostracodes indicate marine to brackish water environments that correspond, in part, to lagoonal or estuarine facies. The presence of the mid-Tertiary (15-My-old) marine foraminifera, Cassigerinela chipolensis, in wells M-11 and M-38, 350 to 500 m deep, is perplexing. These are not laboratory contaminates and, as yet, have not been found in the drilling mud. If further studies confirm their presence at Cerro Prieto, established ideas about the opening of the Gulf of California and about Pacific Coast mid-Tertiary history will need to be rewritten.

  4. Goat milk fatty acid composition in the Peninsula of Baja California, Mexico

    OpenAIRE

    Eduardo Toyes-Vargas; Miguel Cordoba-Matson; José Espinoza-Villavicencio; Alejandro Palacio-Espinosa; Bernardo Murillo-Amador

    2013-01-01

    ABSTRACTObjective. The objective of the study was to determine the composition of fatty acids in milk of Creole goats in an extensive production system in an arid region of the peninsula of Baja California and compare it to two seasons of the year (rainy and dry). Materials and methods. Sampling was conducted during the dry season (June) and after the rainy season (December) in the municipality of Comondú in Baja California Sur. The extensive production system used involved releasing goats to...

  5. Stratigraphy of Reforma Caldera, Baja California Sur, Mexico

    Science.gov (United States)

    García Sánchez, L.; Macias, J. L.; Osorio, L. S.; Pola, A.; Avellán, D. R.; Arce, J. L.; Saucedo, R.; Sánchez, J. M.; García-Tenorio, F.; Cisneros, G.; Reyes-Agustín, G.; Cardona, S.; Jimenez, A.

    2015-12-01

    The Reforma caldera is located at ~35 km to the northwest of Santa Rosalía in the central part of the Baja California peninsula. It has 10 km in diameter and a maximum height of 1200 masl in the center and between 100 and 500 masl in its slopes. Reforma is within a tectonic zone affected by two fault systems: A NW-SE normal fault system linked to the opening of the Gulf of California, and a NNW-SSE and NW-SE strike-slip fault system associated with an active Riedel system. Reforma was built upon Cretaceous granites that outcrop at the caldera center, Miocene to Pliocene volcano-sedimentary rocks of the Comondú group, and Miocene marine sediments of the Santa Rosalía basin. On top of these rocks outcrop at least four submarine to subaerial ignimbrites interbedded with marine fossiliferous beds and the lower Pleistocene deposits associated to the Reforma caldera. These deposits are formed by a ignimbrite that shifts to different lithofacies that change gradually their welding, here dubbed basal, transitional, intermediate, and upper (all of then enriched in black fiammes), followed by a pumice-rich, white fiammes, and vitrophyre lithofacies, which are distributed around the 9 km wide caldera and have been associated to the caldera formation episode. Deposits related to post-caldera volcanism are andesite-basaltic lava flows erupted along the caldera rim through localized feeding dikes and andesitic and rhyolitic domes, and scoria cinder cones exposed inside and outside the caldera. On top of these deposits rest the middle Pleistocene Aguajito caldera deposits.

  6. Hemorragia digestiva baja masiva en pacientes con enfermedad de Crohn

    Directory of Open Access Journals (Sweden)

    M. Barreiro de Acosta

    Full Text Available Objetivo: analizar la frecuencia de las hemorragias masivas en la EC e intentar determinar sus potenciales factores de riesgo (ambientales, propios de la enfermedad y genéticos. Material y métodos: se estudió de manera retrospectiva una cohorte de 174 pacientes -103 mujeres (59% y 71 hombres (41%, edad media de 37 años- con EC, analizándose las hemorragias digestivas masivas que se habían producido en relación con su enfermedad. Se revisaron asimismo potenciales factores de riesgo como hábito tabáquico, localización de la enfermedad y presencia de mutaciones genéticas en CARD15, RTL-4 y CD14, entre otros. Resultados: tres pacientes (1,7% presentaron una hemorragia digestiva masiva que precisó intervención quirúrgica para su resolución. Esta indicación de cirugía supone el 3,4% de las cirugías en relación con la EC. Todos los pacientes eran jóvenes y su enfermedad seguía un patrón inflamatorio y estaba localizada en el íleon. No se ha evidenciado asociación estadísticamente significativa entre las hemorragias digestivas masivas y los potenciales factores de riesgo analizados. Conclusiones: la hemorragia digestiva baja masiva es una complicación poco común, aunque grave de la EC. Se trata habitualmente de pacientes con patrón inflamatorio de la enfermedad y afectación ileal. Para su diagnóstico resulta clave la asociación de endoscopia y arteriografía, y su resolución suele ser quirúrgica.

  7. EXCRECION FRACCIONAL DE UREA BAJA EN HIPONATREMIA INDUCIDA POR HIPOTIROIDISMO

    Directory of Open Access Journals (Sweden)

    Musso CG

    2005-02-01

    Full Text Available ABSTRACTHypothyroidism can cause disturbance of renal hemodinamics, kidney histology, water and electrolyte metabolism, being hyponatremia and glomerular filtration reduction their low prevalent but most significant consequences. All these changes are largely corrected by substitution of exogenous thyroid hormone.Fractional excretion of urea (FEU is a useful index in the evaluation of hyponatremia. However, it was not still reported in the literature the FEU value in hyponatremia induced by hypothyroidism. Because of that we presented a case report showing that the value of FEU and fractional excretion of sodium (FENa were low (FEU: 29% and high (FENa: 2.2 % respectively in a severe hypothyroid patient. Treatment based on thyroid hormone normalized both indeces.RESUMEN:El hipotiroidismo puede causar alteraciones del metabolismo del agua, los electrolitos, la hemodinamia e histología renales, siendo la hiponatremia y la reducción del filtrado glomerular sus consecuencias más significativas, pero poco prevalentes. Todos estos cambios son corregibles con el suministro de hormona tiroidea exógena.La excreción fraccional de urea (EFU es un índice útil en la evaluación de la hiponatremia, pero no se ha descripto aun el valor que este índice alcanza en la hiponatremia inducida por hipotiroidismo. En el presente reporte mostramos que la EFU y excreción fraccional de sodio (EFNa fueron baja (EFU: 29% y alta (EFNa: 2.2% respectivamente en un paciente que padecía hipotiroidismo severo. El tratamiento con hormona tiroidea normalizó el valor de ambos índices.

  8. Aminoglucósidos en las sepsis respiratorias bajas

    Directory of Open Access Journals (Sweden)

    Martha E Triay González

    1998-12-01

    Full Text Available Se realizó un estudio del uso de antibióticos aminoglucósidos en 70 pacientes con diagnóstico de infección respiratoria baja. Se demostró la poca efectividad de estos antimicrobianos en nuestra investigación. Se efectuó un análisis de los costos de tiempo hospitalario y antibióticos empleados en 50 casos que adquirieron la infección en la comunidad y se comparó con un grupo de 50 pacientes con el mismo diagnóstico tratados con cefazolina. Se obtuvieron resultados significativos en cuanto a la eficacia, disminución de la estadía y costo hospitalarios así como el consumo de antibióticos. En nuestro trabajo se determinó que con el uso de la cefazolina se logró un ahorro considerable de $ 11 055,98A study on the use of aminoglycoside antibiotics was conducted among 70 patients with diagnosis of low respiratory infection. The low effectiveness of these antimicrobial drugs was proved in this research. It was made an analysis of the hospital stay costs and of the antibiotics used in 50 cases that got infected in the community. It was also made a comparison with a group of 50 patients with the same diagnosis treated with cefazolin. Significant results were obtained concerning efficacy, and the reduction of hospital stay and cost, and of antibiotics consumption. A considerable saving of $ 11 055.98 was attained with the use of cefazolin

  9. Efecto del templado sobre la permeación de gases a través de filmes de polietileno lineal de baja densidad obtenidos por coextrusión

    OpenAIRE

    Andrio Balado, Andreu

    1998-01-01

    En esta tesis se han estudiado las propiedades difusivas de tres filmes de polietileno lineal de baja densidad a los gases nitrógeno, oxígeno y dióxido de carbono. Se ha medido los coeficientes de permeabilidad, difusión y solubilidad aparentes en función de la temperatura, la presión y el tiempo de templado. La evolución de los resultados con el cambio de presión ha sido interpretada utilizando el modelo dual de sorción, así mismo, la evolución con la temperatura ha sido interpretada en térm...

  10. Desarrollo humano en el noroeste de México: un análisis comparativo de los estados de Sonora, Baja California y Baja California Sur, 1995-2005

    Directory of Open Access Journals (Sweden)

    Francisco José Zamudio Sánchez

    2009-01-01

    Full Text Available Este artículo aborda el desarrollo humano en Sonora, Baja California y Baja California Sur. Se estimaron los valores de cuatro índices: desarrollo humano con producto interno bruto, desarrollo humano con servicios, con género e inequidad; además de curvas de calidad estatal y municipal.Aunque los valores ubican a Baja California Sur en la mejor posición de los indicadores de desarrollo humano y después a Sonora; Baja California ocupa el mejor sitio en equidad en el país.

  11. Whole genome sequencing of Mycobacterium bovis to obtain molecular fingerprints in human and cattle isolates from Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Sarai Estrella Sandoval-Azuara

    2017-10-01

    Conclusions: All isolates from humans had spoligotype patterns that matched those observed in the cattle isolates, and all human isolates shared common ancestors with cattle in Baja California based on SNP analysis. This suggests that most human tuberculosis caused by M. bovis in Baja California is derived from M. bovis circulating in Baja California cattle. These results reinforce the importance of bovine tuberculosis surveillance and control in this region.

  12. Gender and abuse: Partner violence among young people in Baja California

    Directory of Open Access Journals (Sweden)

    Humberto González Galbán

    2010-07-01

    Full Text Available Domestic violence or spousal abuse, largely determined by the existing traditional gender roles, is the issue discussed in this article, which is focusing on the special case of young people of the state of Baja California. During the search of the conditional agents of this social process, there were valued psychological and socio–demographic variables, such as family violence during childhood, immigration status, educational level and age, all these variables were separated by the gender and age (rank 18–29 of the sudied sample.Considering the information provided of the database used; The Survey of Adolescent Reproductive Health of Baja California 2006, it is described and analyzed in this research, several indicators, all of them related with important issues which affect a part of the young population of Baja California, regardless the lack of information and almost non previous research about this theme.

  13. Use of small reactors as an alternative to supply electricity to Baja California Sur; Uso de reactores pequenos como alternativa de suministro de electricidad para Baja California Sur

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, G.; Portes, E.; Ramirez, J. R. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Ortega, G., E-mail: gustavo.alonso@inin.gob.mx [Comision Federal de Electricidad, Rio Rodano No. 14, 06500 Ciudad de Mexico (Mexico)

    2016-09-15

    The state of Baja California Sur (Mexico) does not form part of the national interconnected electrical system of the country, reason why is local its electrical power supply; one of the alternatives to cover future demands is the use of gas-based combined cycles, which presents the additional problem of including a high price for gas transportation in its costs. In order to reduce total costs, including investment, fuels and operation and maintenance in the operation of the Baja California Sur state electricity system in the coming years, mainly due to the estimated natural gas cost order of $11.50 dollars per million BTU, a proposal is presented to reduce the costs of the electrical system by replacing the necessary combined cycles with the new Small Modular Reactor type nuclear reactors, this alternative is economically competitive. (Author)

  14. Factores de riesgo, asociados a intento de suicidio, comparando factores de alta y baja letalidad

    OpenAIRE

    García-Rábago, Horacio; Sahagún-Flores, José E.; Ruiz-Gómez, Alfonso; Sánchez-Ureña, Gustavo M.; Tirado-Vargas, Juan C.; González-Gámez, Jaime G.

    2012-01-01

    Objetivo: El propósito del estudio due identificar los factores de riesgo mas frecuentes asociados a intento de suicidio para determinar si existen diferencias entre los factores de riesgo presentes en pacientes con tentativa de baja letalidad y los de alta letalidad. Método: Se entrevistaron 106 pacientes de ambos sexos, con diagnótico de intento de suicidio, hospitalizados en una unidad psiquiátrica, divididos en dos grupos: uno pacientes con tentativa suicida de baja letalidad y otro con t...

  15. DIETA BAJA EN FODMAP EN EL SÍNDROME DE INTESTINO IRRITABLE

    Directory of Open Access Journals (Sweden)

    CAROLINA FIGUEROA C., DRA.

    2015-09-01

    Full Text Available La dieta baja en FODMAP ha mostrado ser una herramienta eficaz en el manejo de los síntomas del Síndrome de Intestino Irritable (SII. Los estudios recientes aleatorizados, controlados y prospectivos apoyan el uso de esta dieta como parte del tratamiento de esta patología. Los mecanismos mediante los que la dieta baja en FODMAP alivia los síntomas son variados y se relacionan con la fisiopatología del SII. Esta dieta puede generar cambios en la flora intestinal, efecto que aún no ha sido ampliamente estudiado.

  16. Los concheros de Baja California y sus perspectivas de investigación

    OpenAIRE

    Agustín Téllez Duarte

    1987-01-01

    El presente artículo pretende enfatizar sobre la presencia de conchas en sitios arqueológicos, los cuales nos proporcionan una gran cantidad de información cultural sobre los asentamientos humanos, particularmente en los concheros de Baja California. En Baja California se localizan en forma intermitente a todo lo largo de sus costas, tanto en el golfo de California como en el Pacífico. Con este proyecto se pretende rescatar aquellas colecciones que aún puedan conservarse, considerando que las...

  17. Wines of Baja Mexico: A qualitative study examining viticulture, enology, and marketing practices

    Directory of Open Access Journals (Sweden)

    Jorge Covarrubias

    2015-12-01

    Full Text Available Mexico has been producing wine since the 1500, yet very little is known about their viticulture, enology, and marketing practices. This qualitative research study was designed to shed more light on these issues. Based on 10 in-depth interviews with winery owners and winemakers in the Valle de Guadualupe of the Baja Peninsula, where the majority of Mexican wineries are located, this study describes viticulture, enology, and marketing practices for Baja wines. It concludes with a discussion on the future of Mexican wines.

  18. Portal WEB 2.0. utilizando Framework Struts

    OpenAIRE

    Palacín Mateo, Manuel

    2007-01-01

    El propósito de este proyecto es la implementación de un portal interactivo de contactos utilizando las tecnologías J2EE mediante Struts y siguiendo la tendencia Web 2.0. Previo a esta implementación se ha hecho una valoración del mercado actual de los portales de contactos y se han evaluado los servicios que ofrecen para posteriormente añadirlos a la demostración tecnológica. Tras esto se ha explicado lo que es la tendencia Web 2.0. Finalmente se han evaluado las diferentes opciones o tec...

  19. PRODUCCIÓN DE BIOFERTILIZANTES UTILIZANDO Pseudomonas sp.

    OpenAIRE

    Santillana-Villanueva, Nery; Universidad Nacional Agraria La Molina (Perú).

    2006-01-01

    Con el objetivo de producir biofertilizantes utilizando 3 cepas de Pseudomonas sp., se realizaron tres experimentos: el primero, para encontrar un medio de cultivo apropiado para la multiplicación de las bacterias; el segundo, para determinar la sobrevivencia de las cepas de Pseudomonas sp en los biofertilizantes y el tercero para determinar la dosis eficiente de aplicación del biofertilizante en frijol, maíz, papa y tomate, en condiciones de invernadero. Al evaluar los resultados, se determi...

  20. Slab remnants beneath the Baja California peninsula : Seismic constraints and tectonic implications

    NARCIS (Netherlands)

    Paulssen, Hanneke; de Vos, Denise

    2017-01-01

    The formation of the Gulf of California has been related to the cessation of subduction of the Guadalupe and Magdalena microplates. Various studies have identified features that point to the presence of a slab remnant beneath the Baja California peninsula, but its depth range and lateral extent

  1. Herpetofauna associated with palm oases across the Californian-Sonoran transition in northern Baja California, Mexico

    Science.gov (United States)

    Hart Welsh; W. H. Clark; E. Franco-Vizcaíno; J. H. Valdéz-Villavicencio

    2010-01-01

    Ecological boundaries have been of interest to naturalists since the time of Darwin and Wallace because they are transitional zones on the landscape across which distinct changes occur in constitution of plant and animal communities. In the xeric landscapes of the central Baja California Peninsula, fan palm (Erythea armata and ...

  2. Islas Marias Archipelago, Mexico. A Missing Piece to Reconstruct the Paleoposition of Baja California

    Science.gov (United States)

    Schaaf, P. E.; Pompa, V.; Hernandez, T.; Weber, B.; Solis, G.; Villanueva, D.; Perez-Venzor, J.

    2011-12-01

    Paleopositions for southern Baja California peninsula have yielded controversial models over the past 30 years. Mainly based on paleomagnetic data many hypotheses place Baja at lower paleolatitudes in front of southern Mexico or Central America with subsequent northward translations. Other models suggest minor, if any, northward displacements with respect to continental Mexico combined with clockwise rotations. Lithological, geochemical, and geochronological similarities for southern Baja California and Puerto Vallarta (western Mexico Pacific margin) igneous rocks seem to confirm the latter model. To further prove this model we have mapped and collected rocks from Maria Madre, the largest island of the Islas Marias archipelago, located in the mouth of the Gulf of California. In an area of only 145 square kilometers, metamorphic basements rocks (ortho and migmatitic gneisses), highly deformed metasediments, granitoids, acid to intermediate volcanic sequences, and a cover with gently folded marine sediments are exposed. The basement complex with gneisses and metasediments, including garnet-bearing paragneiss and calc silicates, as well as the granodioritic-tonalitic intrusives display an extraordinary accordance with similar units observed in the Los Cabos Block (LCB) of Baja California Sur. Furthermore, U-Pb zircon ages of 162 and 170 Ma for the basement gneisses and of 80 Ma for the granitoids have been reported also from the LCB. Additionally, upper Cretaceous intrusive ages are well known from the Puerto Vallarta batholith in Jalisco and Nayarit, mainland Mexico. Geochemical and isotopic data as well as Nd model ages confirm a magmatic consanguinity of LCB, Islas Marias, and Puerto Vallarta granitoids. The volcanic units of Maria Madre Island include ignimbrites and effusive dacitic-rhyolithic rocks, which can be correlated to the Sierra Madre Occidental province and the Comundú Formation of Baja California. Age determinations are under work to confirm this

  3. Behaviours and opinions towards outdoor smoking bans and cigarette littering in Baja California, Mexico.

    Science.gov (United States)

    Basto-Abreu, Ana C; Christine, Paul J; Zepeda-Tello, Rodrigo; Romero-Martínez, Martín; Aguilar Duque, Julian I; Reynales-Shigematsu, Luz M; Barrientos-Gutierrez, Tonatiuh

    2016-04-01

    Outdoor smoking bans have been implemented to reduce secondhand smoke exposure and cigarette littering. We aimed to explore outdoor smoking behaviours, cigarette littering, and support towards a recently enacted outdoor smoking ban in Baja California, Mexico. From October 2013 to April 2014 a representative sample of 800 adults from urban areas of Baja California was surveyed to obtain information on demographics, smoking status, opinion towards outdoor smoking bans in general and in specific locations, and perceptions and habits regarding cigarette littering. Descriptive statistics and Poisson regression analyses were conducted to estimate prevalence ratios and corresponding 95% CI taking into account the complex survey design. Outdoor smoking was frequently observed, as 86.8% of the population reported having seen people smoking in parks and beaches and 94.4% in open venues such as concerts or stadiums. A smoking ban in all outdoor areas was supported by 71.8% of Baja California residents. Site-specific support ranged from 80% (stadiums) to 89% (public parks). Support for the ban was higher among never and ex-smokers than in current smokers. Cigarette littering was negatively perceived by 98% of the participants, yet 45% of all cigarettes smoked were thrown on the ground. Based on cigarette consumption and butt littering reported in the survey, we estimated that 27 million cigarette butts become litter every month in urban areas of Baja California. Outdoor smoking is still frequent in outdoor areas where people gather, and an important source of littering. We found substantial public support towards the outdoor smoking ban, which should translate into easier implementation and compliance in Baja California, Mexico. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Financial viability of the Sonora-Baja California interconnection line; Viabilidad financiera de la linea de interconexion Sonora-Baja California

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, G. [ININ, Carretera Mexico-Touca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Ortega, G., E-mail: gustavo.alonso@inin.gob.mx [Comision Federal de Electricidad, Rio Rodano No. 14, Col. Cuauhtemoc, 06500 Ciudad de Mexico (Mexico)

    2017-09-15

    In the Development Program of the National Electricity Sector 2015-2029, an electric interconnection line between Sonora and Baja California (Mexico) is proposed, this study analyzes the financial viability of this interconnection line based on the maximum hourly and seasonal energy demand between both regions and proposes alternatives for the supply of electric power that supports the economic convenience of this interconnection line. The results show that additional capacity is required in Sonora to cover the maximum demands of both regions since in the current condition of the National Electric System the interconnection line is not justified. (Author)

  5. Planeamento de uma estrada utilizando CCS Candy - Caso de estudo

    OpenAIRE

    Oliveira, Sara Maria de

    2013-01-01

    O tema desta dissertação foi escolhido tendo em consideração a crescente necessidade de planeamento de empreitadas de construção de estradas, sendo um dos objetivos desta dissertação o de oferecer uma visão global do processo de planeamento da construção de uma estrada, focado apenas no fator tempo, recorrendo a ferramentas informáticas e utilizando um caso de estudo de uma estrada real e já construída. Inicialmente, faz-se uma breve descrição dos métodos de planeamento mais aplicados em p...

  6. Crustal Structure of Southern Baja California Peninsula, Mexico, and its Margins

    Science.gov (United States)

    Gonzalez, A.; Robles-Vazquez, L. N.; Requena-Gonzalez, N. A.; Fletcher, J.; Lizarralde, D.; Kent, G.; Harding, A.; Holbrook, S.; Umhoefer, P.; Axen, G.

    2007-05-01

    Data from 6 deep 2D multichannel seismic (MCS) lines, 1 wide-angle seismic transect and gravity were used to investigate the crustal structure and stratigraphy of the southern Baja California peninsula and its margins. An array of air guns was used as seismic source shooting each 50 m. Each signal was recorded during 16 s by a 6 km long streamer with 480 channels and a spacing of 12.5 m. Seismic waves were also recorded by Ocean Bottom Seismometers (OBS) in the Pacific and the Gulf of California and by portable seismic instruments onshore southern Baja California. MCS data were conventionally processed, to obtain post-stack time-migrated seismic sections. We used a direct method for the interpretation of the wide-angle data, including ray tracing and travel times calculation. In addition to the gravity data recorded onboard, satellite and land public domain data were also used in the gravity modeling. The combined MCS, wide-angle and gravity transect between the Magdalena microplate to the center of Farallon basin in the Gulf of California, crossing the southern Baja California Peninsula to the north of La Paz, allows to verify the existence of the Magdalena microplate under Baja California. We have also confirmed an extensional component of the Tosco-Abreojos fault zone and we have calculated crustal thicknesses. We have also observed the continuation to the south of the Santa Margarita detachment. The MCS seismic sections show a number of fault scarps, submarine canyons and grabens and horsts associated to normal faults offshore southern Baja California peninsula. The normal displacement observed in the Tosco-Abreojos fault zone and some basins in the continental platform, as well as the presence of faulted acoustic basement blocks, evidence that not all extension was accommodated by the Gulf Extensional Province during the middle to late Miocene. Part of the extension was (and is) accommodated in the Baja California Pacific margin. This confirms the observations

  7. Antioxidant screening and phenolic content of ethanol extracts of selected Baja California Peninsula macroalgae.

    Science.gov (United States)

    Tenorio-Rodriguez, Paola A; Murillo-Álvarez, Jesús I; Campa-Cordova, Ángel I; Angulo, Carlos

    2017-02-01

    The Baja California Peninsula in México has about 670 species of macroalgae along its coast. Species richness increases the probability of finding native macroalgae with potential as sources of bioactive compounds suitable for health, pharmacological, and cosmetic ingredients. To understand the biotechnological value of macroalgae from the peninsula, ethanol extracts from 17 macroalgae (four Chlorophyta, six Rhodophyta, seven Ochrophyta) were screened for antioxidant potential. To determine the antioxidant capacity of macroalgal extracts, 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power, and nitric oxide radical scavenging as well as total phenolic content (TPC) were measured. Extracts of the brown macroalgae were most active. Among these, Eisenia arborea, Padina concrecens , and Cystoseira osmundacea had the highest TPC and exhibited the strongest radical scavenging activities. Correlations were found between TPC macroalgal and scavenging capacity, indicating an important role of polyphenols as antioxidants. This suggests that some brown macroalgae from Baja California Peninsula may be a good source of natural bioactive compounds.

  8. Diseño de rotor para un aerogenerador de bajas velocidades

    Directory of Open Access Journals (Sweden)

    Hugo A. Arevalo

    2009-01-01

    Full Text Available En los ultimos afios ha existido un creciente interes en el disefio y el estudio de turbinas eólicas de baja velocidad debido a la mayor cantidad de lugares donde este potencial eólico esta presente. Usando elementos de Ia teoría de momentum del alabe (BEM y la teoría de la circulación, este articulo describe un metodo basado en el analisis del cambio de circulación y momentum a traves de cada estación del alabe, permitiendo calculos mas precisos y optimizando así el rendimiento del rotor en turbinas eólicas de eje horizontal, baja velocidad de viento y paso fijo. La comparaci6n de los resultados obtenidos con datos provenientes de turbinas eólicas reales muestra una alta similitud.

  9. An economical non-destructive method for estimating eelgrass, Zostera marina (Potamogetonaceae leaf growth rates: formal development and use in northwestern Baja California

    Directory of Open Access Journals (Sweden)

    Elena Solana-Arellano

    2008-09-01

    Full Text Available Seagrass beds provide much of the primary production in estuaries; host many fishes and fish larvae, and abate erosion. The present study presents original analytical methods for estimating mean leaf-growth rates of eelgrass (Zostera marina. The method was calibrated by using data collected in a Z. marina meadow at Punta Banda estuary in Baja California, Mexico. The analytical assessments were based on measurements of leaf length and standard regression procedures. We present a detailed explanation of the formal procedures involved in the derivation of these analytical methods. The measured daily leaf-growth rate was 10.9 mm d-1 leaf-1. The corresponding value projected by our method was 10.2 mm d-1 leaf-1. The associated standard errors were of 0.53 and 0.56 mm d-1 leaf-1 respectively. The method was validated by projecting leaf-growth rates from an independent data set, which gave consistent results. The use of the method to obtain the mean leaf growth rate of a transplanted plot is also illustrated. Comparison of our leaf-growth data with previously reported assessments show the significant forcing of sea-surface temperature on eelgrass leaf dynamics. The formal constructs provided here are of general scope and can be applied to equivalent eelgrass data sets in a straightforward manner. Rev. Biol. Trop. 56 (3: 1003-1013. Epub 2008 September 30.Las praderas de pastos marinos abaten la erosión y aportan gran parte de la productividad primaria de los esteros y son refugio de muchos peces y sus larvas. El presente trabajo introduce métodos analíticos para estimar las tasas medias de crecimiento foliar de Zostera marina L. y sus varianzas. La calibración del método se llevó a cabo utilizando datos de una pradera de esta fanerógama en el Estero de Punta Banda Baja California, México. Las referidas estimaciones analíticas, se basan en medias de longitud foliar y en procedimientos estandarizados de regresión. Dichas determinaciones son por

  10. Proyectos de actividad : aplicación para un local en planta baja

    OpenAIRE

    VALERO BIOT, RICARDO

    2011-01-01

    Pretende el presente Proyecto la obtención Licencia de Obra y Licencia Ambiental por parte del Ayuntamiento de Valencia para la actividad de bar-restaurante, habiéndose solicitado el correspondiente Informe de Compatibilidad Urbanística al Ayuntamiento de Valencia Valero Biot, R. (2011). Proyectos de actividad : aplicación para un local en planta baja. http://hdl.handle.net/10251/12467. Archivo delegado

  11. PECTINIDS AND OYSTERS FROM THE PLIOCENE LORETO BASIN (BAJA CALIFORNIA SUR, MEXICO)

    OpenAIRE

    PIAZZA, MICHELE; ROBBA, ELIO

    2017-01-01

    Fourteen pectinid and oyster species from the Pliocene Loreto Basin (Baja California Sur, Mexico) are recorded and discussed with regard to their relationships with closely related taxa. The whole assemblage points toward a Pliocene age. Aequipecten dallasi and Argopecten abietis abietis resulted to be the most useful biostratigraphic taxa, being restricted to Pliocene. The bulk of the considered species were confined within southern regions during the Pliocene. Crassostrea californica osunai...

  12. AUTOCHTHONOUS BIOFACIES IN THE PLIOCENE LORETO BASIN, BAJA CALIFORNIA SUR, MEXICO

    OpenAIRE

    PIAZZA, MICHELE; ROBBA, ELIO

    1998-01-01

    The present paper examines the molluscan and/or echinoid assemblages recovered from two lithostratigraphic units (Piedras Rodadas Sandstone and Arroyo de Arce Norte Sandstone) outcropping in the Pliocene Loreto Basin, Baja California Sur, Mexico. Ten biofacies have been identified, i.e. Trachycardium procerum-Trachycardium senticosum Biofacies, Chione compta-Transennella modesta Biofacies, Laevicardium elenense-Chione kelletii Biofacies, Xenophora sp. 1-Strombus subgracilior Biofacies, Crasso...

  13. Red-on-granite rock painting in the Sierra de San Borja, Baja California

    Directory of Open Access Journals (Sweden)

    Hany Crosby

    1995-01-01

    Full Text Available New discoveries in Baja California, north of the 28th parallel contradict an old tradition, and push the boundary of the Great Mural paintings further north than had been previously suggested. The new area not only displays works akin in size and subject matter to their more southern counterparts, but also shows some changes in choice of surfaces, paint colors, and stylistic conventions. Seven sites are reported; many others are predicted.

  14. Phylogeography of the diamond turbot (Hypsopsetta guttulata) across the Baja California Peninsula

    OpenAIRE

    Schinske, Jeffrey N.; Bernardi, Giacomo; Jacobs, David K.; Routman, Eric J.

    2010-01-01

    We compared morphology and sequenced nuclear and mitochondrial genes from 11 populations of a previously genetically unstudied "Baja California disjunct" species, the diamond turbot (Hypsopsetta guttulata). This species exhibits very limited adult movement and restriction to soft-bottom habitats but has a moderately long pelagic larval duration. Therefore, if pelagic larval duration is correlated with gene flow between Gulf of California and Pacific populations, we expect a reduced level of g...

  15. Tempo and mode of speciation in the Baja California disjunct fish species Anisotremus davidsonii.

    Science.gov (United States)

    Bernardi, Giacomo; Lape, Jennifer

    2005-11-01

    The Baja California region provides a natural setting for studying the early mechanisms of allopatric speciation in marine systems. Disjunct fish populations from several species that occur in the northern Gulf of California and northern Pacific coast of Baja California, but are absent from its southern shores, were previously shown to be genetically isolated, making them excellent candidates for studying allopatry. In addition, one of these species, the sargo Anisotremus davidsonii, has two pairs of congeneric Panamic trans-isthmian geminate species that allow for internal molecular clock calibration. Phylogeographic and demographic approaches based on mitochondrial (cytochrome b) and nuclear (S7 ribosomal protein) sequences showed that A. davidsonii entered the gulf from the south, and later colonized the Pacific coast, approximately 0.6-0.16 million years ago. Pacific coast colonization may have used a route either around the southern cape of Baja California or across the peninsula through a natural seaway. However, while several seaways have been described from different geological times, none matches the dates of population disjunction, yet much geological work remains to be done in that area. At the present time, there is no evidence for dispersal around the southern tip of the Baja California Peninsula. Signatures of incipient allopatric speciation were observed, such as the reciprocal monophyly of disjunct populations for the mitochondrial marker. However, other characteristics were lacking, such as a strong difference in divergence and coalescence times. Taken together, these results suggest that disjunct populations of A. davidsonii may be consistent with the earliest stages of allopatric speciation.

  16. Spanish Missions in the Indigenous Landscape: A View from Mission Santa Catalina, Baja California

    OpenAIRE

    Panich, Lee M.

    2010-01-01

    Mission Santa Catalina was founded on the margins of the Spanish colonial frontier in northern Baja California, but over time it became an important place in the indigenous landscape of the region. Dominican friars established the mission at a crossroads of native interaction, and recent archaeological, archival, and ethnographic research suggests that indigenous mission neophytes continued to engage in dynamic social and economic relationships with other native groupsthroughoutthecolonialper...

  17. Geophysical characterization of subaerial hydrothermal manifestations in Punta Banda, Baja California, Mexico.

    Science.gov (United States)

    Flores-Marquez, L.; Prol-Ledesma, R. M.; Arango, C.; Canet, C.

    2009-04-01

    Important growth of population in Baja California Peninsula has triggered the need for energy and fresh water. The most sustainable possibility for increasing the availability of fresh water is the use of renewable energy sources in desalination plants. The abundance of geothermal manifestations in the peninsula provides a reliable energy source for desalination purposes. Geothermal development of the Baja California Peninsula dates from the 70's, when the Cerro Prieto geothermal field started producing electricity. Two important cities, Tijuana and Ensenada, are located in the north-western area of Baja California. The city of Ensenada has a desalination plant that is due to be replaced and the geothermal resources of the area could be an option for the new desalination plant. Punta Banda, a region near Ensenada, was specially investigated to determine its geothermal potential. Subaerial springs and the submarine vents were sampled and studied in this work, also geological and geochemical studies were performed, moreover geoelectrical surveys were accomplished to characterize the hydrothermal system at depth. Even though saline intrusion is a severe problem in Ensenada (TDS higher than 3000), thermal springs away from the coast and coastal springs have salinities lower than sea water. According to the geoelectrical models obtained from profiles, the inferred conductive features can be related to thermal anomalies. The existence of hot springs located along a trend suggests that the dynamic of the thermal fluid is restricted by secondary faults.

  18. Geomorphology, deformation, and chronology of marine terraces along the pacific coast of central Baja California, Mexico

    Science.gov (United States)

    Woods, Alan J.

    1980-05-01

    Three emergent marine terraces are prominent between Playa El Marron and Arroyo El Salinito and comprise the most extensive Pleistocene planation surfaces in central Baja California, Mexico. The deposits of the lowest terrace, the Tomatal, are 120,000 ± 20,000 yr old (Sangamonian?) while the absolute ages of the two higher and older terraces, the Andrés and Aeropuerto, are unknown. The Tomatal terrace is particularly well developed and comprises degraded sea cliffs, paleodunes, and lagoonal sequences. Shingle paleobeach ridges also occur locally and reflect shore progradation and tombolo formation. The Tomatal shoreline is nearly horizontal at 7 ± 1 m above present mean sea level, whereas the older Aeropuerto terrace has been tilted so that it decreases in elevation toward the southeast. Nonetheless, coastal tilting is not nearly as great as at many other localities in California and Baja California. This is despite the fact that the entire Baja California peninsula has been assumed to be tectonically unstable during the Pleistocene, primarily because of the forces generated by plate motion.

  19. Uranium-series ages of marine terraces, La Paz Peninsula, Baja California Sur, Mexico

    Science.gov (United States)

    Sirkin, L.; Szabo, B. J.; Padilla, G. A.; Pedrin, S. A.; Diaz, E. R.

    1990-03-01

    Uranium-series dating of coral samples from raised marine terrace deposits between 1.5 and 10 m above sea level in the La Paz Peninsula area, Baja California Sur, yielded ages between 123 ka and 138 ka that are in agreement with previously reported results. The stratigraphy and ages of marine units near the El Coyote Arroyo indicate the presence of two high stands of the sea during the last interglacial or oxygen isotope substage 5e at about 140 ka and 123 ka. Accepting 5 m for the sea level during the last interglacial transgression, we calculate average uplift rates for the marine terraces of about ≦70 mm/ka and 40 mm/ka. These slow rates of uplift indicate a relative stability of the La Paz peninsula area for the past 140 000 years. In contrast, areas of Baja California affected by major faultf experienced higher rates of uplift. Rockwell et al. (1987) reported vertical uplift rates of 180 to 300 mm/ka at Punta Banda within the Aqua Blanea fault zone in northern Baja California.

  20. Wind Energy Assessment for Small Urban Communities in the Baja California Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Quetzalcoatl Hernandez-Escobedo

    2016-10-01

    Full Text Available Mexico needs to exploit its renewable resources and many studies have determined the great renewable potential it has using wind energy. However it is necessary to calculate the amount of this resource for small urban communities, which in this country lack essential services such as electricity. This study is focused in the Baja California Peninsula, using GIS as a tool to identify small urban zones with higher wind power. For this work data was analyzed from meteorological stations and recorded every 10 min for two years (2012–2014. Weibull distribution, linear regression, kriging interpolation, power and energy output and useful hours were calculated for each station. It was found that the total energy generated is 38,603,666 kWh per year and the mean of useful hours is 5220 h per year for the whole Peninsula. Maps of Wind Power Density (WPD show a good power per square meter, GIS shows the areas with the most wind power where it can be used i.e., the state of Baja California wind power can generate electricity for 12% of those communities, meanwhile for Baja California Sur, the electric power generation could electrify almost 25% of the total of small urban communities.

  1. Sector externo, crecimiento económico y bienestar en Baja California: 1970-1988

    Directory of Open Access Journals (Sweden)

    Jorge García Montaño

    1990-05-01

    Full Text Available El presente trabajo tiene el objetivo de presentar los efectos del desarrollo del sector externo de Baja California en el crecimiento de la economía local y en relación con algunos indicadores del bienestar social. También se estudian algunos indicadores nacionales comparativos entre la entidad y los promedios nacionales, tal que permitan ubicar las especificidades del desarrollo de Baja California. El trabajo se divide en varios apartados: ciclos económicos, comportamiento del sector externo y sus relaciones con el producto interno bruto y la inflación. Todas estas variables interactúan en este estudio macroeconómico regional.La conclusión, hace referencia a que en Baja California el sector externo cumple el papel determinante para el crecimiento económico y el bienestar social; por lo tanto, cualquier trastorno negativo en sus variables desagregadas impacta inmediatamente las tasas de crecimiento y los niveles de vida de la población bajaca1iforniana, fundamentalmente los cambios extraordinarios del tipo de cambio peso-dólar y los ajustes de las políticas en comercio exterior. De ahí la actualidad del estudio, dado que el Tratado de Libre Comercio de México con Estados Unidos y Canadá tendrá, seguramente, importantes impactos en la entidad.

  2. Los concheros de Baja California y sus perspectivas de investigación

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    Agustín Téllez Duarte

    1987-09-01

    Full Text Available El presente artículo pretende enfatizar sobre la presencia de conchas en sitios arqueológicos, los cuales nos proporcionan una gran cantidad de información cultural sobre los asentamientos humanos, particularmente en los concheros de Baja California. En Baja California se localizan en forma intermitente a todo lo largo de sus costas, tanto en el golfo de California como en el Pacífico. Con este proyecto se pretende rescatar aquellas colecciones que aún puedan conservarse, considerando que las excavaciones de Palmer fueron muy productivas a pesar de haber sido relativamente pequeñas. Se espera que este primer intento de excavación arqueológica-científica de un conchero proporcione datos relevantes para comprender más ampliamente la organización de las antiguas sociedades humanas de Baja California, antes de que se pierdan totalmente los testimonios legados. Y a su vez, motive un mayor interés y apoyo en el estudio de los casi ignorados concheros.

  3. Fishing time and trap ghost fishing for Cancer johngarthi along the Baja California Peninsula's sowthwestern coast, Mexico

    OpenAIRE

    Ramírez Rodríguez, Mauricio; Arreguín Sánchez, Francisco

    2008-01-01

    During trap-fishing investigations on the crab Cancer johngarthi along Baja California peninsula's southwestern coast, Baja California Sur, Mexico, conducted between 2002 and 2006, information was gathered to assess fishing efficiency in terms of the number of crabs caught per trap during one hour of operation (catch per unit of effort, CPUE = c/ht). As a result of vessel operation issues, some trap lines were abandoned, whereas vessels returned to land for repairing, and because the effectiv...

  4. Valoración del paisaje de la selva baja caducifolia en la cuenca baja del río Papagayo (Guerrero, México

    Directory of Open Access Journals (Sweden)

    Arturos García Romero

    2012-02-01

    Full Text Available En la actualidad existe un amplio interés por el valor del paisaje como una alternativa de análisis ambiental, sin embargo, esta aproximación ha sido poco utilizada en los ecosistemas de México. El objetivo de este estudio fue determinar el valor del paisaje en la selva baja caducifolia (SBC de la cuenca baja del río Papagayo, Guerrero, México. Se realizó una clasificación jerárquica de paisajes y se aplicó un índice de valor del paisaje basado en cuatro indicadores: sensibilidad de laderas, fragmentación, calidad visual y significado social. Los resultados indican que el área está constituida por tres sistemas de paisajes –montañas, lomeríos y llanura aluvial– definidos por cambios morfo-litológicos y bioclimáticos; 17 subsistemas de paisajes y 16 paisajes elementales, definidos por los tipos de vegetación, usos de suelo y niveles de perturbación. El valor del paisaje fue heterogéneo, aunque tiende a ser mayor en los subsistemas montañosos de selvas y bosques, debido a que son más inaccesibles, por lo que el significado social y los niveles de perturbación y fragmentación se reducen. En contraste, los subsistemas de lomeríos con selva baja caducifolia tienen alto significado social debido a la cercanía y accesibilidad, lo cual favorece la intensificación de los usos del suelo, el incremento de la fragmentación y la caída de la calidad visual y del valor natural del paisaje. Si bien, la vegetación secundaria de la SBC (acahual ha sido valorada por su importancia en los mecanismos de regeneración de las selvas, en este caso obtuvo un valor reducido debido a la intensidad en el manejo de recursos, tanto en el pastoreo, como en la extracción de leña y la producción de carbón. El método implementado en este estudio permite sintetizar el balance entre la degradación ambiental y los caracteres de la apropiación cultural del paisaje en escalas geográficas amplias.

  5. PUBLICIDADE EM CELULARES UTILIZANDO O SISTEMA DE BUSCA DE PERFIL

    Directory of Open Access Journals (Sweden)

    Bruno Gomes de Araújo

    2010-04-01

    Full Text Available A publicidade vem causando um impacto cada vez mais perceptível na sociedade moderna, o qual se percebe nas mudanças de hábitos e costumes das pessoas. Entretanto, os atuais métodos de transmissões publicitárias estão se tornando problemáticos, devido à incorreta utilização e também devido à grande preocupação com o meio ambiente e com a qualidade de vida. Neste contexto, esse trabalho propõe a criação de um sistema para envio de mensagens publicitárias via celulares. Para tanto, utilizando um mecanismo de busca de perfil. A busca é responsável por localizar os celulares ativos, baseando-se no padrão Bluetooth. Um perfil consiste em todas as informações referentes a um usuário, as quais caracterizam os seus interesses. Após a localização e identificação do perfil o usuário receberá em seu celular mensagens de seu interesse. O processo de localização e sincronização de perfil é realizado de forma totalmente automática, aumentando assim a usabilidade do sistema.

  6. Diseño e implementación de un sistema de transferencias de datos a través de la red eléctrica de baja tensión con la interfaz Labview-arduino empleando la tecnología power line communications (PLC).

    OpenAIRE

    Ponce León, David; Santillán Aguirre, Sergio

    2016-01-01

    La propuesta del proyecto de titulación está basada en la implementación de un nuevo sistema de transferencia mediante tecnología Power Line Communications (PLC), Comunicación por la Red Eléctrica, que se fundamenta en la transmisión de información en diferentes puntos utilizando la red eléctrica ya existente de baja tensión en el Laboratorio de Telecomunicaciones, con la finalidad de contribuir con nuevas opciones de comunicación, de envío y recepción de información para aplicaciones tecnoló...

  7. Volcanic and Tectonic Evolution of The Gulf of California Near Mulege, Baja California Sur: Results From Baja Basins NSF-REU (Research Experience for Undergraduates)

    Science.gov (United States)

    Hutchinson, S. J.; Allard, J.; Acuna, N.; Graettinger, A. H.; Busby, C.

    2017-12-01

    Cenozoic volcanic rocks have been studied along many parts of the Gulf of California margin of Baja California because they provide a record of its volcano-tectonic evolution, from subduction (24-12 Ma), to rifting (820 m thick red bed sequence, sourced to the east by andesitic volcanic rocks eroded from the footwall of a west-dipping normal fault. Proximal alluvial fan bajada deposits are debris-flow dominated, with angular clasts up to 1.3 m in size. Distal braided stream deposits have sandstones and cobble conglomerates, with abundant cut and fill structures and rounded clasts. Adakite trachyandesite block-and-ash-flow tuffs are interstratified with the proximal deposits, representing pyroclastic flows generated by collapse of lava domes plumbed up the basin-bounding fault to the east. (2) The redbeds were cut by a dike swarm that fed a field of lava shield volcanoes. The dikes and lava shields include calcalkaline basaltic andesite, andesite and dacite, as well as magnesian trachyandesite and basaltic andesite. (3) A N-S, subvertical fault stepped into the basin and dropped the lava shields down to the east, while they were eroded off the uplifted footwall to the west. (4) The footwall block was beveled and overlain by plateau-forming magnesian basaltic trachyandesite lavas. Basal clastic sequences in the Baja Gulf of California margin have been inferred to represent Oligocene forearc rocks, with overlying volcanic rocks recording westward sweep of the Miocene arc into the area. However, on the basis of our geochemistry, we infer that all of these rocks record post-subduction (<12 Ma) processes. 1 Acuna et al., this volume

  8. Evaluación del cultivo de la dorada ( Brycon moorei sinuensis en jaulas flotantes utilizando cuatro alimentos concentrados.

    Directory of Open Access Journals (Sweden)

    Robinsón Rosado

    2003-12-01

    Full Text Available El presente estudio se inició el 30 de septiembre del2000 con el cultivo de Dorada (Brycon mooreisinuensis en jaulas flotantes en el reservorio de laGranja Piscícola Tamarindo (El Espinal, Colombia,utilizando cuatro alimentos concentrados durante 180días. Se determinó el crecimiento mediante laganancia en longitud, ganancia en peso, tasa decrecimiento específico, sobre-vivencia final, biomasatotal, factor de condición, factor de conversiónalimenticia. Se sembraron 816 juveniles con longitudpromedio de 17.8 cm y peso promedio de 78.9 g,divididos en cuatro tratamientos con densidad desiembra de 25 peces/cm3 y tres réplicas cada uno.Las dietas balanceadas (proteína bruta y la cantidadde energía (Kcal/Kg suministrada fueron: Tratamiento1: 20% y 2637; tratamiento 2: 32% y 3127;tratamiento 3: 28% y 2852; y tratamiento 4: 24% y2751, respectivamente. El diseño experimental fuecompletamente aleatorio y se aplicó la técnica deanálisis de varianza a los datos biométricos yparámetros físico-químicos. Como prueba designificancia se usó la prueba de Tukey-Kramer con95% de confiabilidad. El modelo matemático de VIONBERTALANFY y la transformación de FOR-WALFORDfueron válidos para el ajuste de las curvas decrecimiento en longitud, peso y la relación longitud– peso. Se puede afirmar que la Dorada consumiólas dietas de origen vegetal de igual manera que lasde origen animal, sin embargo la dieta del 28% deproteína bruta (tratamiento 3 muestra los mejoresresultados, sin diferencias significativas entretratamientos (p > 0.05. De acuerdo con la literaturacitada no hay investigaciones que muestren losrequerimientos nutricionales óptimos para laalimentación de esta especie. En todos los trabajosanteriores, la ganancia de peso diaria fue baja, peromejores que las obtenidas en esta investigación.Mientras que el rendimiento en biomasa fue mayorque los reportados para cultivo en tierra, para todoslos tratamientos en este estudio fue muy bajo.

  9. Movilidad de población y comportamiento reproductivo: El caso de Baja California

    Directory of Open Access Journals (Sweden)

    Gabriel Estrella Valenzuela

    1992-09-01

    Full Text Available Este trabajo tiene como objetivo central evaluar el impacto indirecto que genera la inmigración hacia Baja California a través del comportamiento reproductivo de la población que, al migrar, ha cambiado su residencia habitual a la entidad. Para lograr ese objetivo, se analiza la información de las Encuestas Demográficas de Baja California de 1986 y 1990 con el modelo de los determinantes próximos de la fecundidad. Los resultados de dicho análisis muestran, por una parte, que los patrones reproductivos de la población migrante y no-migrante son c1aramentediferenciados (tanto en términos de fecundidad ilegítima como de formación de uniones, de sus prácticas anticonceptivas y de lactancia postparto, y que de ello se deriva un diferencial de fecundidad que resulta ser 17.5% superior para la población migrante en 1990. Por otra parte, los resultados también permiten estimar que, por cada tres nuevos inmigrantes que por año recibe la entidad, la inmigración acumulada aporta dos nuevos residentes con los nacimientos generados por las mujeres migrantes. Dada la magnitud que adquieren esos procesos (i.e. 59 mil nuevos habitantes por año ~ total, se concluye sugiriendo líneas generales de acción que permitan adecuar la política de población a las condiciones específicas de Baja California

  10. Almacenaje de pupas y adultos del parasitoide Tamarixia triozae (Hyamenoptera: Eulophidae) a temperaturas bajas.

    OpenAIRE

    Cerón González, Claudia

    2013-01-01

    Tamarixia triozae es un ectoparasitoide con alto potencial para su uso en programas de manejo integrado del psílido de la papa, Bactericera cockerelli. Aunque ya se produce comercialmente, no existe información de su almacenaje a bajas temperaturas, esta información puede tener importancia para optimizar la conservación de estos organismos. En el presente trabajo se evaluó la respuesta de pupas y adultos de T. triozae después de almacenarlos a 5, 8 y 10°C por 7, 14 y 21 días. Los resultados s...

  11. Use of a TTA plate for correction of severe patella baja in a Chihuahua.

    Science.gov (United States)

    Edwards, George A; Jackson, Andrew H

    2012-01-01

    A 7 yr old spayed female Chihuahua presented for right hind limb lameness and reduced stifle range of motion. Radiographs showed a marked patella baja of the right stifle and evidence of a previous surgery to correct a medial patellar luxation. A tibial tuberosity osteotomy was performed to allow proximal translation of the tibial tuberosity, which was stabilized with a tibial tuberosity advancement plate. Four weeks postoperatively, lameness and articular range of motion were improved, and the use of anti-inflammatory and analgesic medications was discontinued. The dog was still ambulating well and had no lameness 12 mo postsurgically.

  12. Especialización industrial y desarrollo empresarial en Baja California

    OpenAIRE

    Alejandro Mungaray; Claudio Cabrera

    2003-01-01

    La especialización industrial en Baja California en el sector de productos metálicos, maquina ria y equipo, s e asocia en economías de redes por interacciones de costos entre las grandes empresas asiáticas y del sur de California que conviven en la región conforme a las nuevas reglas del TLCAN y el fuerte peso de la subcontratación y las operaciones intraindustriales. En este contexto, se evalúa el impacto sobre la vida económica y social de las empresas para comprobar...

  13. Crecimiento industrial y riesgo urbano: El caso de Mexicali, Baja California

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    Pablo Jesús González Reyes

    1994-07-01

    Full Text Available El presente artículo consiste en una valoración de situaciones de riesgo ambiental relacionadas con incendios, explosiones y emanaciones tóxicas, debidas al creciente manejo de substancias químicas en la industria manufacturera del área urbana de Mexicali, Baja California. La metodología incluye la utilización de sistemas de información geográfica. Con el uso de esta herramienta se identifican con claridad diversas áreas de riesgo en la ciudad y se proponen, además, algunas alternativas para la toma de decisiones.

  14. The Southern Baja - Islas Marías - Sinaloa Transect: What is common? What was moving?

    Science.gov (United States)

    Schaaf, P. E.; Perez-Venzor, J.; Solis, G.; Hernandez, T.; Arrieta, G. F.; Pompa, V.; Villanueva, D.

    2013-12-01

    The Gulf of California extensional province constitutes an issue of ongoing multidiscipline investigations. It is considered as a result of late Miocene to Pliocene faulting and 'Comondu-type' magmatism related to Pacific-North America plate boundary motions. Transtensional faulting has rifted Baja California obliquely away from mainland Mexico over the past 12 Ma. To understand these processes and to reconstruct transportation distances, it is helpful to look back into the past. In this contribution we present a V-shaped lithological and geochronological profile, starting from the Los Cabos Block, Baja California Sur to the west, passing southerly Islas Marias Islands in the mouth of the Gulf and ending in south-central Sinaloa (Mazatlan region) to the east. All three locations display 80 Ma plutonic rocks of granodioritic to tonalitic compositions with similar Sr and Nd isotope signatures. Voluminous to minor shaped early Cretaceous gabbro outcrops are found south of La Paz (Novillo Massif) and ca. 30 km N of Mazatlan. The basement of the three sites is composed of 160-170 Ma (+/- migmatitic) orthogneisses, covered by schists and paragneisses with detrital zircon peaks at ca. 260, 520, and 1000 Ma. Abundant calc-silicates are found in the southern Los Cabos Block as well as on Maria Madre Island. Sandstones and shales from Islas Marias can be divided into two units with minimum detrital zircon ages of 80 Ma and 21 Ma, respectively. The micropaleontological record in these sediments indicates repeated uplift and subsidence events, related to the opening of the Gulf of California. In Maria Magdalena island, the sedimentary sequence is intruded in sills by < 21 Ma MORB-type gabbros. The overwhelming lithological and geochronological similarities of the Los Cabos Block and Islas Marias rock units give strong evidence for their common and continuous magmatic and metamorphic evolution and confirm a 400-450 km NW displacement of southern Baja. Larger offsets are

  15. Efecto de las Radiaciones Electromágneticas de baja frecuencia en el desarrollo embrionario

    OpenAIRE

    Sastre Yáñez, Javier

    2014-01-01

    En los últimos años la tecnología ha tenido un rápido desarrollo con el objetivo de hacer nuestras vidas más sencillas. Así, se han creado multitud de dispositivos que permiten las comunicaciones de forma inalámbrica, como el teléfono móvil y los dispositivos wifi, los cuales utilizan radiaciones electromagnéticas de baja frecuencia para su uso. Sin embargo, el aumento masivo de usuarios de estos dispositivos ha obligado al mundo científico a estudiar sobre los efectos de este tipo de radiaci...

  16. Las aljamas mudéjares valencianas en la baja Edad Media

    OpenAIRE

    Ruzafa García, Manuel Ginés

    1993-01-01

    Las aljamas, sistema de gobierno local de la minoría mudéjar durante la baja Edad Media, tuvieron una doble funcionalidad basada en la normalización de la vida cotidiana y en el control de las actividades de esta minoría. Mientras en el plano normativo se mostraba una legitimidad basada en el mutuo respeto, siempre bajo el control de la autoridad pública cristiana, la vida cotidiana de las morerías fue el reflejo de unas relaciones de dominación de carácter social clasista. El peso de las oli...

  17. Efectos de la exposicion a bajas concentraciones de plomo en ratones sobre diferentes parametros bioquimicos

    OpenAIRE

    N. Martínez Riera; R.A. Sant Yacumo; N. Riera de Martínez Villa

    2001-01-01

    Las bases moleculares que explicarían los efectos de la exposición crónica a bajos niveles de plomo sobre diferentes procesos bioquímicos, no se encuentran bien esclarecidos aun. Varios estudios sugieren que el plomo (Pb2+) induce alteraciones en diversos parámetros bioquímicos y hematológicos. Este estudio se realizó con el objeto de determinar los efectos de exposición de ratones a bajas concentraciones de Pb2+ sobre las siguientes variables: glucosa plasmática (GP), co...

  18. Whole genome sequencing of Mycobacterium bovis to obtain molecular fingerprints in human and cattle isolates from Baja California, Mexico.

    Science.gov (United States)

    Sandoval-Azuara, Sarai Estrella; Muñiz-Salazar, Raquel; Perea-Jacobo, Ricardo; Robbe-Austerman, Suelee; Perera-Ortiz, Alejandro; López-Valencia, Gilberto; Bravo, Doris M; Sanchez-Flores, Alejandro; Miranda-Guzmán, Daniela; Flores-López, Carlos Alberto; Zenteno-Cuevas, Roberto; Laniado-Laborín, Rafael; de la Cruz, Fabiola Lafarga; Stuber, Tod P

    2017-10-01

    To determine genetic diversity by comparing the whole genome sequences of cattle and human Mycobacterium bovis isolates from Baja California. A whole genome sequencing strategy was used to obtain the molecular fingerprints of 172 isolates of M. bovis obtained from Baja California, Mexico; 155 isolates were from cattle and 17 isolates were from humans. Spoligotypes were characterized in silico and single nucleotide polymorphism (SNP) differences between the isolates were evaluated. A total of 12 M. bovis spoligotype patterns were identified in cattle and humans. Two predominant spoligotypes patterns were seen in both cattle and humans: SB0145 and SB1040. The SB0145 spoligotype represented 59% of cattle isolates (n=91) and 65% of human isolates (n=11), while the SB1040 spoligotype represented 30% of cattle isolates (n=47) and 30% of human isolates (n=5). When evaluating SNP differences, the human isolates were intimately intertwined with the cattle isolates. All isolates from humans had spoligotype patterns that matched those observed in the cattle isolates, and all human isolates shared common ancestors with cattle in Baja California based on SNP analysis. This suggests that most human tuberculosis caused by M. bovis in Baja California is derived from M. bovis circulating in Baja California cattle. These results reinforce the importance of bovine tuberculosis surveillance and control in this region. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Macroalgas submareales de la bahía de Todos Santos, Baja California, México Submareal macroalgae of the Todos Santos Bay, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Raúl Aguilar-Rosas

    2010-12-01

    Full Text Available Con el fin de identificar y caracterizar la composición de especies de la zona submareal de la bahía de Todos Santos, Baja California, México; se realizaron muestreos de macroalgas marinas bentónicas en 7 sitios durante 1995-2000. Como resultado de 25 buceos Scuba entre 3 y 33 m de profundidad se encontraron 150 especies de macroalgas para el área de estudio; 10 son Chlorophyta, 26 Phaeophyta y 114 Rhodophyta. Del total, 47 son registros nuevos para el área de estudio y 2 de éstos, Faucheocolax attenuata Setchell y Minium parvum R.L. Moe, son nuevos para la flora marina del Pacífico de México. Se incluye una revisión de las investigaciones en las que se han considerado las macroalgas presentes en la bahía de Todos Santos y una discusión sobre la composición de las especies encontradas, su distribución vertical y reproducción, así como sobre las especies epífitas y parásitas del área.In order to identify and characterize the species composition of the subtidal zone of the Todos Santos Bay, Baja California, Mexico, benthic marine macroalgae were sampled at 7 sites from 1995 to 2000. As a result of 25 scuba at derds for the study area, of which Faucheocolax attenuata Setchell and R.L Moe Minium parvum are new to the marine flora of Pacific Mexico. We include a research that consider the macroalpths between 3 and 33 m we found a total of 150 species of macroalgae for the study area, of which 10 are Chlorophyta, 26 Phaeophyta and 114 Rhodophyta; 47 species represent new recogae in the Todos Santos Bay and a discussion on the composition of species found, its vertical distribution and reproduction, particularly the species epiphytes and parasites present in the study area.

  20. The invented Baja California: visions of a Mexican territory in the middle 20th century

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    Héctor Mendoza Vargas

    2014-02-01

    Full Text Available This article examines the travels of Peter Gerhard and Ángel Bassols Batalla through the Baja California in the 1950s from a comparative perspective. From the theo-retical viewpoints of the history of geography and the geographical journey as sources of information and working method in situ, the observation and empirical knowledge of the territory are established. The traveling style of both authors involves a cultural consideration, since an invented space emerges before their eyes from their own experience in the peninsula. As a traveler, Peter Gerhard journeyed the peninsula seeking the ancient missions that distinguished Baja California. That is why he organized and integrated the information in a guide, in collaboration with Howard E. Gulick. He conceived the guide for tourists of the United States interested in this region so close to their country. Published in 1956, the guide became the most complete instrument for vacationists in general, and also for sport fishermen, hunters, explorers and campers.

  1. Talla baja: enfoque diagnóstico y bases terapéuticas

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    G. Verónica Mericq, Dra.

    2013-09-01

    Full Text Available La talla baja es un motivo de consulta cada vez más frecuente que el pediatra debe pesquisar. En la evaluación debe incluir una historia clínica completa, examen físico con una correcta evaluación auxiológica y un seguimiento adecuado de la velocidad de crecimiento. De esta forma, los exámenes complementarios irán orientados a confirmar una sospecha diagnóstica. A pesar de que la mayoría de los pacientes tendrá una talla baja idiopática o variante normal, en alrededor de un 5% estaremos frente a patología. El enfoque terapéutico, debe estar siempre orientado a la causa. Existen terapias que pueden mejorar la estatura final pero tienen indicaciones precisas y no están exentas de complicaciones. Un estilo de vida saludable y un ambiente psicosocial favorable, permitirán que el niño desarrolle al máximo su potencial genético.

  2. A Weather Analysis System for the Baja California Peninsula: Tropical Cyclone Season of 2008

    Science.gov (United States)

    Farfán, L. M.

    2009-05-01

    General characteristics of tropical weather systems are documented on a real-time basis. This study covers the warm season of 2008, from May through November, and includes observations from satellite imagery as well as reports from a rain-gauge network. During this season, the basin had 16 tropical storms and three of them made landfall in the Baja California peninsula, in northwestern Mexico. Tropical storm Julio developed in August and tropical storm Lowell made landfall in mid-September. Norbert, in early October, was the most intense hurricane of the season with strong winds and heavy rainfall that caused significant damage to the infrastructure in the southern peninsula. By the next day, the system moved over the mainland, causing major flooding in Sinaloa, Sonora, and Chihuahua. By request of the Baja California government, a meteorological perspective associated with the structure, intensity, and motion of Hurricane Norbert was presented. This consisted of high-resolution satellite imagery used to explain the spatial and temporal patterns of convection. This material provided an integral analysis of Norbert's behavior during its approach and passage over land, and it was one element, used by emergency managers, to determine the extent of the affected areas.

  3. Solar Resource for Urban Communities in the Baja California Peninsula, Mexico

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    Alberto-Jesús Perea-Moreno

    2016-11-01

    Full Text Available Several studies have determined that Mexico has great renewable energy potential, and one of its most abundant resources is solar energy, a source that could be exploited to provide development opportunities to its population, however it is necessary to calculate the amount of this source available. The aim of this study was to assess solar irradiance at urban communities in the Baja California Peninsula. For this purpose data recorded every 10 min during 6 years (2010–2015 by the Automatic Meteorological Stations (AMSs and Synoptic Automatic Meteorological Stations (SAMSs of the National Meteorological System of Mexico (NMS were analyzed. Satellite data from the Surface and Meteorology Energy System (SMSE were also used, and a linear regression was performed to compare the measured and satellite data. The highest R-square value found was 0.97 and the lowest was 0.82. Daily patterns show that Cabo San Lucas had the highest average solar irradiation/day, with 1000 W/m2. Considering the urban areas, total solar irradiation reaching the Peninsula is about 447 × 106 kWh, which represents around 447 times the total Baja California Peninsula yearly energy consumption. Geographic Information System (GIS helped to identify the zones and months with higher solar resources. May is the month registering the highest irradiation, more than 8.1 kWh/m2/day, while the average solar resource for the whole Peninsula is 5.7 kWh/m2/day.

  4. Politic alternation in Baja California: Toward a new balance of powers

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    Cuauhtémoc López Guzmán

    2001-01-01

    Full Text Available Ever since the National Action Party (PAN won the governor elections in the State of Baja California in 1989, Mexico experienced the inauguration of a political alternation in a governor’s office, which brought about the smashing of the myth that it was impossible for the PRI to share power at that level. The scarce forums won or surrendered by the party ever present in power, allowed the opposition to confront and criticize the centralization of power and the neutralization of representation, that is, rather than offering its voters nationalistic discourses, the opposition parties joined the cause of the anti-centralist resent, particularly present in the northern part of the country, and discredited the decaying relationship between the legislative and the executive powers (the presidency, both at a federal and states levels. In view of these considerations, the possibilities of setting the foundations for a new horizontal and vertical relationship among powers in the state of Baja California, which during the last ten years has been governed by the National Action Party, are discussed in this essay.

  5. Desarrollo, identidad cultural y turismo en los oasis de Baja California Sur, México

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    Alexandra Sauvage

    2013-01-01

    Full Text Available This article provides an analysis of the integration of San Miguel and San José de Comondú to the process of economic globalization lived in Baja California Sur, in northwest Mexico. These rural communities are located in one of the largest oasis in the arid Baja California peninsula and face the risks of cultural commodification from the growth of the real estate and tourism sectors. In a context of diffuse integration to new markets and a weak local community involvement in the initiatives to foster economic growth, without a cultural policy that involves comundeños in defining their own heritage and the benefits of its use, the goal of local development attached to the recent public policies is questionable. We propose that a cultural policy should form the backbone of the development programmes now being elaborated, so as to articulate regional development needs with cultural heritage conservation, seeking to avoid the simple commodification of local traditions and recognizing the role of the local community in (redefining their cultural values.

  6. Kekasaran Permukaan Baja Karbon Sedang Akibat Proses Sand-Blasting dengan Variasi Jarak Nosel

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    I Made Widiyarta

    2016-07-01

    Full Text Available Abstrak: Proses sand-blasting merupakan proses yang dilakuan untuk membersihkan dan merubah kekasaran permukaan material. Proses ini umumnya dilakukan sebelum melakukan proses pelapisan permukaan material dengan tujuan untuk meningkatkan daya rekat lapisan pada permukaan material yang dilapisi. Pada penelitian ini, proses sand-blasting dilakukan pada baja karbon sedang dengan variasi jarak nosel untuk memperoleh perubahan kekasaran permukaan material. Hasil pengujian menunjukkan perubahan jarak nosel pada proses sand-blasting memberikan pengaruh yang cukup signifikan pada kekasaran permukaan. Kata kunci: sand-blasting, baja karbon sedang, kekasaran permukaan Abstract: Sand-blasting is a process of surfaces treatment to clean and to roughen surface of material. This process is commonly used in preparing the surface before the coating process in order to increase the bond strength of the coating material on the surface of substrate material. In this work, sand-blasting process is conducted to the medium carbon steel with varying nozzle distance to the surface of material. The experiment results show the different nozzle distance causes the change of surface roughness significantly. Keywords: sand-blasting, carbon steel, surface roughness

  7. Electrical conductivity of the crust in central Baja California, México, based on magnetotelluric observations

    Science.gov (United States)

    Romo, J. M.; Gómez-Treviño, E.; Flores-Luna, C.; García-Abdeslem, J.

    2017-12-01

    Crustal and sub-crustal structure of northwestern Mexico (peninsular California) resulted from major accretion episodes occurred during the long-lived subduction of the Farallon plate beneath the North American plate, since late Jurassic time. A magnetotelluric profile across central Baja California reveals several electrical conductivity anomalies probably associated to the crustal boundaries of distinct Mezosoic terranes juxtaposed in the current peninsular crust. It is known that electrical conductivity is significantly increased by the pervasive presence of conductive minerals generated during metamorphic processes in highly sheared zones. We interpret a striking sub-horizontal conductivity anomaly reveled in the model as explained by the presence of high-salinity fluids released after dehydration of the subducted Magdalena microplate (Farallon plate?). The presence of fluids at the base of the peninsular crust may produce a zone of weakness, which supports the idea that Baja California lithosphere has not been entirely coupled to the Pacific plate. In addition, crustal thickness is estimated in our model in about 35 km beneath the western Peninsular Ranges batholith (PRB) and 20 km beneath the eastern PRB. This crustal thickness is in good agreement with independent estimations of a thinner crust in the Gulf of California margin and a thicker crust along the axial PRB.

  8. PENINGKATAN EFEKTIFITAS DAN EFISIENSI BIAYA KUALITAS MELALUI PENEDEKATAN SIMULASI (Studi Kasus di CV. SINAR BAJA ELEKTRIC

    Directory of Open Access Journals (Sweden)

    I Gede Agus Widyadana

    2003-01-01

    Full Text Available The paper discusses about how to increase product quality and still concern with quality cost. We add factor of time to count quality cost and the effect to quality product. Time has important function in this research, so simulation is used to analyze quality control system. The simulation on CV. Sinar Baja Elektrik shows that the propose method can decrease product reject about 8% and quality cost until 16,89% from total sales. Abstract in Bahasa Indonesia : Makalah ini membahas mengenai upaya untuk meningkatkan kualitas produk dengan memperhatikan biaya kualitas. Penelitian ini memasukan tambahan faktor waktu dalam memperhitungkan biaya kualitas serta dampaknya pada kualitas produk. Oleh karena faktor waktu memegang peranan yang penting, maka analisa sistem pengendalian kualitas pada penelitian ini menggunakan metode simulasi. Hasil simulasi di CV. Sinar Baja Elektrik menunjukan metode yang diusulkan dapat menurunkan hasil rata-rata tingkat kelolosan produk cacat untuk tiap tipe speaker hingga berkisar 8%, dan total biaya kualitas secara keseluruhan dapat diturunkan hingga sebesar 16.89% dari total penjualan. Kata kunci: biaya kualitas, efisiensi, efektivitas, simulasi.

  9. Baja visión y envejecimiento de la población

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    Maritza Miqueli Rodríguez

    Full Text Available El envejecimiento poblacional constituye un tema de gran preocupación mundial por su asociación con diversas enfermedades del ser humano que limitan su calidad de vida; muchas de ellas degenerativas. Se realiza una revisión con el objetivo de obtener una información actualizada sobre las causas de la baja visión y el envejecimiento poblacional. Cuba se sitúa en el cuarto lugar dentro de los países más envejecidos de América Latina. Con el envejecimiento aumentan los cambios fisiológicos y el deterioro visual, por lo que los ancianos de más de 60 años tienen ocho veces más probabilidad de tener un daño visual que los jóvenes. De ahí la importancia de diagnosticar y tratar oportunamente las enfermedades para evitar su progresión y las discapacidades visuales. El glaucoma constituye la segunda causa de ceguera en el mundo y la primera de ceguera irreversible en América Latina. Se sitúa entre las primeras causas de baja visión en Cuba, por lo que se deben desarrollar programas de detección de este, para así continuar elevando la expectativa de vida y proporcionarle una longevidad satisfactoria a nuestra población.

  10. Occurrence of Batrachochytrium dendrobatidis in anurans of the Mediterranean region of Baja California, México

    Science.gov (United States)

    Peralta-Garcia, Anny; Adams, Andrea J.; Briggs, Cheryl J.; Galina-Tessaro, Patricia; Valdez-Villavicencio, Jorge H.; Hollingsworth, Bradford; Shaffer, H. Bradley; Fisher, Robert N.

    2018-01-01

     Chytridiomycosis is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) and is regarded as one of the most significant threats to global amphibian populations. In México, Bd was first reported in 2003 and has now been documented in 13 states. We visited 33 localities and swabbed 199 wild-caught anurans from 7 species (5 native, 2 exotic) across the Mediterranean region of the state of Baja California. Using quantitative PCR, Bd was detected in 94 individuals (47.2% of samples) at 25 of the 33 survey localities for 5 native and 1 exotic frog species. The exotic Xenopus laevis was the only species that tested completely negative for Bd. We found that remoteness, distance to agricultural land, and elevation were the best predictors of Bd presence. These are the first Bd-positive results for the state of Baja California and its presence should be regarded as an additional conservation threat to the region’s native frog species. 

  11. Phytoplankton on the western coasts of Baja California in two different seasons in 1998

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    David U. Hernández-Becerril

    2007-12-01

    Full Text Available Phytoplankton was studied in two different seasons of 1998 (March-April and December, during two cruises along the western coasts of Baja California, in three zones. Two different protocols for obtaining and studying phytoplankton were followed. In the March-April season, phytoplankton had relatively low species richness and was dominated in cell density (up to 93% by coccolithophorids (mainly Emiliania huxleyi, together with nanoplanktonic centric and pennate diatoms, with abundances ranging from 5.4 103 to 1.2 105 cells L-1. In December, phytoplankton had higher species richness and was represented by larger, chain-forming diatom species, such as Pseudonitzschia delicatissima and P. pungens, which were widespread and numerically significant. There was a relative scarcity of coccolithophorids and thecate dinoflagellates, and densities were between 7 102 and 1.4 106 cells L-1. Hydrographic and oceanographic conditions in March-April were influenced by the occurrence of El Niño and the phytoplankton structure was found to be modified accordingly, with nanoplanktonic coccolithophorids and diatoms being significant contributors to the total abundance. In contrast, post-upwelling conditions might have favoured relatively high densities of Pseudonitzschia and other diatoms in December, 1998. Coccolithophorids have not been previously regarded as important contributors to the phytoplankton abundances in Baja California.

  12. The FAMEX Cruise off Baja California (March/April 2002) : Preliminary Results

    Science.gov (United States)

    Michaud, F.; Bourgois, J.; Royer, J.; Dyment, J.; Sichler, B.; Bandy, W.; Mortera, C.; Calmus, T.; Vieyra, M.; Sosson, M.; Pontoise, B.; Bigot-Cormier, F.; Diaz, O.; Hurtado, A.; Pardo, G.; Trouillard-Perrot, C.

    2002-12-01

    The pioneering work on spreading-ridge subduction (Dickinson and Snyder, 1979) describes the evolution of slab geometry beneath southwestern US and northwestern Mexico since the Middle Miocene. This work develops the slab-window concept and the tectonic and magmatic effects of the slab-free geometry on the Cordilleran system. Because no ridge-subduction was proposed to have occurred south of 30°N (Lonsdale, 1991), question arose as to whether a slab-free area also extended beneath southern Baja California. The Chile triple junction area (46°S) is a well-studied example of active ridge-subduction. This area exhibits the effects of slab-free development on the time distribution of magmatism and tectonism within the overriding continental block. Moreover, recent fieldwork conducted along the southern Baja California volcanic belt supports that slab melting under relatively shallow and warm conditions occurred during Upper Miocene time. When combined with the Miocene-Recent volcanic record of Baja California, a parallel drawn between the Chile and Mexico triple junction areas substantiates slab window development beneath southern Baja California peninsula during the past 12-10 m.y. The FAMEX cruise of the R/V Atalante (March-April 2002) was conducted to better constrain the ridge-subduction history in the area off southern Baja California. More than 5000 miles of swath bathymetry, magnetic, gravity record and 6 channels seismic reflection profiles were realized from 29°N to 22°30'N. Also, three magnetic deep-tow profiles were performed to provide a higher resolution of the magnetic signal and age of the corresponding oceanic crust. The study area displays two distinct morphological areas: (1) north of 27°30'N, the Guadalupe rift is a deep trough that trends roughly N-S. On either sides of the rift, the neighboring oceanic fabric trends parallel to it; (2) south of 27°N, the oceanic fabric is much more complicated and strongly contrasts with the regular fabric

  13. Waning Miocene subduction and arc volcanism in Baja California: the San Luis Gonzaga volcanic field

    Science.gov (United States)

    Martín, Arturo; Fletcher, John M.; López-Martínez, Margarita; Mendoza-Borunda, Ramón

    2000-03-01

    Subduction of the Guadalupe-Magdalena microplate beneath Baja California ended in the middle Miocene, and the last volcanic events in the frontal arc extinguished along the present-day eastern margin of the Baja California peninsula. The San Luis Gonzaga area in the north-central Gulf coast contains one of the younger arc-related volcanic centers in northern Baja California. The volcanic succession contains three sequences. The basal sequence (Group 1) is composed of stratified pyroclastic deposits, up to 500 m thick, and subordinate lava flows. The near-vent facies crop out in tilted fault blocks along the present shoreline, whereas the distal facies are exposed across ˜12 km toward the west and includes epiclastic deposits and at least three ash flow tuffs. This sequence is internally concordant and overlies smooth paleosurface developed on granitic basement, and pinches out across the Gulf escarpment. The Potrero Andesite (Group 2) is a series of dacite to basaltic-andesite lava flows from a shield volcano located ˜15 km west of today's coastline; similar source vents also occurs further south of the San Luis Gonzaga area. A sequence of dacite domes (Group 3) intrudes the near-vent facies of Group 1 and contains subordinate volcanic breccia and minor lava flows that overlie Group 1 sequence. Cross-cutting relationships and the abundance of volcanic breccia associated with the domes suggest that these domes were emplaced as semi-rigid intrusions (spines) with low explosive activity. The San Luis Gonzaga volcanic suite ranges in composition from basaltic andesite to dacite with predominant plagioclase and pyroxene and variable amounts of hornblende. Trace-element patterns indicate calc-alkaline to mildly alkaline magmas with high Ba and low Nb contents. Incompatible-element ratios and mineralogical characteristics suggest different magma batches and/or different amount of crustal assimilation for the three sequences that produced contrasting eruptive styles. A

  14. Microdureza de caries incipientes artificiales infiltradas con resinas de baja viscosidad antes y después del termociclado

    OpenAIRE

    X. Zamorano Pino; V. Valenzuela Aránguiz; C. Vial Prado; M. Vidal Tardón

    2015-01-01

    Introducción: En Odontología Mínimamente Invasiva, el procedimiento denominado Infiltración de caries, pretende detener la progresión de las caries incipientes mediante el sellado de las microporosidades del esmalte afectado. Este tratamiento se realiza con la aplicación de resinas de baja viscosidad. El objetivo de este trabajo fue evaluar la microdureza superficial de caries incipientes artificiales infiltradas con resinas de baja viscosidad antes y después del proceso de termociclado. Meto...

  15. Baja prevalencia de la infección por el virus de la hepatitis C en una población de reclusos, Maracaibo, Venezuela

    Directory of Open Access Journals (Sweden)

    Francisca Monsalve

    2009-12-01

    Conclusiones. La prevalencia de la infección por el virus de la hepatitis C en esta población fue baja, lo que evidencia la baja circulación del virus en el reclusorio. El principal factor de riesgo para la adquisición de la infección, al parecer, es el uso de drogas intravenosas.

  16. Proceedings of the Binational Conference on Libraries in California and Baja California (1st, Tijuana, Baja California, Mexico, January 13-14, 1984) = Memorias de la Primera Conferencia Binacional de Bibliotecas de las Californias.

    Science.gov (United States)

    Ayala, Marta Stiefel, Ed.; And Others

    This document includes the text of presentations given at the First Binational Conference on Libraries in California and Baja California, as well as minutes from four roundtables held at the conference. Following a prologue and a brief background on the conference, the following presentations are included: (1) "State Support for Public…

  17. The Palaeodiet of the Pericue Indians of the Cape Region of Baja California Sur, Mexico.

    Science.gov (United States)

    Beer, N.; Gonzalez, S.; Huddart, D.; Rosales-Lopez, A.; Lamb, A.

    2008-05-01

    The archaeology of the Pericue Indians inhabiting the Cape region of Baja California has long been an area of interest. The dolichocranic traits exhibited by this population have lead to suggestions that these people were a relic population of an early coastal migration into North America. The antiquity of directly dated Pericue human remains only reaches 3,000 B.P. with occupation sites dating back to 9,000 B.P. The site of Babisuri cave in Isla Espiritu Santo may demonstrate a very early human presence in Baja California Sur between 36,000 to 45,000 B.P. although the exact nature of this evidence is unclear. Increasing tourist development within this region threatens many archaeological sites particularly coastal shell middens and rock shelters. Current rescue excavations are yielding important information regarding many aspects of the culture of the Pericue Indians. Geochemical evidence of diet {d13C and d15N} taken from Pericue bone samples, modern and archaeological animals and modern plants is helping us to understand the complicated subsistence strategies of this group. Initial results highlight a complicated and diverse diet including marine and terrestrial resources, most likely exploited seasonally. Similarities between the diet of the Pericue and other nearby coastal Indian groups are clear and will be discussed. Pericue Indian material culture, combined with the exploitation of marine mammals and the construction of enormous shell mounds display parallels with other central and North American groups. The exploitation of marine mammals and the associated stone tools display striking similarities to the Chumash people of the Channel Islands of Coastal Southern California. Some of these cultural similarities will be highlighted in this presentation. Current genetic work is attempting to discover the nature of the similarities between the Chumash and Pericue groups as some cultural elements of each group have parallels with the other. Initial genetic

  18. COMPOSICIÓN FLORÍSTICA Y ESTRUCTURA DE LOS BOSQUES RIBEREÑOS DE LA CUENCA BAJA DEL RÍO PAUTO, CASANARE, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Diego Mauricio Cabrera-Amaya

    2016-01-01

    Full Text Available Se caracterizó la composición florística y aspectos de la estructura de la vegetación en bosques ribereños de la cuenca baja del río Pauto (Colombia, Casanare utilizando la información de nueve parcelas de 20 x 50 m (1000 m², se midieron el diámetro a la altura del pecho (DAP, la altura total y cobertura de la copa. Se analizó la riqueza y los valores de importancia por especie y por familia. Se realizó un análisis para establecer una clasificación local de los tipos de bosque, los cuales se describieron en términos de clases diamétricas y altimétricas, diagramas estructurales e índice de predominio fisionómico. Se registraron 185 especies, 127 géneros y 56 familias, la mayor riqueza florística se agrupó en las familias Rubiaceae, Moraceae, Myrtaceae, Fabaceae y Bignoniaceae y en los géneros Ficus, Piper, Psychotria e Inga. Las familias con mayor IVF fueron Arecaceae, Fabaceae, Euphorbiaceae, Moraceae y Verbenaceae. Las especies más importantes según su IVI fueron: Attalea butyracea, Clarisia biflora, Sarcaulus brasiliensis, Dendropanax arboreus e Inga interrupta. Se encontraron seis comunidades, de las cuales sólo la primera se ha mencionado con anterioridad: 1 Palmar de Mauritia flexuosa y Euterpe precatoria, 2 Bosque de galería de Copaifera pubiflora y Homalium racemosum, 3 Bosque de vega de Discocarpus spruceanus y Sloanea terniflora, 4 Bosque de vega de Attalea butyracea y Garcinia madruno, 5 Bosque de galería de Attalea butyracea e Inga interrupta, y 6 Bosque de vega Attalea butyracea y Clarisia biflora. Los bosques presentan múltiples estratos con alturas del dosel desde los 18 m sobre las riberas de los caños, hasta 25 m en las vegas de los ríos. La riqueza y la composición concuerdan con los patrones florísticos de la Orinoquía colombiana, especialmente a nivel de familia, pero son menos las coincidencias a nivel de género y especie. La concentración de individuos en clases diamétricas pequeñas es

  19. Baja concordancia entre la información clínica de atención primaria y hospital

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    Concha Revilla-López

    2016-04-01

    Conclusiones: La baja concordancia de la información diagnóstica contenida en AP y hospital obliga a adoptar medidas que permitan a los profesionales sanitarios a conocer el conjunto de problemas de salud que presenta un paciente.

  20. Phylogeography and Ecological Niche Modeling of the Desert Iguana (Dipsosaurus dorsalis, Baird & Girard 1852) in the Baja California Peninsula.

    Science.gov (United States)

    Valdivia-Carrillo, Tania; García-De León, Francisco J; Blázquez, Ma Carmen; Gutiérrez-Flores, Carina; González Zamorano, Patricia

    2017-09-01

    Understanding the factors that explain the patterns of genetic structure or phylogeographic breaks at an intraspecific level is key to inferring the mechanisms of population differentiation in its early stages. These topics have been well studied in the Baja California region, with vicariance and the dispersal ability of individuals being the prevailing hypothesis for phylogeographic breaks. In this study, we evaluated the phylogeographic patterns in the desert iguana (Dipsosaurus dorsalis), a species with a recent history in the region and spatial variation in life history traits. We analyzed a total of 307 individuals collected throughout 19 localities across the Baja California Peninsula with 15 microsatellite DNA markers. Our data reveal the existence of 3 geographically discrete genetic populations with moderate gene flow and an isolation-by-distance pattern presumably produced by the occurrence of a refugium in the Cape region during the Pleistocene Last Glacial Maximum. Bayesian methods and ecological niche modeling were used to assess the relationship between population genetic structure and present and past climatic preferences of the desert iguana. We found that the present climatic heterogeneity of the Baja California Peninsula has a marked influence on the population genetic structure of the species, suggesting that there are alternative explanations besides vicariance. The information obtained in this study provides data allowing a better understanding of how historical population processes in the Baja California Peninsula can be understood from an ecological perspective. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. 78 FR 20887 - Approval of Subzone Status; Pepsi Cola Puerto Rico Distributing, LLC, Toa Baja, Puerto Rico

    Science.gov (United States)

    2013-04-08

    ... Foreign-Trade Zones Board Approval of Subzone Status; Pepsi Cola Puerto Rico Distributing, LLC, Toa Baja, Puerto Rico On December 7, 2012, the Executive Secretary of the Foreign-Trade Zones (FTZ) Board docketed an application submitted by the Puerto Rico Industrial Development Company, grantee of FTZ 7...

  2. Restricciones de liquidez en microempresas y la importancia del financiamiento informal en Baja California

    Directory of Open Access Journals (Sweden)

    Martín Ramírez-Urquidy

    2009-01-01

    Full Text Available La estructura industrial de México incorpora una proporción significativa de agentes que emprenden negocios a escalas reducidas y en un esquema de informalidad. Esta condición los aleja de los mercados formales de crédito, por lo que enfrentan una restricción permanente de liquidez. Este artículo prueba la hipótesis de que existen microempresas (MES no restringidas a pesar de esta limitación formal. Los resultados ilustran esta posibilidad al encontrar, en una muestra de mes del estado de Baja California, lo que implica el acceso a financiamiento externo y la importancia de las fuentes informales.

  3. Farallon slab detachment and deformation of the Magdalena Shelf, southern Baja California

    Science.gov (United States)

    Brothers, Daniel S.; Harding, Alistair J.; Gonzalez-Fernandez, Antonio; Holbrook, W.S. Steven; Kent, Graham M.; Driscoll, Neal W.; Fletcher, John M.; Lizarralde, Daniel; Umhoefer, Paul J.; Axen, Gary

    2012-01-01

    Subduction of the Farallon plate beneath northwestern Mexico stalled by ~12 Ma when the Pacific-Farallon spreading-ridge approached the subduction zone. Coupling between remnant slab and the overriding North American plate played an important role in the capture of the Baja California (BC) microplate by the Pacific Plate. Active-source seismic reflection and wide-angle seismic refraction profiles across southwestern BC (~24.5°N) are used to image the extent of remnant slab and study its impact on the overriding plate. We infer that the hot, buoyant slab detached ~40 km landward of the fossil trench. Isostatic rebound following slab detachment uplifted the margin and exposed the Magdalena Shelf to wave-base erosion. Subsequent cooling, subsidence and transtensional opening along the shelf (starting ~8 Ma) starved the fossil trench of terrigenous sediment input. Slab detachment and the resultant rebound of the margin provide a mechanism for rapid uplift and exhumation of forearc subduction complexes.

  4. Agave turneri (Agavaceae), a new species from northeastern Baja California, Mexico

    Science.gov (United States)

    Webb, Robert H.; Salazar-Ceseña, J. Mario

    2011-01-01

    Agave turneri, a new species of Agave from the Sierras Cucapá and El Mayor in northeastern Baja California, Mexico, is a medium-sized species that does not produce offsets, has a relatively short and narrow panicle, and has a distinctive flower structure. The closest relatives to this new species are Agave moranii, which occurs approximately 200 km to the south of the type locality, and A. deserti var. simplex, which occurs in Arizona and California. This new species is a narrow endemic restricted to specific granodiorite and tonalite habitats in a hyperarid environment. Agave turneri appears to be a critically endangered owing to its habitat preference for specific types of granite in the Sierra Cucapá, threats due to prolonged drought and global change, and its close proximity to the Mexicali metropolitan area.

  5. SINTESIS PIGMEN BESI OKSIDA BERBAHAN BAKU LIMBAH INDUSTRI BAJA (MILL SCALE

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    Tito Prastyo Rahman

    2013-05-01

    Full Text Available Limbah industri baja (mill scale digunakan sebagai alternatif bahan baku pigmen besi oksida. Kajian ilmiah ini menjelaskan proses pembuatan pigmen besi oksida melalui metode presipitasi dengan media air. Pigmen besi oksida yang menjadi target yaitu pigmen kuning goethit ( -FeOOH dan merah hematit ( -Fe2O3. Goethit diperoleh dengan presipitasi menggunakan amonia dari proses awal terbentuknya ferricssulfat hasil reaksi asam sulfat (H2SO4 dengan limbah mill scale, sedangkan hematit diperoleh dengan proses pemanasan goethit pada temperatur 5000C dan 9000C. Analisa XRD digunakan untuk mengetahui senyawa pigmen yang terkandung dan penggunaan DTA untuk mengetahui pola perubahan fasa akibat proses pemanasan fasa goethit. Analisa warna pigmen menggunakan collorimetri L*a*b System. Warna pigmen yang diperoleh mempunyai tinting strength yang masih kurang dibandingkan dengan pigmen impor.

  6. Elaboración y posterior tratamiento del hormigón a bajas temperaturas

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    Meyer, A.

    1962-09-01

    Full Text Available Not availableEl hormigonado en ambiente frío con heladas requiere un especial cuidado y un control mejor que en el caso de temperaturas normales. En la obra cerrada de invierno, los diferentes elementos o el total de la obra y la preparación del hormigón se efectúan con calefacción y protección. Esto, generalmente, sólo se hace para temperaturas exteriores muy bajas. Las instalaciones especiales en una obra crean un mayor gasto y, en consecuencia, solamente resultan rentables en obras especialmente importantes. En la obra cerrada de invierno, el hormigón se elabora a temperaturas normales, condiciones que se mantienen durante el tratamiento posterior. En este caso, no aparece nada especial al hormigonar bajo estas condiciones.

  7. Hombres violentados en la pareja. Jóvenes de Baja California, México

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    Humberto González Galbán

    2014-01-01

    Full Text Available El objetivo del presente trabajo es contribuir a la creación de conocimiento y conciencia sobre la violencia de pareja de la mujer contra el hombre, ello para el caso es - pec í ¿co de los jóvenes heterosexuales de Baja California. Para tal ¿n se presentan algunos antecedentes de estudio realizados en el contexto internacional y nacional, y se analiza dicha problemática en el escenario bajacaliforniano, que se sustenta en elementos empí - ricos disponibles sobre la entidad. Entre los hallazgos de mayor interés se destaca la alta incidencia de violencia contra los jóvenes en esta parte de la frontera norte de México, características sociodemográ¿cas y sociopsicológicas asociadas a la referida situación y el surgimiento de nuevas interrogantes sobre esta transcendente temática.

  8. Stratigraphy, petrology, and tectonic setting of the Alisitos Group, Baja California, Mexico

    Science.gov (United States)

    Beggs, J. M.

    The Alisitos Group comprises much of the wall-rocks of the western Peninsular Ranges Batholith in Baja California, Mexico; aspects of its stratigraphy, petrology, and tectonic origin are discussed. The Alisitos group was formerly designated Alisitos Formation. A higher rank of stratigraphic nomenclature is suggested because of its wide extent and lithologic diversity. Two new formations are defined within the Alisitos Group in the San Fernando area. The El Progreso Formation includes volcanic and volcaniclastic rocks mainly of silicic composition interstratified with rudist limestones. The type area is the El Progreso area. It is overlain to the southwest by the San Felipito Formation, which includes tuff-breccia, graded tuff beds, and shale as principal rock types. The main canyon of Arroyo San Fernando is designated as type area.

  9. Implementing relational marketing in a coffee selling company in Baja California

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    Isaac Cruz Estrada

    2018-01-01

    Full Text Available The aim of this investigation is to propose a relationship marketing process in a coffee selling company in Baja California as a case study. First, relationship marketing is conceptualized and its contribution to the creation of value in organizations is analyzed; moreover, empirical studies from various authors, who point out the influence of this process on customer satisfaction, are included. 149 surveys were conducted in order to obtain the correlation between the guarantee to offer a product or service and value generation by delivering tangible and intangible elements for customer satisfaction. This proposal belongs to the company where the research was carried out; it can be adapted to organizations which offer a service and are in the situation studied.

  10. Ayudas visuales en niños y adolescentes con baja visión

    OpenAIRE

    Fernández Fernández, Manola Elena

    2017-01-01

    Con el objetivo de conocer las ayudas visuales ópticas y no ópticas usadas con mayor frecuencia en niños y adolescentes, describirlas y reconocer su eficacia en el desempeño escolar, se realiza la presente revisión bibliográfica. Se muestran las causas más frecuentes que ocasionan baja visión en niños y adolescentes, y se presentan las ayudas visuales, que forman parte de su intervención en la rehabilitación visual, clasificándolas en ayudas ópticas, ayudas electrónicas y ayudas no ópticas...

  11. Preliminary geologic studies of Sierra El Aguajito (Baja California, Mexico): a resurgent-type caldera

    Science.gov (United States)

    Garduño-Monroy, V. H.; Vargas-Ledezma, H.; Campos-Enriquez, J. O.

    1993-12-01

    Geologic field studies conducted in the Quaternary volcanic field of Tres Virgenes (State of Baja California Sur, Mexico) revealed the existence of a resurgent caldera. The caldera's eruptive products, the Aguajito sequence, overlie the products of the nearby Reforma caldera (Reforma sequence) whose youngest products have already been dated as Quaternary. The rim of the Aguajito caldera is inferred by the existence of an arcuate alignment of rhyolitic domes. The mean diameter of this subcircular feature is 10 km. The volume of its mapped acidic products is a minimum of 10 km 3. Several horizons within the sequence contain shells. K/Ar dates of the ignimbrites and domes of El Aguajito formation confirm that the unit are Pleistocene. The detailed stratigraphy also shows the evolution of a marine regression partly related to the caldera.

  12. Management by results in Mexico, 2013-2014. Some effects in Baja California

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    José María Ramos García

    2016-07-01

    Full Text Available This paper examines the results-based management (RBM proposal promoted by the Mexican federal government and how this proposal has been applied. This article presents the theory of management according to its results and its effects on competitiveness and well-being. This article analyzes the conceptual elements of the model and the manners in which this model has been instituted both conceptually and operationally in Brazil, Mexico, and the Mexican state of Baja California. Principal findings include the need to strengthen institutional capacities for RBM to enhance competitiveness and well-being at the government level, internalize a vision of strategic change, and prioritize cultural change to generate efficient transparency, accountability and anti-corruption controls by a transversal focus based on the elements of management.

  13. Tratamiento del herpes simple labial con láser de baja potencia

    OpenAIRE

    Bianka M. González; Adel Hernández; Adonis Estevez

    2008-01-01

    Introducción: El herpes simple es causado por Herpes virus hominis, que produce una afección eruptiva aguda de uno o más grupos de vesículas sobre una base eritematosa; puede localizarse en cualquier parte del cuerpo preferentemente en la boca y los genitales precedida y acompañada de ardor y prurito.Objetivos: Se evaluó la efectividad del tratamiento con láser de baja potencia en relación al tratamiento convencional según la evolución clínica, desaparición de síntomas y signos en los pacient...

  14. Possibilities of Mexican SMEs insertion in the aerospace industry value chain, the Baja California case

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    Juana Hernández Chavarria

    2018-01-01

    Full Text Available The goal of this article is to analyze the aerospace industry in Baja California, Mexico. The methodology is based on the application of an electronic questionnaire and face-to-face in depth interviews. Our results shows that the insertion of companies has been conditioned by several factors: the basic certification is only the first step; the real challenge is to find niches of opportunity and bargaining power to achieve a productive contract, which demands entrepreneurial, legal and economic skills. This analysis is a pioneer in the study of Mexican companies participating in this emerging sector. The main limitations were the access to the companies’ information and the rejection to participate in the study. The main finding is there are very few Mexican suppliers integrated to the global value aerospace chain but if the trend of growth is maintained, it may had greater integration in the near future, and possibly a greater economic spill and technology transfer.

  15. Characteristics regarding the consumer of giant squid from Baja California Sur, Mexico

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    Liliana Enriqueta Montaño Méndez

    2015-01-01

    Full Text Available The catch of the giant squid (Dosidicus gigas, represents de second fishing activity most important in volume in Baja California Sur, Mexico; is an essential specie not only at the state level but at the pacific and even the national level. Mexico occupies in the world the eight level in the production of squid, but the national consumption, even though the low price of the product and the high nutritional level, is approximately 0.53 kg per year, very low compared to countries like Japan, Korea and Spain (average consumption per capita is of 3.5 kg . In this context, the objective of this article is to caracterize the sudcalifornia consumer preference; determine the buying habits and the consumption; and also to establish the market areas of the squid in Baja California Sur, which allows the introduction of actions for its commercialization, in order to strengthen the market of this product and its general activity. This is why in 2012 a questioner of 1066 consumers was distribute around the five counties of the state, according to the population density. The results indicate that the principal motive why there is not consumption is the difficulty to find places where to buy it, together with the problems of cooking it. Also, it can be seen the high level of ignorance the consumer has regarding the nutritional level this food has. For this reason, future strategies for the commercialization must be focus on better distribution and new form of presenting this product which facilitates its preparation and consumption, and at the same time create campaign which increase awareness of the nutrition level this product has.

  16. Prevalencia de baja visión y ceguera en un área de salud

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    Lisis Osorio Illas

    2003-10-01

    Full Text Available Nuestro trabajo se propuso determinar la prevalencia de baja visión y ceguera en el policlínico "Elpidio Berovides" en el municipio Lisa; así como conocer diferentes aspectos epidemiológicos relacionados con estas enfermedades. Se analizaron como variables: edad, sexo, antecedentes patológicos familiares (APF y personales (APP, tanto oculares como generales, y por último las afectaciones psicosociales de estos pacientes. Estos datos se analizaron a través de tablas. Como resultado de nuestra investigación encontramos una tasa de prevalencia de baja visión de 230 x 100 000 hab y una tasa de ceguera de 40 x100 000 hab, afectándose principalmente los pacientes mayores de 60 años. Las principales causas de estas enfermedades fueron el glaucoma con un 16 %, la miopía degenerativa (14,8 % y otras enfermedades de la retina. Todos los pacientes afectados presentaron limitaciones desde el punto de vista psicosocial.Our paper was aimed at determining the prevalence of low vision and blindness at "elpidio Berovides" polyclinics, Lisa municipality, Havana City and also finding out different epidemiological aspects related to these diseases. The variables taken were: age, sex, pathological family history and personal history, both general and ocular, and lastly psychosocial effects on these patients. Tables and graphs helped to analyze these data. As a result of our research work, we found a prevalence rate of low vision equals to 230 x 100, 000 pop whereas blind rate is 40 x 100 000 pop, affecting mainly patients over 60 years. The fundamental causes of these diseases were glaucoma, 16%; degenerative myopia, 14.8% and other retinal diseases. All these patients presented with restrictions from the psychosocial viewpoints.

  17. Población de galaxias de baja luminosidad en cúmulos

    Science.gov (United States)

    Valotto, C. A.; Muriel, H.; Moore, B.; García Lambas, D.

    En este trabajo se discute sobre la presencia de un exceso de galaxias de baja luminosidad en medios de alta densidad de galaxias y la posibilidad de que los halos de galaxias cD puedan ser formados a partir de galaxias en cúmulos ricos, los cuales muestran una función de luminosidad (FL) con el extremo débil plano. Se analizaron muestras de cúmulos cercanos obtenidas a partir de los catálogos de Abell y X-ray Sample of Bright Clusters. Los resultados obtenidos muestran que los cúmulos de galaxias que tienen emisión en rayos X detectada poseen una FL plana (α ≈ -1.2), consistente con los valores encontrados para las galaxias de campo. En cambio, los cúmulos de galaxias identificados a partir de distribuciones bidimensionales de galaxias que no tienen su contraparte en rayos X, muestran una FL con una pendiente pronunciada en el extremo débil (α ≈ -1.6). Se examinaron además, los posibles efectos debido a la presencia de una galaxia central dominante sobre el extremo débil de la FL. Se analizaron muestras de acuerdo a la clasificación Bautz-Morgan dividiendo en las submuestras I,I-II y II, II- III, III. Las FL resultantes para ambas muestras son indistinguibles. Nuestros resultados son consistentes con la hipótesis de que los efectos de proyección en cúmulos identificados en dos dimensiones pueden producir un exceso artificial de galaxias de baja luminosidad.

  18. Microseismicity Studies in Northern Baja California: The Sierra Juárez Fault System

    Science.gov (United States)

    Frez, J.; Gonzallez, J.; Nava, F.; Acosta, J.; Carlos, J.; Garcia-Arthur, R.

    2007-12-01

    The Sierra Juarez is one of the major, well defined, and active fault systems of northern Baja California. During two months of 2002, we installed 30 seismological stations (digital, three-components, Reftek instruments) between latitudes 31.6º N and 32.2º N, surrounding the most active part of this system as well as the SE segment of the San Miguel fault and the region in between. Almost half of the stations were installed in the Laguna Salada basin, located East of Sierra Juarez ranges and 1500 m below them. Observations resulted in 4200 high-quality hypocenter and ~500 focal mechanism determinations; magnitudes and rupture planes are still to be determined. For locating we use the Nava and Brune (1982) seismic structure, complemented with station residuals which are small and negative for stations located in the Sierra ranges. For stations installed in the Laguna Salada basin, residuals vary between 0.30s and -0.15s, with the exception of three sites where mean residuals reach -.50s. Seismic activity occurs either aligned (SE segment of the San Miguel fault) or in small clusters with radii ~1.5 km (elsewhere). Predominant depths are around 10 km with a secondary maximum at 5 km. Focal mechanism solutions show a consistent pattern which is common for all northern Baja California, with predominant strike-slip (a nodal plane striking in a NW-SE direction) and normal (T-axes mostly in EW direction) solutions. This pattern is interpreted as a transtensive regime consisting of strike-slip faults intercalated with extension zones; this pattern seems to be repeated at various scales. Also discussed are other details, like the interpretation of normal faulting in the scarp separating the Sierra Juarez ranges from the Laguna Salada basin, the dip of the fault planes, and interpretation of travel time residuals

  19. Goat milk fatty acid composition in the Peninsula of Baja California, Mexico

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    Eduardo Toyes-Vargas

    2013-11-01

    Full Text Available Objective. The objective of the study was to determine the composition of fatty acids in milk of Creole goats in an extensive production system in an arid region of the peninsula of Baja California and compare it to two seasons of the year (rainy and dry. Materials and methods. Sampling was conducted during the dry season (June and after the rainy season (December in the municipality of Comondú in Baja California Sur. The extensive production system used involved releasing goats to roam freely in the rangeland to graze for food, and no additional food or supplements were provided. Results. The most abundant fatty acids were saturated fatty acids (66.3 and 70.9% in the rainy and dry reasons, respectively. The most abundant of these were palmitic, myristic, and stearic acid in both seasons. Monounsaturated fatty acids (15-20% were the most numerous in terms of isomers, but mostly in low concentrations. The largest average constituent of polyunsaturated fatty acids (5-6% was linoleic acid (3% and alpha-linolenic acid (1.2% in both seasons. Branched, fatty acid concentrations were highly variable; the only stable constituents were C15:0 iso (1.5% and C16:0 anti-iso, with 0.7% of total fatty acids. Conclusions. The seasons in this extensive production system significantly effected the composition of most monounsaturated and branched fatty acids in goat milk; however, saturated and polyunsaturated showed only a few compositional changes in abundance of fatty acids. Moreover, season effects were not significant on the total fatty acid content, except for branched fatty acids and omega-3.

  20. ¿Remesas a la baja para el estado de Michoacán?

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    Erik Jonathan Orozco García

    2013-06-01

    Full Text Available El tema de las remesas en un contexto mundial no es nuevo, este ha existido desde nuestra antigüedad con el origen de las migraciones de la humanidad, sin embargo hoy en día con la globalización y gracias a la carencia y crisis por las que pasa en general el mundo y más algunos países como lo son México, India y China se ha visto aún más marcado, ya que los países de destino de todos estos migrantes como lo es Estados de Unidos de América siendo este el principal receptor, han generado diversos problemas, desde el incremento del empleo informal, problemas políticos generando así reformas en sus constituciones, sociales, económicos, sin embargo, y en caso contrario, para los países que de los cuales migran estas persona, tal es el caso de México se vuelve en cierta medida un ingreso no presupuestado para las económicas internas de sus estados, Michoacán es de los principales estados que en gran medida depende de esta remesa enviada por sus compatriotas, esto se puedo observar después de la crisis del 2008, en donde la caída de las remeses para el año 2009 bajaron en promedio del 25%, afectando la propia estabilidad del estado, por eso es indispensable realizar una proyección para los año venideros, es de suma importancia analizar si las remesas para el estado de Michoacán van a la baja, ya que bajo este supuesto el estado podrá tomar las medidas necesarias públicas para contrarrestar su baja o en caso contrario canalizar adecuadamente el gasto por los michoacanos.

  1. PENGARUH VARIASI SUHU POST WELD HEAT TREATMENT ANNEALING TERHADAP SIFAT MEKANIS MATERIAL BAJA EMS-45 DENGAN METODE PENGELASAN SHIELDED METAL ARC WELDING (SMAW

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    Rusiyanto Rusiyanto

    2012-02-01

    Full Text Available Penelitian ini bertujuan Untuk mengetahui nilai kekerasan Vickers material Baja EMS-45 sebelum proses pengelasan dan setelah dilakukan proses pengelasan tanpa post weld heat treatment annealing, Untuk mengetahui berapakah suhu optimal post weld heat treatment annealing untuk material baja EMS-45 dengan variasi suhu yang digunakan 350 o C, 550 o C, dan 750 C. Untuk mengetahui struktur mikro dari material baja EMS-45 akibat variasi suhu post weld heat treatment annealing pada proses pengelasan dengan menggunakan metode pengelasan shielded metal arc welding. Bahan atau material dasar yang digunakan pada penelitian ini adalah Baja EMS-45 dengan ketebalan pelat 10 mm, lebar pelat 20 mm dan panjang 100 mm. Berdasarkan hasil pengujian nilai kekerasan tertinggi setelah proses pengelasan terletak pada daerah Logam Las. Pengelasan non PWHT memiliki nilai kekerasan paling tinggi setelah proses pengelasan yaitu sebesar 183,2 VHN. Suhu optimal Post Weld Heat Treatment Annealing untuk material baja EMS-45 adalah pada suhu 750 C. Karena pada PWHT pada suhu tersebut mengalami penurunan kekerasan yang besar yaitu sebesar 127,2 VHN, sehingga material baja EMS-45 dapat memperbaiki sifat mampu mesinnya. Struktur mikro dari material baja EMS-45 sebelum proses pengelasan berupa grafit serpih, perlit dan ferit, setelah dilakukan proses pengelasan mempunyai struktur mikro berupa matrik ferit dan grafit pada daerah logam las, matrik perlit kasar dan grafit serpih pada daerah HAZ dan struktur perlit, grafit serpih dan ferit pada daerah logam induk o o

  2. Diversidad y abundancia de macroinvertebrados acuáticos y calidad del agua de las cuencas alta y baja del río Gariché, provincia de Chiriquí, Panamá

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    Tomás Ríos

    2013-08-01

    Full Text Available Se determinaron la diversidad y abundancia de macroinvertebrados acuáticos, así como la calidad del agua,en cuatro estaciones de muestreo ubicadas en las subcuencas alta y baja del río Gariché, durante la época seca (eneroa abril y lluviosa (julio a octubre de 2010, utilizando los métodos descritos por Pino & Bernal (2009. Se identifi caronun total de 4 964 individuos, pertenecientes a 50 géneros, 30 familias y nueve órdenes de la clase Insecta. El índicede diversidad de Shannon-Weaver en promedio para la época seca fue de 2.36 y en época lluviosa de 1.95, esdecir, una diversidad media en este ecosistema. En época seca, la abundancia de individuos fue mayor en el ordenHemiptera, familia Veliidae y el género Rhagovelia, seguido del orden Trichoptera, familia Hydroptilidae y el géneroAtanatolica. En época lluviosa, los órdenes más representativos fueron Ephemeroptera, familia Leptophlebiidae y elgénero Thraulodes, seguido de Hemiptera, familia Veliidae y el género Rhagovelia. El índice de Jaccard indicó que lasestaciones con mayor similitud fueron la 1 y 2, con un 65.2 % (época seca y 76.9 % (época lluviosa, mientras que lasimilitud fue baja en las estaciones 1 y 3, con un 33.3 % (época seca y un 41.7 % (época lluviosa. El índice bióticoBMWP´/PAN para la época seca y lluviosa, mostró para las estaciones 1 y 2 aguas de calidad regular, pero en lasestaciones 3 y 4 las aguas son de calidad aceptable. Las variables físicas y químicas mostraron valores dentro de loslímites aceptables durante la época seca, mientras que en la época lluviosa los niveles fueron bajos, de acuerdo con losvalores establecidos por las normas primarias de calidad ambiental y niveles de calidad para las aguas continentalesde uso recreativo con y sin contacto directo, infl uyendo en la heterogeneidad de los macroinvertebrados acuáticosencontrados en cada estación de muestreo.

  3. Diseño de un sistema alternativo para el tratamiento de aguas residuales urbanas por medio de la técnica de lombrifiltros utilizando la especie Eisenia foetida

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    Jacipt Alexander Ramón

    2015-06-01

    Full Text Available La presente investigación tuvo como objetivo diseñar y construir un sistema sobre tratamiento de aguas residuales para la ciudad de Pamplona utilizando como base teórica el sistema de tratamiento Tohá creado por el Dr. Jose Tohá de la Universidad de Chile, proponiendo una serie de procesos que permiten el saneamiento de las aguas servidas después de su uso con fines domésticos, industriales o comerciales, para poder ser vertidas finalmente a cuerpos de agua naturales. Este proceso incluye un tratamiento con lombrifiltros (aserrín y Eisenia foetida, por donde las aguas residuales pasan seguidamente de una cama de carbón activado filtrando y una cama de grava de piedra, permitiendo oxigenar el agua a partir del goteo que existe entre las camas. Finalmente, el efluente sigue a una cama de piedra de rio de gran tamaño y a un decantador para realizar la toma de muestras. De esta manera se obtiene agua tratada con baja carga orgánica dentro de los parámetros que establece la Comisión de Regulación de Agua Potable y Saneamiento Básico CRA en Colombia.

  4. Individual and community factors contributing to anemia among women in rural Baja California, Mexico.

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    Molly A Moor

    Full Text Available Anemia is a public health concern among women in rural Baja California, Mexico. The purpose of this study was to identify the individual and community factors contributing to the disproportionately high prevalence of anemia among women in this region.A cross-sectional study of 118 women (15-49 years was performed in a rural colonia (small settlement in Baja California, Mexico in 2012. Participants completed a survey comprised of demographic, socioeconomic, health, and dietary questions and provided a capillary blood sample. A portable HemoCue was used to measure hemoglobin and diagnose anemia. Anemic participants provided a venous blood sample for laboratory testing to elucidate the etiology of anemia. Anemic participants received vitamin supplements and nutritional counseling. Assessments of six local tiendas (community grocery stores were performed to ascertain the types of food available for purchase within the community.Prevalence of anemia was 22% among women; laboratory tests revealed iron deficiency was the primary etiology in 80.8% of anemia cases. Other causes of anemia in women included vitamin B-12 deficiency (11.5% and combined iron and vitamin B-12 deficiency (7.7%. Women from low SES households and women enrolled in the government assistance program Prospera were significantly more likely to be anemic (OR = 3.48, 95% CI 1.35-8.98 and OR = 2.49, 95% CI 1.02-6.09, respectively. Vitamin supplementation was significantly more common among non-anemic women (OR = 0.12, 95% CI 0.02-0.94. Dietary assessments showed limited consumption of iron absorption enhancing foods such as fruits and vegetables. Assessments of local tiendas revealed at least one type of meat and citrus fruit available for purchase at each store; however, leafy green vegetables were only available for purchase at one store.All cases of anemia were due to nutritional deficiencies. While vitamin supplementation is a temporary solution, improved individual nutrition

  5. Late Pleistocene-Holocene alluvial stratigraphy of southern Baja California, Mexico

    Science.gov (United States)

    Antinao, José Luis; McDonald, Eric; Rhodes, Edward J.; Brown, Nathan; Barrera, Wendy; Gosse, John C.; Zimmermann, Susan

    2016-08-01

    A late Pleistocene to Holocene alluvial stratigraphy has been established for the basins of La Paz and San José del Cabo, in the southern tip of the Baja California peninsula, Mexico. Six discrete alluvial units (Qt1 through Qt6) were differentiated across the region using a combination of geomorphologic mapping, sedimentological analysis, and soil development. These criteria were supported using radiocarbon, optically stimulated luminescence and cosmogenic depth-profile geochronology. Major aggradation started shortly after ∼70 ka (Qt2), and buildup of the main depositional units ended at ∼10 ka (Qt4). After deposition of Qt4, increasing regional incision of older units and the progressive development of a channelized alluvial landscape coincide with deposition of Qt5 and Qt6 units in a second, incisional phase. All units consist of multiple 1-3 m thick alluvial packages deposited as upper-flow stage beds that represent individual storms. Main aggradational units (Qt2-Qt4) occurred across broad (>2 km) channels in the form of sheetflood deposition while incisional stage deposits are confined to channels of ∼0.5-2 km width. Continuous deposition inside the thicker (>10 m) pre-Qt5 units is demonstrated by closely spaced dates in vertical profiles. In a few places, disconformities between these major units are nevertheless evident and indicated by partly eroded buried soils. The described units feature sedimentological traits similar to historical deposits formed by large tropical cyclone events, but also include characteristics of upper-regime flow sedimentation not shown by historical sediments, like long (>10 m) wavelength antidunes and transverse ribs. We interpret the whole sequence as indicating discrete periods during the late Pleistocene and Holocene when climatic conditions allowed larger and more frequent tropical cyclone events than those observed historically. These discrete periods are associated with times when insolation at the tropics was

  6. Individual and community factors contributing to anemia among women in rural Baja California, Mexico

    Science.gov (United States)

    2017-01-01

    Introduction Anemia is a public health concern among women in rural Baja California, Mexico. The purpose of this study was to identify the individual and community factors contributing to the disproportionately high prevalence of anemia among women in this region. Methods A cross-sectional study of 118 women (15–49 years) was performed in a rural colonia (small settlement) in Baja California, Mexico in 2012. Participants completed a survey comprised of demographic, socioeconomic, health, and dietary questions and provided a capillary blood sample. A portable HemoCue was used to measure hemoglobin and diagnose anemia. Anemic participants provided a venous blood sample for laboratory testing to elucidate the etiology of anemia. Anemic participants received vitamin supplements and nutritional counseling. Assessments of six local tiendas (community grocery stores) were performed to ascertain the types of food available for purchase within the community. Results Prevalence of anemia was 22% among women; laboratory tests revealed iron deficiency was the primary etiology in 80.8% of anemia cases. Other causes of anemia in women included vitamin B-12 deficiency (11.5%) and combined iron and vitamin B-12 deficiency (7.7%). Women from low SES households and women enrolled in the government assistance program Prospera were significantly more likely to be anemic (OR = 3.48, 95% CI 1.35–8.98 and OR = 2.49, 95% CI 1.02–6.09, respectively). Vitamin supplementation was significantly more common among non-anemic women (OR = 0.12, 95% CI 0.02–0.94). Dietary assessments showed limited consumption of iron absorption enhancing foods such as fruits and vegetables. Assessments of local tiendas revealed at least one type of meat and citrus fruit available for purchase at each store; however, leafy green vegetables were only available for purchase at one store. Conclusion All cases of anemia were due to nutritional deficiencies. While vitamin supplementation is a temporary solution

  7. Estudio broncoscópico en pacientes con trasplante renal y sepsis respiratoria baja

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    Victoriano Machín González

    1997-08-01

    Full Text Available La infección respiratoria baja constituye uno de los problemas fundamentales que con frecuencia es necesario enfrentar en aquellos pacientes que reciben trasplante renal. Se hace un estudio de 47 enfermos trasplantados, los cuales presentaron como complicación una infección respiratoria baja (IRB evolutivamente en el período comprendido entre enero de 1993 y julio de 1995. Considerando que el éxito del trasplante depende en gran medida de factores inmunológicos y que la sobrevida se debe en parte a la presencia o no de infecciones, y que del total de receptores el 75 % desarrolla algún tipo de infección, se realizó este trabajo apoyándose en el estudio broncoscópico como vía de obtención de muestra microbiológica en estos enfermos. Se hallaron como gérmenes más frecuentes los gramnegativos, y se aislaron microorganismos oportunistas; se demostró la ausencia de complicaciones del proceder en manos expertas y hubo gran correlación clínico-radiológica-broncoscópicaLower respiratory infection constitutes one of the main problems which should frequently be faced in those patients who had undergone a renal transplantation. A study of 47 transplantated patients was performed. Patients presented with a lower respiratory infection as a complication during January 1993 July, 1995. This work was carried out after making a bronchoscopic study as a way to obtain a microbiological sample of these patients taking into account that the sucess of the renal transplantation depends mostly upon immunologic factors and that the survival rate relies mainly on the presence or absence of infections since the total number of recipients may develop some kind of infection. Gramnegative germs were found to be the most frequently and opportunistic microorganisms were isolated. Absence of complications due to this procedure performed by experts was proved, and there was a great clinical, radiologic, and bronchoscopic correlation

  8. Degree of trace metal pyritization in sediments from the Pacific coast of Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Nava Lopez, Carmen; Huerta Diaz, Miguel Angel [Instituto de Investigaciones Oceanologicas, Ensenada, Baja California (Mexico)

    2001-06-01

    We analyzed sediments from a core collected on the Pacific coast of Baja California, 45 km off the city of Tijuana and at 1257 m water depth (32 Celsius degrees 9.5N , 117 Celsius degrees 8.3W), for trace metal content in two operationally-defined fractions, HCl and pyrite. Our results indicate transference of Cu>Ni>Zn>>Hg y Ag from the HCl to the pyrite fraction. Sediments have degrees of pyritization (DOP) that average 7.2{+-} 4.9% with a maximum value of 18.5%. Average degrees of trace metal pyritization (DTMP) range from 6.2 {+-}2.1% to 83{+-} 8% for Mn and Hg, respectively, although maximum values for some metals were closed to 100%. This transference is apparently a function of the solubility products of metal sulfides and the relative abundances of metals in the HCl fraction, as suggested by the significant correlation (p<0.001) observed between these two parameters and the DTMP of a number of trace metals. A similar correlation was obtained from published data of two cores collected in the Gulf of Mexico. [Spanish] Se analizaron sedimentos de un nucleo recolectado en la costa del Pacifico de Baja California 45 km de la costa de la ciudad de Tijuana y a 1257 m de profundidad del agua (32 grados Celsius 9.5N, 117 grados Celsius 8.3W), para determinar su contenido de metales traza en dos fracciones operacionales definidas HCl y pirita. Los resultados indican una transferencia de Cu>Ni>Zn>>Hg y Ag de la fraccion de HCl a la fase piritica. Los grados de piritizacion (DOP) en los sedimentos promediaron 7.2{+-} 4.9%, con un valor maximo de 18.5%. Los valores promedio de los grados de piritizacion de metales traza (DTMP) abarcaron el intervalo de 6.2 {+-}2.1% a 83{+-}18% para Mn y Hg, respectivamente, aunque los valores maximos para algunos metales estuvieron cercanos al 100%. Esta transferencia aparentemente es funcion de los productos de solubilidad de los sulfuros metalicos y de la abundancia relativa de metales en la fraccion HCl, como sugiere la correlacion

  9. Plio-pleistocene volcano-tectonic evolution of la Reforma Caldera, Baja California, Mexico

    Science.gov (United States)

    Demant, Alain; Ortlieb, Luc

    1981-01-01

    La Reforma volcanic complex, in east-central Baja California, shows a characteristic caldera structure, 10 km in diameter. The first eruptive stage, during the Pliocene, was manifested by ash and pumice falls and by subaqueous pumitic flows. In a second stage basic flows were deposited in a near-shore environment (subaerial and pillow lavas). During the early Pleistocene a large ignimbritic eruption, producing mainly pantelleritic tuffs, immediately predated the formation of the caldera itself. Afterwards, along marginal fractures of the caldera, some rhyolitic domes and flows partially covered the thick ignimbritic sheet. A block of Miocene substratum, in the center of the caldera, has been uplifted, nearly 1 km, by "resurgent doming". Small outcrops of diorite might constitute the top of coarse-grained crystallized magmatic bodies, and thus support the "resurgent doming" interpretation. A few basaltic cones were finally built on the flanks of the caldera complex; the latter are not related to the caldera history but to the extension tectonics of the Gulf of California which are also responsible for the Tortuga Island and the Holocene Tres Virgenes tholeiitic cones. South of la Reforma are found the highest (+300 m) Pleistocene marine deposits of the Gulf coast of Baja California. The uplift of this area is due in part to the positive epeirogenic movements of the whole peninsular crustal block, and also to the late doming of the caldera. On the coastal (eastern) flank of La Reforma complex up to seven stepped wave-cut terraces have been preserved, the highest reaching more than +150 m and the lowest ones +25 m. Lateral correlations of the marine terraces along the whole Gulf of California suggest that this volcano-tectonic uplift, that is still active, is of the order of 240 mm/10 3 y. The set of terraces is interpreted to be Middle (700-125 × 10 3y) to Upper (125-80 × 10 3y) Pleistocene, and is tentatively correlated with the paleoclimatic chronology of deep

  10. Migración por empleo en México. La experiencia de Baja California entre 2008 y 2012

    Directory of Open Access Journals (Sweden)

    Alejandro Mungaray Lagarda

    2014-01-01

    Full Text Available Para entender el reto del empleo que enfrenta México, en un contexto de diversidad regional, se ofrece una expli - cación a la paradoja actual de crecimiento del empleo y de la tasa de desempleo que ocurre al mismo tiempo en Baja California. Mediante la estimación de un modelo de datos de panel, se genera evidencia de que los flujos migratorios del interior del país son mayores que el aumento de la po - blación ocupada, debido a que tanto ésta como los salarios y el nivel de competitividad social de Baja California in - fluyen de manera directa en las decisiones de las personas para moverse a dicha entidad.

  11. Comportamientos abusivos de baja intensidad en las organizaciones: una revisión de la literatura y de sus implicancias

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    Lidia Moroni

    2014-10-01

    Full Text Available Los comportamientos abusivos en el trabajo afectan el clima organizacional y deterioran el compromiso de los empleados. Entre ellos los comportamientos abusivos de baja intensidad son los más difíciles de detectar, pues se manifiestan de modo sutil y subjetivo, a través de sucesivas interacciones entre los actores involucrados. La literatura organizacional ofrece múltiples constructos cuyas definiciones y alcances se superponen entre sí y dificultan su adecuado tratamiento. Basado en una revisión de la literatura empírica, este trabajo analiza 14 constructos diferentes referidos como comportamientos abusivos de baja intensidad, con el objetivo de identificar aquellas dimensiones comunes que los caracterizan y examinar los factores del contexto organizacional que facilitan su ocurrencia y propagación. Esta revisión concluye presentando sus implicancias prácticas.

  12. Osprey distribution, abundance, and status in western North America: III. The Baja California and Gulf of California population

    Science.gov (United States)

    Henny, C.J.; Anderson, D.W.

    1979-01-01

    -An estimated 810 ? 55 pairs (minimum estimate) of ospreys (Pandion haliaetus) were nesting in the study area during our survey (24 March-l April 1977). Approximately 174 pairs nested along the Pacific side of Baja California, 255 pairs along the gulf side, 187 pairs on the Midriff Islands, and 194 pairs in coastal Sonora and Sinaloa. Most nested on cliffs adjacent to the sea (59%); some nested on cactus in flat terrain (26%). Seven per cent nested on the ground, three percent nested in mangroves and other trees in the southern portion of the study area,.and four percent nested on man-made structures. The extreme northwestern Baja California population that was extirpated early in this century has not recovered. However, several populations immediately to the south along the Pacific Coast now appear stationary. Pesticide residues in osprey eggs from Mexico were among the lowest reported for the species in North America.

  13. Comportamientos abusivos de baja intensidad en las organizaciones: una revisión de la literatura y de sus implicancias

    Directory of Open Access Journals (Sweden)

    Lidia Moroni

    2014-01-01

    Full Text Available Los comportamientos abusivos en el trabajo afectan el clima organizacional y deterioran el compromiso de los empleados. Entre ellos los comportamientos abusivos de baja intensidad son los más difíciles de detectar, pues se manifiestan de modo sutil y subjetivo, a través de sucesivas interacciones entre los actores involucrados. La literatura organizacional ofrece múltiples constructos cuyas definiciones y alcances se superponen entre sí y dificultan su adecuado tratamiento. Basado en una revisión de la literatura empírica, este trabajo analiza 14 constructos diferentes referidos como comportamientos abusivos de baja intensidad, con el objetivo de identificar aquellas dimensiones comunes que los caracterizan y examinar los factores del contexto organizacional que facilitan su ocurrencia y propagación. Esta revisión concluye presentando sus implicancias prácticas.

  14. Susceptibilidad antimicrobiana de microorganismos causantes de infección de vías urinarias bajas en un hospital pediátrico

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    Briceida López-Martínez

    2014-11-01

    Conclusiones: Los antimicrobianos frecuentemente prescritos para el tratamiento empírico de la infección del tracto urinario no complicada demuestran resistencia importante o baja susceptibilidad cuando se les probó frente a las cepas aisladas.

  15. A missing piece in the puzzle: the presence of Euglossa viridissima in the Baja California Peninsula (Hymenoptera, Apidae

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    Armando Falcón-Brindis

    2018-01-01

    Full Text Available Orchid bees are a conspicuous component of the neotropical bee fauna, with a few species reaching the northernmost natural distribution for the group in northwestern continental Mexico. Among them, Euglossa viridissima Friese is here reported for the first time in the Cape Region of the Baja California peninsula, Mexico, where no species of the group have been found previously. These records are presented, their biogeographical implications discussed, and some interpretations of the local factors that influence the bees is presented.

  16. Screening of extracts of algae from Baja California Sur, Mexico as reversers of the antibiotic resistance of some pathogenic bacteria

    OpenAIRE

    Riosmena Rodríguez, Rafael; Martínez Díaz, Sergio Francisco; Zermeño Cervantes, Lina Angélica; Murillo-Álvarez, Jesús Iván; Muñoz Ochoa, Mauricio

    2010-01-01

    Sixty ethanol extracts of marine flora of Baja California Sur (Mexico) were screened to evaluate the reversing effect of the bacterial resistance to antibiotics in combination with a sublethal concentration of ampicillin or erythromycin. The activity was assayed by using a modification of the classical agar-diffusion method against 3 resistant, pathogenic bacteria; Escherichia coli (ATCC BAA196), Staphylococcus aureus (ATCC BAA42), and Streptococcus pyogenes (ATCC BAA946). From the 60 ethanol...

  17. El riego por aspersión: efecto de la baja presión en la uniformidad

    OpenAIRE

    Faci González, José María

    2013-01-01

    Presentación realizada por el autor en la Jornada Técnica "Sistemas de riego en baja presión", organizada por la Comunidad General de Regantes del Canal de Aragón y Cataluña (CGRCAC), en Binéfar, el 18 de abril de 2013. 1 Fichero .pdf (73 pags.) copia de la presentación original, con Fots., Tabls. y Figs.

  18. Marine Spatial Planning in a Transboundary Context: Linking Baja California with California's Network of Marine Protected Areas

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    Nur Arafeh-Dalmau

    2017-05-01

    Full Text Available It is acknowledged that an effective path to globally protect marine ecosystems is through the establishment of eco-regional scale networks of MPAs spanning across national frontiers. In this work we aimed to plan for regionally feasible networks of MPAs that can be ecologically linked with an existing one in a transboundary context. We illustrate our exercise in the Ensenadian eco-region, a shared marine ecosystem between the south of California, United States of America (USA, and the north of Baja California, Mexico; where conservation actions differ across the border. In the USA, California recently established a network of MPAs through the Marine Life Protection Act (MLPA, while in Mexico: Baja California lacks a network of MPAs or a marine spatial planning effort to establish it. We generated four different scenarios with Marxan by integrating different ecological, social, and management considerations (habitat representation, opportunity costs, habitat condition, and enforcement costs. To do so, we characterized and collected biophysical and socio-economic information for Baja California and developed novel approaches to quantify and incorporate some of these considerations. We were able to design feasible networks of MPAs in Baja California that are ecologically linked with California's network (met between 78.5 and 84.4% of the MLPA guidelines and that would represent a low cost for fishers and aquaculture investors. We found that when multiple considerations are integrated more priority areas for conservation emerge. For our region, human distribution presents a strong gradient from north to south and resulted to be an important factor for the spatial arrangement of the priority areas. This work shows how, despite the constraints of a data-poor area, the available conservation principles, mapping, and planning tools can still be used to generate spatial conservation plans in a transboundary context.

  19. Evolution of the Mexican Triple Junction since 15 Ma : new evidence from the FAMEX cruise, off Baja California (Pacific Ocean)

    Science.gov (United States)

    Royer, J.-Y.; Michaud, F.; Dyment, J.; Bourgois, J.; Sichler, B.; Bandy, W.; Calmus, T.; Mortera, C.; Pontoise, B.; Sosson, M.

    2003-04-01

    In April 2002, R/V L'Atalante collected swath-bathymetry data along with surface and deep-tow magnetic data in the oceanic basin adjacent to Baja California (FAMEX cruise). The new data evidence a series of short extinct spreading-ridge segments extending from the Clarion FZ to the Shirley FZ where it connects with the Guadalupe extinct ridge. This observation suggests that, in this area, the Pacific-Farallon spreading center did not subduct beneath Baja California. Instead, the Pacific-Farallon long spreading segment, between Clarion and Shirley FZ’s, broke into several short segments during a 45deg. clockwise change in spreading direction and complex propagating events, prior to extinction. Magnetic data indicate that this segmentation occurred between 15 Ma (chron 5B) and circa 12 Ma (chron 5A), when seafloor spreading stopped. The new data, together with single-channel seismic data, also evidence recent motion along the Tosco-Abreojos fault that follows the upper-slope of the Baja California margin over several hundred kilometers. Transform motion along the margin may have started when the Magdalena ridge stopped spreading. Based on this new evidence, we propose a revised geodynamical model of the Mexican triple junction (Pacific-Farallon-North America) that attempts to account for the onset of the short-lived and independent Guadalupe and Magdalena micro-plates, and for the unusual volcanism (adakite type + Nb enriched basalts + Morb) observed along Baja California. Previous models suggested that this volcanism resulted from the presence of an asthenospheric window caused by the subduction of the Pacific-Farallon ridge.

  20. Mujer y nación: una historia de la educación en Baja California. 1920-1930

    OpenAIRE

    María del Consuelo López Arámburo

    2005-01-01

    This article forms part of research in progress that aims to examine the intellectual climate prevailing in Mexico in the post-revolutionary period, from 1920 to 1930. The essay explores how the influence of nationalist ideology gradually shifted the role of Mexican women, identifying them as the educators of the nation. The study focuses on Baja California since educators, such as Josefina Rendón Parra (1885-1977), were an important example illustrating how nationalist ideology engineered wo...

  1. Estudio de algunos procesos pedogenéticos en el valle de Ojos Negros, Baja California, México

    Directory of Open Access Journals (Sweden)

    Francisco Raúl Venegas Cardoso

    2012-02-01

    Los procesos de erosión, transporte y acumulación de materiales en las tierras bajas continúan a la fecha, asimismo, la presencia de un proceso relativamente reciente: materiales que están siendo redistribuidos por el viento y depositados sobre diques de metarriolita, provocado por las condiciones de sequía en toda la región.

  2. Current Status of Research on the Shorebirds, Marsh Birds, and Waders of the Peninsula of Baja California

    Science.gov (United States)

    Eric Mellink

    2005-01-01

    Regarding the information on its birds, the peninsula of Baja California has a luxury status, compared to other regions of México. In this sense, it is useful to compare it with its nearest states: Sonora and Sinaloa. While the peninsula measures 143,790 km², Sonora is 184,937 km². Sinaloa (58,092 km²), although much smaller, has a...

  3. : Toward a conceptualization of a paracas urbanism in ánimas altas / ánimas bajas (Ica Valley)?

    OpenAIRE

    Bachir Bacha , Aïcha; Llanos Jacinto , Oscar Daniel

    2015-01-01

    International audience; Since 2009, within the framework of the Ánimas Altas Archaeological Program in Ica, Peru — under the direction of the au-thors — systematic excavations have been carried out in the Ánimas Altas/Ánimas Bajas archaeological complex, the center ofthe Paracas culture in the lower Ica valley. To date, the project has documented public-ceremonial architecture as well as domesticand production areas. Additionally, excavations have revealed evidence of pyramidal complexes cont...

  4. Demografía y economía de una capital estatal. Mexicali, Baja California

    Directory of Open Access Journals (Sweden)

    Gabriel Estrella Valenzuela

    1996-01-01

    Full Text Available This work has as a main objective, to identify, in a general way, the sectors of the economical activity in which the city of Mexicali presents a grade of specialization in respect to the state of Baja California in general. To accomplish such objective, in the first part, the general characteri'stics that have definedthe tendencies of demographic behavior in this zone of the country through the 20th century are marked, with the purpose of making evident the nexus that has existed between the modalities that have assumed the economical development of Mexicali, and the fluctuations that have been observed in the components of its population dynamic. The second part of this work is about the evaluation of the specialization of the economical structure of Mexicali, related to the capacity of creating jobs, and the kind of jobs that are created. In this case, tha analitic perspective ofthe "economical basis" is used, since it's important to show the role the border with the United States has played, in relation to the possibilities -past and present- of development in the economy of this area through the capacity of responding to the external demand of goods and services.

  5. Especialización industrial y desarrollo empresarial en Baja California

    Directory of Open Access Journals (Sweden)

    Alejandro Mungaray

    2003-01-01

    Full Text Available La especialización industrial en Baja California en el sector de productos metálicos, maquina ria y equipo, s e asocia en economías de redes por interacciones de costos entre las grandes empresas asiáticas y del sur de California que conviven en la región conforme a las nuevas reglas del TLCAN y el fuerte peso de la subcontratación y las operaciones intraindustriales. En este contexto, se evalúa el impacto sobre la vida económica y social de las empresas para comprobar si la perspectiva de bienestar social a través del empleo, resultado de la estrategia industrial de atraer inversión extranjera directa, tiene que ver más con la discriminación salarial que con la productividad, y si los incrementos salariales están influidos por alzas en productividad y la especialización. Se parte de que el bienestar es clave en la estrategia de política industrial regional con objetivos competitivos para el desarrollo regional y empresarial, donde este último se inhibe ante la limitada estrategia estatal .

  6. Bioavailability and Natural Pollution of Heavy Metals in Bahia de Magdalena, Baja California, Mexico

    Science.gov (United States)

    Lee, W.; O'Shea, B.

    2012-12-01

    In the pristine environment of Bahia de Magdalena, Baja California, elevated concentrations of heavy metals have been reported in the biota within the bay, such as sea grasses, blue crabs, and marine turtles. While the hypothesized source of these metals has emphasized anthropogenic inputs from a local fish cannery, geologic enrichment of metals from natural ophiolite formations in the Puerto Magdalena region may be an increasingly feasible source. Total (XRF) chromium and nickel concentrations (max 4,450 ppm and 2,396 ppm, respectively) in rock and soil are orders of magnitude higher than average concentrations in the crust and the beach sands directly impacted by waste discharge from the cannery (mean Cr, 55ppm and mean Ni 17ppm at cannery). Bioavailable (HNO3 acid extracted) metals differ between rock and soil versus cannery-impacted sites. Most notably, Ni is very bioavailable (mean 70% total Ni extracted) in pristine ophiolite areas, but almost completely unavailable at cannery-impacted sites. In contrast, Zn is slightly more bioavailable at the impacted cannery site (mean 55% Zn extracted) than the ophiolite rocks (mean 45% Zn extracted). In addition, these results suggest that while metals, such as Cu, Fe, and Mn, have been previously studied in the biota of the bay, other heavy metals such as Ni and Cr should be included in future biological studies within Bahia de Magdalena.

  7. Preferencias de leche fresca de bovino del consumidor de Baja California, Mexico

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    Iliana Enriqueta Montaño Méndez

    2013-01-01

    Full Text Available El documento tiene como objetivo conocer las preferencias del consumidor de Baja California por leche de bovino y sus hábitos de consumo, así como identificar segmentos para el consumo de leche a partir de los principales atributos como presentación, tipo de grasa y precio, e identificar nichos de mercado para nuevos productos. Para determinar las preferencias del consumidor, se utilizaron técnicas del análisis de conjunto, análisis de segmentación y análisis de simulación. Para lo anterior, se diseñó y aplicó un cuestionario a una muestra representativa conformada por 418 consumidores del Estado, para conocer el producto ideal y caracterizar al consumidor bajo diferentes segmentaciones basados en sus preferencias. Los resultados muestran mayor preferencia por leche pasteurizada con tipo de grasa entera, a la cual le atribuyen mejor sabor, seguida por la leche ultra pasteurizada y las fórmulas lácteas. Además se encontró un segmento de mercado para nuevos productos y la valoración positiva al precio situación no habitual dentro de los consumidores agroalimentarios.

  8. Mobile colposcopy in urban and underserved suburban areas in Baja California

    Science.gov (United States)

    Madiedo, Marta; Contreras, Sonia; Villalobos, Octavio; Kahn, Bruce S.; Safir, Amit; Levitz, David

    2016-03-01

    Cervical cancer is the leading cause of cancer death for women in low resource settings, often affecting the most economically disenfranchised segment of the population. The key challenge with cervical cancer is the lack of an effective screening program for many of the at-risk, difficult-to-reach women. Outreach programs that utilize mobile clinics to increase access to screening and care in Baja California have been developed. However, many barriers such as quality assurance, efficient referral remained a challenge in this region. Visualization-based co-tests together with cytology (Pap smears) as a primary screen have been proposed. Here, the mobile colposcope of the enhanced visual assessment (EVA) is used to capture an image immediately following a Pap smear. EVA images were reviewed by expert colposcopists. Initial or preliminary data from pilot services showed that Pap false positives and Pap false negatives maybe reduced by expert review of EVA images. This suggests that reviewing of EVA images may be instrumental in catching inaccurate Pap results, thereby improving care. Thus, there is a need to further explore the benefits of using EVA as additional information when conducting Pap smear screenings.

  9. Subsidence and Extension Rates of Laguna Salada Basin, Northeastern Baja California, Mexico

    Science.gov (United States)

    Contreras, J.; Martin-Barajas, A.; Herguera, J. C.

    2002-12-01

    Laguna Salada basin in northeastern Baja California, Mexico, is an active half-graben product of the trans-tensional tectonics of the Gulf of California. It lies at the boundary between the North America and Pacific plates, 15 km west of the Cerro Prieto-Imperial fault system. We present the results of a time series analysis of the uppermost 980 m of a gamma ray log from the geothermal exploratory well ELS1 drilled in the proximity of the Laguna Salada fault, which bounds the basin on its eastern margin. Our analysis indicates its stratigraphy is cyclical and that the spectrum of the gamma ray log is similar to the spectrum of δ18O Pleistocene variations, which strongly suggest an orbital origin. Based on this, we establish a correlation between the gamma ray log and δ18O stages to constrain ages of sediments with an estimated uncertainty of ~10 kyr. We found that sedimentation rates at ELS1 site have remained constant during the last 780 kyr. The sedimentation rate at the ELS1 site is 1.6 mm/yr. This value is extrapolated to obtain the vertical and perpendicular to strike slip rates of Laguna Salada fault. It was found that the vertical slip component is 4.22 mm/yr and the perpendicular to strike slip component (E-W direction) is 1.55 mm/yr.

  10. Developing a Luminescence Chronology for Fan-terrace Sediments, Los Cabos, Baja California, Mexico

    Science.gov (United States)

    Rhodes, E. J.; Brown, N. D.; Antinao, J.; Huenupi, E. C.; Baker, S. E.; McDonald, E.

    2012-12-01

    Extensive depositional units forming large terrace units within alluvial fans close to the southern tip of Baja California, Mexico, record sedimentation under a very different climatic regime from the present. Dating these sediments presents significant challenges; they contain very sparse organic material suitable for radiocarbon dating; their upper surfaces are heavily bioturbated, in some places eroded and in other locations show signs of continued deposition even after incision and base level fall, rendering them difficult to date using TCN (terrestrial cosmogenic nuclide) methods. Locations that have experienced significant regional tectonic influences associated with rapid erosion (e.g. Transverse Ranges, California, Southern Alps, New Zealand, Himalaya and Tibet) are typically not well-suited for quartz OSL (optically stimulated luminescence) application owing to low signal sensitivity. For this reason, our efforts to develop a chronology for the sandy sediments that characterize these contexts have focussed on IRSL dating of K-feldspar, using newly developed post-infrared IRSL (infra-red stimulated luminescence) approaches. We explore the relative advantages of different techniques, and methods to assess both the degree of incomplete zeroing and signal fading. In particular, we explore how novel single grain IRSL measurements of K-feldspar can be applied to these and similar high energy deposits on timescales ranging from the last 100,000 years to a few decades. Based on our chronology coupled with detailed sedimentological and soil stratigraphy investigations, we are able to exploit these deposits as valuable archives of past environmental and climatic change.

  11. en un área natural protegida en Baja California Sur

    Directory of Open Access Journals (Sweden)

    Elizabeth Olmos-Martínez

    2008-01-01

    Full Text Available Aquí se aborda el concepto de pobreza, enmarcado en el contexto de un área natural protegida (ANP, con la metodología propuesta por la Secretaría de Desarrollo Social (SEDESOL, cuya política pública maneja tres categorías para medirla: pobreza alimentaria, pobreza de capacidades y pobreza de patrimonio. El estudio de caso se efectuó en el ejido San Jorge (ESJ, ubicado dentro de la Reserva de la Biosfera Sierra La Laguna (REBISLA, en Baja California Sur. El análisis está basado en datos recolectados en entrevistas a los pobladores del lugar; se consideró el ingreso real diario per cápita, el cual indica si la persona es capaz de satisfacer las necesidades comprendidas en cada categoría, con un ingreso mínimo indispensable. Los resultados indican que la pobreza en la zona, de 2000 a 2004, no varió significativamente. Se concluyó que los habitantes del ESJ son pobres, según los propios parámetros de SEDESOL, y que su condición no ha mejorado, aunque viven en un ANP. Se analizan algunas alternativas que podrían ayudar a amortiguar este rezago.

  12. The endemic insular and peninsular species Chaetodipus spinatus (Mammalia, Heteromyidae breaks patterns for Baja California.

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    Sergio Ticul Álvarez-Castañeda

    Full Text Available The Baja California peninsula is the second longest, most geographically isolated peninsula on Earth. Its physiography and the presence of many surrounding islands has facilitated studies of the underlying patterns and drivers of genetic structuring for a wide spectrum of organisms. Chaetodipus spinatus is endemic to the region and occurs on 12 associated islands, including 10 in the Gulf of California and two in the Pacific Ocean. This distribution makes it a model species for evaluating natural historical barriers. We test hypotheses associated with the relationship between the range of the species, patterns in other species, and its relationship to Pleistocene-Holocene climatic changes. We analyzed sequence data from mtDNA genes encoding cytochrome b (Cytb and cytochrome c oxidase subunits I (COI and III (COIII in 26 populations including all 12 islands. The matrilineal genealogy, statistical parsimony network and Bayesian skyline plot indicated an origin of C. spinatus in the southern part of the peninsula. Our analyses detected several differences from the common pattern of peninsular animals: no mid-peninsula break exists, Isla Carmen hosts the most divergent population, the population on an ancient southern Midriff island does not differ from peninsular populations, and a mtDNA peninsular discordance occurs near Loreto.

  13. Adaptive Thermal Comfort in Learning Spaces: A Study of the Cold Period in Ensenada, Baja California

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    Julio Rincón

    2017-12-01

    Full Text Available Environmental thermal conditions decisively influence people’s performance, comfort, well-being and mood. In closed spaces, where people spend 80% of their time, thermal perception is a phenomenon studied from a multidisciplinary methodological approach. In Mexico, thermal comfort has been studied in isolation in different cities in the country, specifically at sites with warm, temperate or semi-cold bioclimate. The thermal estimates presented in this paper are the result of a thermal comfort study carried out during the cold period in the city of Ensenada, Baja California, which has a dry temperate bioclimate. The study was carried out from January 30th to March 3rd 2017 and consisted of the application of a questionnaire and the simultaneous recording of temperature, relative humidity and wind speed. The questionnaire was designed based on the subjective assessment scale suggested in ISO 10551 and ANSI/ASHRAE 55, while the instruments for measuring and recording environmental variables were selected and used based on ISO 7726. A database with 983 observations was created, and the data were processed using the Averages Intervals Thermal Sensation method. The thermal comfort range estimated for indoor spaces was 16.8 °C to 23.8 °C, with an ideal neutral temperature of 20.3 °C. The percentage of satisfaction vote with these results was 91%.

  14. AUTOCHTHONOUS BIOFACIES IN THE PLIOCENE LORETO BASIN, BAJA CALIFORNIA SUR, MEXICO

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    MICHELE PIAZZA

    1998-07-01

    Full Text Available The present paper examines the molluscan and/or echinoid assemblages recovered from two lithostratigraphic units (Piedras Rodadas Sandstone and Arroyo de Arce Norte Sandstone outcropping in the Pliocene Loreto Basin, Baja California Sur, Mexico. Ten biofacies have been identified, i.e. Trachycardium procerum-Trachycardium senticosum Biofacies, Chione compta-Transennella modesta Biofacies, Laevicardium elenense-Chione kelletii Biofacies, Xenophora sp. 1-Strombus subgracilior Biofacies, Crassostrea californica osunai Biofacies, Myrakeena angelica Biofacies, Vermetid-Nodipecten Biofacies, Argopecten abietis abietis Biofacies, Aequipecten dallasi Biofacies and Encope Biofacies. The first four biofacies have been defined on the basis of statistical analyses (cluster analysis, MDS. The other six, which are monospecific or definitely low-diversity, were already identified during field work. The deduced paleoecological bearing of biofacies, largely relying upon the comparison to their closest modern counterparts, provides the basis for the paleoenvironmental reconstruction. The latter also considers sedimentological evidence and is framed within the tectonic and sedimentary context recently proposed by American workers. Biofacies point toward environments differing in terms of substrate texture, presence/absence of vegetal cover, energy level, variously distributed within the low tide mark-40 m bathymetric range. 

  15. Deep mitochondrial divergence in Baja California populations of an aquilopelagic elasmobranch: the golden cownose ray.

    Science.gov (United States)

    Sandoval-Castillo, Jonathan; Rocha-Olivares, Axayácatl

    2011-01-01

    Assessing the realized effect of dispersal in the genetic makeup of a species has significant evolutionary, ecological, and economical consequences. Here, we investigate the genetic diversity and population differentiation in the aquilopelagic golden cownose ray Rhinoptera steindachneri from the Gulf of California (GC) and the Pacific coast of Baja California (PCBC) using the mitochondrial NADH2 gene. Low levels of genetic diversity were found with only 4 polymerase chain reaction-restriction fragment length polymorphism haplotypes among 76 specimens. Pacific coast organisms were fixed for a unique haplotype not shared with rays from the gulf; 92% of GC rays possessed a single NADH2 haplotype not found in the Pacific. This produced significant differentiation between the GC and the PCBC (Φ(CT) = 0.972, P < 0.001). A pronounced phylogeographic pattern was found in which GC haplotypes were reciprocally monophyletic relative to a very divergent Pacific lineage (d = 10%). Our results indicate that despite high dispersal potential, GC and PCBC golden cownose ray populations are characterized by highly divergent mitochondrial lineages. Although more evidence is needed to corroborate the genetic isolation and systematic status of PCBC and GC golden cownose rays, our results suggest a possible cryptic species in the region.

  16. Phylogeography of the diamond turbot (Hypsopsetta guttulata) across the Baja California Peninsula.

    Science.gov (United States)

    Schinske, Jeffrey N; Bernardi, Giacomo; Jacobs, David K; Routman, Eric J

    2010-01-01

    We compared morphology and sequenced nuclear and mitochondrial genes from 11 populations of a previously genetically unstudied "Baja California disjunct" species, the diamond turbot ( Hypsopsetta guttulata ). This species exhibits very limited adult movement and restriction to soft-bottom habitats but has a moderately long pelagic larval duration. Therefore, if pelagic larval duration is correlated with gene flow between Gulf of California and Pacific populations, we expect a reduced level of genetic and morphological differentiation. However, if adult habitat and ecology have more effect on gene flow, we expect the populations in the two bodies of water to be more highly differentiated. We used logistic regression to compare morphological features and phylogenetic and population genetic analyses to compare nucleotide sequence data. Gulf of California H. guttulata are different from Pacific populations in morphology and both mitochondrial and nuclear gene sequences. MtDNA shows reciprocal monophyly, and nuclear sequences from the Gulf of California formed a monophyletic group. Population genetic analyses also suggest further population subdivision within the Pacific and within the Gulf of California. We argue that adult ecology has a significant effect on migration rates among populations in the Pacific Ocean and the Gulf of California.

  17. Vicariance and dispersal across Baja California in disjunct marine fish populations.

    Science.gov (United States)

    Bernardi, Giacomo; Findley, Lloyd; Rocha-Olivares, Axayacatl

    2003-07-01

    Population disjunctions, as a first step toward complete allopatry, present an interesting situation to study incipient speciation. The geological formation of the Baja California Peninsula currently divides 19 species of fish into disjunct populations that are found on its Pacific Coast and in the northern part of the Gulf of California (also called the Sea of Cortez), but are absent from the Cape (Cabo San Lucas) region. We studied the genetic makeup of disjunct populations for 12 of these 19 fish species. Phylogeographic patterns for the 12 species can be separated into two major classes: a first group (eight species) showed reciprocal monophyly and high genetic divergence between disjunct populations. A second group (four species) displayed what appeared to be panmictic populations. Population structure between Pacific Coast populations, across the Punta Eugenia biogeographic boundary, was also evaluated. While dispersal potential (inferred by pelagic larval duration) was a poor predictor of population structure between Gulf of California and Pacific populations, we found that population genetic subdivision along the Pacific Coast at Punta Eugenia was always positively correlated with differentiation between Pacific and Gulf of California populations. Vicariant events, ongoing gene flow, and ecological characteristics played essential roles in shaping the population structures observed in this study.

  18. Geothermal Exploration Using Remote Sensing in the South of Baja California Sur, Mexico

    Science.gov (United States)

    Báncora, Cristina; Prol-Ledesma, Rosa María

    2008-05-01

    The area from Ciudad Constitución to Los Cabos in Baja California Sur was studied using a mosaic of four Landsat ETM+images. The main objective was to define favorable areas for utilization and exploitation of geothermal energy. The approach was to spectrally and spatially enhance the images to define characteristics related with geothermal activity, as are the presence of altered rock and main geological structures. The products of hydrothermal alteration are minerals that belong to two main groups: oxides and hydroxyls. Therefore, image processing is necessary to enhance oxides and hydroxyls spectral features and subdue the vegetation spectral characteristics. The band subtraction (4-3, 3-1, 5-7) gave the finest results due to the fact that it is a linear equation that does not cause loss of information when it is stretched. A color composite was done with these three layers and after a detailed visual analysis three areas were point out to be prospective to contain hydrothermal activity.

  19. Cinética de tostación de concentrados de baja ley de molibdenita

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    Vanesa Bazán

    2013-01-01

    Full Text Available El molibdeno es un metal atractivo para la fabricación de aceros y fundiciones debido a que promueve un marcado endurecimiento, aumentando la resistencia mecánica cuando la aleación se somete a enfriamientos controlados en un rango de temperaturas críticas. Esto ha provocado un aumento considerable en la demanda de los productos de molibdeno, el cual proviene de concentrados de molibdenita (MoS2 como subproductos de yacimientos tipo pórfido cuprífero. En este trabajo se presentan resultados de un estudio de concentrados de molibdenita de baja ley, con composiciones levemente distintas, que registran diferencias en los resultados operacionales de tostación. Estas diferencias, se deben en gran parte a los mecanismos de reacción identificados y a las impurezas presentes en el concentrado como el Fe. Se realizan ensayos para la determinación de las condiciones óptimas de recuperación de Mo y se determina las constantes de velocidad para cada muestra.

  20. Estimated Impact of Contextual Variables on Academic Achievement among Students in Baja California

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    Mauricio Carvallo Pontón

    2007-11-01

    Full Text Available In the following article, the effects of diverse variables are analyzed contextually in the educational achievement on a sample of 1,817 students of the sixth grade of elementary school and 1,239 of third year of high school of Baja California, who responded to the National Tests offered by the National Institute for the Evaluation of the Education in 2004. The results observed are consistent with the reported in most of the national and international literature: the women present better performance than the men in reading comprehension, and the men register better performance in math; the students with ages over the ones that correspond to the sixth grade of elementary school or third year of secondary school, present lower performance levels to those of their schoolmates; the students of the morning shift present higher performance levels compared to the evening shift students; and the students of private schools present better results than those of public schools. It was also analyzed, through hierarchical lineal models, the effect of the socioeconomic level of the context of the school and of the professor in the educational achievement. In all the cases, the levels of variance explained turned out to be smaller that the registered in other similar national studies.

  1. Evaluación del aprendizaje de las microempresas de Baja California

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    Michelle Texis Flores

    2015-01-01

    Full Text Available En este trabajo se evalúa el desempeño de 1 183 microempresas, que recibieron servicios de desarrollo empresarial en Baja California, mediante un modelo que utiliza las ventas acumuladas como variable proxy de experiencia, para calcular los coeficientes de elasticidad de aprendizaje por empresa. Se supone que a través de prácticas de asistencia, capacitación y acompañamiento mejora la situación de la microempresa, respecto al uso de los recursos. En consecuencia, el modelo es un instrumento de evaluación que permite determinar si las microempresas desarrollan procesos de aprendizaje durante el periodo en el que reciben apoyo. Se encontró que las que mostraron alguna mejora requieren de nuevos estímulos para incrementar su tasa de aprendizaje. Por otra parte, las que no aprenden representan áreas de oportunidad para el diseño e implementación de servicios de desarrollo empresarial.

  2. The artisanal elasmobranch fishery of the Pacific coast of Baja California Sur, Mexico, management implications

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    Sergio R. Ramirez-Amaro

    2013-09-01

    Full Text Available Artisanal fisheries in Mexico account for approximately 40% of the total national catch. In 2009, Baja California Sur (BCS had the second largest catch of elasmobranchs on the Mexican Pacific coast. This paper characterizes and describes the artisanal elasmobranch fishery of Pacific coast of BCS from 2000 to 2010. Sixty artisanal camps were documented, of which 45 targeted elasmobranchs, using primarily gillnets and longlines. We identified 52 elasmobranch species. Gillnetting accounted for 73.5% of the fishing effort and most frequently captured Rhinobatos productus, Mustelus henlei and Myliobatis californica. Longline fishing accounted for 26.5% of effort, most frequently capturing Prionace glauca and Isurus oxyrinchus. The prevalence of juveniles of several species (e.g., Cephaloscyllium ventriosum, Galeorhinus galeus, Isurus oxyrinchus, and Myliobatis californica within landings suggests that fishing effort may be opportunistically directed at breeding or nursery areas. Despite the dominance of species with wide distributions, we observed a significant biogeographic pattern in the abundance of some species relative to Bahia Magdalena. Results of the present study will be useful to detect changes in the structure of commercially exploited elasmobranch populations, and to provide useful indications for management purposes.

  3. Una exploración de las adaptaciones culturales prehistóricas en Baja California

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    Don Laylander

    1987-09-01

    Full Text Available Esta investigación profundiza acerca de cuáles cambios y cuándo ocurrieron en los estilos y las tecnologías prehistóricas tal como se ven reflejadas en la cultura material que se ha conservado. Al mismo tiempo analiza cómo fue que las sociedades lograron establecerse aquí y cómo fue que pudieron sostenerse y desarrollarse en este medio ecológico, o en su caso, por qué fracasaron en su intento. Con el fin de obtener información acerca de las adaptaciones culturales prehistóricas se recurre a la evidencia etnográfica y lingüística, y a la evidencia arqueológica. Otra fuente de información de las adaptaciones culturales de la Baja California es la analogía etnográfica general. Finalmente se hace un resumen de lo que fueron estas adaptaciones a modo de propuesta, con el fin de que la información resultante sea de utilidad para antropólogos y arqueólogos que partiendo del escrutinio de ésta contribuyan al avance del conocimiento de la prehistoria de esta región.

  4. Comunidades de quitones (Mollusca: Polyplacophora de la Bahía de La Paz, Baja California Sur, México

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    Cedar I García Ríos

    2007-03-01

    Full Text Available A las ocho especies de poliplacóforos registradas en Bahía de la Paz, Baja California Sur, México, o cerca de ella, agregamos a Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata y Acanthochitona arragonites. El análisis de las comunidades estudiadas usando técnicas de ordenación sugiere que podría relacionarse la exposición al oleaje con la riqueza y la diversidad de especies. La comunidad recolectada en condiciones intermedias de exposición al oleaje presentó mayor número de especies y mayor diversidad de acuerdo con el índice de Shannon.Polyplacophoran communities (Mollusca: Polyplacophora at Bahía de La Paz, Baja California Sur, México. Eight species of polyplacophorans have been reported from La Bahía de la Paz, Baja California Sur, Mexico. We add Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata and Acanthochitona arragonites, increasing the known number of species to 15. Ordination analysis of five chiton communities at the site suggests a correlation of wave exposure to species composition and diversity: communities with intermediate wave exposure have more species (richness and higher diversity (Shannon’s index. Rev. Biol. Trop. 55 (1: 177-182. Epub 2007 March. 31.

  5. Dinámica de los componentes demográficos en Baja California, durante el periodo 1985-1990

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    Gabriel Estrella Valenzuela

    1991-09-01

    Full Text Available En este trabajo se identifican los rangos predominantes en la dinámica de los componentes demográficos del estado de Baja California y sus municipios, durante el período 1985-1990. Para ello, se utilizan y combinan datos de estadísticas vitales, censales y de las Encuestas Demográficas de Baja California de 1986 y 1990. A partir del análisis de la mortalidad y la fecundidad, se logra determinar una tendencia de estabilidad en el componente natural de la dinámica demográfica del estado, con variaciones marginales a nivel municipal. En el rubro de crecimiento social, sin embargo, se observa un notable y claro incremento en la movilidad de la población que se sustenta en dos componentes: un incremento en la tasa de emigración desde el estado en su conjunto y una más elevada y consistente tendencia al incremento en las tasas de inmigración hacia Baja California, que revierte la tendencia decreciente del peso del crecimiento social en la entidad

  6. California sea lions (Zalophus californianus californianus) have lower chlorinated hydrocarbon contents in northern Baja California, Mexico, than in California, USA

    International Nuclear Information System (INIS)

    Del Toro, Ligeia; Heckel, Gisela; Camacho-Ibar, Victor F.; Schramm, Yolanda

    2006-01-01

    Chlorinated hydrocarbons (CHs) were determined in blubber samples of 18 California sea lions (Zalophus californianus californianus) that stranded dead along Todos Santos Bay, Ensenada, Baja California, Mexico, January 2000-November 2001. ΣDDTs were the dominant group (geometric mean 3.8 μg/g lipid weight), followed by polychlorinated biphenyls (ΣPCBs, 2.96 μg/g), chlordanes (0.12 μg/g) and hexachlorocyclohexanes (0.06 μg/g). The ΣDDTs/ΣPCBs ratio was 1.3. We found CH levels more than one order of magnitude lower than those reported for California sea lion samples collected along the California coast, USA, during the same period as our study. This sharp north-south gradient suggests that Z. californianus stranded in Ensenada (most of them males) would probably have foraged during the summer near rookeries 500-1000 km south of Ensenada and the rest of the year migrate northwards, foraging along the Baja California peninsula, including Ensenada, and probably farther north. - Results suggest that sea lion prey must also have lower hydrocarbons in Baja California than in California in the USA

  7. California sea lions (Zalophus californianus californianus) have lower chlorinated hydrocarbon contents in northern Baja California, Mexico, than in California, USA

    Energy Technology Data Exchange (ETDEWEB)

    Del Toro, Ligeia [Universidad Autonoma de Baja California (UABC), Facultad de Ciencias Marinas, Ensenada, Baja California (Mexico); Investigacion y Conservacion de Mamiferos Marinos de Ensenada, A.C., Placido Mata 2309 Depto. D-5, Condominio Las Fincas, Ensenada, Baja California 22810 (Mexico); Heckel, Gisela [Investigacion y Conservacion de Mamiferos Marinos de Ensenada, A.C., Placido Mata 2309 Depto. D-5, Condominio Las Fincas, Ensenada, Baja California 22810 (Mexico) and Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, B.C. Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California 22860 (Mexico)]. E-mail: gheckel@cicese.mx; Camacho-Ibar, Victor F. [Instituto de Investigaciones Oceanologicas, UABC, Apdo. Postal 453, Ensenada, Baja California 22860 (Mexico); Schramm, Yolanda [Universidad Autonoma de Baja California (UABC), Facultad de Ciencias Marinas, Ensenada, Baja California (Mexico); Investigacion y Conservacion de Mamiferos Marinos de Ensenada, A.C., Placido Mata 2309 Depto. D-5, Condominio Las Fincas, Ensenada, Baja California 22810 (Mexico)

    2006-07-15

    Chlorinated hydrocarbons (CHs) were determined in blubber samples of 18 California sea lions (Zalophus californianus californianus) that stranded dead along Todos Santos Bay, Ensenada, Baja California, Mexico, January 2000-November 2001. {sigma}DDTs were the dominant group (geometric mean 3.8 {mu}g/g lipid weight), followed by polychlorinated biphenyls ({sigma}PCBs, 2.96 {mu}g/g), chlordanes (0.12 {mu}g/g) and hexachlorocyclohexanes (0.06 {mu}g/g). The {sigma}DDTs/{sigma}PCBs ratio was 1.3. We found CH levels more than one order of magnitude lower than those reported for California sea lion samples collected along the California coast, USA, during the same period as our study. This sharp north-south gradient suggests that Z. californianus stranded in Ensenada (most of them males) would probably have foraged during the summer near rookeries 500-1000 km south of Ensenada and the rest of the year migrate northwards, foraging along the Baja California peninsula, including Ensenada, and probably farther north. - Results suggest that sea lion prey must also have lower hydrocarbons in Baja California than in California in the USA.

  8. MODELAGEM DE PROCESSOS UTILIZANDO O BPMN NA FACULDADE CATÓLICA RAINHA DO SERTÃO

    Directory of Open Access Journals (Sweden)

    Antonio Neuton da Silva Júnior

    2014-06-01

    Full Text Available O presente artigo apresenta o gerenciamento de negócios por processos, suas perspectivas atuais, suas vantagens, o desenvolvimento do projeto Modelagem de Processos utilizando BPMN implementado na Faculdade Católica Rainha do Sertão, as ferramentas utilizadas no projeto, a metodologia e os resultados obtidos a partir do mesmo. Ainda foi descrito os setores utilizados, a modelagem resultante das pesquisas e entrevistas e as sugestões para as melhorias dos processos modelados.

  9. Síntesis de nanoestructuras de Ru, Ni y Pt sobre soportes porosos utilizando CO₂ supercrítico

    OpenAIRE

    Morère Rodríguez, Jacobo

    2015-01-01

    En esta tesis doctoral se propone la utilización de CO2 supercrítico como medio de reacción en la fabricación de materiales compuestos nanoestructurados de Ru, Ni y Pt sobre distintos soportes inorgánicos mediante deposición con uidos supercríticos. Las propiedades de los uidos supercríticos son intermedias entre las de los líquidos y las de los gases. Sus propiedades de transporte son similares a las de los gases presentando baja viscosidad, alta difusividad y tensión super cial muy baja, ...

  10. Spatial influence and oceanic thermal response to Santa Ana events along the Baja California peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R. [Facultad de Ciencias Marinas, Universidad Autonoma de Baja California, Ensenada, Baja California (Mexico)]. E-mail: rubenc@uabc.mx; Mascarenhas, A.; Martinez-Diaz-de-leon, A. [Instituto de Investigaciones Oceanologicas, Universidad Autonoma de Baja California, Ensenada, Baja California (Mexico); Durazo, R. [Facultad de Ciencias Marinas, Universidad Autonoma de Baja California, Ensenada, Baja California, (Mexico); Gil Silva, E. [Instituto de Investigaciones Oceanologicas, Universidad Autonoma de Baja California, Ensenada, Baja California, (Mexico)

    2006-07-15

    Meteorological data were recorded at eight stations located along the coast of the Pacific Ocean and three along the coast of the Gulf of California, aimed to assess the spatial influence of Santa Ana weather conditions in the Baja California peninsula. February 2002 featured two Santa Ana events: one from the 9 to the 12 and another from the 21 to the 22. The first Santa Ana event had the strongest winds, however relative humidity and temperature behaved similarly on both events at some stations. Data from the Pacific Ocean showed typical Santa Ana condition patterns: wind speed and temperature increase opposed to decreased relative humidity values. Data from the Gulf of California did not show the typical temperature rise of a Santa Ana condition, but there was a decrease on the amplitude of the diurnal variability of air temperature and relative humidity as well as a marked increase on wind strength. Wind direction during the Santa Ana events on the Pacific side was NE and NW on the Gulf of California. NE winds are associated to the shift on the position of the North Pacific High Pressure Center, which moves towards the continent. Data suggest that relative humidity may be the best parameter to monitor both occurrence and length of Santa Ana conditions on the Pacific side. Normal weather conditions show a negative air-sea temperature difference, but during both Santa Ana events this difference was positive and higher than 10 degrees Celsius. Latent and sensible heat fluxes drastically increased during both events, reaching values more than three times higher than those for normal conditions, which is due to the presence of strong winds combined with a drier and hotter air mass over the ocean. [Spanish] Con el proposito de estudiar la influencia espacial de condiciones Santa Ana a lo largo de la peninsula de Baja California, se registraron datos meteorologicos en ocho estaciones localizadas en el lado del Pacifico y tres estaciones en el Golfo de California. En

  11. Low-dose glucocorticoids in hyperandrogenism Efecto de bajas dosis de glucocorticoides en el hiperandrogenismo

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    Leonardo Rizzo

    2007-06-01

    Full Text Available To investigate the effect of low-doses of glucocorticoids on androgen and cortisol secretion during the course of the day, we evaluated clinical signs of hyperandrogenism and total, free and bioavailable testosterone, SHBG, and cortisol following two different protocols: A fourteen patients received betamethasone 0.6 mg/day (n=8 or methylprednisolone 4 mg/day (n=6, as single daily oral dose at 11.00 PM, during 30 days, B fourteen patients were evaluated under betamethasone 0.3 mg in a single daily dose at 11.00 PM during six months, 11 out of whom were re-evaluated six months later. Twenty eight women with hyperandrogenism were included and seven normal females were used as control. Blood samples were taken in follicular phase at 8 AM and 7 PM to determine SHBG, cortisol, total, free and bioavailable testosterone. In both protocols, a significant morning and evening decrease in cortisol and testosterone (pCon el objetivo de investigar el efecto de bajas dosis de glucocorticoides sobre la secreción de andrógenos y cortisol en el curso del día, evaluamos signos de hiperandrogenismo, testosterona total, libre y biodisponible y cortisol según dos protocolos diferentes: A catorce pacientes recibieron betametasona 0.6 mg/día (n= 8 o metilprednisolona 4 mg/día (n= 6 en dosis única cotidiana, a las 23 h, durante 30 días, B catorce pacientes fueron evaluadas bajo betametasona 0.3 mg en dosis única cotidiana a la 23 h, administrada durante 6 meses; de ellas, 11 pacientes fueron re-evaluadas 6 meses más tarde. Se incluyeron 28 mujeres con hiperandrogenismo y 7 controles normales. Se obtuvieron muestras de sangre en fase folicular a las 08:00 y 9:00 h para determinar SHBG, cortisol, testosterona total, libre y biodisponible. En ambos protocolos se observó una disminución significativa de cortisol y testosterona (p<0.05 a <0.01, más importante con betametasona (p<0.05. En el protocolo B, los niveles matutinos de SHBG aumentaron

  12. Subsidence of the Laguna Salada Basin, northeastern Baja California, Mexico, inferred from Milankovitch climatic changes

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, Juan; Martin-Barajas, Arturo [Departamento de Geologia, CICESE, Ensenada Baja California (Mexico); Herguera, Juan Carlos [Division de Oceanologia, CICESE, Ensenada Baja California (Mexico)

    2005-01-15

    Laguna Salada in northern Baja California, Mexico, is an active half-graben product of the trans-tensional tectonics of the Gulf of California. It is sensitive to changes in sediment supply from the Colorado River basin. We present a time series analysis of the upper 980 m of a gamma-ray log from a borehole drilled near the Laguna Salada fault. The power spectrum of the gammaray log resembles the spectrum of {delta}{sup 1}8{omicron} Pleistocene isotopic variations from ice cores and from the deep ocean, known to be strongly controlled by Milankovitch cycles. We correlate {delta}{sup 1}8{omicron} stages with silty and sandy intervals in the log. Downcore ages for the last 780 ky are constrained within {approx}10 kyr. We derive a simple time vs. depth calibration relation for the basin over this time interval. Estimated sedimentation rates at the drill site appear to be constant with a value of {approx}1.6 mm/yr. We propose that this subsidence rate is produced by the Laguna Salada fault. [Spanish] La cuenca de Laguna Salada en el norte de Baja California, Mexico, es un semigraben activo producto de la tectonica ranstensional del Golfo de California. Esta cuenca endorreica es sensible a cambios en sedimentacion por variaciones en el aporte e sedimentos de fuentes cercanas y distales transportados por arroyos de las sierras adyacentes y por el Rio Colorado. Esta cuenca es un sitio excepcional para explorar el uso de cambios climaticos ciclicos como herramienta de datacion y estimar tasas de sedimentacion y subsidencia en el area. Para demostrar esto se presenta un analisis de series de tiempo de un registro de rayos de gama de un pozo geotermico exploratorio perforado adyacente a la falla de Laguna Salada, la cual limita el margen oriental de la cuenca. Los resultados del analisis indican que el espectro de los primeros 980 m del registro de rayos gama tiene una alta coherencia con el espectro de registros isotopicos paleoclimaticos de {delta}{sup 1}8{omicron} del

  13. Stratigraphy and geochronology of the Comondú Group near Loreto, Baja California sur, Mexico

    Science.gov (United States)

    Umhoefer, Paul J.; Dorsey, Rebecca J.; Willsey, Shawn; Mayer, Larry; Renne, Paul

    2001-10-01

    Upper Oligocene to Middle Miocene volcanic and sedimentary rocks in the Loreto region, Baja California Sur, are widely exposed and make up the Comondú Group as redefined here following McFall. The Comondú Group is part of a volcanic arc and forearc basin that formed along the northwestern margin of Mexico. Regional to detailed scale mapping, stratigraphic analysis, and geochronology in a 10-20-km-wide and 70-km-long belt from the gulf escarpment to the coast near Loreto reveal three main units in the Comondú Group and a composite thickness of ∼1.5-2 km. (1) The lower clastic unit (∼30-19 Ma) contains 200-300 m of fluvial sandstone and conglomerate with probable local eolian deposits and numerous felsic tuffs and basalt flows that accumulated in a forearc basin. (2) The middle breccia and lava flow unit (∼19-15 Ma) is up to 750 m thick and consists of massive andesite breccia that was deposited as proximal debris flows interbedded with minor andesite lava flows. (3) The upper lava flow and breccia unit (∼15-12 Ma) consists almost entirely of up to ∼600 meters of andesite lava flows a few kilometers west of Loreto that are part of a composite volcano. North and south of Loreto for up to 25 km, the unit is composed of andesite lava flows and massive andesite breccia that formed from thick debris flows near that and other volcanic centers. The three units of the Comondú Group in the Loreto area correlated with the Salto, Pelones, and Ricasón formations of the Bahı´a Concepción area. The lower clastic unit of this study is time equivalent to the marine San Gregorio, El Cien, and Isidro formations on the western and southern Baja California peninsula. The middle and upper units of the Loreto area are the proximal equivalent to the type section of the Comondú Group near the village of Comondú. During deposition of the lower part of the Comondú Group, the arc lay to the east on mainland Mexico in the Sierra Madre Occidental, and then migrated to the

  14. Consideraciones sobre el hidrocefalo de baja presion Considerations on low pressure hydrocephalus

    Directory of Open Access Journals (Sweden)

    E. Herskovits

    1976-12-01

    Full Text Available Se analizan las condiciones fisiopatológicas del sindrome de hidrocéfalo de presión normal. De un grupo de 21 pacientes con sintomatologia clínica correspondiente a esta entidad, se seleccionan 10 que presentan un diagnóstico clínico, radiológico y cisternográfico indudable de la entidad en estudio. Se observó que, a pesar de esta selección solamente un 50% de ellos se vió beneficiado con la colocación de una válvula de baja presión. Surge entonces la hipotésis de que este cuadro es un sindrome multicausal; que por un proceso fisiopatogenico común produce un cuadro clínico, radiológico y cisternográfico similar y que serían beneficiados únicamente aquellos enfermos en los que se soluciona el problema mecánico.The physiopathological conditions of the normal pressure hydrocephalus syndrome are analysed. Within a group of 21 patients with clinical sinto- mathology pertaining this entity, only were 10 selected with a clinical, radiological and cisternografic indubitable diagnosis. It has been noticed that in spite of the stricked selection only a 50% of them have been beneficed by the application of a low pressure valve. Then, the hypothesis that the disease is a multicausal syndrome appears, which by an identical physiopathologic process produces or exhibits a similar clinical, radiological and cisternographic picture. Only those patients on whom the mechanical problem is solved would be beneficed by neurosurgery.

  15. Stratigraphy of Pyroclastic Deposits of EL Aguajito Caldera, Baja California Sur, MÉXICO

    Science.gov (United States)

    Osorio Ocampo, L. S.; Macias, J. L.; García Sánchez, L.; Pola, A.; Saucedo, R.; Sánchez, J. M.; Avellán, D. R.; Cardona, S.; Reyes-Agustín, G.; Arce, J. L.

    2015-12-01

    El Aguajito caldera is located in the State of Baja California Sur, it comprises an area of 450 km2 and sits within the Santa Rosalía Basin which is controlled by NE-SW extensional structures and the NW-SE Cimarron Fault that transects the caldera structure. The oldest rocks are ~90 Ma granodiorites covered by an Oligocene-Miocene volcano-sedimentary sequence, the Miocene Santa Lucia Formation and La Esperanza basalt. Pliocene volcanism is represented by La Reforma caldera, El Aguajito caldera, and the Tres Vírgenes Volcanic complex. This study focuses on the cartography and stratigraphy of area in order to understand the evolution of the volcanic system. The stratigraphy from base to top consists of a series of shallow marine sediments (fossiliferous sandstones) covered by a thick sequence of ignimbrites and pyroclastic flows interbedded with volcaniclastic deposits (Gloria and El Infierno Formations). On top of these deposits is El Aguajito caldera, it consists of a 2 m thick pumice fallout followed by an ignimbrite with three transitional lithofacies: a ≤30-m thick light-pink pyroclastic flow enriched in pumice at the base that gradually becomes enrich in lithics towards the top with the occurrence of degasing pipes. On top rests a 15 m-thick light-purple ignimbrite slightly welded with fiammes and a sequence of pumiceous pyroclastic flows and fallouts. These deposits have been associate to the caldera formation with a collapse diameter of ~8 km marked by rhyolitic domes exposed along a ring collapse crowned the sequence as well as NW-SE aligned rhyolitic domes parallel to the seashore. This cartography allowed to present a preliminary new geological map with four stratigraphic units recognized so far, that were emplaced under subaerial conditions beginning with a Plinian column followed by the emplacement of El Aguajito ignimbrite with its subsequent caldera collapse and finally the extrusion of resurgent domes.

  16. Perencanaan Modifikasi Rangka Busur Baja pada Jembatan Pemali disertai Damper sebagai Longitudinal Stopper

    Directory of Open Access Journals (Sweden)

    Bintang Mahardhika

    2017-03-01

    Full Text Available Jembatan Pemali merupakan jembatan yang terletak di Kota Brebes. Jembatan ini menjadi akses penting yang menghubungkan antara Kota Semarang dan Kota Jakarta. Jembatan Pemali sering mengalami perbaikan dalam segi struktural setiap bulannya, hal ini diakibatkan oleh semakin padat volume kendaraan terutama truk dengan muatan berat. Permasalahan ini yang melatarbelakangi pembangunan Jembatan Pemali yang baru agar menunjang dalam sarana transportasi. Penelitian ini memodifikasi Jembatan Pemali menjadi sistem busur rangka baja. Jembatan didesain dengan tinggi 18 meter, bentang 100 meter dan lebar 9 meter. Penelitian ini menggunakan kombinasi pembebanan sesuai SNI T-02-2005 dan SNI 1725-2016. Dengan menggunakan progam bantu SAP2000, kombinasi KUAT 1 (SNI-1725-2016 menghasilkan output gaya yang lebih besar daripada kombinasi lainnya sehingga kombinasi tersebut digunakan untuk menentukan profil rangka atas jembatan. Analisis pengaruh damper dengan tipe Lock-Up Device menggunakan progam bantu SAP2000 dengan kombinasi beban yang menentukan dalam perencanaan damper sebagai longitudinal stopper adalah kombinasi EKSTREM I (SNI-1725-2016. Hasil dari analisis dengan progam bantu SAP2000 profil utama yang terbesar pada jembatan busur menggunakan BOX 500x500x25 serta dengan adanya damper struktur utama jembatan mampu mengurangi deformasi sebesar 16%. Dalam merencanakan bangunan bawah jembatan, dilakukan kontrol guling dan geser pada abutment jembatan serta untuk tiang pancang jembatan dilakukan kontrol berdasarkan daya dukung tanah dan tipe material yang digunakan. Dari perencanaan tersebut, didapatkan dimensi abutment 11x11x10 meter serta kebutuhan tiang pancang jembatan 36 buah. Hasil seluruh perhitungan Penelitian ini dituangkan dalam gambar teknik standar.

  17. Molecular epidemiology of Mycobacterium tuberculosis in Baja California, Mexico: A result of human migration?

    Science.gov (United States)

    Flores-López, Carlos A; Zenteno-Cuevas, Roberto; Laniado-Laborín, Rafael; Reynaud, Yann; García-Ortiz, Rosa Alejandra; González-Y-Merchand, Jorge A; Rivera, Sandra; Vázquez-Chacón, Carlos A; Vaughan, Gilberto; Martínez-Guarneros, José Armando; Victoria-Cota, Nelva Lorena; Cruz-Rivera, Mayra; Rastogi, Nalin; Muñiz-Salazar, Raquel

    2017-11-01

    The State of Baja California (BC) exhibits the highest incidence and prevalence rates of tuberculosis (TB), and multidrug-resistant TB (MDR-TB) in Mexico. However information about the circulation of M. tuberculosis lineages in BC and Mexico as a whole is limited. Here, we describe the genetic relationship and genetic diversity among M. tuberculosis clinical isolates (n=140) collected in BC between October 2009 and April 2011 with other regions of Mexico, the United States, and Latin America. All specimens were genotyped based on 24 mycobacterial interspersed repetitive units (MIRU)-variable number of tandem repeats (VNTR) loci. Population structure and minimum spanning tree (MST) analyses were used to assess the genetic diversity and distribution of BC isolates in comparison to USA and South America strains. Among the nine lineages observed, LAM, Haarlem and S were the most frequent identified in BC. Population structure analysis clustered most BC isolates (41%) into three distinctive groups that included strains from San Diego and South America, whereas other BC strains (22%) clustered with other Mexican strains. A subset of isolates (12%) seemed to be autochthonous of BC, while 25% were cosmopolitan and grouped into multiple clusters. It is highly likely that the TB genetic structure observed in BC is due to human migration. Additional studies are required to determine the mechanism involved in the phylogeographic distribution of M. tuberculosis in Mexico. Implementation of domestic molecular TB surveillance programs is required to better understand the molecular epidemiology of TB not only in the region but at the national level. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Mass media, espacio y tiempo en Todos Santos, Baja California Sur

    Directory of Open Access Journals (Sweden)

    Rossana Almada

    2001-01-01

    Full Text Available El artículo que aquí se sintetiza es un primer acercamiento, desde la perspectiva de autores entre los que destaca Manuel Castells, a un proyecto mayor que pretende analizar e interpretar el proceso de transformaciones que ha venido sufriendo el pueblo de Todos Santos, Baja California Sur BCS, debido a la llegada de dos contingentes de inmigrantes: el primero, rocedente de Estados Unidos y Canadá, llegó a comprar las casas del centro del pueblo; algunos con la intención de quedarse e instalar negocios, principalmente de venta de Bienes Raíces, otros, para pasar allí la temporada otoño invierno; y el segundo, traído del interior del país, principalmente de Acayucan Veracruz y de Ocotepec Guerrero como jornaleros agrícolas por una compañía Sinaloense. Esta inmigración ha introducido a Todos Santos dentro de lo que Castells denomina como sociedad red, es decir, dentro de procesos sociales organizados, cada vez más, en torno a redes que constituyen las nuevas formas de organización social. En resumen, el presente trabajo aborda los efectos de la globalización en la transformación de un pueblo sudcaliforniano, a través de la llegada de los inmigrantes arriba mencionados y del uso de los medios de comunicación vía satélite.

  19. Data on the disinfection of liquid manure by gamma irradiation at Baja, Hungary

    International Nuclear Information System (INIS)

    Simon, J.

    1975-01-01

    At Baja in southern Hungary there is a large state farm producing 100,000 swine yearly. The amount of liquid manure produced by the farm daily totals 800-1000 m 3 . The aim of the present investigation was to determine those radiation doses which are completely lethal to microbes that cause various food infections, so that we could provide a liquid manure with a satisfactory microbiological condition and that this sludge, and also the separate water, could be used agriculturally, as up to now the application of this product to vineyards and orchards has been prohibited. The irradiation of samples was carried out with a NORATOM-type gamma-cell equipment with a 60 Co source. The dose rate was 228.2 rad/s, and the activity about 9,000 Ci at the time of our experiments. The results showed that the aeradion of liquid manure, i.e. filling with oxygen, did not influence the effectiveness of the ratiosterilization procedure. We agree therefore with the literature that states that anaerobic bacteria are more radioresistant than aerobic bacteria. In this respect, spores play a subsidiary role, because the vegetative Clostridia are much more resistant than the aerobic spores. It seems reassuring that to destroy Salmonellae a relatively low dose of 0.4 Mrad is sufficient. It is not, however, useful to sterilize Mycobacteria by gamma radiation. No great differences have been observed in the radiosensitivity of the aerobic and anaerobic microbes. The authors point out that by means of radiosterilization the liquid manure becomes a harmless product from the microbiological point of view. Disinfection of liquid manure by gamma irradiation enables it to be reused for its nutritive value. (author)

  20. [Temporal and spatial distribution of shorebirds (Charadriiformes) at San Ignacio Lagoon, Baja California Sur, Mexico].

    Science.gov (United States)

    Mendoza, Luis Francisco; Carmona, Roberto

    2013-03-01

    Baja California Peninsula has several wetlands that represent important ecosystems for shorebirds. San Ignacio Lagoon is one of these sites, and supports 10% of the total abundance of shorebirds reported in this Peninsula. Since there is few information about this group in this area, we studied spatial and temporal changes in abundance and distribution of shorebirds in San Ignacio Lagoon. For this, we conducted twelve monthly censuses (October 2007-September 2008) on the entire internal perimeter of the lagoon, which we divided into four areas: two at the North and two at the South. We observed a seasonal pattern, with the lowest abundance in May (1 585 birds) and the highest in October (47 410). The most abundant species were Marbled Godwits (Limosa fedoa; 55% of the total records), Western Sandpipers (Calidris mauri; 23%), and Willet (Tringa semipalmata; 10%). All three species were more abundant in autumn; for both, the Marbled Godwit and Willet, we observed their highest numbers in winter and spring, while the Western Sandpiper showed noticeable oscillations, reaching a maximum in early winter (December). In summer, Marbled Godwit and Willet were the only birds present but in lower numbers. Here present the first records of the Pacific Red Knot (Calidris canutus roselaari) in the area. Bird abundance and species richness were influenced seasonally by migration and spatially by sites in the lagoon. The greatest shorebird abundance was in the South area of the lagoon, probably because of better accessibility to food. Our results allowed the inclusion of San Ignacio Lagoon in the Western Hemisphere Shorebirds Reserve Network (WHSRN) as a site of international importance.

  1. Turismo y Sustentabilidad en Pequeñas Localidades Localidades Costeras de Baja California Sur (BCS

    Directory of Open Access Journals (Sweden)

    Reyna Ibañez Pérez

    2014-01-01

    Full Text Available El fomento del turismo se realiza en sitios que, aunque pequeños, cuentan con atractivos naturales y culturales, tal es el caso de las zonas costeras. Tan solo en México, se estima que existen más de 1,100 comunidades que dependen directamente de dicha actividad, esta te ndencia se refleja, de igual manera, en pequeñas localidades costeras de Baja California Sur (BCS. En este sentido, el objetivo de este trabajo fue realizar un an álisis exploratorio que permitió detectar a las comunidades costeras de BCS, donde el turismo genera un aporte importante a su economía local, además , se buscó identificar la problemática general que éstas enfrentan. Para realizar dicho estudio se revisó literatura, se organizó información estadística y se elaboró un análisis Fortalezas, Oportunidades, Debilidades y Amenazas (FODA. Los resultad os apuntan a que, en BCS, existen más de 35 localidades ru rales vinculadas con dicha actividad que comparten como problemática la escasa in fraestructura y la carencia de medidas de control de la afluencia turística. La principal recomendación es desarrollar líneas de investigación que permitan aportar elementos para medir la sustentabilidad turística a nivel local y, co n base en ello, diseñar medidas para la adecuada conducción de tan importante actividad.

  2. Pseudo-patella baja: a minor yet frequent complication of total knee arthroplasty.

    Science.gov (United States)

    Bugelli, Giulia; Ascione, Francesco; Cazzella, Niki; Franceschetti, Edoardo; Franceschi, Francesco; Dell'Osso, Giacomo; Svantesson, Eleonor; Samuelsson, Kristian; Giannotti, Stefano

    2017-12-23

    One of the complications in total knee arthroplasty (TKA) is pseudo-patella baja (PPB). PPB is present when there is no shortening of the patellar tendon, but the joint line is elevated. The purpose of this study is to investigate the incidence of PPB after TKA and its clinical effects. A case series of 158 patients undergoing TKA surgery between 1999 and 2012 at the 2nd Department of Orthopaedics and Traumatology, Pisa were retrospectively reviewed. Surgeries were performed by three senior surgeons, using the same surgical procedure for the implantation of a cemented posterior stabilized prosthesis. Lateral radiographs at 30° knee flexion were evaluated and the presence of PPB defined as modified Blackburne-Peel Index (mBPI) of < 0.54. All the patients were clinically evaluated using the Knee Society Score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index score (WOMAC). Anterior knee pain was evaluated by visual analogue scale (VAS) and range of motion (ROM) was assessed through clinical examination. The cohort group consisted of 158 patients, 109 (69.0%) female and 49 (31.0%) male. Median age at time of surgery was 74 years (range 36-87) and median follow-up was 66 months (range 12-163 months). Bilateral TKA surgery was performed in 50 patients, resulting in a total of 208 implants for investigation. On radiological evaluation, 139 (66.8%) showed no abnormalities (no joint line elevation and no patellar tendon shortening) and 55 (26.4%) presented joint line elevation with absence of patellar tendon shortening (PPB). No significant differences were found between the groups in terms of the KSS, WOMAC score, VAS or ROM. Post TKA PPB is a relatively common complication. Careful preoperative planning, adequate soft tissue release, optimal cutting of bone components, on the femoral side in particular, and the use of thin polyethylene inserts can help to avoid this complication. IV.

  3. MODELACIÓN DE VIAJES INTERURBANOS DE PASAJEROS EN SISTEMAS INTERMODALES DE BAJA DEMANDA

    Directory of Open Access Journals (Sweden)

    Thomas Edison Guerrero Barbosa

    Full Text Available Son frecuentes los casos en los que se plantea evaluar opciones para el mejoramiento en el nivel de servicio de un sistema de transporte en el contexto interurbano, siendo este el caso del corredor del Magdalena Medio en Colombia, donde hay tres modos en interacción: carretero, fluvial y ferroviario. Para la planificación de este tipo de sistema para transporte de pasajeros, caracterizado por su baja demanda, se propone un enfoque metodológico que incluye la toma de información directa en puertos, terminales y a bordo de vehículos, involucrando las características que definen el nivel de servicio de los modos y complementada con encuestas de Preferencias Reveladas (PR y de Preferencias Declaradas (PD, lo cual sigue el desarrollo de modelos para estimar la demanda. Como parte de la modelación se especifica una red intermodal, para lo cual fue necesario realizar un inventario de los servicios y de las características de los arcos. Un aspecto interesante es que el enfoque metodológico ha permitido la combinación de distintas fuentes de información, provenientes de datos agregados y de encuestas a individuos tanto de PR como de PD. La experiencia práctica demuestra que se pueden presentar inconvenientes en las especificaciones en los modelos cuando las interacciones en los atributos o los efectos de las variables no incluidas apropiadamente afectan decisiones individuales. La aplicación demuestra que hay percepciones subjetivas fuertemente asociadas a un modo de transporte que afectan significativamente la elección.

  4. Hybrid system of generating electricity, solar eolic diesel San Juanico, Baja California Sur, Mexico; Sistema hibrido de generacion electrica, eolico solar diesel San Juanico, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Huerta, Javier [Comision Federal de Electricidad, La Paz, Baja California Sur (Mexico); Johnston, Peter [Technology Development, Arizona (United States); Napikoski, Chester [Generation Engineering, Arizona (United States); Escutia, Ricardo [Comision Federal de Electricidad, Baja California Sur (Mexico)

    2000-07-01

    The Comision Federal de Electricidad (CFE), and the northamerican electric company Arizona Public Service (APS), made an agreement of collaboration to develop a project of generating electricity with the use of renewable resources. The premises that where agreed on are the following: 1. Focus the project a rural community. 2. The cost of the whole project should be lower than compared to the interconnection to a conventional system. 3. Acceptance of the community, and the governmental authorities. 4. Sustentability of the operation of the system. Several technical and economical analysis where done, such as the evaluation of the solar and eolic resources, study of the environmental impact, negotiation agreements so it would be possible to obtain de economical resources from Niagara Mohawk (NIMO), and the USAID, all of this thru the supervising of the Sandia National Laboratories. After the anemometric and solar radiation measures where made, it was considered that the community of San Juanico, en Baja California Sur, Mexico, was the most feasible one, it was necessary also to consider the aspects of logistics, socials, size of the community and as a detonator for the economic activities of tourism and fishing. The APS formulated the executive project in accordance with the recommendations of the different areas of CFE. The project consists basically in the installation of 10 wind generators of 10 Kw, a battery bank for 432 KWh, plus a diesel generator for emergencies of 80 Kw. Besides the civil and electromechanical installation. It was necessary to involve the community in the knowledge and followup of the project form it's, considering that this factor would be essential, so it could be successful. Lamps of low consumption where installed on the houses and street lightning, to optimize the system. The patronato that is a civil association of the community, is in charge of the administration of the system, it receives support from personnel of CFE. The income

  5. Frecuencias de grupos sanguíneos e incompatibilidades ABO y RhD, en La Paz, Baja California Sur, México Blood group ABO and RhD frequencies and incompatibilities in La Paz, Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Lorenzo del Peón-Hidalgo

    2002-09-01

    Full Text Available Objetivo. Determinar las frecuencias génicas y de fenotipo, y predecir el riesgo de incompatibilidad y aloinmunización materna en la población de La Paz, Baja California Sur, México. Material y métodos. Estudio descriptivo en el que se evaluaron 1 809 disponentes sanguíneos altruistas que acudieron en 1998 al Hospital General de Zona, del Instituto Mexicano del Seguro Social en La Paz, Baja California Sur, México, tipificados por aglutinación en tubo. Las frecuencias génicas fueron estimadas asumiendo condiciones de equilibrio, y las incompatibilidades y riesgo de aloinmunización de acuerdo con la literatura. Los datos fueron evaluados estadísticamente mediante ji². Resultados. La población reveló las siguientes frecuencias en porcentaje: O, 58.49; A, 31.40; B, 8.40; AB, 1.71; RhD, 95.36; y RhD negativo, 4.64 y las frecuencias génicas fueron i, 0.7648; I A, 0.1821; I B, 0.0519; D, 0.7845; d, 0.2155, respectivamente. Las incompatibilidades en parejas y maternofetal fueron 0.3023 y 0.1685 para ABO, 0.0442 y 0.0364 para RhD y 0.0134 y 0.0061 para incompatibilidad doble, respectivamente. La probabilidad de aloinmunización materna fue estimada en 0.0309. Conclusiones. En La Paz, los grupos O y RhD son los más abundantes, aunque las frecuencias están entre las más bajas en México, contrario a lo ocurrido para A y RhD negativo. La probabilidad de aloinmunización materna y las incompatibilidades son también elevadas. Los grupos ancestrales blanco, negro e indio interactuaron en la zona noroeste del país, determinando al migrar a Baja California Sur un mestizaje probablemente similar al resto de la zona noroeste.Objective. To determine genic and phenotypic frequencies and predict the risk of incompatibility and maternal alloimmunization in the population of La Paz. Material and Methods. This descriptive study evaluated 1809 voluntary blood donors attending in 1998 the Hospital General de Zona of Instituto Mexicano del Seguro Social

  6. Perros ferales en la isla de Cedros, Baja California, México: una posible amenaza para los pinnípedos Feral dogs at Isla de Cedros, Baja California, Mexico: a possible threat for pinnipeds

    OpenAIRE

    María Concepción García-Aguilar; Juan Pablo Gallo-Reynoso

    2012-01-01

    La presencia de perros ferales (Canis lupus familiaris) en la isla de Cedros, Baja California, México, fue documentada hace más de 15 años. En el verano de 2009 e invierno 2009/2010, se realizaron 2 campañas de muestreo en la costa noreste de la isla para evaluar los hábitos alimentarios de los perros en las cercanías de las zonas de reproducción y descanso del lobo marino de California (Zalophus californianus) y del elefante marino del norte (Mirounga angustirostris). Los mamíferos constituy...

  7. Using leaf margin analysis to estimate the mid-Cretaceous (Albian) paleolatitude of the Baja BC block

    Science.gov (United States)

    Miller, Ian M.; Brandon, Mark T.; Hickey, Leo J.

    2006-05-01

    The "Baja BC hypothesis", which postulates that western Washington State, British Columbia and southern Alaska originated at the latitude of Mexico, has pitted paleomagnetic results against long-held interpretations about the tectonic evolution of western North America. In this paper we develop a new paleobotanical method for estimating paleolatitude and apply it to this problem. We start by showing that the modern MAT field for North America is well correlated with latitude, demonstrating the feasibility of using MAT to estimate paleolatitude. A compilation of MAT and floral data from 84 modern sites in Central and North America is used to establish a new prediction relationship, MAT = 1.32 + 28.99 P, where P is the proportion of smooth-margined species within a floral sample at a site. Our analysis also includes a more complete estimate of the uncertainties associated with estimating MAT from a measurement of P. Using modern data, we show that MAT and P can be used to estimate latitude as well. We then apply this approach to resolve the paleolatitude of Baja BC. Eleven floral sites from stable North America are used to establish the latitudinal MAT profile for North America during the Albian and Cenomanian. A floral site from the Winthrop Formation, a mid-Cretaceous (110-100 Ma) fluvial unit in the Methow basin of northern Washington State, is linked to the Baja BC block and predates its proposed northward offset. Forty-three morphospecies of dicotyledonous angiosperm leaves from the Winthrop Formation give P = 0.76, which is equivalent to a MAT of 23.4 °C, indicating a subtropical to tropical climate. We use the North American MAT profile to estimate a paleolatitude of 38.4°N for the Winthrop flora, indicating ˜ 2200 km of northward offset relative to stable North America.

  8. Marine reserves help preserve genetic diversity after impacts derived from climate variability: Lessons from the pink abalone in Baja California

    Directory of Open Access Journals (Sweden)

    Adrián Munguía-Vega

    2015-07-01

    Full Text Available Genetic diversity is crucial for the adaptation of exploited species like the pink abalone (Haliotis corrugata, faced with threats from climate change, overfishing and impacts associated with aquaculture production. While marine reserves are commonly used to mitigate risks to marine populations, the duration, size, location and larval connectivity needed for a reserve to help conserve genetic resources is still poorly understood. Here, we examine the effects of fishing, reserves, and restocking on the genetic diversity of 10 populations from central Baja California, Mexico, and Southern California, USA. We demonstrate that each population shows characteristic genetic signatures according to recent management decisions. We found high allelic diversity, particularly rare alleles, a larger effective population size and a lack of a recent genetic bottleneck in pink abalones within a small (0.8 km2, recently established (5 years reserve in Baja California, compared to other fished sites after a climatic bottleneck. Higher diversity may result from the presence of older animals in the reserve. Due to its location, the reserve may also act as an important hub connecting distant populations via larval dispersal. In contrast, a population from California showed genetic isolation, loss of allelic diversity and high relatedness, consistent with the collapse of fisheries in the 1990s and their lack of recovery thereafter. In addition, a fished area in Baja California with a history of restocking for over a decade showed an increase in frequency of related individuals and high genetic differentiation from nearby sites that were consistent with the production of larvae from a few adults in the laboratory. A network of strategically placed small marine reserves that considers ocean circulation patterns could help to maintain genetic diversity and connectivity of exploited populations.

  9. History and status of introduced mammals and impacts to breeding seabirds on the California channel and Northwestern Baja California Islands

    Science.gov (United States)

    McChesney, G.J.; Tershy, B.R.

    1998-01-01

    The California Channel Islands, U.S.A., and Northwestern Baja California Islands, Mexico, host important breeding populations of several seabird species, including the endemic Black-vented Shearwater (Puffinus opisthomelas) and Xantus' Murrelet (Synthliboramphus hypoleucus). Mammals introduced to nearly all of the islands beginning in the late 1800s to early 1900s include: cats (Felis catus), dogs (Canis familiaris), Black Rats (Rattus rattus), rabbits and hares (Leporidae), goats (Capra hirca), sheep (Ovis ones), and other grazers. Cats, dogs and rats are seabird predators, grazers such as goats and sheep cause habitat degredation, and rabbits destroy habitat and compete with hole-nesting seabirds. Cats, which were introduced to at least 19 islands and currently occur on ten islands, have had the greatest impacts on seabirds, including the extinction of the endemic Guadalupe Storm-Petrel (Oceanodroma macrodactyla). Cats are known to have eliminated or severely reduced colonies of Black-vented Shearwaters, Cassin's Auklets (Ptychoramphus aleuticus) and Xantus' Murrelets. Black Rats have occurred on a minimum of seven islands and have reduced numbers of small, hole-nesting alcids on at least one island. At many islands, defoliation and erosion caused by rabbits and large grazing mammals has been severe. Their effects on seabirds are not well documented but potentially are serious. Impacts from introduced mammals have been most severe on islands with no native mammalian predators. On the Northwestern Baja California Islands, temporary and permanent human settlements have led to a greater diversity and source of introductions. Programs to remove introduced mammals and to reduce the possibility of future introductions are needed to restore seabird populations and to preserve the biodiversity of the region. Surveys are needed particularly on the Northwestern Baja California Islands to update the status and distribution of seabirds and to further assess impacts from

  10. La estructura tributaria del Paraguay: presión fiscal baja, inestable y sesgada hacia impruestos indirectos sobre el consumo

    OpenAIRE

    Mendez Orue, Juan Pablo

    2014-01-01

    Metadados do trabalho de conclusão de curso: La estructura tributaria del Paraguay: presión fiscal baja, inestable y sesgada hacia impruestos indirectos sobre el consumo, pela/o discente: Juan Pablo Mendez Orue, sob orientação: Rodrigo Luiz Medeiros da Silva do Centro de Economia e Sociedade, curso de Ciências Econômicas - Economia, Integração e Desenvolvimento da Universidade Federal da Integração Latino-Americana (UNILA), no Repositório Institucional da Unila (RI-UNILA). La estructura t...

  11. Quantifying the Forcing Factors Responsible for the Tectono-Geomorphological Evolution of Neogene Rift Basins, Baja California

    Science.gov (United States)

    El-Sobky, H. F.; Dorobek, S. L.

    2005-12-01

    The Gulf of California and its surrounding land areas provide a classic example of recently rifted continental lithosphere, where back-arc stretching of a continental volcanic arc has culminated in the ongoing seafloor spreading that characterizes the present-day axis of the gulf. The recent tectonic history of eastern Baja California, which includes most of the land area eastward of the main drainage divide that extends north-south along the length of the peninsula, has been dominated by oblique rifting that began at about 5 Ma. Thus, extensional tectonics, bedrock lithology, long-term climatic changes, and evolving surface processes have controlled the tectono-geomorphological evolution of the eastern part of the peninsula since 5 Ma. No previous studies, however, examined the effect of these combined factors on the current tectono-geomorphological characteristics of eastern Baja California. We assume that although long-term climate may have changed along the peninsula over the last several million years, precipitation amounts are likely to have changed in a similar way along the entire length of the peninsula, regardless of the long-term climatic trend. This suggests that climatic variation can be largely ruled out as an explanation for the geomorphologic variability between basins. In an attempt to quantify the factors that affected the geomorphologic development along the eastern side of Baja California, thirty-four drainage basins were extracted from a 15-m-resolution absolute digital elevation model (DEM). The stacked-vector method was applied to utilize the different terrain attributes (e.g., hillshaded relief, aspect, slope, etc.) for supervised classification of bedrock lithologies using object-oriented techniques. Stream-length gradient indices were then measured for the main stream in each of the basins. Bedrock lithologies and alluvium were plotted along the stream profiles to identify any relationship between lithology, structure, and stream gradient

  12. Assessment of landscape change associated with tropical cyclone phenomena in Baja California Sur, Mexico, using satellite remote sensing

    Science.gov (United States)

    Martinez-Gutierrez, Genaro

    Baja California Sur (Mexico), as well as mainland Mexico, is affected by tropical cyclone storms, which originate in the eastern north Pacific. Historical records show that Baja has been damaged by intense summer storms. An arid to semiarid climate characterizes the study area, where precipitation mainly occurs during the summer and winter seasons. Natural and anthropogenic changes have impacted the landscape of southern Baja. The present research documents the effects of tropical storms over the southern region of Baja California for a period of approximately twenty-six years. The goal of the research is to demonstrate how remote sensing can be used to detect the important effects of tropical storms including: (a) evaluation of change detection algorithms, and (b) delineating changes to the landscape including coastal modification, fluvial erosion and deposition, vegetation change, river avulsion using change detection algorithms. Digital image processing methods with temporal Landsat satellite remotely sensed data from the North America Landscape Characterization archive (NALC), Thematic Mapper (TM), and Enhanced Thematic Mapper (ETM) images were used to document the landscape change. Two image processing methods were tested including Image differencing (ID), and Principal Component Analysis (PCA). Landscape changes identified with the NALC archive and TM images showed that the major changes included a rapid change of land use in the towns of San Jose del Cabo and Cabo San Lucas between 1973 and 1986. The features detected using the algorithms included flood deposits within the channels of active streams, erosion banks, and new channels caused by channel avulsion. Despite the 19 year period covered by the NALC data and approximately 10 year intervals between acquisition dates, there were changed features that could be identified in the images. The TM images showed that flooding from Hurricane Isis (1998) produced new large deposits within the stream channels

  13. Higiene e imagen de higiene en la Baja Edad Media : el caso de la ciudad de Gerona

    OpenAIRE

    Gerez Alum, Pau

    2008-01-01

    En esta Tesis nos proponemos dos objetivos oportunamente expuestos en su título: 1- Registrar, cotejar, valorar ciertos datos correspondientes a la Baja Edad Media sobre las condiciones higiénicas de los gerundenses, vistos éstos como un ejemplo de habitantes de una pequeña ciudad-tipo cristiana mediterránea y 2- Deducir, inferir, suponer la imagen que esos mismos gerundenses tenían de la higiene, de lo saludable, de lo limpio y de lo sucio. Estos dos objetivos nos han de permitir t...

  14. Funcionalización de polietileno de baja densidad con anhídrido maleico en estado fundido

    OpenAIRE

    Guzmán,Manuel; A. Murillo,Edwin

    2014-01-01

    En este estudio, polietileno de baja densidad (PEBD) fue modificado con anhídrido maleico (AM) en estado fundido usando concentraciones diferentes de peróxido de dicumilo (DCP) (0.25, 0.50, 0.75 y 1.0 %). Los materiales obtenidos fueron caracterizados por contenido de gel, titulaciones ácido-base, análisis infrarrojo (IR), calorimetría de barrido diferencial (DSC), análisis termogravimétrico (TGA), análisis reológico, propiedades mecánicas, dureza y permeabilidad al oxígeno. El análisis reomé...

  15. Regional stratigraphy, sedimentology, and tectonic significance of Oligocene-Miocene sedimentary and volcanic rocks, northern Baja California, Mexico

    Science.gov (United States)

    Dorsey, Rebecca J.; Burns, Beverly

    1994-01-01

    Upper Oligocene (?) to middle Miocene sedimentary and volcanic rocks in northern Baja California were deposited along the western margin of North America during subduction of the Guadalupe plate and southward migration of the Rivera Triple Junction. Regional mapping and compilation of stratigraphic data reveal a sequence of three regionally traceable stratigraphic units. (1) Oligocene (?) to lower Miocene Mesa Formation: basal quartz-rich fluvial sandstone, grus, conglomerate, and accessory facies, whose detrital compositions reflect the composition of local pre-Tertiary basement rock. (2) Lower to middle Miocene Comondú Formation: laterally variable sequence of volcaniclastic conglomerate, breccia, sandstone, tuff and minor volcanic flow units. (3) Widespread mesa-capping rhyolite tuff, typically welded and crystal-rich, probably upper Miocene in age. The Mesa Formation overlies a highly irregular and deeply dissected erosional surface developed on pre-Tertiary basement rock. The shift from pre-Mesa erosion to widespread (though localized) deposition and valley-filling records the final phase of late Cretaceous to middle Tertiary regional subsidence and eastward transgression that resulted from slow cooling and thermal contraction of Cretaceous arc crust during a temporal gap in magmatic activity along the western Cordilleran margin. Nonmarine sediments of the Mesa Formation were deposited in small, steep-walled paleovalleys and basins that gradually filled and evolved to form through-going, low-energy ephemeral stream systems. The gradational upward transition from the Mesa to Comondú Formation records the early to middle Miocene onset of subduction-related arc magmatism in eastern Baja California and related westward progradation of alluvial volcaniclastic aprons shed from high-standing eruptive volcanic centers. Pre-existing streams were choked with the new influx of volcanic detritus, causing the onset of rapid sediment deposition by stream flows and dilute

  16. Los patronatos pro educación en el Territorio Norte de la Baja California, 1945-1952

    OpenAIRE

    María del Rosario Maríñez

    2010-01-01

    Durante el período de gobierno del presidente Manuel Ávila Camacho (1940-1946) se emprendió un proyecto de federalización educativa centralizada que incorporó a los territorios federales; como respuesta a esa acción gubernamental fueron creados los patronatos pro educación en el Territorio Norte de la Baja California durante el período presidencial de Miguel Alemán Valdés (1946-1952) por parte del gobierno territorial, de la iniciativa privada y funcionarios federales educativos, para tratar ...

  17. in the U.S.-Mexican Border: A Comparative Analysis of Calexico, California and Mexicali, Baja California

    Directory of Open Access Journals (Sweden)

    Kimberly Collins

    2007-01-01

    Full Text Available A lo largo de la frontera EUMéxico, existen problemas en ambos lados que confrontan los gobiernos locales. Ejemplos de estos hechos incluyen inmigración y políticas de seguridad; crecimiento de la población descontrolado que obedece al desarrollo económico; la falta de planeación urbana e infraestructura. Este documento revisa estos problemas mediante un análisis de federalismo en las ciudades hermanas de Calexico, California y Mexicali, Baja California.

  18. Sex education and gender vs. abuse in relationships. Scenario on violence in young people in Baja California

    Directory of Open Access Journals (Sweden)

    Teresa Fernández de Juan

    2014-11-01

    Full Text Available Violence in the relationships of courtship among young people presents growing demonstrations at international and national levels, as it occurs with the increase in the diseases of HIV/AIDS, adolescent pregnancy and sexual transmission. This work emphasizes the main strategy for the prevention of both risk behaviour is directly related to the implementation of an efficient, unprejudiced and timely sex education, especially in schools, with a gender perspective, which is lacking in general sense, at home and in Baja California in particular.

  19. Las epidemias que nunca llegaron: fiebre amarilla (1883) y peste bubónica (1902- 1903) en Baja California.

    Science.gov (United States)

    Fierros-Hernández, Arturo; Ayala-Zúñiga, Alejandro

    2018-01-01

    Este artículo busca aclarar el panorama epidémico que se generó en Baja California a finales del siglo XIX y principios del XX, específicamente el que se dio en 1883 y 1902, años en los que se afirma que ocurrieron epidemias de fiebre amarilla y peste bubónica, respectivamente. Sin embargo, como se demuestra en nuestro estudio, nunca ocurrieron debido a las condiciones sociodemográficas de la zona. Copyright: © 2018 SecretarÍa de Salud.

  20. Análisis de los flujos turísticos en el corredor Los Cabos, Baja California Sur

    Directory of Open Access Journals (Sweden)

    Álvaro López López

    2001-09-01

    Full Text Available The Los Cabos corridor is one of the most dynamic tourism spaces in Mexico. In, around and towards this corridor, intense flows of tourists, migrants, merchandises and information takes place. Diverse in their territorial Impact as they are, most of them act as a link between the southernmost tip of the Baja peninsula and the state of California, in the United States. This is provoking a dissociation of this region of Mexico in its relation with the rest of the country that, to a certain extent, leads to a loss of national sovereignty.

  1. Modelación de una cobertura para el almacenamiento de residuos radiactivos de muy baja actividad en El Cabril

    OpenAIRE

    Fàbregas Oliveras, Gerard

    2012-01-01

    Se ha simulado la celda de residuos radiactivos de muy baja actividad de la instalación de El Cabril. Se han creado dos modelos, el de la celda completa y acabada con una cobertura y el de la celda incompleta durante el relleno con residuos. Se ha utilizado CodeBright para simular los procesos de flujo de agua en medio no saturado, evaporación, flujo de calor y fenómenos atmosféricos. Los resultados muestran un amortiguamiento de las oscilaciones de variables como la presión de líquido y temp...

  2. The role of human capital and learning in Mexican microenterprises: The experience of the state of Baja California

    Directory of Open Access Journals (Sweden)

    Martín Ramírez Urquidi

    2014-01-01

    Full Text Available This work aims at understanding the structure of human capital and learning in low value added microenterprises of Baja California and to determine the role of such factors in microenterprise performance, in order to establish a diagnosis on their contribution and get some public policy implications for the sector. The results confirm the importance of human capital on the performance of these businesses, since there is a relationship between human capital and performance as measured in different ways. The results also account for the heterogeneity in the distribution of microenterprise human capital among locations, sectors, types of business and sex.

  3. Tierras Bajas de Bolivia: II Jornadas de Antropología, Historia y Arqueología

    OpenAIRE

    Combès, Isabelle

    2016-01-01

    Las II Jornadas de Antropología, Historia y Arqueología de las tierras bajas de Bolivia y áreas adyacentes se desarrollaron del 14 al 16 de octubre en Santa Cruz de la Sierra, en los locales del Museo de Historia de la Universidad Autónoma Gabriel René Moreno (UAGRM). Este encuentro fue organizado por el Museo de Historia a través del Centro de Investigaciones Históricas y Antropológicas (CIHA), del Instituto Francés de Estudios Andinos, del programa de posgrado en Historia de la Universidad...

  4. Bedforms, Channel Formation, and Flow Stripping in the Navy Fan, Offshore Baja California

    Science.gov (United States)

    Carvajal, C.; Paull, C. K.; Caress, D. W.; Fildani, A.; Lundsten, E. M.; Anderson, K.; Maier, K. L.; McGann, M.; Gwiazda, R.; Herguera, J. C.

    2017-12-01

    Deep-sea fans store some of the largest volumes of siliciclastic sediment in marine basins. These sandy accumulations record the history of sediment transfer from land to sea, serving as direct records of the geologic history of the continents. Despite their importance, deep-sea fans are difficult to study due to their remote locations in thousands of meters of water depth. In addition, deep-sea fans have a low relief, and geomorphological changes important for the evolution of the fan are often too subtle to be adequately resolved by 3D seismic data or surface-ship bathymetry. To improve our understanding of deep-sea fans, an autonomous underwater vehicle (AUV) was used to acquire high-resolution bathymetry and sub-bottom CHIRP profiles in the proximal sectors of the Navy Fan, offshore Baja California. A remotely operated vehicle was also used to acquire vibracores. The 1-m grid resolution bathymetry shows the seafloor geomorphology in extreme detail revealing different kinds of bedforms, which in combination with the vibracores help to interpret the sedimentary processes active during the Holocene. Morphological elements in the survey area include a main channel, numerous scours, an incipient channel, sediment waves, and a fault escarpment. Several of the scours are interpreted to result from flow stripping at a bend in the main channel. Along high gradient sectors (e.g. > 1o), the scours form bedforms with an erosionally truncated headwall immediately followed down-dip by an upflow accreting sedimentary bulge. These bedforms, the presence of clean sands in the scours and the high gradients suggest that these scours are net-erosional cyclic steps. Scours seem to coalesce along the sediment transport direction to form an incipient channel with abundant rip-up clast gravels. Elsewhere in the survey area, scours are elongated and intimately associated with sediment waves. The acquired dataset illustrates that deep-sea fans may show a variety of processes and

  5. Pre-Miocene palaeogeography of the Los Cabos Block, Baja California Sur: geochronological and palaeomagnetic constraints

    Science.gov (United States)

    Schaaf, P.; Böhnel, H.; Pérez-Venzor, J. A.

    2000-03-01

    The Los Cabos Block (LCB) is located at the southern end of the Baja California peninsula and is composed mainly of intrusive rocks that were emplaced into pre-Cretaceous heterogeneous metasediments and are partly covered by Miocene volcanic and volcaniclastic rocks. Field observations provide evidence that the undeformed, homogeneous gabbronorite of the Sierra El Novillo in the NE part of the LCB is the oldest crystalline unit, which is intruded by undeformed to slightly deformed tonalitic-quartz-dioritic granitoids. For these rocks an Rb-Sr intrusion age of 129±15 Ma and a biotite whole-rock cooling age of 116±2 Ma were obtained. Low initial 87Sr/ 86Sr and high ɛ-Nd values of about 0.7036 and +5 to +6 respectively characterise the intrusives as primitive, mantle-derived granites. Further to the southeast and south, granitoids are more silicic, with abundant deformed sequences — orthogneisses, diatexites and migmatites, among others. From the southern part of the LCB an Rb-Sr intrusion age for the undeformed granites of 115±4 Ma and a biotite cooling age of 90±2 Ma were determined. Initial 87Sr/ 86Sr was determined to be 0.7054 and ɛ-Nd values fall between -2 and 0. The isotopic data do not clearly allow us to characterise the deformed granitoids of the LCB as being intruded by the undeformed unit. Deformation could have been partly due to syn-intrusive tectonics. Palaeomagnetic data suggest minor, if any, northward displacement of the LCB with respect to continental Mexico, corresponding to the rifting in the Gulf of California since the late Miocene, and significant 35-45° clockwise rotations. Possible tilting effects, which may have occurred given the dip of Tertiary volcanics on top of the intrusives, would modify these values for rotation and to a lesser degree of northward displacement. Geochemical, isotopic and palaeomagnetic results and the cooling history of the LCB are similar to those from the Puerto Vallarta Batholith, whereas other Mexican

  6. Lanthanide behavior in hypersaline evaporation ponds at Guerrero Negro, Baja California, Mexico - an environment with halophiles

    Science.gov (United States)

    Choumiline, K.; López-Cortés, A.; Grajeda-Muñoz, M.; Shumilin, E.; Sapozhnikov, D.

    2013-12-01

    Lanthanides are known, in some cases, to be sensitive to changes in water column or sediment chemistry, a fact that allows them to be used as environmental fingerprints. Nevertheless, the behavior of these elements in hypersaline environments is insufficiently understood, especially in those colonized by bacteria, archaea and eukarya halophiles. Extreme environments like the mentioned exist in the artificially-controlled ponds of the 'Exportadora de Sal' salt-producing enterprise located in Guerrero Negro (Baja California, Mexico). Sediment cores from various ponds were collected, subsampled and measured by ICP-MS and INAA. This allowed differencing the behavior of lanthanides and trace elements under a water column salinity gradient along the evaporation sequence of ponds. Sediment profiles (30 mm long), obtained in Pond 5, dominated by Ca and Mg precipitation and at the same time rich in organic matter due to bacterial mat presence, showed highs and lows of the shale-normalized patterns along different in-core depths. Two groups of elements could be distinguished with similar trends: set A (La, Ce, Pr and Nd) and set B (Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The first 'group A' had two prominent peaks at 15 mm and around 22 mm, whereas the 'group B' showed only slight increase at 15 mm and none at 22 mm. Microscopic analyses of prokaryotic cells of a stratified mat in Pond 5 (collected in 2004) showed filamentous bacteria and cyanobacteria with a cell abundance and morphotype richness maxima of prokaryotic cells in a chemocline from 3 mm to 7 mm depth which co-exists nine morphotypes of aerobic and anaerobic prokaryotes Microcoleus chthonoplastes, Leptolyngbya, Cyanothece, Geitlerinema, Spirulina, Chloroflexus, Beggiatoa, Chromatium and Thioploca. Below the 7 mm depth, oxygenic photosynthesis depletes and sulfur reducing compounds increase. The highs of the shale-normalized lanthanide contents of the 'group A' (at 15 mm depth) seem to correlate with the

  7. Evidence for a second impactor at the K-Pg Boundary in Baja California, Mexico

    Science.gov (United States)

    Santa Catharina, Amanda; Kneller, Benjamin Charles; Charao Marques, Juliana; McArthur, Adam Daniel; Kane, Ian Antony; Silvestre Cevallos Ferriz, Sergio Rafael

    2017-04-01

    Controversies remain regarding the trigger, or triggers, of the Cretaceous/Paleogene Mass Extinction. The Chicxulub Impact and the Deccan Volcanism are the main candidates, but discussions about the timing of these events and the magnitude of their effects on the biota are ongoing. Data collected around the globe suggests that profound alterations in the biosphere occurred at this interval, and locations in the Northeastern Atlantic margin and the Gulf of Mexico show evidences of tsunamis and mass waste deposits directly associated with the Chicxulub Impact. Close to El Rosario, Baja California, an enigmatic stratigraphic succession spanning this interval occurs. The succession is distinct from the normal submarine slope deposits in this region and consists of (1) 30 m thick muddy debrites, rich in terrestrial material including fossilized tree trunks up to 2m long and with evidence of exposure to fires, glassy tektites and a horizon rich in gastropods, bivalves, and fragments of corals; (2) an up to 20 m thick coarse grained tuffaceous interval, andesitic in composition, within a channel-like geometry cutting into the debrites, with lapilli (ranging from 1 to 15 cm in size) in discrete sets, fossilized tree trunks close to the base, tektites and shocked quartz; and (3) muddy debrites interbedded with tuffaceous lenses that become less frequent up section. This succession sits between hemipelagic slope deposits, with an abrupt basal contact onto Upper Maastrichtian mudstones and a gradational top, which represents a stabilisation and return to the typical sedimentation environment, with Danian fauna and flora. We believe unit 1 represents material transported onto the slope by the seismic activity caused by the impact of a bolide, which destabilised the coastal region. The tuffaceous channelized unit has been dated (SHRIMP U-Pb in zircons), and its age is indistinguishable from the proposed ages for the K-Pg Boundary. No volcanic activity of this age has been

  8. Evolución de estrellas enanas blancas de Helio de masa baja e intermedia

    Science.gov (United States)

    Althaus, L. G.; Benvenuto, O. G.

    Numerosas observaciones realizadas particularmente en los últimos dos años parecen confirmar que las enanas blancas (EB) de helio de masa baja e intermedia son el resultado de la evolución de sistemas binarios cercanos. Con el objeto de realizar una adecuada interpretación de estos objetos son necesarios modelos de EBs de helio lo más detallado posibles. En este estudio presentamos cálculos detallados de la evolución de EBs de helio con masas entre M=0.1Msolar y M=0.5Msolar a intervalos de 0.05Msolar . Para ello, hemos tenido en cuenta los efectos de temperatura finita mediante un código de evolución estelar lo más actualizado posible. En particular, el transporte de energía es descripto en el marco del nuevo modelo para la convección turbulenta desarrollado por Canuto - Mazzitelli. Además hemos considerado la nueva ecuación de estado para plasmas de helio de Saumon et al. y nuevas opacidades radiativas OPAL. Las pérdidas por neutrinos fueron asimismo tenidas en cuenta. Excepto para las EBs más masivas, nuestros modelos iniciales están ubicados en las cercanías de la correspondiente línea de Hayashi para configuraciones de helio. Nuestros resultados muestran que existe una región prohibida en el diagrama observacional HR donde ninguna EB de helio puede encontrarse. Dicha región es para log{(L/Lsolar )}>= -0.25 and log{Teff} >= 4.45. Hemos encontrado también que los tracks evolutivos en el diagrama HR en el dominio de alta luminosidad (pre - EB) son fuertemente afectados por la eficiencia convectiva y que las pérdidas por neutrinos son importantes en los modelos más masivos. Finalmente hemos analizado la estructura de la zona convectiva externa encontrando que la teoría de Canuto - Mazzitelli conduce a un perfil convectivo muy diferente del dado por cualquier versión de la popular teoría de la mixing length. Si bién este comportamiento es decisivo en el contexto de las inestabilides pulsacionales, los radios y gravedades superficiales de

  9. Judíos extranjeros en el reino de Valencia durante la Baja Edad Media

    Directory of Open Access Journals (Sweden)

    Hinojosa Montalvo, José

    2010-06-01

    Full Text Available During the Late Middle Ages, Valencia became an important business centre, where foreign Jews arrived to the city to trade. It was a commerce that, apart from the land route, preferably used the seaway, even though of the risks of piracy. They and their goods came protected by a safe-conduct from the general Baile of the kingdom. The role of the conversos was very important in their commercial contacts. Apart from the Portuguese Jews, which I took care of in another study, they were predominantly North Africans, others adding up from the Granadan Sultanate, the Mediterranean islands (Sardinia, Sicily and Malta, Provence and Germany. A list of these Jews documented in Valencian sources, as well as an unpublished document that illustrates the activity of a Portuguese Jew in Valencia is attached as an appendix.

    Durante la Baja Edad Media la ciudad de Valencia se convirtió en un importante emporio mercantil, lo que propició que a ella acudieran a negociar judíos extranjeros. Era un comercio que, además de la vía terrestre, utilizaba la vía marítima, a pesar de los riesgos de la piratería. Ellos y sus mercancías venían protegidos por un salvoconducto del baile general del reino. En sus contactos comerciales fue importante el papel de los conversos valencianos. Además de los judíos portugueses, de los que me ocupé en otro estudio, predominaban los norteafricanos, a los que se añadían los del sultanato de Granada, islas del Mediterráneo (Cerdeña, Sicilia y Malta, Provenza y Alemania. Se incluye una lista de estos judíos mencionados en fuentes valencianas, y un documento inédito que ilustra la actividad de un judío portugués en Valencia.

  10. Quaternary Slip History for the Agua Blanca Fault, northern Baja California, Mexico

    Science.gov (United States)

    Gold, P. O.; Behr, W. M.; Rockwell, T. K.; Fletcher, J. M.

    2017-12-01

    The Agua Blanca Fault (ABF) is the primary structure accommodating San Andreas-related right-lateral slip across the Peninsular Ranges of northern Baja California. Activity on this fault influences offshore faults that parallel the Pacific coast from Ensenada to Los Angeles and is a potential threat to communities in northern Mexico and southern California. We present a detailed Quaternary slip history for the ABF, including new quantitative constraints on geologic slip rates, slip-per-event, the timing of most recent earthquake, and the earthquake recurrence interval. Cosmogenic 10Be exposure dating of clasts from offset fluvial geomorphic surfaces at 2 sites located along the western, and most active, section of the ABF yield preliminary slip rate estimates of 2-4 mm/yr and 3 mm/yr since 20 ka and 2 ka, respectively. Fault zone geomorphology preserved at the younger site provides evidence for right-lateral surface displacements measuring 2.5 m in the past two ruptures. Luminescence dating of an offset alluvial fan at a third site is in progress, but is expected to yield a slip rate relevant to the past 10 kyr. Adjacent to this third site, we excavated 2 paleoseismic trenches across a sag pond formed by a right step in the fault. Preliminary radiocarbon dates indicate that the 4 surface ruptures identified in the trenches occurred in the past 6 kyr, although additional dating should clarify earthquake timing and the mid-Holocene to present earthquake recurrence interval, as well as the likely date of the most recent earthquake. Our new slip rate estimates are somewhat lower than, but comparable within error to, previous geologic estimates based on soil morphology and geodetic estimates from GPS, but the new record of surface ruptures exposed in the trenches is the most complete and comprehensively dated earthquake history yet determined for this fault. Together with new and existing mapping of tectonically generated geomorphology along the ABF, our constraints

  11. Percepción de los adolescentes de clase socioeconómica media, baja, urbana y baja marginal de Lima respecto a las prácticas de crianza de sus madres res sus

    Directory of Open Access Journals (Sweden)

    Alegría Majluf

    1993-06-01

    Full Text Available Basándose en un estudio realizado por Majluf en 1989, se llevó a cabo un estudio exploratorio para comprobar el grado de concordancia en la percepción que los hijos adolescentes tienen de las prácticas de crianza de sus madres y las utilizadas por ellas.Se aplicó la prueba de "Prácticas de Crianza" de Block a 160 adolescentes de clase socio económica media, baja-urbana y baja marginal ( 40 en cada CSE provenientes de colegios estatales y particulares de Lima. Los resultados mostraron diferencias entre los adolescentes de CSE M y CSE S-urbana y aquellos que provienen de CSE S-marginal con relación al patrón democrático. No se observaron diferencias en los tres grupos en cuanto al afecto que sus madres les brindan. Se hallaron diferencias significativas con relación al patrón autoritario. Los adolescentes de CSE S-urbana perciben a sus madres como menos autoritarias que los adolescentes de CSE M y menosaún que los de CSE S-marginal. Se discuten ciertas inconsistencias en los resultados.

  12. Avistamientos recientes de águila real (Aquila chrysaetos en la sierra El Mechudo, Baja California Sur, México Recent sightings of Golden Eagle (Aquila chrysaetos in the Sierra El Mechudo, Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Israel Guerrero-Cárdenas

    2013-03-01

    Full Text Available Se reportan nuevos avistamientos de águila real durante 3 años consecutivos (2007-2010 en 2 localidades de la sierra El Mechudo (El Saucito y las Tarabillas, Baja California Sur. Los avistamientos, se realizaron con cámaras-trampa y por observación directa. En BCS, los registros más recientes son de la sierra de la Laguna en el 2000. Se han detectado al menos 4 individuos diferentes, entre juveniles y adultos. La importancia de estos nuevos avistamientos reside en que por primera vez se registra la presencia del águila real en cuerpos de agua dulce.We report new sightings of Golden Eagle for 3 consecutive years (2007-2010 at 2 localities of the Sierra El Mechudo (El Saucito and Tarabillas, Baja California Sur. These sightings were recorded with camera traps and by direct observation. Most recent records from BCS are for the Sierra de la Laguna in 2000. At least 4 different individuals, both juveniles and adults, have been recorded. The importance of these new sightings is that for the first time we registered Golden Eagles infresh water wetlands.

  13. An application of neural network in geophysical prospecting. Electrical resistivity at Las Virgenes geothermal field, Baja California Sur, Mexico; Una aplicacion de las redes neuronales a la prospeccion geofisica. Resistividad electrica en las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Palma Guzman, Sergio Hugo [Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    2000-12-01

    The technology of the neural network is presented with geophysical focus in the Las Virgenes geothermal field, Baja California Sur, Mexico. The results obtained when extrapolating the associative data of the prospecting magnetoteluria and Vertical Electric Sounding, on the area of the geothermal wells to the rest of the area, allows to classify zones of interest for the geothermal exploitation. Also, the use of these associative parameters with the information of the stabilized temperature of the wells, they allow to predict temperatures for the rest of the area. [Spanish] Se presenta una aplicacion de la tecnologia de las redes neuronales con enfoque geofisico en el campo geotermico de Las Virgenes, Baja California Sur, Mexico. Los resultados obtenidos al extrapolar los datos asociativos de las prospecciones geoelectricas de magnetoteluria y sondeos electricos verticales, en la zona de los pozos geotermicos al resto del area, permiten clasificar zonas de interes para la explotacion geotermica. Tambien, la utilizacion de estos parametros asociativos con la informacion de la temperatura estabilizada de los pozos, permiten predecir temperaturas para la misma area.

  14. Mecánica orbital para un viaje interestelar utilizando velas solares

    OpenAIRE

    Rocas Alonso, Marc; Mendez Heredero, Adrià

    2016-01-01

    Es sabido que el espacio es y será objeto de estudios e investigaciones para responder algunas de las preguntas más antiguas de la humanidad. El propósito inicial del trabajo surgió del planteamiento sobre la viabilidad de realizar una misión espacial cuya meta fuese llegar a las inmediaciones de una estrella diferente al Sol utilizando un método de propulsión viable. El trabajo consiste en dos partes considerablemente diferenciadas. En primer lugar se presenta un estudio del estado del...

  15. Obtención de fases del cemento utilizando desechos agrícolas e industriales

    OpenAIRE

    Treviño Cardona, Brenda; Gómez de la Fuente, Idalia

    2002-01-01

    El presente artículo muestra los resultados en la obtenci ón de fases mineralógicas cementicias, utilizando como materia prima cenizas de cascarilla de arroz y ceniza volante mezclados con tres tipos de materiales dolomíticos que contienen carbonatos de calcio en proporciones de 66 y 52%, denotados éstos como cal1 y cal2, respectivamente. Las muestras se prepararon en diferentes proporciones mediante el mezclado de SiO2:CaO, la sílice proviene de ceniza volante y de...

  16. Degradação de poliolefinas utilizando catalisadores zeolíticos

    OpenAIRE

    Valle,Maria Letícia M.; Guimarães,Maria José O. C.; Sampaio,Cristiane M. S.

    2004-01-01

    Neste trabalho foi estudada a degradação de alguns dos principais constituintes dos rejeitos plásticos (polietileno de alta densidade (HDPE), polietileno de baixa densidade (LDPE) e polipropileno (PP)), empregando-se um catalisador exausto de unidades de craqueamento de fluidos (FCC) e um catalisador zeolítico (ADZ3) sintetizado em laboratório. Utilizando técnicas de termogravimetria (TG-DTG) e cromatografia gasosa (CG), foi possível avaliar os produtos gerados no craqueamento destas poliolef...

  17. Obturación de conductos curvos utilizando técnicas termoplásticas

    OpenAIRE

    López, M.; Tissone, S.; Jara Ortiz, M.; Zaracho, O. H.; Bustos, M. J.; Sapienza, María Elena

    2015-01-01

    Conocer las técnicas termoplásticas de obturación de conductos. Los conductos radiculares son sistemas complejos por su anatomía tan particular y por medio de la endodoncia tratamos parte de ese problema. Las técnicas de obturación convencionales, utilizando conos de gutapercha y cemento se podían utilizar en conductos curvos o con ciertas curvaturas: No así en conductos muy curvos por la dificultad de la correcta utilización del instrumental y material. Por todo esto surgen nuevas técnicas d...

  18. Uma proposta de aprendizado da lógica utilizando um ambiente virtual de aprendizagem colaborativa

    OpenAIRE

    Malange, Fernando Cezar Vieira

    2005-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação. Este trabalho realiza o desenvolvimento de um curso básico de Lógica, utilizando tecnologias desenvolvidas para a Internet em atividades educacionais a distância. Oportunizando na abordagem sócio-cultural, a produção do conhecimento básico de lógica, com a utilização de um sistema computacional através de um ambiente virtual de aprendizagem cooperativa. ...

  19. Sistema de evaluación de competencias en Educación Superior utilizando Moodle

    OpenAIRE

    María José BEZANILLA; Sonia ARRANZ

    2016-01-01

    El artículo presenta el diseño de un sistema original de evaluación de competencias utilizando el libro de calificaciones de Moodle. La implantación del modelo de Aprendizaje Basado en Competencias en Educación Superior exige nuevos sistemas de evaluación que sean coherentes con este enfoque. Aunque existen diversos desarrollos tecnológicos para la evaluación de competencias, algunos de los cuales se analizan en este artículo, ninguno responde en su totalidad a modelos com...

  20. AVALIAÇÃO SENSORIAL DE VINHAS RIESLING ITÁLICO NACIONAIS UTILIZANDO PERFIL LIVRE

    OpenAIRE

    BENASSI,Marta de Toledo; DAMÁSIO,Maria Helena; CECCHI,Heloísa Máscia

    1998-01-01

    A literatura cita um grande número de trabalhos envolvendo análise sensorial descritiva para vinhos. Perfil Livre, uma nova técnica descritiva, foi utilizado na caracterização em termos de aparência, sabor e aroma para sete amostras de vinhos brancos Riesling Itálico nacionais. Doze provadores, sem experiência anterior com a técnica, foram selecionados utilizando-se teste triangular. Para o levantamento de atributos foi empregado o método rede. O número de atributos levantados por provador va...

  1. Diseño de redes de cámaras inteligentes utilizando smartphones

    OpenAIRE

    Lahoz Seguido, Fernando

    2017-01-01

    Este Trabajo Fin de Grado (TFG) presenta una herramienta software para controlar de forma remota una red de cámaras inteligentes utilizando smartphones Android. Dicha red compone un sistema de videovigilancia casero que consta de tres partes diferenciadas: teléfonos móviles (cámaras) y aplicaciones cliente y servidor. Este sistema será implementado aprovechando las posibilidades que nos ofrece Android a la hora de controlar las diferentes configuraciones de captura y envío d...

  2. AZUDES Y ACUEDUCTOS DEL SISTEMA DE RIEGO TRADICIONAL DE LA VEGA BAJA DEL SEGURA (ALICANTE, ESPAÑA

    Directory of Open Access Journals (Sweden)

    Arturo Trapote Jaume

    2015-01-01

    Full Text Available En el presente trabajo se describen y analizan las principales obras hidráulicas del sistema de riego tradicional de la comarca de la Vega Baja del Segura, concretamente, los azudes y los acueductos. Los azudes de toma, construidos en el cauce del río Segura, representan el inicio del sistema, desde donde parte una extensa y compleja red de acueductos constituida por acequias y azarbes, como elementos fundamentales, que distribuyen el agua para el regadío. En este estudio se ha llevado a cabo una amplia y profunda investigación documental, tomado datos de campo y captado imágenes in situ que, junto con los diagramas aportados, resultan imprescindibles para comprender la magnitud del sistema. Los resultados obtenidos han servido no sólo para catalogar y caracterizar los elementos que integran el sistema hidráulico del regadío tradicional de la Vega Baja del Segura, sino también para poner de manifiesto un ejemplo real de optimización de recursos hídricos en una zona del sureste peninsular español de escasa e irregular pluviometría. Asimismo, el estudio efectuado revela un sistema de riego sumamente eficiente desde un punto de vista cuantitativo y no tanto desde el cualitativo, debido a la presencia, entre otros contaminantes, de altas concentraciones de sales.

  3. Late quaternary uplift rates of marine terraces on the Pacific coast of North America, southern Oregon to Baja California sur

    Science.gov (United States)

    Muhs, D.R.; Rockwell, T.K.; Kennedy, G.L.

    1992-01-01

    Marine terraces are common landforms along the Pacific coast of North America from southern Oregon to southern Baja California. We report 60 new uranium-series ages of marine terrace corals, hydrocorals, and other fossils. Terraces representing the ca. 80 ka and ca. 125 ka high stands of sea are the most common along the Pacific coast and we have used these ages, along with terrace shoreline angle elevations and paleo-sea-level estimates, to calculate Late Quaternary uplift rates. Uplift rates in the forearc region of the Cascadia subduction zone range from 0.45-1.08 m/kyr. Farther south, along most of the coast west of the San Andreas fault zone, uplift rates range from 0.15-0.35 m/kyr, but some areas have significantly higher rates of uplift and others have apparently experienced little or no uplift in the last 125 ka. In Baja California Sur, west of the East Pacific Rise, little or no uplift has occurred during the Late Quaternary. On average, the magnitude of rates of uplift for the tectonic regimes is as follows: Cascadia subduction zone > San Andreas fault zone region > East Pacific Rise region. ?? 1992.

  4. ESTUDIO TERMOXIDATIVO NO ISOTERMICO POR CALORIMETRÍA DIFERENCIAL DE BARRIDO DE POLIETILENO DE BAJA DENSIDAD FORMULADO CON LIGNINA

    Directory of Open Access Journals (Sweden)

    Irama Piña-Saenz

    2012-01-01

    Full Text Available Se evaluó la capacidad antioxidante de la lignina (LLN en el polietileno de baja densidad (PEBD a través de un método no isotérmico empleando calorimetría diferencial de barrido (DSC. Las muestras bajo estudio, obtenidas de la formulación de PEBD con LLN, se sometieron a tratamientos térmicos a diferentes velocidades de calentamiento (β = 1, 3, 5, 7, 10, 15, 20 ° C/min, en presencia de oxígeno para favorecer la termo-oxidación del material. Se empleó un modelo cinético de degradación termoxidativa isoconversional, ajustada a la ecuación de Arrhenius, para determinar el factor de protección (PF de la lignina en la resina polimérica. Los resultados indican que bajo las formulaciones estudiadas, la lignina presenta una baja capacidad antioxidante en comparación con el Irganox1010. Sin embargo, en las formulaciones que contiene una mezcla de Irganox 1010 y lignina se observó un efecto sinergético en la capacidad antioxidativa de la lignina sobre el aditivo comercial.

  5. Environmental impact of bleufin tuna aquaculture on benthic assemblages in the western coast of Baja California, Mexico

    Science.gov (United States)

    Diaz-Castaneda, V.

    2013-05-01

    Sea-cage farming results in a constant rain of organic waste onto the surrounding benthos. In Baja California there is growing concern over the effects of sea-cages on the local environment: sediment chemistry and benthic communities. Samples were taken in 18 stations using a Van veen grab (0.1 m2) in Bahía Salsipuedes, Baja California in 2003, 2004, 2006 and 2008. Organisms belonging to 7 Phyla were collected: Polychaeta, Mollusca, Crustacea, Echinodermata, Cnidaria, Sipuncula and Bryozoa. Polychaetes were the dominant group followed by crustaceans and mollusks. Polychaetes were represented by 37 families and 157 species. Best represented families were Paraonidae, Cirratulidae, Spionidae, Glyceridae and Maldanidae. This study shows that in the NW area of the bay organic carbon (2.54%) and organic nitrogen (0.95%) are being accumulated (higher concentrations and lower Eh values) and smaller opportunistic species are increasing rapidly near the tuna pens. It is crucial to maintain "healthy" macrofaunal populations in order to enhance decomposition of organic matter and to prevent its excessive accumulation. The most abundant polychaete species were Aphelochaeta multifinis, Mediomastus ambiseta, Prionospio steenstrupi Spiophanes bombyx, Apoprionospio pygnaea, Paraonella sp, Monticellina sp, Aricidea (Allia) ramosa, Spiophanes bombyx and Levinsenia gracilis. The dominant trophic groups were deposit-feeders and carnivores. The buildup of organic matter on the seafloor has attracted scavenger species particularly peracarid crustaceans. Non-metric multidimensional scaling (MDS) separated stations depending of the distance to the tuna pens.

  6. El aporte cultural y educativo de la Baja Edad Media The cultural and educational contribution of the Low Middle Ages

    Directory of Open Access Journals (Sweden)

    Clara Tamayo de Serrano

    2007-12-01

    Full Text Available Este trabajo permite conocer por qué la Baja Edad Media fue un periodo de consolidación de varias de las instituciones educativas, de centros de estudio y del surgimiento de diferentes medios para la difusión de la cultura. También se muestra el proceso histórico mediante el cual, a través de los manuscritos, los códices, los volúmenes, los libros, los relieves, las ilustraciones y las bibliotecas, hubo en la Baja Edad Media una luz, que se ha proyectado al Renacimiento, al mundo moderno y al contemporáneo.This paper explains why the Low Middle Ages was a period for the consolidation educational institutions and study centers and for the rise of different means of propagation of culture. It also shows the historical process by which manuscripts, codices, volumes, books, embossments, illustrations and libraries threw a light into the Low Middle Ages and projected it into the Renaissance, the modern world and the contemporary world.

  7. Alternativa de rehabilitación visual en pacientes con baja visión por afecciones maculares

    Directory of Open Access Journals (Sweden)

    Mayrelis Quintero Busutil

    Full Text Available Objetivo: evaluar los resultados de una modalidad de rehabilitación visual en pacientes con baja visión por afecciones maculares. Método: se realizó un estudio experimental, tipo serie de casos (20 pacientes en el Instituto Cubano de Oftalmología «Ramón Pando Ferrer». Se indicó la realización de ejercicios de localización y relleno. Antes de la rehabilitación y después, se estudió la agudeza visual mejor corregida de cerca con cartilla de Zeiss, velocidad de lectura, presencia de fatiga y rastreo. Resultado: la agudeza visual mejor corregida de cerca mejoró en 16 pacientes que representó el 80 % de los casos estudiados, la velocidad de lectura se incrementó del 73 al 86,5 como promedio; no presentaron fatiga y fue más efectivo el rastreo después de la realización de ejercicios de localización y relleno. Conclusión: la alternativa en la rehabilitación visual de pacientes de baja visión secundaria a afecciones maculares mediante de la realización de ejercicios de localización y relleno, mejora la capacidad visual de los mismos.

  8. Status of the California Red-legged Frog (Rana draytonii) in the State of Baja California, México

    Science.gov (United States)

    Peralta-Garcia, Anny; Hellingsworth, Bradford D.; Richmond, Jonathan Q.; Valdez-Villavicencio, Jorge H.; Ruiz-Campos, Gorgonio; Fisher, Robert N.; Cruz-Hernandez, Pedro; Galina-Tessaro, Patricia

    2016-01-01

    The California Red-legged Frog (Rana draytonii) is a threatened species in the United States that has undergone population declines, especially in southern California. Due to the lack of information on the status of Mexican populations, we surveyed for the presence of R. draytonii in Baja California and assessed possible threats to population persistence. Our study area extended from the U.S.-Mexican border to the southern end of the distribution of the species in the Sierra San Pedro Mártir. We found R. draytonii at six of 15 historical sites, none at five proxy sites (i.e., alternative sites chosen because the historical record lacked precise locality data), and four at 24 additional sites. The 10 occupied sites are within three watersheds in the Sierra San Pedro Mártir (two sites at Arroyo San Rafael, two sites at Arroyo San Telmo, and six sites at Arroyo Santo Domingo). We did not detect R. draytonii at 60% of historical sites, including the highest elevation site at La Encantada and multiple low-elevation coastal drainages, suggesting the species has declined in Baja California. The threats we noted most frequently were presence of exotic aquatic animal species, water diversion, and cattle grazing. Management of remaining populations and local education is needed to prevent further declines.

  9. La baja de largo plazo en los precios de las drogas duras: una explicación

    Directory of Open Access Journals (Sweden)

    Leonardo Raffo López

    2015-07-01

    Full Text Available El propósito de esta investigación es avanzar en la compresión de los mercados ilegales de drogas duras y explicar la baja de largo plazo que se presentó en los precios de los estupefacientes durante las décadas anteriores. Para ello, siguiendo el enfoque de Poret y Téjedo (2006, y teniendo en cuenta la influencia de las redes de tráfico y distribución de las drogas ilícitas, se desarrolló un modelo analítico que permite entender el comportamiento de los mercados de ventas finales de drogas ilegales. Esto resulta novedoso en el ámbito de la economía del crimen y, en particular, en el de la teoría económica de los bienes ilegales. El modelo permitió probar varios resultados importantes, entre ellos, que la expansión y la densificación de las redes de tráfico y distribución de drogas son factores que explican la baja de largo plazo en los precios de las drogas duras.

  10. Calor específico a bajas temperaturas de alcoholes sólidos vítreos y cristalinos

    Directory of Open Access Journals (Sweden)

    Talón, C.

    2004-02-01

    Full Text Available We present and discuss in this work specific-heat experiments at low temperature that we have conducted on different molecular (hydrogenbonded glasses and crystals. Specifically, we have measured the low-temperature specific heat Cp(T for a set of solid alcohols: normal and fully-deuterated ethanol, 1−and 2−propanol, and glycerol. Ethanol exhibits a very interesting polymorphism presenting three different solid phases at low temperature: a fully-ordered (monoclinic crystal, an orientationally-disordered (cubic crystal or “orientational glass”, and the canonical (amorphous structural glass. By measuring and comparing the low-temperature specific heat of the three phases, in the boson peak range, 2−10 K, as well as in the tunneling-states range, below 1K, we are able to provide a quantitative confirmation that “glassy behavior” is not an exclusive property of amorphous solids. On the other hand, propanol is the simplest monoalcohol with two different stereoisomers (1−and 2−propanol, which allows us to study directly the influence of the spatial rearrangement of atoms on the universal properties of glasses. We have measured the specific heat of both isomers, finding a noteworthy quantitative difference between them. Finally, low-temperature specific-heat data of glassy and crystalline glycerol have also been obtained.

    En este trabajo, presentamos y discutimos experimentos de calorimetría a bajas temperaturas que hemos realizado en diferentes vidrios y cristales moleculares (de puentes de hidrógeno. En concreto, hemos medido el calor específico a bajas temperaturas Cp(T para un conjunto de alcoholes sólidos: etanol normal y completamente deuterado, 1−y 2−propanol, y glicerol. El etanol presenta un muy interesante polimorfismo, con tres fases sólidas diferentes a bajas temperaturas: un cristal estable perfectamente ordenado (monoclínico, un cristal (cúbico con desorden orientacional o “vidrio orientacional”, y

  11. Growth and mortality of the fish Citharichthys xanthostigma (Pleuronectiformes: Paralichthyidae off the Western coast of Baja California, México

    Directory of Open Access Journals (Sweden)

    Marco A Martínez-Muñoz

    2010-06-01

    Full Text Available Longfin sanddab (Citharichthys xanthostigma represents a very important fishery resource in Southern and Baja California but are not very well known. The purpose of this study is to provide information on the growth and mortality of longfin sanddab population in the Mexican Pacific Ocean at Baja California, México. Data on growth were obtained for longfin sanddab collected with otter trawls during six cruises off the Western coast of Baja California. A total of 1 017 longfin sanddab were caught over the sampling period, and from 860 specimens, the male to female ratio was 1:1.8. The relationship between total weight (W and standard length (SL is described: W=0.00000743 SL3.196 for females and W=0.00000764 SL3.193 for males. Age groups were estimated from length frequency data, and von Bertalanffy annual growth parameters for all fish data combined were the following: L∞=289.2mm SL, k=0.20, t0=-0.73; for males, they were L∞=265.9mm SL, k=0.21, t0=-0.68, and for females, L∞=293.6mm SL, k=0.23, t0=-0.35. Longfin sanddab caught during this study reached a maximum age of 10 years, and at that age, males attained smaller sizes than females. The age groups had a total mortality (Z rate of 0.82 year-1, a fishing mortality (F of 0.52 year-1, and a natural mortality (M of 0.3 year-1. Although the longfin sanddab is not a target species of commercial fisheries, it suffers high mortality as part of the bycatch in the shrimp fishery. Rev. Biol. Trop. 58 (2: 689-705. Epub 2010 June 02.Se presenta información sobre el crecimiento y mortalidad de la población del C. xanthostigma (lenguado alón en el Pacífico Mexicano de Baja California, México. Datos sobre su crecimiento fueron obtenidos de peces capturados con red de arrastre durante seis cruceros en la costa Oeste de Baja California, México. Se capturaron 1 017 peces en este periodo. La relación machos:hembras de 860 ejemplares fue de 1:1.2. La relación peso total (W y longitud estándar (SL se

  12. Food habits of the silky shark Carcharhinus falciformis (Müller & Henle, 1839) off the western coast of Baja California Sur, Mexico

    OpenAIRE

    Cabrera Chávez, A.A; Galván Magaña, Felipe; Escobar Sánchez, Ofelia

    2010-01-01

    The objective of this study was to establish the trophic niche of the silky shark and to determine the ecological role of this predator in the ecosystem close to Baja California. The trophic spectrum was analyzed from samples taken during summer and autumn (2000–2002) from the fishing camps of Punta Lobos and Punta Belcher on the western coast of Baja California Sur. A total of 263 stomach contents were analyzed (143 with food; 120 empty). The index of relative importance (IRI) showed that at...

  13. Tratamiento del dolor perioperatorio en la baja de combate: experiencia desde el Hospital Militar Español de Herat (Afganistán)

    OpenAIRE

    R. Navarro Suay; R. Tamburri Bariain; L. Sáenz Casco; I. Bodega Quiroga; E. López Soberón

    2015-01-01

    La analgesia siempre se ha considerado uno de los pilares fundamentales de la asistencia médica a la baja de combate. Esta opinión sigue vigente en los actuales conflictos de Irak y Afganistán. La sanidad militar española lleva desplegada en el Hospital Militar de Herat (Afganistán) desde 2005. En este centro se han atendido a casi 30.000 pacientes (algunos de ellos bajas en combate), obteniéndose una importante experiencia en el tratamiento de este tipo de politraumatismo. Se expone el caso ...

  14. Evaluación de biomarcadores no destructivos en sapo gigante (Rhinella marina) de la cuenca baja del Río Coatzacoalcos, Veracruz, México

    OpenAIRE

    Cruz Santiago, Omar

    2016-01-01

    En este estudio se determinó la actividad de biomarcadores no destructivos (glutatión s-transferasa –GST-, malondioaldehído –MDA-, ácido aminolevulínico dehidratasa -δ-ALAD-, parámetros hematológicos –HCM-, butirilcolinesterasa –BChE-, apoptosis, factor de condición –FC- y vitelogenina –VTG-) en sapos gigantes (R. marina) de dos zonas (alta y baja) de la cuenca baja del Río Coatzacoalcos para compararlos con organismos de referencia (sapos mantenidos en laboratorio). De cada estación de muest...

  15. El plan director de la vega baja de Toledo, España: paisaje patrimonial, ecológico y urbano.

    OpenAIRE

    Hernandez Aja, Agustin; Roch Peña, Fernando; Moran Alonso, Nerea; Fernandez Ramirez, Cristina

    2014-01-01

    La Vega Baja de Toledo constituye un gran vacío urbano que, por avatares históricos, se ha mantenido al margen del crecimiento de la ciudad, rodeada por el casco histórico de Toledo, los barrios del ensanche norte y el río Tajo. Su localización privilegiada, junto a la riqueza patrimonial y ecológica del espacio, han sido las bases de la propuesta del Plan Director de la Vega Baja (PDVB). El objetivo del PDVB ha sido articular este vacío y abrirlo a la población, a la vez que proteger y re...

  16. Pequeños pasos, grandes metas : un estudio sobre los actores de talla baja en los siglos XX y XXl

    OpenAIRE

    González Abad, Fernando

    2016-01-01

    “Pequeños pasos, grandes metas” es un estudio del papel que hacen los actores de talla baja en el mundo del séptimo arte, desde sus inicios a finales del siglo XIX cuando los hermanos franceses Lumière, Auguste y Louis, lo patentaron en febrero de 1895. Dicho estudio lo he dividido en dos etapas, con una pequeña introducción sobre las personas de talla baja en la pintura, sobre todo en el denominado Siglo de Oro español, que ocupa desde finales del siglo XV a finales del XVII. En la pri...

  17. Predicting Pinus monophylla forest cover in the Baja California Desert by remote sensing

    Directory of Open Access Journals (Sweden)

    Jonathan G. Escobar-Flores

    2018-04-01

    Full Text Available The Californian single-leaf pinyon (Pinus monophylla var. californiarum, a subspecies of the single-leaf pinyon (the world’s only one-needled pine, inhabits semi-arid zones of the Mojave Desert (southern Nevada and southeastern California, US and also of northern Baja California (Mexico. This tree is distributed as a relict subspecies, at elevations of between 1,010 and 1,631 m in the geographically isolated arid Sierra La Asamblea, an area characterized by mean annual precipitation levels of between 184 and 288 mm. The aim of this research was (i to estimate the distribution of P. monophylla var. californiarum in Sierra La Asamblea by using Sentinel-2 images, and (ii to test and describe the relationship between the distribution of P. monophylla and five topographic and 18 climate variables. We hypothesized that (i Sentinel-2 images can be used to predict the P. monophylla distribution in the study site due to the finer resolution (×3 and greater number of bands (×2 relative to Landsat-8 data, which is publically available free of charge and has been demonstrated to be useful for estimating forest cover, and (ii the topographical variables aspect, ruggedness and slope are particularly important because they represent important microhabitat factors that can determine the sites where conifers can become established and persist. An atmospherically corrected a 12-bit Sentinel-2A MSI image with 10 spectral bands in the visible, near infrared, and short-wave infrared light region was used in combination with the normalized differential vegetation index (NDVI. Supervised classification of this image was carried out using a backpropagation-type artificial neural network algorithm. Stepwise multiple linear binominal logistical regression and Random Forest classification including cross validation were used to model the associations between presence/absence of P. monophylla and the five topographical and 18 climate variables. Using supervised

  18. Rapid subsidence and stacked Gilbert-type fan deltas, Pliocene Loreto basin, Baja California Sur, Mexico

    Science.gov (United States)

    Dorsey, Rebecca J.; Umhoefer, Paul J.; Renne, Paul R.

    1995-08-01

    Pliocene nonmarine to marine sedimentary rocks exposed in the Loreto basin, Baja California Sur, provide a record of syntectonic subsidence and sedimentation in a transform-rift basin that developed along the western margin of the Gulf of California. A thick sequence of twelve Gilbert-type fan deltas, having a total measured thickness of about 615 m, accumulated near the fault-bounded southwestern margin of this basin. Based on stratal geometries and lithofacies associations, sedimentary rocks are divided into Gilbert-delta topset, foreset and bottomset strata, shell beds and background shallow-marine shelf deposits. Topset strata of each Gilbert-type delta cycle are capped by laterally persistent molluscan shell beds containing diverse assemblages of bivalves, pectens, oysters, gastropods and echinoids. These shell beds are interpreted to be condensed intervals that record sediment starvation during abandonment of the fan-delta plain. Delta abandonment may have been caused by large episodic faulting events, which submerged each pre-existing fan-delta plain, substantially slowed detrital input by drowning of alluvial feeder channels, and created new accommodation space for each new Gilbert-type fan delta. Alternatively, it is possible that delta-plain abandonment was caused by upstream avulsions and autocyclic lateral switching of fan-delta lobes during relatively uniform rates of slip along the basin-bounding fault. Two contrasting, plausible basin models are proposed for the Loreto basin: (1) asymmetric subsidence along a high-angle oblique-slip normal fault, producing a classic half-graben basin geometry with vertically stacked Gilbert-type fan deltas; or (2) lateral stacking and horizontal displacement of strata away from a relatively fixed depocenter due to fault movement in the releasing bend of a listric strike-slip fault. We favor the first model because field relations and simple geometric constraints suggest that most of the total measured section

  19. Lipid Biomarkers for Methanogens in Hypersaline Cyanobacterial Mats for Guerrero Negro, Baja California Sur

    Science.gov (United States)

    Jahnke, Linda L.; Embaye, Tsegereda; Summons, Roger E.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Analyses of sediments from the vicinity of active methane seeps have uncovered a particular suite of lipid biomarker patterns that characterize methane consuming archaea and their syntrophic, sulfate reducing partners. These isoprenoid biomarkers, largely identified by their anomalously light carbon isotopic signatures, have been a topic of intense research activity and are recorded in numerous methane-rich environments from Holocene to Cenozoic. This phenomenon has implications for depleted kerogens at 2.7 Ga on early Earth (Hinrichs 2002). In contrast, the lipid biosignatures of methane producing archaea are not readily identified through distinct isotopic labels and have received comparably little attention in analyses of archaea in environmental samples. Indeed, environmental analyses generally detect only free archaeal lipids, not the intact, polar molecules found in the membrane of living organisms. As part of the Ames NAI, the 'Early Microbial Ecosystem Research Group' (EMERG) is working to understand microbial processes in the hypersaline cyanobacterial mats growing in the salt evaporation ponds of the Exportadora de Sal at Guerrero Negro, Baja California Sur, Mexico. The aim of this study was to develop methods by which we could identify the organisms responsible for methane generation in this environment. While the ester-bound fatty acids, hopanoids and wax esters provide a means to identify most of the bacterial components of these mats, the archaea which Ere evidently present through genomic assays and the fact of intense methane production (Hoehler et al. 200l), have not been identified through their corresponding lipid signatures. Archaeal core lipids present a number of analytical challenges. The core lipids of methanogens comprise C20, C40 and sometimes C25 isoprenoid chains, linked through ether bonds to glycerol. As well as archaeal (C20), sn-2- and sn-3-hydroxyarchaeol are associated particularly with methylotrophic methanogens. Recently, we have

  20. Estrategia de atención de niños hospitalizados por infecciones respiratorias agudas bajas

    Directory of Open Access Journals (Sweden)

    Ferrari Ana M

    2002-01-01

    Full Text Available OBJETIVO: Mejorar la calidad de la atención hospitalaria de los niños con infecciones respiratorias agudas bajas, aumentar los conocimientos sobre esa patología y mejorar la eficiencia en el uso de los recursos asistenciales, por medio de una estrategia que se denominó Plan de Invierno.MÉTODOS: La estrategia se basó en la utilización de protocolos de diagnóstico y tratamiento, internación por cuidados progresivos y por enfermedad, adecuación de los recursos asistenciales y creación de un sistema de registro permanente, informatizado. Se incorporó la investigación sistemática de la etiología viral para racionalizar el uso de la medicación y reducir las infecciones intrahospitalarias. RESULTADOS: Durante la aplicación del Plan (19/V-19/IX/99 ingresaron 3.317 niños; 1.347 (40.61% presentaban infecciones respiratorias agudas bajas. Se captaron 1.096 (81%, de los cuales 71% eran menores de un año. Predominaron las infecciones respiratorias virales (68%. Los criterios de ingreso fueron saturación de oxígeno <95%, polipnea, tiraje o derrame pleural en el 92.4% de los niños. La magnitud de la demanda impidió que las pautas de aislamiento individual o en grupo se cumplieran en todos los casos. El uso de la medicación se ajustó a lo recomendado en un elevado porcentaje: no recibieron antibióticos 73% de las bronquiolitis ni 72% de las neumonías virales, y 96% de las neumonias bacterianas los recibieron según pauta; se redujo el uso de broncodilatadores y de corticoides. El gasto en medicamentos disminuyó fundamentalmente en el grupo de los corticoides y tuvo el mayor impacto en el costo por día/cama de antibióticos. CONCLUSIONES: Disminuir la morbimortalidad por infecciones respiratorias agudas bajas requiere continuar mejorando la calidad de la atención hospitalaria y fortalecer los programas de promoción de salud y de control de las enfermedades prevalentes, en el primer nivel de atención.

  1. Estrategia de atención de niños hospitalizados por infecciones respiratorias agudas bajas

    Directory of Open Access Journals (Sweden)

    Ana M Ferrari

    2002-06-01

    Full Text Available OBJETIVO: Mejorar la calidad de la atención hospitalaria de los niños con infecciones respiratorias agudas bajas, aumentar los conocimientos sobre esa patología y mejorar la eficiencia en el uso de los recursos asistenciales, por medio de una estrategia que se denominó Plan de Invierno.MÉTODOS: La estrategia se basó en la utilización de protocolos de diagnóstico y tratamiento, internación por cuidados progresivos y por enfermedad, adecuación de los recursos asistenciales y creación de un sistema de registro permanente, informatizado. Se incorporó la investigación sistemática de la etiología viral para racionalizar el uso de la medicación y reducir las infecciones intrahospitalarias. RESULTADOS: Durante la aplicación del Plan (19/V-19/IX/99 ingresaron 3.317 niños; 1.347 (40.61% presentaban infecciones respiratorias agudas bajas. Se captaron 1.096 (81%, de los cuales 71% eran menores de un año. Predominaron las infecciones respiratorias virales (68%. Los criterios de ingreso fueron saturación de oxígeno <95%, polipnea, tiraje o derrame pleural en el 92.4% de los niños. La magnitud de la demanda impidió que las pautas de aislamiento individual o en grupo se cumplieran en todos los casos. El uso de la medicación se ajustó a lo recomendado en un elevado porcentaje: no recibieron antibióticos 73% de las bronquiolitis ni 72% de las neumonías virales, y 96% de las neumonias bacterianas los recibieron según pauta; se redujo el uso de broncodilatadores y de corticoides. El gasto en medicamentos disminuyó fundamentalmente en el grupo de los corticoides y tuvo el mayor impacto en el costo por día/cama de antibióticos. CONCLUSIONES: Disminuir la morbimortalidad por infecciones respiratorias agudas bajas requiere continuar mejorando la calidad de la atención hospitalaria y fortalecer los programas de promoción de salud y de control de las enfermedades prevalentes, en el primer nivel de atención.

  2. Composición del aceite esencial de Tagetes lacera, planta endémica de Baja California Sur, México Composition of essential oil of Tagetes lacera, endemic plant from Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Francisco Díaz-Cedillo

    2012-06-01

    Full Text Available Es escasa la información sobre la biología y química de Tagetes lacera Brand. (Asteraceae, especie endémica de Baja California Sur (BCS, México, que por su porte alto y presencia de aroma es una fuente de aceites esenciales útil para el control de plagas y enfermedades de cultivos agrícolas. A partir de partes aéreas de plantas en floración de T. lacera recolectadas en la sierra de la Laguna, BCS se obtuvo aceite esencial mediante hidrodestilación. Por medio del procedimiento de análisis CG-EM, se identificaron 6 compuestos principales: E-tagetona (26.2%, crisantenona (24.8%, verbenona (22.1%, α-thujeno (20.5%, β-pineno (3.1% y α-pineno (1.9%.It is scarce the background on the biology and chemistry of Tagetes lacera Brand. (Asteraceae, an endemic species from Baja California Sur (BCS, Mexico that considering its plant high and odor is an essential oil source to obtain biopesticides. From aerial parts of plants fully flowered of T. lacera picked in Sierra de la Laguna, BCS, essential oil was obtained by hydrodistillation. Using GC-MS analysis, 6 major compounds were identified: E-tagetone (26.2%, chrysanthenone (24.8%, verbenone (22.1%, α-thujene (20.5%, β-pinene (3.1%, α-pinene (1.9%.

  3. New and noteworthy waterfowl records at artificial wetlands from Baja California Sur, Mexico Registros nuevos y sobresalientes de anátidos en humedales artificiales de Baja California Sur, México

    Directory of Open Access Journals (Sweden)

    Roberto Carmona

    2011-06-01

    Full Text Available We present 9 recent records of rare waterfowls in Baja California Sur, all of them in artificial wetlands: 3 freshwater sites and 1 concentration area for a saltworks. We present the first records of the Ross's Goose in the state. The remaining 8 species are: Black-bellied Whistling-Duck (breeding, Fulvous Whistling-Duck, Greater White-fronted Goose, Snow Goose, Cackling Goose, Tundra Swan, Mallard and Hooded Merganser. To this list we added an historical compilation of the records of these species in artificial sites of the state. The artificial wetlands are no replacement for their natural counterparts, they are nevertheless an important part of the region's landscape mosaic. As the records of the present work exemplify, this man-made habitat increases the regional species richness, and should be considered as important areas that need to be protected.Presentamos registros recientes de 9 especies de anátidos raros en Baja California Sur, todos ellos realizados en humedales creados por el hombre: 3 sitios dulceacuícolas y 1 área de concentración para la producción de sal. Se incluyen los primeros registros del ganso de Ross (Chen rossii para el estado. Las 8 especies restantes son: Dendrocygna autumnalis (anidación, D. bicolor, Anser albifrons, Chen caerulesens, Branta hutchinsii, Cygnus columbianus, Anas platyrhynchos y Lophodytes cucullatus. A la lista, agregamos una recopilación histórica de los registros de estas especies en humedales artificiales del estado. Aunque estos sitios no deben sustituir a sus contrapartes naturales, actualmente forman parte del mosaico paisajístico que ofrece la región; adicionalmente, incrementan la riqueza de especies de la región, por lo que es necesario brindarles protección.

  4. Detección de fraude bancario en tiempo real utilizando tecnologías de procesamiento distribuido

    OpenAIRE

    Mansilla Montero, Javier

    2016-01-01

    En este Trabajo de Fin de Máster se desarrollará un sistema de detección de fraude en pagos con tarjeta de crédito en tiempo real utilizando tecnologías de procesamiento distribuido. Concretamente se considerarán dos tecnologías: TIBCO, un conjunto de herramientas comerciales diseñadas para el procesamiento de eventos complejos, y Apache Spark, un sistema abierto para el procesamiento de datos en tiempo real. Además de implementar el sistema utilizando las dos tecnologías propuestas, un objet...

  5. A Study on the Attitudes and Opinions of Engineering Students from the University of Baja California, Mexico, on Science, Technology, and Society

    Science.gov (United States)

    Oliveros Ruiz, Maria Amparo; Sevilla Garcia, Juan Jose; Schorr, Michael

    2010-01-01

    A proposal is presented for the incorporation of the concepts of STS into the teaching of science and technology at the Faculty of Engineering, Mexicali Campus, of the University of Baja California. The method outlined for the development of research and the application of the "Opinions Questionnaire on Science, Technology and Society"…

  6. Respuesta clínica en pacientes mexicanos con síndrome de intestino irritable tratados con dieta baja en carbohidratos fermentables (FODMAP

    Directory of Open Access Journals (Sweden)

    N. Pérez y López

    2015-07-01

    Conclusiones: En este primer estudio en población mexicana con SII se observó mejoría significativa de los principales síntomas incluyendo dolor, distensión y flatulencia tras una dieta baja FODMAP.

  7. Mujer y nación: una historia de la educación en Baja California. 1920-1930

    Directory of Open Access Journals (Sweden)

    María del Consuelo López Arámburo

    2005-01-01

    Full Text Available This article forms part of research in progress that aims to examine the intellectual climate prevailing in Mexico in the post-revolutionary period, from 1920 to 1930. The essay explores how the influence of nationalist ideology gradually shifted the role of Mexican women, identifying them as the educators of the nation. The study focuses on Baja California since educators, such as Josefina Rendón Parra (1885-1977, were an important example illustrating how nationalist ideology engineered women´s role in Mexico´s reconstruction. Education with a spiritual dimension was the key doorway through which women gained access to the modern era. In a society that had yet to grant them the right to vote, education was also the doorway through which women gained acceptance as citizens. Finally, this study proposes the remaking of history through the mythological discourses, such as the legends that were fashionable in that period.

  8. Business competitiveness in the small and medium-sized enterprises of the manufacturing sector in Baja California

    Directory of Open Access Journals (Sweden)

    Manuel Alejandro Ibarra Cisneros

    2017-01-01

    Full Text Available The objective of this research is to determine the competitiveness level of the manufacturing small and medium-sized enterprises (SMEs of Baja California and to identify which areas within them affect this competitiveness. The methodology used is descriptive, correlational, and cross-sectional; the systemic competitiveness model is developed at the micro level, and a measurement instrument with 64 questions is used on 195 companies in the state; in addition, traditional multiple linear regressions are performed to test the hypotheses. One of the findings is that the SMEs in the state have a medium-low competitiveness level and do not show any relationship between the size of the companies and their competitiveness; however, the production-operations area prove to be more important for their competitiveness level. Although the measurement instrument that is used has no proportionality at the municipality and subsector level, it does allow us to approach the internal operation of the SMEs.

  9. Reconnaissance geologic map of the Loreto and part of the San Janier quadrangles, Baja California Sur, Mexico

    Science.gov (United States)

    McLean, Hugh

    1988-01-01

    The Loreto area of Baja California Sur, Mexico, contains a diverse association of igneous, sedimentary, and metasedimentary rocks exposed in the foothills and arroyos between the Sierra La Giganta and Gulf of California. The Loreto area was selected for this study to examine the possible relation of the marine rocks to the opening of the Gulf of California, and to determine the stratigraphic and structural relations between basement rocks composed of granitic and prebatholithic rocks and overlying Tertiary (mainly Miocene) sedimentary and volcanic rocks, and by a sequence of Pliocene marine and nonmarine sedimentary rocks. The Pliocene marine rocks lie in a structural depression informally called here, the Loreto embayment. This geologic map and report stem from a cooperative agreement between the U.S. Geological Survey and the Consejo de Recursos Minerales of Mexico that was initiated in 1982.

  10. Radiación fetal a dosis bajas de rayos X en la rata albina (Rattus norvegicus albinus

    Directory of Open Access Journals (Sweden)

    L. A. Zorrilla

    1994-06-01

    Full Text Available Con el objetivo de obtener información sobre los efectos patológicos a corto plazo en el feto, causados por la exposición a dosis bajas de rayos X de sus progenitoras, se irradiaron ratas albinas el día 12 de la gestación y se investigaron sus repercusiones con parámetros morfológicos y hematológicos; se observaron alteraciones significativas como hipoplasia medular, retardo del crecimiento fetal, malformaciones congénitas y mortalidad. Una extrapolación animal-humano en cuanto adosis-efecto, alertasobre los posibles riesgos de desarrollo embriofetal humano causados por madres que se exponen a estas dosis consideradas por muchos como no perjudiciales.

  11. LAS MUJERES EN LA MIGRACIÓN INTERNA Y EL EMPLEO INFORMAL EN BAJA CALIFORNIA SUR, MÉXICO

    Directory of Open Access Journals (Sweden)

    ALBA E. GÁMEZ

    2010-01-01

    Full Text Available Este artículo analiza las características del fenómeno migratorio en Baja California Sur, en la costa norte del Pacífico mexicano, donde el turismo y la agricultura de exportación son dos sectores atractores de población. Esto ha estimulado una tasa de crecimiento demográfico promedio de 10% en la última década en regiones como Los Cabos, de las que se alimentan los sectores formal e informal. El propósito de este artículo es contribuir a la comprensión de la participación de las mujeres migrantes en el mercado laboral informal.

  12. LAS MUJERES EN LA MIGRACIÓN INTERNA Y EL EMPLEO INFORMAL EN BAJA CALIFORNIA SUR, MÉXICO

    OpenAIRE

    ALBA E. GÁMEZ; TAMAR DIANA WILSON; ANTONINA IVANOVA BONCHEVA

    2010-01-01

    Este artículo analiza las características del fenómeno migratorio en Baja California Sur, en la costa norte del Pacífico mexicano, donde el turismo y la agricultura de exportación son dos sectores atractores de población. Esto ha estimulado una tasa de crecimiento demográfico promedio de 10% en la última década en regiones como Los Cabos, de las que se alimentan los sectores formal e informal. El propósito de este artículo es contribuir a la comprensión de la participación de las mujeres migr...

  13. Capacidades institucionales y desempeño de los organismos operadores de agua en Hermosillo, Sonora, y Mexicali, Baja California

    Directory of Open Access Journals (Sweden)

    Edmundo Loera Burnes

    2017-01-01

    Full Text Available Con el enfoque de capacidad institucional, aquí se analizan los factores políticos que influyeron en la asignación de recursos jurídicos, organizacionales y humanos para la Comisión Estatal de Servicios Públicos de Mexicali y para Agua de Hermosillo. También cómo influye el titular del Ejecutivo en su operación, y cómo se refleja la influencia de los factores institucionales en su desempeño. Si bien el estudio muestra la baja capacidad de ambos organismos en el aspecto de recursos humanos, el de Mexicali es superior en los otros rubros, y eso se traduce en más planeación y, por lo tanto, en mejor desempeño.

  14. Progress within the manufacturing sector in Baja California during the transition towards economic opening (1975-1993: A systematic perspective

    Directory of Open Access Journals (Sweden)

    Lya Margarita Niño Contreras

    2003-01-01

    Full Text Available This article studies some of the main economic figures of the industrialization process in system of cities of Baja California within the historic period from 1975 to 1993. Due to its economic relevance, the analysis is focused on the manufacturing sector. A new role is developing among industrial groups with growing changes that began in the late seventies. In this analysis the “shift & share” technique is still useful to identify that kind of industrial behavior. This level of aggregation was used before (CONEPO, 1988 in order to achieve some objectives in accordance with a regional economics scope. At the same time, this period of analysis brings some light into a recent economic phase of special interest, taking into consideration main figures in the national manufacturing sector of the same period.

  15. Unraveling the channel–lobe transition zone with high-resolution AUV bathymetry: Navy Fan, offshore Baja California, Mexico

    Science.gov (United States)

    Carvajal, Cristian; Paull, Charles K.; Caress, David W.; Fildani, Andrea; Lundsten, Eve M.; Anderson, Krystle; Maier, Katherine L.; McGann, Mary; Gwiazda, Roberto; Herguera, Juan Carlos

    2017-01-01

    Ultra-high-resolution (1 m * 1 m * 0.25 m) bathymetry was acquired with an autonomous underwater vehicle (AUV) over a sector of the Navy Fan offshore Baja California. The survey specifically targeted an area where the former interpretation of the fan showed a channel–lobe transition; however, the lobe and the transition were not recognized. Instead, the newly acquired bathymetry shows that the previously identified channel continues basinward changing its overall morphology and stratigraphic architecture, becoming gradually but significantly wider (650–1000 m) and of lower relief (3–4 m). Cores from the channel thalweg recovered mud-poor (fans, which provides the basis for an accurate morphometric characterization and the understanding of sedimentary processes and morphodynamics associated with the delivery of sediment into the deep sea.

  16. Comunicaciones rurales en Cuba utilizando Redes Tolerantes al Retraso e Interrupciones

    Directory of Open Access Journals (Sweden)

    Andrés Subert Semanat

    2010-09-01

    Full Text Available Normal 0 21 false false false ES-TRAD X-NONE X-NONE MicrosoftInternetExplorer4 st1:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} La arquitectura Internet se ha extendido de forma imparable por todo el mundo, no obstante, las premisas que sustentan esta arquitectura no son aplicables a entornos donde es imposible mantener una comunicación extremo a extremo fiable, con baja latencia y bajas tasas de error; donde la comunicación entre los nodos sea casual o planificada. Las Redes tolerantes al retardo e interrupciones (DTN se han convertido en una solución para las comunicaciones en este tipo de entorno. En este trabajo se presenta un primer acercamiento al uso de esta arquitectura para solucionar los problemas de comunicación en poblados de la Sierra Maestra en Cuba. Para esto se estudian las tecnologías más utilizadas en entornos rurales y se evalúa la implementación de algunas de ellas en la Sierra Maestra. Por último se analiza al empleo de las DTN en el país.

  17. Eficacia resistente de pilares de hormigón armado de baja calidad reforzados por dos procedimientos diferentes

    Directory of Open Access Journals (Sweden)

    Ramírez Ortiz, J. L.

    1975-07-01

    Full Text Available This research deals with the possibility of the strengthening of bad quality reinforced concrete columns, in isolated stories, by two usual methods: the increase of the cross section with concrete, ?nd the backing up of rolled steel angles to the edges of the column. The experimental work has consisted in the manufacturing, strengthening and testing of eighteen reinforced concrete columns with a low quality concrete. At a certain height above their bases a widening has been provided to represent the presence of a flat slab. From the compression tests data and conclusions concerning the strength efficiency of the two types of strengthening have been obtained, also information on the distribution of forces between the original columns and the strengthening, as well as on the deformations, cracking and type of failure.La investigación trata sobre la posibilidad de refuerzo en pisos aislados de pilares de hormigón armado de baja calidad, por dos métodos usuales: el recrecido de la sección transversal con hormigón y el adosado de angulares de acero a las aristas del pilar. La experimentación ha consistido en la fabricación, refuerzo y ensayo de dieciocho pilares de hormigón armado de baja calidad. A una cierta altura sobre sus bases se dispuso un ensanchamiento para representar la presencia de un forjado plano. De los ensayos de compresión se han sacado datos y conclusiones referentes a la eficacia de los dos procedimientos de refuerzo, distribución de esfuerzos entre pilar original y refuerzo, deformaciones, agrietamientos y forma de rotura.

  18. Pengaruh pH, Kecepatan Putar dan Asam Asetat terhadap Karakteristik CO2 Corrosion Baja ASME SA516 grade 70

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    Faris Adham

    2017-01-01

    Full Text Available Fenomena korosi merupakan sesuatu yang pasti terjadi pada setiap logam. Laju korosi dari suatu material dipengaruhi oleh beberapa faktor diantaranya yaitu nilai pH lingkungan dan karakteristik aliran fluida yang kontak langsung dengan logam. Pada oil and gas industry, baja ASME SA 516 grade 70 sering digunakan sebagai material flowline dan banyak terjadi CO2 Corrosion. Penelitian ini bertujuan untuk melakukan studi laju korosi material baja ASME SA 516 grade 70 yang mengandung CO2. Penelitian dilakukan dengan metoda weight loss menggunakan alat Rotating Cylinder Electrode (RCE selama 10 hari dan metode Polarization selama 1 jam. Selain itu digunakan pula XRD dan SEM guna mendukung data-data analisa. Pada penelitian ini digunakan media elektrolit NaCl 3,5% dengan kandungan CH3COOH sebesar 0 ppm dan 1500 ppm dengan variasi kecepatan putaran yaitu 0 RPM, 150 RPM, 300 RPM, dan 450 RPM pada pH 5 dan 6. Pada pengujian polarization, didapatkan hasil laju korosi tertinggi sebesar 9.9323 mm/y pada larutan CH3COOH 1500 ppm pH 5 dan kecepatan putar 450 RPM, sedangkan data dari pengujian weight loss sebesar 4.8795 mm/y. Hasil pengamatan SEM menunjukkan adanya perbedaan morfologi pada permukaan spesimen karena pengaruh kecepatan putaran. Kecepatan putaran mengakibatkan tergerusnya produk korosi oleh aliran. Pada pengujian XRD dengan menggunakan spesimen pH 5 dengan kandungan 0 ppm dan 1500 ppm 0 RPM ditemukan FeCO3, Fe(OH3 dan senyawa FeOOH sebagai produk korosi.

  19. TURISMO MÉDICO EN LOS ALGODONES, BAJA CALIFORNIA, MÉXICO: EXPLORACIÓN DEL CAPITAL HUMANO

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    Sonia Guadalupe Zermeño-Flores

    2016-06-01

    Full Text Available El presente documento es una exploración del capital humano (CH de los profesionistas de salud respecto a la capacitación y el desarrollo de conocimientos, habilidades y actitudes en la prestación de servicios médicos al paciente-turista de Vicente Guerrero, mejor conocido como Los Algodones (LAL en el Estado de Baja California. Éste se distingue por ofrecer a los visitantes que llegan principalmente del norte de Estados Unidos y Canadá durante la temporada de invierno servicios de salud, especialmente en el campo de la higiene dental y la optometría, así como venta de medicamentos A esto se agregan las estrategias de competitividad en la frontera de Baja California (México y California (Estados Unidos. El presente artículo es tanto un estudio cuantitativo como cualitativo, que comprende tres etapas. La primera etapa consistió en la revisión de literatura del turismo médico (TM y sus implicaciones para el capital humano. La segunda etapa fue la consulta de datos básicos de la entidad, que se sometió al análisis estadístico de los profesionistas instalados oficialmente en las empresas que operan en el TM. La tercera etapa se enfocó en la realización de entrevistas a profundidad a profesionistas de la salud de alto prestigio en la sociedad de Los Algodones.

  20. Early Miocene shortening in the lower Comondú Group in Baja California Sur (México)

    Science.gov (United States)

    Bonini, Marco; Cerca, Mariano; Moratti, Giovanna; López-Martínez, Margarita; Corti, Giacomo; Gracia-Marroquín, Diego

    2017-11-01

    The Late Oligocene-Early Miocene volcaniclastic deposits of Baja California Sur form most of the exposed western margin of the Gulf of California rift. In some places these deposits, collectively referred to as Comondú Group, show complex deformation patterns given by the coexistence of tectonic and gravitational features. The area north of La Paz is characterized by the occurrence of several slump bodies, which are displaced by normal faults connected with the rift opening. In some places we have identified 100's m scale thrust-related folds and reverse faults that we have interpreted as shortening features. The latter displace the slump layers and are offset by the normal faults. If confirmed, this would represent the first report of a shortening event in the Early Miocene volcaniclastic deposits of Baja California Sur. The observed shortening has modest magnitude (ca 3-5% bulk shortening), and has been detected in a sector extending over 100 km north from La Paz. New 40Ar-39*Ar ages, integrated with existing radiometric age datasets, constrain the timing of this shortening episode. The rocks affected by shortening have ages between 24 and 21 Ma, and are capped by undeformed volcanic rocks with ages spanning between 19.4 and 17.2 Ma. These relationships define an intra-Early Miocene unconformity, which we interpret to be related to the shortening deformation. The available timing constraints allow us to infer that a main ENE-to-ESE-trending shortening was short-lived, possibly ca. 19.4-21 Ma. The account of this shortening event may shed some light on the complex subduction and microplate processes that preceded the continental rifting of the Gulf of California.

  1. Baja percepción de riesgo en el consumo de alcohol en adolescentes españoles

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    Cristian Suárez-Relinque

    Full Text Available Según los estudios recientes, los adolescentes españoles muestran una baja percepción del riesgo asociado al consumo de alcohol. El objetivo de la presente investigación es analizar los factores que favorecen esta baja percepción a partir de la opinión de un grupo de 32 profesionales/expertos en adolescencia, familia, escuela, medios de comunicación y políticas locales. Se utilizó una metodología cualitativa, fundamentada en Grounded Theory, a partir de la información obtenida mediante 5 grupos de discusión guiados por entrevistas semiestructuradas. Se identificaron 12 factores o subcategorías agrupados en 4 categorías generales: riesgo a corto plazo, inmediatez y percepción de invulnerabilidad (categoría “pensamiento adolescente”; concepción benévola del alcohol, normalización del consumo y binomio alcohol-diversión (categoría “normas sociales”; consumo habitual en los padres, inconsistencia verbal-no verbal en el modelado parental, consumo sin riesgo en los medios, consumo con resultados positivos en los medios (categoría “modelos sociales”; excesivo contenido sanitario, riesgo a largo plazo (categoría “discurso preventivo”. Tras discutir los resultados en el contexto de la literatura científica actual, se realizan varias propuestas con el objetivo de aumentar la percepción del riesgo en los adolescentes: incidir con mayor fuerza en contenidos sobre los riesgos a corto plazo del alcohol; orientar las estrategias educativas dirigidas al adolescente, también hacia los agentes de socialización, especialmente los padres; incidir en políticas centradas en la sustancia y en reducir la oferta.

  2. EL PLAN DIRECTOR DE LA VEGA BAJA DE TOLEDO, ESPAÑA: PAISAJE PATRIMONIAL, ECOLÓGICO Y URBANO.

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    AGUSTÍN HERNÁNDEZ AJA

    2014-01-01

    Full Text Available La Vega Baja de Toledo constituye un gran vacío urbano que, por avatares históricos, se ha mantenido al margen del crecimiento de la ciudad, rodeada por el casco histórico de Toledo, los barrios del ensanche norte y el río Tajo. Su localización privilegiada, junto a la riqueza patrimonial y ecológica del espacio, han sido las bases de la propuesta del Plan Director de la Vega Baja (PDVB. El objetivo del PDVB ha sido articular este vacío y abrirlo a la población, a la vez que proteger y regenerar sus valores ecológicos y culturales. Para ello ha sido necesario integrar distintos elementos: la fachada urbana de Toledo, el río Tajo con su vegetación de ribera y sus bienes patrimoniales que testimonian la sucesión de aprovechamientos históricos, y como cuerpo central del ámbito, el yacimiento arqueológico de lo que puede ser una gran ciudad visigoda. El planteamiento general del PDVB ha sido tratar el espacio como un continuo abierto, una sucesión de paisajes con su propio carácter, que alberguen distintos usos y funciones: Desde el jardín clásico que rodearía al circo romano, llegando hasta el río, con una vegetación, mobiliario y recorridos acordes con las ruinas existentes; pasando por el jardín patrimonial del yacimiento, para el que se proponen plantaciones e itinerarios efímeros que cambien a la par que avanzan las excavaciones; hasta el paisaje más puramente agrícola del vivero o paisaje de ribera, de gran valor ecológico en relación con la fauna aviar.

  3. Key species and impact of fishery through food web analysis: A case study from Baja California Sur, Mexico

    Science.gov (United States)

    Rocchi, Marta; Scotti, Marco; Micheli, Fiorenza; Bodini, Antonio

    2017-01-01

    Ecosystem-Based Management (EBM) aims to support the protection of natural ecosystems and to improve economic activities. It requires considering all of the actors interacting in social-ecological systems (e.g., fish and fishers) in the understanding that their interplay determines the dynamic behavior of the single actors as well as that of the system as a whole. Connections are thus central to EBM. Within the ecological dimension of socio-ecological systems, interactions between species define such connections. Understanding how connections affect ecosystem and species dynamics is often impaired by a lack of data. We propose food web network analysis as a tool to help bridge the gap between EBM theory and practice in data-poor contexts, and illustrate this approach through its application to a coastal marine ecosystem in Baja California Sur, Mexico. First, we calculated centrality indices to identify which key (i.e., most central) species must be considered when designing strategies for sustainable resource management. Second, we analyzed the resilience of the system by measuring changes in food web structure due to the local extinction of vulnerable species (i.e., by mimicking the possible effect of excessive fishing pressure). The consequences of species removals were quantified in terms of impacts on global structural indices and species' centrality indices. Overall, we found that this coastal ecosystem shows high resilience to species loss. We identified species (e.g., Octopus sp. and the kelp bass, Paralabrax clathratus) whose protection could further decrease the risk of potential negative impacts of fishing activities on the Baja California Sur food web. This work introduces an approach that can be applied to other ecosystems to aid the implementation of EBM in data-poor contexts.

  4. Modelo matricial para la asignación del costo utilizando activity basing cost

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    Julio César Millán-Solarte

    2014-01-01

    Full Text Available Esta investigación presenta la propuesta para asignación de los costos, utilizando la metodología ABC, bajo el modelo matricial. Esto implica la construcción de matrices, entendidas estas como un arreglo ordenado de m filas por n columnas. El costo total para la realización de una actividad se basará en el número de veces que dicha actividad se realice durante un período específico. A partir de lo anterior, se puede obtener el costo total de la fabricación del producto (o la prestación de un servicio si se suman las actividades necesarias para su elaboración.

  5. Reconhecimento de padrões de falhas em motores trifásicos utilizando redes neurais

    OpenAIRE

    Reis, Aderson Jamier Santos

    2010-01-01

    Este trabalho apresenta um sistema de diagnóstico de falhas (rotor, estator e contaminação) do motor de indução trifásico através dos parâmetros do circuito equivalente e utilizando técnicas de reconhecimento de padrões. A tecnologia de detecção de falhas em motores está evoluindo e tornando cada vez mais importante na área de máquinas elétricas. As redes neurais possuem a habilidade de classificar relações não lineares entre sinais através da identificação de padrões dos sinai...

  6. Projeto de acopladores ópticos utilizando algoritmo genético

    OpenAIRE

    Jaqueline Oliveira Zampronio

    2016-01-01

    Resumo: Este projeto é uma proposta de um novo acoplador óptico para a aplicação em circuitos ópticos integrados. O dispositivo foi desenvolvido utilizando o método dos elementos finitos vetorial 3D associado com o algoritmo genético e leva em consideração guias de onda com diferentes altura, largura e índices de refração. O comprimento total do acoplador óptico é de apenas 4,22 µm e o seu funcionamento é baseado em pequenos segmentos cilíndricos que interferem na propagação da onda eletromag...

  7. GLUE: um modelo de Clusterização utilizando mobilidade.

    OpenAIRE

    Silva, Fernando Augusto Medeiros

    2013-01-01

    Programa de Pós-Graduação em Ciência da Computação. Departamento de Ciência da Computação, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto. O uso de clusters em MANETs é comum em situações de roteamento e entrega de conteúdo. O aumento do uso de smartphones com suporte a comunicação ponto a ponto, em especial o WiFi Direct, justifica o uso de algoritmos de clusterização adaptados a esses dispositivos e seus casos de uso. Em um cenário de turistas utilizando sm...

  8. Projeto e desenvolvimento de um carro robô controlado por smartphone, utilizando a plataforma Amarino

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    Otávio Souza Martins Gomes

    2015-01-01

    Full Text Available Este artigo mostra a construção de um carro robô controlado por dispositivos móveis utilizando o sistema operacional Android e uma placa de prototipagem open source (Arduino. Utilizou-se de motores para sua movimentação e sensores para interação com o ambiente. O envio de comandos foi realizado utilizando a tecnologia Bluetooth e é capaz de movimentar o carro robô em todas as direções de acordo com os comandos do usuário. Sensores instalados no carro coletam informações do ambiente que são enviadas ao dispositivo Android. A construção bem sucedida deste carro robô mostra que é possível implementar novas funcionalidades para esse produto, bem como apoiar outros projetos relacionados a esse tema.Palavras-chave: Arduino. Android. Bluetooth. Carro robô. Robótica. Project and development of a robot car controlled by smartphone, using the platform amarinoABSTRACTThis work shows the build of a robot car controlled by mobile devices employing Android operating system and an open source prototyping board (Arduino. Motors for its movements and sensors for its environment interaction were employed. The commands are transmitted using Bluetooth technology which can move the robot car in all directions according to the user commands. Sensors installed in the car collect the environment information which is sent to the Android device. The success build of this robot car shows that new features can be possible implemented as well as to support other projects related to this research area.Keywords: Arduino. Android. Bluetooth. Robot car. Robotic.

  9. Densidad de ungulados en bosques de baja y alta presión de caza en el nororiente de la Amazonía peruana

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    Rolando Aquino

    2015-01-01

    Full Text Available Se proporciona información sobre tamaño de rebaño en pecaríes y densidad poblacional de éstos y otros ungulados para los bosques de baja y alta presión de caza del nororiente peruano. Durante el recorrido de 610 km de transecto de Noviembre-Diciembre 2012 en bosques de baja presión de caza y de 1218 km desde Febrero-Junio y Agosto-Octubre 2013 en bosques de alta presión de caza, fueron registrados 76 y 40 encuentros pertenecientes a seis y cinco especies, respectivamente; siendo los más comunes Pecari tajacu (35% y Mazama americana  (28%. El tamaño de rebaño en P. tajacu varió desde 2 a 8 individuos (tamaño promedio: 3,4±1,6 a 6±1,2. La densidad poblacional estimada para los ungulados fueron más altas en bosques de baja presión de caza sobresaliendo Tayassu pecari con 23,8 individuos/km2, seguido por P. tajacu con 14,4 individuos/km2, en tanto que la más baja fue para Tapirus terrestris (0,08 individuos/km2 y correspondió a los bosques de alta presión de caza. En los bosques de baja presión de caza, los encuentros más frecuentes con ungulados ocurrieron en el palmal de altura (46% y palmal de planicie (31%, en tanto que en el pantano arbóreo no hubo encuentros.

  10. Densidad de ungulados en bosques de baja y alta presión de caza en el nororiente de la Amazonía peruana

    Directory of Open Access Journals (Sweden)

    Rolando Aquino

    2014-12-01

    Full Text Available Se proporciona información sobre tamaño de rebaño en pecaríes y densidad poblacional de éstos y otros ungulados para los bosques de baja y alta presión de caza del nororiente peruano. Durante el recorrido de 610 km de transecto de noviembre-diciembre 2012 en bosques de baja presión de caza y de 1218 km desde febrero-junio y agosto-octubre 2013 en bosques de alta presión de caza, fueron registrados 76 y 40 encuentros pertenecientes a seis y cinco especies, respectivamente; siendo los más comunes Pecari tajacu (35% y Mazama americana (28%. El tamaño de rebaño en P. tajacu varió desde 2 a 8 individuos (tamaño promedio: 3,4±1,6 a 6±1,2. La densidad poblacional estimada para los ungulados fue más alta en bosques de baja presión de caza sobresaliendo Tayassu pecari con 23,8 individuos/km2, seguido por P. tajacu con 14,4 individuos/km2, en tanto que la más baja fue para Tapirus terrestris (0,08 individuos/km2 y correspondió a los bosques de alta presión de caza. En los bosques de baja presión de caza, los encuentros más frecuentes con ungulados ocurrieron en el palmal de altura (46% y palmal de planicie (31%, en tanto que en el pantano arbóreo no hubo encuentros.

  11. Diseño de multiplicador de 64 bits utilizando la técnica de barrido superpuesto

    OpenAIRE

    Montalvo Ramírez, Luis

    1987-01-01

    Se presenta el desarrollo del novel algoritmo de multiplicación por barrido superpuesto de 3-bits, así como también los aspectos importantes del diseño de la arquitectura, redes lógicas y layout de un multiplicador de 64-bits utilizando como caso de estudio.

  12. La resolución de problemas geométricos en Matemática utilizando la computadora

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    Osmany Guzmán-Simón

    2017-11-01

    Full Text Available Se presenta un análisis donde se plantean los fundamentos psicopedagógicos que sustentan el desarrollo de habilidades en la resolución de problemas geométricos en la asignatura Matemática, utilizando la computadora.

  13. Perros ferales en la isla de Cedros, Baja California, México: una posible amenaza para los pinnípedos Feral dogs at Isla de Cedros, Baja California, Mexico: a possible threat for pinnipeds

    Directory of Open Access Journals (Sweden)

    María Concepción García-Aguilar

    2012-09-01

    Full Text Available La presencia de perros ferales (Canis lupus familiaris en la isla de Cedros, Baja California, México, fue documentada hace más de 15 años. En el verano de 2009 e invierno 2009/2010, se realizaron 2 campañas de muestreo en la costa noreste de la isla para evaluar los hábitos alimentarios de los perros en las cercanías de las zonas de reproducción y descanso del lobo marino de California (Zalophus californianus y del elefante marino del norte (Mirounga angustirostris. Los mamíferos constituyeron el grupo consumido más importante en la alimentación de los perros (85.4%. Los resultados de este estudio muestran que en la costa noreste de la isla de Cedros los perros se alimentan de pinnípedos: el elefante marino fue la especie que más se consumió, con el mayor porcentaje en ambas temporadas (43.3% en verano y 51.9% en invierno; el lobo marino, fue la segunda durante el verano (23.3%, aunque su porcentaje disminuyó en el invierno (5.8%. Además del potencial impacto que el consumo por los perros pueda tener sobre las poblaciones de los pinnípedos, una amenaza adicional es la posible transmisión de los patógenos caninos, con serias consecuencias epizoóticas.The presence of feral dogs (Canis lupus familiaris in Isla de Cedros, Baja California, Mexico, has been documented for over 15 years. In the summer of2009 and the winter of 2009/2010, 2 sampling surveys were conducted in the northeast coastal portion of the island to assess the diet of feral dogs in the vicinity of hauled out California sea lions (Zalophus californianus and northern elephant seals (Mirounga angustirostris. Mammals were the most important prey group in the diet of dogs (85.4%. Our results show that in the northeast coast of Isla de Cedros, feral dogs feed on pinnipeds: the elephant seal was the most important prey in both seasons (43.3% in summer and 51.9% in winter, followed by the sea lion as the second most important prey during the summer (23.3%, while its

  14. Food webs including parasites, biomass, body sizes, and life stages for three California/Baja California estuaries

    Science.gov (United States)

    Hechinger, Ryan F.; Lafferty, Kevin D.; McLaughlin, John P.; Fredensborg, Brian L.; Huspeni, Todd C.; Lorda, Julio; Sandhu, Parwant K.; Shaw, Jenny C.; Torchin, Mark E.; Whitney, Kathleen L.; Kuris, Armand M.

    2001-01-01

    This data set presents food webs for three North American Pacific coast estuaries and a “Metaweb” composed of the species/stages compiled from all three estuaries. The webs have four noteworthy attributes: (1) parasites (infectious agents), (2) body-size information, (3) biomass information, and (4) ontogenetic stages of many animals with complex life cycles. The estuaries are Carpinteria Salt Marsh, California (CSM); Estero de Punta Banda, Baja California (EPB); and Bahía Falsa in Bahía San Quintín, Baja California (BSQ). Most data on species assemblages and parasitism were gathered via consistent sampling that acquired body size and biomass information for plants and animals larger than ∼1 mm, and for many infectious agents (mostly metazoan parasites, but also some microbes). We augmented this with information from additional published sources and by sampling unrepresented groups (e.g., plankton). We estimated free-living consumer–resource links primarily by extending a previously published version of the CSM web (which the current CSM web supplants) and determined most parasite consumer–resource links from direct observation. We recognize 21 possible link types including four general interactions: predators consuming prey, parasites consuming hosts, predators consuming parasites, and parasites consuming parasites. While generally resolved to the species level, we report stage-specific nodes for many animals with complex life cycles. We include additional biological information for each node, such as taxonomy, lifestyle (free-living, infectious, commensal, mutualist), mobility, and residency. The Metaweb includes 500 nodes, 314 species, and 11 270 links projected to be present given appropriate species' co-occurrences. Of these, 9247 links were present in one or more of the estuarine webs. The remaining 2023 links were not present in the estuaries but are included here because they may occur in other places or times. Initial analyses have examined

  15. Estrés psicosocial y baja resiliencia, un factor de riesgo de hipertensión arterial

    Directory of Open Access Journals (Sweden)

    Lucas Almada

    2010-01-01

    Full Text Available IntroducciónEl estrés psicosocial crónico (EPC fue propuesto como un factor de riesgo cardiovascular (FRC; sin embargo, la complejidad y la falta de medidas objetivas para evaluarlo, unidas al hecho de que no todas las personas reaccionan ante él de igual manera, determinaron que en la actualidad no se cuente con estudios concluyentes al respecto.ObjetivosDeterminar si la baja resiliencia (BR frente al EPC se asocia con hipertensión arterial y daño de órgano blanco en pacientes ambulatorios libres de tratamiento que concurren a realizarse un examen periódico de salud y comprobar si esta asociación tiene relación con el patrón de activación neurohormonal.Material y métodosSe realizó un estudio preliminar, observacional transversal, en el que se enrolaron en forma consecutiva 53 individuos, 32 varones y 21 mujeres. Los pacientes completaron dos cuestionarios: uno para medir EPC y el otro, la Escala de Resiliencia de Connor-Davidson. Quedaron divididos en cuatro grupos: 1, sin EPC y con resiliencia normal (RN; 2, sin EPC y con baja resiliencia (BR; 3, con EPC y RN; 4, con EPC y BR.ResultadosEl porcentaje de hipertensos fue superior en el grupo 4 (p < 0,001, como también el de individuos con incremento de la circunferencia de la cintura (ICC (p = 0,05. Si bien los niveles de noradrenalina, cortisol y ácido vanililmandélico fueron ligeramente superiores en el grupo 4, las diferencias no alcanzaron significación estadística. Para determinar si el EPC unido a BR es un factor de riesgo para el desarrollo de hipertensión arterial se empleó un modelo de regresión logística, controlado por confundidores; el odds ratio fue de 10,9 con intervalos de confianza del 95%, inferior de 1,8 y superior de 65,2.ConclusionesDatos preliminares sugieren que individuos con EPC unido a BR tienen un riesgo alto para el desarrollo de hipertensión arterial.

  16. Latitudinal changes of euphausiid assemblages related to the morphological variability of the sound scattering layer along Baja California, October 1994

    Directory of Open Access Journals (Sweden)

    J. Gómez-Gutiérrez

    1999-03-01

    Full Text Available Latitudinal changes in the euphausiid assemblages were compared to the morphological structure (size and compactness of the sound scattering layer (SSL during ten 24-h surveys made in October 1994 along the west coast of Baja California, México. During October, upwelling was found in the northern area from Punta Eugenia (28°N to Ensenada (30°N dominated by temperate species from the California Current System. In the southern sector of the peninsula, a northward movement of tropical waters transports a tropical zooplankton assemblage near Bahia Magdalena (24°N. The aggregation and the dispersion of the whole SSL (plankton and nekton were investigated using a single beam vertical echosounder, Simrad EY-200, working at 200 kHz and the Hydro Acoustic Data Acquisition System (HADAS that estimates patch variables of density and compactness. The size and shape of the SSL were obtained from the echogram visualization. The euphausiid species composition was obtained using an Isaacs-Kidd midwater trawl, bongo nets, and opening-closing nets. At Ensenada and Punta Eugenia, an area inhabited by a temperate euphausiid assemblage, large and dense SSLs were recorded over the continental shelf (mean sizes were 10-km and 7-km long with mean compactness of 15% and 19%. These regions were dominated by the neritic species Nyctiphanes simplex and the temperate species Nematoscelis difficilis, Euphausia pacifica, and Thysanoessa spinifera. In the southern area, a tropical euphausiid assemblage, dominated by Euphausia eximia, E tenera, and E. distinguenda, inhabits smaller and dispersed SSLs (mean size 5-km long and 11% compactness located in the offshore area. The euphausiid biomass of the most abundant species indicated, N. simplex and N. difficilis, had their highest standing stock in the north (393 and 643 mg C 1000 m-3, with E. eximia in the southern area (186 mg C 1000 m-3. Euphausiid assemblage development in different biological environments, is evidenced

  17. Clientelismo y corrupción en contextos de baja estatalidad, una relación mutualista

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    Emilio Moya Díaz

    Full Text Available Resumo El presente artículo tiene como finalidad indagar el tipo de relación que se establece entre el clientelismo político y la corrupción en contextos de baja estatalidad. La corrupción y el clientelismo son dos fenómenos bien diferenciados con características propias y que, si bien son distinguibles a nivel teórico, a nivel empírico es difícil su distinción. En contextos de baja estatalidad se establece una relación de mutualismo ya que las redes que los componen se superponen, se comunican y se benefician unas con otras. Para cumplir con el objetivo de la investigación, se utilizó una metodología de carácter cualitativo. Para la recolección de la información se realizaron 30 entrevistas en profundidad (9 autoridades municipales, 4 funcionarios municipales, 14 presidentes de organizaciones sociales y comunitarias y 3 proveedores de bienes y servicios al municipio. El contexto en que se realizó la investigación fueron tres municipios de la Región de la Araucanía en Chile que presentan un grado bajo de estatalidad. Las entrevistas fueron analizadas a partir del análisis fenomenológico buscando explicar y describir las relaciones entre clientelismo y corrupción. Entre los principales resultados obtenidos se destaca que existe un tipo de relación que puede llegar a ser muy beneficiosa, es decir mutualista, entre el clientelismo y la corrupción. El artículo pretende ser un aporte empírico a la discusión sobre las relaciones que se establecen entre clientelismo político y corrupción en determinados contextos. Al mismo tiempo, los conceptos de clientelismo político y corrupción son entendidos como un fenómeno social que quebrantan la formalidad de los procesos y, por tanto, no se circunscriben a fenómenos que necesariamente están ligados a la ilegalidad. En otras palabras, son conceptos que se entienden desvinculados de una connotación moral.

  18. The vascular flora and floristic relationships of the Sierra de La Giganta in Baja California Sur, Mexico La flora vascular y las relaciones florísticas de la sierra de La Giganta de Baja California Sur, México

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    José Luis León de la Luz

    2008-06-01

    Full Text Available The Sierra de La Giganta is a semi-arid region in the southern part of the Baja California peninsula of Mexico. Traditionally, this area has been excluded as a sector of the Sonoran Desert and has been more often lumped with the dry-tropical Cape Region of southern Baja California peninsula, but this classical concept of the vegetation has not previously been analyzed using formal documentation. In the middle of the last century, Annetta Carter, a botanist from the University of California, began explorations in the Sierra de La Giganta that lasted 24 years, she collected 1 550 specimens and described several new species from this area, but she never published an integrated study of the flora. Our objectives, having developed extensive collections in the same area over the past years, are to provide a comprehensive species list and description of the vegetation of this mountain range. We found a flora of 729 taxa, poorly represented in tree life-forms (3.1%, a moderate level (4.4% of endemism, and the dominance of plants in the sampling plots is composed mainly for legume trees and shrubs. Additionally, using a biogeographical approach, we compare our list with other known lists of plants from 5 areas, 3 in the Cape Region, 1 in the Sonoran Desert, and other in the thornscrub area of NW Mexico. We conclude that the La Giganta flora has a mixed composition, primarily made up of plants shared with the lowlands of the southern Cape Region, but also share an important proportion of the flora with the desert mountains of the central peninsula and some with the Sonoran desertscrub of mainland Mexico. Consequently we support that the La Giganta flora is part of a floristic continuum along the volcanic mountains of the southern peninsula that eventually could be considered a new eco-region in the same peninsular land.La sierra de La Giganta se localiza en el estado de Baja California Sur, México, en una región semi-árida. Tradicionalmente, esta

  19. Heavy metals in geochemical sediment fractions of the border region between Baja California, Mexico, and California, USA; Metales pesados en fracciones geoquimicas de sedimentos de la region fronteriza de Baja California, Mexico, y California, EUA

    Energy Technology Data Exchange (ETDEWEB)

    Villaescusa-Celaya, Julio A; Gutierrez-Galindo, Efrain A; Flores-Munoz, Gilberto [Instituto de Investigaciones Oceanologicas, Universidad Autonoma de Baja California, Ensenada, B.C., (Mexico)

    1997-03-01

    The concentrations of the heavy metals Cu, Zn, Ni, Cr, Pb, Cd, Ag, Mn and Fe in the different geochemical sediment fractions are determined in this study, as a means of assessing the impact of residual wastewater on the coastal sediments of the region. During an oceanographic cruise in April 1992 (ECOBAC IV), 20 samples of surface sediments were collected from the coastal shelf of the border region between Baja California (Mexico) and California (USA), The sediment samples were subjected to a sequential extraction procedure designed to obtain the geochemical fractions defined as: exchangeable (F1), carbonates (F2), Fe and Mn oxyhydroxides (F3), organic matter/sulfides (F4) and residual or lithogenic (F5). The operational speciation of the metals indicates that the principal phases in the sediments that accumulate metal are the detrital or lithogenic matrix, the Fe and Mn oxyhydroxides and the organic Matter/sulfides, in this order. In general, the spatial distribution of the heavy metals in the reactive phase (defined as the sum of F1-F4) tended to increase in concentration in offshore sediments. The heavy metals in the reactive phase are apparently controlled by the concentration of reactive iron in the sediments, except for Pb, Cd and Ag, suggesting that the latter elements are controlled by other processes, such as particulate matter of biogenic origin. In contrast, the spatial distribution of heavy metals in the detrital phase behaved inversely, that is, the greatest concentrations of metals are found close to the coast off the wastewater treatment plant at Punta Bandera, Baja California. The average concentrations of total metals (sum of F1-F5) were 7.6, 40, 21, 68, 428, 11, 0.10 and 0.025 {mu}g{sup -}1 for Cu, Zn, Ni, Cr, Mn, Pb, Cd and Ag, respectively, and 2.3% for Fe. These concentrations are similar to those reported for uncontaminated reference sediments from southern California, indicating that a large amount of pollutants from the effluent of residual

  20. Estudio histológico comparativo de la reparación ósea entre hueso alveolar y extra-alveolar en los cerdos sometidos a osteotomía con alta y baja velocidad, con refrigeración líquida Comparative study of bone repair between alveolar and extra-alveolar bone in pigs subjected to osteotomy at low speed and high speed with liquid refrigeration

    Directory of Open Access Journals (Sweden)

    Henrique José Baldo de Toledo

    2012-03-01

    Full Text Available Introducción: Teniendo en cuenta que el proceso de reparación ósea en los cerdos se muestra en una mayor proximidad entre las variables histológicas estudiadas en comparación con otros modelos biológicos, el presente estudio tenía como objetivo evaluar el proceso histológico de la reparación ósea de osteotomías realizadas en huesos alveolares y extra-alveolar, utilizando instrumentos rotatorios con refrigeración líquida. Material y método: Dieciocho cerdos Large White con peso comprendido entre 20 y 25Kg fueron divididos en tres grupos de seis animales cada uno, con cada grupo formado por tres animales para evaluar la reparación de osteotomías con baja y alta velocidades en el hueso alveolar y tres en área extra-alveolar en los períodos de estudio de 7, 14 y 28 días. Resultados: Se observó que en el hueso alveolar en los tiempos post-operatorio de 14 y 28 días, los mejores resultados de reparación fueron en las osteotomías realizadas con baja velocidad, mientras que en el período post-operatorio de siete días, los resultados con alta velocidad fueron ligeramente mejores tanto en áreas alveolares como extra-alveolares. Para la metodología utilizada, no se encontraron diferencias estadísticamente significativas en el proceso de reparación ósea alveolar y extra-alveolar. Conclusiones: El proceso de reparación, por medio de análisis microscópico en la región alveolar y extra-alveolar, son similares con mejores resultados observados en osteotomías hechas con taladros en baja velocidad en los tiempos de catorce y veintiocho días y en el post-operatorio de siete días, los resultados con taladros de alta velocidad y la refrigeración fueron ligeramente mejores. Los trabajos de investigación utilizando cerdos como modelo animal son perfectamente viables.Introduction: Taking into account the bone repair process in pigs has shown a greater similarity among the histological variables studied compared to other biological

  1. Modelaje geológico y de recursos del yacimiento Pastelillo utilizando el krigeaje de indicadores

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    José Q. Cuador-Gil

    2005-03-01

    Full Text Available En ocasiones la complejidad y variabilidad de un yacimiento mineral hace dificil establecer dominios geológicos homogéneos que puedan ser utilizados para aplicar control geológico a la estimación de los parámetros más relevantes. La imposibilidad de crear un modelo geológico con unidades bien definidas conduce a trabajar con poblaciones heterogéneas, lo cual degrada considerablemente la calidad de las estimaciones. Tal es el caso de Pastelillo, yacimiento de materia prima para cemento, en el que es difícil reproducir la geometría de los distintos tipos tecnológicos utilizando el método tradicional de correlación geológica. Las distintas litologías que conforman el yacimientos están completamente mezcladas tanto en el plano como en la vertical y estos frecuentes cambios faciales provocan una gran variabilidad litológica y tecnológica en el yacimiento. Teniendo en cuenta lo anterior se propone emplear un método de interpolación espacial que permita hacer estimaciones en presencia de poblaciones complejas. En el artículo se establece un modelo tecnológico y de recursos para el yacimiento Pastelillo a partir del empleo de una técnica de estimación de la geoestadística no lineal: el krigeaje de indicadores.

  2. Biossorção de azul de metileno utilizando resíduos agroindustriais

    Directory of Open Access Journals (Sweden)

    Andressa C. Honorato

    2015-07-01

    Full Text Available O presente trabalho avaliou a capacidade de adsorção do corante azul de metileno nos resíduos da palha de milho e da bainha do palmito pupunha in natura. A caracterização dos resíduos foi determinada utilizando-se a microscopia eletrônica de varredura e espectroscopia na região do infravermelho a qual indicou a presença de grupos carboxílicos, hidroxila e carbonila. O tempo necessário para que o sistema atingisse o equilíbrio para ambos os resíduos foi de 240 min, seguindo uma cinética descrita pelo modelo de pseudo-segunda ordem. A capacidade máxima de adsorção foi de 102,8 mg g-1 para o resíduo da palha de milho, seguindo o modelo de isoterma de Langmuir e 50,9 mg g-1 para o resíduo de palmito pupunha, sendo que o modelo que melhor se ajusta foi Freundlich. Desta forma, esses resíduos são promissores para a adsorção do corante azul de metileno em efluentes.

  3. Comparativo das propriedades do concreto autoadensável (CAA utilizando areia fina e cinza volante

    Directory of Open Access Journals (Sweden)

    B. F. Tutikian

    Full Text Available O objetivo deste artigo é contribuir para a tomada de decisão sobre a definição do uso de materiais finos responsáveis pela resistência à segregação do concreto auto-adensável (CAA. Neste estudo, amostras de CAA foram dosadas com cinza volante, um material pozolânico, e areia fina, que é um material não pozolânico, utilizando o método de dosagem proposto por Tutikian & Dal Molin (2007 [1]. Foi observado que a utilização de cinza volante aumentou a resistência à compressão, principalmente nas idades mais avançadas, assim como os valores de módulo de deformação e velocidade das ondas de ultrasom. Também diminuiu a penetração de íons cloretos, para os mesmos valores de resistência em comparação com os CAA com areia fina e o custo final dos CAA com cinza volante foi inferior. Foram apresentados tanto os diagramas de dosagem como os de desempenho.

  4. UTILIZANDO O MÉTODO TODIM PARA AVALIAR AS MELHORES EMPRESAS PARA TRABALHAR

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    Renato Teixeira da Silva

    2011-06-01

    Full Text Available Este artigo expõe uma nova proposta de ordenação das 5 melhores empresas para trabalhar em termos de qualidade do ambiente de trabalho e qualidade na gestão de pessoas utilizando-se do método TODIM como suporte científico para tal. A ordenação inicial, proposta pela revista Você/SA Exame, utiliza como método classificador o índice de felicidade no trabalho, uma soma ponderada de índices resultantes da percepção dos funcionários, das práticas da empresa e da constatação feita por jornalistas em visitas às empresas. Este trabalho, que utiliza o método TODIM, considera esses itens como critérios de avaliação e realiza uma análise comparativa das alternativas. Ao final, é executada uma comparação entre as ordenações e uma análise de sensibilidade, analisando as especificidades de cada método de ordenação e a consistência de seus resultados.

  5. DESARROLLO DE APIO MINIMAMENTE PROCESADO FORTIFICADO CON VITAMINA E, UTILIZANDO LA INGENIERIA DE MATRICES

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    YISELL JOHAN MARTELO CASTAÑO

    2011-01-01

    Full Text Available El objetivo de este trabajo fue desarrollar un producto minimamente procesado fortificado con vitamina E, a partir de apio (Apium graveolens L. var.dulce, utilizando la ingenieria de matrices como metodologia de obtencion de alimentos funcionales. Trozos de apio impregnados al vacio con dl¿¿tocoferol acetato emulsificado en una solucion isotonica al vegetal de NaCl, 1,2%, fueron evaluados en funcion del tiempo de almacenamiento y el envasado (con y sin vacio, en terminos de la cuantificacion de sus propiedades fisicoquimicas, color, textura, estabilidad de la vitamina E y caracteristicas sensoriales. Se formulo la emulsion con el objetivo de adicionar teoricamente un 73% del Valor Diario Recomendado (VDR vitamina E/100 g de apio fresco y su cuantificacion se realizo por HPLC. La respuesta a la impregnacion en la matriz fue de 12,10+-1,15%, lo cual permitio alcanzar un 112% VDR vitamina E/100g apio fresco, manteniendose este contenido durante el almacenamiento de 9 dias en ambos tipos de envasado. Los parametros fisicoquimicos del producto fueron afectados por la IV, el tiempo y el envasado, manteniendo su coloracion verdosa y presentando disminucion en la firmeza. La ingenieria de matrices constituye una metodologia efectiva para el desarrollo de apio minimamente procesado adicionado con vitamina E.

  6. Resección quirúrgica de mucocele utilizando relleno siliconado

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    Adel Martínez

    2014-01-01

    Full Text Available El mucocele es una lesión que afecta especialmente las glándulas salivales menores; se forma debido a la extravasación de saliva mucosa producto de un trauma por mordedura. Teniendo en cuenta el factor causal, el mucocele se puede clasificar como quiste de extravasación mucosa o quiste de retención mucosa. Afecta primordialmente el labio inferior y se manifiesta como un nódulo, translúcido y circunscrito con un contenido mucoso o muestra una elevación del color de la mucosa que la cubre. El tratamiento consiste en la resección quirúrgica de la lesión, que incluya las glándulas salivales menores afectadas. Se realizó la revisión de una caso clínico de paciente de 18 años de edad, que presenta mucocele profundo, el cual fue tratado con resección quirúrgica utilizando como relleno de la cavidad quística una silicona fluida, que permite mantener los reparos anatómicos y así poder realizar la remoción completa de la lesión y las glándulas afectadas.

  7. PROPUESTA INFORMÁTICA PARA SELECCIONAR PERSONAL POR COMPETENCIAS UTILIZANDO TÉCNICAS DE INTELIGENCIA ARTIFICIAL

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    Raúl Martínez Rodríguez

    2006-12-01

    Full Text Available

    La selección de personal por competencias es un tema muy reciente que esta cautivando a las empresas que quieren asegurarse de contar con el personal calificado y competente. Su objetivo es seleccionar al candidato más idóneo para desempeñar un cargo ocupacional específico, teniendo en cuenta su potencial y capacidad de adaptación; lo que precisa ser más coherentes y no simplistas en el tratamiento de la información que se posee. En el presente trabajo se presenta una propuesta informática para realizar esta selección utilizando técnicas de inteligencia artificial (IA, que pueden proporcionar una solución satisfactoria a un problema real de gestión de personal.

  8. Cálculo del factor de efectividad utilizando colocación ortogonal sobre elementos finitos

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    Javier Fontalvo Alzate

    1999-09-01

    Full Text Available En el presente documento se resuelve el problema del cálculo del factor de efectividad para la transferencia de masa y calor con reacción química en un pellet catalítico utilizando una técnica adecuada especialmente para números de Thiele elevados en donde la solución se restringe a una pequeña zona muy cercana a la superficie. La técnica aprovecha la rapidez de convergencia de la colocación ortogonal y la facilidad de ubicación de elementos en zonas en donde se presentan grandes gradientes del método para las diferencias finitas. La eficiencia del método está basada en la utilización del método LV para la descomposición de matrices. Se muestran comparaciones con otros métodos numéricos de solución del problema.

  9. Monitoramento do processo de compressão de ibuprofeno utilizando controle estatístico

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    Sara Elis Bianchi

    2012-04-01

    Full Text Available O Controle Estatístico de Processo (CEP é uma ferramenta bastante utilizada para auxiliar no controle da qualidade de parâmetros físicos como peso médio, dureza e friabilidade. Através das cartas de controle é possível detectar desvios dos parâmetros do processo, reduzindo a quantidade de produtos fora da especificação e, consequentemente, os custos da produção. A avaliação de trinta lotes de ibuprofeno em uma indústria farmacêutica, utilizando controle estatístico de processo, permitiu o fornecimento de informações imprescindíveis para a investigação detalhada dos pontos críticos do processo, diagnosticando as possíveis não conformidades na etapa de compressão deste fármaco. Desta maneira, podem-se propor atividades de melhoria, através da identificação e eliminação das causas especiais de variação no processo, com a finalidade de produzir comprimidos com qualidade.

  10. Análisis de la vulnerabilidad y resiliencia económica de Baja California en el contexto de la crisis financiera internacional

    Directory of Open Access Journals (Sweden)

    Salvador GONZÁLEZ ANDRADE

    2017-01-01

    Full Text Available Este trabajo analiza la vulnerabilidad económica y la resiliencia económica de Baja California, México, en el contexto de la crisis financiera internacional de 2007. Se propone una aproxima - ción metodológica para elaborar índices de vulnerabilidad y de resiliencia, y el desempeño económico de 2003 a 2014 se compara con el que tienen otras entidades. El desempeño econó - mico se mide desagregando el PIBE en sus componentes cíclico y no cíclico (tendencia. Se con - cluye que ante el shock externo, Baja California posee vulnerabilidad económica, pero también presenta una destacada resiliencia económica.

  11. [Length, body weight and sex of the golden Coryphaena hippurus (Perciformes: Coryphaenidae), of the littoral of Sinaloa, Nayarit and Baja California Sur, Mexico].

    Science.gov (United States)

    Madrid, J V; Beltrán-Pimienta, R

    2001-01-01

    Dolphin fish population data were recorded from landings in Sinaloa, Nayarit and Baja Califonia Sur, Mexico, in 1997. Of 3,211 organisms, only 2,812 produced complete biometric data. The maximal length and weight were 192 cm and 30 kg. The three sampling sites and the climatic periods also were associated with different size (P < 0.05). The covariate analysis of weight and length relationships indicated significative differences (P < 0.05) for total data and by sex. Condition factor was higher throughout the study period in Mazatlán, and the variation was higher, in the spring. The sexual ratio was in Mazatlán constant, while there were more males in Nayarit in the fall and the spring and in Los Cabos in the spring. There may be population differences, between the central mexican Pacific Coast and the Peninsula of Baja data.

  12. Community Liaison as Factor for Image and Positioning of the Autonomous University of Baja California, Mexico, in the Social and Productive Context

    Directory of Open Access Journals (Sweden)

    Víctor Manuel Alcántar Enríquez

    2009-05-01

    Full Text Available This study presents the results of an extensive research on the society’s perceptions of the activities the Autonomous University of Baja California (UABC, for its acronym in Spanish Universidad Autónoma de Baja California develops in Mexico. This non-experimental research uses an explorative-descriptive methodology, with a transactional research design based on a holistic method and an illuminative evaluation, which analyzes the institutional positioning of UABC in several social sectors, as well as its determining factors. Results support the hypothesis that liaison activities have a significant effect on the regional positioning of the UABC as a higher education institution. The results also helped to identify weaknesses and opportunities that could direct future institutional efforts. In addition, this study provides new elements on liaison, institutional image, and positioning, as well as a conceptual model that involves these variables.

  13. Pronóstico de la velocidad del viento utilizando modelos de arima y redes neuronales artificiales.

    OpenAIRE

    Jiménez Mejía, Miguel

    2012-01-01

    México cuenta con un gran potencial eólico, en el Istmo de Tehuantepec se estima que se podrían instalar más de 6,000 MW eólicos. Otros sitios con gran potencial eólico están localizados en Baja California, Zacatecas, Hidalgo, Veracruz, Sinaloa y Yucatán. Instituciones gubernamentales como Comisión Federal de Electricidad (CFE) y el Instituto de Investigaciones Eléctricas (IIE), estudian estos sitios con gran potencial energético y desarrollan proyectos para la explotación de l...

  14. Claves de sustentabilidad de agroecosistemas tradicionales basados en regadíos y ganadería extensiva en oasis de Baja California (México)

    OpenAIRE

    Tenza, Alicia; Breceda, Aurora; Cariño, Micheline; Martínez-Fernández, Julia; Giménez, Andrés

    2015-01-01

    [EN] The oases are the traditional agro-ecosystems in the Baja California Peninsula. They were the cornerstones of its socio economic and cultural development until the second half of the twentieth century, when regional development process marginalized them. Under the theoretical and methodological approach of System Dynamics we present a multidisciplinary study that integrate traditional ecological knowledge and scientific knowledge to build a dynamic simulation model about the...

  15. STRATIGRAPHIC AND TECTONIC EVOLUTION OF LA PURISIMA AREA (BAJA CALIFORNIA, MEXICO) DURING LATE OLIGOCENE AND MIOCENE: IMPLICATIONS FOR THE PACIFIC MARGIN EVOLUTION

    OpenAIRE

    ZANCHI, A.; GELATI, R.; ROBBA, E.

    2017-01-01

    The study of the Neogene sequences outcropping in the La Purisima area, Baja California Sur, Mexico, has demonstrated the presence of regional unconformities separating the main sedimentary bodies. On the basis of stratigraphic and structural analyses, we propose a new statigraphic framework in terms of depositional sequences. The Lower Sedimentary Sequence (San Gregorio Formation Auctorum) is mainly composed of silicized shales with phosphatic nodules and subordinate tuffìtes. The sequence i...

  16. Location of Moderate-Sized Earthquakes Recorded by the NARS-Baja Array in the Gulf of California Region Between 2002 and 2006

    Science.gov (United States)

    Castro, Raul R.; Perez-Vertti, Arturo; Mendez, Ignacio; Mendoza, Antonio; Inzunza, Luis

    2011-08-01

    We relocated the hypocentral coordinates of small to moderate-sized earthquakes reported by the National Earthquake Information Center (NEIC) between April 2002 and August 2006 in the Gulf of California region and recorded by the broadband stations of the network of autonomously recording seismographs (NARS-Baja array). The NARS-Baja array consists of 19 stations installed in the Baja California peninsula, Sonora and Sinaloa, Mexico. The events reported by the preliminary determinations of epicenters (PDE) catalog within the period of interest have moment magnitudes ( M w) ranging between 1.1 and 6.7. We estimated the hypocentral location of these events using P and S wave arrivals recorded by the regional broadband stations of the NARS-Baja and the RESBAN ( Red Sismológica de Banda Ancha) arrays and using a standard location procedure with the HYPOCENTER code ( Lienert and Havskov in Seism Res Lett 66:26-36, 1995) as a preliminary step. To refine the location of the initial hypocenters, we used the shrinking box source-specific station term method of Lin and Shearer (J Geophys Res 110, B04304, 2005). We found that most of the seismicity is distributed in the NW-SE direction along the axis of the Gulf of California, following a linear trend that, from north to south, steps southward near the main basins (Wagner, Delfin, Guaymas, Carmen, Farallon, Pescadero and Alarcon) and spreading centers. We compared the epicentral locations reported in the PDE with the locations obtained using regional arrival times, and we found that earthquakes with magnitudes in the range 3.2-5.0 mb differ on the average by as much as 43 km. For the M w magnitude range between 5 and 6.7 the discrepancy is less, differing on the average by about 25 km. We found that the relocated epicenters correlate well with the main bathymetric features of the Gulf.

  17. Introducción a la aparatología ortodóncica de autoligado : baja fricción

    OpenAIRE

    Grynberg, Eduardo; Pastor, Laura; Lopez, Marcela; Villafañe, Deborah; Iranzo, Andrea; Blas, Fernanda; Calatayud, Laura

    2015-01-01

    Los bracket de autoligado son presentados al ámbito de la ortodoncia, como un sistema de alta eficiencia, al servicio de la baja fricción. 13 casos fueron tratados durante el ciclo de cursos de ortodoncia, dictados por el Dr. Edgardo Grynberg, en la Facultad de Odontología de la Universidad de Cuyo, Mendoza, con aparatologia de autoligado en combinación con arcos superelasticos, en los cuales se aprecio una importante dismi...

  18. Prevalencia de la infección por papilomavirus humano en una población de baja incidencia de cancer de cuello uterino

    OpenAIRE

    Múgica van Herckenrode, Carmen

    2014-01-01

    182 p. SE HA INVESTIGADO LA PREVALENCIA DE LA INFECCION POR PAPILOMAVIRUS HUMANO (HPU) EN MUESTRAS DE CUELLO UTERINO DE MUJERES DE UNA POBLACION DE BAJA INCIDENCIA DE CANCER DE CERVIX, MEDIANTE TECNICAS DE DETECCION GENICA (HIBRIDACION DE DNA CON EL METODO DE SLOT-BLOT Y PCR) CON EL OBJETIVO DE DETERMINAR EL PAPEL DEL VIRUS EN EL PROCESO ONCOGENICO DEL CERVIX. SE HA VALORADO, ADEMAS, LA UTILIDAD DE LOS MARCADORES MOLECULARES Y CITOLOGICOS DE LA INFECCION POR HPV PAR...

  19. Theory of the Sagnac's interferometer of low birefringence and twist fiber; Teoria del interferometro de Sagnac de fibra de baja birrefrigencia y torcida

    Energy Technology Data Exchange (ETDEWEB)

    Estudillo-Ayala, J. M.; Kuzin, E. A.; Ibarra-Escamilla, B. [Instituto Nacional de Astrofisica, Optica y Electronica, Puebla (Mexico); Rojas-Laguna, R. [Universidad de Guanajuato, Guanajuato (Mexico)

    2001-06-01

    The fibre Sagnac interferometer of low birefringence and twist in the lineal region is examined numerically, a method is shown to measure the birefringence in the fibers and rotation of the axes inside of the interferometer fibre loop. [Spanish] El interferometro de Sagnac de fibra de baja birrefrigencia y torcida en la region lineal es numericamente examinado, se muestra un metodo para medir la birrefrigencia en las fibras y rotacion de los ejes dentro de la fibra del lazo del interferometro.

  20. Screening of extracts of algae from Baja California sur, Mexico as reversers of the antibiotic resistance of some pathogenic bacteria.

    Science.gov (United States)

    Muñoz-Ochoa, M; Murillo-Alvarez, J I; Zermeño-Cervantes, L A; Martínez-Diaz, S; Rodríguez-Riosmena, R

    2010-09-01

    Sixty ethanol extracts of marine flora of Baja California Sur (Mexico) were screened to evaluate the reversing effect of the bacterial resistance to antibiotics in combination with a sublethal concentration of ampicillin or erythromycin. The activity was assayed by using a modification of the classical agar-diffusion method against 3 resistant, pathogenic bacteria; Escherichia coil (ATCC BAA196), Staphylococcus aureus (ATCC BAA42), and Streptococcus pyogenes (ATCC BAA946). From the 60 ethanolic extracts, 12 (20%) of them in combination with ampicillin were able to reverse the resistance of Staphylococcus aureus and 8 (13%) with erythromycin yielded the same reversal with Streptococcus pyogenes. An extract from Sargassum horridum was the only one that reversed the resistance to antibiotics against both Staphylococcus aureus and Streptococcus pyogenes. Our findings suggest that some algae may be source of compounds with the potential to reverse the antibiotic resistance of some bacteria. In addition, of the assayed extracts, 35 (57%) showed inhibitory activity against Staphylococcus aureus, 48 (78%) were active against Streptococcus pyogenes, but none was active against Escherichia coil. The most active extracts were from Laurencia spp., Gelidium robustum, Chnoospora implexa, Padina mexicana, Gracilaria subsecundata, and Dictyopteris undulata.

  1. Late cretaceous foraminifera, paleoenvironments, and paleoceanography of the rosario formation, San Antonio del Mar, Baja California, Mexico

    Science.gov (United States)

    Maestas, Y.; MacLeod, K.G.; Douglas, R.; Self-Trail, J.; Ward, P.D.

    2003-01-01

    The 315 m of Rosario Formation exposed at the San Antonio del Mar (SADM) section (Baja California, Mexico) contains moderately-to-well preserved benthic and planktic foraminifera, calcareous nannofossils, and molluscs. Nannofossils suggest most of the SADM section was deposited within a narrow interval of the late Campanian (CC21-CC22), whereas foraminifera and molluscs suggest a younger maximum age (younger than the Globotruncana ventricosa Zone) and allow deposition over a longer interval of time. Planktic foraminifera at SADM represent common Tethyan taxa. They are largely restricted to the lower and middle portions of the section and comprise 0-???40% of foraminiferal assemblages. Stable isotopic analyses of Rugoglobigerina rugosa yield ??18OV-PDB values from -2.27%, to -2.82%, corresponding to salinity-corrected paleotemperature estimates of 26-30??C for the Late Cretaceous eastern Pacific. These estimates are as warm as modern tropical temperatures and are similar to tropical paleotemperature estimates from ??18O analyses of exceptionally preserved Maastrichtian samples; however, they are considerably warmer than most tropical Campanian-Maastrichtian estimates. Benthic foraminifera indicate outer shelf paleodepths with a slight increase in depth or decrease in benthic oxygen levels in the upper parts of the interval studied. The change in the benthic assemblage corresponds to an ???1??? positive shift in benthic ??O18, suggesting a relationship between benthic assemblages and an inferred increase in the local intensity of upwelling.

  2. Marine diet and tobacco exposure affects mercury concentrations in pregnant women (I from Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Ramón Gaxiola-Robles

    2014-01-01

    Full Text Available Seafood provides essential polyunsaturated fatty acids (PUFA and other nutrients to pregnant women and their fetus(es while a diet rich in finfish can be a major pathway of monomethyl mercury (MeHg+ exposure. We measured total mercury concentration ([THg] in hair samples provided by 75 women in Baja California Sur (BCS to assess its relationship with age, parity, tobacco smoke exposure, and diet based on survey methodologies. Generalized linear models (GLM were used to explain the possible association of the different variables with [THg] in hair. Median [THg] in hair was 1.52 μg g−1, ranging from 0.12 to 24.19 μg g−1 and varied significantly by segment. Approximately 72% (54/75 of those evaluated exceed 1 μg g−1 [THg] and 8% (6/75 exceed 5 μg g−1 [THg] in hair. Although frequency of fish consumption contributed significantly to explaining hair [THg], fish consumption only explained 43% of [THg] in a GLM incorporating tobacco exposure and body mass index. This study establishes possible relationships among multiple potential sources of exposure and other factors related to [THg] in hair of women in the prenatal period. A more detailed examination of other sources of exposure and factors contributing to [THg] is warranted.

  3. Vegetation history along the eastern, desert escarpment of the Sierra San Pedro Mártir, Baja California, Mexico

    Science.gov (United States)

    Holmgren, Camille A.; Betancourt, Julio L.; Rylander, Kate A.

    2011-05-01

    Plant macrofossils from 38 packrat middens spanning the last ~ 33,000 cal yr BP record vegetation between ~ 650 and 900 m elevation along the eastern escarpment of the Sierra San Pedro Mártir, northern Baja California. The middens span most of the Holocene, with a gap between ~ 4600 and 1800 cal yr BP, but coverage in the Pleistocene is uneven with a larger hiatus between 23,100 and 14,400 cal yr BP. The midden flora is relatively stable from the Pleistocene to Holocene. Exceptions include Pinus californiarum, Juniperus californica and other chaparral elements that were most abundant > 23,100 cal yr BP and declined after 14,400 cal yr BP. Despite being near the chaparral/woodland-desertscrub ecotone during glacial times, the midden assemblages reflect none of the climatic reversals evident in the glacial or marine record, and this is corroborated by a nearby semi-continuous pollen stratigraphy from lake sediments. Regular appearance of C 4 grasses and summer-flowering annuals since 13,600 cal yr BP indicates occurrence of summer rainfall equivalent to modern (JAS average of ~ 80-90 mm). This casts doubt on the claim, based on temperature proxies from marine sediments in the Guaymas Basin, that monsoonal development in the northern Gulf and Arizona was delayed until after 6200 cal yr BP.

  4. Problemáticas del comportamiento sexual y reproductivo de las jóvenes inmigrantes de Baja California

    Directory of Open Access Journals (Sweden)

    Humberto González Galbán

    2013-01-01

    Full Text Available Entre los aspectos que son analizados en el presente artículo se encuentran los vinculados a la sexualidad y la reproducción de las mujeres inmigrantes de Baja California, donde se manifiestan inequidades con relación al resto de los jóvenes, tales como las mayores afecta- ciones por enfermedades de transmisión sexual y los más altos niveles de embarazos –gene- ralmente no planificados–, lo que a su vez tiene implicaciones como una mayor frecuencia del abandono escolar, la salida involuntaria del hogar paterno así como otras problemáticas familiares, todo lo que incide negativamente en la salud de las jóvenes migrantes y en sus condiciones de vida en general. La atención médica, que puede contribuir a atenuar efec- tos no deseados de dicha situación, también es recibida en menor medida por las jóvenes inmigrantes, lo que conjuntamente con las desventajosas condiciones socioeconómicas en que viven y/o el contar, en un menor grado, con redes familiares y sociales de apoyo, las convierte en una población más vulnerable y necesitada de trabajo comunitario que atienda sus problemáticas sexuales y reproductivas.

  5. Characterisation of an enamelled metallic object found in Guerrero Negro (Baja California) by PIXE and RBS techniques

    Science.gov (United States)

    Calvo del Castillo, H.; Ruvalcaba, J. L.; Calderón, T.; Salinas Nolasco, M. F.; Mejía, L. M.; Perdigón, K.

    2008-05-01

    The coast of Guerrero Negro (Baja California) has been known for a long time by archaeologists for its shipwrecks. Archaeologists are recovering objects that come from sunken Spanish galleons in the colonial period, and reach the American coast in the frontier of the USA with Mexico. An enamelled metallic object was found next to the beach in Guerrero Negro. We have analysed the piece with proton induced X-ray emission (PIXE) and Rutherford backscattering (RBS) in an attempt to establish whether the object could come from one of the colonial shipwrecks and to valuate its cleaning process. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) have been also performed in three samples taken from the object in order to observe the heterogeneity of the material. The materials found revealed the presence of typical lead-glass enamels from with pigments such as cuprite (red), or lead-tin yellow used in colonial times. The metallic part consisted of brass. As for the cleaning process, the average efficiency considered as the weight% of chlorine removed, was of 83.4% for brass and 100% for enamels.

  6. Biological influences on modern sulfates: Textures and composition of gypsum deposits from Guerrero Negro, Baja California Sur, Mexico

    Science.gov (United States)

    Vogel, Marilyn B.; Des Marais, David J.; Parenteau, Mary N.; Jahnke, Linda L.; Turk, Kendra A.; Kubo, Michael D. Y.

    2010-01-01

    Gypsum (CaSO 4·2H 2O) deposits from a range of sedimentary environments at Guerrero Negro, Baja California Sur, Mexico were investigated for microscale texture and composition in order to differentiate features formed under substantial microbial influence from those for which microbial effects were relatively minor or absent. Gypsum deposits were classified according to their sedimentary environment, textures, crystal habit, brine composition and other geochemical factors. The environments studied included subaqueous sediments in anchialine pools and in solar salterns, as well as subsurface sediments of mudflats and saltpans. Gypsum that developed in the apparent absence of biofilms included crystals precipitated in the water column and subsedimentary discs that precipitated from phreatic brines. Subsedimentary gypsum developed in sabkha environments exhibited a sinuous microtexture and poikilitically enclosed detrital particles. Water column precipitates had euhedral prismatic habits and extensive penetrative twinning. Gypsum deposits influenced by biofilms included bottom nucleated crusts and gypsolites developing in anchialine pools and saltern ponds. Gypsum precipitating within benthic biofilms, and in biofilms within subaerial sediment surfaces provided compelling evidence of biological influences on crystal textures and habits. This evidence included irregular, high relief surface textures, accessory minerals (S°, Ca-carbonate, Sr/Ca-sulfate and Mg-hydroxide) and distinctive crystal habits such as equant forms and crystals having distorted prism faces.

  7. Millimeter-scale resolution of trace metal distributions in microbial mats from a hypersaline environment in Baja California, Mexico.

    Science.gov (United States)

    Huerta-Diaz, M A; Delgadillo-Hinojosa, F; Siqueiros-Valencia, A; Valdivieso-Ojeda, J; Reimer, J J; Segovia-Zavala, J A

    2012-11-01

    Microbial mats from two ponds with different salinities from the saltern of Guerrero Negro (Mexico) points toward millimeter-scale coherent variations in trace metal (Me) concentrations (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn). Total, HCl-leachable and pyrite-associated Me showed a trend of increasing concentrations with increasing depth suggesting gradual addition of reactive Me probably as a result of metal sulfide precipitation at depth. The trends in Me profiles can be ascribed to the establishment and maintenance of microzones that promote geochemical processes, bacterial population distributions, and differential mass transport within the mats. Degrees of trace metal pyritization (1 ± 1% for Zn to 24 ± 7% for Cd) as well as metals associated with the pyrite fraction (Negro. Calculated enrichment factors showed that Ni (2.6 ± 2.1), Co (5.5 ± 4.0), Pb (9.4 ± 7.4), and Cd (57 ± 39) were, on average, enriched in the microbial mats of Guerrero Negro. Natural enrichments of Cd, Pb, and Co in sediments along the coast of Baja California and metabolical requirements of Co and Ni by the predominant cyanobacteria in the Guerrero Negro mats may explain these enrichments. Metal characteristics in microbial mats could be advantageously used as biosignatures to identify their presence in the geological record or in other planetary systems. © 2012 Blackwell Publishing Ltd.

  8. Pengaruh Jenis Katalis terhadap Kekuatan Tarik dan Stabilitas Termal Polidimetilsiloksan (PDMS untuk Lapisan Pelindung Baja AISI 1050

    Directory of Open Access Journals (Sweden)

    Muhammad Atha Illah

    2013-03-01

    Full Text Available Polisiloksan adalah polimer yang paling banyak digunakan sebagai lapisan pelindung pada baja karena memiliki sifat yang unggul dibandingkan polimer lain. Polidimetilsiloksan (PDMS adalah salah satu  keluarga polisiloksan yang paling banyak digunakan dalam bentuk karet Room-Temperature Vulcanization (RTV. Pada penelitian ini, PDMS divulkanisir menggunakan katalis Bluesil Catalyst 60R (komersial, NaOH 2 M, H2SO4 2 M, Poli aminoamid, dan Red 683 (komersial dengan variasi komposisi masing-masing katalis 2 - 10 wt%. Katalis yang bisa membentuk karet silikon hanyalah Bluesil Catalyst 60R dan Red 683. Pada percobaannya, waktu pematangan semakin cepat seiring bertambahnya komposisi katalis yang diberikan. Elastisitas karet silikon sangat tinggi, karena sifat inilah karet silikon tidak pecah ketika diuji fleksural hingga 180o. Hasil pengujian tarik menunjukkan karet dengan Bluesil Catalyst 60R 6wt% memiliki kekuatan tarik paling optimum yaitu 1,625 MPa. Penambahan Bluesil Catalyst 60R 10wt% juga memberikan nilai kestabilan termal  karet silikon yang paling baik, berat sisanya adalah 39,172 % pada temperatur 800oC.

  9. Characterisation of an enamelled metallic object found in Guerrero Negro (Baja California) by PIXE and RBS techniques

    International Nuclear Information System (INIS)

    Calvo del Castillo, H.; Ruvalcaba, J.L.; Calderon, T.; Salinas Nolasco, M.F.; Mejia, L.M.; Perdigon, K.

    2008-01-01

    The coast of Guerrero Negro (Baja California) has been known for a long time by archaeologists for its shipwrecks. Archaeologists are recovering objects that come from sunken Spanish galleons in the colonial period, and reach the American coast in the frontier of the USA with Mexico. An enamelled metallic object was found next to the beach in Guerrero Negro. We have analysed the piece with proton induced X-ray emission (PIXE) and Rutherford backscattering (RBS) in an attempt to establish whether the object could come from one of the colonial shipwrecks and to valuate its cleaning process. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) have been also performed in three samples taken from the object in order to observe the heterogeneity of the material. The materials found revealed the presence of typical lead-glass enamels from with pigments such as cuprite (red), or lead-tin yellow used in colonial times. The metallic part consisted of brass. As for the cleaning process, the average efficiency considered as the weight% of chlorine removed, was of 83.4% for brass and 100% for enamels

  10. Phytoplankton oceanographic characterization during El Niño 2004 event in the Northwest region of Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Miranda-Alvarez, A. C.

    2016-09-01

    Full Text Available An oceanographic cruise in front of the Coast of Baja California was carried from the 9th to the 29th day of July in 2004, in 91 stations at 10 m depth. The aim of this study was to identify the variability of phytoplankton and its oceanographic characterization in the coast-ocean region during an anomalous year with El Niño characteristics. Results showed a taxonomic composition of 21 phytoplankton genera in an interval size called nano-microphytoplankton: Gymnodinium, Scrippsiella, Ceratium, Coscinodiscus, Oxytoxum, Gyrodinium, Protoperidinium, Nitzschia, Gonyaulax. On the other hand, spatial distribution of light absorption coefficient for phytoplankton (aph440 and chlorophyll-a (Chl-a concentration showed high values in front of the San Quintin coast and south of Punta Eugenia, detecting a clear decrease towards the oceanic zone. In regard to the taxonomic composition of phytoplankton, a dominance of dinoflagellates in contrast to diatoms was observed, results coinciding with the basic characteristics of phytoplankton ecology during an El Niño event.

  11. Simulation of flow in the upper North Coast Limestone Aquifer, Manati-Vega Baja area, Puerto Rico

    Science.gov (United States)

    Cherry, Gregory S.

    2001-01-01

    A two-dimensional computer ground-water model was constructed of the Manati-Vega Baja area to improve the understanding of the unconfined upper aquifer within the North Coast Province of Puerto Rico. The modeled area covers approximately 79 square miles within the municipios of Manati and Vega Baja and small portions of Vega Alta and Barceloneta. Steady-state two-dimensional ground-water simulations were correlated to conditions prior to construction of the Laguna Tortuguero outlet channel in 1940 and calibrated to the observed potentiometric surface in March 1995. At the regional scale, the unconfined Upper North Coast Limestone aquifer is a diffuse ground-water flow system through the Aguada and Aymamon limestone units. The calibrated model input parameters for aquifer recharge varied from 2 inches per year in coastal areas to 18 inches per year in the upland areas south of Manati and Vega Baja. The calibrated transmissivity values ranged from less than 500 feet squared per day in the upland areas near the southern boundary to 70,000 feet squared per day in the areas west of Vega Baja. Increased ground-water withdrawals from 1.0 cubic foot per second for 1940 conditions to 26.3 cubic feet per second in 1995, has reduced the natural ground-water discharge to springs and wetland areas, and induced additional recharge from the rivers. The most important regional drainage feature is Laguna Tortuguero, which is the major ground-water discharge body for the upper aquifer, and has a drainage area of approximately 17 square miles. The discharge to the sea from Laguna Tortuguero through the outlet channel has been measured on a bi-monthly basis since 1974. The outflow represents a combination of ground- and surface-water discharge over the drainage area. Hydrologic conditions, prior to construction of the Laguna Tortuguero outlet channel in 1943, can be considered natural conditions with minimal ground-water pumpage (1.0 cubic foot per second), and heads in the lagoon

  12. Characterisation of an enamelled metallic object found in Guerrero Negro (Baja California) by PIXE and RBS techniques

    Energy Technology Data Exchange (ETDEWEB)

    Calvo del Castillo, H. [Departamento de Geologia y Geoquimica, Universidad Autonoma de Madrid (Spain); Instituto de Fisica, Universidad Nacional Autonoma de Mexico (Mexico); Centre Europeen d' Archeometrie - I.P.N.A.S., Universite de Liege, Allee du 6 Aout, 10 Bat-15, Sart Tilman, 4000-Liege 1 (Belgium)], E-mail: hcalvo@ulg.ac.be; Ruvalcaba, J.L. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico (Mexico); Calderon, T. [Departamento de Geologia y Geoquimica, Universidad Autonoma de Madrid (Spain); Salinas Nolasco, M.F. [Coordinacion de Conservacion del Patrimonio Cultural, Instituto Nacional de Antropologia e Historia (Mexico); Mejia, L.M. [Direccion de Arqueologia Subacuatica, Instituto Nacional de Antropologia e Historia (Mexico); Perdigon, K. [Coordinacion de Conservacion del Patrimonio Cultural, Instituto Nacional de Antropologia e Historia (Mexico)

    2008-05-15

    The coast of Guerrero Negro (Baja California) has been known for a long time by archaeologists for its shipwrecks. Archaeologists are recovering objects that come from sunken Spanish galleons in the colonial period, and reach the American coast in the frontier of the USA with Mexico. An enamelled metallic object was found next to the beach in Guerrero Negro. We have analysed the piece with proton induced X-ray emission (PIXE) and Rutherford backscattering (RBS) in an attempt to establish whether the object could come from one of the colonial shipwrecks and to valuate its cleaning process. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) have been also performed in three samples taken from the object in order to observe the heterogeneity of the material. The materials found revealed the presence of typical lead-glass enamels from with pigments such as cuprite (red), or lead-tin yellow used in colonial times. The metallic part consisted of brass. As for the cleaning process, the average efficiency considered as the weight% of chlorine removed, was of 83.4% for brass and 100% for ename0008.

  13. Anthropogenic contamination of metals in sediments of the Santa Rosalía harbor, Baja California peninsula.

    Science.gov (United States)

    Shumilin, Evgueni; Jiménez-Illescas, Ángel Rafael; López-López, Silverio

    2013-03-01

    To know the environment impact on a harbor of the Santa Rosalía port on the Baja California peninsula, the concentrations of metals (Cd, Co, Cu, Mn, Pb, U and Zn) in harbor sediments were determined for 13 stations and compared with their average upper Earth´s crust abundance. The mean enrichment factors, calculated using Al as a normalizer, were higher than the unity for Ag, Ba, Bi, Cd, Co, Cu, Mn, Ni, Pb, Sb, U, V and Zn. Concentrations of slightly enriched Cd in the sediments are below the effect range low (ERL) sediment quality guidelines value only at three stations. The levels of Pb in the harbor sediments at four stations (1, 6, 9 and 11) are between the ERL (46.7 mg kg(-1)) and the effect range medium (ERM) (218 mg kg(-1)), and Pb content in the rest of the sediment samples is higher than the ERM, demonstrating the high extent of the anthropogenic impact of this metal on the sedimentary environment. The total concentrations of the potentially toxic elements Cu (3,390 ± 804 mg kg(-1)) and Zn (1,916 ± 749 mg kg(-1)) very strongly exceed their ERM, showing a high possibility of toxicological danger for marine biota, living inside or entering the harbor.

  14. Diagnóstico socioambiental como fundamento para una estrategia de educación ambiental en Colonet, Baja California

    Directory of Open Access Journals (Sweden)

    Rosa Hidemi Ortega Armenta

    2012-01-01

    Full Text Available Colonet, Baja California, es una comunidad rural localizada en una zona árida, donde existe la propuesta de construir un megaproyecto portuario. Ahí se realizó un diagnóstico socioambiental, con el fin de identificar la problemática actual del medio ambiente y posibles soluciones, a través del análisis de la percepción social y las amenazas ambientales. El desabasto de agua se percibe como el problema principal debido a factores sociales y políticos, y las prácticas agrícolas se identificaron como la amenaza ambiental primordial. Estos resultados demuestran la necesidad de mejorar la organización comunitaria, con base en mayor y mejor información. Se identificaron las soluciones y se diseñaron cuatro escenarios. Aquí se propone una estrategia de educación ambiental, que fomente la organización y participación informada en la comunidad, para lograr la tecnificación agrícola orgánica y la gestión integrada de recursos hídricos.

  15. Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico.

    Science.gov (United States)

    Ley-Quiñónez, C; Zavala-Norzagaray, A A; Espinosa-Carreón, T L; Peckham, H; Marquez-Herrera, C; Campos-Villegas, L; Aguirre, A A

    2011-09-01

    Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 μg g⁻¹), followed by Selenium (10.92 μg g⁻¹). The mean concentration of toxic metal Cadmium was 6.12 μg g⁻¹ and 1.01μg g⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn>Se>Ni>Cu>Mn>Cd>Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Comparative analysis of the reproductive strategy of lion's paw scallop Nodipecten subnodosus in Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Marco A Angel-Dapa

    2015-07-01

    Full Text Available The reproductive strategy of lion's paw scallop Nodipecten subnodosus was evaluated in a culturing system in Bahía Tortugas, Baja California Sur, Mexico during an annual cycle, comparing its response with data previously reported at other localities. High frequencies of ripe gonads throughout the year indicate that reproduction was continuous, with two main ripening/spawning events: July-September and December-March. A continuous breeding is also reported for the species in Bahía Magdalena, Bahía Juncalito, and Bahía de Los Angeles. These eutrophic areas are Biological Active Centers where gametogenesis appears to be regulated by the energy taken from recently ingested food following an opportunistic strategy. However, the digestive gland index decreased and the muscle indices increased during one of the breeding peaks, suggesting that some stored reserves are also used to sustain gametogenesis (conservative strategy partially. High incidences of atretic oocytes are likely associated with atypical daily variations in water temperature from May through September (12 to 33°C, or with stressful conditions in the culturing system in summer. Despite this, the culturing system set in Bahía Tortugas appears beneficial for a continuous reproduction of N. subnodosus.

  17. Triggered surface slips in southern California associated with the 2010 El Mayor-Cucapah, Baja California, Mexico, earthquake

    Science.gov (United States)

    Rymer, Michael J.; Treiman, Jerome A.; Kendrick, Katherine J.; Lienkaemper, James J.; Weldon, Ray J.; Bilham, Roger; Wei, Meng; Fielding, Eric J.; Hernandez, Janis L.; Olson, Brian P.E.; Irvine, Pamela J.; Knepprath, Nichole; Sickler, Robert R.; Tong, Xiaopeng; Siem, Martin E.

    2011-01-01

    The April 4, 2010 (Mw7.2), El Mayor-Cucapah, Baja California, Mexico, earthquake is the strongest earthquake to shake the Salton Trough area since the 1992 (Mw7.3) Landers earthquake. Similar to the Landers event, ground-surface fracturing occurred on multiple faults in the trough. However, the 2010 event triggered surface slip on more faults in the central Salton Trough than previous earthquakes, including multiple faults in the Yuha Desert area, the southwestern section of the Salton Trough. In the central Salton Trough, surface fracturing occurred along the southern San Andreas, Coyote Creek, Superstition Hills, Wienert, Kalin, and Imperial Faults and along the Brawley Fault Zone, all of which are known to have slipped in historical time, either in primary (tectonic) slip and/or in triggered slip. Surface slip in association with the El Mayor-Cucapah earthquake is at least the eighth time in the past 42 years that a local or regional earthquake has triggered slip along faults in the central Salton Trough. In the southwestern part of the Salton Trough, surface fractures (triggered slip) occurred in a broad area of the Yuha Desert. This is the first time that triggered slip has been observed in the southwestern Salton Trough.

  18. Uma Abordagem de Monitoração de Tráfego de Rede utilizando Lógica Difusa

    OpenAIRE

    Silveira, Enio Rovere; Universidade Federal de Santa Catarina; Dantas, M. A.R.; Universidade Federal de Santa Catarina

    2005-01-01

    Neste artigo, apresentamos um trabalho de pesquisa de monitoração de tráfego de rede utilizando uma abordagem de lógica difusa. Nossa contribuição está focada na criação de um protótipo que pudesse ser avaliado em uma configuração real de produção de uma grande organização, utilizando-se de hardware e software existentes na empresa. Resultados experimentais obtidos através de estudos de casos reais no ambiente, indicam o sucesso da abordagem na melhoria da monitoração de tráfego da rede....

  19. Análise de sinais monocromáticos utilizando dados do detector de ondas gravitacionais ALLEGRO.

    OpenAIRE

    Fernanda Gomes de Oliveira

    2010-01-01

    O presente trabalho foi desenvolvido na busca pela detecção de sinais de ondas gravitacionais monocromáticos utilizando dados do detector ALLEGRO. Fizemos dois procedimentos para análise de dados baseados no método do periodograma de Welch, o qual é um método para detecção de sinais monocromáticos imersos em ruídos. Este método basicamente faz estimativas do espectro de potências utilizando médias dos periodogramas. Dessa forma é possível obter um espectro de potências o qual reforça a presen...

  20. Longitud, peso y sexo del dorado Coryphaena hippurus (Perciformes: Coryphaenidae, del litoral de Sinaloa, Nayarit y Baja California Sur, México

    Directory of Open Access Journals (Sweden)

    J.V. Madrid

    2001-12-01

    Full Text Available Poblaciones de dorado (Pisces fueron muestreadas en Sinaloa, Nayarit y Baja Califonia Sur, México, en 1997. Unos 3211 organismos fueron analizados. Las tallas máximas fueron de 192 cm y 30 Kg. Hay diferentes tallas asociadas a las zonas y épocas climática (P Dolphin fish population data were recorded from landings in Sinaloa, Nayarit and Baja Califonia Sur, Mexico, in 1997. Of 3 211 organisms only 2 812 produced complete biometric data. The maximal length and weight were 192 cm and 30 Kg. The three sampling sites and the climatic periods also were associated with different size (P < 0.05. The covariate analysis of weight and length relationships indicated significative differences (P < 0.05 for total data and by sex. Condition factor was higher throughout the study period in Mazatlán, and the variation was higher, in the spring. The sexual ratio was in Mazatlán was constant, while there were more males in Nayarit in the fall and the spring and in Los Cabos in the spring. There may be population differences, between the central mexican Pacific Coast and the Peninsula of Baja data

  1. Políticas nacionales y agricultura en la frontera: estudio comparativo de Baja California y País Vasco

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    José Ramón Mauleón Gómez

    1986-05-01

    Full Text Available Este artículo parte del hecho de que el desarrollo agrario en las regiones fronterizas de Baja California (México y del País Vasco (España han sido diferentes. En efecto, se constata el distinto desarrollo de los tipos de explotación agraria, aunque en ambas zonas el tipo de unidad de producción más común es la que podría definirse como "explotación familiar". En Baja California, a diferencia del País Vasco, se ha ido consolidando un tipo que podría ser calificado de "capitalista". El objetivo de este estudio es profundizar en las causas de ese diferente modelo de desarrollo agrario mediante un análisis comparativo de las características de ambas zonas. Dentro de esta comparación se analiza especialmente a Baja California, de modo que el País Vasco es empleado únicamente como punto de referencia.

  2. Learning processes and productive modernization of learning in agriculture from northwestern Mexico: Cases of commercial agriculture of the coast of Hermosillo, Sonora and organic agriculture of the southern zone of Baja California Sur

    OpenAIRE

    Abel O. Villa Rodríguez; Álvaro Bracamonte Sierra

    2013-01-01

    The process of open markets has created import changes in the Mexican agriculture sector, very much noted in the so called crop pattern, the institutional frame that guides the agro–productive commercial relationships and trade organization. The agriculture in the Northwest region, particularly La Costa de Hermosillo in the State of Sonora and southern Baja in Baja Peninsula, shows a big transformation. This corresponds to Global Production Networks (gpn), a vertical integration with intensiv...

  3. TRATAMENTO CONTRA O ADENOCARCINOMA MAMÁRIO HUMANO POR MEIO DA TERAPIA FOTODINÂMICA UTILIZANDO O AZUL DE METILENO

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    Bianca Silva Prado

    2017-04-01

    Full Text Available A terapia fotodinâmica (TFD é um método alternativo para o tratamento contra o câncer, possui baixa toxicidade sistêmica podendo ter ação localizada. O seu mecanismo de ação é baseado na combinação de um fotossensibilizador, luz e o oxigênio presente nos tecidos. Com o trabalho avaliou-se a ação do fotossensibilizador azul de metileno (AM no tratamento contra o adenocarciona mamário humano por meio da TFD. As células foram cultivadas utilizando o meio de cultura Leibovitz’s complementado com 10% de soro fetal bovino e mantidas em estufa para crescimento. O tratamento via TFD foi realizado utilizando o fotossensibilizador AM em três diferentes concentrações sendo irradiadas com LEDs 660 nm. A viabilidade celular foi realizada utilizando o método de exclusão Azul de Tripan. Os resultados obtidos sugerem que o azul de metileno apresenta grande potencial, pois possibilitou uma redução da taxa de viabilidade celular sob irradiação e baixa citotoxicidade quando não irradiando.

  4. Distribución espacial y temporal de aves playeras (Orden: Charadriiformes en Laguna San Ignacio, Baja California Sur, México Temporal and spatial distribution of shorebirds (Charadriiformes at San Ignacio Lagoon, Baja California Sur, Mexico

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    Luis Francisco Mendoza

    2013-03-01

    Full Text Available Con la pérdida o degradación de humedales han declinado las poblaciones de algunas especies tales como las aves playeras. En vista de que ha crecido el interés internacional por los estudios ecológicos sobre estas especies, se determinó la abundancia, distribución y riqueza espacio-temporal de las aves playeras en Laguna San Ignacio, Península de Baja California. Se realizaron 12 censos mensuales (octubre 2007-septiembre 2008 en el perímetro interno de la laguna; la cual se dividió en cuatro zonas, dos al norte y dos al sur. Temporalmente las abundancias menores se presentaron en mayo (1 585 aves y las mayores en octubre (47 410. Las especies más abundantes fueron: el picopando canelo (Limosa fedoa; 55% de los registros totales, el playero occidental (Calidris mauri; 23% y el playero pihuiuí (Tringa semipalmata; 10%. Estas especies fueron más abundantes en otoño. El picopando canelo y el playero pihuiuí estabilizaron sus números en invierno y primavera y estuvieron presentes en verano en bajos números, el playero occidental mostró oscilaciones notorias. Se presentan los primeros reportes del playero rojizo del Pacifico (Calidris canutus roselaari para la zona. La riqueza y abundancia estuvieron influenciadas temporal y espacialmente por las aves migratorias. Las mayores abundancias se presentaron al sur de la laguna, probablemente por la disponibilidad del alimento. Los resultados presentes permitieron incluir al área en la Red Hemisférica de Reservas para las Aves Playeras como sitio de importancia internacional.Baja California Peninsula has several wetlands that represent important ecosystems for shorebirds. San Ignacio Lagoon is one of these sites, and supports 10% of the total abundance of shorebirds reported in this Peninsula. Since there is few information about this group in this area, we studied spatial and temporal changes in abundance and distribution of shorebirds in San Ignacio Lagoon. For this, we conducted twelve

  5. Constraints on the rheology of the lower crust in a strike-slip plate boundary: evidence from the San Quintín xenoliths, Baja California, Mexico

    Science.gov (United States)

    van der Werf, Thomas; Chatzaras, Vasileios; Marcel Kriegsman, Leo; Kronenberg, Andreas; Tikoff, Basil; Drury, Martyn R.

    2017-12-01

    The rheology of lower crust and its transient behavior in active strike-slip plate boundaries remain poorly understood. To address this issue, we analyzed a suite of granulite and lherzolite xenoliths from the upper Pleistocene-Holocene San Quintín volcanic field of northern Baja California, Mexico. The San Quintín volcanic field is located 20 km east of the Baja California shear zone, which accommodates the relative movement between the Pacific plate and Baja California microplate. The development of a strong foliation in both the mafic granulites and lherzolites, suggests that a lithospheric-scale shear zone exists beneath the San Quintín volcanic field. Combining microstructural observations, geothermometry, and phase equilibria modeling, we estimated that crystal-plastic deformation took place at temperatures of 750-890 °C and pressures of 400-560 MPa, corresponding to 15-22 km depth. A hot crustal geotherm of 40 ° C km-1 is required to explain the estimated deformation conditions. Infrared spectroscopy shows that plagioclase in the mafic granulites is relatively dry. Microstructures are interpreted to show that deformation in both the uppermost lower crust and upper mantle was accommodated by a combination of dislocation creep and grain-size-sensitive creep. Recrystallized grain size paleopiezometry yields low differential stresses of 12-33 and 17 MPa for plagioclase and olivine, respectively. The lower range of stresses (12-17 MPa) in the mafic granulite and lherzolite xenoliths is interpreted to be associated with transient deformation under decreasing stress conditions, following an event of stress increase. Using flow laws for dry plagioclase, we estimated a low viscosity of 1.1-1.3×1020 Pa ṡ s for the high temperature conditions (890 °C) in the lower crust. Significantly lower viscosities in the range of 1016-1019 Pa ṡ s, were estimated using flow laws for wet plagioclase. The shallow upper mantle has a low viscosity of 5.7×1019 Pa ṡ s

  6. Clasificador neuronal de fallos en rodamientos utilizando entradas basadas en transformadas wavelet packet y de Fourier

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    Víctor Gómez

    2013-01-01

    Full Text Available En este artículo se propone y se evalúa experimentalmente un método de diagnóstico de fallas en rodamientos utilizando la clasificación de patrones provenientes de las señales de las vibraciones mecánicas. El método utiliza pre-procesamientos con las transformadas de Fourier y wavelet packet para luego alimentar una red neuronal clasificadora que determina el tipo de fallo. Para evaluar las variables de entrada se realiza un análisis de varianza ANOVA comparando el efecto que tienen los factores: velocidad, carga, falla en pista externa y falla en elemento rodante sobre cada uno de los parámetros propuestos como entradas para las redes neuronales artificiales (RNA. Una vez seleccionadas las variables de entrada más adecuadas, se realiza la búsqueda del clasificador más apropiado explorando diversas configuraciones de red neuronal. Se han entrenado alrededor de 2000 RNA con el propósito de encontrar el clasificador más adecuado. Los resultados de validación muestran que para el algoritmo de entrenamiento tipo gradiente conjugado escalado (trainscg se alcanza un porcentaje de éxito en la clasificación del 88,5 %, mientras que para el algoritmo de entrenamiento de Levenberg-Marquardt (trainlm se logra un 91,8 %. Adicionalmente, se resalta que en 7 ocasiones se logró el 100 % de aciertos en la clasificación.

  7. Evaluación de ataques UDP Flood utilizando escenarios virtuales como plataforma experimental

    Directory of Open Access Journals (Sweden)

    Walter Fuertes

    2012-05-01

    Full Text Available Los ataques por denegación de servicio (DoS tienen como propósito imposibilitar el acceso a los servicios de una organización durante un periodo indefinido; por lo general, están dirigidos a los servidores de una empresa, para que no puedan ser accedidos por usuarios autorizados. El presente trabajo se enfoca en la evaluación de ataques DoS tipo UDP Flood, utilizando como plataforma de experimentación un entorno virtual de red que permite identificar cómo actúan dichos ataques en la saturación del ancho de banda; para llevarlo a cabo se diseñó e implementó una red híbrida con segmentación WAN, LAN y DMZ que inhabilita el acceso interno y externo a un servicio Web expuesto. Las herramientas evaluadas fueron UPD Unicorn, Longcat Flooder y UDPl.pl Script de Perl; las dos primeras instaladas sobre Windows, y la última, sobre Linux. Para validar está investigación se desarrolló un mecanismo de detección y mitigación de los ataques a nivel del firewall e IDS/IPS, evitando de este modo la saturación de la red. Finalmente, se evaluó el consumo dememoria, CPUy ancho de banda durante el ataque, la detección y la evasión, con el fin de determinar cuál genera mayor impacto. Los resultados demuestran que el mecanismo detecta, controla y mitiga los ataques. 

  8. Evaluación de ataques UDP Flood utilizando escenarios virtuales como plataforma experimental

    Directory of Open Access Journals (Sweden)

    Deyci Toscano

    2011-07-01

    Full Text Available Los ataques por denegación de servicio (DoS tienen como propósito imposibilitar el acceso a los servicios de una organización durante un periodo indefinido; por lo general, están dirigidos a los servidores de una empresa, para que no puedan ser accedidos por usuarios autorizados. El presente trabajo se enfoca en la evaluación de ataques DoS tipo UDP Flood, utilizando como plataforma de experimentación un entorno virtual de red que permite identificar cómo actúan dichos ataques en la saturación del ancho de banda; para llevarlo a cabo se diseñó e implementó una red híbrida con segmentación WAN, LAN y DMZ que inhabilita el acceso interno y externo a un servicio Web expuesto. Las herramientas evaluadas fueron UPD Unicorn, Longcat Flooder y UDPl.pl Script de Perl; las dos primeras instaladas sobre Windows, y la última, sobre Linux. Para validar está investigación se desarrolló un mecanismo de detección y mitigación de los ataques a nivel del firewall e IDS/IPS, evitando de este modo la saturación de la red. Finalmente, se evaluó el consumo dememoria, CPUy ancho de banda durante el ataque, la detección y la evasión, con el fin de determinar cuál genera mayor impacto. Los resultados demuestran que el mecanismo detecta, controla y mitiga los ataques.

  9. CÓMO MEJORAR LA EFICIENCIA OPERATIVA UTILIZANDO EL TRABAJO EN EQUIPO

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Franco

    2000-01-01

    Full Text Available En este artículo se presenta un modelo para aumentar la eficiencia operativa de diversas organizaciones de la economía con el fin de mejorar sus resultados financieros y por consiguiente su competitividad. Este modelo permite aprovechar los talentos de las personas que laboran en la empresa, organizándolos en equipos o grupos para que puedan identificar y aprovechar oportunidades de mejoramiento que conduzcan a un aumento significativo de la eficiencia productiva. La metodología que aquí se expone es particularmente útil para las empresas medianas y pequeñas que regularmente no cuentan con recursos ni infraestructura suficiente para introducir los cambios que CÓMO MEJORAR LA EFICIENCIA OPERATIVA UTILIZANDO EL TRABAJO EN EQUIPO CARLOS ALBERTO FRANCO Director MBA de la Universidad Icesi en convenio con la Universidad de Tulane. Ingeniero Eléctrico de la Universidad del Valle. Máster en Ingeniería de Carnegie Mellon University, Pisttsburg. Ph.D. en Ingeniería Eléctrica de USC (U.S.A. FRANCISCO VELÁSQUEZ V. Director del Programa de Administración de Empresas Plan Diurno. Ingeniero Electricista de la Universidad del Valle. Magister en Administración del Instituto de Estudios Superiores de Monterrey, Campus ciudad de México. mejoren su productividad. El modelo se puede aplicar directamente por los jefes o supervisores de cada una de las áreas de la empresa, sin necesidad de recurrir a asesorías costosas.

  10. Acceso remoto seguro a cuentas de usuario utilizando plataformas de virtualización

    Directory of Open Access Journals (Sweden)

    Walter Fuertes, Maritza Enríquez y Diego Veloz

    2011-05-01

    Full Text Available En  las  universidades  persiste  el  problema  de  la subutilización de recursos tecnológicos; sin embargo, sesigue  incurriendo en gastos por adquisición de servidores,hardware  y  software. Frente  a  este  escenario,  en  laindustria se han venido desarrollando las tecnologías devirtualización, que ahorran energía y costos de inversiónde hardware. En  consecuencia,  el  artículo propone  elacceso remoto seguro a cuentas de usuario en un servidoruniversitario  virtualizado;  para  llevarlo  a  cabo  sediseñaron  e  implementaron  varias  topologías  deexperimentación, utilizando Virtual Box 3.1.3 y VMwareServer 2.0.2,  y  se  evaluaron diversas  tecnologías  deconexiones remotas seguras, bajo  idénticas condicionesy parámetros de  comprobación. En  cada  topología  seevaluó el rendimiento del servidor, el performance y  laseguridad  de  la  red  en  producción. Los  resultadosmuestran  la  funcionalidad  de  este  proyecto  deinvestigación  que  facilita  el  acceso  remoto  seguro deusuarios a los recursos informáticos universitarios.

  11. Productividad en una celda de manufactura flexible simulada en promodel utilizando path networks type crane

    Directory of Open Access Journals (Sweden)

    María Elena Bernal Loaiza

    2015-04-01

    Full Text Available Esta investigación se centra en el diseño de una simulación del proceso de una celda de manufactura flexible (FMC de la Facultad de Ingeniería Industrial de la Universidad Tecnológica de Pereira, con el propósito de medir y elegir aquella alternativa de solución que mejore en mayor grado la productividad del sistema actual utilizando los resultados que proporciona el software Promodel. Para realizar lo anterior se utilizaron etapas de la simulación como definición del sistema, formulación del modelo, identificación de variables, recolección de datos, implementación e interpretación.Como resultado, se calculó la productividad teniendo en cuenta las variables del modelo y tiempo de la simulación, al mismo tiempo se interpretó la información de cada una de las locaciones, hallando el porcentaje de utilización y total de entidades para las locaciones con capacidad unitaria; para las locaciones con mayor capacidad se encuentra información referente al porcentaje de tiempo vacío, parcialmente ocupado, lleno y no disponible respecto del tiempo disponible. A diferencia de otras simulaciones, en este diseño en la parte de redes se utilizó el tipo de red Crane, asociado a los recursos del modelo. El cual facilita el desplazamiento de los brazos robots con las piezas que circulan a través del sistema.

  12. Cardiomioplastia celular utilizando el factor estimulante del crecimiento de colonias de granulocitos

    Directory of Open Access Journals (Sweden)

    Fabián Alberto Jaimes Barragán

    2008-11-01

    Full Text Available INTRODUCCIÓN: el presente estudio tuvo como objetivo evaluar la eficacia y seguridad de la cardiomioplastia celular utilizando el factor estimulante de colonias de granulocitos en pacientes con cardiopatía isquémica. MÉTODOS: se llevó a cabo un estudio de “antes y despúes” para datos longitudinales comparando variables ecocardiográficas, número de Mets alcanzados en la prueba de esfuerzo antes, 2, 6 y 12 meses después del procedimiento, también se evaluaron la mortalidad y los efectos adversos de la terapia. RESULTADOS: la mediana de la fracción de eyección antes de implantar las células fue de 30% con un rango intercuartil de 28-35%; la media de los Mets fue de 6 con un rango intercuartil de 5-7; ambas variables, al igual que los volúmenes ventriculares en fin de diástole y sístole se incrementaron de forma significativa después del procedimiento. Un paciente presentó infección de la herida quirúrgica y tres murieron dos meses después de la implantación (uno por choque séptico y dos por choque cardiogénico. CONCLUSIÓN: en Medellín, Colombia, es factible hacer la cardiomioplastia celular; se trata de un procedimiento seguro que logra una mejoría sostenida de la fracción de eyección y los Mets más allá de los beneficios obtenidos con la revascularización y la terapia farmacológica óptima.

  13. Seasonal diet composition of Fundulus lima (Cyprinodontiformes: Fundulidae in two oasis systems of Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Dinora Acosta Zamorano

    2011-12-01

    Full Text Available Fundulus lima inhabits river drainage systems and is threatened after the introduction of cichlids in the area. To support conservation programs, the spatial and temporal variation of the diet composition of this endangered killifish, was determined in two oasis systems of Baja California Sur, Mexico (San Ignacio and La Purisima river drainages, during rainy and dry seasons. F. lima was captured by using passive and active capture techniques. A total of 192 stomach contents of F. lima was analyzed. The contribution of each prey item in the diet composition was quantified by means of the indices of occurrence frequency (% OF, numerical (%N and volume (%V percentages. The relative importance of each prey item was determined according to the percentage of the Relative Importance Index (%RII. The similarity of the diet was calculated between hydrological basins (populations combined by basin, seasons (rainy versus dry months, sexes and size classes, by using Schoener’s resource overlap index. We used two ecological indices to determine the type of feeding strategy exhibited by the fish: (1 niche breadth of Levins and (2 proportional similarity of Feisinger. Sand was the most abundant item in the stomach content of killifishes from both drainages (39% and 47%, respectively. Diet composition was similar for both drainages (74% as well as among their respective size classes; however, it was different between sexes. In both drainages, F. lima predated mainly on diatom algae, dipterous and trichopteran larvae, and fish scales during the dry season; while it preferred dipterous larvae, filamentous algae and ostracods in the rainy season. A feeding strategy of opportunist type was exhibited by F. lima during the rainy season, changing to specialist type during the dry season. This information will be the basis for future investigations related to the conservation of this endangered species and its habitat. Rev. Biol. Trop. 59 (4: 1669-1678. Epub 2011

  14. New insights into North America-Pacific Plate boundary deformation from Lake Tahoe, Salton Sea and southern Baja California

    Science.gov (United States)

    Brothers, Daniel Stephen

    three offshore faults are synchronous with Colorado River diversions into the basin. The final study was used coincident wide-angle seismic refraction and multichannel seismic reflection surveys that spanned the width of the of the southern Baja California (BC) Peninsula. The data provide insight into the spatial and temporal evolution of the BC microplate capture by the Pacific Plate. Seismic reflection profiles constrain the upper crustal structure and deformation history along fault zone on the western Baja margin and in the Gulf of California. Stratal divergence in two transtensional basins along the Magdalena Shelf records the onset of extension across the Tosco-Abreojos and Santa Margarita faults. We define an upper bound of 12 Ma on the age of the pre-rift sediments and an age of ˜8 Ma for the onset of extension. Tomographic imaging reveals a very heterogeneous upper crust and a narrow, high velocity zone that extends ˜40 km east of the paleotrench and is interpreted to be remnant oceanic crust.

  15. Interannual summer variability in oceanic euphausiid communities off the Baja California western coast during 1998-2008

    Science.gov (United States)

    Parés-Escobar, Fernanda; Lavaniegos, Bertha E.; Ambriz-Arreola, Israel

    2018-01-01

    Euphausiids are a major component of the zooplankton biomass due to their large size, contributing with high carbon content to other trophic levels in the pelagic ecosystem. We analyzed the summer interannual variability in euphausiid species composition based on carbon mass of the Baja California oceanic domain during 1998-2008. Selection of one exclusive season allowed the emphasis of interannual changes in order to research possible biological impacts. During the period 1998-2008 prevailed intense interannual activity, with four El Niño events, two of them (1997-1998 and 2006-2007) with SST anomalies propagating toward the eastern Pacific (EP-El Niño), while the other two (2002-2003 and 2004-2005) had SST anomalies limited to the central Pacific (CP-El Niño). There were also La Niña events in 1998-2000 and 2007-2008. The species with higher biomass contribution off Baja California were Nematoscelis difficilis, Euphausia gibboides, Thysanoessa gregaria, Euphausia eximia, Nyctiphanes simplex, and Euphausia pacifica, with a global geometric mean of 156, 66, 38, 30, 21, and 13 μg C m-3 respectively. N. difficilis and E. pacifica were dominant in the northern area (29.5-32°N), N. difficilis and E. gibboides in the central area (27-29.5°N), and E. eximia dominated in the southern area (24.5-27°N). 1998-2008 biomass anomalies showed a variety of patterns by species with the clearest footprint, in most of the species, during the strong EP-El Niño 1997-1998. CP-El Niño events also left a footprint in the biomass of some species but this was not always by anomalies of the same nature as EP-El Niño. The best examples were N. difficilis and N. simplex, which presented lightly positive anomalies during July 1998 but were strongly negative in the summer of 2003 and 2004. The opposite was observed in E. recurva, with a negative anomaly in July 1998 but positive in 2004 and 2005. The biophysical coupling between the species assemblage and environmental variables

  16. Testing Pixel Translation Digital Elevation Models to Reconstruct Slip Histories: An Example from the Agua Blanca Fault, Baja California, Mexico

    Science.gov (United States)

    Wilson, J.; Wetmore, P. H.; Malservisi, R.; Ferwerda, B. P.; Teran, O.

    2012-12-01

    We use recently collected slip vector and total offset data from the Agua Blanca fault (ABF) to constrain a pixel translation digital elevation model (DEM) to reconstruct the slip history of this fault. This model was constructed using a Perl script that reads a DEM file (Easting, Northing, Elevation) and a configuration file with coordinates that define the boundary of each fault segment. A pixel translation vector is defined as a magnitude of lateral offset in an azimuthal direction. The program translates pixels north of the fault and prints their pre-faulting position to a new DEM file that can be gridded and displayed. This analysis, where multiple DEMs are created with different translation vectors, allows us to identify areas of transtension or transpression while seeing the topographic expression in these areas. The benefit of this technique, in contrast to a simple block model, is that the DEM gives us a valuable graphic which can be used to pose new research questions. We have found that many topographic features correlate across the fault, i.e. valleys and ridges, which likely have implications for the age of the ABF, long term landscape evolution rates, and potentially provide conformation for total slip assessments The ABF of northern Baja California, Mexico is an active, dextral strike slip fault that transfers Pacific-North American plate boundary strain out of the Gulf of California and around the "Big Bend" of the San Andreas Fault. Total displacement on the ABF in the central and eastern parts of the fault is 10 +/- 2 km based on offset Early-Cretaceous features such as terrane boundaries and intrusive bodies (plutons and dike swarms). Where the fault bifurcates to the west, the northern strand (northern Agua Blanca fault or NABF) is constrained to 7 +/- 1 km. We have not yet identified piercing points on the southern strand, the Santo Tomas fault (STF), but displacement is inferred to be ~4 km assuming that the sum of slip on the NABF and STF is

  17. Moldeo por inyección a baja presión de suspensiones cerámicas

    Directory of Open Access Journals (Sweden)

    Millán, A. J.

    1999-04-01

    ón del material orgánico, etc. Estas características son las responsables del escaso auge industrial de este proceso, quedando solo al alcance de las grandes corporaciones. Una alternativa satisfactoria para reducir los costos y la complejidad del proceso es la Inyección a Baja Presión. Recientemente se ha comprobado la posibilidad de emplear esta técnica haciendo uso de suspensiones acuosas, lo que facilita enormemente la manipulación, simplifica la maquinaria y abarata significativamente los costos. Esta técnica permite reducir el contenido de material polimérico hasta un 2-3 % vol., respecto al 20-50 % vol., típicamente usado en la técnica de alta presión, de manera que no se requiere un tratamiento especial para su eliminación, disminuyendo considerablemente el nivel de rechazos. En este trabajo se describen las ventajas y limitaciones del proceso de moldeo por inyección a baja presión (LPIM en agua y se analizan los parámetros críticos, como son las propiedades reológicas de la suspensión a la temperatura de inyección y la influencia del aditivo gelificante, para la obtención de piezas de Al2O3.

  18. Seasonal diet composition of Fundulus lima (Cyprinodontiformes: Fundulidae in two oasis systems of Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Dinora Acosta Zamorano

    2011-12-01

    Full Text Available Fundulus lima inhabits river drainage systems and is threatened after the introduction of cichlids in the area. To support conservation programs, the spatial and temporal variation of the diet composition of this endangered killifish, was determined in two oasis systems of Baja California Sur, Mexico (San Ignacio and La Purisima river drainages, during rainy and dry seasons. F. lima was captured by using passive and active capture techniques. A total of 192 stomach contents of F. lima was analyzed. The contribution of each prey item in the diet composition was quantified by means of the indices of occurrence frequency (% OF, numerical (%N and volume (%V percentages. The relative importance of each prey item was determined according to the percentage of the Relative Importance Index (%RII. The similarity of the diet was calculated between hydrological basins (populations combined by basin, seasons (rainy versus dry months, sexes and size classes, by using Schoener’s resource overlap index. We used two ecological indices to determine the type of feeding strategy exhibited by the fish: (1 niche breadth of Levins and (2 proportional similarity of Feisinger. Sand was the most abundant item in the stomach content of killifishes from both drainages (39% and 47%, respectively. Diet composition was similar for both drainages (74% as well as among their respective size classes; however, it was different between sexes. In both drainages, F. lima predated mainly on diatom algae, dipterous and trichopteran larvae, and fish scales during the dry season; while it preferred dipterous larvae, filamentous algae and ostracods in the rainy season. A feeding strategy of opportunist type was exhibited by F. lima during the rainy season, changing to specialist type during the dry season. This information will be the basis for future investigations related to the conservation of this endangered species and its habitat. Rev. Biol. Trop. 59 (4: 1669-1678. Epub 2011

  19. Perfil epidemiológico del accidente ofídico en las tierras bajas de Guatemala

    Directory of Open Access Journals (Sweden)

    Dennis Guerra-Centeno

    2017-03-01

    Full Text Available Se describe el perfil epidemiológico del accidente ofídico en las tierras bajas de Guatemala a partir del análisis de 305 expedientes de casos atendidos en los hospitales regionales de Escuintla y San Benito, Petén, entre 2008 y 2013. De los 305 casos, 169 correspondieron al Hospital Regional de Escuintla y 136 al Hospital Regional de San Benito Petén. Los casos del Hospital Regional de Escuintla correspondieron a pacientes provenientes de los departamentos de Escuintla, Santa Rosa, Chimaltenango, Retalhuleu, Suchitepéquez, Sacatepéquez, Sololá y Guatemala. Los casos del Hospital Regional de San Benito Petén correspondieron a pacientes provenientes del área centro y norte de Petén, y algunos referidos del área sur. La edad media de la víctima fue 25.2 años. La enfermedad afectó más a hombres (61.3% que a mujeres (38.7%. La mayoría de los afectados (28.3% eran agricultores. Las especies de serpiente que se consignaron en los expedientes con mayor frecuencia fueron Bothrops asper (serpiente barba amarilla en la región norte y Crotalus simus (serpiente cascabel en la región sur. La mayoría de las mordeduras ocurrieron en los miembros inferiores. Los eventos de mordedura ocurrieron durante el día y durante la noche en proporciones similares. El tiempo medio que tarda la víctima en llegar al hospital fue de 5.6 horas. Se describen también otros aspectos epidemiológicos y se discuten las implicaciones ecológicas y sociales de los datos generados.

  20. Candida species diversity and antifungal susceptibility patterns in oral samples of HIV/AIDS patients in Baja California, Mexico.

    Science.gov (United States)

    Clark-Ordóñez, Isadora; Callejas-Negrete, Olga A; Aréchiga-Carvajal, Elva T; Mouriño-Pérez, Rosa R

    2017-04-01

    Candidiasis is the most common opportunistic fungal infection in HIV patients. The aims of this study were to identify the prevalence of carriers of Candida, Candida species diversity, and in vitro susceptibility to antifungal drugs. In 297 HIV/AIDS patients in Baja California, Mexico, Candida strains were identified by molecular methods (PCR-RFLP) from isolates of oral rinses of patients in Tijuana, Mexicali, and Ensenada. 56.3% of patients were colonized or infected with Candida. In Tijuana, there was a significantly higher percentage of carriers (75.5%). Out of the 181 strains that were isolated, 71.8% were Candida albicans and 28.2% were non-albicans species. The most common non-albicans species was Candida tropicalis (12.2%), followed by Candida glabrata (8.3%), Candida parapsilosis (2.2%), Candida krusei (1.7%), and Candida guilliermondii (1.1%). Candida dubliniensis was not isolated. Two associated species were found in 11 patients. In Mexicali and Ensenada, there was a lower proportion of Candida carriers compared to other regions in Mexico and worldwide, however, in Tijuana, a border town with many peculiarities, a higher carrier rate was found. In this population, only a high viral load was associated with oral Candida carriers. Other factors such as gender, use of antiretroviral therapy, CD4+ T-lymphocyte levels, time since diagnosis, and alcohol/ tobacco consumption, were not associated with Candida carriers. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Transformations of Mangrove Forests in Bahia Magdalena, Baja California Sur, Mexico: Two Decade Results Based on Landsat Imageries

    Science.gov (United States)

    Suresh Babu, S.; Abdul Rahaman, S.; Muthushankar, G.; Jonathan, M. P.

    2014-12-01

    Mangrove forests which thrive along the tropical and subtropical regions are the most productive ecosystems in the world with a wide range of ecological and economical services to mankind. With the rapid urbanization across the globe, these forests tend to be destroying at an alarming rate. The area of concern for this study, Bahia Magdalena is very important for the economy of the state as nearly 50% of the artisan fisheries are established in the mangrove zone. Henceforth this study is an attempt for a regional assessment and to accurately quantify the mangroves using LANDSAT imageries for over two decades in Bahia Magdalena, Baja California. Satellite imageries from the year 1986 through 2014 were analysed to assess the prolonged changes taking place in and around the mangrove reserve. Using the estimates of land use/cover for all the years, the spatio - temporal data was validated using ArcGIS software. The results revealed that the spatial extent of mangroves are decreasing until 2005 due to the developmental plans such as tourism, shrimp farming and establishment of industries in this part of the country. During the past 10 years (~ after 2005) there is no much change in the area extent of mangrove reserves due to afforestation and conservation efforts. Thus the unbiased dataset generated may be widely used for an improved understanding of the role of mangrove forests in the socio economic aspects, protection from natural disasters, identify possible areas for conservation, restoration and rehabilitation; and improve estimates of the amount of carbon stored in mangrove vegetation and the associated marine environment. Keywords: Mangroves, LANDSAT, Bahia Magdalena, México.

  2. Fuel oil combustion with low production of nitrogen oxides; Combustion de combustoleo con baja produccion de oxidos de nitrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Escalera Campoverde, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-09-01

    This work presents the results of the theoretical-experimental study of the effects of the secondary air jet directed perpendicularly to the flame axis in the fuel oil combustion in a 500 Kw furnace. The main purpose of this study was to obtain low nitrogen oxides (NO{sub x}) emissions without increasing the CO, which is observed in low NO{sub x} conventional burners. The experimental results showed a significative reduction of the NO{sub x} and of the CO, from 320 to 90 ppm and from 50 ppm to negligible values, respectively. A commercial computational code of fluid dynamics was employed for modeling the combustion in base line conditions, without secondary air and with the injection of secondary air. The experimental results were compared with calculated ones. [Espanol] En este trabajo se presentan los resultados del estudio teorico experimental de los efectos de los chorro de aire secundario dirigidos en forma perpendicular al eje de la flama en la combustion del combustoleo en un horno de 500 kW. El proposito principal del estudio fue obtener bajas emisiones de oxidos de nitrogeno (NO{sub x}) sin incrementar el CO, lo cual se observa en quemadores convencionales de bajo NO{sub x}. Los resultados experimentales demostraron una reduccion significativa del NO{sub x} y del CO: de 320 a 90 ppm y de 50 ppm a valores despreciables, respectivamente. Se empleo un codigo computacional comercial de dinamica de fluidos para modelar la combustion en condiciones de linea base, sin aire secundario, y con la inyeccion del aire secundario. Se comparan resultados experimentales con los calculados.

  3. Community Based Flood Modeling in Southern and Baja California to Meet End User Needs for Decision-Making

    Science.gov (United States)

    Sanders, B. F.

    2017-12-01

    Flooding of coastal and fluvial systems are the most significant natural hazards facing society, and damages have been escalating for decades globally and in the U.S. Almost all metropolitan areas are exposed to flood risk. The threat from river flooding is especially high in India and China, and coastal cities around the world are threatened by storm surge and rising sea levels. Several trends including rising sea levels, urbanization, deforestation, and rural-to-urban population shifts will increase flood exposure in the future. Flood impacts are escalating despite advances in hazards science and extensive effort to manage risks. The fundamental issue is not that flooding is becoming more severe, even though it is in some places, but rather that societies are become more vulnerable to flood impacts. A critical factor contributing to the escalation of flood impacts is that the most vulnerable sectors of communities are left out of processes to prepare for and respond to flooding. Furthermore, the translation of knowledge about flood hazards and vulnerabilities into actionable information for communities has not been effective. In Southern and Baja California, an interdisciplinary team of researchers has partnered with stakeholders in flood vulnerable communities to co-develop flood hazard information systems designed to meet end-user needs for decision-making. The initiative leveraged the power of advanced, fine-scale hydraulic models of flooding to craft intuitive visualizations of context-sensitive scenarios. This presentation will cover the ways by which the process of flood inundation modeling served as a focal point for knowledge development, as well as the unique visualizations that populate on-line information systems accessible here: http://floodrise.uci.edu/online-flood-hazard-viewers/

  4. Petrology and Geochemistry of Abandoned Spreading Center Lavas Off Baja California: Implications for Intraplate Magmatism in Eastern Pacific

    Science.gov (United States)

    Tian, L.; Castillo, P. R.; Lonsdale, P. F.

    2008-12-01

    Abundant volcanism at active spreading centers is caused by adiabatic decompression melting of the upper mantle, but the origin of volcanism at abandoned spreading centers is an enigma. Guadalupe Island and Sara, Rosana, Rosa, and Nithya seamounts are volcanoes built on abandoned spreading centers between 26°N and 29°N in the eastern Pacific offshore Baja California. Lava samples from these volcanoes comprise predominantly of mildly to moderately alkalic basalts and their differentiates. Relative to mid-ocean ridge basalts (MORB) from the East Pacific Rise (EPR), they have higher abundances of incompatible elements and higher highly/moderately incompatible trace element ratios (e.g., Ba/Zr ~1.3). These lavas have enriched REECH patterns, with light REE enrichment up to 300X chondrites. These trace element characteristics combined with their moderately radiogenic Sr, Nd and Pb isotopic compositions indicate they originated from a geochemically enriched mantle source. In detail, the lavas have a moderate range of composition that overlaps with those of lavas from another spreading center (Davidson Seamount) and nearby seamounts (e.g., Pioneer, Rodriguez) offshore southern California and tholeiitic to alkalic seamounts near the EPR. Together, these intraplate lavas define a compositional continuum ranging from MORB-like to ocean island basalt (OIB)-like. In the case of abandoned spreading centers, the 87Sr/86Sr and 143Nd/144Nd compositions of Sara, Rosana and Nithya seamount lavas greatly overlap with those of EPR seamount lavas, but those of Rosa seamount and Guadalupe Island lavas are within the HIMU field for OIB. Thus our results suggest that volcanism at abandoned spreading centers and intraplate volcanism in eastern Pacific as a whole result from a complex interplay between mantle melting dynamics and lithospheric tectonic processes.

  5. Late Neogene stratigraphy and tectonic control on facies evolution in the Laguna Salada Basin, northern Baja California, Mexico

    Science.gov (United States)

    Martín-Barajas, A.; Vázquez-Hernández, S.; Carreño, A. L.; Helenes, J.; Suárez-Vidal, F.; Alvarez-Rosales, J.

    2001-10-01

    The Laguna Salada Basin (LSB) in northeastern Baja California records late-Neogene marine incursions in the Salton Trough and progradation of the Colorado River delta. Early subsidence and subsequent tectonic erosion are related to evolution of the Sierra El Mayor detachment fault during late Miocene time (stratigraphy of uplifted blocks on the east-central margin of the Laguna Salada Basin and from three exploratory wells allows reconstruction of the main sedimentary and tectonic events. Marine mudstone and sandstone, and subordinate conglomerate of the Imperial Formation tectonically overlie metamorphic and granitic basement. Microfossils, lithology, and sedimentary structures in the Imperial Formation define Upper Miocene (<6 Ma) outer-shelf facies that grade up-section into inner-shelf and tide-dominated delta plain deposits of the ancient Colorado River. Lower Pliocene (˜4-2 Ma) reddish, sub-arkosic fluvial sandstone and siltstone of the Palm Spring Formation defines progradation of non-marine fluvio-deltaic deposits over the marine Imperial Formation. Continuous outcrops of the Palm Spring are less than 170-m thick, but correlative deposits are more than 570 m thick in the lower part of a 2400-m deep geothermal exploratory well on the eastern margin of LSB. Interfingering fluvial-sandstone deposits and prograding alluvial fanglomerates with coarse debris-flow and rock-avalanche deposits crudely mark the onset of vertical slip along the Laguna Salada fault and rapid uplift of Sierra Cucapa and Sierra El Mayor. Up to 2 km of Quaternary alluvial-fan and lacustrine deposits accumulated along the eastern margin of LSB, whereas lower subsidence rates produced a thinner sedimentary wedge over a ramp-like crystalline basement along the western margin. In early Pleistocene time (˜2-1 Ma), the Laguna Salada became progressively isolated from the Colorado River delta complex, and the Salton Trough by activity on the Elsinore and Laguna Salada fault zones.

  6. Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico

    International Nuclear Information System (INIS)

    Ley-Quinonez, C.; Zavala-Norzagaray, A.A.; Espinosa-Carreon, T.L.; Peckham, H.; Marquez-Herrera, C.; Campos-Villegas, L.; Aguirre, A.A.

    2011-01-01

    Highlights: → We report baseline levels of selected heavy metals in blood of Pacific loggerhead turtles. → Blood was used to measure in a relatively non-invasive way baseline values of heavy metals. → Zn and Cd were found in high concentrations compared to levels reported in other parts of the world. → Cu concentrations in blood are high as they relate to concentrations in muscle. → No correlations were found between of heavy metals and metalloids analyzed and the size of the turtles. - Abstract: Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto Lopez Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 μg g -1 ), followed by Selenium (10.92 μg g -1 ). The mean concentration of toxic metal Cadmium was 6.12 μg g -1 and 1.01 μg g -1 respectively. Mean concentrations of metals followed this pattern: Zn > Se > Ni > Cu > Mn > Cd > Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.

  7. Comparison of diazotroph community structure in Lyngbya sp. and Microcoleus chthonoplastes dominated microbial mats from Guerrero Negro, Baja, Mexico.

    Science.gov (United States)

    Omoregie, Enoma O; Crumbliss, Lori L; Bebout, Brad M; Zehr, Jonathan P

    2004-03-01

    The nitrogenase activity and phylogenetic diversity of nitrogen fixing microorganisms in several different cyanobacterial mat types from Guerrero Negro, Baja California, Mexico were investigated by acetylene reduction assay, and by amplification and sequencing of the nitrogenase nifH gene. Acetylene reduction assays performed on a Lyngbya sp. and two Microcoleus chthonoplastes dominated microbial mats showed a typical diel pattern of nitrogenase activity in these mats. The highest rates of activity were found at night, with 40 and 37 micromol C(2)H(4) m(-2) h(-1) measured in the Microcoleus mats, and 9 micromol C(2)H(4) m(-2) h(-1) in the Lyngbya mat. Nitrogenase sequences were obtained that clustered with sequences from cyanobacteria, gamma-Proteobacteria, and cluster 3 of nifH. In addition, novel and divergent sequences were also recovered. The composition of nifH sequence types recovered differed between the Lyngbya and Microcoleus mats. Interestingly, nifH sequences belonging to filamentous cyanobacteria were absent in most mat samples even though both mats were dominated by filamentous cyanobacteria. nifH sequences clustering with those of unicellular cyanobacteria were found, some of which were virtually identical to the nifH sequence from Halothece sp. MPI96P605, which had previously been isolated from the mat. In manipulation experiments, the Lyngbya and Microcoleus mats were allowed to re-colonize a cleared surface. In these developing mats, nifH sequences not previously observed in the mats were discovered. Our results showed that organisms capable of N(2) fixation were present in N(2) fixing mats, that the composition of the N(2) fixing communities differs between mats, and that filamentous cyanobacterial diazotrophs may not have a large role in the early stages of mat development.

  8. Patterns of microbial diversity along a salinity gradient in the Guerrero Negro solar saltern, Baja CA Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Jesse G Dillon

    2013-12-01

    Full Text Available The goal of this study was to use environmental sequencing of 16S rRNA and bop genes to compare the diversity of planktonic bacteria and archaea across ponds with increasing salinity in the Exportadora de Sal (ESSA evaporative saltern in Guerrero Negro, Baja CA S., Mexico. We hypothesized that diverse communities of heterotrophic bacteria and archaea would be found in the ESSA ponds, but that bacterial diversity would decrease relative to archaea at the highest salinities. Archaeal 16S rRNA diversity was higher in Ponds 11 and 12 (370 & 380 g l-1 total salts respectively compared to Pond 9 (180 g l-1 total salts. Both Pond 11 and 12 communities had high representation (47 and 45% of clones respectively by Haloquadratum walsbyi-like (99% similarity lineages. The archaeal community in Pond 9 was dominated (79% by a single uncultured phylotype with 99% similarity to sequences recovered from the Sfax saltern in Tunisia. This pattern was mirrored in bop gene diversity with greater numbers of highly supported phylotypes including many Haloquadratum-like sequences from the two highest salinity ponds. In Pond 9, most bop sequences, were not closely related to sequences in databases. Bacterial 16S rRNA diversity was higher than archaeal in both Pond 9 and Pond 12 samples, but not Pond 11, where a non-Salinibacter lineage within the Bacteroidetes >98% similar to environmental clones recovered from Lake Tuz in Turkey and a saltern in Chula Vista, CA was most abundant (69% of community. This OTU was also the most abundant in Pond 12, but only represented 14% of clones in the more diverse pond. The most abundant OTU in Pond 9 (33% of community was 99% similar to an uncultured gammaproteobacterial clone from the Salton Sea. Results suggest that the communities of saltern bacteria and archaea vary even in ponds with similar salinity and further investigation into the ecology of diverse, uncultured halophile communities is warranted.

  9. Patterns of microbial diversity along a salinity gradient in the Guerrero Negro solar saltern, Baja CA Sur, Mexico.

    Science.gov (United States)

    Dillon, Jesse G; Carlin, Mark; Gutierrez, Abraham; Nguyen, Vivian; McLain, Nathan

    2013-01-01

    The goal of this study was to use environmental sequencing of 16S rRNA and bop genes to compare the diversity of planktonic bacteria and archaea across ponds with increasing salinity in the Exportadora de Sal (ESSA) evaporative saltern in Guerrero Negro, Baja CA S., Mexico. We hypothesized that diverse communities of heterotrophic bacteria and archaea would be found in the ESSA ponds, but that bacterial diversity would decrease relative to archaea at the highest salinities. Archaeal 16S rRNA diversity was higher in Ponds 11 and 12 (370 and 380 g l(-1) total salts, respectively) compared to Pond 9 (180 g l(-1) total salts). Both Pond 11 and 12 communities had high representation (47 and 45% of clones, respectively) by Haloquadratum walsbyi-like (99% similarity) lineages. The archaeal community in Pond 9 was dominated (79%) by a single uncultured phylotype with 99% similarity to sequences recovered from the Sfax saltern in Tunisia. This pattern was mirrored in bop gene diversity with greater numbers of highly supported phylotypes including many Haloquadratum-like sequences from the two highest salinity ponds. In Pond 9, most bop sequences, were not closely related to sequences in databases. Bacterial 16S rRNA diversity was higher than archaeal in both Pond 9 and Pond 12 samples, but not Pond 11, where a non-Salinibacter lineage within the Bacteroidetes >98% similar to environmental clones recovered from Lake Tuz in Turkey and a saltern in Chula Vista, CA was most abundant (69% of community). This OTU was also the most abundant in Pond 12, but only represented 14% of clones in the more diverse pond. The most abundant OTU in Pond 9 (33% of community) was 99% similar to an uncultured gammaproteobacterial clone from the Salton Sea. Results suggest that the communities of saltern bacteria and archaea vary even in ponds with similar salinity and further investigation into the ecology of diverse, uncultured halophile communities is warranted.

  10. Funcionalización de polietileno de baja densidad con anhídrido maleico en estado fundido

    Directory of Open Access Journals (Sweden)

    Manuel Guzmán

    2014-01-01

    Full Text Available En este estudio, polietileno de baja densidad (PEBD fue modificado con anhídrido maleico (AM en estado fundido usando concentraciones diferentes de peróxido de dicumilo (DCP (0.25, 0.50, 0.75 y 1.0 %. Los materiales obtenidos fueron caracterizados por contenido de gel, titulaciones ácido-base, análisis infrarrojo (IR, calorimetría de barrido diferencial (DSC, análisis termogravimétrico (TGA, análisis reológico, propiedades mecánicas, dureza y permeabilidad al oxígeno. El análisis reométrico indicó que el tiempo óptimo para obtener las mezclas es alrededor de 7.5 minutos. El análisis IR mostró que el AM fue injertado en el esqueleto del PEBD, el grado de injerto incrementó con el contenido de DCP y el más alto grado de injerto (1.12 ± 0.015 %, fue exhibido por la muestra obtenida empleando la mayor cantidad de DCP (1 %. La estabilidad térmica de las muestras funcionalizadas fue ligeramente mayor que la del PEBD. La cristalinidad de las muestras funcionalizadas fue diferente a la exhibida por el PEBD. El comportamiento reológico presentado por las muestras fue seudoplástico. Las propiedades mecánicas, dureza y la permeabilidad al oxigeno fueron dependientes de la cantidad de DCP y AM injertado en el PEBD.

  11. Política local y abastecimiento urbano: el pescado en guadalajara en la baja Edad Media

    Directory of Open Access Journals (Sweden)

    José Miguel LÓPEZ VILLALBA

    2009-01-01

    Full Text Available RESUMEN: El pescado fue uno de los pilares de la dieta medieval castellana. En las ciudades del interior, la lejanía del mar impedía un comercio fluido de sus productos, lo que propició su sustitución por los peces procedentes de los ríos cercanos. De este modo se creó un mercado piscícola que permitía el abastecimiento permanente de estos núcleos urbanos. El ejemplo de Guadalajara, ciudad interior, resulta significativo para el conocimiento del suministro y posterior ingesta de estos alimentos y, por lo tanto, de la dieta en las ciudades castellanas de la meseta. Tanto más cuando su estudio se hace comparativamente con las cercanas localidades de Madrid y Toledo. La necesidad de regular el abasto en todas sus fases dio lugar a una serie de disposiciones, principalmente actas y ordenanzas, que son las fuentes primarias de este trabajo. Palabras clave: Abastecimiento. Pescado. Baja Edad Media. Concejo. Documentos. Dieta.ABSTRACT: One of the mainstays of the medieval diet in Castile was fish. In the inland cities the distance from the sea made almost impossible a fluent trade of sea products, which propitiated its replacement by fish from nearby rivers. Thus a fishing market was created to supply these cities. Guadalajara, as in inner city, is a good example of the supply and consumption of such food and also gives an idea of the diet in the Castilian cities, especially if the study is made comparing Guadalajara with other cities near to Madrid and Toledo. The need to regulate the supply in each stage, originated a number of provisions, basically minutes and by-laws, which are the basil sources of the present research.

  12. Hydrogeochemical characterization of the thermal springs in northeastern of Los Cabos Block, Baja California Sur, México.

    Science.gov (United States)

    Hernández-Morales, Pablo; Wurl, Jobst

    2017-05-01

    The existence of hot springs in the northeastern part of Los Cabos Baja California Sur (BCS), is known from pre-Hispanic times, but their hydrochemical composition had not been previously described. Several springs are located within the watershed of Santiago, and the objective of this study was to define the hydrogeochemical composition of the thermal springs and to characterize the geothermal reservoir. A total of 16 water samples were taken in 11 geothermal manifestations under dry (June 2014) and humid (March 2015) conditions. A geothermal system of low enthalpy and low mineralization was found along the San José del Cabo Fault (FSJC), with an average salinity (TDS) of 261 mg/L and an alkaline pH (8.5-9.5). The hydrogeochemical composition corresponds to the sodium-bicarbonate type, and geothermometers (silica and Na-K) indicate temperatures ranging from 70 to 115 °C for the deep thermal reservoir in conditions of equilibrium. The thermal springs with these hydrogeochemical characteristics differ in respect to the hydrochemical composition of the springs, formally described on several sites of BCS. Br/Cl and B/Cl ratios as well as the enrichment factor (EF) indicate that rainwater with a seawater component represents the source of the thermal spring water. In the springs, a mixture between thermal water and surface water is observed, combined with a relatively deep water circulation, allowing a calcium-sodium exchange, according to the host rock geochemistry. The higher temperatures found at some hot springs are related to the main trace of the San José del Cabo Fault.

  13. Boron and strontium isotope compositions of groundwater from the La Paz arid coastal aquifer, Baja California Sur, Mexico

    Science.gov (United States)

    Mahlknecht, Jürgen; Rosner, Martin; Meixner, Anette

    2016-04-01

    In groundwater studies boron and strontium isotopic compositions can be used to identify natural and anthropogenic sources as well as processes related to groundwater recharge, flow and mixing. The La Paz arid costal aquifer in Baja California Sur, Mexico, is the most important source of drinking and irrigation water for La Paz area and suffers from anthropogenic contamination and intensive exploitation of the aquifer causing seawater intrusion and general groundwater abatement. The relatively un-radiogenic 87Sr/86Sr isotope ratios of the La Paz groundwater range in a narrow field between 0.7054 and 0.7062. In contrast to strontium the boron isotope composition displays a large variability between +27 and +55 permil d11B. The relatively low 87Sr/86Sr ratios of the La Paz groundwater highlight a significant contribution of strontium derived from local terrestrial sediments and igneous rocks with known 87Sr/86Sr ratios between 0.705 and 0.7035. The large variability of d11B values indicate that multiple sources and processes determine the boron isotope composition of La Paz groundwater. Rainwater (high d11B), seawater (~+40 permil) due to seawater intrusions, wastewater (low to medium d11B) and boron derived from the local geology (low to medium d11B) explain most of the observed groundwater d11B variability. However, d11B values higher than modern seawater point to significant boron isotope fractionation by preferential absorption of 10B onto clay minerals during the evolution of some groundwater samples. Due to low boron concentrations in rainwater a significant contribution of 11B-rich rainwater (>+40 permil) on the La Paz groundwater is unlikely.

  14. Application of MODIS-ASTER (MASTER) simulator data to geological mapping of young volcanic regions in Baja California, Mexico

    Science.gov (United States)

    Dmochowski, Jane Ellen

    Visible, near infrared, short-wave infrared, and thermal infrared multi-channel remote sensing data, MODIS-ASTER (MASTER), are used to extract geologic information from two volcanic regions in Baja California, Mexico: Tres Virgenes-La Reforma Volcanic Region and the volcanic island of Isla San Luis. The visible and near infrared and short-wave infrared data were atmospherically corrected and classified. The resulting classification roughly delineates surfaces that vary in their secondary minerals. Attempts to identify these minerals using ENVI's Spectral Analyst(TM) were moderately successful. The analysis of the thermal infrared data utilizes the shift to longer wavelengths in the Reststrahlen band as the mineralogy changes from felsic to mafic to translate the data into values of weight percent SiO2. The results indicate that the general approach tends to underestimate the weight percent SiO2 in the image. This discrepancy is removed with a "site calibration," which provides good results in the calculated weight percent SiO2 with errors of a few percent. However, errors become larger with rugged topography or low solar angle at the time of image acquisition. Analysis of bathymetric data around Isla San Luis, and consideration of the island's alignment with the Ballenas transform fault zone to the south and volcanic seamounts nearby, suggest Isla San Luis is potentially volcanically active and could be the product of a "leaky" transform fault. The results from the image analysis in the Tres Virgenes-La Reforma Volcanic Region show the La Reforma and El Aguajito volcanic centers to be bimodal in composition and verify the most recent volcanism in the Tres Virgenes region to be basaltic-andesite. The results of fieldwork and image analysis indicate that the volcanic products of the central dome of La Reforma are likely a sequence of welded ash flow tuffs and lavas of varied composition, evidence of its origin as a caldera.

  15. Propagación y crecimiento inicial del abarco (Cariniana pyriformis Miers, utilizando semillas silvestres

    Directory of Open Access Journals (Sweden)

    Harlenson Pinilla Cespedes

    2016-12-01

    Full Text Available Se realizó la propagación de la especie forestal Abarco Cariniana Pyriformis Miers, con el objetivo de analizar su comportamiento en vivero utilizando semillas botánicas no mejoradas. Se utilizó un diseño completamente aleatorio con arreglo factorial compuesto por 10 factores por condición lumínica -luz y sombra- y 45 unidades experimentales. Se utilizaron diferentes combinaciones de sustratos orgánicos. Las semillas fueron sometidas a un tratamiento pre-germinativo en presencia de un testigo. Las variables evaluadas fueron porcentaje de germinación, crecimiento en altura y diámetro y porcentaje de supervivencia. La especie comenzó la germinación 13 días después de la siembra y se extendió hasta el día 27. Los resultados del proceso de germinación fueron de 60 % y 40% a plena exposición solar y bajo malla poli-sombra, respectivamente. El crecimiento en altura de las plántulas muestra al factor CF con el mejor valor 28,94 cm, bajo condiciones de luz y el factor EF, con 25,56 cm a plena exposición de sombra. Mientras el incremento en diámetro los factores DF y EF registraron valores de 1,04 cm y 0,84 cm, bajo las condiciones sol y sombra respetivamente. Las semillas de esta especie son no-fotoblásticas, es decir que para su germinación es indiferente la presencia o ausencia de luz. Las plántulas ubicadas en la condición ambiental sol registraron mejores valores promedios en las variables diámetro y altura. Por tanto, esta condición ejerce efecto positivo para el crecimiento inicial de las plántulas de Abarco C. pyriformis. 

  16. Seguimiento de la reactogenicidad de la vacuna DTP cubana, utilizando dos métodos paralelos

    Directory of Open Access Journals (Sweden)

    María de los Ángeles Peña Machado

    2005-05-01

    Full Text Available Con el objetivo de caracterizar la reactogenicidad de la vacuna Antidiftérica-Antitetánica- Antipertusis (DTP cubana, desarrollada por el Instituto Finlay, se realizó un estudio utilizando dos métodos o fuentes de información diferentes y paralelos. La primera se obtuvo de un ensayo clínico (EC Fase IV, abierto, no controlado, en el que se incluyeron 57 lactantes. La segunda fuente de información se obtuvo de los reportes de los eventos temporalmente asociados a la vacunación (ETAV, recepcionados por la Unidad Coordinadora Nacional de Farmacovigilancia (UCNFv que incluyen a 86 lactantes que fueron atendidos por sospechas de ETAV. En el EC se aplicaron 167 dosis, los eventos adversos esperados e inesperados se observaron en un escaso número de lactantes, fueron mayoritariamente ligeros y autolimitados en el tiempo y su frecuencia de aparición se redujo en la 2da y 3ra dosis. El dolor fue el evento local más frecuente y la fiebre fue el evento general que más se presentó. No se reportaron vómitos y la anorexia, la somnolencia, y el llanto persistente aparecieron en un número limitado de sujetos vacunados.Se presentaron 12 eventos no esperados, solo en 2 de ellos se consideró que existía relación causal con la vacunación. Se reportó un evento adverso grave (niña hospitalizada por síndrome febril prolongado postvacunación, que se estudió y demostró que fue causado por una sepsis urinaria persistente provocada por una malformación vesico-ureteral. Los 86 reportes recepcionados por la UCNFv incluían un total de 141 ETAV, dentro de los síntomas locales, el eritema alcanzó un 9,30% y la induración un 5,81%, la fiebre fue un síntoma frecuente aunque no se especifica la temperatura corporal alcanzada. Aunque existen varias diferencias con relación a las condiciones en que se realiza la vigilancia de eventos adversos en un EC o en la práctica clínica habitual, los resultados aquí analizados nos confirman que la

  17. Cosecha de café con aire utilizando aspiración.

    Directory of Open Access Journals (Sweden)

    Campillo O. Pablo Ignacio

    2000-12-01

    Full Text Available Las ventosas son utilizadas para sujetar y para transportar productos industriales, avícolas y agrícolas. Por su diseño, por los materiales utilizados en su fabricación y por la amplia gama de tamaños, las ventosas se adaptan a diferentes formas y rugosidades superficiales. Estos dispositivos pueden ser empleados para desprender frutos maduros en cosechadores operados por el hombre o en equipos robotizados. En este estudio se evaluaron cuatro tipos de ventosas en la sujeción y el desprendimiento de frutos maduros de café (Coffea arabica var. Colombia: de Fuelle 1, Fuelle 2, Multifuelle y Profunda. Se midieron las siguientes variables: área de contacto de la ventosa, proporción de agarre (proporción de frutos agarrados en una rama, proporción de desprendimiento (proporción de frutos maduros desprendidos en una rama, fuerza media de desprendimiento (N y presión media de vacío (kPa. Los resultados obtenidos, indicaron que la proporción de agarre fue del 100 % y la proporción de desprendimiento fue superior al 86 % para todas las ventosas estudiadas. La presión media de vacío varió entre valores de –57 kPa y –45 kPa para todas las ventosas. La fuerza media de desprendimiento varió para cada ángulo y cada ventosa, encontrándose valores entre 3,0 y 10 N. El desprendimiento del fruto de café, utilizando un sistema neumático de vacío con ventosas, depende del tipo de ventosa utilizada, siendo independiente del ángulo en el que actúa. La ventosa más adecuada, según los resultados obtenidos, para agarrar y desprender frutos maduros de café, fue la de tipo Multifuelle.

  18. Geochemical characteristics of water from the reservoir of the hydrothermal system of Las Tres Virgenes, Baja California Sur, Mexico; Caracteristicas geoquimicas de las aguas del reservorio del sistema hidrotermal actual de Las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gonalez Partida, Eduardo [Universidad Nacional Autonoma de Mexico (Mexico); Tello Hinojosa, Enrique [Comision Federal de Electricidad (Mexico); Pal Verma, Mahendra [Instituto de Investigaciones Electricas (Mexico)

    2001-03-01

    The Las Tres Virgenes geothermal field is a liquid dominated system. The separated produced by the wells are sodium-chloride type, which is a characteristic of totally equilibrated geothermal brine. The temperature of water-rock interaction in the reservoir is 280 Celsius degrees. the chemical composition of gases corresponds to the one expected in a geothermal environment. The CO{sub 2} is the predominating gas and it is superior in 90% in weight to the total of existing gases. The gas contents is less than 1% in weight, in the case of the wells LV-1 and LV-3. It is also possible to conclude that the gases are in equilibrium with the liquid phase at a temperature of 280 Celsius degrees. With respect to water quality, it is saline, from high to very high and the contents of exchangeable sodium is also very high, resulting in waters not fit for agricultural usage. [Spanish] El yacimiento geotermico de Las Tres Virgenes, en Baja California Sur, Mexico, es un sistema de liquido dominante, en donde el agua separada producida por los pozos presenta un caracter clorurado-sodico caracteristico de una salmuera de origen geotermico totalmente equilibrada. El sistema agua-roca se encuentra en equilibrio a una temperatura de 280 grados centigrados , dicha temperatura son congruentes con las estimadas para las fases gaseosas y liquidas. La composicion quimica de los gases corresponde a la esperada en un ambiente geotermico. El CO{sub 2} es el predominante y es superior a 90% en peso del total de los gases presentes. El contenido de gas es menor de 1% en peso en el caso de los pozos LV-1 y LV-3. Tambien se puede concluir que los gases estan en equilibrio en las fases liquidas a una temperatura de 280 grados centigrados. Con respecto a la calidad del agua, presenta una salinidad de alta a muy alta y el contenido de sodio intercambiable tambien es muy alto, por lo que dichas aguas no son muy aptas para el cultivo.

  19. Adaptación del frijol a suelos de baja fertilidad bajo presión de enfermedades foliares en Costa Rica

    Directory of Open Access Journals (Sweden)

    Rodolfo Araya

    2000-01-01

    Full Text Available El objetivo de este estudio fue identificar germoplasma y líneas mejoradas de alta productividad, en suelos de baja fertilidad y bajo presión de antracnosis y mancha angular. Durante 1996 y 1997 se evaluaron fuentes de tolerancia a la baja fertilidad de diversa procedencia geográfica y con resistencia para otros factores bióticos y abióticos. Se caracterizaron 562 genotipos, 251 mejorados y 311 criollos, en dos localidades de Costa Rica: Fraijanes (1750 msnm; 15,3 °C; 3025 mm; 10º09’ Latitud norte y 84°12’ Longitud oeste y Alajuela (840 msnm, 23,1 °C; 1966 mm; 10°01’ Latitud norte y 84° 16’ Longitud oeste. La densidad de siembra fue de 15 semillas por metro lineal y el tamaño de parcela varió con base en la disponibilidad de semilla; a la siembra sólo se adicionó inoculante de Rhizobium tropici al surco de siembra (4 kg/ha. La línea A321, el testigo local UCR 55, A483, G11640; G19696, G10843 y BAC50 mostraron alto rendimiento en las dos localidades. Los genotipos de alto rendimiento en una localidad fueron: en Alajuela: Guanajuato 132, Negro INIFAP, VAX 2, MAR 3 y en Fraijanes G13860, G92, MOC112, Bayo Alteño, J 117; Negro 8025 y A 247. Se identificó germoplasma no mejorado de diferente acervo genético, procedente de México, Perú y Guatemala, con tolerancia a suelos de baja fertilidad. Esto indica la importancia de evaluar material criollo y del intercambio de germoplasma entre países. Los genotipos superiores serán utilizados en el mejoramiento del frijol común para agricultura de bajo uso de insumos

  20. Remagnetization of Cretaceous forearc strata on Santa Margarita and Magdalena Islands, Baja California Sur: Implications for northward transport along the California margin

    Science.gov (United States)

    Hagstrum, Jonathan T.; Sedlock, Richard L.

    1998-12-01

    Paleomagnetic data for two sections of Cretaceous forearc strata with different structural attitudes on Santa Margarita and Magdalena Islands in Baja California Sur, Mexico, indicate that these rocks have been remagnetized, probably during the late Cenozoic. The in situ paleomagnetic directions, however, are similar to data from other Cretaceous rocks on peninsular California with unexpectedly shallow inclinations and easterly declinations. These data have been interpreted as indicating either northward tectonic transport (10°-15° of latitude) and clockwise rotation (>20°) or compaction shallowing of magnetic inclinations in sedimentary rocks combined with southwestward tilting of plutonic rocks. The available paleomagnetic data for Cretaceous forearc strata in southern and Baja California can be divided into three groups: (1) sections with normal-polarity magnetizations that fail fold tests and are remagnetized, (2) sections with normal-polarity magnetizations with no or inconclusive fold tests that may or may not be remagnetized, and (3) sections with both normal-and reversed-polarity intervals where pervasive remagnetization has not occurred. Other rocks of the Mesozoic Great Valley Group, Coast Range ophiolite, and Franciscan Complex in California also have secondary magnetizations with directions similar to younger geomagnetic field directions. Although these widespread remagnetizations could have variable local causes, we propose regional burial and uplift, related to changes in subduction parameters, as a possible explanation. Two episodes of remagnetization are apparent: one in the Late Cretaceous and a second in the late Cenozoic. On the other hand, the unremagnetized and apparently reliable data from sedimentary and plutonic rocks on the Baja Peninsula consistently indicate northward translation (14° ± 3°) and clockwise rotation (29° ± 8°) with respect to North America since the Late Cretaceous.

  1. The physicochemical characterization of cave paintings of Baja California; Caracterizacion fisicoquimica de pigmentos y soportes en pinturas murales: caso Mayapan, Yucatan

    Energy Technology Data Exchange (ETDEWEB)

    Valdez, B.; Cobo, J.; Schorr, M. [Area de Corrosion y Materiales, Instituto de Ingenieria, Universidad Autonoma de Baja California, Blvd. Benito Juarez, S/N, 21280, Mexicali, B.C. (Mexico); Cota, L. [Centro de Ciencias de la Materia Condensada, UNAM, Ensenada, B.C. (Mexico); Oviedo, F. [Centro INAH - BC, Ensenada, B.C. (Mexico)]. e-mail: benval@iing.mxl.uabc.mx

    2006-07-01

    The Palaeolithic paintings of Baja California constitute an important contribution to the national, historic and cultural patrimony of Mexico. The aim of this investigation was to determine the physicochemical characteristics, the microstructure and texture of these polychrome paintings, painted on rocks encountered in the mountainous, desert/arid zones of Baja California and Baja California South. The first stage of this work was devoted to the examination and recording of the cave paintings of 'El Vallecito', a narrow fluvial valley displaying large granitic rocks emerging from the sandy soil. Tiny painting samples were collected and analyzed by SEM, EDS and FTIR techniques. The painters used four main colours: red, black, yellow and white. The paint raw materials are mineral pigments: white (kaolin, calcite, and gypsum), red (hematite), yellow (ochre, limonite), black (charcoal from burnt wood or calcined bones) and water as a diluent and/or a binder, all encountered in the painters habitat. The minerals were collected, ground and sometimes heated to change their tone. By mixing with water, a spreadable paste or a thick slurry was produced, which was applied with the fingers for lines or a piece of animal skin for figures, respectively. The 100% solids, dry paint converts into a dense, hard layer, incrusted into the grainy, rough, hollow granite rock surface. This paint might be called {sup s}tone on stone{sup ,} explaining its permanence for centuries enduring heat, wind and weather. A simulation of the painting technique was done at the Materials and Corrosion Laboratory, UABC by collecting mineral pigments, preparing the paint as a paste or slurry and applying it on a granitic rock. Knowing the paint composition, production and application techniques will be useful in e conservation and restoration of cave paintings and stone-built, ancient structures such as pyramids, cathedrals and monuments. (Author)

  2. Sediment Cd and Mo accumulation in the oxygen-minimum zone off western Baja California linked to global climate over the past 52 kyr

    Science.gov (United States)

    Dean, W.E.; Zheng, Yen; Ortiz, J.D.; VanGeen, A.

    2006-01-01

    Concentrations of organic carbon (orgC), cadmium (Cd), and molybdenum (Mo) were measured in two sediment cores raised from depths of 430 and 700 m within the oxygen-minimum zone (OMZ) off southern Baja California at a temporal resolution of e10.5 kyr over the past 52 kyr. These records are supplemented with diffuse spectral reflectance (DSR) measurements obtained on board ship soon after collection at a resolution of e10.05 kyr. In the core from 700 m depth, a component extracted from the DSR data and the three geochemical proxies generally vary in concert with each other and over a wide range (4-22% orgC; 1-40 mg/kg Cd; 5-120 mg/kg Mo). Intervals of increased orgC, Cd, and Mo accumulation generally correspond to warm periods recorded in the oxygen-isotopic composition of Greenland ice, with the exception of the Bolling/Allerod which is only weakly expressed off Baja California. Concentrations of the biogenic proxies are higher in the core from 430 m depth, but erratic sediment accumulation before 15 ka precludes dating of the older intervals that are laminated and contain elevated orgC, Cd, and Mo concentrations. The new data provide further evidence of an intimate teleconnection between global climate and the intensity of the OMZ and/or productivity along the western margin of North America. On the basis of a comparison with Cd and Mo records collected elsewhere in the region, we conclude that productivity may actually have varied off southern Baja California by no more than a factor of 2 over the past 52 kyr. Copyright 2006 by the American Geophysical Union.

  3. Polimorfismo GHRd3 del gen del receptor de la hormona de crecimiento en niños peruanos con talla baja idiopática

    Directory of Open Access Journals (Sweden)

    Carlos Del Águila

    2016-01-01

    Full Text Available Objetivos. Describir la estandarización de la detección molecular y la frecuencia del polimorfismo de GHRd3 del gen del receptor de la hormona de crecimiento en una población de niños peruanos con talla baja idiopática. Materiales y métodos. Se estudiaron 64 muestras de sangre periférica de pacientes con diagnóstico de talla baja idiopática atendidos en el servicio de endocrinología del Instituto Nacional de Salud del Niño en Lima, Perú. La amplificación del exón 3 se llevó a cabo empleando los cebadores G1, G2 y G3 optimizándose las condiciones de PCR, como la temperatura de hibridización y las concentraciones de magnesio. Resultados. Se determinó la especificidad de los cebadores a 67 °C y no se obtuvo diferencias entre las concentraciones de magnesio probadas. El 67% de los pacientes fueron homocigotos para GHRfl, 28% fueron heterocigotos y 5% fueron homocigotos para GHRd3. Conclusiones. La técnica permitió establecer los genotipos de los pacientes con talla baja idiopática, determinándose que solo el 5% de ellos presenta el genotipo susceptible de mejor respuesta al tratamiento con rhGH, lo cual puede ser considerado en la decisión de iniciar la terapia.

  4. Estudo do manto superior sob o Brasil Central utilizando tomografia sísmica de tempo de percurso

    OpenAIRE

    Azevedo, Paulo Araújo de

    2013-01-01

    Neste trabalho, apresentamos os resultados de tomografia sísmica de tempo de percurso utilizando ondas P no Brasil Central. Foram realizadas inversões para dados registrados durante os anos de 2008-2012 por 15 estações distribuídas na área de estudo. Além disso, esses dados foram incluídos no banco de dados utilizado por Rocha et al. (2011), a fim de melhorar a resolução das anomalias em algumas regiões dentro da área de estudo. O objetivo foi estudar o manto superior sob o Brasil Central, pr...

  5. Especificação do micronúcleo FreeRTOS utilizando o método B

    OpenAIRE

    Galvão, Stephenson de Sousa Lima

    2011-01-01

    Este trabalho apresenta uma contribuição para o esforço internacional do Verified Software Repository através da especificação formal da biblioteca de sistema de tempo real FreeRTOS. Tal especificação foi realizada de forma abstrata utilizando o método B. Para isso, propriedades disponibilizadas por essa biblioteca foram elencadas e selecionadas como requisitos da especificação, a qual foi construída centrada nas funcionalidades responsáveis pela utilização dessas propriedades....

  6. Sorologia da hanseníase utilizando PGL-I: revisão sistemática

    OpenAIRE

    Moura,Rodrigo Scaliante de; Calado,Karla Lucena; Oliveira,Maria Leide W.; Bührer-Sékula,Samira

    2008-01-01

    A sorologia utilizando o antígeno espécie-específico do Mycobacterium leprae, PGL-I, pode ser um marcador de carga bacteriana em pacientes com hanseníase. Estudos identificaram potencial de uso da sorologia na classificação de pacientes para fins de tratamento, monitoramento de terapia, risco de recidiva e na seleção dos contatos com maior risco de adoecer. Foi realizada uma revisão sistemática e 26 artigos foram incluídos na análise comparativa. Avaliamos os resultados do uso da sorologia PG...

  7. Estudo da degradação do metil parabeno utilizando processos Fenton, foto-Fenton e eletro-Fenton

    OpenAIRE

    Carlos Dante Gamarra Güere

    2014-01-01

    Os disruptores endócrinos são frequentemente relatados na literatura como contaminantes de ambientes aquáticos. Por isso, os processos oxidativos avançados (POAs) têm sido estudados como alternativa para o tratamento em meio aquoso. Os POAs consistem na oxidação de compostos orgânicos por radicais hidroxilas com alto poder oxidante. Diante desses aspectos, o presente trabalho tem como principal objetivo o estudo da degradação do metil parabeno (MeP) por processos Fenton, utilizando planejame...

  8. Generando entornos de investigación y desarrollo utilizando redes inalámbricas de sensores (WSN)

    OpenAIRE

    Sosa, Eduardo Omar; Godoy, Diego Alberto

    2013-01-01

    Las Redes Inalámbricas de Sensores (WSN) jugarán un papel preponderante tanto en las actividades académicas y como en el desarrollo en nuestro país. En este artículo se reportan actividades desarrolladas en dos universidades argentinas, utilizando a la tecnología WSN como disparador de actividades de investigación, desarrollo. La aplicación de ésta tecnología de última generación se enmarcan en el dominio de “Internet de las Cosas” y “Ciudades Inteligentes”. Las actividades teórico-práctic...

  9. Procedimiento para la gestión de mantenimiento utilizando herramientas de la cuarta generación

    OpenAIRE

    Aracelis Barrios; Maritza Ortiz

    2013-01-01

    El presente artículo presenta el diseño de un procedimiento para una gestión de mantenimiento sistémico, utilizando un conjunto de herramientas, que enfocan el uso de los recursos de la empresa asociados con las Personas, los Procesos y la Tecnología, orientados a mejorar la productividad, la toma de decisiones acertadas y a maximizar el rendimiento de los equipos, considerando entre otros, los factores de Confiabilidad, Mantenibilidad, Seguridad, Calidad y Medio Ambiente. El desarrollo del p...

  10. Desenvolvimento de recobrimento retardante de chama em tecido de algodão utilizando bentonita sódica

    OpenAIRE

    Zottis, Ricardo

    2012-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Química Os acabamentos retardantes de chama são substâncias aplicadas nos substratos têxteis com intuito de dificultar a ignição e tornar demorada a propagação da chama, reduzindo os riscos de incêndios. Neste trabalho foi investigada a incorporação de argila no tratamento retardante de chama em tecido de algodão utilizando bentonita sódica juntamente com aditivos fo...

  11. Aplicación de Técnicas de Secado a Baja Temperatura para la Estabilización de Biocatalizadores

    OpenAIRE

    BÁEZ MARTÍN, MIGUEL

    2014-01-01

    [ES] Las técnicas actuales de estabilización de biocatalizadores por deshidratación presentan como principal inconveniente la disminución de la viabilidad de las estructuras biológicas procesadas. Y entre estas técnicas destaca la liofilización a vacío, cuyo elevado coste de operación impide su aplicación a gran escala. Una alternativa interesante a la liofilización es el secado convectivo a baja temperatura. Sin embargo, se trata de un proceso extremadamente lento. La implementación de ultra...

  12. Seroprevalencia de micosis pulmonares en pacientes con sintomatología de enfermedad respiratoria crónica baja: Alto Huallaga, Perú 2004

    Directory of Open Access Journals (Sweden)

    Walter Gómez

    2006-06-01

    Full Text Available Objetivo: Detectar por serología la presencia de micosis de localización pulmonar (Paracoccidioides brasiliensis, Aspergillus sp. e Histoplasma capsulatum, en pacientes con síntomas de enfermedad respiratoria crónica. Diseño: Estudio transversal. Lugar: Alto Huallaga (selva de los departamentos de Huánuco y San Martín, Perú. Pacientes: Se incluyó personas procedentes de seis distritos (Rupa Rupa, Tocache, Uchiza, Santa Lucia, Aucayacu y Puerto Inca - Sungaro con diagnóstico de enfermedad respiratoria crónica baja, tres episodios o más de bronquitis al año y/o tos con expectoración por más de tres meses y en quienes se descartó tuberculosis pulmonar mediante baciloscopia directa. Intervenciones: Por cada persona se llenó una ficha clínica-epidemiológica durante abril a septiembre de 2004, seguido de la toma de una muestra de suero (10 mL para las pruebas de inmunodifusión para Histoplasma capsulatum, Paraccocidiodes brasiliensis, Aspergilus sp, y Aspergillus fumigatus. Principales medidas de resultados: Seroprevalencia de micosis a Histoplasma capsulatum, Aspergilosis spp. y Paracoccidioides brasiliensis. Resultados: De 640 casos, 327 (51,1% fueron de sexo masculino, edad promedio 37,1 años y tiempo de enfermedad de 7,4 meses. La seroprevalencia de micosis fue 1,7% (11/640: 4 Histoplasma capsulatum y 7 Aspergilosis spp. No se obtuvo casos positivos de Paracoccidioides brasiliensis y, en los casos positivos, solo se encontró asociación con 'baja de peso' (p = 0,004. Conclusión: Si bien la frecuencia micoserológica obtenida fue baja, se sugiere en esta zona endémica considerar a las micosis dentro del diagnóstico diferencial de casos con enfermedades respiratorias crónicas bajas, así como la utilización de técnicas de inmunodifusión para el diagnóstico de estas etiologías.

  13. Valoración socioambiental de los recursos naturales: el caso de los recursos minerales en la parte central de Baja California Sur, México

    OpenAIRE

    Luis F. Beltrán Morales; Víctor Sevilla Unda; Macià Blázquez Salom; Federico Salinas Zavala; Felipe García Rodrígez

    2005-01-01

    Se seleccionaron 15 localidades ubicadas en el radio de influencia de dos depósitos evaluados de fosfato, esto con la finalidad de aplicar el método de valoración contingente del recurso y su medio ambiente: el depósito de Tembabichi en el margen del Golfo de California y el depósito de Santo Domingo en la costa del Pacífico en Baja California Sur, México. Se encontró una disposición media a pagar por los habitantes del área de estudio de $29.77 pesos mensuales para colaborar con el medio amb...

  14. Características electrónicas de diferentes dispositivos somentidos a radiación baja de neutrones y gamma

    OpenAIRE

    Zong, Yi

    2006-01-01

    En esta memoria, se han presentado las características electrónicas de diferentes dispositivos en tecnología CMOS (Switches Analógicos, Circuitos de Supervisión, Amplificadores de Aislamiento y Conversores Analógico-Digitales), incluyendo las de los dispositivos discretos sometidos a radiación baja de neutrones y gamma residual (5x1012-1014 n·cm-2 y 0.2-2 kGy (Si)). Los experimentos de radiación se realizaron en una fuente de neutrones especialmente dedicada. Para ello, se diseñó un sistema a...

  15. Características electrónicas de diferentes dispositivos somentidos a radiación baja de neutrones y gamma

    OpenAIRE

    Zong, Yi

    2011-01-01

    En esta memoria, se han presentado las características electrónicas de diferentes dispositivos en tecnología CMOS (Switches Analógicos, Circuitos de Supervisión, Amplificadores de Aislamiento y Conversores Analógico-Digitales), incluyendo las de los dispositivos discretos sometidos a radiación baja de neutrones y gamma residual (5x1012-1014 n·cm-2 y 0.2-2 kGy (Si)). Los experimentos de radiación se realizaron en una fuente de neutrones especialmente dedicada. Para ello, se diseñó un sistema a...

  16. Epidemiología Inversa: baja concentración de LDL modificadas y morbimortalidad cardiovascular en pacientes en hemodiálisis

    OpenAIRE

    Wikinski, Regina; Cacciagiú, Leonardo; López, Graciela; Gónzalez, Ana Inés; Lucero, Diego Martín; Zago, Valeria; Schreier, Laura Ester

    2015-01-01

    La disminución de colesterol-LDL (c-LDL) se considera meta principal del tratamiento de pacientes con riesgo cardiovascular. Sin embargo, pacientes con Enfermedad Renal Crónica (ERC) en hemodiálisis presentan c-LDL menor de 100 mg/dL, aumentos moderados de triglicéridos y baja frecuencia de colesterol-HDL por debajo de valores deseables. Esta condición se encuadra dentro del fenómeno conocido como “epidemiología inversa”, en la cual la conocida asociación prevalente entre hipercolesterolemia,...

  17. MECANISMO DE ACCION DE ANTICONCEPTIVOS ORALES: ¿CUMPLEN LOS ACO DE BAJAS DOSIS CON EL OBJETIVO DE INHIBIR LA OVULACION?

    OpenAIRE

    Busquets C.,Maritza; Preisler,Jessica; Poli,Cecilia

    2002-01-01

    La inhibición de la ovulación es el principal mecanismo o efecto buscando en los casos de utilización terapéutica o contraceptiva de los anticonceptivos orales (ACO). Los mecanismos de acción secundarios postfertilización tienen reparos éticos para aquellas pacientes que consideran la concepción como el comienzo del desarrollo de la persona humana. Quisimos saber en qué medida se inhibe la ovulación mediante la administración de ACO de bajas dosis, como primera aproximación al problema ético ...

  18. Prevalencia de sífilis congénita en tres hospitales públicos de Baja California, México, 2012-2015

    Directory of Open Access Journals (Sweden)

    Jorge Luis Arellano-Estrada

    2017-08-01

    Full Text Available Señor editor: Presentamos los resultados de un estudio descriptivo con base en datos de estudio epidemiológico (EE de caso para sífilis congénita (SC. El formato contiene antecedentes, síntomas, evolución y asociación con factores de riesgo (FR del binomio madre-hijo. El análisis se basa en identificar la prevalencia de SC en los Hospitales de la Secretaría de Salud (SSa de los municipios de Tijuana, Playas de Rosarito y Tecate, Baja California, de 2012 a 2015.

  19. Frecuencias de grupos sanguíneos e incompatibilidades ABO y RhD, en La Paz, Baja California Sur, México

    Directory of Open Access Journals (Sweden)

    del Peón-Hidalgo Lorenzo

    2002-01-01

    Full Text Available Objetivo. Determinar las frecuencias génicas y de fenotipo, y predecir el riesgo de incompatibilidad y aloinmunización materna en la población de La Paz, Baja California Sur, México. Material y métodos. Estudio descriptivo en el que se evaluaron 1 809 disponentes sanguíneos altruistas que acudieron en 1998 al Hospital General de Zona, del Instituto Mexicano del Seguro Social en La Paz, Baja California Sur, México, tipificados por aglutinación en tubo. Las frecuencias génicas fueron estimadas asumiendo condiciones de equilibrio, y las incompatibilidades y riesgo de aloinmunización de acuerdo con la literatura. Los datos fueron evaluados estadísticamente mediante ji². Resultados. La población reveló las siguientes frecuencias en porcentaje: O, 58.49; A, 31.40; B, 8.40; AB, 1.71; RhD, 95.36; y RhD negativo, 4.64 y las frecuencias génicas fueron i, 0.7648; I A, 0.1821; I B, 0.0519; D, 0.7845; d, 0.2155, respectivamente. Las incompatibilidades en parejas y maternofetal fueron 0.3023 y 0.1685 para ABO, 0.0442 y 0.0364 para RhD y 0.0134 y 0.0061 para incompatibilidad doble, respectivamente. La probabilidad de aloinmunización materna fue estimada en 0.0309. Conclusiones. En La Paz, los grupos O y RhD son los más abundantes, aunque las frecuencias están entre las más bajas en México, contrario a lo ocurrido para A y RhD negativo. La probabilidad de aloinmunización materna y las incompatibilidades son también elevadas. Los grupos ancestrales blanco, negro e indio interactuaron en la zona noroeste del país, determinando al migrar a Baja California Sur un mestizaje probablemente similar al resto de la zona noroeste.

  20. Los ejercicios del core como opción terapéutica para el manejo de dolor de espalda baja

    OpenAIRE

    Andrea Calvo Soto; Esperanza Gómez Ramirez

    2017-01-01

    Los problemas de espalda son una causa frecuente de consulta médica y acarrean múltiplesgastos para los sistemas de salud por concepto de medicamentos, servicios e incapacidades.El National Institute of Neurological Disorders and Stroke (NINDS) señala que los síntomas enla espalda baja incluyen dolor muscular, de tipo disparo o dolor punzante, flexibilidad limitada,disminución del rango de movimiento o incapacidad para mantenerse erguido.De acuerdo con la Organización Mundial de la Salud (OMS...

  1. Prevalencia de sífilis congénita en tres hospitales públicos de Baja California, México, 2012-2015

    OpenAIRE

    Jorge Luis Arellano-Estrada; Cinthia Selene López-Lara; Erendida Barreras-Valenzuela

    2017-01-01

    Señor editor: Presentamos los resultados de un estudio descriptivo con base en datos de estudio epidemiológico (EE) de caso para sífilis congénita (SC). El formato contiene antecedentes, síntomas, evolución y asociación con factores de riesgo (FR) del binomio madre-hijo. El análisis se basa en identificar la prevalencia de SC en los Hospitales de la Secretaría de Salud (SSa) de los municipios de Tijuana, Playas de Rosarito y Tecate, Baja California, de 2012 a 2015.

  2. Análisis y control de convertidores continua-continua para módulos reguladores de baja tensión

    OpenAIRE

    Garcés Miguel, Pedro

    2009-01-01

    El suministro de potencia para cargas que exigen altas corrientes, bajos voltajes y grandes y rápidos cambios en la corriente absorbida, además de una estrecha tolerancia en el voltaje de alimentación, representa un gran desafío al diseño de los convertidores para módulos reguladores de baja tensión. En esta tesis, se analizan distintas topologías de convertidores y controles susceptibles de ser aplicados en este tipo de sistemas de alimentación. Se propone una nueva topología de convertidor,...

  3. Assessment of Blue Carbon Storage by Baja California (Mexico) Tidal Wetlands and Evidence for Wetland Stability in the Face of Anthropogenic and Climatic Impacts

    OpenAIRE

    Watson, Elizabeth Burke; Hinojosa Corona, Alejandro

    2017-01-01

    Although saline tidal wetlands cover less than a fraction of one percent of the earth’s surface (~0.01%), they efficiently sequester organic carbon due to high rates of primary production coupled with surfaces that aggrade in response to sea level rise. Here, we report on multi-decadal changes (1972–2008) in the extent of tidal marshes and mangroves, and characterize soil carbon density and source, for five regions of tidal wetlands located on Baja California’s Pacific coast. Land-cover chang...

  4. Syntectonic Deposition of Plio-Quaternary Sediments in the Santa Rosalia Basin of Baja California Sur, Mexico

    Science.gov (United States)

    Michels, A.; Johnson, L.; Niemi, T. M.

    2017-12-01

    Plio-Quaternary sediments of the Tirabuzón, Infierno, and Santa Rosalía formations record syntectonic deposition in the Santa Rosalía basin—an oblique-rift-margin basin along the Gulf of California in Baja California Sur, Mexico. These deposits unconformably overlie the upper Miocene, Cu-Zn-Co-Mn-rich Boleo Formation. The Mesa Soledad outcrops, exposed on the Minera Boleo mine property, show interfingering of marine and terrestrial deposits of the three formations along the inland margin of the basin in an area that has not previously been studied. Faults that cut the Pliocene section of the mesa are mostly steeply-dipping, NW- and NE-striking faults with normal displacement determined from stratigraphic offset and steep plunge in striations. Two stratigraphic sections were measured on either side of one of these high-angle, NW-striking fault that has a normal throw of 26 m. Our analyses of sediment grain size, fossil assemblages, and sedimentary petrography indicate a mismatch of the stratigraphic units across the fault and suggest a component of strike slip. North of the fault, poorly-sorted, well-rounded, fluvial gravels from the Pliocene-aged, Tirabuzón Formation unconformably underlie fossiliferous marine deposits from the late-Pliocene to Pleistocene? -aged Infierno Formation. South of the fault, marine deposits of the Tirabuzón Formation grade upward into imbricated, clast-supported beach gravel, and finally into non-marine conglomerates. The absence of the Infierno Formation on the southern side of the fault suggests the deposits were either eroded unevenly due to uplift or laterally displaced by strike-slip movement. Fossiliferous sandstones and conglomerates of the Santa Rosalía Formation unconformably cap the entire outcrop and show no displacement from faulting. The Santa Rosalía Formation is overlain by the 1.4 Ma La Reforma ignimbrite (Schmidt 2006), indicating that the style of deformation of the basin changed at approximately this time.

  5. Genotipificación por VNTR de aislados de Mycobacterium bovis de ganado sacrificado en Baja California, México

    Directory of Open Access Journals (Sweden)

    Carlos Martínez-Vidal

    2011-01-01

    Full Text Available En México, la tuberculosis bovina (TBB es uno de los principales problemas que enfrenta la ganadería nacional. Las diferentes técnicas de genotipificación pueden ayudar a establecer la relación que existe entre las diferentes cepas presentes en una región y determinar algunos factores que incidan posteriormente en los programas de control y erradicación de la enfermedad. En el presente trabajo se aplicó la técnica de número variable de repeticiones en secuencia (VNTR a 11 aislados provenientes de ganado sacrificado en un rastro de Mexicali BC, y a 10 aislados de ganado sacrificado en un rastro de Tijuana. Se utilizaron oligonucleótidos específicos para amplificar los loci ETR-A, ETR-B, QUB-11a, QUB-11b, QUB-1895, QUB-26, QUB-3232 y QUB-3336, determinándose el parentesco relativo entre las cepas aisladas, así como el poder discriminatorio para cada locus en particular y para todos los loci en su conjunto. Se obtuvieron 14 perfiles alélicos al utilizar los ocho loci con un poder discriminatorio de 0.90 siendo el locus QUB 3336 el que mostró el mayor poder discriminatorio (h=0.72 en tanto el locus ETR-B mostró un nulo poder discriminatorio (h=0.00. En un dendrograma, se observaron seis grupos genéticos, en los cuales se encuentran indistintamente aislados de Tijuana y Mexicali Baja California; sin embargo, se encontraron genotipos específicos para cada una de las dos regiones. Los resultados sugieren que aunque el movimiento de ganado y la compra-venta en la región han provocado la dispersión de cepas en estas dos áreas, se puede discernir el origen de la mayoría de los aislados.

  6. Análisis documental de los rituales de posesión en la Baja Edad Media

    Directory of Open Access Journals (Sweden)

    Tomás Puñal Fernández

    2002-01-01

    Full Text Available Las cartas de posesión constituyen uno de los tipos diplomáticos más interesantes de la documentación notarial privada. Mediante un esquema sencillo, casi en forma de acta notarial, sin demasiados tecnicismos ni muchas de las abundantes y complicadas cláusulas jurídicas presentes en la documentación notarial, son el más fiel reflejo de la expresividad popular de la baja Edad Media, que recurre a la palabra y al signo ritual como manera de manifestar sus deseos. La documentación del ceremonial y los rituales de posesión provenientes del derecho consuetudinario y de prácticas ancestrales se combina con la práctica jurídica, ambas generadoras de derechos y deberes. Su estudio, análisis y significado, tanto a través de los formularios de la época, como de los registros notariales y de la propia documentación encontrada en algunos fondos monásticos son el objetivo de este trabajo, ofreciendo la existencia de una documentación, fiasta la fecha, poco conocida.The letters of possession are one of the most interesting notarial types of the prívate notarial documentation. Through a simple form, like a notarial document, without using neither too many technical words ñor many complicated legal clauses, usually present in the notarial documents, they are the most faithful reflection of the people's behaviour in the Middie Ages; who used the oral expressions and the ritual signs as a way to show their wishes. The ceremony's documentation and the possessions rituals, coming from the Common Law and from the oíd practices, are combined with the legal practices, and both genérate rights and obligations. The goal of this paper is to study, analyse and find the meaning of these documents, both using the forms and the notarial records, and the Information found in the monastic archives; showing ttie existence of several documents not very well known so far.

  7. AUV Mapping and ROV Exploration of Los Frailes Submarine Canyon, Cabo Pulmo National Marine Park, Baja California Sur, Mexico

    Science.gov (United States)

    Troni, G.; Caress, D. W.; Graves, D.; Thomas, H. J.; Thompson, D.; Barry, J. P.; Aburto-Oropeza, O.; Johnson, A. F.; Lundsten, L.

    2015-12-01

    Los Frailes submarine canyon is located at the south boundary of the Cabo Pulmo National Marine Park on the southeast tip of the Baja California Peninsula. During the Monterey Bay Aquarium Research Institute (MBARI) 2015 Gulf of California expedition we used an autonomous underwater vehicle (AUV) to map this canyon from 50 m to 450 m depths, and then explored the canyon with a small remotely operated vehicle (ROV). This three day R/V Rachel Carson cruise was a collaboration with the Center for Marine Biodiversity and Conservation at Scripps Institution of Oceanography and the Centro para la Biodiversidad Marina y la Conservación in La Paz. The MBARI AUV D. Allan B. collected high resolution bathymetry, sidescan, and subbottom profiles of Los Frailes submarine canyon and part of the north Cabo Pulmo deep reef. In order to safely generate a 1-m lateral resolution multibeam bathymetry map in the nearshore high relief terrain, the mapping operations consisted of an initial short survey following the 100-m isobath followed by a series of short, incremental AUV missions located on the deep edge of the new AUV bathymetry. The MBARI Mini-ROV was used to explore the submarine canyon within the detailed map created by the MBARI AUV. The Mini-ROV is a 1.2-m-long, 350 kg, 1,500-m-depth-rated ROV designed and constructed by MBARI. It is controlled by six 600-watt thrusters and is equipped with a high-definition video camera and navigation sensors. This small ROV carries less accurate, lower cost navigation sensors than larger vehicles. We implemented new algorithms to localize combining Doppler velocity log sensor data and low-cost MEMS-based inertial sensor data with sporadic ultra-short baseline position measurements to provide a high accuracy position estimation. The navigation performance allowed us to colocate the ROV video imagery with the 1-m resolution bathymetric map of the submarine canyon. Upper Los Frailes Canyon is rugged and, aside from small sand pockets along

  8. A Re-examination of Shallow Paleomagnetic Inclinations From the Cretaceous Valle Group Sedimentary Rocks, Baja California, Mexico

    Science.gov (United States)

    Li, Y.; Kodama, K. P.; Smith, D. P.

    2001-05-01

    A paleomagnetic, rock magnetic, and sedimentological study was conducted in order to determine whether depositional/compactional processes have caused the shallow inclinations observed in the Valle Group sedimentary rocks. A total of 126 samples (14 sites) were collected from the middle Cenomanian section of the Valle along the northern coast of the Vizcaino Peninsula, Baja California, approximately 20 km east of Punta Eugenia at Campito. Samples were subjected to detailed thermal and alternating field (af) demagnetization, typically in 14 steps to 610° C for thermal demagnetization and ~24 steps to 130 mT for af demagnetization. NRMs were strong for marine sedimentary rocks, typically 10 mA/m. The mean of the site means for the demagnetized data was Inc=54.2° , Dec=306° , α 95=4.8° , N=12, in geographic coordinates, and Inc=20.5° , Dec=341.3° , α 95=4° , N=12 in stratigraphic coordinates. AMS fabrics have minimum axes clustered nearly perpendicular to bedding, typical of primary depositional/compactional fabrics. Some sites exhibited minimum axes clustering about 10° from the vertical and maximum axes clustered about 10° from the horizontal suggesting that currents and/or initial bedding dip affected the magnetization of these samples at deposition. Since the stratigraphy of the Valle Group dips consistently to the NE at approximately 50° , we sampled a tight slump fold at one site in order to constrain the age of magnetization. Both the AMS fabric and the characteristic remanence (ChRM) fail the fold test at the 95% confidence level. At another site, we sampled adjacent beds each approximately 5 cm thick composed of coarse, medium, or fine-grained sandstone. The directions of these beds are within 2° of each other. These results can be interpreted to indicate either a late remagnetization of the Valle group or an acquisition of the Valle's detrital remanence after slumping, but early in the rock's post-depositional history. Smith and Busby's (1993

  9. Mapping mantle-melting anomalies in Baja California: a combined subaereal-submarine noble gas geochemistry new data set.

    Science.gov (United States)

    Spelz, R. M.; Negrete-Aranda, R.; Hilton, D. R.; Virrueta, C.; Tellez, M.; Lupton, J. E.; Evans, L. J.; Clague, D. A.; Zierenberg, R. A.; Neumann, F.

    2017-12-01

    In active tectonic settings, the presence of helium in aqueous fluids with 3He/4He ratios greater than in-situ production values ( 0.05 RA where RA = air He or 1.4 x 10-6) indicates the contribution of mantle-derived volatiles to the total volatile inventory. This is an indicative of the presence of mantle-derived melts, which act to transfer volatiles from the solid Earth towards the surface. Thus, He has the potential to map regions of the underlying mantle which are undergoing partial melting - a phenomenon which should also be evident in the seismic record. Reports of high 3He/4He in hot springs in Baja California (BC) has prompted us to initiate a survey of the region to assess relationship(s) between He isotopes and geophysical images of the underlying mantle. Previous studies report 3He/4He ratios of 0.54 RA for submarine hot springs (Punta Banda 108oC) and 1.3 RA for spring waters (81oC) at Bahia Concepcion. Our new survey of hot springs in northern BC has revealed that all 12 localities sampled to date, show the presence of mantle He with the highest ratio being 1.74RA (21% mantle-derived) at Puertecitos on the Gulf coast. He ratios are generally lower on the Pacific coast with the minimum mantle He contribution being 5% at Santa Minerva (0.11RA). Thus, preliminary trends are of a west-to-east increase in the mantle He signal across the peninsula. In the Gulf of California, recent He analyses from the newly discovered Meyibo (350 °C) and Auka (250-290 °C) hydrothermal fields at Alarcon rise and Pescadero basin, respectively, show high 3He/4He ratios ( 8RA), typical of MORB's. These ratios are higher than the ones reported for Guaymas Basin (6.95 RA), suggesting that primordial He signal from the mantle increases following a North-South direction along the Gulf axis. He results presented in this study correlate well with high resolution Rayleigh wave tomography images by DiLuccio et al (2014). Shear velocity variations in the BC crust and upper mantle

  10. Conceptualization of groundwater flow of a coastal arid aquifer using isotopic and chemical tools: La Paz, Baja California Sur, Mexico

    Science.gov (United States)

    Tamez-Melendez, Carol; Hernández-Antonio, Arturo; Mahlknecht, Jürgen

    2016-04-01

    Groundwater from the La Paz coastal aquifer in Baja California Sur, Mexico, is the main source of drinking water for the local population. Due to its proximity to the coast, sea water intrusion is the main factor of salinization of groundwater. Other geochemical processes also affect the quality of the aquifer threating its vulnerability. Forty-seven samples were analyzed for ion chemistry and isotopes. A hierarchical cluster analysis was performed for a better interpretation resulting in three main groups and proved for geographical correspondence. Deuterium and d18O ranged from -82 to -52.1 and from -11.6 to -7 permil, respectively, showing that the main recharge originates in the Sierra el Novillo, flowing toward SE-NW direction and in accordance to deuterium excess (d) high evaporation effects (d>10‰) are mostly in the middle portion of the study area and in El Centenario due to high kinetic isotope fractioning related to elevated temperatures. Hydrogeochemistry analyses demonstrated salinization mainly due to sea water intrusion and in second instance due water-rock interaction, where enrichment of Na+ (ranges from 35.7 to 1089 mg/L-1) was present in some samples probably due to weathering of silicates and/or cation exchange in soils with Ca2+ (27.7 to 658 mg/L-1) at clay-surfaces. High concentrations of NO3-2 (ranges from 1.4 to 48.8 mg/L-1), Cl- (ranges from 54.4 to 2960 mg/L-1) and Na+ show that anthropogenic input is mainly coming from an agricultural area (El Centenario-Chametla) where heavy groundwater extractions are made for irrigational purposes, lowering the groundwater table up to 10 m and consequently promoting upconing and salinity concentrations (NaCl). Carbon-13 and radiocarbon ranged from -12.3 to -9.1‰ and from 29.5 to 100.4 pmC, respectively. Distribution of ages (up to ~5000 years) indicates two flow trends (E-W and SE-NW).

  11. La terapia láser de baja potencia en la medicina cubana Low potency laser therapy in Cuban medicine

    Directory of Open Access Journals (Sweden)

    Adel Hernández Díaz

    2008-06-01

    Full Text Available El surgimiento y desarrollo del láser fue posible gracias a los avances previamente logrados en otras disciplinas científicas en el pasado siglo. Desde el punto de vista práctico puede ser considerado como un haz estrecho de luz monocromática y coherente que puede encontrarse en el rango visible, infrarrojo o ultravioleta del espectro de las radiaciones electromagnéticas. Motivados por la incorporación de los equipos láser de producción nacional en las salas de rehabilitación de los policlínicos universitarios de la atención primaria y otros centros de salud del país, nos dimos a la tarea de realizar este trabajo, cuyo objetivo fundamental es presentar las distintas aplicaciones del láser de baja potencia en la medicina, y los equipos láser cubanos disponibles en la red nacional de salud pública. Además se muestran los efectos terapéuticos de la radiación láser y los mecanismos internos para lograrlos, y se detallan ampliamente las contraindicaciones de la terapia. Este tipo de tratamiento ofrece muchas posibilidades de ayuda terapéutica y permite ser utilizado con éxito en patologías de diversas especialidades. La terapia láser constituye un tratamiento de primera línea para muchas de las afecciones con que acuden los pacientes a consulta médica.The appearance and development of laser was possible thanks to the advances previously attained in other scientific disciplines in the last century. From the practical point of view, it may be considered as a narrow monochromatic and coherent beam of light that may be found in the visible infrared or ultraviolet range of the spectrum of electromagnetic radiations. Motivated by the introduction of the laser equipment of national production into the rehabilitation wards of the teaching polyclinics and other health centres of the country, we made this paper aimed at presenting the different applications of low potency laser in the medical sphere, as well as the Cuban laser

  12. Baja California: Field Study

    Science.gov (United States)

    Frey, John; Stewart, Jack

    1974-01-01

    Describes how to plan and execute an extended field trip which provides first hand observation of biological and cultural systems. Socialization of the participants was achieved through common planning and goal achievement. (BR)

  13. Medial meniscus transplantation using cyanoacrylate in rabbits Transplante de menisco medial utilizando cianoacrilato em coelhos

    Directory of Open Access Journals (Sweden)

    Leandro José Reckers

    2006-04-01

    Full Text Available PURPOSE: To evaluate meniscal transplantation using as fixation method a synthetic glue derived from cyanoacrylate acid. METHODS: Twenty rabbits were used, of which 10 for autologous transplantation and 10 for homologous transplantation. For the autologous transplantation the meniscus was removed, and then transplanted in the same animal, using the synthetic glue. For the homologous transplantation, the study was divided into two stages: 1- Removal of the meniscus which was maintained at a temperature of 73ºC. 2- Use of cyanoacrylate acid-derived surgical adhesive for meniscal retransplantation in a different rabbit 30 days after the transplant. RESULTS: Due to complications, euthanasia had to be anticipated to the 15th day in the homologous group and to the 18th day in the autologous group. Macroscopically, knees submitted to transplantation presented whitish secretions from the surgical incision up to deep planes. Necrosis was observed in both groups. Statistical analysis has shown that mild (p=0.043 and moderate (p=0.001 complications emerged in a significantly earlier way in the homologous group, where euthanasia was also performed earlier (p=0,005. CONCLUSION: Synthetic surgical adhesives derived from cyanoacrylate acid promoted cortical to medullary bone necrosis bone in both groups.OBJETIVO: Avaliar macroscópica e histologicamente o transplante meniscal, utilizando-se a cola sintética derivada do ácido cianoacrilato como método de fixação. MÉTODOS: Foram utilizados 20 coelhos, tendo 10 realizado transplante autólogo e 10, homólogo. Para o transplante autólogo, o menisco foi retirado e em seguida transplantado no mesmo animal, sendo fixado com a cola sintética. Para o transplante homólogo o estudo foi dividido em duas etapas: 1- retirada do menisco e manutenção a uma temperatura de 73°C negativos. 2- Utilização do adesivo cirúrgico derivado do ácido cianoacrilato para reimplantar num coelho diferente 30 dias após o

  14. Radiopacity of restorative materials using digital images Radiopacidade de materiais restauradores utilizando imagens digitais

    Directory of Open Access Journals (Sweden)

    Leda Maria Pescinini Salzedas

    2006-04-01

    Full Text Available The radiopacity of esthetic restorative materials has been established as an important requirement, improving the radiographic diagnosis. The aim of this study was to evaluate the radiopacity of six restorative materials using a direct digital image system, comparing them to the dental tissues (enamel-dentin, expressed as equivalent thickness of aluminum (millimeters of aluminum. Five specimens of each material were made. Three 2-mm thick longitudinal sections were cut from an intact extracted permanent molar tooth (including enamel and dentin. An aluminum step wedge with 9 steps was used. The samples of different materials were placed on a phosphor plate together with a tooth section, aluminum step wedge and metal code letter, and were exposed using a dental x-ray unit. Five measurements of radiographic density were obtained from each image of each item assessed (restorative material, enamel, dentin, each step of the aluminum step wedge and the mean of these values was calculated. Radiopacity values were subsequently calculated as equivalents of aluminum thickness. Analysis of variance (ANOVA indicated significant differences in radiopacity values among the materials (PA radiopacidade dos materiais tem sido valorizada como importante requisito, incrementando o diagnóstico radiográfico. O objetivo deste estudo foi avaliar, no sistema digital Digora, as densidades radiográficas de 06 materiais restauradores comparando-os aos tecidos dentais (esmalte e dentina, expressos em milímetros de alumínio (mm Al. Foram confeccionadas 05 amostras de cada material e três cortes de um molar extraído hígido (incluindo esmalte e dentina, com 2 mm de espessura, e um penetrômetro de alumínio com 09 degraus. Sobre cada placa óptica foram colocados amostras dos diferentes materiais, um corte do dente humano, o penetrômetro e a identificação, e feita a exposição utilizando um aparelho de raios X. Foram obtidas 05 medidas de densidade radiográfica de

  15. Acute lower gastrointestinal hemorrhage originating in the small intestine Hemorragia digestiva baja severa originada en el intestino delgado

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    A. Ríos

    2006-03-01

    Full Text Available Introduction: lower gastrointestinal hemorrhage (LGIH is generally self-limiting, and the most frequent etiologies are located at colonic level. The objective here is to analyze the diagnostic and therapeutic handling of acute LGIH when its etiology was located in the small intestine. Patients and methods: between 1975 and March 2002, 12 acute cases of LGIH originating in the small intestine were admitted to our service. All consulted the hospital with acute rectorrhage, requiring a transfusion of at least 3 units of concentrated red blood cells. The mean age was 54 ± 21 years, 58% were women, and 83% had experienced previous episodes of LGIH. Results: in eleven cases (92% an urgent lower and upper endoscopy was performed without locating the source of bleeding. An arteriography was indicated in 7 patients (58%, which located the bleeding origin in 5 of them. In two cases a scintigraphy was performed, showing a Meckel's diverticulum in one patient and a normal image in another. All were operated on; in 8 cases (67%, surgery was urgent; in 9 cases, a tumor was found, and in three additional patients, a case of Meckel's diverticulum was found, with a resection being carried out for all lesions. Histology showed a leiomyoma in 7 cases, a Meckel's diverticulum in 3 cases, a leiomyoblastoma in 1, and an angioma in the remaining case. After a mean follow-up of 132 ± 75 months, the leiomyoblastoma resulted in death, and there was a relapse in the case of angioma, which was successfully embolized with interventional radiology. Conclusions: acute LGIH originating in the small intestine should be considered a possible etiology when digestive endoscopy does not locate the source of bleeding, with arteriography being a useful diagnostic technique for bleeding localization. Surgery is the definitive treatment - it confirms the etiology and rules out the presence of malignancy.Introducción: la hemorragia digestiva baja (HDB es generalmente autolimitada y

  16. UTILIZANDO NANOTUBOS DE TiO2 COMO FOTOCATALISADOR NA DEGRADAÇÃO DO CORANTE VERMELHO CONGO

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    Nilmalice Coelho Rocha

    2011-02-01

    Full Text Available Nanotubos de TiO2 foram sintetizados em um sistema hidrotérmico. Os nanomateriais foram caracterizados por microscopia eletrônica de varredura (MEV e área superficial. O TiO2 anatase e os nanotubos de TiO2 foram utilizados no processo de fotodegradação do corante vermelho congo. A capacidade de fotodegradação de ambos catalisadores foram comparadas. O corante foi degradado por 90 minutos, utilizando ambos catalisadores, estes apresentaram alta atividade catalítica próximo ao pH 2. A capacidade de fotodegradação do corante utilizando TiO2 anatase e nanotubos de TiO2 em meio iônico mostrou-se favorável com a adição de NaCl na concentração de 0,03 mol/L.

  17. Ecología trófica del pez Arothron meleagris (Tetraodontiformes: Tetraodontidae en el arrecife de Los Frailes, Baja California Sur, México

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    Xchel G Moreno

    2009-06-01

    Full Text Available Con la finalidad de determinar los hábitos alimenticios del tamboril de oro Arothron meleagris, así como sus posibles variaciones de alimentación por talla y sexo, se realizaron muestreos mensuales de noviembre 2004 a octubre 2005, en el arrecife de Los Frailes, Baja California Sur, México. Se capturaron un total de 101 ejemplares, en los cuales todos los estómagos contenían alimento. Se aplicó el índice de importancia relativa (IIR para determinar los principales categorías alimenticias (ítems, los cuales fueron: Echinometra vanbrunti (26.25 %, Porifera (12.63 %, Pocillopora spp. (11.84%, Bryozoa (5.37 % y Porites spp. (4.83 %. El índice de Levin indica baja amplitud del nicho trófico (Bi= 0.12 por lo que se le puede considerar como un depredador especialista con marcadas preferencias hacia algunos tipos alimentarios. El índice de Morisita-Horn indicó que existe un traslape alto entre las dietas por sexo (hembras y machos o = 0.78, temporadas (cálida y fría o = 0.95 y entre tallas (chica y mediana o = 0.94, chica y grande o = 0.74, mediana y grande o = 0.83.

  18. Associations between trace elements and clinical health parameters in the North Pacific loggerhead sea turtle (Caretta caretta) from Baja California Sur, Mexico.

    Science.gov (United States)

    Ley-Quiñónez, César Paúl; Rossi-Lafferriere, Natalia Alejandra; Espinoza-Carreon, Teresa Leticia; Hart, Catherine Edwina; Peckham, Sherwood Hoyt; Aguirre, Alfredo Alonso; Zavala-Norzagaray, Alan Alfredo

    2017-04-01

    This study investigated selected trace elements toxicity in sea turtles Caretta caretta population from Baja California Sur (BCS), Mexico, by analyzing associations among Zn, Se, Cu, As, Cd, Ni, Mn, Pb, and Hg with various biochemical parameters (packed cell volume, leukocytes, and selected blood parameters), and whether their concentrations could have an impact on the health status of sea turtles. Blood samples from 22 loggerhead (C. caretta) sea turtles from BCS, Mexico, were collected for trace elements on biochemistry parameter analyses. Significant associations among trace element levels and the biochemistry parameters were found: Cd vs ALP (R 2  = 0.874, p ˂ 0.001), As vs ALP (R 2  = 0.656, p ˂ 0.001), Mn vs ALP (R 2  = 0.834, p ˂ 0.001), and Ni vs LDH (R 2  = 0.587, p ˂ 0.001). This study is the first report of the biochemical parameters of the North Pacific loggerhead sea turtle (C. caretta) from Baja California Sur, Mexico, and it is the first to observe several associations with toxic and essential trace elements. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements and the results suggest that, based on the associations with health clinical parameters, high levels of Cd and As could be representing a risk to the North Pacific loggerhead population health.

  19. Optimización de recursos hídricos y armonización de sus usos: el Consorcio de Aguas de la Marina Baja

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    Antonio Gil Olcina

    2010-01-01

    Full Text Available En la Marina Baja, comarca alicantina de la seca región climática del Sureste Ibérico, el difícil desafío de conjugar el extraordinario desarrollo turístico y urbano de su franja litoral, que polariza Benidorm, con disponibilidades hídricas exiguas e irregulares, ha requerido un conjunto de actuaciones del mayor interés, para la optimización de éstas y la armonización de sus usos, protagonizadas por el Consorcio de Aguas de la Marina Baja. Dichas iniciativas incluyen: mayor y mejor regulación de recursos epigeos, potenciación sostenible de los subterráneos, y reutilización de aguas depuradas, con superposición de dos sistemas independientes -aguas blancas y depuradas-, que funcionan al unísono; sin que falte, para conjurar el riesgo extremo de una sequía prolongada e intensa, la posibilidad de emplear caudales foráneos.

  20. Late Miocene adakites and Nb-enriched basalts from Vizcaino Peninsula, Mexico: Indicators of East Pacific Rise subduction below southern Baja California?

    Science.gov (United States)

    Aguillón-Robles, Alfredo; Calmus, Thierry; Benoit, Mathieu; Bellon, Hervé; Maury, René C.; Cotten, Joseph; Bourgois, Jacques; Michaud, François

    2001-06-01

    A typical slab melt association was emplaced from 11 to 8 Ma in the Santa Clara volcanic field, Vizcaino Peninsula, Baja California Sur. It includes adakitic domes and associated pyroclastic flow deposits, together with lava flows of niobium-enriched basalts. The trace element and isotopic (Sr-Nd-Pb) signatures of adakites are consistent with melting of altered mid-ocean ridge basalts, and the sources of the Nb-enriched basalts contain an enriched mantle wedge component. Such associations commonly form at depths of 70 80 km during low-dip subduction of very young oceanic crust. However, the Santa Clara field is relatively close (100 km) to the paleotrench, which suggests that the genesis of its adakites and Nb- enriched basalts occurred in a very high thermal regime linked to the subduction of the then-active Guadalupe spreading center of the East Pacific Rise. Our data suggest that the asthenospheric window documented below northern Baja California also developed beneath the south of the peninsula during the Neogene. This hypothesis is consistent with the spatial distribution and the ages of adakites and magnesian andesites from this region.

  1. Baja visión en la población pediátrica de Las Tunas Low vision of the pediatric population in Las Tunas province

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    Yunia Herbania Labrada Rodríguez

    2006-12-01

    Full Text Available Se presentan los resultados de un estudio descriptivo en 35 pacientes ciegos y débiles visuales matriculados en la Escuela de Ciegos de la provincia Las Tunas. Los pacientes fueron agrupados según categoría visual, sexo, y etiología de baja visión. El sexo masculino fue el más afectado, el mayor número de pacientes eran débiles visuales y las etiologías más frecuentes de baja visión fueron la catarata congénita y la retinopatía de la prematuridadThe results of a descriptive study of 35 blind and impaired vision patients, who study at the School for Blind People in Las Tunas province were presented in this paper. The patients were grouped according to their visual category, sex and etiology of low vision. Males were the most affected, the highest number of patients had impaired vision and the most common causes of low vision were congenital cataract and prematurity retinopathy

  2. Validación de un cuestionario para evaluar causas administrativas de la baja notificación de reacciones adversas a los medicamentos

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    Lisset Ortiz Zamora

    Full Text Available RESUMEN Objetivo Diseñar y validar una encuesta para conocer las causas de tipo administrativo que pueden influir en la baja notificación de reacciones adversas a medicamentos (RAM. Métodos El cuestionario se diseñó a partir de una revisión bibliográfica y una tormenta de ideas. Las variables que se consideraron que pueden influir en la notificación fueron la carga de trabajo de los profesionales y su percepción del control de la actividad de farmacovigilancia. Para su validación, se encuestó a 60 profesionales de una muestra de conveniencia. La confiabilidad se calculó con la alfa de Cronbach y el coeficiente de Kuder Richardson. La validez de contenido se cuantificó con el coeficiente de Kendall y la de criterio, mediante la concordancia con el criterio establecido. Resultados El cuestionario tipo encuesta quedó constituido por 15 preguntas y estructurado en dos partes, información general y causas administrativas de la baja notificación de RAM. La alfa de Cronbach fue 0,87, el coeficiente de Kuder Richardson, 0,9033, y la validez total, 1,51, resultante de 70% de concordancia y un coeficiente de correlación por rangos de 0,81. Conclusiones La confiabilidad de la encuesta validada fue aceptable-elevada y su validez, aceptable.

  3. Population genetic structure of annual and perennial populations of Zostera marina L. along the Pacific coast of Baja California and the Gulf of California.

    Science.gov (United States)

    Muñiz-Salazar, Raquel; Talbot, Sandra L; Sage, George K; Ward, David H; Cabello-Pasini, Alejandro

    2005-03-01

    The Baja California peninsula represents a biogeographical boundary contributing to regional differentiation among populations of marine animals. We investigated the genetic characteristics of perennial and annual populations of the marine angiosperm, Zostera marina, along the Pacific coast of Baja California and in the Gulf of California, respectively. Populations of Z. marina from five coastal lagoons along the Pacific coast and four sites in the Gulf of California were studied using nine microsatellite loci. Analyses of variance revealed significant interregional differentiation, but no subregional differentiation. Significant spatial differentiation, assessed using theta(ST) values, was observed among all populations within the two regions. Z. marina populations along the Pacific coast are separated by more than 220 km and had the greatest theta(ST) (0.13-0.28) values, suggesting restricted gene flow. In contrast, lower but still significant genetic differentiation was observed among populations within the Gulf of California (theta(ST) = 0.04-0.18), even though populations are separated by more than 250 km. This suggests higher levels of gene flow among Gulf of California populations relative to Pacific coast populations. Direction of gene flow was predominantly southward among Pacific coast populations, whereas no dominant polarity in the Gulf of California populations was observed. The test for isolation by distance (IBD) showed a significant correlation between genetic and geographical distances in Gulf of California populations, but not in Pacific coast populations, perhaps because of shifts in currents during El Niño Southern Oscillation (ENSO) events along the Pacific coast.

  4. Population genetic structure of annual and perennial populations of Zostera marina L. along the Pacific coast of Baja California and the Gulf of California

    Science.gov (United States)

    Munoz-Salazar, R.; Talbot, S.L.; Sage, G.K.; Ward, D.H.; Cabello-Pasini, Alejandro

    2005-01-01

    The Baja California peninsula represents a biogeographical boundary contributing to regional differentiation among populations of marine animals. We investigated the genetic characteristics of perennial and annual populations of the marine angiosperm, Zostera marina, along the Pacific coast of Baja California and in the Gulf of California, respectively. Populations of Z. marina from five coastal lagoons along the Pacific coast and four sites in the Gulf of California were studied using nine microsatellite loci. Analyses of variance revealed significant interregional differentiation, but no subregional differentiation. Significant spatial differentiation, assessed using θ values, was observed among all populations within the two regions. Z. marina populations along the Pacific coast are separated by more than 220 km and had the greatest θ (0.13-0.28) values, suggesting restricted gene flow. In contrast, lower but still significant genetic differentiation was observed among populations within the Gulf of California (θ = 0.04-0.18), even though populations are separated by more than 250 km. This suggests higher levels of gene flow among Gulf of California populations relative to Pacific coast populations. Direction of gene flow was predominantly southward among Pacific coast populations, whereas no dominant polarity in the Gulf of California populations was observed. The test for isolation by distance (IBD) showed a significant correlation between genetic and geographical distances in Gulf of California populations, but not in Pacific coast populations, perhaps because of shifts in currents during El Nino Southern Oscillation (ENSO) events along the Pacific coast.

  5. Los ejercicios del core como opción terapéutica para el manejo de dolor de espalda baja

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    Andrea Calvo Soto

    2017-01-01

    Full Text Available Los problemas de espalda son una causa frecuente de consulta médica y acarrean múltiplesgastos para los sistemas de salud por concepto de medicamentos, servicios e incapacidades.El National Institute of Neurological Disorders and Stroke (NINDS señala que los síntomas enla espalda baja incluyen dolor muscular, de tipo disparo o dolor punzante, flexibilidad limitada,disminución del rango de movimiento o incapacidad para mantenerse erguido.De acuerdo con la Organización Mundial de la Salud (OMS, el dolor lumbar es una causa im-portante de discapacidad y se produce en proporciones similares en todas las culturas, interfierecon la calidad de vida y el rendimiento en el trabajo.Este artículo analiza los ejercicios del core como una opción de intervención para el dolor deespalda baja, en cuanto a su descripción, sus efectos sobre el dolor, la función y otras variablesde cualidades físicas.

  6. La dinámica territorial de las principales instituciones bancarias en la península de Baja California: estructura e interrelaciones

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    Lilia Susana Padilla Sotelo

    2001-03-01

    Full Text Available This research analyzes the territorial distribution of the main banking institutions within the Baja California peninsula´s urban space. It starts by providing a background on the spatial organization of banking institutions in the study area and their relationship within the national context, stressing their borderline location. The location-focused analysis, through examining the territorial distribution of the 158 bank offices from the seven main Institutions, allows to detect a considerable concentration in small and mid-sized urban towns located to the north. Also, banks tend to be located at the most populated towns having differential behaviors. Since this aspect is related to the economic activity that takes place in them, these towns have become preferential spaces, resulting in territorial unbalances. The cities of Tijuana and Mexicali stand out, followed to a lesser extent by La Paz and Ensenada, The territorial distribution of banking institutions in Baja California follows the same behavior pattern as the one that occurs at a national level, i.e. location according to the specific area of specialty.

  7. Assessment of Blue Carbon Storage by Baja California (Mexico) Tidal Wetlands and Evidence for Wetland Stability in the Face of Anthropogenic and Climatic Impacts.

    Science.gov (United States)

    Watson, Elizabeth Burke; Hinojosa Corona, Alejandro

    2017-12-24

    Although saline tidal wetlands cover less than a fraction of one percent of the earth's surface (~0.01%), they efficiently sequester organic carbon due to high rates of primary production coupled with surfaces that aggrade in response to sea level rise. Here, we report on multi-decadal changes (1972-2008) in the extent of tidal marshes and mangroves, and characterize soil carbon density and source, for five regions of tidal wetlands located on Baja California's Pacific coast. Land-cover change analysis indicates the stability of tidal wetlands relative to anthropogenic and climate change impacts over the past four decades, with most changes resulting from natural coastal processes that are unique to arid environments. The disturbance of wetland soils in this region (to a depth of 50 cm) would liberate 2.55 Tg of organic carbon (C) or 9.36 Tg CO₂eq. Based on stoichiometry and carbon stable isotope ratios, the source of organic carbon in these wetland sediments is derived from a combination of wetland macrophyte, algal, and phytoplankton sources. The reconstruction of natural wetland dynamics in Baja California provides a counterpoint to the history of wetland destruction elsewhere in North America, and measurements provide new insights on the control of carbon sequestration in arid wetlands.

  8. Assessment of Blue Carbon Storage by Baja California (Mexico Tidal Wetlands and Evidence for Wetland Stability in the Face of Anthropogenic and Climatic Impacts

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    Elizabeth Burke Watson

    2017-12-01

    Full Text Available Although saline tidal wetlands cover less than a fraction of one percent of the earth’s surface (~0.01%, they efficiently sequester organic carbon due to high rates of primary production coupled with surfaces that aggrade in response to sea level rise. Here, we report on multi-decadal changes (1972–2008 in the extent of tidal marshes and mangroves, and characterize soil carbon density and source, for five regions of tidal wetlands located on Baja California’s Pacific coast. Land-cover change analysis indicates the stability of tidal wetlands relative to anthropogenic and climate change impacts over the past four decades, with most changes resulting from natural coastal processes that are unique to arid environments. The disturbance of wetland soils in this region (to a depth of 50 cm would liberate 2.55 Tg of organic carbon (C or 9.36 Tg CO2eq. Based on stoichiometry and carbon stable isotope ratios, the source of organic carbon in these wetland sediments is derived from a combination of wetland macrophyte, algal, and phytoplankton sources. The reconstruction of natural wetland dynamics in Baja California provides a counterpoint to the history of wetland destruction elsewhere in North America, and measurements provide new insights on the control of carbon sequestration in arid wetlands.

  9. Defendiendo la igualdad de la objeción de nivelar a la baja | Defending the Equality from the Levelling Down Objection

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    Silvina Ribotta

    2017-12-01

    Full Text Available Resumen: La objeción de nivelar a la baja es una de las principales objeciones que se le realizan a la igualdad, especialmente al igualitarismo como principio distributivo. Y cómo se responde a esta objeción, depende de qué tipo de igualitarismo se defienda y cuál sea, por lo tanto, la igualdad que se pretende. En el presente artículo, parto de una explicación general del concepto de igualdad y de los distintos tipos de igualitarismos y sus características centrales, para luego analizar los argumentos y justificaciones que dan los autores que discuten la objeción de nivelar a la baja. Todo ello con el objetivo de construir analíticamente una propuesta de igualdad más resistente. Abstract: The Levelling Down Objection is one of the main complaints against equality, specially against egalitarianism as a distributive principle. How this objection is responded depends on what version of egalitarianism is assumed, and therefore on which kind of equality is pursued. This article examines the concept of equality and the different egalitarian approaches as well as its main features. Then, the arguments and justifications given by the egalitarian authors to confront the levelling down objections are analyzed. The main goal is to analytically build a stronger more consistent idea of equality.

  10. Comparación entre ancianos sanos con alta y baja reserva cognitiva y ancianos con deterioro cognitivo / Comparison between Healthy Elderly with High and Low Cognitive Reserve and Cognitive Impairment Elderly

    OpenAIRE

    Juan Carlos Melendez Moral; Teresa Mayordomo Rodríguez; Alicia Sales Galán

    2013-01-01

    Este trabajo presenta la comparación de las características de sujetos con alta y baja reserva cognitiva, y sujetos con baja reserva cognitiva y deterioro cognitivo, diferenciados a partir del desarrollo de una medida ponderada de reserva cognitiva. Mediante un diseño correlacional se evaluaron 200 personas con edad superior a 65 años, no institucionalizados. Los resultados mostraron, por un lado, que el grupo de alta reserva cognitiva obtuvo mejores puntuaciones tanto en el nivel de deterior...

  11. Influencia de los factores agroclimáticos en la productividad de albahaca ( Ocimum basilicum L .) en una zona árida de Baja California Sur, México

    OpenAIRE

    Francisco Higinio Ruiz Espinoza; Pablo Marrero Labrador; Orestes Cruz La Paz; Bernardo Murillo Amador; José Luis García Hernández

    2008-01-01

    En la Universidad Autónoma de Baja California Sur situada al sur del Estado de Baja California Sur, México, se desarrolló un experimento durante 3 años (2002 2004). Evaluándose los datos climáticos en la zona, a partir de la información proporcionada por la Comisión Nacional del Agua. Las variables climáticas evaluadas fueron temperatura (T), humedad relativa (HR), evaporación (E), promediados por décadas para el período correspondiente al desarrollo de la investigación, mientras qu...

  12. Aproximación proteómica al estudio de la respuesta diferencial del metabolismo energético al estrés por bajas temeperaturas en tomate y pimiento

    OpenAIRE

    Sánchez-Bel, Paloma; Egea, Isabel; Sánchez-Ballesta, M. Teresa; Sevillano, Laura; Martínez-Madrid, Concepción; Romojaro, Félix; Bolarín, M. Carmen; Flores, Borja

    2012-01-01

    Tomate (Solanum lycopersicum) y pimiento (Capsicum annuum), son dos especies hortofrutícolas pertenecientes a la familia Solanaceae susceptibles a sufrir daños por frío cuando se almacenan a bajas temperaturas, lo que afecta seriamente a la calidad de los frutos, siendo causa de importantes pérdidas económicas en el sector agro-alimentario. Una de las principales respuestas celulares al estrés por bajas temperaturas consiste en el mantenimiento de la homeostasis osmótica por la acumulación de...

  13. Evaluación del rendimiento de sistemas de riego por aspersión de baja pluviosidad como resultado de la aplicación de la extensión como soporte técnico

    OpenAIRE

    Cisneros, F.; Pacheco T., E.

    2007-01-01

    La poca disponibilidad de agua, la baja productividad y la escasez de mano de obra son las principales razones que han motivado una propuesta de adaptación del sistema de riego por aspersión de baja pluviosidad y bajo costo en terreros de altas pendientes. Pasar del riego tradicional por surco a riego por aspersión, significa un enorme cambio tecnológico. La introducción de nuevas tecnologías sin acompañamiento de capacitación a menudo no logra los resultados que podrían ser obtenidos de apli...

  14. Baja diferenciación genética entre poblaciones de sardina, Sardinella aurita, del oriente venezolano

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available Debido a la gran importancia de Sardinella aurita como recurso pesquero de la región del Caribe, se estudió la diferenciación genética entre las poblaciones de Mochima, Golfo de Cariaco y Morro de Puerto Santo, en el oriente de Venezuela, y se compararon los niveles de variación y subdivisión poblacional con las poblaciones del Mediterráneo y la costa Atlántica de África, anteriormente reportadas. Para esto, se obtuvieron 15 individuos de cada una de tres poblaciones, utilizando una muestra de músculo para extraer el ADN total. Se amplificó un fragmento que incluye la región de control del ADN mitocondrial y se determinaron los patrones de restricción por medio del análisis por RFLP con las enzimas Taq I, Eco RI, Hae III y Alu I. La amplificación de esta región produjo un fragmento de aproximadamente 1000 bp o, rara vez, uno de 1100 pb. El análisis de RFLP demostró la presencia de sólo un haplotipo con las dos variantes de tamaño. El FST resultante del análisis de las diferencias entre poblaciones venezolanas fue menor de 0.06 y el AMOVA demostró que no existían diferencias significativas entre ellas. Estos resultados concuerdan con la presencia de poca diferenciación genética entre estas poblaciones, por lo que no se puede descartar la presencia de una población panmíctica en esta región. Una comparación de las poblaciones venezolanas con las poblaciones del Mediterráneo y África, reportadas con anterioridad, produjeron valores de FST muy bajos entre las venezolanas y las del Mediterráneo, mientras que las comparaciones entre las de Mauritania, Senegal, Costa de Marfil y Ghana produjeron valores de FST diez veces mayores.

  15. Hemorragia digestiva baja masiva en pacientes con enfermedad de Crohn Major acute bleeding in patients with Crohn's disease

    Directory of Open Access Journals (Sweden)

    M. Barreiro de Acosta

    2007-07-01

    Full Text Available Objetivo: analizar la frecuencia de las hemorragias masivas en la EC e intentar determinar sus potenciales factores de riesgo (ambientales, propios de la enfermedad y genéticos. Material y métodos: se estudió de manera retrospectiva una cohorte de 174 pacientes -103 mujeres (59% y 71 hombres (41%, edad media de 37 años- con EC, analizándose las hemorragias digestivas masivas que se habían producido en relación con su enfermedad. Se revisaron asimismo potenciales factores de riesgo como hábito tabáquico, localización de la enfermedad y presencia de mutaciones genéticas en CARD15, RTL-4 y CD14, entre otros. Resultados: tres pacientes (1,7% presentaron una hemorragia digestiva masiva que precisó intervención quirúrgica para su resolución. Esta indicación de cirugía supone el 3,4% de las cirugías en relación con la EC. Todos los pacientes eran jóvenes y su enfermedad seguía un patrón inflamatorio y estaba localizada en el íleon. No se ha evidenciado asociación estadísticamente significativa entre las hemorragias digestivas masivas y los potenciales factores de riesgo analizados. Conclusiones: la hemorragia digestiva baja masiva es una complicación poco común, aunque grave de la EC. Se trata habitualmente de pacientes con patrón inflamatorio de la enfermedad y afectación ileal. Para su diagnóstico resulta clave la asociación de endoscopia y arteriografía, y su resolución suele ser quirúrgica.Objective: we aimed at evaluating the frequency of acute severe bleeding in CD and its potential association to some risk factors, including clinical features of CD, environmental factors, and genetic alterations. Material and methods: 174 consecutive patients with CD (103 female (59% and 71 men (41%, with a mean age of 37 years were included. We analyzed all major acute lower gastrointestinal (GI hemorrhage related to CD. Potential risk factors like smoking, site of disease, and presence of gene mutations in CARD15, TLR-4, and

  16. Cadmium and phosphate variability during algal blooms of the dinoflagellate Lingulodinium polyedrum in Todos Santos Bay, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Mejia, E. [Posgrado en Oceanografía Costera, Instituto de Investigaciones Oceanológicas/Facultad de Ciencias Marinas, Universidad Autónoma de Baja California, Campus Sauzal, Carretera Transpeninsular Ensenada-Tijuana No. 3917, Ensenada, Baja California CP 22860 (Mexico); Lares, M.L., E-mail: llares@cicese.mx [División de Oceanología, Departamento de Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada, Km 107 Carretera Transpeninsular Ensenada-Tijuana, Ensenada, Baja California CP 22880 (Mexico); Huerta-Diaz, M.A.; Delgadillo-Hinojosa, F. [Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Campus Sauzal, Carretera Transpeninsular Ensenada-Tijuana No. 3917, Ensenada, Baja California CP 22860 (Mexico)

    2016-01-15

    Dinoflagellate algal blooms (DABs), with Lingulodinium polyedrum as the dominant species, have increased over the past few years in coastal areas off Baja California, Mexico. Vertical and temporal variability of particulate cadmium (Cd{sub p}), dissolved Cd (Cd{sub d}), PO{sub 4}{sup 3−} and Cd{sub d}/PO{sub 4}{sup 3−} were investigated during two intense DABs of L. polyedrum that occurred during the fall of 2011 and 2012 in Todos Santos Bay. Results were then, compared with data gathered in the absence of algal blooms during the autumn of 2013. In both algal blooms, L. polyedrum tended to be concentrated near the surface throughout the duration; however, during DAB 2011 the number of cells was twice as abundant ([10.0 ± 8.0] × 10{sup 5} cells L{sup −1}) as in DAB 2012 ([5.0 ± 4.4] × 10{sup 5} cells L{sup −1}). During DAB 2011, Cd{sub p} increased significantly (up to 1.02 ± 0.99 nmol kg{sup −1}) and was positively correlated with the cell abundance of L. polyedrum, suggesting that this dinoflagellate is able to assimilate and concentrate Cd{sub d}. Likewise, Cd{sub d} (up to 0.71 ± 0.17 nM) increased in the days of highest cell abundance, which could be attributed to uptake and subsequent regeneration of Cd{sub d} resulting from the remineralization of organic particulate matter produced during the bloom, as well as with the presence of organic ligands secreted by L. polyedrum that could keep Cd{sub d} in solution. During DAB 2011, dissolved Cd{sub d}/PO{sub 4}{sup 3−} ratios exhibited high vertical and temporal variability in the upper 5 m of the water column, but remained virtually constant near the bottom, suggesting a depth-dependent decoupling between these two dissolved components during the bloom development. Given the observed differences in the vertical and temporal variability of Cd{sub d}, Cd{sub p}, and PO{sub 4}{sup 3−} between these two intense DABs, we propose the existence of an abundance threshold of approximately 10{sup 6

  17. VARIACIONES EN BAJA FRECUENCIA DE LA PRECIPITACIÓN ESTACIONAL EN LA REGIÓN PAMPA AMARILLA Y POSIBLES FORZANTES

    Directory of Open Access Journals (Sweden)

    Germán Russián

    2015-06-01

    Full Text Available Se estudia el ciclo anual de precipitación en la región Pampa Amarilla (RPA. La mayor parte de la RPA presenta máximo en marzo, seguido de noviembre y diciembre, y mínimo en invierno. El acumulado octubre-marzo (verano resulta significativamente distinto al acumulado abril- septiembre (invierno. Se analizan las variaciones, tendencias y cambios de las series temporales en verano e invierno. Las series más largas seleccionadas sobre el centro y norte de La Pampa, muestran cambio positivo y significativo por tendencia lineal, del orden del 44% de la media regional en verano. Tras una prolongada sequía (1930-1950 el cambio estival irrumpe en la década de los setenta (centro-norte de La Pampa, y en la década de los sesenta (centro-este de La Pampa. Este cambio brusco ha producido una larga fase húmeda extendida hasta comienzos de los dos mil. El cambio de la década del setenta puede estar asociado al cambio de las condiciones medias de la Temperatura superficial del mar (TSM del Pacífico central ecuatorial. Para el período de prolongada fase húmeda (1969-2009 en el sector centro y norte de la RPA hay un aumento (disminución de las precipitaciones de verano (invierno mientras que hacia el centro-sudoeste de la RPA, los cambios son negativos y significativos. La exploración de la circulación troposférica y la TSM revela que la variabilidad interanual de la precipitación está modulada por teleconexiones remotas trópico-extratrópico. Se descarta cualquier posible relación con el Modo Anular del Sur. En verano, el mecanismo de interacción es la modulación de la corriente en chorro subtropical en el Pacífico Sur hacia Sudamérica, generada por anomalías en la circulación de la celda de Hadley sobre el Pacifico ecuatorial central. El mecanismo podría estar asociado a la baja y la alta frecuencia del fenómeno El Niño. En invierno, la teleconexión está dada por la propagación de ondas cuasi estacionarias de Rossby desde la

  18. Intolerância glicêmica e o prognóstico perinatal em gestantes utilizando anti-retrovirais

    Directory of Open Access Journals (Sweden)

    El Beitune Patrícia

    2003-01-01

    Full Text Available OBJETIVOS: estudar o efeito das drogas anti-retrovirais sobre o metabolismo glicêmico em gestantes portadoras do HIV-1 e a ação dessas medicações sobre o prognóstico perinatal. MÉTODOS: estudo prospectivo realizado em 57 gestantes divididas em três grupos: grupo AZT, utilizando zidovudina (n=20; grupo TT, utilizando zidovudina+lamivudina+nelfinavir (n=25, e grupo controle, gestantes normais (n=12. Obteve-se a área sob a curva (ASC das glicemias após teste oral de tolerância à glicose com 75 g de glicose em quatro oportunidades durante a gravidez (1º=14-20 semanas, 2º=21-26 semanas, 3º=27-32 semanas e 4º=33-38 semanas. O prognóstico perinatal levou em consideração as taxas de prematuridade, restrição de crescimento intra-útero (RCIU, baixo peso ao nascer, mortalidade perinatal e transmissão vertical do HIV-1. Os dados foram analisados utilizando-se os testes não paramétricos do c², de Friedman e de Kruskal-Wallis. RESULTADOS: os valores da mediana da ASC foi de 11.685 mg/dL-2h para o grupo controle, 13.477 mg/dL-2h para o grupo AZT e 13.650 mg/dL-2h para o grupo TT (p=0,049. Não se observou efeito deletério dos anti-retrovirais sobre as taxas de prematuridade, baixo peso ao nascer, RCIU e índices de Apgar. Não houve nenhum caso de transmissão vertical do HIV-1. CONCLUSÕES: verificou-se o desenvolvimento de intolerância glicêmica em gestantes que utilizaram tratamento tríplice, não sendo observado naquelas que utilizaram apenas AZT. Não houve efeitos deletérios dos anti-retrovirais sobre o prognóstico perinatal.

  19. Análise diferencial do proteoma da polpa do mamão durante o amadurecimento utilizando eletroforese bidimensional

    OpenAIRE

    Silvia Beserra Nogueira

    2010-01-01

    O mamão papaia (Carica papaya L.) é uma fruta tropical de grande relevância comercial uma vez que o Brasil é o maior produtor mundial e terceiro maior exportador da fruta. Contudo, por ser uma fruta climatérica, tem uma vida pós-colheita limitada, devido ao rápido Amaciamento da polpa. Neste trabalho foi realizada uma investigação proteômica comparativa de polpa do mamão verde e maduro. Várias centenas de componentes protéicos (spots) foram resolvidos em géis 2-DE (faixa de pH 4-7) utilizando...

  20. Procedimiento para la gestión de mantenimiento utilizando herramientas de la cuarta generación

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    Aracelis Barrios

    2013-01-01

    Full Text Available El presente artículo presenta el diseño de un procedimiento para una gestión de mantenimiento sistémico, utilizando un conjunto de herramientas, que enfocan el uso de los recursos de la empresa asociados con las Personas, los Procesos y la Tecnología, orientados a mejorar la productividad, la toma de decisiones acertadas y a maximizar el rendimiento de los equipos, considerando entre otros, los factores de Confiabilidad, Mantenibilidad, Seguridad, Calidad y Medio Ambiente. El desarrollo del procedimiento permite utilizar de manera sistémica, la información obtenida al aplicar el mantenimiento productivo total (TPM, el análisis de modo y efectos de las fallas del mantenimiento centrado en confiabilidad (RCM, para evaluar los riesgos causados por las fallas en los equipos mediante la aplicación de la Lógica Difusa.

  1. Rendimiento intelectual de niños-infantes antes a adolescentes de clase socio-económica media y baja de Lima y de algunas provincias

    Directory of Open Access Journals (Sweden)

    Alegría Majluf

    1984-06-01

    Full Text Available La recopilación y revisión de un conjunto de estudios comparativos referentes al rendimiento intelectual de niños peruanos (desde la infancia hasta la adolescencia conducidos por diferentes investigadores, muchos de ellos no publicados, muestran que: Los niños de las zonas marginales o de los Pueblos Jóvenes de Lima y de algunas provincias rinden intelectualmente, tanto en pruebas psicométricas y Piagetianas, en forma disminuida y significativamente más baja que los niños de las clases más acomodadas. La disminución intelectual constatada en estos niños tiende a acentuarse aún más con la edad y en las zonas rurales más que en las urbanas. Los varones, en general, muestran un desempeño mejor que las mujeres, aún en la infancia. El desarrollo físico de los niños de la Clase socio-económica baja es, así mismo, poco satisfactorio. Las medidas antropométricas revelan un deficiente desarrollo físico. Los niños que viven en la altura son de menor peso y estatura que los niños que viven en baja altura o en la Costa. Los pre-escolares de las zonas pauperizadas muestran, en general, inmadurez para el aprendizaje y posteriormente retraso en la lectura y en el rendimiento escolar. En conclusión, la disminución generalizada en el rendimiento intelectual, físico y escolar de los niños de las zonas marginales, la que parece acentuarse aún más con la edad y en las zonas rurales, evidencia la necesidad de estudiar en forma más sistemática el perfil del niño peruano para poder obtener normas nacionales y regionales, las que permitirán una mejor planificación de los programas de intervención integral.

  2. Diseño de circuitos integrados analógicos de baja potencia para acondicionamiento de señales débiles : Orientación a concepciones para microsistemas

    OpenAIRE

    Ceballos, José Luis

    2001-01-01

    El presente trabajo trata el diseño de circuitos integrados analógicos que implementan el procesamiento y acondicionamiento de señales eléctricas tanto de baja como de media frecuencia, presentando técnicas novedosas en las concepciones circuitales, y con una orientación a los Microsistemas. Departamento de Electrotecnia

  3. Utilización de placas de ELISA de alta y de baja avidez en la determinación de anticuerpos contra la toxina de cólera

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    Elizabeth Castañeda

    1998-06-01

    Full Text Available Los sueros de un estudio de inmunogenicidad de una vacuna oral de células enteras de Vibrio cholerae 01 más la subunidad B recombinante de la toxina (CEIsBr fueron procesados para la determinación de anticuerpos antitoxina de cólera en placas de ELlSA de alta y de baja avidez. Los títulos de anticuerpos antitoxina, de la clase IgG, de los sueros prevacunales estuvieron incrementados de 5 a 7 veces, en las placas de alta avidez, comparados con los títulos obtenidos en las placas de baja avidez. Igualmente, los títulos de los sueros post vacunales fueron 3 veces superiores cuando se realizó la misma comparación de placas. Por consiguiente, la tasa de seroconversión medida en las placas de alta avidez fue de 39%, comparada con 68% al utilizar las placas de baja avidez. El suero control de alto título de anticuerpos no detectó el problema. Se sugiere utilizar placas de baja avidez al determinar anticuerpos contra la toxina de cólera por la técnica de ELISA.

  4. Comparación entre ancianos sanos con alta y baja reserva cognitiva y ancianos con deterioro cognitivo / Comparison between Healthy Elderly with High and Low Cognitive Reserve and Cognitive Impairment Elderly

    Directory of Open Access Journals (Sweden)

    Juan Carlos Melendez Moral

    2013-03-01

    Full Text Available Este trabajo presenta la comparación de las características de sujetos con alta y baja reserva cognitiva, y sujetos con baja reserva cognitiva y deterioro cognitivo, diferenciados a partir del desarrollo de una medida ponderada de reserva cognitiva. Mediante un diseño correlacional se evaluaron 200 personas con edad superior a 65 años, no institucionalizados. Los resultados mostraron, por un lado, que el grupo de alta reserva cognitiva obtuvo mejores puntuaciones tanto en el nivel de deterioro cognitivo como en la medida ponderada de reserva que el grupo de baja reserva cognitiva y, por otro lado, el grupo de baja reserva cognitiva mostró un perfil similar al del grupo de deterioro cognitivo, existiendo solamente diferencias en cuanto a la edad. Las diferencias observadas permiten plantear la medida como una variable que se debe tener en cuenta en el diagnóstico de enfermedades neurodegenerativas y su utilidad para establecer posibles tratamientos.

  5. HISTERECTOMÍA TOTAL LAPAROSCÓPICA: RESULTADOS EN 3 AÑOS DE DESARROLLO DE LA TÉCNICA UTILIZANDO EL MANIPULADOR UTERINO DE CLERMONT FERRAND

    OpenAIRE

    Corvalán A.,Jaime; Roos T.,Andrés; Lattus O.,José; Barrera C.,Verónica; Gallardo E.,Ángela; Flores M.,José; Flores O.,Rodrigo; Fuentes A.,Verónica

    2004-01-01

    Damos a conocer una casuística de histerectomía total laparoscópica en un período de 3 años utilizando el manipulador uterino de Clermont Ferrand; se analizan los resultados, seguimiento y complicaciones

  6. El papel de los comités Pro-Estado en la creación del estado de Baja California

    Directory of Open Access Journals (Sweden)

    Lawrence Douglas Taylor

    1999-01-01

    Full Text Available El artículo trata del papel de los Comités Pro-Estado en la formación de Baja California como estado. Se analizan las raíces de la autonomía política en la península, que se remontan al Porfiriato, así como el impacto de la Revolución Mexicana sobre este proceso. Se examinan los diversos movimientos pro- estado que surgieron de 1929 en adelante la composición de sus grupos de integrantes, sus objetivos y contribuciones principales en términos de dirigir el sentimiento popular hacia la realización de esta meta.

  7. Efectos biológicos de la radiación láser de baja potencia en la reparación hística

    OpenAIRE

    María Isela Garrigo Andreu¹; Carolina Valiente Zaldívar²

    1996-01-01

    Se realiza una revisión bibliográfica sobre la literatura de los últimos 10 años, de investigaciones experimentales y clínicas sobre los efectos biológicos de la radiación láser de baja potencia en la reparación hística. Los posibles mecanismos de acción al nivel celular, en la producción de sustancia colágena, sobre las fibras colágenas, elásticas y vasos sanguíneos, su acción sobre la regeneración de fibras nerviosas y la cicatrización de tejido óseo.A review of the literature from the last...

  8. Diseño y construcción de sensores automatizados de gases de efecto invernadero en la baja troposfera

    OpenAIRE

    Palacios, Jesús; Falcón, Nelson; Muñoz, Erith

    2015-01-01

    La determinación del contenido de monóxido de carbono (CO) y metano (CH4) en la baja troposfera tiene gran importancia en los estudios de cambio climático y polución del aire. Por este motivo, este trabajo se enfocó en el diseño, construcción y calibración de un instrumento que permita medir la concentración de CO y CH4, además de la temperatura y presión ambiental. El dispositivo diseñado cuenta con un circuito de acople para los sensores de CO, CH4, temperatura y ...

  9. Emprendimientos de micro y pequeñas empresas mexicanas en un escenario local de crisis económica: El caso de Baja California, 2008-2011

    Directory of Open Access Journals (Sweden)

    Alejandro MUNGARAY LAGARDA

    2015-01-01

    Full Text Available En este trabajo se analiza la aplicación de una política pública regional que favorece el desa - rrollo de las micro y pequeñas empresas en la economía de Baja California para compensar l a generación de empleo. Mediante los modelos de regresión estimados, se encuentra que en un escenario de crisis económica global donde la producción y el empleo en la gran empresa se restringen y el trabajador es sustituido por procesos más tecnif i cados, la proliferación de micros y pequeñas empresas son un mecanismo compensatorio para minimizar los efectos del desempleo.

  10. Juventud, readaptación y sueños truncados: Centro de Diagnóstico para Adolescentes de Tijuana, Baja California

    Directory of Open Access Journals (Sweden)

    María Ruth Velázquez Gutiérrez

    2015-01-01

    Full Text Available la violencia no es un problema de pobreza o marginación; se vincula al deterioro de condi-ciones de vida, desintegración familiar y bajas expectativas de adolescentes y jóvenes en elfuturo.este abandono los orilla a conductas antisociales tipificadas en delincuencia juvenily su reclusión en el sistema penitenciario entijuana.el estudio sitúa en perspectiva las me-didas instrumentadas en elcentro de Diagnóstico paraadolescentes detijuana y sugierecambios en las prácticas de reinserción, por lo menos en lo educativo.el ejercicio se apoya enentrevistas con adolescentes recluidos para entender y explicar mejor este fenómeno.

  11. Arsenic and mercury contamination of sediments of geothermal springs, mangrove lagoon and the Santispac bight, Bahía Concepción, Baja California peninsula.

    Science.gov (United States)

    Leal-Acosta, María Luisa; Shumilin, Evgueni; Mirlean, Nicolai; Sapozhnikov, Dmitry; Gordeev, Vyacheslav

    2010-12-01

    In order to find out the environmental impact on the coastal zone, the composition of sediments of the intertidal geothermal hot spring zone and adjacent area of Playa Santispac in the pristine Bahía Concepción (Baja California peninsula) was studied. High concentrations of As (13-111 mg kg⁻¹) and Hg (0.55-25.2 mg kg⁻¹) were found in the sediments of the geothermal sources. Arsenic and Hg concentrations decrease rapidly in the adjacent small mangrove lagoon sediments and reach background levels (0.7-2.6 mg kg⁻¹ and 6-60 μg kg⁻¹ respectively) in the marine sediments collected in front of Playa Santispac.

  12. Administración de la pesquería del atún aleta azul en Baja California. Una visión global

    OpenAIRE

    Raúl Jesús del Moral Simanek; Juan Guillermo Vaca Rodríguez

    2009-01-01

    La administración de la pesquería del atún aleta azul en la región noroeste de nuestro país depende de contar con una visión global sobre este recurso, el cual México comparte, sobre todo, con Japón, cuya flota captura 74 por ciento y consume casi 100 por ciento de la producción total. Es importante considerar que esta especie desova al sur de Japón y que sólo parte del recurso migra hacia las costas mexicanas de la península de Baja California, por lo que el manejo que las autoridad...

  13. Transición de fase de baja temperatura en cerámicas de PZT ricas en circonio

    Directory of Open Access Journals (Sweden)

    Jiménez, B.

    1999-10-01

    correspondientes a las transiciones de fase ferroparaeléctrica. Teniendo en cuenta el diagrama de fases, las muestras con x<6% se encuentran en la fase antiferroeléctrica ortorrómbica y la que tiene la composición con x = 15% se encuentra en la fase ferroeléctrica con estructura romboédrica (RB en la zona de baja temperatura. En la composición con x = 5% todas las características medidas presentan anomalías a la temperatura de110ºC en el primer recorrido térmico subiendo la temperatura, donde se produce el cambio de fase antiferroeléctrica- ferroeléctrica con estructura romboédrica. En el recorrido de enfriamiento la fase ferroeléctrica se mantiene hasta los 28ºC, temperatura en que se pasa de nuevo a la fase antiferroeléctrica. Se produce, por tanto, una histéresis térmica muy grande. La temperatura de la transición ferro-ferroeléctrica de la composición x = 15% se comporta de acuerdo con el diagrama de fases y la de 3.5% con un aditivo de 2.5% de Nb tiene una temperatura de transición muy alejada de la que le correspondería por el diagrama de fases.

  14. Using Drone Imagery and Photogrammetry to Map Basin Stratigraphy and Structures Exposed in Mine, Road, and Arroyo Outcrops, Santa Rosalia, Baja California Sur, Mexico

    Science.gov (United States)

    Banes, A.; Alvarez Ortega, K. G.; Henry, M.; Niemi, T.

    2017-12-01

    During the 2017 Baja Basins Research Experience for Undergraduates (REU), a DJI Phantom 3 Advanced Quadcopter drone equipped with a GPS-enabled, 12 Megapixel camera was manually flown to collect aerial photographs of several geologic outcrops on the Minera Boléo and Lucifer mines in central Baja California Sur. The strip mine faces, roadcuts, and arroyos exposed Neogene to Quaternary sediments of the Santa Rosalía basin including the basal Cu-Zn-Mn-Co-bearing Miocene Boléo Formation that is actively being mined. It is overlain by Plio-Quaternary marine and non-marine deposits. Photographs were collected with a 70% overlap and processed into geographically-referenced, orthophotomosaics using Agisoft Photoscan. The output models have an adequate resolution for viewing bedding and fault characteristics. Measurements can be made inside the 3D models, making drones a useful tool for studying the geometry of stratigraphic, structural, and geomorphologic features. The studied sites included: 1) roadcuts on Mesa Soledad that exposed oblique-slip faults and syntectonically deposited non-marine and marine conglomerates and sandy, fossil-rich Pliocene beach sediment; 2) outcrops of the Boléo Fm in the Texcoco mine area that showed the detailed stratigraphic relationship between ore seams (mantos) and faults; 3) outcrops where sandstone samples were collected for detrital zircon geochronology; 4) strip mine 3120 that exposed faults and folds in the Boléo Formation; and 5) faults in Miocene volcanic rocks in the Arroyo Infierno near the Lucifer mine. This study shows that photogrammetry and modeling of geologic structures exposed in mine and road outcrops can provide useful information for reconstructing basin architecture and clarifying structural evolution of the Santa Rosalia Basin.

  15. Isopods of the genus Ligia as potential biomonitors of trace metals from the gulf of California and pacific coast of the Baja California peninsula.

    Science.gov (United States)

    García-Hernández, Jaqueline; Hurtado, Luis A; Leyva-García, Germán; Güido-Moreno, Adrián; Aguilera-Márquez, Daniela; Mazzei, Veronica; Ferrante, Margherita

    2015-02-01

    Supralittoral and high intertidal coastal zones are exposed to pollution from both marine and terrestrial sources and undergo higher deposition rates than the subtidal zone. It is therefore important to identify organisms for this section of the coastal area that can be tolerant to contaminants. The aim of this study was to determine if supralittoral isopods of the genus Ligia can be used as biomonitors, since they are abundant and widely distributed. For this purpose, concentrations of trace elements were determined in Ligia isopods in toto from 26 locations across the Gulf of California and Pacific coast of the Baja California peninsula, which were collected during the summers of 2009 and 2010. The concentrations of trace elements followed the order of; Zn≥Cu>As>Cd>Pb>Hg. Elevated concentrations of copper (up to 1010 μg/g) were detected in Ligia from Santa Rosalía (SRo), a locality where industrial mining of copper has historically occurred. Industrial and municipal sewage discharges appear to have contributed to the high concentrations of zinc (326 μg/g) and lead (144 μg/g) found in organisms from Guaymas location. The high mercury concentration in organisms from Mazatlán (M) (2.01 μg/g) was associated with a thermoelectric plant. Natural sources of metals were also detected; coastal upwelling appears to be associated with high cadmium concentrations in Ligia from Punta Baja (PB) (256 μg/g) in the Pacific coast, whereas hydrothermal vents may have contributed to high concentrations of arsenic at Ensenada (E) (61 μg/g). Our results suggest that Ligia isopods reflect the natural and anthropogenic inputs of trace metals in the environment and could potentially be used as biomonitor organisms of the intertidal rocky shores of the Gulf of California and Pacific coast. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. El impacto de las tecnologías de la información y comunicación en la industria manufacturera de Baja California

    Directory of Open Access Journals (Sweden)

    Lourdes Alicia González Torres

    2017-04-01

    Full Text Available En este artículo se analizó el comportamiento de la adopción de las tecnologías de la información y comunicación en los subsectores manufactureros de Baja California, para determinar sus efectos en los resultados económicos y los cambios que generan en las empresas. Para ello se utilizaron seis dimensiones del modelo desarrollado por Karmarkar y Mangal (2004, y con la tau-b de Kendall se calculó la correlación entre el grado de adopción de dichas tecnologías y los resultados económicos. Aunque éstos no se compararon con los de otros estudios, puesto que aquí sólo se seleccionó cierto tipo de empresas, se logró exponer la situación del sector manufacturero estatal, en relación con el uso de las tecnologías. Por lo que se puede concluir que la adopción de éstas influye positivamente en los resultados de las empresas. ________________________ This paper analyzes the performance of the adoption of information and communication technologies in manufacturing sub-sectors of Baja California in order to determine their effects on the economic results and the changes generated in the companies. For this purpose, six dimensions of the model developed by Karmarkar and Mangal (2004 were utilized, and using the Kendall’s tau-b the correlation between the level of adoption of such technologies and the economic results was calculated. Although these were not compared to those of other studies, since only certain types of companies were selected, the situation of state manufacturing sector was set out in relation to the use of these technologies. Therefore, it can be concluded that the adoption of such technologies has a positive influence on the performance of companies.

  17. Diálogo de saberes ambientales entre Europa-América. Agroecosistemas oasianos en Baja California Sur s. XVIII-XX

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    Ortega Santos, Antonio

    2015-06-01

    Full Text Available During two centuries, Oasis Communities of Baja California had been living in a intense connection with their environment. With the arrival of Jesuits, a deep extermination of biocultural heritage and socioenvironmental knowledges of these communities, repopulating of vegetable garden and drylands with people –in many cases, settler from the south of Spain- reconstructing the territorial identity as ranchera to manage the ecosystems under pattern of self-competence and under-consumption, due to the strong environmental constraints of lower california agro-ecosystem. At the beginning of XXIth century, Oasis Communities are fighting against the loss of community heritage, embedded in Eden with enormous bio-cultural dimension, rescuing and keeping crops from Europe with the Jesuits arrival. This frame allow us to draw a colonization process of ecosystems during contemporary age.Desde hace más de dos siglos, las Comunidades Oasianas de Baja California Sur han estado viviendo en íntima conexión con su medio ambiente. Con la llegada de los Jesuitas se produjo un intenso proceso de exterminio biocultural de los saberes sociambientales de esas comunidades, repoblando estas huertas y llanos con población -en muchos casos colonos- procedentes del sur de España-, redimensionado la identidad territorial como ranchera que gestionó los ecosistemas bajo pautas de autosuficiencia y subconsumo, dadas las fuertes constricciones socioambientales de agroecosistemas sudcalifornianos. A inicios del siglo XXI, las comunidades oasianas luchan contra la pérdida de sus saberes comunitarios, enclavados en edenes de enorme potencial biocultural, rescatando y manteniendo los cultivos traídos con la llegada de los jesuitas. Este marco nos permite describir un proceso de colonización de los ecosistemas a lo largo de los dos últimos siglos.

  18. Paralelización del Algoritmo Expectación–Maximización Utilizando OpenCL

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    Ernesto Insua-Suárez

    2014-12-01

    Full Text Available Actualmente, las organizaciones y empresas almacenan grandes volúmenes de datos para lograr sus propósitos. Una de las variantes para obtener información valiosa consiste en el empleo de la Minería de datos. Dentro de esta, existen diferentes tareas, una de ellas es el agrupamiento. En esta tarea los datos se agrupan según sus semejanzas entre si y diferencias con elementos de otros grupos. Dentro de los algoritmos que realizan estos agrupamientos se encuentra Expectación-Maximización, el cual presenta elevados tiempos de ejecución en la medida que aumenta el tamaño de los datos. En el presente artículo se discute acerca de la paralelización del algoritmo, utilizando técnicas de programación paralela. El diseño del algoritmo propuesto se basa en el uso de las tarjetas de procesamiento gráfico, GPU. OpenCL, lenguaje empleado para la programación en arquitecturas híbridas, permite aprovechar las arquitecturas de hardware disponibles, con lo que se logra disminuir el tiempo de ejecución de la implementación realizada. La razón principal por lo cual es posible mejorar este tiempo se debe a la cantidad de procesos paralelos que se pueden lanzar en hilos de procesamientos independientes. Para el logro de los resultados descritos se integran conocimientos del campo de la Minería de datos y la Computación Paralela y Distribuida. Como parte de esta investigación, se realizó una implementación del algoritmo utilizando las bibliotecas de OpenCL, para disminuir su tiempo de ejecución. La implementación logra disminuir en un 82% la implementación secuencial. Esto significa que el algoritmo paralelo se ejecuta 5,5 veces más rápido que su correspondiente implementación secuencial.

  19. Preditores de prováveis transtornos mentais comuns (TMC em prostitutas utilizando o Self-Reporting Questionnaire

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    Carlos Eduardo Leal Vidal

    2014-09-01

    Full Text Available Objetivo Avaliar a prevalência de prováveis transtornos mentais comuns (TMC e os fatores associados em um grupo de prostitutas de Minas Gerais. Métodos Estudo transversal utilizando o Self-Reporting Questionnaire (SRQ-20 em mulheres cadastradas na Associação de Prostitutas de Minas Gerais (Aprosmig. Avaliaram-se características sociodemográficas e aspectos do trabalho na prostituição. Teste do qui-quadrado foi empregado na análise de associação entre variáveis categóricas sociodemográficas e a presença de prováveis TMC. A análise dos fatores associados à presença de prováveis TMC foi realizada por meio de modelo de regressão logística. Resultados Foram entrevistadas 216 prostitutas. A prevalência global de prováveis TMC foi de 57,9%, mais observada em mulheres com baixa escolaridade, história de violência física e ingresso precoce na prostituição. Conclusão Os resultados deste estudo mostraram que a prevalência de prováveis TMC entre prostitutas foi superior à observada na população geral, indicando a necessidade de melhorar os cuidados com a saúde dessas mulheres.

  20. Análise Regional para Implantação de Aterro Sanitário Utilizando Software Livre

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    Carina Barbosa Colman

    2016-09-01

    Full Text Available Áreas com aptidão para implantação de aterro sanitário na região Sul do Estado de Mato Grosso do Sul, foram identificadas por meio de Sistemas de Informações Geográficas (SIG utilizando análise multicritério. Atribuíram-se pesos diferenciados para a determinação de áreas consideradas com ou sem restrição para instalação do referido aterro. As classes mais propícias para a instalação do aterro apresentam as maiores áreas (220.800 hectares, representando 78% da área de estudo, nos municípios de Tacuru e Iguatemi. As classes com maior restrição apresentaram-se pouco representativas na área estudada, cabendo ao município de Coronel Sapucaia, o maior quantitativo com cerca de 47 hectares. Fez-se aqui uma primeira aproximação desse tipo de estudo, pois a inclusão de outras variáveis de ordem socioambiental (opinião dos moradores locais,e normas como o Código Florestal e Zoneamento Ecológico Econômico, pode implicar em mais restrições e potencialidades para a localização desse tipo de empreendimento.

  1. HACIA EL AGARRE DE OBJETOS UTILIZANDO APRENDIZAJE ROBÓTICO POR IMITACIÓN Y DATOS DE FUERZA

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    Carlos Andrés Peña Solórzano

    Full Text Available En este artículo se trata el agarre de objetos en robótica. Específicamente, agarres de precisión y la fuerza requerida en los puntos de contacto entre la mano y el objeto para realizar una buena sujeción. Se propone adquirir los datos de sensores de fuerza utilizando un guante de datos y codificándolos mediante aprendizaje por imitación. Se utilizan imágenes RGB y de profundidad para determinar la ubicación y orientación de los objetos. Se prueban varias configuraciones mano-objeto en simulación, comparando la calidad del agarre al utilizar las fuerzas máximas, mínimas y promedio truncado. La variación de la calidad obtenida es pequeña y en algunos casos despreciable, permitiendo concluir que al seleccionar siempre las fuerzas máximas, se obtiene un agarre que se ajusta bien a múltiples configuraciones. Además, se presenta un sistema de adquisición de datos de fuerza de bajo costo y una etapa de procesamiento de imágenes que permite determinar la ubicación y orientación de los objetos.

  2. Aspectos ambientais e genéticos da prolificidade em caprinos utilizando modelos bayesianos de limiar e linear

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    N.P.S. Santos

    2013-06-01

    Full Text Available Foram estimados os componentes de variância e os parâmetros genéticos da característica prolificidade, utilizando-se inferência bayesiana sob modelo animal linear e de limiar. A prolificidade de cabras mestiças foi estudada com informações referentes ao período de oito anos consecutivos. As análises foram realizadas com cadeias de 500.000 ciclos. Considerou-se burn-in dos 15.000 valores iniciais, sendo tomados valores a cada 250 ciclos, para se obter a distribuição a posteriori com 1.940 amostras. Os efeitos do mês de cobrição e da ordem de parto e o efeito linear do peso à cobrição foram significativos. As herdabilidades foram de 0,03 e 0,18 para o modelo linear e o modelo de limiar, respectivamente. O uso do modelo de limiar mostrou-se adequado, produzindo estimativas superiores acerca dos parâmetros estimados.

  3. Validação Interna de Base de Conhecimentos utilizando Modelagem Matemática Bayesiana x Conexionista

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    Lucimar Fossatti de Carvalho

    2009-09-01

    Full Text Available Neste artigo, investigamos o aprendizado de máquina baseado na modelagem matemática envolvendo modelos bayesianos x conexionistas, aplicado no auxílio ao diagnóstico de eventos epilépticos (EEs e eventos não epilépticos (ENEs. Para esta finalidade alguns algoritmos de aprendizado de máquina foram comparados incluindo o aprendizado conexionista através das regras Delta Generalizada, Hebb, Oja, juntamente com o aprendizado em redes bayesianas. Foram considerados para este estudo 122 pacientes os quais apresentavam sintomas relacionados com EEs e ENEs. Os resultados empíricos desta pesquisa indicam que: (1 ambas as abordagens bayesianas e conexionistas são bastante similares, mostrando que os resultados são coerentes, mesmo utilizando heurísticas distintas; (2 o índice de acertos de casos positivos (EEs, por meio da modelagem bayesiana pode estar relacionado com a facilidade de implementação das probabilidades condicionais. Concluiu-se, portanto, que os modelos investigados fornecem informações importantes para o desenvolvimento de novas pesquisas tanto na área bayesiana como na área conexionista.

  4. Práticas experimentais no ensino de física nuclear utilizando material de baixo custo

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    Cleber Adelar Boff

    2017-05-01

    Full Text Available Uma das dificuldades para o Ensino de Física Moderna é a pouca difusão da experimentação, principalmente para o ensino de Física Nuclear, seja no Ensino Médio ou no Superior.  As atividades sugeridas na literatura geralmente simbolizam o fenômeno real através de simulações. Isso acontece, pois as práticas experimentais, geralmente, envolvem algum tipo de detector de radiação de custo elevado e uma fonte de radiação ionizante que requer cuidados especiais de manuseio e armazenagem, sendo sujeita a regulamentação altamente burocrática no Brasil. O presente trabalho supera estas dificuldades e propõe duas práticas de Física Nuclear experimental utilizando uma câmara de ionização de baixo custo: a medida de filhos do Radônio-222 coletados do ar de ambientes fechados, e a medida do alcance de partículas alfa emitidas pelos filhos do Tório-232 presentes em camisinhas de lampião. O artigo mostra os procedimentos experimentais e os resultados esperados, indicando que as práticas podem servir de suporte para aulas de Física Nuclear.

  5. CARACTERÍSTICAS MORFOLÓGICAS E VARIABILIDADE GENÉTICA DE ARATICUM UTILIZANDO MARCADORES RAPD E MICROSSATÉLITES

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    MARCELA VERSIANI VENÂNCIO PIRES

    2015-03-01

    Full Text Available RESUMO Neste trabalho, objetivou-se avaliar a variabilidade genética da coleção de trabalho de acessos de araticum da Embrapa Cerrados e outros materiais próximos ao Distrito Federal, utilizando marcadores moleculares RAPD, microssatélites e análise de características morfológicas. Folhas de 18 acessos de araticum foram coletadas e utilizadas para a extração das amostras de DNA genômico, as quais foram amplificadas para obtenção de marcadores moleculares RAPD e microssatélites. Na análise morfológica, foram avaliadas 23 características dos acessos de araticum. As dissimilaridades genéticas entre os 18 genótipos de araticum evidenciaram a variabilidade genética dos acessos e as análises de agrupamento levaram à formação de três grupos de similaridade. Verificaram-se coeficientes de dissimilaridades genéticas baixos entre os materiais oriundos da Embrapa Cerrados e altos entre os outros materiais. Esses acessos são importantes fontes de variabilidade para o enriquecimento da atual coleção de trabalho da Embrapa Cerrados e para futuros estudos de caracterização morfológica e agronômica.

  6. Degradación de toxafeno en medio líquido por Bjerkandera sp BOL13 utilizando diferentes sustratos

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    Martha Lacayo

    2006-12-01

    Full Text Available ESTE TRABAJO INVESTIGA LA DEGRADACIÓN DEL PLAGUICIDA toxafeno utilizando hongos producidos por la descomposición de la madera (white-rot fungus Bjerkandera sp BOL13. La especie Bjerkandera sp BOL13 degradó el toxafeno al utilizar tres diferentes sustratos (virutas de madera, cáscara de trigo y melaza de caña en medio líquido por un período de 38 días. Aproximadamente el 85% del toxafeno fue degradado cuando se utilizó la cáscara de trigo como sustrato principal. La producción de lignina peroxidasa (LiP fue solamente estimulada cuando la cáscara de trigo estuvo presente en el medio líquido. Aunque la enzima xilanasa se encontró en todos los sustratos, la cáscara de trigo soportó la más alta producción de xilanasa. Una cantidad insignificante de ß-glucosidasa y celulasa fueron encontradas en las muestras del medio líquido. Según la literatura, éste es el primer trabajo de investigación referente a la degradación de toxafeno con hongos Bjerkandera sp producidos por la descomposición de la madera

  7. Estudo de falhas em rolamentos provenientes de tensões e correntes parasitas utilizando o sensor Shaft Probe

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    Jorge Nei Brito

    2011-12-01

    Full Text Available Neste trabalho é apresentado um estudo de falhas em rolamentos provenientes de tensões e correntes parasitas que circulam no eixo do motor utilizando o sensor shaft probe. A análise de tensão e corrente parasita é uma técnica preditiva, recentemente lançada no mercado. O sensor é apoiado no eixo do motor e os sinais são coletados através do coletor/analisador de dados UltraSpec 8000. Os testes foram realizados em uma bancada onde os diferentes níveis de tensões e correntes foram introduzidos no rolamento dianteiro de um motor elétrico. Um gerador de corrente contínua acoplado ao motor, através de um acoplamento flexível, foi usado como sistema de carga. O objetivo é conhecer os níveis das amplitudes de tensão e corrente nos rolamentos, permitindo uma vida útil maior. A análise de vibração, por ser uma técnica preditiva tradicional, também foi utilizada para validação dos testes experimentais.

  8. Crecimiento y mortalidad de la madreperla Pinctada mazatlanica en poblaciones naturales del litoral oriental de Baja California Sur, México

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    Humberto Wright-López

    2009-06-01

    Full Text Available La madreperla Pinctada mazatlanica esta en veda desde 1939 y considerada en peligro de extinción, cambiando su categoría a protección especial en 1994. El presente estudio estima su crecimiento y mortalidad en bancos naturales en el periodo 1992-93 y 1997-99. Se registró el alto de la concha de ostras en poblaciones desde el paralelo 28º a 23º LN del litoral oriental de Baja California Sur, abarcando 38 estaciones, 2 bahías y 6 islas. La longitud máxima estimada fue 187.22mm (179.83-195.81mm, P > 0.95. Las frecuencias de longitud se ordenaron en un "año virtual". Los parámetros de crecimiento de von Bertalanffy estimados con el programa ELEFAN I fueron: o = 193.31mm, k=0.54año-1, t0= -0.1805 años, C=0.49 y WP=0.75; el índice de desempeño del crecimiento fue’=4.305. La mortalidad total fue de Z=2.03 año-1 por longitud convertida a curva de captura. La regresión peso total y la altura tuvo la expresión W(i=0.0005418 * L(i2.7301. Los parámetros de crecimiento fueron similares a los de Pinctada margaritifera de bancos de mar abierto y diferentes a aquellos de ostras perleras en repoblamiento en bahía de La Paz. La mortalidad mostró valores parecidos a los estimados para Pinctada radiata del Mar Rojo.Growth and mortality of the mother-of-pearl Pinctada mazatlanica in natural populations of the east coast of Baja California Sur, Mexico. The Mexican Pacific mother-of-pearl Pinctada mazatlanica was placed in forbidden fisheries status for the Mexican Federal Government and considered in extinction danger since 1939. This decree was modified in 1994 to allow the capture of spat for research or marine culture. We estimated the growth and mortality of mother-of-pearl from the eastern littoral of South Baja California wild stock in the periods 1992-93 and 1997-99. We used 38 sample stations at 2 bays and 6 insular complexes. The maximum length was 187.22 mm (179.83-195.81 mm, P > 0.95. Seasonal von Bertalanffy growth (ELEFAN I routine

  9. CORRECCION DE ILUMINACION PARA IMAGENES AEREAS DE CULTIVOS TOMADAS A BAJA ALTITUD ILLUMINATION CORRECTION FOR AERIAL AGRICULTURE IMAGES TAKEN AT LOW ALTITUDE

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    Juan Camilo Mejía Ospina

    2007-12-01

    Full Text Available En este trabajo se propone un método para realizar correcciones de color de imágenes aéreas de cultivos tomadas a baja altitud, en diferentes fechas, horas y condiciones de nubosidad. El método no requiere que la escena posea superficies o datos concretos que sirvan de estándar para realizar la corrección sobre la iluminación presente. El está basado en la técnica de constancia de color llamada gamut mapping, a la cual se le han hecho algunas variaciones aprovechando las características propias de las imágenes aéreas. El método permite, para imágenes capturadas bajo diferentes condiciones de iluminación, su normalización de modo que sean comparables entre ellas. En particular se aplicó a plantaciones de banano, pero puede ser extendido a cualquier tipo de cultivo, siempre que se utilice fotografía aérea de baja altitud. Se probó y validó usando imágenes simuladas debido a las dificultades encontradas durante la etapa de adquisición de imágenes reales.A new method is presented in order to carry out the color corrections of aerial agriculture images taken at low altitude, in different dates, times and conditions of cloudiness. The method does not require scene targets or specific data in order to develop the correction of the actual illumination. It is based on the constancy of color technique called gamut mapping, which was adapted to take advantage of the own characteristics of the aerial images. For images captured under different conditions of illumination, the method allows its normalization for comparison purposes. It was applied to banana plantations, but it can be extended to any type of agriculture images, registered by aerial images at low altitude. It was proven and validated using synthetic images because of some difficulties found during the acquisition stage of real images.

  10. The role of tropical cyclones on landscape dynamics in southern Baja California, Mexico based on Late Pleistocene-Holocene alluvial stratigraphy

    Science.gov (United States)

    McDonald, Eric; Antinao, Jose Luis; Rhodes, Edward J.; Brown, Nathan; Gosse, John

    2015-04-01

    Region-wide alluvial records provide evidence that time-transgressive changes in climate can be a major driver of landscape evolution. Historically, landfall of eastern Pacific tropical cyclones in southwestern North America during the late summer and early fall provide the strongest storms that have demonstrated geomorphic impact on the landscape. The alluvial fan record of the southern portion of Baja California (Mexico) was investigated to determine if linkages exist between region-wide fluvial deposits and tropical cyclones. The regional distribution and Pleistocene to Holocene morphostratigraphy of alluvial fans has been established for the southern portion of Baja California with primary focus on the La Paz and San José del Cabo basins. Six discrete morphopedosedimentary alluvial units (Qt1 through Qt6) were differentiated across the region using a combination of geomorphologic mapping, sedimentological analysis, and soil development further reinforced with geochronology using radiocarbon, optically stimulated luminescence and cosmogenic depth-profiles. A first phase of regional aggradation began before ~ 100 ka (Qt1) and culminated ~10 ka (Qt4). After deposition of Qt4, increasing regional incision of older units and the progressive development of a channelized alluvial landscape coincide with deposition of Qt5 and Qt6 units in a second, incisional phase. All units are conformed of multiple 1-3 m thick alluvial packages deposited in upper-flow regime and representing individual storms. Aggradational units (Qt1-Qt4) covered broad (>2 km) channels in the form of sheetflood deposition while incisional stage deposits are mostly confined to channels of ~0.5-2 km width. Continuous deposition of the thicker sequences is demonstrated by closely spaced luminescence dates in vertical profiles. In a few places disconformities between major units are evident and indicated by partly eroded buried soils. Analysis of historical terraces as part of the younger units

  11. Placental biomarkers of PAH exposure and glutathione-S-transferase biotransformation enzymes in an obstetric population from Tijuana, Baja California, Mexico

    International Nuclear Information System (INIS)

    Dodd-Butera, Teresa; Quintana, Penelope J.E.; Ramirez-Zetina, Martha; Batista-Castro, Ana C.; Sierra, Maria M.; Shaputnic, Carolyn; Garcia-Castillo, Maura; Ingmanson, Sonja; Hull, Stacy

    2017-01-01

    Environmental exposures along the US-Mexico border have the potential to adversely affect the maternal-fetal environment. The purpose of this study was to assess placental biomarkers of environmental exposures in an obstetric population at the California-Baja California border in relation to detoxifying enzymes in the placenta and nutritional status. This study was conducted on consenting, full-term, obstetric patients (n=54), delivering in a hospital in Tijuana, Baja California (BC), Mexico. Placental polyaromatic hydrocarbon (PAH)-DNA adducts were measured in addition to placental glutathione-S-transferase (GST) activity and genotype, maternal serum folate, and maternal and umbilical cord blood lead and cadmium levels. A questionnaire was administered to the mothers to determine maternal occupation in a maquiladora, other exposures, and obstetric indicators. In univariate analysis, maternal serum folate levels were inversely correlated with total PAH-DNA adducts (rho=−0.375, p=0.007); adduct #1 (rho=−0.388, p=0.005); and adduct #3 (rho =−0.430, p=0.002). Maternal lead levels were significantly positively correlated with cord blood lead levels (rho=0.512, p<0.001). Cadmium levels were generally very low but significantly higher in mothers exposed to environmental tobacco smoke (ETS) (either at work or at home, n=10). In multivariate analysis, only maternal serum folate levels remained as a significant negative predictor of total DNA-PAH adducts levels in placenta. These findings affirm that placental tissue is a valuable and readily available source of human tissue for biomonitoring; and indicate that further study of the role of nutrition in detoxification and mitigation of environmental exposures in pregnant women is warranted. - Highlights: • Maternal-fetal environment susceptible to toxic exposures at US-Mexico border. • Lower serum folate was correlated with higher PAH-DNA adduct levels at birth. • Placental DNA adducts in GST mu (-) cord blood

  12. Numerical simulation of groundwater artificial recharge in a semiarid-climate basin of northwest Mexico, case study the Guadalupe Valley Aquifer, Baja California

    Science.gov (United States)

    Campos-Gaytan, J. R.; Herrera-Oliva, C. S.

    2013-05-01

    In this study was analyzed through a regional groundwater flow model the effects on groundwater levels caused by the application of different future groundwater management scenarios (2007-2025) at the Guadalupe Valley, in Baja California, Mexico. Among these studied alternatives are those scenarios designed in order to evaluate the possible effects generated for the groundwater artificial recharge in order to satisfy a future water demand with an extraction volume considered as sustainable. The State of Baja California has been subject to an increment of the agricultural, urban and industrials activities, implicating a growing water-demand. However, the State is characterized by its semiarid-climate with low surface water availability; therefore, has resulted in an extensive use of groundwater in local aquifer. Water level measurements indicate there has been a decline in water levels in the Guadalupe Valley for the past 30 years. The Guadalupe Valley aquifer represents one the major sources of water supply in Ensenada region. It supplies about 25% of the water distributed by the public water supplier at the city of Ensenada and in addition constitutes the main water resource for the local wine industries. Artificially recharging the groundwater system is one water resource option available to the study zone, in response to increasing water demand. The existing water supply system for the Guadalupe Valley and the city of Ensenada is limited since water use demand periods in 5 to 10 years or less will require the construction of additional facilities. To prepare for this short-term demand, one option available to water managers is to bring up to approximately 3.0 Mm3/year of treated water of the city of Ensenada into the valley during the low-demand winter months, artificially recharge the groundwater system, and withdraw the water to meet the summer demands. A 2- Dimensional groundwater flow was used to evaluate the effects of the groundwater artificial recharge

  13. Tectono-stratigraphic evolution of the Comondú Group from Bahía de La Paz to Loreto, Baja California Sur, Mexico

    Science.gov (United States)

    Drake, William R.; Umhoefer, Paul J.; Griffiths, Alexis; Vlad, Ann; Peters, Lisa; McIntosh, William

    2017-11-01

    The late Oligocene to mid-Miocene volcanic and volcaniclastic rocks of the Comondú Group are well exposed along the Main Rift Escarpment of Baja California Sur from the Bahía de La Paz region to Bahía Concepción. New mapping and stratigraphic analysis of the Comondú Group from Bahía de La Paz to Loreto reveal facies trends and correlations that form the foundation for a continuous stratigraphic framework for the Comondú Group along a 300 km-long transect on the eastern coast of the Baja California peninsula. Broad but distinct lithostratigraphic trends, alluvial fan facies, and volcanic and volcaniclastic facies record an overall coarsening-upwards package that includes ignimbrite deposits within increasingly proximal alluvial fan deposits, both derived from the east. Geochronology of the unit, including 32 isotope ages and 12 previously unpublished 40Ar/39Ar ages, provide the timing of four main increasingly proximal depositional events. Non-marine sandstone, defining the base of the Comondú Group, was first deposited between 26 Ma and 24 Ma. Emplacement of rhyolitic ignimbrites initiated between 24 Ma and 23 Ma and marked a westward expansion of volcanic activity affiliated with the Sierra Madre Occidental ignimbrite sequences in southern Sinaloa, western Durango, and northern Nayarit. A change in volcanism occurred at 19 Ma to 18 Ma with more ignimbrites, increased intermediate compositions, and the appearance of local vents and proximal volcanic facies. A final localized change of volcanism occurred from 14 to 12 Ma in the Loreto area with an increase of proximal alluvial fan deposits and local volcanoes in the Upper Comondú Group. The bulk of the Upper Comondú Group is absent south of the Loreto area and has either been removed by erosion as a source for the Magdalena Fan in the Pacific Ocean, or was focused primarily in the Loreto area and northward. We use a pre-rift tectonic reconstruction of the Gulf of California to align broad stratigraphic

  14. Eruption and magma crystallization ages of Las Tres Vírgenes (Baja California) constrained by combined 230Th/ 238U and (U-Th)/He dating of zircon

    Science.gov (United States)

    Schmitt, Axel K.; Stockli, Daniel F.; Hausback, Brian P.

    2006-11-01

    Las Tres Vírgenes volcano is a calc-alkaline composite cone located near the main Gulf of California escarpment on the E coast of the Baja California peninsula. High-sensitivity ion microprobe U-series ( 230Th/ 238U) ages for zircon from La Vírgen tephra average 121 - 10 + 12 ka (1σ; MSWD = 2.7), with discrete age peaks at ˜ 100 and 160 ka. The noble gas mass spectrometric (U-Th)/He zircon age, corrected for disequilibrium and pre-eruptive storage, is 36 ± 3 ka. This result for the eruption age of La Vírgen tephra is significantly older than previously postulated historic or Holocene ages that were based on an 18th century map reference and 14C dating of accidental charcoal, respectively. The new (U-Th)/He zircon age is consistent with a > 26 ± 4 ka age derived from cosmogenic He exposure dating of an overlying basaltic lava flow [Hausback, B.P. and Abrams, M.J., 1996. Plinian eruption of La Virgen Tephra, Volcán Las Tres Virgenes, Baja California Sur, Mexico. Eos, Transactions, American Geophysical Union, 77(46, Suppl.): 813-814.]. U-Pb zircon analysis of ignimbrites erupted from the adjacent Early Pleistocene La Reforma and El Aguajito calderas yielded ages of 1.38 ± 0.03 Ma ( n = 12; MSWD = 1.0) and 1.17 ± 0.07 Ma ( n = 23; MSWD = 1.3), respectively. No evidence for these ages is found among La Vírgen zircons, whereas pre-Quaternary zircon xenocrysts are common. The La Vírgen magma, therefore, evolved unrelated to Early Pleistocene magmatism in adjacent calderas, but assimilated local basement rocks. A gap between average Th-U and (U-Th)/He zircon ages suggests that zircon crystallization was discontinuous in the La Vírgen magma chamber. In addition, partial resorption of zircon suggests episodic thermal rejuvenation, most likely by basaltic recharge. Based on the zircon record, the > 100 ka lifetime of the thermal anomaly that sustained repeated intrusive pulses significantly exceeds the age of the last eruption. This strengthens the view that Tres

  15. Advances in understanding the tectonic evolution of the Santa Rosalia Basin and its stratiform ore deposits: Results of the Baja Basins Research Experience for Undergraduates

    Science.gov (United States)

    Niemi, T. M.; Busby, C.; Murowchick, J. B.; Martinez Gutierrez, G.; Antinao Rojas, J. L.; Graettinger, A.; Dorsey, R. J.

    2017-12-01

    Studies conducted during the three years of the Baja Basins REU program made progress toward solving a number of geologic questions in the Santa Rosalía Basin (SRB) of central Baja California. Geochemistry and 40Ar/39Ar geochronology on volcanic rocks within the SRB record the transition from subduction (13.32-9.95 Ma) to rifting (younger than 9.42 Ma) prior to deposition of the upper Miocene Boleo Formation. In contrast, magnesian andesite lavas and intrusions on the south margin of the SRB are dated at 6.1 +/- 0.3 Ma, and may have provided the heat engine for Boleo basin mineralization, which occurs in stratabound layers called "mantos". Mineralizing fluids in the Boleo Fm had near-neutral pH, evolved from a low Eh to more oxidizing conditions, were relatively low-temperature (near ambient T during manto ore deposition), and likely derived the Cu, Zn, Co, and Mn by leaching of mafic minerals in the volcanic rocks underlying the basin. Deposition of the ores was driven by oxidation as warm spring fluids vented to subaerial or near-shore marine environments, producing blankets of precipitated oxides interlayered with detrital fine to very coarse clastic beds. Integration of geologic map and fault data with detailed sedimentology and stratigraphic analysis provides evidence for syn-basinal tilting in two orthogonal directions during deposition of the Boleo Formation and Plio-Quaternary Tirabuzón, Infierno, and Santa Rosalia formations. Pronounced tilting toward the SE is revealed by southeastward thickening and coarsening of deposits in the Boleo Formation, and was synchronous with northeastward tilting and thickening due to slip on a network of NW-striking oblique normal faults. We hypothesize that the basin formed, subsided, and deformed as a pull-apart basin in a releasing step-over between two propagating transform faults that opened the late Miocene Gulf of California. The neotectonic evolution and uplift history of the SRB is documented through mapping of

  16. Diseño y Análisis de desempeño de un inversor de voltaje utilizando controladores inteligentes

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    Juan jose Salazar

    2013-11-01

    Full Text Available El presente documento describe el desarrollo de controladores inteligentes, para la supresión de armónicos en inversores monofásicos con modulación senoidal por ancho de pulso (SPWM. En la primera fase se diseño un controlador PI que sirve como modelo de referencia para la obtención de los patrones de entrenamiento de la red neuronal. Posteriormente se diseño un controlador PD lógico difuso utilizando una base de 25 reglas. Las simulaciones realizadas con el mkodelo matemático del inversor y utilizando "SimPowerSystems" de MATLAB indican que es posible obtener una onda senoidal pura con un mínimo de distorsión armónica total (THD mediante el uso de los controladores inteligentes propuestos.

  17. UTILIZAÇÃO DE UM SISTEMA PARA A REDUÇÃO DO ÁCIDO CIANÍDRICO PRESENTE NA MANIPUEIRA UTILIZANDO ENERGIA SOLAR

    OpenAIRE

    Rebouças, Cyrus Santos; de Freitas, Andrea Gonçalves Bueno; Universidade Federal de Sergipe; Bery, Carla Crislan de Souza; Universidade Federal de Sergipe; da Silva, Isabelly Pereira; Universidade Federal de Sergipe; Oliveira Júnior, Antônio Martins de; Universidade Federal de Sergipe- UFS; da Silva, Gabriel Francisco; Universidade Federal de Sergipe-UFS

    2015-01-01

    O objetivo deste trabalho é avaliar a cinética de remoção do ácido cianídrico (HCN) presente na manipueira, coletada de casas de farinhas do estado de Sergipe, utilizando como meio de remoção do mesmo um sistema solar, conhecido como concentrador solar do tipo linear, de seção parabólica, cilíndrico e articulado em apenas um eixo.

  18. Prevalencia del síndrome de Down en México utilizando los certificados de nacimiento vivo y de muerte fetal durante el periodo 2008-2011

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    María del Carmen Sierra Romero

    2014-09-01

    Conclusiones: La importancia de este trabajo radica en iniciar una vigilancia epidemiológica del recién nacido con SD a nivel nacional y por entidad federativa, utilizando sistemas de información censales disponibles en el país a partir del 2008. Se observó un aumento en el riesgo de tener un hijo con SD a partir de los 35 años de edad materna, como ha sido reportado en otros estudios.

  19. EFECTO DEL CONTENIDO DE SODIO EN LA OBTENCIÓN DE Na+ -B-ALÚMINA UTILIZANDO EL MÉTODO DE PRECURSOR POLIMÉRICO

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    VANESSA RUIZ

    2011-01-01

    Full Text Available En este trabajo se muestran los resultados obtenidos al emplear el metodo de precursor polimerico (Pechini para sintetizar polvos ceramicos de Na + B Àalumina, utilizando sales inorganicas, tomando como parametro de estudio la cantidad inicial del precursor de sodio y su efecto sobre la fase cristalina obtenida al final del proceso. Los polvos fueron caracterizados utilizando espectroscopia Infrarroja (FTIR, Difraccion de Rayos X (DRX y Microscopia Electronica de Barrido (MEB. Se encontro que el efecto de la cantidad de sodio inicial en la muestra es determinante en la naturaleza del producto final obtenido. Utilizando la cantidad estequiometrica de NaOH requerida, para la obtencion del compuesto NaAl11O17, se obtuvo al final del proceso (1450oC a-alumina y B-alumina y/o Na2Al2xO3x1 en muestras tratadas termicamente entre 1000oC y 1350oC. Cuando se uso una mayor cantidad de NaOH, muestra no estequiometrica, se obtuvo un solido con el compuesto NaAl11O17 como fase mayoritaria.

  20. Instalación eléctrica en baja tensión y centro de transformación de una nave industrial de fabricación de llantas

    OpenAIRE

    Urdánoz Ciriza, José Javier

    2010-01-01

    En el siguiente proyecto se va a describir la instalación eléctrica en baja tensión de una nave industrial dedicada al mecanizado y pintura de llantas de aleación para coches. La instalación eléctrica constará de: - Instalación de alumbrado general tanto interior como exterior, de emergencia y de señalización. - Instalación de fuerza y tomas de corriente. - Centro de transformación de media a baja tensión. - Protección eléctrica de las líneas que alimentan todas las in...

  1. Las armas como concepto fiscal y de diferenciación social en la Baja Edad Media (Aplicación al caso de Ciudad Rodrigo

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    Bernal Estévez, Angel

    1988-12-01

    Full Text Available La organización fiscal medieval es un aspecto que da carácter a la población. Podría decirse que la simple estratificación social en estamentos se consagra en la práctica con un planteamiento fiscal selectivo que obedece a esa división jurídica. El concepto de exento o de pechero, que viene a ser casi lo mismo que decir privilegiado o no privilegiado, es tan explícito, claro y significativo para una gran parte de la población —salvando ciertas excepciones—, que da base a una definición generalizadora '. ¿Podría decirse que la esencia o el factor definidor de esta situación disyuntiva son las armas y/o el oficio de las arcas? Sin ningún género de dudas. Se puede comprobar a través de una visión general de los estamentos que conforman la sociedad medieval y de su evolución a lo largo de toda la Baja Edad Media.

  2. Captura de atún aleta azul en Baja California, México: ¿pesquería regional o maquiladora marina?

    Directory of Open Access Journals (Sweden)

    Raúl Jesús del Moral-Simanek

    2009-01-01

    Full Text Available El atún aleta azul, capturado por la flota mexicana en las costas de la península de Baja California, se destinaba al enlatado local, para ofrecer a los consumidores nacionales un producto barato y con valor nutritivo alto. Sin embargo, esto cambió en la última década con la llegada de inversionistas, sobre todo japoneses. Ahora el atún se captura, engorda y exporta a los mercados japonés y estadounidense, que pagan un precio elevado, para satisfacer su demanda de sashimi. Esto tiene repercusiones positivas en el orden social y económico en México y Japón; determinadas a partir del trabajo de campo directo e indirecto realizado en el marco de esta investigación. Además, se identificaron algunas similitudes entre el comportamiento de las empresas estudiadas y la industria maquiladora de exportación, lo que abrió un debate sobre el tema.

  3. La incorporación de la nobleza al alto clero en el reino de Castilla durante la Baja Edad Media

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    Díaz Ibáñez, Jorge

    2005-12-01

    Full Text Available In this article we study how a lot of clergymen members of the castillan nobility joined, between 13th and 15th centuries, to the high ecclesiastical hierarchy of the kingdom, mainly to the Episcopacy and chapters of the cathedrals, where there will be clergymen proceeding from low nobility and also from high noble families like Manrique, Carrillo, Fonseca, Mendoza, Albornoz, Gómez de Toledo, Guzman or Luna.

    En este artículo se estudia cómo muchos clérigos procedentes de la nobleza castellana alcanzaron entre los siglos XIII y XIV la más alta jerarquía eclesiástica del reino, sobre todo dentro del episcopado y en los cabildos catedralicios, donde habrá tanto clérigos procedentes de la baja y mediana nobleza como de grandes linajes tales como los Manrique, Carrillo, Fonseca, Mendoza, Albornoz, Gómez de Toledo, Guzman o Luna.

  4. Spatio-temporal evolution of aseismic ground deformation in the Mexicali Valley (Baja California, Mexico from 1993 to 2010, using differential SAR interferometry

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    O. Sarychikhina

    2015-11-01

    Full Text Available Ground deformation in Mexicali Valley, Baja California, Mexico, the southern part of the Mexicali-Imperial valley, is influenced by active tectonics and human activity, mainly that of geothermal fluid extraction in the Cerro Prieto Geothermal Field. Significant ground deformation, mainly subsidence (~ 18 cm yr−1, and related ground fissures cause severe damage to local infrastructure. The technique of Differential Synthetic Aperture Radar Interferometry (DInSAR has been demonstrated to be a very effective remote sensing tool for accurately measuring the spatial and temporal evolution of ground displacements over broad areas. In present study ERS-1/2 SAR and ENVISAT ASAR images acquired between 1993 and 2010 were used to perform a historical analysis of aseismic ground deformation in Mexicali Valley, in an attempt to evaluate its spatio-temporal evolution and improve the understanding of its dynamic. For this purpose, the conventional 2-pass DInSAR was used to generate interferograms which were used in stacking procedure to produce maps of annual aseismic ground deformation rates for different periods. Differential interferograms that included strong co-seismic deformation signals were not included in the stacking and analysis. The changes in the ground deformation pattern and rate were identified. The main changes occur between 2000 and 2005 and include increasing deformation rate in the recharge zone and decreasing deformation rate in the western part of the CPGF production zone. We suggested that these changes are mainly caused by production development in the Cerro Prieto Geothermal Field.

  5. Geological and Sedimentological Evidence of a Large Tsunami Occurring ~1100 Year BP from a Small Coastal Lake along the Bay of La Paz in Baja California Sur, Mexico

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    Terrence A. McCloskey

    2015-12-01

    Full Text Available The importance of small-scale seismic events in enclosed water bodies, which can result in large tsunami waves capable of affecting comprehensive damage over small, geographically-confined areas are generally overlooked, although recognizing the occurrence of such events is a necessary element in adequately assessing the risk of natural hazards at specific locations. Here we present evidence for a probable large localized tsunami that occurred within the Bay of La Paz, Baja California Sur, ~1100 year before present (BP, which resulted in the creation of a shelly ridge at an elevation of ~2 m above mean high water (MHW. This ridge consists of a continuous wedge of poorly mixed marine sands and shells ~50 cm in depth deposited along the entire seaward edge of the lake. The marine shells collected from terrestrial environments around the lake include species from a variety of environments, including offshore species with minimum preferred depths of >13 m. The evidence suggests that this material was likely deposited by a tsunami with a runup of 2–3.6 m above MHW, probably associated with the slumping of an island along the tectonically active eastern edge of the bay.

  6. El turismo alternativo: una opción para el desarrollo local en dos comunidades indígenas de Baja California

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    Nora L. Bringas R.

    2004-01-01

    Full Text Available Se analiza la relación entre desarrollo local, turismo alternativo y sustentabilidad. Nuestro punto de partida radica en la inquietud proveniente de dos de las comunidades indígenas de Baja California, México, la cual refiere a la exploración del turismo alternativo como una vía para el desarrollo. Aclaramos que los casos que analizamos no se refieren a una evaluación a posteriori del desarrollo de un proyecto de corte turístico. Más bien, este trabajo se enfoca en analizar la puesta en marcha de dicho proyecto: el surgimiento, la movilización y el involucramiento de nuevos actores con variados mecanismos de actuación y distintas capacidades, intereses y ámbitos de influencia. Esto nos permite ofrecer, a manera de contexto, algunos elementos necesarios para la estructuración de políticas para un turismo de corte alternativo enmarcadas en la sustentabilidad.

  7. Can the Adoption of Desalination Technology Lead to Aquifer Preservation? A Case Study of a Sociotechnical Water System in Baja California Sur, Mexico

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    Jamie McEvoy

    2015-09-01

    Full Text Available There is growing concern about the sustainability of groundwater supplies worldwide. In many regions, desalination—the conversion of saline water to freshwater—is viewed as a way to increase water supplies and reduce pressure on overdrawn aquifers. Using data from reports, articles, interviews, a survey, and a focus group, this paper examines if, and how, the adoption of desalination technology can lead to aquifer preservation in Baja California Sur (BCS, Mexico. The paper outlines existing institutional arrangements (i.e., laws, rules, norms, or organizations surrounding desalination in BCS and concludes that there are currently no effective mechanisms to ensure aquifer preservation. Four mechanisms that could be implemented to improve groundwater management are identified, including: 1 integrated water-and land-use planning; 2 creation of an institute responsible for coordinated and consistent planning; 3 improved groundwater monitoring; and 4 implementation of water conservation measures prior to the adoption of desalination technology. This paper concludes that viewing water technologies, including desalination, as sociotechnical systems—i.e., a set of technological components that are embedded in complex social, political, and economic contexts—has the potential to create a more sustainable human–environment–technology relationship. By assessing desalination technology as a sociotechnical system, this study highlights the need to focus on institutional development and capacity building, especially within local water utilities and urban planning agencies.

  8. Effects of environmental variability on recruitment and bioeconomic modelling in the Pacific sardine (Sardinops sagax caerulea fishery from Magdalena Bay, Baja California Sur, Mexico

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    Juan Antonio de Anda-Montañez

    2010-03-01

    Full Text Available Ricker's stock-recruitment equation, including the multivariate ENSO index (MEI as an environmental variable, was fitted to data of the Pacific sardine (Sardinops sagax caerulea fishery from Magdalena Bay, Baja California Sur, Mexico. The equation was then incorporated into an age-structured, bioeconomic model. Uncertainty was incorporated by using environmental fluctuations; seven-year projections, equivalent to one sardine generation, were computed. Five management options were considered in the projections: open access, effort at maximum sustainable economic yield (fMSE, catch at maximum sustainable yield (CMSY, equivalent effort level applied in the year 2004 (f2004, and an arbitrary catch quota of 40000 tons (CQ40000. Projection results were summarised by the indicator Net Present Value (NPV of the fishery for the modelled period. The strategies that involved some regulation in the effort level (fMSE and f2004 yielded the largest NPV. On the other hand, the strategies that involved regulation of the catch predicted—in addition to a lower NPV—a substantial increase in the effort to achieve the desired catch level. This study is the first bioeconomic approach for a sardine fishery management plan in this region.

  9. Violencia laboral intramuros. Hostigamiento sexual y otras formas de violencia contra la mujer en las maquiladoras de Sonora y Baja California

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    Mireya Scarone Adarga

    2014-01-01

    Full Text Available El objetivo del presente artículo es identificar los comportamientos en torno al hostigamiento sexual y otras formas de violencia contra la mujer en el ámbito laboral de la maquiladora en los estados de Sonora y Baja California. Para analizar dichas conductas se requirió de herramientas de la metodología cualitativa, como las entrevistas semiestructuradas y grupos focales, que se les hicieron durante 2012 a 31 trabajadoras de maquiladoras de las entidades mencionadas. En los relatos se identificó la violencia psicológica, física, económica, sexual, verbal y simbólica. Se encontró una asociación entre expresiones de diversas formas de violencia laboral y el hostigamiento sexual con la organización del trabajo y la estructura laboral de la maquiladora, que es clave para comprender la subordinación y desvalorización del trabajo femenino en este sector.

  10. Pycnogonids associated with the giant lion´s-paw scallop Nodipecten subnodosus (Sowerby) in Ojo de Liebre Bay, Guerrero Negro, Baja California Sur, Mexico.

    Science.gov (United States)

    de León-Espinosa, Angel; de León-González, Jesus A

    2015-01-01

    Five species of epibenthic pycnogonids collected on the giant lion´s-paw scallop Nodipecten subnodosus are recorded. A new species of Eurycyde, Eurycyde bamberi, is described. Of the 19 species known in this genus; the new species is closest to Eurycyde hispida Kroyer, 1844 but differs from it in the absence of plumose spines and the shapes of the lateral process, first coxa, and ocular tubercle. The new species represents the third member of Eurycyde from the eastern Pacific in addition to Eurycyde spinosa Hilton, 1916 and Eurycyde clitellaria Stock, 1955. Besides Eurycyde bamberi, the following species were collected: Nymphopsis duodorsospinosa Hilton, 1942c; Callipallene californiensis (Hall, 1913); Nymphon lituus Child, 1979; and Pycnogonum rickettsi Schmitt, 1934. Pycnogonum rickettsi is recorded for first time from Mexican waters, as is Nymphon lituus from the western coast of Baja California Peninsula. Each of these four species are re-described and re-illustrated in order to fill in existing gaps in the literature of the region.

  11. Un acercamiento a los actores ribereños en la pesca de camarón en San Felipe, Baja California

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    Virginia Guadalupe López Torres

    2016-01-01

    Full Text Available Desde hace varios años, los gobiernos nacionales y las instituciones internacionales han generado un conjunto de estrategias con el objetivo de disminuir los problemas ambientales, mediante la creación de reservas naturales. A pesar de ello, las acciones no consensuadas sobre la conser - vación no resuelven el deterioro ambiental, debido a que se debilita el tejido social necesario para impulsar un proceso de desarrollo comunitario sustentable; la conservación se trasforma en una actividad o interés ilegítimo para la población local, lo que endurece las posturas y dificulta la búsqueda conjunta de soluciones. Esto es lo que ha sucedido recientemente con los pescadores del puerto de San Felipe, Baja California, quienes en un par de ocasiones han cerrado la vía de comunicación terrestre entre Mexicali y el puerto, y se ha llegado al extremo de cerrar la garita internacional Mexicali-Calexico. Este malestar social, que amenaza con un mayor escalamiento, es el resultado de la negativa de los pescadores de San Felipe (y ahora también del Golfo de Santa Clara, en Sonora para modificar su arte de pesca, acorde con lo que plantea la nueva norma oficial mexicana.

  12. S(+ cetamina em baixas doses: atualização S(+ cetamina en bajas dosis: actualización Low S(+ ketamine doses: a review

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    Ana Luft

    2005-08-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A utilização, em baixas doses, de cetamina e de seus isômeros apresenta perspectivas promissoras em anestesia e na analgesia pós-operatória. O objetivo desse trabalho foi revisar as propriedades do uso de baixas doses de cetamina que justifiquem seu uso em anestesia e em analgesia pós-operatória. CONTEÚDO: Vários artigos da literatura sugerem que a cetamina apresenta propriedades de analgesia preemptiva e preventiva em relação à dor pós-operatória, diminuindo o consumo de opióides e melhorando a satisfação dos pacientes. Os fenômenos de tolerância e de hiperalgesia induzidos pela utilização de opióides podem ser atenuados pelo uso da cetamina em baixas doses. Ela diminui o consumo de anestésicos inalatórios e possivelmente apresenta propriedades que podem ser interessantes na proteção da célula nervosa isquêmica. Efeitos promissores, como a neuroproteção e a melhora de resultados, em longo prazo, necessitam de mais estudos. CONCLUSÕES: Em baixas doses a S(+ cetamina apresenta, na maioria dos estudos, efeito preventivo, diminuindo a sensibilização do SNC, a tolerância e a hiperalgesia induzida por opióides, o consumo de anestésicos, o uso de analgésicos e a incidência de efeitos adversos pós-operatórios.JUSTIFICATIVA Y OBJETIVOS: La utilización, en bajas dosis, de cetamina y de sus isómeros presenta perspectivas promisorias en anestesia y en la analgesia pos-operatoria. El objetivo de ese trabajo es revisar las propiedades del uso de bajas dosis de cetamina que justifiquen su uso en anestesia y en analgesia pos-operatoria. CONTENIDO: Varios artículos de la literatura sugieren que la cetamina presenta propiedades de analgesia preemptiva y preventiva con relación al dolor pos-operatorio, disminuyendo el consumo de opioides y mejorando la satisfacción de los pacientes. Los fenómenos de tolerancia y de hiperalgesia inducidos por la utilización de opioides pueden ser atenuados

  13. Deep-water bivalve mollusks collected during the TALUD XV cruise off the west coast of the southern Baja California Peninsula, Mexico

    Science.gov (United States)

    Valentich-Scott, Paul; Suárez-Mozo, Nancy Yolimar

    2016-01-01

    Abstract Background During the TALUD XV research cruise off the southern part of the Baja California Peninsula, Mexico, samples of macro-invertebrates obtained in the deep-sea (296–2136 m) revealed a rich fauna of bivalves (17 species belonging to 10 families). The number of species per station varied from one to five. The richest families were Nuculidae, Nuculanidae, Neilonellidae, Limidae, and Cuspidariidae. Solemyidae, Lucinidae, Poromyidae, Verticordiidae, and Pectinidae were each represented by a single species. Some species groups need a thorough revision and were tentatively identified (Nuculana cf. hamata, Limatula cf. saturna). New information Significant new distribution information is provided for two species, both recorded for the first time from off western Mexico: Ennucula panamina with an extension of its known distribution over 20° of latitude north and Jupiteria callimene with an extension of 16° 42' of latitude to the north. One species (Ennucula taeniolata) is reported in shallower depth and one in deeper water (Acesta sphoni). New records are provided for an additional nine species. Environmental and habitat conditions are given for the first time for many of the bivalve species. PMID:27346956

  14. Biomagnification of mercury and its antagonistic interaction with selenium in yellowfin tuna Thunnus albacares in the trophic web of Baja California Sur, Mexico.

    Science.gov (United States)

    Ordiano-Flores, Alfredo; Rosíles-Martínez, Rene; Galván-Magaña, Felipe

    2012-12-01

    Mercury and selenium concentrations were determined in muscle of 37 yellowfin tuna (Thunnus albacares) captured aboard of Mexican purse-seiners boats off western coast of Baja California Sur, between Punta Eugenia and Cabo Falso, from October to December 2006. Also, its prey (mainly, jumbo squid Dosidicus gigas and pelagic red crab Pleuroncodes planipes) were analyzed from the stomach contents. All the mercury values obtained were lower that mercury content recommended by standard legal limits for seafood adopted by Mexican norms (typically 0.5-1.0μg g(-1)). Mercury concentrations vary between 0.06 and 0.51μg g(-1) in yellowfin tuna, and from 0.01 to 0.20μg g(-1) in its prey, suggesting that mercury can accumulate in prey tissues and that of their predator. Biomagnification factors (BMF) between predator-prey associations were calculated. The BMFs were >1, indicating that mercury biomagnifies along the food web of yellowfin tuna. In all species studied there was a molar excess of selenium over mercury. The rank order of mean selenium/mercury molar ratios was for pufferfish (42.62)> diamond squid (15.09)>yellowfin tuna (10.29)>pelagic red crab (10.05)>panama lightfish (9.54)> jumbo squid (8.91). The selenium health benefit value (Se-HBV) was calculated to have an improved understanding of the health benefits and risk of fish consumption. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Efectos de una simetría facial alta, media y baja en un condicionamiento clásico de actitudes hacia logos

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    Danilo Zambrano R.

    2016-01-01

    Full Text Available Con 34 estudiantes de la Universidad de Ibagué (17 de cada sexo y una media de 21 años, se evaluó el efecto de la simetría facial (SF en un Condicionamiento Clásico de Actitudes, mediante un procedimiento simultáneo donde los estímulos incondicionados fueron rostros femeninos con baja, media y alta SF, y como estímulos a condicionar tres logos (Xua, Xue y Xuo. Los resultados muestran una mejor evaluación de los rostros con alta SF; un cambio entre las evaluaciones realizadas antes y después a los logos y, finalmente, que la marca asociada a alta SF obtuvo una evaluación más positiva. Se valora el impacto del estudio en la operacionalización del atractivo físico, la identificación de estímulos incondicionados y las ventajas del procedimiento en la evaluación de comunicaciones persuasivas.

  16. Risks of low dose ionising radiation exposures Riesgos derivados de la exposición a dosis bajas de radiación ionizante

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    Almudena Real Gallego

    2010-12-01

    Full Text Available Although ionising radiation has been shown to have several beneficial applications for humans, it can also produce detrimental effects in humans and the environment. To adequately protect man and environment from the potential harmful effects of ionising radiation, is essential to know in detail the biological effects produced by it, its characteristics and the various factors that influence these effects. That is the objective of this article, describe the current status of knowledge about biological effects induced by ionising radiation, with special emphasis on those effects occurring after low dose exposures.La radiación ionizante ha mostrado tener diversas aplicaciones beneficiosas para el hombre, pero también puede dañar la salud de las personas y el medio ambiente. Para proteger adecuadamente al hombre de los posibles efectos nocivos de la radiación ionizante es imprescindible conocer en detalle los efectos biológicos producidos por esta, sus características y los distintos factores que influyen en dichos efectos. Ese es el objetivo de este artículo: describir el estado actual del conocimiento sobre los efectos biológicos que puede producir la radiación ionizante, con especial énfasis en aquellos efectos que se producen tras la exposición a dosis bajas.

  17. Interacciones de pesquerías ribereñas en Bahía Magdalena-Almejas, Baja California Sur

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    Miguel A. Ojeda Ruiz de la Peña

    2012-01-01

    Full Text Available Con el fin de aportar al desarrollo de un modelo conceptual sobre la pesca ribereña o artesanal en el área de Bahía Magdalena-Almejas, Baja California Sur, se jerarquizó la importancia de 14 pesquerías de la región. La calificación se basó en un análisis cualitativo por puntos y en la estimación de un índice de importancia relativa, con indicadores como los promedios de captura, valor y frecuencia de registro de especies objetivo en desembarcos de embarcaciones menores, de 1998 a 2009; entre ellas están: almeja catarina, escama, camarón, callo de hacha, tiburón, jaiba, calamar, almeja pata de mula, rayas, lisa, pulpo, abulón, langosta y caracol chino. La interacción temporal entre varias de ellas es controlada por vedas oficiales, pero cuando ocurre se reconocen posibles efectos por pesca incidental e ilegal y modificaciones al ecosistema.

  18. Analysis of drought and desertification by means of aridity indices and the estimation of water gap in Baja California Sur, Northwest Mexico

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    Enrique Troyo Diéguez

    2013-10-01

    Full Text Available In Baja California Sur (BCS, Mexico, dry-semi warm and warm climates prevail associated to an extreme trend of diurnal temperatures and the environmental dryness. In this State, the maximum summer t exceeds 40° C and the minimum varies from 5 to 12° C, with a minimal for the State of 2° C in winter, at the top of the Sierra de La Laguna; only Los Cabos region has a warm humid climate. Because precipitation in the state is low, oscillating from 310 mm in the southern area of the state to 120 mm per year in the northern portion, predictions and scenarios under climate conditions point to an intensification of droughts. The aim of this work was to carry out a comparative analysis of trends of temperature, precipitation and hydro-environmental aridity among contrasting localities of BCS, by means of the application of Aridity Indexes and the determination of the Standardized Water Gap (BHE, through a numerical scale modification of the De Martonne Index. With the values of temperature and precipitation for the different climate change scenarios for four weather stations, the indicators Hydro Environmental Availability Index (IDHA and Hydro Environmental Drought Index (ISHA were calculated to determine their trend and the consequent BHE, an innovative quantification of wáter deficit, which is proposed in this paper. The máximum value of BHE (10 units, indicating prevalence of drought, is observed from February to June in almost the entire state.

  19. Valoración socioambiental de los recursos naturales: el caso de los recursos minerales en la parte central de Baja California Sur, México

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    Luis F. Beltrán Morales

    2012-02-01

    Full Text Available Se seleccionaron 15 localidades ubicadas en el radio de influencia de dos depósitos evaluados de fosfato, esto con la finalidad de aplicar el método de valoración contingente del recurso y su medio ambiente: el depósito de Tembabichi en el margen del Golfo de California y el depósito de Santo Domingo en la costa del Pacífico en Baja California Sur, México. Se encontró una disposición media a pagar por los habitantes del área de estudio de $29.77 pesos mensuales para colaborar con el medio ambiente de su región. Hipotéticamente se daría una valoración contingente en el total del área de estudio de $227 859.58 pesos mensuales, es decir, $2 734 314.9 pesos anuales. Es una cantidad considerable de recursos para contribuir a mejoras en el medio ambiente por comunidades rurales con signos de marginación socioeconómica.

  20. La descentralización: una mirada desde las políticas públicas y las relaciones intergubernamentales en Baja California

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    Martha Cecilia Jaramillo Cardona

    2010-01-01

    Full Text Available Otorgar autonomía política a los gobiernos no basta para asegurar o mejorar los servicios públicos, así lo muestra el análisis teórico de la presente investigación. Es necesario considerar la descentralización desde otros enfoques, porque sólo así se abren espacios para establecer relaciones francas, y tomar decisiones conjuntas entre Estado y sociedad para lograr las metas. Por tanto, el objetivo aquí es analizar la importancia del concepto descentralización y sus implicaciones, a partir de las políticas públicas y relaciones intergubernamentales. La descentralización constituye la oportunidad para que las administraciones locales diseñen políticas públicas acordes a las necesidades reales de sus regiones, y para que establezcan relaciones coordinadas entre los diversos ámbitos de gobierno. La investigación se realizó de 2003 a junio de 2006 en el estado de Baja California.