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Sample records for baja california sur

  1. [Marine algae of Baja California Sur, Mexico: nutritional value].

    Science.gov (United States)

    Carrillo Domínguez, Silvia; Casas Valdez, Margarita; Ramos Ramos, Felipe; Pérez-Gil, Fernando; Sánchez Rodríguez, Ignacio

    2002-12-01

    The Baja California Peninsula is one of the richest regions of seaweed resources in México. The objective of this study was to determine the chemical composition of some marine algae species of Baja California Sur, with an economical potential due to their abundance and distribution, and to promote their use as food for human consumption and animal feeding. The algae studied were Green (Ulva spp., Enteromorpha intestinalis, Caulerpa sertularoides, Bryopsis hypnoides), Red (Laurencia johnstonii, Spyridia filamentosa, Hypnea valentiae) and Brown (Sargassum herporizum, S. sinicola, Padina durvillaei, Hydroclathrus clathrathus, Colpomenia sinuosa). The algae were dried and ground before analysis. In general, the results showed that algae had a protein level less than 11%, except L. johnstonii with 18% and low energy content. The ether extract content was lower than 1%. However, the algae were a good source of carbohydrates and inorganic matter. PMID:12868282

  2. Wind power potential of Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Jaramilli, O.A.; Saldana, R.; Miranda, U. [Instituto de Investigaciones Electricas, Energias No Convencionales, Cuernavaca, Morelos (Mexico)

    2004-10-01

    This work is an analysis of wind characteristics of Baja California Sur (BCS), Mexico, during the period from February 1997 to February 1998. Fifteen wind stations located in the eastern coastal area recorded the wind speed and wind direction for this region. The wind resources of BCS were recorded and the annual average wind speed, power density, and annual energy density at 10 m above ground level are presented here. We considered the wind data from El Cardon, BCS, as a case study. This location can be considered to be representative of the 15 wind stations that were installed in BCS. Using the Weibull probability density function, we estimated the wind energy output and the capacity factor for two different wind turbines during the year. The capacity factors for both wind turbines were estimated at close to 25%. Considering the wind energy output and the capacity factor, we estimated the levelized production costs for both wind turbines. Taking into account two different discount rates of 7% and 10%, we developed data for the levelized production cost of both wind turbines. (Author)

  3. Among-population variation in monthly and annual survival of the Baja California Tree Frog, Pseudacris hypochondriaca curta, in desert oases of Baja California Sur, Mexico

    OpenAIRE

    Luja, V H; Rodriguez-Estrella, R; M Schaub; Schmidt, B R

    2015-01-01

    Survival is an important component of the demography of an animal. We estimated monthly and annual survival probabilities of three populations of the Baja California Treefrog (Pseudacris hypochondriaca curta) inhabiting desert oases of Baja California Sur, Mexico. We used data from a two-year mark recapture study to estimate survival. Recapture probabilities varied widely among months and there was no clear temporal pattern underlying the fluctuations. Annual survival was 27 and 29% for t...

  4. 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.

  5. DIVERSITY OF HELMINTHS OF FRESHWATER FISH IN THE OASES OF BAJA CALIFORNIA SUR, MEXICO

    OpenAIRE

    Mendez, Oscar

    2013-01-01

    Some oases have been evaluated and characterized on the basis of certain biological groups. However, there is nothing known of the helminths in these freshwater environments. We analyzed the diversity of helminths of freshwater fish in thirteen desert oases of Baja California Sur (BCS), Mexico. There were 472 individuals of nine species of fish examined. 24 helminth species were recorded on 273 fish (58%); of these, 176 (64%) were parasitized with a single species and 97 (36%) ...

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

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    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.

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

    OpenAIRE

    Francisco José Zamudio Sánchez; José Luis Romo Lozano; Florencio C. Santiago Santiago

    2009-01-01

    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.

  8. OLEAJE DE VIENTO Y ONDAS DE INFRAGRAVEDAD EN LA ZONA COSTERA DE BAJA CALIFORNIA SUR

    OpenAIRE

    Troyo Diéguez, Sergio

    2009-01-01

    Entre los problemas de desarrollo de la zona costera del estado de Baja California Sur se encuentran los relacionados con la navegación, la evolución de ecosistemas costeros, la erosión de playas y los de ingeniería costera y procesos litorales. Esta tesis trata sobre ondas de viento gravitacionales superficiales, incluyendo ondas de infragravedad, en la zona costera del estado. El objetivo principal consiste en caracterizar el oleaje de viento, las ondas de infragravedad y las variaciones es...

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

    OpenAIRE

    Reyna Ibañez Pérez

    2014-01-01

    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 c...

  10. Potencial bioactivo de algas del género Codium, recolectadas en Baja California Sur, México

    OpenAIRE

    Marín Álvarez, Alejandro

    2013-01-01

    Se evaluó la actividad antibacteriana, antiviral y citotóxica de extractos y productos naturales de Codium amplivesiculatum, C. simulans, C. cuneatum y C. fragile recolectadas en las costas de Baja California Sur, México. Se realizó el fraccionamiento de extractos etanólicos de algas del género Codium, recolectadas en tres localidades de Baja California Sur, México, por medio de columnas cromatográficas sílica gel 60 Å (230-400 de malla) utilizando mezclas de solventes de polaridad creciente....

  11. 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.

  12. 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 Este artículo ofrece un análisis de la integración de dos comunidades rurales, San Miguel y San José de Comondú, a los procesos de globalización económica que vive Baja California Sur, en el noroeste mexicano. Ese proceso permite advertir los riesgos de la patrimonialización y comodificación culturales de una ruralidad presionada por el crecimiento de los sectores de bienes raíces y turismo. Proponemos aquí que una avenida de conciliación es el establecimiento de una política cultural como eje principal de los proyectos de desarrollo de la entidad, que evite la mera comodificación de las tradiciones locales para el turismo, y reconozca el rol de los habitantes locales en la definición de los valores culturales locales.

  13. 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

  14. Chaetognatha in the Bahía Magdalena lagoon complex, Baja California Sur, México: Species Composition and assemblages

    OpenAIRE

    Cota Meza, María Soledad

    2011-01-01

    The chaetognaths from 187 zooplankton samples collected from the Bahía Magdalena lagoon complex, Baja California Sur, México during March, June, July, August, September, November, and December 1982 were studied. Twelve species belonging to two genera were identified. Sagitta euneritica and S. enflata were the most abundant and most frequent species with maximum abundance in July (40,000 org/100 m3 and 6100 org/100 m3 respectively). Sagitta pacifica, S. regularis and S. pseudoserratodentata we...

  15. 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. 

  16. 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.

  17. en un área natural protegida en Baja California Sur

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    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.

  18. Late Quaternary Faulting along the San Juan de los Planes Fault Zone, Baja California Sur, Mexico

    Science.gov (United States)

    Busch, M. M.; Coyan, J. A.; Arrowsmith, J.; Maloney, S. J.; Gutierrez, G.; Umhoefer, P. J.

    2007-12-01

    As a result of continued distributed deformation in the Gulf Extensional Province along an oblique-divergent plate margin, active normal faulting is well manifest in southeastern Baja California. By characterizing normal-fault related deformation along the San Juan de los Planes fault zone (SJPFZ) southwest of La Paz, Baja California Sur we contribute to understanding the patterns and rates of faulting along the southwest gulf-margin fault system. The geometry, history, and rate of faulting provide constraints on the relative significance of gulf-margin deformation as compared to axial system deformation. The SJPFZ is a major north-trending structure in the southern Baja margin along which we focused our field efforts. These investigations included: a detailed strip map of the active fault zone, including delineation of active scarp traces and geomorphic surfaces on the hanging wall and footwall; fault scarp profiles; analysis of bedrock structures to better understand how the pattern and rate of strain varied during the development of this fault zone; and a gravity survey across the San Juan de los Planes basin to determine basin geometry and fault behavior. The map covers a N-S swath from the Gulf of California in the north to San Antonio in the south, an area ~45km long and ~1-4km wide. Bedrock along the SJPFZ varies from Cretaceous Las Cruces Granite in the north to Cretaceous Buena Mujer Tonalite in the south and is scarred by shear zones and brittle faults. The active scarp-forming fault juxtaposes bedrock in the footwall against Late Quaternary sandstone-conglomerate. This ~20m wide zone is highly fractured bedrock infused with carbonate. The northern ~12km of the SJPFZ, trending 200°, preserves discontinuous scarps 1-2km long and 1-3m high in Quaternary units. The scarps are separated by stretches of bedrock embayed by hundreds of meters-wide tongues of Quaternary sandstone-conglomerate, implying low Quaternary slip rate. Further south, ~2 km north of the

  19. 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.

  20. 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

    OpenAIRE

    Francisco Díaz-Cedillo; Miguel A. Serrato-Cruz; Mario Arce-Montoya; José L León-de la Luz

    2012-01-01

    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...

  1. 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

  2. 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

  3. Morfometría en la Cuenca Hidrológica de San José del Cabo, Baja California Sur, México Morfometry in San José del Cabo Hidrologic Basin, South Baja California, México

    OpenAIRE

    Genaro Martínez; José de J. Díaz

    2011-01-01

    La cuenca hidrológica-forestal de San José del Cabo, localizada al sur de la península de Baja California, México, es la de mayor extensión en el estado de Baja California Sur y es considerada como una de las principales fuentes de recursos hídricos. Los acuíferos que suministran agua a las áreas turísticas y urbanas están en las partes bajas (planicies aluviales) de la cuenca. Un complejo cristalino constituido por rocas ígneas y metamórficas caracteriza la región montañosa de la cuenca. Aná...

  4. 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

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    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

  5. Aspectos alimentarios del dorado coryphaena hippurus linnaeus, 1758 en Cabo San Lucas, Baja California Sur, México

    OpenAIRE

    Bernabé Aguilar Palomino; Felipe Galván Magaña; L. Andrés Abitia Cárdenas; Arturo F. Muhlia Melo; Jesús Rodríguez Romero

    1998-01-01

    Se presenta el análisis del contenido estomacal de 500 dorados, Coryphaena hippurus, capturados por pesca deportiva entre la línea de costa y 25 millas afuera, frente a Cabo San Lucas, Baja California Sur, México. Se identificaron 51 organismos presa en el componente trófico del dorado, los cuales pertenecen a tres grandes grupos: peces, cefalópodos y crustáceos, representando en orden del índice de importancia relativa el 56.3%, 23.1% y 20.6%, respectivamente. De las 51 presas, 18 registraro...

  6. Lista sistemática de los peces de la Isla Cerravalo, Baja California Sur, México

    OpenAIRE

    Horacio Pérez España; Humberto Chávez-Ramos; Jesús Rodríguez Romero; L. Andrés Abitia Cárdenas; Felipe Galván Magaña

    1996-01-01

    The tirst check-list of fishes from Cerralvo Island, Baja California Sur, Mexico, is reported here. A total of 174 species, belonging to 132 genera and 70 families were registered. This list includes species collected and observed in the area between 1990 and 1993, as well as species previously reported in the literature between 1944 and 1993. Cerralvo Island has 77 species from the Panamic Province, 52 with a wide distribution in the eastern Pacific, 14 from the Mexican Province, 12 from the...

  7. Geological synthesis of Las Tres Virgenes geothermal area, Baja California Sur, Mexico. Sintesis geologica de la zona geotermica de Las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Hernandez, Aida (Departamento de Exploracion, Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico))

    1998-01-15

    The Las Tres Virgenes geothermal area is placed in middle Baja California Peninsula, in a zone affected by deformational events since Late Miocene. As a result of tensional stress, NW-SE faults were generated. During this process the Santa Rosalia basin was formed starting the deposition of marine sediments. At the same time La Reforma and Aguajito volcanic centers were emplaced, their deposits were interfingered with sand deposits. At the end of the volcanic activity at Aguajito, the stress regimen changed, old normal faults were reactivated as lateral faults and a pull apart system was initiated. NE-SW and NNE-SSW faults resulted from this deformational stage, and Las Tres Virgenes volcanic products were erupted through this weakness zone. The hydrothermal active system is hosted in a grid constructed by NE-SW, NW-SE faults within the granodioritic basement under the El Azufre volcano. The fluid's discharged take place at Las Viboras zone where intense superficial fracturing is present, associated with El Azufre dextral fault. Drilling results from seven wells confirm the existence of high temperatures making feasible the exploitation of this resource to generate electric energy.

  8. 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.

  9. 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.

  10. Challenges and opportunities for implementing sustainable energy strategies in coastal communities of Baja California Sur, Mexico

    Science.gov (United States)

    Etcheverry, Jose R.

    This dissertation explores the potential of renewable energy and efficiency strategies to solve the energy challenges faced by the people living in the biosphere reserve of El Vizcaino, which is located in the North Pacific region of the Mexican state of Baja California Sur. This research setting provides a practical analytical milieu to understand better the multiple problems faced by practitioners and agencies trying to implement sustainable energy solutions in Mexico. The thesis starts with a literature review (chapter two) that examines accumulated international experience regarding the development of renewable energy projects as a prelude to identifying the most salient implementation barriers impeding this type of initiatives. Two particularly salient findings from the literature review include the importance of considering gender issues in energy analysis and the value of using participatory research methods. These findings informed fieldwork design and the analytical framework of the dissertation. Chapter three surveys electricity generation as well as residential and commercial electricity use in nine coastal communities located in El Vizcaino. Chapter three summarizes the fieldwork methodology used, which relies on a mix of qualitative and quantitative research methods that aim at enabling a gender-disaggregated analysis to describe more accurately local energy uses, needs, and barriers. Chapter four describes the current plans of the state government, which are focused in expanding one of the state's diesel-powered electricity grids to El Vizcaino. The Chapter also examines the potential for replacing diesel generators with a combination of renewable energy systems and efficiency measures in the coastal communities sampled. Chapter five analyzes strategies to enable the implementation of sustainable energy approaches in El Vizcaino. Chapter five highlights several international examples that could be useful to inform organizational changes at the federal

  11. Geochemistry of a Tertiary sedimentary phosphate deposit: Baja California Sur, Mexico

    Science.gov (United States)

    Piper, D.Z.

    1991-01-01

    The San Gregorio Formation in Baja California Sur, a phosphate-enriched sedimentary unit of late Oligocene to early Miocene age, has been analyzed in two areas (La Purisima and San Hilario) for its chemical composition (major oxides, Cu, Cd, Cr, Co, V, and rare-earth elements - REE) and isotopic composition (??18O and ??13C). A detrital and a marine component were determined from major oxides. The detrital component consists of an unaltered volcanic-ash fraction and a terrigenous clay-silt fraction. The marine component, which accumulated initially as biogenic and hydrogenous material, is now present as opal-A, opal-CT, CaCO3, organic matter, and an authigenic phosphate fraction, mostly pelletal and composed of the carbonate-fluorapatite mineral francolite. The minor elements have been partitioned into these components by assuming a constant composition for the two detrital fractions. The composition of the marine component of minor elements can then be interpreted by assuming that the stoichiometry of the original accumulating organic matter was equal to that of modern plankton. The Cu and Cd contents in the marine component of all rocks require that the seawater-derived fractions of these two metals were supplied to the seafloor solely by organic matter. Enrichments of Cr and V at both sites required an additional marine input. On the basis of their geochemistry in the modern ocean, Cr and V could have precipitated, or been adsorbed, onto settling particles from an O2 minimum zone in which the O2 content was low enough to promote denitrification rather than oxygen respiration. An enrichment of the REE, now within the apatite fraction, resulted from their adsorption onto particulates also in the O2 minimum zone and to the dissolution and alteration of biogenic phases (predominantly silica) within the sediment. Co and Fe2O3 show no enrichment above a detrital contribution. The ??18O-values of apatites from the La Purisima site are heavier than those of apatites

  12. MT data modelling at Las Tres Virgenes, Baja California Sur, Mexico, geothermal zone. Modelado de datos magnetotelurgicos en el campo geotermico de Las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Palma Guzman, Sergio Hugo (Departamento de Exploracion, Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico))

    1998-01-15

    An interpretation of MT soundings at the Las Tres Virgenes, Baja California Sur, Mexico, geothermal project, was conducted, to actualize the geoelectric model of the reservoir, with the support provided by new drilling data. MT data were collected during the Comision Federal de Electricidad 1992 and 1994 campaigns. The use of apparent resistivity maps, tipper and apparent profiles lets us to identify TE and TM modes, as well as the lateral variations related to structural geology changes. These results were used to prepare sections based on Bostick inversion of TE mode of each sounding. Results were correlated to lithology reported by recent exploratory drilling. MT comprehensive studies let us delineate the reservoir limits, and the main geologic structures related to geothermal fluids production.

  13. 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.

  14. 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...

  15. Variabilidad de la abundancia de zooplancton en Bahía Magdalena Baja California Sur, México (1997-2001 Zooplankton abundance variability in Magdalena Bay, Baja California Sur, Mexico (1997-2001

    Directory of Open Access Journals (Sweden)

    Sergio Hernández-Trujillo

    2010-01-01

    Full Text Available Se analizaron muestras de zooplancton de 16 campañas oceanógraficas, efectuadas en Bahía Magdalena, Baja California Sur, México, entre agosto de 1997 y marzo de 2001. Se identificó un total de 26 grupos taxonómicos, de los cuales los más abundantes y frecuentes fueron copépodos y quetognatos; en 2000-2001 se observó una tendencia a disminuir entre 10 y 20 el número de grupos de zooplancton. La biomasa zooplanctónica y abundancia de copépodos disminuyeron en el periodo de estudio, en contraste con los quetognatos que tuvieron un ligero aumento. Las fluctuaciones de abundancia de zooplancton no estuvieron relacionadas con la concentración de clorofila-α, a diferencia de los máximos de abundancia de zooplancton, que estuvieron asociados a los cambios de la temperatura superficial del mar. El ciclo estacional de la abundancia del zooplancton en Bahía Magdalena, indicó que en invierno el promedió fue mayor de 65.000 ind 100 m-3 , valor que aumentó en primavera a más de 99.000 ind 100 m-3 , se mantuvo en verano alrededor de 100.000 ind 100 m-3 y en otoño descendió rápidamente a casi 40.000 ind 100 m-3.Zooplankton were studied from 16 oceanographic surveys carried out in Magdalena Bay, Baja California Sur, Mexico, between August 1997 and March 2001. Twenty-six taxonomic groups were identified, the most abundant and frequent of which were copepods and chaetognaths. In 2000-2001, the number of zooplankton groups tended to decrease by 10 to 20. Both zooplankton biomass and copepod abundance declined, unlike chaetognaths, which increased slightly. Fluctuations in zooplankton abundance were independent of the chlorophyll-a concentration, whereas the maximum zooplankton abundances were associated with changes in the sea surface temperature. The seasonal zooplankton abundance cycle in Magdalena Bay indicated that, in winter, the averaged was than 65,000 ind 100 m-3 , a value that increased to more than 99,000 ind 100 m-3 in spring

  16. 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

    Directory of Open Access Journals (Sweden)

    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

  17. Chaetognatha in the Bahía Magdalena lagoon complex, Baja California Sur, México: species composition and assemblages.

    Science.gov (United States)

    Cota Meza, M S

    2011-07-01

    The chaetognaths from 187 zooplankton samples collected from the Bahia Magdalena lagoon complex, Baja California Sur, Mexico during March, June, July, August, September, November, and December 1982 were studied. Twelve species belonging to two genera were identified. Sagitta euneritica and S. enflata were the most abundant and most frequent species with maximum abundance in July (40,000 org/100 m(3) and 6100 org/100 m(3) respectively). Sagitta pacifica, S. regularis and S. pseudoserratodentata were stenothermic (21 to 25 degrees C), whereas the rest of the species were eurythermic (15.5 to 29.5 degrees C). Sagitta euneritica contributed considerably to the zooplanktonic biomass, increasing the density in particular in BahíaAlmejas. The analysis of the species assemblages (Morisita index) showed that S. pacifica and S. regularis interact more frequently in August when there is a change of the water masses that converge in this zone during summer, when the California Countercurrent predominates. The composition of taxa during winter is characterized by the dominance of S. euneritica. Entering the warm period, an abrupt change occurs in taxa composition of the three zones studied: channels, Bahía Magdalena, and BahíaAlmejas. The amplitude and distribution of S. peruviana was influenced possibility by the oceanographic conditions of ENSO 1982. PMID:22315819

  18. Desalination and Water Security: The Promise and Perils of a Technological Fix to the Water Crisis in Baja California Sur, Mexico

    OpenAIRE

    Jamie McEvoy

    2014-01-01

    Across the globe, desalination is increasingly being considered as a new water supply source. This article examines how the introduction of desalinated water into the municipal water supply portfolio has affected water security in the coastal tourist city of Cabo San Lucas in Baja California Sur (BCS), Mexico. It also analyses the competing discourses surrounding desalination in the region and discusses alternative water management options for achieving water security. This article challenges...

  19. Can the Adoption of Desalination Technology Lead to Aquifer Preservation? A Case Study of a Sociotechnical Water System in Baja California Sur, Mexico

    OpenAIRE

    Jamie McEvoy

    2015-01-01

    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 ...

  20. 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.

  1. 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.

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

    International Nuclear Information System (INIS)

    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.

  3. 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...

  4. Coastal dynamics off Cabo Pulmo, Baja California Sur, México

    Science.gov (United States)

    Trasviña-Castro, A.; Gonzalez-Rodriguez, E.; Zaitsev, O. V.

    2013-05-01

    Cabo Pulmo is the one of the few coral reefs of the Mexican Pacific. It is located to the north of the Tropic of Cancer (at 23.5° N) and therefore formally in the subtropical region. It is part of the Gulf of California but its location near the tip of the Peninsula pose questions about the exchange of properties with the neighboring Pacific Ocean, some of which will be addressed here. It was declared National Park in 1995. Since then it became a no-take zone and a nature reserve for the preservation of the large variety of species found there. We report results based on meteorological and hydrographic observations as well as current measurements gathered between October 2010 and February 2012. These results include the presence of coastal currents forced by the tide, the wind and remote forcing. We believe the latter are associated, sometimes, to the mesoscale circulation of the entrance to the Gulf of California and, at other times, to coastal jets coming from the interior of the Gulf. We use displacement diagrams to discuss the trends of the residual circulation along the coast. During autumn, winter and even in spring the residual coastal flow is towards the Equator. This is attributed to the influence of the Northwesterly winds that blow over the Gulf of California in these months. It is in summer that the coastal residual circulation exhibits a poleward component being more intense during Southeasterly wind events. Finally, we present evidence of coastal exchange with the Pacific Ocean in the form of an intense jet. This coastal jet flows equatorward past Cabo Pulmo, continues towards the Pacific side of the Peninsula and generates offshore filaments when turning the cape.

  5. Estimación de biomasa fitoplanctónica, derivada de datos de satélite, frente a Baja California Sur

    OpenAIRE

    Saúl Álvarez Borrego; Eduardo Santamaría del Ángel; Iriana Leticia Zuria Jordan; Frank E. Müller Karger

    1995-01-01

    Se utilizaron todas las estimaciones disponibles de la concentración de pigmentos fotosintéticos derivadas de datos generados por el sensor Coastal Zone Color Scanner (CZCS) en el periodo 19781986, para interpretar las variaciones espaciales y temporales de la biomasa de fítoplancton, en un transecto de punta San Hipólito (27”N, ll4”30’0) a cabo Corrientes (20”3O’N, 105”30’0), frente al sur de Baja California, México. Las mayores concentraciones de pigmentos fotosintéticos se presentaron cerc...

  6. 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).

  7. El cardón Pachycereus pringlei, nuevo hospedero para Scyphophorus acupunctatus (Coleoptera: Curculionidae) en Baja California Sur, México The giant cardon cactus Pachycereus pringlei, a new host for Scyphophorus acupunctatus (Coleoptera: Curculionidae) in Baja California Sur, Mexico

    OpenAIRE

    Yolanda Maya; Carlos Palacios-Cardiel; Ma. Luisa Jiménez

    2011-01-01

    Se presenta el primer registro de una cactácea, Pachycereus pringlei (cardón), especie dominante del matorral xerófilo de la península de Baja California, como hospedero de Scyphophorus acupunctatus (picudo del agave). A partir de observaciones y la recolección de individuos adultos y larvas, se pudo establecer que el picudo del agave causa al menos 3 tipos de daño al cardón: 1), barrenado en la región apical de los brazos por los adultos; 2), consumo de la médula de los brazos por las larvas...

  8. Seismic activity at the Las Tres Virgenes, B. C. S, Mexico, geothermal field. Actividad sismica del campo geotermico de Las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero Guadarrama, Jose Luis (Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico))

    1998-05-15

    A study of the seismic activity at Las Tres Virgenes Geothermal field in Baja California Sur (Baja California Sur), Mexico is presented. Four monitoring periods are comprised: 28 January to 12 May 1993; 5 January to 24 April 1994; 25 May to 19 August 1995 and 30 August to 02 November 1995. The influence of the geological structure on the seismic activity of the field was considered by means of: a velocities model based on field geology, borehole data, a reflection seismic profile, considerations on the thermal gradient in the zone, and local and regional geophysical models. Site corrections that were considered necessary to improve the velocities model were determined trough simulation runs of seismic events at 4 km depth with reference to sea level and to a mean topographic height of 400 m. Main interpretation consists in the correlation of epicenters with the volcanic edifices and tectonics, identifying the maximum activity zones related with geothermal interest areas. Registered seismic information constitutes a framework for the study of the future seismic activity during reservoir exploitation.

  9. Frecuencias de grupos sanguíneos e incompatibilidades ABO y RhD, en La Paz, Baja California Sur, México

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    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.

  10. Epiphytic diatoms associated with red mangrove (Rhizophora mangle) prop roots in Bahía Magdalena, Baja California Sur, Mexico.

    Science.gov (United States)

    Siqueiros Beltrones, D A; López Fuerte, F O

    2006-06-01

    The first floristic inventory of benthic diatoms is provided for the Bahia Magdalena-Bahia Almejas lagoon system. Samplings were carried out during November of 1999. The oxydized samples were mounted permanently. Eighty six diatom taxa were identified, out of which 59 are new records for the Bahia Magdalena area, and 12 taxa are new for the Baja California peninsula. Taxa recorded previously as rare in other substrata are common or abundant on the epiphytic macroalgae of mangrove prop roots. Other species are mainly epipelic forms, while 24 are commonly found as tychoplankton in the area. Certain taxa appear to be characteristic of mangrove systems in general. PMID:18494299

  11. Morfometría en la Cuenca Hidrológica de San José del Cabo, Baja California Sur, México Morfometry in San José del Cabo Hidrologic Basin, South Baja California, México

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    Genaro Martínez

    2011-06-01

    Full Text Available La cuenca hidrológica-forestal de San José del Cabo, localizada al sur de la península de Baja California, México, es la de mayor extensión en el estado de Baja California Sur y es considerada como una de las principales fuentes de recursos hídricos. Los acuíferos que suministran agua a las áreas turísticas y urbanas están en las partes bajas (planicies aluviales de la cuenca. Un complejo cristalino constituido por rocas ígneas y metamórficas caracteriza la región montañosa de la cuenca. Análisis de imagen Landsat ETM, fotografías aéreas y modelo digital de elevación fueron usados para cartografiar la geomorfología, geología y desarrollar un análisis morfométrico en la margen occidental de la cuenca. Rasgos estructurales tales como alineamientos rectos o curvilíneos y diques fueron obtenidos del modelo digital de elevación. Parámetros morfométricos y análisis estructural de siete subcuencas se derivaron para determinar áreas potenciales de captura hacia la Cuenca Hidrológica de San José del Cabo (CHSJ. Del análisis se identificó que la captura toma lugar en la parte serrana de la cuenca, dentro del basamento cristalino a través de un sistema de fracturamiento interconectado. Se proponen dos subcuencas como las principales áreas de recarga hacia la CHSJC. Los resultados muestran que la investigación con imagen Landsat y el modelo digital de elevación proporcionan, una fuente acertada de datos e información para la identificación de áreas de recarga y descarga a una escala regional.The San José del Cabo basin is located in the southern tip of the Baja California peninsula in México. The basin is one of the largest in the state and is considered the major water source for the state. The aquifers and wells that supply water to the urban and tourist areas are in the lower areas (alluvial plains of the basin; however the aquifers recharge takes place in the mountain region. A crystalline complex basement made

  12. 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.

  13. Manejo de un sitio de anidación para la conservación de Sternula antillarum (Charadriiformes: Laridae) en Baja California Sur, México Nesting site management for Sternula antillarum (Charadriiformes: Laridae) conservation in Baja California Sur, Mexico

    OpenAIRE

    Edgar Amador; Renato Mendoza-Salgado; Eduardo Palacios

    2008-01-01

    El gallito marino menor (Sternula antillarum) es una especie sujeta a protección especial, que anida en colonias pequeñas en hábitats costeros. Las mareas altas son un problema para la anidación de S. antillarum en Baja California Sur, pues causan la inundación de algunas colonias. Para reducir el impacto potencial del flujo de marea alta sobre los nidos, se elevó 20 cm el nivel del suelo por medio de una plataforma elevada construida con llantas de desecho rellenas y cubiertas de arena. La o...

  14. El cardón Pachycereus pringlei, nuevo hospedero para Scyphophorus acupunctatus (Coleoptera: Curculionidae en Baja California Sur, México The giant cardon cactus Pachycereus pringlei, a new host for Scyphophorus acupunctatus (Coleoptera: Curculionidae in Baja California Sur, Mexico

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    Yolanda Maya

    2011-09-01

    Full Text Available Se presenta el primer registro de una cactácea, Pachycereus pringlei (cardón, especie dominante del matorral xerófilo de la península de Baja California, como hospedero de Scyphophorus acupunctatus (picudo del agave. A partir de observaciones y la recolección de individuos adultos y larvas, se pudo establecer que el picudo del agave causa al menos 3 tipos de daño al cardón: 1, barrenado en la región apical de los brazos por los adultos; 2, consumo de la médula de los brazos por las larvas, que puede ser tan extenso que ocasiona la muerte del cardón y 3, perforaciones en diversos sitios de los brazos, por donde las larvas eliminan los desechos, que pueden ser entrada de otros parásitos o que por lo menos dejan cicatrices en forma de tumor. El éxito de este insecto en el cardón podría representar una amenaza para las poblaciones naturales de esta cactácea e incluso para los servicios ambientales de los matorrales xerófilos.This is the first record of a cactus, Pachycereus pringlei (giant cardon, which is a dominant species of the xerophyllous scrub in the Baja California peninsula, as a host of Scyphophorus acupunctatus (agave weevil. Based on observations and the sampling of adults and larvae, it was possible to establish that this weevil causes at least 3 types of damage to the cardon: 1, drilling of the tip of the branches by adults; 2, consumption of the branch medulla by larvae, which can be so extended that could cause the cardon’s death, and 3, perforations in the branches, used by larvae to eliminate wastes, that could serve as entrance to other pests and remain as tumor-like scars. The success that this insect seems to have by using the giant cardon cactus as host represents a threat to its natural populations and even to the xerophillous scrub environmental services.

  15. 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.

  16. 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

  17. Vent fluid chemistry in Bahía Concepción coastal submarine hydrothermal system, Baja California Sur, Mexico

    Science.gov (United States)

    Prol-Ledesma, R. M.; Canet, C.; Torres-Vera, M. A.; Forrest, M. J.; Armienta, M. A.

    2004-10-01

    Shallow submarine hydrothermal activity has been observed in the Bahía Concepción bay, located at the Gulf coast of the Baja California Peninsula, along faults probably related to the extensional tectonics of the Gulf of California region. Diffuse and focused venting of hydrothermal water and gas occurs in the intertidal and shallow subtidal areas down to 15 m along a NW-SE-trending onshore-offshore fault. Temperatures in the fluid discharge area vary from 50 °C at the sea bottom up to 87 °C at a depth of 10 cm in the sediments. Chemical analyses revealed that thermal water is enriched in Ca, As, Hg, Mn, Ba, HCO 3, Li, Sr, B, I, Cs, Fe and Si, and it has lower concentrations of Cl, Na, SO 4 and Br than seawater. The chemical characteristics of the water samples indicate the occurrence of mixing between seawater and a thermal end-member. Stable isotopic oxygen and hydrogen composition of thermal samples plot close to the Local Meteoric Water Line on a mixing trend between a thermal end-member and seawater. The composition of the thermal end-member was calculated from the chemistry of the submarine samples data by assuming a negligible amount of Mg for the thermal end-member. The results of the mixing model based on the chemical and isotopic composition indicate a maximum of 40% of the thermal end-member in the submarine vent fluid. Chemical geothermometers (Na/Li, Na-K-Ca and Si) were applied to the thermal end-member concentration and indicate a reservoir temperature of approximately 200 °C. The application of K-Mg and Na/Li geothermometers for vent fluids points to a shallow equilibrium temperature of about 120 °C. Results were integrated in a hydrogeological conceptual model that describes formation of thermal fluids by infiltration and subsequent heating of meteoric water. Vent fluid is generated by further mixing with seawater.

  18. Melampodium sinuatum (Asteraceae) endémica del extremo sur de la península de Baja California en peligro de extinción Melampodium sinuatum (Asteraceae), an endangered endemic species to the southernmost tip of the Baja California Peninsula

    OpenAIRE

    Jose Luis Villaseñor; J. Ismael Calzada; Patricia Dávila

    2011-01-01

    Melampodium sinuatum Brandegee, especie endémica del extremo sur del estado de Baja California Sur, México, constituye una especie poco conocida debido a su rareza y distribución restringida. No se conoce de más de 5 sitios; todos ellos amenazados por las actividades humanas. El escaso número de individuos por población, así como la estrecha superficie que abarca su área de distribución la colocan como una especie en inminente peligro de extinción, por lo que es imperativo realizar acciones e...

  19. Eficiencia en el uso del agua en maíz (Zea Mays L.) con riego por goteo, en el Valle de la Paz, Baja California Sur, México

    OpenAIRE

    Sergio Zamora Salgado; Liborio Fenech Larios; Francisco H. Ruiz Espinoza; Wilfredo Pérez Duarte; Aldo López Gómez

    2007-01-01

    Con el objetivo de evaluar la eficiencia en el uso del agua del maíz en riego por goteo se estableció un experimento en el campo agrícola de la Universidad Autónoma de Baja California Sur, Baja California Sur, México (24o10 L N; 1100 19 LW), en diciembre del 2003. El clima es desértico cálido, con una temperatura media anual de 29,6 OC, y una precipitación media mensual de 184,8 mm. La calidad del agua está clasificada como C4S2. Los tratamientos fueron láminas que resultaron del pro...

  20. Isotopic-chemical study of fluid of producing wells and natural springs from Las Tres Virgenes, Baja California Sur systems, Mexico. Estudio quimico-isotopico de fluidos de pozos productores y manantiales del sistema Las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Portugal Marin, Enrique; Barragan, Rosa Maria; Arellano Gomez, Victor Manuel (Instituto de Investigaciones Electricas, Cuernavaca (Mexico)); Tello H, Enrique (Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)); Garcia, Consuelo (Residencia del Campo Geotermico Las Tres Virgenes, Baja California Sur (Mexico))

    1998-09-15

    Results of the chemical and isotopic studies from springs, domestic and geothermal wells in Las Tres Virgenes, Baja California Sur, Mexico are presented. Three water types were found to be in the study zone. Sulphate-type water at the North, bicarbonate-type waters at the South and sodium chloride type at the West. The last group includes the reservoir water. The estimated geothermometric temperature for the LV-1 well was 259 degrees Celsius with CCG geothermometer, while the estimated temperature for the springs were low, due to high dilution of the deep fluid with groundwater. The isotopic data (d[sup 18]O and dD) were used to define the local meteoric line, the isotopic composition of the reservoir recharge and the possible elevation where the reservoir recharge is likely to occur. Finally a discussion about the possible origin of the geothermal water based on the isotopic data is presented.

  1. Interacciones de pesquerías ribereñas en Bahía Magdalena-Almejas, Baja California Sur

    Directory of Open Access Journals (Sweden)

    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.

  2. 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. PMID:23059106

  3. 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.

  4. Normal Fault Basin Geometries From Gravity Analyses in the La Paz - Los Cabos Region, Baja California Sur, Mexico

    Science.gov (United States)

    Busch, M. M.; Coyan, J. A.; Arrowsmith, J. R.; Umhoefer, P. J.; Martinez-Gutierrez, G.

    2008-12-01

    The southern cape region of the Baja California peninsula is ruptured by an array of roughly north-striking, left-stepping active normal faults, which accommodate regional transtension. Dominant faults within this system include the Carrizal, San Juan de los Planes (SJP) (and offshore Espiritu Santo fault), La Gata, and San Jose del Cabo (SJC) faults. We conducted gravity surveys across the basins bounded by these faults to gain insight into fault slip rates and basin evolution to better understand the role of upper-crustal processes during development of an obliquely rifted plate margin. The geodetic location of each gravity observation station was measured to cm-scale accuracy with real-time kinematic GPS and the relative gravity was measured with a LaCoste and Romberg Model G gravity meter to an accuracy of 0.01 mgal. Gravity data were modeled as a 2D two-layer model with a bedrock density of 2.67 g/cm3 and a basin fill density of 2.1 or 2.2 g/cm3. The hanging wall of the east-dipping Carrizal fault hosts the La Paz basin. In the subsurface, this basin is a half-graben that is manifest as two smaller basins (few hundred meters deep) separated by a bedrock high, which likely reflects the two main east-dipping splays (Carrizal and Centenario faults). The SJP basin is a graben bound by the SJP fault on the west and the La Gata fault on the east and has a modeled maximum depth of approximately 1.5 km. This basin is marked by a series of relict normal faults dipping toward the basin center. The maximum depth to bedrock is just northwest of center, asymmetric toward the SJP fault, indicating that slip may be greater along the SJP than along the La Gata fault. It might also mark the possible location of basin inception, indicating that as the basin evolved, faulting moved outward to the presently active SJP and La Gata Faults. The SJC basin has a maximum depth of approximately 2.5 km. The favored gravity model depicts the SJC basin as resulting from slip along a series

  5. [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 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.

  6. California Sur, México

    Directory of Open Access Journals (Sweden)

    Francisco Higinio Ruiz Espinoza

    2008-01-01

    Full Text Available 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 que las variables biológicas fueron rendimiento, área foliar (AF e índice de área foliar (IAF, tasa relativa de crecimiento (TRC, tasa de asimilación neta (TAN y masa seca. Se aplicó un análisis estadístico descriptivo y multivariado, las medias se compararon por Tukey al 5 % de probabilidad, con análisis factorial, empleando el programa STATISTICA 6.0. Los resultados mostraron la relación de la temperatura y la humedad relativa con el rendimiento, lo que establece que para el máximo rendimiento de albahaca en las condiciones en que se condujo el experimento la temperatura de 32 oC y la humedad relativa de 58 % fueron las mejores

  7. Caracterización del peligro por inundaciones en el oasis La Purísima, Baja California Sur, México

    Directory of Open Access Journals (Sweden)

    Jobst Wurl

    2015-01-01

    Full Text Available En el estado de Baja California Sur existen solo cuatro oasis con extensiones mayores a 2.0 km 2 ; La Purísima (2.25 km 2 representa el tercero en extensión. En el pasado el oasis fue frecuentemente afectado por inundaciones resultantes de los eventos extremos de precipitación, que generaron graves daños en la cuenca. Se realizó un diagnóstico del oasis La Purísima, con respecto a posibles inundaciones como consecuencia de lluvias extremas, lo cual incluye el análisis estadístico de la precipitación para la elaboración de un modelo hidrológico e hidráulico, con el fin de calcular el caudal máximo, el volumen y la frecuencia de crecidas en los cursos del arroyo Cadegomo bajo diferentes escenarios de lluvias extremas. Finalmente se elaboró un mapa de peligro por inundación según los escenarios elaborados Se efectuó un análisis de la ocurrencia de inundaciones en el pasado y sus efectos en el oasis por medio de evidencias históricas de inundación de la zona, para verificar su posible aplicación en la calibración de los modelos. Los caudales resultantes de los eventos de precipitación extremos generan un incremento importante de los niveles en el drenaje de la cuenca. La respuesta del arroyo es un incremento en el área de inundación de hasta 14% respecto al tiempo de retorno de 20 años. Un evento de 1 000 años generaría un incremento en el área de inundación de 67% y bajas, afectando las zonas de la región urbana, así como todos los lotes de cultivo

  8. Capillary electrophoresis finger print technique (CE-SSCP): an alternative tool for the monitoring activities of HAB species in Baja California Sur Costal.

    Science.gov (United States)

    Herrera-Sepúlveda, Angélica; Hernandez-Saavedra, Norma Y; Medlin, Linda K; West, Nyree

    2013-10-01

    In Mexican waters, there is no a formal and well-established monitoring program of harmful algal blooms (HAB) events. Until now, most of the work has been focused on the characterization of organisms present in certain communities. Therefore, the development of new techniques for the rapid detection of HAB species is necessary. Capillary electrophoresis finger print technique (CE-SSCP) is a fingerprinting technique based on the identification of different conformers dependent of its base composition. This technique, coupled with capillary electrophoresis, has been used to compare and identify different conformers. The aim of this study was to determine if CE-SSCP analysis of ribosomal RNA (rRNA) gene fragments could be used for a rapid identification of toxic and harmful HAB species to improve monitoring activities along the coasts of Baja California Sur, Mexico.Three different highly variable regions of the 18S and 28S rRNA genes were chosen and their suitability for the discrimination of different dinoflagellate species was assessed by CE-SSCP.The CE-SSCP results obtained for the LSU D7 fragment has demonstrated that this technique with this gene region could be useful for the identification of the ten dinoflagellates species of different genera.We have shown that this method can be used to discriminate species and the next step will be to apply it to natural samples to achieve our goal of molecular monitoring for toxic algae in Mexican waters. This strategy will offer an option to improve an early warning system of HAB events for coastal BCS, allowing the possible implementation of mitigation strategies. A monitoring program of HAB species using molecular methods will permit the analysis of several samples in a short period of time, without the pressure of counting with a taxonomic expert in phytoplankton taxonomy. PMID:22744160

  9. [Spatial and biogeographic characterization of macroalgal assemblages from Bahía del Rincón, Baja California Sur, Mexico].

    Science.gov (United States)

    Riosmena-Rodríguez, R; Hinojosa-Arango, G; López-Vivas, J M; León-Cisneros, K; Holguin-Acosta, E

    2005-01-01

    Macroalgal studies in Baja California Sur have dealt mainly with occurrence and seasonality, but some areas are poorly known even for these basic data. Bahia del Rincón-La Rivera is an important high-productivity fisheries area where coastal infrastructure development is under way. A spatial characterization of the marine flora from Bahia del Rincón-La Rivera was done by intensive sampling at different depths and localities with skin and SCUBA diving. At least 500 m2 were surveyed in each site. Additionally. quantitative sampling was done in ten random 25 cm2 quadrates per site. In the intertidal section, density and cover estimates were used. We also investigated the historical records and geographical affinities. A total of 72 species were identified (most were red algae: 62%). We found no general trend in the biogeographical affinities, which varied with each taxonomic group. Most brown algae species were tropical-endemic; red algae temperate-cosmopolite and green algae tropical-cosmopolite. In the spatial assemblage structure we found a high similarity between the intertidal areas, but a low similarity in shallow or deeper areas (3-5 m). This pattern was the same when we compared the abundance of the main species. We suggest that there are significant spatial differences in recruitment and development of the assemblages in relation to vertical distribution (depth) and position along the shore. There is a clear-cut Gelidium-Jania belt in the intertidal zone and a Padina-Dictyota belt below the low tide. Sporadic and year-round species occur in the intertidal zone, annual and perennial species below the low tide line. Sites differ in recruitment and this affects the abundance of other species (such as coraline and Caulerpa species). Temperature and sedimentation affect seasonality, but community structure is relatively constant throughout the year.

  10. Cestodes of the blue shark, Prionace glauca (Linnaeus 1758), (Carcharhiniformes: Carcharhinidae), off the west coast of Baja California Sur, Mexico.

    Science.gov (United States)

    Méndez, Oscar; Galván-Magaña, Felipe

    2016-01-01

    The cestode species recovered from the spiral intestines of 27 blue sharks (Prionace glauca) (Linnaeus, 1758) are reported from the western coast of Baja California Sur (BCS). The sampling was undertaken on a monthly basis from January 2003 to January 2004. The helminthological examination indicated the presence of four species of cestodes: Platybothrium auriculatum Yamaguti, 1952; Prosobothrium japonicum Yamaguti, 1934; Anthobothrium caseyi (Yamaguti, 1934) Ruhnke & Caira, 2009; and Paraorygmatobothrium prionacis (Yamaguti, 1934) Ruhnke, 1994. Of all the 27 sharks examined, 88.8% were infected with at least one cestode species. The most frequent species was P. auriculatum infecting 85% of the spiral intestines examined. In contrast the species with the highest mean intensity was P. prionacis (80.4 200). The species richness of cestodes in P. glauca is very similar in other regions of the world despite its wide distribution; however, this richness is low compared with other species of sharks within the same family. The feeding and host-specific are important factors that influence the parameters of infection of cestodes in this shark. On the west coast of BCS, Prionace glauca feeds mainly on red crab Pleuroncodes planipes Stimpson, 1860; squids Gonatus californiensis Young, 1972, Ancistrocheirus lesueurii (D'Orbigny, 1842), Haliphron atlanticus Steenstrup, 1861, and low proportion of fish teleosts as Merluccius productus (Ayres, 1855), Sardinops sp. Hubbs, 1929 and Scomber japonicus Houttuyn, 1872. We speculate that these prey could be involved as the second intermediate hosts of these cestodes, as in other members of these genera, although the life cycles of none are known. PMID:27394312

  11. Arsenic content in groundwater from the southern part of the San Antonio-El Triunfo mining district, Baja California Sur, Mexico

    Science.gov (United States)

    Wurl, Jobst; Mendez-Rodriguez, Lía; Acosta-Vargas, Baudilio

    2014-10-01

    The San Antonio-El Triunfo mining district is located in a mountain region 60 km southeast of La Paz, the capital of the Mexican state of Baja California Sur. Mining activities, focused on gold and silver extraction, which began in the second half of the 18th century; the main activity took place between 1878 and 1911. The minerals were treated through the cyanide method, burned, and smelted. In effect between 800,000 and 1 million tons of mine waste materials were scattered in an area of approximately 350-400 km2. This area contains today several byproducts as a result from arsenopyrite oxidation, such as arsenolite (As2O3). The aim of this study was to analyze groundwater composition in order to define the actual concentrations of relevant parameters to detect ore mining contaminations, especially in respect to arsenic. In the autumn of 2010, 29 groundwater samples were obtained using flow-through bailer or down-hole pump methods, and a total of 37 variables were measured in each sample. Arsenic (dissolved) exceeded the values established by the World Health Organization (WHO, 2011) (0.01 mg/L) in 41% of the monitored sites. The maximum concentration of arsenic found in one observation well was 0.45 mg/L. Four water samples, which were characterized by elevated concentration of boron (max. conc. 9.5 mg/L), fluoride (max. conc. 3.25 mg/L) and alkaline pH values (>9), showed a composition typical for hydrothermal water. Because all four samples had arsenic concentration under 0.008 mg/L, we conclude that no significant impact of arsenic from hydrothermal fluids is found in the study area.

  12. Diet of blue marlin Makaira mazara off the coast of Cabo San Lucas, Baja California Sur, Mexico

    OpenAIRE

    Abitia Cárdenas, Leonardo Andrés; Galván Magaña, Felipe; Gutiérrez Sánchez, Francisco Javier; Rodríguez Romero, Jesús; Aguilar Palomino, Bernabé; Moehl Hitz, Almiae

    1999-01-01

    Analysis of the stomach contents of 204 blue marlin (Makaira mazara) caught by the sport-fishing fleet of Cabo San Lucas in the southern Gulf of California is presented. The specimens sampled were caught during the summer and fall of 1987, 1988, and 1989 when the sea is warm (28-30°C). Blue marlin were found to feed on 35 prey species, 3 of which represented 90% of the total stomach contents by frequency of occurrence. The main prey were epipelagic organisms from the oceanic zone and demersal...

  13. Manejo de un sitio de anidación para la conservación de Sternula antillarum (Charadriiformes: Laridae en Baja California Sur, México Nesting site management for Sternula antillarum (Charadriiformes: Laridae conservation in Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Edgar Amador

    2008-06-01

    Full Text Available El gallito marino menor (Sternula antillarum es una especie sujeta a protección especial, que anida en colonias pequeñas en hábitats costeros. Las mareas altas son un problema para la anidación de S. antillarum en Baja California Sur, pues causan la inundación de algunas colonias. Para reducir el impacto potencial del flujo de marea alta sobre los nidos, se elevó 20 cm el nivel del suelo por medio de una plataforma elevada construida con llantas de desecho rellenas y cubiertas de arena. La ocupación de este sitio por S. antillarum se monitoreó durante las temporadas reproductivas de 1990, y de 2002 a 2005. Las mareas altas no afectaron los nidos establecidos sobre la plataforma y la densidad de nidos sobre ella fue mayor que la que hubo en el terreno natural de la planicie costera adyacente. Este método de manejo del hábitat de anidación de S. antillarum es una buena alternativa en los sitios con riesgo por flujo de marea.The Least Tern (Sternula antillarum is a threatened seabird species that breeds in small colonies on coastal habitats. High tides constitute a problem for their reproduction in Baja California Sur, since they cause flooding of some colonies. To reduce the potential impact of high tides on the nests, the level of the ground was elevated by 20 cm, through an elevated platform that was built by using discarded tires filled and covered with sand. The occupation of this site by Least Terns was monitored during the breeding seasons of 1990 and from 2002 to 2005. High tides did not affect the nests established on the platform and density of nests on this platform was higher than on the natural adjacent mudflat area. This nesting habitat management method for the Least Tern is an appropriate alternative for those sites affected by high tides.

  14. Estructura de la avifauna durante el periodo invierno-primavera en el Estero Rancho Bueno, Baja California Sur, México Structure of the avifauna during the winter-spring season in Estero Rancho Bueno, Baja California Sur, México

    Directory of Open Access Journals (Sweden)

    Edgar Amador

    2006-12-01

    Full Text Available Mensualmente, de noviembre de 1993 a junio de 1994, se contaron las aves en un ambiente de manglar en Estero Rancho Bueno de la costa occidental de Baja California Sur. Sumaron en total 5965 aves de 56 especies de 10 órdenes y 21 familias. La estacionalidad estuvo definida por 31 residentes, 22 migratorias y tres indeterminadas. La mayoría de las especies se consideran costeras y/o estuarinas; sin embargo, hay algunas terrestres. Existen indicios de que por lo menos 2 especies se reproducen en el área, 4 presentan alguna categoría en la normatividad y 5 se utilizan comercialmente. La comunidad de aves es más diversa a principios de invierno y disminuye hacia finales de primavera, coincidiendo con la menor riqueza de especies y el aumento en la dominancia del pelícano café (Pelecanus occidentalis, gaviota occidental (Larus occidentalis y gaviota pico anillado (Larus delawarensis. El análisis para las áreas con manglar y sin manglar indicó que el número total de individuos (N, el número de individuos de la especie más abundante (Nmax y la riqueza de especies (S son mayores en el hábitat de áreas abiertas, mientras que la equidad (E siempre fue mayor en el hábitat de manglar.Periodic surveys were conducted from November 1993 to June 1994 in Estero Rancho Bueno, a mangrove lagoon environment on the west coast of Baja California Sur. We found 5,65 birds (56 species. The avifauna included 31 resident, 22 migratory, and 3 species of undeterminated migratory status. Most of the species were coastal and estuarine birds; however there were some terrestial and wide-ranging birds. There is evidence that at least 2 species breed in the area; 4 species are protected by Mexican law and 5 species have commercial value. Different indices show that the bird community diversity is lower by the end of spring and the dominance of the Brown Pelican (Pelecanus occidentalis, the Western Gull (Larus occidentalis, and the Ring-billed Gull (L. delawarensis

  15. Temporal constraints on landscape evolution in response to rifting along the western margin of the Gulf of California, central Baja California Sur, Mexico

    Science.gov (United States)

    Mark, C.; Gupta, S.; Carter, A.; Mark, D. F.; Gautheron, C.; Martin Barajas, A.

    2011-12-01

    Rift escarpments and the high-elevation rift flanks associated with them are prominent topographic features at many developing and established passive margins. Numerical models and field investigations typically indicate that there are two principal mechanisms of rift escarpment evolution, commonly termed plateau downwearing and scarp retreat; however, many commonly studied passive margins are ancient, and have thus experienced significant post-rift modification, resulting in controversy as to which model is applicable at any particular margin. Rift flank uplift and the associated landscape changes have been less well studied; the erosional response to such uplift is often sufficient to bevel or erase the pre-rift landscape but insufficient to reset low-temperature thermochronometers, hindering field investigation. We present observations on rift landscape evolution from the Gulf of California: a ~1700 km long, highly oblique rift system. Although the precise timing of rifting remains controversial, it is known to have begun no earlier than the Mid-Miocene, and the incipient passive margins bounding the Gulf therefore retain many youthful features and provide an excellent natural laboratory for investigating landscape responses to rifting. This study examines the exhumation history of the escarpment and the development of the rift flank drainage network in the Loreto area of the Baja California Peninsula, which forms the western rift margin. Apatite (U-Th)/He (AHe) and apatite fission track (AFT) ages obtained from two escarpment-perpendicular transects from the footwall of the Loreto fault indicate that footwall denudation in response to rift flank uplift occurred at ~5.5 Ma. This age is younger than ages reported for other fundamental rift structures along the Baja California margin, and may indicate either a diachronous onset of rifting or a westward migration of extension after rifting began. A closely overlapping 40Ar/39Ar age from a lava situated near the

  16. Caracterización de facies, ambientes sedimentarios y procesos de depósito de la sucesión volcanosedimentaria El Coyote, Baja California Sur, México

    OpenAIRE

    Puy y Alquiza, María de Jesús

    2006-01-01

    El presente estudio comprendió la caracterización de Facies, ambientes sedimentarios y procesos de los depósito de la sucesión volcanosedimentaria El Coyote, que se encuentra localizada en la parte Sur de la Península de Baja California a 20 km al Noreste de la Ciudad de La Paz. El conocimiento de todos los procesos que intervinieron en su formación proporcionaron una visión regional de la evolución geológica a lo largo del margen continental del Mioceno inferior-Mioceno superior. Los depósit...

  17. Percepción de la población frente al cambio climático en áreas naturales protegidas de Baja California Sur, México

    OpenAIRE

    Olmos Martínez, Elizabeth; González Ávila, María Eugenia; Contreras Loera, Marcela Rebeca

    2014-01-01

    Este trabajo muestra la percepción de la población humana asentada en las siete áreas naturales protegidas federales de Baja California Sur, desde el punto de vista del conocimiento empírico sobre los cambios en el medio ambiente y recursos naturales ante efectos del Cambio Climático (CC). Se recolectaron datos a partir de la aplicación de 250 encuestas cualitativas en 2011. Los resultados muestran que la mayor parte de la población conoce el significado de CC y que los efectos que perciben s...

  18. Halocoryza Alluaud 1919, sea-side beetles of the Indian, Atlantic (sensu lato, and Pacific Oceans: a generic synopsis and description of a remarkable new species from Baja California Sur, México (Coleoptera, Carabidae, Scaritini, Clivinina

    Directory of Open Access Journals (Sweden)

    Terry Erwin

    2011-09-01

    Full Text Available Information on the three previously described species of Halocoryza Alluaud is updated and a new species for the genus from Isla Carmen, Sea of Cortés, Baja California Sur, México is described. Halocoryza whiteheadiana sp. n. was found at UV light on a beach of that island. This species does not fit the profile of the other three species, i.e., living on coralline beach sands, or in the Mangrove intertidal zone. Two alternative possibilities as to why this is so are suggested and a study plan for testing these possibilities is proposed.

  19. Variación mensual de los estadios gonádicos de Sagitta euneritica, (Chaetognatha) en el complejo lagunar, Bahía Magdalena, Baja California Sur, México

    OpenAIRE

    María Soledad Cota-Meza; María Ana Fernández-Álamo; José Nicolás Álvarez-Cadena; Eduardo González-Rodríguez

    2012-01-01

    Se determinaron la abundancia y proporción de los estadios gonádicos del quetognato Sagitta euneritica en el com- plejo lagunar Bahía Magdalena (CLBM), Baja California Sur, México. Las recolectas se realizaron durante los meses de marzo, junio, julio, agosto, septiembre y noviembre de 1982. S. euneritica fue la especie numéricamente dominante y con más amplia distribución, aportando el 81% de la abundancia total del grupo. S. euneritica se encontró principal- mente en los estadios juveniles 0...

  20. Seismicity, focal mechanisms, and stress distribution in the Tres Virgenes volcanic and geothermal region, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Victor; Munguia, Luis [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (Mexico)

    2006-01-15

    In October 1993 we carried out a seismic monitoring in the Tres Virgenes volcanic region in order to record the background seismicity associated with the volcanic structures, the geothermal field and the tectonic features of the area. Hypocenters for 257 microearthquakes were located in the volcanic edifices and along the northwest right-lateral, strike-slip La Virgen fault. Focal depths range from close to the Earth surface to about 8 km. Shallow depths occur mainly in the volcanic edifices. Deeper seismic events occurred outside the volcanic area. The duration magnitudes of the located microearthquakes range between 1 and 3. The Vp/Vs ratio and the low-Q values estimated suggest heterogeneous material properties in the volcanic structures mainly toward the El Azufre fault and the El Aguajito Caldera, where hydrothermal activity has been reported. The P- and T-axes of focal mechanisms for 90 microearthquakes suggest that the region is under N-S compression and E-W extension, in agreement with the regional tectonic stress field of the NW-SE right-lateral strike-slip transform fault system of the Gulf of California. [Spanish] En octubre de 1993 se llevo a cabo un monitoreo sismico en la region volcanica Las Tres Virgenes con el proposito de registrar la actividad sismica asociada a las estructuras volcanicas, al campo geotermico y a la tectonica local. Se localizaron 257 microsismos con hipocentros en los edificios volcanicos y a lo largo de la falla de rumbo, lateral derecha conocida como falla La Virgen. La profundidad focal de los sismos varia desde los muy cercanos a la superficie de la Tierra hasta los 8 km. Las profundidades someras ocurren principalmente en los edificios volcanicos. Los sismos mas profundos ocurren fuera del area volcanica. La magnitud de duracion de los microsismos localizados varia entre 1 y 3. La razon Vp/Vs y los valores bajos de Q que se estimaron en la zona sugieren un material con propiedades heterogeneas bajo las estructuras

  1. Melampodium sinuatum (Asteraceae endémica del extremo sur de la península de Baja California en peligro de extinción Melampodium sinuatum (Asteraceae, an endangered endemic species to the southernmost tip of the Baja California Peninsula

    Directory of Open Access Journals (Sweden)

    Jose Luis Villaseñor

    2011-09-01

    Full Text Available Melampodium sinuatum Brandegee, especie endémica del extremo sur del estado de Baja California Sur, México, constituye una especie poco conocida debido a su rareza y distribución restringida. No se conoce de más de 5 sitios; todos ellos amenazados por las actividades humanas. El escaso número de individuos por población, así como la estrecha superficie que abarca su área de distribución la colocan como una especie en inminente peligro de extinción, por lo que es imperativo realizar acciones encaminadas a protegerla, las que sin lugar a dudas redundarán en beneficio de otras especies también endémicas de la región donde prospera M. sinuatum e igualmente en riesgo, debido al fuerte impacto antropocéntrico, sobre todo por actividades turísticas, y para las que no existe resguardo alguno.Melampodium sinuatum Brandegee, a species endemic to the southernmost tip of the state of Baja California Sur, Mexico, is poorly known, mostly due to its rarity and narrow geographic distribution range. Historically the species has been collected at only 5 localities and all of these are currently threatened by human activities. The scarce number of individuals per population and its narrow geographic distribution contribute to this species being critically endangered, and it is urgent to carry out activities to help it escape extinction. Without a doubt, such activities will also benefit other endemic species that grow in the vicinity and similarly lack conservation strategies to protect them from the impact of touristic activities in the region.

  2. Vertebrados terrestres registrados mediante foto-trampeo en arroyos estacionales y cañadas con agua superficial en un hábitat semiárido de Baja California Sur, México Terrestrial vertebrates recorded by camera traps in areas with seasonal streams and creeks of superficial waters in a semiarid habitat of Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Erika Mesa-Zavala

    2012-03-01

    Full Text Available Los cuerpos de agua superficial (CAS permanentes o efímeros (pozas, tinajas, escurrimientos, etc. que se encuentran en depresiones del terreno, como arroyos y cañadas, son soporte fundamental para el ecosistema en zonas áridas. Mediante el uso de cámaras-trampa, en este estudio se identifican especies de vertebrados terrestres silvestres presentes en 4 sitios con agua superficial, en el extremo sur de la sierra El Mechudo, Baja California Sur, y se analiza el uso de los CAS por las especies en los periodos de actividad. En cada sitio se caracterizó el hábitat (topografía, vegetación y agua. Los 4 sitios mostraron diferencias en sus características ambientales. Se identificaron 41 especies de vertebrados terrestres (3 reptiles, 31 aves y 7 mamíferos. Se encontraron también varias especies de murciélagos que no fueron identificadas. La riqueza de especies y frecuencia de visita fue diferente en cada sitio. Con excepción de 3 especies de mamíferos, el horario de actividad fue similar en los 4 sitios. La presente investigación aporta información sobre la importancia de los CAS en zonas semiáridas, describiendo el hábitat, las especies y su comportamiento, elementos básicos para la conservación y manejo de los recursos naturales.Permanent or ephemeral water ponds (puddles, catchments, drains, and so on located on ground depressions, such as streams and creeks, are a fundamental support for ecosystems in dry areas. This study identified the species of native terrestrial vertebrates in 4 sites in the southernmost part of the Sierra El Mechudo, B.C.S., including how such species use these bodies of water based on the periods of species activity. Habitats were characterized in 4 sites (topography, vegetation, and water sources; camera-traps were placed around water ponds from March to October 2007. The 4 sites differed in their environmental characteristics. Overall, there were 41 species of terrestrial vertebrates (3 reptiles, 31

  3. Revisión estratigráfica de Punta Coyote (Baja California Sur, México e implicaciones para el volcanismo de la Sierra Madre Occidental y el arco Comondú

    Directory of Open Access Journals (Sweden)

    Puy-Alquiza, M. J.

    2010-12-01

    Full Text Available We present new stratigraphic evidence for a migration of the Upper Volcanic Supergroup that formed the Sierra Madre Occidental (SMO volcanic arc in northwestern Mexico during the Oligocene-Miocene. Particularly we discuss the transition from the frontal arc to the Comondú volcanic arc in Punta Coyote, Baja California Peninsula. This information complements the knowledge of the stratigraphic evolution of the Oligocene-Miocene volcanic arc in Baja California and its correlation with the Upper Volcanic Supergroup of the Sierra Madre Occidental in northwestern Mexico. We present new stratigraphic and sedimentologic data of the volcanosedimentary succession of the lower unit of the Comondú group near of La Paz, Baja California Sur, Mexico, in Punta Coyote. Facies analysis and new 40Ar /39Ar dating allowed to interpret the sedimentary environment and evolution of volcanic pulses in the lower unit of the Comondú group in Punta Coyote. The study area was part of the forearc basin westward to the SMO volcanic arc during the Oligocene to early Miocene. The sedimentary environment of the lower unit of the Comondú group was initially a braided river system that prograded to an alluvial fan environment and three tuffs units: Los Azabaches tuff (30.6±0.4 Ma, La Capilla and El Oro tuffs (22.0±0.4 Ma. The succession studied provides new stratigraphic information related to the evolution of the Oligocene-Miocene volcanic arc in the Baja California Peninsula and its correlation with the Upper Volcanic Supergroup of the SMO in northwestern Mexico.

    Se presentan nuevos datos sobre la estratigrafía y sedimentología de la sucesión volcanosedimentaria de la Unidad Inferior del Grupo Comondú (UIGC al noreste de la ciudad de La Paz, en Punta Coyote, Baja California Sur, México. El análisis de facies, así como las nuevas dataciones 40Ar /39Ar permitieron interpretar la evolución del ambiente sedimentario y

  4. Horizontal movements, vertical-habitat utilization and diet of the jumbo squid ( Dosidicus gigas) in the Pacific Ocean off Baja California Sur, Mexico

    Science.gov (United States)

    Bazzino, Gastón; Gilly, William F.; Markaida, Unai; Salinas-Zavala, César A.; Ramos-Castillejos, Jorge

    2010-07-01

    We deployed four pop-up archival-transmitting (PAT) tags on jumbo squid ( Dosidicus gigas) collected in the Pacific Ocean off the main entrance to Magdalena Bay on the Baja California peninsula in June 2005. This is the first successful deployment of PAT tags on jumbo squid in an area outside the Gulf of California. Summary data were obtained through the ARGOS satellite system for three of the tags; the fourth tag was physically recovered. All of the tagged squid tended to remain on the shallow continental shelf for several days after tagging and then moved offshore into deeper water. Three of the four squid appeared to migrate in a general southerly direction while the fourth remained offshore of Magdalena Bay. All of the squid spent most daylight hours at depths that were associated with the hypoxic oxygen minimum layer, and at night they spent a majority of time in the upper 50 m of the water column. Stomach content analysis and tag temperature-depth data during the first days after tagging revealed that the squid were feeding on pelagic red crabs ( Pleuroncodes planipes) and several larger, neritic fishes over the continental shelf off Magdalena Bay during a seasonal nearshore upwelling. Comparison of our results with those previously collected in the Gulf of California reveal that Dosidicus gigas can vary its behavior and diet to suit local environmental conditions. This adaptability is likely to be an important factor in the ability of D. gigas to invade and colonize new areas.

  5. 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. PMID:26692802

  6. Mapping variations in weight percent silica measured from multispectral thermal infrared imagery - Examples from the Hiller Mountains, Nevada, USA and Tres Virgenes-La Reforma, Baja California Sur, Mexico

    Science.gov (United States)

    Hook, S.J.; Dmochowski, J.E.; Howard, K.A.; Rowan, L.C.; Karlstrom, K.E.; Stock, J.M.

    2005-01-01

    Remotely sensed multispectral thermal infrared (8-13 ??m) images are increasingly being used to map variations in surface silicate mineralogy. These studies utilize the shift to longer wavelengths in the main spectral feature in minerals in this wavelength region (reststrahlen band) as the mineralogy changes from felsic to mafic. An approach is described for determining the amount of this shift and then using the shift with a reference curve, derived from laboratory data, to remotely determine the weight percent SiO2 of the surface. The approach has broad applicability to many study areas and can also be fine-tuned to give greater accuracy in a particular study area if field samples are available. The approach was assessed using airborne multispectral thermal infrared images from the Hiller Mountains, Nevada, USA and the Tres Virgenes-La Reforma, Baja California Sur, Mexico. Results indicate the general approach slightly overestimates the weight percent SiO2 of low silica rocks (e.g. basalt) and underestimates the weight percent SiO2 of high silica rocks (e.g. granite). Fine tuning the general approach with measurements from field samples provided good results for both areas with errors in the recovered weight percent SiO2 of a few percent. The map units identified by these techniques and traditional mapping at the Hiller Mountains demonstrate the continuity of the crystalline rocks from the Hiller Mountains southward to the White Hills supporting the idea that these ranges represent an essentially continuous footwall block below a regional detachment. Results from the Baja California data verify the most recent volcanism to be basaltic-andesite. ?? 2005 Elsevier Inc. All rights reserved.

  7. 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.

  8. Revisión estratigráfica de Punta Coyote (Baja California Sur, México) e implicaciones para el volcanismo de la Sierra Madre Occidental y el arco Comondú

    OpenAIRE

    Puy-Alquiza, M. J.; Miranda-Avilés, R.; M. López-Martínez

    2010-01-01

    We present new stratigraphic evidence for a migration of the Upper Volcanic Supergroup that formed the Sierra Madre Occidental (SMO) volcanic arc in northwestern Mexico during the Oligocene-Miocene. Particularly we discuss the transition from the frontal arc to the Comondú volcanic arc in Punta Coyote, Baja California Peninsula. This information complements the knowledge of the stratigraphic evolution of the Oligocene-Miocene volcanic arc in Baja California and its correlation with the Upper ...

  9. Silica-carbonate stromatolites related to coastal hydrothermal venting in Bahía Concepción, Baja California Sur, Mexico

    Science.gov (United States)

    Canet, Carles; Prol-Ledesma, Rosa María; Torres-Alvarado, Ignacio; Gilg, H. Albert; Villanueva, Ruth Esther; Cruz, Rufino Lozano-Santa

    2005-01-01

    Submarine diffused seepage (from 5 to 15 m depth) and intertidal focused gasohydrothermal venting take place on the West shore of the Bahía Concepción Bay, on Baja California, Mexico. The intertidal venting consists of a cluster of hot springs that occur a few meters offshore, with vent temperatures up to 62 °C and a pH of 6.68. Two irregularly shaped patches of silica-carbonate hot spring deposits occur around the main intertidal vent areas. In addition, a fossil bed of silica-carbonate hot spring deposits of about 75 m long crops out along a cliff next to the active vent area. Both fossil and modern silica-carbonate deposits are finely laminated, and form columnar, bulbous and smooth undulating microstromatolites up to 10 cm thick. Noncrystalline opal-A is the only silica phase present in the modern and fossil hot spring deposits and occurs as microspheres up to 300 nm in diameter forming porous aggregates and irregular clusters, chains and spongy filament networks. The silica supersaturation state of the thermal fluid necessary for opal precipitation is achieved by cooling when it reaches the surface. The presence of preserved microbial remains (diatoms and possibly filamentous microbes) in both modern and fossil deposits reflects the biological activity around the hot springs. The biological activity constrains the fabrics and the textures of the deposit, and could mediate silica deposition. Calcite is the most abundant crystalline phase in the hot spring deposits and forms discontinuous horizons of subhedral bladed crystals within the silica aggregates. Calcite crystals are unusually enriched in 13C, with δ13C V-PDB values between +3.0‰ and +9.3‰. The large 13C enrichment is attributable to a geothermal CO 2 degassing process, which yields calcite supersaturation. The δ18O V-PDB values in calcite, between -10.0‰ and -6.6‰, indicate precipitation from a hot spring fluid that is a mixture of seawater and meteorically derived water. With the methods

  10. Learning in Baja California micro-enterprises

    OpenAIRE

    Michelle Texis Flores; Alejandro Mungaray Lagarda; Martín Ramírez Urquidy; Natanael Ramírez Angulo

    2011-01-01

    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 r...

  11. The supra-detachment tectono-sedimentary record of rifted margins: the example of the Los Barriles Basin, SE Baja California Sur.

    Science.gov (United States)

    Masini, Emmanuel; Robin, Cécile; Geoffroy, Laurent; Strzerzynski, Pierre

    2010-05-01

    The study of rifted margins have shown that the main controlling structures are changing from classical high-angle faults to low-angle detachment fault dominated extension when the crust thins to less than 10 km, which is the case in hyper-extended, magma-poor rifted margins. While the stratigraphic record related to classical high-angle faulting is well constrained, little is known about the tectono-sedimentary evolution of hyper-extended rift systems. A major question remains, how supra-detachment tectono-sedimentary systems are recorded in the stratigraphic record? This remains largely unexplored and must be better constrained by observations. In our poster, we present preliminary results from our study of a rift basin floored by a low-angle detachment system exposed at the southeastern edge of the Baja California Peninsula in the so-called Los Barriles area in the Gulf of California. This area represents one of the best examples of an active transtensional rift system from which the tectono-sedimentary evolution of the rift to drift transition can be studied in the field. The syn-tectonic sedimentary sequence is floored by a detachment fault and is limited oceanward by an extensional allochthon. The syn- to post-tectonic stratigraphy can be summarized into 4 main formations: (1) The Pescadero fluvial fm. (no available ages) evolves upsection from poorly organized polymictic in components and faulted breccias to more granitic and stratified conglomerates. It overlies the extensional allochthon and is tilted continentwards. The channel incisions show EW paleoflows and the upper Pescadero fm. is transitional to the following Refugio fm. (2) The overlying Refugio fm. (Lower Pliocene) occurs as thick marine sandy deposits within the basin axis, is granitic in composition and has average paleocurrents directions trending N-S. The upper part of the fm. is transitional to the following Barriles fm. (3) The Barriles fm. (Upper Miocene - Lower Pleistocene) occurs as very

  12. The 2006 Bahía Asunción Earthquake Swarm: Seismic Evidence of Active Deformation Along the Western Margin of Baja California Sur, Mexico

    Science.gov (United States)

    Munguía, Luis; Mayer, Sergio; Aguirre, Alfredo; Méndez, Ignacio; González-Escobar, Mario; Luna, Manuel

    2015-10-01

    The study of the Bahía Asunción earthquake swarm is important for two reasons. First, the earthquakes are clear evidence of present activity along the zone of deformation on the Pacific margin of Baja California. The swarm, with earthquakes of magnitude M w of up to 5.0, occurred on the coastline of the peninsula, showing that the Tosco-Abreojos zone of deformation is wider than previously thought. Second, the larger earthquakes in the swarm caused some damage and much concern in Bahía Asunción, a small town located in the zone of epicenters. We relocated the larger earthquakes with regional and/or local seismic data. Our results put the earthquake sources below the urban area of Bahía Asunción, at 40-50 km to the north of the teleseismically determined epicenters. In addition, these new locations are in the area of epicenters of many smaller events that were located with data from local temporary stations. This area trends in an E-W direction and has dimensions of approximately 15 km by 10 km. Most earthquakes had sources at depths that are between 4 and 9 km. A composite focal mechanism for the smaller earthquakes indicated right-lateral strike-slip motion and pure-normal faulting occurred during this swarm. Interestingly, the ANSS earthquake catalog of the United States Geological Survey (USGS) reported each one of these faulting styles for two large events of the swarm, with one of these earthquakes occurring 2 days before the other one. We associate the earthquake with strike-slip mechanism with the San Roque Fault, and the earthquake with the normal faulting style with the Asunción Fault. However, there is need of further study to verify this possible relation between the faults and the earthquakes. In addition, we recorded peak accelerations of up to 0.63g with an accelerometer installed in Bahía Asunción. At this site, an earthquake of M w 4.9 produced those high values at a distance of 4.1 km. We also used the acceleration dataset from this site

  13. Crecimiento económico, desarrollo sustentable y turismo: Una aproximación del posicionamiento de Baja California Sur (BCS en el Barómetro de Sustentabilidad

    Directory of Open Access Journals (Sweden)

    Reyna Ibáñez Pérez

    2011-01-01

    Full Text Available Uno de los mayores anhelos de toda sociedad es alcanzar un nivel económico elevado; otro es el de tener la oportunidad de disfrutar eternamente de los servicios proporcionados por la madre naturaleza. Sin embargo, las tendencias indican que se experimenta un deterioro importante en el ambiente, a la par, de una elevada concentración de pobreza. Esto, aunado a la dependencia que algunas entidades y países han desarrollado en relación a actividades -como la turística- se ha convertido en una de las preocupaciones centrales de los gobiernos, el establecer mediciones para determinar si las pautas de crecimiento y desarrollo, van acorde con el cuidado del ambiente y el bienestar de las personas. Por ello, dentro de este artículo se analizan la evolución del crecimiento económico y posicionamiento de Baja California Sur (BCS -un estado con importante actividad turística- en el Barómetro de Sustentabilidad. En la introducción, se aprecia la evolución del concepto de crecimiento y desarrollo, para continuar con la caracterización de la zona de estudio. Posteriormente, se detalla la metodología empleada. Enseguida, se estudia la situación actual del sector turístico en BCS y la evolución del crecimiento y desarrollo económico. En el análisis de resultados, se describen los factores que ubican a BCS en un nivel Medio de sustentabilidad. Finalmente, se presentan algunas reflexiones en relación a los retos que en materia de turismo, crecimiento económico, desarrollo sustentable afronta BCS.

  14. Capacidad de carga turÍstica como base para el manejo sustentable de actividades ecoturísticas en Unidades de Manejo Ambiental (UMA de Baja California Sur (BCS

    Directory of Open Access Journals (Sweden)

    Reyna Ibañez Pérez

    2016-01-01

    Full Text Available Existen zonas ejidales con UMA ́s, que desean incursionar en el turismo alternativo; tal es el caso del Nuevo Centro Poblacional Ejidal (NCPE, Ley Federal de Aguas Número 3, que se extiende a tres municipios de Baja California Sur (BCS, posee una UMA y se destaca por buscar opciones para reactivar su economía. En este trabajo se presentan los resultados de un estudio de Capacidad de Carga Turística (CCT, realizada en dos senderos de ese ejido, mediante la aplicación de la metodología de Cifuentes, que busca establecer el número máximo de visitas que puede recibir un área con base en sus condiciones físicas, biológicas y de manejo; cuya estimación, requirió de la revisión de censos de flora y fauna, de información geológica, climatológica, geográfica, ambiental, social, económica, turística, así como trabajo de campo. Los resultados indican que, en el NCPE, Ley Federal de Aguas Número 3, existen dos senderos con potencialidad turística para los cuales, se ha estimado una Capacidad de Carga Efectiva (CCE de 18 visitantes/día para el sendero del arroyo El Camarón y de 10 visitantes/día sendero del arroyo El Saucito. Las cifras anteriores, son un referente para el establecimiento de medidas de control de las visitas en ambos senderos

  15. Learning in Baja California micro-enterprises

    Directory of Open Access Journals (Sweden)

    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.

  16. Geology, Geochemistry and Re-Os systematics of manganese deposits from the Santa Rosalía Basin and adjacent areas in Baja California Sur, México

    Science.gov (United States)

    Del Rio Salas, R.; Ruiz, J.; Ochoa-Landín, L.; Noriega, O.; Barra, F.; Meza-Figueroa, D.; Paz-Moreno, F.

    2008-06-01

    The manganese ores in the Santa Rosalía region, western Mexico, are mainly stratiform horizons or mantos, constrained to the initial stages of sedimentary cycles of the Miocene Boléo Formation. The manganese mineralization is generally restricted to isolated paleo-basins and related to NW-SE faults formed during the early stages of the opening of the Gulf of California. Jasper, Fe, and Mn oxides associated to the NW-SE structures may represent feeder zones for the mineralized system. The manganese oxide minerals include pyrolusite, cryptomelane, todorokite, hollandite, jacobsite, and pyrochroite. Trace elements in the manganese ores indicate a hydrothermal origin for the deposits of the Santa Rosalía area. Rare earth elements (REE) patterns obtained for manganese minerals from the Lucifer and El Gavilán deposits also support a hydrothermal origin, whereas the middle REE enrichment observed in samples from the Boléo district indicates mixing between hydrothermal and hydrogenous sources. Osmium and rhenium concentrations of the manganese minerals range between 33-173 ppt and 0.14-89 ppb, respectively. The initial 187Os/188Os ratios in the manganese oxides from Lucifer and the Boléo district range between 0.43 to 0.51 and 0.70 to 0.74, respectively. These ratios are different from seawater at 7 Ma (0.84-0.89), which suggests important contributions of osmium from underlying rocks such as the Miocene volcanic rocks and the Cretaceous quartz-monzonite basement. Field evidence, manganese oxide mineralogy coupled with major and trace element geochemistry and Re-Os systematics support a hydrothermal origin for the manganese deposits from the Santa Rosalía region. The ore deposition style indicates an exhalative-intraformational environment restricted to isolated basins in a diagenetic stage related to the initial evolution of the Gulf of California.

  17. Hydrochemical-isotopic and hydrogeological conceptual model of the Las Tres Vı´rgenes geothermal field, Baja California Sur, México

    Science.gov (United States)

    Portugal, E.; Birkle, P.; Barragán R, R. M.; Arellano G, V. M.; Tello, E.; Tello, M.

    2000-09-01

    water from the Gulf of California in the deep reservoir. Both conditions indicate recharge of the reservoir by meteoric water during glacial periods in Holocene or Pleistocene time, or a magmatic origin of the reservoir fluids. The slightly positive slope of the δ18O- δD line of geothermal fluids and its intermediate isotopic composition—between the surface samples and magmatic ("andesitic") water indicate that magmatic ("andesitic") water contributes approximately 30% to the geothermal fluid composition, whereas "fossil" meteoric water represents the major component (70%). The geothermal reservoir is considered to represent a hydrostatic, stagnant flow system. Based on the observed linear correlation between the isotopic composition and the altitude of the surface manifestations, the isotopic composition and altitude of the former recharge were determined as δ 18O=-9.7‰ and δ D=-67.3‰, and 350 m.a.s.l., respectively. This altitude is interpreted as mean (average) recharge elevation. Scarcity of permanent rivers, low density of springs and domestic wells, as well as low precipitation rates, reflect restricted distribution of shallow groundwater systems in the study zone. These systems are related to isolated, local aquifers composed of valley fillings.

  18. 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

  19. Sistema Híbrido (Solar-Eólico) con apoyo de gas natural para la generación de energía eléctrica en Baja California Sur (México)

    OpenAIRE

    Fernández Ribaya, Yolanda

    2012-01-01

    Una aplicación prometedora de las energías renovables son las instalaciones de sistemas híbridos, formados por energías renovables (solar, eólica, biomasa e hidráulica) y energías convencionales. El estado mexicano de Baja California cuenta con importantes recursos eólicos y solares para la generación de electricidad; sin embargo debido a su naturaleza intermitente, estas fuentes requieren de un sistema de apoyo convencional para garantizar el suministro eléctrico. Este estudio describe el de...

  20. Experiential environmental learning: A case study of innovative pedagogy in Baja Sur, Mexico

    Science.gov (United States)

    Schneller, Andrew Jon

    This mixed methods case study describes an innovative two-semester middle school environmental learning course that departs from traditional Mexican expository pedagogy through the incorporation of experiential and service learning. This research takes place in a small middle school in Pescadero, Baja California Sur, Mexico. The research approach utilized in the study adds to the handful of studies in this cross-disciplinary field by employing quantitative methodologies to measure course outcomes on student environmental knowledge, perceptions, and actions, while simultaneously qualitatively describing the behavioral, educational, environmental, and social experiences of students. This research employs Dewey's theories of experience---as well as those of more contemporary authenticity theorists---in order to identify the philosophies that advocate incorporating experiential pedagogy within the curriculum. Implications for Mexican educational policy, practical pedagogical applications, and theory are discussed.

  1. Glory, Vortex Street off Baja California

    Science.gov (United States)

    2007-01-01

    On June 19, 2007, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured both a vortex street and a glory visible amid the lattice of clouds over the Pacific Ocean off Baja California. In this image, the swirling clouds known as vortex streets appear along the left edge of the image, stretching southward from Isla Guadalupe. Another NASA satellite captured an earlier example of vortex streets in June 2000. These atmospheric vortices, known as Von Karman vortex streets, often occur in the wake of an obstacle to air flow, such as an island. Stratocumulus clouds--low-lying, sheets of puffy clouds-- over the ocean show the impact of the island on air flow visible though their alternating pattern of clockwise and counter-clockwise swirls. Southeast of the vortex street, a glory, which resembles a rainbow, hovers above the cloud cover. The glory is faint but large, 200 to 300 kilometers long, along a north-south orientation. This phenomenon can occur when the satellite passes directly between the Sun and a bank of clouds below. (People also observe them while looking down on clouds from airplanes.) Not just any kind of cloud can produce a glory; only clouds composed entirely of water droplets (as opposed to ice crystals) can make them. The droplets that form glories generally have diameters of less than 50 micrometers (a micrometers is a millionth of a meter). The water droplets bend the light, showing its different wavelengths, or colors. In this glory, reds and oranges are most visible. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center.

  2. 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...

  3. Seasonal changes in a fish assemblage associated with mangroves in a coastal lagoon of Baja California Sur, Mexico Cambios estacionales de la comunidad de peces asociada a zonas de manglar en una laguna costera de Baja California Sur, México

    Directory of Open Access Journals (Sweden)

    Jesús Rodríguez-Romero

    2011-07-01

    Full Text Available The fish assemblage in a coastal lagoon with mangroves known as "Rancho Bueno" was determined and associated with environmental parameters. We used an experimental otter trawl net to catch the fish, and 62 fish species were identified from 48 genera and 30 families. The most abundant species were: Etropus crossotus, Eucinostomus gracilis, Paralabrax maculatofasciatus, Sphoeroides annulatus, and Eucinostomus dowii. The water temperature changed seasonally, being warm from July through December and cold from January through June. We found more fish species during the warm season than during the cold season. The southern area of the coastal lagoon had the highest diversity and species richness. The small size of the fishes registered confirms the ecological role of coastal lagoons as nursery areas that offer protection and feeding to commercially important fish near Bahía Magdalena, Mexico.Se determinó la estructura de peces asociada a factores ambientales en una laguna costera con manglar denominada "Rancho Bueno". Se utilizó una red de arrastre experimental para la captura y se identificaron 62 especies de peces de 48 géneros y 30 familias. Las especies más importantes fueron Etropus crossotus, Eucinostomus gracilis, Paralabrax maculatofasciatus, Sphoeroides annulatus y Eucinostomus dowii. La temperatura del agua varió estacionalmente, siendo cálida de julio a diciembre y fría de enero a junio. Se registró un mayor número de especies de peces durante la época cálida comparada con la época fría. La zona sur de la laguna costera presentó una mayor diversidad y riqueza específica. El menor tamaño de los peces registrados, confirma el papel ecológico de las lagunas costeras, consideradas como áreas de crianza las cuales proporcionan protección y alimentación a los peces de importancia comercial cerca de Bahía Magdalena, México.

  4. A new species of Ceanothus from northern Baja California

    Science.gov (United States)

    Boyd, Steve; Keeley, Jon E.

    2002-01-01

    Ceanothus bolensis S. Boyd & J. Keeley is a new species in the subgenus Cerastes from northwestern Baja California, Mexico. It is well represented at elevations above 1000 m on Cerro Bola, a basaltic peak approximately 35 km south of the U.S./Mexican border. It is characterized by small, obovate to oblanceolate, cupped, essentially glabrous leaves with sparsely toothed margins, pale blue flowers, and globose fruits lacking horns. Principal components analysis on morphological traits shows it to be distinct from other members of Cerastes which are distributed away from the coast in southern California and Baja California, Mexico. These phenetic comparisons also suggest that Ceanothus otayensis should not be subsumed under C. crassifolius, as treated in the Jepson Manual, but rather should be retained at specific rank as well.

  5. Neogene sedimentary evolution of Baja California in relation to regional tectonics

    Science.gov (United States)

    Helenes, J.; Carreño, A. L.

    1999-11-01

    During the Neogene, the tectonic and sedimentary evolution of the Baja California Peninsula followed four stages: (1) during the early Miocene (22 Ma), the initiation of transform motion between Pacific and North American plates, caused a rapid subsidence in the Continental Borderland Province and in some adjacent areas.This subsidence coincided in time with with a global rise in sea level. At this time, the eastern and southern parts of the peninsula did not show any evidence of subsidence. (2) During the middle Miocene (12 Ma), normal and strike slip faulting migrated eastward, causing subsidence in the northern part of the Gulf of California, where the oldest Tertiary marine sedimentary rocks were deposited. The areas in central Baja California Sur and the central part of the Gulf itself received abundant volcanic deposits related to continental extension. (3) During the late Miocene (8 Ma), the western margin of the Peninsula changed to a slightly compressive regime, while the northern part of the Gulf contained a marine basin with upper bathyal environments. The central area of the Gulf continued receiving abundant volcanic deposits, while the Los Cabos block received marine sedimentation, correlatable with sedimentary units reported from the continental margins in Nayarit, Jalisco and Michoacán. (4) Beginning in the early Pliocene (5 Ma), the present configuration of the Gulf of California developed through right-lateral strike slip and extension in the Gulf itself. Since Pliocene times, the Gulf presents widespread marine sedimentation with deep basins reaching lower bathyal depths.

  6. The physicochemical characterization of cave paintings of Baja California

    International Nuclear Information System (INIS)

    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 stone on stone, 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)

  7. 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.

  8. Recognition on space photographs of structural elements of Baja California

    Science.gov (United States)

    Hamilton, W.

    1971-01-01

    Gemini and Apollo photographs provide illustrations of known structural features of the peninsula and some structures not recognized previously. An apparent transform relationship between strike-slip and normal faulting is illustrated by the overlapping vertical photographs of northern Baja California. The active Agua Blanca right-lateral strike-slip fault trends east-southeastward to end at the north end of the Valle San Felipe and Valle Chico. The uplands of the high Sierra San Pedro Martir are a low-relief surface deformed by young faults, monoclines, and warps, which mostly produce west-facing steps and slopes; the topography is basically structural. The Sierra Cucapas of northeasternmost Baja California and the Colorado River delta of northwesternmost Sonora are broken by northwest-trending strike-slip faults. A strike-slip fault is inferred to trend northward obliquely from near Cabo San Lucas to La Paz, thence offshore until it comes ashore again as the Bahia Concepcion strike-slip fault.

  9. 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.

  10. Determinación e interpretación de la calidad del agua y del suelo en el Distrito de Riego 066 Del Valle de Santo Domingo, Baja California Sur.

    OpenAIRE

    Marín Celestino, Ana Elizabeth

    2013-01-01

    La calidad del agua y del suelo en un área agrícola son factores principales que repercuten en su sustentabilidad, debido a que una baja calidad en estos recursos reduce los rendimientos y causa toxicidad en los cultivos entre otros efectos adversos, afectando la productividad de la actividad y al ambiente. En el Distrito de Riego 066 del Valle de Santo Domingo se han detectado alteraciones notables en estos recursos, por esta razón este estudio planteó como objetivo evaluar e interpretar la ...

  11. 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

  12. 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.

  13. 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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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 .

  17. Sloughed skin: a method for the systematic colletion of tissue samples from Baja California blue whales

    OpenAIRE

    Gendron, Diane; Mesnick, S.L.

    2001-01-01

    The frequency of occurrence of naturally sloughed skin was investigated to verify the feasibility of this method to study blue whale genetics off Baja California. Sloughed skin was recorded in 97% of 337 surfacing intervals with blue whales, Balaenoptera musculus, along the Baja California peninsula, Mexico. No significant difference (P>0.05) was found in size of pieces of skin sloughed from whales in different habitats, sea surface temperatures or whether they were alone or in pairs. Samp...

  18. Análisis de la sequía y desertificación mediante índices de aridez y estimación de la brecha hídrica en Baja California Sur, noroeste de México

    Directory of Open Access Journals (Sweden)

    Enrique Troyo Diéguez

    2014-01-01

    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 dry-ness. 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 water deficit, which is proposed in this paper. The maximum value of BHE (10 units, indicating prevalence of drought, is observed from February to June in almost the entire state. Results suggest that BHE tend to increase and intensify under climate change conditions, which is more evident from the South towards the North of the State. According to the trends of the indexes IDHA, ISHA and BHE, under six scenarios of climatic change for four regions of BCS , BHE can be estimated with a major significance for the region Gustavo Díaz Ordaz-Vizcaíno, Mulegé County, in the North of the State, where may reach a value BHE max = 10 and BHE min = 7.23, values which suggest extreme

  19. 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 Libraries…

  20. Reunión subregional de planificación de ODINCARSA (Red de Datos e Información Oceanográficos para las Regiones del Caribe y América del Sur), Universidad Autónoma de Baja California (UABC) Ensenada, Mexico, 7-10 December 2009,

    OpenAIRE

    2010-01-01

    La reunión se inició el 7 de diciembre de 2009 en el Instituto de Investigaciones Oceanológicas (IIO) de la Universidad Autónoma de Baja California. El Dr. Carlos Torres, en representación de los anfitriones, dio la bienvenida a los participantes. Hizo uso de la palabra el Sr. Peter Pissierssens, Coordinador del Programa IODE y Jefe de la Oficina de Proyectos de la COI para IODE en Ostende. Su alocución figura en el Anexo IV. Seguidamente se dirigió a los presentes el biólogo Francisco Bri...

  1. 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.

  2. 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

  3. Seasonality of the transitional region of the California Current System off Baja California

    Science.gov (United States)

    Durazo, Reginaldo

    2015-02-01

    Hydrographic data collected over the period 1997-2013 are analyzed to investigate the seasonality of hydrographic features and associated geostrophic flows off the Baja California peninsula. The upper ocean in the region was found to be homogeneous in winter and spring but subdivided into two regions in the summer and autumn. In the first case, the system typically shows relatively low-temperature and salinity waters, which give it a subarctic character. In the second, only the region north of Punta Eugenia (28°N) maintains subarctic characteristics, while the southern region receives an inflow of tropical and subtropical waters that results from the weakening of northwesterly winds, which allows the poleward advection of surface waters. Also during this period, a positive wind stress curl promotes the zonal advection of North Pacific's eastern edge waters into the coast and to the north as a surface coastal flow. Average seasonal patterns of geostrophic flow at 200 dbar revealed that the differentiation into provinces is also evident at that depth, with two clearly defined cyclonic structures in summer and autumn, both separated at the latitude of Punta Eugenia. The analyses conducted also showed a clear continuity of the California undercurrent along the shelf break, with more diffuse currents in the winter. Poleward flows were observed throughout the water column, especially in summer and autumn, although the origin of the surface flow does not necessarily involve a surfacing of the California Undercurrent.

  4. Diversity of free-living marine nematodes (Enoplida) from Baja California assessed by integrative taxonomy

    OpenAIRE

    Pereira, Tiago José; Fonseca, Gustavo; Mundo-Ocampo, Manuel; Guilherme, Betânia Cristina; Rocha-Olivares, Axayácatl

    2010-01-01

    We used morphological and molecular approaches to evaluate the diversity of free-living marine nematodes (order Enoplida) at four coastal sites in the Gulf of California and three on the Pacific coast of Baja California, Mexico. We identified 22 morphological species belonging to six families, of which Thoracostomopsidae and Oncholaimidae were the most diverse. The genus Mesacanthion (Thoracostomopsidae) was the most widespread and diverse. Five allopatric species, genetically and morphologic...

  5. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Primer registro de una colonia de Leptonycteris curasoae (Chiroptera: Phyllostomidae) en Baja California, México First record of a Leptonycteris curasoae (Chiroptera: Phyllostomidae) colony in Baja California, Mexico

    OpenAIRE

    Aldo A. Guevara-Carrizales; Roberto Martínez-Gallardo; Arnulfo Moreno-Valdez

    2010-01-01

    En el presente trabajo se registra por primera vez una colonia del murciélago filostomido Leptonycteris curasoae para Baja California, México, que también constituye la segunda localidad en el estado donde se registra esta especie.We report the first record of a colony of the phillostomid bat Leptonycteris curasoae for Baja California, Mexico. This region represents the second locality reported for this species in the state.

  8. The status of shark and ray fishery resources in the Gulf of California: applied research to improve management and conservation

    OpenAIRE

    Joseph J Bizzarro; Smith, Wade D.; Robert E Hueter; Tyminski, John; Márquez– Farías, J. Fernando; Castillo–Géniz, J. Leonardo; Cailliet, Gregor M.; Villavicencio–Garayzar, Carlos J.

    2009-01-01

    Seasonal surveys were conducted during 1998–1999 in Baja California, Baja California Sur, Sonora, and Sinaloa to determine the extent and activities of artisanal elasmobranch fisheries in the Gulf of California. One hundred and forty–seven fishing sites, or camps, were documented, the majority of which (n = 83) were located in Baja California Sur. Among camps with adequate fisheries information, the great majority (85.7%) targeted elasmobranchs during some part of the year. Most small, demers...

  9. Remote sensing exploration for metallic mineral resources in central Baja California

    Science.gov (United States)

    Baker, R. N.

    1977-01-01

    Remote sensor data (primarily LANDSAT) was analyzed by photogeologic and computer-assisted enhancement techniques to evaluate the metallic mineral potential of Baja California. Overlays were prepared at 1:1,000,000 and 1:500,000 and included known geologic relationships and mineral occurrences, lineament, drainage and structural patterns, tonal anomalies, and enhancement results. Computer-assisted enhancement and classification of the test sites was performed using the IMAGE 100 system to identify subtle tonal anomalies thought related to mineralization using known sites as analysis guides. Mineral potential maps of Baja California were generated from these analyses and the ten highest priority targets visited. Preliminary assay results (atomic absorption analysis) for the samples recovered showed moderate to high geochemical anomalies for Copper (10 of 12 samples), Zinc (3 of 12 samples) and Lead (4 of 12 samples).

  10. Assessing neuropsychological performance in a migrant farm working Colonia in Baja California, Mexico: a feasibility study.

    Science.gov (United States)

    Bousman, Chad A; Salgado, Hugo; Hendrix, Terence; Fraga, Miguel; Cherner, Mariana

    2011-08-01

    Neuropsychological impairments (NPI) can lead to difficulties in daily functioning and ultimately contribute to poor health outcomes. However, evidence for the feasibility of NPI assessment in resource-limited settings using tests developed in high literacy/high education cultures is sparse. The main objectives were to: (1) determine the feasibility and appropriateness of conducting neuropsychological assessments among a migrant farm worker population in Baja California, Mexico and (2) preliminary describe neuropsychological test performance in this unique population. A neuropsychological test battery was administered to 21 presumably healthy adults (8 men, 13 women) during a two-day international health services and research collaboration. All but one neuropsychological test (i.e. figure learning) was feasible and appropriate to administer to the study population. Contrary to expectations, participants performed better on verbal rather than nonverbal neuropsychological tests. Results support inclusion of neuropsychological tests into future studies among migrant farm worker populations in Baja California, Mexico. PMID:21264515

  11. Assessing Neuropsychological Performance in a Migrant Farm Working Colonia in Baja California, Mexico: A Feasibility Study

    OpenAIRE

    Bousman, Chad A.; Salgado, Hugo; Hendrix, Terence; Fraga, Miguel; Cherner, Mariana; ,

    2011-01-01

    Neuropsychological impairments (NPI) can lead to difficulties in daily functioning and ultimately contribute to poor health outcomes. However, evidence for the feasibility of NPI assessment in resource-limited settings using tests developed in high literacy/high education cultures is sparse. The main objectives were to: (1) determine the feasibility and appropriateness of conducting neuropsychological assessments among a migrant farm worker population in Baja California, Mexico and (2) prelim...

  12. Coastal upwelling activity on the Pacific shelf of the Baja California Peninsula

    OpenAIRE

    O. Zaytsev; Cervantes Duarte, Rafael; Montante, Orzo; Gallegos García, A.

    2003-01-01

    High primary productivity on the Pacific coast of the Baja California Peninsula is usually related to coastal upwelling activity that injects nutrients into the euphotic zone in response to prevailing longshore winds (from the northwest to north). The upwelling process has maximum intensity from April to June, with the coastal upwelling index varying from 50 to 300 m3/s per 100 m of coastline. Along the entire coast of the peninsula, the upwelling intensity changes in accordance with local wi...

  13. 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.

  14. Heavy metal accumulation in four species of sea turtles from the Baja California peninsula, Mexico.

    Science.gov (United States)

    Gardner, Susan C; Fitzgerald, Sionnan L; Vargas, Baudilio Acosta; Rodríguez, Lia Méndez

    2006-02-01

    Heavy metals were assessed in four species of sea turtles from the Baja California Peninsula, Mexico, representing the first report of heavy metal concentrations in tissues of post-yearling sea turtles from the Eastern Pacific. Concentrations of Cd measured in C. mydas kidney (653 microg/g dry wt) were the highest ever reported for any sea turtle species. Cd accumulated preferentially in kidney and the ratios of kidney to liver Cd in Baja California turtles were among the highest reported for sea turtles globally. Zn, Ni, and Mn concentrations were also significantly higher in kidney than other tissues, while Cu and Fe were greatest in liver, and all metals were lowest in muscle. With the exception of one value (69.9 microg/g in kidney of C. caretta), Pb was low in all tissues from Baja California. In comparisons across species, kidney of C. mydas had greater Zn and Ni concentrations as compared to other species, although there was no difference in liver metal levels among the species. Positive correlations were detected in the concentrations of Cd, Cu and Ni with the straight carapace length of C. caretta. PMID:16502335

  15. 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.

  16. 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.

  17. Una mirada hacia las organizaciones civiles de apoyo al migrante en Baja California y Sonora

    Directory of Open Access Journals (Sweden)

    José Ascensión Moreno Mena

    2013-01-01

    Full Text Available Los migrantes en tránsito, los que intentan cruzar y los devueltos de Estados Unidos, que son presa de todo tipo de autoridad y del crimen organizado, demandan mucha atención, que no es brindada debidamente por el sector gubernamental. Ante tal situación, la sociedad civil organizada en Baja California y Sonora ha tenido que asistir a los deportados y aspirantes a ingresar al vecino país, incluyendo la promoción y defensa de los derechos humanos y la conformación de redes formales e informales. Baja California, debido a su larga experiencia en el tránsito de migrantes, está mejor preparado para atenderlos en cuanto a equipos e infraestructura física y humana no gubernamental. Los datos presentados son resultado de una encuesta aplicada a 21 de las 23 organizaciones civiles existentes en Baja California y a 9 de las 11 en Sonora.

  18. Cryptic vicariance in Gulf of California fishes parallels vicariant patterns found in Baja California mammals and reptiles.

    Science.gov (United States)

    Riginos, Cynthia

    2005-12-01

    Comparisons across multiple taxa can often clarify the histories of biogeographic regions. In particular, historic barriers to movement should have affected multiple species and, thus, result in a pattern of concordant intraspecific genetic divisions among species. A striking example of such comparative phylogeography is the recent observation that populations of many small mammals and reptiles living on the Baja California peninsula have a large genetic break between northern and southern peninsular populations. In the present study, I demonstrate that five species of near-shore fishes living on the Baja coastline of the Gulf of California share this genetic pattern. The simplest explanation for this concordant genetic division within both terrestrial and marine vertebrates is that the Baja Peninsula was fragmented by a Plio-Pleistocene marine seaway and that this seaway posed a substantial barrier to movement for near-shore fishes. For some fish species, the signal of this vicariance in mtDNA has been eroded by gene flow and is not evident with classic, equilibrium measures of population structure. Yet, significant divisions are apparent in coalescent analyses that jointly estimate divergence with gene flow. The genetic divisions within Gulf of California fishes also coincide with recognized biogeographic regions based on fish community composition and several environmental factors. It is likely that adaptation to regional environments and present-day oceanographic circulation limit gene exchange between biogeographic regions and help maintain evidence of past vicariance. PMID:16526514

  19. 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...

  20. 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

  1. Potential toxicity of chemical elements in beach sediments near Santa Rosalía copper mine, Baja California Peninsula, Mexico

    Science.gov (United States)

    Jonathan, M. P.; Shumilin, E.; Rodríguez-Figueroa, G. M.; Rodriguez-Espinosa, P. F.; Sujitha, S. B.

    2016-10-01

    A total of 17 beach sediment samples were analyzed for the determination of thirty-one chemical elements to generate a geochemical data set from the Santa Rosalía mining area in the State of Baja California Sur (south), Mexico. Results indicate that the beach sediments were enriched in Cu, Zn, Co, Pb, Cd (3856, 2599, 635, 236, 240 mg kg-1, respectively) and in Mn (2.01%) due to a century of mining and smelting activities. Comparison of these concentration with ecotoxicological sediment quality criteria (ERL, ERM, LEL, SEL) indicated the values of As, Cd, Co, Cr, Cu, Ni, Pb, Sr, Zn and Mn were higher than the permissible limits. Average values of the calculated geoaccumulation index (Igeo) suggest that the key elements such as Mn, Ba, Cd, Co, Mo, Pb, Sr, Zn are categorized in class 4 to 6 encompassing the strongly polluted to extremely polluted groups. The association and enrichment of the above elements are also well supported statistically (factor analysis) which points to the role of Fe-Mn oxides as the main scavengers for retaining these chemical elements.

  2. 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

  3. Configuración parlamentaria y productividad legislativa en el Congreso de Baja California

    OpenAIRE

    Cuauhtémoc López Guzmán

    2002-01-01

    Este trabajo presenta un análisis estático y dinámico del Congreso del Estado de Baja California. El enfoque estático aborda el origen histórico del congreso, sus facultades constitucionales y la composición partidista. El enfoque dinámico integra un estudio comparativo de la productividad legislativa en dos grandes periodos: el periodo de gobierno unificado (1953- 1989) y el periodo de gobiernos divididos (1989-2001). Además, se construyeron indicadores para analizar la dinámica parlamentari...

  4. Una mirada hacia las organizaciones civiles de apoyo al migrante en Baja California y Sonora

    OpenAIRE

    José Ascensión Moreno Mena; Lya Niño Contreras

    2013-01-01

    Los migrantes en tránsito, los que intentan cruzar y los devueltos de Estados Unidos, que son presa de todo tipo de autoridad y del crimen organizado, demandan mucha atención, que no es brindada debidamente por el sector gubernamental. Ante tal situación, la sociedad civil organizada en Baja California y Sonora ha tenido que asistir a los deportados y aspirantes a ingresar al vecino país, incluyendo la promoción y defensa de los derechos humanos y la conformación de redes formales e informale...

  5. Evaluación del aprendizaje de las microempresas de Baja California

    OpenAIRE

    Michelle Texis Flores; Martín Arturo Ramírez Urquidy

    2015-01-01

    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 ...

  6. Preliminary assessment of biodiesel generation from meat industry residues in Baja California, Mexico

    International Nuclear Information System (INIS)

    Oil derived fuels constituted a main energy source during the last fifty years, although their high price limited their accessibility. Prospective studies indicated that economic and environmental problems promoted biodiesel production using biomass and residues like animal fat, along with meat and bones, among others. The regional inventory of the available fat in meat industry, as well as the estimation of the biodiesel potential production demonstrated that the biodiesel generated from animal fat, combined with diesel from oil in a 2% biodiesel blend could power 25% of the trucks and passenger vehicles registered in 2007 in Baja California, Mexico. (author)

  7. Algunos geosímbolos de Baja California. Identidad y memoria colectiva de la ruralidad

    OpenAIRE

    Alberto Tapia Landeros

    2009-01-01

    Este documento presenta una descripción de algunos lugares de Baja California que históricamente han sido nombrados por el ser humano nativo y colono en virtud de su utilidad como orientadores al viajar, porque poseen agua, han sido testigos de algún hecho relevante, son mencionados por motivos religiosos, reconocidos en cultos indígenas, destacados por razones políticas y cualquier otra causa para asignarles un significado simbólico. El conocimiento de estos sitios se ha obtenido a través de...

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Commercial Whaling, Especially for Gray Whales, Eschrichtius robustus, and Humpback Whales, Megaptera novaeangliae, at California and Baja California Shore Stations in the 19th Century (1854–1899)

    OpenAIRE

    Reeves, Randall R.; Smith, Tim D.

    2010-01-01

    Shore whaling along North America’s California and Baja California coasts during 1854–99 was ancillary to the offshore and alongshore American whale fishery, which had begun in the North Pacific in the early 1800’s and was flourishing by the 1840’s. From its inception at Monterey, Calif., in the mid 1850’s, the shore fishery, involving open boats deployed from land to catch and tow whales for processing, eventually spread from Monterey south to San Diego and Baja California and north...

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Numerical understanding of regional scale water table behavior in the Guadalupe Valley aquifer, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    J. R. Campos-Gaytan

    2006-05-01

    Full Text Available A regional groundwater flow model was developed, in order to evaluate the water table behavior in the region of the Guadalupe Valley, in Baja California, Mexico. 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 semi-arid climate with low surface water availability; resulting in an extensive use of groundwater in local aquifer. Based on historic piezometric information of the last two decades, however, a negative evolution could be observed, resulting a negative storage volume. So far, there is not an integral hydrogeological evaluation that determine the real condition of the groundwater resource, and that permit to planning a management of the Guadalupe Valley Aquifer. A steady-state calibration model was carried out in order to obtain the best possible match to measured levels at the Guadalupe Valley Aquifer. The contours of calculated water table elevations for January 1983 were reproduced. Generally, the comparison of the observed and calculated water table configurations have a good qualitative and quantitatively adjustment. Nowadays, it is count with a hydrogeological model that can be used for simulates the groundwater flow in the region of the Guadalupe Valley.

  13. 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.

  14. The Surface Expression of Radiocarbon Anomalies near Baja California during Deglaciation

    Science.gov (United States)

    Lindsay, C. M.; Lehman, S.; Marchitto, T. M.; Ortiz, J. D.; van Geen, A.

    2013-12-01

    In 2007, Marchitto et al. noted that periods of declining atmospheric radiocarbon activity (Δ14C) during the Heinrich 1 and Younger Dryas stadials coincided with intervals of rising atmospheric CO2, as well as extremely 14C-depleted carbon at intermediate depths near Baja California, Mexico. They interpreted this as evidence of aged carbon emerging through the intermediate ocean to the atmosphere from an isolated deep marine reservoir, and proposed that the signal was transported to Baja from the Southern Ocean via Antarctic Intermediate Water. Here we report on measurements from the same core used by Marchitto et al. (2007) that enable us to reconstruct the Δ14C of surface waters. 14C was measured in mono-specific samples of G. ruber, G. sacculifer and G. bulloides planktonic foraminifera. Independent calendar ages were provided by the published age model, which tied diffuse spectral reflectance to the layer-counted GISP2 oxygen isotope record. Preliminary results reveal that surface ocean Δ14C relative to the coeval atmosphere was lower during periods of low benthic Δ14C, consistent with upwelling and subsequent mixing and/or partial atmospheric equilibration of the intermediate-depth signal. Planktic Δ14C was higher during the Bølling-Allerød/Antarctic Climate Reversal (BA/ACR), reflecting upwelling of better-ventilated waters at a time when benthic Δ14C had a modern-like offset from the atmosphere. G. ruber Δ14C is lower than in other planktonic species during deglaciation. We propose that this offset arises from a late summer G. ruber calcification habitat and a spring G. bulloides and G. sacculifer habitat, combined with a seasonal change in the source of coastal upwelling waters from northern in the spring to southern in late summer, as the shelf-trapped poleward California Undercurrent strengthens. This interpretation invokes a southern hemisphere source for depleted carbon at the Baja surface, via northward, coastal advection of southern

  15. Geomagnetic Paleosecular Variation and Tectonic Correction for the Past 12 Ma in Baja California, Mexico

    Science.gov (United States)

    Garcia-Amador, B. I.; Alva-Valdivia, L. M.; Canon-Tapia, E.

    2014-12-01

    During the last 30 years, study of Paleosecular Variation (PSV) has been analyzed within specific timescales (e.g. 0-5 Ma; 5-22.5 Ma; etc.), considering the main criteria variation in directions of paleomagnetic data due to displacement of tectonic plates, and the scarcity of spatial and temporal distribution of rock outcrops, we propose using the previous geological and geophysical studies comprising the tectonic displacement of Baja California for the last 12 Ma, a method (working in space and time) to precise the PSV of our paleomagnetic sites (assuming a thermoremanent magnetization). We completed two paleomagnetic rock field sampling works: Loreto-Santa Rosalia-Punta Abreojos (between 26° and 27.4° N), with 156 cores from 16 sites; and San Borja and Jaraguay volcanic fields (between 28° and 30° N), with 230 cores from 27 sites. These sites are mainly volcanic rocks (andesite-basalt) with radiometric ages previously reported. We selected those younger than 12 Ma age without effect of rotation or flattening within the peninsula. Rock magnetic experiments were done to characterize the magnetic carrier of the remanence, such as susceptibility vs. low and high temperature, hysteresis, FORC, Koenigsberger ratio determination and directional analysis. Our results suggest that in most of the cases (80%) we have a contribution of TM0 to TM20, and magnetic domain of PSD + SP. In addition to our data, we gathered all paleomagnetic works in volcanic rocks younger than 12 Ma along Baja California. For the PSV, we calculated the angular standard deviation (SB) of the VGPs with respect to its mean average and also to the geographic axis. Both results were compared with the calculation of the SB once the correction of paleomagnetic sites based on the tectonic displacement was applied. Finally, all results (with and without correction) were compared with Model G and TK03.GAD, finding that data of the SB with tectonic correction are the best fit models, suggesting a

  16. Laylander and Moore (eds.): The Prehistory of Baja California: Advances in the Archaeology of the Forgotten Peninsula

    OpenAIRE

    Foster, John W.; Fitzgerald, Richard T

    2007-01-01

    The Prehistory of Baja California: Advances in the Archaeology of the Forgotten Peninsula Don Laylander and Jerry D. Moore (eds.) Gainesville: University Press of Florida, 2006 254 pp., maps, illustrations, tables, bibliography, index; $55.00, (cloth). ISBN: 0-8130-2939-2

  17. Sea-surface temperature gradients across blue whale and sea turtle foraging trajectories off the Baja California Peninsula, Mexico

    Science.gov (United States)

    Etnoyer, Peter; Canny, David; Mate, Bruce R.; Morgan, Lance E.; Ortega-Ortiz, Joel G.; Nichols, Wallace J.

    2006-02-01

    Sea-surface temperature (SST) fronts are integral to pelagic ecology in the North Pacific Ocean, so it is necessary to understand their character and distribution, and the way these features influence the behavior of endangered and highly migratory species. Here, telemetry data from sixteen satellite-tagged blue whales ( Balaenoptera musculus) and sea turtles ( Caretta caretta, Chelonia mydas, and Lepidochelys olivacea) are employed to characterize 'biologically relevant' SST fronts off Baja California Sur. High residence times are used to identify presumed foraging areas, and SST gradients are calculated across advanced very high resolution radiometer (AVHRR) images of these regions. The resulting values are compared to classic definitions of SST fronts in the oceanographic literature. We find subtle changes in surface temperature (between 0.01 and 0.10 °C/km) across the foraging trajectories, near the lowest end of the oceanographic scale (between 0.03 and 0.3 °C/km), suggesting that edge-detection algorithms using gradient thresholds >0.10 °C/km may overlook pelagic habitats in tropical waters. We use this information to sensitize our edge-detection algorithm, and to identify persistent concentrations of subtle SST fronts in the Northeast Pacific Ocean between 2002 and 2004. The lower-gradient threshold increases the number of fronts detected, revealing more potential habitats in different places than we find with a higher-gradient threshold. This is the expected result, but it confirms that pelagic habitat can be overlooked, and that the temperature gradient parameter is an important one.

  18. 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.

  19. Baja California y sus misiones en la década de 1780

    Directory of Open Access Journals (Sweden)

    Esponera Cerdán, Alfonso

    2001-06-01

    Full Text Available The current article studies a document found in the General Archive of the Nation in Mexico City, that is dated the 12th of May 1783. Written by the dominico Luis Sales, it offers an interesting vision about the land and the peoples of Low Californian Peninsula.

    En este artículo se analiza un documento hallado en el Archivo General de la Nación en Ciudad de México fechado el 12 de mayo de 1783. Escrito por el dominico Luis Sales ofrece una interesante visión sobre la tierra y las gentes de la península de Baja California.

  20. Stable isotope composition of surface and groundwater in Baja California, Mexico

    International Nuclear Information System (INIS)

    Based on a total of 135 stable isotope analysis (δ18O, δD) carried out on surface and groundwater samples, as well as on rainwater samples between 2004 and 2011 in 5 different regions in Baja California, an isotopic evaluation of the region was established. The results showed a depletion gradient of -0.25 0/00 δ18O per 100 m rise in elevation throughout the study area. Considering an unaltered δ18O signature for the thermal springs, the recharge areas of these waters are at elevations over 1400 m outside of the present watersheds, indicating the presence of regional flow systems next to the local flow regime feeding the cold springs and wells. The Mesa de Andrade area has a completely different signature with values of -105 for δ18O and -13 for δD. (authors)

  1. Hazardous waste shipping in the northern border of Mexico: The situation of Baja California

    Directory of Open Access Journals (Sweden)

    Ramón A. Castillo Ponce

    2013-01-01

    Full Text Available In this document we evaluate the determinants of shipments of hazardous waste to the US. We consider a sample of firms operating in the state of Baja California for the 2008–2010 sample period. The analysis consists on the estimation of two econometric specifications. The first refers to a truncated model in the spirit of Tobit. The second is a probabilistic model. The results of the Tobit model suggest that size, location and origin of the firm influence the amount of shipments. In particular, shipments are positively associated with larger firms; those located in the municipality of Tijuana and those whose origin is foreign. The probabilistic model finds that a depreciation of the Mexican peso contributes to an increase in the likelihood of sending a shipment. This may be the result of an improvement in the border economic environment due to the depreciation of the currency.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Stable isotope composition of surface and groundwater in Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Kretzschmar, Thomas G. [CICESE, Carret. Ensenada-Tijuana No 3819, Ensenada 22860 (Mexico); Frommen, Theresa [FU Berlin Malteserstr. 74-100, 12249 Berlin (Germany)

    2013-07-01

    Based on a total of 135 stable isotope analysis (δ{sup 18}O, δD) carried out on surface and groundwater samples, as well as on rainwater samples between 2004 and 2011 in 5 different regions in Baja California, an isotopic evaluation of the region was established. The results showed a depletion gradient of -0.25 0/00 δ{sup 18}O per 100 m rise in elevation throughout the study area. Considering an unaltered δ{sup 18}O signature for the thermal springs, the recharge areas of these waters are at elevations over 1400 m outside of the present watersheds, indicating the presence of regional flow systems next to the local flow regime feeding the cold springs and wells. The Mesa de Andrade area has a completely different signature with values of -105 for δ{sup 18}O and -13 for δD. (authors)

  4. 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

  5. Geochemistry of igneous rocks from the Cerro Prieto geothermal field, northern Baja California, Mexico

    Science.gov (United States)

    Herzig, C. T.

    1990-08-01

    Fractional crystallization of basaltic magma, derived from an oceanic affinity source region present beneath the Salton Trough and emplaced into a pull-apart basin of this continental rift regime, produced a tholeiitic suite of hypabyssal rocks consisting of basalt, andesite and dacite within the Cerro Prieto geothermal field, located in northern Baja California, Mexico. Higher light-rare-earth-element abundances for a basalt from the Cerro Prieto geothermal field in comparison to basalts from the Gulf of California and the East Pacific Rise suggest partial assimilation of crustal materials into the parental magmas generated beneath the Salton Trough. The crustal contaminant may be present near the surface today in the form of granitoids of the Peninsular Ranges batholith, at deeper levels as hydrothermally altered materials near the base of the Salton Trough, or may be a relict feature of Tertiary subduction contained within the upper mantle beneath the Salton Trough. The Sr isotopic compositions of dacites from the nearby Cerro Prieto volcano range from 0.7029 to 0.7036, indicating an oceanic affinity source for these rocks. The suite of hypabyssal rocks of tholeiitic affinity present within the Cerro Prieto geothermal field, related by fractional crystallization, link the dacite volcano of Cerro Prieto to gabbroic plutons inferred to exist beneath the Cerro Prieto geothermal field.

  6. 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.

  7. CCALBATC - bathymetric contours for the central California region between Point Arena and Point Sur.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — CCALBATC consists of bathymetric contours at 10-m and 50-m intervals for the area offshore of central California between Point Arena to the north and Point Sur to...

  8. Diversity of free-living marine nematodes (Enoplida) from Baja California assessed by integrative taxonomy.

    Science.gov (United States)

    Pereira, Tiago José; Fonseca, Gustavo; Mundo-Ocampo, Manuel; Guilherme, Betânia Cristina; Rocha-Olivares, Axayácatl

    2010-01-01

    We used morphological and molecular approaches to evaluate the diversity of free-living marine nematodes (order Enoplida) at four coastal sites in the Gulf of California and three on the Pacific coast of Baja California, Mexico. We identified 22 morphological species belonging to six families, of which Thoracostomopsidae and Oncholaimidae were the most diverse. The genus Mesacanthion (Thoracostomopsidae) was the most widespread and diverse. Five allopatric species, genetically and morphologically differentiated, were found in two localities in the Gulf of California (M. sp1 and M. sp2) and three in the Pacific coast (M. sp3, M. sp4 and M. sp5). Overall, we produced 19 and 20 sequences for the 18S and 28S genes, respectively. Neither gene displayed intraspecific polymorphisms, which allowed us to establish that some morphological variation was likely either ontogenetic or due to phenotypic plasticity. Although 18S and 28S phylogenies were topologically congruent (incongruence length difference test, P > 0.05), divergences between species were much higher in the 28S gene. Moreover, this gene possessed a stronger phylogenetic signal to resolve relationships involving Rhabdodemania and Bathylaimus. On the other hand, the close relationship of Pareurystomina (Enchilidiidae) with oncholaimids warrants further study. The 28S sequences (D2D3 domain) may be better suited for DNA barcoding of marine nematodes than those from the 18S rDNA, particularly for differentiating closely related or cryptic species. Finally, our results underline the relevance of adopting an integrative approach encompassing morphological and molecular analyses to improve the assessment of marine nematode diversity and advance their taxonomy. PMID:24391248

  9. Geoelectrical analysis of Las Tres Virgenes geothermal zone, Baja California Sur, Mexico. Analisis geoelectrico de la zona geotermica de Las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Bigurra Pimentel, Emilio (Departamento de Exploracion, Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico))

    1998-01-15

    On the basis of vertical electric sounding (VES) analysis it is possible to define three geoelectrical environments in Las Tres Virgenes geothermal area. From the surface to 250 m depth, apparent resistivity values change from 12000 Ohm.m. to 200 Ohm.m. This layer is composed by Las Tres Virgenes volcanic material, Aguajito ignimbrite and Santa Rosalia basin deposits. Underlaying this high resistivity layer, from 250 m to 1500 m depth, there is an extensive conductive layer with low resistivity values from 15 Ohm.m to 3 Ohm. m. This conductive layer includes the aquifer of the area, the Santa Lucia and Comondu formations and the top of granitic basement. Under this low resistivity layer, there is a zone of medium resistivity values from 20 Ohm.m to 100 Ohm.m, corresponding to El Azufre and El Partido volcanoes area, and the Agua Caliente hydrothermal zone. The decrease of resistivity values in this middle resistivity layer is associated with hot rock zones produced by magmatic intrusions (volcanoes zone). High horizontal gradients are associated with geologic faults with normal component of fractures, and high vertical gradients with changes in electrical layers, some of them with superficial evidences, but other appearing only at depth. The intersection of NW-SE with NE-SW trends are important, because those zones provide the paths for the hydrothermal fluids circulation; examples of these zones are: Los Azufres volcano area, El Partido volcano and Agua Caliente geothermal zone.

  10. 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

  11. 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

  12. New geologic slip rates for the Agua Blanca Fault, northern Baja California, Mexico

    Science.gov (United States)

    Gold, P. O.; Behr, W. M.; Fletcher, J. M.; Hinojosa-Corona, A.; Rockwell, T. K.

    2015-12-01

    Within the southern San Andreas transform plate boundary system, relatively little is known regarding active faulting in northern Baja California, Mexico, or offshore along the Inner Continental Borderland. The inner offshore system appears to be fed from the south by the Agua Blanca Fault (ABF), which strikes northwest across the Peninsular Ranges of northern Baja California. Therefore, the geologic slip rate for the ABF also provides a minimum slip rate estimate for the offshore system, which is connected to the north to faults in the Los Angeles region. Previous studies along the ABF determined slip rates of ~4-6 mm/yr (~10% of relative plate motion). However, these rates relied on imprecise age estimates and offset geomorphic features of a type that require these rates to be interpreted as minima, allowing for the possibility that the slip rate for the ABF may be greater. Although seismically quiescent, the surface trace of the ABF clearly reflects Holocene activity, and given its connectivity with the offshore fault system, more quantitative slip rates for the ABF are needed to better understand earthquake hazard for both US and Mexican coastal populations. Using newly acquired airborne LiDAR, we have mapped primary and secondary fault strands along the segmented western 70 km of the ABF. Minimal development has left the geomorphic record of surface slip remarkably well preserved, and we have identified abundant evidence meter to km scale right-lateral displacement, including new Late Quaternary slip rate sites. We verified potential reconstructions at each site during summer 2015 fieldwork, and selected an initial group of three high potential slip rate sites for detailed mapping and geochronologic analyses. Offset landforms, including fluvial terrace risers, alluvial fans, and incised channel fill deposits, record displacements of ~5-80 m, and based on minimal soil development, none appear older than early Holocene. To quantitatively constrain landform ages

  13. 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.

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

    OpenAIRE

    Víctor Manuel Alcántar Enríquez; José Luis Arcos Vega

    2009-01-01

    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 sec...

  15. Effect of nutrient availability on understory algae during El Niño conditions at Central Pacific Baja California

    OpenAIRE

    Hernández Carmona, Gustavo; Riosmena Rodríguez, Rafael; Serviere Zaragoza, Elisa; Ponce Díaz, Germán

    2011-01-01

    An experimental study of the effect of artificial nutrient supply on understory algae was made during 1997 El Niño Southern Oscillation (ENSO) at the Mexican Pacific coast of Baja California. Twelve quadrats of 1 m2 were placed on the sea bed. Six quadrats were used as controls, and six were treatments with added artificial nutrients. Nutrients were supplied using polyvinyl chloride (PVC) pipes filled with slow-release inorganic fertilizer. The algae species composition and cover in each quad...

  16. 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

  17. Variability on the Hypoxic Conditions in the Northwestern Region of the Baja California Peninsula

    Science.gov (United States)

    Bustos-Serrano, H.

    2015-12-01

    The NW region of the Baja California peninsula in México is dominated by the California Current System (CCS). Dissolved oxygen (DO) is a key variable in water bodies because it is considered as a health in biological processes. Hypoxic conditions (DO 60 to 120 μmol kg-1) occur naturally in large areas of the ocean. In the Eastern Pacific, the DO can be altered by eutrophication, derived from anthropogenic activity, especially in shallow and enclosed seas. Fluctuations in the conditions of hypoxia zones may have significant ecological and economic impact. It is of interest in assessing whether hypoxic conditions in the vicinity of Bahia de Todos Santos (BTS) and Coronado Islands in México are altered by anthropogenic activity (Figs. 1 and 2 respectively). For the present study, we worked with data collected from oceanographic expeditions during the period October 2010 to June 2015. The DO was determined using a CTD (SBE Model 25) and by sea water collection with hydrographic bottles using a modification of the Winkler method. The signs of hypoxia are evident in the area near BTS and in the vicinity of Coronado´s Islands, mainly on locations between the Todos Santos Islands and the peninsula of Punta Banda, which shows that the hypoxic zone begins to occur in shallow water between 50-200 m depth. This particular area corresponds to the point where the Mexican Navy determined as a site for dredging materials from the ports of Ensenada and El Sauzal, it is possible that the anthropogenic activity alters the natural conditions of hypoxia in the area to enlarge. In June 2012 for the first time in that region we obtained sediment samples below 700 m depth, which are mixed terrigenous clastic and oceanic sediments.

  18. Evaluación del aprendizaje de las microempresas de Baja California

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. Antecedentes históricos de los indígenas de Baja California

    Directory of Open Access Journals (Sweden)

    Julia Bendímez Patterson

    1987-09-01

    Full Text Available Este estudio explica la forma como se han ido desenvolviendo los primeros pobladores de esta región, inicia en el periodo paleo-indígena, para después avanzar paulatinamente en el tiempo hasta llegar al problema actual que caracteriza a muchas de las comunidades indígenas de nuestro país. No obstante que la historia ha sido documentada por la sociedad dominante, sin contar con la versión de los actores nativos, y en lo que se refiere a estas sociedades, ésta es sumamente escueta. En la actualidad, la conciencia de muchos mexicanos no-indígenas está permeada con la concepción heredada desde la época colonial y continuamos marginándolos y considerándolos como un obstáculo para la modernización, al grado que, actualmente quedan menos de 1,000 indígenas en las comunidades de Baja California.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Relationships between eastern Pacific tropical cyclones and convective rainfall in Baja California, Mexico

    Science.gov (United States)

    Farfan, L. M.; Cosio, M. A.

    2007-05-01

    The influence of tropical cyclones in rainfall patterns over the Baja California peninsula is examined. The impact of these systems, over the southern portion of the peninsula, is analyzed and the study period is limited to the summer of 2004. This is associated with the field phase of the North American Monsoon Experiment (NAME), which is intended to improve predictions of warm season precipitation over North America. We used the best-track dataset from the U.S. National Hurricane Center to classify, based on distance from the circulation center, systems that approached the peninsula at ranges of 400-, 800- and 1200-km. During the season of 2004, activity was below the long-term annual mean with nine systems developing between July and September. Four cases were selected for subsequent analysis: Tropical Storm Blas, Hurricane Frank, Hurricane Howard, and Hurricane Javier. Data from the upper-air station at La Paz were used to evaluate humidity changes during the storm approach and rain gauge reports provided information to determine the spatial distribution of the convective precipitation. Our analysis shows that, when compared with a base period of 15 years, 2004 resulted in below normal precipitation over the southern peninsula. In contrast, above normal conditions occurred in the central peninsula.

  3. 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.

  4. Novel patterns of historical isolation, dispersal, and secondary contact across Baja California in the Rosy Boa (Lichanura trivirgata)

    Science.gov (United States)

    Wood, D.A.; Fisher, R.N.; Reeder, T.W.

    2008-01-01

    Mitochondrial DNA (mtDNA) sequence variation was examined in 131 individuals of the Rosy Boa (Lichanura trivirgata) from across the species range in southwestern North America. Bayesian inference and nested clade phylogeographic analyses (NCPA) were used to estimate relationships and infer evolutionary processes. These patterns were evaluated as they relate to previously hypothesized vicariant events and new insights are provided into the biogeographic and evolutionary processes important in Baja California and surrounding North American deserts. Three major lineages (Lineages A, B, and C) are revealed with very little overlap. Lineage A and B are predominately separated along the Colorado River and are found primarily within California and Arizona (respectively), while Lineage C consists of disjunct groups distributed along the Baja California peninsula as well as south-central Arizona, southward along the coastal regions of Sonora, Mexico. Estimated divergence time points (using a Bayesian relaxed molecular clock) and geographic congruence with postulated vicariant events suggest early extensions of the Gulf of California and subsequent development of the Colorado River during the Late Miocene-Pliocene led to the formation of these mtDNA lineages. Our results also suggest that vicariance hypotheses alone do not fully explain patterns of genetic variation. Therefore, we highlight the importance of dispersal to explain these patterns and current distribution of populations. We also compare the mtDNA lineages with those based on morphological variation and evaluate their implications for taxonomy. ?? 2007 Elsevier Inc. All rights reserved.

  5. Parallel rapid HIV testing in pregnant women at Tijuana General Hospital, Baja California, Mexico.

    Science.gov (United States)

    Viani, Rolando M; Araneta, Maria Rosario G; Spector, Stephen A

    2013-03-01

    The objectives of this study were to evaluate the performance of parallel rapid HIV testing and the presence of HIV-associated risk factors in pregnant women with unknown HIV status in Baja California, Mexico. Pregnant women attending the delivery unit or the prenatal clinic at Tijuana General Hospital had blood drawn for parallel rapid HIV testing with Determine™ HIV-1/2 and Uni-Gold™ Recombigen(®) HIV. The parallel rapid HIV test performance was compared to the enzyme immunoassay (EIA) and western blot. From September 2007 to July 2008, 1,383 (94%) of 1,464 women in labor and 1,992 (96%) of 2,075 women in prenatal care were enrolled. The HIV seroprevalence among women screened during labor (19/1,383, 1.37%, 95% CI: 0.85-2.18%) was significantly higher compared to those seeking prenatal care (5/1,992, 0.25%, 95% CI: 0.09-0.62%; pwomen testing positive by parallel rapid HIV testing 24 had a positive confirmatory western blot and one (0.03%) was confirmed as false positive. Additionally, two (0.06%) women had parallel rapid HIV discordant testing results; both tested negative by western blot. All women who tested negative by rapid testing had negative results on pooled EIA antibody testing. The overall sensitivity, specificity, and positive and negative predictive values of parallel rapid HIV testing were 100%, 99.9%, 96%, and 100%, respectively. These findings document a very high acceptance rate and an excellent performance of the parallel rapid HIV testing strategy during pregnancy.

  6. Morphology and sedimentology of two contemporary fan deltas on the southeastern Baja California Peninsula, Mexico

    Science.gov (United States)

    Nava-Sanchez, Enrique; Cruz-Orozco, Rodolfo; Gorsline, Donn S.

    1995-08-01

    The San Juan de Los Planes drainage basin is located on the southeastern margin of the Baja California Peninsula, approximately 20 km southeast of the city of La Paz. Pleistocene alluvial fans have been built into the basin from the surrounding areas of high relief and are presently being eroded. At the fan apex, the dissection depth ranges from 20 to 40 m, and is 6 to 15 m at the coast. The sediments have been redeposited in several active modern fan deltas built out into the narrow shelf of La Ventana Bay. Shelf width ranges from 0 to 5 km (average 3 km). Wave energy is delivered from southeasterly storms and from the local sea breeze winds; the respective wave heights average 2 and 1 m. The Agua Caliente and Las Canoas fan deltas, the subjects of this paper, are located on the active El Sargento Fault Zone and are fed by channels that deeply dissect the older fan surfaces. The Agua Caliente fan delta is a classic Gilbert-type delta with a steeply inclined delta front. Wave reworking and redistribution of the sediments at the delta face are important and a wave-cut terrace has developed at about 6 m depth. The Las Canoas fan delta is a shoal-water-profile, Hjulstrom type with a gently inclined delta front. Wave energy is less important. The alignments of the coasts of both fans are controlled by the fault line. Sediment supply is largest for the Las Canoas fan delta. The fan deltas are examples of this depositional form as it has developed in an arid, tectonically active, high-relief and narrow neo-trailing edge margin.

  7. La Baja California inventada: visiones sobre un territorio mexicano a mediados del siglo XX

    Directory of Open Access Journals (Sweden)

    Héctor Mendoza Vargas

    2015-01-01

    Full Text Available Resumen. Este artículo examina los viajes de Peter Gerhard y Ángel Bassols Batalla por la Baja California en los años cincuenta. Ante sus ojos emerge un espacio inventado a partir de la experiencia de cada uno en la península. Gerhard, como viajero, integraba una imagen práctica, placentera y lúdica dirigida a los turistas estadounidenses que con la rapidez y la seguridad del automóvil, podrían disfrutar del sol, las playas, los ranchos y la aventura del pasado histórico en los sitios misionales, además de la caza y la pesca deportiva. Por su parte, Bassols Batalla se adentró al territorio como explorador y, a través de una planeación racional de sus travesías y del análisis geoeconómico como metodología, concluyó que era necesario favorecer la colonización, la consolidación del Estado, el interés nacional y la reafirmación de la soberanía. La comparación entre las visiones de ambos autores señala coincidencias y diferencias que ayudan a comprender la relevancia del viaje geográfico como fuente de información y método de trabajo, indispensable para entender la realidad de una región aislada de México.

  8. Detachment Faulting and Hanging-wall Segmentation in the Gulf Extensional Province, Baja California

    Science.gov (United States)

    Seiler, C.; Fletcher, J. M.; Quigley, M. C.; Gleadow, A. J.; Kohn, B. P.

    2007-12-01

    The opening of the Gulf of California, caused by the re-localization of the Pacific -- North America plate boundary, is a premier example of an incipient passive margin. The San Felipe area in northern Baja California comprises a typical basin and range-style topography, produced by Neogene extension affecting the Gulf Extensional Province (GEP). The > 100 km long Sierra San Pedro Mártir (SSPM) escarpment is defined by an east-down normal fault system, separating the unextended western part of the peninsula from the GEP. The hanging-wall of the SSPM fault is characterized by several fault-bound blocks that have been rotated around both vertical and horizontal axes. The Las Cuevitas and the Santa Rosa detachments are two major fault systems in the Sierra San Felipe that are responsible for segmentation of the hanging-wall of the SSPM fault. The curvilinear, NE to NNW striking Las Cuevitas Detachment extends for more than 43 km and brings Neogene volcanics and sediments in contact with the Mesozoic basement of the footwall. The detachment dips at 15-50° and accommodates more than 4-6 km of east-down displacement. Faulting appears to preferentially occur at the contact of Mesozoic metamorphics to granitoid intrusives with transfer faults translating deformation between the faulted contacts. Fission track and (U-Th)/He thermochronology constrain the initiation of deformation on the Las Cuevitas detachment to the latest Miocene. The > 45 km long and equally curvilinear Santa Rosa Detachment system consists of a low-angle normal fault system (15-35° dip) with transfer zones facilitating the transfer of strain between individual segments of the detachment fault. The slip direction varies between top-to-the-east and top-to-the-south, a possible explanation for the change in strike from NW to NE to NW. The roughly 4-5 km offset of Neogene volcanic and sedimentary deposits has created the necessary space for syntectonic deposition in the Santa Rosa Basin. The onset of

  9. Differential Energy Radiation from Two Earthquakes with Similar Mw: The Baja California 2010 and Haiti 2010 Earthquakes

    Science.gov (United States)

    Meng, L.; Shi, B.

    2010-12-01

    The Baja, Mexico, earthquake of the April 4, 2010, Mw 7.2 occurred in northern Baja California at shallow depth along the principal plate boundary between the North American and Pacific plates, 2 people killed in the Mexicali area. The January 12, 2010, Mw 7.0, Haiti, earthquake occurred in the vicinity of Port-au-Prince, the capital of Haiti, on the Enriquillo Plantain Garden Fault, and with estimates of almost 250,000 deaths. International media reports of such kind of disasters by Haiti earthquake is just resulted from poor building structure design comparing with Mexicali area. Although the moment magnitude of the Haiti earthquake is similar as the Baja earthquake, but the radiated energy of the Haiti earthquake almost as 15 times as the Baja earthquake, resulting stronger near-fault ground motions. For the Haiti earthquake and Baja earthquake with the similar moment magnitude, two special finite fault models are constructed to simulate the near-fault strong ground motion for comparison purpose. We propose a new technique based on the far-field energy integrand over a simple finite fault to estimate S-wave energy radiation with associated the composite source model. The fault slip distributions on both faults are generated based on the composite source model in which the subevent-source-function is described by Brune’s pulse. The near-field peak ground accelerations (PGAs) including the shallow velocity structures (V30, average shear-velocity down to 30 m ) from the Haiti earthquake is almost as 20 times as from Baja earthquake, while the peak ground velocities (PGVs) including the shallow velocity structures from Yushu earthquake is almost as 8 times as from the Baja earthquake. Therefore, the radiated seismic energy plays a significant role in determining the levels of strong grounds in which stronger ground accelerations usually could cause much more property damages on the ground. The source rupture dynamics related to the frictional overshoot and

  10. Alternativas de control en la pudrición radical de cebolla para el Valle de la Trinidad, Baja California Control Alternatives for Onion root rot in the Trinity Valley, Baja California

    OpenAIRE

    Armando Pulido-Herrera; Emma Zavaleta-Mejía; Lourdes Cervantes-Díaz; Onécimo Grimaldo-Juárez

    2012-01-01

    La pudrición radical en cebolla es la enfermedad más importante en el Valle de la Trinidad, Baja California, México. Con el propósito de evaluar estrategias de control para la enfermedad se realizaron tres experimentos durante 2007, 2008 y 2009. En el experimento I (2007) los tratamientos fueron: 1) Tiofanato metílico; 2) Smicobac (Trichoderma + Bacillus sp. + Azospirillum sp. + Pseudomonas sp.); 3) estiércol de bovino (EB); 4) residuos de cebolla (RC); 5) solarización plástico transparente (...

  11. Gobernanza de la infraestructura y sustentabilidad ecosistémica en Punta Colonet, Baja California, México Governance of infrastructure and ecosystem sustainability in Punta Colonet, Baja California state, Mexico

    OpenAIRE

    Ricardo V. Santes Álvarez; Hugo Riemann González

    2013-01-01

    Este artículo estudia la problemática sociopolítica y ambiental de la probable construcción del puerto de Punta Colonet, en Baja California. Anunciado como el principal proyecto de infraestructura del gobierno federal, su concepción olvida objetivos de conservación de recursos e intereses locales. El surgimiento de la dualidad entre "desarrollistas" y "conservacionistas" solamente enmascara una preocupación mayor: la fortaleza institucional. Consecuentemente, el análisis se sustenta en términ...

  12. Polychlorinated Biphenyls and Biotransformation Enzymes in Three Species of Sea Turtles from the Baja California Peninsula of Mexico

    OpenAIRE

    Richardson, K L; Lopez Castro, M.; Gardner, S. C.; Schlenk, D.

    2009-01-01

    Concentrations of polychlorinated biphenyls (PCBs) as well as the expression patterns of cytochrome P450 (CYP) enzymes and glutathione-S-transferase (GST) activities were measured in livers of loggerhead (Caretta caretta), green (Chelonia mydas), and olive ridley (Lepidocheyls olivacea) sea turtles from the Baja California peninsula of Mexico. The mean concentrations of total PCBs were 18.1, 10.5, and 15.2 ng/g wet weight (ww) respectively for the three species and PCB 153 was the dominant co...

  13. Mercury dispersal to arroyo and coastal sediments from abandoned copper mine operations, el Boléo, Baja California.

    Science.gov (United States)

    Kot, Fyodor; Shumilin, Evgueni; Rodríguez-Figueroa, Griselda Margarita; Mirlean, Nicolai

    2009-01-01

    Evidence for mercury dispersal in an arid coastal region of central Baja California (Mexico) suggests that abandoned copper mining operations are a noticeable source of mercury in the environment. There is a generally elevated level of mercury in alluvium of arroyos throughout the mining district (0.14-0.18 mg kg(-1)). In the first several dozen meters surrounding two of the biggest mines, mercury levels range from 0.26 to 3.16 mg kg(-1), forming a halo of anomalously high concentrations. The coastal marine sediments, particularly those close to the copper smelter in the town of Santa Rosalía, also display some mercury enrichment. PMID:18800200

  14. Mercury dispersal to arroyo and coastal sediments from abandoned copper mine operations, El Boléo, Baja California

    OpenAIRE

    Kot, Fydor; Shumilin, Evgueni; Rodríguez Figueroa, Griselda Margarita; Mirlean, Nicolai

    2009-01-01

    Evidence for mercury dispersal in an arid coastal region of central Baja California (Mexico) suggests that abandoned copper mining operations are a noticeable source of mercury in the environment. There is a generally elevated level of mercury in alluvium of arroyos throughout the mining district (0.14–0.18 mg kg-1). In the first several dozen meters surrounding two of the biggest mines, mercury levels range from 0.26 to 3.16 mg kg-1, forming a halo of anomalously high concentrations. The coa...

  15. El papel del capital humano y el aprendizaje en las microempresas de base social en Baja California

    OpenAIRE

    Martin Ramírez Urquidy; Michelle Texis Flores; José Gabriel Aguilar Barceló

    2014-01-01

    Este trabajo tiene como objetivos conocer la estructura del capital humano y el aprendizaje en las microempresas de base social del estado de Baja California y determinar el papel de éste sobre el desempeño micro­ empresarial. Ello con el fin de establecer un diagnóstico sobre su contribución y obtener algunas implicaciones de política pública para el sector en esta temática. Los resultados afirman la importancia del capital humano sobre el desempeño de este tipo de negocios, pues existe una ...

  16. La territorialidad del indígena americano de la tierra alta del norte de la Baja California

    OpenAIRE

    Ralph Michelsen

    1991-01-01

    Ralph Michelsen explora la idea de territorialidad entre los indígenas de Baja California como sujetos de otro tipo de realidad; un tiempo cuando el usufructo de la tierra se ceñía a reglas aborígenes particulares en contraste con las formas de tenencia de la tierra actuales y la noción de "país" que en el mundo prevalece. Su finalidad se logra mediante una reconstrucción histórica que le permite hacer propuestas sobre la percepción del espacio geográfico por los miembros de unidades lingüíst...

  17. Gobernanza de la infraestructura y sustentabilidad ecosistémica en Punta Colonet, Baja California, México Governance of infrastructure and ecosystem sustainability in Punta Colonet, Baja California state, Mexico

    Directory of Open Access Journals (Sweden)

    Ricardo V. Santes Álvarez

    2013-03-01

    Full Text Available Este artículo estudia la problemática sociopolítica y ambiental de la probable construcción del puerto de Punta Colonet, en Baja California. Anunciado como el principal proyecto de infraestructura del gobierno federal, su concepción olvida objetivos de conservación de recursos e intereses locales. El surgimiento de la dualidad entre "desarrollistas" y "conservacionistas" solamente enmascara una preocupación mayor: la fortaleza institucional. Consecuentemente, el análisis se sustenta en términos de normativas, actuación gubernamental y participación social. Asimismo, se presenta una propuesta de equilibrio entre infraestructura y sustentabilidad mediante un esquema alternativo de gobernación, el cual sugiere acordar la creación de un área esencial para la conservación.This article studies the sociopolitical and environmental problems associated with the likely construction of a port at Punta Colonet in Baja California State. Announced as the federal government's main infrastructure project, it overlooks earlier commitments to conserving local resources and interests. The confrontation that has emerged between "developmentalists" and "conservationists" glosses over a major concern: institutional strength. As a result, the analysis is mainly based on regulations, government action and social participation. Moreover, a balance is proposed between infrastructure and sustainability through an alternative governance framework, whereby an area would be created especially for conservation.

  18. 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

  19. Mapping mantle-melting anomalies in Baja California: a combined helium-seismology approach

    Science.gov (United States)

    Negrete-Aranda, R.; Spelz, R. M.; Hilton, D. R.; Tellez, M.; González-Yahimovich, O.

    2015-12-01

    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; Vidal, 1982) and 1.3 RA for spring waters (81oC) at Bahia Concepcion (Forrest et al.,2005). Our new survey of hot springs in northern BC has revealed that all 6 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 Sierra Juárez (0.11RA). Thus, preliminary trends are of a west-to-east increase in the mantle He signal across the peninsula. He results presented in this study correlate well with high resolution Rayleigh wave tomography images by Forsythe et al. (2007). Shear velocity variations in the BC crust and upper mantle have been interpreted as low velocity anomalies associated with dynamic upwelling and active melt production. More extensive sampling throughout BC coupled with analysis of other geochemical indicators of mantle degassing (e.g. CO2) will allow more detailed characterization of the extent and distribution of mantle melts in the region, facilitating assessment of the region's geothermal

  20. Red de mercadeo y rentabilidad de flor de corte en el Valle de Mexicali, Baja California, México Marketing network and profitability of cut flower for Mexicali Valley, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Blancka Yesenia Samaniego-Gámez

    2012-06-01

    Full Text Available La comercialización de flor de corte para Baja California aportó durante 2004 poco más de 122 millones de pesos, considerando semilla para flor y producción de flor de corte. Debido a la exportación de casi la totalidad de la producción estatal de flor cortada, el mercado local representa una oportunidad para la introducción de productos de calidad a precios competitivos de empresas nacionales, siendo Mexicali una ciudad cercana Estados Unidos de América, y aunado al poder adquisitivo de la población es la rentabilidad de las producciones de algodón y hortalizas del Valle de Mexicali, una de las principales zonas productoras del país. Por lo anterior y aunado al importante número de florerías localizadas en la zona se planteó como objetivo describir la red de mercadeo y rentabilidad de la flor de corte en el Valle de Mexicali. Se realizó un estudio de mercado y el diagnóstico para elaborar el análisis FODA, se determinaron las estrategias para el aprovechamiento del potencial económico. El sistema de redes de distribución y mercadeo actual consiste en trasladar las flores de corte desde los centros de producción, Córdoba, Veracruz y distrito de Coatepec Harinas, Estado de México, hasta el Valle de Mexicali, Baja California conservando la calidad y óptima vida de florero hasta su consumo final, asimismo, se requiere de una adecuada planeación de la cadena productiva debido a la presencia de una demanda insatisfecha a lo largo del año, la población cuenta con el potencial económico y la tradición de obsequiar flores lo cual garantiza una buena rentabilidad. Las especies de mayor interés de los consumidores son rosas (Rosa gigantea y R. chinensis L., lilis asiáticas (Lilium spp., polar [Dendranthemaxgrandiflorum (Ramat Kitamura c. v. Polaris White], clavel (Dianthus caryophyllus, gerbera (Gerbera jamesonii H. Boluxex Hook F. y lilis orientales (Lilium spp..Cut flower commercialization for Baja California contributed

  1. New kinematic models for Pacific-North America Motion from 3 Ma to Present, II: Evidence for a “Baja California Shear Zone”

    Science.gov (United States)

    Dixon, Timothy; Farina, Fred; DeMets, Charles; Suarez-Vidal, Francisco; Fletcher, John; Marquez-Azua, Bertha; Miller, Meghan; Sanchez, Osvaldo; Umhoefer, Paul

    2000-12-01

    We use new models for present-day Pacific-North America motion to evaluate the tectonics of offshore regions west of the Californias. Vandenburg in coastal Alta California moves at the Pacific plate velocity within uncertainties (˜1 mm/yr) after correcting for strain accumulation on the San Andreas and San Gregorio-Hosgri faults with a model that includes a viscoelastic lower crust. Modeled and measured velocities at coastal sites in Baja California south of the Agua Blanca fault, a region that most previous models consider Pacific plate, differ by 3-8 mm/yr, with coastal sites moving slower that the Pacific plate. We interpret these discrepancies in terms of strain accumulation on known on-shore faults, combined with right lateral slip at a rate of 3-4 mm/yr on additional faults offshore peninsular Baja California in the Pacific. Offshore seismicity, offset Quaternary features along the west coast of Baja California, and a discrepancy between the magnetically determined spreading rate in the Gulf Rise and the total plate rate from a geological model provide independent evidence for a “Baja California shear zone.”

  2. Correlation between seismicity and the distribution of thermal and carbonate water in southern and Baja California, United States and Mexico

    Science.gov (United States)

    Gastil, Gordon; Bertine, Kathe

    1986-04-01

    A comparison of the distribution of thermal and thermal-related springs and wells in southern California, United States, and Baja California, Mexico, with the abundance of earthquakes of magnitude 4 or greater shows as close a relationship between thermal waters and the distribution of seismicity as to the distribution of active faults. It appears that the distribution of thermal water variations in the geothermal gradient in turn influences the stress accumulation capability of the rocks at depth. Thus, areas with abundant thermal waters (and hence steep geothermal gradients) release stress by frequent moderate earthquakes; areas lacking thermal waters, such as the central Transverse Ranges, accumulate stresses that are released by infrequent large earthquakes.

  3. Magnetic Fabric and Paleomagnetism of the Peninsular Ranges Batholith, Sierra San Pedro M rtir, Baja California.

    Science.gov (United States)

    Knight, M.; Herrero-Bervera, E.; Molina-Garza, R. S.; Böhnel, H. N.

    2003-12-01

    We summarize results of recent paleomagnetic, structural, petrologic and magnetic fabric studies along an east-west (60 km long) transect across the Peninsular Ranges Batholith (PRB) in north-central Baja California. The transect includes both magnetite rich plutons from the western sector of the PRB, and ilmenite rich plutons from the eastern sector, as well as plutons on the eastern and western side of major tectonic discontinuities. We include results for 8 plutons, included well-characterized bodies such as San Pedro M rtir (SP), San José (SJ) and La Zarza (LZ), and relatively little known plutons such as Potrero (PO), Aguaje del Burro (AB), El Milagro (MI), and San Telmo (ST). Plutons on the western sector of the PRB yield a paleomagnetic pole at 82° N-186.4° E (A95=4.8° ). When rotated into a pre- Gulf of California position, the pole (79.2° -188.2° ) is statistically undistinguishable from the North American reference pole. In contrast, SP, SJ and PO plutons, on either side of the NW trending Main Martir Thrust yield clearly discordant direction that can only be reconciled with results for the western plutons assuming southwestward tilt of ˜ 25° for SP and greater than 45° for SJ and PO. We find strong evidence in support of tilt of the plutons from thermochronological, structural, and geobarometric data. These data will be discussed elsewhere. Here we focus on magnetic fabric data. AMS for SJ is strongly developed with high values for degree of anisotropy (P= 1.14 a 1.40), but marked east-west asymmetry that contrasts with the general symmetry of the pluton along a north-south axis. Oblate fabrics (T ˜ +0.4) with dispersed lineation directions dominate the west side of the pluton and prolate fabrics (T ˜ -0.15) with steep to vertical lineations dominate on its eastern side. This fabric is interpreted to result from magma flow. SP, a much larger pluton and sensibly asymmetric, displays high degrees of anisotropy (P ˜1.2) on its western side but

  4. Active Pacific North America Plate boundary tectonics as evidenced by seismicity in the oceanic lithosphere offshore Baja California, Mexico

    Science.gov (United States)

    Hauksson, Egill; Kanamori, Hiroo; Stock, Joann; Cormier, Marie-Helene; Legg, Mark

    2014-03-01

    Pacific Ocean crust west of southwest North America was formed by Cenozoic seafloor spreading between the large Pacific Plate and smaller microplates. The eastern limit of this seafloor, the continent-ocean boundary, is the fossil trench along which the microplates subducted and were mostly destroyed in Miocene time. The Pacific-North America Plate boundary motion today is concentrated on continental fault systems well to the east, and this region of oceanic crust is generally thought to be within the rigid Pacific Plate. Yet, the 2012 December 14 Mw 6.3 earthquake that occurred about 275 km west of Ensenada, Baja California, Mexico, is evidence for continued tectonism in this oceanic part of the Pacific Plate. The preferred main shock centroid depth of 20 km was located close to the bottom of the seismogenic thickness of the young oceanic lithosphere. The focal mechanism, derived from both teleseismic P-wave inversion and W-phase analysis of the main shock waveforms, and the 12 aftershocks of M ˜3-4 are consistent with normal faulting on northeast striking nodal planes, which align with surface mapped extensional tectonic trends such as volcanic features in the region. Previous Global Positioning System (GPS) measurements on offshore islands in the California Continental Borderland had detected some distributed Pacific and North America relative plate motion strain that could extend into the epicentral region. The release of this lithospheric strain along existing zones of weakness is a more likely cause of this seismicity than current thermal contraction of the oceanic lithosphere or volcanism. The main shock caused weak to moderate ground shaking in the coastal zones of southern California, USA, and Baja California, Mexico, but the tsunami was negligible.

  5. Genetic structure of desert ground squirrels over a 20-degree-latitude transect from Oregon through the Baja California peninsula.

    Science.gov (United States)

    Whorley, Joshua R; Alvarez-Castañeda, S Ticul; Kenagy, G J

    2004-09-01

    The genetic structure of populations over a wide geographical area should reflect the demographic and evolutionary processes that have shaped a species across its range. We examined the population genetic structure of antelope ground squirrels (Ammospermophilus leucurus) across the complex of North American deserts from the Great Basin of Oregon to the cape region of the Baja California peninsula. We sampled 73 individuals from 13 major localities over this 2500-km transect, from 43 to 22 degrees north. Our molecular phylogeographical analysis of 555 bp of the mitochondrial cytochrome b gene and 510 bp of the control region revealed great genetic uniformity in a single clade that extends from Oregon to central Baja California. A second distinct clade occupies the southern half of the peninsula. The minimal geographical structure of the northern clade, its low haplotype diversity and the distribution of pairwise differences between haplotypes suggest a rapid northward expansion of the population that must have followed a northward desert habitat shift associated with the most recent Quaternary climate warming and glacial retreat. The higher haplotype diversity within the southern clade and distribution of pairwise differences between haplotypes suggest that the southern clade has a longer, more stable history associated with a southern peninsular refugium. This system, as observed, reflects both historical and contemporary ecological and evolutionary responses to physical environmental gradients within genetically homogeneous populations. PMID:15315683

  6. Antimony in the Contaminated Site of El Triunfo, Baja California Sur, Mexico

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    Marmolejo-Rodríguez A. J.

    2013-04-01

    Full Text Available Antimony has properties similar to arsenic with some of its compounds toxic to humans. Therefore it is necessary to control the wastes accumulated by anthropogenic activities, such as mining, where it is in tailings to be released to the environment. According to the Environment Protection Agency, the maximum value in sediments is 11.2 mg Sb kg–1 and the Earth’s crust average is 0.2 mg Sb kg–1. In this semiarid area, the drainage basin El Carrizal is impacted with wastes of an abandoned gold mine at the Mining District El Triunfo (MD – ET which have tailings with 17,600 mg kg–1 of antimony. In the main dry river (arroyo, the Sb content is between 0.6 and 122 mg kg–1. This element is transported from the source throughout the fluvial basin to discharge into the Pacific Ocean. In the arroyo mouth we collected one sedimentary core and the sediment from dunes (28.6 – 45.7 and 6.43 – 7.74 mg Sb kg–1. This research concluded the antimony is enriched in this semiarid system, with Normalized Enrichment Factors severely enriched mainly in arroyo sediments close to the MD-ET

  7. Range extension for Sagitta peruviana (Chaetognatha:Sagittoidea) in Bahia Magdalena, Baja California Sur, Mexico

    OpenAIRE

    Cota Meza, María Soledad; Fernández del Alamo, M.A.

    1998-01-01

    In August and September of 1982 we recorded 6 041 and 318 individuals/100 m3 of S. peruviana (Sund, 1961), at 24° 15¢ to 25° 20¢ N and 111° 30¢, to 112° 12¢ W, respectively. It was first described from Perú (Sund, P. N. 1961. Pac. Sci. 15: 1-350) and later found in Colombia (Pineda-Polo, F 1971, p. 309-335 In Costlow (ed.). Fertility of the sea), Panamá (Pineda-Polo, F. 1978. Taxonomy of chaetognaths of the Bight of Panamá... Bol. Dept. Biol. Universidad de Valle, Colombia: 371-439.), Costa R...

  8. 1997-98 El Niño effects on the pelagic ecosystem of the California current off Baja California, Mexico

    OpenAIRE

    Bertha E Lavaniegos; Gilberto Gaxiola Castro; Luis C. Jiménez Pérez; María R. González Esparza; Timothy Baumgartner; Joaquín García Cordova

    2003-01-01

    We analyze the plankton response to 1997-98 El Niño in the southern region (26-32°N) of the California Current, from four IMECOCAL cruises. Integrated chlorophyll a showed a moderate increase at the end of the ENSO, but chlorophyll in Vizcaino Bay remained fairly constant. The medians were higher than 40 mg m-2 through 1998. Zooplankton biomass showed a local decrease from Punta Baja (30°N) to Vizcaino Bay, but not in other areas. The zooplankton decrease was mainly due to the lower abundance...

  9. Geochemical survey of medium temperature geothermal resources from the Baja California Peninsula and Sonora, México

    Science.gov (United States)

    Barragán R, R. M.; Birkle, P.; Portugal M, E.; Arellano G, V. M.; Alvarez R, J.

    2001-09-01

    Waters from hot springs and deep wells from Cerritos in the northern Baja California Peninsula and deep wells from the Riı´to zone (Sonora state) were studied in order to classify medium temperature geothermal resources to be exploited in NW-Mexico. Geochemical characteristics of San Felipe and Punta Estrella coastal springs indicate the mixing of seawater and meteoric components with secondary leaching of evaporates. Reservoir temperatures for both zones were estimated up to 225°C. Mixing of high portions of seawater (>80 wt%) with local waters could be the origin for the Puertecitos coastal spring, with a reservoir temperature estimation of 195°C. The El Coloradito coastal spring is composed of meteoric water with a reservoir temperature of 127°C. The formation of thermal manifestations along the Baja California coast could be related to the heating up of convecting seawater along extensional tectonic structures, as observed for submarine hydrothermal vents at the Gulf of California and along the East Pacific Rise. Volcanic steam-heated waters with a reservoir temperature of 135°C were found at the Valle Chico inland springs from the Baja California Peninsula. Deep fluids from the Riı´to zone originated by evaporation of infiltrated waters with similar characteristics to those located in the Mexicali Valley. Reservoir temperature of 192 and 126°C are estimated for the Riı´to deep wells ER-1B (ER) and R-1, respectively. The Riı´to artesian wells M-1, M-2 and M-4 indicate reservoir temperatures from 109 to 118°C. Isotopic data define the artesian wells as typical surface water or shallow groundwater from the Mexicali Valley. The Cerritos deep fluids of the Mexicali Valley show a close chemical and isotopic relationship to the adjacent Cerro Prieto reservoir fluids suggesting a similar origin and a possible connection of both aquifer systems. Conductive cooling of Cerro Prieto discharge fluids could originate the cooler Cerritos system (130

  10. Alternativas de control en la pudrición radical de cebolla para el Valle de la Trinidad, Baja California Control Alternatives for Onion root rot in the Trinity Valley, Baja California

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    Armando Pulido-Herrera

    2012-02-01

    Full Text Available La pudrición radical en cebolla es la enfermedad más importante en el Valle de la Trinidad, Baja California, México. Con el propósito de evaluar estrategias de control para la enfermedad se realizaron tres experimentos durante 2007, 2008 y 2009. En el experimento I (2007 los tratamientos fueron: 1 Tiofanato metílico; 2 Smicobac (Trichoderma + Bacillus sp. + Azospirillum sp. + Pseudomonas sp.; 3 estiércol de bovino (EB; 4 residuos de cebolla (RC; 5 solarización plástico transparente (SPT, 6 solarización plástico negro (SPN; 7 SPT + EB; 8 SPT + RC; 9 SPN + EB; 10 SPN + RC; 11 Trichodef (Trichoderma harzianum;y 12testigo. En el experimento II (2008, los tratamientos fueron los mismos excepto el tratamiento 2, sustituido porprotector (extractos vegetales; y en el experimento III (2009 los tratamientos fueron: 1 SPT + estiércol de ovino (EO; 2 SPN + EO; 3 SPT; 4 SPN; 5 control biológico (Trichoderma spp.; y 6 control químico (2- (tiocianometiltio benzotiazol 30%. Los resultados indicaron que los tratamientos solarización plástico transparente con o sin enmiendas orgánicas, presentaron incrementos significativos (p≤ 0.05 de 22 a 34% en el rendimiento y diámetro del bulbo con respecto al control biológico y químico; sin embargo, en estos dos últimos tratamientos la incidencia y severidad se redujo significativamente (p≤ 0.05, por lo que la solarización con plástico transparente y el control biológico, son alternativas viables para el control de la pudrición radical en cultivos de cebolla en Baja California, México.Onion's root rot is the most important disease in the Trinidad Valle, Baja California, Mexico. In orderto evaluate strategies to control this disease, three experiments were conducted during 2007, 2008 and 2009. In experiment I (2007 the treatments were: 1 Thiophanate methyl; 2 Smicobac (Trichoderma+Bacillus sp. + Azospirillum sp. + Pseudomonas sp.; 3 cattle manure (EB; 4 waste of onion (RC; 5 clear plastic

  11. Patterns of microbial diversity along a salinity gradient in the Guerrero Negro solar saltern, Baja CA Sur, Mexico

    OpenAIRE

    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 ...

  12. Influencia de los Contaminantes Atmosféricos en las Infecciones Respiratorias Agudas en Mexicali-Baja California, México Influence of Atmospheric Pollutants on Acute Respiratory Infections in Mexicali-Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Martha Ramírez-Rembao

    2009-01-01

    Full Text Available El objetivo de este estudio es identificar la relación entre los contaminantes: ozono, monóxido de carbono, partículas suspendidas(PM10, temperatura y humedad con la incidencia de morbilidad por Infecciones Respiratorias Agudas (IRAs en el área urbana de Mexicali en el estado de Baja California en México. Se recolectó información de estaciones de monitoreo del aire establecidas en Mexicali, en el período 2001-2005, y se utilizaron modelos de regresión lineal simple y múltiple para analizar estas variables, relacionándolas con IRAs. Se encontró un alto coeficiente de determinación de monóxido de carbono con IRAs en el occidente y centro de la ciudad, bajo con ozono y PM10 y elevado con temperatura. Basado en los resultados este estudio proporciona, se evidencia la alta relación entre el monóxido de carbono y la temperatura con las infecciones respiratorias agudas.The objective of this research is to identify the relationship between pollutants (ozone, carbon monoxide, PM10, temperature and humidity and the morbidity of acute respiratory infections (ARI in Mexicali, state of Baja California in Mexico. Information was obtained from air monitoring stations in Mexicali, during the period 2001-2005. Simple lineal and multiple regression models were used to relate the variables and acute respiratory infections. A high coefficient of determination of carbon monoxide and ARI was found in the western and central areas of the city. A lower coefficient was found with ozone and suspended particles but temperature showed a high coefficient. Based on the results, this research study provides evidence of the high relationship between carbon monoxide, temperature and ARI.

  13. 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" is…

  14. Cambio de uso del suelo y vegetación en la Península de Baja California, México

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    Fernando Antonio Rosete Vergés

    2008-01-01

    Full Text Available Este trabajo analiza el cambio de uso de suelo y de vegetación en la Península de Baja California, al nivel de tipo de vegetación, durante el periodo 1978 (Serie I de INEGI a 2000 (Inventario Nacional Forestal a escala 1:250 000. Se realizó un análisis espacial de la información en ambiente de sistemas de información geográfica (SIG para identificar los cambios durante el periodo analizado. Se elaboró una matriz de transición y se agruparon los cambios encontrados en tres procesos principales de cambio de uso del suelo: desmatorralización, recuperación y crecimiento de manchas urbanas (como un indicador de urbanización. En el periodo analizado (22 años se dan cambios en el 7.7 % del territorio peninsular. Los procesos de desmatorralización y urbanización son más intensos en la zona norte de la pe¬nínsula, mientras que la recuperación es mayor en la zona sur. La desmatorralización para actividades agropecuarias es la más importante en la península. La urbanización en magnitud es el proceso menos importante, pero durante el periodo analizado la superficie ocupada por los asentamientos humanos se incrementó en casi un 270 %.

  15. 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

  16. Gobiernos de coalición: un nuevo diseño institucional en el Congreso de Baja California

    OpenAIRE

    Cuauhtémoc López Guzmán

    2014-01-01

    Este trabajo analiza la relación entre poderes en Baja California; no se fundamenta en las teorías de la representación, sino en la Teoría de la Elección Racional, sitúa a los actores políticos individuales como entes egoístas, maximizadores e instrumentales al estructurar conductas bajo el principio de mejor ganancia y menor pérdida. La metodología empleada combina el modelo de elección racional y el neoinstitucionalismo en la vertiente de la Teoría de los Costos de Transacción Política. Par...

  17. Trabajadores agrícolas migrantes en Baja California. Vinculación con la migración internacional

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    Ma. Eugenia Anguiano Téllez

    1989-09-01

    Full Text Available En este ensayo los jornaleros agrícolas migrantes son clasificados en dos estratos: el primero, considera la migración internacional, es decir, aquéllos que se internan en Estados Unidos con el propósito de conseguir empleo; y el segundo, corresponde a la migración interna de los trabajadores agrícolas que permanecen en Baja California para laborar en los valles de Mexicali y San Quintín.En este trabajo se señalan las diferencias entre estos dos estratos, tanto de carácter económico como en los niveles de educación; asimismo, se comparan las características de los jornaleros agrícolas migrantes que cruzan a Estados Unidos por Mexicali y por Tijuana, según su actividad económica de procedencia y su expectativa de empleo en los Estados Unidos.

  18. Relationshipe Between Self-potential Anomalies and Hydraulic Flow In A Geothermal System: Application To Cerro-prieto, Baja California

    Science.gov (United States)

    Saracco, G.; Revil, A.; Pessel, M.

    The Cerro Prieto geothermal field is located in the alluvial plain of the Mexicali Valley, northern Baja California, Mexico, at about 35 km southeast of the city of Mexicali. The Cerro Prieto geothermal field is one of several high temperature water-dominated geothermal fields within the Salton Trough. We analyze here the self-potential distri- bution at the ground surface in order to determine the pattern of fluid flow in te sub- surface of this geothermal field. Various methods of analysis of self-potential anoma- lies are employed to reach this purpose. We use density probability tomography of monopolar and dipolar electrical sources and an Euler-type analysis. The hydraulic flow pattern found in this geothermal field is in agreement with that detemined from the heat flux inside the structure.

  19. 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.

  20. La territorialidad del indígena americano de la tierra alta del norte de la Baja California

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    Ralph Michelsen

    1991-01-01

    Full Text Available Ralph Michelsen explora la idea de territorialidad entre los indígenas de Baja California como sujetos de otro tipo de realidad; un tiempo cuando el usufructo de la tierra se ceñía a reglas aborígenes particulares en contraste con las formas de tenencia de la tierra actuales y la noción de "país" que en el mundo prevalece. Su finalidad se logra mediante una reconstrucción histórica que le permite hacer propuestas sobre la percepción del espacio geográfico por los miembros de unidades lingüísticas y/o de parentesco.

  1. Strain Localisation at Rift Segment Boundaries: An Example from the Bocana Transfer Zone in Central Baja California, Mexico

    Science.gov (United States)

    Seiler, C.; Gleadow, A. J.; Kohn, B. P.

    2012-12-01

    Rifts are commonly segmented into several hundred kilometre long zones of opposing upper-plate transport direction with boundaries defined by accommodation and transfer zones. A number of such rift segments have been recognized in the northern Gulf of California, a youthful oceanic basin that is currently undergoing the rift-drift transition. However, detailed field studies have so far failed to identify suitable structures that could accommodate the obvious deformation gradients between different rift segments, and the nature of strain transfer at segment boundaries remains enigmatic. The situation is even less clear in central and southern Baja California, where a number of rift segments have been hypothesized but it is unknown whether the intervening segment boundaries facilitate true reversals in the upper-plate transport direction, or whether they simply accommodate differences in the timing, style or magnitude of deformation. The Bocana transfer zone (BTZ) in central Baja California is a linear, WNW-ESE striking structural discontinuity separating two rift segments with different magnitudes and styles of extensional deformation. North of the BTZ, the Libertad fault is part of the Main Gulf Escarpment, which represents the breakaway fault that separates the Gulf of California rift to the east from the relatively stable western portion of the Baja peninsula. The N-striking Libertad escarpment developed during the Late Miocene (~10-8Ma) and exhibits a topographic relief of ca. 1,000m along a strike-length of ca. 50km. Finite displacement decreases from ~1000m in the central fault segment to ~500m further south, where the fault bends SE and merges with the BTZ. In the hanging wall of the Libertad fault, a series of W-tilted horsts are bound along their eastern margins by two moderate-displacement E-dipping normal faults. South of the BTZ, extension was much less than further north, which explains the comparatively subdued relief and generally shallower tilt of

  2. Bio-optical characteristics of a phytoplankton bloom event off Baja California Peninsula (30 31°N)

    Science.gov (United States)

    Barocio-León, Óscar A.; Millán-Núñez, Roberto; Santamaría-del-Ángel, Eduardo; Gonzalez-Silvera, Adriana; Trees, Charles C.; Orellana-Cepeda, Elizabeth

    2008-03-01

    A phytoplankton bloom was detected in the Southern California Current System, off the Baja California Peninsula (Mexico) on June 2003 with chlorophyll- a concentration (TChl a) of 10.13 mg m -3. Two stations (D1 and D2) were sampled on June 24, and D2 was resampled 6 days later; chlorophyll- a concentration had decreased by about one half. LAC MODIS-Chl a images were obtained and showed the spread of the bloom on the day after sampling. The phytoplankton community consisted primarily of dinoflagellate temporary cysts, mainly at the surface and at 5 m in station D1. Two Pseudo-nitzschia species ( P. australis, P. seriata) were also very abundant. Samples from the bloom had a specific phytoplankton absorption coefficient ( aph*(λ)) lower than the rest of the samples. Values varied from 0.0186 to 0.0455 m 2 mg -1 for aph*(440) and from 0.0092 to 0.0294 m 2 mg -1 for aph*(675), with ratios aph*(440): aph*(675) ranging from 0.99 to 2.20. These low ratios were associated with the combined effect of packaging, and with the relatively high ratios of fucoxanthin, peridinin, diadinoxanthin and chlorophyll- c2 to TChl a. Samples from the surface and 5 m depth at station D1 had higher ratios of Perid:TChl a (0.12-0.32) than the rest of the samples, suggesting that cysts have similar Perid:TChl a as free-living dinoflagellates. An unusual absorption spectrum with a broad maximum around 480-500 nm was associated with the high proportion of cysts and diatoms. The slope of the spectra between 443 and 488 nm was a good index to differentiate bloom samples containing high proportions of dinoflagellate temporary cysts. Further investigation of the absorption properties of dinoflagellate cysts is needed in order to detect these waters by remote sensing. Although much work is still necessary to understand and explain the bio-optical properties of a bloom, the present study is the first assessment off the Baja California coast to simultaneously consider aspects such as absorption

  3. Diversidad filogenética de especies de Microcoleus de costras biológicas de suelo de la península de Baja California, México Phylogenetic diversity of Microcoleus species from biological desert crusts of the Baja California Peninsula, Mexico

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    Alejandro López-Cortés

    2010-04-01

    Full Text Available Microcoleus vaginatus fue proclamada como especie cosmopolita. Este supuesto no lo confirman los estudios morfológicos previos que se realizaron en poblaciones naturales de costras de suelo en una región con historia geológica particular, llamada sierra de la Laguna (SL, al sur de la península de Baja California (México. Por ello, en este estudio se comparó la estructura de comunidades de cianobacterias, con énfasis en el género Microcoleus, en costras biológicas de 10 localidades situadas a lo largo de la península. Se analizaron y cotejaron poblaciones naturales de cianobacterias con cepas tipo de colecciones públicas: Microcoleus sociatus (Sammlung von Algenkulturen Germany-SAG 26.92, M. paludosus (SAG 1445. 1a, M. vaginatus (Pasteur Culture Collection-PCC 9802 y M. chthonoplastes (PCC 7420. Se realizaron análisis microscópicos y de clusters de patrones de bandeado de secuencias del 16S rRNA, obtenidos por electroforesis de gel en gradiente desnaturalizante (DGGE. En los análisis microscópicos de muestras naturales no se detectaron morfotipos de M. vaginatus en 6 de las 10 localidades, 4 de ellas de la SL. La comparación de patrones de bandeado obtenidos por DGGE mostró diferencias significativas en la estructura de las comunidades de cianobacterias y ausencia de bandas equivalentes a M. vaginatus (PCC9802, en todas las localidades de la SL.Microcoleus vaginatus has been proclaimed to be a cosmopolitan species. However, morphological studies performed on natural populations of cyanobacterial crusts in a region with a particular geological history at the southern part of the Baja California Peninsula, Mexico, called Sierra de la Laguna (SL, do not support the last assertion. We compared the community structure of cyanobacteria, with emphasis in the genus Microcoleus, in biological desert crusts from 10 different localities along the Baja California Peninsula. We analyzed natural cyanobacterial populations and matched them with

  4. PATHOGENIC LEPTOSPIRA SEROVARS IN FREE-LIVING SEA LIONS IN THE GULF OF CALIFORNIA AND ALONG THE BAJA CALIFORNIA COAST OF MEXICO.

    Science.gov (United States)

    Avalos-Téllez, Rosalía; Carrillo-Casas, Erika M; Atilano-López, Daniel; Godínez-Reyes, Carlos R; Díaz-Aparicio, Efrén; Ramírez-Delgado, David; Ramírez-Echenique, María F; Leyva-Leyva, Margarita; Suzán, Gerardo; Suárez-Güemes, Francisco

    2016-04-28

    The California sea lion ( Zalophus californianus ), a permanent inhabitant of the Gulf of California in Mexico, is susceptible to pathogenic Leptospira spp. infection, which can result in hepatic and renal damage and may lead to renal failure and death. During summer 2013, we used the microscopic agglutination test (MAT) to investigate the prevalence of anti-Leptospira antibodies in blood of clinically healthy sea lion pups from seven rookery islands on the Pacific Coast of Baja California (Pacific Ocean) and in the Gulf of California. We also used PCR to examine blood for Leptospira DNA. Isolation of Leptospira in liquid media was unsuccessful. We found higher antibody prevalence in sea lions from the rookery islands in the gulf than in those from the Pacific Coast. Antibodies against 11 serovars were identified in the Gulf of California population; the most frequent reactions were against serovars Bataviae (90%), Pyrogenes (86%), Wolffi (86%), Celledoni (71%), and Pomona (65%). In the Pacific Ocean population, MAT was positive against eight serovars, where Wolffi (88%), Pomona (75%), and Bataviae (70%) were the most frequent. Serum samples agglutinated with more than one Leptospira serovar. The maximum titer was 3,200. Each island had a different serology profile, and islands combined showed a distinct profile for each region. We detected pathogenic Leptospira DNA in 63% of blood samples, but we found no saprophytic Leptospira. Positive PCR results were obtained in blood samples with high and low MAT titers. Together, these two methods enhance the diagnosis and interpretation of sea lion leptospirosis. Our results may be related to human activities or the presence of other reservoirs with which sea lions interact, and they may also be related to sea lion stranding. PMID:26967136

  5. Teleconnections between upwelling along the Pacific coast of Baja California and marine and terrestrial gross primary production

    Science.gov (United States)

    Reimer, J. J.; Vargas, R.; Gaxiola-Castro, G.; Hernandez-Ayon, M.; Lara-Lara, R.

    2012-12-01

    Terrestrial processes are closely connected to the oceans through teleconnections in the atmosphere. The global terrestrial carbon cycle is known to be affected by a teleconnection to large scale atmospheric events such as El Niño/Southern Oscillation (ENSO; 2 to 7 year cycles), Pacific Decadal Oscillation (PDO), and North Atlantic Oscillation (NAO; decadal cycles). ENSO and PDO are the predominate atmospheric patterns which impact the Pacific coast of North America. Correlations between ENSO indices and gross primary production have shown that ENSO may partially explain the variability in the global terrestrial carbon cycle. We hypothesize that the remaining variability (for those ecosystems along eastern basin margins) may be explained by the teleconnection between terrestrial primary production and upwelling along continental margins. The study sites were selected along the Baja California peninsula due to the fact that each one is characterized by year round coastal upwelling (though stronger during the boreal spinr/summer months) and their respective terrestrial climate characteristics: 1. Punta Colonet/Sierra San Pedro Martir is located in a mediterranean climate with conifer forest; 2. Punta Abre Ojos (just south of Guerrero Negro) is located in the central desert region; 3. at approximate 29°00' N (west of Bahía de los Angeles) is in the central desert region but is also characterized by fog; and 4. Magdalena Bay is located in a subtropical desert region with sporadic rain events (here the marine portion of the transect will extend out from the mouth of the bay). Using ten years of MODIS Terra and Aqua (terrestrial gross primary production [TGPP]) and SeaWif's (chlorophyll a [chl. a] as a proxy for biomass) data for four transects along the Baja California peninsula (extending from approximately 300 km off the coast to up to 50 km inland depending on the transect) the gross primary production will be analyzed in relation to upwelling (represented by sea

  6. 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.

  7. Northern Baja California Indian women's concepts of illness and healing: Implications for public health and clinical practitioners.

    Science.gov (United States)

    Longstreth, G F; Wilken-Robertson, M

    2010-01-01

    Lay health care workers (promotores) interviewed 313 female members of remote Indian groups in northern Baja California, Mexico regarding: (1) common childhood and adult illnesses and endorsement of 'traditional' and modern therapies; (2) illness causation beliefs and knowledge of biomedical principles; and (3) the relation of ethnic identity with concepts of effective biomedical and non-biomedical therapy. The most common illnesses/symptoms reported in adults were diabetes, hypertension, high cholesterol, cold/flu, diarrhoea, low/variable blood pressure and arthritis; and in children, cold/flu, diarrhoea, bronchitis, cough, fever, empacho and dehydration. Of 285 informants, more reported at least one childhood disorder than who reported at least one adult disorder was most helped by traditional therapy [83 (29.1%) versus 44 (15.4%); P<0.0001] and both therapies [81 (28.4%) versus 42 (14.7%); P<0.001]. They reported eight naturalistic and two personalistic illness causes and manifested variable biomedical knowledge. Indian or mixed Indian/Mexican ethnic self-identity predominated, and Indian identity was unrelated to endorsement of traditional therapy. The 'biocultural synthesis' is a useful theoretical framework for viewing the findings. The Indians' pluralistic concepts have important implications for public health care workers and biomedical practitioners.

  8. Decreased Anemia Prevalence Among Women and Children in Rural Baja California, Mexico: A 6-Year Comparative Study.

    Science.gov (United States)

    Moor, Molly A; Fraga, Miguel A; Garfein, Richard S; Harbertson, Judith; Rodriguez-Lainz, Alfonso; Rashidi, Hooman H; Elder, John P; Brodine, Stephanie K

    2016-08-01

    Anemia is a public health problem in Mexico. This study sought to determine the prevalence and correlates of anemia among women and children residing in a rural farming region of Baja California, Mexico. An existing partnership between universities, non-governmental organizations, and an underserved Mexican community was utilized to perform cross-sectional data collection in 2004-2005 (Wave 1) and in 2011-2012 (Wave 2) among women (15-49 years) and their children (6-59 months). All participants completed a survey and underwent anemia testing. Blood smears were obtained to identify etiology. Nutrition education interventions and clinical health evaluations were offered between waves. Participants included 201 women and 99 children in Wave 1, and 146 women and 77 children in Wave 2. Prevalence of anemia significantly decreased from 42.3 to 23.3 % between Waves 1 and 2 in women (p women in Wave 1, consumption of iron absorption enhancing foods (green vegetables and fruits high in vitamin C) was protective against anemia (p = 0.043). Women in Wave 2 who ate ≥4 servings of green, leafy vegetables per week were less likely to be anemic (p = 0.034). Microscopic examination of blood smears revealed microcytic, hypochromic red blood cells in 90 % of anemic children and 68.8 % of anemic women, consistent with iron deficiency anemia.

  9. Audio magnetotelluric study applied to hydrogeology at Santo Tomás Valley, Baja California, México

    Science.gov (United States)

    Islas, A. C.; Romo, J. M.

    2009-12-01

    The Santo Tomás valley, located 50 km southeast of Ensenada, Baja California, is one of the most important viniculture zones in all of Mexico. Therefore, aquifer characterization is very important for the area. A geophysical study was conducted using the audio-magnetotelluric method (AMT) to determinate the electric conductivity of the basin. 82 AMT stations were measured in three profiles with a North-South orientation. Data was collected using a Stratagem EH4 (by Geometrics) in frequencies between 10 Hz to 100 kHz. To determinate basement and water table depths we made 2D ground resistivity models, using an inversion regularized algorithm. The results show a conductive zone from a few meters up to depths of 200 meters; this unit can be interpreted as the aquifer zone. The models show a less conductive zone (~1000 Ohm-m) in the first 20 meters, which is interpreted as the vadose zone. Finally, we have a very resistive unit corresponding to the basement, estimated around 200 meters depth.

  10. 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. PMID:23277367

  11. Gobiernos de coalición: un nuevo diseño institucional en el Congreso de Baja California

    Directory of Open Access Journals (Sweden)

    Cuauhtémoc López Guzmán

    2014-01-01

    Full Text Available Este trabajo analiza la relación entre poderes en Baja California; no se fundamenta en las teorías de la representación, sino en la Teoría de la Elección Racional, sitúa a los actores políticos individuales como entes egoístas, maximizadores e instrumentales al estructurar conductas bajo el principio de mejor ganancia y menor pérdida. La metodología empleada combina el modelo de elección racional y el neoinstitucionalismo en la vertiente de la Teoría de los Costos de Transacción Política. Para concluir, se enfatiza que los componentes conductuales y representativos de todo legislador se asocian a un dilema enfrentado por la disciplina partidista versus la responsabilidad legislativa. Estos comportamientos opuestos son analizados para identificar la viabilidad del modelo de un gobierno de coalición.

  12. 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.

  13. Drug-scene familiarity and exposure to gang violence among residents in a rural farming community in Baja California, Mexico.

    Science.gov (United States)

    Volkmann, Tyson; Fraga, Miguel A; Brodine, Stephanie K; Iñiguez-Stevens, Esmeralda; Cepeda, Alice; Elder, John P; Garfein, Richard S; Viidai Team

    2013-01-01

    We examined drug-scene familiarity and exposure to gang violence among residents of a migrant farming community in rural Baja California, Mexico. In October 2010, 164 members of a single colonia (community) underwent an interviewer-administered survey to assess 'exposure to gang violence' and 'drug-scene familiarity', as well as other health indicators. Logistic regression was used to identify correlates of exposure to gang violence. Overall, 20% of participants were male, the median age was 27 years, 24% spoke an indigenous language, 42% reported exposure to gang violence and 39% reported drug-scene familiarity. Factors independently associated with exposure to gang violence included being younger (adjusted odds ratio [AOR] =0.80 per 5-year increase, 95% confidence interval [CI]=0.67-0.96), living in the community longer (AOR=1.47 per 5-year increase, 95% CI=1.11-1.72), higher educational attainment (AOR=1.70 per 5-year increase, 95% CI=1.07-1.12) and drug-scene familiarity (AOR=5.10, 95% CI=2.39-10.89). Exposure to gang violence was very common in this community and was associated with drug-scene familiarity, suggesting a close relationship between drugs and gang violence in this rural community. In a region characterised by mass migration from poorer parts of Mexico, where drugs and gangs have not been previously reported, emerging social harms may affect these communities unless interventions are implemented.

  14. 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.

  15. Fluoride, nitrate and water hardness in groundwater supplied to the rural communities of Ensenada County, Baja California, Mexico

    Science.gov (United States)

    Daesslé, L. W.; Ruiz-Montoya, L.; Tobschall, H. J.; Chandrajith, R.; Camacho-Ibar, V. F.; Mendoza-Espinosa, L. G.; Quintanilla-Montoya, A. L.; Lugo-Ibarra, K. C.

    2009-07-01

    The hydrogeochemistry of 26 wells belonging to ten different aquifers in the county of Ensenada, Baja California, is studied. These wells are all used to supply the rural communities in the region, which comprise ~37,000 inhabitants, excluding the city of Ensenada. High total dissolved solids (TDS) concentrations (maximum 7.35 g l-1) indicate that salt is a ubiquitous contaminant in the aquifers due to seawater intrusion. The aquifers that support extensive agriculture activities (Maneadero, San Quintín, San Simón and El Rosario) are characterized by higher N-NO3 concentrations (maximum 20 mg l-1) derived from fertilizers. Fluoride concentrations exceed the 1.5 mg l-1 Mexican official limit in only four wells. The enrichments of F- in the southern aquifers are thought to be associated to water-rock interactions controlled mainly by Na-Ca equilibrium reactions with fluorite, as suggested from high dissolved Na concentrations in these waters. In the northern aquifer of Maneadero, no enrichment of Na is found and a geothermal source for F- is likely. Water is hard to moderately hard, with Ca/Mg ratios >1. Although drinking water directly from the tap is not a common practice in these localities, most sources have concentrations of major ions and TDS that exceed the Mexican official limits.

  16. 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 (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.

  17. Tropical-Depression Precipitation In Southwestern North America: An Isotope Record From Arizona, And Isotope Signatures In Baja California Groundwater

    Science.gov (United States)

    Eastoe, C. J.; Hess, G.; Mahieux, S.

    2011-12-01

    A 30-year data set of O and H isotopes in individual precipitation events in Tucson, Arizona, includes entries identified with rainfall associated with tropical depressions, which occasionally pass through southern Arizona. Tropical-depression rain events yielding > 7 mm have a δ18O range -9 to -16 per mil, compared to volume-weighted average summer rainfall with δ18O = -6 per mil, a set of isotope effects similar to those observed in south Texas. The isotope signature of tropical-depression rain is present in groundwater of central and southern Baja California (BC), where summer and fall rain make up at least 50% of annual precipitation. Tritium-bearing groundwater at Todos los Santos (southern BC) has a δ18O range of -8 to -11 per mil and d-parameters near 10. Altitude effects related to adjacent, 1800 m mountains do not explain the isotope data. Groundwater of similar isotope character is present near the Tres Virgenes geothermal field (central BC), but not at Santo Tomas (northern BC). Large deuterium excess (d > 15) is not observed in any of the data.

  18. Decreased Anemia Prevalence Among Women and Children in Rural Baja California, Mexico: A 6-Year Comparative Study.

    Science.gov (United States)

    Moor, Molly A; Fraga, Miguel A; Garfein, Richard S; Harbertson, Judith; Rodriguez-Lainz, Alfonso; Rashidi, Hooman H; Elder, John P; Brodine, Stephanie K

    2016-08-01

    Anemia is a public health problem in Mexico. This study sought to determine the prevalence and correlates of anemia among women and children residing in a rural farming region of Baja California, Mexico. An existing partnership between universities, non-governmental organizations, and an underserved Mexican community was utilized to perform cross-sectional data collection in 2004-2005 (Wave 1) and in 2011-2012 (Wave 2) among women (15-49 years) and their children (6-59 months). All participants completed a survey and underwent anemia testing. Blood smears were obtained to identify etiology. Nutrition education interventions and clinical health evaluations were offered between waves. Participants included 201 women and 99 children in Wave 1, and 146 women and 77 children in Wave 2. Prevalence of anemia significantly decreased from 42.3 to 23.3 % between Waves 1 and 2 in women (p vegetables and fruits high in vitamin C) was protective against anemia (p = 0.043). Women in Wave 2 who ate ≥4 servings of green, leafy vegetables per week were less likely to be anemic (p = 0.034). Microscopic examination of blood smears revealed microcytic, hypochromic red blood cells in 90 % of anemic children and 68.8 % of anemic women, consistent with iron deficiency anemia. PMID:26856732

  19. Drug-scene familiarity and exposure to gang violence among residents in a rural farming community in Baja California, Mexico

    Science.gov (United States)

    Volkmann, Tyson; Fraga, Miguel A.; Brodine, Stephanie K.; Iñiguez-Stevens, Esmeralda; Cepeda, Alice; Elder, John P.; Garfein, Richard S.

    2012-01-01

    We examined drug-scene familiarity and exposure to gang violence among residents of a migrant farming community in rural Baja California, Mexico. In October 2010, 164 members of a single colonia (community) underwent an interviewer-administered survey to assess ‘exposure to gang violence’ and ‘drug-scene familiarity’, as well as other health indicators. Logistic regression was used to identify correlates of exposure to gang violence. Overall, 20% of participants were male, the median age was 27 years, 24% spoke an indigenous language, 42% reported exposure to gang violence, and 39% reported drug-scene familiarity. Factors independently associated with exposure to gang violence included being younger (AOR=0.80 per 5-year increase, 95% CI=0.67–0.96), living in the community longer (AOR=1.47 per 5-year increase, 95% CI=1.11–1.72), higher educational attainment (AOR=1.70 per 5-year increase, 95% CI=1.07–1.12), and drug-scene familiarity (AOR=5.10, 95%CI=2.39–10.89). Exposure to gang violence was very common in this community and was associated with drug-scene familiarity, suggesting a close relationship between drugs and gang violence in this rural community. In a region characterised by mass migration from poorer parts of Mexico, where drugs and gangs have not been previously reported, emerging social harms may affect these communities unless interventions are implemented. PMID:23072623

  20. 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.

  1. 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.

  2. Microstructural and seismic properties of the upper mantle underneath a rifted continental terrane (Baja California): An example of sub-crustal mechanical asthenosphere?

    Science.gov (United States)

    Palasse, L. N.; Vissers, R. L. M.; Paulssen, H.; Basu, A. R.; Drury, M. R.

    2012-09-01

    The Gulf of California rift is a young and active plate boundary that links the San Andreas strike-slip fault system in California to the oceanic spreading system of the East Pacific Rise. The xenolith bearing lavas of the San Quintin volcanic area provide lower crust and upper mantle samples from beneath Baja California peninsula. The microstructures, crystallographic preferred orientations (CPO) and petrology of the San Quintin xenoliths suggest that the continental lithosphere in this region has undergone several stages of deformation, recrystallisation and melt-rock interaction. Melt-rock interactions have led to enrichment in olivine while fine-grained microstructures suggest intense deformation in an active shear zone in the shallow upper mantle. In this study we highlight the effect of the fine-grained mylonitic shear zone development in the upper mantle as an important process of weakening of continental lithosphere. The results of the microstructural study show a reduction in CPO strength with increasing grain size reduction. Most CPOs are consistent with dominant slip on the {0kl}[100] system. As a consequence, corresponding seismic anisotropies decrease for both P- and S-waves with increasing grain size reduction. The shallow crystallographic fabric can be related to active shear zones, which accommodate the relative motion between the Northern Baja terrane and the Pacific plate. Estimates of the strain rate, stress and viscosity indicate that the shallow mantle beneath Northern Baja is thermally and chemically lithospheric but mechanically has similar viscosity as the asthenosphere. The Northern Baja terrane is an interesting case of continental crust lying directly on low viscosity upper mantle.

  3. Efecto de los vientos Santa Ana en las propiedades bio-ópticas frente a Baja California

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available A partir de las propiedades bio-ópticas, los coeficientes de absorción por partículas, detritos y fitoplancton (ap, adT, aφ se evaluó el efecto de los vientos Santa Ana en el océano frente a Baja California ocurridos durante octubre de 1999. Los vientos medidos en la estación meteorológica frente a la Bahía de Todos Santos y los determinados a partir de información de satélite indicaron tres eventos Santa Ana, caracterizados por baja humedad relativa, alta temperatura del aire y vientos con dirección predominante del este-noreste. Los valores del coeficiente de absorción de detritos (adT fueron hasta diez veces mayores en las muestras superficiales de octubre, con relación a las de enero, abril y agosto de 1999. Los altos valores de adT se debieron al material inorgánico aero-transportado por los vientos tierra-mar ocurridos del 9 al 11 y del 17 al 20 de octubre. Los coeficientes de absorción de las particulas (ap y el fitoplancton (aφ en la zona eufótica fueron mayores en abril, como resultado de la abundancia del fitoplancton. Los valores de ap, aφ y Kd para la zona eufótica fueron ajustados a una función de potencia con la clorofila como variable independiente, con una variancia explicada de 37%, 72% y 16%, respectivamente. Cuando se excluyeron del ajuste los valores de adT medidos en la superficie durante octubre, la clorofila explicó 82% de la variabilidad en los coeficientes de absorción (ap y aφ y 87% en Kd. A partir de la ecuación que relaciona la reflectancia de la radiancia espectral ascendente (Rrs con la clorofila, se determinó que ~80% de la variabilidad en la clorofila superficial es explicada por la razón de reflectancia Rrs(443/Rrs(555 medida en la zona de estudio. Las estimaciones regionales de clorofila a partir de información bioóptica obtenida en la columna de agua no fueron afectadas fuertemente por el polvo aero-transportado durante los vientos Santa Ana ocurridos en octubre de 1999.

  4. Subsidence History of the Laguna Salada Basin in Northeastern Baja California, Mexico

    Science.gov (United States)

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

    2008-12-01

    The Salton Trough region in southern California and the Mexicali valley in northwestern Mexico are areas of (i) rapid subsidence due to trans-tension along the San Andreas-Imperial fault system, and (ii) high flux of sediments transported by the Colorado River, all of which confer this region with a high potential to preserve a complete record of climatic and tectonic activity information. Here we present the subsidence history of the Laguna Salada basin, and the history of activity of the master bounding faults on its eastern side. The Laguna Salada is a lacustrine basin located west of the Mexicali valley and to the south of the Salton Trough. Sedimentological as well as time series analyses performed on two 42 m-long cores drilled in the center of the basin, estimated to span the past 50 and 70KaBP, indicate a modulation of the late Quaternary stratigraphy by cyclic variations in lake level driven by Milankovitch forcing. Based on these results we derive the long-term history of the basin from a gamma-ray log recovered from a 2.8 km-deep geothermal borehole drilled by the Mexican Power Company adjacent to the Laguna Salada fault. The stratigraphy of the deep borehole reveals a history of activity pulses related to the initial breakage of the Laguna Salada fault and its interaction with neighboring faults. A first pulse started at 1.5 Ma and records the initiation of the Laguna Salada fault and rapid uplift of the crystalline block of the Sierra Cucapa. A second pulse started around 1 Ma, and is very likely related to the hard linking of the Laguna Salada fault with the Cañada David detachment by the Cañon Rojo fault. The onset of the Laguna Salada fault at 1.5 Ma appears to be synchronous with an early Pleistocene regional fault reorganization among the San Jacinto, San Andreas and Elsinore fault systems in southern California, suggesting that this reorganization may have affected a large area from San Gorgonio pass to the northern Gulf of California.

  5. Submarine Neotectonic Investigations of the Bahia Soledad Fault, off Northern Baja California Near the US - Mexico Border

    Science.gov (United States)

    Anderson, K.; Lundsten, E. M.; Paull, C. K.; Caress, D. W.; Thomas, H. J.; Maier, K. L.; McGann, M.; Herguera, J. C.; Gwiazda, R.; Arregui, S.; Barrientos, L. A.

    2015-12-01

    The Monterey Bay Aquarium Research Institute (MBARI) conducted detailed surveys at selected sites on the seafloor along the Bahia Soledad Fault offshore of Northern Baja California, Mexico, during a two-ship expedition in the spring of 2015. The Bahia Soledad Fault is a NNW-trending strike-slip fault that is likely continuous with the San Diego Trough Fault offshore of San Diego, California. Constraining the style of deformation, continuity, and slip rate along this fault system is critical to characterizing the seismic hazards to the adjacent coastal areas extending from Los Angeles to Ensenada. Detailed morphologic surveys were conducted using an autonomous underwater vehicle (AUV) to provide ultra high-resolution multibeam bathymetry (vertical precision of 0.15 m and horizontal resolution of 1.0 m). The AUV also carried a 2-10 kHz chirp sub-bottom profiler and an Edgetech 110kHz and 410kHz sidescan. The two sites along the Bahia Soledad Fault each run ~6 km along the fault with ~1.8 km wide footprint. The resulting bathymetry shows these fault zones are marked with distinct lineations that are flanked by ~1 km long elongated ridges and depressions which are interpreted to be transpressional pop-up structures and transtensional pull-apart basins up to 100 m of relief. Offset seismic reflectors that extend to near the seafloor confirm that these lineations are fault scarps. The detailed bathymetric maps and sub-bottom profiles were used to locate key sites where deformed stratigraphic horizons along the fault are within 1.5 m of the seafloor. These areas were sampled using a remotely operated vehicle (ROV) equipped with a vibracoring system capable of collecting precisely located cores that are up to 1.5 m long. The coupled use of multibeam imagery and surgically-collected stratigraphic samples will enable to constrain the frequency and timing of recent movements on this fault which will be useful to incorporated into future seismic hazard assessment.

  6. Distribution, genetic structure, and conservation status of the rare microendemic species, Guaiacum unijugum (Zygophyllaceae in the Cape Region of Baja California, Mexico Distribución, estructura genética y conservación de la especie microendémica Guaiacum unijugum (Zygophyllaceae en la región de los Cabos de Baja California, México

    Directory of Open Access Journals (Sweden)

    Ross A. McCauley

    2010-12-01

    Full Text Available Guaiacum unijugum is a rare shrub endemic to a 70 km stretch of coastline extending east from San José del Cabo in Baja California and is the least well-known of the 4 species of Guaiacum in Mexico. To increase our knowledge of this species and assess its conservation status we surveyed the extent of occurrence using both herbarium material and field work, assessed levels of genetic diversity, determined its phylogenetic relationships, and completed an evaluation of risk of extinction (MER. Herbarium material identified 5 known localities of occurrence with field work verifying the continued persistence of 4 of these with an additional site discovered. Genetic analysis across the small range using 17 microsatellite loci showed very low levels of genetic diversity with a mean expected heterozygosity (H E of 0.162 over all polymorphic loci. Most loci were found to be monomorphic and genetic divergence was small, maintained by the presence of rare private alleles in widely-separated populations. Phylogenetic analysis indicated a sister group relationship to G. coulteri along the Pacific coast suggesting vicariance for the origin and occurrence of G. unijugum. The unique evolutionary history coupled with current small population sizes warrants increased conservation via listing as a critically endangered species.Guaiacum unijugum es un arbusto endémico en un área de aproximadamente 70 km en la región de Los Cabos, Baja California Sur, siendo la menos estudiada de las 4 especies de Guaiacum en México. Para incrementar nuestro conocimiento sobre esta especie y determinar su estatus de conservación se realizó un censo de sus poblaciones determinándose su estructura genética, su relación filogenética con otros miembros del género y se calculó su riesgo de extinción (MER. La revisión de material de herbario, confirmó la presencia de 4 poblaciones a las que se sumó el hallazgo de 1 más. Mediante el uso de 17 loci de microsatélites se

  7. Hydrography of Bahia Todos Santos, Baja California: Results of more than twenty five years of investigations.

    Science.gov (United States)

    Bustos-Serrano, H.; Canino-Herrera, S. R.; Morales-Chavez, R.; Martinez-Garcia, G. M.

    2007-05-01

    The first study of Bahia Todos Santos (BTS) was reported by Walton in 1955. We conducted oceanographic studies in BTS since 1979. The BTS has a connection with a coastal lagoon named Estero de Punta Banda (EPB), two islands at the western portion and the Port of Ensenada. The general hydrographic characteristics are: In winter the water became homogeneous, less saline (33.6) low temperature (13°C), low oxygen (~3mL L-1) and rich in nutrient concentration. The isothermal top layer has relatively high temperature (>17°C) and oxygen concentration (>6mL L-1). The intermediate transition layer (seasonal thermocline) has minimum salinity, maximum oxygen and high stability. During fall there is distribution of heat from the surface layer to the entire water column. The thermic waves propagate with decrease amplitude in ~3 months, from surface to bottom water. The California Current flow generally southward off the western United States and northern Mexico and is one of the major coastal upwelling of the word oceans. The upwelling events in BTS appear regularly at the SW portion and were typically characterized by an increase in pCO2, decrease of O2, increase of nutrients and a lower temperature. Upwelling activity increases surface nutrient availability causing rise in the primary productivity and hence increased zooplankton biomass. The annual upwelling event which had a maximum strength on May, the seasonal warming and cooling, and the water advection were the dominant modifying processes for the variability of seawater characteristics. Higher salinities are located close to the coastline and lower off the bay. The levels of oxygen, alkalinity, pH and chlorophyll indicate that the maximum concentration of phytoplankton is located at the center of the bay. The nitrification support the primary productivity and the NO3 levels were below detection limits; the N/P ratio in 2005 was from 10 to 25; and for 2006 was below 5. There is a net enrichment of anthropogenic

  8. 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)

  9. 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.

  10. WATER TEMPERATURE, SALINITY, and HYDROSTATIC PRESSURE collected from R/V Point Sur in Entrance to the Gulf of California from 2013-04-19 to 2013-05-02 (NCEI Accession 0131072)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hydrographic data were collected in Pescadero Basin (at the entrance to the Gulf of California) and subsequently along the West Coast of Baja California and...

  11. Variación espacio-temporal de la densidad poblacional de erizo rojo Strongylocentrotus franciscanus (Echinodermata: Echinoidea: Strongylocentrotidae) en Baja California Spatial and temporal variation of the population density of the red sea urchin Stronngylocenntrotus franciscanus (Echinodermata: Echinoidea: Strongylocentrotidae) in Baja California

    OpenAIRE

    Julio S. Palleiro-Nayar; Gabriela Montaño-Moctezuma; Óscar Sosa-Nishizaki

    2012-01-01

    Se estimó la densidad poblacional de erizo rojo, Strongylocentrotus franciscanus, en 10 localidades de la costa occidental de Baja California, México, donde se realiza la extracción comercial de este recurso pesquero. Se compararon las estimaciones realizadas en cuatro años muestreados: 2003, 2005, 2006 y 2008. Las variaciones observadas en las localidades analizadas indicaron diferencias espacio-temporales para la densidad de erizo rojo y diferencias en la estructura de tallas, las cuales es...

  12. Violencia laboral intramuros. Hostigamiento sexual y otras formas de violencia contra la mujer en las maquiladoras de Sonora y Baja California

    OpenAIRE

    Mireya Scarone Adarga

    2014-01-01

    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 identi...

  13. EFECTO DE LAS AGUAS RESIDUALES TRATADAS SOBRE EL CRECIMIENTO, FOTOSÍNTESIS Y RENDIMIENTO EN VIDES TEMPRANILLO (Vitis vinifera) EN BAJA CALIFORNIA, MÉXICO

    OpenAIRE

    Dinora Acosta-Zamorano; Víctor Macías-Carranza; Leopoldo Mendoza-Espinosa; Alejandro Cabello-Pasini

    2013-01-01

    Baja California es una zona semidesértica donde la agricul - tura, incluyendo la viticultura, está limitada por la dispo - nibilidad de agua. Ensenada es una ciudad adyacente a la zona viticultural donde 100 % de las aguas de drenaje son tratadas, no son reutilizadas y se vierten al mar. Por tanto, el objetivo de este estudio fue evaluar el efecto de las aguas residuales tratadas (ART) sobre el crecimiento, la fotosínte - sis y el rendimiento de vid ( Vitis vinifera var. Tempranillo) en el Va...

  14. Cambio de uso del suelo y vegetación en la Península de Baja California, México

    OpenAIRE

    Fernando Antonio Rosete Vergés; José Luis Pérez Damián; Gerardo Bocco

    2008-01-01

    Este trabajo analiza el cambio de uso de suelo y de vegetación en la Península de Baja California, al nivel de tipo de vegetación, durante el periodo 1978 (Serie I de INEGI) a 2000 (Inventario Nacional Forestal) a escala 1:250 000. Se realizó un análisis espacial de la información en ambiente de sistemas de información geográfica (SIG) para identificar los cambios durante el periodo analizado. Se elaboró una matriz de transición y se agruparon los cambios encontrados en tres procesos principa...

  15. Estimación del efecto de variables contextuales en el logro académico de estudiantes de Baja California

    OpenAIRE

    Mauricio Carvallo Pontón; Joaquín Caso Niebla; Luis Ángel Contreras Niño

    2007-01-01

    En el presente estudio se analizan los efectos de diversas variables contextuales en el logro educativo de una muestra de 1,817 estudiantes de sexto año de primaria y 1,239 de tercero de secundaria de Baja California, quienes respondieron a las Pruebas Nacionales aplicadas por el Instituto Nacional para la Evaluación de la Educación en 2004. Los resultados observados son consistentes con los reportados en la mayor parte de la literatura nacional e internacional: las mujeres presentan mejor de...

  16. Distribution, genetic structure, and conservation status of the rare microendemic species, Guaiacum unijugum (Zygophyllaceae) in the Cape Region of Baja California, Mexico

    OpenAIRE

    Ross A. McCauley; Cortés-Palomec, Aurea C.; Ken Oyama

    2010-01-01

    Guaiacum unijugum is a rare shrub endemic to a 70 km stretch of coastline extending east from San José del Cabo in Baja California and is the least well-known of the 4 species of Guaiacum in Mexico. To increase our knowledge of this species and assess its conservation status we surveyed the extent of occurrence using both herbarium material and field work, assessed levels of genetic diversity, determined its phylogenetic relationships, and completed an evaluation of risk of extinction (MER). ...

  17. Organizaciones no gubernamentales y la contaminación del aire en la frontera de Baja California, México-California, Estados Unidos. Contexto y desafíos

    OpenAIRE

    José María Ramos; Marcela Reyes

    2006-01-01

    Aquí se analiza el papel de las principales organizaciones no gubernamentales (ONG) ambientalistas, con respecto a la contaminación del aire en la frontera de Mexicali, Baja California (BC), México y Valle Imperial, California en Estados Unidos (EEUU). Los temas principales son los antecedentes de la polución del aire en la zona mencionada; el papel de las ONG, la gestión asociada y el marco institucional y legal de la participación ciudadana, ...

  18. Aislamiento de Microsatélites y flujo Genético en Dosidicus Gigas (D'Orbigny, 1835) entre el Golfo de California y La Costa Occidental de La Península de Baja California, México

    OpenAIRE

    Millán, A.M.

    2010-01-01

    El calamar gigante, Dosidicus gigas (D'Orbigny, 1835) es una especie semioceánica y nerítica endémica del Pacífico Oriental, distribuida desde el norte de California E.U.A (43º N) hasta el sur de Chile (20°S), incluyendo el Golfo de California. Habita aguas desde la superficie hasta 1000 metros de profundad. Particularmente dentro del Golfo de California (México), es considerado uno de los recursos pesqueros más importantes, sin embargo el manejo de la pesquería de éste cefalóp...

  19. La dinámica territorial de las principales instituciones bancarias en la península de Baja California: estructura e interrelaciones

    Directory of Open Access Journals (Sweden)

    Lilia Susana Padilla y Sotelo

    2001-01-01

    Full Text Available Este trabajo muestra la distribución territorial de las principales instituciones bancarias en el espacio urbano de la península de Baja California Se inicia con los antecedentes de la organización de la banca de la zona y su relación en el contexto nacional en donde destaca su localización fronteriza. El análisis locacional a través del examen de distribución territorial de las 158 sucursales bancarias de las siete principales instituciones permite detectar una sustancial en concentración en comunidades urbanas de la porción norte, tanto en pequeñas como en medias, y una marcada tendencia a ubicarse en localidades de rango poblacional con comportamientos diferenciados, aspecto que se relaciona con la actividad económica que se realiza en las mismas, lo que las convierte en espacios preferenciales, resultado de desequilibrios territoriales. Sobresalen las ciudades de Tijuana y Mexicali y, en menor proporción, las de La Paz y Ensenada. La distribución territorial de las instituciones bancarias en la península de Baja California sigue el mismo patrón de comportamiento que el de la escala nacional, el de ubicación, de acuerdo con la especialidad.

  20. Synthesis of gravity, magnetic and thermal studies at the Las Tres Virgenes geothermal zone, Baja California Sur, Mexico. Sintesis de los estudios de gravimetria, magnetometria y termometria en la zona geotermica de Las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Estrada, Gerardo (Departamento de Exploracion, Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)); Gonzalez Lopez, Macario (Residencia General de Cerro Prieto, Mexicali (Mexico))

    1998-01-15

    Las Tres Virgenes geothermal zone is located in the NE-SW central sector of a sigmoidal basin that regionally has a NW-SE trend. In the local deepest zone there is a NE-SE granodioritic basement horst acting as hydrologic barrier, that makes the fluids flow up. After moving in a direction parallel to the local horst, waters continue its regional SE-NW movement controlled by regional tectonics. The flanks of the granodioritic basement horst, and local N-S faulting act as fluid paths in the hydrothermal zone, but regional NW-SE regional faults determine the general flow direction. Both regional and local tectonics show magnetic evidences of the emplacement of magmatic bodies of intermediate to basic composition. Those along NW-SE trends are more noticeable but we consider they are not the present day heat source. Intermediate magmatism along NE-SW local trend seems to be less extensive but it is younger, so, we consider it constitutes the heat source of the hydrothermal system. Thermal data suggest that the heat source is located below the volcanic chain toward the S or SW of the wells, phenomena related with the general displacement of magmatism from NE to SW along the volcanic chain. However, recent intensive faulting permits a higher permeability in the northern sector in which there are slightly smaller temperatures but at shallower depths and with higher flow rates.

  1. Geological Evidence That Resolves the Baja-BC Controversy: Detrital Zircons Indicate That Vancouver Island Was Adjacent to Southern California in the Late Cretaceous

    Science.gov (United States)

    Guest, B.; Matthews, W.; Coutts, D. S.; Bain, H.; Hubbard, S. M.

    2015-12-01

    The Baja-BC hypothesis is at the center of a great earth sciences controversy. It stems from paleomagnetic observations that require large-scale displacements of continental crust from low latitudes (Baja, California) to moderate latitudes (British Columbia). Many geologists dispute the scale of the displacements due to a lack of corroborating geological evidence. We provide a robust, geological dataset that confirms the paleomagnetic observations. Detrital zircons from Cretaceous to Paleocene sandstone of the Nanaimo Group, which crops out in western Vancouver Island and the Gulf Islands of southwest British Columbia, are analyzed. The data show a clear transition from local 300 Ma grains in the Maastrichtian-Paleogene. An identical pattern is observed in detrital zircon datasets from southern California forearc basin deposits, and schists interpreted as the subducted remnants of forearc deposits. With a high-n dataset (n=3041) we are able to rule out possible >300 Ma source regions in Canada and the northern United States, and uniquely tie Nanaimo Group rocks to the Mojave-Sonora region of SW United States. This implies that at the end of the Cretaceous, Vancouver Island and western mainland BC were adjacent to southern California and northwestern Mexico, requiring 1900 km of displacement during the latest Cretaceous and Paleocene, consistent with paleomagnetic results. An implication of this result is that the western Coast Batholith of southwest BC was positioned between the northern Peninsular Ranges and southern Sierra Nevada batholiths in the late Cretaceous, and likely represents a displaced segment of a once continuous Cordilleran arc batholith. These results have broad implications for our understanding of episodic arc magmatism in the Cordillera, the tectonic evolution of western North America, Laramide orogenesis, the development and extent of the Nevadaplano, and the onset of Basin and Range extension.

  2. Dinámica del plancton en la región sur de la Corriente de California

    OpenAIRE

    Hernández Trujillo, Sergio; Gómez Ochoa, Francisco Javier; Verdugo Díaz, Gerardo

    2001-01-01

    Se efectuó el análisis de la abundancia de la biomasa zooplanctónica, del micro y nanofitoplancton y de Calanus pacificus Brodsky 1948 en combinación con datos de temperatura superficial del mar en la costa occidental de la península de Baja California, entre febrero de 1983 y septiembre de 1991. La biomasa del zooplancton presentó una tendencia estacional de variación de la abundancia. Respecto al fitoplancton, la abundancia mensual de la fracción nanofitoplancton (< 20 µm) fue mayor, en ...

  3. [Asteroidea, Echinoidea y Holothuroidea in shallow bottoms of Bahía de Loreto, Baja California Sur, Mexico].

    Science.gov (United States)

    Holguin Quiñones, O; Wright López, H; Solís Marín, F

    2000-12-01

    To evaluate echinoderm distribution, abundance and density a double 50 m transect, with a side observation range of 2.5 m was used at each of 11 stations (bimonthly samplings, Aug. 1997-Febr. 1998). In Bahía de Loreto the Phylum Echinodermata consists of 26 taxa. The greatest mean abundance by transect and mean densities in order of importance for Echinoidea were: Echinometra vanbrunti (94.1 +/- 52.9 ind, 0.25 ind/m2), Centrostephanus coronatus (38.15 +/- 9.15 ind, 0.06 ind/m2), Tripneustes depressus (28.68 +/- 6.86 ind, 0.039 ind/m2), Eucidaris thouarsii (10.66 +/- 3.37 ind, 0.025 ind/m2) and Diadema mexicanum (11.75 +/- 4.92 ind, 0.023 ind/m2); for Asteroidea were: Phataria unifascialis, Mithrodia bradleyi and Acanthaster planci. Asteroidea was the dominant class with 12 species, followed by Echinoidea with ten and Holothuroidea was represented by four species. PMID:11487923

  4. General characteristics of the diet of Trachinotus paitensis (Teleostei: Carangidae) from San Ignacio Lagoon, Baja California Sur, Mexico.

    Science.gov (United States)

    Cruz Escalona, V H; Abitia Cárdenas, L A

    2004-03-01

    The food habits of Trachinotus paitensis, in San Ignacio Lagoon B.C.S., Mexico, were investigated. We observed that T. paitensis is carnivorous, feeding mainly on benthic invertebrates (the gastropods Anachis spp., Bittium spp., and the crustacean larvae). We concluded that T. paitensis is an opportunist predator that impacts mainly on epibenthic invertebrates.

  5. Seasonal changes in a fish assemblage associated with mangroves in a coastal lagoon of Baja California Sur, Mexico

    OpenAIRE

    Jesús Rodríguez-Romero; Laura del Carmen López-González; Felipe Galván-Magaña; Francisco J. Sánchez-Gutiérrez; Roxana B Inohuye-Rivera; Juan C. Pérez-Urbiola

    2011-01-01

    The fish assemblage in a coastal lagoon with mangroves known as Rancho Bueno was determined and associated with environmental parameters. We used an experimental otter trawl net to catch the fish, and 62 fish species were identified from 48 genera and 30 families. The most abundant species were: Etropus crossotus, Eucinostomus gracilis, Paralabrax maculatofasciatus, Sphoeroides annulatus, and Eucinostomus dowii. The water temperature changed seasonally, being warm from July through December...

  6. Geogenic metal mobility in a coastal inlet impacted by cannery discharge, Magdalena Bay, Baja California Sur, Mexico.

    Science.gov (United States)

    O'Shea, Beth; Capistrano, Christian; Lee, William

    2016-08-15

    Magdalena Bay is an important habitat for marine organisms, some of which have been the subject of metal bioaccumulation studies. Cannery waste is discharged into the bay providing a plausible source of contamination but this study finds that some metals occur geogenically. Bay sediments and rocks (n=59) were analyzed for total metals and clustered (HCA) into two distinct groups with PCA indicating concentrations of Cr, Cu, Mn, and Ni influenced samples near ophiolite outcrops, which reported some metal concentrations exceeding averages in the crust by an order of magnitude (up to 4450ppm Cr and 1269ppm Ni). Metals at the cannery are rarely elevated above crustal averages except Zn (max. 160ppm), however, acid-extracted Zn was below recommended sediment quality guidelines in contrast to 80% of ophiolitic samples reporting Ni extractability exceeding such guidelines. This study raises awareness of geogenic metals when considering sources of contamination in marine environments. PMID:27251444

  7. Evolution of the 2014-2015 sea surface temperature warming in the central west coast of Baja California, Mexico, recorded by remote sensing

    Science.gov (United States)

    Robinson, Carlos J.

    2016-07-01

    Extraordinarily warm sea surface temperatures were present in the California Current System during 2014-2015. In several locations surface waters temperature registered new record high in the recent time series. This study focuses in the evolution of the warming in the southern part of the California Current System (CCS), off the west coast of Baja California, Mexico. Analysis of monthly sea surface temperature (SST), sea level pressure, and wind speed as measured by satellite from January 1988 to December 2015 show that recent warming occurred during two distinct periods. From May 2014 to April 2015, SST warming was related to weak coastal winds not associated to El Niño. During this period occurred the longest sustained record of 15 months of negative wind anomalies in the series. A reduction of wind stress suggests a weakened coastal upwelling, and consequently, cold water not transported into the surface. The second process of warming occurred from September to December 2015, during a strong El Niño condition.

  8. 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.

  9. Geochemistry of the Mesozoic bedded cherts of Central Baja California (Vizcaino-Cedros-San Benito): implications for paleogeographic reconstruction of an old oceanic basin

    Science.gov (United States)

    Rangin, Claude; Steinberg, Michel; Bonnot-Courtois, Chantal

    1981-07-01

    In central Baja California (Vizcaino Peninsula, and Cedros and San Benito Islands) two distinct radiolarian bedded chert sequences of late Triassic and late Jurassic/lowermost Cretaceous age, can be differentiated on lithostratigraphic and geochemical criteria. These bedded chert sequences are part of the conformable sedimentary cover of more or less dismembered ophiolites, which are overthrusted by the San Andrès-Cedros volcanic arc system of middle late Jurassic age. Major and trace elements permit paleogeographic zonation of the late Jurassic/lowermost Cretaceous radiolarites lying conformably upon ophiolites considered as fragments of an oceanic basin floor which developed westward of the San Andrès volcanic arc. Progressive accretion of this oceanic basin floor, along the continental margin is supported by the fact that the more distal radiolarian chert sequences belong to the lowermost structural units of this area.

  10. 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.

  11. Primary colonization and breakdown of igneous rocks by endemic, succulent elephant trees ( Pachycormus discolor) of the deserts in Baja California, Mexico

    Science.gov (United States)

    Bashan, Yoav; Vierheilig, Horst; Salazar, Bernardo G.; de-Bashan, Luz E.

    2006-07-01

    Trees growing in rocks without soil are uncommon. In two arid regions in Baja California, Mexico, field surveys found large numbers of rock-colonizing elephant trees ( Pachycormus discolor (Benth.) Coville ex Standl. (Mexican name: copalquin) growing in igneous rocks (granite and basalt) as primary colonizers without the benefit of soil or with a very small amount of soil generated by their own growth. Many adult trees broke large granite boulders and were capable of wedging, growing in, and colonizing rocks and cliffs made of ancient lava flows. This is the first record of a tree species, apart from the previously recorded cacti, capable of primary colonization of rocks and rock rubble in hot deserts.

  12. El papel de los comités Pro-Estado en la creación del estado de Baja California

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    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.

  13. Status of the peregrine falcon in the Rocky Mountains and the southwestern United States, Baja California, and Mexico (south of Texas)

    Science.gov (United States)

    Porter, Ron; Craig, G.R.; Ellis, D.H.; Enderson, J.H.; Hunt, W.G.; Schaeffer, Philip P.; Ehlers, Sharyn M.

    1978-01-01

    About 31 pairs of peregrines still nest north of Mexico, from Idaho and Montana south through West Texas, New Mexico and Arizona. At least thirty-six additional pairs nest in Mexico. Although the nesting sites are occupied, the tissues of the peregrine?s prey species still contain high concentrations of pesticides. The eggs in some Rocky Mountain eyries have shells which are precariously thin and have high residue levels of DDE in their contents. Increasing economic development is encroaching on the peregrine habitat throughout its range in western North America. In Baja California. and Mexico south of Texas this involves increased agricultural activity including use of organochlorine pesticides, increased tourism and increased use of the Gulf of California both for commercial and sport fishing, with their potential disturbance of eyrie sites and reduction of the peregrine?s aquatic feeding prey base. As the fish in the Gulf decrease in number, some of the avian species on which peregrines prey will likewise decrease. This ultimately may effect the peregrine. These factors may have been involved in the demise of the peregrine on Baja California?s Pacific coast. Furthermore, throughout its range, residential, industrial, mining, geothermal, recreational and other types of development and land use practices sometimes destroy habitat essential to the survival of the peregrine. A recent request for the protection of an historical site in California as Critical Habitat under Section 7 of the Endangered Species Act was rejected because peregrines, although observed there, were not known to have produced eggs or young at the site for several decades. With inadequate protection of abandoned, but still suitable, historical eyrie sites, the peregrine may have an insufficient number of eyries to reoccupy in recovery attempts. The lack of present occupancy of a site, without biological evidence that the site is no longer suitable for reoccupancy, is insufficient cause to give

  14. 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

  15. Natural history, ecology, and conservation of the genus Polyphylla Harris, 1841. 1. New species from the southwestern United States and Baja California, Mexico, with notes on distribution and synonymy (Coleoptera: Scarabaeidae: Melolonthinae)

    OpenAIRE

    La Rue, Delbert A.

    2016-01-01

    Four new species of the genus Polyphylla Harris (Coleoptera: Scarabaeidae: Melolonthinae) from the southwestern United States and Baja California, Mexico, are described and illustrated: Polyphylla anivallis, P. koso, P. morroensis, and P. socorriana. Two nomenclatural changes are proposed: Polyphylla ratcliffei Young is placed into synonymy with P. avittata Hardy and Andrews, new synonymy; P. uteana Tanner is removed from synonymy and reinstated as a valid species, reinstated status. The fema...

  16. The Cooperativism and Agricultural Credit in Baja California, Mexico (1930-1950: A first approach El cooperativismo y la financiación agrícola en Baja California, México (1930-1950: Una aproximación inicial

    Directory of Open Access Journals (Sweden)

    Jesús Méndez Reyes

    2011-01-01

    Full Text Available In order to the neoclassic conventional theory the operation of the credit markets face two basic difficulties: the asymmetric or imperfect information and the adverse selection of the borrower come together with the nonpayment risk. On and other side, more heterodox, the collectivism, the social capital and the creation of informal nets and credit societies, use to low down the transaction costs related to the financing problem. This kind of organization makes easier the development of cooperativism in economy. In México, after the Revolution and the establishment of an authoritarian political and vertical regimen, the cooperativism became one of the referents of the rural organization in order to get credit of private and public banks. In the northeast of the country and Baja California peninsula, the existence of fishing, cattle raising, farming and transportation cooperatives means a blunt of economical activity and one of the channels of development in the zone. The purpose of this article is to shape what kind of cooperativism was set up in the Northern District of Baja California and what type of relation kept with the national cooperative movement between 1930 and 1950.Para la teoría neoclásica convencional el funcionamiento de los mercados de crédito soporta dos dificultades básicas: la información imperfecta o asimétrica y la selección adversa del prestatario aunada al riesgo del no pago. En el otro extremo, más heterodoxo, el colectivismo, el capital social y la formación de redes informales y sociedades de crédito suelen reducir los costes de transacción ligados al problema de la financiación. Este tipo de organización facilita el desenvolvimiento del cooperativismo en la economía. En México, después de la Revolución y la conformación de un régimen político autoritario y vertical, el cooperativismo se constituyó en uno de los referentes de la organización campesina para conseguir crédito de la banca pública y

  17. Biomonitoring with Micronuclei Test in Buccal Cells of Female Farmers and Children Exposed to Pesticides of Maneadero Agricultural Valley, Baja California, Mexico

    Science.gov (United States)

    Castañeda-Yslas, Idalia Jazmin; Arellano-García, María Evarista; García-Zarate, Marco Antonio; Ruíz-Ruíz, Balam; Zavala-Cerna, María Guadalupe; Torres-Bugarín, Olivia

    2016-01-01

    Feminization of the agricultural labor is common in Mexico; these women and their families are vulnerable to several health risks including genotoxicity. Previous papers have presented contradictory information with respect to indirect exposure to pesticides and DNA damage. We aimed to evaluate the genotoxic effect in buccal mucosa from female farmers and children, working in the agricultural valley of Maneadero, Baja California. Frequencies of micronucleated cells (MNc) and nuclear abnormalities (NA) in 2000 cells were obtained from the buccal mucosa of the study population (n = 144), divided in four groups: (1) farmers (n = 37), (2) unexposed (n = 35), (3) farmers' children (n = 34), and (4) unexposed children (n = 38). We compared frequencies of MNc and NA and fitted generalized linear models to investigate the interaction between these variables and exposition to pesticides. Differences were found between farmers and unexposed women in MNc (p < 0.0001), CC (p = 0.3376), and PN (p < 0.0001). With respect to exposed children, we found higher significant frequencies in MNc (p < 0.0001), LN (p < 0.0001), CC (p < 0.0001), and PN (p < 0.004) when compared to unexposed children. Therefore working as a farmer is a risk for genotoxic damage; more importantly indirectly exposed children were found to have genotoxic damage, which is of concern, since it could aid in future disturbances of their health. PMID:26981119

  18. Lack of knowledge about mother-to-child HIV transmission prevention in pregnant women at Tijuana General Hospital, Baja California, Mexico.

    Science.gov (United States)

    Becka, Chandra M; Chacón-Cruz, Enrique; Araneta, Maria Rosario; Viani, Rolando M

    2015-01-01

    The objective of this study was to identify determinants of human immunodeficiency virus (HIV) knowledge regarding mother-to-child transmission (MTCT) among pregnant women at Tijuana General Hospital, Baja California, Mexico. Between March and November 2003, patients from the prenatal care (n = 1294) and labor and delivery (L&D) units (n = 495) participated in a cross-sectional study to measure HIV knowledge. Less than one-third (30%) knew that HIV could be transmitted to a child during delivery, and 36% knew that HIV could be transmitted by breast-feeding. Only 27% knew that an MTCT could be prevented. Prenatal patients were more likely to know that MTCT was preventable (prenatal: 31% versus L&D 25%; P = .02). Logistic regression indicated that prenatal patients (odds ratio = 1.49, confidence interval 1.07-2.07) were more likely to know that HIV could be transmitted through breast-feeding. Overall, both groups had poor knowledge regarding MTCT of HIV.

  19. 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.

  20. Patterns of distribution, temporal fluctuations and some population parameters of four species of flatfish (Pleuronectidae off the western coast of Baja California

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    Marco A Martínez-Muñoz

    2013-11-01

    Full Text Available We examined the spatial and temporal abundance as well as some biological features of the four Pleuronectidae species living in the shallow and deep marine waters off the western coast of Baja California: spotted turbot Pleuronichthys ritteri (Starks & Morris, 1907; hornyhead turbot Pleuronichthys verticalis (Jordan & Gilbert, 1880; slender sole Lyopsetta exilis (Jordan & Gilbert, 1880, and Dover sole Microstomus pacificus (Lockington, 1879. Flatfishes were sampled by otter trawls during six cruises, between October 1988 and September 1990. The area sampled covers three geographic regions (Southern, Central and Northern and three depths (inner, middle and outer shelf. The data were analyzed to quantify the ecological variation in environmental factors and spatial assemblages. Spatial patterns of the Pleuronectidae assemblages were determined by depth, sediment type and geographical region. The distribution of Pleuronectidae species across the shelf also varies in time depending on the oceanic regimes. The sex ratio was approximately 1:1 for all four species. Standard length ranged from 45 to 261 mm, with the most frequent sizes ranging from 90 to 130 mm. For turbots, the length-weight relationships varied between sexes, geographical regions and seasons of the year.

  1. 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.

  2. 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.

  3. 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

  4. Cadmium concentration in liver and muscle of silky shark (Carcharhinus falciformis) in the tip of Baja California south, México.

    Science.gov (United States)

    Terrazas-López, Rafael; Arreola-Mendoza, Laura; Galván-Magaña, Felipe; Anguiano-Zamora, Marlene; Sujitha, S B; Jonathan, M P

    2016-06-15

    Cadmium concentrations were determined in the tissues of muscle and liver of Carcharhinus falciformis (silky shark) sampled in Todos Santos, Baja California South, Mexico. This is one of the main shark species for human consumption in Mexico. Results indicate that accumulation of Cd varied in both sexes, based on its metabolism, sex, maturity and other biological characteristics. High Cd values were observed in the liver of adults of male (529.61μgg(-1)) and female (457.43μgg(-1)), whereas, in muscular tissues it was low (0.37μgg(-1)) than the prescribed permissible limits for seafood (0.5μgg(-1)). Substantial correlations were observed between body length and Cd values in adults except young male due to faster growth rate and its metabolism. The study indicated the impact of environmental conditions in the accumulation of Cd and its risk to the food web structure in the marine environment and health hazard for humans. PMID:27016957

  5. POLÍTICAS PÚBLICAS DE JUVENTUD EN BAJA CALIFORNIA (1983-2002: AVANCES ADMINISTRATIVOS Y DESAFÍOS POLÍTICO-CULTURALES

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    Alejandro Monsiváis Carrillo

    2004-01-01

    Full Text Available A partir del análisis de las políticas públicas de juventud en Baja California durante el período 1983-2002, se muestra que, paralelamente al desarrollo de instituciones que buscan la eficiencia en la administración pública, se reproducen sistemas de creencias y prácticas de naturaleza política. Las transformaciones de las políticas públicas de juventud en esta entidad van acompañadas de una noción de juventud que representa una dificultad intrínseca para el desarrollo de una política pública efectiva. Lo juvenil, desde la mirada gubernamental, aparece como una condición de la vida privada de los individuos, ante la cual el Estado asume una posición tutelar. El impacto de esta situación en la cultura política es poco propicio para la socialización de los jóvenes como ciudadanos democráticos.

  6. Spatio-temporal evolution of aseismic ground deformation in the Mexicali Valley (Baja California, Mexico) from 1993 to 2010, using differential SAR interferometry

    Science.gov (United States)

    Sarychikhina, O.; Glowacka, E.

    2015-11-01

    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.

  7. 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.

  8. Anisotropy of Magnetic Susceptibility (AMS) of the Neogene Volcanic Succession at the Sierra Juarez - Las PintasVolcanic Province, Northeastern Baja California, Mexico: Preliminary Results

    Science.gov (United States)

    Mendoza-Borunda, R.; Cañón-Tapia, E.; Suárez-Vidal, F.; Gradilla-Martínez, L.

    2010-12-01

    The Sierra Juarez-Las Pintas Volcanic Province is among the largest in northern Baja California. For this work, we focused on a bimodal volcanic succession of late Miocene age, composed of an extensive ignimbrite unit and few dispersed basaltic flows that crop out in central Sierra Juarez and northern Sierra Las Tinajas. The ignimbrite is zoned, composed by three distinctive members: a basal unwelded white tuff, a mid-section unwelded orange tuff, and an upper red welded tuff. The basaltic flows are olivine-rich. Samples were collected in five sites that define a NE-SW section across the Sierra Juarez Escarpment, in the western boundary of the so-called Gulf Extensional Province. In each of these sites a stratigraphic column composed of more than one geologic unit was sampled. The total number of analyzed cores is ca. 160. The preliminary results show vertical and lateral variations of the AMS of the ignimbrite that can be interpreted in terms of the local flow direction and processes of emplacement of these volcanic deposits. Such variations, in turn, are likely to reflect variations in the dynamics of the eruptive process that produced them. Although the AMS of all the rocks in this province display a complex set of orientations, in this work is shown that when examined in detail important clues concerning the geological evolution of the province can be obtained from these data.

  9. 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.

  10. Daily food intake of Kajikia audax (Philippi, 1887) off Cabo San Lucas, Gulf of California, Mexico

    OpenAIRE

    Leonardo A. Abitia-Cárdenas; Felipe Galván-Magaña; Víctor H Cruz-Escalona; Peterson, Mark S.; Jesús Rodríguez-Romero

    2011-01-01

    The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae), were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub mackerel (Scomber japonicus), California pilchard (Sardinops caeruleus), and jumbo squid (Dosi...

  11. Daily food intake of Kajikia audax (Philippi, 1887) off Cabo San Lucas, Gulf of California, Mexico

    OpenAIRE

    Abitia Cárdenas, Leonardo Andrés; Galván Magaña, Felipe; Cruz Escalona, Víctor Hugo; Peterson, Mark S.; Rodriguez Romero, Jesús

    2011-01-01

    The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae), were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub Mackerel (Scomber japonicus), California pilchard (Sardinops caeruleus), and jumbo squid (Dosi...

  12. Variación espacio-temporal de la densidad poblacional de erizo rojo Strongylocentrotus franciscanus (Echinodermata: Echinoidea: Strongylocentrotidae en Baja California Spatial and temporal variation of the population density of the red sea urchin Stronngylocenntrotus franciscanus (Echinodermata: Echinoidea: Strongylocentrotidae in Baja California

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    Julio S. Palleiro-Nayar

    2012-04-01

    Full Text Available Se estimó la densidad poblacional de erizo rojo, Strongylocentrotus franciscanus, en 10 localidades de la costa occidental de Baja California, México, donde se realiza la extracción comercial de este recurso pesquero. Se compararon las estimaciones realizadas en cuatro años muestreados: 2003, 2005, 2006 y 2008. Las variaciones observadas en las localidades analizadas indicaron diferencias espacio-temporales para la densidad de erizo rojo y diferencias en la estructura de tallas, las cuales estuvieron influenciadas principalmente por la intensidad de la pesca y al esporádico reclutamiento en cada sitio. Se encontraron dos localidades (Isla San Jerónimo y Arrecife Sacramento que destacaron por presentar una alta densidad de erizo rojo y una amplia estructura de tallas, predominando individuos de tallas entre 50 a 80 mm diámetro de caparazón, lo que podría indicar que la intensidad de pesca aparentemente tiene un menor efecto que en los otros sitios.Density estimations of red sea urchin Strongylocentrotus franciscanus were recorded in ten sites with commercial fisheries on the west coast of Baja California, Mexico. The estimations for the years 2003, 2005, 2006 and 2008 were compared. The variations observed in the study sites indicate important spatial and temporal differences in density and size structure, influenced by fishing intensity and sporadic recruitment in each site. We found two sites (San Jeronimo Island and Sacramento Reef with a high density and wide size structure; with a predominance of individuals of sizes from 50 to 80 mm with lest impact possible in fishing mortality for all sites.

  13. Derechos colectivos y consulta previa: territorio cucapá y recursos pesqueros en Baja California, México

    OpenAIRE

    Alejandra Navarro Smith; Yacotzin Bravo Espinosa; Catalina López-Sagástegui

    2015-01-01

    Las demandas de reconocimiento de derechos territoriales y de uso de los recursos naturales que los pescadores cucapás le hacen al Estado mexicano, desde 1993, después de la creación de la Reserva del Alto Golfo de California y Delta del Río Colorado (en adelante, la Reserva), son unas más en el panorama de los problemas socioambientales y de despojo territorial, que afectan a los pueblos originarios en México. La característica particular en este caso es que el Estado mismo es quien construy...

  14. Agave azul y el desarrollo sustentable en la cuenca baja del río Ayuquila, Costa Sur de Jalisco (1994-2004

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    Peter R.W. Gerritsen

    2011-01-01

    Full Text Available El agave azul (Agave tequilana Weber es un cultivo nuevo para la cuenca del río Ayuquila en la Costa Sur de Jalisco, y es importante para su progreso agropecuario. Sin embargo, se observan efectos socioambientales negativos. Desde 2003 se han estudiado las condiciones del cultivo y su expansión, así como alternativas posibles. Los resultados muestran un crecimiento acelerado desde su introducción, a mitad de la década de 1990. Se destaca una concentración de propietarios privados y a través de contratos. Si bien sembrar esta planta puede ser redituable, las tendencias cíclicas de sobreproducción y escasez han originado una falta de incentivos para hacerlo y un deterioro de la capacidad productiva. Se discuten las perspectivas del avance agropecuario basado en el cultivo del agave azul, y se ofrecen algunas recomendaciones para fomentar la sustentabilidad de su sistema de producción comercial.

  15. Thermal-maturity trends within Franciscan rocks near Big Sur, California: Implications for offset along the San Gregorio San Simeon Hosgri fault zone

    Science.gov (United States)

    Underwood, Michael B.; Laughland, Matthew M.; Shelton, Kevin L.; Sedlock, Richard L.

    1995-09-01

    Conventional neotectonic interpretations place the Lucia and Point Sur subterranes of the Franciscan subduction complex on opposite sides of the San Gregorio San Simeon Hosgri dextral fault system and connect that system through the Sur fault zone. Our reconstructed paleotemperature contours, however, are not offset across the San Simeon segment, so differential displacement between the subterranes after peak heating appears to have been negligible. One explanation is that dextral slip on the faults has totaled only 5 10 km. A second possibility is that a discrete Hosgri San Simeon segment extends offshore of the amalgamated Point Sur and Lucia subterranes and that an en echelon stepover transfers dextral slip eastward to the San Gregorio Palo Colorado segment. In either case, the Sur fault zone appears to play a relatively insignificant role in the late Cenozoic tectonic evolution of central California.

  16. Paleomagnetism of mesozoic red chert from Cedros Island and the San Benito Islands, Baja California, Mexico revisited

    Science.gov (United States)

    Hagstrum, Jonathan T.; Sedlock, Richard L.

    1992-02-01

    Previous paleomagnetic study of Mesozoic subduction-complex rocks on Cedros Island and the San Benito Islands, Mexico, shows that these rocks have been remagnetized; a single-polarity magnetization was found in chert sections and underlying pillow basalt deposited during a mixed-polarity interval of the geomagnetic field. Reanalysis of the Cedros and San Benito chert samples (101 total) shows that 13 samples also retain a high blocking-temperature component of magnetization (600° to 680°C) indicating a polarity stratigraphy and deposition of the bedded chert near 2° ± 3° paleolatitude. These data are similar to those for red chert in California and Japan implying that many of the Mesozoic ophiolitic chert sequences now exposed around the Pacific rim were initially deposited within the equatorial zone of high biologic productivity. These new data also support accretion of the Cedros and San Benito chert to the American margin at tropical paleolatitudes requiring significant northward translation (and clockwise rotation) to bring them to their present position with respect to the continental interior.

  17. Daily food intake of Kajikia audax (Philippi, 1887) off Cabo San Lucas, Gulf of California, Mexico Tasa de consumo diario de alimento de Kajikia audax (Philippi, 1887) frente a Cabo San Lucas, golfo de California, México

    OpenAIRE

    Leonardo A. Abitia-Cárdenas; Felipe Galván-Magaña; Víctor H Cruz-Escalona; Peterson, Mark S.; Jesús Rodríguez-Romero

    2011-01-01

    The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae), were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub mackerel (Scomber japonicus), California pilchard (Sardinops caeruleus), and jumbo squid (Dosi...

  18. Genetic damage and exposure to pesticides among agricultural workers from Valle de San Quintín, Baja California, México

    Directory of Open Access Journals (Sweden)

    Erika Zúñiga Violante

    2012-12-01

    Full Text Available Various studies have shown the ability of pesticides to induce genetic damage (GD that can cause health effects. In the present work, a genotoxicological study was conducted monitoring residents from the agricultural region of the San Quintin Valley (SQV, Baja California, Mexico. The objective was to determine if occupational and environmental exposure to pesticides in the region of the SQV is a factor in GD, and to find out if women are more vulnerable to this effect. A questionnaire was administered to 88 residents of the SQV to establish inclusion and exclusion criteria for the study; of these, 40 agreed to participate (25 occupationally exposed to pesticides and 15 environmentally exposed to them, with similar numbers of men and women. All participants signed an informed consent form. The micronuclei technique (MN was used, which blocks cytokinesis in peripheral blood samples, to evaluate GD by counting the number of MN and Chromatin Bridges in 1000 bi-nucleated cells (BNC. The results of this measure of genetic damage were then correlated with the degree of occupational pesticide exposure of the participants. Environmentally exposed men had less GD than women with MN means of 8.1± (1.83 and 13.1(±1.7 respectively, whereas occupational exposure affected both sexes, men with a mean of MN equal to 15.9 (± 2.9, and women with 18.12 (± 1.7. Based on our results, it can be concluded that occupational exposure to pesticides is a factor in GD, with women showing greater vulnerability than men. The time of exposure at work was shown to be directly related to the increased number of MN.

  19. Educación para la prevención del VIH-SIDA para inmigrantes indígenas en Baja California

    Directory of Open Access Journals (Sweden)

    Elizabeth Maier

    2007-01-01

    Full Text Available El objetivo del presente artículo es anclar el análisis de una experiencia de investigación-acción en educación, para la prevención del VIH-SIDA en comunidades indígenas inmigrantes en Baja California, a un marco teórico y fenomenológico que organice las dimensiones múltiples de la problemática, y permita mayor comprensión del significado de la pandemia para estas comunidades, el sentido de la participación de las actoras principales del proyecto, sus resultados, las implicaciones de la articulación de la perspectiva de género y una orientación cultural para su éxito. Se utiliza la categoría vulnerabilidad, para ejemplificar las condiciones de vida tan frágiles de las comunidades indígenas de origen y recepción, los significados subalternos de la identidad tradicional de las indígenas y los riesgos propios de la migración. El artículo interpreta el ejercicio de promoción de la salud comunitaria a partir del sentido cultural de género de las comunidades de origen, los significados históricos y subjetivos de la emigración indígena creciente y los ensayos consiguientes de reorganización social, cultural y genérica, causados por la dislocación migratoria. A partir de este complejo rompecabezas teórico, histórico, fenomenológico y relacional, en los últimos apartados se examina la mecánica del proyecto, sus contenidos y el cúmulo de resultados que la experiencia arrojó a la comunidad y a las promotoras.

  20. Structural Geometry of a Sector of the Colorado River Delta, Baja California, Mexico, Based on Seismic Reflections

    Science.gov (United States)

    Chanes-Martínez, J. Juan; González-Escobar, Mario; Suárez-Vidal, Francisco; Gallardo-Mata, Clemente G.

    2014-07-01

    A structural study in the SW section of the Colorado River delta using seismic reflection data is presented. The study area is located along the Cerro Prieto transform fault, which extends from the northern Gulf of California through the Mexicali Valley and is an active fault within the Pacific-North American plate boundary zone. The research was supported by a database of five seismic profiles with a total length of 215 km, collected in the early 80's by Petróleos Mexicanos. The results show a high density of faults, most of which are buried by sediments. Within the Cerro Prieto fault zone, several faults were identified, such as: Palmas, Mesa, and Pangas Viejas, until now unknown. In addition, even though the Indiviso fault was investigated and superficially identify prior to this work, herein mapped at depth. West of the Cerro Prieto fault zone lies the Las Tinajas basin, bound by the Dunas and Saldaña faults and by the Montague basin to the southeast. The deformation zone along the plate boundary is 18-km-wide, stretching from the Cerro Prieto fault in the east to the Pangas Viejas fault in the west. The orientations of the faults are NW-SE, and if projected from the southern side of the Sierra Cucapah southward, the faults tend to join the Cerro Prieto fault. In the Las Tinajas basin, the acoustic basement is deeper than 5,000 m. Some of the largest vertical displacements generated by the 2010 7.2-Mw El Mayor-Cucapah earthquake occurred southeast of the epicenter and coincided with the location of the Pangas Viejas Fault, which is buried by sediments. Before this event, seismic activity was very low, and no structures were known in the area. In this paper, we demonstrate that there are at least seven major faults that may now pose a high seismic hazard.

  1. Neogene Tectonic History of the Sierra San Pedro Mártir, Baja California Revealed by Careful Pairing of Cosmogenic Sampling with Topographic Analysis

    Science.gov (United States)

    Rossi, M. W.; Quigley, M.; Fletcher, J. M.; Whipple, K. X.; Díaz-Torres, J. J.; Seiler, C.; Fifield, L. K.; Heimsath, A. M.

    2015-12-01

    The Sierra San Pedro Mártir (SSPM), MX defines a prominent section of the Main Gulf Escarpment that marks the breakaway fault of the Gulf of California rift. The SSPM is an uplifted rift shoulder that has the highest topography and relief in Baja California, with local elevations exceeding 3,000 m and range relief (summit to baselevel) ranging from ~500 to 2,500 m. Prior studies report Eocene apatite fission track ages from the base of the escarpment and indicate low total exhumation, thus limiting the use of low-temperature thermochronology to constrain the timing and pattern of Neogene faulting of this important structure. However, topography is expected to record tectonic, climatic, and rock strength controls on long-term denudation rates in active margins, and morphometric analysis offers an alternative approach, particularly when combined with cosmogenic 10Be-derived, catchment-averaged denudation rates. Denudation rates and topographic metrics in the SSPM record along-strike gradients in rock uplift that increase asymmetrically from fault tips to a maximum within the northern half of the range. Surface uplift of an Eocene paleo-erosion surface and slope-break knickpoints found at increasingly higher elevations in northern segments of the SSPM fault system suggest that range asymmetry is due to a recent northward acceleration in rock uplift rate. By characterizing the relationship between channel steepness and 10Be-derived denudation rates, we extrapolate millennial-scale denudation rates to million-year time-scales to estimate ages for the transient increase in rock uplift rates as well as the initial onset of faulting. From this, we predict that the SSPM fault system initiated during the Middle Miocene (~16-14 Ma) in the center of the range and ~11-8 Ma ago near the fault tips. These age estimates are consistent with independent, regional geologic constraints and show that careful pairing of cosmogenic denudation rates with topographic analysis can be used

  2. Interaction of Extreme Halophilic Archaea With the Evaporites of the Solar Salterns Guerrero Negro Baja California, Mexico

    Science.gov (United States)

    Tamez, P.; Lopez-Cortés, A.

    2008-12-01

    morphology. Other strain match, with 99% of similarity, with three sequences Haloarcula: Haloarcula japonica (EF645686), Haloarcula hispanica (DQ089681) and Haloarcula marismortui (X61689), differences among them were only 3 base pairs. We suggest that strain, C205030908, could correspond to Haloarcula californiae previously reported by Javor et al, (1982), from which there is not sequence known. Nested-PCR-DGGE analysis showed a pattern of 11 bands, meaning the archaeal community is more complex than we could detect by culture approach.

  3. Derechos colectivos y consulta previa: territorio cucapá y recursos pesqueros en Baja California, México

    Directory of Open Access Journals (Sweden)

    Alejandra Navarro Smith

    2015-07-01

    Full Text Available Las demandas de reconocimiento de derechos territoriales y de uso de los recursos naturales que los pescadores cucapás le hacen al Estado mexicano, desde 1993, después de la creación de la Reserva del Alto Golfo de California y Delta del Río Colorado (en adelante, la Reserva, son unas más en el panorama de los problemas socioambientales y de despojo territorial, que afectan a los pueblos originarios en México. La característica particular en este caso es que el Estado mismo es quien construye los marcos legales en materia de protección a las especies —sin consultar debidamente a dichos pueblos—, volviendo ilegal la presencia cucapá en esa zona y vulnerando sus derechos como población indígena del delta. En consecuencia, las autoridades medioambientales y de pesca mexicanas han constituido la zona del delta del río Colorado como un territorio en disputa, al implementar esquemas de protección ambiental y de pesca, sustentados en modelos disciplinarios, que únicamente se alimentan de información biológica y pesquera. El conflicto se genera cuando se deja al elemento humano fuera de los análisis, como si las comunidades asentadas en los territorios protegidos y usuarias de los recursos no formaran parte de los ecosistemas. Al crear el núcleo de la Reserva en el mismo lugar donde se encontraban los campamentos de pesca del pueblo cucapá se volvió ilegal el aprovechamiento de los recursos pesqueros en la zona. En este contexto se han criminalizado las acciones de resistencia con las que los cucapás responden ante la regulación medioambiental del delta del río Colorado. Al ver imposibilitada la continuidad de su práctica pesquera, los habitantes se organizan para defender su acceso al territorio y, en un sentido más amplio, sus formas de vida y de trabajo. Este caso, en particular, visibiliza maneras contemporáneas por las que el Estado despoja el territorio y desaparece prácticas culturales propias de los pueblos

  4. Estimación de Factores de Emisión de PM10 y PM2.5, en Vías Urbanas en Mexicali, Baja California, México Estimation of PM10 and PM2.5 Emission Factors, in City Roadways of Mexicali, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Lourdes M Meza

    2010-01-01

    Full Text Available El objetivo de esta investigación es estimar los factores de emisión (FE que permitan valorar la cantidad de material particulado de las vías pavimentadas y no pavimentadas de la ciudad de Mexicali, Baja California, México. Se empleó el modelo AP-42 de la US EPA, bajo un diseño estadístico al azar, correspondiente a 60 sitios de muestreo en un mapa georeferenciado con proyección UTM 11 Norte. Se obtuvieron los valores de carga y porcentaje de sedimento menor a 75 µm en laboratorio, velocidad y número de vehículos, en campo. La estimación de los FE corresponden a 0.92 Kg. PM10/VKT y 0.73 Kg. PM2.5 /VKT en vías pavimentadas y 2.33 Kg. PM10/VKT y 0.58 Kg. PM2.5 /VKT en vías no pavimentadas, respectivamente. El valor de FE propio determina la cantidad de material particulado a suspenderse y la relación de los factores de emisión (PM10 y PM2.5 en ambas vías indica que es necesario hacer mantenimiento y control de flujo de vehículos.The objective of this research was to estimate the emission factors (EF for evaluating the amount of particulate matter from paved and unpaved roads in the city of Mexicali, Baja California, Mexico. The model used was AP-42 of the U.S. EPA, under a random statistical design, corresponding to 60 sampling sites in a georeferenced map UTM 11 North projection. Load values were obtained and percent of sediment less than 75 µm in the laboratory, speed and number of vehicles in the field. The estimated FE correspond to 0.92 kg PM10/VKT and 0.73 kg PM2.5 / VKT on paved road and 2.33 kg PM10/VKT and 0.58 kg PM2.5 / VKT on unpaved roads, respectively. The value of FE determines the amount of particulate matter to be suspended and the relation of the emission factors (PM10 and PM2.5 in both roadways indicate that maintenance and control of vehicle flux may be needed.

  5. Impacto espacial diferenciado en el consumo y adicción a las drogas en la frontera norte de México: el caso del Estado de Baja California

    Directory of Open Access Journals (Sweden)

    Pablo Jesús González Reyes

    2011-12-01

    Full Text Available En el artículo se resalta la distribución del uso de drogas en México, destacando el papel de la región del norte, la cual presenta los porcentajes de consumo más altos del país. A un nivel más específico, se abordan las implicaciones individuales y sociales en el abuso del consumo de bebidas alcohólicas entre la población, así como los efectos del ambiente familiar, trayectorias escolares y laborales de los adictos a las drogas ilícitas en Baja California, al igual que las correlaciones estadísticas entre adicción a drogas y otras variables sociales. El objetivo principal fue evidenciar el impacto espacial diferenciado que tiene el proceso del consumo de drogas en México. Para esto, se utilizaron datos empíricos provenientes de encuestas nacionales de adicciones de los años 1993, 1998, 2002 y 2008, coordinadas por la Secretaría de Salud, e información generada a través de diversos estudios realizados en Baja California, a efectos de dimensionar este problema de salud a nivel local. Los resultados concluyen que la región norte de México presenta un efecto más severo en el problema del uso y abuso de drogas, figurando de manera primordial el Estado de Baja California.

  6. Efecto del blanqueamiento del coral por baja temperatura en los crustáceos decápodos asociados a arrecifes del suroeste del golfo de California Effect of coral bleaching induced by low temperature on reef-associated decapod crustaceans of the southwestern Gulf of California

    Directory of Open Access Journals (Sweden)

    Luis Hernández

    2010-10-01

    Full Text Available El blanqueamiento del coral es consecuencia de un estrés natural o antropogénico sobre los arrecifes. En la región del Pacífico tropical este, el blanqueamiento del coral se asocia comúnmente con el incremento de la temperatura superficial del mar, pero también se puede presentar por temperaturas bajas. A principio de 2008 se registró una anomalía de temperatura extraordinariamente baja, de hasta 1.8 °C menor al promedio registrado en los últimos 25 años, que se manifestó con un severo blanqueamiento de corales en varias localidades al sur del golfo de California, alcanzando cifras de hasta el 90% del coral blanqueado. El objetivo del presente trabajo fue describir los cambios en el ensamblaje de decápodos asociados a los arrecifes en la región afectada. Las bahías de La Paz (24° N y Loreto (26° N fueron visitadas antes, durante y después del evento, realizándose censos visuales en 6 sitios de cada bahía. Los resultados muestran que la riqueza y dominancia de decápodos cambió por efecto del blanqueamiento. La afectación fue diferencial entre ambas localidades: la fauna coralina de la región de Loreto fue más afectada que la de bahía de La Paz y los cambios en los ensamblajes de decápodos fueron diferentes.Coral reef bleaching is a common stress response to natural or anthropogenic events. In the Tropical East Pacific, coral reef bleaching has been commonly associated to temperature increase of the sea surface, but it can also occur with low temperatures. In early 2008, an abnormality of very low temperature was recorded, up to 1.8 °C lower than the average temperature in the last 25 years, and a severe coral bleaching was observed in numerous localities in the southern part of the Gulf of California, which rose up to 90% of coral bleaching in some places. The aim of this work was to describe changes in decapod assemblages associated to coral reefs in the affected region. La Paz (24°N and Loreto (26°N bays were

  7. La micro y pequeña empresa como generadora de empleo en Baja California durante la crisis de 2008-2009

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    Alejandro Mungaray Lagarda

    2016-01-01

    Full Text Available El objetivo del trabajo ha sido evaluar la importancia de la conformación del tejido empresarial en la evolución de la actividad económica y la generación de empleo en Baja California en el entorno de la crisis global de 2008-2009, con énfasis en el comportamiento de la micro y pequeña empresa. Lo anterior se consigue a través de la metodología de un análisis de correspondencias de carácter exploratorio y otro econométrico con fines confirmatorios en los cuales se utilizaron variables de los estratos empresariales y los sectores económicos una vez revisados los indicadores poblacionales, migratorios y de la estructura productiva. Como resultados se encontró una relación directa y significativa de las microempresas con el volumen de negocios y el empleo durante la crisis, sin embargo, en el periodo post-crisis (2010-2014 la aportación de la pequeña empresa resultó muy superior. Por su parte, las grandes empresas, mostraron menor sensibilidad general y una reducción de su capacidad para generar empleo aún durante el periodo post-crisis. En cualquier caso, debemos señalar que la limitante es que los resultados deben ser tomados con cautela debido a la alta segregación por estrato. Se concluye que no es posible rechazar la hipótesis de que la micro, pero sobre todo la pequeña empresa jugó un papel estratégico en la generación de empleo y dinamismo económico durante el periodo de crisis, contribuyendo incluso a aminorar su impacto, por lo que se debe fortalecer una política industrial que favorezca el aprendizaje y la innovación de este sector empresarial.

  8. Economic, environmental and social impacts of geothermal development, and energy savings and efficient use of power in Baja California, Mexico; Impactos economicos, ambientales y sociales del desarrollo geotermico y del ahorro y uso eficiente de la electricidad en Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Campbell R, Hector E.; Montero A, Gisela [Universidad Autonoma de Baja California, Instituto de Ingenieria, Mexicali, Baja California (Mexico)]. E-mail: hecr@iing.mxl.uabc.mx; Lambert A., Alejandro A. [Universidad Autonoma de Baja California, Facultad de Ingenieria, Mexicali, Baja California (Mexico)

    2011-01-15

    This essay of electrical planning for Baja California, Mexico, includes diagnosis of power production and consumption from 1994-2005, prospective to 2025 if historical trends are maintained, discussion of a systemic plan and its impact on the prospective through energy savings and energy efficient use, combined with an increase of the geothermal energy share. Diagnosis indicates that geothermal capacity in 1998 accounted for 57% of total electric capacity in Baja California, and by 2004 73% of this total electric capacity was based on natural gas, increasing energy dependence on fossil fuels. During this period, electric generation changed from a ratio of 2 to 1 (geothermal steam to fuel oil) to 1 to 1 (geothermal steam to natural gas). The unit cost of natural gas energy with an efficiency of 50% is 24 times the cost of the same unit of geothermal steam with 16% efficiency. Power generation, with fuel oil or simple cycle turbines firing natural gas, costs twice that of combined cycle turbines, while the costs are three times less with geothermal steam. In 2005, as a consequence of a minor contribution of geothermal energy to the power-generation total, production costs increased, reaching $122.80 USD/MWh. The replacement of fuel oil, as power fuel, decreased the SO{sub x} emissions from 4.16 kg/MWh to 0.19 kg/MWh. The combined-cycle fired by natural gas diminished the relative emissions of NO{sub x} and CO{sub 2} by 30%, but the 2.6 million tons of CO{sub x} given off each year did no vary significantly. Using geothermal energy avoids burning 20 million barrels of oil equivalent annually. The Prospective 2005-2025 indicates Baja California requires the installation of an additional 4500 MW to reach 7200 MW. The energy portfolio will become more dependent on natural gas increasing its share from 60% to 86%. Geothermal energy will decrease its share in installed capacity to 10%, eliminating the damping effect on the cost of production. SO{sub x} emissions will

  9. Structural and Seismic Stratigrapic study in the Center of the Magdalena Shelf in the Western Margin of Baja California Based on Seismic Reflection Data

    Science.gov (United States)

    González-Escobar, Mario; Salazar-Cárdenas, Rosa M.; Munguía, Luis; Martín, Arturo; Suárez-Vidal, Francisco

    2016-09-01

    The Magdalena Shelf is a shallow, low-relief surface located along the Baja California Pacific margin. As part of a forearc basin, the shelf was a convergent margin setting before the oblique divergent plate boundary formed in the Gulf of California at 12 Ma. It is thought that since 12-8 Ma, this basin has been a transtensional or strike-slip basin. To constrain the geometry, structural characteristics and some stratigraphic relationships, an active-source, seismic-reflection study was carried out in the central part of the shelf. As a result, the analyzed data show faults, basins and unconformities. Two out of four observed basins are clearly controlled by the Santa Margarita and San Lázaro faults that dip ~40° NE; a third basin is controlled by the Tosco-Abreojos fault. These three basins are part of the deformation zone that is associated with the Tosco-Abreojos fault system. The Iray-Margarita basin, on the other hand, is a fourth basin located at the northeast sector of the study area. An additional feature observed is a stepover lying between the overlapping ends of the Santa Margarita and San Lázaro faults. Small faults oriented sub-parallel to the above major faults are present, mainly throughout the western sector of the study area. Some of those minor faults cut through the seafloor indicating recent tectonic activity. Santa Margarita, San Lázaro and Tosco-Abreojos are also the names given to half-grabens controlled by the active faults that have the same names. The first two basins are affected by many more small faults in comparison with what we see in the third basin. Tectonically, this means that those two basins are the more active in the area of study. In all four basins, the upper seismic sequence consists of sediments controlled by faults of Neogene age. We found that the Iray-Santa Margarita basin is the deepest of all four basins (beyond the resolution of the data, >5 km), and lack of minor faults there indicates that the basin is not

  10. Evaluación del impacto socioeconómico de la Reserva de la Biosfera Alto Golfo de California y Delta del Río Colorado en la actividad pesquera ribereña de San Felipe, Baja California, México

    OpenAIRE

    Carlos Israel Vázquez León; José Luis Fermán Almada

    2010-01-01

    Desde 1993 las comunidades de Puerto Peñasco y Golfo de Santa Clara, Sonora, y San Felipe, Baja California, en México, están vinculadas por la Reserva de la Biosfera Alto Golfo de California y Delta del Río Colorado; creada para proteger varias especies endémicas, entre ellas al mamífero conocido como vaquita marina (Phocoenasinus) y la totoaba (Totoaba macdonaldii).Aquí se analiza el efecto socioeconómico que en la pesca de San Felipe tuvo en 1994 y 2002 la creación de la reserva; concebida ...

  11. An annotated distributional checklist of exotic freshwater fishes from the Baja California Peninsula, Mexico Lista comentada sobre la distribución de peces dulceacuícolas exóticos de la península de Baja California, México

    Directory of Open Access Journals (Sweden)

    Gorgonio Ruiz-Campos

    2012-03-01

    Full Text Available We documented the distributional status of 27 exotic fish species in the inland waters of the Baja California Peninsula, Mexico, based on voucher specimens collected from 122 sites between 1977 and 2010, and on published records. The species reported here are representatives of genera from the Atlantic drainages of North America (Ictalurus, Ameiurus, Pylodictis, Morone, Lepomis, Pomoxis, Dorosoma, Cyprinella, and Micropterus, Middle America (Poecilia, Gambusia, and Xiphophorus, Eurasia (Cyprinus and Carassius, and Africa (Tilapia and Oreochromis. The family containing the highest number of species is Centrarchidae (7 species followed by Ictaluridae and Poeciliidae (6 species each. Four species were determined to be invasive due to their wide distribution and fast dispersal through the Peninsula (Gambusia affinis, Poecilia reticulata, Lepomis cyanellus, and Tilapia sp. cf. zillii. We analyze the impacts of exotic species on the native populations of 3 species with problems of conservation: Cyprinodon macularius (endangered, Fundulus lima (endangered, and Gasterosteus aculeatus (vulnerable. Alien fishes have been introduced for a variety of reasons in Mexico: ornament, sport, aquaculture, biological control, and by accident. In some cases fish introductions were carried out for more than one reason.El estatus de la distribución de peces exóticos es documentado para 27 especies en las aguas continentales de la península de Baja California, México, basado en registros de ejemplares recolectados en 122 localidades durante el período de 1977 a 2010, así como registros referidos en la literatura. Las especies aquí reportadas son representativas de géneros que proceden de la vertiente Atlántica de Norteamérica (Ictalurus, Ameiurus, Pylodictis, Morone, Lepomis, Pomoxis, Dorosoma, Cyprinella y Micropterus, Mesoamérica (Poecilia, Gambusia y Xiphophorus, Eurasia (Cyprinus y Carassius y África (Tilapia y Oreochromis. La familia con mayor n

  12. Comparative study of the amplification of ground motion using seismic noise and recent earthquakes adjacent to the Cerro Prieto volcano, Baja California

    Science.gov (United States)

    Vega, F. D.; Vidal-Villegas, A.

    2009-12-01

    We have chosen an area of approximately 79 km2, centered around the Cerro Prieto volcano, in the Mexicalli valley, Baja California, based on elevated registered acceleration data. The GEO station, located in the Cerro Prieto geothermal field has registered seismic accelerations on the order of 492 gales. The local residents near the study area have reported feeling numerous smaller magnitude earthquakes, compared to those of the nearby populated city of Mexicalli. Does there exist an amplified seismic signal in the area? If so, what is the cause of the amplification? The objective of our study is to answer these questions and determine the subsurface (0-50 m) structure in 4 specific sites. To obtain these answers, we registered seismic noise samples using short period seismometers (1 s), intermediate (5 s) and 16 bit recorders, along a linear profile which crosses the volcano with an 18 degree NE orientation. Furthermore, we analyzed ground-motion data (from 2004-2006), obtained from 24-bit accelerographs. Using both types of data (noise and accelegraphs) we calculated the H/V spectral ratios, and the relative ratios between both sites. To determine the subsurface structure, we used a unidimensional model of the H/V ratios, based on the methodology used by Huerta-Lopez et al., 2005. The H/V spectral ratios from the seismic noise adjacent to the volcano display amplitude of 1 in the frequency range (0.8 - 30 Hz). In contrast, the amplitude in the volcano crater (159 m.a.s.l.) was 6 in the frequency range (0.8 - 3 Hz). The average H/V relative ratio of the crater and the adjacent sites is 4, with frequencies between 0.8 and 1.2 Hz. The S-wave H/V ratios for the VCP acceleration station (110 m.a.s.l.), are near 8, with frequencies between 1 and 2. The H/V spectral ratios from the seismic noise for the geothermal field display amplitude of 4 for frequencies between 0.8 and 1.3 Hz, while the results from the S wave display amplitudes of 5 between 1.5 and 3 Hz. In the

  13. Post subduction thermal regime of the western North America and effects on the Great Valley, Sierra Nevada and northern Baja California provinces

    Science.gov (United States)

    Erkan, Kamil

    the region shows that there is a significant lateral component of the heat flow in to the Sierra Nevada due to Basin and Range province and due to basal heating. The model further suggests that the lateral heating results in considerable thermal uplift at the eastern edge of the Sierra Nevada region. The model is also applicable in the Northern Baja California since this region was part of the same tectonic setting as the Sierra Nevada arc before the inland jump of the San Andreas Fault. The Coast Ranges are interesting with having spots of magmatic and volcanic arc activity likely associated with the cessation of subduction. The third paper is a study related to one of these spots 90 km north of San Francisco, characterized by elevated heat flow in an area of 2500 km2 (The Geysers anomaly). The geothermal system is associated with a very young (˜2 My) bimodal volcanism and magma intrusion at crustal levels. Taking advantage of a sealed, vapor dominated geothermal system due to rocks of very low permeability, forward and inverse models of the deeper magmatic source were constructed. We used extensive heat flow data that were collected over more than 20 years time period. The models revealed that the magmatic source in the Geysers must be as shallow as 7-8 km in order to satisfy the thermal data. Furthermore, the magma system must cover most of the thermally anomalous region. Another type of geothermal system is characterized by rising of hot waters by buoyancy forces without the necessity of a magmatic source at depth. We studied one of these systems in interior Alaska, called Chena Hot Springs, in the fourth paper. The explored system is 1 km long and temperatures are only 74°C. Although the system is moderate in temperature, the low-temperature surface conditions enable the system to be exploited for production of electricity. The geochemical analyses show that the source temperatures are around 121°C. We analyzed the temperature data from 17 exploration wells in

  14. Reprobación en las carreras del área de Ciencias de la Salud de la Universidad Autónoma de Baja California, México

    Directory of Open Access Journals (Sweden)

    Elías Torres Balcázar

    2015-10-01

    Full Text Available Esta investigación explora las causas de reprobación de los estudiantes del segundo semestre de las carreras del área de la Salud (Medicina, Enfermería y Actividad Física y Deportes de la Universidad Autónoma de Baja California, en Ensenada, Mexico. Se identificaron 49 estudiantes reprobados con quienes se realiz6 un diseño investigativo de carácter exploratorio-descriptivo, cuyos resultados permitieron determinar que las principales causas de reprobación se debieron al desempeño academico de los estudiantes, deficiencias en las tecnicas de estudio, poca dedicaci6n a las actividades académicas y el nerviosismo que les provoca enfrentarse a los exámenes. A lo anterior se agrega que la mayor parte no acude al docente para aclarar dudas. A partir de estos resultados, se sugieren diversas estrategias para resolver el problema de reprobación. AbstractThis paper explores causes of failure in students of second semester in Health Program careers (Medicine, Nursing, Physical Activity and Sports at Universidad Autonoma de Baja California, in Ensenada, Mexico. 49 students who failed were identified; they were applied an exploratory and descriptive research design, whose results allowed to determine that the major causes of failure were due to the students’ academic performance; deficient study techniques; little time for academic activities; and stress before term exams. In addition to the aforementioned reasons, most of the students do not ask the teacher to clarify doubts. From these results, a variety of strategies are recommended in order to avoid failures in the Health Program.

  15. Observation of wind forced circulation on the continental shelf off Point Sur, California from a self-contained acoustic doppler current profiler.

    OpenAIRE

    Abbott, Christopher Lynn

    1991-01-01

    Approved for public release; distribution is unlimited To study the current structure of the California Current as it manifests itself on the continental shelf a subsurface mooring, P1, was anchored 5km west of Point Sur at 36(o), 17' N, 121(o), 59' W from 28 February through 11 May 1990. the P1 mooring, placed on the 84 m isobaths, consisted of a self-contained acoustic Doppler current profiler (SC-ADCP) housed in a syntactic foam sphere and secured to an anchor. The mooring geometry pl...

  16. Residential tourism and migration of foreign retirees in Mexico: A case study on the environmental impacts and public services in Baja California Sur

    Directory of Open Access Journals (Sweden)

    Diego Armando Casas-Beltrán

    2013-07-01

    Full Text Available Migration of foreign retirees in Mexico has increased, especially in Los Cabos, where settlements trailer type are increasing and are moving into rural coastal areas of high ecological value, without the knowledge of impacts that may result. Thus the aim of this paper is to contribute to the understanding of this type of settlement, by documenting a case study, the characteristics of their community, their environmental impacts and implications for the provision of public services. We conclude that the town will become a short-term retreat site, because while it does not have high densities, its environmental implications are significant and broad coverage. Its current demand for services is minimal, but may cause conflicts in the future, especially with the water

  17. Análisis funcional de la red trófica de Bahía Magdalena Baja California Sur, México

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    Víctor H Cruz-Escalona

    2013-07-01

    Full Text Available El objetivo del presente estudio fue desarrollar un modelo trófico (ECOPATH con ECOSIM para caracterizar la estructura y función de la trama alimentaria de Bahía Magdalena. El modelo consta de 24 grupos funcionales, siendo dominado por grupos de niveles tróficos secundarios y terciarios, que generan un tercio de los flujos de biomasa total. Los flujos totales del sistema y la eficiencia de transferencia promedio entre niveles tróficos, encajan bien en el rango reportado para otros ecosistemas costeros tropicales del mundo. Una fracción alta de los flujos totales se destina para el mantenimiento de la estructura de la red trófica. El índice de conectancia (IC fue igual a 0,2, esto significa que sólo hay 20% de las conexiones totales posibles en la trama alimentaria. Una jerarquización de los diversos componentes del sistema en términos de su contribución a la función del sistema reveló que los productores primarios bentónicos y los detritos contribuyen 53% al total de la ascendencia. La idea de un control de la energía de arriba hacia abajo (a través de los principales depredadores es consistente con otros hallazgos, dicho resultado sugiere que las especies de nivel trófico superior afectan negativamente a otros componentes del ecosistema. Se sugiere emplear el modelo en el corto plazo, para realizar aproximaciones exploratorias que pongan a prueba hipótesis relacionadas con los mecanismos bióticos y abióticos que ocasionen cambios en la estructura y función de la red trófica a través del tiempo, y por tanto contribuyan a entender como la estructura de la trama trófica puede contribuir a la resiliencia de las comunidades biológicas marinas.

  18. Juventud, readaptación y sueños truncados: Centro de Diagnóstico para Adolescentes de Tijuana, Baja California

    OpenAIRE

    María Ruth Velázquez Gutiérrez; Jesús Méndez Reyes

    2015-01-01

    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...

  19. Microstructural and seismic properties of the upper mantle underneath a rifted continental terrane (Baja California): An example of sub-crustal mechanical asthenosphere?

    NARCIS (Netherlands)

    Palasse, L.N.; Vissers, R.L.M.; Paulssen, H.; Basu, A.R.; Drury, M.R.

    2012-01-01

    The Gulf of California rift is a young and active plate boundary that links the San Andreas strike-slip fault system in California to the oceanic spreading system of the East Pacific Rise. The xenolith bearing lavas of the San Quintin volcanic area provide lower crust and upper mantle samples from b

  20. 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.

  1. Interdisciplinary approach on evaluation and sustainable usage of the water resources in the semi-arid Northwest Mexico to counter the imbalance of water: Case study Valle de Guadalupe, Baja California

    Science.gov (United States)

    Kretzschmar, T.; Hernandez, R.; Valenzuela, C.; Cabello, A.

    2012-12-01

    In the Baja California peninsula are several watersheds present, of which the hydrogeological conditions are of great importance to communities in the area. The Valle de Guadalupe watershed, for instance has a wine industry of national importance. Irrigation of crops is carried out exclusively with water from the aquifer, which consists of Quaternary sediments filling this depression of Post-Miocene age. Apart from the use of the aquifer by the wine industry, the water utility of Ensenada operates 10 drinking water wells with a total capacity of 320 L/s or 42% of supply in the valley. In the arid northern Mexico mountain front recharge is an important recharge source to the aquifers. Other important recharge sources are related to direct infiltration of the precipitation, recharge from runoff into streams (mountain block recharge) and the provision by active faults. The knowledge of the aquifer is crucial to maintain sustainable management of water resources in the Valle de Guadalupe. This intense use of water resources is reflected in a degradation of the aquifer water quality and reduced water table. The integrated approach for a sustainable evaluation and usage of the aquifer includes besides the hydrogeological evaluation, the determination of the water stress on the vineyards as well as the usage of treated waste water as alternative resource as well the evaluation of the effects of climatic variations and measurement and modeling of the vegetation, the main interface between atmosphere and soil, affecting the hydrology in the process of interception, infiltration, runoff and evapotranspiration. With these detailed ongoing studies we expect to identify and counter imbalance of water in the study area. This requires 1) modeling and hydrogeological studies for the determination of the present and future imbalance 2) estimation of the impacts of industrial activities on water resources 3) characterization of alternative water sources, 4) optimization of the water

  2. The social representation of drug trafficking like laborer optionAt first glance, the State of Baja California (Mexico) and the Department of Valle del Cauca (Colombia) do not have much in common. They belong to different countries and have significant di

    OpenAIRE

    Lilian Paola Ovalle

    2010-01-01

    At first glance, the State of Baja California (Mexico) and the Department of Valle del Cauca (Colombia) do not have much in common. They belong to different countries and have significant differences in their history and their social, cultural, political and economic structures. However these places have a commonality--namely the fact that for more than three decades they have become epicenters of drug trafficking. In both of these territories, trafficking groups and international business ne...

  3. Nuclear and mtDNA lineage diversity in wild and cultured Pacific lion-paw scallop, Nodipecten subnodosus (Baja California Peninsula, Mexico).

    Science.gov (United States)

    Petersen, Jessica L; Ibarra, Ana Maria; May, Bernie

    2010-01-01

    Pacific lion-paw scallops were collected from natural aggregations in Laguna Ojo de Liebre (Pacific Ocean), the Gulf of California, and from aquaculture facilities for genetic diversity analyses. Mitochondrial DNA sequencing uncovered two highly supported clades separated by 2.5% divergence. Data from ten microsatellite markers suggest individuals from these mitogroups are introgressed, raising questions about the mitotype origin. Some evidence suggests gene flow between La Paz and Ojo de Liebre; otherwise the Gulf of California and Ojo de Liebre are acting as two distinct populations. It is unclear whether translocations between sites have influenced the observed genetic structure or whether gene flow has been facilitated by past geologic events. Finally, scallops spawned for aquaculture are unique from the wild and have significantly less diversity. These results warrant the attention of managers and producers who should work to monitor and conserve genetic diversity in both wild and aquaculture populations. PMID:24391254

  4. Nuclear and mtDNA lineage diversity in wild and cultured Pacific lion-paw scallop, Nodipecten subnodosus (Baja California Peninsula, Mexico)

    OpenAIRE

    Petersen, Jessica L; Ibarra, Ana Maria; May, Bernie

    2010-01-01

    Pacific lion-paw scallops were collected from natural aggregations in Laguna Ojo de Liebre (Pacific Ocean), the Gulf of California, and from aquaculture facilities for genetic diversity analyses. Mitochondrial DNA sequencing uncovered two highly supported clades separated by 2.5% divergence. Data from ten microsatellite markers suggest individuals from these mitogroups are introgressed, raising questions about the mitotype origin. Some evidence suggests gene flow between La Paz and Ojo de Lie...

  5. Petrography of volcaniclastic rocks in intra-arc volcano-bounded to fault-bounded basins of the Rosario segment of the Lower Cretaceous Alisitos oceanic arc, Baja California, Mexico

    Science.gov (United States)

    Marsaglia, K. M.; Barone, M.; Critelli, S.; Busby, C.; Fackler-Adams, B.

    2016-05-01

    The Rosario segment of the Early Cretaceous Alisitos oceanic magmatic arc in Baja California displays a record of arc-axis sedimentation and volcanism that is well preserved in outcrops within a southern volcano-bounded and a northern fault-bounded basin that flanked an intervening subaerial edifice. This record includes volcanic and volcaniclastic rocks that range from felsic to mafic in composition. Volcaniclastic/tuffaceous sandstone samples from two previously published measured sections are mainly composed of volcanic clasts with moderate plagioclase content. Locally quartz and/or potassium feldspar are present in trace to moderate amounts. The proportions of volcanic lithic types exhibiting vitric, microlitic, lathwork, and felsitic textures are highly variable with no distinct stratigraphic trends, likely as a function of the mixed styles of eruption and magma compositions that produced pyroclasts, as well as erosion-produced epiclastic debris. The volcaniclastic fill of the basins is consistent with an oceanic arc setting, except for the relatively high felsitic volcanic lithic content, likely associated with subaerial, as opposed to the more common submarine felsic magmatism associated with arc extension in oceanic settings. There are no major differences in compositional modes of tuff and sandstone between the fault-bounded and volcano-bounded basin strata, even though they exhibit distinctly different volcaniclastic facies. This suggests that proximal arc-axis basins of varying types around a single major subaerial edifice provide a faithful record of volcanic trends in the arc segment, regardless of variation in transport and depositional processes.

  6. Diagnóstico de conocimiento, actitudes y estrategias de equidad de género en servidoras y servidores públicos de primer nivel en Baja California

    Directory of Open Access Journals (Sweden)

    Elizabeth Maier

    2011-01-01

    Full Text Available El presente artículo se basa en el Diagnóstico de conocimientos, actitudes y estrategias de equidad de género de funcionarias y funcionarios de primer nivel en Baja California, estudio cuyo objetivo fue evaluar los conocimientos y las receptividades o resistencias de servidoras y servidores públicos bajacalifornianos sobre la equidad de género; así mismo, se aprecia la transversalidad de la aplicación de la perspectiva de género como guía metodológica de su ejercicio de políticas públicas. La hipótesis implícita al estudio insiste en la necesidad de contar con estrategias de progresiva capacitación en la temática para promover la creciente desautorización del complejo enjambre cultural de inequidad de género que todavía define el acceso diferencial a las oportunidades y beneficios económicos, sociales y políticos en el estado.

  7. High-resolution seismic-reflection and marine-magnetic data from offshore central California--San Gregorio to Point Sur

    Science.gov (United States)

    Sliter, Ray W.; Johnson, Samuel Y.; Watt, Janet T.; Scheirer, Daniel S.; Allwardt, Parker; Triezenberg, Peter J.

    2013-01-01

    The U.S. Geological Survey collected high-resolution seismic-reflection data on four surveys (S-N1-09-MB, S-15-10-NC, S-06-11-MB, and S-04-12-MB) and marine-magnetic data on one survey (S-06-11-MB) between 2009 and 2012, offshore of central California between San Gregorio and Point Sur. This work was supported in part by the California Seafloor Mapping Program. The survey areas span about 120 km of California's coast (including Monterey Bay). Most data were collected aboard the U.S. Geological Survey R/V Parke Snavely. Cumulatively, approximately 1,410 km of single-channel seismic-reflection data were acquired, mainly using a SIG 2mille minisparker. About 44 km of data were collected simultaneously using an EdgeTech Chirp 512. Subbottom acoustic penetration spanned tens to several hundreds of meters, variable by location. Marine magnetic data were collected on approximately 460 km of track lines (mainly in southern Monterey Bay) using a Geometrics G882 cesium-vapor marine magnetometer. This report includes maps and navigation files of the surveyed transects, linked to Google Earth™ software, as well as digital data files showing images of each transect in SEG-Y and JPEG formats. The images of bedrock, sediment deposits, and tectonic structure provide geologic information that is essential to hazard assessment, regional sediment management, and coastal and marine spatial planning at Federal, State and local levels, as well as to future research on the geomorphic, sedimentary, tectonic, and climatic record of central California.

  8. Estudio preliminar del sistema reproductor del Calamar Gigante del Golfo de Baja California Dosidicus gigas (D'Orbigny, 1935) Mollusca: Cephalopoda

    OpenAIRE

    Ochoa Báez, Rosa Isabel

    1980-01-01

    El calamar gigante del Golfo California es un recurso potencial de gran importancia para México. Como base para estudiar el ciclo de madurez gonadal, se describe el sistema reproductor de ejemplares colectados durante 1980. En las hembras existe un ovario, un par de glándulas nidamentales y un par de glándulas nidamentales accesorias; en su histología presenta ovocitos de diversos estadios de maduración con células foliculares en cordones. La maduración avanzada coincide con la presencia de p...

  9. Rentabilidad de Unidades Representativas de Producción Pesquera del calamar gigante Dosidicus gigas en el Golfo de California

    OpenAIRE

    Víctor Hernández-Trejo; Mauricio Ramírez-Rodríguez; Germán Ponce-Díaz; Luis Almendarez-Hernández

    2014-01-01

    La pesca del calamar gigante en México se desarrolla principalmente en el Golfo de California, en las costas de Baja California Sur (B.C.S) y Sonora (Son.), por cooperativas y empresas privadas que operan embarcaciones menores (pangas) y barcos camaroneros. Las diferencias en la rentabilidad de empresas tipo se evaluaron con los datos de ingresos y costos totales de operación en el año 2008, consensuados por representantes de empresas calamareras que definieron dos tipos de unidades represent...

  10. Seasonal changes in a fish assemblage associated with mangroves in a coastal lagoon of Baja California Sur, Mexico Cambios estacionales de la comunidad de peces asociada a zonas de manglar en una laguna costera de Baja California Sur, México

    OpenAIRE

    Jesús Rodríguez-Romero; Laura del Carmen López-González; Felipe Galván-Magaña; Francisco J. Sánchez-Gutiérrez; Roxana B Inohuye-Rivera; Juan C. Pérez-Urbiola

    2011-01-01

    The fish assemblage in a coastal lagoon with mangroves known as "Rancho Bueno" was determined and associated with environmental parameters. We used an experimental otter trawl net to catch the fish, and 62 fish species were identified from 48 genera and 30 families. The most abundant species were: Etropus crossotus, Eucinostomus gracilis, Paralabrax maculatofasciatus, Sphoeroides annulatus, and Eucinostomus dowii. The water temperature changed seasonally, being warm from July through December...

  11. Productividad secundaria en los esteros de la barra de arena El Mogote en la Ensenada de La Paz, Baja California Sur, México Secondary productivity in the estuaries of El Mogote sand bar in Ensenada de La Paz, Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Jorge A. López-Rocha

    2012-04-01

    Full Text Available Los ecosistemas de manglar son un hábitat crítico para numerosas especies y su productividad es importante por su contribución de detritos orgánicos y su producción secundaria. El objetivo del trabajo fue definir indicadores de productividad secundaria para establecer una línea base que permita medir alteraciones en el sistema de manglar por posibles perturbaciones naturales o antropogénicas. Como indicadores se escogieron los moluscos bivalvos pata de mula, Anadara tuberculosa y el ostión de mangle, Crassostrea palmula. Se realizaron muestreos en tres esteros de agosto de 2007 a julio de 2009. Se estimó la abundancia y la producción secundaria con base en el incremento de biomasa. Para la estimación del incremento en peso se usaron las tasas de crecimiento individual obtenidas mediante un análisis de distribuciones de frecuencia de tallas. La abundancia promedio fue de 1.27 y 510 ind · m-2 de la pata de mula y ostión de mangle respectivamente. Se estimó una tasa de crecimiento de 4.91 mm · mes-1 (3.67 g · mes-1 para la pata de mula y de 3.80 mm · mes-1 (0.18 g · mes-1 para el ostión de mangle. La producción secundaria promedio de pata de mula fue de 4.51 g · m-2 · mes-1 y fue mayor durante la primavera, mientras que para el ostión de mangle fue de 97.9 g · m-2 · mes-1, registrándose la máxima producción durante el verano. Los resultados obtenidos demuestran que estos indicadores de calidad del bentos son adecuados para medir alteraciones al sistema de manglar de la Ensenada de La Paz, B. C. S., México.Mangrove ecosystems are critical habitats for many species, and their productivity is important because of their contribution of organic detritus and secondary production. The objective of this study was to identify suitable indicators of secondary productivity of mangrove systems, in order to establish a baseline for measuring changes in the mangrove system due to natural or anthropogenic potential disturbances. The bivalve mollusks chosen as indicators of secondary productivity were the mangrove cockle Anadara tuberculosa and the mangrove oyster Crassostrea palmula. Samples were collected in three estuaries from August 2007 to July 2009. Abundance and secondary production were estimated from biomass increase, calculated from individual growth rates determined using length frequency distributions analysis. The average abundance was 1.27 and 510 ind · m-2 of mangrove cockle and mangrove oyster respectively. It was estimated a growth rate of 4.91 mm · month-1 (3.67 g · month-1 for mangrove cockle and 3.80 mm · month-1 (0.18 g · month-1 for the mangrove oyster. The mean secondary production of mangrove cockle was 4.51 g · m-2 · month-1 and was higher during spring, while for the mangrove oyster it was 97.9 g · m-2 · month-1, and the maximum production was recorded during summer. The results show that these indicators of benthos quality are suitable for measuring changes of the mangrove system in the Ensenada of La Paz, B. C. S., Mexico.

  12. Un caso de baja segregada en niveles altos en el sur de Sudamérica: descripción del ciclo de vida y su relación con la precipitación A case of high level cut-off cyclonic vortex over southern South America: description of the life cycle and its relation to precipitation

    Directory of Open Access Journals (Sweden)

    Alejandro Anibal Godoy

    2011-09-01

    Full Text Available En este trabajo se analiza el ciclo de vida de una baja segregada que afectó el sur de Sudamérica entre el 26 de Marzo y el 2 de Abril del 2007 y se explora la relación existente entre las diferentes etapas de este sistema y la precipitación ocurrida sobre la franja central de Argentina. Además se evalúa si otros procesos coadyuvaron para la ocurrencia de la misma. Las características más relevantes de este sistema son su larga duración y el lento desplazamiento, ya que entre el inicio y el fin de su vida se desplaza sólo 780 km, manteniéndose estacionario, durante las etapas de segregación y madurez, por más de 56 hs frente a la costa central chilena. Esta última característica favorece la formación de un sistema de baja presión sobre el noroeste de Argentina y la persistencia de una corriente en chorro en capas bajas del norte que se extiende desde el centro de Bolivia hasta norte argentino. La masa de aire con características tropicales conducida por esta configuración y la convergencia en niveles bajos favorecieron el desarrollo convectivo. La precipitación acumulada durante estas etapas, en algunas regiones del sur del litoral argentino, superó los 300 mm, produciendo extensas inundaciones en la región. Durante la etapa de decaimiento (96 hs de duración, el sistema se debilita a medida que se desplaza hacia el este y las precipitaciones afectaron las provincias del centro-oeste de Argentina donde la lluvia en 48 horas duplicó el promedio mensual de marzo.This paper describes the life cycle of a high level cut-off cyclonic vortex that affected southern South America between 26 March and 2 April 2007, and explores the relationship between the evolution stages of the system and the rainfall over central Argentina. The possibility of other processes contributing to rainfall is also analyzed. The most relevant characteristics of this system were its length and slow displacement: from its development to decay it moved only

  13. Estimation of Seismic and Aseismic Deformation in Mexicali Valley, Baja California, Mexico, in the 2006-2009 Period, Using Precise Leveling, DInSAR, Geotechnical Instruments Data, and Modeling

    Science.gov (United States)

    Sarychikhina, Olga; Glowacka, Ewa; Robles, Braulio; Nava, F. Alejandro; Guzmán, Miguel

    2015-11-01

    Ground deformation and seismicity in Mexicali Valley, Baja California, Mexico, the southern part of the Mexicali-Imperial valley, are influenced by active tectonics and human activity. In this study, data from two successive leveling surveys in 2006 and 2009/2010 are used to estimate the total deformation occurred in Mexicali Valley during 2006-2009. The leveling data span more than 3.5 years and include deformation from several natural and anthropogenic sources that acted at different temporal and spatial scales during the analyzed period. Because of its large magnitude, the aseismic anthropogenic deformation caused by fluid extraction in the Cerro Prieto geothermal field obscures the deformation caused by other mechanisms and sources. The method of differential interferograms stacking was used to estimate the aseismic (interseismic tectonic and anthropogenic) components of the observed displacement, using SAR images, taken in 2007 during a period when no significant seismicity occurred in the study area. After removing the estimated aseismic signal from the leveling data, residual vertical displacement remained, and to identify possible sources and mechanisms of this displacement, a detailed analysis of records from tiltmeters and creepmeters was performed. The results of this analysis suggest that the residual displacement is mainly caused by moderate-sized seismicity in the area of study. Modeling of the vertical ground deformation caused by the coseismic slip on source fault (primary mechanism) of the two most important earthquakes, May 24, 2006 (Mw = 5.4) and December 30, 2009 (Mw = 5.8), was performed. The modeling results, together with the analysis of geotechnical instruments data, suggests that this moderate-sized seismicity influences the deformation in the study area by coseismic slip on the source fault, triggered slip on secondary faults, and soft sediments deformation.

  14. Composición espacial y temporal de la avifauna de humedales pequeños costeros y hábitat adyacentes en el noroeste de Baja California, México

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available Se determinó la composición espacio-temporal de la avifauna en 13 humedales pequeños costeros del noroeste de Baja California entre febrero y diciembre de 2002. Se registraron 17,978 individuos pertenecientes a 187 especies, 121 géneros y 47 familias. Las familias con mayor número de especies fueron Anatidae (17, Scolopacidae (17 y Laridae (12. Los humedales con mayor riqueza específica fueron El Rosario (126, Santo Tomás (107 y La Misión (95, los cuales en conjunto incluyeron al 86% del total de especies observadas. Setenta y seis especies (41% fueron residentes permanentes, 73 (39% visitantes estacionales, y 38 (20% visitantes ocasionales. Con base en la presencia o ausencia de las especies se distinguen cuatro grupos de humedales: (a San Simón, (b La Salina, (c El Descanso-El Ciprés y (d un grupo de nueve sitios que está subdividido en dos ramas de cuatro y cinco localidades, respectivamente: (d.1 San Telmo-Santo Tomás-El Rosario-La Misión y (d.2 San Rafael-San Miguel- El Salado-Santo Domingo-Cantamar. La presencia o ausencia de un cuerpo de agua permanente, los tipos de hábitat y la presencia o ausencia de influencia antropogénica en cada localidad fueron los factores que contribuyeron al agrupamiento de estos humedales. La riqueza y abundancia de especies estuvieron correlacionadas con la diversidad de hábitats. Se documentaron evidencias de reproducción para 20 especies.

  15. Evaluación del impacto socioeconómico de la Reserva de la Biosfera Alto Golfo de California y Delta del Río Colorado en la actividad pesquera ribereña de San Felipe, Baja California, México

    Directory of Open Access Journals (Sweden)

    Carlos Israel Vázquez León

    2010-01-01

    Full Text Available Desde 1993 las comunidades de Puerto Peñasco y Golfo de Santa Clara, Sonora, y San Felipe, Baja California, en México, están vinculadas por la Reserva de la Biosfera Alto Golfo de California y Delta del Río Colorado; creada para proteger varias especies endémicas, entre ellas al mamífero conocido como vaquita marina (Phocoenasinus y la totoaba (Totoaba macdonaldii.Aquí se analiza el efecto socioeconómico que en la pesca de San Felipe tuvo en 1994 y 2002 la creación de la reserva; concebida como un arreglo institucional de regulación pesquera, centrada en la protección ambiental y ecológica. La conclusión general es que deben incorporarse consideraciones socioeconómicas en el diseño de indicadores de eficiencia y evaluación para el éxito de la reserva territorial.

  16. Some characteristics of the complex El Mayor-Cucapah, MW7.2, April 4, 2010, Baja California, Mexico, earthquake, from well-located aftershock data from local and regional networks.

    Science.gov (United States)

    Frez, J.; Nava Pichardo, F. A.; Acosta, J.; Munguia, L.; Carlos, J.; García, R.

    2015-12-01

    Aftershocks from the El Mayor-Cucapah (EMC), MW7.2, April 4, 2010, Baja California, Mexico, earthquake, were recorded over two months by a 31 station local array (Reftek RT130 seismographs loaned from IRIS-PASSCAL), complemented by regional data from SCSN, and CICESE. The resulting data base includes 518 aftershocks with ML ≥ 3.0, plus 181 smaller events. Reliable hypocenters were determined using HYPODD and a velocity structure determined from refraction data for a mesa located to the west of the Mexicali-Imperial Valley. Aftershock hypocenters show that the El Mayor-Cucapah earthquake was a multiple event comprising two or three different ruptures of which the last one constituted the main event. The main event rupture, which extends in a roughly N45°W direction, is complex with well-defined segments having different characteristics. The main event central segment, located close to the first event epicenter is roughly vertical, the northwest segment dips ~68°NE, while the two southeast segments dip ~60°SW and ~52°SW, respectively, which agrees with results of previous studies based on teleseismic long periods and on GPS-INSAR. All main rupture aftershock hypocenters have depths above 10-11km and, except for the central segment, they delineate the edges of zones with largest coseismic displacement. The two southern segments show seismicity concentrated below 5km and 3.5km, respectively; the paucity of shallow seismicity may be caused by the thick layer of non-consolidated sediments in this region. The ruptures delineated by aftershocks in the southern regions correspond to the Indiviso fault, unidentified until the occurrence of the EMC earthquake. The first event was relocated together with the aftershocks; the epicenter lies slightly westwards of published locations, but it definitely does not lie on, or close to, the main rupture. The focal mechanism of the first event, based on first arrival polarities, is predominantly strike-slip; the focal plane

  17. Structure and geomorphology of the "big bend" in the Hosgri-San Gregorio fault system, offshore of Big Sur, central California

    Science.gov (United States)

    Johnson, S. Y.; Watt, J. T.; Hartwell, S. R.; Kluesner, J. W.; Dartnell, P.

    2015-12-01

    The right-lateral Hosgri-San Gregorio fault system extends mainly offshore for about 400 km along the central California coast and is a major structure in the distributed transform margin of western North America. We recently mapped a poorly known 64-km-long section of the Hosgri fault offshore Big Sur between Ragged Point and Pfieffer Point using high-resolution bathymetry, tightly spaced single-channel seismic-reflection and coincident marine magnetic profiles, and reprocessed industry multichannel seismic-reflection data. Regionally, this part of the Hosgri-San Gregorio fault system has a markedly more westerly trend (by 10° to 15°) than parts farther north and south, and thus represents a transpressional "big bend." Through this "big bend," the fault zone is never more than 6 km from the shoreline and is a primary control on the dramatic coastal geomorphology that includes high coastal cliffs, a narrow (2- to 8-km-wide) continental shelf, a sharp shelfbreak, and a steep (as much as 17°) continental slope incised by submarine canyons and gullies. Depth-converted industry seismic data suggest that the Hosgri fault dips steeply to the northeast and forms the eastern boundary of the asymmetric (deeper to the east) Sur Basin. Structural relief on Franciscan basement across the Hosgri fault is about 2.8 km. Locally, we recognize five discrete "sections" of the Hosgri fault based on fault trend, shallow structure (e.g., disruption of young sediments), seafloor geomorphology, and coincidence with high-amplitude magnetic anomalies sourced by ultramafic rocks in the Franciscan Complex. From south to north, section lengths and trends are as follows: (1) 17 km, 312°; (2) 10 km, 322°; (3)13 km, 317°; (4) 3 km, 329°; (5) 21 km, 318°. Through these sections, the Hosgri surface trace includes several right steps that vary from a few hundred meters to about 1 km wide, none wide enough to provide a barrier to continuous earthquake rupture.

  18. Recurso Eólico en Baja California

    OpenAIRE

    Zamora Machado Marlene; Leyva Sánchez Elia; Lambert Arista Alejandro A.

    2011-01-01

    La energía eólica proviene de manera indirecta del sol, una fuente ilimitada de energía a escala humana. El viento se genera por el diferencial de temperaturas en la atmósfera terrestre, permitiendo su circulación y convirtiéndose en energía cinética, para producir energía. Por su carácter limpio e inagotable, la energía eólica requiere de más explotación en el mundo. En México existe potencial eólico en algunas regiones como el Istmo de Tehuantepec en Oaxaca, Tabasco, Zacatecas, la península...

  19. School administrator preparation in Baja California

    OpenAIRE

    CHARLES L. SLATER; Esparza, Elena; Peña, Rosa M.; Topete, Carlos; Álvarez, Isaías; Cerecedo, Trinidad; García, José María

    2005-01-01

    A team of US and Mexican researchers used focus groups to determine challenges faced by rural school directors who worked in isolated, poor communities. They had no preparation before becoming directors. Their stories express frustration with teachers who do not come to school on time and are not committed to education. Yet the directors throw themselves into their work and persist over the years. They ask for training in how to work with teachers, and they bring qualities of idealism and ...

  20. La fotografía de Julius Shulman y la construcción de la imagen de la arquitectura del sur de California

    Directory of Open Access Journals (Sweden)

    Daniel Díez Martínez

    2014-10-01

    Full Text Available A Julius Shulman le correspondió, casi en exclusiva, la labor de cronista gráfico de la arquitectura moderna en el sur de California. Consciente de la dificultad de hacer ver al público la belleza de estas construcciones, Shulman desarrolló un lenguaje propio con un marcado sentido escenográfico, un encuentro entre la fotografía arquitectónica clásica y la publicidad contemporánea inspirada en la cultura pop en la que la colocación de los muebles en intervalos estratégicos, la iluminación, la elección y actitud de los modelos o la vegetación estaban cuidadosamente estudiados para guiar la vista del espectador hacia la arquitectura y el estilo de vida que de esta se desprendía. El artículo propone una visión transversal de la fotografía de Shulman y establece lazos entre su obra y la tensión política que se respiraba en los Estados Unidos de la Guerra Fría. Gracias a las “escenas” capturadas en sus fotografías, la arquitec­tura moderna californiana quedaría por siempre asociada al contexto creado por el fotógrafo, dando lugar a imágenes que el tiempo ha elevado a la categoría de iconos culturales del siglo XX. Como la arquitectura que retrataba, la fotografía se convirtió en una exaltación de la modernidad entendida como una nueva era de bienestar, prosperidad y progreso.

  1. Intraguild predation by shore crabs affects mortality, behavior, growth, and densities of California horn snails

    Science.gov (United States)

    Lorda, J.; Hechinger, R.F.; Cooper, S. D.; Kuris, A. M.; Lafferty, Kevin D.

    2016-01-01

    The California horn snail, Cerithideopsis californica, and the shore crabs, Pachygrapsus crassipesand Hemigrapsus oregonensis, compete for epibenthic microalgae, but the crabs also eat snails. Such intraguild predation is common in nature, despite models predicting instability. Using a series of manipulations and field surveys, we examined intraguild predation from several angles, including the effects of stage-dependent predation along with direct consumptive and nonconsumptive predator effects on intraguild prey. In the laboratory, we found that crabs fed on macroalgae, snail eggs, and snails, and the size of consumed snails increased with predator crab size. In field experiments, snails grew less in the presence of crabs partially because snails behaved differently and were buried in the sediment (nonconsumptive effects). Consistent with these results, crab and snail abundances were negatively correlated in three field surveys conducted at three different spatial scales in estuaries of California, Baja California, and Baja California Sur: (1) among 61 sites spanning multiple habitat types in three estuaries, (2) among the habitats of 13 estuaries, and (3) among 34 tidal creek sites in one estuary. These results indicate that shore crabs are intraguild predators on California horn snails that affect snail populations via predation and by influencing snail behavior and performance.

  2. Non-selective in situ grazing of diatoms by juvenile Green Abalone (Haliotis fulgens Philippi, 1945 in the Baja California Peninsula Consumo in situ no selectivo de diatomeas por juveniles de abulón azul (Haliotis fulgens Philippi, 1945 en la Península de Baja California

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    Uri Argumedo Hernández

    2010-04-01

    determinaron sus abundancias relativas; 42% fueron epifitas. Catorce taxa representaron el 80% de la abundancia total; de estos 12 han sido propuestos como los más importantes en la dieta de juveniles de abulón en la costa W de BCS. Los valores de diversidad (H' variaron entre 1.05 y 4.47 y dependieron más de la dominancia que de la riqueza de especies, reflejando la diversidad de diatomeas en el hábitat. Estas observaciones y la baja similitud medida entre contenidos intestinales, muestran que la riqueza y diversidad de especies de diatomeas ingeridas por juveniles de abulón serán similares aun cuando la composición de especies de diatomeas sea distinta entre especímenes. Esto nos permite concluir que la ingestión de diatomeas por juveniles de abulón es no selectiva y que la estructura de las asociaciones de diatomeas es más importante que los taxa específicos en su dieta.

  3. Spatial variation of biomass of seaweed assemblages in the temperate-tropical transition zone of Baja California Peninsula, Mexico Variación espacial de la biomasa de macroalgas en una zona de transición templado-tropical en la Península de Baja California, México

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    Margarita Casas Valdez

    2008-08-01

    Full Text Available Biomass changes of seaweed assemblages in four locations in a temperate-tropical transition zone were analyzed between October 1996 and August 1997. Locations with lower temperature, a high index of upwelling, and high quantities of hard substrate presented the largest values of biomass of seaweed (El Cardoncito (7.2 kg m-2, and Las Boyitas (6.2 kg m-2 and the biggest quantity of species of temperate affinity. Conversely, El Datilito (0.366 kg m-2, with a higher temperature, no evidence of upwelling, sandy substrate, and located in protected shallow waters, presented the lowest values of biomass and the lowest proportion of temperate affinity seaweed. The PCA and similarity analysis showed a close relationship between El Cardoncito and Las Boyitas. El Datilito was categorized as independent location, while Chester Rock (4.3 kg m-2 displayed intermediate characteristics. The close relationship observed between the first two locations can be explained by the similarity of their high biomass and physiographic and environmental characteristics. El Datilito has very different physiographic and environmental characteristics and a very low biomass.Se analizaron los cambios en la biomasa de las asociaciones de macroalgas en una zona de transición templado-tropical entre octubre de 1996 y agosto de 1997 en cuatro localidades. Las localidades con la temperatura más baja, alto índice de surgencias y mayor dominancia de sustrato duro presentaron los mayores valores de biomasa de macroalgas (El Cardoncito (7.2 kg m-2 y Las Boyitas (6.2 kg m-2 y la mayor cantidad de especies de afinidad templada. Por el contrario El Datilito (0.366 kg m-2 en donde la temperatura fue más alta, no hay evidencia de surgencias, el sustrato es arenoso, es un área más somera y protegida, presentó el menor valor de biomasa de macroalgas y la menor proporción de algas de afinidad templada. Los análisis de componentes principales y similaridad mostraron una estrecha relaci

  4. The social representation of drug trafficking like laborer optionAt first glance, the State of Baja California (Mexico and the Department of Valle del Cauca (Colombia do not have much in common. They belong to different countries and have significant di

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    Lilian Paola Ovalle

    2010-11-01

    Full Text Available At first glance, the State of Baja California (Mexico and the Department of Valle del Cauca (Colombia do not have much in common. They belong to different countries and have significant differences in their history and their social, cultural, political and economic structures. However these places have a commonality--namely the fact that for more than three decades they have become epicenters of drug trafficking. In both of these territories, trafficking groups and international business networks have appropriated the region in order to frame their illegal project. This paper summarizes the findings of field research conducted during December 2008. Knowing and comparing the social representations of drug trafficking in these two territories, offers significant elements that help understand the integration processes and social penetration of drug trafficking in local contexts—and shed light on processes that have helped consolidate these practices as viable labor options.

  5. Expansión turística y acumulación por desposesión: el caso de Cabo San Lucas, Baja California Sur (México

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    Jesús Bojórquez Luque

    2014-01-01

    Full Text Available En México, en la década de 1980, se intensifica el modelo neoliberal a tal punto que inicia el fenómeno de neoliberalización del espacio. En ese marco se llevaron a cabo reformas constitucionales para dar sostén jurídico a estos procesos de apropiación de activos públicos, entre estas, la reforma del Artículo 27 (1992, que actuó para colocar a la tierra de propiedad social (ejidal y comunal, que antes era inalienable e inembargable, en la condición de objeto transable. A la luz del concepto de acumulación por desposesión, de David Harvey, se analiza el ejido Cabo San Lucas, de la ciudad homónima, cuyo suelo entró de lleno al mercado inmobiliario urbano y a la especulación por compañías constructoras e inmobiliarias.

  6. Gas geochemistry of a shallow submarine hydrothermal vent associated with the El Requesón fault zone, Bahía Concepción, Baja California Sur, México

    Science.gov (United States)

    Forrest, Matthew J.; Ledesma-Vazquez, Jorge; Ussler, William; Kulongoski, Justin T.; Hilton, David R.; Greene, H. Gary

    2005-01-01

    We investigated hydrothermal gas venting associated with a coastal fault zone along the western margin of Bahía Concepción, B.C.S., México. Copious discharge of geothermal liquid (≈ 90 °C) and gas is occurring in the intertidal and shallow subtidal zones (to a depth of 13 m) through soft sediments and fractures in rocks along a ∼750 m linear trend generally sub-parallel to an onshore fault near Punta Santa Barbara. Hydrothermal activity shows negative correlation with tidal height; temperatures in the area of hydrothermal activity were up to 11.3 °C higher at low tide than at high tide (measured tidal range ≈ 120 cm). Gas samples were collected using SCUBA and analyzed for chemical composition and stable isotope values. The main components of the gas are N2 (≈ 53%; 534 mmol/mol), CO2 (≈ 43%; 435 mmol/mol), and CH4 (≈ 2.2%; 22 mmol/mol). The δ13C values of the CH4 (mean = − 34.3‰), and the ratios of CH4 to C2H6(mean = 89), indicate that the gas is thermogenic in origin. The carbon stable isotopes and the δ15N of the N2 in the gas (mean = 1.7‰) suggest it may be partially derived from the thermal alteration of algal material in immature sedimentary organic matter. The He isotope ratios (3He / 4He = 1.32 RA) indicate a significant mantle component (16.3%) in the gas. Here, we suggest the name El Requesón fault zone for the faults that likely formed as a result of extension in the region during the late Miocene, and are currently serving as conduits for the observed hydrothermal activity.

  7. Validación histológica de los estadios de madurez gonádica de las hembras de calamar gigante (Dosidicus gigas) en el Golfo de California, México

    OpenAIRE

    JG Díaz-Uribe; A Hernández-Herrera; E Morales-Bojórquez; S Martínez-Aguilar; MC Suárez-Higuera; A Hernández-López

    2006-01-01

    Se analizó la estructura de ovocitos en las gónadas de hembras de calamar gigante (Dosidicus gigas), para validar los estadios morfocromáticos de madurez sexual, basados en una escala de seis etapas. Las muestras fueron obtenidas quincenalmente en el área de Santa Rosalía, Baja California Sur, entre junio del 2001 y noviembre del 2002. De cada gónada se obtuvieron cortes histológicos para contar el número de ovocitos en cada nivel de desarrollo. Con la frecuencia de ovocitos en cada nivel de ...

  8. Daño genético y exposición a plaguicidas en trabajadores agrícolas del Valle de San Quintín, Baja California, México Genetic damage and exposure to pesticides among agricultural workers from Valle de San Quintín, Baja California, México Danos genéticos e exposição a pesticidas em trabalhadores agrícolas do Vale San Quintin, Baixa California, México

    Directory of Open Access Journals (Sweden)

    J. Claudia Leyva Aguilera

    2012-12-01

    Full Text Available Diferentes estudios muestran la capacidad de los plaguicidas para inducir daño genético (DG con diversos efectos en la salud. En el presente trabajo se estudia la genotoxicidad en residentes del valle agrícola de San Quintín, Baja California, México (VSQ. El objetivo fue determinar si la exposición laboral y ambiental a plaguicidas en la región del VSQ es un factor de DG y explorar si las mujeres son más vulnerables a dicho efecto. Se aplicó un cuestionario a 88 residentes del VSQ para determinar los factores de inclusión y exclusión del estudio, 40 aceptaron participar, 25 expuestos ocupacionalmente a plaguicidas y 15 ambientalmente expuestos, con similar número de hombres y mujeres. Todos los participantes firmaron un consentimiento informado. Se utilizó la técnica de micronúcleos (MN por bloqueo de la citocinesis en sangre periférica para evaluar el DG con la frecuencia de MN y Puentes de Cromatina en 1000 células binucleadas (CBN; se exploró la correlación del DG con el tiempo de exposición ocupacional a plaguicidas. Los hombres ambientalmente expuestos tuvieron menos DG que las mujeres con medias de MN de 8,1 (±1,83 y 13,1 (±1,7 respectivamente; en cambio, la exposición laboral afectó a los dos sexos: los hombres tuvieron una media de MN igual a 15,9 (±2,9 y en las mujeres fue 18,1 (±1,7. Se concluye que la exposición laboral a plaguicidas es un factor de DG, las mujeres mostraron mayor vulnerabilidad al DG. El tiempo de exposición laboral se relaciona directamente con el aumento del número de MN.Various studies have shown the ability of pesticides to induce genetic damage (GD that can cause health effects. In the present work, a genotoxicological study was conducted monitoring residents from the agricultural region of the San Quintin Valley (SQV, Baja California, Mexico. The objective was to determine if occupational and environmental exposure to pesticides in the region of the SQV is a factor in GD, and to

  9. Efecto del blanqueamiento del coral por baja temperatura en los crustáceos decápodos asociados a arrecifes del suroeste del golfo de California Effect of coral bleaching induced by low temperature on reef-associated decapod crustaceans of the southwestern Gulf of California

    OpenAIRE

    Luis Hernández; Héctor Reyes-Bonilla; Balart, Eduardo F

    2010-01-01

    El blanqueamiento del coral es consecuencia de un estrés natural o antropogénico sobre los arrecifes. En la región del Pacífico tropical este, el blanqueamiento del coral se asocia comúnmente con el incremento de la temperatura superficial del mar, pero también se puede presentar por temperaturas bajas. A principio de 2008 se registró una anomalía de temperatura extraordinariamente baja, de hasta 1.8 °C menor al promedio registrado en los últimos 25 años, que se manifestó con un severo blanqu...

  10. Establishment of a One Health Surveillance Initiative in the CA/Baja CA Border Region

    OpenAIRE

    Marikos, Sarah C.; Ferran, Karen L.; Iniguez-Stevens, Esmeralda; NAVARRO, FRANCISCO JAVIER MONGE

    2013-01-01

    Objective To showcase One Border One Health, a binational, multidiscipli-nary initiative in the California/Baja California (CA/BC) border region whose aim is to reconfigure traditional species-specific approaches to surveillance for emerging and re-emerging pathogens. Introduction The CA/BC border region encompasses a wide range of ecosystems, topography, dense urban areas, and agricultural developments that coexist in a limited geographic area and create numerous human-animal-environmental i...

  11. The involvement of citizens evaluating public security policies: Baja California’s case

    Directory of Open Access Journals (Sweden)

    Pablo Jesús González Reyes

    2003-07-01

    Full Text Available This paper emphasizes the importance of citizen involvement in the evaluation processes of public security policy in Baja California, as a revealing need of establishing new options for public management, through which relationships of mutual responsibility between society and government are enacted.

  12. Los vidrios de baja emisividad

    Directory of Open Access Journals (Sweden)

    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

  13. California coast sablefish - Reproductive Life History Analysis of Sablefish Populations off the Washington and California Coasts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sablefish (Anoplopoma fimbria) have a wide distribution along the Pacific coast, extending from Baja California to Alaska, the Bering Sea and through to the eastern...

  14. Experiences in public policies at Baja California’s NGOs

    Directory of Open Access Journals (Sweden)

    José Ascención Moreno Mena

    2003-07-01

    Full Text Available This project is an approach to the experiences that the Non Governmental Organizations (NGOs from Baja California have had regarding their policy advocacy. It is said that despite they have just begun to participate, since most of the times, they have just gotten to the point of formulating the problem, and incorporating it to the public agenda. However, they have transcended to national public levels. Two examples are presented herein, as studies of case, which describe how the local NGOs have been able to include into the national discussion agenda a problem that emerged from the private field, as well as the influence that it exerted over the legislative changes. It concludes that through NGOs participation, a more transparent relation between the civil society and the State is beginning. This job is the result of documentary investigation and a number of interviews performed to members of NGOs.

  15. 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.

  16. Geochemical Anomaly of CO Remote Sensing Associated with Baja California Mw 7.2 Earthquake in Mexico%墨西哥下加利福尼亚Mw7.2地震前后CO遥感地球化学异常

    Institute of Scientific and Technical Information of China (English)

    崔月菊; 杜建国; 周晓成; 陈志; 李营; 刘雷; 谢超; 张炜斌

    2011-01-01

    利用AIRS产品数据提取了2010年4月4日墨西哥下加利福尼亚Mw 7.2地震前后震中及其附近CO总量和CO体积混合比随时间变化的信息,讨论了CO气体地球化学变化与地震活动的关系.数据表明,下加利福尼亚地震前约一个月CO总量升高,高出前两年同期平均值2~4×1017 mole/crm2,在地震发生前后CO总量和近地表CO体积混合比有波动现象,且8日平均数据的标准偏差增大,约为非地震时段的2倍.该现象应该归因子地震孕育发生过程中地应力作用使岩石圈脱气增强、大气电磁和化学反应引起的CO含量的增加.研究结果表明利用卫星高光谱遥感数据提取与地震有关的CO气体地球化学信息,对地震监测预报有重要意义.%The variations of CO total column and the CO volume mixing ratio over time in epicenter and vicinity area of Baja California MW 7. 2 earthquake (April 4th 2010, Mexico) were extracted from AIRS database; the geochemi-cal variations of CO and earthquake activities were carefully correlated. The extracted data showed that CO total column, one month before the earthquake, increased and was higher than the corresponding mean values (2~4× 1017 mole/cm2) of 2008~2009; CO total column and CO volume mixing ratio (near-surface) fluctuated and the standard deviations of 8-day average before and after the earthquake increased to as high as about 2 times of the non-seismic period. These phenomena were attributed to increasing gas leakage from the lithosphere, a result of the earthquake related stress and increasing photo-chemical reactions in the atmosphere, a result of variation of atmospheric electromagnetism related to the earthquake. The results indicate that geochemical information of CO obtained by satellite hyperspectral remote sensing can be connected with earthquake, indicating potential application in monitoring and forecasting earthquake.

  17. El proceso de industrialización en Baja California

    Directory of Open Access Journals (Sweden)

    Agustín Sández Pérez

    1988-01-01

    Full Text Available El presente trabajo plantea como propósito central indagar sobre uno de los periodos del desarrollo industrial bajacaliforniano. Este ensayo aborda el papel de la política gubernamental y su efecto sobre la estructura económica de esta región fronteriza. Su historia económica presenta diversas modalidades de participación del capital extranjero. Los enfoques y actitudes del gobierno mexicano en su relación con los Estados Unidos han resultado cada vez más determinantes sobre los acontecimientos económicos regionales.

  18. Poder de mercado en microempresas de Baja California

    Directory of Open Access Journals (Sweden)

    Alejandro Mungaray

    2007-01-01

    Full Text Available El presente trabajo analiza la posibilidad de que algunos tipos de microempresas puedan actuar con poder de mercado, pese a la marginación socioeconómica en la que operan. Al concentrarse en zonas carentes de infraestructura y con rasgos de marginación, esas empresas se ven con posibilidades de fijar un precio mayor al del mercado, actuando en un marco de competencia distinto al de competencia perfecta. El consumidor, por su parte, está dispuesto a pagar un precio más elevado por el mismo bien, debido a lo alto de los costos (en términos de tiempo y esfuerzo que trae consigo el adquirirlo en zonas más comerciales. Este trabajo se fundamenta en un análisis de 29 microempresas, en el cual los resultados muestran una relación positiva entre el índice de Lerner y el nivel de marginación de las colonias donde se concentran.

  19. Seismotectonics of the Cerro Prieto Geothermal Field, Baja California, Mexico.

    Science.gov (United States)

    Rebollar, C. J.; Reyes, L. M.; Quintanar, L.; Arellano, J. F.

    2002-12-01

    We studied the background seismic activity in the Cerro Prieto geothermal field (CPGF) using a network of 21 digital stations. Earthquakes are located below the exploitation area of the CPGF, between 3 and 12 km depth, within the basement. Earthquakes follow roughly a N30°E trend perpendicular to the Cerro Prieto fault. This activity is located on a horst-like structure below the geothermal field and coincides with the zone of maximum subsidence in the CPGF. Two earthquake swarms occurred along the SE-NW strike of the Cerro Prieto fault and in the neighborhood of the Cerro Prieto volcano. Magnitudes range from -0.3 to 2.5. A Vp/Vs=1.91 ratio of the activity below the volcano suggests a water-saturated medium and/or a partial-melt medium. We calculated 76 focal mechanisms of individual events. On June 1 and September 10, 1999, two earthquakes of Mw 5.2 and 5.3 occurred in the basement at depths of 7.4 and 3.8 km below the CPGF. Maximum peak accelerations above the hypocenter ranged from 128.0 to 432.0 cm/s2. Waveform modeling results in a fault geometries given by strike=236°, dip=60°, rake=-58° (normal) and strike=10°, dip=90°, rake=159° (right lateral strike-slip) for the June and September events. Observed triangular source time function of 0.7 seconds and a double source with a total duration of 1.9 seconds for the June and September events were used to calculate the synthetics seismograms. Static stress drops and seismic moments for the June and September events are: Δ\\sigma=82.5 MPa (825 bars), Mo= 7.65x1016 Nm (7.65x1023 dyne-cm) and Δ\\sigma=31.3 MPa (313 bars) and Mo=1.27x1017 Nm (1.27x1024 dyne-cm). These stress drops are typical of continental events rather than stress drops of events originated in spreading centers. We concluded from the focal mechanisms of the background seismicity and June and September 1999 events, that a complex stress environment exits in the CPGF due to the continual thinning of the crust in the Cerro Prieto basin.

  20. Developing New Management Techniques for Sharks in the Drift Gillnet Fishery of the Southern California Bight

    OpenAIRE

    Graham, Jeffrey B.; Cartamil, Daniel P.

    2009-01-01

    The Southern California Bight (SCB) is a contiguous geographical region that extends from Point Conception, California to northern Baja California and west into the California Current. This region’s productive ecosystem supports various recreational and commercial fisheries, some of which target pelagic sharks. For example, the common thresher shark (Alopias vulpinus) comprises the largest commercial shark fishery in California waters (the California drift gillnet fishery, or CA-DGF. Mako sha...

  1. Washington coast sablefish - Reproductive Life History Analysis of Sablefish Populations off the Washington and California Coasts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sablefish (Anoplopoma fimbria) have a wide distribution along the Pacific coast, extending from Baja California to Alaska, the Bering Sea and through to the eastern...

  2. El Banco del Sur

    OpenAIRE

    Espejo, Silvana

    2012-01-01

    En este trabajo abordaremos las características principales del Banco del Sur como una institución financiera sudamericana. Primero presentaremos sus principales características y explicaremos las características de un banco de desarrollo regional. Luego, expondremos el proceso de conformación del mismo haciendo un recorrido por sus principales antecedentes. Por último, cerraremos con una evaluación sobre el estado actual del Banco del Sur. (Párrafo extraído del texto a modo de resumen)...

  3. Local district constituencies and representation inequality. Baja California’s situation, 1992-2004

    Directory of Open Access Journals (Sweden)

    Leopoldo Martínez Herrera

    2008-01-01

    Full Text Available Regardless of the reformist advancements of the election system, there are still unresolved issues. In the case of Mexico and in the midst of a debate on our transition process we place the issue of district overrepresentation, wich by generating multiple effects configures a point of deep discussion thus concerning the system of representation, the integration of the house of representatives, the parties system and above all it puts a debate on the following premise: "a vote per citizen", that is, the principle of equalness in democracy, which translated to the field of elections means, as Bovero stated, assigning an equal-valve decition quota to each citizen. In the case of Baja California, our purpose is to demonstrate that the issues related to the deficient district representation, the integration of the parties within the house of representatives, and as a consequence the athrophy of the parties system continue to be an actual problem on this transition process that haven't been able to trascend the margins of regional and local dynamics of politics and power. This study includes an analysis of territorial-demography of legislative representation of Baja California, taking as a reference all research undertaken on similar phenomena by Diego Reynoso, FLACSO researcher.

  4. El papel de la membrana corioalantoídea en la retención de contaminantes organoclorados (plaguicidas) y su relación con otras variables ambientales: sedimentos y plasma de tortuga marina golfina (Lepidochelys olivacea) de Baja California Sur, México.

    OpenAIRE

    Sergio Rosales Ledezma; Orlando Lugo Lugo; Tania Zenteno Zavín; Lia Celina Méndez Rodríguez

    2011-01-01

    Se ha sugerido que las tortugas al consumir sus alimentos, como algas, sargazo y vegetación marina pueden ingerir agua y sedimentos contaminados por compuestos órganoclorados (OCs). También se considera que la exposición a los bifenilos policlorados (PCBs) por parte de las tortugas marinas es de manera directa y la transferencia de estos contaminantes se daría desde la madre hacia los huevos y posiblemente perturbar el nacimiento de las crías. La acumulación de los OCs en los huevos de aves y...

  5. Agotamiento hidro-agrícola a partir de la Revolución Verde: extracción de agua y gestión de la tecnología de riego en Baja California Sur, México

    Directory of Open Access Journals (Sweden)

    Enrique Troyo-Diéguez

    2010-01-01

    Full Text Available Se analizan algunos de los avances más relevantes alcanzados en el ámbito de la productividad agrícola, en relación con el uso del agua y la transferencia tecnológica, así como los beneficios que puede aportar la tecnología de riego. Dentro de los factores que afectan la productividad en zonas áridas, destacan la sequía y la escasez de agua. Se vislumbran dos motivos para desarrollar mejoramiento hidro-agrícola dirigido a condiciones de aridez y escasez de agua: el primero es maximizar la productividad y consecuentemente el rendimiento; el segundo es mejorar los agroecosistemas, incluyendo la infraestructura y la tolerancia a la sequía. En México, en la última década se ha promovido la investigación, mejoramiento y transferencia tecnológica. La gestión de la tecnología de riego ha sido positiva en algunos distritos, como en el 066 del Valle de Santo Domingo, B. C. S., donde la productividad del agua se incrementó de 2.1 a 5.3 pesos por m3 de agua aplicada, aunque en otros no existen evidencias de cambios positivos, como en el 038 del Río Mayo, Sonora; ahí la productividad permanece sin cambios, en 1.5 pesos por m3 de agua. Se reitera que una agricultura de alta tecnología puede poner en riesgo la calidad ambiental y que la problemática del agua puede agravarse en el futuro inmediato.

  6. Geodynamics of the Gulf of California from surface wave tomography

    NARCIS (Netherlands)

    Zhang, X.; Paulssen, H.

    2012-01-01

    The Gulf of California, which forms part of the Pacific-North American plate boundary, is an ideal place to investigate upper mantle dynamics in a continental rifting area. With 19 seismic stations located around the gulf, the NARS-Baja experiment (2002-2008) was designed to image its crustal and ma

  7. Parliamentary set-up and productivity within Baja California’s Congress

    Directory of Open Access Journals (Sweden)

    Cuauhtémoc López Guzmán

    2002-07-01

    Full Text Available This document presents a static and dynamic analysis of the Congress of Baja California, Mexico. The static portion encompasses the historic origin of the congress, its constitutional functions, and partisan composition.The dynamic section is a comparative study of the legislative productivity during two periods: the period of a unified government (1953-1989, and the period of a divided government (1989-2001. Additionally, metrics are constructed to analyze the parliamentary dynamics under a divided majority format with the purpose of rationalizing the institutional, political, and partisan conditions that create, between the executive and legislative powers, an environment of cooperation and conflict that affects the yeild of the institution and democracy.

  8. Organic geochemistry of endoevaporitic environments: Microbial diversity and lipid biomarkers from gypsum deposits at the E.S.S.A Salt Works, Guerrero Negro, Baja, Mexico

    Science.gov (United States)

    Vogel, M. B.; Des Marais, D. J.; Jahnke, L. L.; Turk, K. A.; Kubo, M. D.

    2006-12-01

    We report lipid biomarker distributions and microbial diversity of endoevaporitic microbial communities from the gypsum crystallizer pond (Pond #9; ~170 % salinity) at the Exportadora de Sal, (ESSA) salt works in Guerrero Negro, Baja California Sur, Mexico. According to phylogenetic analysis using 16S rRNA sequences, gypsum crusts from this system host stratified communities of unicellular cyanobacteria (orange Euhalothece), filamentous cyanobacteria (green Oscillatoria), purple sulfur bacteria (Chromatium), and other halophilic microorganisms. Lipids collected from spatially discrete horizons of the crust indicate a shift in C16, C18 and C19 fatty acids from lower concentrations in the upper aerobic layers to higher concentrations in the deeper anaerobic zones of the crust. Compound specific isotopic analyses (CSIA) of fatty acids differentiate the more abundant C16, C18 and C19 homologues as isotopically lighter (~ -20% to -25% δ13C VPDB) from C15, C17 and C20 homologues which are isotopically heavier (~ -14% to -19% δ13C VPDB) and occur in lower abundance. CSIA of multiple compound classes reveals that gypsum domain lipids have significantly lighter δ13C values than those of lipids from the laminated benthic microbial mats living at lower salinities (i.e. ~100% to 115% salinity) in the ESSA system. This isotopic effect is consistent with intensive internal nutrient cycling within the crust. Squalane/squalene were detected in extracts from the gypsum crust indicating the presence of archaea. Diploptene is the most abundant triterpenoid of the C28 C32 hopanoids. Branched alkanes with quaternary substituted carbons (BAQCs) were also detected. These compounds have been linked with sulfur oxidizing microbial activity, which is known to be a major respiratory process in the crust's internal O2 budget (Sørensen et al., 2004). Abundant organosulfur compounds (OSC) and thiacycloalkanes in extracts indicate a vigorous internal sulfur cycle that influences both

  9. Réflexions critiques sur le maintien en emploi de travailleurs vieillissants faiblement qualifiés : responsabilité sociale ou individuelle ? Critical reflection on keeping older low-skilled workers employed : a social or individual responsibility ? Reflexiones críticas sobre el mantenimiento en el empleo de trabajadores de baja calificación que envejecen : responsabilidad social o individual ?

    Directory of Open Access Journals (Sweden)

    Thibauld Moulaert

    2009-05-01

    Full Text Available Cet article propose une réflexion pluridisciplinaire (médecins du travail et sociologue sur la nécessité de prolonger les carrières à partir du cas limite de travailleurs faiblement qualifiés de deux entreprises : une entreprise de ramassage de déchets (Cleanbel et une entreprise de distribution alimentaire (Distribel. Croisant réalité pratique et ergonomie d’un côté et enjeu de responsabilité et réflexion sociologique de l’autre, il montre les limites d’un questionnement sur l’emploi des salariés vieillissants quand est occulté le travail analysé au départ de l’activité réelle. En explorant le cas de travailleurs faiblement qualifiés, il montre aussi les marges de manœuvre étroites d’une action sociale possible ou voulue qui pose in fine la question de la responsabilité de cette action : est-elle collective (portée par l’Etat et l’entreprise ou individuelle (portée par le travailleur ?This article proposes multidisciplinary (occupational physicians and sociologist reflection on the need for prolonging careers. It is based on the limit case of low skilled workers in two companies : a waste collection company (Cleanbel, and a supermarket chain (Distribel. It intersects practical reality and ergonomics on the one hand, and aspects of responsibility and sociological reflection on the other. It shows the limitations of reflection on the employment of aging workers when the analysis of the actual work activity is not taken into account. By exploring the case of low-skilled workers, it also shows the narrow margin of manoeuvre for any possible or desired social action. In the end, we question the responsibility of this action : is it a collective one (of the State or company or an individual one (of the worker ?Este artículo propone una reflexión pluridisciplinaria (médicos laborales y sociólogo sobre la necesidad de prolongar las carreras profesionales, basada en el caso extremo de los trabajadores

  10. California Bioregions

    Data.gov (United States)

    California Department of Resources — California regions developed by the Inter-agency Natural Areas Coordinating Committee (INACC) were digitized from a 1:1,200,000 California Department of Fish and...

  11. California State Waters Map Series—Offshore of Monterey, California

    Science.gov (United States)

    Johnson, Samuel Y.; Dartnell, Peter; Hartwell, Stephen R.; Cochrane, Guy R.; Golden, Nadine E.; Watt, Janet T.; Davenport, Clifton W.; Kvitek, Rikk G.; Erdey, Mercedes D.; Krigsman, Lisa M.; Sliter, Ray W.; Maier, Katherine L.; Johnson, Samuel Y.; Cochran, Susan A.

    2016-08-18

    IntroductionIn 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath bathymetry data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow subsurface geology.The Offshore of Monterey map area in central California is located on the Pacific Coast, about 120 km south of San Francisco. Incorporated cities in the map area include Seaside, Monterey, Marina, Pacific Grove, Carmel-by-the-Sea, and Sand City. The local economy receives significant resources from tourism, as well as from the Federal Government. Tourist attractions include the Monterey Bay Aquarium, Cannery Row, Fisherman’s Wharf, and the many golf courses near Pebble Beach, and the area serves as a gateway to the spectacular scenery and outdoor activities along the Big Sur coast to the south. Federal facilities include the Army’s Defense Language Institute, the Naval Postgraduate School, and the Fleet Numerical Meteorology and Oceanography Center (operated by the Navy). In 1994, Fort Ord army base, located between Seaside and Marina, was closed; much of former army base land now makes up the Fort Ord National Monument, managed by the U.S. Bureau of Land Management as part of the National Landscape Conservation System. In addition, part of the old Fort Ord is now occupied by California State University, Monterey Bay.The offshore part of the map area lies entirely within the Monterey Bay National

  12. Comentarios desde el Sur

    Directory of Open Access Journals (Sweden)

    Tatiana Cordero Velásquez

    2011-05-01

    Full Text Available Este texto ahonda en las preguntas que plantea el Dossier: ¿Cómo se piensa lo queer en AméricaLatina? La autora analiza los contenidos de lo político en lo queer, sus aportes y limites, y la pertinenciadel concepto. Subraya la ausencia de una perspectiva de género en los estudios gay yqueer anteriores, y la relación entre sujetos LGBTI y la academia en la trayectoria de lo queer ennuestro contexto. Analiza el lugar de lo femenino en tres de los cinco artículos que abordan lasidentidades gay y trans y la ausencia de análisis sobre lo masculino en lo lésbico, bisexual o transmasculino como reflejo de la estratificación en la producción de conocimiento en torno al ‘cuerpopolítico queer’. A la vez, destaca la contribución de este dossier a la producción de conocimientoen el Sur así como a la complejización de este debate.

  13. Teatro-cine Eileen Norris - California (EE.UU.

    Directory of Open Access Journals (Sweden)

    Martin, Albert C.

    1978-10-01

    Full Text Available This building forms a part of the substructure of the Department of the Cinema of the University of Southern California. Among its various functions, it includes the practical teaching of cinematography. It consists of a ground floor for accesses and auditorium, with a surface measuring 1,950 m2, and a basement of the same extension, designed for a film library and film deposit. The auditorium has a capacity for 350 spectators and is equipped with a screen adaptable to the projection of 16, 35 and 70 mm films, as well as equipment for the projection of slides and video tapes. It can also be conditioned as a lecture hall, for which purpose, complete sets of equipment fort simultaneous translation have been installed. On the outside, the architecture presents a neoclassical design, based on a portico of four large white cement columns, which combines with Marble exteriors on the walls.

    Este edificio forma parte de la infraestructura del Departamento de Cine de la Universidad de California del Sur. Entre sus diversas funciones comprende la enseñanza práctica de la cinematografía. Consta de una planta baja destinada a accesos y auditorio, de 1.950 m2 de superficie, y un sótano, de la misma extensión, destinado a biblioteca de cine y a depósito de películas. El auditorio tiene capacidad para 350 espectadores y cuenta con una pantalla adaptable a la proyección de films de 16, 35 y 70 mm, así como con equipos para la proyección de diapositivas y cintas de video-tapes. Puede acondicionarse, igualmente, como sala de conferencias, para lo cual se han instalado unos completos equipos de traducción simultánea. Exteriormente, la arquitectura presenta un diseño neoclásico, basado en un pórtico de cuatro grandes columnas de cemento blanco que combina con revestimientos de mármol y en los paramentos verticales.

  14. Daily food intake of Kajikia audax (Philippi, 1887 off Cabo San Lucas, Gulf of California, Mexico Tasa de consumo diario de alimento de Kajikia audax (Philippi, 1887 frente a Cabo San Lucas, golfo de California, México

    Directory of Open Access Journals (Sweden)

    Leonardo A Abitia-Cárdenas

    2011-11-01

    Full Text Available The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae, were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub mackerel (Scomber japonicus, California pilchard (Sardinops caeruleus, and jumbo squid (Dosidicus gigas; together these represented ~55% of the striped marlin diet. The daily food consumption was estimated to be 2 kg per day, or ~3.6% of the mean body weight of K. audax. The total biomass of the prey consumed by the striped marlin during the 27 months of sampling around Los Cabos was estimated at 24.8 ton, of which the chub mackerel represented ~29% (7.2 ton, California pilchard just under 16% (3.9 ton, and jumbo squid ~10% (2.5 ton. The feeding habits of K. audax are discussed in terms of the distribution of the epipelagic (neritic and oceanic zones, demersal, and benthic prey, confirming that striped marlin migrate vertically and horizontally in search of their food.Se estimó la tasa de consumo diario de alimento del marlín rayado Kajikia audax (Perciformes: Istiophoridae, sobre la base de análisis cualitativos y cuantitativos de su espectro trófico. Se analizó el contenido estomacal de 505 ejemplares capturados por la flota deportiva frente a Cabo San Lucas, Baja California Sur, México muestreados de octubre 1987 a diciembre 1989. Las presas más importantes fueron la macarela del Pacífico (Scomber japonicus, sardina monterrey (Sardinops caeruleus y calamar gigante (Dosidicus gigas, que en conjunto representaron aproximadamente el 55% de la dieta. La tasa de consumo de alimento fue estimado en 2 kg diarios, lo cual representó aproximadamente el 3,6% del peso corporal de K. audax. La biomasa total de presas consumidas por el marlín rayado

  15. Effects of Extreme Drought and Megafires on Sky Island Conifer Forests of the Peninsular Ranges, Southern California

    OpenAIRE

    Goforth, Brett Russell

    2009-01-01

    Conifer populations in the Peninsular Range of southern California and Baja California form isolated biogeographic "sky-islands" on mountains with orographic enhanced precipitation. Fire suppression management altered burning patterns in southern California since ca. 1900. Significant changes in tree composition, density, and diameters are documented over a 75-year period in mixed conifer forest at Cuyamaca Mt. by replicating ground-based measurements sampled in 1932 for the Weislander Vegeta...

  16. A study of the population structure of the Pacific sardine Sardinops sagax (Jenyns, 1842) in Mexico based on morphometric and genetic analyses

    OpenAIRE

    Cota Gómez, Víctor Manuel; De La Cruz Agüero, José; García Gasca, Silvia Alejandra; García Rodríguez, Francisco Javier

    2011-01-01

    Several studies on the Pacific sardine Sardinops sagax have focused on the identification of stock composition and boundaries, using morphometric and genetic analysis. In this study, geometric morphometric body landmarks and control region mtDNA sequences were used to examine the population structure of sardines along the Pacific coast of the Baja California Peninsula. Samples from commercial landings in Ensenada (ENS), Baja California, and Bahia Magdalena (BM), Baja California Sur, were obta...

  17. Prospección oceanográfica y biológica en el sur del Perú durante "El Niño 1997-98"

    Directory of Open Access Journals (Sweden)

    Marco Quiroz

    2014-06-01

    Full Text Available El Oceanográfico y biológicas fueron estudiados en la zona sur del Perú en 36 estaciones distribuidas en los perfiles perpendicular respecto a la costa hasta 80 MN, de 13 a 16 en 1998, durante la fase de mayor intensidad de "El Niño 1997-1998". Los resultados mostraron una presencia generalizada de agua superficial subtropical, con una pobreza de la densidad de fitoplancton y la diversidad; y muy baja densidad de recursos pelágicos, como consecuencia de la profundización o la migración hacia el sur de los cardúmenes.

  18. Pengaruh Media Pendingin Pada Proses Hardening Terhadap Strukturmikro Baja Mangan Hadfield AISI 3401 PT Semen Gresik

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    Mohammad Ismanhadi Syahputra

    2013-09-01

    Full Text Available Baja Mangan Hadfield termasuk dalam kategori baja mangan austenitic dengan kandungan Mn (mangan yang tinggi, antara 12-14% Mn dan 0.8-1.25% C. Baja mangan hadfield memiliki kekerasan, kekuatan, ketangguhan, serta ketahanan terhadap aus yang tinggi. Proses hardening diberikan dengan melakukan pendinginan yang relatif cepat dengan menggunakan media pendingin air, oli, polivinylalcohol 10%, dan polyvinylalcohol 40% bertujuan untuk mendapatkan nilai kekerasan yang lebih tinggi yakni dengan pendinginan air 275VHN sedangkan tanpa perlakuan 206VHN. Viskositas dari media pendingin yang berbeda-beda berpengaruh terhadap laju pendinginan pada baja mangan hadifield.. Jenis media pendingin yang bervariasi mempengaruhi perubahan austenit menjadi martensit.  Strukturmikro yang terbentuk pada baja mangan hadfield yang mengalami proses hardening tampak butir-butir kristal yang seluruhnya martensit, sedangkan pada baja mangan hadfield yang tanpa mendapatkan perlakuan tampak karbida mangan lamellar dengan matriks austenit.

  19. Innovative public management process: The situation of Personalized Attention Modules for Baja California’s migrants

    Directory of Open Access Journals (Sweden)

    José Ascención Moreno Mena

    2010-01-01

    Full Text Available Two examples that allow surmising the possibilities and obstacles of strategic alliances between the civil society and local governments seeking to develop programs that help solve the problems the community demands are featured in this research. The studies that were analyzed take place in the State of Baja California, and are based on documentary information and on interviews with key informants, which in this case, are the program leaders. The first of them has to do with the experience of a migrant support office in Mexicali, which is under the exclusive direction of a civil organization; while the second entails a program for the attention of migrants that were deported from the United States, whereby such program has been used by the federal government to spearhead a more encompassing public policy in the regional sphere. The two examples portray innovative public stewardship cases. The breakthroughs and obstacles to carry out such types of processes are presented. Furthermore, it is concluded that these two examples may be the seed of a new governance.

  20. Hypoxic cyclicity in sediments of Soledad Basin, Baja Mexico: A record of high-frequency climate fluctuations?

    Science.gov (United States)

    Westman, A. E.; Brooks, G. R.; Lea, C.

    2007-05-01

    The sedimentary record in Soledad Basin, 45 km west of Baja, Mexico, shows high-frequency oscillations in hypoxia, which can be linked to fluctuations in climate. Soledad Basin, a semi-enclosed basin with a sill depth of 290m, has been shown to exhibit variable levels of hypoxia throughout the geologic past. Located at the intersection of the California Current and California Undercurrent, Soledad Basin is highly responsive to changes in current strength and upwelling, the combination of which creates fluctuations in hypoxia. During climatic cool periods, the California Current is weakened decreasing upwelling and biologic productivity along the Baja Borderland. This causes increased hypoxia in Soledad Basin. The California Undercurrent is also weakened during these cooler periods and brings less nutrients and oxygen to the basin further increasing hypoxia. Since Soledad Basin sediments are undisturbed and have accumulated rapidly, this is a prime location to study high frequency variations in hypoxia in the sedimentary record. The objective of this study was to examine how and to what extent hypoxic events have been recorded in the sedimentary record of Soledad Basin, and gain insight into what controls these events. Surface sediment samples and a single 1.1m gravity core were collected aboard the S.S.V. Robert C. Seamans on a SEA Semester cruise in October 2005. The core was taken at a depth of 490 m near the deepest point of the basin. The core contained laminated sediments consisting of >95% mud. Using 210Pb analysis, a sedimentation rate of 15 cm over the past 100 years was determined, which is consistent with previous research. Trace metal analyses were performed at the cm-scale on selected intervals between 0.34-0.44m and 0.78-0.92m. These intervals correspond to dark organic-rich (>15% organic content) laminations alternating with lighter layers containing less organic material (<15% organic content). All sediments were found to be enriched in Molybdenum

  1. Les torsions sur testicules cryptorchides

    Science.gov (United States)

    Gharbi, Mohamed; Amri, Najmeddine; Chambeh, Wahib; Braiek, Salem; Kamel, Rafik El

    2010-01-01

    Résumé But : La cryptorchidie est une pathologie assez fréquente en urologie. Elle est associée à un risque élevé d’infertilité et de dégénérescence. Elle semble aussi être associée à un risque important de torsion. Cette entité est très peu abordée dans la littérature. Nous rapportons tous les cas de torsion sur testicule cryptorchide observés à notre service dans le but de mieux caractériser cette pathologie et de réduire ainsi le taux d’orchidectomies. Méthodologie : Il s’agit d’une étude rétrospective portant sur tous les cas de torsion sur testicule cryptorchide opérés dans notre service d’urologie entre 1999 et 2007. Les patients ont fait l’objet d’une description basée sur le résumé de leurs observations. Résultats : Les patients étaient âgés de 7 mois à 39 ans. La torsion touchait le testicule droit dans 53 % des cas. Le tableau clinique comportait une douleur au niveau de la région inguinale d’apparition soudaine avec une masse sous-cutanée inflammatoire et douloureuse à ce niveau et surtout un hémiscrotum homolatéral vide. Dans 60 % des cas, le diagnostic était tardif et une orchidectomie a été réalisée. Dans les autre cas, un abaissement du testicule a été réalisé avec orchidopexie controlatéral dans le même temps opératoire. Conclusion : Bien qu’il s’agisse d’une pathologie peu courante, la torsion sur testicule cryptorchide doit être étudiée davantage. Le diagnostic précoce permettra de sauver et d’abaisser le testicule et faciliter ainsi le dépistage d’une éventuelle dégénérescence. PMID:21191497

  2. La resiliencia como respuesta a los alumnos con baja autoestima

    OpenAIRE

    del Mazo-Maestu, Mª Beatriz

    2016-01-01

    El trabajo Fin de Máster que aquí se presenta versa sobre una propuesta de intervención psicopedagógica destinada a tres alumnos de primero de educación secundaria obligatoria de un colegio concertado de la capital de Burgos que muestran actitudes y comportamientos como alarma a una baja autoestima. Dicha propuesta se basa en un conjunto de sesiones para desarrollar la inteligencia emocional y la autoestima como parte de un programa de aplicación de resiliencia al aula. S...

  3. Subcontratación en microempresas y pequeñas empresas de Baja California

    Directory of Open Access Journals (Sweden)

    Natanael Ramírez Angulo

    2004-01-01

    Full Text Available Este artículo demuestra que la subcontratación es un elemento fundamental para incrementar la competitividad de las microempresas y pequeñas empresas cuando favorece dos condiciones: 1 la generación de mayor valor agregado en sus productos, y 2 la capitalización de sus ganancias en un mayor nivel de inversión (subcontratación activa. Asimismo, aplicando un ejercicio de teoría de juegos, se discute un modelo conceptual sobre el proceso mediante el cual los beneficios se transforman en ingresos a través de una relación de subcontratación.

  4. Estrategias de cálculo mental utilizadas por estudiantes del nivel secundaria de Baja California

    OpenAIRE

    Jeannette Cortés; Eduardo Backhoff; Javier Organista

    2004-01-01

    Se conoce que el cálculo mental o estimativo ayuda a los estudiantes a desarrollar el sentido del número y a mejorar la comprensión de las relaciones numéricas. Por lo anterior, este trabajo tuvo el propósito de conocer el nivel de solución de problemas estimativos que tienen los estudiantes de 2º año de secundaria, así como identificar las estrategias mentales que utilizan los mejores estimadores. Para ello, se administró una prueba, traducida y adaptada del modelo de Reys et al. (1982), a 2...

  5. Geophysical Exploration of Faults, Fissures, and Fractures at Four Sites in Mexicali, Baja California, Mexico

    Science.gov (United States)

    Lázaro-Mancilla, O.; Gonzalez-Fernandez, A.; Contreras-Corvera, A.; Stock, J. M.; Moreno-Ayala, D.; Ramirez-Hernandez, J.; Carreon-Diazconti, C.; Lopez, D. A. L.; Lopez, J. R.

    2014-12-01

    We conducted field geophysical measurements in areas in the City of Mexicali that are associated with geological faults, fissures, and fractures. The study sites are: 1) Instituto Tecnologico de Mexicali 2) The buried trace of the Michoacan de Ocampo fault in the urban zone 3) Rio Nuevo 4) A site reported by Frez (2013) with ground rupture SW of Cerro Prieto At Site 1, seismic reflection profiling used a cable with 24 geophones at 1 m spacing. The source was a 3.6 kg sledge hammer, with 3 impacts per shot point. 347 shot points at 2 m spacing provided 6 fold coverage along a straight line with minimal elevation changes. Sample rate was 2000/s, and record length 1 s; reflections were seen down to 0.3 s TWTT. Processing included: frequency filter, fk filter, predictive deconvolution, geometry, velocity analysis, NMO and stacking. Lateral changes in the seismic section are due to surface modification and/or the presence of faults.At site 2, we measured 222Radon in 36 locations along 17 profiles across the fault, using inherent alpha spectrometry with a Durridge RAD7 detector. Each site was measured at a depth of 60 cm, with 31 five-minute readings in a 3 hour period, interspersed with 10 minute of background purge and 3 five-minute background measurements. In a profile parallel to the fault, 78% of the readings were > 100 pCi/L, confirming the presence of the fault along the swath surveyed. At Site 3 we compiled observations of post-earthquake cracks, conducted reconnaissance, and measured some profiles using 100 MHz GPR. These observations showed that the cracks are associated with ground failure due to earthquake shaking. At Site 4 our new 222Radon gas measurements complemented a pre-existing profile that had high 222Radon values lacking a structural explanation. Related to this we found that this region has two NW-SE trending features: a magnetic anomaly low of 360 nT (Evans, Summer and Castillo, 1972) and a graben reported by the Mexican Geological Survey in 2003. Earthquake patterns and seismic studies in a wider area north of the border indicate a possible buried fault a few km west of the Imperial fault, as well as short NE-striking faults controlling basement structure. These results highlight some very useful methods for finding fault traces in a flat region covered with agricultural fields or disturbed by anthropogenic activity.

  6. Observaciones sobre la función de las tablas de Baja California

    Directory of Open Access Journals (Sweden)

    Gianfranco Cassiano V.

    1987-09-01

    Full Text Available El presente escrito reúne y analiza determinada información acerca de las tablas que fueron halladas en esta región, proporcionando datos de estos objetos tanto de carácter morfológico, etnográfico, como de su posible función social. Es fundamental el estudio de los procesos productivos donde interviene el artefacto, como objeto y como medio de trabajo, así como analizar la morfología, el tipo del sitio y el contexto arqueológico, su asociación con el contexto, la filiación cultural y su lugar en el tiempo. En suma, estas tablas son la expresión reciente de una necesidad más antigua: la de reproducir y reforzar las relaciones sociales de producción y las bases del prestigio dentro del grupo, utilizando los patrones de descendencia y la estructura de parentesco.

  7. Use of digital multispectral videography to assess seagrass distribution in San Quintin Bay, Baja California, Mexico

    Science.gov (United States)

    Ward, D.H.; Tibbitts, T.L.; Morton, Alexandra; Carrera-Gonzalez, Eduardo; Kempka, R.

    2004-01-01

    Apparent threats to the spatial distribution of seagrass in San Quinti??n Bay prompted us to make a detailed assessment of habitats in the bay. Six coastal habitats and three seagrass subclasses were delineated using airborne digital multispectral videography (DMSV), Eelgrass, Zostera marina, was the predominant seagrass and covered 40% (1949 ha) of the areal extent of the bay in 1999. Eelgrass grew over a wide range of tidal depths from about -3.0 in mean lower low water (MLLW) to about 1.0 m MLLW, but greatest spatial extent occurred in intertidal areas -0.6 m to 1.0 m MLLW. Exposed-continuous (i.e., high density) eelgrass was the most abundant habitat in the bay. Widgeongrass, Ruppia maritima, was the only other seagrass present and covered 3% (136 ha) of the areal extent of the entire bay. Widgeongrass grew in single species stands in the upper intertidal (??? 0.4 MLLW) and intermixed with eelgrass at lower tidal depths. Overall accuracy of the six habitat classes and three subclasses in the DMSV map was relatively high at 84%. Our detailed map of San Quintin Bay can be used in future change detection analyses to monitor the health of seagrasses in the bay.

  8. Shallow Miocene basaltic magma reservoirs in the Bahia de Los Angeles basin, Baja California, Mexico

    Science.gov (United States)

    Delgado-Argote, Luis A.; García-Abdeslem, Juan

    1999-01-01

    The basement in the Bahı´a de Los Angeles basin consists of Paleozoic metamorphic rocks and Cretaceous granitoids. The Neogene stratigraphy overlying the basement is formed, from the base to the top, by andesitic lava flows and plugs, sandstone and conglomeratic horizons, and Miocene pyroclastic flow units and basaltic flows. Basaltic dikes also intrude the whole section. To further define its structure, a detailed gravimetric survey was conducted across the basin about 1 km north of the Sierra Las Flores. In spite of the rough and lineal topography along the foothills of the Sierra La Libertad, we found no evidence for large-scale faulting. Gravity data indicates that the basin has a maximum depth of 120 m in the Valle Las Tinajas and averages 75 m along the gravimetric profile. High density bodies below the northern part of the Sierra Las Flores and Valle Las Tinajas are interpreted to be part of basaltic dikes. The intrusive body located north of the Sierra Las Flores is 2.5 km wide and its top is about 500 m deep. The lava flows of the top of the Sierra Las Flores, together with the distribution of basaltic activity north of this sierra, suggests that this intrusive body continues for 20 km along a NNW-trending strike. Between the sierras Las Flores and Las Animas, a 0.5-km-wide, 300-m-thick intrusive body is interpreted at a depth of about 100 m. This dike could be part of the basaltic activity of the Cerro Las Tinajas and the small mounds along the foothills of western Sierra Las Animas. The observed local normal faulting in the basin is inferred to be mostly associated with the emplacement of the shallow magma reservoirs below Las Flores and Las Tinajas.

  9. Breve descripción de la comunidad Cucapá del Rio Hardy, Baja California

    Directory of Open Access Journals (Sweden)

    Julia Bendímez Patterson

    1995-01-01

    Full Text Available In this artic1e a brief description is made about the present state of the cucapa people from El Mayor. In order to accomplish this some historic events, accounts about their way of making a living and the transformation of their natural environment are taken into consideration. The purpose is to illustrate the difficulty challenge that this ancestral group faces in the near future.

  10. Mixtecos en Baja California: El caso de San Quintín

    Directory of Open Access Journals (Sweden)

    Everardo Garduño

    1991-01-01

    Full Text Available En este trabajo se presentan los múltiples aspectos por los que el valle de San Quintín es un lugar propicio para la horticultura; pero sobre todo el por qué es un polo de atracción de flujos migratorios provenientes, en su mayoria, de la Mixteca oaxaqueña. El autor hace un análisis de las condiciones de vida y trabajo de todos los migrantes indígenas en San Quintín, de su proceso de aculturación y de su integración social.

  11. STATISTICAL CHARACTERIZATION OF PRECIPITABLE WATER VAPOR AT SAN PEDRO MARTIR SIERRA IN BAJA CALIFORNIA

    Directory of Open Access Journals (Sweden)

    A. Otárola

    2009-01-01

    Full Text Available Presentamos datos del vapor de agua precipitable durante 2006 para la Sierra de San Pedro Mártir obtenidos de mediciones de la emisión atmosférica como función del ángulo de elevación por un radiómetro operando a la frecuencia de 210 GHz. Las mediciones de este radiómetro se combinan con valores de temperatura y presión atmosférica a nivel del suelo en el sitio para determinar una relación matemática para la conversión de la opacidad atmosférica al cenit a 210 GHz y la columna de vapor de agua precipitable para San Pedro Mártir. Los datos del vapor de agua precipitable se analizan estadísticamente para conocer su función de densidad de probabilidad y su distribución acumulativa, así como para determinar el número de horas continuas al año en que el vapor de agua precipitable permanece por debajo de los umbrales de 1 mm, 2 mm y 3 mm. Esta información es de interés para evaluar el desempeño de telescopios operando desde la región del óptico hasta longitudes de onda milimétricas en este sitio.

  12. Carbon isotope geochemistry of hydrocarbons in the Cerro Prieto geothermal field, Baja California Norte, Mexico

    Science.gov (United States)

    Des Marais, D. J.; Stallard, M. L.; Nehring, N. L.; Truesdell, A. H.

    1988-01-01

    Hydrocarbon abundances and stable-isotopic compositions were measured in wells M5, M26, M35 and M102, which represent a range of depths (1270-2000 m) and temperatures (275-330 degrees C) in the field. In order to simulate the production of the geothermal hydrocarbons, gases were collected from the pyrolysis of lignite in the laboratory. This lignite was obtained from a well which sampled rock strata which are identical to those occurring in the field, but which have experienced much lower subsurface temperatures. In both the well and the laboratory observations, high-temperature environments favored higher relative concentrations of methane, ethane and benzene and generally higher delta 13C-values in the individual hydrocarbons. The best correlation between the laboratory and well data is obtained when laboratory-produced gases from experiments conducted at lower (400 degrees C) and higher (600 degrees C) temperatures are mixed. This improved correlation suggests that the wells are sampling hydrocarbons produced from a spectrum of depths and temperatures in the sediments.

  13. Bimodal distribution of risk for childhood obesity in urban Baja California, Mexico.

    Science.gov (United States)

    Wojcicki, Janet M; Jimenez-Cruz, Arturo; Bacardi-Gascon, Montserrat; Schwartz, Norah; Heyman, Melvin B

    2012-08-01

    In Mexico, higher socioeconomic status (SES) has been found to be associated with increased risk for obesity in children. Within developed urban areas, however, there may be increased risk among lower SES children. Students in grades 4-6 from five public schools in Tijuana and Tecate, Mexico, were interviewed and weight, height and waist circumference (WC) measurements were taken. Interviews consisted of questions on food frequency, food insecurity, acculturation, physical activity and lifestyle practices. Multivariate logistic models were used to assess risk factors for obesity (having a body mass index [BMI] ≥95th percentile) and abdominal obesity (a WC >90th percentile) using Stata 11.0. Five hundred and ninety students were enrolled; 43.7% were overweight or obese, and 24.3% were obese and 20.2% had abdominal obesity. Independent risk factors for obesity included watching TV in English (odds ratio [OR] 1.60, 95% confidence interval [CI] 1.06-2.41) and perceived child food insecurity (OR 1.57, 95% CI 1.05-2.36). Decreased risk for obesity was associated with female sex (OR 0.64, 95% CI 0.43-0.96), as was regular multivitamin use (OR 0.63, 95% CI 0.42-0.94). Risk obesity was also decreased with increased taco consumption (≥1×/week; OR 0.64, 95% CI 0.43-0.96). Independent risk factors for abdominal obesity included playing video games ≥1×/week (OR 1.18, 95% CI 1.11-2.96) and older age group (10-11 years, OR 2.47, 95% CI 1.29-4.73 and ≥12 years, OR 2.21, 95% CI 1.09-4.49). Increased consumption of tacos was also associated with decreased risk for abdominal obesity (≥1×/week; OR 0.56, 95% CI 0.40-1.00). We found a bimodal distribution for risk of obesity and abdominal obesity in school aged children on the Mexican border with the United States. Increased risk for obesity and abdominal obesity were associated with factors indicative of lower and higher SES including watching TV in English, increased video game playing and perceived food insecurity. Increased consumption of tacos (≥1×/week) was associated with decreased risk, possibly suggesting an association with children from middle income families. Regular multivitamin use was protective and future studies may focus on micronutrient supplementation as a means to prevent obesity in children or further investigate factors associated with vitamin use. Additionally, future studies need to examine the processes of acculturation on both sides of the US-Mexican border that contribute to increased risk for obesity in children in relation to SES. PMID:22669641

  14. Bimodal Distribution of Risk for Childhood Obesity in Urban Baja California, Mexico

    OpenAIRE

    Wojcicki, Janet M.; Jimenez-Cruz, Arturo; Bacardi-Gascon, Montserrat; Schwartz, Norah; Heyman, Melvin B.

    2012-01-01

    In Mexico, higher socioeconomic status (SES) has been found to be associated with increased risk for obesity in children. Within developed urban areas, however, there may be increased risk among lower SES children. Students in grades 4–6 from five public schools in Tijuana and Tecate, Mexico, were interviewed and weight, height and waist circumference (WC) measurements were taken. Interviews consisted of questions on food frequency, food insecurity, acculturation, physical activity and lifest...

  15. Model of the heat source of the Cerro Prieto magma-hydrothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Williams, A.E.; Schiffman, P.; Cox, B.

    1982-08-10

    Earlier studies at Cerro Prieto by UCR have led to the development of a qualitative model for field flow in the geothermal system before it was drilled and perturbed by production. Current efforts are directed towards numerical modelling of heat and mass transfer in the system in this undisturbed state. A two-dimensional model assumes that the heat sources were a single basalt/gabbro intrusion which provided heat to the system as it cooled. After compiling various information on the physical properties of the reservoir, the enthalpy contained in two 1cm thick section across the reservoir orthogonal to each other was calculated. Next various shapes, sizes and depths for the intrusion as initial conditions and boundary conditions for the calculation of heat transfer were considered. A family of numerical models which so far gives the best matches to the conditions observed in the field today have in common a funnel-shaped intrusion with a top 4km wide emplaced at a depth of 5km some 30,000 to 50,000 years ago, providing heat to the geothermal system. Numerical modelling is still in progress. Although none of the models so far computed may be a perfect match for the thermal history of the reservoir, they all indicate that the intrusive heat source is young, close and large.

  16. Carbon isotope geochemistry of hydrocarbons in the Cerro Prieto geothermal field, Baja California Norte, Mexico.

    Science.gov (United States)

    Des Marais, D J; Stallard, M L; Nehring, N L; Truesdell, A H

    1988-01-01

    Hydrocarbon abundances and stable-isotopic compositions were measured in wells M5, M26, M35 and M102, which represent a range of depths (1270-2000 m) and temperatures (275-330 degrees C) in the field. In order to simulate the production of the geothermal hydrocarbons, gases were collected from the pyrolysis of lignite in the laboratory. This lignite was obtained from a well which sampled rock strata which are identical to those occurring in the field, but which have experienced much lower subsurface temperatures. In both the well and the laboratory observations, high-temperature environments favored higher relative concentrations of methane, ethane and benzene and generally higher delta 13C-values in the individual hydrocarbons. The best correlation between the laboratory and well data is obtained when laboratory-produced gases from experiments conducted at lower (400 degrees C) and higher (600 degrees C) temperatures are mixed. This improved correlation suggests that the wells are sampling hydrocarbons produced from a spectrum of depths and temperatures in the sediments.

  17. Numerical Wind Modeling for the San Pedro Mártir Sierra in Baja California

    Directory of Open Access Journals (Sweden)

    K. Vogiatzis

    2004-01-01

    Full Text Available Presentamos la simulación numérica del viento en la Sierra de San Pedro Mártir para realizar una evaluación preliminar de los posibles sitios donde instalar nuevos telescopios. Como criterio inicial, se eligieron los puntos más altos de la sierra, pero a la vez de fácil acceso. Se presentan la altura de la capa límite y el efecto de la turbulencia en los diferentes sitios para velocidades y direcciones del viento típicas.

  18. Proceedings: third symposium on the Cerro Prieto geothermal field, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    These proceedings include both English and Spanish versions of each paper presented at the symposium. Illustrations and tables, which have been placed between the two versions, include captions in both languages. Forty-one papers are included. Five papers were indexed for EDB previously. Separate abstracts were prepared for thirty-three papers and three were listed by title.

  19. Subsidence monitoring with geotechnical instruments in the Mexicali Valley, Baja California, Mexico

    Science.gov (United States)

    Glowacka, E.; Sarychikhina, O.; Márquez Ramírez, V. H.; Robles, B.; Nava, F. A.; Farfán, F.; García Arthur, M. A.

    2015-11-01

    The Mexicali Valley (northwestern Mexico), situated in the southern part of the San Andreas fault system, is an area with high tectonic deformation, recent volcanism, and active seismicity. Since 1973, fluid extraction, from the 1500-3000 m depth range, at the Cerro Prieto Geothermal Field (CPGF), has influenced deformation in the Mexicali Valley area, accelerating the subsidence and causing slip along the traces of tectonic faults that limit the subsidence area. Detailed field mapping done since 1989 (González et al., 1998; Glowacka et al., 2005; Suárez-Vidal et al., 2008) in the vicinity of the CPGF shows that many subsidence induced fractures, fissures, collapse features, small grabens, and fresh scarps are related to the known tectonic faults. Subsidence and fault rupture are causing damage to infrastructure, such as roads, railroad tracks, irrigation channels, and agricultural fields. Since 1996, geotechnical instruments installed by CICESE (Centro de Investigación Ciéntifica y de Educación Superior de Ensenada, B.C.) have operated in the Mexicali Valley, for continuous recording of deformation phenomena. Instruments are installed over or very close to the affected faults. To date, the network includes four crackmeters and eight tiltmeters; all instruments have sampling intervals in the 1 to 20 min range. Instrumental records typically show continuous creep, episodic slip events related mainly to the subsidence process, and coseismic slip discontinuities (Glowacka et al., 1999, 2005, 2010; Sarychikhina et al., 2015). The area has also been monitored by levelling surveys every few years and, since the 1990's by studies based on DInSAR data (Carnec and Fabriol, 1999; Hansen, 2001; Sarychikhina et al., 2011). In this work we use data from levelling, DInSAR, and geotechnical instruments records to compare the subsidence caused by anthropogenic activity and/or seismicity with slip recorded by geotechnical instruments, in an attempt to obtain more information about the process of fault slip associated with subsidence.

  20. The lambeosaurine dinosaur Magnapaulia laticaudus from the late cretaceous of Baja California, Northwestern Mexico.

    Directory of Open Access Journals (Sweden)

    Albert Prieto-Márquez

    Full Text Available The taxonomy, osteology, phylogenetic position, and historical biogeography of the lambeosaurine hadrosaurid Magnapaulia laticaudus (new combination are revised. The diagnosis of this species is amended on the basis on two autapomorphies (i.e., longest haemal arches of proximal caudal vertebrae being at least four times longer than the height of their respective centra; base of prezygapophyses in caudal vertebrae merging to form a bowl-shaped surface and a unique combination of characters (i.e., downturned cranioventral process of the maxilla; tear-shaped external naris with length/width ratio between 1.85 and 2.85; neural spines of dorsal, sacral, and proximal caudal vertebrae being at least four times the height of their respective centra. A maximum parsimony analysis supports a sister taxon relationship between M. laticaudus and Velafrons coahuilensis. Both taxa constitute a clade of southern North American lambeosaurines, which forms a sister relationship with the diverse clade of helmet-crested lambeosaurines from northern North America that includes well-known genera like Corythosaurus, Lambeosaurus, and Hypacrosaurus. According to the results of a Dispersal-Vicariance analysis, southern North American lambeosaurines split from the northern forms via vicariance from a common ancestor that lived in both the northern and southern regions of the continent.

  1. Design and Optimisation of Sae Mini Baja Chassis

    Directory of Open Access Journals (Sweden)

    P. Anjani Devi

    2014-09-01

    Full Text Available The objective is to design and develop the roll cage for All - Terrain Vehicle accordance with the rulebook of BAJA 2014 given by SAE. The frame of the SAE Baja vehicle needs to be lightweight and structurally sound to be competitive but still protect the driver. The vehicle needs to traverse all types of off-road conditions including large rocks, downed logs, mud holes, steep inclines, jumps and off camber turns. During the competition events there is significant risk of rollovers, falling from steep ledges, collisions with stationary objects, or impacts from other vehicles. Material for the roll cage is selected based on strength and availability. A software model is prepared in Pro-engineer. Later the design is tested against all modes of failure by conducting various simulations and stress analysis with the aid of ANSYS 13. Based on the result obtained from these tests the design is modified accordingly. A target of 2 is set for Yield Factor of Safety.

  2. California Air Basins

    Data.gov (United States)

    California Department of Resources — Air ResourcesCalifornia Air Resources BoardThe following datasets are from the California Air Resources Board: * arb_california_airbasins - California Air BasinsThe...

  3. Talla baja y enfermedades raras Low height and rare diseases

    Directory of Open Access Journals (Sweden)

    M.J. Chueca

    2008-01-01

    Full Text Available La baja talla constituye el primer motivo de consulta en endocrinología pediátrica. En un alto porcentaje su etiología es clara y obedece fundamentalmente a variantes de normalidad. Sin embargo, en aproximadamente un 20% esta baja talla es patológica y obliga a estudios exhaustivos. La asociación de enfermedades raras (ER con talla baja es altamente frecuente. En este trabajo repasamos las etiologías de la baja talla en enfermedades raras, describiendo: - las formas genéticas de la hormona de crecimiento (GH bien sean aisladas o asociadas a malformaciones de la línea media u otras. - aquellas de gran importancia por su repercusión clínica como el Síndrome de Turner, Síndrome de Noonan y el Síndrome de Willi-Prader. - Las frecuentes displasias óseas, con alteración genética en algunos casos para el gen SHOX, situado en el brazo corto del cromosoma Xp. La importancia de estos diagnósticos radica en la posibilidad de hacer un tratamiento precoz y eficaz, en algunos de ellos, con GH. En conclusión, el diagnóstico de enfermedades raras con baja talla es un reto actual y habitual en endocrinología pediátrica por los grandes avances de la genética molecular y la posibilidad de tratamiento en algunas de ellas. Implica siempre un abordaje multidisciplinario por la asociación frecuente de patología que presenta y a su vez, ofrece la posibilidad de realizar el oportuno consejo genético.Low stature is the main reason of consultation in paediatric endocrinology. In a high percentage of cases, its etiology is clear and fundamentally answers to variants of normality. However, in approximately 20% of cases low stature is pathological and requires exhaustive studies. The association of rare diseases (RD with low height is very frequent. In this article we review the etiology of low height, describing: - The genetic forms of the growth hormone (GH, whether isolated or associated with malformations of the average line or others. - Those

  4. La piraterie sur le web

    CERN Multimedia

    2002-01-01

    Les échanges de toutes sortes sont facilités à l'extrême par le web: des forums, des vidéoconférences, le commerce à distance, ou tout simplement la célérité des courriers électroniques ou la convivialité des chats, tout cela participe de la société de communication. Une certaine partie du monde découvre le nouvel horizon des échanges quasi instantanés, mais... les transactions sur le web sont-elles vraiment s res?

  5. Turkey vulture and California condor

    Science.gov (United States)

    Pattee, O.H.; Wilbur, S.R.

    1989-01-01

    Populations of turkey vultures in the western states appear stable, with no evidence of recent significant changes in distribution. Turkey vultures occupy a variety of habitats, nest in diverse situations and utilize a wide variety of carrion. Consequently, no particular limiting factor is likely to have a major effect on the total population. California condor numbers, in contrast, have continued to decline. With the capture of the last wild bird in 1987, the species has been extirpated from the wild. Reestablishment will depend on production and introduction of captive-reared birds, hopefully within the next 10 years. In the 18th century, condors inhabited areas along the Pacific coast from British Columbia to Baja California. Since 1950, the range has been restricted to a six county area adjacent to the southern San Joaquin Valley of California. Within this area, there appears to be no shortage of suitable nest sites; all recently used nest sites are within federally-controlled lands. Suitable foraging grounds have continued to diminish and are now largely limited to private rangelands and some Bureau of Land Management rangelands within the foothills of the San Joaquin Valley. Only these areas continue to supply the large mammal carcasses that the California condor needs for survival. The habitat of the condor is subject to a variety of land use practices and development pressures. Excessive mortality, coupled with low reproductive potential, continues to threaten the recovery of the species. Development of management practices to reduce mortality, particularly those that are contaminant-related, and of a preserve design to insure adequate habitat for the reintroduced population are still necessary for eventual recovery of the species.

  6. Regards sur le Mozambique contemporain

    Directory of Open Access Journals (Sweden)

    Fabrice Folio

    2008-12-01

    Full Text Available Cet article esquisse un état des lieux géographique de la république du Mozambique. L’organisation spatiale de ce pays s’inscrit à la fois dans des mutations en cours et dans un héritage complexe. Une approche multiscalaire permet d’en rendre compte tout en recourant à la dimension géohistorique. L’influence d’enjeux et d’acteurs extérieurs sur l’aménagement de cet espace est prégnante. Les réalités spatiales et les logiques socio-économiques en cours peuvent en témoigner, que ce soit la forme singulière de ce pays ou encore le hiatus croissance/développement observé sur place. Les lignes de force originales, inscrites sur l’espace mozambicain, associent en fait des « pénétrantes » transnationales couplées à une excentration historique de sa première ville et de nouveaux pré-carrés dynamiques, inscrits dans la mondialisation, dont il faudra questionner la cohérence sociale et territoriale.The aim of this article is to draw out the geographical broad lines of the republic of Mozambique. The country’s spatial organisation is part of the present mutations as well as its complex heritages. Different scales will be considered. Moreover, we will point out both the historical and geographical background. The paper will try to demonstrate that lots of outer stakes as well as external actors have played a major role on the spatial reality of Mozambique. The contemporaneous spatial and socio-economical realities can attest to this point, such as the specific physiognomy of this territory or the gap between national growth and social development. Finally, the spatial Mozambican singularities display several internal “corridors” connected to foreign countries, the localisation of the capital-city, Maputo, at the extreme south periphery of the country and new strategic areas linked to globalisation. The social and spatial coherence of the latter will be issued.

  7. Causas de la baja productividad del sector petrolero y como superarlas: El caso de Ecuador

    OpenAIRE

    Ramón Espinasa

    2007-01-01

    En Ecuador es conspicua la baja productividad del Sector Petrolero dada la base de reservas del país. El presente ensayo explora las causas de esta baja productividad y plantea medidas para aumentarla en el corto y mediano plazos. El trabajo se divide en tres capítulos. El primero investiga cuáles son las causas de este pobre desempeño y baja productividad del sector petrolero de Ecuador. El segundo describe cómo ha evolucionado el marco institucional del sector petrolero hasta la situación a...

  8. Experiments with the SUR 100 training reactor

    International Nuclear Information System (INIS)

    This paper contains a compilation of various experiments using the SUR - 100 reactor for training purposes, which have been widly proved in practical work at the School for Nuclear Technology of the Karlsruhe Research Center. (orig.)

  9. Analisa Laju Korosi Pada Pelat Baja Karbon Dengan Variasi Ketebalan Coating

    OpenAIRE

    Yudha Kurniawan Afandi; Irfan Syarif Arief; Amiadji Amiadji

    2015-01-01

    Baja karbon rendah adalah baja yang paling banyak digunakan sebagai bahan pembuatan kapal. Sebagai moda transportasi yang beroperasi pada lingkungan laut yang korosif, maka diperlukan suatu perlindungan coating agar korosi yang terjadi bisa diperkecil. Pada pengujian ini, coating sengaja divariasikan ketebalannya. Hal ini mengacu pada tidak meratanya proses coating pada pelat lambung kapal, dikarenakan pengerjaan coating dilakukan secara manual dengan area yang dicat cukup luas. Sehingga kemu...

  10. Perencanaan Bangunan Komposit Baja-Beton Bertingkat Tahan Gempa Sesuai Peta Gempa 2010

    OpenAIRE

    Amin, Nasrul

    2011-01-01

    Perkembangan teknologi saat ini juga berimbas pada dunia konstruksi yang juga mengalami kemajuan yang cukup drastis terutama di bidang desain. Kayu dan beton yang selama ini digunakan penuh dalam setiap pembangunan gedung kini sudah mulai beralih menggunakan material baja. Karena diharapkan dengan menggunakan material baja ini dapat mengurangi terciptanya sampah-sampah konstruksi yang selama ini masih menjadi masalah bagi lingkungan. sebagai hasilnya terciptalah berbagai met...

  11. Studi Respon Seismik Penggunaan Steel Slit Damper (SSD pada Portal Baja

    Directory of Open Access Journals (Sweden)

    Lisa Ika Arumsari

    2012-09-01

    Full Text Available Salah satu metode yang dapat digunakan untuk mengurangi dampak dari beban gempa terhadap portal baja adalah menggunakan peredam. Steel Slit Damper (SSD adalah salah satu jenis peredam yang dibuat dari sejumlah pelat baja lunak berbentuk segi-4 yang dimodelkan sebagai pegas-pegas yang disusun secara seri. Energi akibat gempa disalurkan melalui strip-strip damper yang mudah meleleh ketika perangkat mengalami deformasi inelastis siklik. SSD mendisipasi energi melalui pembentukan sendi plastis atau pelelehan pelat damper. Pada penelitian ini dilakukan analisa respon seismik Steel Slit Damper (SSD pada portal baja 1 lantai yang menerima beban lateral berupa beban gempa, dengan membandingkan portal baja konvensional, portal baja inverted-v, dan portal baja dengan SSD. Hasil analisa menunjukkan bahwa gaya geser, gaya normal, dan momen yang dihasikan portal dengan SSD lebih kecil hingga 80,49% dari gaya-gaya yang dihasilkan portal konvensional, tetapi gaya-gaya tersebut masih lebih besar daripada yang dihasilkan portal inverted-V. Portal dengan SSD dapat memperkecil simpangan sebesar 94,12% pada portal konvensional dan sebesar 33,33% pada portal bracing inverted-v. Hasil penelitian juga menunjukkan bahwa portal SSD memiliki daktilitas 105,85% lebih tinggi dari portal konvensional dan 298,67% lebih tinggi dari portal bracing inverted-v

  12. 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.

  13. California State Waters Map Series: offshore of San Gregorio, California

    Science.gov (United States)

    Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Watt, Janet T.; Golden, Nadine E.; Endris, Charles A.; Phillips, Eleyne L.; Hartwell, Stephen R.; Johnson, Samuel Y.; Kvitek, Rikk G.; Erdey, Mercedes D.; Bretz, Carrie K.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Dieter, Bryan E.; Chin, John L.; Cochran, Susan A.; Cochrane, Guy R.; Cochran, Susan A.

    2014-01-01

    the northern and southern parts of the map area are the result of right-lateral motion on strands of the San Gregorio Fault system. In the south, headlands near Pescadero Point have been uplifted by motion along the west strand of the San Gregorio Fault (also called the Frijoles Fault), which separates rocks of the Pigeon Point Formation south of the fault from rocks of the Purisima Formation north of the fault. The regional uplift in this map area has caused relatively shallow water depths within California's State Waters and, thus, little accommodation space for sediment accumulation. Sediment is observed offshore in the central part of the map area, in the shelter of the headlands north of the east strand of the San Gregorio Fault (also called the Coastways Fault) around Miramontes Point (about 5 km north of the map area) and also on the outer half of the California's State Waters shelf in the south where depths exceed 40 m. Sediment in the outer shelf of California's State Waters is rippled, indicating some mobility. The Offshore of San Gregorio map area lies within the cold-temperate biogeographic zone that is called either the "Oregonian province" or the "northern California ecoregion." This biogeographic province is maintained by the long-term stability of the southward-flowing California Current, an eastern limb of the North Pacific subtropical gyre that flows from Oregon to Baja California. At its midpoint off central California, the California Current transports subarctic surface (0–500 m deep) waters southward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. The south end of the Oregonian province is at Point Conception (about 350 km south of the map area), although its associated phylogeographic group of marine fauna may extend beyond to the area offshore of Los Angeles in southern California. The ocean off of central California has experienced a warming

  14. Low Frequency Waves Through the Gulf of California: Observations and Models

    Science.gov (United States)

    Flores-Morales, A. L.; Pares-Sierra, A.

    2007-05-01

    Long time series of sea surface temperature and surface height along the Mexican Pacific coast show that propagating coastal Kelvin waves, some cases propagate to the interior of the Gulf of California, while in some other cases they completely skip the gulf and the waves propagate through the gulf mouth to the western side of the peninsula de Baja California and to the north. Using satellite observations to identified events and a combination of numerical (ROMS) and analytical model, we investigate this phenomena focusing on discerning the set of conditions (mainly intensity and frequency of the waves) that determine which of these two main outcomes develops. Preliminary results are presented.

  15. Assessing the geologic and climatic forcing of biodiversity and evolution surrounding the Gulf of California

    Science.gov (United States)

    Dolby, Greer; Bennett, Scott E K.; Lira-Noriega, Andres; Wilder, Benjamin T.; Munguia-Vega, Adrian

    2015-01-01

    For almost a century the Baja California peninsula (Peninsula), Gulf of California (Gulf), and broader Sonoran Desert region (figure 1) have drawn geologists and biologists alike to study its unique physical and evolutionary processes (e.g., Wittich 1920; Darton 1921; Nelson 1921; Johnston 1924; Beal 1948; Durham and Allison 1960). The challenge remains to untangle the long, intricate, and at times enigmatic geological and climatological histories that have shaped the high levels of endemism and biodiversity observed in the region today (Van Devender 1990; Grismer 2000; Riddle et al. 2000).

  16. California Political Districts

    Data.gov (United States)

    California Department of Resources — This is a series of district layers pertaining to California'spolitical districts, that are derived from the California State Senateand State Assembly information....

  17. Huasteca 200, variedad de soya de baja sensibilidad al fotoperiodo corto para el trópico de México Huasteca 200, soybean cultivar less sensitive to short photoperiod for the Mexican Tropic

    Directory of Open Access Journals (Sweden)

    Nicolás Maldonado Moreno

    2010-12-01

    Full Text Available Para los ambientes tropicales o de días cortos, se requieren variedades con periodo juvenil largo o baja sensibilidad al fotoperiodo corto para garantizar un crecimiento de planta adecuado y un potencial de rendimiento aceptable. Huasteca 200 es una variedad que tiene baja sensibilidad al fotoperiodo corto del trópico, por lo que tiene una excelente adaptación en las siembras "tardías" del verano. Florece a 52 días después de la siembra, las plantas alcanzan una altura de 109 cm, tiene un ciclo de 118 días. Es resistente a las enfermedades y plagas presentes en el sur de Tamaulipas y otras regiones del trópico mexicano. El rendimiento promedio de varios ensayos fue de 2 160.4 kg ha-1, 8% superior al del cultivar Tapachula 86. Está adaptada a las regiones tropicales de tierras bajas con clima húmedo y subhúmedo con promedio anual de precipitaciones de 800 a 1 000 mm y temperatura promedio de 25 a 27 ° C.For tropical or short days environments, cultivar with long juvenile period or low sensitivity to short photoperiod are required to ensure proper plant growth and acceptable yield potential. Huasteca 200 is a cultivar that has low sensitivity to tropics short photoperiod so it has an excellent adaptation in "late" summer sowings. Flowering occurs 52 days after sowing; their plants reach 109 cm height. Has a cycle of 118 days. It is resistant to diseases and pests in southern Tamaulipas and other regions of Mexican tropic. The average yield of several trials was 2 160.4 kg ha-1, 8% superior to that of cultivar Tapachula 86. Is adapted to tropical lowland regions with humid and subhumid climate with average annual rainfall from 800 to 1 000 mm, and average temperature from 25 to 27 °C.

  18. El volcanismo del Terciario superior del sur de Mendoza

    Directory of Open Access Journals (Sweden)

    F. E. Nullo

    2002-06-01

    Full Text Available Se describe por primera vez la petrografía y geoquímica de unidades volcánicas terciarias del sur de la provincia de Mendoza. Se analizan la nomenclatura estratigráfica y sus edades, estableciéndose una secuencia de eventos magmáticos ocurridos durante el Neógeno, comenzando con la evolución de un retro-arco, seguido por un arco magmático más joven. Se intenta respetar la nomenclatura estratigráfica existente, sin embargo, la definición de unidades se ha realizado sobre la base de las edades radimétricas y sus edades de cristalización, más sobre sus características petrográficas. La actividad magmática se extiende desde el Oligoceno superior al Mioceno superior, correspondiendo a el Ciclo Eruptivo Molle y el Ciclo Eruptivo Huincán, y comenzó con un episodio magmático basáltico inicial (CEM. Esta actividad se generó en la corteza inferior dominada por la concentración de gabros, dioritas y rocas híbridas (granulitas máficas. Debido a un engrosamiento de la corteza como consecuencia de la actividad tectónica durante Mioceno superior o por el estancamiento de magmas o por la combinación de ambos procesos, la formación de granulitas granatíferas resultó un producto distintivo de la corteza inferior. Con el desarrollo del arco magmático (CEH en el Mioceno superior, los magmas ascendieron desde la fuente mantélica, encontrándose con una corteza inferior granatífera, perdiendo capacidad de ascenso por falta de contraste de densidades, produciéndose una fusión extendida, la homogeinización y el ascenso, en equilibrio con la corteza baja, proceso que caracteriza el volcanismo de un arco magmático.

  19. Criterios geológico-hidrológicos para recomendaciones del uso de suelo en zonas conurbadas sujetas a afectaciones por lluvias intensas. Caso de estudio: sur de la ciudad de Tuxtla Gutiérrez, Chiapas

    OpenAIRE

    Gloria Espíritu Tlatempa

    2013-01-01

    Actualmente en la zona conurbana sur de la ciudad de Tuxtla Gutiérrez se manifiestan movimientos geológicos en donde la urbanización promueve su propia vulnerabilidad principalmente ante lluvias intensas provocadas por fenómenos hidrometeorológicos como tormentas tropicales y huracanes, e incluso de lluvias ordinarias, impactando además a otras partes bajas de la ciudad. Este trabajo determina zonas potencialmente activas e inactivas y su vulnerabilidad física en cuatro cuencas a escala 1:20 ...

  20. 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.

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

    OpenAIRE

    Garcia Rabago, Horacio; Sahagun Flores, Jose Ernesto; Ruiz Gomez, Alfonso; Sanchez Ureña, Gustavo Manuel; Tirado Vargas, Juan Carlos; Gonzalez Gamez, Jaime Guillermo

    2012-01-01

    Objetivo El propósito del estudio fue Identificar los factores de riesgo más 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 diagnóstico de intento de suicidio, hospitalizados en una unidad psiquiátrica, divididos en dos grupos: uno pacientes con tentativa suicida de baja letalidad y otro con te...

  2. Binational Studies Leading to an Ecosystems-based Management Strategy for Common Thresher Shark in the Southern California Bight (SCB).

    OpenAIRE

    Graham, Jeffrey B.; Cartamil, Daniel P.

    2010-01-01

    Survey of the Mexican SCB Sector Artisanal and Commercial Shark Fisheries Hypotheses: a) Common thresher sharks represent a substantial portion of the catch of artisanal and commercial shark fisheries in the Mexican SCB sector. b) Exploitation of common threshers and other elasmobranchs is important to the economy of northern Baja California and, by extension, is directly linked to U.S. fishery management. Mexican SCB Longlining Survey Hypotheses: a) Thresher shark nursery grounds extend sout...

  3. Source Functions and Path Effects from Earthquakes in the Farallon Transform Fault Region, Gulf of California, Mexico that Occurred on October 2013

    Science.gov (United States)

    Castro, Raúl R.; Stock, Joann M.; Hauksson, Egill; Clayton, Robert W.

    2016-07-01

    We determined source spectral functions, Q and site effects using regional records of body waves from the October 19, 2013 (M w = 6.6) earthquake and eight aftershocks located 90 km east of Loreto, Baja California Sur, Mexico. We also analyzed records from a foreshock with magnitude 3.3 that occurred 47 days before the mainshock. The epicenters of this sequence are located in the south-central region of the Gulf of California (GoC) near and on the Farallon transform fault. This is one of the most active regions of the GoC, where most of the large earthquakes have strike-slip mechanisms. Based on the distribution of the aftershocks, the rupture propagated northwest with a rupture length of approximately 27 km. We calculated 3-component P- and S-wave spectra from ten events recorded by eleven stations of the Broadband Seismological Network of the GoC (RESBAN). These stations are located around the GoC and provide good azimuthal coverage (the average station gap is 39°). The spectral records were corrected for site effects, which were estimated calculating average spectral ratios between horizontal and vertical components (HVSR method). The site-corrected spectra were then inverted to determine the source functions and to estimate the attenuation quality factor Q. The values of Q resulting from the spectral inversion can be approximated by the relations Q_{P} = 48.1 ± 1.1 f^{0.88 ± 0.04} and Q_{S} = 135.4 ± 1.1 f^{0.58 ± 0.03} and are consistent with previous estimates reported by Vidales-Basurto et al. (Bull Seism Soc Am 104:2027-2042, 2014) for the south-central GoC. The stress drop estimates, obtained using the ω2 model, are below 1.7 MPa, with the highest stress drops determined for the mainshock and the aftershocks located in the ridge zone. We used the values of Q obtained to recalculate source and site effects with a different spectral inversion scheme. We found that sites with low S-wave amplification also tend to have low P-wave amplification, except

  4. Isolation by distance among California sea lion populations in Mexico: redefining management stocks.

    Science.gov (United States)

    González-Suárez, M; Flatz, R; Aurioles-Gamboa, D; Hedrick, P W; Gerber, L R

    2009-03-01

    Understanding the spatial structure of a population is critical for effective assessment and management. However, direct observation of spatial dynamics is generally difficult, particularly for marine mammals. California sea lions (Zalophus californianus) are polygynous pinnipeds distributed along the Pacific coast of North America. The species' range has been subdivided into three management stocks based on differences in mitochondrial DNA, but to date no studies have considered nuclear genetic variation, and thus we lack a comprehensive understanding of gene flow patterns among sea lion colonies. In light of recent population declines in the Gulf of California, Mexico, it is important to understand spatial structure to determine if declining sea lion colonies are genetically isolated from others. To define population subdivision and identify sex biases in gene flow, we analysed a 355-bp sequence of the mitochondrial DNA control region and 10 polymorphic microsatellite loci from 355 tissue samples collected from six colonies distributed along Mexican waters. Using a novel approach to estimate sex biases in gene flow, we found that male sea lions disperse on average 6.75 times more frequently than females. Analyses of population subdivision strongly suggest a pattern of isolation by distance among colonies and challenge current stock definitions. Based on these results, we propose an alternative classification that identifies three Mexican management units: Upper Gulf of California, Southern Baja Peninsula, and Upper Pacific Coast of Baja. This revised classification should be considered in future assessment and management of California sea lion populations in Mexican waters. PMID:19226320

  5. Enquêtes sur les soucoupes volantes

    OpenAIRE

    Lagrange, Pierre

    2007-01-01

    La dispute autour du mot « preuve » se réduit à une question : Qu'est-ce qui constitue une preuve ? Faut-il qu'un ovni atterrisse à l'entrée du Pentagone, près des bureaux des chefs d'État-Major ? Ou bien est-ce une preuve quand une station de radar au sol détecte un ovni, envoie un jet l'intercepter, que le pilote du jet le voit et le suit sur son radar pour finir par le voir disparaître à une vitesse phénoménale ? Ou est-ce une preuve quand un pilote tire sur un ovni et maintient son histoi...

  6. Mise en oeuvre du krigeage sur arbre.

    OpenAIRE

    Polus, Edwige; de Fouquet, Chantal

    2010-01-01

    Un modèle de fonctions aléatoires définies sur une topologie d'arbre (de Fouquet & Bernard-Michel, 2006) a été développé pour l'estimation de concentrations le long d'un réseau hydrographique. Le principe consiste à décomposer le réseau en filets élémentaires joignant chaque " source " à " l'exutoire ". La concentration Z au point x s'exprime comme une combinaison linéaire Z(x)=$\\Sum$ wiYi(x) de variables aléatoires élémentaires Yi définies sur ces filets, dont les coefficients wi dépendent d...

  7. Roles des contraintes sur les signaux de transition de phase

    CERN Document Server

    Regnard, V

    2003-01-01

    Ce papier presente la notion de signal de transition de phase pour un systeme de taille finie. Il se concentre sur le role des contraintes physiques sur ces signaux et la robustesse quant au changement d'ensemble statistique. Des resultats obtenus avec un modele de gaz sur reseau sont presentes en analogie avec les observations effectuees en collisions d'ions lourds aux energies intermediaires.

  8. Remesas Sur-Sur: Importancia del Corredor Costa Rica-Nicaragua

    OpenAIRE

    Ricardo Monge-González; Oswald Céspedes-Torres; Juan Carlos Vargas-Aguilar

    2009-01-01

    El presente estudio, procura brindar un poco de luz en el campo del impacto de los flujos de remesas en América Latina, al estudiar la importancia relativa del corredor Costa Rica-Nicaragua (sur-sur) mediante el análisis de los resultados de una encuesta estadísticamente representativa a una muestra de hogares nicaragüenses receptores de remesas desde Costa Rica, comisionada por los autores durante el primer semestre del año 2009, así como contrastar estos resultados con aquellos de la litera...

  9. Las necesidades de información en la comunidad de vitivinicultores de la región de Baja California: una aproximación An approach to information needs of a community of winemakers in Baja California

    OpenAIRE

    Fermín López Franco

    2010-01-01

    Los vitivinicultores manifiestan necesidades de información y comportamiento informativo, pero no conocen los aspectos de este proceso. Por ejemplo, no se tiene la certeza del lugar y las fuentes de información a las que acuden a fin de llevar a cabo sus diferentes actividades como son la selección de la uva de acuerdo con la zona, la siembra, el cuidado, la cosecha, producción y comercialización de la vid, además del embotellamiento de sus productos. En este artículo se presentan algunos asp...

  10. Changes in steam production due to the reservoir conditions in Cerro Prieto, Baja California; Cambios en la produccion de vapor debido a las condiciones del yacimiento en Cerro Prieto, Baja California

    Energy Technology Data Exchange (ETDEWEB)

    Morales Cardenas, Ramon; Rodriguez Rodriguez, Marco H. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)]. E-mail: marco.rodriguez01@gfe.gob.mx

    2011-07-15

    In more than 35 years of exploitation, thermodynamic conditions have changed in the Cerro Prieto geothermal reservoir. The effects are analyzed of the changes to the reservoir and their consequences to steam production in different field zones. For steam production, the most important features of reservoir fluids are enthalpies and pressures. The evolution of these features is presented in an enthalpy-pressure diagram. Here it can be seen that some reservoir zones have almost reached abandonment conditions. [Spanish] En mas de 35 anos de explotacion el yacimiento geotermico de Cerro Prieto ha experimentado cambios en sus condiciones termodinamicas. En este trabajo se analiza el efecto de esos cambios del yacimiento y su repercusion en la produccion de vapor para las diferentes zonas en las que se ha dividido el campo. Las propiedades mas importantes del fluido en el yacimiento para la produccion de vapor son su entalpia y su presion, por lo que se presenta la evolucion de esas propiedades en un diagrama de presion-entalpia, en el que se observa que hay zonas del yacimiento que estan proximas a alcanzar condiciones de abandono.

  11. Geophysical exploration with transient electromagnetic soundings in three geothermal zones of Baja California, Mexico: Tres Virgenes, Puertecitos and Bahia Concepcion; Exploracion geofisica con sondeos electromagneticos transitorios en tres zonas geotermicas de Baja California, Mexico: Tres Virgenes, Puertecitos y Bahia Concepcion

    Energy Technology Data Exchange (ETDEWEB)

    Flores, Carlos; Vazquez, Rogelio; Gonzalez, Carlos A; Romo, Jose M; Velasco, Nector; Lopez, Addier [CICESE, Ensenada, B.C. (Mexico)

    1999-04-01

    The results obtained from transient electromagnetic soundings (TDEM) applied to three geothermal zones are briefly commented, emphasizing instead the out of contract work done by the Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE), both in the application of other geophysical techniques and the subsequent data analysis. This work includes several VLF (very low frequency) electromagnetic profiles in Bahia Concepcion and a magnetotelluric profile in Puertecitos. Regarding the data analysis, an algorithm to assess stratified models was constructed and applied to several Bahia Concepcion soundings and to the TDEM and Schlumberger data from Tres Virgenes in order to compare the resolving powers of these methods. Finally an imaging procedure based on smoothness constraints is being applied nowadays to characterize the geometry of the electric conductors under the Tres Virgenes hot springs. [Spanish] Se comentan los resultados de la aplicacion del modo de sondeo electromagnetico transitorio (TDEM) en tres zonas geotermicas, dando enfasis al trabajo realizado fuera de contrato por el Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE), tanto en la aplicacion de otras tecnicas geofisicas como en el analisis posterior de los datos. Estos trabajos comprenden el levantamiento de perfiles electromagneticos con el metodo VLF (very low frequency) en Bahia Concepcion y de un perfil magnetotelurico en Puertecitos. En relacion con analisis de los datos, se implemento un algoritmo de evaluacion de modelos estratificados, usandose en sondeos de Bahia Concepcion. Esta tecnica se aplico a los datos TDEM y Schlumberger de Tres Virgenes para comparar sus poderes de resolucion. Finalmente, un procedimiento de construccion de imagenes de resistividad, basado en condiciones de suavidad, se esta aplicando actualmente a los datos de Tres Virgenes para caracterizar la geometria de los conductores electricos bajo las manifestaciones hidrotermales.

  12. Los mitos como parte del sistema de creencias de los indígenas de Baja California

    Directory of Open Access Journals (Sweden)

    Julia Bendímez Patterson

    1991-01-01

    Full Text Available Los indígenas de la península tenían sistemas de creencias, mitos y rituales que conjuntamente se pueden definir como una religión o religiones. En este trabajo se examinan particularmente los mitos y algunos rituales como parte de la cosmovisión de los californios.

  13. New Technologies and Learning Environments: A Perspective from Formal and Non-Formal Education in Baja California, Mexico

    Science.gov (United States)

    Zamora, Julieta Lopez; Reynaga, Francisco Javier Arriaga

    2010-01-01

    This paper presents results of two research works, the first approaches non-formal education and the second addresses formal education. In both studies in-depth interview techniques were used. There were some points of convergence between them on aspects such as the implementation of learning environments and the integration of ICT. The interview…

  14. Water flowing north of the border: export agriculture and water politics in a rural community in Baja California.

    Science.gov (United States)

    Zlolniski, Christian

    2011-01-01

    Favored by neoliberal agrarian policies, the production of fresh crops for international markets has become a common strategy for economic development in Mexico and other Latin American countries. But as some scholars have argued, the global fresh produce industry in developing countries in which fresh crops are produced for consumer markets in affluent nations implies “virtual water flows,” the transfer of high volumes of water embedded in these crops across international borders. This article examines the local effects of the production of fresh produce in the San Quintín Valley in northwestern Mexico for markets in the United States. Although export agriculture has fostered economic growth and employment opportunities for indigenous farm laborers, it has also led to the overexploitation of underground finite water resources, and an alarming decline of the quantity and quality of water available for residents’ domestic use. I discuss how neoliberal water policies have further contributed to water inequalities along class and ethnic lines, the hardships settlers endure to secure access to water for their basic needs, and the political protests and social tensions water scarcity has triggered in the region. Although the production of fresh crops for international markets is promoted by organizations such as the World Bank and Inter-American Development Bank as a model for economic development, I argue that it often produces water insecurity for the poorest, threatening the UN goal of ensuring access to clean water as a universal human right. PMID:22171411

  15. Trace Elements in the Marine Sediments of the La Paz Lagoon, Baja California Peninsula, Mexico: Pollution Status in 2013.

    Science.gov (United States)

    Pérez-Tribouillier, Habacuc; Shumilin, Evgueni; Rodríguez-Figueroa, Griselda Margarita

    2015-07-01

    To determine the actual concentrations of trace elements in surface sediments from the La Paz Lagoon, as well as their associations and possible origins, 91 sediment samples were analyzed for more than 50 elements using a combination of ICP-MS and ICP-AES. The results of a principal component analysis are used to distinguish four associative groups within the elements. Natural enrichment of As, Cd and U occurs due to the supply of weathered phosphorites from the El Cien formation located to the north-west of the lagoon. Sediment quality indices for potentially toxic trace elements do not show any probable impact on the biota of the lagoon. Only the concentrations of As in 30 % of the stations and Cu in 20 % of them exceed related effect range low levels. The highest concentration of Pb (36.8 mg kg(-1)) was measured in the sediments near the City of La Paz. PMID:25773702

  16. Water flowing north of the border: export agriculture and water politics in a rural community in Baja California.

    Science.gov (United States)

    Zlolniski, Christian

    2011-01-01

    Favored by neoliberal agrarian policies, the production of fresh crops for international markets has become a common strategy for economic development in Mexico and other Latin American countries. But as some scholars have argued, the global fresh produce industry in developing countries in which fresh crops are produced for consumer markets in affluent nations implies “virtual water flows,” the transfer of high volumes of water embedded in these crops across international borders. This article examines the local effects of the production of fresh produce in the San Quintín Valley in northwestern Mexico for markets in the United States. Although export agriculture has fostered economic growth and employment opportunities for indigenous farm laborers, it has also led to the overexploitation of underground finite water resources, and an alarming decline of the quantity and quality of water available for residents’ domestic use. I discuss how neoliberal water policies have further contributed to water inequalities along class and ethnic lines, the hardships settlers endure to secure access to water for their basic needs, and the political protests and social tensions water scarcity has triggered in the region. Although the production of fresh crops for international markets is promoted by organizations such as the World Bank and Inter-American Development Bank as a model for economic development, I argue that it often produces water insecurity for the poorest, threatening the UN goal of ensuring access to clean water as a universal human right.

  17. La colonización de Baja California con mexicanos provenientes de Estados Unidos (1935-1939

    Directory of Open Access Journals (Sweden)

    Fernando Saúl Alanís Enciso

    2001-01-01

    Full Text Available La migración internacional en el espacio fronterizo México-Guatemala se ha vuelto en los últimos años de alto riesgo. En este artículo presentamos algunos resultados preliminares de un proyecto de investigación que tiene como objetivo documentar y analizar la situación de riesgo en la ruta principal que han utilizado los migrantes centroamericanos (en este caso, indocumentados de paso en la costa chiapaneca, conocida como el Soconusco, en la frontera México-Guatemala. El análisis presenta los resultados del rastreo de registros en instituciones que tienen contacto con los migrantes, de las entrevistas en profundidad y de la observación participante. Se describen algunas de estas situaciones señalándolas en los mapas de riesgo, para elaborar un registro espacial de los peligros que permita explorar de qué manera el espacio refleja la situación de riesgo que viven los migrantes y cómo contribuye al fenómeno

  18. Molecular identification of Fusarium species isolated from transgenic insect-resistant cotton plants in Mexicali valley, Baja California.

    Science.gov (United States)

    Gonzalez-Soto, T; González-Mendoza, D; Troncoso-Rojas, R; Morales-Trejo, A; Ceceña-Duran, C; Garcia-Lopez, A; Grimaldo-Juarez, O

    2015-10-02

    Cotton production in the Mexicali valley is adversely affected by wilt and root rot disease associated with Fusarium species. In the present study, we sought to isolate and identify the Fusarium species in the rhizosphere of transgenic insect-resistant cotton plants grown in the Mexicali valley. Our analyses isolated four native fungi from the rhizosphere of cotton plants, namely, T-ICA01, T-ICA03, T-ICA04, and T-ICA08. These fungal isolates were categorized as belonging to Fusarium solani using their phenotypic characteristics and ITS region sequence data. Examination of the infection index showed that T-ICA03 and T-ICA04 caused systemic colonization (90%) of seeds followed by the occurrence of radicle and coleoptile decay. In contrast, T-ICA08 strain was less pathogenic against seed tissues (40%) in comparison to the other strains isolated. Our study showed that in transgenic insect-resistant cotton the disease "Fusarium wilt" is caused by the fungus, F. solani. Future studies are necessary to characterize the F. solani populations to determine whether phenological stages might influence the genetic diversity of the fungal populations present.

  19. A structurally controlled fan-delta complex at the southern margin of the peninsular range forearc basin complex (Baja California)

    Energy Technology Data Exchange (ETDEWEB)

    Morris, W.R.; Busby-Spera, C. (Univ. of California, Santa Barbara (USA))

    1990-05-01

    A confined trunk fan delta and its structurally controlled tributary fan deltas are extremely well exposed along the southern margin of the Rosario embayment. This fan-delta complex consists of nonmarine to deep marine deposits almost continuously exposed for over 20 km in the down-paleoslope direction. Facies and stratal patterns in the fan-delta complex were controlled by local faulting, climatic variation, and eustasy, resulting in relative sea level fluctuations. Basin bathymetry and drainage patterns were controlled by a series of half-grabens that formed along north-south-trending faults that lay along the northern margin of an east-west-trending depression. Breccias were initially shed into the north-south-trending half-grabens; axial drainage systems were later established within the grabens, making up the tributary fan deltas. These tributary fan deltas fed a voluminous trunk fan delta confined to the east-west-trending depression. The trunk and tributary fan delta deposits show two major progradational to retrogradational cycles that record relative sea level fluctuations. Progradation in the shallow-marine environment is represented by conglomerate channels cut into ripple-laminated or bioturbated siltstone and HCS sandstones, overlain by conglomerate mouth bar deposits interstratified with nearshore sandstone deposits. Retrogradation in the shallow marine environment is recorded by either a vertical clastic facies transition or a clastic-carbonate facies transition. The clastic facies transition consists of nearshore sandstone deposits overlain by offshore bioturbated siltstones. The clastic-carbonate facies transition consists of the development of red algal patch reefs and rhodoliths on top of fan-delta conglomeratic lobes, mudstone and sandstone bank channel margins, or paleobasement highs. The clastic-carbonate facies transition reflects low sediment supply controlled by climatic conditions.

  20. Vino de calidad: Base de desarrollo endógeno en el Valle de Guadalupe, Baja California

    Directory of Open Access Journals (Sweden)

    Leandro Sánchez Zepeda

    2010-01-01

    Full Text Available Con información directa e indirecta obtenida en 2000 y 2005, en este artículo se analiza la organización productiva del conglomerado industrial constituido por las bodegas del Valle de Guadalupe y sus prácticas vitícolas y enológicas en la elaboración de vino tinto con un alto grado de calidad, como principal factor para desarrollar una diferenciación de producto que les permite competir a escala internacional e influir en el desarrollo económico de su entorno.

  1. Waste Management in Mexico: key variables in play . The case of the Autonomous University of Baja California

    NARCIS (Netherlands)

    C. Armijo de Vega

    2006-01-01

    textabstractSoil pollution, water pollution, excessive levels of noise and air pollution are phenomena present wherever human have congregated in appreciable numbers. This has been taking place for centuries. As the human population increases and its activities diversify the impact on the environ

  2. Curie point depth from spectral analysis of aeromagnetic data from Cerro Prieto geothermal area, Baja California, México

    Science.gov (United States)

    Espinosa-Cardeña, J. M.; Campos-Enriquez, J. O.

    2008-10-01

    Using aeromagnetic data acquired in the area from the Cerro Prieto geothermal field, we estimated the depth to the Curie point isotherm, interpreted as the base of the magnetic sources, following statistical spectral-based techniques. According to our results the Curie point isotherm is located at a depths ranging from 14 to 17 km. Our result is somewhat deeper than that obtained previously based only in 2-D and 3-D forward modeling of previous low-quality data. However, our results are supported by independent information comprising geothermal gradients, seismicity distribution in the crust, and gravity determined crustal thickness. Our results imply a high thermal gradient (ranging between 33 and 38 °C/km) and high heat flow (of about 100 mW/m 2) for the study area. The thermal regime for the area is inferred to be similar to that from the Salton trough.

  3. Fault Length Vs Fault Displacement Evaluation In The Case Of Cerro Prieto Pull-Apart Basin (Baja California, Mexico) Subsidence

    Science.gov (United States)

    Glowacka, E.; Sarychikhina, O.; Nava Pichardo, F. A.; Farfan, F.; Garcia Arthur, M. A.; Orozco, L.; Brassea, J.

    2013-05-01

    The Cerro Prieto pull-apart basin is located in the southern part of San Andreas Fault system, and is characterized by high seismicity, recent volcanism, tectonic deformation and hydrothermal activity (Lomnitz et al, 1970; Elders et al., 1984; Suárez-Vidal et al., 2008). Since the Cerro Prieto geothermal field production started, in 1973, significant subsidence increase was observed (Glowacka and Nava, 1996, Glowacka et al., 1999), and a relation between fluid extraction rate and subsidence rate has been suggested (op. cit.). Analysis of existing deformation data (Glowacka et al., 1999, 2005, Sarychikhina 2011) points to the fact that, although the extraction changes influence the subsidence rate, the tectonic faults control the spatial extent of the observed subsidence. Tectonic faults act as water barriers in the direction perpendicular to the fault, and/or separate regions with different compaction, and as effect the significant part of the subsidence is released as vertical displacement on the ground surface along fault rupture. These faults ruptures cause damages to roads and irrigation canals and water leakage. Since 1996, a network of geotechnical instruments has operated in the Mexicali Valley, for continuous recording of deformation phenomena. To date, the network (REDECVAM: Mexicali Valley Crustal Strain Measurement Array) includes two crackmeters and eight tiltmeters installed on, or very close to, the main faults; all instruments have sampling intervals in the 1 to 20 minutes range. Additionally, there are benchmarks for measuring vertical fault displacements for which readings are recorded every 3 months. Since the crackmeter measures vertical displacement on the fault at one place only, the question appears: can we use the crackmeter data to evaluate how long is the lenth of the fractured fault, and how quickly it grows, so we can know where we can expect fractures in the canals or roads? We used the Wells and Coppersmith (1994) relations between fault length and fault displacement to calculate fault length growth when displacement increase with time. We applied this relationship to the data collected, during the period 2004-2009, along the part of Cerro Prieto fault which is the SW limit of the Cerro Prieto pull-apart subsidence basin, and estimated that, for the present rate of subsidence, the length of rupture will migrate along the fault with a velocity of about 220 m/year.

  4. Monitoring and modeling land subsidence at the Cerro Prieto Geothermal Field, Baja California, Mexico, using SAR interferometry

    Science.gov (United States)

    Carnec, Claudie; Fabriol, Hubert

    Images derived from repeat-pass spaceborne interferometric synthetic aperture radar (InSAR) systems offer the possibility of mapping surface deformation of small spatial extent and monitoring its spatio-temporal evolution. A slow local subsidence has been detected at the Cerro Prieto geothermal field from images acquired by the European Space Agency remote sensing satellites ERS-1/2 between 1993 and 1997. Although agricultural activity in the area limited the investigation, interferometric monitoring revealed that the ground deformation is associated with the withdrawal of geothermal fluid and agreed with the leveling data. Modeling of the subsidence was carried out assuming elastic deformation in a half-space from simple point sources, of which five were necessary to reproduce the fringe patterns observed on the interferograms. The depths and locations of three of the sources are compatible with the location of the known reservoir. The study improves prior knowledge of the displacement field and of the mecanisms involved in the subsidence phenomenon.

  5. K?Ar dating and geological significance of clastic sediments of the Paleocene Sepultura Formation, Baja California, México

    Science.gov (United States)

    Téllez Duarte, Miguel Agustín.; López Martínez, Margarita

    2002-12-01

    At its type locality, the Paleocene Sepultura Formation consists of two members: a lower glauconitic-rich clastic section and an upper calcareous section. Three samples of authigenic glauconite pellets from two localities with good clastic sediment exposures were dated using K-Ar. At the type locality of Mesa La Sepultura, pellets from the middle of the clastic section yield a date of 60±1 Ma (weighted average of four experiments), and pellets from the top of the clastic unit give a date of 60±1 Ma (weighted average of two experiments). Pellets from the base of the section at La Mesa, 60 km distant, give a date of 59±1 Ma (one experiment). Dates obtained are in good agreement with those reported by biostratigraphy and confirm a Late Danian age. Our results differ from those reported elsewhere, in which low potassium content glauconites yield younger K-Ar ages than expected. An explanation for our observed agreement in ages could be related to the tectonic setting of forearc basins, where the low geothermal gradient prevents argon loss and reliable dates can be obtained.

  6. Persistent organic pollutants associated to water fluxes and sedimentary processes in the Colorado River delta, Baja California, México.

    Science.gov (United States)

    Lugo-Ibarra, K C; Daesslé, L W; Macías-Zamora, J V; Ramírez-Álvarez, N

    2011-09-01

    Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were studied in sediment cores from two distinctive modern channels of the Colorado River (CR) delta. Their abundance and temporal changes are associated with flood-flows from the CR across the USA-Mexico border. The CR channel is directly exposed to river flood-flows while the Hardy River (HR) is a local channel derived mainly from agricultural runoff, geothermal effluents, and treated urban wastewater. Different headwater compositions and degrees of exposure to flood-flows appear to be the factors controlling the composition of persistent organic pollutants (POPs). Enrichment of OCPs (46 ng g(-1) dwt in HR and 4.37 ng g(-1) dwt in CR) occurred during or a few years after flooding. PCB-138 (4.2 ng g(-1)dwt) is enriched in HR suggesting its origin in dielectric oils from the geothermal power plant. PCB-28 (2.1 ng g(-1)dwt) in CR may be related with atmospheric input and/or re-deposition of upstream sediments. In surficial sediments (0-3 cm), only HR exceeds international sediment quality guidelines (4,4'-DDE=8.16 ng g(-1)dwt and ΣDDT=8.34 ng g(-1)dwt).

  7. Vertical movement along the Cerro Prieto transform fault, Baja California, Mexico - a mechanism for geothermal energy renewal

    Energy Technology Data Exchange (ETDEWEB)

    Vonder Haar, S.; Noble, J.E.; Puente Cruz, I.

    1979-03-01

    Data from 53 geothermal wells to depths of 1 to 3 km on either side of the right-lateral Cerro Prieto fault, as well as geophysical data, indicate vertical displacements of this fault of 400 to 600 m. This episoidic vertical movement has offset deltaic sandstone reservoirs that are primarily at 1200 m and 1800 m depth and contain 250{sup 0} to 345{sup 0}C water. A major fracture system for convective fluid movement has been thus maintained, with production at 150 MW.

  8. Ángeles Sin Fronteras , A.C. y el proceso de deportación a Mexicali, Baja California

    Directory of Open Access Journals (Sweden)

    Tatiana E. Lara San Luis

    2014-01-01

    Full Text Available Las políticas migratorias estadounidenses que buscan a toda costa repatriar mexicanos desde los Estados Unidos no son nuevas. Contrario a lo que se pueda pensar, la deportación y repatriación hacia la frontera norte de México forman parte de un largo proceso histórico. En el caso de la frontera noroeste del país, la necesidad de dar solución a las deportaciones masivas, iniciadas luego de la década de 1990, o más bien, mejorar las condiciones en que se realizan, ha impulsado la formación de asociaciones —civiles o religiosas— destinadas a proporcionar apoyo a los connacionales recién llegados. Un ejemplo claro de ellas es la conformada por migrantes deportados y ciudadanos de la ciudad de Mexicali, Ángeles Sin Fronteras, quienes a partir de la puesta en marcha del Hotel del Migrante, proporcionan alojamiento y comida de manera gratuita a varones deportados a dicha población. Asimismo, permiten la participación activa de la comu � nidad a partir de donaciones y la interacción de los migrantes en la que se vuelve su nueva ciudad, generando mecanismos de sobrevivencia para quienes han quedado a la intemperie.

  9. Teale California shoreline

    Data.gov (United States)

    California Department of Resources — California Spatial Information System (CaSIL) is a project designed to improve access to geo-spatial and geo-spatial related data information throughout the state...

  10. California Condor Critical Habitat

    Data.gov (United States)

    California Department of Resources — These Data identify (in general) the areas where critical habitat for the California Condor occur. Critical habitat for the species consists of the following 10...

  11. The California Border Health Collaborative: A Strategy for Leading the Border to Better Health

    Directory of Open Access Journals (Sweden)

    Charles Edwards Matthews III

    2015-05-01

    Full Text Available There are hundreds of departments and organizations working on border health issues in the California/Baja California border region trying to protect and improve health without a collaborative structure that integrates jurisdictions and organizations. As a result, there is a need to effectively improve the health in the border region by coordinating these organizations to work together and benefit from each other’s best practices. The newly developed California Border Health Collaborative (CBHC can provide the leadership and collaborative culture to positively improve the health of the border region. This article aims to describe the development process of this collaborative to include key ingredients to success, the roles of mulit-level jurisdictions, and policy implications.This article describes the methods used to develop key aspects of collaborative leadership, strategic alignment and a common vision toward the building of this collective impact approach to border health. In addition, we describe the role of key local County (County of San Diego Live Well San Diego initiative, State, (California Department of Public Health- Office of Binational Border Health, Federal (US-Mexico Border Health Commission’s Leaders across Borders, Academia (e.g., University of California San Diego and San Diego State University and non-profit entities (e.g., Project Concern International, San Ysidro Health Center in forming the BHCC. Evaluating the consortium development process included a literature review of similar processes, a review of internal documents and an analysis of developmental events. To this point the CBHC has built a strong, cohesive collaborative on the U.S. side of the border. It is sharing and leveraging local expertise to address many border health issues. Even more importantly, the BHCC has reached a key stage in which it can effectively engage its Baja California, Mexico counterparts in a manner that will prove extremely powerful

  12. El clima de la selva baja caducifolia en México

    Directory of Open Access Journals (Sweden)

    Irma Trejo Vázquez

    1999-01-01

    Full Text Available Se analizan las principales características climáticas de la selva baja caducifolia mexicana. Con base en datos de 390 estaciones climatológicas, se describen elementos tales como precipitación, temperaturas, días con lluvias apreciables, meses secos y tipo de clima, con el fin de conocer el ámbito climático de este tipo de vegetación. El clima más propicio para esta selva es el cálido subhúmedo (Awo, pero se distribuye también en condiciones más secas o de mayor humedad, gracias a la combinación de factores ambientales. La variación ambiental en la que se desarrolla la selva baja influye en sus características fisonómicas y estructurales.

  13. 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.

  14. COMPTABILITÉ BASÉE SUR LA CONNAISSANCE

    OpenAIRE

    Tugui, Alexandru

    2005-01-01

    International audience Dans la future société basée sur la connaissance, les connaissances constitueront des pièces de travails habituées qui seront manipulées très facilement. La comptabilité ne fait pas exception à cette pratique et aboutira à cet état suite à la standardisation des procédures, des pratiques et des méthodes comptables, au traitement intégré des données de l'entreprise, du niveau de plus en plus performant des technologies de communication, des réalisations du domaine de ...

  15. Sur8 mediates tumorigenesis and metastasis in colorectal cancer

    Science.gov (United States)

    Lee, Young-Mi; Kaduwal, Saluja; Lee, Kug Hwa; Park, Jong-Chan; Jeong, Woo-Jeong; Choi, Kang-Yell

    2016-01-01

    Sur8, a scaffold protein of the Ras pathway, interacts with Ras and Raf and modulates the Ras-extracellular signal-regulated kinase (ERK) pathway. Here we show that Sur8 is overexpressed in established human colorectal cancer (CRC) cell lines and CRC patient tissues. Moreover, Sur8 expression is increased during liver metastasis in CRC patients. Sur8 knockdown decreases ERK and Akt activities in CRC cell lines, regardless of their K-Ras, B-Raf or PI3K mutation status. Overexpression or knockdown of Sur8 increases or decreases, respectively, the proliferation or transformation of CRC cell lines. Sur8 knockdown attenuates the migration and invasion of HCT116 CRC cells. Subcutaneous or orthotopic injection of HCT116 cells harboring a doxycycline (Dox)-mediated Sur8 knockdown system in nude mice resulted in decreased tumorigenic potential and inhibited the liver metastatic potential of HCT116 cells. Taken together, our data support the role of Sur8 as a promoter of tumorigenesis and liver metastasis in CRC through its modulation of the Ras-ERK and PI3K-Akt signaling pathways. PMID:27469030

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

    Directory of Open Access Journals (Sweden)

    Arturo García Romero

    2005-01-01

    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.

  17. Understanding Climate Change on the California Coast: Accounting for Extreme Daily Events among Long-Term Trends

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    Christopher Potter

    2014-02-01

    Full Text Available The majority of weather station records indicate that surface air temperatures have been warming in California between 1950 and 2005. Temperature data from the mid-1990s to the present were analyzed for stations on California Central Coast near Big Sur (Monterey County to better understand potential for climate change in this biologically unique region. Results showed that daily temperatures in both the winter and summer seasons have cooled the Big Sur coast, particularly after 2003. A current hypothesis is that observed coastal California cooling derives from greenhouse gas-induced regional warming of the inland Central Valley and Sierra Nevada foothill areas, resulting in stronger sustained on-shore sea-breeze flow. Closer examination of daily temperature records at a station location near the Big Sur coast revealed that, even as average monthly maximum temperatures (Tmax have decreased gradually, the number of extreme warm summer days (Tmax > 37 °C has also increased by several fold in frequency. Overall patterns in the station records since the mid-1990s indicated that diurnal temperature ranges are widening on the Big Sur coast, with markedly cooler nighttime temperatures (frequently in the wet winter season followed by slightly higher-than-average daytime temperatures, especially during the warm, dry summer season.

  18. Convective upwelling in the mantle beneath the Gulf of California.

    Science.gov (United States)

    Wang, Yun; Forsyth, Donald W; Savage, Brian

    2009-11-26

    In the past six million years, Baja California has rifted obliquely apart from North America, opening up the Gulf of California. Between transform faults, seafloor spreading and rifting is well established in several basins. Other than hotspot-dominated Iceland, the Gulf of California is the only part of the world's seafloor-spreading system that has been surrounded by enough seismometers to provide horizontal resolution of upper-mantle structure at a scale of 100 kilometres over a distance great enough to include several spreading segments. Such resolution is needed to address the long-standing debate about the relative importance of dynamic and passive upwelling in the shallow mantle beneath spreading centres. Here we use Rayleigh-wave tomography to image the shear velocity in the upper 200 kilometres or so of the mantle. Low shear velocities similar to those beneath the East Pacific Rise oceanic spreading centre underlie the entire length of the Gulf, but there are three concentrated locations of anomalously low velocities spaced about 250 kilometres apart. These anomalies are 40 to 90 kilometres beneath the surface, at which depths petrological studies indicate that extensive melting of passively upwelling mantle should begin. We interpret these seismic velocity anomalies as indicating that partial melting triggers dynamic upwelling driven by either the buoyancy of retained melt or by the reduced density of depleted mantle. PMID:19940924

  19. Recherche sur les Juifs du Maroc

    OpenAIRE

    Michel Abitbol

    2008-01-01

    Le Centre de recherche sur les Juifs du Maroc (CRJM) a été créé, en mai 1994, à Paris à l’initiative de Monsieur Robert Assaraf, après de longs mois de concertations, de discussions et d’études préalables. Il s’agit d’une institution internationale, à vocation universitaire et scientifique qui s’est fixé pour but essentiel de développer, par tous les moyens, la connaissance et l’étude de l’histoire des Juifs du Maroc. Une histoire trois fois millénaire qui remonte à la destruction du premier ...

  20. Enquête LMD sur le web

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    Colette Cauvin

    2003-02-01

    Full Text Available En relation avec la mise en place des LMD, une enquête sur le web a été entreprise en janvier 2003 afin de connaître les orientations et les choix des diverses universités délivrant des diplômes de géographie ou d’une discipline similaire. Grâce à R. Schlumberger (laboratoire Image et Ville de nombreux sites ont été consultés et analysés. Qu’elle en soit remerciée.   Cependant, la lecture des informations a été plus malaisée que prévue en raison, en particulier, de la multiplicité des langue...

  1. Retour sur l'Etat local

    OpenAIRE

    REIGNER, H; Epstein, R.

    2011-01-01

    L'Etat local, dont l'étude a été à l'origine de travaux fondateurs sur le système politico-administratif, ne figure plus parmi les objets privilégiés de la science politique française. Ce constat renvoie moins à un désintérêt des politistes qu'à la fragmentation de leurs approches et à la dilution de l'objet qui en découle. L'hypothèse de cette Section Thématique est que l'Etat local demeure un objet fécond pour la recherche, permettant en particulier d'alimenter et d'articuler deux controver...

  2. Anthropogenic and authigenic uranium in marine sediments of the central Gulf of California adjacent to the Santa Rosalía mining region

    OpenAIRE

    Shumilin, Evgueni; Rodríguez Figueroa, Griselda Margarita; Sapozhnikov, Dmitry; Sapozhnikov, Yuri; Choumiline, Konstantin

    2012-01-01

    To investigate the causes of uranium (U) enrichment in marine sediments in the eastern sector of the Gulf of California, surface sediments and sediment cores were collected adjacent to the Santa Rosalı´a copper mining region in the Baja California peninsula. Three coastal sediment cores were found to display high concentrations of U (from 54.2 ± 7.3 mg kg-1 to 110 ± 13 mg kg-1) exceeding those found in the deeper cores (1.36 ± 0.26 mg kg-1 in the Guaymas Basin to 9.31 ± 3.03 mg kg-1 in the SR...

  3. Epistemologías del Sur

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    Boaventura de Sousa Santos

    2011-01-01

    Full Text Available Es un hecho irreversible que el logos eurocéntrico ha implosionado en sus propias fuentes de desarrollo político y económico. El peligro de esta crisis es total porque abarca su hegemonía y a la humanidad y a la naturaleza. ¿De qué alternativas disponemos para superar este fin de milenio y su hecatombe? Es evidente que estamos viviendo los "tiempos póstumos" o de "filosofía finisecular" de una Modernidad que luce, por otra parte, rebasable desde otra episteme histórico-cultural que reconozca la relación ecosistema del hombre en el conjunto de la diversidad existencial de los seres vivos que pueblan este planeta. Esta otra epistemología que tiene su génesis en la Teoría Crítica y se recrea enAmérica Latina, desde el Sur, se asume desde la praxis de un logos emancipador que fractura los límites hegemónicos del "capitalismo sin fin" y del "colonialismo sin fin", ya que hace posible recuperar desde la "sociología de las emergencias", la presencia de los pueblos milenarios que han logrado la recreación de su habitat a través de una relación simbiótica directa, con los ciclos o procesos de génesis y muerte de la Madre Tierra (Pachamama. La sabiduría ancestral que porta el pensamiento de estos pueblos originarios, expresados por sus tradiciones, ritos, magias, hasta sus representaciones antropomórficas de la realidad, son síntomas de que el ocaso de la civilización, nomuere con Occidente, sino que renace desde el Sur con el "Sumak Kawsay".

  4. Kekasaran dan Morfologi Hasil Pengelasan TIG Baja Tahan Karat 316 dengan Kadar Sulfur Berbeda

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    Abdullah Shahab

    2010-01-01

    Full Text Available The presence of impurities in stainless steel can unexpectedly create a problem in welding. The difference of a small amount of impurities, from heat to heat, can induce the inconsistency in welding especially in automatic welding. This study is conducted to asses the influence of sulfur content of the steel on morphology of weld which is represented by the variation of weld pool and surface roughness of weld. The effect of sulfur on surface roughness of weld is studied in TIG welding of 316 stainless steels with different sulfur content. The influence of sulfur on the weld geometry, characterized by the ratio of depth and width of the weld (D/W, is studied in welding with various parameters. The variation of the weld geometry is conjointly studied in relation to the surface roughness of weldment. The effect of sulfur is also studied using a stationary arc with different current and duration. The variation of the diameter of a circular pool and the degree of protuberance which possibly emerged beneath the specimen is related to the sulfur content of the steel. The results of the study show the salient effect of sulfur on the surface roughness of weld. The surface roughness of steel with high sulfur content always more perturbed than that of steel with lower one; the different movement of liquid, characteristic of these two steels is posited to explain the difference. Greater degree of roughness is accompanied by a greater value of the ratio D/W. The results of the study with stationary arc show some points of a paramount importance. The effect of sulfur which hitherto considered advantageous to the formation of a weld with a higher ratio of D/W, turn out to be effective only in a specific range of welding parameters. In a different range, the weld geometry is more influenced by the arc characteristic, the anode spot. Abstract in Bahasa Indonesia: Keberadaan elemen impuritis dalam baja tahan karat seringkali tanpa diduga bisa menimbulkan masalah

  5. The Role of Rift Obliquity in Formation of the Gulf of California

    Science.gov (United States)

    Bennett, Scott Edmund Kelsey

    The Gulf of California illustrates how highly oblique rift geometries, where transform faults are kinematically linked to large-offset normal faults in adjacent pull-apart basins, enhance the ability of continental lithosphere to rupture and, ultimately, hasten the formation of new oceanic basins. The Gulf of California rift has accommodated oblique divergence of the Pacific and North America tectonic plates in northwestern Mexico since Miocene time. Due to its infancy, the rifted margins of the Gulf of California preserve a rare onshore record of early continental break-up processes from which to investigate the role of rift obliquity in strain localization. Using new high-precision paleomagnetic vectors from tectonically stable sites in north-central Baja California, I compile a paleomagnetic transect of Miocene ignimbrites across northern Baja California and Sonora that reveals the timing and distribution of dextral shear associated with inception of this oblique rift. I integrate detailed geologic mapping, basin analysis, and geochronology of pre-rift and syn-rift volcanic units to determine the timing of fault activity on Isla Tiburon, a proximal onshore exposure of the rifted North America margin, adjacent to the axis of the Gulf of California. The onset of strike-slip faulting on Isla Tiburon, ca. 8 - 7 Ma, was synchronous with the onset of transform faulting along a significant length of the nascent plate boundary within the rift. This tectonic transition coincides with a clockwise azimuthal shift in Pacific-North America relative motion that increased rift obliquity. I constrain the earliest marine conditions on southwest Isla Tiburon to ca. 6.4 - 6.0 Ma, coincident with a regional latest Miocene marine incursion in the northern proto-Gulf of California. This event likely flooded a narrow, incipient topographic depression along a ˜650 km-long portion of the latest Miocene plate boundary and corresponds in time and space with formation of a newly

  6. PREDIKSI WAKTU LAYAN BANGUNAN BETON TERHADAP KERUSAKAN AKIBAT KOROSI BAJA TULANGAN

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    Agus Santosa Sudjono

    2005-01-01

    Full Text Available Concrete is known as a porous building material, this can causes materials outside the concrete mass infiltrate into the concrete. Concrete structures constructed around the beach/seashore tend to have deterioration problems due to salt attack. This paper discusses models to predict the service life of concrete structure based on the deterioration problems. The service life of concrete structure is divided into three periods. Period I is time needed by Cl−ion to infiltrate into concrete up to the surface of the reinforcement, period II is time needed by corrosion products to fill the transition zone pores, and period III is deterioration time. The value of parameters used in the proposed equations is derived from the result of experiments. Finally, the proposed equations were evaluated by the relationship between variations of depth of concrete cover, water cement ratio (W/C and distance of structure from shore line with service life. It could be concluded that the results of the prediction is satisfactory. Abstract in Bahasa Indonesia : Beton dikenal sebagai bahan bangunan yang berpori. Sifat ini menyebabkan senyawa dari luar dapat berinfiltrasi ke dalam beton. Bangunan beton yang dibangun di sekitar daerah pantai/laut cenderung mengalami kerusakan akibat serangan garam klorida. Makalah ini mendiskusikan model untuk memprediksi waktu layan bangunan beton terhadap kerusakan akibat korosi baja tulangan. Waktu layan bangunan beton dibagi menjadi tiga periode. Periode I adalah waktu yang dibutuhkan oleh ion Cl− untuk melakukan infiltrasi sampai ke permukaan baja tulangan, Periode II adalah waktu yang dibutuhkan oleh senyawa hasil korosi untuk mengisi pori-pori yang ada di transition zone, dan Periode III adalah waktu kerusakan pada bangunan beton. Parameter-parameter yang digunakan dalam persamaan yang diusulkan ditentukan dari hasil pengukuran di laboratorium. Persamaan tersebut dievaluasi dalam hal hubungan antara variasi tebal selimut beton

  7. Cretaceous Apparent Polar Wander Relative to the Major Cratons and Displacement Estimates of Baja British Columbia

    Science.gov (United States)

    Enkin, R. J.

    2004-12-01

    When paleogeographic interpretations derived from independent observations conflict, the methods and results from each discipline come under careful scrutiny, as illustrated by the Baja British Columbia controversy. Cretaceous paleomagnetic data from a large region of the Canadian Cordillera render paleopoles which are far-sided with respect to cratonic North American poles, suggesting this region, designated Baja British Columbia, translated northward during Late Cretaceous - Paleogene time. Criticism of this interpretation based on other geological reasoning prompted me to perform new reviews of Cretaceous to Eocene paleomagnetic results from the Cordillera and from the major cratons of the globe. The global review follows the method of Besse and Courtillot (1991; 2002). One difference between our methods is that I compiled paleomagnetic results from highly studied rock units to single results to balance data weightings spatially and temporally, thus reducing the number of individual results. For the period 160 to 40 Ma, 51 poles were included compared to 92 poles by Besse and Courtillot (2002). Differences between apparent polar wander paths in their and my analyses are never significant at 95% confidence, however mean pole positions differ by up to 500 km, which is important for paleogeographic analysis. The global distribution of sampling localities and the tight clustering of the paleomagnetic poles after plate reconstruction provide invaluable confirmation of plate tectonically derived Euler rotations, the reliability of paleomagnetic remanence directions, and the geocentric dipole geometry of the geomagnetic field. My Cordilleran review shows that paleolatitudes derived from plutons and remagnetized rocks are significantly more scattered than those derived from bedded rocks. Using bedded rocks only, the paleomagnetic record shows that Baja British Columbia sat 2100 ± 500 km south of its present position with respect to cratonic North America during the

  8. Aproximación a la arquitectura popular en la Mancha Baja. El caso de Manzanares

    OpenAIRE

    Sánchez-Migallón Jiménez, Teodoro

    2015-01-01

    La tesis se compone de una primera parte introductoria, en la que se recogen las distintas opiniones y definiciones de la arquitectura “popular”, el estado de la cuestión, comentando los artículos y publicaciones realizados sobre la Mancha. La segunda parte profundiza en aspectos generales previos al análisis edificatorio central de la tesis, con los siguientes capítulos: -Estudio de los condicionantes físicos, históricos, socio-económicos y culturales de la comarca de la Mancha Baja. Acotand...

  9. Máquina refrigeradora por absorción de baja potencia

    OpenAIRE

    Villanueva Sierra, Jesus

    2004-01-01

    El objetivo de este proyecto es el diseño de una maquina refrigeradora por absorción de baja potencia, que funcione principalmente con energía solar. El diseño de esta maquina se realizará para que pueda funcionar con energía proveniente de colectores planos. Utilizaremos como fluido refrigerante “R-717 – NH3 – Amoniaco”. El cual tiene grandes ventajas con respecto al resto de refrigerantes que actualmente se utilizan, como detallaremos posteriormente. El uso final de est...

  10. El modelo de identidad del reino de Mallorca en la Baja Edad Media

    OpenAIRE

    Tudela Villalonga, Luis

    2011-01-01

    El Reino de Mallorca definió su modelo de identidad a lo largo de la Baja Edad Media. En este período, fue creando sus rasgos más característicos en diversos ámbitos como el institucional, el territorial, el judicial, o el fiscal entre otros. En el siglo XIII, la ocupación cristiana de las Islas Baleares fijó el marco regulador de convivencia de los repobladores y propició la creación de una nueva administración a todos los niveles, mientras que la dinastía privativa mallorquina favoreció la ...

  11. Contenido de metales en sedimentos y en Emerita analoga (Stimpson, 1857, en bahía Mejillones del Sur, Chile

    Directory of Open Access Journals (Sweden)

    Marcos Guiñez

    2015-03-01

    Full Text Available Se determinó la concentración de Cu, Cd, Ni y Zn en sedimentos intermareales y Emérita analoga (Stimpson, 1857, en ocho sectores de la bahía de Mejillones del sur, Chile. Sólo el Zn presentó un cierto grado de contaminación en los sedimentos de la bahía con un índice de geoacumulación de 2,8. Al analizar el contenido de metales en E. analoga, se determinó que esta especie estaría bioacumulando algunos de los metales analizados pero en baja magnitud, a excepción del Zn con un factor de bioacumulación de 2,07. El dendrograma de similitud realizado con datos del índice de bioacumulación, relacionó los valores de este índice con la distribución espacial de las principales industrias y zonas urbanas. Esta concordancia permite establecer que E. analoga estaría respondiendo como un indicador de la salud ambiental para este sistema. Además, es importante destacar que esta bahía está experimentando los primeros indicios de una zona industrial moderadamente impactada. Por lo tanto, es necesario realizar mediciones constantes, que abarquen más de una matriz ambiental, para controlar el impacto antrópico en este ecosistema marino costero altamente productivo.

  12. Las alternativas al Neoliberalismo como forma de reproducir la particularidad del capital en América del Sur

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    Juan Kornblihtt

    2016-05-01

    Full Text Available La particularidad en América del Sur es su rol jugado en el desarrollo de capital que se valoriza a una tasa de ganancia normal pese a tener una baja productividad para recuperar la renta de la tierra cedida a los terratenientes al comprar materias primas. En el artículo, se analiza cómo esa especificidad se transforma a partir de la posguerra y se pasa de políticas de industrialización a políticas neoliberales y nuevamente a políticas alternativas al neoliberalismo. Se estudia el carácter de las políticas alternativas al neoliberalismo adoptadas en los 2000 que se suponen favorables al “pueblo” por sobre el mercado. Se plantea que las mismas reproducen la particularidad de la acumulación de capital en la región bajo un proceso de transformación cuyo resultado es un peso cada vez menor de la valorización del capital industrial como forma de apropiar la renta de la tierra con la consecuente expansión de la sobrepoblación relativa. El artículo cierra con las perspectivas políticas de la clase obrera como forma de transformación del capital en la región.

  13. Quelques commentaires sur les personnages de fiction

    Directory of Open Access Journals (Sweden)

    Umberto Eco

    2010-06-01

    Full Text Available L’auteur met en place des observations et développe des analyses sur le statut des personnages de fiction, mettant à contribution les ressources de l’histoire, de la littérature, de la sémiotique, de la logique et de la narratologie. De quelle vie particulière vivent les personnages de roman, qui fait que nous sommes capables de les tenir pour plus réels que des personnages réels, et que nous sommes enclins à éprouver les sentiments qu’ils éprouvent, même si nous savons qu’ils n’existent pas ? Comment ces personnages de fiction existent-ils, selon quelle « partition » leur existence se développe-t-elle au point d’interférer avec la nôtre ? L’interrogation porte sur la nature de ce flux émotionnel qui s’écoule du lecteur vers les personnages de fiction et les investit de valeur, sur ce qui se projette de la vie vers le roman, entraînant avec lui le lecteur qui se trouve de la sorte impliqué malgré lui dans l’histoire, et se trouve pris dans le mécanisme de l’identification et de la vie fictive.Some commentaries about fiction charactersPutting into form a number of observations and developing an analysis on the status of fiction characters, the author draws on resources coming from history, literature, semiotic, logic et narration. What is that particular life lived by fiction characters that enable us to consider them as being more real than real characters, and to experience the feelings that they experience, even though we know that they do not exist? How do these characters exist? In other words, according to what “script” does their existence develop to the point of interfering with ours? The questioning centres on the nature of the emotional flux which flows from the reader towards the fictional characters thus giving them value, and on what it is which is projected from real life towards the novel and which is capable of sweeping up the reader who, without having particularly intended to do

  14. E/I corrected paleolatitudes for the sedimentary rocks of the Baja British Columbia hypothesis

    Science.gov (United States)

    Krijgsman, Wout; Tauxe, Lisa

    2006-02-01

    Paleomagnetic inclinations from sediments of the western terranes of Canada are consistently too shallow for their reconstructed paleogeographic positions. Two contradicting explanations for these discrepancies are: (1) terranes have been displaced northward with respect to the stable American craton by several thousands of kilometres between the Late Cretaceous (˜ 75 Ma) and the Eocene (˜50 Ma) and (2) sedimentary inclination error has caused a shallow bias in the paleomagnetic directions. Here, we apply the elongation/inclination (E/I) method to paleomagnetic data sets from sedimentary rocks of supposedly allochtonous terranes of western North America to correct for inclination flattening. Our results indicate that the paleomagnetic directions from the continental Silverquick sediments (95-92 Ma) of southern British Colombia are not seriously affected by inclination error, because the magnetic signal most likely concerns a chemical remanent magnetisation (CRM). In contrast, the marine sediments of the Nanaimo Group (84-72 Ma) of Vancouver Island region appear seriously affected by inclination flattening ( f = 0.7) and the E/I corrected mean inclinations are about 9° steeper than the original data. We arrive at corrected inclinations/paleolatitudes of I** = 57°/ λ = 38°N for the Silverquick and I** = 55°/ λ = 36°N for the Nanaimo sediments. Our corrected paleolatitudes indicate that the Canadian terranes were indeed located adjacent to the Baja Californian margin during the Late Cretaceous, thus supporting the Baja BC hypothesis.

  15. Authentic Assessment in California.

    Science.gov (United States)

    Educational Leadership, 1989

    1989-01-01

    Describes the teacher-developed California Assessment Program (CAP) writing measure, designed to support California's reform curriculum and based on matrix sampling techniques. This program will be supplemented by literature and mathematics assessments. The greatest challenge is designing an assessment to match the state's new history and social…

  16. California's English Learner Students

    Science.gov (United States)

    Hill, Laura E.

    2012-01-01

    English Learner (EL) students in California's schools are numerous and diverse, and they lag behind their native-English-speaking peers. Closing the achievement gap for EL students has been a long-standing goal for California educators, and there are some signs of success. Now that EL funding and curriculum issues are receiving a fresh level of…

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

    OpenAIRE

    Agustín Hernández Aja; Fernando Roch Peña; Nerea Morán Alonso; Cristina Fernández Ramírez

    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...

  18. 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...

  19. Réflexions sur la science contemporaine

    CERN Document Server

    Darriulat, Pierre

    2007-01-01

    L'auteur y brosse à grands traits un tableau de la science contemporaine : réductionnisme, déterminisme, abstraction, méthodes, mécanismes de validation et interactions entre observation et théorie... ainsi qu'un portrait de ses artisans et une critique des stéréotypes les plus courants (philistin, iconoclaste, apprenti sorcier...) L'accent est mis sur le fait que la science, dont une des missions consiste à dénoncer les illusions du sens commun, ne poursuit pas une quête de vérité absolue mais se contente aujourd'hui d'une vérité simplement meilleure que celle d'hier. La circularité de la science lui interdit de répondre à des questions essentielles comme «Pourquoi ce monde plutôt que rien ?» Pour tenter d'y répondre, le physicien Pierre Darriulat entreprend, avec candeur et bienveillance, un voyage chez les philosophes. Comment la métaphysique s'évade-t-elle du cercle ? Quelle connaissance autre que scientifique nous propose-t-elle ? La circularité condamnant la science au silence...

  20. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Pengaruh variasi Holding Time Pada Perlakuan Panas Quench Annealing Terhadap Sifat mekanik dan Mikro Struktur Pada Baja mangan AISI 3401

    Directory of Open Access Journals (Sweden)

    Boby Endi Kurniawan

    2014-03-01

    Full Text Available 800x600 Baja mangan merupakan salah satu baja penting yang digunakan dalam industri dan memiliki aplikasi yang luas karena mempunyai wear resisten yang baik, kemampuan work hardening yang tinggi dengan ketangguhan dan keuletan yang tinggi. Tujuan dari penelitian ini adalah menganalisa pengaruh perubahan struktur mikro dan sifat mekanik pada baja mangan austenitic AISI 3401 .Penelitian baja mangan austenitk AISI 3401 ini dilakukan dengan perlakuan quench annneling pada temperature 10000C dengan empat variasi waktu tahan 30 menit, 60 menit, 120 menit yang diikuti pendinginan cepat media air, dan tanpa perlakuan. Kemudian dilakukan pengujian metalografi untuk mengetahui struktur mikro, uji kekerasan untuk mengetahui sifat mekanik dan uji XRD untuk menganalisis fasa hasil dari perlakuan quench annealing pada temperature 10000C dengan menggunakan empat variasi tersebut. Hasil penelitian diperoleh adanya pembentukan karbida dan austenit pada semua spesimen. Sedangkan hasil uji kekerasan yang didapatkan nilai yang tertinggi adalah pada waktu tahan 30 menit, yaitu 27 HRc Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4

  3. La energía geotérmica de baja entalpía

    OpenAIRE

    Cárcel Carrasco, Francisco Javier; MARTÍNEZ MÁRQUEZ, DAVID

    2015-01-01

    [ES] Se habla mucho sobre la necesidad de mejorar la eficiencia energética y el uso de energías renovables. La energía geotérmica de baja entalpía puede ser una buena alternativa de uso, aunque no tiene demasiado arraigo en España. Su utilización puede ser aplicada en múltiples aplicaciones industriales y domésticas consiguiendo rendimientos térmicos importantes, con una instalación sencilla. En este artículo se muestra de una manera general cual es la función de la energía geotérmica de ba...

  4. Pengaruh Kecepatan Pengelasan pada Submerged Arc Welding Baja SM 490 Terhadap Ketangguhan Beban Impak

    Directory of Open Access Journals (Sweden)

    Suharno Suharno

    2004-01-01

    Full Text Available The effect of welding speed of SM 490 steel submerged arc welded on impact charpy toughness was investigated. The welding speed is one of the parameter that affecting physics and mechanical properties, specially the impact charpy toughness. The result show that the welding speed of 6,35 mm/s give the highest impact toughness of 1,825 joule/mm2. Abstract in Bahasa Indonesia : Pengaruh kecepatan pengelasan pada submerged arc welding (SAW atau pengelasan busur terendam baja SM 490 terhadap ketangguhan beban impak telah diselidiki. Kecepatan pengelasan merupakan salah satu parameter pengelasan yang berpengaruh terhadap sifat fisis dan mekanis, khususnya ketangguhan impak charpy. Hasil penelitian menunjukkan bahwa ketangguhan impak tertinggi sebesar 1,825 Joule/mm2, diperoleh pada kecepatan pengelasan 6,35 mm/s. Kata kunci: Las busur rendam, kecepatan pengelasan, ketangguhan impak.

  5. El clima de la selva baja caducifolia en México

    OpenAIRE

    Irma Trejo Vázquez

    1999-01-01

    Se analizan las principales características climáticas de la selva baja caducifolia mexicana. Con base en datos de 390 estaciones climatológicas, se describen elementos tales como precipitación, temperaturas, días con lluvias apreciables, meses secos y tipo de clima, con el fin de conocer el ámbito climático de este tipo de vegetación. El clima más propicio para esta selva es el cálido subhúmedo (Awo), pero se distribuye también en condiciones más secas o de mayor humedad, gracias a la combin...

  6. Elaboración y posterior tratamiento del hormigón a bajas temperaturas

    Directory of Open Access Journals (Sweden)

    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. Modelado del secado de granos en lecho fijo a bajas temperaturas de aire

    OpenAIRE

    Martinello, Miriam

    2015-01-01

    Se estudió el proceso de secado de maíz a bajas temperaturas para proponer un método más ecológico y que conduzca a granos de mayor calidad y valor. Se abordó el modelado matemático de la transferencia de calor y materia y su implementación numérica. Los balances de masa y de energía se propusieron tanto para el aire intergranular como para los granos. Se consideraron variantes de modelización: equilibrio térmico y másico y no equilibrio; inclusión de términos de acumulación en el aire (no e...

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.

  10. California Ocean Uses Atlas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a result of the California Ocean Uses Atlas Project: a collaboration between NOAA's National Marine Protected Areas Center and Marine Conservation...

  11. California Watershed Hydrologic Units

    Data.gov (United States)

    California Department of Resources — This dataset is intended to be used as a tool for water-resource management and planning activities, particularly for site-specific and localized studies requiring...

  12. Earthquakes in Southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — There have been many earthquake occurrences in Southern California. This set of slides shows earthquake damage from the following events: Imperial Valley, 1979,...

  13. Coastal California Digital Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This digital ortho-imagery dataset is a survey of coastal California. The project area consists of approximately 3774 square miles. The project design of the...

  14. California Harpoon Fishery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vessel logbook and landings data from harpoon vessels that fish within 200 miles of the California coast, from 1974 to present. The harpoon...

  15. The Oxbow School, California.

    Science.gov (United States)

    Pearson, Clifford A.

    2003-01-01

    Describes the design of the Oxbow School, an art- and design-oriented high school in Napa, California, including the educational context and design goals. Includes information on the architects, as well as floor plans and photographs. (EV)

  16. California Data Exchange Center

    Science.gov (United States)

    ... to make July &28;Water Smart Month.&29; &28;Conserving ... Remote sensors today indicate that statewide, snowpack water content is 54 percent of ... California ranked first, along with Texas, on ...

  17. Retour sur la logique de l’usage

    OpenAIRE

    Perriault, Jacques

    2015-01-01

    Publié il y a vingt-cinq ans, l’ouvrage « La logique de l’usage » a connu un succès important dans les recherches portant sur les technologies de l’information et de la communication. Néanmoins, ce succès s’est souvent traduit par une assimilation à la sociologie des usages, dont l’ouvrage se distingue pourtant fortement. L’entretien, reposant sur le travail de retour sur les textes majeurs des SIC s’étant intéressés à la technique entrepris dans le séminaire Usages des Dispositifs Sociotechn...

  18. Sur les Ecrits de Jean Carbonnier (1908-2003

    Directory of Open Access Journals (Sweden)

    Robert Pageard

    2009-09-01

    Full Text Available Cette centaine de textes divers, présentés et commentés par une équipe de juristes, d’historiens, de sociologues ou d’anthropologues, donne une très vivante vision de la personnalité et des activités d’un penseur qui joua un rôle important dans l’enseignement et l’ évolution de la seconde moitié du XXe siècle.Tout est dit dans cet ouvrage sur l’exceptionnelle érudition de Jean Carbonnier en maints domaines, sur l’élégance et la finesse de sa langue, sur la clarté de son expression. Cette clar...

  19. Sur le concept d’engagement

    Directory of Open Access Journals (Sweden)

    Howard S. Becker

    2006-10-01

    Full Text Available Le terme « engagement » connaît un succès grandissant dans les débats sociologiques. Dans ce texte, l’auteur examine les utilisations du concept d'engagement afin de comprendre les raisons de sa popularité grandissante, il signale la nature d'un des mécanismes sociaux auquel le terme se réfère implicitement, et développe une théorie embryonnaire des conditions et des processus sociaux impliqués dans le fonctionnement de ce mécanisme. Étant donné la variété sémantique du terme, il s'avère infructueux de spéculer sur son « véritable » sens. Une des images évoquées par « l'engagement » a été retenue pour en préciser la signification.On the Concept of CommitmentThe term "commitment" is experiencing a growing success in sociological debates. In this article, the author examines the uses of the concept of commitment in order to understand the reasons for its growing popularity. He also points out the nature of one of the social mechanisms to which the term implicitly refers, and he develops a preliminary theory of the social conditions and processes implied in the functioning of this mechanism. Given the semantic variety of the term, it proves useless to speculate on its “true” meaning. In order to clarify the meaning of the term, the author adopts one of the images evoked by “commitment”.Sobre el concepto de compromisoEl término “compromiso” goza de un éxito creciente en los debates sociológicos. En este texto el autor analiza las utilizaciones de este concepto con el fin de comprender las razones de esta creciente popularidad e indica la naturaleza de uno de los mecanismos sociales indicados por ese término, desarrollando seguidamente una teoría embrionaria de las condiciones y de los procesos sociales inherentes a este mecanismo. Teniendo en cuenta la variedad semántica del término es inútil especular acerca de su “verdadero” significado. Con el fin de precisar su significado, el autor

  20. La fachada sur en clima mediterráneo

    OpenAIRE

    Soro Espín, Mikel

    2013-01-01

    Esta tesina investiga la fachada Sur del clima mediterráneo y los elementos constructivos flexibles que hacen que esta fachada tenga un correcto funcionamiento térmico durante los diferentes periodos climáticos del año. Concretamente, la tesina ha centrado la investigación en la fachada Sur de edificios residenciales plurifamiliares del clima Mediterráneo. Se ha definido la función térmica de la fachada, sus requerimientos térmicos en diferentes periodos del clima Mediterráneo ...