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Sample records for california peninsula mexico

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

    OpenAIRE

    Quetzalcoatl Hernandez-Escobedo

    2016-01-01

    Mexico needs to exploit its renewable resources and many studies have determined the great renewable potential it has using wind energy. However it is necessary to calculate the amount of this resource for small urban communities, which in this country lack essential services such as electricity. This study is focused in the Baja California Peninsula, using GIS as a tool to identify small urban zones with higher wind power. For this work data was analyzed from meteorological stations and reco...

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

    Directory of Open Access Journals (Sweden)

    Quetzalcoatl Hernandez-Escobedo

    2016-10-01

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

  3. Polychlorinated biphenyls and biotransformation enzymes in three species of sea turtles from the Baja California peninsula of Mexico.

    Science.gov (United States)

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

    2010-01-01

    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 congener in all samples. Total PCB concentrations were dominated by penta- and hexa-chlorinated biphenyls. The mean estimated TEQs were 42.8, 22.9, and 10.4 pg/g (ww) for loggerhead, green, and olive ridley, respectively, and more than 70% was accounted for by non-ortho PCBs. Western blots revealed the presence of hepatic microsomal proteins that cross-reacted with anti-CYP2K1 and anti-CYP3A27 antibodies but not with anti-CYP1A antibody. There were no significant differences in GST activities between species. Grouping congeners based on structure-activity relationships for CYP isoenzymes suggested limited activity of CYP1A contribution to PCB biotransformation in sea turtles. These results suggest potential accumulation of PCBs that are CYP1A substrates and provide evidence for biotransformation capacity, which differs from known animal models, highlighting the need for further studies in reptiles, particularly those threatened with extinction.

  4. Nutrient fluxes and net metabolism in a coastal lagoon SW peninsula of Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Cervantes Duarte, R.

    2016-09-01

    Full Text Available Fluxes of nutrients and net metabolism were estimated in coastal lagoon Magdalena Bay using LOICZ biogeochemical model. In situ data were obtained from 14 sites in the lagoon and also from a fixed site in the adjacent ocean area. Intense upwelling (February to July and faint upwelling (August to January were analyzed from monthly time series. The Temperature, nitrite + nitrate, ammonium and phosphate within the lagoon showed significant differences (p<0.05 between the two periods. Salinity (p=0.408 was more homogeneous (no significantly different due to mixing processes. During the intense upwelling period, nutrients increased in and out of the lagoon due to the influence of Transitional Water and Subartic Water transported by the California Current. However, during the faint upwelling, from August to January, the Transition Water and Subtropical Surface Water were predominant. Magdalena Bay showed denitrification processes of throughout the year as it occurred in other semi-arid coastal lagoons. It also showed a net autotrophic metabolism during intense upwelling and heterotrophic metabolism during faint upwelling. Understanding nutrient flows and net metabolism through simple biogeochemical models can provide tools for better management of the coastal zone.

  5. Hyperparasitism by the bacteriophage (Caudovirales) infecting Candidatus Xenohaliotis californiensis (Rickettsiales-like prokaryote) parasite of wild abalone Haliotis fulgens and Haliotis corrugata from the Peninsula of Baja California, Mexico.

    Science.gov (United States)

    Cruz-Flores, Roberto; Cáceres-Martínez, Jorge; Muñoz-Flores, Monserrat; Vásquez-Yeomans, Rebeca; Hernández Rodriguez, Mónica; Ángel Del Río-Portilla, Miguel; Rocha-Olivares, Axayácatl; Castro-Longoria, Ernestina

    2016-10-01

    Candidatus Xenohaliotis californiensis (CXc) is a Rickettsiales-like prokaryote that is considered the causal agent of Withering Syndrome (WS), a chronic disease of abalone, from the west coast of North America and it is listed by the International Organization for Animal Health (OIE) as a reportable agent due to its pathogenicity. This bacterium in red abalone Haliotis rufescens, black abalone Haliotis cracherodii, and yellow abalone Haliotis corrugata from California, US and Baja California, Mexico has been found to be infected by a bacteriophage. To date, there is no information on the epizootiology of CXc and its bacteriophage in natural populations of abalone; furthermore, it is unknown if the bacteriophage was also present in CXc infecting blue abalone Haliotis fulgens. The objective of this study was to determine the distribution, prevalence and intensity of CXc, as well as to determine the distribution and prevalence of the bacteriophage and to study interactions between host sex and hyperparasitism in blue abalone and yellow abalone. Tissue samples were obtained from seven localities where the commercial capture of wild abalone is carried out. Samplings were conducted throughout the 2012-2013 capture seasons and a total of 182 blue abalone and 170 yellow abalone were obtained. The prevalence and intensity of CXc and the prevalence of the bacteriophage were determined by histology. The identity of CXc was confirmed by PCR, product sequence analysis and in situ hybridization while the identity of the bacteriophage was corroborated by TEM. The prevalence of CXc infected and uninfected by the bacteriophage was 80% in blue abalone and 62% in yellow abalone. Low infection intensities were found in 86% of blue abalone and 82% of yellow abalone. Infection intensity was significantly higher in undifferentiated yellow abalone. The bacteriophage in CXc showed a prevalence of 22% and 31% in blue abalone and yellow abalone respectively. These results show that CXc and

  6. Terrestrial Birds and Conservation Priorities in Baja California Peninsula

    Science.gov (United States)

    Ricardo Rodriguez-Estrella

    2005-01-01

    The Baja California peninsula has been categorized as an Endemic Bird Area of the world and it is an important wintering area for a number of aquatic, wading and migratory landbird species. It is an important area for conservation of bird diversity in northwestern México. In spite of this importance, only few, scattered studies have been done on the ecology...

  7. California-Mexico gas exports eyed

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that two California utilities have proposed providing natural gas transportation services to Mexico. The arrangement would provide a second U.S. export sales point at the U.S.-Mexico border and perhaps help alleviate an expected surplus of gas pipeline capacity available to California. Mexico currently imports about 200 MMcfd of U.S. gas via pipelines in Texas

  8. 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

  9. 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.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  11. Shaded Relief with Height as Color, Yucatan Peninsula, Mexico

    Science.gov (United States)

    2003-01-01

    This shaded relief image of Mexico's Yucatan Peninsula show a subtle, but unmistakable, indication of the Chicxulub impact crater. Most scientists now agree that this impact was the cause of the Cretatious-Tertiary Extinction, the event 65 million years ago that marked the sudden extinction of the dinosaurs as well as the majority of life then on Earth.Most of the peninsula is visible here, along with the island of Cozumel off the east coast. The Yucatan is a plateau composed mostly of limestone and is an area of very low relief with elevations varying by less than a few hundred meters (about 500 feet.) In this computer-enhanced image the topography has been greatly exaggerated to highlight a semicircular trough, the darker green arcing line at the upper left corner of the peninsula. This trough is only about 3 to 5 meters (10 to 15 feet) deep and is about 5 km. wide (3 miles), so subtle that if you walked across it you probably would not notice it, and is a surface expression of the crater's outer boundary. Scientists believe the impact, which was centered just off the coast in the Caribbean, altered the subsurface rocks such that the overlying limestone sediments, which formed later and erode very easily, would preferentially erode on the vicinity of the crater rim. This formed the trough as well as numerous sinkholes (called cenotes) which are visible as small circular depressions.Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwestern slopes appear bright and southeastern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.For a smaller, annotated version of this image, please select Figure 1, below: [figure removed for brevity, see original site] (Large image: 1.5 m

  12. Review: The Yucatán Peninsula karst aquifer, Mexico

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Gondwe, Bibi Ruth Neuman; Charvet, Guillaume

    2011-01-01

    in the vicinity of the North American/Caribbean plate boundary and has been reshaped by a series of tectonic events over its long geologic history. At the end of the Cretaceous period, the Yucatán Peninsula was hit by a large asteroid, which formed the Chicxulub impact crater. The Yucatán Peninsula karst aquifer...

  13. 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

  14. Oligocene cetaceans from Baja California Sur, Mexico

    OpenAIRE

    Hernández Cisneros, Atzcalli Ehécatl; González Barba, Gerardo; Fordyce, Robert Ewan

    2017-01-01

    Abstract Baja California Sur has an important Cenozoic marine fossil record which includes diverse but poorly known Oligocene cetaceans from Mexico. Here we review the cetacean fossil record including new observations from materials that elucidate the evolution of the Neoceti in the Pacific basin. Fossils were collected from outcrops of the El Cien Formation (Oligocene-Early Miocene) and from San Gregorio Formation (Late Oligocene). The specimens belong to the paleontological collection of Mu...

  15. Modeling carbon stocks in a secondary tropical dry forest in the Yucatan Peninsula, Mexico

    Science.gov (United States)

    Zhaohua Dai; Richard A. Birdsey; Kristofer D. Johnson; Juan Manuel Dupuy; Jose Luis Hernandez-Stefanoni; Karen. Richardson

    2014-01-01

    The carbon balance of secondary dry tropical forests of Mexico’s Yucatan Peninsula is sensitive to human and natural disturbances and climate change. The spatially explicit process model Forest-DeNitrification-DeComposition (DNDC) was used to estimate forest carbon dynamics in this region, including the effects of disturbance on carbon stocks. Model evaluation using...

  16. Some helminth parasites of Epinephelus morio (Pisces: Serranidae) from the peninsula of Yucatan, Mexico

    NARCIS (Netherlands)

    Moravec, F.; Vidal-Martínez, V.M.; Aguirre-Macedo, M.L.

    1995-01-01

    Moravec, F., V.M. Vidal-Martinez & M.L. Aguirre-Macedo, 1995. Some helminth parasites of Epinephelus morio (Pisces: Serranidae) from the Peninsula of Yucatan, Mexico. Studies Nat. Hist. Caribbean Region 72: 55-68. One nematode species, Hysterothylacium eurycheilum, the acanthocephalan Gorgorhynchus

  17. Elements of success in cooperatives conformed by Maya women in the Yucatan Peninsula, Mexico

    NARCIS (Netherlands)

    Osorio Vazqez, Maria Cristina; Bressers, Johannes T.A.; Franco Garcia, Maria Laura; Boer, C.L.; Reyes Maya, Oscar Ivan

    2016-01-01

    This paper describes different elements leading to the success of cooperatives formed by indigenous Maya women of the Yucatan Peninsula in Mexico. These elements have shown to facilitate the sustainability (permanence over time) of the cooperatives and their presence in the market, while improving

  18. Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

    Science.gov (United States)

    Back, W.; Lesser, J.M.

    1981-01-01

    Two critical objectives of water management in the Yucatan are: (1) to develop regional groundwater supplies for an expanding population and tourism based on the Mayan archeological sites and excellent beaches; and (2) to control groundwater pollution in a chemically sensitive system made vulnerable by geologic conditions. The Yucatan peninsula is a coastal plain underlain by permeable limestone and has an annual rainfall of more than 1000 mm. Such a setting should provide abundant supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that decrease the amount of available fresh water. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed by extensive use of groundwater. The religion was water-oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supplies by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution resulting from the use of a sewage disposal well adjacent to each supply well. The modern phase of water management began in 1959 when the Secretari??a de Recursos Hidra??ulicos (S.R.H.) was charged with the responsibility for both scientific investigations and development programmes for water-supply and sewage-disposal systems for cities, villages and islands. ?? 1981.

  19. [Distribution of Ecteinascidia turbinata (Ascidiacea: Perophoridae) in mangroves of the Yucatán Peninsula, Mexico].

    Science.gov (United States)

    Carballo, J L

    2000-01-01

    The ascidian Ecteinascidia turbinata synthesizes some of the most promising substances against solid-type tumors, but the only available source are the natural populations of this tunicate, which is reared or collected in different parts of the world. A total of 33 locations were sampled in the Gulf of Mexico and the Yucatan Peninsula. The tunicate was not found in Veracruz, Tabasco and Campeche, but it was well established on mangrove roots in the Yucatan Peninsula where we estimated densities more or less equal to one colony and an average production of 115 g of biomass per lineal meter of mangrove coastline in one location (Río Lagartos). Sustainable management appears to be possible.

  20. Elements of success in cooperatives conformed by Maya women in the Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Maria Cristina Osorio Vázquez

    2016-05-01

    Full Text Available This paper describes different elements leading to the success of cooperatives formed by indigenous Maya women of the Yucatan Peninsula in Mexico. These elements have shown to facilitate the sustainability (permanence over time of the cooperatives and their presence in the market, while improving the work environment and enhancing the practice of honesty. All these elements have generated an increase in the number of clients and beneficiaries due to their trustable relationships. As can be appreciated in this study, indigenous Maya women living in the Yucatan Peninsula are demonstrating an innovative way to do business, which has resulted in greater social benefits and profitability through social capital, ethical leadership and monitoring of actions.

  1. Contaminants in the coastal karst aquifer system along the Caribbean coast of the Yucatan Peninsula, Mexico

    International Nuclear Information System (INIS)

    Metcalfe, Chris D.; Beddows, Patricia A.; Bouchot, Gerardo Gold; Metcalfe, Tracy L.; Li Hongxia; Van Lavieren, Hanneke

    2011-01-01

    Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico may result in contamination of groundwater resources that eventually discharge into Caribbean coastal ecosystems. We deployed two types of passive sampling devices into groundwater flowing through cave systems below two communities to evaluate concentrations of contaminants and to indicate the possible sources. Pharmaceuticals and personal care products accumulated in the samplers could only have originated from domestic sewage. PAHs indicated contamination by runoff from highways and other impermeable surfaces and chlorophenoxy herbicides accumulated in samplers deployed near a golf course indicated that pesticide applications to turf are a source of contamination. Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health, thus damaging the tourism-based economy of the region. - Research highlights: → Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico is contaminating groundwater resources that discharge into Caribbean coastal ecosystems. → Passive sampling devices deployed in groundwater flowing through cave systems below two communities in the Riviera Maya accumulated: pharmaceuticals and personal care products originating from domestic sewage. → PAHs originating from runoff from highways and other impermeable surfaces; chlorophenoxy herbicides originating from pesticide applications to lawns and turf. → Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health in the region. - Contaminants accumulated in passive samplers deployed in flooded cave systems in the Yucatan Peninsula in Mexico indicate contamination by domestic sewage, runoff and applications of pesticides

  2. Contaminants in the coastal karst aquifer system along the Caribbean coast of the Yucatan Peninsula, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Metcalfe, Chris D., E-mail: cmetcalfe@trentu.ca [Worsfold Water Quality Centre, Trent University, Peterborough, ON, K9J 7B8 (Canada); Beddows, Patricia A. [Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL (United States); Bouchot, Gerardo Gold [Departemento de Recursos del Mar, CINVESTAV Unidad Merida, Yucatan (Mexico); Metcalfe, Tracy L.; Li Hongxia [Worsfold Water Quality Centre, Trent University, Peterborough, ON, K9J 7B8 (Canada); Van Lavieren, Hanneke [UN University Institute for Water, Environment and Health (UNU-INWEH), Hamilton, ON (Canada)

    2011-04-15

    Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico may result in contamination of groundwater resources that eventually discharge into Caribbean coastal ecosystems. We deployed two types of passive sampling devices into groundwater flowing through cave systems below two communities to evaluate concentrations of contaminants and to indicate the possible sources. Pharmaceuticals and personal care products accumulated in the samplers could only have originated from domestic sewage. PAHs indicated contamination by runoff from highways and other impermeable surfaces and chlorophenoxy herbicides accumulated in samplers deployed near a golf course indicated that pesticide applications to turf are a source of contamination. Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health, thus damaging the tourism-based economy of the region. - Research highlights: > Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico is contaminating groundwater resources that discharge into Caribbean coastal ecosystems. > Passive sampling devices deployed in groundwater flowing through cave systems below two communities in the Riviera Maya accumulated: pharmaceuticals and personal care products originating from domestic sewage. > PAHs originating from runoff from highways and other impermeable surfaces; chlorophenoxy herbicides originating from pesticide applications to lawns and turf. > Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health in the region. - Contaminants accumulated in passive samplers deployed in flooded cave systems in the Yucatan Peninsula in Mexico indicate contamination by domestic sewage, runoff and applications of

  3. CONTRIBUTION TO THE KNOWLEDGE OF THE ARACHNIDS IN THE YUCATAN PENINSULA, MEXICO (EXCLUDING ARANAE AND ACARI)

    OpenAIRE

    Hugo Delfin Gonzalez; Virginia Meléndez-Ramírez; Pablo C. Manrique-Saide; Abdiel Martin-Park; Carlos Arisqueta-Chablé

    2017-01-01

    The Chelicerata are the second group of arthropods with the highest diversity after insects and they can inhabit almost all types of environments. The most current classification recognizes 11 orders and estimates in the number of species vary from 52,000 to 100,000. We have made an extensive literature review on the diversity of arachnids in the Yucatan Peninsula (YP) (excluding spiders and ticks). In Mexico there are 834 known species which represent 6% of the worldwide diversity. In the YP...

  4. Contaminants in the coastal karst aquifer system along the Caribbean coast of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Metcalfe, Chris D; Beddows, Patricia A; Bouchot, Gerardo Gold; Metcalfe, Tracy L; Li, Hongxia; Van Lavieren, Hanneke

    2011-04-01

    Intensive land development as a result of the rapidly growing tourism industry in the "Riviera Maya" region of the Yucatan Peninsula, Mexico may result in contamination of groundwater resources that eventually discharge into Caribbean coastal ecosystems. We deployed two types of passive sampling devices into groundwater flowing through cave systems below two communities to evaluate concentrations of contaminants and to indicate the possible sources. Pharmaceuticals and personal care products accumulated in the samplers could only have originated from domestic sewage. PAHs indicated contamination by runoff from highways and other impermeable surfaces and chlorophenoxy herbicides accumulated in samplers deployed near a golf course indicated that pesticide applications to turf are a source of contamination. Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health, thus damaging the tourism-based economy of the region. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Bartonella Infection in Hematophagous, Insectivorous, and Phytophagous Bat Populations of Central Mexico and the Yucatan Peninsula.

    Science.gov (United States)

    Stuckey, Matthew J; Chomel, Bruno B; Galvez-Romero, Guillermo; Olave-Leyva, José Ignacio; Obregón-Morales, Cirani; Moreno-Sandoval, Hayde; Aréchiga-Ceballos, Nidia; Salas-Rojas, Mónica; Aguilar-Setién, Alvaro

    2017-08-01

    Although emerging nonviral pathogens remain relatively understudied in bat populations, there is an increasing focus on identifying bat-associated bartonellae around the world. Many novel Bartonella strains have been described from both bats and their arthropod ectoparasites, including Bartonella mayotimonensis , a zoonotic agent of human endocarditis. This cross-sectional study was designed to describe novel Bartonella strains isolated from bats sampled in Mexico and evaluate factors potentially associated with infection. A total of 238 bats belonging to seven genera were captured in five states of Central Mexico and the Yucatan Peninsula. Animals were screened by bacterial culture from whole blood and/or polymerase chain reaction of DNA extracted from heart tissue or blood. Bartonella spp. were isolated or detected in 54 (22.7%) bats, consisting of 41 (38%) hematophagous, 10 (16.4%) insectivorous, and three (4.3%) phytophagous individuals. This study also identified Balantiopteryx plicata as another possible bat reservoir of Bartonella . Univariate and multivariate logistic regression models suggested that Bartonella infection was positively associated with blood-feeding diet and ectoparasite burden. Phylogenetic analysis identified a number of genetic variants across hematophagous, phytophagous, and insectivorous bats that are unique from described bat-borne Bartonella species. However, these strains were closely related to those bartonellae previously identified in bat species from Latin America.

  6. Monogeneans of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Mendoza-Franco, E F; Scholz, T; Vivas-Rodríguez, C; Vargas-Vázquez, J

    1999-01-01

    During a survey of the parasites of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula the following species of monogeneans were found on cichlid, pimelodid, characid and poeciliid fishes: Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodriguez-Canul, 1994 from Cichlasoma urophthalmus (Günther) (type host), Cichlasoma friedrichsthali (Heckel), Cichlasoma octofasciatum (Regan), and Cichlasoma synspilum Hubbs, all new host records; Sciadicleithrum meekii Mendoza-Franco, Scholz et Vidal-Martínez, 1997 from Cichlasoma meeki (Brind); Urocleidoides chavarriai (Price, 1938) and Urocleidoides travassosi (Price, 1938) from Rhamdia guatemalensis (Günther); Urocleidoides costaricensis (Price et Bussing, 1967), Urocleidoides heteroancistrium (Price et Bussing, 1968), Urocleidoides anops Kritsky et Thatcher, 1974, Anacanthocotyle anacanthocotyle Kritsky et Fritts, 1970, and Gyrodactylus neotropicalis Kritsky et Fritts, 1970 from Astyanax fasciatus; and Gyrodactylus sp. from Gambusia yucatana Regan. Urocleidoides chavarriai, U. travassosi, U. costaricensis, U. heteroancistrium, U. anops, Anacanthocotyle anacanthocotyle and Gyrodactylus neotropicalis are reported from North America (Mexico) for the first time. These findings support the idea about the dispersion of freshwater fishes and their monogenean parasites from South America through Central America to southeastern Mexico, following the emergence of the Panamanian isthmus between 2 and 5 million years ago.

  7. CONTRIBUTION TO THE KNOWLEDGE OF THE ARACHNIDS IN THE YUCATAN PENINSULA, MEXICO (EXCLUDING ARANAE AND ACARI

    Directory of Open Access Journals (Sweden)

    Hugo Delfin Gonzalez

    2017-08-01

    Full Text Available The Chelicerata are the second group of arthropods with the highest diversity after insects and they can inhabit almost all types of environments. The most current classification recognizes 11 orders and estimates in the number of species vary from 52,000 to 100,000. We have made an extensive literature review on the diversity of arachnids in the Yucatan Peninsula (YP (excluding spiders and ticks. In Mexico there are 834 known species which represent 6% of the worldwide diversity. In the YP 63 records were found (58 species and 5 genera of arachnids, which represent 6.8% of the Mexican species. According to our research, 28 of the 58 species (48% in the YP were also record in other parts of Mexico, the continent and the world. Undoubtedly, the state of Yucatan is the best represented of the YP. In order to have a better understanding of the diversity of arachnid species is important to promote biological compendiums and sampling programs, which will improve the representation of this group and probably increasing the number of local species.

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

    Science.gov (United States)

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

    2017-09-01

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

  9. Current depression among women in California according to residence in the California-Mexico border region.

    Science.gov (United States)

    Ryan-Ibarra, Suzanne; Epstein, Joan Faith; Induni, Marta; Wright, Michael A

    2012-05-01

    To estimate the prevalence of current depression; examine the relationship between current depression and immigration, health status, health care access, and health behaviors; and assess differences by California-Mexico border region (Imperial and San Diego Counties) among women in California. Using a cross-sectional, representative sample of adult women from the California Women's Health Survey (n = 13 454), a statewide telephone survey, prevalence of current depression and predictors of depression were examined in California and according to border region residence. Depression was assessed with the eight-item Patient Health Questionnaire. The prevalence of current depression for women in California was 12.0%. It was similar in the border (13.0%) and the nonborder (11.9%) regions. Odds of current depression in women were lower among recent immigrants (depression and health status, health care access, and binge drinking were larger in the border region than outside the border region. Similar prevalences of current depression were observed among those who live in the border region of California and in those who do not, but the relationship between depression and health status, health care access, and binge drinking varied by border region residence. Ideally, future surveillance of depression and its predictors along the Mexico-California border will be conducted binationally to inform interventions and tracking such as the Healthy Border Program's objectives.

  10. A possible connection between post-subduction arc magmatism and adakite-NEB rock association in Baja California, Mexico

    Science.gov (United States)

    Castillo, P. R.

    2007-05-01

    Late Miocene to Recent arc-related magmatism occurs in Baja California, Mexico despite the cessation of plate subduction along its western margin at ~12.5 Ma. It includes calcalkaline and K-rich andesites, tholeiitic basalts and basaltic andesites, alkalic basalts similar to many ocean island basalts (OIB), magnesian and basaltic andesites with adakitic affinity (bajaiites), adakites, and Nb-enriched basalts (NEB). A popular model for the close spatial and temporal association of adakite (plus bajaiite) and NEB in Baja California is these are due to melting of the subducted Farallon/Cocos plate, which in turn is caused by the influx of hot asthenospheric mantle through a window created in the subducted slab directly beneath the Baja California peninsula [e.g., Benoit, M. et. al. (2002) J. Geol. 110, 627-648; Calmus, T. et al. (2003) Lithos 66, 77-105]. Here I propose an alternative model for the cause of post-subduction magmatism in Baja California in particular and origin of adakite-NEB rock association in general. The complicated tectonic configuration of the subducting Farallon/Cocos plate and westward motion of the North American continent caused western Mexico to override the hot, upwelling Pacific mantle that was decoupled from the spreading centers abandoned west of Baja California. The upwelling asthenosphere is best manifested east of the peninsula, beneath the Gulf of California, and is most probably due to a tear or window in the subducted slab there. The upwelling asthenosphere is compositionally heterogeneous and sends materials westward into the mantle wedge beneath the peninsula. These materials provide sources for post-subduction tholeiitic and alkalic magmas. Portions of tholeiitic magmas directly erupted at the surface produce tholeiitic lavas, but some get ponded beneath the crust. Re-melting and/or high-pressure fractional crystallization of the ponded tholeiitic magmas generate adakitic rocks. Alkalic magmas directly erupted at the surface

  11. Monomorphic pathogens: The case of Candidatus Xenohaliotis californiensis from abalone in California, USA and Baja California, Mexico.

    Science.gov (United States)

    Cicala, Francesco; Moore, James D; Cáceres-Martínez, Jorge; Del Río-Portilla, Miguel A; Hernández-Rodríguez, Mónica; Vásquez-Yeomans, Rebeca; Rocha-Olivares, Axayácatl

    2018-05-01

    Withering syndrome (WS) is a chronic wasting disease affecting abalone species attributed to the pathogen Candidatus Xenohaliotis californiensis (CXc). Wild populations of blue (Haliotis fulgens) and yellow (H. corrugata) abalone have experienced unusual mortality rates since 2009 off the peninsula of Baja California and WS has been hypothesized as a possible cause. Currently, little information is available about the genetic diversity of CXc and particularly the possible existence of strains differing in pathogenicity. In a recent phylogenetic analysis, we characterized five coding genes from this rickettsial pathogen. Here, we analyze those genes and two additional intergenic non-coding regions following multi-locus sequence typing (MLST) and multi-spacer typing (MST) approaches to assess the genetic variability of CXc and its relationship with blue, yellow and red (H. rufescens) abalone. Moreover, we used 16S rRNA pyrosequencing reads from gut microbiomes of blue and yellow abalone to complete the genetic characterization of this prokaryote. The presence of CXc was investigated in more than 150 abalone of the three species; furthermore, a total of 385 DNA sequences and 7117 16S rRNA reads from Candidatus Xenohaliotis californiensis were used to evaluate its population genetic structure. Our findings suggest the absence of polymorphism in the DNA sequences of analyzed loci and the presence of a single lineage of CXc infecting abalone from California (USA) and Baja California (Mexico). We posit that the absence of genetic variably in this marine rickettsia may be the result of evolutionary and ecological processes. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Interaction of landscape varibles on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Plasencia–Vázquez, A. H.

    2014-12-01

    Full Text Available The loss, degradation, and fragmentation of forested areas are endangering parrot populations. In this study, we determined the influence of fragmentation in relation to vegetation cover, land use, and spatial configuration of fragments on the potential geographical distribution patterns of parrots in the Yucatan Peninsula, Mexico. We used the potential geographical distribution for eight parrot species, considering the recently published maps obtained with the maximum entropy algorithm, and we incorporated the probability distribution for each species. We calculated 71 metrics/variables that evaluate forest fragmentation, spatial configuration of fragments, the ratio occupied by vegetation, and the land use in 100 plots of approximately 29 km², randomly distributed within the presence and absence areas predicted for each species. We also considered the relationship between environmental variables and the distribution probability of species. We used a partial least squares regression to explore patterns between the variables used and the potential distribution models. None of the environmental variables analyzed alone determined the presence/absence or the probability distribution of parrots in the Peninsula. We found that for the eight species, either due to the presence/absence or the probability distribution, the most important explanatory variables were the interaction among three variables, particularly the interactions among the total forest area, the total edge, and the tropical semi–evergreen medium– height forest. Habitat fragmentation influenced the potential geographical distribution of these species in terms of the characteristics of other environmental factors that are expressed together with the geographical division, such as the different vegetation cover ratio and land uses in deforested areas.

  13. Wildlife uses and hunting patterns in rural communities of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Santos-Fita, Dídac; Naranjo, Eduardo J; Rangel-Salazar, José Luis

    2012-10-02

    Subsistence hunting is a traditional practice providing food and many other goods for households in the Yucatan Peninsula, southeast Mexico. Economic, demographic, and cultural change in this region drive wildlife habitat loss and local extinctions. Improving our understanding about current practices of wildlife use may support better management strategies for conserving game species and their habitat. We aimed to evaluate if wildlife use remained relevant for the subsistence of rural residents of the Yucatan Peninsula, as well as if local hunting practices were related to environmental, geographical, and cultural factors. Fieldwork was done between March 2010 and March 2011. Information was obtained through conversations, interviews, and participant observation. Record forms allowed recording animals hunted, biomass extracted, distance intervals to hunting sites, habitat types and seasonality of wildlife harvests. Data were analyzed using one-way Analysis of Variance, and Generalized Linear Models. Forty-six terrestrial vertebrate species were used for obtaining food, medicine, tools, adornments, pets, ritual objects, and for sale and mitigating damage. We recorded 968 animals taken in 664 successful hunting events. The Great Curassow, Ocellated Turkey, paca, white-tailed deer, and collared peccary were the top harvested species, providing 80.7% of biomass (10,190 kg). The numbers of animals hunted and biomass extracted declined as hunting distances increased from villages. Average per capita consumption was 4.65 ± 2.7 kg/person/year. Hunting frequencies were similar in forested and agricultural areas. Wildlife use, hunting patterns, and technologies observed in our study sites were similar to those recorded in previous studies for rural Mayan and mestizo communities in the Yucatan Peninsula and other Neotropical sites. The most heavily hunted species were those providing more products and by-products for residents. Large birds such as the Great Curassow and

  14. Wildlife uses and hunting patterns in rural communities of the Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Santos-Fita Dídac

    2012-10-01

    Full Text Available Abstract Background Subsistence hunting is a traditional practice providing food and many other goods for households in the Yucatan Peninsula, southeast Mexico. Economic, demographic, and cultural change in this region drive wildlife habitat loss and local extinctions. Improving our understanding about current practices of wildlife use may support better management strategies for conserving game species and their habitat. We aimed to evaluate if wildlife use remained relevant for the subsistence of rural residents of the Yucatan Peninsula, as well as if local hunting practices were related to environmental, geographical, and cultural factors. Methods Fieldwork was done between March 2010 and March 2011. Information was obtained through conversations, interviews, and participant observation. Record forms allowed recording animals hunted, biomass extracted, distance intervals to hunting sites, habitat types and seasonality of wildlife harvests. Data were analyzed using one-way Analysis of Variance, and Generalized Linear Models. Results Forty-six terrestrial vertebrate species were used for obtaining food, medicine, tools, adornments, pets, ritual objects, and for sale and mitigating damage. We recorded 968 animals taken in 664 successful hunting events. The Great Curassow, Ocellated Turkey, paca, white-tailed deer, and collared peccary were the top harvested species, providing 80.7% of biomass (10,190 kg. The numbers of animals hunted and biomass extracted declined as hunting distances increased from villages. Average per capita consumption was 4.65 ± 2.7 kg/person/year. Hunting frequencies were similar in forested and agricultural areas. Discussion Wildlife use, hunting patterns, and technologies observed in our study sites were similar to those recorded in previous studies for rural Mayan and mestizo communities in the Yucatan Peninsula and other Neotropical sites. The most heavily hunted species were those providing more products and by

  15. Climate and cultural history of the Northeastern Yucatan Peninsula, Quintana Roo, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hodell, D.A. [Department of Geological Sciences, University of Florida, 241 Williamson Hall, P.O. Box 112120, Gainesville, FL 32611 (United States); Brenner, M.; Curtis, J.H. [Land Use and Environmental Change Institute (LUECI), University of Florida, Gainesville, FL (United States)

    2007-07-15

    We inferred the Holocene paleoclimate history of the northeastern Yucatan Peninsula, Mexico, by studying stratigraphic variations in stable isotopes (d 18O and d 13C) and lithologic properties (organic matter and carbonate content) in sediment cores taken in 6.3 and 16.2 m of water from Lake Punta Laguna. We present a simple model to explain the lithologic and isotopic variations, and discuss the inferred paleoclimate history in terms of its relation to ancient Maya cultural development. We find evidence for lower lake level and drier climate at about the same time as each major discontinuity in Maya cultural history: Preclassic Abandonment (150-250 A.D.), Maya Hiatus (534 to 593 A.D.), Terminal Classic Collapse (750-1050 A.D.), and Postclassic Abandonment (mid-fifteenth century). Although these broad temporal correlations suggest climate played a role in Maya cultural evolution, chronological uncertainties preclude a detailed analysis of climate changes and archaeologically documented cultural transformations.

  16. Groundwater geochemistry of the Yucatan Peninsula, Mexico: Constraints on stratigraphy and hydrogeology

    Science.gov (United States)

    Perry, Eugene; Paytan, Adina; Pedersen, Bianca; Velazquez-Oliman, Guadalupe

    2009-03-01

    SummaryWe report 87Sr/ 86Sr and ion concentrations of sulfate, chloride, and strontium in the groundwater of the northern and central Yucatan Peninsula, Mexico. Correlation between these data indicates that ejecta from the 65.95 m.y. old Chicxulub impact crater have an important effect on hydrogeology, geomorphology, and soil development of the region. Ejecta are present at relatively shallow subsurface depths in north-central Yucatan and at the surface along the Rio Hondo escarpment in southeast Quintana Roo, where they are referred to as the Albion Formation. Anhydrite/gypsum (and by inference celestite) are common in impact ejecta clasts and in beds and cements of overlying Paleocene and Lower Eocene rocks cored around the margin of the crater. The sulfate-rich minerals that are found in rocks immediately overlying the impact ejecta blanket, may either be partially mobilized from the ejecta layer itself or may have been deposited after the K/T impact event in an extensive pre-Oligocene shallow sea. These deposits form a distinctive sedimentary package that can be easily traced by the Eocene-Cretaceous 87Sr/ 86Sr signal. A distinct Sr isotopic signature and high SO 4/Cl ratios are observed in groundwater of northwestern and north-central Yucatan that interacts with these rocks. Moreover, the distribution of the gypsum-rich stratigraphic unit provides a solution-enhanced subsurface drainage pathway for a broad region characterized by dissolution features (poljes) extending from Chetumal, Quintana Roo to Campeche, Campeche. The presence of gypsum quarries in the area is also consistent with a sulfate-rich stratigraphic "package" that includes ejecta. The distinctive chemistry of groundwater that has been in contact with evaporite/ejecta can be used to trace flow directions and confirms a groundwater divide in the northern Peninsula. Information about groundwater flow directions and about deep subsurface zones of high permeability is useful for groundwater and

  17. 76 FR 34181 - Pistachios Grown in California, Arizona, and New Mexico; Proposed Amendments to Marketing Order

    Science.gov (United States)

    2011-06-13

    ...; FV11-983-1 PR] Pistachios Grown in California, Arizona, and New Mexico; Proposed Amendments to... amendments to Marketing Agreement and Order No. 983, which regulates the handling of pistachios grown in California, Arizona, and New Mexico, were proposed by the Administrative Committee for Pistachios (Committee...

  18. 75 FR 64681 - Pistachios Grown in California, Arizona, and New Mexico; Continuance Referendum

    Science.gov (United States)

    2010-10-20

    ... Service 7 CFR Part 983 [Doc. No. AMS-FV-10-0077; FV10-983-3 CR] Pistachios Grown in California, Arizona..., Arizona, and New Mexico pistachio producers to determine whether they favor continuance of the marketing order regulating the handling of pistachios grown in California, Arizona, and New Mexico. DATES: The...

  19. Reverse polarity magnetized melt rocks from the Chicxulub impact structure, Yucatan Peninsula, Mexico

    Science.gov (United States)

    Urrutia-Fucugauchi, Jaime; Marin, Luis E.; Sharpton, Virgil L.; Quezada, Juan Manuel

    1993-03-01

    Further paleomagnetic data for core samples of melt rock recovered in the Petroleos Mexicanos (PEMEX) exploratory wells within the Chicxulub structure, northern Yucatan peninsula, Mexico are reported. A previous report by Sharpton showed that the rocks studied contain high iridium levels and shocked breccia clasts, and an Ar-40/Ar-39 age of 65.2 plus or minus 0.4 Ma. The geomagnetic polarity determined for two samples is reverse (R) and was correlated with chron 29R that includes the K/T boundary. Our present analysis is based on two samples from each of three clasts of the melt rock from PEMEX well Y6-N17 (1295 to 1299 m b.s.l.). This study concentrates on the vectorial nature and stability of the remanence (NRM), the magnetic mineralogy and remanence carriers (i.e., the reliability and origin of the record), and on the implications (correlation with expected paleolatitude and polarity). The relative orientation of the drill core samples with respect to the horizontal is known. Samples were stable under alternating field (AF) and thermal treatments, and after removal of a small component they exhibited single-vectorial behavior. The characteristic remanence inclinations show small dispersion and a mean value (-43 deg) in close agreement with the expected inclination and paleolatitude (derived from the North American apparent polar wander path). Isothermal remenence (IRM) acquisition experiments, Lowrie-Fuller tests, coercivity and unblocking temperature spectra of NRM and saturation IRM, susceptibility and Q-coefficient analyses, and the single-component nature indicate a dominant mineralogy of iron-rich titanomagnetites with single or pseduo-single domain states. The stable characteristic magnetization may be interpreted as a result of shock heating of the rock at the time of formation of the inpact structure and its polarity, age, and paleolatitude are consistent with a time about the K/T boundary.

  20. Baseline study of morphometric traits of wild Capsicum annuum growing near two biosphere reserves in the Peninsula of Baja California for future conservation management.

    Science.gov (United States)

    Murillo-Amador, Bernardo; Rueda-Puente, Edgar Omar; Troyo-Diéguez, Enrique; Córdoba-Matson, Miguel Víctor; Hernández-Montiel, Luis Guillermo; Nieto-Garibay, Alejandra

    2015-05-10

    Despite the ecological and socioeconomic importance of wild Capsicum annuum L., few investigations have been carried out to study basic characteristics. The peninsula of Baja California has a unique characteristic that it provides a high degree of isolation for the development of unique highly diverse endemic populations. The objective of this study was to evaluate for the first time the growth type, associated vegetation, morphometric traits in plants, in fruits and mineral content of roots, stems and leaves of three wild populations of Capsicum in Baja California, Mexico, near biosphere reserves. The results showed that the majority of plants of wild Capsicum annuum have a shrub growth type and were associated with communities consisting of 43 species of 20 families the most representative being Fabaceae, Cactaceae and Euphorbiaceae. Significant differences between populations were found in plant height, main stem diameter, beginning of canopy, leaf area, leaf average and maximum width, stems and roots dry weights. Coverage, leaf length and dry weight did not show differences. Potassium, sodium and zinc showed significant differences between populations in their roots, stems and leaves, while magnesium and manganese showed significant differences only in roots and stems, iron in stems and leaves, calcium in roots and leaves and phosphorus did not show differences. Average fruit weight, length, 100 fruits dry weight, 100 fruits pulp dry weight and pulp/seeds ratio showed significant differences between populations, while fruit number, average fruit fresh weight, peduncle length, fruit width, seeds per fruit and seed dry weight, did not show differences. We concluded that this study of traits of wild Capsicum, provides useful information of morphometric variation between wild populations that will be of value for future decision processes involved in the management and preservation of germplasm and genetic resources.

  1. Tuluweckelia cernua, a new genus and species of stygobiont amphipod crustacean (Hadziidae) from anchialine caves on the Yucatan Peninsula in Mexico

    NARCIS (Netherlands)

    Holsinger, John R.

    1990-01-01

    Tuluweckelia cernua, a new genus and species of stygobiont amphipod is described from six anchialine caves near the northeastern coast of the state of Quintana Roo on the Yucatan Peninsula in Mexico. The new genus is closely allied morphologically with Mayaweckelia Holsinger, which is also recorded

  2. Early results from genetic trials on the growth of Spanish cedar and itssusceptibility to the shoot borer moth in the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Sheila E. Ward; Kevyn E. Wightman; Bartolo. Rodriguez Santiago

    2008-01-01

    Cedrela odorata (Spanish cedar) is a neotropical broadleaf tree species that is in high demand for furniture and interior fittings. In 1998, seed collections were made from Spanish cedar in the Yucatan Peninsula, Mexico, for genetic conservation and tree improvement projects. Progeny from these collections were established in genetic trials at Bacalar, Noh Bec, and Zoh...

  3. Shaded Relief with Height as Color and Landsat, Yucatan Peninsula, Mexico

    Science.gov (United States)

    2003-01-01

    The top picture is a shaded relief image of the northwest corner of Mexico's Yucatan Peninsula generated from Shuttle Radar Topography Mission (SRTM) data, and shows a subtle, but unmistakable, indication of the Chicxulub impact crater. Most scientists now agree that this impact was the cause of the Cretatious-Tertiary Extinction, the event 65 million years ago that marked the sudden extinction of the dinosaurs as well as the majority of life on Earth. The pattern of the crater's rim is marked by a trough, the darker green semicircular line near the center of the picture. This trough is only about 3 to 5 meters (10 - 15 feet) deep and is about 5 km (3 miles) wide; so subtle that if you walked across it you probably would not notice it. It is the surface expression of the buried crater's outer boundary. Scientists believe the impact, which was centered just off the coast in the Caribbean, altered the subsurface rocks such that the overlying limestone sediments, which formed later and erode very easily, would preferentially erode along the crater rim. This formed the trough as well as numerous sinkholes (called cenotes) which are visible as small circular depressions.The bottom picture is the same area viewed by the Landsat satellite, and was made by displaying the Thematic Mapper's Band 7 (mid-infrared), Band 4 (near-infrared) and Band 2 (green) as red, green and blue. These colors were chosen to maximize the contrast between different vegetation and land cover types, with native vegetation and cultivated land showing as green, yellow and magenta, and urban areas as white. The circular white area near the center of the image is Merida, a city of about 720,000 population. Notice that in the SRTM image, which shows only topography, the city is not visible, while in the Landsat image, which does not show elevations, the trough is not visible.Two visualization methods were combined to produce the SRTM image: shading and color coding of topographic height. The shade

  4. The SAFRR Tsunami Scenario: Improving Resilience for California from a Plausible M9 Earthquake near the Alaska Peninsula

    Science.gov (United States)

    Ross, S.; Jones, L.; Wilson, R. I.; Bahng, B.; Barberopoulou, A.; Borrero, J. C.; Brosnan, D.; Bwarie, J.; Geist, E. L.; Johnson, L.; Kirby, S. H.; Knight, W.; Long, K.; Lynett, P. J.; Miller, K.; Mortensen, C. E.; Nicolsky, D.; Oglesby, D. D.; Perry, S. C.; Plumlee, G. S.; Porter, K. A.; Real, C. R.; Ryan, K. J.; Suleimani, E.; Thio, H. K.; Titov, V.; Wein, A. M.; Whitmore, P.; Wood, N. J.

    2013-12-01

    The SAFRR Tsunami Scenario models a hypothetical but plausible tsunami, created by an Mw9.1 earthquake occurring offshore from the Alaskan peninsula, and its impacts on the California coast. We present the likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental impacts, social vulnerability, emergency management, and policy implications for California associated with the tsunami scenario. The intended users are those who must make mitigation decisions before and rapid decisions during future tsunamis. Around a half million people would be present in the scenario's inundation area in residences, businesses, public venues, parks and beaches. Evacuation would likely be ordered for the State of California's maximum mapped tsunami inundation zone, evacuating an additional quarter million people from residences and businesses. Some island and peninsula communities would face particular evacuation challenges because of limited access options and short warning time, caused by the distance between Alaska and California. Evacuations may also be a challenge for certain dependent-care populations. One third of the boats in California's marinas could be damaged or sunk, costing at least 700 million in repairs to boats and docks, and potentially much more to address serious issues due to sediment transport and environmental contamination. Fires would likely start at many sites where fuel and petrochemicals are stored in ports and marinas. Tsunami surges and bores may travel several miles inland up coastal rivers. Debris clean-up and recovery of inundated and damaged areas will take days, months, or years depending on the severity of impacts and the available resources for recovery. The Ports of Los Angeles and Long Beach (POLA/LB) would be shut down for a miniμm of two days due to strong currents. Inundation of dry land in the ports would result in 100 million damages to cargo and additional

  5. Indication of a species in an extinction vortex: The ocellated turkey on the Yucatan peninsula, Mexico

    NARCIS (Netherlands)

    Kampichler, C.; Calmé, S.; Weissenberger, H.; Arriaga-Weiss, S.

    2010-01-01

    The ocellated turkey Meleagris ocellata (OT) is a large, unmistakable endemic bird of the Yucatan peninsula. The species has suffered a considerable loss of distributional area as well as local abundance between 1980 and 2000 and is classified as endangered according to Mexican norms. We applied

  6. 75 FR 68681 - Pistachios Grown in California, Arizona, and New Mexico; Modification of the Aflatoxin Regulations

    Science.gov (United States)

    2010-11-09

    ... FIR] Pistachios Grown in California, Arizona, and New Mexico; Modification of the Aflatoxin..., Arizona, and New Mexico pistachio marketing order (order). The interim rule streamlined the aflatoxin sampling and testing procedures under the order's rules and regulations for pistachios to be shipped for...

  7. Beyond the colours: discovering hidden diversity in the Nymphalidae of the Yucatan Peninsula in Mexico through DNA barcoding.

    Directory of Open Access Journals (Sweden)

    Blanca R Prado

    Full Text Available BACKGROUND: Recent studies have demonstrated the utility of DNA barcoding in the discovery of overlooked species and in the connection of immature and adult stages. In this study, we use DNA barcoding to examine diversity patterns in 121 species of Nymphalidae from the Yucatan Peninsula in Mexico. Our results suggest the presence of cryptic species in 8 of these 121 taxa. As well, the reference database derived from the analysis of adult specimens allowed the identification of nymphalid caterpillars providing new details on host plant use. METHODOLOGY/PRINCIPAL FINDINGS: We gathered DNA barcode sequences from 857 adult Nymphalidae representing 121 different species. This total includes four species (Adelpha iphiclus, Adelpha malea, Hamadryas iphtime and Taygetis laches that were initially overlooked because of their close morphological similarity to other species. The barcode results showed that each of the 121 species possessed a diagnostic array of barcode sequences. In addition, there was evidence of cryptic taxa; seven species included two barcode clusters showing more than 2% sequence divergence while one species included three clusters. All 71 nymphalid caterpillars were identified to a species level by their sequence congruence to adult sequences. These caterpillars represented 16 species, and included Hamadryas julitta, an endemic species from the Yucatan Peninsula whose larval stages and host plant (Dalechampia schottii, also endemic to the Yucatan Peninsula were previously unknown. CONCLUSIONS/SIGNIFICANCE: This investigation has revealed overlooked species in a well-studied museum collection of nymphalid butterflies and suggests that there is a substantial incidence of cryptic species that await full characterization. The utility of barcoding in the rapid identification of caterpillars also promises to accelerate the assembly of information on life histories, a particularly important advance for hyperdiverse tropical insect

  8. Beyond the Colours: Discovering Hidden Diversity in the Nymphalidae of the Yucatan Peninsula in Mexico through DNA Barcoding

    Science.gov (United States)

    Prado, Blanca R.; Pozo, Carmen; Valdez-Moreno, Martha; Hebert, Paul D. N.

    2011-01-01

    Background Recent studies have demonstrated the utility of DNA barcoding in the discovery of overlooked species and in the connection of immature and adult stages. In this study, we use DNA barcoding to examine diversity patterns in 121 species of Nymphalidae from the Yucatan Peninsula in Mexico. Our results suggest the presence of cryptic species in 8 of these 121 taxa. As well, the reference database derived from the analysis of adult specimens allowed the identification of nymphalid caterpillars providing new details on host plant use. Methodology/Principal Findings We gathered DNA barcode sequences from 857 adult Nymphalidae representing 121 different species. This total includes four species (Adelpha iphiclus, Adelpha malea, Hamadryas iphtime and Taygetis laches) that were initially overlooked because of their close morphological similarity to other species. The barcode results showed that each of the 121 species possessed a diagnostic array of barcode sequences. In addition, there was evidence of cryptic taxa; seven species included two barcode clusters showing more than 2% sequence divergence while one species included three clusters. All 71 nymphalid caterpillars were identified to a species level by their sequence congruence to adult sequences. These caterpillars represented 16 species, and included Hamadryas julitta, an endemic species from the Yucatan Peninsula whose larval stages and host plant (Dalechampia schottii, also endemic to the Yucatan Peninsula) were previously unknown. Conclusions/Significance This investigation has revealed overlooked species in a well-studied museum collection of nymphalid butterflies and suggests that there is a substantial incidence of cryptic species that await full characterization. The utility of barcoding in the rapid identification of caterpillars also promises to accelerate the assembly of information on life histories, a particularly important advance for hyperdiverse tropical insect assemblages. PMID:22132140

  9. Use of geophysical methods to characterize groundwater in karstic rocks near Puerto Morelos, Yucatan Peninsula, Mexico

    Science.gov (United States)

    cerda Garcia, C. G.; Carpenter, P. J.; Leal-Bautista, R. M.

    2017-12-01

    Geophysical surveys were used to determine the depth of the freshwater/saltwater interface and groundwater preferential flow pathways along the Ruta de los Cenotes, near Puerto Morelos (northeast part of the Yucatán peninsula). The Yucatán Peninsula is a limestone platform that allows quick recharge of the aquifer, the main supply of water for this region. The water in the aquifer is divided into freshwater and saltwater zones. A Schlumberger resistivity sounding along the road near one cenote suggests the water table is 5 meters deep and the freshwater/saltwater interface is 38 meters deep. A time-domain electromagnetic (TEM) sounding suggests the freshwater/saltwater interface is 45 meters deep. The depth of the interface determines the volume of fresh water available. Preferential flow pathways in the vadose and saturated zones are karst conduits where groundwater percolates downward in the vadose zone. These were identified using resistivity profiling and spontaneous self-potential (SP) geophysical methods. Interpretation of SP profile Line SP1, located 3 m south of the cenote, suggests two fractures, which appear to extend south as far as SP profile Line SP2, 15 m south of the cenote; both lines are parallel to each other. SP anomalies suggest water flow along these fractures. The use of noninvasive geophysical methods, specifically SP, resistivity and TEM are useful for exploring the karst system in the Yucatán peninsula.

  10. First report of myxomatosis in Mexico.

    Science.gov (United States)

    Licón Luna, R M

    2000-07-01

    An outbreak of myxomatosis occurred between September and October 1993 on a rabbit farm in Punta Colnett (Ensenada, Baja California in northwestern Mexico, Transpeninsular Highway, km 128) and was confirmed by the Mexico-USA Commission for Prevention of Foreign Diseases of Animals (CPA). This represents the first officially confirmed case of the disease in Mexico. Like the cases in California (USA), the brush rabbit (Sylvilagus bachmani) seems to be the carrier of the virus, since serum samples from wild rabbits from different areas of the peninsula of Baja California were found to contain antibodies against the myxoma virus.

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

    Directory of Open Access Journals (Sweden)

    María C García-Aguilar

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

  12. Detection of different Leishmania spp. and Trypanosoma cruzi antibodies in cats from the Yucatan Peninsula (Mexico) using an iron superoxide dismutase excreted as antigen.

    Science.gov (United States)

    Longoni, Silvia S; López-Cespedes, Angeles; Sánchez-Moreno, Manuel; Bolio-Gonzalez, Manuel E; Sauri-Arceo, Carlos H; Rodríguez-Vivas, Roger I; Marín, Clotilde

    2012-09-01

    Although human leishmaniasis has been reported in 20 states in Mexico, no case of leishmaniasis has been reported in cats to date. In the Yucatan Peninsula, it has been found that dogs may act as reservoirs for at least three Leishmania species (Leishmania mexicana, Leishmania braziliensis, and Leishmania panamensis). In this study we identified specific antibodies against these three Leishmania spp. and Trypanosoma cruzi in the sera from 95 cats from two States on the Yucatan Peninsula, namely Quintana Roo and Yucatan, by ELISA and Western blot techniques using whole extract and an iron superoxide dismutase excreted by the parasites as antigens. As well as demonstrating the presence of trypanosomatid antibodies in the feline population on the Yucatan Peninsula, we were also able to confirm the high sensitivity and specificity of the iron superoxide dismutase antigen secreted by them, which may prove to be very useful in epidemiological studies. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Characterization of emissions sources in the California-Mexico Border Region during Cal-Mex 2010

    Science.gov (United States)

    Zavala, M. A.; Lei, W.; Li, G.; Bei, N.; Barrera, H.; Tejeda, D.; Molina, L. T.; Cal-Mex 2010 Emissions Team

    2010-12-01

    The California-Mexico border region provides an opportunity to evaluate the characteristics of the emission processes in rapidly expanding urban areas where intensive international trade and commerce activities occur. Intense anthropogenic activities, biomass burning, as well as biological and geological sources significantly contribute to high concentration levels of particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), nitrogen oxides (NOx), volatile organic compounds (VOCs), air toxics, and ozone observed in the California-US Baja California-Mexico border region. The continued efforts by Mexico and US for improving and updating the emissions inventories in the sister cities of San Diego-Tijuana and Calexico-Mexicali has helped to understand the emission processes in the border region. In addition, the recent Cal-Mex 2010 field campaign included a series of measurements aimed at characterizing the emissions from major sources in the California-Mexico border region. In this work we will present our analyzes of the data obtained during Cal-Mex 2010 for the characterization of the emission sources and their use for the evaluation of the recent emissions inventories for the Mexican cities of Tijuana and Mexicali. The developed emissions inventories will be implemented in concurrent air quality modeling efforts for understanding the physical and chemical transformations of air pollutants in the California-Mexico border region and their impacts.

  14. [Diversity, structure and regeneration of the seasonally dry tropical forest of Yucatán Peninsula, Mexico].

    Science.gov (United States)

    Hernández-Ramírez, Angélica María; García-Méndez, Socorro

    2015-09-01

    Seasonally dry tropical forests are considered as the most endangered ecosystem in lowland tropics. The aim of this study was to characterize the floristic composition, richness, diversity, structure and regeneration of a seasonally dry tropical forest landscape constituted by mature forest, secondary forest and seasonally inundated forest located in the Northeastern part of the Yucatán Peninsula, Mexico. We used the Gentry's standard inventory plot methodology (0.1 ha per forest type in 2007) for facilitating comparison with other Mesoamerican seasonally dry tropical forests. A total of 77 species belonging to 32 families were observed in the study area. Fabaceae and Euphorbiaceae were the families with the largest taxonomic richness in the three forest types. Low levels of β diversity were observed among forest types (0.19-0.40), suggesting a high turnover of species at landscape level. The non-regenerative species were dominant (50-51 %), followed by regenerative species (30- 28 %), and colonizer species (14-21 %) in the three forest types. Zoochory was the most common dispersal type in the study area. The 88 % of the observed species in the study area were distributed in Central America. Some floristic attributes of the seasonally dry tropical forest of the Yucatán Peninsula, fall into the values reported for Mesoamerican seasonally dry tropical forests. Natural disturbances contributed to explain the high number of individuals, the low number of liana species, as well as the low values of basal area observed in this study. Our results suggested that the seasonally dry tropical forest of Yucatán Peninsula seems to be resilient to natural disturbances (hurricane) in terms of the observed number of species and families, when compared with the reported values in Mesoamerican seasonally dry tropical forests. Nonetheless, the recovery and regeneration of vegetation in long-term depends on animal-dispersed species. This study highlights the importance of

  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. Fish community structure in freshwater karstic water bodies of the Sian Ka'an Reserve in the Yucatan peninsula, Mexico

    Science.gov (United States)

    Zambrano, L.; Vazquez-Dominguez, E.; Garcia-Bedoya, D.; Loftus, W.F.; Trexler, J.C.

    2006-01-01

    We evaluated the relationship between limnetic characteristics and fish community structure (based on species richness, abundance and individual size) in contrasting but interconnected inland aquatic habitats of freshwater karstic wetlands in the Yucatan peninsula, Mexico. In the western hemisphere, freshwater karstic wetlands are found in south-eastern Mexico, northern Belize, western Cuba, Andros Island, Bahamas and the Everglades of southern Florida. Only in the Everglades have fish communities been well described. Karstic wetlands are typically oligotrophic because calcium carbonate binds phosphorus, making it relatively unavailable for plants. Fourteen permanent and seasonally flooded water bodies were sampled in both wet and dry seasons in Sian Ka'an Biosphere Reserve, in the Mexican state of Quintana Roo. Water systems were divided by morphology in four groups: cenotes with vegetation (CWV), cenotes without vegetation (CNV), wetlands (WTL), and temporal cenotes (TPC). Discriminant analysis based on physical characteristics such as turbidity, temperature, depth and oxygen confirmed that these habitats differed in characteristics known to influence fish communities. A sample-based rarefaction test showed that species richness was significantly different between water systems groups, showing that WTL and CWV had higher richness values than CNV and TPC. The most abundant fish families, Poeciliidae, Cichlidae and Characidae, differed significantly in average size among habitats and seasons. Seasonal and inter-annual variation, reflecting temporal variation in rainfall, strongly influenced the environmental differences between shallow and deep habitats, which could be linked to fish size and life cycles. Five new records of species were found for the reserve, and one new record for Quintana Roo state. ?? 2006 by Verlag Dr. Friedrich Pfeil.

  17. Antibodies to West Nile virus in asymptomatic mammals, birds, and reptiles in the Yucatan Peninsula of Mexico.

    Science.gov (United States)

    Farfán-Ale, José A; Blitvich, Bradley J; Marlenee, Nicole L; Loroño-Pino, María A; Puerto-Manzano, Fernando; García-Rejón, Julián E; Rosado-Paredes, Elsy P; Flores-Flores, Luis F; Ortega-Salazar, Andres; Chávez-Medina, Jaidy; Cremieux-Grimaldi, Juan C; Correa-Morales, Favián; Hernández-Gaona, Gerson; Méndez-Galván, Jorge F; Beaty, Barry J

    2006-05-01

    Surveillance for evidence of West Nile virus (WNV) infection in taxonomically diverse vertebrates was conducted in the Yucatan Peninsula of Mexico in 2003 and 2004. Sera from 144 horses on Cozumel Island, Quintana Roo State, 415 vertebrates (257 birds, 52 mammals, and 106 reptiles) belonging to 61 species from the Merida Zoo, Yucatan State, and 7 farmed crocodiles in Ciudad del Carmen, Campeche State were assayed for antibodies to flaviviruses. Ninety (62%) horses on Cozumel Island had epitope-blocking enzyme-linked immunosorbent assay (ELISA) antibodies to flaviviruses, of which 75 (52%) were seropositive for WNV by plaque reduction neutralization test (PRNT). Blocking ELISA antibodies to flaviviruses also were detected in 13 (3%) animals in the Merida Zoo, including 7 birds and 2 mammals (a jaguar and coyote) seropositive for WNV by PRNT. Six (86%) crocodiles in Campeche State had PRNT-confirmed WNV infections. All animals were healthy at the time of serum collections and none had a history of WNV-like illness.

  18. Mapping Satellite Inherent Optical Properties Index in Coastal Waters of the Yucatán Peninsula (Mexico

    Directory of Open Access Journals (Sweden)

    Jesús A. Aguilar-Maldonado

    2018-06-01

    Full Text Available The Yucatán Peninsula hosts worldwide-known tourism destinations that concentrate most of the Mexico tourism activity. In this region, tourism has exponentially increased over the last years, including wildlife oriented tourism. Rapid tourism development, involving the consequent construction of hotels and tourist commodities, is associated with domestic sewage discharges from septic tanks. In this karstic environment, submarine groundwater discharges are very important and highly vulnerable to anthropogenic pollution. Nutrient loadings are linked to harmful algal blooms, which are an issue of concern to local and federal authorities due to their recurrence and socioeconomic and human health costs. In this study, we used satellite products from MODIS (Moderate Resolution Imaging Spectroradiometer to calculate and map the satellite Inherent Optical Properties (IOP Index. We worked with different scenarios considering both holiday and hydrological seasons. Our results showed that the satellite IOP Index allows one to build baseline information in a sustainable mid-term or long-term basis which is key for ecosystem-based management.

  19. Effects of precipitation regime and soil nitrogen on leaf traits in seasonally dry tropical forests of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Roa-Fuentes, Lilia L; Templer, Pamela H; Campo, Julio

    2015-10-01

    Leaf traits are closely associated with nutrient use by plants and can be utilized as a proxy for nutrient cycling processes. However, open questions remain, in particular regarding the variability of leaf traits within and across seasonally dry tropical forests. To address this, we considered six leaf traits (specific area, thickness, dry matter content, N content, P content and natural abundance (15)N) of four co-occurring tree species (two that are not associated with N2-fixing bacteria and two that are associated with N2-fixing bacteria) and net N mineralization rates and inorganic N concentrations along a precipitation gradient (537-1036 mm per year) in the Yucatan Peninsula, Mexico. Specifically we sought to test the hypothesis that leaf traits of dominant plant species shift along a precipitation gradient, but are affected by soil N cycling. Although variation among different species within each site explains some leaf trait variation, there is also a high level of variability across sites, suggesting that factors other than precipitation regime more strongly influence leaf traits. Principal component analyses indicated that across sites and tree species, covariation in leaf traits is an indicator of soil N availability. Patterns of natural abundance (15)N in foliage and foliage minus soil suggest that variation in precipitation regime drives a shift in plant N acquisition and the openness of the N cycle. Overall, our study shows that both plant species and site are important determinants of leaf traits, and that the leaf trait spectrum is correlated with soil N cycling.

  20. Petrography of the Nimun and Baca pottery (Ware Celestun Roja): Canbalam Ceramic Sphere of the Yucatan Peninsula, Mexico

    International Nuclear Information System (INIS)

    Obando, Luis G.; Jimenez Alvarez, Socorro del Pilar

    2016-01-01

    The ware Celestun Red (of the Nimun and Baca ceramic typologies) is one of the most diagnosis ceramics of the northwestern coast of Mexico's Yucatan Peninsula and subject of ongoing debate regarding its distribution and origin. Although ceramics from coastal Campeche and Yucatan have been the focus of years of investigation, scholars still do not know if Celestun Red was manufactured locally during the Late Classic (A.D. 600-900) or was made and exchanged by the regional elite. The first petrographic description of Celestun Red are provide, and use to contribute to a formal definition of the Cambalan Ceramic Sphere. These petrographic observations show that the detrital components were rhyolite fragments, vitroclastic tuffs, pumice, shards of glass, quartzes, plagioclase, calcite, hematite, magnetite and other minor contributors. The clay matrix is phyllomorphic, with a parallel, rectilinear fabric of fine grains. granulometricaly, the detrital components have been characterized as fine to medium sands. The pastes pastes present evidence of diagenetic processes, most notably porosity in the primary ceramic matrix. These space are in some cases filled by secondary calcite deposits. Evidence of manufacturing was also observed, such as the fracture and bending of the paste that took place to produce the rims of these ceramic objects. (author) [es

  1. Metazoan parasite infracommunities of Florida pompano (Trachinotus carolinus) from the coast of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Sánchez-Ramírez, Claudia; Vidal-Martínez, Victor M

    2002-12-01

    Metazoan parasite infracommunities of the Florida pompano (Trachinotus carolinus) were studied in terms of species composition, species richness, diversity, numerical dominance, and similarity. Seventy-five fishes were collected from 4 localities along the Yucatan Peninsula coast and 24 parasite species recovered. Most were digeneans (8 species) and nematodes (7). Other species were monogeneans (3). aspidogastreans (2), cestodes (1), acanthocephalans (1), and crustaceans (2). Only 4 species were common in at least I locality. Mean values for species richness, abundance, diversity, numerical dominance, and similarity in total (all species in the individual fish), gastrointestinal, and ectoparasite infracommunities were within ranges observed for most helminth infracommunities of marine fishes from temperate and tropical latitudes. These infracommunities had low species richness, abundance, diversity, and predictability (except ectoparasite infracommunities) and high dominance. Within the predictable element (common species), the specialist monogenean Pseudobicotylophora atlantica was the main reason for the increase in predictability because it was the only common species at all 4 localities. Host feeding habits, the distribution of intermediate hosts and infective stages, the local species pool, and a phylogenetic component seem to be determining the characteristics of these metazoan parasite infracommunities.

  2. 77 FR 21841 - Pistachios Grown in California, Arizona, and New Mexico; Decreased Assessment Rate

    Science.gov (United States)

    2012-04-12

    ... FIR] Pistachios Grown in California, Arizona, and New Mexico; Decreased Assessment Rate AGENCY... the assessment rate established for the Administrative Committee for Pistachios (Committee) for the 2011-12 and subsequent production years from $0.0007 to $0.0005 per pound of assessed weight pistachios...

  3. 76 FR 60361 - Pistachios Grown in California, Arizona, and New Mexico; Decreased Assessment Rate

    Science.gov (United States)

    2011-09-29

    ...; FV-983-2 IR] Pistachios Grown in California, Arizona, and New Mexico; Decreased Assessment Rate...: This rule decreases the assessment rate established for the Administrative Committee for Pistachios... weight pistachios. The Committee locally administers the marketing order which regulates the handling of...

  4. Health Care among the Kumiai Indians of Baja California, Mexico: Structural and Social Barriers

    Science.gov (United States)

    Fleuriet, K. Jill

    2009-01-01

    In this article, the author documents the illness and health care problems facing indigenous communities in Baja California, Mexico, by using ethnographic data from research she conducted from 1999 to 2001 with rural, indigenous Kumiai and with their primary health care providers in urban Ensenada. The author contends that barriers to care are…

  5. Planktonic cyanobacteria of the tropical karstic lake Lagartos from the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Valadez, Francisco; Rosiles-González, Gabriela; Almazán-Becerril, Antonio; Merino-Ibarra, Martin

    2013-06-01

    The tropical karstic lakes on the Mexican Caribbean Sea coast are numerous. However, there is an enormous gap of knowledge about their limnological conditions and micro-algae communities. In the present study, surface water samples were collected monthly from November 2007 to September 2008 to provide taxonomical composition and biovolume of planktonic cyanobacteria of the lake Lagartos from State of Quintana Roo, Mexico. Water temperature, pH, conductivity, salinity, soluble reactive phosphorus (SRP), dissolved inorganic nitrogen (DIN), and soluble reactive silica (SRSi) levels were also analyzed. A total of 22 species were identified. Chroococcales and Oscillatoriales dominated the phytoplankton assemblages during the study period. Chroococcus pulcherrimus, Coelosphaerium confertum, Cyanodyction iac, Phormidium pachydermaticum and Planktolyngbya contorta were recorded for the first time in Mexico. A surplus of DIN (mean value of 42.7 microM) and low concentrations of SRP (mean value of 1.0 microM) promoted the enhanced growth and bloom formation of cyanobacteria. The mean biovolume was 3.22 x 10(8) microm3/mL, and two biovolume peaks were observed; the first was dominated by Microcystis panniformis in November 2007 (7.40 x 10(8) microm3/mL), and the second was dominated by Oscillatoriaprinceps in April 2008 (6.55 x 10(8) microm3/mL). Water quality data, nitrates enrichment, and trophic state based on biovolume, indicated that Lagartos is a hyposaline, secondarily phosphorus-limited, and eutrophic lake, where the cyanobacteria flora was composed mainly by non-heterocystous groups.

  6. Planktonic Cyanobacteria of the tropical karstic lake Lagartos from the Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Francisco Valadez

    2013-06-01

    Full Text Available The tropical karstic lakes on the Mexican Caribbean Sea coast are numerous. However, there is an enormous gap of knowledge about their limnological conditions and micro-algae communities. In the present study, surface water samples were collected monthly from November 2007 to September 2008 to provide taxonomical composition and biovolume of planktonic cyanobacteria of the lake Lagartos from State of Quintana Roo, Mexico. Water temperature, pH, conductivity, salinity, soluble reactive phosphorus (SRP, dissolved inorganic nitrogen (DIN, and soluble reactive silica (SRSi levels were also analyzed. A total of 22 species were identified. Chroococcales and Oscillatoriales dominated the phytoplankton assemblages during the study period. Chroococcus pulcherrimus, Coelosphaerium confertum, Cyanodyction iac, Phormidium pachydermaticum and Planktolyngbya contorta were recorded for the first time in Mexico. A surplus of DIN (mean value of 42.7µM and low concentrations of SRP (mean value of 1.0µM promoted the enhanced growth and bloom formation of cyanobacteria. The mean biovolume was 3.22X10(8µm³/mL, and two biovolume peaks were observed; the first was dominated by Microcystis panniformis in November 2007 (7.40X10(8µm³/mL, and the second was dominated by Oscillatoria princeps in April 2008 (6.55X10(8µm³/mL. Water quality data, nitrates enrichment, and trophic state based on biovolume, indicated that Lagartos is a hyposaline, secondarily phosphorus-limited, and eutrophic lake, where the cyanobacteria flora was composed mainly by non-heterocystous groups.

  7. Unmanned aerial vehicle observations of water surface elevation and bathymetry in the cenotes and lagoons of the Yucatan Peninsula, Mexico

    Science.gov (United States)

    Bandini, Filippo; Lopez-Tamayo, Alejandro; Merediz-Alonso, Gonzalo; Olesen, Daniel; Jakobsen, Jakob; Wang, Sheng; Garcia, Monica; Bauer-Gottwein, Peter

    2018-04-01

    Observations of water surface elevation (WSE) and bathymetry of the lagoons and cenotes of the Yucatán Peninsula (YP) in southeast Mexico are of hydrogeological interest. Observations of WSE (orthometric water height above mean sea level, amsl) are required to inform hydrological models, to estimate hydraulic gradients and groundwater flow directions. Measurements of bathymetry and water depth (elevation of the water surface above the bed of the water body) improve current knowledge on how lagoons and cenotes connect through the complicated submerged cave systems and the diffuse flow in the rock matrix. A novel approach is described that uses unmanned aerial vehicles (UAVs) to monitor WSE and bathymetry of the inland water bodies on the YP. UAV-borne WSE observations were retrieved using a radar and a global navigation satellite system on-board a multi-copter platform. Water depth was measured using a tethered floating sonar controlled by the UAV. This sonar provides depth measurements also in deep and turbid water. Bathymetry (wet-bed elevation amsl) can be computed by subtracting water depth from WSE. Accuracy of the WSE measurements is better than 5-7 cm and accuracy of the water depth measurements is estimated to be 3.8% of the actual water depth. The technology provided accurate measurements of WSE and bathymetry in both wetlands (lagoons) and cenotes. UAV-borne technology is shown to be a more flexible and lower cost alternative to manned aircrafts. UAVs allow monitoring of remote areas located in the jungle of the YP, which are difficult to access by human operators.

  8. Bothriocephalus pearsei n. sp. (Cestoda: Pseudophyllidea) from cenote fishes of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Scholz, T; Vargas-Vázquez, J; Moravec, F

    1996-10-01

    The cestode Bothriocephalus pearsei n. sp. is described from the intestine of the cichlid Cichlasoma urophthalmus (Günther) from cenote (= sinkhole) Zaci near Valladolid, Yucatan, Mexico. The pimelodid catfish Rhamdia guatemalensis Günther, which also harbored conspecific cestodes, seems to represent accidental or postcyclic host of B. pearsei. The new species differs from congeners mainly by the morphology of the scolex, which is clavate, with the maximum width in its middle part, has a distinct but weakly muscular apical disc; 2 short and wide bothria distinctly demarcated in their anterior part, becoming indistinct posteriorly in the middle part of the scolex, and 2 elongate, lateral grooves. In addition to the scolex morphology, the new species can be differentiated from Bothriocephalus species parasitizing North American freshwater fishes as follows: B. claviceps (Goeze, 1782), a specific parasite of eels in the Holarctic, B. cuspidatus Cooper, 1917, occurring mostly in perciform fishes in North America, B. musculosus Baer, 1937 found in the cichlid Cichlasoma biocellata (Regan) (= C. octofasciatum (Regan)), and B. texomensis Self, 1954, described from Hiodon alosoides (Rafinesque), are much larger, with strobilae consisting of relatively short and very wide proglottids versus small-sized strobila (length 26-32 mm) composed of about 70 proglottids, which are only slightly wider than they are long (ratio 1:1-3), rectangular, or even longer than wide in the last proglottids in B. pearsei. Bothriocephalus formosus Mueller and Van Cleave, 1932, described from Percopsis omiscomaycus (Walbaum) in the USA, can be distinguished from B. pearsei, besides the different shape of the scolex, by the distribution of vitelline follicles, which are not separated into 2 lateral fields and are present along the midline of proglottids in the former species. Bothriocephalus acheilognathi, a widely distributed parasite of fishes of many families, in particular of cyprinids

  9. 76 FR 57001 - Pistachios Grown in California, Arizona, and New Mexico; Proposed Amendment of Marketing Order No...

    Science.gov (United States)

    2011-09-15

    ... Service 7 CFR Part 983 [Doc. No. AMS-FV-10-0099; FV11-983-1 PR] Pistachios Grown in California, Arizona... pistachios grown in California, Arizona, and New Mexico, and provides growers with the opportunity to vote in... Administrative Committee for Pistachios (Committee), which is responsible for local administration of the order...

  10. Isla Guadalupe, Mexico (GUAX, SCIGN/PBO) a Relative Constraint for California Borderland and Northern Gulf of California Motions.

    Science.gov (United States)

    Gonzalez-Garcia, J. J.

    2004-12-01

    Using ITRF2000 as a common reference frame link, I analyzed survey mode and permanent GPS published results, together with SOPAC public data and results (http://sopac.ucsd.edu), in order to evaluate relative present day crustal deformation in California and northern Mexico. The crustal velocity field of Mexico (Marquez-Azua and DeMets, 2003) obtained from continuous GPS measurements conducted by Instituto Nacional de Geografia e Informatica (INEGI) for 1993-2001, was partially used. The preferred model for an instantaneous rigid motion between North-America and Pacific plates (NAPA), is obtained using results of Isla Guadalupe GPS surveys (1991-2002) giving a new constraint for Pacific plate (PA) motion (Gonzalez-Garcia et al., 2003). It produces an apparent reduction of 1 mm/yr in the absolute motion in the border zone between PA and North-America (NA) plates in this region, as compared with other GPS models (v.g. Prawirodirdjo and Bock, 2004); and it is 3 mm/yr higher than NNRNUVEL-1A. In the PA reference frame, westernmost islands from San Francisco (FARB), Los Angeles (MIG1), and Ensenada (GUAX); give current residuals of 1.8, 1.7 and 0.9 mm/yr and azimuths that are consistent with local tectonic setting, respectively. In the NA reference frame, besides the confirmation of 2 mm/yr E-W extension for the southern Basin and Range province in northern Mexico; a present day deformation rate of 40.5 mm/yr between San Felipe, Baja California (SFBC) and Hermosillo, Sonora, is obtained. This rate agrees with a 6.3 to 6.7 Ma for the "initiation of a full sea-floor spreading" in the northern Gulf of California. SFBC has a 7 mm/yr motion in the PA reference frame, giving then, a full NAPA theoretical absolute motion of 47.5 mm/yr. For Puerto Penasco, Sonora (PENA) there is a NAPA motion of 46.2 mm/yr and a residual of 1.2 mm/yr in the NA reference frame, this site is located only 75 km to the northeast from the Wagner basin center. For southern Isla Guadalupe (GUAX) there

  11. Status and Causes of Soil Salinization of Irrigated Agricultural Lands in Southern Baja California,Mexico

    International Nuclear Information System (INIS)

    Endo, T.; Yamamoto, S.; Fujiyama, H.; Honna, T.; Larrinaga, J.A.

    2011-01-01

    Selected farmlands in southern Baja California, Mexico, were surveyed to determine the levels and the causes of salinization/sodication in irrigated agricultural soil. The salt dynamics observed in profiles differed from farm to farm. Low EC and high ph levels were observed in the profiles of sandy fields, because the salt composition of these soils can easily change when salts are leached by irrigation water that contains carbonates of sodium. On the other hand, high levels of salinity and sodicity were observed in the soils of clayey fields. Soil salinization/sodication is complexly interrelated with soil characteristics, the amount and composition of salts in the soil, the quantity and quality of irrigation water applied, and the irrigation methods used. Our findings indicate that irrigation water in Baja California should be supplied at a rate that is sufficient to meet crop requirements without exacerbating salt accumulation.

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

    International Nuclear Information System (INIS)

    Toscano, Lydia; Montero, Gisela; Stoytcheva, Margarita; Campbell, Hector; Lambert, Alejandro

    2011-01-01

    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)

  13. First record of a neonate California sea lion (Zalophus californianus) in Manzanillo, Colima, Mexico

    OpenAIRE

    Ortega-Ortiz, Christian D.; Elorriaga-Verplancken, Fernando; Rodríguez-Téllez, Leslie; Olivos-Ortiz, Aramis; Gaviño-Rodríguez, Juan Heberto

    2013-01-01

    We present the first report of a neonate California sea lion near Manzanillo, Colima, Mexico, about 900 km from the southernmost breeding colonies recognized for the species. The sighting occurred June 25th, 2011, and during the 2 following days, in La Boquita beach. Near the site of the sighting, sea surface temperature (SST) was recorded. SST values were some of the lowest recorded in the region (21-24° C), similar to the ones typically recorded in feeding areas in the southern Gulf of Cali...

  14. Remote sensing studies and morphotectonic investigations in an arid rift setting, Baja California, Mexico

    Science.gov (United States)

    El-Sobky, Hesham Farouk

    The Gulf of California and its surrounding land areas provide a classic example of recently rifted continental lithosphere. The recent tectonic history of eastern Baja California has been dominated by oblique rifting that began at ˜12 Ma. Thus, extensional tectonics, bedrock lithology, long-term climatic changes, and evolving surface processes have controlled the tectono-geomorphological evolution of the eastern part of the peninsula since that time. In this study, digital elevation data from the Shuttle Radar Topography Mission (SRTM) from Baja California were corrected and enhanced by replacing artifacts with real values that were derived using a series of geostatistical techniques. The next step was to generate accurate thematic geologic maps with high resolution (15-m) for the entire eastern coast of Baja California. The main approach that we used to clearly represent all the lithological units in the investigated area was objectoriented classification based on fuzzy logic theory. The area of study was divided into twenty-two blocks; each was classified independently on the basis of its own defined membership function. Overall accuracies were 89.6%, indicating that this approach was highly recommended over the most conventional classification techniques. The third step of this study was to assess the factors that affected the geomorphologic development along the eastern side of Baja California, where thirty-four drainage basins were extracted from a 15-m-resolution absolute digital elevation model (DEM). Thirty morphometric parameters were extracted; these parameters were then reduced using principal component analysis (PCA). Cluster analysis classification defined four major groups of basins. We extracted stream length-gradient indices, which highlight the differential rock uplift that has occurred along fault escarpments bounding the basins. Also, steepness and concavity indices were extracted for bedrock channels within the thirty-four drainage basins. The

  15. Seroprevalence of antibodies against the excreted antigen superoxide dismutase by Trypanosoma cruzi in dogs from the Yucatan Peninsula (Mexico).

    Science.gov (United States)

    López-Cespedes, A; Longoni, S S; Sauri-Arceo, C H; Rodríguez-Vivas, R I; Villegas, N; Escobedo-Ortegón, J; Barrera-Pérez, M A; Sánchez-Moreno, M; Bolio González, M E; Marín, C

    2013-06-01

    Numerous studies have shown the role of dogs as a reservoir for the American trypanosomiasis, as the bridge connecting sylvatic and peridomestic cycles. The objective of this study was to determine the prevalence of American trypanosomiasis in the dog population (630 sera) from seven localities in the Yucatan Peninsula (city of Mérida and the towns of Molas, Playa del Carmen, Akumal, Xcalacoop, Xcalac and Xahuachol). These data are key for developing control measures for the disease. The sera were analysed to detect antibodies against Trypanosoma cruzi, using Fe-SOD excreted as the antigenic fraction by ELISA and Western blot as confirmation. The total prevalence found in the Yucatan Peninsula was some 14.76%, with 10.74% in the state of Yucatan (city of Mérida, towns of Molas and Xcalacoop) and 21.34% in the state of Quintana Roo (towns of Playa del Carmen, Akumal, Xcalac and Xahuachol). However, a more thorough epidemiological study of the dog population, both wild and urban, in the Yucatan Peninsula will be required to design a control strategy for these diseases, paying particular attention to the population affected and even broadening the study to other Mexican states as well as neighbouring countries. These results again confirm that iron-superoxide dismutase excreted by T. cruzi constitutes a good source of antigen for serodiagnosis in epidemiological studies. © 2012 Blackwell Verlag GmbH.

  16. Brownfields Samoa Peninsula, CA: Sustainable Solutions for Historic Houses in Northern California, A Voluntary Green Code & Green Rehabilitation Manual

    Science.gov (United States)

    This manual was created to help homeowners choose sustainable strategies for restoring and rehabilitating many of the smaller, Victorian-style, wood-framed houses built in Northern California during the late 1800s and early 1900s.

  17. 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

  18. Volatile organic compound measurements in the California/Mexico border region during SCOS97

    International Nuclear Information System (INIS)

    Zielinska, B.; Sagebiel, J.; Harshfield, G.; Pasek, R.

    2001-01-01

    Measurements of volatile organic compounds (VOC) were carried out in the California/Mexico border region during the Southern California Ozone Study in the summer of 1997 (SCOS97). Integrated 3-h samples were collected in Rosarito (south of Tijuana, Mexico) and in Mexicali during intensive operational periods (IOP), twice per IOP day. VOC were collected using stainless-steel 6-l canisters; carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated C18 SepPak cartridges. The canister samples were analyzed for speciated volatile hydrocarbons (C 2 -C 12 ), CO, CO 2 , CH 4 , methyl t-butyl ether (MTBE), and halogenated hydrocarbons. DNPH-impregnated cartridges were analyzed for 14 C 1 -C 7 carbonyl compounds. The concentrations of all species were higher at Mexicali than in Rosarito. A good correlation between total non-methane hydrocarbons (TNMHC), CO, and other pollutants associated with motor vehicle emissions observed for Mexicali indicates that the main source of TNMHC at this site is vehicular traffic

  19. 77 FR 36119 - Pistachios Grown in California, Arizona, and New Mexico; Order Amending Marketing Order No. 983

    Science.gov (United States)

    2012-06-18

    ...; FV11-983-1 FR] Pistachios Grown in California, Arizona, and New Mexico; Order Amending Marketing Order... amends Marketing Agreement and Order No. 983 (order), which regulates the handling of pistachios grown in... Committee for Pistachios (Committee), which is responsible for local administration of the order. The...

  20. A new species of palaemonid shrimp, Chacella tricornuta spec. nov (Crustacea: Decapoda: Palaemonidae) from the southeastern Gulf of California, Mexico

    NARCIS (Netherlands)

    Hendrickx, M.E.

    1990-01-01

    A new species of the palaemonid shrimp genus Chacella Bruce is described from the Gulf of California, Mexico, in the eastern Pacific, and represents the second known species of this genus. The type-species, Chacella kerstitchi (Wicksten, 1983), was described from a single female captured off the

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

    Science.gov (United States)

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

    2017-11-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

  3. A new fossil peccary from the Pleistocene-Holocene boundary of the eastern Yucatán Peninsula, Mexico

    Science.gov (United States)

    Stinnesbeck, Sarah R.; Frey, Eberhard; Stinnesbeck, Wolfgang; Avíles Olguín, Jeronimo; Zell, Patrick; Terrazas Mata, Alejandro; Benavente Sanvicente, Martha; González González, Arturo; Rojas Sandoval, Carmen; Acevez Nuñez, Eugenio

    2017-08-01

    Here we describe the left mandibular ramus of a fossil peccary from the submerged karst cave system in the southeastern Mexican state of Quintana Roo. The specimen, which was discovered in the Muknal cave northwest of Tulúm, is a new genus and species of peccary termed Muknalia minima. The taxon likely dates from the latest Pleistocene and differs significantly from all extant peccaries and their Pleistocene relatives by a concave notch at the caudal edge of the mandibular ramus and prominent ventrally directed angular process. These diagnostic osteological differences suggest that the masticatory apparatus differed from all other peccaries, which may hint to an ecological isolation on the late Pleistocene Yucatán Peninsula.

  4. [Distribution of aquatic and raptor birds in a freshwater artificial pond of Baja California Sur, Mexico].

    Science.gov (United States)

    Castillo-Guerrero, J A; Carmona, R

    2001-01-01

    We determined the taxonomic composition and spatial-temporal distribution of aquatic and raptor birds in a freshwater artificial pond of El Centenario, Baja California Sur, México, during 24 biweekly censuses (April, 1998 to March, 1999). The pond is particularly attractive for birds because of its variety of food items. A total 25,563 records of 69 species were done, among them the first report of Chlidonias niger and Phalaropus tricolor for the region. Species richness and abundance were determined for the migrant component, mostly Anatidae (16 species and 55.6% of the total abundance) and shorebirds (18 species and 13.3%). The greater number of species and individuals was in C the deepest and more heterogeneous section of the pond. The most important species was Oxyura jamaicensis (30% of the total observed individuals), with highest abundance in the peninsula. The artificial pond presented an atypical and distinct ornithological composition because it is located in an arid region, and acts as a resting site for migrant birds. The site included species that usually live in freshwater and coastal areas, a characteristic reflected in their high richness. It contributes noticeably to the local avian biodiversity.

  5. [Prenatal care and hospital maternal mortality in Tijuana, Baja California, Mexico].

    Science.gov (United States)

    Gonzaga-Soriano, María Rode; Zonana-Nacach, Abraham; Anzaldo-Campos, María Cecilia; Olazarán-Gutiérrez, Asbeidi

    2014-01-01

    To describe the prenatal care (PC) received in women with maternal hospital deaths from 2005 to 2011 in Tijuana, Baja California, Mexico. Were reviewed the medical chars and registrations of the maternal deaths by the local Committees of Maternal Mortality. There were 44 maternal hospital deaths. Thirty (68%) women assisted to PC appointments during pregnancy, the average number of PC visits was 3.8 and 18 (41%) had an adequate PC (≥ 5 visits). Six (14%) women didn't know they were pregnant; 19 (43%), 21 (48%) y 4 (9%) maternal deaths were due to direct, indirect obstetric cause or non-obstetric causes. Eighteen (18%), 2 (4 %) and 34 (77%) of the maternal deaths occurred during pregnancy, delivery or puerperium. It is necessary pregnancy women have an early, periodic and systematic PC to identify opportunely risk factors associated with pregnancy complications.

  6. Metal concentrations in demersal fish species from Santa Maria Bay, Baja California Sur, Mexico (Pacific coast).

    Science.gov (United States)

    Jonathan, M P; Aurioles-Gamboa, David; Villegas, Lorena Elizabeth Campos; Bohórquez-Herrera, Jimena; Hernández-Camacho, Claudia J; Sujitha, S B

    2015-10-15

    Concentrations of 11 trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, As, Hg) in 40 fish species from Santa Maria Bay, Baja California Sur, Mexico, the strategically important area for marine mammals and organisms were analyzed. Based on their concentrations the ranking of metals Fe>Zn>Ni>Cr>Mn>Pb>Cu>Co>As>Cd>Hg suggests that organism size, metabolism and feeding habits are correlated with metal concentrations. Local geological formations affect the concentrations of different metals in the aquatic environment and are subsequently transferred to fishes. The correlation analysis suggests that metabolism and nurturing habits impact the concentration of metals. Concentrations of Fe and Mn appear to be influenced by scavenging and absorption processes, which vary by species. The considerable variability in the metal concentrations obtained in different species underscores the importance of regular monitoring. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Cyanobacterial diversity in extreme environments in Baja California, Mexico: a polyphasic study.

    Science.gov (United States)

    López-Cortés, A; García-Pichel, F; Nübel, U; Vázquez-Juárez, R

    2001-12-01

    Cyanobacterial diversity from two geographical areas of Baja California Sur, Mexico, were studied: Bahia Concepcion, and Ensenada de Aripez. The sites included hypersaline ecosystems, sea bottom, hydrothermal springs, and a shrimp farm. In this report we describe four new morphotypes, two are marine epilithic from Bahia Concepcion, Dermocarpa sp. and Hyella sp. The third, Geitlerinema sp., occurs in thermal springs and in shrimp ponds, and the fourth, Tychonema sp., is from a shrimp pond. The partial sequences of the 16S rRNA genes and the phylogenetic relationship of four cyanobacterial strains (Synechococcus cf. elongatus, Leptolyngbya cf. thermalis, Leptolyngbya sp., and Geitlerinema sp.) are also presented. Polyphasic studies that include the combination of light microscopy, cultures and the comparative analysis of 16S rRNA gene sequences provide the most powerful approach currently available to establish the diversity of these oxygenic photosynthetic microorganisms in culture and in nature.

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

    Directory of Open Access Journals (Sweden)

    Liliana Enriqueta Montaño Méndez

    2015-01-01

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

  10. Profiles of environmental contaminants in hawksbill turtle egg yolks reflect local to distant pollution sources among nesting beaches in the Yucatán Peninsula, Mexico.

    Science.gov (United States)

    Muñoz, Cynthia C; Vermeiren, Peter

    2018-04-01

    Knowledge of spatial variation in pollutant profiles among sea turtle nesting locations is limited. This poses challenges in identifying processes shaping this variability and sets constraints to the conservation management of sea turtles and their use as biomonitoring tools for environmental pollutants. We aimed to increase understanding of the spatial variation in polycyclic aromatic hydrocarbon (PAH), organochlorine pesticide (OCP) and polychlorinated biphenyl (PCB) compounds among nesting beaches. We link the spatial variation to turtle migration patterns and the persistence of these pollutants. Specifically, using gas chromatography, we confirmed maternal transfer of a large number of compounds (n = 68 out of 69) among 104 eggs collected from 21 nests across three nesting beaches within the Yucatán Peninsula, one of the world's most important rookeries for hawksbill turtles (Eretmochelys imbricata). High variation in PAH profiles was observed among beaches, using multivariate correspondence analysis and univariate Peto-Prentice tests, reflecting local acquisition during recent migration movements. Diagnostic PAH ratios reflected petrogenic origins in Celestún, the beach closest to petroleum industries in the Gulf of Mexico. By contrast, pollution profiles of OCPs and PCBs showed high similarity among beaches, reflecting the long-term accumulation of these pollutants at regional scales. Therefore, spatial planning of protected areas and the use of turtle eggs in biomonitoring needs to account for the spatial variation in pollution profiles among nesting beaches. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Occurrence of Pepper Mild Mottle Virus (PMMoV) in Groundwater from a Karst Aquifer System in the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Rosiles-González, Gabriela; Ávila-Torres, Gerardo; Moreno-Valenzuela, Oscar A; Acosta-González, Gilberto; Leal-Bautista, Rosa María; Grimaldo-Hernández, Cinthya D; Brown, Judith K; Chaidez-Quiroz, Cristóbal; Betancourt, Walter Q; Gerba, Charles P; Hernández-Zepeda, Cecilia

    2017-12-01

    The Yucatan Peninsula of Mexico hosts a karst aquifer system that is the only source of freshwater for the area; however, it is vulnerable to human-mediated contamination. Pepper mild mottle virus (PMMoV) is one of the most abundant RNA viruses associated with human feces, making it a viable indicator for tracking fecal pollution in aquatic environments, including groundwater. In this study, groundwater samples collected from a karst aquifer from fresh and brackish water locations were analyzed for fecal indicator bacteria, somatic and male F+ specific coliphages, and PMMoV during the rainy and dry seasons. Total coliform bacteria were detected at all sites, whereas Escherichia coli were found at relatively low levels water type (p > 0.05). Physicochemical and indicator bacteria were not correlated with PMMoV concentrations. The abundance and prevalence of PMMoV in the karst aquifer may reflect its environmental persistence and its potential as a fecal indicator in this karst aquifer system.

  12. Price, Virtues, Principles: How to Discern What Inspires Best Practices in Water Management? A Case Study about Small Farmers in the Yucatan Peninsula of Mexico

    Directory of Open Access Journals (Sweden)

    Rafael R. Ramírez

    2016-04-01

    Full Text Available Improving water practices among small farmers in a water scarce area like the Yucatan Peninsula in Mexico is a complex task. Despite government attempts to enforce regulations and question the possibility of adjusting prices, the misuse of this scarce resource continues. Most farmers are, at best, motivated to aim for a minimum level of compliance, with very few striving to engage in best practices. This article seeks to make a proposal about the best drivers for inspiring best practices in an effort to improve the use of water management in the area. It proposes that a virtue ethics approach that explicitly focuses on the cultivation of an attitude of respect for water founded on three key principles (participation, hydrosolidarity and proactive engagement is the best solution for Yucatan. This hypothesis is the result of developing a singular methodology based on Partial Least Squares (PLS, according to structural equation modeling (SEM, that could be replicated anywhere to ascertain which measures are best suited in a particular context. Using a small sample size, this research ascertains what is required to achieve best practices with regards to the management of water in that particular area.

  13. Risks for abuse against pregnant Hispanic women: Morelos, Mexico and Los Angeles County, California.

    Science.gov (United States)

    Castro, Roberto; Peek-Asa, Corinne; García, Lorena; Ruiz, Agustín; Kraus, Jess F

    2003-11-01

    Although violence against women is gaining international attention as a prevention priority, little is known about how risks differ across countries. A comparative study of violence against pregnant Mexican women in Morelos, Mexico, and Latina women in Los Angeles County, California, United States. In 1998 and 1999, women in prenatal clinics were interviewed about psychological abuse and sexual and physical violence by their partner, during and the 1 year prior to the index pregnancy. The overall response rate for Morelos was 99%, with a sample size of 914; Los Angeles County had a response rate of 96.9%, with a sample size of 219. Women in Morelos reported a higher prevalence of violence compared to women in the California (14.8% v 11.9%, respectively). A partner aged child were more than 25 times more likely to be abused during pregnancy than women not reporting this type of abuse. The identification of factors associated with violence against women, especially as they differ by culture and ethnicity, will help clinicians to better identify victims and to design and implement culturally appropriate prevention programs.

  14. Minimum area thresholds for rattlesnakes and colubrid snakes on islands in the Gulf of California, Mexico.

    Science.gov (United States)

    Meik, Jesse M; Makowsky, Robert

    2018-01-01

    We expand a framework for estimating minimum area thresholds to elaborate biogeographic patterns between two groups of snakes (rattlesnakes and colubrid snakes) on islands in the western Gulf of California, Mexico. The minimum area thresholds for supporting single species versus coexistence of two or more species relate to hypotheses of the relative importance of energetic efficiency and competitive interactions within groups, respectively. We used ordinal logistic regression probability functions to estimate minimum area thresholds after evaluating the influence of island area, isolation, and age on rattlesnake and colubrid occupancy patterns across 83 islands. Minimum area thresholds for islands supporting one species were nearly identical for rattlesnakes and colubrids (~1.7 km 2 ), suggesting that selective tradeoffs for distinctive life history traits between rattlesnakes and colubrids did not result in any clear advantage of one life history strategy over the other on islands. However, the minimum area threshold for supporting two or more species of rattlesnakes (37.1 km 2 ) was over five times greater than it was for supporting two or more species of colubrids (6.7 km 2 ). The great differences between rattlesnakes and colubrids in minimum area required to support more than one species imply that for islands in the Gulf of California relative extinction risks are higher for coexistence of multiple species of rattlesnakes and that competition within and between species of rattlesnakes is likely much more intense than it is within and between species of colubrids.

  15. Is There any Relationship Between the Santa Elena Depression and Chicxulub Impact Crater, Northwestern Yucatan Peninsula, Mexico?

    Science.gov (United States)

    Lefticariu, L.

    2005-05-01

    isolated saline lake (Middle Eocene), and 3) shallow marine water (Middle-Late Eocene?). In places, the deeper-water facies are similar to those within the Chicxulub Sedimentary Basin. The shallow-water facies is similar to those occurring outside the Basin. In general, quartz and silicates are rare in the Cenozoic sedimentary carbonate of the northwestern Yucatan Peninsula. Therefore, their presence in the UNAM 5 core could be attributed to either impact breccia reworking or silicic volcanic processes. Quartz, chert, zeolite, and clay also are common in the suevite breccia of both Yax-1 and UNAM 5 cores. The fact that the Santa Elena Depression was a distinct sedimentary basin during much of the Paleogene could be explained by any or a combination of the following hypotheses: 1) In spite of being located outside the cenote ring, the Depression is a sub-basin of the larger and deeper Chicxulub Sedimentary Basin and is therefore located within the Chicxulub Impact Crater, 2) the Depression coincides with an impact crater distinct from the Chicxulub Impact Crater, 3) the Depression formed after the Chicxulub bolide impact due to slumping, crater wall failure, or larger-scale tectonic processes. The lack of conclusive evidence for multiple impact breccia layers in the northwestern Yucatan Peninsula, corroborated with the presence on top of the impact breccia from UNAM 5 core of deeper-water limestone similar to that of Late Paleocene-Early Eocene age from Yax-1 core, would be more consistent with either the first or third hypothesis.

  16. Mexico.

    Science.gov (United States)

    Semaan, Leslie

    The text explores Mexico's history, geography, art, religion, and lifestyles in the context of its complex economy. The text focuses on Mexico's economy and reasons for its current situation. Part I of this teaching unit includes: Teacher Overview, Why Study Mexico, Mexico Fact Sheet, Map of Mexico, the Land and Climate, History, Government,…

  17. Evolution of the east-central San Jose del Cabo basin, Baja California Sur, Mexico

    Science.gov (United States)

    McTeague, M. S.; Umhoefer, P. J.; Schwennicke, T.; Ingle, J. C.; Cortes Martinez, M.

    2006-12-01

    The San Jose del Cabo basin at the southern tip of the Baja California peninsula records the early tectonic evolution of the west side of the Gulf of California. This study focused on the east central margin of the basin. The basal La Calera Formation unconformably overlies Cretaceous granite and consists of conglomerate, pebbly sandstone and conglomerate, and sandstone deposited in alluvial fans and fan-deltas. Deposition of the La Calera Formation was from ca. 9-14 Ma. The lower member of the Trinidad Formation was deposited beginning ca. 9-13 Ma and consists of sandstone, mudstone, and shelly mudstone deposited in nearshore and estuarine environments. These age estimates are based on sedimentation rates and foraminifera and coccoliths from the NN 11A nannozone (7.4 8.6 Ma, GTS 2004). The middle member of the Trinidad Formation consists of deeper water mudstones deposited by turbidity currents and suspension settling in a shelf to slope and conglomerates deposited by submarine debris flows on the shelf. The basin began earlier than previously thought. The oldest marine rocks are ca.9-13 Ma, while sedimentation on the east side began at ca. 9-14 Ma, synchronous with estimates of initiation of offset on the San Jose del Cabo fault. The Zapote fault is a down-to-the-east normal and sinistral-oblique fault that exposes a wedge of granite and older strata in the footwall to the west. The fault was active during sedimentation in the late Miocene and possibly later. The fault divides the study area into an eastern hanging wall subbasin and western footwall subbasin. The eastern subbasin formed an embayment in the eastern margin of the Cabo basin. A regional flooding surface (ca. 8 Ma) can be correlated across the fault that marks a major marine incursion. Depositional systems evolved rapidly from coarse-grained terrestrial systems to fine-grained marine and estuarine systems. The Cabo basin provides an excellent analogue for comparison with offshore basins, which are

  18. Hydrogeothermal Convective Circulation Model for the Formation of the Chicxulub Ring of Cenotes in the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Monroy-Rios, E.; Beddows, P. A.

    2015-12-01

    Despite being deeply buried, the topography and geophysical characteristics of the multi-ring Chicxulub impact structure are reflected on the now subaerial Yucatan Peninsula with aligned arcs of cenotes (sinkholes), forming the "Ring of Cenotes". A pending question is the determination of the geological, geochemical, structural features and associated processes that have led to void development, and the upwards propagation of the voids, cross cutting over 1000 m of super-deposited carbonate sequences. Drawing from the published literature on drill core and geophysical surveys undertaken by Pemex, UNAM, and IODP/ICDP, numerical modeling, and general carbonate platform hydrothermal reactive transport models, we provide a conceptual model for the genesis of the Ring of Cenotes. In horizontally bedded carbonate platforms, geothermal gradients will drive convective flow, with strong vertical components specifically in the platform center. In the Yucatan Platform, a high occurrence of anhydrite and dolomite at depth evokes early burial dolomitization and anhydritization, sourcing Mg from seawater. The Chicxulub impact near the center of the platform produced a low permeability and high thermal conductivity melt rock that arguably extends to the basement rock at 3.5 km below surface. Heat of impact enforced the pre-existing geothermal circulation pattern, and even with depletion of the heat of impact, the high thermal conductivity of the crystalline melt would lead to enhanced geothermal gradients in the center of the platform. The cenotes overlying the crater are deep (150+ m) vertical shafts with most (but not all) breaching the surface. The pit geomorphology suggests a bottom-up formation. Excess Si in the shallow groundwater points to a convective circulation with strong vertical components geochemically linking the granodioritic basement rock to the surface. Water temperature and conductivity profiles support ongoing vertical flux in some deep pit cenotes. Within

  19. Displacement of Aphytis chrysomphali by Aphytis melinus, parasitoids of the California red scale, in the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Juan Ramon Boyero

    2014-02-01

    Full Text Available Parasitoids are the main natural enemies of the California red scale, Aonidiella aurantii (Maskell and on occasion can regulate their populations. To increase their effectiveness, inoculative or augmentative releases of parasitoids are promoted. Previous to the implementation of any release strategy an important and necessary step is to acquire knowledge on the parasitoid fauna associated with this key phytophagous pest. Parasitoids were surveyed and quantified in Spanish citrus orchards between 2005 and 2009. Aphytis melinus DeBach (87.1% resulted as the dominant species, followed by Aphytis chrysomphali (Mercet (15.9%, Encarsia perniciosi (Tower (2.4% and Aphycus hederaceus (Westwood (0.004%. Overall, higher levels of parasitism were recorded in fruit than in twigs. Scales in fruit were parasitized at similar levels by the different parasitoid species whereas E. perniciosi was more active in twigs. Data eventually reveal the recent displacement of A. chrysomphali by A. melinus. The implications of these results on the biological control of A. aurantii are discussed and this information will be useful in the decision of IPM strategies for this pest.

  20. Public Outreach and Educational Experiences in Mexico and Latin American communities in California

    Science.gov (United States)

    Andres De Leo-Winkler, Mario; Canalizo, Gabriela; Pichardo, Barbara; Arias, Brenda

    2015-08-01

    I have created and applied diverse methods in public outreach at National Autonomous Univerisity of Mexico (UNAM) since 2001.A student-led volunteer astronomical club has been created, the biggest in Mexico. We serve over 10,000 people per year. We have created public outreach activities for the general audience: archeo-astronomical outings, scientific movie debates, conferences, courses, public telescope viewings. We have also worked with juvenile delinquents to offer them scientific opportunities when released from jail.I've also created and worked the social media for the Institute of Astronomy UNAM, which is currently the biggest social media site on astronomy in Spanish in the world. I've created and organized a mass photo exhibition (over 1 million people served) for the Institute of Astronomy, UNAM which was citizen-funded through an online platform, the first of its kind in the country. Together with my colleages, we created workshops on astronomy for children with the Mexican's government funding.I've participated in several radio and television programs/capsules designed to bring astronomy to the general audience, one in particular ("Astrophysics for Dummies") was very successful in nation-wide Mexican radio.I am currently applying all experiences to develop a new public outreach project on astronomy for the University of California - Riverside and its on-campus and surrounding Latin American communities. We are offering new workshops for blind and deaf children. We want to integrate the Latino community to our outreach activities and offer science in their language in a simple and entertaining fashion. We have also successfully applied astrophotography as a course which brings social-science and arts undergraduate students into natural sciences.Sharing experiences, success and failure stories will help new and experienced educators and public outreach professionals learn and better from past experiences.

  1. 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

  2. Fetal mummification in silky shark (Carcharhinus falciformis from the Gulf of California, Mexico

    Directory of Open Access Journals (Sweden)

    Jonathan Sandoval-Castillo

    2008-06-01

    Full Text Available The aim of this work was the description of fetal mummification in silky shark. During July of 2001 in Santa Maria fishing camp, Gulf of California Mexico, fourteen pregnant female of silky sharks were captured. In all of them the embryos were found to be dehydrated. However, total observations were possible in only two litters. Six embryos in each analyzed litters were found. All the embryos were mummified, complete and without maceration. Because the litters were totally mummificated in several females, it was suggested that fetal mummification was produced by the environmental condition.A mumificação fetal é caracterizada pela desidatração de embriões mortos dentro do útero da mãe. A perda de embriões pode afetar a sustentabilidade da população explorada, tornando o estudo deste fenômeno de suma importância. Em Julho de 2001 quatorze femeas grávidas do tubarão lombo preto foram capituradas durante uma amostragem no campo pesqueiro de Santa Maria, Golfo de California, México. Todas as fêmeas capturadas apresentaram embriões mumificados. Infelizmente, observações detalhadas dos embriões foram possíveis em apenas duas fêmeas. Cada fêmea analizada apresentava seis embriões, todos completamente mumificados e sem maceração. Embriões completamente mumificados foram encontrados em muitas fêmeas, o que sugere que a mumificação fetal desses embriões pode ter sido causada por condições ambientais.

  3. Eco-bio-social determinants for house infestation by non-domiciliated Triatoma dimidiata in the Yucatan Peninsula, Mexico.

    Directory of Open Access Journals (Sweden)

    Eric Dumonteil

    Full Text Available BACKGROUND: Chagas disease is a vector-borne disease of major importance in the Americas. Disease prevention is mostly limited to vector control. Integrated interventions targeting ecological, biological and social determinants of vector-borne diseases are increasingly used for improved control. METHODOLOGY/PRINCIPAL FINDINGS: We investigated key factors associated with transient house infestation by T. dimidiata in rural villages in Yucatan, Mexico, using a mixed modeling approach based on initial null-hypothesis testing followed by multimodel inference and averaging on data from 308 houses from three villages. We found that the presence of dogs, chickens and potential refuges, such as rock piles, in the peridomicile as well as the proximity of houses to vegetation at the periphery of the village and to public light sources are major risk factors for infestation. These factors explain most of the intra-village variations in infestation. CONCLUSIONS/SIGNIFICANCE: These results underline a process of infestation distinct from that of domiciliated triatomines and may be used for risk stratification of houses for both vector surveillance and control. Combined integrated vector interventions, informed by an Ecohealth perspective, should aim at targeting several of these factors to effectively reduce infestation and provide sustainable vector control.

  4. Palaeoenvironmental Evolution of Cenote Aktun Ha (Carwash) on the Yucatan Peninsula, Mexico and its Response to Holocene Sea-Level Rise

    Science.gov (United States)

    Gabriel, J. J.; Reinhardt, E. G.; Peros, M. C.; Davidson, D. E.; van Hengstum, P. J.; Beddows, P. A.

    2008-12-01

    A 61-cm core was obtained from 4 metres below the water table in Cenote Aktun Ha, on the Yucatan Peninsula, Mexico. The cenote is 8.6 km from the Caribbean coast and its formation and evolution have been largely affected by sea-level change. The base of the core dates to 6940 - 6740 cal yr BP and overlying sediments were deposited rapidly over the subsequent ~200 years. The pollen record shows that the cenote evolved from a marsh dominated by red mangrove (Rhizophora mangle) and fern (Polypodiaceae) to an open-water system. These vegetation changes were controlled by water level and salinity and are thus useful indicators of past sea level. At the base, the d13C isotopic ratios reveal the influence of terrestrial vegetation (-29‰), but shift to more negative values up-core (-33‰), indicating an influence from particulate matter in the flooded cenote pool. Although microfossil populations were nearly absent through most of the core, the microfossil assemblage in the upper 6 cm of the core is dominated by juvenile Ammonia tepida and the thecamoebian genus Centropyxis. These populations indicate open-water conditions in the cenote and a major environmental shift around 6600 cal yr BP, which is related to sea-level rise in the Caribbean basin. These data fit well with previously established sea-level curves for the Caribbean Sea. Our reconstruction of the environmental history of Cenote Aktun Ha helps elucidate the floral and hydrological history of the region, and highlights the utility of cenote sediments for studying the Holocene sea-level history of the Caribbean Sea.

  5. Sources and transport of black carbon at the California-Mexico border

    Science.gov (United States)

    Shores, Christopher A.; Klapmeyer, Michael E.; Quadros, Marina E.; Marr, Linsey C.

    2013-05-01

    At international border areas that suffer from poor air quality, assessment of pollutant sources and transport across the border is important for designing effective air quality management strategies. As part of the Cal-Mex 2010 field campaign at the US-Mexico border in San Diego and Tijuana, we measured black carbon (BC) concentrations at three locations in Mexico and one in the United States. The measurements were intended to support the following objectives: to characterize the spatial and temporal variability in BC, to estimate the BC emission inventory, to identify potential source areas of BC emissions, and to assess the cross-border transport of BC. Concentrations at Parque Morelos, the campaign's supersite, averaged 2.2 μg m-3 and reached a maximum value of 55.9 μg m-3 (1-min average). Sharp, regularly occurring peaks around midnight were suggestive of clandestine industrial activity. BC concentrations were more than two times higher, on average, in Tijuana compared to San Diego. BC and carbon monoxide (CO) were strongly correlated at the three sites in Mexico. The ΔBC/ΔCO ratio of 5.6 ± 0.5 μg m-3 ppm-1 in Tijuana, or 4.7 ± 0.5 μg m-3 ppm-1 when adjusted for seasonal temperature effects to represent an annual average, was comparable to that in other urban areas. Tijuana's emissions of BC were estimated to be 230-890 metric tons per year, 6-23% of those estimated for San Diego. Large uncertainties in this estimate stem mainly from uncertainties in the CO emission inventory, and the lower end of the estimate is more likely to be accurate. Patterns in concentrations and winds suggest that BC in Tijuana was usually of local origin. Under typical summertime conditions such as those observed during the study, transport from Tijuana into the US was common, crossing the border in a northeasterly direction, sometimes as far east as Imperial County at the eastern edge of California.

  6. [Distribution of aquatic birds in oxidation lagoons of La Paz city in South Baja California, Mexico].

    Science.gov (United States)

    Zamora-Orozco, Elvia Margarita; Carmona, Roberto; Brabata, Georgina

    2007-06-01

    Taxonomic composition, spatial and temporal distribution of aquatic birds in oxidation lagoons (LO) of La Paz city in south Baja California, Mexico, were determined during 24 censuses realized in two-week intervals (April/98-March/99). There are five lagoons of5 Ha each and 17 ha of terrains constantly flooded that serve as feeding areas for cattle and birds. One hundred twenty three species were observed, 75 of which were aquatic birds. A total of 46 041 observations were made (average 1 918 birds/census). Richness and abundance of aquatic birds were influenced mainly by migration of anatids and sandpipers. The first group had the greatest abundance due to its affinity towards fresh water bodies. The terrains were the favorite sites of dabbling ducks (Anas) and sandpipers. In contrast, two of the most abundant species (Oxyura jamaicensis, 12.5% of all species, and Fulica americana, 8.8 %) restricted their presence to the oxidation lagoons. LO presented a bird structure of its own and atypical, according to the dryness of the region.

  7. First record of Pseudomyicola spinosus in Argopecten ventricosus in Baja California, Mexico.

    Science.gov (United States)

    Cáceres-Martínez, Carlos; Chávez-Villalba, Jorge; Garduño-Méndez, Laura

    2005-06-01

    This is the first record of the copepod Pseudomyicola spinosus in the scallop Argopecten ventricosus in northwestern Mexico, and describes: (1) the known annual prevalence and intensity of this copepod on scallops from culture sites (Gulf of California) and natural populations (Pacific coast), (2) the histopathological effects caused on the soft tissues of scallops, and (3) the relationship between prevalence and intensity records and environmental parameters. The copepod was present throughout the period of investigation, showing similar prevalence and ratio of copepod to scallop patterns in both cultured scallops and wild specimens from natural habitats. Highest prevalence and ratio values were detected in summer-autumn at both sites, probably because scallops showed a weak condition from the combined effects of spawning, reabsorption of residual gametes, and high temperature. The condition index of A. ventricosus showed a significant correlation with the presence of the copepod in Magdalena Bay (-0.67). P. spinosus was observed in the gills of scallops, producing alterations or rupture of filaments, and in the stomach, causing detachment and loss of the epithelium. No relationship between copepod infestation with temperature, salinity, chlorophyll, and seston were found during the investigation. Although P. spinosus was present year-round at both sites, no association between infestation and scallop mortalities was detected.

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

    Directory of Open Access Journals (Sweden)

    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. 

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

    Science.gov (United States)

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

    2017-10-01

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

  10. Modeling of Trans-boundary Transport of Air Pollutants in the California-Mexico Border Region during Cal-Mex 2010

    Science.gov (United States)

    Bei, N.; Zavala, M. A.; Lei, W.; Li, G.; Molina, L. T.

    2010-12-01

    The US and Mexico share a common air basin along the ~200 km border between California and Baja California. The economical activities in this region are heavily influenced by the international trade and commerce between Mexico and the US that mainly occurs through the borders of the sister cities of San Diego-Tijuana and Calexico-Mexicali. The diversity and differences in the characteristics of emissions sources of air pollutants in the California-Mexico border region make this an important area for the study of the chemistry and trans-boundary transport of air pollutants. During May-June of 2010, the Cal-Mex 2010 field campaign included a series of measurements aimed at characterizing the emissions from major sources in the California-Mexico border region and assessing the possible impacts of these emissions on local and regional air quality. In this work we will present the results of the use of the Comprehensive Air quality model with extensions (CAMx) in a modeling domain that includes the sister cities of San Diego-Tijuana and Calexico-Mexicali for studying events of trans-boundary transport of air pollutants during Cal-Mex 2010. The measurements obtained during the Cal-Mex 2010 field campaign are used in the evaluation of the model performance and in the design of air quality improvement policies in the California-Mexico border region.

  11. 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

  12. 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.

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

    Science.gov (United States)

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

    2017-12-01

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

  14. 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

  15. Structure of the 1906 near-surface rupture zone of the San Andreas Fault, San Francisco Peninsula segment, near Woodside, California

    Science.gov (United States)

    Rosa, C.M.; Catchings, R.D.; Rymer, M.J.; Grove, Karen; Goldman, M.R.

    2016-07-08

    High-resolution seismic-reflection and refraction images of the 1906 surface rupture zone of the San Andreas Fault near Woodside, California reveal evidence for one or more additional near-surface (within about 3 meters [m] depth) fault strands within about 25 m of the 1906 surface rupture. The 1906 surface rupture above the groundwater table (vadose zone) has been observed in paleoseismic trenches that coincide with our seismic profile and is seismically characterized by a discrete zone of low P-wave velocities (Vp), low S-wave velocities (Vs), high Vp/Vs ratios, and high Poisson’s ratios. A second near-surface fault strand, located about 17 m to the southwest of the 1906 surface rupture, is inferred by similar seismic anomalies. Between these two near-surface fault strands and below 5 m depth, we observed a near-vertical fault strand characterized by a zone of high Vp, low Vs, high Vp/Vs ratios, and high Poisson’s ratios on refraction tomography images and near-vertical diffractions on seismic-reflection images. This prominent subsurface zone of seismic anomalies is laterally offset from the 1906 surface rupture by about 8 m and likely represents the active main (long-term) strand of the San Andreas Fault at 5 to 10 m depth. Geometries of the near-surface and subsurface (about 5 to 10 m depth) fault zone suggest that the 1906 surface rupture dips southwestward to join the main strand of the San Andreas Fault at about 5 to 10 m below the surface. The 1906 surface rupture forms a prominent groundwater barrier in the upper 3 to 5 m, but our interpreted secondary near-surface fault strand to the southwest forms a weaker barrier, suggesting that there has been less or less-recent near-surface slip on that strand. At about 6 m depth, the main strand of the San Andreas Fault consists of water-saturated blue clay (collected from a hand-augered borehole), which is similar to deeply weathered serpentinite observed within the main strand of the San Andreas Fault at

  16. San Juanico, BCS, Mexico, hybrid electric plant renewable energies in the rural communities development; Planta electrica hibrida San Juanico, B.C.S., Mexico, las energias renovables en el desarrollo de las comunidades rurales

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Rios, Serafin [Gerencia de Proyectos Geotermoelectricos, Comision Federal de Electricidad (Mexico)

    1999-08-01

    The hybrid electric plant of San Juanico, B.C.S., Mexico, is described in terms of its environmental goals, operating process and contribution to the development of that rural community of the Baja California Peninsula. San Juanico hybrid electric plant is organized in three electrical generation systems that work in parallel: one uses solar energy, another wind energy and a third one uses diesel fuel. [Spanish] Se describe la planta hibrida de San Juanico, BCS, Mexico, en terminos de los objetivos ambientales que condujeron a su realizacion, asi como de su proceso operativo y de la participacion que tiene en el desarrollo de esa comunidad rural de la peninsula de Baja California, Mexico. La planta hibrida de San Juanico esta constituida por tres sistemas de generacion de electrcicidad que operan en paralelo: uno utiliza energia radiante del sol, otro energia del viento y un tercero utiliza diesel.

  17. 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

  18. 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 that

  19. 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.

  20. Finite source modelling of magmatic unrest in Socorro, New Mexico, and Long Valley, California

    Science.gov (United States)

    Fialko, Yuri; Simons, Mark; Khazan, Yakov

    2001-07-01

    We investigate surface deformation associated with currently active crustal magma bodies in Socorro, New Mexico, and Long Valley, California, USA. We invert available geodetic data from these locations to constrain the overall geometry and dynamics of the inferred deformation sources at depth. Our best-fitting model for the Socorro magma body is a sill with a depth of 19km, an effective diameter of 70km and a rate of increase in the excess magma pressure of 0.6kPayr-1. We show that the corresponding volumetric inflation rate is ~6×10-3km3yr-1, which is considerably less than previously suggested. The measured inflation rate of the Socorro magma body may result from a steady influx of magma from a deep source, or a volume increase associated with melting of the magma chamber roof (i.e. crustal anatexis). In the latter case, the most recent major injection of mantle-derived melts into the middle crust beneath Socorro may have occurred within the last several tens to several hundreds of years. The Synthetic Interferometric Aperture Radar (InSAR) data collected in the area of the Long Valley caldera, CA, between June 1996 and July 1998 reveal an intracaldera uplift with a maximum amplitude of ~11cm and a volume of 3.5×10-2km3. Modelling of the InSAR data suggests that the observed deformation might be due to either a sill-like magma body at a depth of ~12km or a pluton-like magma body at a depth of ~8km beneath the resurgent dome. Assuming that the caldera fill deforms as an isotropic linear elastic solid, a joint inversion of the InSAR data and two-colour laser geodimeter data (which provide independent constraints on horizontal displacements at the surface) suggests that the inferred magma chamber is a steeply dipping prolate spheroid with a depth of 7-9km and an aspect ratio in excess of 2:1. Our results highlight the need for large radar look angles and multiple look directions in future InSAR missions.

  1. 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

  2. Pandemic (H1N1) 2009 Surveillance in Marginalized Populations, Tijuana, Mexico, and West Nile Virus Knowledge among Hispanics, San Diego, California, 2006

    Centers for Disease Control (CDC) Podcasts

    This podcast describes public health surveillance and communication in hard to reach populations in Tijuana, Mexico, and San Diego County, California. Dr. Marian McDonald, Associate Director of CDC's Health Disparities in the National Center for Emerging and Zoonotic Infectious Diseases, discusses the importance of being flexible in determining the most effective media for health communications.

  3. Validation of the ISAAC Standardized Questionnaire Used by Schoolchildren from Mexicali, Baja California, Mexico

    OpenAIRE

    Gorozave-Car, Karla; Barraza-Villarreal, Albino; Escamilla-Núñez, Consuelo; Hernandez-Cadena, Leticia; Sanín-Aguirre, Luz Helena; Cortez-Lugo, Marlene; Blanco-Muñoz, J.; Riojas-Rodríguez, Horacio; Moreno-Macias, Hortensia; Romieu, Isabelle

    2013-01-01

    Background. In Mexico, several studies have been conducted under the ISAAC methodology; nevertheless, no validation studies of the ISAAC questionnaire based on objective clinical testing in our country have been published. Aims of the Study. To validate the ISAAC questionnaire, used in a study of prevalence of allergic diseases, based on medical, respiratory, and allergic evaluations of schoolchildren being 11 to 16 years old in Mexicali, Mexico. Material and Methods. We conducted a cross-sec...

  4. 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...

  5. [Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico].

    Science.gov (United States)

    López-Martínez, Juana; Acevedo-Cervantes, Alejandro; Herrera-Valdivia, Eloisa; Rodríguez-Romero, Jesús; Palacios-Salgado, Deivis S

    2012-03-01

    The Gulf of California has a high variety of ecosystems that allow different services and the fishery resources play a prominent role in its ecology, evolution and economics. Fish coastal species have been previously reported for most coastal areas, especially those species that are subject to fishing, however, little is known on the species from deep sea zones, due to sampling difficulties. We studied the deep sea fishes collected with trawl nets during three research surveys in the Gulf of California, Mexico in 2004-2005. We provide a systematic checklist and some notes on biogeographical aspects. For this, 74 fishing hauls were done, and a total of 9 898 fishes were captured, belonging to two classes, 15 orders, 35 families, 53 genera and 70 species. The best represented families in number of species were: Paralichthyidae (eight), Serranidae (six), and Scorpaenidae and Triglidae with five species each one. The typical families from deep waters were: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae and Cynoglossidae. Size range varied from 13cm for the Splinose searobin (Bellator xenisma) to 234cm in the Pacific Cutlassfish (Trichiurus nitens). The biogeographical affinity showed that species with affinity to the East Tropical Pacific (ETP) dominated, followed by species from San Diego-Panamic, San Diego-Panamic-Peruvian-Chilean and Oregonian-Cortes provinces, respectively. A biogeographic overlap was found in the fauna, which reflects the Gulf of California's geographical position, with distribution limits of species from temperate, tropical and warm-temperature transition affinities, divisions that characterize the Gulf of California. Taxonomic status of fish with a focus on composition, location, characterization and zoogeography are fundamental to any subject of biodiversity and fisheries management actions.

  6. The 2010 M w 7.2 El Mayor-Cucapah Earthquake Sequence, Baja California, Mexico and Southernmost California, USA: Active Seismotectonics along the Mexican Pacific Margin

    Science.gov (United States)

    Hauksson, Egill; Stock, Joann; Hutton, Kate; Yang, Wenzheng; Vidal-Villegas, J. Antonio; Kanamori, Hiroo

    2011-08-01

    The El Mayor-Cucapah earthquake sequence started with a few foreshocks in March 2010, and a second sequence of 15 foreshocks of M > 2 (up to M4.4) that occurred during the 24 h preceding the mainshock. The foreshocks occurred along a north-south trend near the mainshock epicenter. The M w 7.2 mainshock on April 4 exhibited complex faulting, possibly starting with a ~M6 normal faulting event, followed ~15 s later by the main event, which included simultaneous normal and right-lateral strike-slip faulting. The aftershock zone extends for 120 km from the south end of the Elsinore fault zone north of the US-Mexico border almost to the northern tip of the Gulf of California. The waveform-relocated aftershocks form two abutting clusters, each about 50 km long, as well as a 10 km north-south aftershock zone just north of the epicenter of the mainshock. Even though the Baja California data are included, the magnitude of completeness and the hypocentral errors increase gradually with distance south of the international border. The spatial distribution of large aftershocks is asymmetric with five M5+ aftershocks located to the south of the mainshock, and only one M5.7 aftershock, but numerous smaller aftershocks to the north. Further, the northwest aftershock cluster exhibits complex faulting on both northwest and northeast planes. Thus, the aftershocks also express a complex pattern of stress release along strike. The overall rate of decay of the aftershocks is similar to the rate of decay of a generic California aftershock sequence. In addition, some triggered seismicity was recorded along the Elsinore and San Jacinto faults to the north, but significant northward migration of aftershocks has not occurred. The synthesis of the El Mayor-Cucapah sequence reveals transtensional regional tectonics, including the westward growth of the Mexicali Valley and the transfer of Pacific-North America plate motion from the Gulf of California in the south into the southernmost San

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

    Directory of Open Access Journals (Sweden)

    D.A Siqueiros Beltrones

    2006-06-01

    Full Text Available The first floristic inventory of benthic diatoms is provided for the Bahía Magdalena- Bahía 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 Bahía 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. Rev. Biol. Trop. 54(2: 287-297. Epub 2006 Jun 01.Se presenta el primer inventario florístico de diatomeas bénticas para el Sistema Lagunar Bahía Magdalena-Bahía Almejas. Se hicieron muestreos en noviembre de 1999. En las muestras oxidadas y montadas permanentemente, se identificaron 86 táxones, de los cuales 59 son nuevos registros para el área de Bahía Magdalena, y 12 son nuevos para la península de Baja California. Táxones previamente registrados como escasos en otros sustratos son comunes o abundantes sobre macroalgas epífitas de raíces primarias de mangle. Otras species son principalmente formas epipélicas, mientras que 24 son constituyentes comunes del ticoplancton del área. Ciertos táxones parecen ser característicos de sistemas de manglar en general.

  8. 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.

  9. A legacy of change: The lower Colorado River, Arizona-California-Nevada, USA, and Sonora-Baja California Norte, Mexico

    Science.gov (United States)

    Mueller, G.A.; Marsh, P.C.; Minckley, W.L.

    2005-01-01

    The lower Colorado is among the most regulated rivers in the world. It ranks as the fifth largest river in volume in the coterminous United States, but its flow is fully allocated and no longer reaches the sea. Lower basin reservoirs flood nearly one third of the river channel and store 2 years of annual flow. Diverted water irrigates 1.5 million ha of cropland and provides water for industry and domestic use by 22 million people in the southwestern United States and northern Mexico. The native fish community of the lower Colorado River was among the most unique in the world, and the main stem was home to nine freshwater species, all of which were endemic to the basin. Today, five are extirpated, seven are federally endangered, and three are being reintroduced through stocking. Decline of the native fauna is attributed to predation by nonnative fishes and physical habitat degradation. Nearly 80 alien species have been introduced, and more than 20 now are common. These nonnative species thrived in modified habitats, where they largely eliminated the native kinds. As a result, the lower Colorado River has the dubious distinction of being among the few major rivers of the world with an entirely introduced fish fauna. ?? 2005 by the American Fisheries Society.

  10. Deep-water polychaetes (Annelida from the southeastern Gulf of California, Mexico

    Directory of Open Access Journals (Sweden)

    Nuria Méndez

    2006-09-01

    Full Text Available Polychaetes inhabiting deep-sea soft bottoms from the southeastern Gulf of California were collected during four oceanographic cruises during 2000 and 2001. Sampling of benthic organisms was performed with a benthic sledge to collect epifauna and a Karling dredge for epifauna and infauna, in a depth range from 732 to 2 250 m. A list of the polychaetes that were collected and their distribution are presented here. A total of 73 species (distributed among 33 families were identified. Moreover, 11 species were identified only to genus level and 20 species only to family level. With the exception of Ancistrosyllis hartmanae and Melinnampharete eoa, all identified species have been previously reported in soft bottoms of the Gulf of California or in adjacent areas. Additional previously unreported information is provided herein regarding depth ranges, geographical distribution, morphology and tubes inhabited by the organisms. The morphology of the ampharetids Amage sp. and Samytha sp. does not coincide with that of other species in these genera reported for the Gulf of California, which suggests that they are probably undescribed species. Rev. Biol. Trop. 54 (3: 773-785. Epub 2006 Sept. 29.Se recolectaron anélidos poliquetos de fondos profundos del SE del golfo de California durante cuatro campañas oceanográficas entre 2000 y 2001. El muestreo de organismos bentónicos se llevó a cabo mediante una draga de arrastre bentónica para recolectar epifauna y una draga tipo Karling para epifauna y endofauna, en un intervalo de profundidad de 732 a 2 250 m. Se presenta un listado de poliquetos con su distribución dentro del área de estudio. En total se identificaron 73 especies (distribuidas en 33 familias. Además, 11 especies fueron identificadas a nivel genérico y 20 a nivel de familia. Con excepción de Ancistrosyllis hartmanae y Melinnampharete eoa, todas las especies habían sido registradas en fondos blandos del golfo de California o zonas

  11. 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

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

    OpenAIRE

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

    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 abnormali...

  13. Feeding habits of dolphinfish (Coryphaena hippurus) in the southeastern Gulf of California, Mexico

    OpenAIRE

    Tripp Valdez, Arturo; Galvan Magaña, Felipe; Ortega García, Sofía

    2010-01-01

    The objective of the study was to identify key elements of the feeding ecology of the dolphinfish, which is a high tropic predator important for sport and artisanal fishing in the Mexican Pacific. Feeding habits were investigated during the years 2000–2003. This species is seasonal in the southern Gulf of California and probably remains there because of the abundant prey. The contents of 232 dolphinfish stomachs were analyzed, identifying 98 prey species, although only eight of these were wel...

  14. Seismic Structural Setting of Western Farallon Basin, Southern Gulf of California, Mexico.

    Science.gov (United States)

    Pinero-Lajas, D.; Gonzalez-Fernandez, A.; Lopez-Martinez, M.; Lonsdale, P.

    2007-05-01

    Data from a number of high resolution 2D multichannel seismic (MCS) lines were used to investigate the structure and stratigraphy of the western Farallon basin in the southern Gulf of California. A Generator-Injector air gun provided a clean seismic source shooting each 12 s at a velocity of 6 kts. Each signal was recorded during 6- 8 s, at a sampling interval of 1 ms, by a 600 m long digital streamer with 48 channels and a spacing of 12.5 m. The MCS system was installed aboard CICESE's (Centro de Investigacion Cientifica y de Educacion Superior de Ensenada) 28 m research vessel Francisco de Ulloa. MCS data were conventionally processed, to obtain post- stack time-migrated seismic sections. The MCS seismic sections show a very detailed image of the sub-bottom structure up to 2-3 s two-way travel time (aprox. 2 km). We present detailed images of faulting based on the high resolution and quality of these data. Our results show distributed faulting with many active and inactive faults. Our study also constrains the depth to basement near the southern Baja California eastern coast. The acoustic basement appears as a continuous feature in the western part of the study area and can be correlated with some granite outcrops located in the southern Gulf of California islands. To the East, near the center of the Farallon basin, the acoustic basement changes, it is more discontinuous, and the seismic sections show a number of diffracted waves.

  15. Mexico.

    Science.gov (United States)

    1993-01-01

    The background notes on Mexico provide text and recent statistical information on the geography, population, government, economy, and foreign relations, specifically the North American Free Trade Agreement with US. The 1992 population is estimated at 89 million of which 60% are mestizo (Indian-Spanish), 30% are American Indian, 9% are Caucasian, and 1% are other. 90% are Roman Catholic. There are 8 years of compulsory education. Infant mortality is 30/1000 live births. Life expectancy for males is 68 years and 76 years for females. The labor force is comprised of 30% in services, 24% in agriculture and fishing, 19% in manufacturing, 13% in commerce, 7% in construction, 4% in transportation and communication, and .4% in mining. There are 31 states and a federal district. Gross domestic product (GDP) per capita was $3200 in 1991. Military expenditures were .5% of GDP in 1991. The average inflation rate is 19%. Mexico City with 20 million is the largest urban center in the world. In recent years, the economy has been restructured with market oriented reforms; the result has been a growth of GDP of 3.6% in 1991 from 2% in 1987. Dependence on oil exports has decreased. There has been privatization and deregulation of state-owned companies. Subsidies to inefficient companies have been stopped. Tariff rates were reduced. The financial debt has been reduced and turned into a surplus of .8% in 1992. Mexico's foreign debt has been reduced from its high in 1987 of $107 billion. Agricultural reforms have been ongoing for 50 years. Land was redistributed, but standards of living and productivity have improved only slightly. Rural land tenure regulations have been changed, and other economic reforms are expected. Mexico engages in ad hoc international groups and is selective about membership in international organizations.

  16. Organchlorine content and shell thickness in brown booby (Sula leucogaster) eggs in the Gulf of California and the southern Pacific coast of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Mellink, Eric, E-mail: emellink@cicese.m [Departamento de Biologia de la Conservacion, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, B.C. Carretera Tijuana-Ensenada Km. 107, 22860 Ensenada, B.C. (Mexico); Riojas-Lopez, Monica E., E-mail: meriojas@cucba.udg.m [Departamento de Ecologia, Centro Universitario de Ciencias Biologicas y Agropecuarias, Universidad de Guadalajara, Km. 15.5 Carretera a Nogales, 45100 Zapopan, Jalisco (Mexico); Luevano-Esparza, Jaime, E-mail: jluevano@cicese.m [Departamento de Biologia de la Conservacion, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, B.C. Carretera Tijuana-Ensenada Km. 107, 22860 Ensenada, B.C. (Mexico)

    2009-07-15

    We determined egg concentrations of organochlorines and thickness of eggshells from brown boobies at eight colonies ranging from the northern Gulf of California to southern Mexico. The only common residue was that of DDE, which was found in almost all eggs. DDE content apparently reflected pre-1990 DDT use in nearby agricultural areas and, at one site, intensive mosquito control for high-end tourism development. There were no inter-colony differences in eggshell thickness, and variation in this variable likely reflected individual bird characteristics and/or individual feeding source. This variable was not a good proxy to DDE exposure of brown boobies, under current DDE levels in the brown booby trophic chain. In the northern Gulf of California, eggshell thickness has recovered to pre-DDT conditions. Our data indicate that the Gulf of California and southwestern coast of Mexico have a healthy near-shore marine environment, as far as organochlorines are concerned. - Wide-range, current picture of organochlorine presence in the environment along the western coast of Mexico.

  17. Organchlorine content and shell thickness in brown booby (Sula leucogaster) eggs in the Gulf of California and the southern Pacific coast of Mexico

    International Nuclear Information System (INIS)

    Mellink, Eric; Riojas-Lopez, Monica E.; Luevano-Esparza, Jaime

    2009-01-01

    We determined egg concentrations of organochlorines and thickness of eggshells from brown boobies at eight colonies ranging from the northern Gulf of California to southern Mexico. The only common residue was that of DDE, which was found in almost all eggs. DDE content apparently reflected pre-1990 DDT use in nearby agricultural areas and, at one site, intensive mosquito control for high-end tourism development. There were no inter-colony differences in eggshell thickness, and variation in this variable likely reflected individual bird characteristics and/or individual feeding source. This variable was not a good proxy to DDE exposure of brown boobies, under current DDE levels in the brown booby trophic chain. In the northern Gulf of California, eggshell thickness has recovered to pre-DDT conditions. Our data indicate that the Gulf of California and southwestern coast of Mexico have a healthy near-shore marine environment, as far as organochlorines are concerned. - Wide-range, current picture of organochlorine presence in the environment along the western coast of Mexico.

  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 children 24-59 months (p = 0.066), and from 71.4 to 45.8 % in children 6-23 months (p = 0.061). Among 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.

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

    Science.gov (United States)

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

    2017-04-01

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

  20. Submicron organic aerosol in Tijuana, Mexico, from local and Southern California sources during the CalMex campaign

    Science.gov (United States)

    Takahama, S.; Johnson, A.; Guzman Morales, J.; Russell, L. M.; Duran, R.; Rodriguez, G.; Zheng, J.; Zhang, R.; Toom-Sauntry, D.; Leaitch, W. R.

    2013-05-01

    The CalMex campaign was conducted from May 15 to June 30 of 2010 to study the properties and sources of air pollution in Tijuana, Mexico. In this study, submicron organic aerosol mass (OM) composition measured by Fourier Transform Infrared Spectroscopy (FTIR), Aerosol Chemical Speciation Monitor (ACSM), and X-ray spectromicroscopy are combined with statistical analysis and measurements of other atmospheric constituents. The average (±one standard deviation) OM concentration was 3.3 ± 1.7 μg m-3. A large source of submicron aerosol mass at this location was determined to be vehicular sources, which contributed approximately 40% to the submicron OM; largely during weekday mornings. The O/C ratio estimated from ACSM measurements was 0.64 ± 0.19; diurnal variations in this value and the more oxygenated fraction of OM as determined from Positive Matrix Factorization and classification analyses suggest the high degree of oxygenation originates from aged OM, rather than locally-produced secondary organic aerosol. A large contribution of this oxygenated aerosol to Tijuana from various source classes was observed; some fraction of this aerosol mass may be associated with non-refractory components, such as dust or BC. Backtrajectory simulations using the HYSPLIT model suggest that the mean wind vector consistently originated from the northwest region, over the Pacific Ocean and near the Southern California coast, which suggests that the origin of much of the oxygenated organic aerosol observed in Tijuana (as much as 60% of OM) may have been the Southern California Air Basin. The marine aerosol contribution to OM during the period was on average 23 ± 24%, though its contribution varied over synoptic rather than diurnal timescales. BB aerosol contributed 20 ± 20% of the OM during the campaign period, with notable BB events occurring during several weekend evenings.

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

    Science.gov (United States)

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

    2017-01-01

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

  2. Tuberculosis testing among populations with high HIV risk in Tijuana, Baja California, Mexico.

    Science.gov (United States)

    Velasquez, Michele G; Laniado-Laborin, Rafael; Rodwell, Timothy C; Cerecer, Paris; Lozada, Remedios; Cuevas-Mota, Jazmine; Burgos, Jose Luis; Garfein, Richard S

    2012-07-01

    To assess the prevalence of prior tuberculin skin testing (TST) among populations at risk for HIV infection in Tijuana, Mexico, and to identify factors associated with TST. Sex workers, injection drug users, noninjecting drug users, and homeless persons > 18 years old were recruited by using targeted sampling for risk assessment interviews and serologic testing for HIV and Mycobacterium tuberculosis infection. Univariate and multivariate logistic regression were used to identify correlates of self-reported TST history. Of 502 participants, 38.0% reported prior TST, which was associated with previous incarceration in the United States of America [odds ratio (OR) = 13.38; 95% confidence interval (CI) = 7.37-24.33] and injection drug use (OR = 1.99; 95% CI = 1.27- 3.11). Positive results on serologic tests for M. tuberculosis infection (57%) and HIV (4.2%) were not associated with a prior TST. A history of TST was lower in HIV-positive participants even though TST is indicated for persons with HIV in Mexico. Fewer than half the individuals at high risk for HIV in this study had a history of TST; however, TST was fairly common among those individuals with a prior history of incarceration. Increased tuberculosis screening is needed for populations at risk of contracting HIV in Tijuana, particularly those outside of criminal justice settings.

  3. 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…

  4. Fecal steroid hormones reveal reproductive state in female blue whales sampled in the Gulf of California, Mexico.

    Science.gov (United States)

    Valenzuela-Molina, Marcia; Atkinson, Shannon; Mashburn, Kendall; Gendron, Diane; Brownell, Robert L

    2018-05-15

    Steroid hormone assessment using non-invasive sample collection techniques can reveal the reproductive status of aquatic mammals and the physiological mechanisms by which they respond to changes in their environment. A portion of the eastern North Pacific blue whale (Balaenoptera musculus) population that seasonally visits the Gulf of California, Mexico has been monitored using photo-identified individuals for over 30 years. The whales use the area in winter-early spring for nursing their calves and feeding and it therefore is well suited for fecal sample collection. Using radioimmunoassays in 25 fecal samples collected between 2009 and 2012 to determine reproductive state and stress, we validated three steroid hormones (progesterone, corticosterone and cortisol) in adult female blue whales. Females that were categorized as pregnant had higher mean fecal progesterone metabolite concentrations (1292.6 ± 415.6 ng·g -1 ) than resting and lactating females (14.0 ± 3.7 ng·g -1 ; 23.0 ± 5.4 ng·g -1 , respectively). Females classified as pregnant also had higher concentrations of corticosterone metabolites (37.5 ± 9.9 ng·g -1 ) than resting and lactating females (17.4 ± 2.0 ng·g -1 ; 16.8 ± 2.8 ng·g -1 , respectively). In contrast, cortisol metabolite concentrations showed high variability between groups and no significant relationship to reproductive state. We successfully determined preliminary baseline parameters of key steroid hormones by reproductive state in adult female blue whales. The presence of pregnant or with luteal activity and known lactating females confirms that the Gulf of California is an important winter-spring area for the reproductive phase of these blue whales. The baseline corticosterone levels we are developing will be useful for assessing the impact of the increasing coastal development and whale-watching activities on the whales in the Gulf of California. Copyright © 2018 Elsevier Inc. All

  5. 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.

  6. Total Mercury in Squalid Callista Megapitaria squalida from the SW Gulf of California, Mexico: Tissue Distribution and Human Health Risk.

    Science.gov (United States)

    Romo-Piñera, Abril K; Escobar-Sánchez, Ofelia; Ruelas-Inzunza, Jorge; Frías-Espericueta, Martín G

    2018-03-01

    We evaluated the total Hg concentration in different tissues of squalid callista Megapitaria squalida in order to measure Hg distribution in tissue and to estimate human health risk. Samples were obtained by free diving in the SW Gulf of California, Mexico. Concentrations are given on a wet weight basis. A total of 89 squalid callista specimens were obtained, presenting an average Hg concentration of 0.07 ± 0.04 µg g -1 . There were no significant differences (p > 0.05) in Hg concentration between tissues (visceral mass = 0.09 ± 0.08 µg g -1 ; mantle = 0.06 ± 0.07 µg g -1 ; muscle = 0.06 ± 0.04 µg g -1 ). The low Hg values found in squalid callista and its low risk quotient (HQ = 0.03) suggest that the consumption of squalid callista does not represent a human health risk. However, HQ calculated using MeHg was > 1, it which could indicate a potential risk related to consumption of clams.

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

    Science.gov (United States)

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

    2011-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Álvaro López López

    2001-09-01

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

  9. Lagoon microbialites on Isla Angel de la Guarda and associated peninsular shores, Gulf of California (Mexico)

    Science.gov (United States)

    Johnson, Markes E.; Ledesma-Vázquez, Jorge; Backus, David H.; González, Maria R.

    2012-07-01

    Examples of two closed lagoons with extensive growth of Recent microbialites showing variable surface morphology and internal structure are found on Isla Angel de la Guarda in the Gulf of California. Comparable lagoonal microbialites also occur ashore from Ensenada El Quemado on the adjacent peninsular mainland of Baja California. The perimeters of all three lagoons feature crusted structures indicative of thrombolites with a knobby surface morphology 2 cm to 3 cm in relief and internal clotting without any sign of laminations. Outward from this zone, thrombolitic construction thins to merge with a white calcified crust below which a soft substratum of dark organic material 4 cm to 6 cm in thickness is concealed. The substratum is laminated and heavily mucilaginous, as observed along the edges of extensive shrinkage cracks in the overlying crust. The thrombolitic crust is anchored to the shore, while the thinner crust and associated stromatolitic mats float on the surface of the lagoons. Laboratory cultures of the dark organic material yielded the solitary cyanobacterium Chroococcidiopsis as the predominant taxon interspersed with filamentous forms. In decreasing order of abundance, other morphotypes present include Phormidium, Oscillatoria, Geitlerinema, Chroococus, and probably Spirulina. The larger of the two island lagoons follows an east-west azimuth and covers 0.225 km2, while the smaller lagoon has a roughly north-south axis and covers only 0.023 km2. The salinity of water in the smaller lagoon was measured as148 ppt. Pliocene strata along the edge of the smaller modern lagoon include siltstone bearing calcified platelets suggestive of a microbial origin. Dry lagoons abandoned during the later Quaternary occur inland at higher elevations on the island, but retain no fossils except for sporadic white crusts cemented on cobbles around distinct margins. Raised Quaternary lagoons parallel to the big lagoon on Isla Angel de la Guarda are partly obscured by flood

  10. A potential third Manta Ray species near the Yucat?n Peninsula? Evidence for a recently diverged and novel genetic Manta group from the Gulf of Mexico

    OpenAIRE

    Hinojosa-Alvarez, Silvia; Walter, Ryan P.; Diaz-Jaimes, Pindaro; Galv?n-Maga?a, Felipe; Paig-Tran, E. Misty

    2016-01-01

    We present genetic and morphometric support for a third, distinct, and recently diverged group of Manta ray that appears resident to the Yucatán coastal waters of the Gulf of Mexico. Individuals of the genus Manta from Isla Holbox are markedly different from the other described manta rays in their morphology, habitat preference, and genetic makeup. Herein referred to as the Yucatán Manta Ray, these individuals form two genetically distinct groups: (1) a group of mtDNA haplotypes divergent (0....

  11. 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.

  12. 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)

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

    International Nuclear Information System (INIS)

    Kretzschmar, Thomas G.; Frommen, Theresa

    2013-01-01

    Based on a total of 135 stable isotope analysis (δ 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 18 O per 100 m rise in elevation throughout the study area. Considering an unaltered δ 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 18 O and -13 for δD. (authors)

  14. Mexico

    International Nuclear Information System (INIS)

    2003-06-01

    This document summarizes the key energy data for Mexico: 1 - energy organizations and policy: Ministry of energy (SENER), Comision Reguladora de Energia (CRE), Ministry of Finances, Ministry of trade and industrial development (SECOFI), national commission for energy savings (CONAE); 2 - companies: federal commission of electricity (CFE), Minera Carbonifera Rio Escondido (MICARE - coal), Pemex (petroleum); 3 - energy production: resources, electric power, petroleum, natural gas; 4 - energy consumption; 5 - stakes and perspectives. Some economic and energy indicators are summarized in a series of tables: general indicators, supply indicators (reserves, refining and electric capacity, energy production, foreign trade), demand indicators (consumption trends, end use, energy independence, energy efficiency, CO 2 emissions), energy status per year and per energy source. (J.S.)

  15. Evaluating Environmental Governance along Cross-Border Electricity Supply Chains with Policy-Informed Life Cycle Assessment: The California-Mexico Energy Exchange.

    Science.gov (United States)

    Bolorinos, Jose; Ajami, Newsha K; Muñoz Meléndez, Gabriela; Jackson, Robert B

    2018-05-01

    This paper presents a "policy-informed" life cycle assessment of a cross-border electricity supply chain that links the impact of each unit process to its governing policy framework. An assessment method is developed and applied to the California-Mexico energy exchange as a unique case study. CO 2 -equivalent emissions impacts, water withdrawals, and air quality impacts associated with California's imports of electricity from Mexican combined-cycle facilities fueled by natural gas from the U.S. Southwest are estimated, and U.S. and Mexican state and federal environmental regulations are examined to assess well-to-wire consistency of energy policies. Results indicate most of the water withdrawn per kWh exported to California occurs in Baja California, most of the air quality impacts accrue in the U.S. Southwest, and emissions of CO 2 -equivalents are more evenly divided between the two regions. California energy policy design addresses generation-phase CO 2 emissions, but not upstream CO 2 -eq emissions of methane during the fuel cycle. Water and air quality impacts are not regulated consistently due to varying U.S. state policies and a lack of stringent federal regulation of unconventional gas development. Considering local impacts and the regulatory context where they occur provides essential qualitative information for functional-unit-based measures of life cycle impact and is necessary for a more complete environmental impact assessment.

  16. Lithofacies of deep marine basalts emplaced on a Jurassic backarc apron, Baja California (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Busby-Spera, C.J.

    1987-09-01

    Basalts of the mid-Jurassic Gran Canon Formation, Cedros Island, Mexico, were emplaced on a volcaniclastic apron in a deep marine backarc basin. Elongate pillows and lava tubes, as well as paleocurrent data from the volcaniclastic apron, indicate a southward regional paleoslope away from the island arc source. Basalts emplaced on relatively proximal parts of the apron are nearly entirely pillowed and have thick flow units with mega-pillows. Basalts on distal parts of the apron (about 15 to 20 km down paleo-current) are dominated by pillow fragment breccias (flow foot rubble), and individual lava flows are generally thin, with small pillows, suggesting that the distal ends of lava flows, erupted upslope, are represented. These distal flow fronts, however, are interstratified with features that typically form close to a vent, including thick massive to mega-pillowed lavas and lava tubes up to 8 m in diameter. It is inferred that a fissure (or system of fissures) extended from the arc into the backarc basin, erupting basalt lavas onto both proximal and distal parts of the volcaniclastic apron. Such intraplate volcanism may be common on the hot frontal arc side of backarc basins. 26 references.

  17. Mammalophilic feeding behaviour of Culex quinquefasciatus mosquitoes collected in the cities of Chetumal and Cancun, Yucatán Peninsula, Mexico.

    Science.gov (United States)

    Janssen, Nele; Fernandez-Salas, Ildefonso; Díaz González, Esteban Eduardo; Gaytan-Burns, Alejandro; Medina-de la Garza, Carlos E; Sanchez-Casas, Rosa María; Börstler, Jessica; Cadar, Daniel; Schmidt-Chanasit, Jonas; Jöst, Hanna

    2015-11-01

    The studie describes the blood-feeding behaviour of mosquitoes in Mexico, to understand host-vector relationships and dynamics of disease transmission. From September 2012 to November 2012 and in November 2013, 911 blood-fed Cx. quinquefasciatus mosquitoes were collected with aspirators inside houses in Chetumal and Cancun. Blood meals were analysed by PCR and subsequent Sanger sequencing of the cytochrome b gene. 93.3% of mosquitoes fed on mammals, 6.5% on birds and 0.2% on reptiles. The most frequent vertebrate hosts were humans (65.4%), dogs (23.2%), chicken (5.4%), cattle (2.2%) and cats (1.8%). Cx. quinquefasciatus most frequently fed on humans and dogs in both studied cities, which is in contrast to a previous study that demonstrated lower prevalence of mammalian blood in engorged Cx. quinquefasciatus. © 2015 John Wiley & Sons Ltd.

  18. Fish Larvae Response to Biophysical Changes in the Gulf of California, Mexico (Winter-Summer

    Directory of Open Access Journals (Sweden)

    Raymundo Avendaño-Ibarra

    2013-01-01

    Full Text Available We analyzed the response of fish larvae assemblages to environmental variables and to physical macro- and mesoscale processes in the Gulf of California, during four oceanographic cruises (winter and summer 2005 and 2007. Physical data of the water column obtained through CTD casts, sea surface temperature, and chlorophyll a satellite imagery were used to detect mesoscale structures. Zooplankton samples were collected with standard Bongo net tows. Fish larvae assemblages responded to latitudinal and coastal-ocean gradients, related to inflow of water to the gulf, and to biological production. The 19°C and 21°C isotherms during winter, and 29°C and 31°C during summer, limited the distribution of fish larvae at the macroscale. Between types of eddy, the cyclonic (January registered high abundance, species richness, and zooplankton volume compared to the other anticyclonic (March and cyclonic (September. Thermal fronts (Big Islands of January and July affected the species distribution establishing strong differences between sides. At the mesoscale, eddy and fronts coincided with the isotherms mentioned previously, playing an important role in emphasizing the differences among species assemblages. The multivariate analysis indicated that larvae abundance was highly correlated with temperature and salinity and with chlorophyll a and zooplankton volume during winter and summer, respectively.

  19. Spatial distribution of heavy metals in urban dust from Ensenada, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    José L. Cortés

    2017-01-01

    Full Text Available E n Ensenada, Baja California, los barcos y vehículos emiten partículas con metales pesados. Las partículas se transportan con el viento y se depositan en el suelo, donde se mezclan con él dando lugar a los polvos urbanos. Los metales pesados pueden afectar la salud de la población, por lo que se requiere un diagnóstico rápido para encontrar soluciones. El objetivo de este trabajo fue identificar las zonas con mayor contaminación en la ciudad. Se tomaron 86 muestras de polvo urbano sobre diferentes sustratos (suelo, cemento y asfalto. Los metales se analizaron mediante f luorescencia de rayos X. Las diferencias entre los sustratos se identificaron mediante un análisis de varianza. Por otra parte, se hizo un análisis para conocer la distribución espacial de los metales pesados, utilizando la interpolación con kriging ordinario. El asfalto contiene las mayores concentraciones de Cr, Ni, Pb y Zn; el cemento contiene mayores concentracions de Cu y V; y el suelo es el que más Rb contiene. El mapa que integra las clases de mayor concentración de metales indica que la zona suroeste, donde se localiza el puerto y pasa la carretera transpeninsular, es la más contaminada.

  20. 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

  1. 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

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

    Directory of Open Access Journals (Sweden)

    E. Glowacka

    2015-11-01

    Full Text Available 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

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

    Science.gov (United States)

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

    1995-08-01

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

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

    International Nuclear Information System (INIS)

    Ley-Quinonez, C.; Zavala-Norzagaray, A.A.; Espinosa-Carreon, T.L.; Peckham, H.; Marquez-Herrera, C.; Campos-Villegas, L.; Aguirre, A.A.

    2011-01-01

    Highlights: → We report baseline levels of selected heavy metals in blood of Pacific loggerhead turtles. → Blood was used to measure in a relatively non-invasive way baseline values of heavy metals. → Zn and Cd were found in high concentrations compared to levels reported in other parts of the world. → Cu concentrations in blood are high as they relate to concentrations in muscle. → No correlations were found between of heavy metals and metalloids analyzed and the size of the turtles. - Abstract: Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto Lopez Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 μg g -1 ), followed by Selenium (10.92 μg g -1 ). The mean concentration of toxic metal Cadmium was 6.12 μg g -1 and 1.01 μg g -1 respectively. Mean concentrations of metals followed this pattern: Zn > Se > Ni > Cu > Mn > Cd > Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.

  5. A potential third Manta Ray species near the Yucatán Peninsula? Evidence for a recently diverged and novel genetic Manta group from the Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Silvia Hinojosa-Alvarez

    2016-11-01

    Full Text Available We present genetic and morphometric support for a third, distinct, and recently diverged group of Manta ray that appears resident to the Yucatán coastal waters of the Gulf of Mexico. Individuals of the genus Manta from Isla Holbox are markedly different from the other described manta rays in their morphology, habitat preference, and genetic makeup. Herein referred to as the Yucatán Manta Ray, these individuals form two genetically distinct groups: (1 a group of mtDNA haplotypes divergent (0.78% from the currently recognized Manta birostris and M. alfredi species, and (2 a group possessing mtDNA haplotypes of M. birostris and highly similar haplotypes. The latter suggests the potential for either introgressive hybridization between Yucatán Manta Rays and M. birostris, or the retention of ancestral M. birostris signatures among Yucatán Manta Rays. Divergence of the genetically distinct Yucatán Manta Ray from M. birostris appears quite recent (<100,000 YBP following fit to an Isolation-with-Migration model, with additional support for asymmetrical gene flow from M. birostris into the Yucatán Manta Ray. Formal naming of the Yucatán Manta Ray cannot yet be assigned until an in-depth taxonomic study and further confirmation of the genetic identity of existing type specimens has been performed.

  6. A potential third Manta Ray species near the Yucatán Peninsula? Evidence for a recently diverged and novel genetic Manta group from the Gulf of Mexico.

    Science.gov (United States)

    Hinojosa-Alvarez, Silvia; Walter, Ryan P; Diaz-Jaimes, Pindaro; Galván-Magaña, Felipe; Paig-Tran, E Misty

    2016-01-01

    We present genetic and morphometric support for a third, distinct, and recently diverged group of Manta ray that appears resident to the Yucatán coastal waters of the Gulf of Mexico. Individuals of the genus Manta from Isla Holbox are markedly different from the other described manta rays in their morphology, habitat preference, and genetic makeup. Herein referred to as the Yucatán Manta Ray, these individuals form two genetically distinct groups: (1) a group of mtDNA haplotypes divergent (0.78%) from the currently recognized Manta birostris and M. alfredi species, and (2) a group possessing mtDNA haplotypes of M. birostris and highly similar haplotypes. The latter suggests the potential for either introgressive hybridization between Yucatán Manta Rays and M. birostris , or the retention of ancestral M. birostris signatures among Yucatán Manta Rays. Divergence of the genetically distinct Yucatán Manta Ray from M. birostris appears quite recent (birostris into the Yucatán Manta Ray. Formal naming of the Yucatán Manta Ray cannot yet be assigned until an in-depth taxonomic study and further confirmation of the genetic identity of existing type specimens has been performed.

  7. A new cryptogonimid (Digenea) from the Mayan cichlid, Cichlasoma urophthalmus (Osteichthyes: Cichlidae), in several localities of the Yucatán Peninsula, Mexico.

    Science.gov (United States)

    Razo-Mendivil, Ulises; Rosas-Valdez, Rogelio; Pérez-Ponce de León, Gerardo

    2008-12-01

    Oligogonotylus mayae n.sp. is described from the intestine of the Mayan cichlid Cichlasoma urophthalmus (Günther) in Ría Lagartos, Ría Celestún, and Estero Progreso, Yucatán State. This is the second species described for Oligogonotylus Watson, 1976, the other being O.manteri Watson, 1976. The new species is readily distinguished from O. manteri by the anterior extension of the vitelline follicles. In O. Manteri, Vitelline follicles are found entirely in the hindbody, extending posteriorly to mid-testicular level. Vitelline follicles in the new species extend from teh anterior margin of posterior testis to the region between the bentral sucker and the pharynx. comparison of approximately 1,850 bases of ribosomal DNA (ITS1, ITS2, 5.8S, and 28S), and 400 bases of cytochrome c oxidase subunit I (cox1) strongly supports the status of O. mayae as a new species, as compared to O. manteri collected from cichlids in other localities of Mexico, Belize, and Guatemala.

  8. Pandemic (H1N1) 2009 Surveillance in Marginalized Populations, Tijuana, Mexico, and West Nile Virus Knowledge among Hispanics, San Diego, California, 2006

    Centers for Disease Control (CDC) Podcasts

    2010-08-10

    This podcast describes public health surveillance and communication in hard to reach populations in Tijuana, Mexico, and San Diego County, California. Dr. Marian McDonald, Associate Director of CDC's Health Disparities in the National Center for Emerging and Zoonotic Infectious Diseases, discusses the importance of being flexible in determining the most effective media for health communications.  Created: 8/10/2010 by National Center for Emerging and Zoonotic Infectious Diseases, National Center for Immunization and Respiratory Diseases.   Date Released: 8/10/2010.

  9. Geochemical characteristics of water from the reservoir of the hydrothermal system of Las Tres Virgenes, Baja California Sur, Mexico; Caracteristicas geoquimicas de las aguas del reservorio del sistema hidrotermal actual de Las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gonalez Partida, Eduardo [Universidad Nacional Autonoma de Mexico (Mexico); Tello Hinojosa, Enrique [Comision Federal de Electricidad (Mexico); Pal Verma, Mahendra [Instituto de Investigaciones Electricas (Mexico)

    2001-03-01

    The Las Tres Virgenes geothermal field is a liquid dominated system. The separated produced by the wells are sodium-chloride type, which is a characteristic of totally equilibrated geothermal brine. The temperature of water-rock interaction in the reservoir is 280 Celsius degrees. the chemical composition of gases corresponds to the one expected in a geothermal environment. The CO{sub 2} is the predominating gas and it is superior in 90% in weight to the total of existing gases. The gas contents is less than 1% in weight, in the case of the wells LV-1 and LV-3. It is also possible to conclude that the gases are in equilibrium with the liquid phase at a temperature of 280 Celsius degrees. With respect to water quality, it is saline, from high to very high and the contents of exchangeable sodium is also very high, resulting in waters not fit for agricultural usage. [Spanish] El yacimiento geotermico de Las Tres Virgenes, en Baja California Sur, Mexico, es un sistema de liquido dominante, en donde el agua separada producida por los pozos presenta un caracter clorurado-sodico caracteristico de una salmuera de origen geotermico totalmente equilibrada. El sistema agua-roca se encuentra en equilibrio a una temperatura de 280 grados centigrados , dicha temperatura son congruentes con las estimadas para las fases gaseosas y liquidas. La composicion quimica de los gases corresponde a la esperada en un ambiente geotermico. El CO{sub 2} es el predominante y es superior a 90% en peso del total de los gases presentes. El contenido de gas es menor de 1% en peso en el caso de los pozos LV-1 y LV-3. Tambien se puede concluir que los gases estan en equilibrio en las fases liquidas a una temperatura de 280 grados centigrados. Con respecto a la calidad del agua, presenta una salinidad de alta a muy alta y el contenido de sodio intercambiable tambien es muy alto, por lo que dichas aguas no son muy aptas para el cultivo.

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

    Science.gov (United States)

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

    2012-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Dinora Acosta Zamorano

    2011-12-01

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

  12. 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

    Hypersaline environments have been significant reservoirs for the long-term evolution of specifically adapted microorganisms. Characterized to have higher salt concentrations (up to 35 g/L), they are worldwide distributed and have a commercial significance. Exportadora de Sal, Guerrero Negro, Mexico has a multipond salterns system designed to harvest common salt (NaCl) from sea water. To achieve this purpose, sea water is pumped through a set of shallow ponds where water evaporates and salts concentrate. Sequential precipitation of CaCO3, CaSO4 2H2O and NaCl occurs in a mineral formations call it evaporites. In the interior of those gypsum-encrusted and halite-encrusted minerals, communities of extremely salt-loving archaea prosper. Previous studies have showed the influence of Haloarchaeal cells in the formation of larger fluid inclusions than crystals formed in sterile salt solutions. S-layer envelopes and cells of Haloarcula strain SP8807 contributed to the nucleation of new crystals of NaCl. Given the significance of the scope in phylogenetic archaeal diversity research, this study had a polyphasic approach. SEM micrographs from a 21- 31% (w/v) gradient salt multipond system evaporites, gave an insight profile of the extreme halophilic archaeal communities thriving in the surface of the gypsum and halite evaporites. Halite crystals were form after 21 days of incubation in solid medium with archaeal cells. Both culture and non-culture dependent methods, Nested-PCR-DGGE analysis and sequencing of 16S rDNA amplified fragment genes from environmental samples and isolated strains were used for this purpose. We isolate three strains from Pond 9 (21.07% total salt concentration) and one strain from Cristallizer 20 (25.15% total salt concentration). 16S rDNA signaling gave 99% of similarity with Halogeometricum borinquense, sequence AF002984, two other strains were 99% of similarity with Halobacterium salinarum, sequence AJ496185 these strains shown different colony

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

    Directory of Open Access Journals (Sweden)

    Sarai Estrella Sandoval-Azuara

    2017-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Víctor M. Gruel Sández

    2013-01-01

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

  15. Current depression among women in California according to residence in the California-Mexico border region Depresión actual en las mujeres en California según el lugar de residencia en la región fronteriza entre California y México

    Directory of Open Access Journals (Sweden)

    Suzanne Ryan-Ibarra

    2012-05-01

    Full Text Available OBJECTIVE: To estimate the prevalence of current depression; examine the relationship between current depression and immigration, health status, health care access, and health behaviors; and assess differences by California-Mexico border region (Imperial and San Diego Counties among women in California. METHODS: Using a cross-sectional, representative sample of adult women from the California Women's Health Survey (n = 13 454, a statewide telephone survey, prevalence of current depression and predictors of depression were examined in California and according to border region residence. Depression was assessed with the eight-item Patient Health Questionnaire. RESULTS: The prevalence of current depression for women in California was 12.0%. It was similar in the border (13.0% and the nonborder (11.9% regions. Odds of current depression in women were lower among recent immigrants (OBJETIVO: Calcular la prevalencia de la depresión actual; examinar la relación entre la depresión actual y la inmigración, el estado de salud, el acceso a la atención de la salud y las conductas relacionadas con la salud; y evaluar las diferencias en la región fronteriza entre California (condados Imperial y San Diego y México en las mujeres. MÉTODOS: Se empleó una muestra transversal y representativa de mujeres adultas de la Encuesta de Salud de la Mujer de California (n = 13 454, una encuesta telefónica estatal, para examinar la prevalencia de depresión actual y los factores predictivos de depresión tanto en California como según el lugar de residencia en la región fronteriza. La depresión se evaluó mediante el Cuestionario de Salud del Paciente-8. RESULTADOS: La prevalencia de depresión actual en las mujeres en California fue 12,0%, y fue semejante en las regiones fronteriza (13,0% y no fronteriza (11,9% del estado. Las probabilidades de presentar depresión actual fueron menores en las mujeres que habían inmigrado recientemente (< 5 años o de 5 a

  16. 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

  17. 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

  18. Placental biomarkers of PAH exposure and glutathione-S-transferase biotransformation enzymes in an obstetric population from Tijuana, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dodd-Butera, Teresa, E-mail: tdbutera@csusb.edu [California State University San Bernardino, Department of Nursing, 5500 University Parkway, San Bernardino, CA 92407 (United States); San Diego State University, Graduate School of Public Health, San Diego, CA (United States); Union Institute & University, Cincinnati, OH (United States); Quintana, Penelope J.E., E-mail: jquintan@mail.sdsu.edu [San Diego State University, Graduate School of Public Health, San Diego, CA (United States); Ramirez-Zetina, Martha, E-mail: martharz8@hotmail.com [Instituto Mexicano del Seguro Social Tijuana, BC (Mexico); Batista-Castro, Ana C., E-mail: anabatista101@hotmail.com [Instituto Mexicano del Seguro Social Tijuana, BC (Mexico); Hospital General de Tijuana, Tijuana (Mexico); Sierra, Maria M., E-mail: sierramer@gmail.com [San Diego State University, Graduate School of Public Health, San Diego, CA (United States); Shaputnic, Carolyn, E-mail: cshaputnic@ucsd.edu [San Diego State University, Graduate School of Public Health, San Diego, CA (United States); University of California, San Diego, Western FASD Practice and Implementation Center, Department of Pediatrics, Division of Dysmorphology-Teratology, San Diego, CA (United States); Garcia-Castillo, Maura, E-mail: mauragarcia@gmail.com [Xochicalco Universidad Escuela de Medicina, BC (Mexico); Institute for Public Health, San Diego State University, San Diego, CA (United States); Ingmanson, Sonja, E-mail: sonejah@yahoo.com [San Diego State University, Graduate School of Public Health, San Diego, CA (United States); Hull, Stacy, E-mail: hulst74@hotmail.com [San Diego State University, Graduate School of Public Health, San Diego, CA (United States)

    2017-01-15

    Environmental exposures along the US-Mexico border have the potential to adversely affect the maternal-fetal environment. The purpose of this study was to assess placental biomarkers of environmental exposures in an obstetric population at the California-Baja California border in relation to detoxifying enzymes in the placenta and nutritional status. This study was conducted on consenting, full-term, obstetric patients (n=54), delivering in a hospital in Tijuana, Baja California (BC), Mexico. Placental polyaromatic hydrocarbon (PAH)-DNA adducts were measured in addition to placental glutathione-S-transferase (GST) activity and genotype, maternal serum folate, and maternal and umbilical cord blood lead and cadmium levels. A questionnaire was administered to the mothers to determine maternal occupation in a maquiladora, other exposures, and obstetric indicators. In univariate analysis, maternal serum folate levels were inversely correlated with total PAH-DNA adducts (rho=−0.375, p=0.007); adduct #1 (rho=−0.388, p=0.005); and adduct #3 (rho =−0.430, p=0.002). Maternal lead levels were significantly positively correlated with cord blood lead levels (rho=0.512, p<0.001). Cadmium levels were generally very low but significantly higher in mothers exposed to environmental tobacco smoke (ETS) (either at work or at home, n=10). In multivariate analysis, only maternal serum folate levels remained as a significant negative predictor of total DNA-PAH adducts levels in placenta. These findings affirm that placental tissue is a valuable and readily available source of human tissue for biomonitoring; and indicate that further study of the role of nutrition in detoxification and mitigation of environmental exposures in pregnant women is warranted. - Highlights: • Maternal-fetal environment susceptible to toxic exposures at US-Mexico border. • Lower serum folate was correlated with higher PAH-DNA adduct levels at birth. • Placental DNA adducts in GST mu (-) cord blood

  19. Placental biomarkers of PAH exposure and glutathione-S-transferase biotransformation enzymes in an obstetric population from Tijuana, Baja California, Mexico

    International Nuclear Information System (INIS)

    Dodd-Butera, Teresa; Quintana, Penelope J.E.; Ramirez-Zetina, Martha; Batista-Castro, Ana C.; Sierra, Maria M.; Shaputnic, Carolyn; Garcia-Castillo, Maura; Ingmanson, Sonja; Hull, Stacy

    2017-01-01

    Environmental exposures along the US-Mexico border have the potential to adversely affect the maternal-fetal environment. The purpose of this study was to assess placental biomarkers of environmental exposures in an obstetric population at the California-Baja California border in relation to detoxifying enzymes in the placenta and nutritional status. This study was conducted on consenting, full-term, obstetric patients (n=54), delivering in a hospital in Tijuana, Baja California (BC), Mexico. Placental polyaromatic hydrocarbon (PAH)-DNA adducts were measured in addition to placental glutathione-S-transferase (GST) activity and genotype, maternal serum folate, and maternal and umbilical cord blood lead and cadmium levels. A questionnaire was administered to the mothers to determine maternal occupation in a maquiladora, other exposures, and obstetric indicators. In univariate analysis, maternal serum folate levels were inversely correlated with total PAH-DNA adducts (rho=−0.375, p=0.007); adduct #1 (rho=−0.388, p=0.005); and adduct #3 (rho =−0.430, p=0.002). Maternal lead levels were significantly positively correlated with cord blood lead levels (rho=0.512, p<0.001). Cadmium levels were generally very low but significantly higher in mothers exposed to environmental tobacco smoke (ETS) (either at work or at home, n=10). In multivariate analysis, only maternal serum folate levels remained as a significant negative predictor of total DNA-PAH adducts levels in placenta. These findings affirm that placental tissue is a valuable and readily available source of human tissue for biomonitoring; and indicate that further study of the role of nutrition in detoxification and mitigation of environmental exposures in pregnant women is warranted. - Highlights: • Maternal-fetal environment susceptible to toxic exposures at US-Mexico border. • Lower serum folate was correlated with higher PAH-DNA adduct levels at birth. • Placental DNA adducts in GST mu (-) cord blood

  20. Cadmium and phosphate variability during algal blooms of the dinoflagellate Lingulodinium polyedrum in Todos Santos Bay, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Mejia, E. [Posgrado en Oceanografía Costera, Instituto de Investigaciones Oceanológicas/Facultad de Ciencias Marinas, Universidad Autónoma de Baja California, Campus Sauzal, Carretera Transpeninsular Ensenada-Tijuana No. 3917, Ensenada, Baja California CP 22860 (Mexico); Lares, M.L., E-mail: llares@cicese.mx [División de Oceanología, Departamento de Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada, Km 107 Carretera Transpeninsular Ensenada-Tijuana, Ensenada, Baja California CP 22880 (Mexico); Huerta-Diaz, M.A.; Delgadillo-Hinojosa, F. [Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Campus Sauzal, Carretera Transpeninsular Ensenada-Tijuana No. 3917, Ensenada, Baja California CP 22860 (Mexico)

    2016-01-15

    Dinoflagellate algal blooms (DABs), with Lingulodinium polyedrum as the dominant species, have increased over the past few years in coastal areas off Baja California, Mexico. Vertical and temporal variability of particulate cadmium (Cd{sub p}), dissolved Cd (Cd{sub d}), PO{sub 4}{sup 3−} and Cd{sub d}/PO{sub 4}{sup 3−} were investigated during two intense DABs of L. polyedrum that occurred during the fall of 2011 and 2012 in Todos Santos Bay. Results were then, compared with data gathered in the absence of algal blooms during the autumn of 2013. In both algal blooms, L. polyedrum tended to be concentrated near the surface throughout the duration; however, during DAB 2011 the number of cells was twice as abundant ([10.0 ± 8.0] × 10{sup 5} cells L{sup −1}) as in DAB 2012 ([5.0 ± 4.4] × 10{sup 5} cells L{sup −1}). During DAB 2011, Cd{sub p} increased significantly (up to 1.02 ± 0.99 nmol kg{sup −1}) and was positively correlated with the cell abundance of L. polyedrum, suggesting that this dinoflagellate is able to assimilate and concentrate Cd{sub d}. Likewise, Cd{sub d} (up to 0.71 ± 0.17 nM) increased in the days of highest cell abundance, which could be attributed to uptake and subsequent regeneration of Cd{sub d} resulting from the remineralization of organic particulate matter produced during the bloom, as well as with the presence of organic ligands secreted by L. polyedrum that could keep Cd{sub d} in solution. During DAB 2011, dissolved Cd{sub d}/PO{sub 4}{sup 3−} ratios exhibited high vertical and temporal variability in the upper 5 m of the water column, but remained virtually constant near the bottom, suggesting a depth-dependent decoupling between these two dissolved components during the bloom development. Given the observed differences in the vertical and temporal variability of Cd{sub d}, Cd{sub p}, and PO{sub 4}{sup 3−} between these two intense DABs, we propose the existence of an abundance threshold of approximately 10{sup 6

  1. Cadmium and phosphate variability during algal blooms of the dinoflagellate Lingulodinium polyedrum in Todos Santos Bay, Baja California, Mexico

    International Nuclear Information System (INIS)

    Gutierrez-Mejia, E.; Lares, M.L.; Huerta-Diaz, M.A.; Delgadillo-Hinojosa, F.

    2016-01-01

    Dinoflagellate algal blooms (DABs), with Lingulodinium polyedrum as the dominant species, have increased over the past few years in coastal areas off Baja California, Mexico. Vertical and temporal variability of particulate cadmium (Cd_p), dissolved Cd (Cd_d), PO_4"3"− and Cd_d/PO_4"3"− were investigated during two intense DABs of L. polyedrum that occurred during the fall of 2011 and 2012 in Todos Santos Bay. Results were then, compared with data gathered in the absence of algal blooms during the autumn of 2013. In both algal blooms, L. polyedrum tended to be concentrated near the surface throughout the duration; however, during DAB 2011 the number of cells was twice as abundant ([10.0 ± 8.0] × 10"5 cells L"−"1) as in DAB 2012 ([5.0 ± 4.4] × 10"5 cells L"−"1). During DAB 2011, Cd_p increased significantly (up to 1.02 ± 0.99 nmol kg"−"1) and was positively correlated with the cell abundance of L. polyedrum, suggesting that this dinoflagellate is able to assimilate and concentrate Cd_d. Likewise, Cd_d (up to 0.71 ± 0.17 nM) increased in the days of highest cell abundance, which could be attributed to uptake and subsequent regeneration of Cd_d resulting from the remineralization of organic particulate matter produced during the bloom, as well as with the presence of organic ligands secreted by L. polyedrum that could keep Cd_d in solution. During DAB 2011, dissolved Cd_d/PO_4"3"− ratios exhibited high vertical and temporal variability in the upper 5 m of the water column, but remained virtually constant near the bottom, suggesting a depth-dependent decoupling between these two dissolved components during the bloom development. Given the observed differences in the vertical and temporal variability of Cd_d, Cd_p, and PO_4"3"− between these two intense DABs, we propose the existence of an abundance threshold of approximately 10"6 cells L"−"1 of L. polyedrum above which Cd and PO_4"3"− significantly increased due to remineralization in coastal

  2. April 2008 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to US/Mexico Border

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This lidar point data set collected during low tide conditions along an approximately 500-700 meter wide strip of the Southern California coastline within an area...

  3. November 2007 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to US/Mexico Border

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This lidar point data set was collected during low tide conditions along an approximately 500-700 meter wide strip of the Southern California coastline within an...

  4. September 2008 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to US/Mexico Border

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This lidar point data set was collected during low tide conditions along an approximately 500-700 meter wide strip of the Southern California coastline within an...

  5. March 2009 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to US/Mexico Border

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This lidar point data set was collected during low tide conditions along an approximately 500-700 meter wide strip of the Southern California coastline within an...

  6. Results and evaluation of the first study of organochlorine contaminants (PCDDs, PCDFs, PCBs and DDTs), heavy metals and metalloids in birds from Baja California, Mexico

    International Nuclear Information System (INIS)

    Jimenez, Begona; Rodriguez-Estrella, Ricardo; Merino, Ruben; Gomez, Gema; Rivera, Laura; Jose Gonzalez, Maria; Abad, Esteban; Rivera, Josep

    2005-01-01

    Organochlorine compounds (OCs) including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p-p'-DDE), heavy metals (Pb, Cd, Zn, Cu), and arsenic were measured in house sparrows (Passer domesticus) and common ground doves (Columbina passerina) from Baja California Sur, Mexico. Concentrations of PCDD/Fs were low, with 21 pg/g for house sparrows, and 7.7 pg/g for common ground doves. Non-ortho-PCB concentrations in house sparrow and common ground doves were 58 and 254 pg/g, respectively, and are within the highest concentrations reported in species that are in the low levels of food webs. The major differences in organochlorine levels between species were found for ortho-PCBs and DDTs. ortho-PCB levels were higher in the seedeater species, whereas DDT levels were higher in the omnivorous species. Heavy metal levels were far below those associated with negative effects. - Capsule: The first data on contaminants in birds from Baja California is given

  7. Results and evaluation of the first study of organochlorine contaminants (PCDDs, PCDFs, PCBs and DDTs), heavy metals and metalloids in birds from Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Begona [Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)]. E-mail: bjimenez@iqog.csic.es; Rodriguez-Estrella, Ricardo [Centro de Investigaciones Biologicas del Noroeste, Mar Bermejo 195, Apdo. Postal 128, La Paz, Baja California Sur (Mexico); Merino, Ruben [Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Gomez, Gema [Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Rivera, Laura [Centro de Investigaciones Biologicas del Noroeste, Mar Bermejo 195, Apdo. Postal 128, La Paz, Baja California Sur (Mexico); Jose Gonzalez, Maria [Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Abad, Esteban [Department of Ecotechnologies, Research and Development Center, CSIC, Jordi Girona, 18-26, 08034 Barcelona (Spain); Rivera, Josep [Department of Ecotechnologies, Research and Development Center, CSIC, Jordi Girona, 18-26, 08034 Barcelona (Spain)

    2005-01-01

    Organochlorine compounds (OCs) including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p-p'-DDE), heavy metals (Pb, Cd, Zn, Cu), and arsenic were measured in house sparrows (Passer domesticus) and common ground doves (Columbina passerina) from Baja California Sur, Mexico. Concentrations of PCDD/Fs were low, with 21 pg/g for house sparrows, and 7.7 pg/g for common ground doves. Non-ortho-PCB concentrations in house sparrow and common ground doves were 58 and 254 pg/g, respectively, and are within the highest concentrations reported in species that are in the low levels of food webs. The major differences in organochlorine levels between species were found for ortho-PCBs and DDTs. ortho-PCB levels were higher in the seedeater species, whereas DDT levels were higher in the omnivorous species. Heavy metal levels were far below those associated with negative effects. - Capsule: The first data on contaminants in birds from Baja California is given.

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

    Science.gov (United States)

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

    2017-12-01

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

  9. 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.

  10. Prevalence and Correlates of Heroin–Methamphetamine Co-Injection Among Persons Who Inject Drugs in San Diego, California, and Tijuana, Baja California, Mexico

    Science.gov (United States)

    Meacham, Meredith C.; Strathdee, Steffanie A.; Rangel, Gudelia; Armenta, Richard F.; Gaines, Tommi L.; Garfein, Richard S.

    2016-01-01

    Objective: Although persons who inject drugs (PWID) in the western United States–Mexico border region are known to inject both heroin and methamphetamine, little is known about the prevalence and risks associated with co-injection of this depressant–stimulant combination (also known as “goofball” and “Mexican speedball”). Method: Baseline data from parallel cohort studies of PWID conducted concurrently in San Diego, CA, and Tijuana, Mexico, were used to estimate the prevalence and identify correlates of heroin–methamphetamine co-injection. PWID older than 18 years of age who reported injecting illicit drugs in the past month (N = 1,311; 32.7% female) were recruited in San Diego (n = 576) and Tijuana (n = 735) and completed interviewer-administered questionnaires. Bivariate and multivariable logistic regression analyses were used to identify correlates of heroin–methamphetamine co-injection. Results: The prevalence of co-injection in the past 6 months was 39.9% overall and was higher in Tijuana (55.8%) than in San Diego (19.8%). In multivariable analyses adjusting for study cohort, distributive syringe sharing, purchasing syringes prefilled with drugs, finding it hard to get new syringes, reporting great or urgent need for treatment, and younger age were independently associated with co-injection. Past-6-month overdose was significantly associated with higher odds of co-injection in San Diego than in Tijuana. Conclusions: These findings indicate that heroin–methamphetamine co-injection is more common in Tijuana than in San Diego, yet this practice was only associated with overdose in San Diego. Heroin–methamphetamine co-injection was also independently associated with HIV-associated injection risk behaviors. Overdose-prevention interventions should address co-injection of depressants and stimulants. PMID:27588536

  11. Prevalence and Correlates of Heroin-Methamphetamine Co-Injection Among Persons Who Inject Drugs in San Diego, California, and Tijuana, Baja California, Mexico.

    Science.gov (United States)

    Meacham, Meredith C; Strathdee, Steffanie A; Rangel, Gudelia; Armenta, Richard F; Gaines, Tommi L; Garfein, Richard S

    2016-09-01

    Although persons who inject drugs (PWID) in the western United States-Mexico border region are known to inject both heroin and methamphetamine, little is known about the prevalence and risks associated with co-injection of this depressant-stimulant combination (also known as "goofball" and "Mexican speedball"). Baseline data from parallel cohort studies of PWID conducted concurrently in San Diego, CA, and Tijuana, Mexico, were used to estimate the prevalence and identify correlates of heroin-methamphetamine co-injection. PWID older than 18 years of age who reported injecting illicit drugs in the past month (N = 1,311; 32.7% female) were recruited in San Diego (n = 576) and Tijuana (n = 735) and completed interviewer-administered questionnaires. Bivariate and multivariable logistic regression analyses were used to identify correlates of heroin-meth-amphetamine co-injection. The prevalence of co-injection in the past 6 months was 39.9% overall and was higher in Tijuana (55.8%) than in San Diego (19.8%). In multivariable analyses adjusting for study cohort, distributive syringe sharing, purchasing syringes prefilled with drugs, finding it hard to get new syringes, reporting great or urgent need for treatment, and younger age were independently associated with co-injection. Past-6-month overdose was significantly associated with higher odds of co-injection in San Diego than in Tijuana. These findings indicate that heroin-methamphetamine co-injection is more common in Tijuana than in San Diego, yet this practice was only associated with overdose in San Diego. Heroin-methamphetamine coinjection was also independently associated with HIV-associated injection risk behaviors. Overdose-prevention interventions should address co-injection of depressants and stimulants.

  12. 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

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

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    Luis Francisco Mendoza

    2013-03-01

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

  14. 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

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    Francisco Díaz-Cedillo

    2012-06-01

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

  15. Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico.

    Science.gov (United States)

    Meacham, Meredith C; Roesch, Scott C; Strathdee, Steffanie A; Lindsay, Suzanne; Gonzalez-Zuniga, Patricia; Gaines, Tommi L

    2018-01-01

    Patterns of polydrug use among people who inject drugs (PWID) may be differentially associated with overdose and unique human immunodeficiency virus (HIV) risk factors. Subgroups of PWID in Tijuana, Mexico, were identified based on substances used, route of administration, frequency of use and co-injection indicators. Participants were PWID residing in Tijuana age ≥18 years sampled from 2011 to 2012 who reported injecting an illicit substance in the past month (n = 735). Latent class analysis identified discrete classes of polydrug use characterised by 11 indicators of past 6 months substance use. Multinomial logistic regression examined class membership association with HIV risk behaviours, overdose and other covariates using an automated three-step procedure in mplus to account for classification error. Participants were classified into five subgroups. Two polydrug and polyroute classes were defined by use of multiple substances through several routes of administration and were primarily distinguished from each other by cocaine use (class 1: 5%) or no cocaine use (class 2: 29%). The other classes consisted primarily of injectors: cocaine, methamphetamine and heroin injection (class 3: 4%); methamphetamine and heroin injection (class 4: 10%); and heroin injection (class 5: 52%). Compared with the heroin-only injection class, memberships in the two polydrug and polyroute use classes were independently associated with both HIV injection and sexual risk behaviours. Substance use patterns among PWID in Tijuana are highly heterogeneous, and polydrug and polyroute users are a high-risk subgroup who may require more tailored prevention and treatment interventions. [Meacham MC, Roesch SC, Strathdee SA, Lindsay S, Gonzalez-Zuniga P, Gaines TL. Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico. Drug Alcohol Rev 2018;37:128-136].

  16. Continental rupture and the creation of new crust in the Salton Trough rift, Southern California and northern Mexico: Results from the Salton Seismic Imaging Project

    Science.gov (United States)

    Han, Liang; Hole, John A.; Stock, Joann M.; Fuis, Gary S.; Kell, Annie; Driscoll, Neal W.; Kent, Graham M.; Harding, Alistair J.; Rymer, Michael J.; González-Fernández, Antonio; Lázaro-Mancilla, Octavio

    2016-10-01

    A refraction and wide-angle reflection seismic profile along the axis of the Salton Trough, California and Mexico, was analyzed to constrain crustal and upper mantle seismic velocity structure during active continental rifting. From the northern Salton Sea to the southern Imperial Valley, the crust is 17-18 km thick and approximately one-dimensional. The transition at depth from Colorado River sediment to underlying crystalline rock is gradual and is not a depositional surface. The crystalline rock from 3 to 8 km depth is interpreted as sediment metamorphosed by high heat flow. Deeper felsic crystalline rock could be stretched preexisting crust or higher-grade metamorphosed sediment. The lower crust below 12 km depth is interpreted to be gabbro emplaced by rift-related magmatic intrusion by underplating. Low upper mantle velocity indicates high temperature and partial melting. Under the Coachella Valley, sediment thins to the north and the underlying crystalline rock is interpreted as granitic basement. Mafic rock does not exist at 12-18 km depth as it does to the south, and a weak reflection suggests Moho at 28 km depth. Structure in adjacent Mexico has slower midcrustal velocity, and rocks with mantle velocity must be much deeper than in the Imperial Valley. Slower velocity and thicker crust in the Coachella and Mexicali valleys define the rift zone between them to be >100 km wide in the direction of plate motion. North American lithosphere in the central Salton Trough has been rifted apart and is being replaced by new crust created by magmatism, sedimentation, and metamorphism.

  17. Continental rupture and the creation of new crust in the Salton Trough rift, southern California and northern Mexico: Results from the Salton Seismic Imaging Project

    Science.gov (United States)

    Han, Liang; Hole, John A.; Stock, Joann M.; Fuis, Gary S.; Kell, Annie; Driscoll, Neal W.; Kent, Graham M.; Rymer, Michael J.; Gonzalez-Fernandez, Antonio; Aburto-Oropeza, Octavio

    2016-01-01

    A refraction and wide-angle reflection seismic profile along the axis of the Salton Trough, California and Mexico, was analyzed to constrain crustal and upper mantle seismic velocity structure during active continental rifting. From the northern Salton Sea to the southern Imperial Valley, the crust is 17-18 km thick and approximately one-dimensional. The transition at depth from Colorado River sediment to underlying crystalline rock is gradual and is not a depositional surface. The crystalline rock from ~3 to ~8 km depth is interpreted as sediment metamorphosed by high heat flow. Deeper felsic crystalline rock could be stretched pre-existing crust or higher grade metamorphosed sediment. The lower crust below ~12 km depth is interpreted to be gabbro emplaced by rift-related magmatic intrusion by underplating. Low upper-mantle velocity indicates high temperature and partial melting. Under the Coachella Valley, sediment thins to the north and the underlying crystalline rock is interpreted as granitic basement. Mafic rock does not exist at 12-18 depth as it does to the south, and a weak reflection suggests Moho at ~28 km depth. Structure in adjacent Mexico has slower mid-crustal velocity and rocks with mantle velocity must be much deeper than in the Imperial Valley. Slower velocity and thicker crust in the Coachella and Mexicali valleys define the rift zone between them to be >100 km wide in the direction of plate motion. North American lithosphere in the central Salton Trough has been rifted apart and is being replaced by new crust created by magmatism, sedimentation, and metamorphism.

  18. Childhood asthma along the United States/ Mexico border: hospitalizations and air quality in two California counties El asma infantil en la frontera mexicana-estadounidense: hospitalizaciones y calidad del aire ambiental en dos condados de California

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    Paul B English

    1998-06-01

    Full Text Available Since the passage of the North American Free Trade Agreement in 1993, there has been an increasing need to monitor environmental health trends that may be related to the rapid industrialization of the United States/Mexico border. We studied two counties on the California/Baja California border to obtain baseline data on trends in childhood asthma hospitalizations and two pollutants that aggravate asthma, ozone and particulate matter (less than 10 microns in diameter, from 1983 to 1994. Hospital discharge records of children 14 years and younger were analyzed, and rates by county, race, and sex were age-adjusted to the 1990 California population. Data on five ozone and particulate matter indices obtained from the California Environmental Protection Agency were used. Imperial County had the highest childhood asthma hospitalization rates in California for non-Hispanic whites and African-Americans, and the second highest for Hispanics. San Diego County had rates below the state average. Over the time period examined, rates in Imperial County increased 59%, while those in San Diego County decreased 9%. Maximum ozone levels increased 64% in Imperial County but decreased 46% in San Diego County. Particulate matter levels were four times higher in Imperial than in San Diego County. High rates of childhood asthma hospitalizations in Imperial County may be partially related to high levels of poverty and worsening air quality conditions produced by increased burdens on the local airshed. Asthma prevalence surveys and binational time-series analyses examining asthma-pollutant relationships are needed.Desde que se firmó el Tratado de Libre Comercio en 1993, ha aumentado la necesidad de monitorear problemas de salud que podrían relacionarse con la rápida industrialización de la frontera mexicana-estadounidense. Estudiamos dos condados de la fontera entre California y Baja California con objeto de obtener datos de base sobre las tendencias observadas de

  19. Lunar phase and catch success of the striped marlin (Tetrapturus audax in sport fishing at Los Cabos, Baja California Sur, Mexico

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    G. Ponce-Díaz

    2003-06-01

    Full Text Available The influence of the lunar phases on the catch-per-unit effort (CPUE of the striped marlin (Tetrapturus audax captured by the Cabo San Lucas, Baja California Sur, Mexico sport-fishing fleet from October 1987 to June 1989 was analyzed. The information is from 3 377 fishing trips by 13 vessels that represent about 10 % of the fleet. The analysis of the CPUE showed a maximum in January 1988 and a minimum in February 1989. Taking into account the knowledge of the factors that had influence on the fishing success is important in the resource management. No significant difference during the full moon compared with results during other lunar phases was found.Se analizó la influencia de las fases lunares sobre la captura por unidad de esfuerzo en el marlín rayado (Tetraptus audax capturado por la flota deportiva en Cabo San Lucas, Baja California Sur, desde octubre de 1987 a junio de 1989. La información de 3377 viajes de pesca por 13 embarcaciones que representan cerca de un 10% de la flota. El análisis mostró un máximo en enero de 1988 y un mínimo en febrero de 1989. Tomar en consideración el conocimiento de los factores que tuvieron influencia en el éxito en la pesca es importante en el manejo de los recursos. No se encontró diferencias significativas durante la luna llena comparado con los resultados obtenidos durante las otras fases de la luna.

  20. 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...

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

    Science.gov (United States)

    Dorsey, Rebecca J.; Burns, Beverly

    1994-01-01

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

  2. Teledermatology in Tijuana, Mexico.

    Science.gov (United States)

    Brown, Megan

    2016-12-01

    The Health Frontiers in Tijuana (HFiT) clinic is a binational partnership between the University of California, San Diego School of Medicine (San Diego, California); the Universidad Autónoma de Baja California School of Medicine (Tijuana, Mexico); and Desayunador Salesiano Padre Chava, a community grassroots organization in Tijuana, Mexico. Health Frontiers in Tijuana provides accessible quality health care for the underserved in Tijuana's Zona Norte. This article is a narrative meant to share my clinical experience as a dermatology resident who worked with HFiT to establish teledermatology services at this clinic.

  3. Radiated Seismic Energy of Earthquakes in the South-Central Region of the Gulf of California, Mexico

    Science.gov (United States)

    Castro, Raúl R.; Mendoza-Camberos, Antonio; Pérez-Vertti, Arturo

    2018-05-01

    We estimated the radiated seismic energy (ES) of 65 earthquakes located in the south-central region of the Gulf of California. Most of these events occurred along active transform faults that define the Pacific-North America plate boundary and have magnitudes between M3.3 and M5.9. We corrected the spectral records for attenuation using nonparametric S-wave attenuation functions determined with the whole data set. The path effects were isolated from the seismic source using a spectral inversion. We computed radiated seismic energy of the earthquakes by integrating the square velocity source spectrum and estimated their apparent stresses. We found that most events have apparent stress between 3 × 10-4 and 3 MPa. Model independent estimates of the ratio between seismic energy and moment (ES/M0) indicates that this ratio is independent of earthquake size. We conclude that in general the apparent stress is low (σa < 3 MPa) in the south-central and southern Gulf of California.

  4. Analysis of drought and desertification by means of aridity indices and the estimation of water gap in Baja California Sur, Northwest Mexico

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    Enrique Troyo Diéguez

    2013-10-01

    Full Text Available In Baja California Sur (BCS, Mexico, dry-semi warm and warm climates prevail associated to an extreme trend of diurnal temperatures and the environmental dryness. In this State, the maximum summer t exceeds 40° C and the minimum varies from 5 to 12° C, with a minimal for the State of 2° C in winter, at the top of the Sierra de La Laguna; only Los Cabos region has a warm humid climate. Because precipitation in the state is low, oscillating from 310 mm in the southern area of the state to 120 mm per year in the northern portion, predictions and scenarios under climate conditions point to an intensification of droughts. The aim of this work was to carry out a comparative analysis of trends of temperature, precipitation and hydro-environmental aridity among contrasting localities of BCS, by means of the application of Aridity Indexes and the determination of the Standardized Water Gap (BHE, through a numerical scale modification of the De Martonne Index. With the values of temperature and precipitation for the different climate change scenarios for four weather stations, the indicators Hydro Environmental Availability Index (IDHA and Hydro Environmental Drought Index (ISHA were calculated to determine their trend and the consequent BHE, an innovative quantification of wáter deficit, which is proposed in this paper. The máximum value of BHE (10 units, indicating prevalence of drought, is observed from February to June in almost the entire state.

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

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    Jamie McEvoy

    2014-10-01

    Full Text Available 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 the notion that desalination is an appropriate and sufficient technological solution for arid regions. The findings provide evidence of increased yet delimited water security at a neighbourhood scale while identifying new vulnerabilities related to desalination, particularly in the context of the global South. This article concludes that implementing a technological fix on top of a water management system that is plagued with more systemic and structural problems does little to improve long-term water management and is likely to foreclose or forestall other water management options. This multi-scalar analysis contributes to the emerging literature on water security by considering both a narrow and broad framing of water security and identifying a range of factors that influence water security.

  6. 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.

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

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    Idalia Jazmin Castañeda-Yslas

    2016-01-01

    Full Text Available 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.

  8. 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. © The Author(s) 2014.

  9. 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.

  10. Long-term change in eelgrass distribution at Bahía San Quintín, Baja California, Mexico, using satellite imagery

    Science.gov (United States)

    Ward, David H.; Morton, Alexandra; Tibbitts, T. Lee; Douglas, David C.; Carrera-Gonzalez, Eduardo

    2003-01-01

    Seagrasses are critically important components of many marine coastal and estuarine ecosystems, but are declining worldwide. Spatial change in distribution of eelgrass, Zostera marina L., was assessed at Bahía San Quintín, Baja California, Mexico, using a map to map comparison of data interpreted from a 1987 Satellite Pour l'Observation de la Terre multispectral satellite image and a 2000 Landsat Enhanced Thematic Mapping image. Eelgrass comprised 49% and 43% of the areal extent of the bay in 1987 and 2000, respectively. Spatial extent of eelgrass was 13% less (-321 ha) in 2000 than in 1987 with most losses occurring in subtidal areas. Over the 13-yr study period, there was a 34% loss of submerged eelgrass (-457 ha) and a 13% (+136 ha) gain of intertidal eelgrass. Within the two types of intertidal eelgrass, the patchy cover class (turbidity caused by a single flooding event in winter of 1992-1993. Recent large-scale agricultural development of adjacent uplands may have exacerbated the effects of the flood. Oyster farming was not associated with any detectable losses in eelgrass spatial extent, despite the increase in number of oyster racks from 57 to 484 over the study period.

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

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    V.H. Cruz Escalona

    2004-03-01

    Full Text Available 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 invertebratesFueron investigados los hábitos alimenticios de Trachinotus paitensis, en la laguna San Ignacio B.C.S., México. Se observó que T. paitensis es carnívoro, y se alimenta principalmente de invertebrados bénticos (los gastrópodos Anachis spp., Bittium spp., y larvas de crustáceos. En conclusión esta especie es un depredador oportunista que tiene un impacto principalmente sobre las poblaciones de invertebrados epibénticos

  12. 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

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    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

  13. 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

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

    Science.gov (United States)

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

    2011-01-01

    Plant macrofossils from 38 packrat middens spanning the last ~ 33,000 cal yr BP record vegetation between ~ 650 and 900 m elevation along the eastern escarpment of the Sierra San Pedro Mártir, northern Baja California. The middens span most of the Holocene, with a gap between ~ 4600 and 1800 cal yr BP, but coverage in the Pleistocene is uneven with a larger hiatus between 23,100 and 14,400 cal yr BP. The midden flora is relatively stable from the Pleistocene to Holocene. Exceptions include Pinus californiarum, Juniperus californica and other chaparral elements that were most abundant > 23,100 cal yr BP and declined after 14,400 cal yr BP. Despite being near the chaparral/woodland-desertscrub ecotone during glacial times, the midden assemblages reflect none of the climatic reversals evident in the glacial or marine record, and this is corroborated by a nearby semi-continuous pollen stratigraphy from lake sediments. Regular appearance of C4 grasses and summer-flowering annuals since 13,600 cal yr BP indicates occurrence of summer rainfall equivalent to modern (JAS average of ~ 80–90 mm). This casts doubt on the claim, based on temperature proxies from marine sediments in the Guaymas Basin, that monsoonal development in the northern Gulf and Arizona was delayed until after 6200 cal yr BP.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Miranda-Alvarez, A. C.

    2016-09-01

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

  17. The distribution and behaviour of 230Th and 231 Pa at an ocean margin, Baja California, Mexico

    International Nuclear Information System (INIS)

    Shimmield, G.B.; Price, N.B.; Bacon, M.P.; Anderson, R.F.

    1986-01-01

    Uranium, Th and Pa isotopes were measured in sediments collected by box core along a transect normal to the Baja California continental margin. Six cores were analysed, ranging in depositional environment from manganese nodule-bearing, pelagic, red clay to hemipelagic sediments displaying Mn reduction in the upper 5 cm. In the hemipelagic cores, solid-phase Mn peaks due to diagenetic remobilisation occur within the upper layers which are well mixed with respect to unsupported 230 Th and 231 Pa. The fact that 230 Th and 231 Pa are not concentrated at the Mn peaks suggests that little mobility of these nuclides occurs within the sediment column. Unsupported 230 Th/ 231 Pa activity ratios in the biomixed layer of the sediments range from 10.9 to 6.6, generally decreasing towards the inshore stations. The flux of 230 Th and 231 Pa across the sediment/water interface is almost in balance with the theoretical water column supply in the most distal core, but rapidly increases inshore. This evidence from the sediment column confirms that enhanced 230 Th and 231 Pa removal occurs at ocean margins, and that 231 Pa is removed from the water column to the sediments in preference to 230 Th. (author)

  18. Geochemistry of Dissolved Trace Metals in the Waters of Bahia Magdalena, Baja California Sur, Pacific Coast, Mexico

    Science.gov (United States)

    Suresh Babu, S.

    2016-12-01

    Forty two samples were acquired from the surface and bottom water profiles along 5 transects spread over Bahia Magdalena lagoon, Baja California Sur to assess the behavior of trace metals in a high influenced upwelling region on the Pacific coast. To elaborate the fate of metals, also the physico-chemical parameters (pH, temperature, salinity, conductivity, dissolved oxygen). Determination of the concentrations of trace metals (Fe, Mn, Cr, Cu, Co, Pb, Ni, Zn, Cd As, Hg) were measured using Atomic absorption spectrometry. The results demonstrated high values of As, Ni and Co which is attributed to the local geology and phosphate deposits. Low values of Fe and Mn are attested to the oxic conditions of the lagoon which are responsible for the oxidation of Fe and Mn. The region witnesses raised temperatures (28.92ºC) and salinities of 35.2 PSU for its arid climatic conditions and high rates of evaporation. In general, the region presented minor quantities of dissolved trace metals due to dispersion and high intense interaction with the open sea. The results were also compared with other studies to understand the enrichment pattern in this side of the pacific coast which experiences various geothermal activities and upwelling phenomenon.

  19. 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

  20. IDENTIFICATION AND CHARACTERIZATION OF Eimeria spp. DURING EARLY NATURAL INFECTION IN GOAT KIDS IN BAJA CALIFORNIA SUR, MEXICO

    Directory of Open Access Journals (Sweden)

    Ramón Cepeda-Palacios

    2015-12-01

    Full Text Available The aim of this study was to characterize the natural infection by Eimeria spp. in goat kids, and to describe some pathophysiological responses to eimerosis in kids under intensive rearing conditions in B.C.S, Mexico. Nineteen adult crossbred does naturally infected with mixed Eimeria spp. and 20 Anglo Nubian x Creole crossbred kids were used. Oocyst per gram of feces (OPG and identification of Eimeria species were determined in does (during the pre-kidding and post-kidding periods and kids. Clinical signs, hematocrit, hemoglobin and alkaline phosphatase activity in blood serum were evaluated. OPG (mean±SD was significantly higher (P<0.05 in pre-kidding (9,478±7,599 than in post-kidding (5,313±2,909 period. Oocyst elimination in feces began at age 59±9 days in kids. Eimerian species identified were E. arloingi, E. jolchijevi, E. ninakohlyakimovae, E. hirci, E. christenseni and E. alijevi. Kids were humanely sacrificed to evaluate pathological lesions. Intestinal lesions and lesion severity showed differences in duodenum, jejunum, ileum, cecum and colon, being more severe in duodenum. In conclusion, OPG increased during the late pregnancy in does which favored a doe-kid transmission mechanism. Our results support the notion of Eimeria reproduction rhythms during the late pregnancy period in goats, and this reproduction contribute to vertical transmission of Eimeria to the newborn. However, coccidian outbreaks are developed and clinically observed only when stressing factors such as when weaning occur. Coccidia had devastating effects on the intestine of kids, which might cause long-term permanent malabsortion consequences. Â

  1. Fractionation and risk assessment of Fe and Mn in surface sediments from coastal sites of Sonora, Mexico (Gulf of California).

    Science.gov (United States)

    Jara-Marini, Martín E; García-Camarena, Raúl; Gómez-Álvarez, Agustín; García-Rico, Leticia

    2015-07-01

    The aim of this study was to evaluate Fe and Mn distribution in geochemical fractions of the surface sediment of four oyster culture sites in the Sonora coast, Mexico. A selective fractionation scheme to obtain five fractions was adapted for the microwave system. Surface sediments were analyzed for carbonates, organic matter contents, and Fe and Mn in geochemical fractions. The bulk concentrations of Fe ranged from 10,506 to 21,918 mg/kg (dry weight, dry wt), and the bulk concentrations of Mn ranged from 185.1 to 315.9 mg/kg (dry wt) in sediments, which was low and considered as non-polluted in all of the sites. The fractionation study indicated that the major geochemical phases for the metals were the residual, as well as the Fe and Mn oxide fractions. The concentrations of metals in the geochemical fractions had the following order: residual > Fe and Mn oxides > organic matter > carbonates > interchangeable. Most of the Fe and Mn were linked to the residual fraction. Among non-residual fractions, high percentages of Fe and Mn were linked to Fe and Mn oxides. The enrichment factors (EFs) for the two metals were similar in the four studied coasts, and the levels of Fe and Mn are interpreted as non-enrichment (EF < 1) because the metals concentrations were within the baseline concentrations. According to the environmental risk assessment codes, Fe and Mn posed no risk and low risk, respectively. Although the concentrations of Fe and Mn were linked to the residual fraction, the levels in non-residual fractions may significantly result in the transference of other metals, depending on several physico-chemical and biological factors.

  2. Bioaccumulation of trace metals in farmed pacific oysters Crassostrea gigas from SW Gulf of California coast, Mexico.

    Science.gov (United States)

    Jonathan, M P; Muñoz-Sevilla, N P; Góngora-Gómez, Andrés Martin; Luna Varela, Raquel Gabriela; Sujitha, S B; Escobedo-Urías, D C; Rodríguez-Espinosa, P F; Campos Villegas, Lorena Elizabeth

    2017-11-01

    The aim of the study was to evaluate the bioavailability of trace metals (Chromium, Copper, Nickel, Lead, Zinc, Cadmium, Arsenic, and Mercury) in the commercially consumed Crassostrea gigas oysters collected over a 12-month growth period (2011-12) from an experimental cultivation farm in La Pitahaya, Sinaloa State, Mexico. Sediment and water samples were also collected from four different zones adjacent to the cultivation area to identify the concentration patterns of metals. The results revealed that sewage disposals, fertilizers used for agricultural practices and shrimp culture are the major sources for the enrichment of certain toxic metals. The metal concentrations in oysters presented a decreasing order of abundance (all values in mg Kg -1 ): Zn (278.91 ± 93.03) > Cu (63.13 ± 31.72) > Cr (22.29 ± 30.23) > Cd (14.54 ± 4.28) > Ni (9.41 ± 11.33) > Pb (2.22 ± 1.33) > As (0.58 ± 0.91) > Hg (0.04 ± 0.06). Bioconcentration Factor (BCF) and Biota Sediment Accumulation Factor (BSAF) exhibited that C. gigas in the region are strong accumulators for Zn and Cd respectively. Thus, the present study proves to fulfill the gap in understanding the rate of bioaccumulation of metals in C. gigas which is regarded as the most sought after oyster species globally. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The herpetofauna of Sonora, Mexico, with comparisons to adjoining states

    Directory of Open Access Journals (Sweden)

    Enderson, E. F.

    2009-01-01

    Full Text Available Situated in the topographically complex transition between the Neotropics and the temperate biomes of North America,the state of Sonora, Mexico, has an extraordinarily diverse herpetofauna. Surprisingly little research has been conductedon the state’s amphibians and reptiles and many systematic and biogeographic questions remain unanswered. Tofacilitate future research, we provide a checklist of Sonora’s herpetofauna, documenting species presence based onmuseum specimens, our fieldwork, and published research. Sonora’s herpetofauna is placed in a regional biogeographicperspective via a checklist for the six adjoining states together with faunal analyses. A total of 402 species ofamphibians and reptiles are recorded from these seven states. Sonora has the greatest species richness (187 species,followed by Chihuahua (169 species, and Sinaloa (146 species. Sonora's herpetofauna is most similar to that ofChihuahua, with which it shares a long border. Eleven biogeographic affinity-based faunal groups are recognized. Ofthese, three are dominant in Sonora: a core group classified as "Sonoran" demonstrates strong affinity to SonoranDesertscrub and Sinaloan Thornscrub communities; a Tropical group - with many species reaching their northerndistributional limits in the state; and a Madrean group consisting largely of montane species. Our state-level faunalanalysis provides some evidence of peninsular depauperization of the herpetofauna on the Baja California peninsula duein part to the small number of Neotropical species present in Baja California Sur. Our faunal analysis points towarddistinctive mainland and peninsular Sonoran Desert herpetofaunas centered on Sonora and the Baja CaliforniaPeninsula, respectively, each with about 50 non-insular species, and each with species-level endemism nearing 50%.

  4. Incidence of organochlorine pesticides and the health condition of nestling ospreys (Pandion haliaetus) at Laguna San Ignacio, a pristine area of Baja California Sur, Mexico.

    Science.gov (United States)

    Rivera-Rodríguez, Laura B; Rodríguez-Estrella, Ricardo

    2011-01-01

    We identified and quantified organochlorine (OC) pesticide residues in the plasma of 28 osprey (Pandion haliaetus) nestlings from a dense population in Laguna San Ignacio, a pristine area of Baja California Sur, Mexico, during the 2001 breeding season. Sixteen OC pesticides were identified and quantified. α-, β-, δ- and γ-hexachlorocyclohexane, heptaclor, heptachlor epoxide, endosulfan I and II, endosulfan-sulfate, p,p'-DDE, p,p'-DDD, aldrin, dieldrin, endrin, endrin aldehyde, and endrin ketone were the OCs found in the plasma of nestlings, ranging from 0.002 to 6.856 pg/μl (parts per billion). No differences were found in the concentration of pesticides between genders (P > 0.05). In our work, the concentrations detected in the plasma were lower than those reported to be a threat for the species and that affect the survival and reproduction of birds. The presence of OC pesticides in the remote Laguna San Ignacio osprey population is an indication of the ubiquitous nature of these contaminants. OCs are apparently able to travel long distances from their source to the study area. A significant relationship between hemoglobin and mean corpuscular hemoglobin concentrations and OC concentrations were found suggesting that a potential effect on the health of chicks may exist in this osprey population caused by the OC, e.g. anemia. The total proteins were positively correlated with α-BHC, endosulfan I, and p,p'-DDD. It has been suggested that OC also affects competitive interactions and population status over the long term in vertebrate species, and our results could be used as reference information for comparison with other more exposed osprey populations.

  5. Early development and life cycle of Contracaecum multipapillatum s.l. from a brown pelican Pelecanus occidentalis in the Gulf of California, Mexico.

    Science.gov (United States)

    Valles-Vega, Isabel; Molina-Fernández, Dolores; Benítez, Rocío; Hernández-Trujillo, Sergio; Adroher, Francisco Javier

    2017-08-09

    The initial developmental stages of Contracaecum multipapillatum (von Drasche, 1882) Lucker, 1941 sensu lato were studied using eggs obtained from the uteri of female nematodes (genetically identified) found in a brown pelican Pelecanus occidentalis from Bahía de La Paz (Gulf of California, Mexico). Optical microscopy revealed a smooth or slightly rough surface to the eggs. Egg dimensions were approximately 53 × 43 µm, although after the larvae had developed inside, egg size increased to 66 × 55 µm. Hatching and survival of the larvae were greater at 15°C than at 24°C, and increased salinity resulted in a slight increase in hatching but seemed to reduce survival at 24°C, but not at 15°C. The recently hatched larvae measured 261 × 16 µm within their sheath. When placed in culture medium, the larvae grew within their sheath, and a small percentage (~2%) exsheathed completely (314 × 19 µm). The larvae continued to grow and develop once they had exsheathed, attaining mean dimensions of 333 × 22 µm. Although they did not moult during culture, optical microscopy revealed a morphology typical of third-stage larvae. Finally, the genetic identity between the larval parasites collected from mullet Mugil curema and adult female parasites collected from the brown pelican suggests a life cycle of C. multipapillatum in which the mullet are involved as intermediate/paratenic hosts and the brown pelicans as final hosts in the geographical area of Bahía de La Paz.

  6. Impacts of using an ensemble Kalman filter on air quality simulations along the California-Mexico border region during Cal-Mex 2010 field campaign.

    Science.gov (United States)

    Bei, Naifang; Li, Guohui; Meng, Zhiyong; Weng, Yonghui; Zavala, Miguel; Molina, L T

    2014-11-15

    The purpose of this study is to investigate the impact of using an ensemble Kalman filter (EnKF) on air quality simulations in the California-Mexico border region on two days (May 30 and June 04, 2010) during Cal-Mex 2010. The uncertainties in ozone (O3) and aerosol simulations in the border area due to the meteorological initial uncertainties were examined through ensemble simulations. The ensemble spread of surface O3 averaged over the coastal region was less than 10ppb. The spreads in the nitrate and ammonium aerosols are substantial on both days, mostly caused by the large uncertainties in the surface temperature and humidity simulations. In general, the forecast initialized with the EnKF analysis (EnKF) improved the simulation of meteorological fields to some degree in the border region compared to the reference forecast initialized with NCEP analysis data (FCST) and the simulation with observation nudging (FDDA), which in turn leading to reasonable air quality simulations. The simulated surface O3 distributions by EnKF were consistently better than FCST and FDDA on both days. EnKF usually produced more reasonable simulations of nitrate and ammonium aerosols compared to the observations, but still have difficulties in improving the simulations of organic and sulfate aerosols. However, discrepancies between the EnKF simulations and the measurements were still considerably large, particularly for sulfate and organic aerosols, indicating that there are still ample rooms for improvement in the present data assimilation and/or the modeling systems. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Frequency and sources of basin floor turbidites in alfonso basin, Gulf of California, Mexico: Products of slope failures

    Science.gov (United States)

    Gonzalez-Yajimovich, Oscar E.; Gorsline, Donn S.; Douglas, Robert G.

    2007-07-01

    Alfonso Basin is a small margin basin formed by extensional tectonics in the actively rifting, seismically active Gulf of California. The basin is centered at 24°40' N and 110° 38' W, and is a closed depression (maximum depth 420 m) with an effective sill depth of about 320 m (deepest sill), a width of 20 km and length of 25 km. Basin floor area below a depth of 350 m is about 260 km 2. The climate is arid to semiarid but was wetter during the early (ca. 10,000-7000 Calendar years Before Present [BP]) and middle Holocene (ca. 7000-4000 Cal. Years BP). Basin-wide turbidity currents reach the floor of Alfonso Basin at centennial to millennial intervals. The peninsular drainages tributary to the basin are small and have maximum flood discharges of the order of 10 4m 3. The basin-floor turbidites thicker than 1 cm have volumes of the order of 10 6m 3 to 10 8m 3 and require a much larger source. The largest turbidite seen in our cores is ca. 1 m thick in the central basin floor and was deposited 4900 Calendar Years Before Present (BP). Two smaller major events occurred about 1500 and 2800 Cal. Years BP. Seismicity over the past century of record shows a clustering of larger epicenters along faults forming the eastern Gulf side of Alfonso Basin. In that period there have been four earthquakes with magnitudes above 7.0 but all are distant from the basin. Frequency of such earthquakes in the basin vicinity is probably millennial. It is concluded that the basin-wide turbidites thicker than 1 cm must be generated by slope failures on the eastern side of the basin at roughly millennial intervals. The thin flood turbidites have a peninsular source at centennial frequencies.

  8. 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.

  9. Microfaunal evidence of age and depositional environments of the Cerro Prieto section (Plio-Pleistocene), Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ingle, J.C. Jr.

    1982-01-01

    Microfossils including benthic and planktic foraminifera, ostracodes, calcareous algae, fish skeletal material, and fragments of pelecypods were found in 14 core samples from depths of 185 to 1952 m in the Cerro Prieto geothermal field, providing evidence of both the age and depositional history of sediments comprising the 3000-m-thick Pliocene and Pleistocene section in this area. Ostracodes of brackish water and marine origin constitute the most common microfossils present in this sequence occurring in 8 samples; in situ littoral and neritic species of benthic foraminifera occur in 5 samples with planktic species present in 2 samples. Distributional patterns of ostracodes and foraminifera together with previously analyzed lithofacies (Lyons and van de Kamp, 1980) indicate that the Cerro Prieto section represents an intertonguing complex of alluvial, deltaic, estuarine, and shallow marine environments deposited along the front of the Colorado River delta as it prograded across the Salton Trough during Pliocene and Pleistocene time. Foraminiferal evidence indicates that a sand and shale unit commonly present at depths between 700 and 1100 m represents a significant mid-Pleistocene marine incursion in the Cerro Prieto area. Tentative correlation of the Cerro Prieto section with the well dated Palm Springs Formation of the Imperial Valley, California area suggests that the Pliocene/Pleistocene boundary occurs at a depth of approximately 2000 m in the area of well M-93. Reworked specimens of Cretaceous foraminifera and fragments of the Cretaceous pelecypod Inoceramus were found in five samples further substantiating the Colorado Plateau provenance of a significant portion of the Colorado River deltaic sediments in the Cerro Prieto area.

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

    Science.gov (United States)

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

    2017-01-01

    Ultra-high-resolution (1 m * 1 m * 0.25 m) bathymetry was acquired with an autonomous underwater vehicle (AUV) over a sector of the Navy Fan offshore Baja California. The survey specifically targeted an area where the former interpretation of the fan showed a channel–lobe transition; however, the lobe and the transition were not recognized. Instead, the newly acquired bathymetry shows that the previously identified channel continues basinward changing its overall morphology and stratigraphic architecture, becoming gradually but significantly wider (650–1000 m) and of lower relief (3–4 m). Cores from the channel thalweg recovered mud-poor (< 5%) well-sorted sands, interpreted as deposited by fully turbulent flows. The cores also show several mud-rich (9–18%) poorly sorted sands, probably indicating deposition from more cohesive flows.The high-resolution bathymetry shows large sectors of the seafloor sculpted by elaborate bedforms and scours. The overbank area north of the channel exhibits the most numerous and prominent scours, interpreted to have been largely generated by flow stripping at a bend in the channel. Along high-gradient sectors (more than approximately 1¯) of this area, the scours are largest and deepest. Some of these scours show an erosional headwall and a distal upflow-dipping depositional bulge, forming repetitive bedforms interpreted as erosional cyclic steps associated with locked-in-place trains of hydraulic jumps. The scours seem to coalesce to form an incipient channel, which would likely drive the avulsion of the main channel. Further basinward, average gradients decrease (< 0.6¯ ) and scours become smaller and less deep suggesting a gradient control on erosion. The southern channel margin and adjacent overbank area exhibit a trend of scours that are elongated transverse to flow, that successively repeat themselves basinwards, and that at times merge with sediment waves. Probably these scours are genetically linked to sediment waves

  11. The Korean Peninsula

    International Nuclear Information System (INIS)

    Jeon Bu-Guan

    1994-01-01

    A realistic approach to North-South arms control and disarmament would require a step-by-step formula encompassing measures for political and military confidence building, arms limitation and reduction. The most fundamental and important condition for achieving meaningful results in disarmament talks is securing political and military confidence. The problem which arose on the Korean peninsula originates from relations of North Korea and IAEA. North Korean position poses a serious threat to the Non-proliferation Treaty, in particular to the IAEA Safeguards regime. Nuclear non-proliferation and the ultimate elimination of nuclear weapons are the primary concerns of the post-cold war era. The Government of South Korea hopes that this issue can be solved through dialogue and negotiations

  12. The nuclear peninsula

    International Nuclear Information System (INIS)

    Zonabend, F.

    1993-01-01

    This book reports a study of the social and psychological implications for the people who work in or live near a high-risk industrial establishment. The establishment focussed on the studies is the nuclear reprocessing plant at la Hague on the Cotentin Peninsula in Normandy, France. The ways in which those working in the plant and living nearby come to terms with the risks in their daily lives is described. A sociology of the nuclear work place with its diversions and hierarchies is developed and an explanation offered for the often unexpected responses of the workers to the fear of irradiation and contamination. By analysing work practices and the language of the work-place it is shown how workers and locals can recognise the possibility of nuclear catastrophe while, at the same time, denying that it could ever happen to them. (UK)

  13. Tectono-Stratigraphy of the Seeps on the Guaymas Basin at the Sonora Margin, Gulf of California, Mexico

    Science.gov (United States)

    Figueroa Albornoz, L. J.; Mortera-Gutierrez, C. A.; Bandy, W. L.; Escobar-Briones, E. G.; Godfroy, A.; Fouquet, Y.

    2013-05-01

    Recently several hydrothermal and gas seeps systems has been located precisely at the Sonora margin within the Guaymas Basin (GB), Gulf of California. Since late 1970's , several marine studies had reported two main hydrothermal systems in the Guaymas Rift (one at the Northern Rift, and other at the Southern Rift) and a cold seeps system at the Satellite Basin in the Sonora-margin lower edge. During the campaign BIG10, onboard the IFREMER vessel, NO L'Atalante, the EM122 echo-sounder log more than 30,000 water column acoustic images, which allows us to create a data base of the bubble plumes active systems on the northern part of the GB and the Sonora Margin. These plumes are the expression on the water column of an active seeps site during the cruise time. These images document the presence of the cold seep activity around the scarp of the Guaymas Transform Fault (GTF), and within the Satellite Basin. Few active plumes are first located off-axis, on both sides of the Northern Rift. Although it is not observed any plume within NR. Sub-bottom profiles and bathymetric data logged during the campaign GUAYRIV10, onboard the UNAM vessel, BO EL PUMA, are analyzed to determine the shallow tectonic-stratigraphy of GB near the Sonora Margin. We analyze 17 high-resolution seismic profiles (13 with NE-SW strike and 3 with NW-SE strike). From this data set, the continental shelf stratigraphy at the Sonora Margin tilts toward the slope, showing 3 low angle unconformities due to tectonics and slope angle changes. The strata slope changes angle up to 60°. However, the constant trans-tension shear along the GTF causes gravitation instability on the slope, generating a few submarine landslides close to the Northern Rift, and the rotation of blocks, tilting toward the shelf. To the north, the GTF splits in two fault escarpments, forming a narrow pull-apart basin, known as Satellite Basin. The submarine canyon from the Sonora River flows through the Satellite Basin into the GB

  14. Fish larvae and juveniles checklist (Pisces from the northern Yucatán Peninsula, Mexico, with 39 new records for the region Listado de larvas y juveniles de peces del norte de la península de Yucatán, México, con 39 nuevos registros para la región

    Directory of Open Access Journals (Sweden)

    Víctor García-Hernández

    2009-04-01

    Full Text Available A taxonomic checklist for fish larvae and juveniles occurring at Yalahau (June 2001-May 2002, Celestún (July 1994-June 1995, Chelem (July 1999-June 2000 and Río Lagartos (November 1996- October 1997 lagoons located in the northern part of the Yucatán Peninsula is presented. Sampling was carried out for 5 minutes using a zooplankton net for larvae, while a Renfro net was hauled for 50 m2 to capture juveniles. This work aims to provide the current state of the taxonomic composition and general distribution for 34 377 fish larvae and juveniles. Our samples represent 2 classes, 17 orders, 45 families, 83 genera and 117 species were caught, including 39 new records, where 24 have been found only in the Gulf of Mexico, 3 in the Caribbean Sea, and 90 are common to both regions. This study updates and increases the number of species in larval and juvenile stages previously reported. It was found that early reef larval stages were more abundant towards the East of the Yucatán Peninsula and less to the West. The high number of shared species (90 suggests that the northern region of the Yucatán Peninsula is a transition zone for fish larvae and juveniles between the Gulf of Mexico and the Caribbean Sea.Se presenta un listado taxonómico de larvas y juveniles de peces de las lagunas de Yalahau (junio 2001-may 2002, Celestún (julio 1994-junio 1995, Chelem (julio 1999-junio 2000 y Río Lagartos (noviembre1996- octubre 1997 del norte de la península de Yucatán. Se actualiza e incrementa el registro en el número de especies del lugar reportado en estudios previos y se hacen observaciones sobre la distribución general de las larvas y juveniles de peces del área. Los muestreos se realizaron durante 5 minutos con una red de zooplancton para las larvas de peces y una red Renfro para los juveniles cubriendo un área de 50 m2. Se registraron 2 clases, 17 órdenes, 45 familias, 83 géneros y 117 especies, incluyendo a 39 nuevos registros, y de las cuales 24

  15. Are whale sharks exposed to persistent organic pollutants and plastic pollution in the Gulf of California (Mexico)? First ecotoxicological investigation using skin biopsies.

    Science.gov (United States)

    Fossi, Maria Cristina; Baini, Matteo; Panti, Cristina; Galli, Matteo; Jiménez, Begoña; Muñoz-Arnanz, Juan; Marsili, Letizia; Finoia, Maria Grazia; Ramírez-Macías, Dení

    2017-09-01

    The whale shark (Rhincodon typus) is an endangered species that may be exposed to micro- and macro-plastic ingestion as a result of their filter-feeding activity, particularly on the sea surface. In this pilot project we perform the first ecotoxicological investigation on whale sharks sampled in the Gulf of California exploring the potential interaction of this species with plastic debris (macro-, micro-plastics and related sorbed contaminants). Due to the difficulty in obtaining stranded specimens of this endangered species, an indirect approach, by skin biopsies was used for the evaluation of the whale shark ecotoxicological status. The levels of organochlorine compounds (PCBs, DDTs), polybrominated diphenyl ethers (PBDEs) plastic additives, and related biomarkers responses (CYP1A) were investigated for the first time in the whale shark. Twelve whale shark skin biopsy samples were collected in January 2014 in La Paz Bay (BCS, Mexico) and a preliminary investigation on microplastic concentration and polymer composition was also carried out in seawater samples from the same area. The average abundance pattern for the target contaminants was PCBs>DDTs>PBDEs>HCB. Mean concentration values of 8.42ng/g w.w. were found for PCBs, 1.31ng/g w.w. for DDTs, 0.29ng/g w.w. for PBDEs and 0.19ng/g w.w. for HCB. CYP1A-like protein was detected, for the first time, in whale shark skin samples. First data on the average density of microplastics in the superficial zooplankton/microplastic samples showed values ranging from 0.00items/m 3 to 0.14items/m 3 . A focused PCA analysis was performed to evaluate a possible correlation among the size of the whale sharks, contaminants and CYP1A reponses. Further ecotoxicological investigation on whale shark skin biopsies will be carried out for a worldwide ecotoxicological risk assessment of this endangerd species. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. The Geology of Mexico: A Quantitative Evaluation of a Course Designed to Increase the Number of Hispanic Students Participating in the Geosciences at California State University, Sacramento

    Science.gov (United States)

    Hammersley, Lisa C.; Levine, R.; Cornwell, K.; Kusnick, J. E.; Hausback, B. P.

    2012-01-01

    We present a quantitative evaluation of the effectiveness of a newly developed introductory course, Geology of Mexico, in attracting Hispanic students, encouraging them to take more geology courses, and recruiting them to the major. The student population in the Geology of Mexico course was 93% Hispanic compared with 18.5% in Physical Geology. We…

  17. From continental to oceanic rifting in the Gulf of California

    Science.gov (United States)

    Ferrari, Luca; Bonini, Marco; Martín, Arturo

    2017-11-01

    The continental margin of northwestern Mexico is the youngest example of the transition from a convergent plate boundary to an oblique divergent margin that formed the Gulf of California rift. Subduction of the Farallon oceanic plate during the Cenozoic progressively brought the East Pacific Rise (EPR) toward the North America trench. In this process increasingly younger and buoyant oceanic lithosphere entered the subduction zone until subduction ended just before most of the EPR could collide with the North America continental lithosphere. The EPR segments bounding the unsubducted parts of the Farallón plate remnants (Guadalupe and Magdalena microplates) also ceased spreading (Lonsdale, 1991) and a belt of the North American plate (California and Baja California Peninsula) became coupled with the Pacific Plate and started moving northwestward forming the modern Gulf of California oblique rift (Nicholson et al., 1994; Bohannon and Parsons, 1995). The timing of the change from plate convergence to oblique divergence off western Mexico has been constrained at the middle Miocene (15-12.5 Ma) by ocean floor morphology and magnetic anomalies as well as plate tectonic reconstructions (Atwater and Severinghaus, 1989; Stock and Hodges, 1989; Lonsdale, 1991), although the onset of transtensional deformation and the amount of right lateral displacement within the Gulf region are still being studied (Oskin et al., 2001; Fletcher et al., 2007; Bennett and Oskin, 2014). Other aspects of the formation of the Gulf of California remain not well understood. At present the Gulf of California straddles the transition from continental transtension in the north to oceanic spreading in the south. Seismic reflection-refraction data indicate asymmetric continent-ocean transition across conjugate margins of rift segments (González-Fernández et al., 2005; Lizarralde et al., 2007; Miller and Lizarralde, 2013; Martín-Barajas et al., 2013). The asymmetry may be related to crustal

  18. Impact of the North American Free Trade Agreement on transportation in the border areas of the United States : with emphasis on the California-Mexico border

    Science.gov (United States)

    1999-08-01

    This report identifies impacts of the North ?American Free Trade Agreement (NAFTA) on transportation in the U.S. border areas. Emphasis is on the California-Baja California border zone. Focus is on the identification of recommendations to the Califor...

  19. New tectonic data constrain the mechanisms of breakup along the Gulf of California

    Science.gov (United States)

    Bot, Anna; Geoffroy, Laurent; Authemayou, Christine; Graindorge, David

    2014-05-01

    The Gulf of California is resulting from an oblique-rift system due to the separation of the Pacific and the North American plates in the ~N110E to ~N125E trend. The age, nature and orientation of strain which ended with continental break-up and incipient oceanization at ~3.6 Ma, is largely misunderstood. It is generally proposed that early stages of extension began at around 12 Ma with strain partitioning into two components: a pure ENE directed extension in the Gulf Extensional Province (which includes Sonora and the eastern Baja California Peninsula in Mexico) and a dextral strike-slip displacement west of the Baja California Peninsula along the San Benito and Tosco-Abreojos faults. This evolution would have lasted ~5-6 Ma when a new transtensional strain regime took place. This regime, with extension trending ~N110E +/-10° , led to the final break-up and the subsequent individualization of a transform-fault system and subordoned short oceanic ridges. This two-steps interpretation has recently been challenged by authors suggesting a continuous transtensional extension from 12Ma in the trend of the PAC-NAM plates Kinematic. We question both of those models in term of timing and mode of accommodation basing ourselves on field investigations in Baja California Sur (Mexico). The volcano-sedimentary formations of the Comondù group dated 25 to 20 Ma exhibit clear examples of syn-sedimentary and syn-magmatic extensive deformations. This extension, oriented N65° E+/-15° , is proposed to initiate during the Magdalena Plate subduction. It would be related to the GOC initialization. In addition to this finding, we present tectonic and dating evidences of complex detachment-faulting tectonics varying in trend and kinematics with time and space for the development to the south of Baja California Sur. The extension associated with the early detachment-fault system trended ~N110E. From ~17 Ma to, probably, ~7-8 Ma, this extension controlled the early development of the San

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

    Directory of Open Access Journals (Sweden)

    Abel O. Villa Rodríguez

    2013-01-01

    Full Text Available The process of open markets has created import changes in the Mexican agriculture sector, very much noted in the so called crop pattern, the institutional frame that guides the agro–productive commercial relationships and trade organization. The agriculture in the Northwest region, particularly La Costa de Hermosillo in the State of Sonora and southern Baja in Baja Peninsula, shows a big transformation. This corresponds to Global Production Networks (gpn, a vertical integration with intensive extraterritorial interaction resulting in a process of productive escalation that favors; learning and the creation of new competitive capabilities indispensable to comply with high standards in international markets. These capabilities are reflected in improvements in product quality, productive efficiency and the development of new functions for the players involved in the production and trade of produce. It also reflects the transition to more sophisticated productive units where players are located in other territories. This study focuses on analyzing the roll of gpn in the transformation of the agricultural sector in the northwest region of Mexico, particularly the process that took place in modernizing both places.

  1. March 2007 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to the US/Mexico Border

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This lidar point data set was collected during low tide conditions along an approximately 500-700 meter wide strip of the Southern California coastline within an...

  2. Stratigraphy of Karaburun Peninsula

    Directory of Open Access Journals (Sweden)

    Burhan Erdoğan

    1990-06-01

    Full Text Available In the Karaburun peninsula, a tectonic bell with a thick Mesozoic succession is located bordering the Izmir-Ankara zone on its western side. In the stratigraphic column of the Karaburun belt, the oldest unit is the Lower and Middle Carboniferous Alandere formation consisting dominantly of fossiliferous limestones. Lower Triassic rocks rest directly above this unit and Upper Carboniferous and Permian sections are missing. The Lower Triassic is represented by rock units showing facies changes in short distances along vertical and horizontal directions. In this part of the section, the Karareis and Gerence formations are differentiated which are collectively named as the Denizgiren group. The Karareis formation is composed of intercalations of sandstones, bedded-black cherts, pelagic limestones and mafic volcanics, whereas the Gerence formation composed dominantly of ammonitic red limestones, thinly-bedded gray limestones, and cherty limestones. The Karareis and Gerence formations grade laterally into each other and range in age from Scythian to Late Anisian. The Camiboğazı formation resting with a gradational contact on each of these units consists of massive limestones with reefal facies in places and yields an age of Ladinian-Camian. The Güvercinlik formation lies conformably above the Camiboğazı formation and consists of algal stromatolites, megalodon-bearing limestones, and quartzitic sandstone intervals. This unit ranges in age from Norian-Rheatian. The Nohutalan formation which is dominantly represented by thick-bedded neritic limestones overlies the Güvercinlik formation gradationally and yields an age ranging from Liassic to Albian. This unit appears to be lithologically continuous in the field without any indications of a break in the stratigraphic or structural record, however, the Dogger age has not been determined which may probably indicate a presence of a hiatus. Above this Mesozoic comprehensive succession with an age

  3. Sr and Nd isotope geochemistry and tectonics during subduction and rifting in Sierra Santa Ursula, Sonora, Northwestern Mexico

    International Nuclear Information System (INIS)

    Mora-Klepeis, G.

    2000-01-01

    The western margin of North America was affected by a convergent plate boundary from the Cretaceous through the Early Tertiary. Volcanic rocks produced by subduction-related arc magmatism in northwestern Mexico are concentrated in two northwest-trending belts subparallel to the continental margin. One of these is the Sierra Madre Occidental, where mid-Tertiary magmatism consisted mostly of calc-alkaline rhyolitic ignimbrite and minor andesite produced between ∼ 46 and 28 Ma (McDowell et al., 1990). The second (younger) northwest-trending belt is located along the eastern margin of the Baja California Peninsula and in the Gulf of California region of mainland Mexico. This belt is composed mostly of andesite, but includes some basalt and dacite whose ages range from about 24 to 11 Ma (Hausback, 1984). A transition to rifting began after a mid-Tertiary cessation of subduction, eventually creating the Gulf of California extensional province. Four markedly different magma types comprising mainly tholeiitic and alkalic rocks and minor calc-alkaline and peralkaline rocks were erupted throughout the last 13 Ma and record the history of rifting of the Gulf of California (Sawlan, 1991). The aim of the present paper is to distinguish the nature of the 24-8.5 Ma magmatism emplaced on the eastern side of the Gulf of California in the state of Sonora, by the use of stratigraphic, geochemical and isotopic data. Preliminary Sr and Nd results show that three groups of magmas are present in the area suggesting a heterogeneous source. This can be interpreted as the result of magmas being erupted at different stages of subduction and rifting during the tectonic evolution of this part on North America

  4. 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

  5. Geology of Southern Quintana Roo (Mexico) and the Chicxulub Ejecta Blanket

    Science.gov (United States)

    Schönian, F.; Tagle, R.; Stöffler, D.; Kenkmann, T.

    2005-03-01

    In southern Quintana Roo (Mexico) the Chicxulub ejecta blanket is discontinuously filling a karstified pre-KT land surface. This suggests a completely new scenario for the geological evolution of the southern Yucatán Peninsula.

  6. Population structure and sexual maturity of the calico box crab Hepatus epheliticus Linnaeus (Brachyura, Hepatidae from Yucatan Peninsula, Mexico Estructura poblacional y madurez sexual en el cangrejo caja moteado Hepatus epheliticus Linnaeus (Brachyura, Hepatidae procedente de la Península del Yucatán, México

    Directory of Open Access Journals (Sweden)

    Patricio Hernáez

    2012-07-01

    Full Text Available The calico box crab Hepatus epheliticus is an abundant species from shallow and continental shelf waters of the Atlantic coast of USA and Mexico. Information about population structure and sexual maturity is absent, even though this crab is caught to be used as bait for the octopus fishery in the Campeche Bank, Mexico. In order to achieve such information, a total of 768 individuals were collected from January to March 2010 through baited traps installed in the Yucatan Peninsula, Mexico. Our results showed that sex ratio is biased towards more males than females (1:0.55, contradicting to that reported in other brachyuran crabs. The absence of ovigerous females suggests that they did not enter into the traps during embryogenesis. Males reached a larger maximum size than females (64.0 ± 6.15 and 58.4 ± 5.60 mm carapace width, respectively. The general scheme of growth being positive allometric throughout ontogeny of both sexes. Males presented a transition phase from juveniles to adult corresponding to the puberty moult. The estimation of the onset of functional sexual maturity revealed a steady situation for the population, with 21.5 and 13.8% of males and females, respectively, morphologically immature at the time of catch. This study constitutes the first report on population structure and sexual maturity in a population of the calico box crab H. epheliticus.El cangrejo caja moteado Hepatus epheliticus es un abundante braquiuro perteneciente a la familia Hepatidae, distribuido desde aguas someras hasta la plataforma continental en la costa atlántica de Estados Unidos y México. La información sobre su demografía poblacional y madurez sexual es actualmente inexistente, aun cuando esta especie es intensamente capturada como carnada en la pesquería del pulpo del estado de Campeche, México. Entre enero y marzo de 2010, se colectaron 768 especímenes usando trampas instaladas en la Península de Yucatán, México. Los resultados mostraron una

  7. A paleomagnetic investigation of vertical-axis rotations in coastal Sonora, Mexico: Evidence for distributed transtensional deformation during the Proto-Gulf shift from a subduction-dominated to transform-dominated plate boundary in the Gulf of California

    Science.gov (United States)

    Herman, Scott William

    The history of late Miocene (Proto-Gulf) deformation on the Sonoran margin of the Gulf of California is key to understanding how Baja California was captured by the Pacific plate and how strain was partitioned during the Proto-Gulf period (12.5-6 Ma). The Sierra el Aguaje and Sierra Tinajas del Carmen are located in southwestern coastal Sonora, Mexico, and represent the eastern rifted margin of the central Gulf of California. The ranges are composed of volcanic units and their corresponding volcaniclastic units which are the result of persistent magmatic activity between 20 and 8.8 Ma, including three packages of basalt and andesite that make excellent paleomagnetic recorders. Based on cross cutting relations and geochronologic data for pre-, syn-, and post-tectonic volcanic units, most of the faulting and tilting in the Sierra El Aguaje is bracketed between 11.9 and 9.0 Ma, thus falling entirely within Proto-Gulf time. A paleomagnetic investigation into possible vertical axis rotations in the Sierra el Aguaje has uncovered evidence of clockwise rotations between ~13º and ~105º with possible translations. These results are consistent with existing field relations, which suggest the presence of large (>45°) vertical axis rotations in this region. This evidence includes: a) abrupt changes in the strike of tilted strata in different parts of the range, including large domains characterized by E-W strikes b) ubiquitous NE-SW striking faults with left lateral-normal oblique slip, that terminate against major NW-trending right lateral faults, and c) obliquity between the general strike of tilted strata and the strike of faults. These rotations occurred after 12 Ma and largely prior to 9 Ma, thus falling into the Proto-Gulf period. Such large-scale rotations lend credence to the theory that the area inboard of Baja California was experiencing transtension during the Proto-Gulf period, rather than the pure extension that would be the result of strain partitioning

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

    Directory of Open Access Journals (Sweden)

    T. van der Werf

    2017-12-01

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

  9. Hurricane Ike Deposits on the Bolivar Peninsula, Galveston Bay, Texas

    Science.gov (United States)

    Evans, Cynthia A.; Wilkinson, M. J.; Eppler, Dean

    2011-01-01

    In September 2008, Hurricane Ike made landfall on Galveston Bay, close to the NASA Johnson Space Center (JSC). The storm flooded much of the area with a storm surge ranging from 11 -20 feet. The Bolivar peninsula, the southeastern coast of Galveston Bay, experienced the brunt of the surge. Several agencies collected excellent imagery baselines before the storm and complementary data a few days afterward that helped define the impacts of the storm. In April of 2011, a team of scientists and astronauts from JSC conducted field mapping exercises along the Bolivar Peninsula, the section of the Galveston Bay coast most impacted by the storm. Astronauts routinely observe and document coastal changes from orbit aboard the International Space Station. As part of their basic Earth Science training, scientists at the Johnson Space Center take astronauts out for field mapping exercises so that they can better recognize and understand features and processes that they will later observe from the International Space Station. Using pre -storm baseline images of the Bolivar Peninsula near Rollover Pass and Gilchrist (NOAA/Google Earth Imagery and USGS aerial imagery and lidar data), the astronauts mapped current coastline positions at defined locations, and related their findings to specific coastal characteristics, including channel, jetties, and other developments. In addition to mapping, we dug trenches along both the Gulf of Mexico coast as well as the Galveston Bay coast of the Bolivar peninsula to determine the depth of the scouring from the storm on the Gulf side, and the amount of deposition of the storm surge deposits on the Bay side of the peninsula. The storm signature was easy to identify by sharp sediment transitions and, in the case of storm deposits, a layer of storm debris (roof shingles, PVC pipes, etc) and black, organic rich layers containing buried sea grasses in areas that were marshes before the storm. The amount of deposition was generally about 20 -25 cm

  10. Mexico and Central America.

    Science.gov (United States)

    Bronfman, M

    1998-01-01

    This article reviews the literature on migration and HIV/AIDS in Mexico and Central America, including Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama. Most migrants travel to the US through Mexico. US-Mexico trade agreements created opportunities for increased risk of HIV transmission. The research literature focuses on Mexico. Most countries, with the exception of Belize and Costa Rica, are sending countries. Human rights of migrants are violated in transit and at destination. Migration policies determine migration processes. The Mexican-born population in the US is about 3% of US population and 8% of Mexico's population. About 22% arrived during 1992-97, and about 500,000 are naturalized US citizens. An additional 11 million have a Mexican ethnic background. Mexican migrants are usually economically active men who had jobs before leaving and were urban people who settled in California, Texas, Illinois, and Arizona. Most Mexican migrants enter illegally. Many return to Mexico. The main paths of HIV transmission are homosexual, heterosexual, and IV-drug-injecting persons. Latino migrants frequently use prostitutes, adopt new sexual practices including anal penetration among men, greater diversity of sexual partners, and use of injectable drugs.

  11. Defeating Mexico’s Drug Trafficking Organizations: The Range of Military Operations in Mexico

    Science.gov (United States)

    2012-06-08

    Nuevo Leon, Chihuahua , Baja California, and Sinaloa (see figure 2) with 60 percent of all killings in 2008 reported in three cities: Tijuana, Baja...California; Culiacan, Sinaloa; and Ciudad Juarez, Chihuahua .2 Ciudad Juarez had the highest rate of DTO related deaths; this is significant for the U.S...Northern Mexico states are: Baja California, Baja California Sur, Sonora, Chihuahua , Coahuila, Nuevo Leon, Tamaulipas, and Sinaloa (see figure 2

  12. 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"…

  13. Wind characteristics on the Yucatan Peninsula based on short term data from meteorological stations

    International Nuclear Information System (INIS)

    Soler-Bientz, Rolando; Watson, Simon; Infield, David

    2010-01-01

    Due to the availability of sparsely populated and flat open terrain, the Yucatan Peninsula located in eastern Mexico is a promising region from the perspective of wind energy development. Study of the diurnal and seasonal wind resource is an important stage in the move towards commercial exploitation of wind power in this Latin American region. An analysis of the characteristics of the wind resource of the Yucatan Peninsula is presented in this paper, based on 10 min averaged wind speed data from nine meteorological stations, between 2000 and 2007. Hourly and monthly patterns of the main environmental parameters have been examined. Highly directional behaviour was identified that reflects the influence of winds coming from the Caribbean Sea and the Gulf of Mexico. The characteristics of the wind speed variation observed at the studied sites reflected their proximity to the coast and whether they were influenced by wind coming predominantly from over the land or predominantly from over the sea. The atmospheric stability over the eastern seas of the Yucatan Peninsula was also analysed to assess thermal effects for different wind directions. The findings were consistent with the variation in average wind speeds observed at the coastal sites where winds came predominantly from over the sea. The research presented here is to be used as a basis for a wind atlas for the Yucatan Peninsula.

  14. Neighborhoods, Social and Cultural Correlates of Obesity Risk among Latinos living on the U.S.-Mexico border in Southern California.

    Science.gov (United States)

    Baquero, Barbara; Molina, Marisa; Elder, John P; Norman, Gregory J; Ayala, Guadalupe X

    2016-01-01

    We explored the relationship between obesity and neighborhood-related, social, and cultural variables and possible moderation by acculturation and cross-national practices. We obtained data from the 2009 San Diego Prevention Research Center's community survey, which used multistage sampling methods to recruit 397 adult respondents and conducted multilevel logistic analytic methods. Nearly half of the respondents were obese. Respondents had low acculturation scores and reported crossing the U.S.-Mexico border about three times per month, mostly to visit family and friends. Neighborhoods where respondents lived were predominantly Latino and had 27% home ownership. A significant cross-level interaction emerged: those who reported crossing the border and reported higher levels of collective efficacy were more likely to be obese than those who had not crossed. Study findings provide evidence of the complex relationship among obesity risk factors in a U.S.-Mexico border community that warrant further examination to prevent and control obesity.

  15. New records of non-resident pinnipeds from the Gulf of California, Mexico Registros nuevos de pinnípedos no-residentes en el golfo de California, México

    Directory of Open Access Journals (Sweden)

    Juan Pablo Gallo-Reynoso

    2010-04-01

    Full Text Available Although the California sea lion (Zalophus californianus is the only pinniped resident in the Gulf of California, there are occasional records of 3 additional species; here we report 4 recent records of the Guadalupe fur seal (Artocephalus townsendi, 6 of the northern elephant seal (Mirounga angustirostris and 2 of the harbor seal (Phoca vitulina. Harbor seals have been observed mostly during the winter-spring months of El Niño years, before water temperature warms in the summer. It is possible that juveniles and subadult and adult males of A. townsendi and M. angustirostris are using the Gulf as an alternative feeding area during the season of intensive feeding as individuals disperse more and more widely as their populations grow.Aunque en el golfo de California, el único pinnípedo residente es el lobo marino de California (Zalophus californianus, existen registros ocasionales de otras 3 especies; en la presente nota se proporcionan 4 registros recientes de lobo fino de Guadalupe (Arctocephalus townsendi, 6 de elefante marino del norte (Mirounga angustirostris y 2 de foca común (Phoca vitulina. La foca común se ha observado principalmente durante los meses de invierno-primavera en años de El Niño, antes del calentamiento anual del agua en verano. Es posible que los juveniles y los machos sub-adultos y adultos tanto de A. townsendi como de M. angustirostris hagan uso del golfo como un sitio alternativo durante la temporada de alimentación intensiva como de su expansión geográfica debido a su incremento poblacional.

  16. Seismology in Mexico

    Science.gov (United States)

    Lomnitz, C.

    1982-01-01

    Mexico is situated at the intersection of four major crustal Plates: the Americas Plate, the Pacific Plate, the Caribbean Plate, and the Cocos Plate. The interaction of these four plates is very complex. The pattern of earthquake risk is, therefore, among the most complicated in the world. The average release of seismic energy each is 55x1021 ergs-more than twice the figure for California

  17. California Bioregions

    Data.gov (United States)

    California Natural Resource Agency — 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...

  18. Overfishing Drivers and Opportunities for Recovery in Small-Scale Fisheries of the Midriff Islands Region, Gulf of California, Mexico: the Roles of Land and Sea Institutions in Fisheries Sustainability

    Directory of Open Access Journals (Sweden)

    Ana Cinti

    2014-03-01

    Full Text Available Institutions play an important role in shaping individual incentives in complex social-ecological systems, by encouraging or discouraging resource overuse. In the Gulf of California, Mexico, there is widespread evidence of declines in small-scale fishery stocks, largely attributed to policy failures. We investigated formal and informal rules-in-use regulating access and resource use by small-scale fishers in the two most important fishing communities of the Midriff Islands region in the Gulf of California, which share several target species and fishing grounds. The Midriff Islands region is a highly productive area where sustainable use of fisheries resources has been elusive. Our study aimed to inform policy by providing information on how management and conservation policies perform in this unique environment. In addition, we contrast attributes of the enabling conditions for sustainability on the commons in an effort to better understand why these communities, albeit showing several contrasting attributes of the above conditions, have not developed sustainable fishing practices. We take a novel, comprehensive institutional approach that includes formal and informal institutions, incorporating links between land (i.e., communal land rights and sea institutions (i.e., fisheries and conservation policies and their effects on stewardship of fishery resources, a theme that is practically unaddressed in the literature. Insufficient government support in provision of secure rights, enforcement and sanctioning, and recognition and incorporation of local arrangements and capacities for management arose as important needs to address in both cases. We highlight the critical role of higher levels of governance, that when disconnected from local practices, realities, and needs, can be a major impediment to achieving sustainability in small-scale fisheries, even in cases where several facilitating conditions are met.

  19. WIPP conceptual design report. Addendum D. A report to Holmes and Narver, Inc., Anaheim, California on alternative energy sources for Waste Isolation Pilot Plant, Carlsbad, New Mexico

    International Nuclear Information System (INIS)

    1977-03-01

    This report presents the results of a technical and economic analysis of alternative methods of meeting the energy needs of a proposed Waste Isolation Pilot Plant (WIPP) to be located in southeastern New Mexico. The WIPP is a facility for underground storage of radioactive wastes in a deep salt bed. The report analyzes a total of sixteen possible methods for meeting WIPP energy requirements, consisting of purchased electricity and on-site generation in various combinations from full purchased to full on-site

  20. 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.

  1. Social Capital, Organic Agriculture, and Sustainable Livelihood Security: Rethinking Agrarian Change in Mexico

    Science.gov (United States)

    Getz, Christy

    2008-01-01

    This paper explores the relevance of extra local market linkages and local-level social capital to sustainable livelihood outcomes in two agrarian communities on Mexico's Baja Peninsula. Contextualized by the specificity of Mexico's transition from state-directed rural development to neoliberally-guided rural development in the 1990s, findings…

  2. Economic Stratification Differentiates Home Gardens in the Maya Village of Pomuch, Mexico

    NARCIS (Netherlands)

    Poot-Pool, W.S.; Wal, van der J.C.; Flores-Guido, S.; Pat-Fernández, J.M.; Esparza-Olguín, L.

    2012-01-01

    Economic Stratification Differentiates Home Gardens in the Maya Village of Pomuch, Mexico. In this paper, we analyze if economic stratification of peasant families in a Maya village in the Yucatán Peninsula of Mexico influences species composition and structure of home gardens. Our general

  3. Leishmania spp. Epidemiology of Canine Leishmaniasis in the Yucatan Peninsula

    Directory of Open Access Journals (Sweden)

    A. López-Céspedes

    2012-01-01

    Full Text Available Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico. A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high.

  4. Leishmania spp. epidemiology of canine leishmaniasis in the Yucatan Peninsula.

    Science.gov (United States)

    López-Céspedes, A; Longoni, S S; Sauri-Arceo, C H; Sánchez-Moreno, M; Rodríguez-Vivas, R I; Escobedo-Ortegón, F J; Barrera-Pérez, M A; Bolio-González, M E; Marín, C

    2012-01-01

    Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high.

  5. A scanning electron microscopy study of early development in vitro of Contracaecum multipapillatum s.l. (Nematoda: Anisakidae) from a brown pelican (Pelecanus occidentalis) from the Gulf of California, Mexico.

    Science.gov (United States)

    Molina-Fernández, Dolores; Valles-Vega, Isabel; Hernández-Trujillo, Sergio; Adroher, Francisco Javier; Benítez, Rocío

    2017-10-01

    Eggs obtained from the uteri of female nematodes, genetically identified as Contracaecum multipapillatum s.l., found in a brown pelican (Pelecanus occidentalis) from Bahía de La Paz, Gulf of California, Mexico, were used to study the early developmental stages of this anisakid by scanning electron microscopy (SEM). Egg dimensions were approximately 54 × 45 μm measured by SEM. Observation of the eggs revealed an outer surface of fibrous appearance. The newly hatched larvae were ensheathed and highly motile. Observation with SEM showed that the sheaths of the larvae were striated and revealed an excretory pore and a cleft near the anterior end of the sheath, presumably to facilitate the opening of the sheath for the emergence of the larva. The hatched larvae were placed in nutritive culture medium, where they grew within their sheath, some exsheathing completely 2 weeks later. The surface patterns of the sheath and the cuticle of the exsheathed larvae were clearly different. Although they did not moult during culture, SEM revealed a morphology typical of third-stage larvae of Contracaecum from fish, as previously observed by optical microscopy. Thus, we suggest that newly hatched larvae from eggs of C. multipapillatum are third larval stage but with sheath of the second larval stage, as occuring in other anisakids.

  6. 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.

  7. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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

  10. Structural and Tectonic Map Along the Pacific-North America Plate Boundary in Northern Gulf of California, Sonora Desert and Valle de Mexicali, Mexico, from Seismic Reflection Evidence

    Science.gov (United States)

    Gonzalez-Escobar, M.; Suarez-Vidal, F.; Mendoza-Borunda, R.; Martin Barajas, A.; Pacheco-Romero, M.; Arregui-Estrada, S.; Gallardo-Mata, C.; Sanchez-Garcia, C.; Chanes-Martinez, J.

    2012-12-01

    Between 1978 and 1983, Petróleos Mexicanos (PEMEX) carried on an intense exploration program in the northern Gulf of California, the Sonora Desert and the southern part of the Mexicali Valley. This program was supported by a seismic reflection field operation. The collected seismic data was 2D, with travel time of 6 s recording, in 48 channels, and the source energy was: dynamite, vibroseis and air guns. Since 2007 to present time, the existing seismic data has been re-processing and ire-interpreting as part of a collaboration project between the PEMEX's Subdirección de Exploración (PEMEX) and CICESE. The study area is located along a large portion of the Pacific-North America plate boundary in the northern Gulf of California and the Southern part of the Salton Trough tectonic province (Mexicali Valley). We present the result of the processes reflection seismic lines. Many of the previous reported known faults were identify along with the first time described located within the study region. We identified regions with different degree of tectonic activity. In structural map it can see the location of many of these known active faults and their associated seismic activity, as well as other structures with no associated seismicity. Where some faults are mist placed they were deleted or relocated based on new information. We included historical seismicity for the region. We present six reflection lines that cross the aftershocks zone of the El Mayor-Cucapah earthquake of April 4, 2010 (Mw7.2). The epicenter of this earthquake and most of the aftershocks are located in a region where pervious to this earthquake no major earthquakes are been reported. A major result of this study is to demonstrate that there are many buried faults that increase the seismic hazard.

  11. Influenza seasonality goes south in the Yucatan Peninsula: The case for a different influenza vaccine calendar in this Mexican region.

    Science.gov (United States)

    Ayora-Talavera, Guadalupe; Flores, Gerardo Montalvo-Zurbia; Gómez-Carballo, Jesus; González-Losa, Refugio; Conde-Ferraez, Laura; Puerto-Solís, Marylin; López-Martínez, Irma; Díaz-Quiñonez, Alberto; Barrera-Badillo, Gisela; Acuna-Soto, Rodolfo; Livinski, Alicia A; Alonso, Wladimir J

    2017-08-24

    While vaccination may be relatively straightforward for regions with a well-defined winter season, the situation is quite different for tropical regions. Influenza activity in tropical regions might be out of phase with the dynamics predicted for their hemispheric group thereby impacting the effectiveness of the immunization campaign. To investigate how the climatic diversity of Mexico hinders its existing influenza immunization strategy and to suggest that the hemispheric vaccine recommendations be tailored to the regional level in order to optimize vaccine effectiveness. We studied the seasonality of influenza throughoutMexico by modeling virological and mortality data.De-trended time series of each Mexican state were analyzed by Fourier decomposition to describe the amplitude and timing of annual influenza epidemic cycles and to compare with each the timing of the WHO's Northern and Southern Hemispheric vaccination schedule. The timings of the primary (major) peaks of both virological and mortality data for most Mexican states are well aligned with the Northern Hemisphere winter (December-February) and vaccine schedule. However, influenza peaks in September in the three states of the Yucatan Peninsula. Influenza-related mortality also peaks in September in Quintana Roo and Yucatan whereas it peaks in May in Campeche. As the current timing of vaccination in Mexico is between October and November, more than half of the annual influenza cases have already occurred in the Yucatan Peninsula states by the time the Northern Hemispheric vaccine is delivered and administered. The current Northern Hemispheric influenza calendar adopted for Mexico is not optimal for the Yucatan Peninsula states thereby likely reducing the effectiveness of the immunization of the population. We recommend that Mexico tailor its immunization strategy to better reflect its climatologic and epidemiological diversity and adopt the WHO Southern Hemisphere influenza vaccine and schedule for the

  12. Lead, cadmium and mercury in the blood of the blue-footed booby (Sula nebouxii) from the coast of Sinaloa, Gulf of California, Mexico

    International Nuclear Information System (INIS)

    Lerma, Miriam; Castillo-Guerrero, José Alfredo; Ruelas-Inzunza, Jorge; Fernández, Guillermo

    2016-01-01

    We used blood samples of the Blue-footed Booby, considering sex (female and male) and age-class (adult and chick) of individuals at different breeding stages during two breeding seasons (2010–2011 and 2011–2012) in Isla El Rancho, Sinaloa, to determine lead, cadmium, and mercury concentrations. Lead and cadmium concentrations were below our detection limit (0.05 and 0.36 ppm, respectively). A higher concentration of mercury was found in early stages of breeding, likely related to changes in mercury environmental availability. Mercury concentrations in adults did not relate with their breeding output. Males and adults had higher mercury concentration than females and chicks. We provide information of temporal, sex and age-related variations in the concentrations of mercury in blood of the Blue-footed Booby. - Highlights: • We obtain baseline blood concentrations of mercury of the Blue-footed Booby breeding at Isla El Rancho, Sinaloa, Mexico. • Mercury concentrations decreased gradually as the breeding season progressed, possibly due to changes in mercury environmental availability. • Adult males had higher mercury concentration than adult females throughout the breeding season. • Pre-fledging chicks had lower mercury concentration than adults, without sex-related differences.

  13. A stepped wedge, cluster-randomized trial of a household UV-disinfection and safe storage drinking water intervention in rural Baja California Sur, Mexico.

    Science.gov (United States)

    Gruber, Joshua S; Reygadas, Fermin; Arnold, Benjamin F; Ray, Isha; Nelson, Kara; Colford, John M

    2013-08-01

    In collaboration with a local non-profit organization, this study evaluated the expansion of a program that promoted and installed Mesita Azul, an ultraviolet-disinfection system designed to treat household drinking water in rural Mexico. We conducted a 15-month, cluster-randomized stepped wedge trial by randomizing the order in which 24 communities (444 households) received the intervention. We measured primary outcomes (water contamination and diarrhea) during seven household visits. The intervention increased the percentage of households with access to treated and safely stored drinking water (23-62%), and reduced the percentage of households with Escherichia coli contaminated drinking water (risk difference (RD): -19% [95% CI: -27%, -14%]). No significant reduction in diarrhea was observed (RD: -0.1% [95% CI: -1.1%, 0.9%]). We conclude that household water quality improvements measured in this study justify future promotion of the Mesita Azul, and that future studies to measure its health impact would be valuable if conducted in populations with higher diarrhea prevalence.

  14. Tuberculosis testing among populations with high HIV risk in Tijuana, Baja California, Mexico Prueba de tuberculosis en poblaciones con riesgo alto de VIH en Tijuana, Baja California, México

    Directory of Open Access Journals (Sweden)

    Michele G. Velasquez

    2012-07-01

    Full Text Available OBJECTIVE: To assess the prevalence of prior tuberculin skin testing (TST among populations at risk for HIV infection in Tijuana, Mexico, and to identify factors associated with TST. METHODS: Sex workers, injection drug users, noninjecting drug users, and homeless persons > 18 years old were recruited by using targeted sampling for risk assessment interviews and serologic testing for HIV and Mycobacterium tuberculosis infection. Univariate and multivariate logistic regression were used to identify correlates of self-reported TST history. RESULTS: Of 502 participants, 38.0% reported prior TST, which was associated with previous incarceration in the United States of America [odds ratio (OR = 13.38; 95% confidence interval (CI = 7.37-24.33] and injection drug use (OR = 1.99; 95% CI = 1.27- 3.11. Positive results on serologic tests for M. tuberculosis infection (57% and HIV (4.2% were not associated with a prior TST. CONCLUSIONS: A history of TST was lower in HIV-positive participants even though TST is indicated for persons with HIV in Mexico. Fewer than half the individuals at high risk for HIV in this study had a history of TST; however, TST was fairly common among those individuals with a prior history of incarceration. Increased tuberculosis screening is needed for populations at risk of contracting HIV in Tijuana, particularly those outside of criminal justice settings.OBJETIVO: Evaluar la prevalencia de la prueba de la tuberculina previa, e identificar los factores asociados con ella, en poblaciones con riesgo de infección por el VIH en Tijuana, México. MÉTODOS: Se reclutó a profesionales del sexo, consumidores de drogas inyectables y no inyectables y personas sin hogar > 18 años de edad mediante un muestreo dirigido a fin de efectuar entrevistas para evaluar el riesgo y pruebas serológicas para la infección por el VIH y Mycobacterium tuberculosis. Para identificar la correlación de los antecedentes de la prueba de la tuberculina

  15. Contributions to improve fallow system in Yucatan State Mexico

    Science.gov (United States)

    Gabriel Uribe Valle; Juan Jiménez-Osornio; Roberto Dzib Echeverría

    2006-01-01

    More than 25 percent of earth warming can be attributes to deforestation practices such as crop rotations performed in southeast part of Mexico. In the Yucatan peninsula 20 percent of staple foods such as maize and beans are produced under slash and burn system. It has been practiced for many centuries by native Mayans however population pressure and food scarcity made...

  16. Avian Habitat Data; Seward Peninsula, Alaska, 2012

    Data.gov (United States)

    Department of the Interior — This data product contains avian habitat data collected on the Seward Peninsula, Alaska, USA, during 21 May – 10 June 2012. We conducted replicated 10-min surveys...

  17. Screening of polyhydroxyalkanoate-producing bacteria and PhaC-encoding genes in two hypersaline microbial mats from Guerrero Negro, Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Carolina A. Martínez-Gutiérrez

    2018-05-01

    Full Text Available Hypersaline microbial mats develop through seasonal and diel fluctuations, as well as under several physicochemical variables. Hence, resident microorganisms commonly employ strategies such as the synthesis of polyhydroxyalkanoates (PHAs in order to resist changing and stressful conditions. However, the knowledge of bacterial PHA production in hypersaline microbial mats has been limited to date, particularly in regard to medium-chain length PHAs (mcl-PHAs, which have biotechnological applications due to their plastic properties. The aim of this study was to obtain evidence for PHA production in two hypersaline microbial mats of Guerrero Negro, Mexico by searching for PHA granules and PHA synthase genes in isolated bacterial strains and environmental samples. Six PHA-producing strains were identified by 16S rRNA gene sequencing; three of them corresponded to a Halomonas sp. In addition, Paracoccus sp., Planomicrobium sp. and Staphylococcus sp. were also identified as PHA producers. Presumptive PHA granules and PHA synthases genes were detected in both sampling sites. Moreover, phylogenetic analysis showed that most of the phylotypes were distantly related to putative PhaC synthases class I sequences belonging to members of the classes Alphaproteobacteria and Gammaproteobacteria distributed within eight families, with higher abundances corresponding mainly to Rhodobacteraceae and Rhodospirillaceae. This analysis also showed that PhaC synthases class II sequences were closely related to those of Pseudomonas putida, suggesting the presence of this group, which is probably involved in the production of mcl-PHA in the mats. According to our state of knowledge, this study reports for the first time the occurrence of phaC and phaC1 sequences in hypersaline microbial mats, suggesting that these ecosystems may be a novel source for the isolation of short- and medium-chain length PHA producers.

  18. Perceptions of fishers to sea turtle bycatch, illegal capture and consumption in the San Ignacio-Navachiste-Macapule lagoon complex, Gulf of California, Mexico.

    Science.gov (United States)

    Aguilar-González, Myrna E; Luna-González, Antonio; Aguirre, Alonso; Zavala-Norzagaray, Alan A; Mundo-Ocampo, Manuel; González-Ocampo, Héctor A

    2014-01-01

    In this study, 10% of all registered fishermen in the coastal towns of Navachiste in Sinaloa, in northwestern Mexico, answered a survey designed to collect data on their perceptions of the following topics: the impact of turtle meat consumption; human health; bycatch; illegal turtle fishing; the illegal sea turtle market; the local economy; pollution; environmental education; the success of protective legislation; and sea turtle-based ecotourism. Perceptions were analyzed using the fuzzy logic method through classification into 5 fuzzy membership sets: VL, very low; L, low; M, moderate; H, high; VH, very high. The 9 topics generated decision areas upon applying fuzzy inference that revealed the membership level of the answers in each fuzzy set. The economic potential of sea turtle-based ecotourism and the economic profitability of the illegal turtle meat market were perceived as VL. Conservation legislation was perceived as H, although inefficiently applied due to corruption. Ecotourism and impacts on sea turtles were perceived as VL, because they were deemed unprofitable activities at the individual and community levels. Environmental education was perceived as L, because it centers on nesting, hatching and releasing turtles and is directed at elementary and middle-school students. While fishers perceive a serious negative impact of fishing activities on sea turtles in the San Ignacio-Navachiste-Macapule area, they do not see themselves individually as part of the problem. Achieving sea turtle conservation in this region requires: suitable ecotourism infrastructure, government investments in promotion, and studies to estimate the minimum number of tourists needed to assure profitability. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

  19. Sredinnyy Khrebet, Kamchatka Peninsula, Russia

    Science.gov (United States)

    2002-01-01

    The Kamchatka Peninsula in eastern Russia is shown in this scene created from a preliminary elevation model derived from the first data collected during the Shuttle Radar Topography Mission (SRTM) on February 12, 2000. Sredinnyy Khrebet, the mountain range that makes up the spine of the peninsula, is a chain of active volcanic peaks. Pleistocene and recent glaciers have carved the broad valleys and jagged ridges that are common here. The relative youth of the volcanism is revealed by the topography as infilling and smoothing of the otherwise rugged terrain by lava, ash, and pyroclastic flows, particularly surrounding the high peaks in the south central part of the image. Elevations here range from near sea level up to 2,618 meters (8,590 feet). Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space

  20. Geochemical Relationships between Volcanic and Plutonic Upper to Mid Crustal Exposures of the Rosario Segment, Alisitos Arc (Baja California, Mexico): An Outstanding Field Analog to the Izu-Bonin-Mariana Arc

    Science.gov (United States)

    Morris, R.; DeBari, S. M.; Busby, C. J.; Medynski, S.

    2015-12-01

    Exposed paleo-arcs, such as the Rosario segment of the Cretaceous Alisitos Arc in Baja California, Mexico, provide an opportunity to explore the evolution of arc crust through time. Remarkable 3-D exposures of the Rosario segment record crustal generation processes in the volcanic rocks and underlying plutonic rocks. In this study, we explore the physical and geochemical connection between the plutonic and volcanic sections of the extensional Alisitos Arc, and elucidate differentiation processes responsible for generating them. These results provide an outstanding analog for extensional active arc systems, such as the Izu-Bonin-Mariana (IBM) Arc. Upper crustal volcanic rocks have a coherent stratigraphy that is 3-5 km thick and ranges in composition from basalt to dacite. The most felsic compositions (70.9% SiO2) are from a welded ignimbrite unit. The most mafic compositions (51.5% SiO2, 3.2% MgO) are found in basaltic sill-like units. Phenocrysts in the volcanic units include plagioclase +/- amphibole and clinopyroxene. The transition to deeper plutonic rocks is clearly an intrusive boundary, where plutonic units intrude the volcanic units. Plutonic rocks are dominantly a quartz diorite main phase with a more mafic, gabbroic margin. A transitional zone is observed along the contact between the plutonic and volcanic rocks, where volcanics have coarsely recrystallized textures. Mineral assemblages in the plutonic units include plagioclase +/- quartz, biotite, amphibole, clinopyroxene and orthopyroxene. Most, but not all, samples are low K. REE patterns are relatively flat with limited enrichment. Normalization diagrams show LILE enrichment and HFSE depletion, where trends are similar to average IBM values. We interpret plutonic and volcanic units to have similar geochemical relationships, where liquid lines of descent show the evolution of least to most evolved magma types. We provide a model for the formation and magmatic evolution of the Alisitos Arc.

  1. Using Drone Imagery and Photogrammetry to Map Basin Stratigraphy and Structures Exposed in Mine, Road, and Arroyo Outcrops, Santa Rosalia, Baja California Sur, Mexico

    Science.gov (United States)

    Banes, A.; Alvarez Ortega, K. G.; Henry, M.; Niemi, T.

    2017-12-01

    During the 2017 Baja Basins Research Experience for Undergraduates (REU), a DJI Phantom 3 Advanced Quadcopter drone equipped with a GPS-enabled, 12 Megapixel camera was manually flown to collect aerial photographs of several geologic outcrops on the Minera Boléo and Lucifer mines in central Baja California Sur. The strip mine faces, roadcuts, and arroyos exposed Neogene to Quaternary sediments of the Santa Rosalía basin including the basal Cu-Zn-Mn-Co-bearing Miocene Boléo Formation that is actively being mined. It is overlain by Plio-Quaternary marine and non-marine deposits. Photographs were collected with a 70% overlap and processed into geographically-referenced, orthophotomosaics using Agisoft Photoscan. The output models have an adequate resolution for viewing bedding and fault characteristics. Measurements can be made inside the 3D models, making drones a useful tool for studying the geometry of stratigraphic, structural, and geomorphologic features. The studied sites included: 1) roadcuts on Mesa Soledad that exposed oblique-slip faults and syntectonically deposited non-marine and marine conglomerates and sandy, fossil-rich Pliocene beach sediment; 2) outcrops of the Boléo Fm in the Texcoco mine area that showed the detailed stratigraphic relationship between ore seams (mantos) and faults; 3) outcrops where sandstone samples were collected for detrital zircon geochronology; 4) strip mine 3120 that exposed faults and folds in the Boléo Formation; and 5) faults in Miocene volcanic rocks in the Arroyo Infierno near the Lucifer mine. This study shows that photogrammetry and modeling of geologic structures exposed in mine and road outcrops can provide useful information for reconstructing basin architecture and clarifying structural evolution of the Santa Rosalia Basin.

  2. 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

    2016-03-03

    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.

  3. Powering Mexico

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This article examines Mexico's demand for electricity and the market for independent power generation. The topics discussed in the article include the outlook for the 1990s for growth in Mexico's economy and energy demand, renewable energy, energy conservation, small-scale, off-grid renewable energy systems, and estimates of Mexico's market for electric power generating equipment

  4. Mexico Geoid Heights (MEXICO97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for Mexico, and North-Central America, is the MEXICO97 geoid model. The computation used about one million terrestrial and marine gravity...

  5. Fauna de arañas del suelo de una comunidad árida-tropical en Baja California Sur, México Ground surface spider fauna in an arid tropical community in Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    María Luisa Jiménez

    2010-08-01

    Full Text Available Se describe la temporalidad y diversidad de arañas del suelo del matorral sarcocaule en la región del Cabo en Baja California Sur. Durante 1991-1992 se realizaron colectas semanales por medio de trampas de caída. Se capturaron 4 322 ejemplares de 53 especies. Las familias con mayor abundancia fueron Miturgidae (42.2%, Oonopidae (23.5%, Caponiidae (8.0% y Gnaphosidae (7.9%. Las especies más abundantes fueron Syspira tigrina Chamberlin (37.1%; Oonops nov. sp. (13.7%, Scaphiella hespera Chamberlin (7.8% y Tarsonops sternalis Chamberlin (5.2%, que constituyeron el 63.7% del total de individuos. Gnaphosidae fue la más rica en especies (11, seguida por Salticidae (7. La riqueza de especies fue constante durante todo el año, con un ligero ascenso en el verano (29 y una ligera disminución en el invierno (24. La diversidad por estación del año se mantuvo en un intervalo de H'= 3.3 -3.7. La abundancia relativa se incrementó en primavera y otoño. La mayor riqueza específica se encontró en otoño. La abundancia relativa y la diversidad de arañas se pueden considerar altas, a pesar del fuerte dominio de la familia Miturgidae. En la mayoría de las especies, la distribución mostró una marcada estacionalidad.Seasonal distribution, specific richness, and diversity of xeric shrub ground spiders were studied at a site in the Cape Region. Weekly collections of spiders were made in 1991-1992 using pit-fall traps. We captured 4 322 specimens in 53 families. Families with the highest number of individuals were: Miturgidae (42% Oonopidae (23.5%, Caponiidae (8.0%, and Gnaphosidae (7.9%. The most abundant species were Syspira tigrina Chamberlin (37.1%; Oonops nov. sp. (13.7%, Scaphiella hespera Chamberlin (7.8%, and Tarsonops sternalis Chamberlin (5.2%, representing 63.7% of the total specimens captured. Gnaphosidae was the richest in species (11 followed by Salticidae (7. Species richness was nearly constant during all the year, with a small increase in

  6. Baja California: literatura y frontera

    Directory of Open Access Journals (Sweden)

    Gabriel Trujillo Muñoz

    2014-06-01

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

  7. Mitochondrial DNA structure in the Arabian Peninsula

    Directory of Open Access Journals (Sweden)

    Cabrera Vicente M

    2008-02-01

    Full Text Available Abstract Background Two potential migratory routes followed by modern humans to colonize Eurasia from Africa have been proposed. These are the two natural passageways that connect both continents: the northern route through the Sinai Peninsula and the southern route across the Bab al Mandab strait. Recent archaeological and genetic evidence have favored a unique southern coastal route. Under this scenario, the study of the population genetic structure of the Arabian Peninsula, the first step out of Africa, to search for primary genetic links between Africa and Eurasia, is crucial. The haploid and maternally inherited mitochondrial DNA (mtDNA molecule has been the most used genetic marker to identify and to relate lineages with clear geographic origins, as the African Ls and the Eurasian M and N that have a common root with the Africans L3. Results To assess the role of the Arabian Peninsula in the southern route, we genetically analyzed 553 Saudi Arabs using partial (546 and complete mtDNA (7 sequencing, and compared the lineages obtained with those present in Africa, the Near East, central, east and southeast Asia and Australasia. The results showed that the Arabian Peninsula has received substantial gene flow from Africa (20%, detected by the presence of L, M1 and U6 lineages; that an 18% of the Arabian Peninsula lineages have a clear eastern provenance, mainly represented by U lineages; but also by Indian M lineages and rare M links with Central Asia, Indonesia and even Australia. However, the bulk (62% of the Arabian lineages has a Northern source. Conclusion Although there is evidence of Neolithic and more recent expansions in the Arabian Peninsula, mainly detected by (preHV1 and J1b lineages, the lack of primitive autochthonous M and N sequences, suggests that this area has been more a receptor of human migrations, including historic ones, from Africa, India, Indonesia and even Australia, than a demographic expansion center along the

  8. 77 FR 14349 - Availability of Report: California Eelgrass Mitigation Policy

    Science.gov (United States)

    2012-03-09

    ... contributed to these losses, impacts from human population expansion and associated pollution and upland... aquatic site under the 404(b)(1) guidelines of the Clean Water Act (40 CFR 230.43). Pursuant to the... California (U.S./Mexico border to Pt. Conception), central California (Point Conception to San Francisco Bay...

  9. Neogene vertebrates from the Gargano Peninsula, Italy

    NARCIS (Netherlands)

    Freudenthal, M.

    1971-01-01

    Fissure-fillings in Mesozoic limestones in the Gargano Peninsula yield rich collections of fossil vertebrates, which are characterized by gigantism and aberrant morphology. Their age is considered to be Vallesian or Turolian. The special features of the fauna are probably due to isolation on an

  10. First dinosaur tracks from the Arabian Peninsula

    NARCIS (Netherlands)

    Schulp, Anne S.; Al-Wosabi, Mohammed; Stevens, Nancy J.

    2008-01-01

    Background: The evolutionary history of Mesozoic terrestrial vertebrates from the Arabian Peninsula is virtually unknown. Despite vast exposures of rocky outcrops, only a handful of fossils have yet been described from the region. Here we report a multi-taxon dinosaur track assemblage near Madar

  11. Historic magmatism on the Reykjanes Peninsula, Iceland

    DEFF Research Database (Denmark)

    Peate, David W.; Baker, Joel A.; Jakobssen, Sveinn P.

    2009-01-01

    We present new compositional data on a suite of historic lava flows from the Reykjanes Peninsula, Iceland. They were erupted over a short time period between c. 940 and c. 1340 AD and provide a snap-shot view of melt generation and evolution processes beneath this onshore, 65 km long, ridge segment...

  12. Crustal parameters in the Iberian Peninsula

    Science.gov (United States)

    Banda, E.

    1988-06-01

    The structure of the crust in the Iberian Peninsula has been investigated for the last 15 years by Spanish and Portuguese groups in close collaboration with other European institutions. The first experiments were carried out in Portugal (Mueller et al., 1973) with the aim of investigating the crustal structure of the Hercynian belt in the southwest corner of the Iberian peninsula. Other experiments have been subsequently realized to study different aspects of the crust in various regions of Portugal. In Spain the main effort has been focused in Alpine areas, with the first experiments in the Alboran Sea and the Betic Cordilleras (Working Group for Deep Seismic Sounding in Spain, 1974-1975, 1977; Working Group for Deep Seismic Sounding in the Alboran Sea, 1974-1975, 1978). Follow-up experiments until 1981 completed the work in the Betic Cordillera. Extensive experiments were carried out in the Pyrenees in 1978. Further surveys covered the Balearic Islands in 1976, the Valencia Trough in 1976 and 1983, and the Celtiberian Chain (or Iberic system) in 1981. The Hercynian belt has only been studied in detail in the northwest corner of Spain in 1982, with smaller studies in the central Iberian Massif in 1976 and 1986. Mostaanpour (1984) has compiled some crustal parameters (crustal thickness, average crustal velocity and Pn velocity) for western Europe. Meanwhile, more complete data are available for the Iberian Peninsula. The results presented here were derived from a large number of seismic refraction experiments which have been carried out mostly along or close to coastal areas of the Iberian Peninsula. Offshore explosions of various sizes were used as the energy source in most cases, in addition to some quarry blasts. Unfortunately this leaves most of the inner part of the Iberian Peninsula unsurveyed. Our purpose is to summarize some of the crustal parameters obtained so far and to detail the appropriate literature for the interested reader.

  13. 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).

  14. 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

  15. Kelp gulls, Larus dominicanus (Aves: Laridae, breeding in Keller Peninsula, King George Island, Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Joaquim O. Branco

    2009-09-01

    Full Text Available We examined the distribution, abundance and density of the Kelp Gull, Larus dominicanus (Lichtenstein, 1823, at Keller Peninsula on two occasions during the breeding season of 2007-2008 (once for incubation and once for chick stages and compared our results with previously published data. We present information on the number of eggs, incubation success, and initial development of L. dominicanus chicks in the studied sites. The abundance and density of the species has remained statistically similar in Keller Peninsula over the last 30 years (since 1978-1979. Although the abundance and density were almost unchanged, we recorded alterations in the occupation of the breeding areas by L. dominicanus, mainly the abandonment of breeding sites in the eastern portion of Keller Peninsula. The results of the present study compared with similar previous investigations on the abundance of L. dominicanus indicate that the populations have been in equilibrium over the years.

  16. Bilingual Rapping in Yucatán, Mexico: Strategic Choices for Maya Language Legitimation and Revitalisation

    Science.gov (United States)

    Cru, Josep

    2017-01-01

    This paper explores the sociolinguistic practices of a group of young bilingual rappers in the Yucatán Peninsula of Mexico. Against the background of ongoing language shift to Spanish in the region, the language choices of a group of Maya youths involved in Hip Hop culture and their agency as policy-makers at the grassroots level is analysed.…

  17. Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    Science.gov (United States)

    Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

    2015-01-01

    The Alaska Peninsula is composed of the late Paleozoic to Quaternary sedimentary, igneous, and minor metamorphic rocks that record the history of a number of magmatic arcs. These magmatic arcs include an unnamed Late Triassic(?) and Early Jurassic island arc, the early Cenozoic Meshik arc, and the late Cenozoic Aleutian arc. Also found on the Alaska Peninsula is one of the most complete nonmetamorphosed, fossiliferous, marine Jurassic sedimentary sections known. As much as 8,500 m of section of Mesozoic sedimentary rocks record the growth and erosion of the Early Jurassic island arc.

  18. West Nile virus infection of birds, Mexico.

    Science.gov (United States)

    Guerrero-Sánchez, Sergio; Cuevas-Romero, Sandra; Nemeth, Nicole M; Trujillo-Olivera, María Teresa Jesús; Worwa, Gabriella; Dupuis, Alan; Brault, Aaron C; Kramer, Laura D; Komar, Nicholas; Estrada-Franco, José Guillermo

    2011-12-01

    West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006-2008, we tested this hypothesis in candidate avian amplifying hosts: domestic chickens, rock pigeons, house sparrows, great-tailed grackles, and clay-colored thrushes. Only great-tailed grackles and house sparrows were competent amplifying hosts for both strains, and deaths occurred in each species. Tecate strain viremia levels were higher for thrushes. Both strains produced low-level viremia in pigeons and chickens. Our results suggest that certain avian hosts within Mexico are competent for efficient amplification of both northern and southern WNV strains and that both strains likely contribute to bird deaths.

  19. El género Bauhinia (Fabaceae, Caesalpinioideae, Cercideae en la península de Yucatán (México, Belice y Guatemala The genus Bauhinia (Fabaceae, Caesalpinioideae, Cercideae in Yucatán Peninsula (Mexico, Belice and Guatemala

    Directory of Open Access Journals (Sweden)

    Rafael Torres-Colín

    2009-08-01

    Full Text Available Se presenta información del género Bauhinia, tribu Cercideae en la provincia biótica de la península de Yucatán. Se reconocen 5 especies nativas: Bauhinia divaricata L., B. erythrocalyx Wunderlin, B. jenningsii P. Wilson, B. herrerae (Britton et Rose Standl. et Steyerm. y B. ungulata L., así como 2 introducidas: B. monandra Kurz y B. variegata L. Se presenta una clave para identificación, descripciones morfológicas, mapas de distribución, fotografías de las especies e información de los nombres comunes y uso en la región.General information about the genus Bauhinia in the Yucatán Peninsula Biotic Province is presented. Five native species, B. divaricata L, B. erythrocalyx Wunderlin, B. jenningsii P. Wilson, B. herrerae (Britton et Rose Standl. et Steyerm., B. ungulata L. and 2 exotic species, B. monandra Kurz and B. variegata L., are recognized. Species identification key, morphological descriptions, distribution maps, and photographs are presented. Additional information of common names and uses in the region is included.

  20. Mammal (Mammalia Fauna of Kapıdağ Peninsula

    Directory of Open Access Journals (Sweden)

    Erdem HIZAL

    2008-01-01

    Full Text Available The number of studies on mammals of Kapıdag Peninsula is insufficent. The present study is based on mammal species collected and observed in Kapıdag Peninsula. Kapıdag Peninsula was visited as a total of 226 days between 2001-2007. Field collections yielded 32 mammal species from 6 orders: Insectivora (5, Chiroptera (9,Lagomorpha (1, Rodentia (7, Carnivora (7, Artiodactyla (3. Of the species recorded in this study are rare for Kapıdag Peninsula: Lynx lynx and Felis silvestris.

  1. Paralytic shellfish toxin profile in strains of the dinoflagellate Gymnodium cataenatum and the scallop Argopecten ventricosus G.B. Sowerby II from Bahia Concepción, Gulf of California, Mexico

    OpenAIRE

    Band Schmidt, Christine Johanna; Bustillos Guzmán, José J.; Gárate Lizárraga, Ismael; Lechuga Deveze, Carlos; Reinhardt, K.; Luckas, Bernd

    2005-01-01

    Gymnodinium catenatum Graham is a paralytic shellfish poison (PSP) producer that was described for the first time from the Gulf of California in 1943. During the last decade, its distribution along the Mexican Pacific coastline has increased. In Bahía Concepción, a coastal lagoon on the western side of the Gulf of California, G. catenatum has been linked to significant PSP concentrations found in mollusks. In this study, we describe the saxitoxin profile of 16 strains of G. catenatum, and cat...

  2. High-Resolution Aeromagnetic Survey over the Yucatan Peninsula - Implications for Chicxulub Impact, Secondary Craters and Regional Crustal Structures

    Science.gov (United States)

    Fucugauchi, J. U.; Lopez-Loera, H.; Rebolledo-Vieyra, M.

    2011-12-01

    We present the initial results of a low-altitude high-resolution aeromagnetic study over the Yucatan peninsula. Area surveyed extends from 86W to 91W and 18N to 21N, covering the peninsula and adjacent continental margin of Gulf of Mexico and Caribbean Sea. Aeromagnetic surveys are integrated into a regional map, and regional and residual anomalies are separated using spectral and least-squares methods. For the study, aeromagnetic field was reduced to the pole and several data filtering techniques were used, including first and second vertical derivatives, analytical signal, and upward and downward analytical continuations. The region is characterized by large amplitude broad elongated magnetic anomalies oriented north-south in the northern sector of the continental shelf, and northwest-southeast and northeast-southwest over the western and eastern sides of the peninsula, respectively. Major regional anomalies extend from the continental shelf into the peninsula, whereas other anomaly trends in the central northern sector, at northeast limit of Chicxulub crater, are restricted to the shelf. Largest anomaly on the east extends over the Holbox fracture zone. At its southern end, south of Chetumal a parallel trend extends over the Rio Hondo fault zone between Quintana Roo and Belize. On the western peninsula the anomaly is characterized by two parallel trends offset between Yucatan and Campeche. The central zone of Chicxulub is characterized by a semi-circular anomaly pattern, surrounded by long wavelength small amplitude anomalies extending to the east on the peninsula and shelf, isolated from the regional broad anomalies. To the south of Chicxulub anomaly, there is an elongated low with a central high extending southward from the terrace zone inside the crater rim. The elongated magnetic anomaly correlates with a broad gravity low, which is apparent south of the concentric zone of anomalies. To the north of Chicxulub anomaly, a magnetic high inside the crater is

  3. Ecoregions of California

    Science.gov (United States)

    Griffith, Glenn E.; Omernik, James M.; Smith, David W.; Cook, Terry D.; Tallyn, Ed; Moseley, Kendra; Johnson, Colleen B.

    2016-02-23

    (2000), and Omernik and Griffith (2014).California has great ecological and biological diversity. The State contains offshore islands and coastal lowlands, large alluvial valleys, forested mountain ranges, deserts, and various aquatic habitats. There are 13 level III ecoregions and 177 level IV ecoregions in California and most continue into ecologically similar parts of adjacent States of the United States or Mexico (Bryce and others, 2003; Thorson and others, 2003; Griffith and others, 2014).The California ecoregion map was compiled at a scale of 1:250,000. It revises and subdivides an earlier national ecoregion map that was originally compiled at a smaller scale (Omernik, 1987; U.S. Environmental Protection Agency, 2013). This poster is the result of a collaborative project primarily between U.S. Environmental Protection Agency (USEPA) Region IX, USEPA National Health and Environmental Effects Research Laboratory (Corvallis, Oregon), California Department of Fish and Wildlife (DFW), U.S. Department of Agriculture (USDA)–Natural Resources Conservation Service (NRCS), U.S. Department of the Interior–Geological Survey (USGS), and other State of California agencies and universities.The project is associated with interagency efforts to develop a common framework of ecological regions (McMahon and others, 2001). Reaching that objective requires recognition of the differences in the conceptual approaches and mapping methodologies applied to develop the most common ecoregion-type frameworks, including those developed by the USDA–Forest Service (Bailey and others, 1994; Miles and Goudy, 1997; Cleland and others, 2007), the USEPA (Omernik 1987, 1995), and the NRCS (U.S. Department of Agriculture–Soil Conservation Service, 1981; U.S. Department of Agriculture–Natural Resources Conservation Service, 2006). As each of these frameworks is further refined, their differences are becoming less discernible. Regional collaborative projects such as this one in California

  4. Origin of honeybees (Apis mellifera L.) from the Yucatan peninsula inferred from mitochondrial DNA analysis.

    Science.gov (United States)

    Clarke, K E; Oldroyd, B P; Javier, J; Quezada-Euán, G; Rinderer, T E

    2001-06-01

    Honeybees (Apis mellifera L.) sampled at sites in Europe, Africa and South America were analysed using a mitochondrial DNA restriction fragment length polymorphism (RFLP) marker. These samples were used to provide baseline information for a detailed analysis of the process of Africanization of bees from the neotropical Yucatan peninsula of Mexico. Radical changes in mitochondrial haplotype (mitotype) frequencies were found to have occurred in the 13-year period studied. Prior to the arrival of Africanized bees (1986) the original inhabitants of the Yucatan peninsula appear to have been essentially of southeastern European origin with a smaller proportion having northwestern European ancestry. Three years after the migration of Africanized bees into the area (1989), only very low levels of maternal gene flow from Africanized populations into the resident European populations had occurred. By 1998, however, there was a sizeable increase in the proportion of African mitotypes in domestic populations (61%) with feral populations having 87% of mitotypes classified as African derived. The results suggest that the early stages of Africanization did not involve a rapid replacement of European with African mitotypes and that earlier studies probably overestimated the prevalence of African mitotypes.

  5. Distribution of some Calanoida (Crustacea: Copepoda from the Yucatán Peninsula, Belize and Guatemala

    Directory of Open Access Journals (Sweden)

    Gerd-Oltmann Brandorff

    2012-03-01

    Full Text Available Southern Mexico and Central America have many water bodies of different morphology and water chemistry with an interesting zooplankton fauna, originating from North or South America. A set of 63 samples, taken in 2005 and 2008, from water bodies of the Yucatan Peninsula karst, Belize and Guatemala, were studied for the content of calanoid copepods. Old and recent literature was used to determine animals to species level. Drawings were prepared with a microscope and a camera lucida. A total of 32 samples with totally six species contained calanoid copepods: one estuarine pseudodiaptomid and five freshwater diaptomids. Pseudodiaptomus marshi was found at different salinities. It is confirmed that the commonest diaptomids in the Yucatan Peninsula are Arctodiaptomus dorsalis and Mastigodiaptomus nesus. The former was also recorded from Lake Amatitlan. Mastigodiaptomus nesus is as widespread as A. dorsalis but it is absent from the Lake Peten area in Guatemala. Mastigodiaptomus reidae was found in two shallow habitats, these specimens differ from those from the type locality by having a set of peculiar large spine-like processes on the last thoracic and the urosome segments of the females. Leptodiaptomus siciloides was found only in Lake Ayarza with high salinity. Prionodiaptomus colombiensis occurred in the highlands of Guatemala in Lago de Güija and in the Peten area in Laguna Sacpuy. We contributed with our occurrence records to a better knowledge of the geographic distribution of some calanoid copepods. Morphological findings in some species are of value for taxonomic differentiation between species.

  6. Preliminary study of long-term wind characteristics of the Mexican Yucatan Peninsula

    International Nuclear Information System (INIS)

    Soler-Bientz, Rolando; Watson, Simon; Infield, David

    2009-01-01

    Mexico's Yucatan Peninsula is one of the most promising areas for wind energy development within the Latin American region but no comprehensive assessment of wind resource has been previously published. This research presents a preliminary analysis of the meteorological parameters relevant to the wind resource in order to find patterns in their long-term behaviour and to establish a foundation for subsequent research into the wind power potential of the Yucatan Peninsula. Three meteorological stations with data measured for a period between 10 and 20 years were used in this study. The monthly trends of ambient temperature, atmospheric pressure and wind speed data were identified and are discussed. The directional behaviour of the winds, their frequency distributions and the related Weibull parameters are presented. Wind power densities for the study sites have been estimated and have been shown to be relatively low (wind power class 1), though a larger number of suitable sites needs to be studied before a definitive resource evaluation can be reported.

  7. Crossing Pedagogical Borders in the Yucatan Peninsula

    Science.gov (United States)

    Willhauck, Susan

    2009-01-01

    A challenging intercultural teaching experience provided an opportunity for engaging embodied pedagogies that facilitated border crossings of language, age, gender, and experience. Influenced by the work of Augusto Boal, the author describes how improvisation, role-play, music, and drawing led seminary students in Mexico into sacred time and space…

  8. Colored Height and Shaded Relief, Kamchatka Peninsula

    Science.gov (United States)

    2002-01-01

    Russia's Kamchatka Peninsula, lying between the Sea of Okhotsk to the west and the Bering Sea and Pacific Ocean to the east, is one of the most active volcanic regions along the Pacific Ring of Fire. It covers an area about the size of Colorado but contains more than 100 volcanoes stretching across the 1000-kilometer-long (620-mile-long) land mass. A dozen or more of these have active vents, with the youngest located along the eastern half of the peninsula. This color-coded shaded relief image, generated with data from the Shuttle Radar Topography Mission (SRTM), shows Kamchatka's volcanic nature to dramatic effect.Kliuchevskoi, one of the most active and renowned volcanoes in the world, dominates the main cluster of volcanoes called the Kliuchi group, visible as a circular feature in the center-right of the image. The two other main volcanic ranges lie along northeast-southwest lines, with the older, less active range occupying the center and western half of Kamchatka. The younger, more active belt begins at the southernmost point of the peninsula and continues upward along the Pacific coastline.Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the north-south direction, so northern slopes appear bright and southern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and brown to white at the highest elevations.The Shuttle Radar Topography Mission flew aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (200

  9. Sinai Peninsula, Shaded Relief and Colored Height

    Science.gov (United States)

    2004-01-01

    The Sinai Peninsula, located between Africa and Asia, is a result of those two continents pulling apart from each other. Earth's crust is cracking, stretching, and lowering along the two northern branches of the Red Sea, namely the Gulf of Suez, seen here on the west (left), and the Gulf of Aqaba, seen to the east (right). This color-coded shaded relief image shows the triangular nature of the peninsula, with the coast of the Mediterranean Sea forming the northern side of the triangle. The Suez Canal can be seen as the narrow vertical blue line in the upper left connecting the Red Sea to the Mediterranean. The peninsula is divided into three distinct parts; the northern region consisting chiefly of sandstone, plains and hills, the central area dominated by the Tih Plateau, and the mountainous southern region where towering peaks abound. Much of the Sinai is deeply dissected by river valleys, or wadis, that eroded during an earlier geologic period and break the surface of the plateau into a series of detached massifs with a few scattered oases. Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed

  10. Provenance and U-Pb geochronology of the Upper Cretaceous El Chanate Group, northwest Sonora, Mexico, and its tectonic significance

    Science.gov (United States)

    Jacques-Ayala, C.; Barth, A.P.; Wooden, J.L.; Jacobson, C.E.

    2009-01-01

    The Upper Cretaceous El Chanate Group, northwest Sonora, Mexico, is a 2.8km thick clastic sedimentary sequence deposited in a continental basin closely related to volcanic activity. It consists of three formations: the Pozo Duro (oldest), the Anita, and the Escalante (youngest). Petrographic study, conglomerate pebble counts, and U-Pb geochronology of detrital zircons were performed to determine the source and age of this sequence, and to interpret its tectonic setting. In the sandstones of all three formations, the most abundant grains are those of volcanic composition (Q38F22L 40, Q35F19L46, and Q 31F22L47, respectively). The Pozo Duro Formation includes well-rounded quartz-arenite clast conglomerates, whereas conglomerates of the two upper units have clasts predominantly of andesitic and rhyolitic composition. The most likely source for these sediments was the Jurassic volcanic arc exposed in northern Sonora and southern Arizona. Zircons from five sandstone samples define two main age groups, Proterozoic and Mesozoic. The first ranges mostly from 1000 to 1800Ma, which suggests the influence of a cratonic source. This zircon suite is interpreted to be recycled and derived from the same source area as the quartz-rich sandstone clasts in the basal part of the section. Mesozoic zircons range from Triassic to Late Cretaceous, which confirms the proposed Late Cretaceous age for the sequence, and also corroborates Jurassic felsic source rocks. Another possible source was the Alisitos volcanic arc, exposed along the western margin of the Baja California Peninsula. Of regional significance is the great similarity between the El Chanate Group and the McCoy Mountains Formation of southeastern California and southwestern Arizona. Both are Cretaceous, were deposited in continental environments, and have similar zircon-age patterns. Also, both exhibit intense deformation and locally display penetrative foliation. These features strongly suggest that both units underwent

  11. Modeling the Seasonal and Interannual Variability of the Northern Gulf of California Salinity

    Science.gov (United States)

    2011-02-15

    Schwartzlose (1979), Masas de agua del Golfo de California, Cienc . Mar., 6, 43–63. Argote, M. L., A. Amador, M. F. Lavı’n, and J. R. Hunter (1995...entrance of the Gulf of California, Mexico, Cienc . Mar., 26, 561–583. Enfield, D. B. (1987), The intraseasonal oscillation in eastern Pacific sea levels

  12. Natality and calf mortality of the Northern Alaska Peninsula and Southern Alaska Peninsula caribou herds

    Directory of Open Access Journals (Sweden)

    Richard A. Sellers

    2003-04-01

    Full Text Available We studied natality in the Northern Alaska Peninsula (NAP and Southern Alaska Peninsula (SAP caribou (Rangifer tarandus granti herds during 1996-1999, and mortality and weights of calves during 1998 and 1999- Natality was lower in the NAP than the SAP primarily because most 3-year-old females did not produce calves in the NAP Patterns of calf mortality in the NAP and SAP differed from those in Interior Alaska primarily because neonatal (i.e., during the first 2 weeks of life mortality was relatively low, but mortality continued to be significant through August in both herds, and aggregate annual mortality was extreme (86% in the NAP Predators probably killed more neonatal calves in the SAP, primarily because a wolf den (Canis lupus was located on the calving area. Despite the relatively high density of brown bears (Ursus arctos and bald eagles (Haliaeetus leucocephalus, these predators killed surprisingly few calves. Golden eagles (Aquila chrysaetos were uncommon on the Alaska Peninsula. At least 2 calves apparently died from pneu¬monia in the range of the NAP but none were suspected to have died from disease in the range of the SAP. Heavy scav¬enging by bald eagles complicated determining cause of death of calves in both the NAP and SAP.

  13. California Political Districts

    Data.gov (United States)

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

  14. Planktonic Cyanobacteria of the tropical karstic lake Lagartos from the Yucatan Peninsula, Mexico Las cianobacterias planctónicas del lago tropical cárstico Lagartos de la Península de Yucatán, México

    Directory of Open Access Journals (Sweden)

    Francisco Valadez

    2013-06-01

    Full Text Available The tropical karstic lakes on the Mexican Caribbean Sea coast are numerous. However, there is an enormous gap of knowledge about their limnological conditions and micro-algae communities. In the present study, surface water samples were collected monthly from November 2007 to September 2008 to provide taxonomical composition and biovolume of planktonic cyanobacteria of the lake Lagartos from State of Quintana Roo, Mexico. Water temperature, pH, conductivity, salinity, soluble reactive phosphorus (SRP, dissolved inorganic nitrogen (DIN, and soluble reactive silica (SRSi levels were also analyzed. A total of 22 species were identified. Chroococcales and Oscillatoriales dominated the phytoplankton assemblages during the study period. Chroococcus pulcherrimus, Coelosphaerium confertum, Cyanodyction iac, Phormidium pachydermaticum and Planktolyngbya contorta were recorded for the first time in Mexico. A surplus of DIN (mean value of 42.7µM and low concentrations of SRP (mean value of 1.0µM promoted the enhanced growth and bloom formation of cyanobacteria. The mean biovolume was 3.22X10(8µm³/mL, and two biovolume peaks were observed; the first was dominated by Microcystis panniformis in November 2007 (7.40X10(8µm³/mL, and the second was dominated by Oscillatoria princeps in April 2008 (6.55X10(8µm³/mL. Water quality data, nitrates enrichment, and trophic state based on biovolume, indicated that Lagartos is a hyposaline, secondarily phosphorus-limited, and eutrophic lake, where the cyanobacteria flora was composed mainly by non-heterocystous groups.Los lagos cársticos tropicales en la costa del Caribe mexicano son numerosos. Sin embargo, existe un enorme desconocimiento acerca de sus condiciones limnológicas y de las comunidades de microalgas que se desarrollan en ellos. El objetivo del presente estudio fue estudiar las condiciones limnológicas en las que crecen las poblaciones de cianobacterias planctónicas del lago Lagartos, Quintana Roo

  15. The combined effects of acidification and hypoxia on pH and aragonite saturation in the coastal waters of the California current ecosystem and the northern Gulf of Mexico

    Science.gov (United States)

    Feely, Richard A.; Okazaki, Remy R.; Cai, Wei-Jun; Bednaršek, Nina; Alin, Simone R.; Byrne, Robert H.; Fassbender, Andrea

    2018-01-01

    Inorganic carbon chemistry data from the surface and subsurface waters of the West Coast of North America have been compared with similar data from the northern Gulf of Mexico to demonstrate how future changes in CO2 emissions will affect chemical changes in coastal waters affected by respiration-induced hypoxia ([O2] ≤ 60 μmol kg-1). In surface waters, the percentage change in the carbon parameters due to increasing CO2 emissions are very similar for both regions even though the absolute decrease in aragonite saturation is much higher in the warmer waters of the Gulf of Mexico. However, in subsurface waters the changes are enhanced due to differences in the initial oxygen concentration and the changes in the buffer capacity (i.e., increasing Revelle Factor) with increasing respiration from the oxidation of organic matter, with the largest impacts on pH and CO2 partial pressure (pCO2) occurring in the colder West Coast waters. As anthropogenic CO2 concentrations begin to build up in subsurface waters, increased atmospheric CO2 will expose organisms to hypercapnic conditions (pCO2 >1000 μatm) within subsurface depths. Since the maintenance of the extracellular pH appears as the first line of defense against external stresses, many biological response studies have been focused on pCO2-induced hypercapnia. The extent of subsurface exposure will occur sooner and be more widespread in colder waters due to their capacity to hold more dissolved oxygen and the accompanying weaker acid-base buffer capacity. Under present conditions, organisms in the West Coast are exposed to hypercapnic conditions when oxygen concentrations are near 100 μmol kg-1 but will experience hypercapnia at oxygen concentrations of 260 μmol kg-1 by year 2100 under the highest elevated-CO2 conditions. Hypercapnia does not occur at present in the Gulf of Mexico but will occur at oxygen concentrations of 170 μmol kg-1 by the end of the century under similar conditions. The aragonite saturation

  16. September 1985 Mexico City, Mexico Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The magnitude 8.1 earthquake occurred off the Pacific coast of Mexico. The damage was concentrated in a 25 square km area of Mexico City, 350 km from the epicenter....

  17. 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

    In 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 sonar 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 (to about 100 m) subsurface geology. The Offshore of San Gregorio map area is located in northern California, on the Pacific coast of the San Francisco Peninsula about 50 kilometers south of the Golden Gate. The map area lies offshore of the Santa Cruz Mountains, part of the northwest-trending Coast Ranges that run roughly parallel to the San Andreas Fault Zone. The Santa Cruz Mountains lie between the San Andreas Fault Zone and the San Gregorio Fault system. The nearest significant onshore cultural centers in the map area are San Gregorio and Pescadero, both unincorporated communities with populations well under 1,000. Both communities are situated inland of state beaches that share their names. No harbor facilities are within the Offshore of San Gregorio map area. The hilly coastal area is virtually undeveloped grazing land for sheep and cattle. The coastal geomorphology is controlled by late Pleistocene and Holocene slip in the San Gregorio Fault system. A westward bend in the San Andreas Fault Zone, southeast of the map area, coupled with right-lateral movement along the San Gregorio Fault system have caused regional folding and uplift. The coastal area consists of high coastal bluffs and vertical sea cliffs. Coastal promontories in

  18. 2013-2014 USGS Lidar: Olympic Peninsula (WA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS Olympic Peninsula Washington LIDAR LiDAR Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G13PD00849...

  19. Cook Inlet and Kenai Peninsula, Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  20. Cook Inlet and Kenai Peninsula, Alaska ESI: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the locations of volcanos in Cook Inlet and Kenai Peninsula, Alaska. Vector points in the data set represent the location of the volcanos....

  1. Macrofouling community structure in Kanayama Bay, Kii Peninsula (Japan)

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Harada, E.

    An investigation on the macrofouling community in Kanayama Bay, Kill Peninsula, Japan was undertaken from June 1994 to May 1995 by exposing fiber reinforced plastic (FRP) panels at subsurface and bottom (2.2 m) depths. The composition and abundance...

  2. Cook Inlet and Kenai Peninsula, Alaska ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  3. 24 arc-second Kenai Peninsula Bororugh Alaska Elevation Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 24 arc-second Kenai Peninsula Bororugh Alaska Elevation Grid provides bathymetric data in ASCII raster format of 24 second resolution in geographic coordinates....

  4. A Satellite Based Fog Study of the Korean Peninsula

    National Research Council Canada - National Science Library

    McDonald, David K

    2007-01-01

    Fog has always been a difficult phenomenon to forecast. Its unpredictable nature and propensity to quickly decrease visibilities have had adverse effects on military operations for many years across the Korean peninsula...

  5. Cook Inlet and Kenai Peninsula, Alaska ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for razor clams in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent locations of...

  6. Cook Inlet and Kenai Peninsula, Alaska ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for herring spawning areas in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent...

  7. Cook Inlet and Kenai Peninsula, Alaska ESI: FISHL (Fish Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for anadromous fish streams in Cook Inlet and Kenai Peninsula, Alaska. Vector lines in this data set represent...

  8. Timber resource statistics for the Olympic Peninsula, Washington.

    Science.gov (United States)

    Patricia M. Bassett; Daniel D. Oswald

    1961-01-01

    This report summarizes a 1978-79 timber resource inventory of five counties in the Olympic Peninsula of Washington: Clallam, Grays Harbor, Jefferson, Mason, and Thurston. Detailed tables of forest area, timber volume, growth, mortality, and harvest are presented.

  9. Endemic earthworms (Oligochaeta: Lumbricidae) of the Balkan Peninsula: a review.

    Science.gov (United States)

    Trakić, Tanja; Valchovski, Hristo; Stojanović, Mirjana

    2016-11-10

    A list of the endemic earthworms of the Balkan Peninsula is presented. Comprehensive information on the ecology, distribution on the Balkan Peninsula and zoogeographical type of all endemics is given. The list comprises 90 species and subspecies, belonging to 11 genera of the family Lumbricidae. The largest number of the Balkan endemic earthworms belongs to a narrow range group (63.3%). Broad range endemic species take part with 36.7%. Our study shows that the degree of endemism on the Balkan Peninsula is extremely high (about 40%) suggesting an important process of autochthonous speciation on the Balkan Peninsula. This appearance is attributable to relative isolation of the mountains compared to the lowlands within the context of paleoenvironmental changes.

  10. Climate Change Scenarios in the Yucatan Peninsula to the year 2020

    Science.gov (United States)

    Orellana, R.; Espadas, C.; Conde, C.; Gay, C.

    2010-03-01

    A topic that has not been sufficiently analyzed is that the global warming is already affecting, and that it will have worst consequences in those regions with transitional climates, which have more sensibility to changes. This is the case of the Yucatan Peninsula which is semi-arid in their northern portion, and toward the south is subhumid, with a tendency to be more rainy toward the south. To have an estimation of what could happen in the future, the Intergovernmental Panel of Climatic Change (IPCC) has promoted the use of General Circulation Models (GCM), as well as the construction of possible emission scenarios that integrate different global and regional socioeconomic and demographic conditions, which project then a possible increase of emissions of greenhouse gases. These conditions are recognized as the decisive forces that will determine the variations of temperature and of precipitation. These projections are useful for the analysis of climatic change, and in particular for the assessments of the possible impacts and of the initiatives of adaptation and of mitigation that should be implemented in every country or region. In Mexico, most of those evaluations of climate change have been carried out generally at country level. For that reason, it is necessary to direct the research at regional level. In this work, we evaluated the potential climatic changes on the Yucatan Peninsula, considering the different changes of temperature and precipitation as a consequence for different emission scenarios and for the horizon 2020. To project the environmental responses of the region, we used as a base scenario the available temperature and precipitation information of the period 1961-1990, registered in 85 meteorological stations of the peninsula. With these data, we generated climate change scenarios using the outputs of four General Circulation Models: HADLEY, ECHAM, GFDL and CGCM, and the emission scenarios A1FI, A2, B1 and B2. The outputs of these models were

  11. A third case of amelia in Morelet's crocodile from the Yucatan Peninsula.

    Science.gov (United States)

    Charruau, Pierre; Niño-Torres, Carlos A

    2014-07-03

    Congenital defects in crocodilians have received little interest. In the context of global change and increasing threats to biodiversity, data on birth defects occurring in wildlife could be of importance for estimating the health of species populations and their ecosystems. Herein, we report the first case of amelia (i.e. absence of limbs) in Morelet's crocodiles Crocodylus moreletii from Mexico and the third on the southern Yucatan Peninsula. The crocodile in question was a juvenile (41 cm total length) captured in July 2012 in the Río Hondo, the river that forms the border between Mexico and Belize south of the state of Quintana Roo. The prevalence of this malformation in the C. moreletii population of Río Hondo (0.35%) is similar to that reported in 2 previous cases in Belize. Several causes of birth defects in crocodilians have previously been cited in the literature. Although we do not have relevant information to elucidate this case, we discuss some plausible explanations for this birth defect.

  12. A new species of Dalbergia (Leguminosae from Malay Peninsula

    Directory of Open Access Journals (Sweden)

    Bambang - Sunarno

    2003-12-01

    Full Text Available SUNARNO, BAMBANG & OHASHI, HIROSHI. 2002. A new species of Dalbergia (Leguminosae from Malay Peninsula. Reinwardtia 12(1: 117–119. ⎯ A new species, Dalbergia johoriensis from the Malay Peninsula is described. It is close to D. rostrata and D. havilandii but readily distinguished by the grooved midrib beneath, flowers with narrower standard and wings and style hairy in the lower part.

  13. Modelling of sediment transport at Muria peninsula coastal, Jepara

    International Nuclear Information System (INIS)

    Heni Susiati; Yarianto SBS; Wahyu Pandoe; Eko Kusratmoko; Aris Poniman

    2010-01-01

    Modelling of transport sediment modelling at Muria Peninsula have been done. In this study we had been used mathematical model that consist of hydrodynamics and sediment transport . Data input for modelling has been used tidal, monsoon wind, and river debit. Simulation result of sediment transport modelling showed that tides pattern and seasonal variations are the main causes of variations in the suspended sediment distribution in Muria Peninsula. (author)

  14. Characteristics of lithology and tectonic setting in the Korean peninsula

    International Nuclear Information System (INIS)

    Lee, Byungjoo; Chae, Byunggon; Choi, Junghae

    2011-01-01

    The west coast of the Korean Peninsula is bounded by the Korean Bay to the north and the Yellow Sea to the south; the east coast is bounded by the East Sea. Two hundred kilometers separate the peninsula from eastern China. The Japanese islands of Honshu and Kyushu are located 206 kilometers to the southeast, just across the Korea Strait. Because of its unique geographical location, Chinese culture filtered into Japan through Korea; a common cultural sphere of Buddhism and Confucianism was thus established between the three countries. The total area of the peninsula, including the islands, is 222,154 square kilometers of which about 45 percent, excluding the area in the Demilitarized Zone, constitutes the territory of South Korea. There are about 3,000 islands belonging to Korea. The islands are located mostly around the Yellow Sea; Ulleungdo, the largest island in the East Sea, serves as a major fishery base as does Dokdo island. Important islands within South Korea territory include Jejudo, the largest island, which lies off the southwest corner of the peninsula, Geojedo, Ganghwado, and Namhaedo. Nearly 70 percent of the Korean Peninsula is covered by mountains and hills. Located mostly in the southern and the western regions, these hills give way gradually to increasingly higher mountains toward the eastern and the northern end. On the whole, the western and southern slopes of the peninsula are wide with some plains and basins along rivers, while the eastern slope is very narrow because the high mountains hug the East Sea coastline

  15. Characteristics of lithology and tectonic setting in the Korean peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byungjoo; Chae, Byunggon; Choi, Junghae [KIGAM, Daejeon (Korea, Republic of)

    2011-07-01

    The west coast of the Korean Peninsula is bounded by the Korean Bay to the north and the Yellow Sea to the south; the east coast is bounded by the East Sea. Two hundred kilometers separate the peninsula from eastern China. The Japanese islands of Honshu and Kyushu are located 206 kilometers to the southeast, just across the Korea Strait. Because of its unique geographical location, Chinese culture filtered into Japan through Korea; a common cultural sphere of Buddhism and Confucianism was thus established between the three countries. The total area of the peninsula, including the islands, is 222,154 square kilometers of which about 45 percent, excluding the area in the Demilitarized Zone, constitutes the territory of South Korea. There are about 3,000 islands belonging to Korea. The islands are located mostly around the Yellow Sea; Ulleungdo, the largest island in the East Sea, serves as a major fishery base as does Dokdo island. Important islands within South Korea territory include Jejudo, the largest island, which lies off the southwest corner of the peninsula, Geojedo, Ganghwado, and Namhaedo. Nearly 70 percent of the Korean Peninsula is covered by mountains and hills. Located mostly in the southern and the western regions, these hills give way gradually to increasingly higher mountains toward the eastern and the northern end. On the whole, the western and southern slopes of the peninsula are wide with some plains and basins along rivers, while the eastern slope is very narrow because the high mountains hug the East Sea coastline.

  16. Wind resource characterization in the Arabian Peninsula

    KAUST Repository

    Yip, Chak Man Andrew

    2015-12-28

    Wind energy is expected to contribute to alleviating the rise in energy demand in the Middle East that is driven by population growth and industrial development. However, variability and intermittency in the wind resource present significant challenges to grid integration of wind energy systems. These issues are rarely addressed in the literature of wind resource assessment in the Middle East due to sparse meteorological observations with varying record lengths. In this study, the wind field with consistent space–time resolution for over three decades at three hub heights (50m, 80m, 140m) over the whole Arabian Peninsula is constructed using the Modern Era Retrospective-Analysis for Research and Applications (MERRA) dataset. The wind resource is assessed at a higher spatial resolution with metrics of temporal variations in the wind than in prior studies. Previously unrecognized locations of interest with high wind abundance and low variability and intermittency have been identified in this study and confirmed by recent on-site observations. In particular, the western mountains of Saudi Arabia experience more abundant wind resource than most Red Sea coastal areas. The wind resource is more variable in coastal areas along the Arabian Gulf than their Red Sea counterparts at a similar latitude. Persistent wind is found along the coast of the Arabian Gulf.

  17. Airborne pollen trends in the Iberian Peninsula.

    Science.gov (United States)

    Galán, C; Alcázar, P; Oteros, J; García-Mozo, H; Aira, M J; Belmonte, J; Diaz de la Guardia, C; Fernández-González, D; Gutierrez-Bustillo, M; Moreno-Grau, S; Pérez-Badía, R; Rodríguez-Rajo, J; Ruiz-Valenzuela, L; Tormo, R; Trigo, M M; Domínguez-Vilches, E

    2016-04-15

    Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Microbiology of Kamchatka Peninsula Hot Springs

    Science.gov (United States)

    Bonch-Osmolovsk, E.

    2005-12-01

    Hot springs of Uzon Caldera, Geyser Valley, Moutnovsky Volcano (Kamchatka Peninsula) served as the sources of isolation of numerous thermophilic prokaryotes, many of them representing new taxa. Among new isolates there were hyperthermophilic archaea - neutrophilic or acidophilic anaerobic organotrophs, able to use a wide range of polymeric organic substrates. Bacterial isolates were in majority represented by moderate thermophiles - organotrophs and lithoautotrophs. Latter group consisted of anaerobes oxidizing molecular hydrogen in the course of sulfate, sulfur or iron reduction, and of anaerobic CO-oxidizing, hydrogen-producing bacteria. Some of new isolates represented deep phylogenetic lineages in Bacteria domain. Microbial activity in Kamchatka hot springs was studied by means of radioisotopic tracing. The rates of methanogenesis, acetogenesis, inorganic carbon assimilation, acetate oxidation were determined in three different hot springs with pH ranging from 3.0 to 8.5 and water temeperature being in the range from 55 to 85oC. The results indicated the presence and activity of novel metabolic groups of thermophilic prokaryotes that so far have not been known in laboratory cultures.

  19. Pharmaceutical ethnobotany in Northern Navarra (Iberian Peninsula).

    Science.gov (United States)

    Cavero, R Y; Akerreta, S; Calvo, M I

    2011-01-07

    This paper provides significant ethnobotanical information on pharmaceutical plant uses in Northern Navarra from an area known both for its high biological diversity and its cultural significance, suggesting the survival of uses lost elsewhere. Collect, analyze and evaluate the ethnobotanical knowledge about medicinal plants in Northern Navarra (Iberian Peninsula) with 4243 km(2) and 71,069 inhabitants. We performed semi-structured interviews with 253 informants (mean age 69; 61% women, 39% men) in 120 locations, identified the plant reported and analyzed the results, comparing them with those from other territories. The informants reported data on 174 medicinal plants belonging to 63 botanical families. This work is focused on human medicinal plant uses, which represent 98% of the pharmaceutical uses (1725 use reports). The species with the highest number of cites are Chamaemelum nobile, Sambucus nigra and Verbena officinalis, with a long tradition of use in The Mountain (Navarra). All different plant parts are used; aerial part is exploited more frequently than other plant parts. Most of the listed remedies use a single ingredient, typically soaked in water. Usually, the administration is primarily oral followed by topical applications. The main ailments treated are digestive troubles, wounds and dermatological problems, and respiratory affections. Informants reported 24 new or scarcely cited uses for 23 medicinal plants. For 35% of the species (8) we have not found bibliographical references in the scientific literature and 48% (11) have only one to three references. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  20. 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

  1. Mexico; Mexique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    This document summarizes the key energy data for Mexico: 1 - energy organizations and policy: Ministry of energy (SENER), Comision Reguladora de Energia (CRE), Ministry of Finances, Ministry of trade and industrial development (SECOFI), national commission for energy savings (CONAE); 2 - companies: federal commission of electricity (CFE), Minera Carbonifera Rio Escondido (MICARE - coal), Pemex (petroleum); 3 - energy production: resources, electric power, petroleum, natural gas; 4 - energy consumption; 5 - stakes and perspectives. Some economic and energy indicators are summarized in a series of tables: general indicators, supply indicators (reserves, refining and electric capacity, energy production, foreign trade), demand indicators (consumption trends, end use, energy independence, energy efficiency, CO{sub 2} emissions), energy status per year and per energy source. (J.S.)

  2. Floristic affinities of the lowland savannahs of Belize and southern Mexico.

    Science.gov (United States)

    Canché-Estrada, Idalia Arely; Ortiz-Díaz, Juan Javier; Tun-Garrido, Juan

    2018-01-01

    Environmental heterogeneity of Belize and southern Mexico savannahs as well as their geographical location suggest that these plant communities share floristic elements, making them conducive to a phytogeographical analysis. The aim of this study was to analyse the floristic affinities of nine savannahs of Belize and southern Mexico and to explain the similarities and differences amongst them. A binary data matrix containing 915 species was built based on the authors' own collections and on nine floristic lists already published. A second data matrix, consisting of 113 species representing trees, was also used since most literature on neotropical savannahs has focused on this life form. In addition, the ten most species-rich families as well as the characteristic species present in more than five savannahs were analysed. Floristic similarities were calculated using the Jaccard index. Dendrograms obtained in both types of analysis showed clusters with low similarity values, corresponding to geographic locations formed by the savannahs of Belize-Tabasco and the Yucatan Peninsula. The floristic affinities of the savannahs may be explained in terms of heterogeneity in climate and physiography. The Yucatan Peninsula and Belize-Tabasco groups have differences in climate type and the amount of rainfall. In addition, the Yucatan Peninsula savannahs are established at the bottom of karstic valleys, while the Belize and Tabasco savannahs develop on extensive flatlands. The savannahs of Oaxaca have the same climate type and amount of rainfall as those of the Yucatan Peninsula but they are distributed along peaks and the slopes of shale hills. Fabaceae and Poaceae mainly dominated the local floras with 121 and 116 species each; remarkably, Melastomataceae was absent in the Yucatan Peninsula and Oaxaca. Nine species occurred in five to seven savannahs, confirming that they are widespread in both Belize and southern Mexico, and the Neotropics. Geographic location and floristic

  3. Potamogeton schweinfurthii in the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Petit, Albert

    2012-12-01

    Full Text Available We provide the first records for the Iberian Peninsula of Potamogeton schweinfurthii A. Benn., a species distributed mainly in Africa that was not discovered in Europe until 2005, where it is assumed to be indigenous but it has generally been confused with P. lucens. The Iberian specimens, which for the most part are from recent collections, have been identified based on morphological characteristics and molecular studies. We have detected 8 localities, 4 in the northeastern area of the Peninsula (Catalonia and Navarra and 4 from the West (south and north of Portugal and western Andalusia. Our studies show that it is a very rare species on a regional level. Although it is a mainly tropical and subtropical species, we have found that P. schweinfurthii (both natural populations and those cultivated has a high tolerance to climates with severe winters and frequent frosts. The large proportion of populations found in anthropogenic habitats, and the fact that most European records are from the past half-century, suggest that P. schweinfurthii may have experienced a recent expansion favoured by the construction of large number of artificial water bodies in the Mediterranean region. This raises the possibility that P. schweinfurthii in Europe is a species that forms temporary populations and has a naturally unstable area.Se aportan las primeras citas de Potamogeton schweinfurthii A. Benn. en la Península Ibérica, una especie de área básicamente africana que no fue descubierta en Europa hasta 2005, donde se supone que es autóctona y en general había sido confundida con P. lucens. Los ejemplares ibéricos han sido identificados por sus caracteres morfológicos y por estudios moleculares y, en su mayor parte, proceden de recolecciones recientes. Se ha detectado en 8 localidades, 4 del noreste peninsular (Cataluña y Navarra y 4 del oeste (sur y norte de Portugal y Andalucía occidental. Según la información actualmente disponible, se trataría de

  4. Saker Falcon on the Crimean Peninsula

    Directory of Open Access Journals (Sweden)

    Igor V. Karyakin

    2016-02-01

    Full Text Available In this article we made a revaluation of a number of the Saker (Falco cherrug on the Crimean Peninsula based on data obtained in an expedition conducted in May 9–26 of 2015. During this expedition Sakers were observed on 58 sites (31 times they were seen on pylons of power lines, 14 – on cliffs in the foothills of Crimean Mountains, 8 – on the coastal cliffs and 4 on the coastal precipices, and one adult male was seen in the forest shelter belt near Syvash lagoon. We revealed 49 breeding territories of Saker including 42 occupied nests with successful breeding. The estimation of the total number of breeding population on peninsula is 145–184 (mean 165 breeding pairs, including 125–159 (mean 142 pairs which breeding attempts were successful in 2015. The distance between the neighboring pairs is 1.95–15.21 km (mean 6.56±3.37 km, n=43. Pylons of power lines were used by 30 breeding pairs (61.22% out of 49, and 29 successful nests (69.05% out of 42 were built on pylons. Supposedly, 63.83% of all breeding pairs in Crimea are bred on pylons, and the percentage of successful nests out of the total number of nests in population is 71.89%. From the 34 nests that were built on pylons, 24 (70.59% were located on the concrete pylons and 10 (29.41% on the metal ones. On cliffs and precipices we found 24 nests in total. Eighteen (75% of them were built on a bare ground, while the others were found in the nests built by other bird species (most of them were made in the former nests of the Raven (Corvus corax, and one pair occupies a nest of the Long-legged Buzzard (Buteo rufinus located on cliff. The percentage of successful nests out of occupied ones was 85.71%. We found broods of 1–4 nestlings, which in average (n=23 makes 2.83±0.78 nestling per successful nest. The majority of broods (65.22% consisted of 3 nestlings. On 20 breeding territories (90.91% male birds were older then 2 years old, and two breeding territories (9.09% were occupied

  5. A dendrochronology based fire history of Jeffry pine-mixed conifer forests in the Sierra San Pedro Martir, Mexico

    Science.gov (United States)

    Scott L. Stephens; Carl N. Skinner; Samantha J. Gill

    2003-01-01

    Conifer forests in northwestern Mexico have not experienced systematic fire suppression or logging, making them unique in western North America. Fire regimes of Pinus jeffreyi Grev. & Balf. mixed conifer forests in the Sierra San Pedro Martir, Baja California, Mexico, were determined by identifying 105 fire dates from 1034 fire scars in 105 specimens. Fires were...

  6. Persistence of DACA-Mexico Origin College Students in the United States-Mexican Borderlands: A Correlational Study

    Science.gov (United States)

    Dominguez, Marguerite Nicole

    2017-01-01

    This was a correlational study of 30 Deferred Action for Childhood Arrivals-Mexico origin (D-MO) students at 2- and 4-year higher education institutions in the 4-state United States-Mexican Borderlands region (California, Arizona, Texas, and New Mexico). The study used an online survey to gain a better understanding of the relationship of four…

  7. North Atlantic Oscillation and moisture transport towards the Iberian Peninsula during winter

    Science.gov (United States)

    Ordóñez, Paulina; Liberato, Margarida L. R.; Gouveia, Célia; Trigo, Ricardo M.

    2013-04-01

    The North Atlantic Oscillation (NAO) is the major source of interannual variability in winter precipitation over the Iberian Peninsula (IP). Recent works have identified the most important sources of moisture that supply the IP during different seasons of the year, including the nearby western Mediterranean and the tropical-subtropical North Atlantic corridor that extends from the Gulf of Mexico to the IP, and the IP itself (Gimeno et al., 2010). However, although rainfall is directly related to the moisture supply, the relationship between the water vapor transported towards IP and the NAO phase remains unclear. In this work the moisture transport towards IP was analyzed using a Lagrangian diagnosis method, which relies on the Lagrangian particle dispersion model FLEXPART. This methodology computes budgets of evaporation minus precipitation (E-P) by evaluating changes in the specific humidity along back-trajectories. Here we have computed (for each day) the evolution of moisture of the particles bound for Iberia up to 10 days prior to their arrival. The analysis was constrained to the winter (DJF) season, responsible for the largest fraction of precipitation, for the 20 years of ECMWF Reanalyses ERA40 dataset from 1980 to 2000. The contribution of the NAO phase on the water budgets is examined using composites of the obtained (E - P) fields for the 5 most extreme positive and negative NAO years of the study period. Results confirm that the IP is dominated by positive (negative) E-P anomalies during positive (negative) NAO phase. Additionally an anomalous water vapor sink (source) region located approximately over the Gulf Stream is found during positive (negative) NAO phase. Gimeno L., Nieto R., Trigo R.M. , Vicente-Serrano S.M, Lopes-Moreno J.I., (2010) "Where does the Iberian Peninsula moisture come from? An answer based on a Lagrangian approach". J. Hydrometeorology, 11, 421-436 DOI: 10.1175/2009JHM1182.1.

  8. Feeding ecology of juvenile marine fish in a shallow coastal lagoon of southeastern Mexico

    OpenAIRE

    Daniel Arceo-Carranza; Xavier Chiappa-Carrara

    2015-01-01

    Many species of marine fish use coastal lagoons during early stages of their life cycles due to the protection provided by their turbid waters and complex structure of the environment, such as mangroves and mudflats, and the availability of food derived from the high productivity of these sites. In this study, we analyzed the diet of six species of juvenile marine fishes that use a karstic lagoon system in the northwest portion of the Yucatan Peninsula, Mexico. Through stomach contents analys...

  9. 76 FR 38416 - Notice of Segregation of Public Lands in the States of Arizona, California, Colorado, Nevada, New...

    Science.gov (United States)

    2011-06-30

    ... Segregation of Public Lands in the States of Arizona, California, Colorado, Nevada, New Mexico, and Utah... laws, but not the mineral leasing or material sales acts, for a period of 2 years for the purpose of..., approximately 677,384 acres of public lands located in the States of Arizona, California, Colorado, Nevada, New...

  10. The Blue-gray Tanager (Thraupis episcopus in the state of Guerrero, Mexico

    Directory of Open Access Journals (Sweden)

    Epifanio Blancas-Calva

    2017-10-01

    Full Text Available We recorded the Blue-gray Tanager (Thraupis episcopus on the southeastern coastal plain of the state of Guerrero, Mexico, in urban areas with cover of scattered trees of native and introduced species. The current range known for this taxon comprises lowlands of eastern Mexico, from south-central Nuevo Leon to the Yucatan peninsula, including eastern Oaxaca and the Pacific slope on the coastal plain of Chiapas. However, there are no published previous records of the species in Guerrero. Possibly T. episcopus is a species that has expanded its range in episodes of active dispersal.

  11. Nuevo registro del tiburón narizón, Apristurus nasutus de Buen, 1959, (Carcharhiniformes: Scyliorhinidae) en el Golfo de California, México New record of Largenose Catshark, Apristurus nasutus de Buen, 1959, (Carcharhiniformes: Scyliorhinidae) in the Gulf of California, Mexico

    OpenAIRE

    Alejandro Acevedo-Cervantes; Juana López-Martínez; Eloisa Herrera-Valdivia; Jesús Rodríguez-Romero

    2009-01-01

    Se recolectaron 143 ejemplares de tiburón narizón Apristurus nasutus (de Buen, 1959), durante un crucero de prospección en junio de 2007. Las muestras provinieron de tres lances realizados con una red de arrastre entre los 250 y los 460 m de profundidad, en la parte media y alta del Golfo de California. El hallazgo representa el primer registro de la especie en aguas mexicanas y por consiguiente la ampliación de su ámbito de distribución. Los organismos capturados se encontraron agrupados en ...

  12. The bivalve Anopaea (Inoceramidae) from the Upper Jurassic-lowermost Cretaceous of Mexico

    Science.gov (United States)

    Zell, Patrick; Crame, J. Alistair; Stinnesbeck, Wolfgang; Beckmann, Seija

    2015-07-01

    In Mexico, the Upper Jurassic to lowermost Cretaceous La Casita and coeval La Caja and La Pimienta formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous inoceramid bivalves of the genus Anopaea not formally described previously from Mexico. Anopaea bassei (Lecolle de Cantú, 1967), Anopaea cf. stoliczkai (Holdhaus, 1913), Anopaea cf. callistoensis Crame and Kelly, 1995 and Anopaea sp. are rare constituents in distinctive Tithonian-lower Berriasian levels of the La Caja Formation and one Tithonian horizon of the La Pimienta Formation. Anopaea bassei was previously documented from the Tithonian of central Mexico and Cuba, while most other members of Anopaea described here are only known from southern high latitudes. The Mexican assemblage also includes taxa which closely resemble Anopaea stoliczkai from the Tithonian of India, Indonesia and the Antarctic Peninsula, and Anopaea callistoensis from the late Tithonian to ?early Berriasian of the Antarctic Peninsula. Our new data expand the palaeogeographical distribution of the high latitude Anopaea to the Gulf of Mexico region and substantiate faunal exchange, in the Late Jurassic-earliest Cretaceous, between Mexico and the Antarctic Realm.

  13. Subsurface imaging in a sector of Cerro Prieto transform fault near to pull-apart basin, Mexicali Valley, Baja California, Mexico, based on crooked lines 2D seismic reflection.

    Science.gov (United States)

    Mares-Agüero, M. A.; González-Escobar, M.; Arregui, S.

    2016-12-01

    In the transition zone between San Andres continental transformation system and the coupled transform faults system and rifting of Gulf of California is located the Cerro Prieto pull-apart basin delimitated by Imperial fault (northeast) and Cerro Prieto fault (CPF) (southwest), this last, is the limit west of Cerro Prieto geothermic field (CPGF). Crooked lines 2D seismic reflection, covering a portion near the intersection of CPF and CPGF are processed and interpreted. The seismic data were obtained in the early 80's by Petróleos Mexicanos (PEMEX). By decades, technical and investigation works in Cerro Prieto geothermic field and its vicinity had mapped faults at several depths but do not stablish a clear limit where this faults and CPF interact due the complex hydrothermal effects imaging the subsurface. The profiles showing the presence of a zone of uplift effect due to CPF. Considering the proximity of the profiles to CPF, it is surprising almost total absence of faults. A strong reflector around 2 km of depth, it is present in all profiles. This seismic reflector is considered a layer of shale, result of the correlation with a well located in the same region.

  14. New Mexico Parks

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of parks in New Mexico, in point form, with limited attributes, compiled using available data from a...

  15. New Mexico State Parks

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the generalized physical boundaries of New Mexico State Parks, in polygonal form with limited attributes, compiled using...

  16. New Mexico Ghost Towns

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data provides locations and non-spatial attributes of many ghost towns in the State of New Mexico, compiled from various sources. Locations provided with...

  17. Groundwater recharge studies using isotope-chemical techniques in wadi gharandal, sinai peninsula(E G))

    International Nuclear Information System (INIS)

    Awad, M.A.A.; Salem, W.M.; Ezzeldin

    1999-01-01

    Wadi Gharandal lies on southwestern part of sinai peninsula with its outlets into the Gulf of suez. Eight groundwater samples were collected from quaternary aquifer in wadi gharandal to identify the sources of replenishment and evaluation of its water quality. The variation in chemical composition of water samples is due to water-rock interaction and the effect of sea spray. The distribution of chemical species in the examined groundwater samples is controlled by geography and climate conditions prevailing in the area of study. The salinity increase towards the gulf of suez. The isotopic data indicate that precipitation and floods are considered to be the main sources of recharge in this area. The investigated groundwater samples are found to be suitable for irrigation purposes based on sodium adsorption ratio (SAR) and unsuitable for domestic usages due to high salinity and hardness values

  18. Southwest Regional Climate Hub and California Subsidiary Hub assessment of climate change vulnerability and adaptation and mitigation strategies

    Science.gov (United States)

    Emile Elias; Caiti Steele; Kris Havstad; Kerri Steenwerth; Jeanne Chambers; Helena Deswood; Amber Kerr; Albert Rango; Mark Schwartz; Peter Stine; Rachel Steele

    2015-01-01

    This report is a joint effort of the Southwest Regional Climate Hub and the California Subsidiary Hub (Sub Hub). The Southwest Regional Climate Hub covers Arizona, California, Hawai‘i and the U.S. affiliated Pacific Islands, Nevada, New Mexico, and Utah and contains vast areas of western rangeland, forests, and high-value specialty crops (Figure 1). The California Sub...

  19. Surface circulation patterns in the Gulf of California derived from MODIS Aqua 250 m

    Science.gov (United States)

    Martínez-Flores, G.; Salinas-González, F.; Gutiérrez de Velasco-Sanromán, G.; Godínez-Orta, L.

    2009-04-01

    The Gulf of California (GC) is a marginal elongated and semi-enclosed sea located at northwest of Mexico, between the Peninsula of Baja California and the mainland Mexico. The considered area average 150 km in width and 1500 km in length, from the mouth of the Colorado River to Cabo Corrientes, Jalisco. It has a maximum depth of 3600 m at the southern inlet and the northern region average 200 m in deep. The study of superficial circulation patterns in the GC is of interest because its relevance to the mechanisms of transport for distribution of a variety of materials -plankton, contaminants, microalgae, etc.- and its association with areas of sedimentary deposits, zones where there is a higher probability for fishing or related to the presence of certain species of marine life. Recent studies explain the circulation of the GC as a result of the Pacific Ocean's forcing, wind, heat fluxes on the sea surface and the interaction between the flow produced by these agents and bathymetry. The objective of this work was to obtain evidence of the patterns of surface circulation using a spatial resolution of 250 m over a period of two to seven days (depending on cloud cover), which offered images from the MODIS Level 1B. This essay is an attempt to contribute with more information to the understanding of the regional dynamics of the GC and its local influence on the zones bordering the coast. Thus, MODIS Aqua 250 m data was used, to which algorithms were applied in order to enhance the contrast of reflectance levels of these bands (0.620-0.670 and 0.841-0.876 µm) within the marine environment. The results are associated with suspended particulate matter (SPM), which we used as tracers of the surface circulation, using a sequence of images from January 2004 to December 2008. Algorithms for dust and cloud detection were used and incorporated with thermal band images, in which zones of terrigenous contribution by eolian transport were identified. Furthermore, pluvial

  20. English Teaching in Mexico.

    Science.gov (United States)

    Salazar, Denise

    2002-01-01

    Discusses teaching English in Mexico, a country with important social, cultural, and economic ties to the United States. Looks at the various English teaching situations as well as teacher education for teachers in Mexico. Concludes that the English teaching situation in Mexico reflects great diversity and growth, and that the knowledge of English…

  1. Psychology in Mexico

    Science.gov (United States)

    Ruiz, Eleonora Rubio

    2011-01-01

    The first formal psychology course taught in Mexico was in 1896 at Mexico's National University; today, National Autonomous University of Mexico (UNAM in Spanish). The modern psychology from Europe and the US in the late 19th century were the primary influences of Mexican psychology, as well as psychoanalysis and both clinical and experimental…

  2. Possibilities for wind energy on the Kola peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, J; Rathmann, O; Lundsager, P [and others

    1999-03-01

    This paper presents an extensive feasibility study regarding the introduction of wind energy in the energy supply of the Kola peninsula in north-western Russia that was carried out during 1996-97. The study covers as well grid connected wind turbines as autonomous systems and a wind atlas was prepared. Special emphasis is put on non-technical activities and objectives like financing models, international funding and a sound politic support. The wind resources on the Kola peninsula are excellent and there are still no reasons to why wind energy installations couldn`t be carried out successfully. Recommendations for starting this development are presented. (au)

  3. Impact of the 2015 El Niño-Southern Oscillation on the Abundance and Foraging Habits of Guadalupe Fur Seals and California Sea Lions from the San Benito Archipelago, Mexico.

    Directory of Open Access Journals (Sweden)

    Fernando R Elorriaga-Verplancken

    Full Text Available The abundance of California sea lions (Zalophus californianus (CSLs and Guadalupe fur seals (Arctocephalus philippii townsendi (GFSs from the San Benito Archipelago (SBA was determined through nine monthly surveys in 2014-2015. Assessment of their foraging habits was examined based on the isotopic analysis of pups (maternal indicators (SIAR/SIBER-R. Environmental variability between 2014 and 2015 was also analyzed, in terms of sea surface temperature (SST and chlorophyll (Chl-a concentration. Both otariids reached their highest abundance in July of both years; however, relative to 2014, the 2015 survey showed a 59.7% decline in the total GFS abundance and a 42.9% decrease of GFS pups, while total CSL abundance decreased 52.0% and CSL pup presence decreased in 61.7%. All monthly surveys for both otariids showed a similar trend (>50% decrease in 2015. Compared to 2014, the 2015 GFSs isotopic niche was three times larger (2.0 in 2015, 0.6 in 2014 and the δ13C was significantly lower. CSLs also showed significantly lower δ13C and higher δ15N in 2015. Interannual segregation was greater for CSLs, and their pup body mass was also significantly lower during the 2015 breeding season (mean = 8.7 kg than in the same season of 2014 (mean = 9.9 kg. The decrease in δ13C for both otariids reflected a more oceanic foraging; most likely associated with the decline in primary productivity in surrounding areas to the SBA, related to a higher SST caused by the 2015 ENSO, with a subsequent increase in foraging effort. These would explain the fewer observed individuals on land, especially pups, which showed diminished body condition (CSLs. This study highlights the importance of marine mammals as sentinel species that respond dynamically to changes in environment, providing valuable information on the effect of ENSO on pinnipeds in Mexican waters.

  4. California Condor Critical Habitat

    Data.gov (United States)

    California Natural Resource Agency — 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...

  5. Teale California shoreline

    Data.gov (United States)

    California Natural Resource Agency — California Spatial Information System (CaSIL) is a project designed to improve access to geo-spatial and geo-spatial related data information throughout the state of...

  6. California Workforce: California Faces a Skills Gap

    Science.gov (United States)

    Public Policy Institute of California, 2011

    2011-01-01

    California's education system is not keeping up with the changing demands of the state's economy--soon, California will face a shortage of skilled workers. Projections to 2025 suggest that the economy will continue to need more and more highly educated workers, but that the state will not be able to meet that demand. If current trends persist,…

  7. Sacramento Metropolitan Area, California

    Science.gov (United States)

    1992-02-01

    addition, several Federal candidate species, the California Hibiscus , California tiger salamander, Sacramento Anthicid Beetle, Sacramento Valley tiger...Board, California Waste Management Board, and Department of Health Services contribute to this list. The Yolo County Health Services Agency maintains and...operation and maintenance of the completed recreational facility. Recreation development is limited to project lands unless health and safety

  8. Ciguatera fish poisoning. A southern California epidemic.

    Science.gov (United States)

    Barton, E D; Tanner, P; Turchen, S G; Tunget, C L; Manoguerra, A; Clark, R F

    1995-01-01

    Ciguatera fish poisoning results from the bioconcentration of a variety of toxins produced by marine dinoflagellates. Signs and symptoms vary widely, but it usually presents as gastrointestinal and neurologic complaints beginning shortly after the ingestion of fish containing the toxins. Symptoms may persist for months and sometimes even years. Although cases have been reported throughout the United States, epidemics are most common along tropical and subtropical coasts and usually involve the ingestion of large carnivorous fish. We review the literature and report the first epidemic of 25 cases of ciguatera fish poisoning presenting to area hospitals in Southern California that were successfully tracked by the Department of Health Services and isolated to fish caught off the coast of Baja California, Mexico. Images Figure 1. PMID:7667980

  9. Eremophila alpestris (Alaudidae: A new bird species and family for the Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Barbara MacKinnon

    2015-06-01

    Full Text Available Eremophila alpestris (Alaudidae: una especie y familia nuevas para la Península de Yucatán, México Se reporta el primer registro de Eremophila alpestris el 23 de noviembre del 2002, en Progreso, costa norte de la Península de Yucatán, México. La población migratoria más cercana esta en la costa de Texas y posiblemente este individuo cruzo el Golfo de México.

  10. Eremophila alpestris (Alaudidae): A new bird species and family for the Yucatan Peninsula, Mexico

    OpenAIRE

    Barbara MacKinnon; Jaques Laesser; James Rotenberg; Luís I. Tellez

    2015-01-01

    Eremophila alpestris (Alaudidae): una especie y familia nuevas para la Península de Yucatán, México Se reporta el primer registro de Eremophila alpestris el 23 de noviembre del 2002, en Progreso, costa norte de la Península de Yucatán, México. La población migratoria más cercana esta en la costa de Texas y posiblemente este individuo cruzo el Golfo de México.

  11. Fish functional groups in a tropical wetland of the Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Fernando Córdova-Tapia

    Full Text Available ABSTRACT The characterization of species' functional traits is a major step in the understanding and description of communities in natural habitats. The classification of species into functional groups is a useful tool to identify redundancy and uniqueness. We studied the fish community of a pristine freshwater wetland in the Sian Ka'an Biosphere Reserve by analysing two multidimensional functions: food acquisition and locomotion. We investigated changes in the functional group structure between habitats (permanent and temporary pools and seasons (dry and wet. Six functional groups with different ecological characteristics were detected, two of which had high functional redundancy and three of them were represented by single species with unique ecological functions. In permanent pools during the dry season, functional group richness and diversity were lower, while evenness was higher. During the wet season, all functional groups were detected and similar functional group structure was found between habitats. These results suggest an effect of environmental filtering during the dry season and niche complementarity during the wet season.

  12. Trends in photochemical smog in the Cape Peninsula and the ...

    African Journals Online (AJOL)

    There has been growing public concern over reports of increasing air pollution in the Cape Peninsula. Attention has been focused on the 'brown haze' and on photochemical smog. Because of deficiencies in the monitoring equipment, information on trends in photochemical smog levels over the past decade is limited.

  13. A sketch of language history in the Korean Peninsula.

    Science.gov (United States)

    Lee, Sean

    2015-01-01

    Among 7100 languages spoken on Earth, the Koreanic language is the 13th largest, with about 77 million speakers in and around the Korean Peninsula. In comparison to other languages of similar size, however, surprisingly little is known about the evolution of the Koreanic language. This is mainly due to two reasons. The first reason is that the genealogical relationship of the Koreanic to other neighboring languages remains uncertain, and thus inference from the linguistic comparative method provides only provisional evidence. The second reason is that, as the ancestral Koreanic speakers lacked their own writing system until around 500 years ago, there are scant historical materials to peer into the past, except for those preserved in Sinitic characters that we have no straightforward way of interpreting. Here I attempt to overcome these disadvantages and shed some light on the linguistic history of the Korean Peninsula, by analyzing the internal variation of the Koreanic language with methods adopted from evolutionary biology. The preliminary results presented here suggest that the evolutionary history of the Koreanic language is characterized by a weak hierarchical structure, and intensive gene/culture flows within the Korean Peninsula seem to have promoted linguistic homogeneity among the Koreanic variants. Despite the gene/culture flows, however, there are still three detectable linguistic barriers in the Korean Peninsula that appear to have been shaped by geographical features such as mountains, elevated areas, and ocean. I discuss these findings in an inclusive manner to lay the groundwork for future studies.

  14. Recolonisation of the Robberg Peninsula (Plettenberg Bay, South ...

    African Journals Online (AJOL)

    The Cape fur seal Arctocephalus pusillus pusillus colony at Robberg Peninsula, Plettenberg Bay, on the south-east coast of South Africa, was driven to extinction by indiscriminate harvesting by the late 1800s. Seals only began to recolonise this site in the 1990s. This study describes the recolonisation process from 2000 to ...

  15. Timberland resources of the Kenai Peninsula, Alaska, 1987.

    Science.gov (United States)

    Willem W.S. van Hees; Frederic R. Larson

    1991-01-01

    The 1987 inventory of the forest resources of the Kenai Peninsula was designed to assess the impact of the spruce beetle (Dendroctonus rufipennis (Kirby)) on the timberland component of the forest resource. Estimates of timberland area, volumes of timber, and growth and mortality of timber were developed. These estimates of timber resource...

  16. Timber resource of Michigan's Southern Lower Peninsula Unit, 1980.

    Science.gov (United States)

    Jerold T. Hahn

    1982-01-01

    The fourth inventory of the timber resource of Michigan's Southern Lower Peninsula Survey Unit shows a 12% decline in commercial forest area and a 26% gain in growing-stock volume between 1966 and 1980. Presented are highlights and statistics on area, volume, growth, mortality, removals, utilization, and biomass.

  17. Modeling of Regional Climate over Red Sea and Arabian Peninsula

    KAUST Repository

    Stenchikov, Georgiy L.

    2011-04-09

    Observations, re-analyses, and climate model simulations show strong surface temperature trends in Middle East and Arabian Peninsula in the last 30 years. Trends are especially pronounced in summer exceeding +1K/decade. However, some regions, e.g., the So

  18. Drought variability and change across the Iberian Peninsula

    Science.gov (United States)

    Coll, J. R.; Aguilar, E.; Ashcroft, L.

    2017-11-01

    Drought variability and change was assessed across the Iberian Peninsula over more than 100 years expanding through the twentieth century and the first decade of the twenty-first century. Daily temperature and precipitation data from 24 Iberian time series were quality controlled and homogenized to create the Monthly Iberian Temperature and Precipitation Series (MITPS) for the period 1906-2010. The Standardized Precipitation Index (SPI), driven only by precipitation, and the Standardized Precipitation Evapotranspiration Index (SPEI), based on the difference between the precipitation and the reference evapotranspiration (ET0), were computed at annual and seasonal scale to describe the evolution of droughts across time. The results confirmed that a clear temperature increase has occurred over the entire Iberian Peninsula at the annual and seasonal scale, but no significant changes in precipitation accumulated amounts were found. Similar drought variability was provided by the SPI and SPEI, although the SPEI showed greater drought severity and larger surface area affected by drought than SPI from 1980s to 2010 due to the increase in atmospheric evaporative demand caused by increased temperatures. Moreover, a clear drying trend was found by the SPEI for most of the Iberian Peninsula at annual scale and also for spring and summer, although the SPI did not experience significant changes in drought conditions. From the drying trend identified for most of the Iberian Peninsula along the twentieth century, an increase in drought conditions can also be expected for this region in the twenty-first century according to future climate change projections and scenarios.

  19. Crustal structure beneath the southern Korean Peninsula from local earthquakes

    Science.gov (United States)

    Kim, Kwang-Hee; Park, Jung-Ho; Park, Yongcheol; Hao, Tian-Yao; Kim, Han-Joon

    2017-05-01

    The 3-D subsurface structure beneath the southern Korean Peninsula is poorly known, even though such information could be key in verifying or rejecting several competing models of the tectonic evolution of East Asia. We constructed a 3-D velocity model of the upper crust beneath the southern Korean Peninsula using 19 935 P-wave arrivals from 747 earthquakes recorded by high-density local seismic networks. Results show significant lateral and vertical variations: velocity increases from northwest to southeast at shallow depths, and significant velocity variations are observed across the South Korea Tectonic Line between the Okcheon Fold Belt and the Youngnam Massif. Collision between the North and South China blocks during the Early Cretaceous might have caused extensive deformation and the observed negative velocity anomalies in the region. The results of the tomographic inversion, combined with the findings of previous studies of Bouguer and isostatic gravity anomalies, indicate the presence of high-density material in the upper and middle crust beneath the Gyeongsang Basin in the southeastern Korean Peninsula. Although our results partially support the indentation tectonic model, it is still premature to discard other tectonic evolution models because our study only covers the southern half of the peninsula.

  20. 78 FR 10595 - Olympic Peninsula Resource Advisory Committee

    Science.gov (United States)

    2013-02-14

    ... DEPARTMENT OF AGRICULTURE Forest Service Olympic Peninsula Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Outreach for new RAC Replacement members. SUMMARY: Interested citizens are... information, please contact Donna Nemeth at 360-956-2274 or Bill Shelmerdine at 360-956- 2282. Dated: February...

  1. 77 FR 65359 - Olympic Peninsula Resource Advisory Committee

    Science.gov (United States)

    2012-10-26

    ... DEPARTMENT OF AGRICULTURE Forest Service Olympic Peninsula Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Outreach for new RAC members. SUMMARY: Interested citizens are invited to... information, please contact Donna Nemeth at 360-956-2274 or Bill Shelmerdine at 360-956- 2282. Dated: October...

  2. The oceanic forecasting system near the Shimokita Peninsula, Japan

    International Nuclear Information System (INIS)

    In, Teiji; Nakayama, Tomoharu; Matsuura, Yasutaka; Shima, Shigeki; Ishikawa, Yoichi; Awaji, Toshiyuki; Kobayashi, Takuya; Kawamura, Hideyuki; Togawa, Orihiko; Toyoda, Takahiro

    2007-01-01

    The oceanic forecasting system off the Shimokita Peninsula was constructed. To evaluate the performance of this system, we carried out the hindcast experiment for the oceanic conditions in 2003. The results showed the system had good reproducibility. Especially, it was able to reproduce the feature of seasonal variation of the Tsugaru Warm Water (TWW). We expect it has enough performance in actual forecasting. (author)

  3. Dynamic thinning of glaciers on the Southern Antarctic Peninsula

    NARCIS (Netherlands)

    Wouters, B.; Martin-Espanol, A.; Helm, V.; Flament, T.; van Wessem, J. M.; Ligtenberg, S. R. M.; van den Broeke, M. R.; Bamber, J. L.

    2015-01-01

    Growing evidence has demonstrated the importance of ice shelf buttressing on the inland grounded ice, especially if it is resting on bedrock below sea level. Much of the Southern Antarctic Peninsula satisfies this condition and also possesses a bed slope that deepens inland. Such ice sheet geometry

  4. Origin of the flora of the Malay Peninsula

    NARCIS (Netherlands)

    Ridley, H.N.

    1937-01-01

    In my work on the Malay Peninsula, I included such plants as were known from the districts of North Kedah, Perlis and Setul. Botanically however, the Malayan flora ceases at a line running from a little north of Kedah peak Lat. 6.5, to Kota Bahru in North Kelantan Lat. 6.10. It is in fact

  5. Operations in California during the Mexican American War

    Science.gov (United States)

    2016-05-26

    assertion that he was on private business. On December 10, 1845 he arrived at Vera Cruz and proceeded overland to Mexico City where the Paredes revolution...Majesty’s Ship “Collingwood” From 1844-1848 (Paris, France: E . Briére, rue Sainte-Anne, 1850), 162-163.The policy of non- interference toward...From 1844-1848. Paris, France: E . Briére, rue Sainte-Anne, 1850. Watson, Douglas S. “The First Mail Contract in California.” California Historical Quarterly 10, no. 4 (December 1931): 353-354.

  6. 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.

  7. Plate boundary deformation at the latitude of the Salton Trough - northern Gulf of California (Invited)

    Science.gov (United States)

    Stock, J. M.

    2013-12-01

    Along the Pacific-North America plate boundary zone, the segment including the southern San Andreas fault to Salton Trough and northern Gulf of California basins has been transtensional throughout its evolution, based on Pacific-North America displacement vectors calculated from the global plate circuit (900 × 20 km at N54°W since 20 Ma; 460 × 20 km at N48°W since 11 Ma). Nevertheless, active seismicity and focal mechanisms show a broad zone of plate boundary deformation within which the inferred stress regime varies locally (Yang & Hauksson 2013 GJI), and fault patterns in some regions suggest ongoing tectonic rotation. Similar behavior is inferred to have occurred in this zone over most of its history. Crustal structure in this region is constrained by surface geology, geophysical experiments (e.g., the 2011 Salton Seismic Imaging Project (SSIP), USGS Imperial Valley 1979, PACE), and interdisciplinary marine and onland studies in Mexico (e.g., NARS-Baja, Cortes, and surveys by PEMEX). Magnetic data (e.g., EMAG-2) aids in the recognition of large-scale crustal provinces and fault boundaries in regions lacking detailed geophysical surveys. Consideration of existing constraints on crustal thickness and architecture, and fault and basin evolution suggests that to reconcile geological deformation with plate motion history, the following additional factors need to be taken into account. 1) Plate boundary displacement via interacting systems of rotating blocks, coeval with slip on steep strike slip faults, and possibly related to slip on low angle extensional faults (e.g, Axen & Fletcher 1998 IGR) may be typical prior to the onset of seafloor spreading. This fault style may have accommodated up to 150 km of plate motion in the Mexican Continental Borderland and north of the Vizcaino Peninsula, likely between 12 and 15 Ma, as well as explaining younger rotations adjacent to the Gulf of California and current deformation southwest of the Salton Sea. 2) Geophysical

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

    Directory of Open Access Journals (Sweden)

    Nur Arafeh-Dalmau

    2017-05-01

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

  9. Final Environmental Assessment for Continued Personnel Recovery Training Operations Within the Gulf of Mexico WTA Moody Air Force Base, Georgia

    Science.gov (United States)

    2010-06-01

    occurring on the Eastern Yucatan Peninsula, Mexico (Marquez 1990 and TEWG 2000); and (5) a Dry Tortugas nesting subpopulation, occurring in the...islands of the Dry Tortugas , near Key West, Florida (NMFS SEFSC 2001). The recently published recovery plan for the Northwest Atlantic population of...southern Virginia); (2) the Peninsular Florida Recovery Unit (Florida/Georgia border through Pinellas County, Florida); (3) the Dry Tortugas Recovery

  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

    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.

  11. Helminths of brown bears (Ursus arctos) in the Kola Peninsula.

    Science.gov (United States)

    Bugmyrin, S V; Tirronen, K F; Panchenko, D V; Kopatz, A; Hagen, S B; Eiken, H G; Kuznetsova, A S

    2017-06-01

    We present data on the species composition of helminths in brown bears (Ursus arctos) from the Murmansk Region, Russia. The absence of any information about helminths of brown bear in the region necessitated the conduct of these studies. Samples were collected in 2014 and 2015 in the southern part of the Kola Peninsula from the White Sea coastal habitats. Annually, in the study area, 1-3 bears are legally hunted and biological samples for examination are very difficult to obtain. Therefore, we used fecal samples. We studied 93 feces and identified parasite eggs identified in 43 of them by morphometric criteria. The surveys revealed eggs of the following helminths: Dicrocoelium sp., Diphyllobothrium sp., Anoplocephalidae, Capillariidae, Baylisascaris sp., Strongylida 1, and Strongylida 2. These results represent the first reconnaissance stage, which allowed characterizing the taxonomic diversity and prevalence of parasites of brown bears of the Kola Peninsula.

  12. Border Encounters: American Cultural Politics and the U.S.-Mexico Border

    OpenAIRE

    Reimer, Jennifer Andrea

    2011-01-01

    AbstractBorder Encounters: American Cultural Politics and the U.S.-Mexico BorderbyJennifer Andrea ReimerDoctor of Philosophy in Ethnic StudiesUniversity of California, BerkeleyProfessor José David Saldívar, Co-ChairProfessor Laura E. Pérez, Co-ChairBorder Encounters: American Cultural Politics and the U.S.-Mexico Border is a transnational, interdisciplinary cultural study of the contemporary U.S.-Mexico border that argues for the critical role of the international border in the racial past, p...

  13. 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

  14. The Power of Cinema on the Korean Peninsula

    OpenAIRE

    Samyel Lee

    2015-01-01

    Abstract: The Korean peninsula is constantly in a dynamic discussion of identity and direction. For South Korean society, it is no surprise that the Korean War and the existential threat that North Korea poses loom large over its collective conscience. Although mostly disregarded within scholarly discussions in international relations, cinema has always been, and continues to be, an insightful, powerful, and transformative forum. This essay discusses the ways in which cinema as an art form ha...

  15. Marine exotic isopods from the Iberian Peninsula and nearby waters.

    Science.gov (United States)

    Martínez-Laiz, Gemma; Ros, Macarena; Guerra-García, José M

    2018-01-01

    Effective management of marine bioinvasions starts with prevention, communication among the scientific community and comprehensive updated data on the distribution ranges of exotic species. Despite being a hotspot for introduction due to numerous shipping routes converging at the Strait of Gibraltar, knowledge of marine exotics in the Iberian Peninsula is scarce, especially of abundant but small-sized and taxonomically challenging taxa such as the Order Isopoda. To fill this gap, we conducted several sampling surveys in 44 marinas and provide the first comprehensive study of marine exotic isopods from the Iberian Peninsula, the southern side of the Strait of Gibraltar (northern Africa) and the Balearic Islands. Exotic species included Ianiropsis serricaudis (first record for the Iberian Peninsula and Lusitanian marine province), Paracerceis sculpta (first record for the Alboran Sea ecoregion), Paradella dianae , Paranthura japonica (earliest record for the Iberian Peninsula) and Sphaeroma walkeri . Photographs with morphological details for identification for non-taxonomic experts are provided, their worldwide distribution is updated and patterns of invasion are discussed. We report an expansion in the distribution range of all species, especially at the Strait of Gibraltar and nearby areas. Ianiropsis serricaudis and Paranthura japonica are polyvectic, with shellfish trade and recreational boating being most probable vectors for their introduction and secondary spread. The subsequent finding of the studied species in additional marinas over the years points at recreational boating as a vector and indicates a future spread. We call for attention to reduce lags in the detection and reporting of small-size exotics, which usually remain overlooked or underestimated until the invasion process is at an advanced stage.

  16. Geochemical signatures of tephras from Quaternary Antarctic Peninsula volcanoes

    OpenAIRE

    Kraus,Stefan; Kurbatov,Andrei; Yates,Martin

    2013-01-01

    In the northern Antarctic Peninsula area, at least 12 Late Plelstocene-Holocene volcanic centers could be potential sources of tephra layers in the region. We present unique geochemical fingerprints for ten of these volcanoes using major, trace, rare earth element, and isotope data from 95 samples of tephra and other eruption products. The volcanoes have predominantly basaltic and basaltic andesitic compositions. The Nb/Y ratio proves useful to distinguish between volcanic centers located on ...

  17. Dynamical characteristics of the seasonal circulations over the Korea peninsula

    International Nuclear Information System (INIS)

    1989-10-01

    This paper reports dynamical characteristics of the seasonal circulations over the Korean peninsula. It consists of summary, research method, result, consideration and conclusion. It introduces the method of research ; characteristics of circulation over seasonal wind in Asia, characteristic of upper jet stream related cold wave and monsoon in East Asia and dynamics of pulsation and maintain of high atmospheric pressure in siberia in winter. It was reported by Korea science foundation in 1989.

  18. Wild reindeer of the Kamchatka Peninsula - past, present, and future

    Directory of Open Access Journals (Sweden)

    Vladimir Mosolov

    1996-01-01

    Full Text Available A unique subspecies of wild reindeer (Rangifer tarandus phylarchus Hollister that is endemic to the Kamchatka Peninsula has been declining in number since the 1950s due to commercial hunting, increasing industrial development and competition with domestic reindeer. The largest remaining herd of wild reindeer occurs in the Kronotsky Reserve in northeastern Kamchatka, and the reserve is now critical to the preservation of this subspecies of reindeer.

  19. Salinity and temperature variations around Peninsula Malaysia coastal waters

    International Nuclear Information System (INIS)

    Abdul Kadir Ishak; Jeremy Andy Anak Dominic; Nazrul Hizam Yusof; Mohd Rafaei Murtadza

    2004-01-01

    Vertical profiles of salinity and temperature were measured at several offshore stations along east and west coast of Peninsula Malaysia coastal waters. The measurements which covered South China Sea and Straits of Malacca were made during sampling cruises for Marine Database Project for Peninsula Malaysia, and during an IAEA regional training course for Marine Pollution Project. The results show that the water temperature is highest at the surface and minimum at bottom, while the salinity is lowest at the surface and highest at the bottom. In Malacca Straits, the highest surface water temperature was 30.6 degree C and the lowest bottom water temperature was 20.4 degree C, recorded at a station located in Andaman Sea. The same station also recorded the highest surface and bottom salinity i.e. 31.3 ppt and 34.4 ppt, respectively. For South China Sea, the maximum surface water temperature was 30.4 degree C and the minimum bottom temperature was 25.9 degree C, while the highest surface salinity was 33.2 ppt and the highest bottom salinity was 34.1 ppt. The water in South China Sea also showed some degrees of stratifications with thermocline zones located between 10-40 m water depths. In Malacca Straits, stronger thermocline develops at higher latitude, while at lower latitude the water is more readily mixed. Beside the spatial variations, the seawater temperature and salinity around Peninsula Malaysia also subjected to temporal variation as seawater. (Author)

  20. Russia and the Issues of the Korean Peninsula

    Directory of Open Access Journals (Sweden)

    George D. Toloraya

    2014-01-01

    Full Text Available The importance of Korean Peninsula in Russian foreign strategy is based on the need to preserve peace and stability in the Russia's Far East "soft underbelly" and to be a part of international efforts to solve the Korean problem, as well as to promote regional economic cooperation. In 1990-s Russia's position on the peninsula weakened, mainly because of the rupture of ties with North Korea, while relations with South Korea were reactive in nature. Rebalancing relations with the two Koreas in 2000-s increased Russia's involvement into Korean settlement, including the 6- party format. Russia/s relations with North Korea are now based on good neighborhood principle, however, they are far from idyllic as Russia disapproves of Pyongyang's behavior, especially its nuclear and missile activities. However to influence the situation more Russia should deepen its ties with the current Pyongyang leadership regardless of how irritating its behavior might be. Relations with the ROK are aimed at becoming strategic, but in reality are limited due to ROK's alliance with the USA. However South Korea has become the third most important economic partner in Asia. Russia is especially interested in three- party projects, such as Trans-Korean railroad (linked to Transsiberan transit way, gas pipeline and electricity grid. However implementation of these project is negatively influenced by the tensions in Korean peninsula. It can be solved only by multilateral efforts for comprehensive solution combining security guarantees for North Korea and its abandonment of nuclear option.

  1. Onshore and offshore apatite fission-track dating from the southern Gulf of California: Insights into the time-space evolution of the rifting

    Science.gov (United States)

    Balestrieri, Maria Laura; Ferrari, Luca; Bonini, Marco; Duque-Trujillo, Jose; Cerca, Mariano; Moratti, Giovanna; Corti, Giacomo

    2017-11-01

    We present the results of a apatite fission-track (AFT) study on intrusive rocks in the southern Gulf of California, sampled along the eastern margin of Baja California Sur (western rift margin), as well as from islands and submerged rifted blocks within the Gulf of California, and from the conjugate Mexican margin (Nayarit state). For most of the samples U-Pb zircon and 40Ar-39Ar mineral ages were already available (Duque-Trujillo et al., 2015). Coupled with the new AFT data these ages provide a more complete information on cooling after emplacement. Our samples span a wide range of ages between 5.5 ± 1.1 and 73.7 ± 5.8 Ma, and show a general spatial distribution, with late Miocene AFT ages (about 6 Ma) aligned roughly NW-SE along a narrow offshore belt, parallel to Baja California Peninsula, separating older ages on both sides. This pattern suggests that in Late Miocene, deformation due to plate transtension focused at the eastern rheological boundary of the Baja California block. Some Early Miocene AFT ages onshore Baja California could be related to plutons emplaced at shallow depths and thermal resetting associated with the onset of volcanism at 19 Ma in this part of the Peninsula. On the other hand, an early extensional event similar to that documented in the eastern Gulf cannot be ruled out in the westernmost Baja California.

  2. The roles of microbial selenate reduction and selenium sorption on selenium immobilization in littoral sediment from the hypersaline Salton Sea, California

    OpenAIRE

    Villa-Romero, Juan Fernando

    2015-01-01

    The Salton Sea in California was formed between 1905-1907 by an accident that diverted Colorado River water to the Salton Sea Basin of the Colorado desert. Since 1924 the Salton Sea serves as an agricultural drainage reservoir maintained by agricultural and municipal wastewater inputs from the Coachella and Imperial Valleys in California and the Mexicali Valley in Mexico. Today, the Salton Sea is California's largest lake by area (975 km2) and constitutes a vital habitat for more than a milli...

  3. Composition and fluxes of submarine groundwater along the Caribbean coast of the Yucatan Peninsula

    Science.gov (United States)

    Null, Kimberly A.; Knee, Karen L.; Crook, Elizabeth D.; de Sieyes, Nicholas R.; Rebolledo-Vieyra, Mario; Hernández-Terrones, Laura; Paytan, Adina

    2014-04-01

    Submarine groundwater discharge (SGD) to the coastal environment along the eastern Yucatan Peninsula, Quintana Roo, Mexico was investigated using a combination of tracer mass balances and analytical solutions. Two distinct submarine groundwater sources including water from the unconfined surficial aquifer discharging at the beach face and water from a deeper aquifer discharging nearshore through submarine springs (ojos) were identified. The groundwater of nearshore ojos was saline and significantly enriched in short-lived radium isotopes (223Ra, 224Ra) relative to the unconfined aquifer beach face groundwater. We estimated SGD from ojos using 223Ra and used a salinity mass balance to estimate the freshwater discharge at the beach face. Analytical calculations were also used to estimate wave set-up and tidally driven saline seepage into the surf zone and were compared to the salinity-based freshwater discharge estimates. Results suggest that average SGD from ojos along the Yucatan Peninsula Caribbean coast is on the order of 308 m3 d-1 m-1 and varies between sampling regions. Higher discharge was observed in the southern regions (568 m3 d-1 m-1) compared to the north (48 m3 d-1 m-1). Discharge at the beach face was in the range of 3.3-8.5 m3 d-1 m-1 for freshwater and 2.7 m3 d-1 m-1 for saline water based on the salinity mass balance and wave- and tidally-driven discharge, respectively. Although discharge from the ojos was larger in volume than discharge from the unconfined aquifer at the beach face, dissolved inorganic nitrogen (DIN) was significantly higher in beach groundwater; thus, discharge of this unconfined beach aquifer groundwater contributed significantly to total DIN loading to the coast. DIN fluxes were up to 9.9 mol d-1 m-1 from ojos and 2.1 mol d-1 m-1 from beach discharge and varied regionally along the 500 km coastline sampled. These results demonstrate the importance of considering the beach zone as a significant nutrient source to coastal waters

  4. [Aging in Mexico].

    Science.gov (United States)

    Contreras de Lehr, E

    1986-01-01

    Demographic social and economic aspects of the situation of the elderly in Mexico are described with special emphasis upon education programmes and types of care in nursing homes. Considering the future trends of an increase in Mexico's elderly population, the author calls for more efforts in research and training in the field of gerontology. First results in this area are reported.

  5. Spain: Europe's California.

    Science.gov (United States)

    Wilvert, Calvin

    1994-01-01

    Contends that, as Spain integrates into the European Economic Community, it is considered to be Europe's California. Asserts that making regional comparisons between California and Spain can be an effective teaching method. Provides comparisons in such areas as agriculture and tourism. (CFR)

  6. Strangers in Paradise: The Life and Literature of Foreign-Born Women in California.

    Science.gov (United States)

    Friedman, Adele C.

    This paper presents student research from a class project on the Life and Literature of Foreign-Born Women in California. It examines the role of these women in agriculture, the arts, and political and economic life. Specific accounts of women from Russia, Poland, France, and Mexico are given. Others mentioned include those women born in America…

  7. Differential reproductive maturity between allopatric populations of Homalodisca vitripennis (Hemiptera: Cicadellidae) in California

    Science.gov (United States)

    Homalodisca vitripennis (Germar) is native to southeastern U.S. and northeastern Mexico. It was detected in southern California in the late 1980s and in the San Joaquin Valley in 1999, where it transmits the bacterium Xylella fastidiosa Wells et al. to grapevines and other crops. The reproductive ...

  8. Final Environmental Assessment: Western Range Command Transmit Site Vandenberg Air Force Base, California

    Science.gov (United States)

    2005-01-20

    between the U.S. and Canada, Japan, Mexico and the former Soviet Union for the protection of migratory birds. Under the Act, taking, killing or...Song sparrow I Northern mockingbird I Brown-headed cowbird I Fox sparrow !Lazuli bunting !California towhee !Spotted towhee IBushtit !Black

  9. California Institute for Water Resources - California Institute for Water

    Science.gov (United States)

    Resources Skip to Content Menu California Institute for Water Resources Share Print Site Map Resources Publications Keep in Touch QUICK LINKS Our Blog: The Confluence Drought & Water Information University of California California Institute for Water Resources California Institute for Water Resources

  10. 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...

  11. An annotated checklist of the Chilopoda and Diplopoda (Myriapoda) of the Abrau Peninsula, northwestern Caucasus, Russia

    Science.gov (United States)

    Semenyuk, Irina I.; Tuf, Ivan H.

    2016-01-01

    Abstract Background The Abrau Peninsula is located in northwestern Caucasus between the cities of Novorossiysk and Anapa, Krasnodar Province, Russia. This paper contains an annotated checklist of the Chilopoda and Diplopoda inhabiting the Abrau Peninsula. New information The fauna of the Abrau Peninsula comprises 17 centipede (4 orders) and 16 millipede (6 orders) species. Henia taurica, hitherto known only from the Crimea, has now been reported from several localities in the studied region. The study also reveals two possibly new millipede species. Statistical analyses showed that habitat preferences of myriapod species within the Abrau Peninsula are caused by species geographic distribution pattern and microbiotope preferences. PMID:27346949

  12. Geothermal development of the Salton Trough, California and Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, T.D.; Howard, J.H.; Lande, D.P. (eds.)

    1975-04-01

    A geological description is given of the Salton Trought followed by a chronological history of attempts to exploit the area's geothermal resources. In addition, detailed descriptions are given of all ongoing geothermal projects in the area and the organizations conducting them.

  13. Mexico's nuclear paradox

    International Nuclear Information System (INIS)

    Redclift, M.

    1989-01-01

    Opposition to Mexico's nuclear reactors at Laguna Verde has grown during the last two years. The nuclear programme is blamed for being expensive and wasteful, and the decision to rely on the USA contradicts Mexico's espoused policy of greater independence from the USA. The way in which petroleum revenues were used to precipitate the nuclear option is compared with the lack of urgency given to renewable energy and greater energy efficiency. From a social and environmental perspective, as well as an economic one, Mexico's nuclear programme is judged expensive and irrelevant. (author)

  14. Predictability of the California Current System

    Science.gov (United States)

    Miller, Arthur J.; Chereskin, T.; Cornuelle, B. D.; Niiler, P. P.; Moisan, J. R.; Lindstrom, Eric (Technical Monitor)

    2001-01-01

    The physical and biological oceanography of the Southern California Bight (SCB), a highly productive subregion of the California Current System (CCS) that extends from Point Conception, California, south to Ensenada, Mexico, continues to be extensively studied. For example, the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program has sampled this region for over 50 years, providing an unparalleled time series of physical and biological data. However, our understanding of what physical processes control the large-scale and mesoscale variations in these properties is incomplete. In particular, the non-synoptic and relatively coarse spatial sampling (70km) of the hydrographic grid does not completely resolve the mesoscale eddy field (Figure 1a). Moreover, these unresolved physical variations exert a dominant influence on the evolution of the ecosystem. In recent years, additional datasets that partially sample the SCB have become available. Acoustic Doppler Current Profiler (ADCP) measurements, which now sample upper-ocean velocity between stations, and sea level observations along TOPEX tracks give a more complete picture of the mesoscale variability. However, both TOPEX and ADCP are well-sampled only along the cruise or orbit tracks and coarsely sampled in time and between tracks. Surface Lagrangian drifters also sample the region, although irregularly in time and space. SeaWiFS provides estimates of upper-ocean chlorophyll-a (chl-alpha), usually giving nearly complete coverage for week-long intervals, depending on cloud coverage. Historical ocean color data from the Coastal Zone Color Scanner (CZCS) has been used extensively to determine phytoplankton patterns and variability, characterize the primary production across the SCB coastal fronts, and describe the seasonal and interannual variability in pigment concentrations. As in CalCOFI, these studies described much of the observed structures and their variability over relatively large space and

  15. The Permanent GPS Network In The Iberian Peninsula

    Science.gov (United States)

    Fernandes, R. M. S.; Bastos, L.; Ambrosius, B. A. C.; Noomen, R.

    In recent years, the number of permanent GPS sites in the Iberia Peninsula has in- creased significantly: in the beginning of 1996 there were just 2 sites with publicly available data. This number had risen to 15 by the end of 1999, and recently (end of 2001), it has reached 18. For many sites, the observation time-span is already suffi- ciently long to derive a reliable estimate of the motion of the stations. Combined with the relatively good geographical distribution of the sites, this velocity field contains unique information to study the tectonics of the Iberian Peninsula, both internally and with respect to the rest of Europe. In the framework of a combined DEOS-AOUP research project called GIN (GPS Iberian Network), the data of all available GPS sites in the region (including some in North Africa, the Azores Archipelago and France) are being processed on a daily basis since the middle of 2000 (with backward processing extending to January 1996). Following this project, DEOS became an official LAC (Local Analysis Centre) of EU- REF in the beginning of 2001. The DEOS weekly solutions are included in the official EUREF analysis chain, resulting in weekly coordinate solutions for the entire EU- REF network. The two solutions (GIN &EUREF) are computed by the DEOS-AOUP group using the same software, but applying different strategies. The differences in the solutions are analysed in order to pinpoint data problems and processing errors. Furthermore, the GIN velocity field is compared with the one derived from the offi- cial EUREF solution. Special attention is paid to the different procedures to link the solutions into a unified reference frame. Finally, this paper presents a preliminary interpretation of the contemporary tectonics of the Iberian Peninsula based on the derived velocity fields. There is evidence of significant intra-plate deformation in the Iberia region and there are indications that the Iberian block exhibits a differential motion with respect to

  16. Tephra compositions from Late Quaternary volcanoes around the Antarctic Peninsula

    Science.gov (United States)

    Kraus, S.

    2009-12-01

    Crustal extension and rifting processes opened the Bransfield Strait between the South Shetland Islands and the Antarctic Peninsula during the last 4 Ma. Similar processes on the Peninsula's eastern side are responsible for volcanism along Larsen Rift. There are at least 11 volcanic centers with known or suspected Late Pleistocene / Holocene explosive activity (Fig. 1). Fieldwork was carried out on the islands Deception, Penguin, Bridgeman and Paulet, moreover at Melville Peak (King George Is.) and Rezen Peak (Livingston Is.). Of special importance is the second ever reported visit and sampling at Sail Rock, and the work on never before visited outcrops on the northern slopes and at the summit of Cape Purvis volcano (Fig. 1). The new bulk tephra ICP-MS geochemical data provide a reliable framework to distinguish the individual volcanic centers from each other. According to their Mg-number, Melville Peak and Penguin Island represent the most primitive magma source. Nb/Y ratios higher than 0.67 in combination with elevated Th/Yb and Ta/Yb ratios and strongly enriched LREE seem to be diagnostic to distinguish the volcanoes located along the Larsen Rift from those associated with Bransfield Rift. Sr/Y ratios discriminate between the individual Larsen Rift volcanoes, Paulet Island showing considerably higher values than Cape Purvis volcano. Along Bransfield Rift, Bridgeman Island and Melville Peak have notably lower Nb/Y and much higher Th/Nb than Deception Island, Penguin Island and Sail Rock. The latter displays almost double the Th/Yb ratio as compared to Deception Island, and also much higher LREE enrichment but extraordinarily low Ba/Th, discriminating it from Penguin Island. Such extremely low Ba/Th ratios are also typical for Melville Peak, but for none of the other volcanoes. Penguin Island has almost double the Ba/Th and Sr/Y ratios higher than any other investigated volcano. Whereas the volcanoes located in the northern part of Bransfield Strait have Zr

  17. 222Rn in the Antarctic Peninsula during 1986

    International Nuclear Information System (INIS)

    Pereira, E.B.; Setzer, A.W.; Cavalcanti, I.F.A.

    1988-01-01

    222 Rn was continuously measured at the Brazilian Antarctic Station (62 0 S, 58 0 W) during the year of 1986. Baseline radon concentration averaged 0.02 Bq.m -3 with surges peaking 0.4 Bq.m -3 . The data exhibited a characteristic periodicity of about 25 days and a strong positive association with short term fluctuations of atmospheric temperature. No seasonal variations of radon were observed. Interpretation of the radon surges with reference to synoptic charts and weather satellite pictures showed that the continental influence of radon at the Antarctic Peninsula is very small and comes only from the tip of the South American cone. (author)

  18. New and interesting Orthoptera from the Arabian Peninsula and Socotra

    Directory of Open Access Journals (Sweden)

    Bruno Massa

    2017-06-01

    Full Text Available This paper reports on some interesting taxa recently found in the Arabian Peninsula and the island of Socotra. Among them is a new species of brachypterous grasshopper Sphodromerus carapezzanus sp. n. (Acrididae: Calliptaminae, described from an isolated area in Dhofar (Oman. A female Heteracris hemiptera (Uvarov, 1935 (Acrididae: Eyprepocnemidinae is reported, with morphological characters which do not fully comply with those of any known subspecies. Two species, hitherto rarely documented, are also reported, Phaneroptila insularis Uvarov, 1957 (Tettigoniidae: Phaneropterinae from Socotra and Cataloipus thomasi Uvarov, 1933 (Acrididae: Eyprepocnemidinae from Oman. Pycnodictya dentata Krauss, 1902 (Acrididae: Oedipodinae is reported from Saudi Arabia, constituting a new record for the country.

  19. [Natural focus of tularemia on the Kerchen peninsula (Crimea)].

    Science.gov (United States)

    Golkovskiĭ, G M; Mitsevich, G F; Khaĭtovich, A B; Alekseev, E V; Korchevskiĭ, P G

    1981-10-01

    The study confirming the existence of the steppe-type natural focus of tularemia on the Kerch peninsula has been carried out. For the first time the cultures of Francisella tularensis have been isolated. Voles and house mice play the main role in the circulation of the infection. The parasitic system comprises ticks (Ixodidae and Nyalomma), as well as some species of fleas. In carrying out erizootological studies for detecting tularemia in the Crimea the use of low temperature (0 degrees C) for the preservation of specimens and preparations in recommended.

  20. The Hel Peninsula – Smart Grid Pilot Project

    Directory of Open Access Journals (Sweden)

    Sławomir Noske

    2014-12-01

    Full Text Available The paper presents the scope and results of engineering, and the scope of Smart Grid deployment in the Hel Peninsula. The following functionalities will be described: Fault Detection, Isolation & Recovery – FDIR function, Integrated Volt/Var Control (IVVC function, advanced supervision of LV grid, including distributed energy resources. The paper contains implementation results and research findings, as well as preliminary cost-benefit analysis of the project. Moreover, since Smart Metering and Smart Grid projects are being deployed in the same region – the Hel Peninisula – the benefit achieved by merging the two projects will be explained.

  1. Permian Tethyan Fusulinina from the Kenai Peninsula, Alaska

    Science.gov (United States)

    Stevens, C.H.; Davydov, V.I.; Bradley, D.

    1997-01-01

    Two samples from a large, allochthonous limestone block in the McHugh Complex of the Chugach terrane on the Kenai Peninsula, Alaska, contain species of 12 genera of Permian Fusulinina including Abadehella, Kahlerina, Pseudokahlerina?, Nankinella, Codonofusiella, Dunbarula, Parafusulina?, Chusenella, Verbeekina, Pseudodoliolina, Metadoliolina?, Sumatrina?, and Yabeina, as well as several other foraminiferans and one alga. The assemblage of fusulinids is characteristically Tethyan, belonging to the Yabeina archaica zone of early Midian (late Wordian) age. Similar faunas are known from the Pamirs, Transcaucasia, and Japan, as well as from allochthonous terranes in British Columbia, northwestern Washington, and Koryakia in eastern Siberia.

  2. Upper Mantle Discontinuities Underneath Central and Southern Mexico

    Science.gov (United States)

    Perez-Campos, X.; Clayton, R. W.

    2011-12-01

    Central and southern Mexico are affected by the subduction of Cocos plate beneath North American plate. The MesoAmerican Subduction Experiment (MASE) and the Veracruz-Oaxaca (VEOX) project have mapped the geometry of the Cocos slab. It is characterized in central Mexico by a shallow horizontal geometry up to ~300 km from the trench, then it dives steeply (70°) into the mantle, to its apparent end at 500 km depth. In contrast, some 400 km to the south, the slab subducts smoothly, with a dip angle of ~26° to a depth of 150 km. We use receiver functions from teleseismic events, recorded at stations from MASE, VEOX, and the Servicio Sismológico Nacional (SSN, Mexican National Seismological Service) to map the upper mantle discontinuities and properties of the transition zone in central and southern Mexico. We also use data from the Mapping the Rivera Subduction Zone (MARS) Experiment to get a complete picture of the subduction regime in central Mexico and compare the mantle transition zone in a slab tear regime. The 410 discontinuity shows significant variation in topography in central Mexico, particularly where the slab is expected to reach such depth. The 660 discontinuity shows a smoother topography, indicating that the slab does not penetrate this far down. The results will be compared with a ridge regime in the Gulf of California.

  3. Silencing criticism in Mexico

    Directory of Open Access Journals (Sweden)

    Ximena Suárez

    2017-10-01

    Full Text Available Journalists and human rights defenders in Mexico are being attacked in an attempt to silence their criticism. Many are forced to flee or risk being assassinated. The consequences are both personal and of wider social significance.

  4. New Mexico State Boundary

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The TIGER/Line Shapefiles are an extract of selected geographic and cartographic information from the Census MAF/TIGER database. The Census MAF/TIGER database...

  5. New Mexico Federal Lands

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer consists of federally owned or administered lands of the United States, Puerto Rico, and the U.S. Virgin Islands. Only areas of 640 acres or more are...

  6. New Mexico Mountain Ranges

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The Geographic Names Information System (GNIS) actively seeks data from and partnerships with Government agencies at all levels and other interested organizations....

  7. Mexico - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Mexican Surface Daily Observations taken at 94 observatories located throughout Mexico, beginning in 1872 and going up through 1981. The data resided on paper...

  8. Jojoba, Simmondsia chinensis: an alternative for the economic development of the arid and semi arid zones of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sepulveda Betancourt, J I; Parra Hake, H

    1976-01-01

    Simmondsia chinensis is, in spite of its name, a species indigenous to SE California and Arizona (US) and to the states of Sonora, Baja California Norte and Baja California Sur in Mexico. It is a shrubby forage plant that reaches a height of 1.5 m and can grow under conditions of extreme drought and high salinity provided that frost does not occur; it is thus suitable for many arid and semi-arid parts of Mexico as well as other similar regions of the world. The seed, traditionally associated with medicinal properties, was found in 1933 to produce a liquid wax with properties similar to those of sperm-whale oil, an increasingly scarce product used for the lubrication of machinery run at high temperatures and speeds. Some other uses for S. chinensis wax are listed, and silvicultural research on the species in progress in Baja California Sur and elsewhere is briefly described.

  9. Jojoba, Simmondsia chinensis. An alternative for the economic development of the arid and semi arid zones of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sepulveda Betancourt, J I; Parra Hake, H

    1976-01-01

    S. chinensis is, in spite of its name, a species indigenous to SE California and Arizona (US) and to the states of Sonora, Baja California Norte and Baja California Sur in Mexico. It is a shrubby forage plant that reaches a height of 1.5 m and can grow under conditions of extreme drought and high salinity provided that frost does not occur; it is thus suitable for many arid and semi-arid parts of Mexico as well as other similar regions of the world. The seed, traditionally associated with medicinal properties, was found in 1933 to produce a liquid wax with properties similar to those of sperm-whale oil, an increasingly scarce product used for the lubrication of machinery run at high temperatures and speeds. Some other uses for S. chinensis wax are listed, and silvicultural research on the species in progress in Baja California Sur and elsewhere is briefly described.

  10. University of Southern California

    Data.gov (United States)

    Federal Laboratory Consortium — The focus of the University of Southern California (USC) Children''s Environmental Health Center is to develop a better understanding of how host susceptibility and...

  11. 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 digital...

  12. 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...

  13. Kelp distribution off California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set delineates kelp beds (Nereocystis leutkeana and Macrocystis spp.) along the Pacific Coast of California. Multiple years of kelp mapping data for the...

  14. 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...

  15. California Watershed Hydrologic Units

    Data.gov (United States)

    California Natural Resource Agency — 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 a...

  16. Doing Business in Mexico

    OpenAIRE

    Zimmermann, Thomas A.

    2002-01-01

    On 1 July 2001, a far-reaching free trade agreement between the EFTA States and Mexico entered into force. ”Doing Business in Mexico” provides targeted assistance to Swiss Small and Medium-Sized Enterprises (SME) that wish to tap the potential of Mexico as both an export destination and investment location. This comprehensive guide contains information and advice on market research, market entry, and investment in this fascinating country. Part I introduces the reader to this fascinating ...

  17. Mexico tornado climatology

    Directory of Open Access Journals (Sweden)

    Manuel Macías Medrano

    2013-07-01

    Full Text Available A brief introduction on some features of tornado database in Mexico is exposed showing its substantive criteria. We resent a brief analysis about main Mexican tornadoes´ characteristics, based on data collected between 2000 to 2010, talking about spatial and temporal expressions (historical, seasonal and horary in order to show the importance of it destruction capacity and also the people´s vulnerability in Mexico.

  18. Occupational health in Mexico.

    Science.gov (United States)

    Carreón, Tania; Santos-Burgoa, Carlos; Baron, Sherry; Hernández, Sendy

    2002-01-01

    The authors discuss the maquiladoras and child labor, and offer an overview of the history of occupational safety and health in Mexico that covers laws and regulations, social security, unions, and enforcement of legislation. The organization and structure of the various institutions responsible for occupational safety and health (OSH), as well as administrative procedures, are described. This article concludes with a list of the new challenges for OSH in Mexico.

  19. Migration from Mexico to the United States: A high-speed cancer transition.

    Science.gov (United States)

    Pinheiro, Paulo S; Callahan, Karen E; Stern, Mariana C; de Vries, Esther

    2018-02-01

    Differences and similarities in cancer patterns between the country of Mexico and the United States' Mexican population, 11% of the entire US population, have not been studied. Mortality data from 2008 to 2012 in Mexico and California were analyzed and compared for causes of cancer death among adult and pediatric populations, using standard techniques and negative binomial regression. A total of 380,227 cancer deaths from Mexico and California were included. Mexican Americans had 49% and 13% higher mortality than their counterparts in Mexico among males and females, respectively. For Mexican Immigrants in the US, overall cancer mortality was similar to Mexico, their country of birth, but all-cancers-combined rates mask wide variation by specific cancer site. The most extreme results were recorded when comparing Mexican Americans to Mexicans in Mexico: with mortality rate ratios ranging from 2.72 (95% CI: 2.44-3.03) for colorectal cancer in males to 0.28 (95% CI: 0.24-0.33) for cervical cancer in females. These findings further reinforce the preeminent role that the environment, in its multiple aspects, has on cancer. Overall, mortality from obesity and tobacco-related cancers was higher among Mexican origin populations in the US compared to Mexico, suggesting a higher risk for these cancers, while mortality from prostate, stomach, and especially cervical and pediatric cancers was markedly higher in Mexico. Among children, brain cancer and neuroblastoma patterns suggest an environmental role in the etiology of these malignancies as well. Partnered research between the US and Mexico for cancer studies is warranted. © 2017 UICC.

  20. The Sac Actun System, Quintana Roo, Mexico

    International Nuclear Information System (INIS)

    Kambesis, P. N.; Coke, J. G.

    2016-01-01

    The Sac Actun system, located in northeast Quintana Roo, Mexico, is among the most extensive underwater cave systems located along the Caribbean coast of the Yucatan Peninsula. The cave is composed of linear phreatic conduits that have two forms. The coastal sections of the Sac Actun system are characterized by low horizontal tunnels that form mazes paralleling the coast and rudimentary conduits broken by fracture-controlled rooms. Inland passages are fault/fracture controlled, have a linear, anastomotic configuration, and align perpendicular to the coast. Access to the cave system is gained through cenotes which are the portals into the Yucatan underwater cave systems. The occurrence of drowned speleothems in many parts of the cave system, and sections of air-filled upper level passages are indicative of major fluctuations in sea level. The Sac Actun system is part of one of the most extensive and significant eogenetic karst aquifers in the world. The development of the Sac Actun system, as well as the many other caves systems along the Yucatan Caribbean Coast is controlled by the coastal hydrologic regime, driven by glacio-eustatics, and influenced by stratigraphic and structural controls. The karstic permeability of the aquifer makes it and the Sac Actun system vulnerable to the anthropogenic impacts of increased population growth, quarries, and infrastructure development associated with the burgeoning tourist industry that dominates land use in the region. (Author)

  1. Interanual variability os solar radiation in Peninsula Iberica; Variabilidad interanual de la radiacion solar en la Peninsula Iberica

    Energy Technology Data Exchange (ETDEWEB)

    Pozo-Vazquez, D.; Tovar-Pescador, J.; Gamiz-Fortis, S.; Esteban-Parra, M.; Castro-Diez, Y.

    2004-07-01

    The NAO climatic phenomenon is the main responsible for the interanual cloud cover variability in Europe. We explore the relationship between the NAO and the solar radiation spatio-temporal variability in Europe during winter. Measured monthly sums of sunshine duration and short-wave downward solar flux reanalysis data have been used. Correlation analysis between the NAO index and the measured sunshine duration shows a maximum positive value (+0.75) over the Iberian Peninsula. Accordingly, solar radiation in this area undergoes an interanual variability that can reach up to 30%, with the derived consequences for a reliable solar energy resources evaluation. (Author)

  2. Radiation dates of holocene shorelines in Peninsula Malaysia

    International Nuclear Information System (INIS)

    Tjia, H.D.; Kigoshi, K.

    1977-01-01

    Fifteen newly determined radiocarbon dates indicate the presence of former shorelines up to 3 meters above present high tide level in the tectonically stable Peninsula of Malaysia. The sea level indicators consist of oysters in growth position (9 samples), molluscs in beach deposits (2), corals in growth position (3), and beachrock (1). In the Peninsula living oysters occur up to or slightly above high tide, modern beach deposits may occur as high as 1.5 meters above high tide, and corals live up to low tide level. The literature shows that high tide, and corals live up to low tide level. The literature shows that beachrock marks intertidal zones. Combined with seven previously published ages of raised shorelines in the region, strong evidence is presented for one or more high Holocene, eustatic sea level stands in the continental part of Southeast Asia. Periods of high sea levels occur between 2500 and 2900 yr BP, and between 4200 and 5700 yr BP. There is also some indication of high sea level between 8300 and 9500 yr BP. (author)

  3. How to realize a nuclear-free Korean peninsula

    International Nuclear Information System (INIS)

    Yun, Duk-min

    1992-01-01

    It is certain that, unless the nuclear issue is solved, there can be no progress in inter-Korean relations. To this end, comprehensive and intrusive mutual inspections of any suspicious sites, as well as IAEA inspections, should certainly be implemented. Once international and bilateral arrangements for nuclear inspection are agreed and implemented to the satisfaction of the parties concerned, this will not only solve the problem of nuclear proliferation, but also lay a firm foundation for greater confidence-building measures on the Korean peninsula. This could also be a valuable example for future arms control in Korea. However, even mutual inspection between the two Koreas cannot necessarily guarantee a nuclear-free Korea. The most effective way to ensure the denuclearization of Korea may be to remove elements that the two Koreas perceive as incentives to go nuclear, in parallel with operating a tight and stable verification regime based on mutual and international inspections. Since the major reasons to go nuclear in Korea are military threats and mutual distrust between the two Koreas, no efforts should be spared to rectify these situations. Therefore, confidence- and security-building measures, including full-scale arms control, must be carried out in order to realize and preserve a nuclear-free Korea. In the long run, the greatest contribution to reducing the threat of nuclear proliferation in the Korean peninsula will be through improving overall relations between South and North Korea

  4. Economy Aspect for Nuclear Desalination Selection in Muria Peninsula

    International Nuclear Information System (INIS)

    Sudi, Ariyanto; Alimah, Siti

    2011-01-01

    An assessment of economy aspect for nuclear desalination selection has been carried out. This study compares the costs of water production for the Multi Stage Flash Distillation (MSF), Multi Effect Distillation (MED) and Reverse Osmosis (RO) desalination process coupled to PWR. Economic analysis of water cost are performed using the DEEP-3.1. The results of the performed case study of Muria Peninsula showed that the water cost to desalination process coupled with PWR nuclear power plant (at 5% interest rate, 2750 m 3 /day capacity, 28 o C temperature, 28.700 ppm TDS) with MSF plant is the highest (1.353 $/m 3 ), compared to 0.885 $/m 3 and 0.791 $/m 3 with the MED and RO plants respectively. As for MSF process, water cost by RO are also sensitive to variables, such as the interest rate, temperature and total salinity. However, MED process is sensitive to interest rate and temperature based on the economic aspect. MSF and MED plants produce a high-quality product water with a range of 1.0 - 50 ppm TDS, while RO plants produce product water of 200 - 500 ppm TDS. Water requirements for reactor coolant system in PWR type is about 1 ppm. Based on economic aspect and water requirements for reactor coolant system in PWR type, so co-generation of PWR and MED may be a favourable option for being applied in Muria Peninsula. (author)

  5. Economic Aspect for Nuclear Desalination Selection in Muria Peninsula

    International Nuclear Information System (INIS)

    Sudi, Ariyanto; Alimah, Siti

    2011-01-01

    An assessment of economy aspect for nuclear desalination selection has been carried out. This study compares the costs of water production for the Multi Stage Flash Distillation (MSF), Multi Effect Distillation (MED) and Reverse Osmosis (RO) desalination process coupled to PWR. Economic analysis of water cost are performed using the DEEP-3.1. The results of the performed case study of Muria Peninsula showed that the water cost to desalination process coupled with PWR nuclear power plant (at 5% interest rate, 2750 m 3 /day capacity, 28 o C temperature, 28.700 ppm TDS) with MSF plant is the highest (1.353 $/m 3 ), compared to 0.885 $/m 3 and 0.791 $/m 3 with the MED and RO plants respectively. As for MSF process, water cost by RO are also sensitive to variables, such as the interest rate, temperature and total salinity. However, MED process is sensitive to interest rate and temperature based on the economic aspect. MSF and MED plants produce a high-quality product water with a range of 1.0 - 50 ppm TDS, while RO plants produce product water of 200 - 500 ppm TDS. Water requirements for reactor coolant system in PWR type is about 1 ppm. Based on economic aspect and water requirements for reactor coolant system in PWR type, so co-generation of PWR and MED may be a favourable option for being applied in Muria Peninsula. (author)

  6. 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.

  7. Regional-scale airborne electromagnetic surveying of the Yucatan karst aquifer (Mexico): geological and hydrogeological interpretation

    DEFF Research Database (Denmark)

    Gondwe, Bibi Ruth Neuman; Ottowitz, David; Supper, Robert

    2012-01-01

    -spectral remote sensing imagery, shuttle radar topography data and frequency-domain airborne electromagnetic (AEM) survey data were used to map karst-aquifer structure on the Yucatan Peninsula, Mexico. Anomalous AEM responses correlated with topographic features and anomalous spectral reflectance of the terrain...... as ejecta from the Chicxulub impact (Cretaceous/Paleogene boundary), based on similar resistivity signatures found in borehole logs. Due to limited sensitivity of the AEM survey, the subsurface configuration beneath the low-resistivity layer could not be unambiguously determined. AEM measurements combined...

  8. Environmental injustice along the US-Mexico border: residential proximity to industrial parks in Tijuana, Mexico

    Science.gov (United States)

    Grineski, Sara E.; Collins, Timothy W.; de Lourdes Romo Aguilar, María

    2015-09-01

    Research in the Global North (e.g., US, Europe) has revealed robust patterns of environmental injustice whereby low income and minority residents face exposure to industrial hazards in their neighborhoods. A small body of research suggests that patterns of environmental injustice may diverge between the Global North and South due to differing urban development trajectories. This study uses quantitative environmental justice methods to examine spatial relationships between residential socio-demographics and industrial parks in Tijuana, Baja California Norte, Mexico using 2010 census data for Tijuana’s 401 neighborhoods and municipality-provided locations of industrial parks in the city. Results of spatial lag regression models reveal that formal development is significantly associated with industrial park density, and it accounts for the significant effect of higher socioeconomic status (measured using mean education) on greater industrial density. Higher proportions of female-headed households are also significantly associated with industrial park density, while higher proportions of children and recent migrants are not. The formal development findings align with other studies in Mexico and point to the importance of urban development trajectories in shaping patterns of environmental injustice. The risks for female-headed households are novel in the Mexican context. One potential explanation is that women factory workers live near their places of employment. A second, albeit counterintuitive explanation, is the relative economic advantage experienced by female-headed households in Mexico.

  9. Velázquez en el Purgatorio: los días y los trabajos de un científico en California

    Directory of Open Access Journals (Sweden)

    Bernabéu Albert, Salvador

    2010-04-01

    Full Text Available While the Creole scientist, Velázquez de León, was pursuing the projects of a visitor from Malaga, José de Gálvez, he absented himself from the University of Mexico and spent two years in the distant peninsula of California. The study of this little-known episode in his life shows us the diversity and complexity of social relations in one of the most remote places in the colony. Velázquez failed in his attempts to improve local mining and in his efforts as right-hand man to the visitor, but he wrote several very interesting descriptions and helped to measure the Transit of Venus from his residence in Santa Ana. His fondness for cards, parties and women will help to show the human side of a figure who is too often typecast in laboratories, chapels and respectable learned institutions.

    Siguiendo los proyectos del visitador malagueño José de Gálvez, el científico criollo Velázquez de León se ausentó de la Universidad de México y pasó dos años en la lejana península de California. El estudio de este episodio poco conocido de su vida nos revela la diversidad y complejidad de las relaciones sociales en uno de los lugares más remotos de la colonia. Velázquez fracasó en sus intentos por mejorar la minería local y en sus medidas como lugarteniente del visitador, pero escribió varias descripciones de gran interés y ayudó a medir el Paso de Venus desde su residencia de Santa Ana. Su afición a las cartas, a las fiestas y a las mujeres servirá para humanizar una figura demasiado encasillada en laboratorios, oratorios y respetables instituciones ilustradas.

  10. New Mexico Property Tax Districts

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This layer represents boundaries for New Mexico tax district "OUT" categories and incorporated/municipal "IN" categories as identified on the "Certificate of Tax...

  11. New Mexico State Forestry Districts

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset contains boundaries of the New Mexico Forestry Districts, plus the names of the district offices. It is in a vector digital structure digitized from a...

  12. HSIP Hospitals in New Mexico

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Hospitals in New Mexico The term "hospital" ... means an institution which- (1) is primarily engaged in providing, by or under the supervision of physicians, to...

  13. Private Schools, California, 2009, California Department of Education

    Data.gov (United States)

    U.S. Environmental Protection Agency — California law (California Education Code Section 33190) requires private schools offering or conducting a full-time elementary or secondary level day school for...

  14. The California Hazards Institute

    Science.gov (United States)

    Rundle, J. B.; Kellogg, L. H.; Turcotte, D. L.

    2006-12-01

    California's abundant resources are linked with its natural hazards. Earthquakes, landslides, wildfires, floods, tsunamis, volcanic eruptions, severe storms, fires, and droughts afflict the state regularly. These events have the potential to become great disasters, like the San Francisco earthquake and fire of 1906, that overwhelm the capacity of society to respond. At such times, the fabric of civic life is frayed, political leadership is tested, economic losses can dwarf available resources, and full recovery can take decades. A patchwork of Federal, state and local programs are in place to address individual hazards, but California lacks effective coordination to forecast, prevent, prepare for, mitigate, respond to, and recover from, the harmful effects of natural disasters. Moreover, we do not know enough about the frequency, size, time, or locations where they may strike, nor about how the natural environment and man-made structures would respond. As California's population grows and becomes more interdependent, even moderate events have the potential to trigger catastrophes. Natural hazards need not become natural disasters if they are addressed proactively and effectively, rather than reactively. The University of California, with 10 campuses distributed across the state, has world-class faculty and students engaged in research and education in all fields of direct relevance to hazards. For that reason, the UC can become a world leader in anticipating and managing natural hazards in order to prevent loss of life and property and degradation of environmental quality. The University of California, Office of the President, has therefore established a new system-wide Multicampus Research Project, the California Hazards Institute (CHI), as a mechanism to research innovative, effective solutions for California. The CHI will build on the rich intellectual capital and expertise of the Golden State to provide the best available science, knowledge and tools for

  15. Life histories predict genetic diversity and population structure within three species of octopus targeted by small-scale fisheries in Northwest Mexico

    Science.gov (United States)

    Ceballos-Vázquez, Bertha P.; Arellano-Martínez, Marcial; García-Rodríguez, Francisco J.; Culver, Melanie; Reyes-Bonilla, Hector

    2018-01-01

    The fishery for octopus in Northwest Mexico has increased to over 2,000 tons annually, but to date the specific composition of the catch has been ignored. With at least three main species targeted by artisanal fisheries in the region with distinct life histories, the lack of basic biological information about the distribution, metapopulation size and structure of each species could impede effective fisheries management to avoid overexploitation. We tested if different life histories of three species of octopus could help predict observed patterns of genetic diversity, population dynamics, structure and connectivity and how this information could be relevant to the sustainable management of the fishery. We sequenced two mitochondrial genes and genotyped seven nuclear microsatellite loci to identify the distribution of each species in 20 locations from the Gulf of California and the west coast of the Baja California peninsula. We tested five hypotheses derived from population genetic theory based on differences in the fecundity and dispersal potential for each species. We discovered that Octopus bimaculoides with low fecundity and direct development (without a planktonic phase) had lower average effective population size and genetic diversity, but higher levels of kinship, population structure, and richness of private alleles, than the other two species. These features indicated limited dispersal and high local recruitment. In contrast, O. bimaculatus and O. hubbsorum with higher fecundity and planktonic phase as paralarvae had higher effective population size and genetic diversity, and overall lower kinship and population structure than O. bimaculoides. These observations supported higher levels of gene flow over a larger geographical scale. O. bimaculatus with the longest planktonic paralarval duration and therefore larger dispersal potential had differences in the calculated parameters possibly associated with increased connectivity. We propose O

  16. Earthquake Swarm in Armutlu Peninsula, Eastern Marmara Region, Turkey

    Science.gov (United States)

    Yavuz, Evrim; Çaka, Deniz; Tunç, Berna; Serkan Irmak, T.; Woith, Heiko; Cesca, Simone; Lühr, Birger-Gottfried; Barış, Şerif

    2015-04-01

    The most active fault system of Turkey is North Anatolian Fault Zone and caused two large earthquakes in 1999. These two earthquakes affected the eastern Marmara region destructively. Unbroken part of the North Anatolian Fault Zone crosses north of Armutlu Peninsula on east-west direction. This branch has been also located quite close to Istanbul known as a megacity with its high population, economic and social aspects. A new cluster of microseismic activity occurred in the direct vicinity southeastern of the Yalova Termal area. Activity started on August 2, 2014 with a series of micro events, and then on August 3, 2014 a local magnitude is 4.1 event occurred, more than 1000 in the followed until August 31, 2014. Thus we call this tentatively a swarm-like activity. Therefore, investigation of the micro-earthquake activity of the Armutlu Peninsula has become important to understand the relationship between the occurrence of micro-earthquakes and the tectonic structure of the region. For these reasons, Armutlu Network (ARNET), installed end of 2005 and equipped with currently 27 active seismic stations operating by Kocaeli University Earth and Space Sciences Research Center (ESSRC) and Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum (GFZ), is a very dense network tool able to record even micro-earthquakes in this region. In the 30 days period of August 02 to 31, 2014 Kandilli Observatory and Earthquake Research Institute (KOERI) announced 120 local earthquakes ranging magnitudes between 0.7 and 4.1, but ARNET provided more than 1000 earthquakes for analyzes at the same time period. In this study, earthquakes of the swarm area and vicinity regions determined by ARNET were investigated. The focal mechanism of the August 03, 2014 22:22:42 (GMT) earthquake with local magnitude (Ml) 4.0 is obtained by the moment tensor solution. According to the solution, it discriminates a normal faulting with dextral component. The obtained focal mechanism solution is

  17. Monitoring guidelines improve control of walnut husk fly in California

    International Nuclear Information System (INIS)

    Opp, Susan B.; Reynolds, Katherine M.; Pickel, Carolyn; Olson, William

    2000-01-01

    The walnut husk fly (WHF), Rhagoletis completa Cresson, is a key pest of walnuts (Juglans spp.) in California, where over 95% of the US and approximately two-thirds of the world's commercial walnuts are produced. The primary hosts of this monophagous fruit fly are J. regia L. (commercially grown English walnut), J. californica S. Wats. var. hindsii (northern California black walnut), J. californica var. californica (southern California black walnut) and J. nigra Thunb. (eastern black walnut). Some cultivars of the English walnut are more susceptible than others; the most heavily infested varieties of English walnut include Eureka, Franquette, Hartley, Mayette and Payne. Neither English walnuts nor the walnut husk fly are native to California. So-called 'English' walnuts are sometimes more appropriately called 'Persian' walnuts, in reference to Persia, the origin of J. regia. English walnuts were first planted in southern California in the 1860s. In contrast, the native range of WHF is the mid- and south-central United States where it attacks J. nigra (Boyce 1934). The fly was likely to have been introduced into southern California in the mid-1920s by tourists travelling from Kansas, New Mexico, Texas or Oklahoma. WHF was first documented in California in 1926 in the San Bernardino County when maggots were found in the husks of English walnuts (Boyce 1929). The fly gradually spread throughout walnut growing regions of California. In 1928, only three or four orchards in the San Bernardino County were known to be infested. By 1932, the fly was also found in the Los Angeles and Orange Counties (Boyce 1933), and by 1954, it was found in Ventura, Riverside, and the San Diego Counties, in addition to the northern California county of Sonoma (Anonymous 1966). The spread of the fly in northern California was rapid. By 1958, WHF was found in San Joaquin County; in 1963, the fly was in Amador, Lake, Solano, Tulare and Yolo Counties; in 1964, it was found in Fresno, Mendocino

  18. The Story of California = La Historia de California.

    Science.gov (United States)

    Bartel, Nick

    "The Story of California" is a history and geography of the state of California, intended for classroom use by limited-English-proficient, native Spanish-speaking students in California's urban middle schools. The book is designed with the left page in English and the right page in Spanish to facilitate student transition into…

  19. LLWPA: Implementation in California

    International Nuclear Information System (INIS)

    Gaynor, R.K.; Romano, S.A.

    1987-01-01

    US Ecology has been designated by the State of California to locate, develop and operate a low-level radioactive waste disposal facility. In early 1986, the firm identified eighteen desert basins in southeastern California for siting considerations. Three candidate sites were selected for detailed field characterization work in February, 1987. A preferred site for licensing purposes will be identified in late 1987. California is currently ahead of the siting milestone schedule mandated by the Low-Level Radioactive Waste Policy Amendments Act. It is likely that a license application will be filed in mid-1988, well before the 1990 milestone date. It is anticipated that the site will be constructed around that milestone date. This paper describes the process undertaken by US Ecology to identify three candidate sites for characterization, and the public involvement program supporting this decision. Future activities leading to a final site development are also described

  20. Transit performance measures in California.

    Science.gov (United States)

    2016-04-01

    This research is the result of a California Department of Transportation (Caltrans) request to assess the most commonly : available transit performance measures in California. Caltrans wanted to understand performance measures and data used by : Metr...

  1. Hydrogeology of the Umm Er Radhuma Aquifer (Arabian peninsula)

    Science.gov (United States)

    Dirks, Heiko; Al Ajmi, Hussain; Kienast, Peter; Rausch, Randolf

    2018-03-01

    The aim of this article is to enhance the understanding of the Umm Er Radhuma aquifer's genesis, and its hydraulic and hydrochemical development over time. This is a prerequisite for wise use of the fossil groundwater resources contained within. The Umm Er Radhuma is a karstified limestone aquifer, extending over 1.6 Mio. km2 in the eastern part of the Arabian Peninsula. Both epigene and hypogene karstification contributed to the genesis of what is today the most prolific aquifer in the region. Besides man-made abstractions, even the natural outflows are higher than the small recharge (natural storage depletion). The Umm Er Radhuma shows that large aquifers in arid regions are never in "steady state" (where inflows equal outflows), considering Quaternary climate history. The aquifer's adaption to climate changes (precipitation, sea level) can be traced even after thousands of years, and is slower than the climate changes themselves.

  2. Irregularities of ionospheric VTEC during lightning activity over Antarctic Peninsula

    International Nuclear Information System (INIS)

    Suparta, W; Wan Mohd Nor, W N A

    2017-01-01

    This paper investigates the irregularities of vertical total electron content (VTEC) during lightning activity and geomagnetic quiet days over Antarctic Peninsula in year 2014. During the lightning event, the ionosphere may be disturbed which may cause disruption in the radio signal. Thus, it is important to understand the influence of lightning on VTEC in the study of upper-lower interaction. The lightning data is obtained from World Wide Lightning Location Network (WWLLN) and the VTEC data has analyzed from Global Positioning System (GPS) for O’Higgins (OHI3), Palmer (PALV), and Rothera (ROTH). The results demonstrate the VTEC variation of ∼0.2 TECU during low lightning activity which could be caused by energy dissipation through lightning discharges from troposphere into the thermosphere. (paper)

  3. Current measurement studies around the Cesme Peninsula (Turkey)

    International Nuclear Information System (INIS)

    Taspinar, N.

    1989-04-01

    In order to design coastal structures and marine vehicles safely, it is required to know current climate which shows the variation of the current characteristics with time. There are a wide variety of current meters designed to measure water flow today. Each current meter is capable of recording the influence of mooring arrangement. Here we describe sea water temperatures, salinities and current velocities at offshore of Akburun, Tatlicak Burnu, Kalem Burnu and Kizil Burun areas in Cesme Peninsula 27 August, 1986 to 19 November, 1986. At the end of the investigations, measured significant maximum and average current velocities have been routinely analysed with micro-computers and also the percentages of current velocity have been calculated. (author). 8 refs, 6 figs, 4 tabs

  4. The prehistory of the Arabian peninsula: deserts, dispersals, and demography.

    Science.gov (United States)

    Groucutt, Huw S; Petraglia, Michael D

    2012-05-01

    As a geographic connection between Africa and the rest of Eurasia, the Arabian Peninsula occupies a central position in elucidating hominin evolution and dispersals. Arabia has been characterized by extreme environmental fluctuation in the Quaternary, with profound evolutionary and demographic consequences. Despite the importance of the region, Arabia remains understudied. Recent years, however, have seen major developments in environmental studies and archeology, revealing that the region contains important records that should play a significant role in future paleoanthropological narratives.(1-3) The emerging picture of Arabia suggests that numerous dispersals of hominin populations into the region occurred. Populations subsequently followed autochthonous trajectories, creating a distinctive regional archeological record. Debates continue on the respective roles of regional hominin extinctions and population continuity, with the latter suggesting adaptation to arid conditions. Copyright © 2012 Wiley Periodicals, Inc.

  5. Practice of Propaganda on Korean Peninsula (1945-1960

    Directory of Open Access Journals (Sweden)

    Zhyvora Olexii

    2016-05-01

    Full Text Available The topic of propaganda, which was thought to be a part of the Cold War past, was recently revived by modern and rather successful application in Georgian, Syrian and Ukrainian conflicts. In this regard Korean Peninsula is a perfect example of prolonged use of mutual practice of indoctrination to study its origins. This article discuses the evolution of propaganda use by both Democratic People’s Republic of Korea and Republic of Korea (1945-1960 in cultural, economic and political dimensions. Qualitative text analysis and case study in conjunction with theoretical framework of A. E. Cassirer, S. Langer, E. Barneys and W. Lippmann are used to establish techniques used, and to explain its overall success.

  6. Peninsula Effects on Birds in a Coastal Landscape: Are Coves More Species Rich than Lobes?

    Directory of Open Access Journals (Sweden)

    Sam Riffell

    2012-10-01

    Full Text Available Peninsula effects - decreasing richness with increasing distance along peninsula lobes - have been identified for many taxa on large peninsulas. Peninsula effects are caused by differences in colonization and extinction predicted by island biogeography or by environmental gradients along the peninsula. We compared species-area regressions for cove patches (i.e., mainland to regressions for lobe patches (i.e., on peninsula tips for wet meadow birds along a highly interdigitated shoreline (northern Lake Huron, USA. We conducted analysis both with and without accounting for variation in habitat and landscape characteristics (i.e., environmental gradients of wet meadows. Species-area regressions for coves did not differ from lobes, nor did these results differ when we accounted for gradients. Similarly, few species were more abundant in coves. Peninsula effects may have been lacking because lobe patches were located ≈ 800 m on average from the mainland, and birds are highly mobile and can easily sample patches over these distances. One important caveat was that wet meadow patches > 5 ha were located in coves, so coves would still be important considerations in conservation plans because of the contribution of large patches to reproductive success, dispersal and population dynamics.

  7. Spatial Analysis of b-value Variability in Armutlu Peninsula (NW Turkey

    Directory of Open Access Journals (Sweden)

    Yeken Tekin

    2016-10-01

    Full Text Available Spatial variations of b values were studied by means of 2376 earthquakes with a magnitude completeness of 2.7 in the Armutlu Peninsula (NW Turkey during a 15-year period following the destructive earthquake on August 17, 1999 in Kocaeli. The b value of L6 for the entire Armutlu Peninsula represents a large value for a global value, but this analysis suggested that the distribution of b value around the Armutlu Peninsula varied extensively from 1.2 to 2.6. Several pockets of high bvalue reflected changes in the physical properties of the Armutlu Peninsula. The southern part of the peninsula represents a lower b value against the northern part of the peninsula. A high b value was observed around Termal and Armutlu towns where plenty of geothermal springs occur. Seismic tomography studies revealed a low velocity zone beneath the Termal area where the high b value was imaged in this study. A seismic swarm which is considered to be related with geothermal activity also occurred in 2014 at the same place. This observation suggests that it is possible to propose that the high b value in the northern part of the peninsula could be related to hydrothermal/geothermal activity which contributes to lowering the effective stress.

  8. Solar: California, not dreaming

    Energy Technology Data Exchange (ETDEWEB)

    Jones, J.

    2006-03-15

    The California Solar Initiative (CSI) was approved by the California Public Utilities Commission (PUC) in January 2006. The CSI is the largest solar programme of this kind ever in the USA and provides for $3.2 billion in incentives for solar projects between 2007 and 2017. The PUC will oversee a $2.5 billion programme to provide funding for solar installations on commercial and existing residential buildings, while the California Energy Commission (CEC) will manage a separate $350 million fund targeted at new residential building. Existing solar programmes operated by the PUC and CEC will be consolidated into the CSI. The CEC programme will use already allocated funding, but the PUC programme will be funded through revenues collected from customers of the main gas and electric utilities in California. Funds will be distributed via rebates to householders or companies that install solar. As well as solar photovoltaics (PV), rebates will also go to solar thermal power (concentrating solar power) and solar heating and cooling. CSI funding can be used in combination with existing federal tax credits. The aim is a gradual increase from installation of 40 MW of PV in 2005 to 100 MW by 2009. The CSI is also expected to create favourable market conditions for PV manufacturers in California and to encourage investment in production of solar-grade silicon in or near California. Objections from the International Brotherhood of Electrical Workers (IBEW) appear to have been overcome but a number of other potential snags remain. CSI is expected to be replicated in other US states.

  9. International Uranium Resources Evaluation Project (IUREP) national favourability studies: Mexico

    International Nuclear Information System (INIS)

    1977-07-01

    Reserves of uranium are located in the north eastern part of Mexico, primarily in the states of Tamaulipas and Chihuahua. Most of the remainder of Mexico's reserves are near the Tamaulipas-Neuvo Leon state border in the Tertiary Frio Formation, where they apparently occur in the types of uranium deposits found in Texas, U.S.A. There are two deposits, La Coma and Buenavista, but nothing has been published on dimensions of the ore bodies. Forty-five miles northeast of Hermosillo, in Sonora state is the Los Amoles district where uranium is found associated with gold and other metals in low-grade deposits on the margins of a Cretaceous batholith. Another occurrence is reported in the mining district of Placer de Guadelupe and Puerto del Aire, about 40-50 km northeast of Chihuahua City, in the state of Chihuahua. Reserves of U 3 O 8 which were published in January 1977 by Nuclear Exchange Corporation of Menlo Park, California, are listed. The government of Mexico has not estimated potential resources. It should be noted that much of Mexico appears favourable for uranium, and only 10 percent has been explored. According to NUEXCO (1977), efforts to find uranium are being increased in an attempt to supply Mexico's nuclear reactor requirements through 1990. Activity is reported to be centered in Tamaulipas and Chihuahua states and to a lesser extent in Nueva Leon, Sonora, Coahuila, and Baja California. Major effort will continue to be placed in Chihuahua state to supply the Penna Bianca mill. Correspondence between favorable geological settings for uranium and the geologic regions of Mexico is reported. Mexico is a country with considerable areas that appear promising for discovery of sandstone, vein, and tuff-related deposits. On the other hand, its potential for Precambrian conglomerate and unconformity-related deposits is limited. Considering these geologic factors, as well as the relatively limited amount of exploration done to date, a guesstimate of speculative

  10. Fitting monthly Peninsula Malaysian rainfall using Tweedie distribution

    Science.gov (United States)

    Yunus, R. M.; Hasan, M. M.; Zubairi, Y. Z.

    2017-09-01

    In this study, the Tweedie distribution was used to fit the monthly rainfall data from 24 monitoring stations of Peninsula Malaysia for the period from January, 2008 to April, 2015. The aim of the study is to determine whether the distributions within the Tweedie family fit well the monthly Malaysian rainfall data. Within the Tweedie family, the gamma distribution is generally used for fitting the rainfall totals, however the Poisson-gamma distribution is more useful to describe two important features of rainfall pattern, which are the occurrences (dry months) and the amount (wet months). First, the appropriate distribution of the monthly rainfall was identified within the Tweedie family for each station. Then, the Tweedie Generalised Linear Model (GLM) with no explanatory variable was used to model the monthly rainfall data. Graphical representation was used to assess model appropriateness. The QQ plots of quantile residuals show that the Tweedie models fit the monthly rainfall data better for majority of the stations in the west coast and mid land than those in the east coast of Peninsula. This significant finding suggests that the best fitted distribution depends on the geographical location of the monitoring station. In this paper, a simple model is developed for generating synthetic rainfall data for use in various areas, including agriculture and irrigation. We have showed that the data that were simulated using the Tweedie distribution have fairly similar frequency histogram to that of the actual data. Both the mean number of rainfall events and mean amount of rain for a month were estimated simultaneously for the case that the Poisson gamma distribution fits the data reasonably well. Thus, this work complements previous studies that fit the rainfall amount and the occurrence of rainfall events separately, each to a different distribution.

  11. Mexico: a solar future

    International Nuclear Information System (INIS)

    2016-01-01

    Immersed in the global price instability of fossil fuels and with an upsurge in renewables as the agent for development, countries like Mexico, that largely depend on this resource to generate income and whose national electrical energy generation mainly comes from these fuels, find themselves obliged to take decisions that allow them to maintain their appeal compared to other emerging markets. In this decision-making process, Mexico has been slow to implement its long-awaited Energy Reform that incentivises direct foreign investment and avoids the monopolies that have until recently prevailed in the Mexican energy and electricity sector. (Author)

  12. First records of Eupompha imperialis (Wellman, 1912 (Coleoptera: Meloidae in Mexico

    Directory of Open Access Journals (Sweden)

    López-Estrada, E. Karen

    2015-06-01

    Full Text Available Three populations of Eupompha imperialis (Wellman, 1912 were located in the Mexican states of Baja California and Sonora, in close proximity to the Mexico-USA border. These populations represent the first records for E. imperialis in Mexico. The specimens were observed in sandy areas of the Sonoran Desert, associated with flowering Tiquilia palmeri (Boraginaceae. These new records suggest that, despite the rarity of some species of Eupomphini, further exploration of the northernmost areas of Sonora and Baja California may increase the number of species of Eupomphini and other tribes of Meloidae present in Mexico.Se localizaron tres poblaciones de Eupompha imperialis (Wellman, 1912 en los estados mexicanos de Baja California y Sonora, en las proximidades de la frontera México-Estados Unidos. Estas poblaciones representan los primeros registros de E. imperialis en México. Los ejemplares de E. imperialis se observaron en zonas arenosas del desierto de Sonora, asociados a ejemplares en flor de Tiquilia palmeri (Boraginaceae. Estos nuevos registros sugieren que, a pesar de la rareza de algunas especies de Eupomphini, el desarrollo de nuevas exploraciones en las áreas más septentrionales de Sonora y Baja California permitiría incrementar el número de especies de Eupomphini y de otras tribus de Meloidae presentes en México.

  13. EXPERIMENTAL ANALYSIS OF BIOLOGICAL PARAMETERS AND VECTOR ABILITY OF GLASSY-WINGED SHARPSHOOTERS FROM ALLOPATRIC POPULATIONS IN CALIFORNIA

    Science.gov (United States)

    The glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar), is native to the southeastern United States and northeastern Mexico. It was detected in southern California in the late 1980s and in the San Joaquin Valley in 1999, where it transmits the bacterium Xylella fastidiosa to grapev...

  14. Synthetic natural gas in California: When and why. [from coal

    Science.gov (United States)

    Wood, W. B.

    1978-01-01

    A coal gasification plant planned for northwestern New Mexico to produce 250 MMCFD of pipeline quality gas (SNG) using the German Lurgi process is discussed. The SNG will be commingled with natural gas in existing pipelines for delivery to southern California and the Midwest. Cost of the plant is figured at more than $1.4 billion in January 1978 dollars with a current inflation rate of $255,000 for each day of delay. Plant start-up is now scheduled for 1984.

  15. Financial viability of the Sonora-Baja California interconnection line

    International Nuclear Information System (INIS)

    Alonso, G.; Ortega, G.

    2017-09-01

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

  16. The first educational interferometer in Mexico (FEYMANS): A novel project

    Science.gov (United States)

    Villicana Pedraza, Ilhuiyolitzin; Guesten, Rolf; Saucedo Morales, Julio Cesar; Carreto, Francisco; Valdes Estrada, Erik; Wendolyn Blanco Cardenas, Monica; Rodríguez Garza, Carolina B.; Pech Castillo, Gerardo A.; Ángel Vaquerizo, Juan

    2016-07-01

    An interferometer is composed of several radio telescopes (dishes) separated by a defined distance and used in synchrony. This kind of array produces a superior angular resolution, better than the resolution achieved by a single dish of the same combined area. In this work we propose the First Educational Youth Mexican Array North South, FEYMANS. It consists of an educational interferometer with initially four dishes. This array harvests Mexico's geography by locating each dish at the periphery of the country; creating new scientific links of provincial populations with the capital. The FEYMANS project focus in high school students and their projects on physics, chemistry and astronomy as a final project. Also, it can be used for bachelor theses. The initial and central dish-node is planed to be in Mexico City. After its construction, the efforts will focus to build subsequent nodes, on the Northwest region, Northeast, or Southeast. Region Northwest will give service to Baja California, Sonora and Chihuahua states. Region Northeast will cover Coahuila, Nuevo Leon and Tamaulipas. Finally, region Southeast will give access to Yucatan, Quintana Roo, Campeche, Tabasco and Chiapas. This project has been conceived by young professional astronomers and Mexican experts that will operate each node. Also, we have the technical support of the "Max Planck Institute fuer Radioastronomy in Bonn Germany" and the educational model of the "PARTNeR" project in Spain. This interferometer will be financed by Mexico's Federal Congress and by Mexico City's Legislative Assembly (ALDF).

  17. Higher Education in California

    Science.gov (United States)

    Public Policy Institute of California, 2016

    2016-01-01

    Higher education enhances Californians' lives and contributes to the state's economic growth. But population and education trends suggest that California is facing a large shortfall of college graduates. Addressing this short­fall will require strong gains for groups that have been historically under­represented in higher education. Substantial…

  18. California Budget Simulation

    Science.gov (United States)

    Mallinson, Daniel J.

    2018-01-01

    The California Budget Challenge produced by Next10 provides a useful and intuitive tool for instructors to introduce students to public budgeting. Students will reason through a series of budgeting decisions using information provided on the fiscal and practical implications of their choices. The Challenge is updated with each budget cycle, so it…

  19. Oak management in California

    Science.gov (United States)

    Plumb. Timothy R.; Philip M. McDonald

    1981-01-01

    Native oak species grow on 15 to 20 million acres (6 to 8 million ha) of California land, and have an estimated net volume of about 3 billion ft3 (85 million m3). This resource, valuable not only for traditional wood products, but also for wildlife habitat, watershed protection, and recreational-esthetic values, is not...

  20. California's Perfect Storm

    Science.gov (United States)

    Bacon, David

    2010-01-01

    The United States today faces an economic crisis worse than any since the Great Depression of the 1930s. Nowhere is it sharper than in the nation's schools. Last year, California saw a perfect storm of protest in virtually every part of its education system. K-12 teachers built coalitions with parents and students to fight for their jobs and their…

  1. FELLOWS ADDRESS California Dreaming

    NARCIS (Netherlands)

    Kooten, van Kees

    2017-01-01

    California was the first jurisdiction to mandate a reduction in greenhouse gas (GHG) emissions by 80% below 1990 levels by 2050. This target was subsequently endorsed by the G8 in 2009 and the European Commission in 2014, and is the guiding principle of the 2015 Paris Agreement. To achieve these

  2. NREL + Southern California Gas

    Energy Technology Data Exchange (ETDEWEB)

    Berdahl, Sonja E [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-09

    NREL and Southern California Gas Company are evaluating a new 'power-to-gas' approach - one that produces methane through a biological pathway and uses the expansive natural gas infrastructure to store it. This approach has the potential to change how the power industry approaches renewable generation and energy storage.

  3. California's Future: Higher Education

    Science.gov (United States)

    Johnson, Hans

    2015-01-01

    California's higher education system is not keeping up with the changing economy. Projections suggest that the state's economy will continue to need more highly educated workers. In 2025, if current trends persist, 41 percent of jobs will require at least a bachelor's degree and 36 percent will require some college education short of a bachelor's…

  4. The Sac Actun System, Quintana Roo, Mexico; Sistema Sac Actun, Quintana Roo, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Kambesis, P. N.; Coke, J. G.

    2016-07-01

    The Sac Actun system, located in northeast Quintana Roo, Mexico, is among the most extensive underwater cave systems located along the Caribbean coast of the Yucatan Peninsula. The cave is composed of linear phreatic conduits that have two forms. The coastal sections of the Sac Actun system are characterized by low horizontal tunnels that form mazes paralleling the coast and rudimentary conduits broken by fracture-controlled rooms. Inland passages are fault/fracture controlled, have a linear, anastomotic configuration, and align perpendicular to the coast. Access to the cave system is gained through cenotes which are the portals into the Yucatan underwater cave systems. The occurrence of drowned speleothems in many parts of the cave system, and sections of air-filled upper level passages are indicative of major fluctuations in sea level. The Sac Actun system is part of one of the most extensive and significant eogenetic karst aquifers in the world. The development of the Sac Actun system, as well as the many other caves systems along the Yucatan Caribbean Coast is controlled by the coastal hydrologic regime, driven by glacio-eustatics, and influenced by stratigraphic and structural controls. The karstic permeability of the aquifer makes it and the Sac Actun system vulnerable to the anthropogenic impacts of increased population growth, quarries, and infrastructure development associated with the burgeoning tourist industry that dominates land use in the region. (Author)

  5. Protection gaps in Mexico

    Directory of Open Access Journals (Sweden)

    Andrea Villasenor

    2017-10-01

    Full Text Available With Mexico a major destination – and transit – country for people displaced by violence in the Northern Triangle of Central America, the Mexican government needs urgently to improve its asylum systems and procedures if they are to be fit for purpose.

  6. The Art of Mexico.

    Science.gov (United States)

    Saccardi, Marianne

    1997-01-01

    Provides an annotated bibliography of books for grades K and up which explores the folklore, poetry, fiction, and art of Mexico, and focuses on the Mayans and Aztecs and Diego Rivera and Frida Kahlo. Also suggests various research, reading, drama, music, social studies, physical education, and art activities and lists related videos and Internet…

  7. [Food security in Mexico].

    Science.gov (United States)

    Urquía-Fernández, Nuria

    2014-01-01

    An overview of food security and nutrition in Mexico is presented, based on the analysis of the four pillars of food security: availability, access, utilization of food, and stability of the food supply. In addition, the two faces of malnutrition in Mexico were analyzed: obesity and undernourishment. Data were gathered from the food security indicators of the United Nations's Food and Agriculture Organization, from the Mexican Scale of Food Security, and from the National Health and Nutrition Survey. Mexico presents an index of availability of 3 145 kilocalories per person per day, one of the highest indexes in the world, including both food production and imports. In contrast, Mexico is affected by a double burden of malnutrition: whereas children under five present 14% of stunt, 30% of the adult population is obese. Also, more than 18% of the population cannot afford the basic food basket (food poverty). Using perception surveys, people reports important levels of food insecurity, which concentrates in seven states of the Mexican Federation. The production structure underlying these indicators shows a very heterogeneous landscape, which translates in to a low productivity growth across the last years. Food security being a multidimensional concept, to ensure food security for the Mexican population requires a revision and redesign of public productive and social policies, placing a particular focus on strengthening the mechanisms of institutional governance.

  8. Christmas in Mexico.

    Science.gov (United States)

    Kern County Superintendent of Schools, Bakersfield, CA.

    The Christmas season in Mexico starts on December 16 with "las posadas," a series of religious processions in which families or neighbors reenact Joseph's search for shelter for Mary en route to Bethlehem. Those representing pilgrims travel from home to home until they are finally accepted by those representing innkeepers at a home with…

  9. POTENTIAL DISTRIBUTION OF ORANGE JASMINE (Murraya paniculata IN MEXICO

    Directory of Open Access Journals (Sweden)

    José López-Collado

    2013-04-01

    Full Text Available Orange jasmine (OJ is a common ornamental plant used as green hedge in public and private gardens in Mexico. It also hosts Huanglongbing, a worldwide citrus disease and its vector, Diaphorina citri. For risk analysis and management purpose is important to know its geographic distribution. The potential distribution of OJ was calculated in Mexico using a deductive approach. Based on temperature and precipitation requirements, a relative suitability index was computed by combining the normalized values of both variables. The distribution was overlapped with captures of D. citri to check their spatial similarity. The results showed that the potential of occurrence is high in the Pacific and Gulf of México coastal states, including the Yucatán peninsula, and the lowest values appeared in the north-western states. The OJ distribution overlaps with Huanglongbing occurrence and coincided with captures of D. citri for most of the suitable area but D. citri captures extended beyond the optimal OJ distribution values in the northern regions of México.

  10. Hurricane Risk Variability along the Gulf of Mexico Coastline

    Science.gov (United States)

    Trepanier, Jill C.; Ellis, Kelsey N.; Tucker, Clay S.

    2015-01-01

    Hurricane risk characteristics are examined across the U. S. Gulf of Mexico coastline using a hexagonal tessellation. Using an extreme value model, parameters are collected representing the rate or λ (frequency), the scale or σ (range), and the shape or ξ (intensity) of the extreme wind distribution. These latent parameters and the 30-year return level are visualized across the grid. The greatest 30-year return levels are located toward the center of the Gulf of Mexico, and for inland locations, along the borders of Louisiana, Mississippi, and Alabama. Using a geographically weighted regression model, the relationship of these parameters to sea surface temperature (SST) is found to assess sensitivity to change. It is shown that as SSTs increase near the coast, the frequency of hurricanes in these grids decrease significantly. This reinforces the importance of SST in areas of likely tropical cyclogenesis in determining the number of hurricanes near the coast, along with SSTs along the lifespan of the storm, rather than simply local SST. The range of hurricane wind speeds experienced near Florida is shown to increase with increasing SSTs (insignificant), suggesting that increased temperatures may allow hurricanes to maintain their strength as they pass over the Florida peninsula. The modifiable areal unit problem is assessed using multiple grid sizes. Moran’s I and the local statistic G are calculated to examine spatial autocorrelation in the parameters. This research opens up future questions regarding rapid intensification and decay close to the coast and the relationship to changing SSTs. PMID:25767885

  11. Hurricane risk variability along the Gulf of Mexico coastline.

    Science.gov (United States)

    Trepanier, Jill C; Ellis, Kelsey N; Tucker, Clay S

    2015-01-01

    Hurricane risk characteristics are examined across the U. S. Gulf of Mexico coastline using a hexagonal tessellation. Using an extreme value model, parameters are collected representing the rate or λ (frequency), the scale or σ (range), and the shape or ξ (intensity) of the extreme wind distribution. These latent parameters and the 30-year return level are visualized across the grid. The greatest 30-year return levels are located toward the center of the Gulf of Mexico, and for inland locations, along the borders of Louisiana, Mississippi, and Alabama. Using a geographically weighted regression model, the relationship of these parameters to sea surface temperature (SST) is found to assess sensitivity to change. It is shown that as SSTs increase near the coast, the frequency of hurricanes in these grids decrease significantly. This reinforces the importance of SST in areas of likely tropical cyclogenesis in determining the number of hurricanes near the coast, along with SSTs along the lifespan of the storm, rather than simply local SST. The range of hurricane wind speeds experienced near Florida is shown to increase with increasing SSTs (insignificant), suggesting that increased temperatures may allow hurricanes to maintain their strength as they pass over the Florida peninsula. The modifiable areal unit problem is assessed using multiple grid sizes. Moran's I and the local statistic G are calculated to examine spatial autocorrelation in the parameters. This research opens up future questions regarding rapid intensification and decay close to the coast and the relationship to changing SSTs.

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

    Science.gov (United States)

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

    2005-12-01

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

  13. Multichannel Seismic Reflection Data - SCAR - Antarctic Peninsula 1987-88, SDLS CD-ROM vol 24

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1987-88 in the Antarctic Peninsula, Antarctica, by the Japan National Oil...

  14. Risk-taking behaviour ofCape Peninsula high-school students

    African Journals Online (AJOL)

    behaviour alDong high-school students in the. Cape Peninsula ... Knonenbelt - personal communication). South Africa has ..... vision and film violence increases physical aggression ... violence in the media; revising firearm legislation and.

  15. Cook Inlet and Kenai Peninsula, Alaska ESI: M_MAMPT (Marine Mammal Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for seals and sea lions in Cook Inlet and Kenai Peninsula, Alaska. Vector points in this data set represent locations...

  16. Occurrence, abundance, and habitat use of birds along the northcentral Alaska peninsula, 1976-1980

    Data.gov (United States)

    Department of the Interior — Between spring 1976 and fall 1980 we studied the occurrence, abundance, and habitat use of birds over a 2000 km² segment of the northcentral Alaska Peninsula. During...

  17. Risk-taking behaviour of Cape Peninsula high-school students

    African Journals Online (AJOL)

    Risk-taking behaviour of Cape Peninsula high-school students ... Cluster sampling techniques produced a sam- ple of 7 340 ... Over the past 30 or 40 years increasing percent- ages of ..... many adolescents, caution should be exercised when.

  18. Application of Space Technology to Discovery of Ancient Desert Trade Routes in the Southern Arabian Peninsula

    Science.gov (United States)

    Blom, Ronald; Crippen, Robert; Hedges, George; Zarins, Juris

    1997-01-01

    Over the last decade, an unusual combination of historical research, traditional archaeology, and application of space technolgy has demonstrated the existence of trans-desert trade routes in the sourthern Arabian peninsula.

  19. Cook Inlet and Kenai Peninsula, Alaska ESI: M_MAMMAL (Marine Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for marine mammals in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent locations of...

  20. The Dependency between the Arabian Peninsula Wet Events and Sea Level Pressure Patterns during Spring Season

    KAUST Repository

    El Kenawy, Ahmed M.; McCabe, Matthew; Stenchikov, Georgiy L.; Raj, Jerry

    2014-01-01

    This work investigates the relationships between regional extreme wet events in the Arabian Peninsula during the spring season (MAM) and sea level pressure (SLP) patterns. Based on NCEP/NCAR reanalysis data, S-mode principal components were computed