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Sample records for reserve yucatan mexico

  1. 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.

  2. Education and neoliberalism in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Gabriela Vargas-Cetina

    2016-08-01

    Full Text Available Under neoliberalism, at least in Mexico, education has been recast as a service that is to be sold for money, and not as a right of all Mexicans. The economy itself is now seen as a services economy, where everything is expected to make money. Here we reflect on some of the implications of current education reforms on our work at the Autonomous University of Yucatan.

  3. ( Didelphis virginiana ) from Yucatan, Mexico

    African Journals Online (AJOL)

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana ...

  4. 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...

  5. West Nile Virus in Resident Birds from Yucatan, Mexico.

    Science.gov (United States)

    Chaves, Andrea; Sotomayor-Bonilla, Jesus; Monge, Otto; Ramírez, Abigaíl; Galindo, Francisco; Sarmiento-Silva, Rosa Elena; Gutiérrez-Espeleta, Gustavo A; Suzán, Gerardo

    2016-01-01

    West Nile virus (WNV) in the Americas is thought to be transported at large spatial scales by migratory birds and locally spread and amplified by resident birds. Local processes, including interspecific interactions and dominance of passerine species recognized as competent reservoirs, may boost infection and maintain endemic cycles. Change in species composition has been recognized as an important driver for infection dynamics. Due to migration and changes in species diversity and composition in wintering grounds, changes in infection prevalence are expected. To these changes, we used PCR to estimate the prevalence of WNV in wild resident birds during the dry and rainy seasons of 2012 in Yucatan, Mexico. Serum samples were obtained from 104 wild birds, belonging to six orders and 35 species. We detected WNV in 14 resident birds, representing 11 species and three orders. Prevalences by order was Passeriformes (27%), Columbiformes (6%), and Piciformes (33%). Resident birds positive to WNV from Yucatan may be indicative of local virus circulation and evidence of past virus transmission activity.

  6. Microbial deterioration of Mayan stone buildings at Uxmal, Yucatan, Mexico

    International Nuclear Information System (INIS)

    Ortega-Morales, O.; Guezennec, J.; Hernandez D, G.; Jozsa, P.; Sand, W.; Crassous, P.

    1998-01-01

    The microbial communities associated to Uxmal Mayan monuments (Yucatan, Mexico) and their role in stone deterioration were preliminary characterized by chemical, biochemical, microbiological, microscopical and surface analysis methods under two climatic seasons (1997). The organic matter and organic carbon and nitrogen were in the range of those reported for other stone buildings, indicating that oligo trophic conditions prevail at Uxmal. Quantitative differences in microbial biomass was higher at indoor section were the organic matter content was the highest and micro-environmental conditions (availability of water and protection to direct sunlight) are more suitable for microbial growth. The microbiological analysis underestimated the microbial biomass, as revealed by biochemical approaches. Nitrate and nitrite-oxidizing, metilotrophic and heterotrophic bacteria and fungi were detected in most surfaces. The heterotrophic bacteria were the most abundant microbial group (microbiological data). However, the chlorophyll profiles and Scanning Electron Microscopy showed that the microalgae are the most abundant colonizers in Uxmal stone buildings. EDAX analysis showed that the most surfaces were covered by an organic layer (cells and exo polymers). Gypsum was found in few samples. The large photo trophic biomass seems to play a role in stone bio deterioration by supporting growth of heterotrophic microorganisms (bacteria and fungi) which are known to produce organic acids leading to calcite dissolution and cations chelation. Further studies are being carried out in order to determine the role of exo polysaccharides which are thought to play a role in chemical degradation of limestone substrates in Uxmal. (Author)

  7. 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.

  8. Mercury levels assessment and its relationship with oxidative stress biomarkers in children from three localities in Yucatan, Mexico.

    Science.gov (United States)

    Rangel-Méndez, Jorge A; Arcega-Cabrera, Flor E; Fargher, Lane F; Moo-Puc, Rosa E

    2016-02-01

    Mercury (Hg) is a global pollutant that is released into the environment from geologic and anthropogenic sources. Once it enters an organism, it generates several toxicity mechanisms and oxidative stress has been proposed as the main one. Metal susceptibility is greater in children, which is a result of their physiology and behavior. In Yucatan, Mexico, burning of unregulated garbage dumps and household trash, ingestion of top marine predators, and pottery manufacturing are among the conditions that could promote Hg exposure. However, for Yucatan, there are no published studies that report Hg levels and associated oxidative stress status in children. Therefore, this study aimed to assess Hg levels in blood and urine and oxidative stress biomarkers levels in a sample of 107 healthy children from three localities in Yucatan, Mexico, as well as investigate the relationship between these parameters. Hg was detected in 11 (10.28%) of blood samples and 38 (35.51%) of urine samples collected from the participating children. Fourteen subjects showed Hg above recommended levels. The oxidative stress biomarkers were slightly elevated in comparison with other studies and were statistically different between the sampling sites. No linear correlation between Hg levels and oxidative stress biomarkers was found. Nevertheless, exploratory univariate and multivariate analysis showed non-linear relations among the measured variables. Globally, the study provides, for the first time, information regarding Hg levels and their relationship with oxidative stress biomarkers in a juvenile population from Mexico's southeast (Yucatan) region. In agreement with worldwide concern about Hg, this study should stimulate studies on metal monitoring in humans (especially children) among scientists working in Mexico, the establishment of polices for its regulation, and the reduction of human health risks. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Food intake and nutrition in children 1-4 years of age in Yucatan, Mexico.

    Science.gov (United States)

    Cuanalo de la Cerda, Heriberto E; Ochoa Estrada, Ernesto; Tuz Poot, Felipe R; Datta Banik, Sudip

    2014-01-01

    The National Health and Nutrition Survey 2006 (ENSANUT in Spanish) reported high rates of under-nutrition in children of Yucatan. Is food intake the main cause of under-nutrition in children of the state of Yucatan, Mexico? Identify the primary causes of under-nutrition in pre-school children in Yucatan. A sample of 111 children (59 girls and 52 boys) aged 1-4 years representing Yucatan was taken from a database of ENSANUT 2006 and another national survey, a federal poverty mitigation programme for the state of Yucatan, Mexico entitled "Oportunidades". A human ecology approach together with life history theory was used to analyse anthropometric indices and food intake data from the ENSANUT 2006 and "Oportunidades". Height and weight were significantly correlated to age and total food intake. No correlations were found between age and anthropometric indices or food intake rates. The children in the sample had adequate protein intake but deficient energy intake. No correlation was identified between nutritional status and food intake rates. Pre-schoolers with higher weight-for-height values achieved greater height-for-age. These relationships can be explained by life history theory in that energy intake was used either for maintenance (combating and recovering from infections) or growth. The poor relationship between food intake rates and nutritional status is probably explained by the interaction between high disease incidence and insufficient energy intake. These conditions are endemic in Yucatan due to widespread poor housing, water and sanitation conditions.

  10. 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.

  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. Groundwater-flow modeling in the Yucatan karstic aquifer, Mexico

    Science.gov (United States)

    González-Herrera, Roger; Sánchez-y-Pinto, Ismael; Gamboa-Vargas, José

    2002-09-01

    The current conceptual model of the unconfined karstic aquifer in the Yucatan Peninsula, Mexico, is that a fresh-water lens floats above denser saline water that penetrates more than 40 km inland. The transmissivity of the aquifer is very high so the hydraulic gradient is very low, ranging from 7-10 mm/km through most of the northern part of the peninsula. The computer modeling program AQUIFER was used to investigate the regional groundwater flow in the aquifer. The karstified zone was modeled using the assumption that it acts hydraulically similar to a granular, porous medium. As part of the calibration, the following hypotheses were tested: (1) karstic features play an important role in the groundwater-flow system; (2) a ring or belt of sinkholes in the area is a manifestation of a zone of high transmissivity that facilitates the channeling of groundwater toward the Gulf of Mexico; and (3) the geologic features in the southern part of Yucatan influence the groundwater-flow system. The model shows that the Sierrita de Ticul fault, in the southwestern part of the study area, acts as a flow barrier and head values decline toward the northeast. The modeling also shows that the regional flow-system dynamics have not been altered despite the large number of pumping wells because the volume of water pumped is small compared with the volume of recharge, and the well-developed karst system of the region has a very high hydraulic conductivity. Résumé. Le modèle conceptuel classique de l'aquifère karstique libre de la péninsule du Yucatan (Mexique) consiste en une lentille d'eau douce flottant sur une eau salée plus dense qui pénètre à plus de 40 km à l'intérieur des terres. La transmissivité de l'aquifère est très élevée, en sorte que le gradient hydraulique est très faible, compris entre 7 et 10 mm/km dans la plus grande partie du nord de la péninsule. Le modèle AQUIFER a été utilisé pour explorer les écoulements souterrains régionaux dans cet

  13. Length-weight relationships of coral reef fishes from the Alacran Reef, Yucatan, Mexico

    OpenAIRE

    Gonzalez-Gandara, C.; Perez-Diaz, E.; Santos-Rodriguez, L.; Arias-Gonzalez, J.E.

    2003-01-01

    Length-weight relationships were computed for 42 species of coral reef fishes from 14 families from the Alacran Reef (Yucatan, Mexico). A total of 1 892 individuals was used for this purpose. The fish species were caught by different fishing techniques such as fishhooks, harpoons, gill and trawl nets. The sampling period was from March 1998 to January 2000.

  14. 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...

  15. 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

  16. 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

  17. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico

    OpenAIRE

    Torres-Castro, M.; Noh-Pech, H.; Puerto-Hern?ndez, R.; Reyes-Hern?ndez, B.; Panti-May, A.; Hern?ndez-Betancourt, S.; Yeh-Gorocica, A.; Gonz?lez-Herrera, L.; Zavala-Castro, J.; Puerto, F.I.

    2016-01-01

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplic...

  18. Detection of Rickettsia felis in Wild Mammals from Three Municipalities in Yucatan, Mexico.

    Science.gov (United States)

    Panti-May, Jesús Alonso; Torres-Castro, Marco; Hernández-Betancourt, Silvia; Dzul-Rosado, Karla; Zavala-Castro, Jorge; López-Avila, Karina; Tello-Martín, Raúl

    2015-09-01

    The aim of this study was to provide information of the occurrence of Rickettsia felis in wild mammals from three municipalities in Yucatan, Mexico. The reactivity of rodent serum to Rickettsia antigens was detected in 80.9% (17 of 21) samples using immunofluorescence assay. Polymerase chain reaction identified rickettsial DNA in spleens of 43.5% (10 of 23) rodents and 57.1% (4 of 7) opossums. The identification of the rickettsial DNA was confirmed as R. felis by restriction fragment length polymorphism and DNA sequencing. This study comprises the first report of R. felis detection in wild mammals in Yucatan.

  19. 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.

  20. Fish community structure and dynamics in a coastal hypersaline lagoon: Rio Lagartos, Yucatan, Mexico

    Science.gov (United States)

    Vega-Cendejas, Ma. Eugenia; Hernández de Santillana, Mireya

    2004-06-01

    Rio Lagartos, a tropical coastal lagoon in northern Yucatan Peninsula of Mexico, is characterized by high salinity during most of the year (55 psu annual average). Even though the area has been designated as a wetland of international importance because of its great biodiversity, fish species composition and distribution are unknown. To determine whether the salinity gradient was influencing fish assemblages or not, fish populations were sampled seasonally by seine and trawl from 1992 to 1993 and bimonthly during 1997. We identified 81 fish species, eight of which accounted for 53.1% considering the Importance Value Index ( Floridichthys polyommus, Sphoeroides testudineus, Eucinostomus argenteus, Eucinostomus gula, Fundulus majalis, Strongylura notata, Cyprinodon artifrons and Elops saurus). Species richness and density declined from the mouth to the inner zone where extreme salinity conditions are prominent (>80) and competitive interactions decreased. However, in Coloradas basin (53 average sanity) and in the inlet of the lagoon, the highest fish density and number of species were observed. Greater habitat heterogeneity and fish immigration were considered as the best explanation. Multivariate analysis found three zones distinguished by fish occurrence, abundance and distribution. Ichthyofaunal spatial differences were attributed to selective recruitment from the Gulf of Mexico due to salinity gradient and to changing climatic periods. Estuarine and euryhaline marine species are abundant, with estuarine dependent ones entering the system according to environmental preferences. This knowledge will contribute to the management of the Special Biosphere Reserve through baseline data to evaluate environmental and anthropogenic changes.

  1. A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico

    OpenAIRE

    Cárdenas-Marrufo, MaríaFidelia; Vado-Solis, Ignacio; Pérez-Osorio, Carlos; Peniche-Lara, Gaspar; Segura-Correa, José

    2016-01-01

    Introduction: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. Objective: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. Methods: A cross sectional study on women with spontaneous a...

  2. 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.

  3. 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

  4. 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

  5. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana from Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    M. Torres-Castro

    2016-03-01

    Full Text Available Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13 in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

  6. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico.

    Science.gov (United States)

    Torres-Castro, M; Noh-Pech, H; Puerto-Hernández, R; Reyes-Hernández, B; Panti-May, A; Hernández-Betancourt, S; Yeh-Gorocica, A; González-Herrera, L; Zavala-Castro, J; Puerto, F I

    2016-01-01

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

  7. Local evolution of pyrethroid resistance offsets gene flow among Aedes aegypti collections in Yucatan State, Mexico.

    Science.gov (United States)

    Saavedra-Rodriguez, Karla; Beaty, Meaghan; Lozano-Fuentes, Saul; Denham, Steven; Garcia-Rejon, Julian; Reyes-Solis, Guadalupe; Machain-Williams, Carlos; Loroño-Pino, Maria Alba; Flores-Suarez, Adriana; Ponce-Garcia, Gustavo; Beaty, Barry; Eisen, Lars; Black, William C

    2015-01-01

    The mosquito Aedes aegypti is the major vector of the four serotypes of dengue virus (DENV1-4). Previous studies have shown that Ae. aegypti in Mexico have a high effective migration rate and that gene flow occurs among populations that are up to 150 km apart. Since 2000, pyrethroids have been widely used for suppression of Ae. aegypti in cities in Mexico. In Yucatan State in particular, pyrethroids have been applied in and around dengue case households creating an opportunity for local selection and evolution of resistance. Herein, we test for evidence of local adaptation by comparing patterns of variation among 27 Ae. aegypti collections at 13 single nucleotide polymorphisms (SNPs): two in the voltage-gated sodium channel gene para known to confer knockdown resistance, three in detoxification genes previously associated with pyrethroid resistance, and eight in putatively neutral loci. The SNPs in para varied greatly in frequency among collections, whereas SNPs at the remaining 11 loci showed little variation supporting previous evidence for extensive local gene flow. Among Ae. aegypti in Yucatan State, Mexico, local adaptation to pyrethroids appears to offset the homogenizing effects of gene flow. © The American Society of Tropical Medicine and Hygiene.

  8. 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...

  9. 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...

  10. PES Impact and Leakages over Several Cohorts: The Case of PSA-H in Yucatan, Mexico

    OpenAIRE

    LE VELLY , Gwenole; Sauquet , Alexandre; CORTINA-VILLAR , Sergio

    2015-01-01

    We assess the impact of a payment for environmental services scheme implemented in Mexico, the PSA-H, over the 2005-2012 period. By studying several cohorts of program beneficiaries we are able to shed lights on the permanence of the program's impact. Based on the exploitation of 2.5 to 20m resolution SPOT images and ejido-surveys carried out in 76 ejidos located in the Cono Sur of Yucatan, we find that the program's effects are cancelled after communities choose to withdraw from the program,...

  11. Chitons (Mollusca, Polyplacophora) from Alacranes Reef, Yucatan, Mexico

    Science.gov (United States)

    Reyes-Gómez, Adriana; Ortigosa, Deneb; Simões, Nuno

    2017-01-01

    Abstract This study represents the first comprehensive chiton study from Alacranes Reef, the largest reef system in the Gulf of Mexico. Nine chiton species were found in seven localities within the area, in the intertidal and subtidal to 12 m depth. SEM examination of C. janeirensis, A. hemphilli, T. schrammi and C. floridanus, showed variations in the sculpture and radular teeth morphology when compared to specimens of the same species from Florida Keys, Bahamas and Puerto Rico. The distribution ranges of T. schrammi, L. liozonis and S. floridana are extended into the south-western area of the Gulf of Mexico. Altogether, combining previous literature and the present survey, reports eleven chiton species which have now been recorded within the Alacranes reef area. PMID:28769624

  12. Chitons (Mollusca, Polyplacophora from Alacranes Reef, Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Adriana Reyes-Gómez

    2017-04-01

    Full Text Available This study represents the first comprehensive chiton study from Alacranes Reef, the largest reef system in the Gulf of Mexico. Nine chiton species were found in seven localities within the area, in the intertidal and subtidal to 12 m depth. SEM examination of C. janeirensis, A. hemphilli, T. schrammi and C. floridanus, showed variations in the sculpture and radular teeth morphology when compared to specimens of the same species from Florida Keys, Bahamas and Puerto Rico. The distribution ranges of T. schrammi, L. liozonis and S. floridana are extended into the south-western area of the Gulf of Mexico. Altogether, combining previous literature and the present survey, reports eleven chiton species which have now been recorded within the Alacranes reef area.

  13. 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.

  14. Validation of an indirect ELISA for the diagnosis of Babesia bovis in cattle in Yucatan, Mexico

    International Nuclear Information System (INIS)

    Dominguez, A.J.L.; Rodriguez, V.R.I.; Oura, C.; Cob, G.L.A.

    1998-01-01

    The ELISA kit provided by the FAO/IAEA for the diagnosis of Babesia bovis was validated. In order to determine the appropriate ELISA cut-off point that would serve as the threshold between positive and negative samples, 119 serum samples from a Mexican Babesia-free zone were analyzed. The optimal cut-off point chosen was at 12% of the reactivity of the high positive control serum sample (PP) which resulted in a specificity of 97%. One hundred and ninety-six cattle from Wisconsin, USA, were introduced into Yucatan, Mexico, of which 181 were vaccinated with an attenuated live Babesia bovis vaccine; 15 animals remained as unvaccinated controls. Before and after vaccination all animals were bled and tested by enzyme linked immunosorbent assay (ELISA) and indirect fluorescence antibody test (IFAT). Both tests showed a high degree of correlation in their results. To evaluate an immune response to vaccination the optimal cut-off point chosen was 12% PP resulting in a sensitivity 99% and a specificity 95%. We concluded that the ELISA test has proved to be useful in Yucatan, Mexico for serological surveys and monitoring the efficiency o vaccination programmes. (author)

  15. Pigging the unpiggable: a total integrated maintenance approach of the Progreso Process Pipelines in Yucatan, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Graciano, Luis [PEMEX Refinacion, Mexico, MX (Mexico); Gonzalez, Oscar L. [NDT Systems and Services, Stutensee (Germany)

    2009-07-01

    Pemex Refinacion and NDT Systems and Services, executed a Total Integrated Maintenance Program of the Process Pipeline System in the Yucatan Peninsula in Mexico, in order to modernize, enhance and bring the pipeline system up to the best industry standards and ensure the integrity, reliability and safe operation of the system. This approach consisted in using multi-diameter ultrasonic inspection technology to determine the current status of the pipelines, repair every 'integrity diminishing' feature present on the system and establish a Certified Maintenance Program to ensure the future reliability and safety of the pipelines. Due to the complex nature of the pipeline construction, dated from 1984, several special modifications, integrations and solutions were necessary to improve the in line inspection survey as for all traditionally unpiggable systems. The Progreso Pipeline System consists in 3 major pipelines which transport diesel, jet fuel and gasoline respectively. The outside diameter of two pipelines varies along its length between 12 inches - 14 inches - 16 inches, making the inspection survey more difficult and particularly demanding an Inspection Tool solution. It is located on the coast of the Yucatan Peninsula, at the Mexican Caribbean, and its main purpose is to transport the product from the docked tanker ships to the Pemex Storage and Distribution Terminal. (author)

  16. Effectiveness of a regional self-study perinatal education programme: a successful adaptation in Yucatan, Mexico.

    Science.gov (United States)

    Osorno, Lorenzo R; Campos, Miriam C; Cook, Lynn J; Vela, Gabriela R; Dávila, Jorge R

    2006-08-01

    To evaluate the effectiveness of the Perinatal Continuing Education Programme (PCEP) in a Latin American country. We carried out a study within secondary and tertiary care, and rural Mexican Institute of Social Security (IMSS) hospitals on the Yucatan Peninsula. Participants were doctors, nurses and nursing assistants working with pregnant women and newborns at each hospital. The PCEP was translated into Spanish and then implemented between January 1998 and December 2001. Two nurses at each hospital were trained to co-ordinate the programme and the personnel were invited to participate. Participation involved purchasing the self-teaching books, study outside work hours and participation in skills demonstration and practice sessions. Evaluation included the percentage of personnel who participated in and those who completed the programme, an opinion survey of the programme, level of pre- and post-intervention knowledge, and the quality of neonatal care according to expert-recommended routines. Results were analysed with chi-square and Student's t-tests. A total of 65.3% of the 1421 people in the study population began the programme and 72% of those completed it. Improvement was observed in 14 of 23 (Pevaluated neonatal care practices. Participants rated the written material as very clear and useful in daily practice. The PCEP is an effective strategy for improving the level of knowledge and perinatal care in all regional hospitals on the Yucatan Peninsula, Mexico. This initial application of the PCEP in a Spanish-speaking country was successful.

  17. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO.

    Science.gov (United States)

    Peniche-Lara, Gaspar; Ruiz-Piña, Hugo A; Reyes-Novelo, Enrique; Dzul-Rosado, Karla; Zavala-Castro, Jorge

    2016-01-01

    Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltA and 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households.

  18. 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

  19. 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

  20. 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

  1. Levels of persistent organic pollutants in breast milk of Maya women in Yucatan, Mexico.

    Science.gov (United States)

    Polanco Rodríguez, Ángel G; Inmaculada Riba López, M; Angel DelValls Casillas, T; León, Jesús Alfredo Araujo; Anjan Kumar Prusty, B; Álvarez Cervera, Fernando J

    2017-02-01

    In this study, 24 breast milk samples, obtained from rural Maya women, from municipalities of Yucatan, Mexico, were analyzed for organochlorine pesticide (OCP) residues by gas chromatography. Recent studies have shown that Maya communities have a poor perception about the proper usage and handling of OCP. The karstic soil in this area has a high vulnerability to groundwater pollution by the use of OCP in agriculture and livestock activities. The impact of the ecosystem on human health is much more critical due to the prevailing poverty and a very low educational level of these communities. About 30% of the Maya population consumes water directly from contaminated wells and sinkholes, resulting in a chronic exposure to OCP. The samples served to identify and quantify high levels of OCP residues (18.43 mg/kg of heptachlor epoxide and 1.92 mg/kg of endrin in the metropolitan zone; 2.10 mg/kg of dieldrin, 0.117 mg/kg of endosulfan II, 0.103 mg/kg of heptachlor, 0.178 mg/kg of endrin, and 0.127 mg/kg of endrin aldehyde in the main agricultural zone and on the west coast). The detected levels of OCP residues are a major concern and represent a potential risk to women and children in the region. This could be associated with the high rates of cervical uterine and breast cancer mortality in Yucatan. Thus, regulations on the usage of OCP and their enforcement are necessary, and it is important to establish a yearly monitoring program for OCP residues in breast milk and groundwater, as well as to implement health promotion programs for women in particular and the general population in general.

  2. 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.

  3. 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.

  4. Global Mercury Observatory System (GMOS): measurements of atmospheric mercury in Celestun, Yucatan, Mexico during 2012.

    Science.gov (United States)

    Velasco, Antonio; Arcega-Cabrera, Flor; Oceguera-Vargas, Ismael; Ramírez, Martha; Ortinez, Abraham; Umlauf, Gunther; Sena, Fabrizio

    2016-09-01

    Within the Global Mercury Observation System (GMOS) project, long-term continuous measurements of total gaseous mercury (TGM) were carried out by a monitoring station located at Celestun, Yucatan, Mexico, a coastal site along the Gulf of Mexico. The measurements covered the period from January 28th to October 17th, 2012. TGM data, at the Celestun site, were obtained using a high-resolution mercury vapor analyzer. TGM data show values from 0.50 to 2.82 ng/m(3) with an annual average concentration of 1.047 ± 0.271 ng/m(3). Multivariate analyses of TGM and meteorological variables suggest that TGM is correlated with the vertical air mass distribution in the atmosphere, which is influenced by diurnal variations in temperature and relative humidity. Diurnal variation is characterized by higher nighttime mercury concentrations, which might be influenced by convection currents between sea and land. The back trajectory analysis confirmed that local sources do not significantly influence TGM variations. This study shows that TGM monitoring at the Celestun site fulfills GMOS goals for a background site.

  5. Education, fish consumption, well water, chicken coops, and cooking fires: Using biogeochemistry and ethnography to study exposure of children from Yucatan, Mexico to metals and arsenic.

    Science.gov (United States)

    Arcega-Cabrera, Flor; Fargher, Lane F

    2016-10-15

    Around the world, the nocuous health effects of exposure to environmental contaminants, especially metals and Arsenic, are a growing health concern. This is especially the case in Mexico, where corruption and ineffective political administration are contributing to increasing deterioration in the environment. Importantly, shallow soils and the karstic nature of bedrock in Yucatan, Mexico make the subterranean aquifer especially susceptible to contamination because contaminates are carried to it with little resistance. Given these environmental conditions, we developed a multi/interdisciplinary project to evaluate the impact of metal and Arsenic pollution on a sample of 107 children, ages 6 to 9years, living in the urban areas of Progreso, Merida, and Ticul, in the State of Yucatan using urine and blood samples. In addition, ethnographic research was carried out in the homes of the children that participated in the study to identify potential exposure pathways. This research proved invaluable because the complexity of human social organization, lifestyles, and geographical patterning create an intricate array of exposure pathways that vary across social sectors and geographic space. In the following article, we use nonparametric univariate statistical analysis to reveal potential exposure pathways among sub-populations included in our sample. These analyses show that children from poor/marginal families tend to be exposed to Copper, Lead, and Nickel; whereas, children, from wealthier families, tend to be exposed to Cadmium, Arsenic, and inorganic Copper (Copper Sulfate). Copyright © 2016 Elsevier B.V. All rights reserved.

  6. ESTABLISHMENT OF TREE ASSOCIATION WITH CAOBA AND RAMON IN AN ABANDONED QUARRY IN YUCATAN, MEXICO

    Directory of Open Access Journals (Sweden)

    Patricia Montañez Escalante

    2009-02-01

    Full Text Available The influence of the association trees on the height and diameter growth  of mahogany (Swietenia macrophylla King and ramón (Brosimum alicastrum Sw. plantations during the establishment period in an quarry near the city of Merida, Yucatan, Mexico, was evaluated. Associated trees to mahogany were  tamarindo (Tamarindus indica L. and achiote (Bixa orellana L.. Associated trees to ramón were huaxin (Leucaena leucocephala (Lam de Wit. and pixoy (Guazuma ulmifolia Lam.. Tree association effects on the growth in height and diameter of mahogany and ramón were analyzed. The production of fruits and forage in the associated tree species was determined. There were no significant differences in mahogany and ramón diameter and height growth (p> 0.05 among treatments. To associate the ramón with other species of fast growth like huaxin and pixoy pruning was repeatedly conducted on this species to obtain the light levels required for ramón. The forage production of haxin and pixoy was 2 t dry matter ha-1 y-1 and there were not significant differences (p>0.05. The time required to get productive age in the species like ramon and mahogany offer opportunities to use the interspaces during growth period.

  7. Bioarchaeological investigation of ancient Maya violence and warfare in inland Northwest Yucatan, Mexico.

    Science.gov (United States)

    Serafin, Stanley; Lope, Carlos Peraza; Uc González, Eunice

    2014-05-01

    This study investigates evidence of changes and continuities in ancient Maya violence and warfare in inland northwest Yucatan, Mexico from the Middle Preclassic (600-300 BC) to the Postclassic (AD 1050-1542) through bioarchaeological analysis of cranial and projectile trauma. It is hypothesized that the frequency of violence increases before the Classic Maya collapse and remains high during the Postclassic period. It is also hypothesized that the flat, open terrain was conducive to warfare and resulted in higher trauma frequencies than in other parts of the Maya area. Results show that the frequency of cranial trauma decreases before the Classic collapse and increases in the Postclassic, partially matching the expected chronological trends. The frequency of cranial trauma does not differ significantly from other Maya regions but the pattern does: for all periods, males have more healed injuries than females and they are concentrated on the left side of the anterior of the skull. Some injuries appear to be from small points hafted in wooden clubs. In addition, projectile trauma is evident in a scapula with an embedded arrowhead tip, the first such case reported in a Maya skeleton. Overall, these results suggest greater reliance on open combat and less on raids in this region compared with other parts of the Maya area, possibly due to the flat, open terrain, though the identification of perimortem trauma in both women and men indicates surprise raids on settlements were also practiced. Copyright © 2014 Wiley Periodicals, Inc.

  8. Host-Feeding Preference of the Mosquito, Culex quinquefasciatus, in Yucatan State, Mexico

    Science.gov (United States)

    Garcia-Rejon, Julian E.; Blitvich, Bradley J.; Farfan-Ale, Jose A.; Loroño-Pino, Maria A.; Chi Chim, Wilberth A.; Flores-Flores, Luis F.; Rosado-Paredes, Elsy; Baak-Baak, Carlos; Perez-Mutul, Jose; Suarez-Solis, Victor; Fernandez-Salas, Ildefonso; Beaty, Barry J.

    2010-01-01

    Studies were conducted to determine the host-feeding preference of Culex quinquefasciatus Say (Diptera: Culicidae) in relation to the availability of human and domestic animals in the city of Merida, Yucatan State, Mexico. Mosquitoes were collected in the backyards of houses using resting wooden boxes. Collections were made five times per week from January to December 2005. DNA was extracted from engorged females and tested by PCR using universal avian- and mammalian-specific primers. DNA extracted from avian-derived blood was further analyzed by PCR using primers that differentiate among the birds of three avian orders: Passeriformes, Columbiformes and Galliformes. PCR products obtained from mammalian-derived blood were subjected to restriction enzyme digestion to differentiate between human-, dog-, cat-, pig-, and horse-derived blood meals. Overall, 82% of engorged mosquitoes had fed on birds, and 18% had fed on mammals. The most frequent vertebrate hosts were Galliformes (47.1%), Passeriformes (23.8%), Columbiformes (11.2%) birds, and dogs (8.8%). The overall human blood index was 6.7%. The overall forage ratio for humans was 0.1, indicating that humans were not a preferred host for Cx. quinquefasciatus in Merida. PMID:20578953

  9. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp. FROM YUCATAN, MEXICO

    Directory of Open Access Journals (Sweden)

    Gaspar PENICHE-LARA

    2016-01-01

    Full Text Available Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltAand 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1% from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households.

  10. 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.

  11. 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

  12. Ancient shoreline reconstruction at a Maritime Maya Port in Yucatan, Mexico

    Science.gov (United States)

    Jaijel, Roy; Goodman, Beverly; Glover, Jeffrey; Rissolo, Dominique; Beddows, Patricia; Carter, Alice; Smith, Derek; Ben Avraham, Zvi

    2017-04-01

    Throughout history, worldwide, a major part of the human experience has been to adapt to changing landscapes, and environments. These adaptations can take many forms, sometimes as innovation, manipulation of the conditions, behavioral or technological changes; and in some cases the decision to abandon the area. The northeastern Yucatan peninsula, home of the Maritime maya port site Vista-Alegre, shows signs of such human changes, though little is known about the corresponding landscape and environment. Vista Alegre is located on the meeting point of the Caribbean Sea and the Gulf of Mexico, at the north-eastern tip of the Yucatan peninsula, in the back of the Holbox lagoon. The site was inhabited from the 9th century B.C until the mid 16th century A.D., with an apparent two century abandonment phase from the mid 7th to 9th century A.D. A multidisciplinary effort ("Costa Escondida project") has been investigating the life of past Mayan inhabitants and the broader connections of the site to the Maritime Maya trade network. One of the questions that has arisen is what were the mutual influences between the inhabitants to their surrounding environment. In order to answer that question the site's shoreline geomorphology and climate history is being reconstructed for the past 2-3000 years. The reconstruction is based on multiproxy analysis of marine sediment cores and surface samples, combined with archaeological data. The study presented focuses on the shoreline shifts at the site, revealing the complexity, and significant affect of sea level rise on the marine environment of Vista Alegre. This study contributes to our understanding of the site's possible functions, the environmental challenges the local inhabits contended with, and the identification of ancient harboring locations. The results show five depositional phases over the past 2-3000 years. The ancient shoreline maps show a general trend of sea level rise, though with varying rates over time that relates well

  13. Seasonal abundance of crustaceans associated with artisanal fishery of blue crab (Callinectes sapidus) in Sisal, Yucatan, Mexico

    OpenAIRE

    Celis-Sánchez, José Alfredo; Estrella-Canto, Arely de Jesús; Poot-López, Gaspar Román; González-Salas, Carlos; López-Rocha, Jorge Alberto

    2014-01-01

    Seasonal abundance and selectivity of the main crustacean species associated with blue crab fishing was studied at the port of Sisal, Yucatan, Mexico. For this purpose, 52 crab traps were used, which were divided into four parallel transects placed 100, 150, 200 and 250 m of the shoreline. Each transect consisted of 13 traps 20 m from each other. Traps were set at dusk and checked at dawn, standardizing the fishing effort to 17 hours/trap/day. A total of 832 organisms from eight species were ...

  14. 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.

  15. 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.

  16. A Three-Dimensional Sustainability Evaluation of Jatropha Plantations in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Julio C. Sacramento Rivero

    2016-12-01

    Full Text Available This paper presents a unique sustainability analysis of one of the first attempts to establish a biodiesel industry in Mexico. From 2008, several companies established medium to large-sized Jatropha curcas plantations in Yucatan, hiring local peasants to carry out the agricultural work. After five years, the plantations were abandoned due to poor seed yields and a lack of key knowledge for large-scale cultivation. Based on a multidisciplinary approach, we performed a three-dimensional sustainability evaluation of the potential biodiesel production chain, which included household interviews, a socioeconomic survey, and a life-cycle assessment (LCA. We identified both negative and positive effects in the three dimensions analyzed. Socially and culturally, the local peasant families understood sustainability as their ability to preserve their traditional lifestyle, and associated environmental services with their sense of identity. They therefore considered the jatropha plantations to be positive for sustainability, since they brought income, even though some perceived damage to the natural resources of the surrounding areas. Economically, peasants’ annual household income increased by approximately $1080 USD due to the increased salaries paid by the jatropha companies. The LCA predicted large savings of greenhouse gas emissions (>50% compared to fossil diesel, but also potential negative impacts in some categories (human/ecological toxicity and eutrophication potentials associated with the use of mineral fertilizers, insecticides, and pesticides applied during the cultivation stage. Biodiesel production would be potentially energetically self-sufficient, in addition to producing a 40% energy surplus. Finally, even though the sustainability indicators suggested a positive overall assessment, the reality was that the jatropha projects failed because they were predicated on unrealistically optimistic projections and poor agronomic knowledge of the

  17. An epidemiological study of intestinal parasites of dogs from Yucatan, Mexico, and their risk to public health.

    Science.gov (United States)

    Rodríguez-Vivas, Roger Ivan; Gutierrez-Ruiz, Edwin; Bolio-González, Manuel Emilio; Ruiz-Piña, Hugo; Ortega-Pacheco, Antonio; Reyes-Novelo, Enrique; Manrique-Saide, Pablo; Aranda-Cirerol, Francisco; Lugo-Perez, J A

    2011-08-01

    The prevalence of intestinal parasites in dogs and factors associated were studied in a rural community of Yucatan (southern Mexico), with special attention to those gastrointestinal parasites potentially transmitted to man. One hundred thirty dogs from 91 households were studied. Fecal samples were processed by the centrifugation-flotation and the McMaster techniques. To determine factors associated with zoonotic parasites in dogs, univariate analysis was performed, using sex, age, and body condition as independent variables. Variables with p caninum, Thichuris vulpis, Toxocara canis, and Dipylidium caninum) and coccidian oocysts were detected. A. caninum was the most prevalent parasite (73.8%), followed by T. vulpis (25.4%), T. canis (6.2%), D. caninum (2.3%), and coccidian oocysts (2.3%). The majority of dogs were infected by only one species of parasite (70/130, 53.8%). Mixed infection caused by two or three zoonotic parasites were discovered in 21.3% (30/130) and 3.1% (4/130), respectively. A. caninum showed the highest egg output (42.3% of dogs had ≥ 500 eggs per gram). Factors associated with zoonotic parasites were age (<2 years old; odds ratio = 5.30, p = 0.029) and body condition (poor body condition; odds ratio = 6.69, p = 0.026). In conclusion, young dogs from rural Yucatan, Mexico, with poor body condition had a higher prevalence of intestinal zoonotic parasites as these factors were associated with a higher risk of becoming infected.

  18. 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

  19. 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...

  20. 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

  1. REMOVAL EFFICIENCY OF ORGANIC MATTER OF PIG SLURRY WITH BIODIGESTERS IN YUCATAN STATE, MEXICO

    Directory of Open Access Journals (Sweden)

    W. Trejo-Lizama

    2014-08-01

    Full Text Available In the intensive pig production in the state of Yucatan, 62 biodigesters were installed in the last 10 years. However, the complexities of the anaerobic biodigestion enclose difficulties to reach the expected efficiency. The objective of the present study was to determine the removal efficiency of the organic matter in pig slurry using biodigesters in the state of Yucatan. There were visited 15 pig farms in the state of Yucatan to interview the farmer about the management of the farm and the waste disposal and to take samples of the influent of the collector of the pig slurry and the effluent of the biodigestor and evaluating the samples by laboratory analysis. The removal values found in the present study were 7 percentage points below the reference value of total volatile solids, which represent the organic matter fraction of the solids treated in the biodigestor. More than the 50 % of the farms evaluated were similar or higher than the parameters of reference. The removal efficiency of the organic matter in the pig slurry by biodigesters in the state of Yucatan is close to the reference values. However complementary treatments are necessary to continue the waste slurry treatment.

  2. 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

  3. 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

  4. 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.

  5. Multivariate Statistical Analysis: a tool for groundwater quality assessment in the hidrogeologic region of the Ring of Cenotes, Yucatan, Mexico.

    Science.gov (United States)

    Ye, M.; Pacheco Castro, R. B.; Pacheco Avila, J.; Cabrera Sansores, A.

    2014-12-01

    The karstic aquifer of Yucatan is a vulnerable and complex system. The first fifteen meters of this aquifer have been polluted, due to this the protection of this resource is important because is the only source of potable water of the entire State. Through the assessment of groundwater quality we can gain some knowledge about the main processes governing water chemistry as well as spatial patterns which are important to establish protection zones. In this work multivariate statistical techniques are used to assess the groundwater quality of the supply wells (30 to 40 meters deep) in the hidrogeologic region of the Ring of Cenotes, located in Yucatan, Mexico. Cluster analysis and principal component analysis are applied in groundwater chemistry data of the study area. Results of principal component analysis show that the main sources of variation in the data are due sea water intrusion and the interaction of the water with the carbonate rocks of the system and some pollution processes. The cluster analysis shows that the data can be divided in four clusters. The spatial distribution of the clusters seems to be random, but is consistent with sea water intrusion and pollution with nitrates. The overall results show that multivariate statistical analysis can be successfully applied in the groundwater quality assessment of this karstic aquifer.

  6. 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

  7. Capillaria (Hepatocapillaria) cichlasomae (Nematoda: Capillariidae) from the liver of the cichlid fish Cichlasoma urophthalmus from Yucatan, Mexico.

    Science.gov (United States)

    Moravec, F; Scholz, T; Mendoza Franco, E

    1995-01-01

    Capillaria (Hepatocapillaria) cichlasomae sp. n., parasitic in the liver of the cichlid Cichlasoma urophthalmus (Günther) from a small freshwater lake ("aguada") Xpoc in Yucatan, Mexico, is described. The parasite is characterized mainly by its small body size (male 1.8 mm, female 4.5 mm), the structure of the stichosome (markedly short stichocytes in one row) and the male (the presence of a pair of small subventral postanal papillae) and female (anus distinctly subterminal) caudal ends, and by the size and structure of the spicule (spicule 0.068-0.085 mm long, with marked transverse grooves on surface) and eggs (size 0.053-0.058 x 0.023 mm, with protruding polar plugs). This is the second known Capillaria species from the liver of fish and the first one from the liver of a freshwater fish.

  8. Water Consumption as Source of Arsenic, Chromium, and Mercury in Children Living in Rural Yucatan, Mexico: Blood and Urine Levels.

    Science.gov (United States)

    Arcega-Cabrera, F; Fargher, L F; Oceguera-Vargas, I; Noreña-Barroso, E; Yánez-Estrada, L; Alvarado, J; González, L; Moo-Puc, R; Pérez-Herrera, N; Quesadas-Rojas, M; Pérez-Medina, S

    2017-10-01

    Studies investigating the correlation between metal content in water and metal levels in children are scarce worldwide, but especially in developing nations. Therefore, this study investigates the correlation between arsenic, chromium, and mercury concentrations in drinking and cooking water and in blood and urine samples collected from healthy and supposedly non-exposed children from a rural area in Yucatan, Mexico. Mercury in water shows concentrations above the recommended World Health Organization (WHO) value for drinking and cooking water. Also, 25% of the children show mercury in urine above the WHO recommended value. Multivariate analyses show a significant role for drinking and cooking water as a vector of exposure in children. Also, the factor analysis shows chronic exposure in the case of arsenic, as well as an ongoing detoxification process through urine in the case of mercury. Further studies should be done in order to determine other potential metal exposure pathways among children.

  9. Copro-necrophagous beetle (Coleoptera: Scarabaeidae diversity in an agroecosystem in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Enrique Reyes Novelo

    2007-03-01

    Full Text Available Scarabaeinae are sensitive to structural habitat changes caused by disturbance. We compared copronecrophagous beetle (Scarabaeinae community structure in three differently managed zones within an agroecosystem of the northern Yucatan Peninsula, Mexico. We placed dung and carrion traps once a month from June 2004 through May 2005. The beetle community included 17 species from the genera Canthon, Canthidium, Deltochilum, Pseudocanthon, Malagoniella, Onthophagus, Phanaeus, Copris, Uroxys, Sisyphus and Ateuchus. The secondary vegetation had a higher beetle diversity than the other two zones. Species richness was highest in the Brosimum alicastrum plantation. The pasture had the lowest species diversity and richness, but exhibited the highest abundance of Scarabaeinae in the dry season. The two zones with extensive tree cover were the most diverse. Roller beetles were dominant over burrower species and small-sized species outnumbered large species. Our data show two important issues: beetle species in the pasture extended their activity to the beginning of the dry season, while abundances dropped in the other, unirrigated zones; and the possibility that the Scarabaeinae living in neotropical forests are opportunistic saprophages and have specialized habits for resources other than dung. The B. alicastrum plantation is beneficial to the entire ranch production system because it functions as a dispersion and development area for stenotopic species limited to tree cover. Rev. Biol. Trop. 55 (1: 83-99. Epub 2007 March. 31.Este estudio describe y compara la estructura de la comunidad de escarabajos copronecrófagos (Scarabaeinae en tres zonas con diferente manejo al interior de un agroecosistema localizado en el norte de la Península de Yucatán. A lo largo de un año de muestreo sistemático se encontraron 17 especies de los géneros Canthon, Canthidium, Deltochilum, Pseudocanthon, Malagoniella, Onthophagus, Phanaeus, Copris, Uroxys, Sisyphus y Ateuchus

  10. 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

  11. Restoring the environment, revitalizing the culture: cenote conservation in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Yolanda Lopez-Maldonado

    2017-12-01

    Full Text Available Cenotes are sinkholes through which groundwater may be accessed from the Yucatan Peninsula Aquifer. Historically and culturally, cenotes are also important cultural and spiritual natural sites for the Maya, but they have been contaminated and degraded. We ask the following: What are the present-day meanings, understanding, and values of cenotes for the Maya? Is it possible to adopt a cultural approach for conservation of cenotes in Yucatan? Participant observation, interviews with stakeholders, and underwater exploration in cenotes were used to obtain data. Results indicate that cenotes often retain some spiritual meaning for people but not as important cultural, spiritual, or sacred sites. Little consensus was found regarding the significance of cenotes and how best to protect them. Informants noted changes in water quality, and identified the threats to cenotes including tourism, poor solid waste management, contamination, and deficiency of interest in preservation. Lack of accurate knowledge was a problem: informants did not seem to understand that cenotes are interconnected through the groundwater system. The Yucatan case illustrates how loss of cultural values can be linked to environmental quality and resource degradation. Conversely, it can be argued that cultural revitalization in indigenous communities has the potential to bring back community-based conservation.

  12. First Detection of the Kdr Mutation T929I in Head Lice (Phthiraptera: Pediculidae) in Schoolchildren of the Metropolitan Area of Nuevo Leon and Yucatan, Mexico.

    Science.gov (United States)

    Ponce-Garcia, Gustavo; Villanueva-Segura, Karina; Trujillo-Rodriguez, Gerardo; Rodriguez-Sanchez, Iram P; Lopez-Monroy, Beatriz; Flores, Adriana E

    2017-07-01

    The head louse Pediculus humanus capitis (De Geer) is a hematophagous ectoparasite that inhabits the human scalp. Infestations by this insect are commonly known as pediculosis, which is more common in younger groups. These infestations are asymptomatic; however, skin irritation from scratching occasionally may cause secondary bacterial infections. In recent years, the prevalence of pediculosis has increased in children; this increase has been attributed to louse resistance to the insecticides used as a control measure for infestation. The aim of the present study was to determine the presence and frequency of the knockdown resistance mutation (kdr) T929I in 468 head lice collected from 32 elementary schools in the metropolitan area of Nuevo Leon (24) and Yucatan (8), Mexico. This is the first report of a knockdown resistance (kdr) mechanism in head lice from Mexico. The T929I mutation was present in all of the sampled schools, with variability observed in its allelic and genotypic frequencies. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Superficial methane emissions from a landfill in Merida, Yucatan, Mexico; Emisiones superficiales de metano en un relleno sanitario en Merida, Yucatan, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sauri-Riancho, Maria Rosa [Universidad Autonoma de Yucatan, Yucatan (Mexico)]. E-mail: sriancho@uady.mx; Stentiford, Edward I. [University of Leeds (UK)]. E-mail: e.i.stentiford@leeds.ac.uk; Gamboa-Marrufo, Mauricio; Reza-Bacelis, Gabriela; Cahuich-Poot, Nayla; Mendez-Novelo, Roger [Universidad Autonoma de Yucatan, Yucatan (Mexico)]. E-mails: gmarrufo@uady.mx; gabriela.reza@proactiva.com.mx; nayre63@hotmail.com; mnovelo@uady.mx

    2013-07-15

    On worldwide scale, one of the most important anthropogenic methane sources is landfill disposal for solid wastes. The main goal of this work was to quantify methane emissions at one landfill built in Merida, Mexico. This site had venting wells by which a passive control for biogas movement was exerted. At the venting wells, methane concentrations were measured monthly during a 6 months period. Methane surface emission rate was estimated with the close chamber technique. Obtained results indicated that there are both spatial and seasonal variations in biogas composition. The average methane value during the monitoring period was 21.9% (12.7 to 32.5 V/V) and the surface flow rate was in the range of 0 to 6,004 g CH{sub 4} m-2 d-1, with an average value of 1,480 g CH{sub 4} m-2 d-1, which is a high value in respect to these reported in publications. [Spanish] Entre las fuentes antropogenicas mas importantes de metano a escala mundial se encuentra la disposicion final de los residuos solidos. El objetivo de este trabajo fue cuantificar las emisiones de metano provenientes de un relleno sanitario en Merida, Mexico, en el que el movimiento del biogas se controlaba pasivamente utilizando pozos de venteo. Las concentraciones de metano se midieron mensualmente en los pozos de venteo del sitio a lo largo de un periodo de 6 meses. La tasa de emision superficial de metano se determino utilizando la tecnica de camara cerrada. Los resultados indicaron que existen variaciones considerables tanto espaciales como estacionales de la composicion del biogas proveniente de los pozos de venteo con un promedio de concentracion de metano en el sitio, durante todo el periodo de monitoreo, de 21.9% (12.7 a 32.5 V/V). Los flujos superficiales de gas medidos en diversos puntos a lo largo de la superficie del relleno sanitario tuvieron un promedio de 1,480 g CH{sub 4} m-2 d-1, lo que se considero un valor muy alto cuando se comparo con la informacion hallada en la literatura. El intervalo

  14. 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.

  15. Two new species of dicyemid mesozoans (Dicyemida: Dicyemidae) from Octopus maya Voss & Solis-Ramirez (Octopodidae) off Yucatan, Mexico.

    Science.gov (United States)

    Castellanos-Martinez, Sheila; Aguirre-Macedo, M Leopoldina; Furuya, Hidetaka

    2016-07-01

    Two new dicyemid species are described from the endemic cephalopod Octopus maya Voss & Solis-Ramirez collected off Yucatan, Mexico. The renal sacs of 40 juvenile and adult octopuses from four localities were examined. Dicyema hochbergi n. sp. is a medium-sized species that reaches 2,245 µm in length. The vermiform stages consist of 18-24 peripheral cells, a conical calotte and the extension of the axial cell between the base and middle of the metapolar cells. Infusoriform embryos consist of 39 cells with urn cell containing one germinal cell, two nuclei and solid refringent bodies. Dicyema mexcayae n. sp. is a relatively small species that reaches 1,114 µm in length. The vermiform stages are constituted by 14-16 peripheral cells, an elongate calotte and the axial cell extending forward to the middle of the metapolar cells. The infusoriform embryos consist of 37 cells, two solid refringent bodies and urn cells with two nuclei each. The present study represents the first description of a dicyemid species from O. maya and increases the number of described species from Mexican waters to 11.

  16. 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.

  17. Fecal sterols, seasonal variability, and probable sources along the ring of cenotes, Yucatan, Mexico

    Science.gov (United States)

    Arcega-Cabrera, F.; Velázquez-Tavera, N.; Fargher, L.; Derrien, M.; Noreña-Barroso, E.

    2014-11-01

    Rapid development in Yucatan has had a dramatic impact on the environment, especially the water supply. Groundwater is the only source of water in Yucatan, since surface water is virtually absent due to the karstic nature of the soil. The ring of cenotes (RC) is a geological feature which functions as a source of water and as nodes in the underground river system that canalizes water towards the coast. Numerous productive and domestic activities take place around the RC in the absence of wastewater treatment or sewage systems. Consequently, a number of researchers have hypothesized that pollutants could migrate from the land surface to the underlying aquifer and, eventually, to the coast. Therefore, the present study investigates the relationship among sources of fecal sterols and their levels in cenotes, using the expected levels of fecal sterols obtained by a spatial analysis of the sources and a Pollution Source Index. Accordingly, expected levels are compared with the detected levels of fecal sterols in 5 areas around the RC. Regarding levels, observed during a sampling campaign carried out along the RC during September 2011 (rainy season) and May 2012 (dry season), varied from low to high concentrations of sterols (0.5-2396.42 μg g- 1) and fecal sterols (0.3-1690.18 μg g- 1). These concentrations showed no relationship between neighboring cenotes, where similar fecal sterol concentrations or gradients were expected. When comparing expected fecal sterols levels with the detected ones, only two of the five analyzed areas concur, suggesting that no clear relationship exists among sources and fecal sterols levels at the regional scale. Multivariate analysis showed that fecal sterols were associated with sterols and fine grain particulates during the rainy season, which suggests co-transport. During the dry season, fecal sterols associated with fine grain particulate and organic matter, which indicates a change to a deposition phenomenon. These findings indicate

  18. Settlement patterns and communication routes of the western Maya wetlands: An archaeological and remote-sensing survey, Chunchucmil, Yucatan, Mexico

    Science.gov (United States)

    Hixson, David R.

    This dissertation investigates the role of the seasonal wetlands in the political economy and subsistence strategies of the ancient Maya of Chunchucmil, Yucatan, Mexico. A combination of pedestrian surveys and remote-sensing tasks were performed in order to better understand the settlement patterns and potential communication routes in and through the wetlands between Chunchucmil and the Gulf of Mexico. These western wetlands had been proposed as the principal avenue for interregional trade between coastal merchants and inland consumers, yet were thought to be uninhabited and uncultivable. Following the survey tasks outlined in this dissertation, these wetlands were found to contain an abundance of archaeological settlements and features indicating habitation, utilization, and trade throughout this diverse ecological zone. The remote-sensing platforms utilized in this study include both multispectral (Landsat) and synthetic aperture radar (AirSAR), combined with additional remotely sensed resources. One of the goals of this survey was to test the capabilities of these two sensors for the direct detection of archaeological features from air and space. The results indicate that Landsat can be highly successful at detecting site location and measuring site size under certain environmental conditions. The Airborne Synthetic Aperture Radar proved to be adept at detecting large mounded architecture within the Yucatecan karstic plain, but its further utility is hampered by limitations of resolution, scale, and land cover. One of the salient features of the landscape west of Chunchucmil is a network of stone pathways called andadores. These avenues through the wetlands outline a dendritic network of communication, trade, and extraction routes. The following dissertation places this network and its associated settlements (from suburban centers to diminutive camps) within their regional context, examining the roles they may have played in supporting a large mercantile

  19. 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.

  20. HYDROGEOLOGY AND CONCEPTUAL MODEL OF THE KARSTIC COASTAL AQUIFER IN NORTHERN YUCATAN STATE, MEXICO

    Directory of Open Access Journals (Sweden)

    Miguel J Villasuso-Pino

    2011-04-01

    Full Text Available The coastal zone of northern Yucatan Peninsula (YP is mainly constituted by Tertiary limestones, covered by Pleistocen limestones, where there exist swamps and estuary systems, locally called “rías”, with mouths connecting them to the sea and hence being a way for an important amount of groundwater to discharge, like in Ría Lagartos and Celestún. These limestones have karstic layers located at depths from 8 to 16 meters below terrain surface.  It is in these layers where groundwater mainly flows toward coast, passing below the sand dune and discharging in the sea in the form of submarine springs which in many cases manifest themselves on the marine surface depending on the hydraulic or piezometric fresh water head. The width of the superficial limestone within this coastal fringe, called “caliche”, varies from 5 to 10 kilometers in the study zone (Chuburna-Progreso-Chicxulub.  Its permeability is extremely low, so it constitutes a confining layer that impedes superficial waters to percolate toward groundwater.  The hydraulic head of the groundwater below this confining layer is over the mean sea level and also over the swamp water level, coastal lagoons and estuaries. There are two important hydrological phenomena that occur in this coastal fringe: 1 There is no recharge to the aquifer (groundwater due to limestone rock outcrops is impermeable or semipermeable; and 2 groundwater pressure is not lost, nor saline interfase is rised if the superficial layer is broken.  The groundwater pollution vulnerability within this coastal fringe is less than that for the superficial saline waters of swamps and estuaries, because of caliche’s low intrinsic permeability that impedes percolation.

  1. Education, fish consumption, well water, chicken coops, and cooking fires: Using biogeochemistry and ethnography to study exposure of children from Yucatan, Mexico to metals and arsenic

    International Nuclear Information System (INIS)

    Arcega-Cabrera, Flor; Fargher, Lane F.

    2016-01-01

    Around the world, the nocuous health effects of exposure to environmental contaminants, especially metals and Arsenic, are a growing health concern. This is especially the case in Mexico, where corruption and ineffective political administration are contributing to increasing deterioration in the environment. Importantly, shallow soils and the karstic nature of bedrock in Yucatan, Mexico make the subterranean aquifer especially susceptible to contamination because contaminates are carried to it with little resistance. Given these environmental conditions, we developed a multi/interdisciplinary project to evaluate the impact of metal and Arsenic pollution on a sample of 107 children, ages 6 to 9 years, living in the urban areas of Progreso, Merida, and Ticul, in the State of Yucatan using urine and blood samples. In addition, ethnographic research was carried out in the homes of the children that participated in the study to identify potential exposure pathways. This research proved invaluable because the complexity of human social organization, lifestyles, and geographical patterning create an intricate array of exposure pathways that vary across social sectors and geographic space. In the following article, we use nonparametric univariate statistical analysis to reveal potential exposure pathways among sub-populations included in our sample. These analyses show that children from poor/marginal families tend to be exposed to Copper, Lead, and Nickel; whereas, children, from wealthier families, tend to be exposed to Cadmium, Arsenic, and inorganic Copper (Copper Sulfate). - Highlights: • Metals and Arsenic exposure in children (age 6–9) from Yucatan, Mexico • Quantification of As, Cd, Hg, Pb, Cr, Cu, Ni in Blood and Urine by AAS • Ethnographic research on sociocultural patterns and exposure pathways • Non-parametric statistical analysis • Variation in exposure based on geography, socioeconomic level, and lifestyles

  2. Education, fish consumption, well water, chicken coops, and cooking fires: Using biogeochemistry and ethnography to study exposure of children from Yucatan, Mexico to metals and arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Arcega-Cabrera, Flor [Unidad de Química Sisal, Facultad de Química, Universidad Nacional Autónoma de México (Mexico); Fargher, Lane F., E-mail: fargher@mda.cinvestav.mx [Departamento de Ecología Humana, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional — Unidad Mérida (Mexico)

    2016-10-15

    Around the world, the nocuous health effects of exposure to environmental contaminants, especially metals and Arsenic, are a growing health concern. This is especially the case in Mexico, where corruption and ineffective political administration are contributing to increasing deterioration in the environment. Importantly, shallow soils and the karstic nature of bedrock in Yucatan, Mexico make the subterranean aquifer especially susceptible to contamination because contaminates are carried to it with little resistance. Given these environmental conditions, we developed a multi/interdisciplinary project to evaluate the impact of metal and Arsenic pollution on a sample of 107 children, ages 6 to 9 years, living in the urban areas of Progreso, Merida, and Ticul, in the State of Yucatan using urine and blood samples. In addition, ethnographic research was carried out in the homes of the children that participated in the study to identify potential exposure pathways. This research proved invaluable because the complexity of human social organization, lifestyles, and geographical patterning create an intricate array of exposure pathways that vary across social sectors and geographic space. In the following article, we use nonparametric univariate statistical analysis to reveal potential exposure pathways among sub-populations included in our sample. These analyses show that children from poor/marginal families tend to be exposed to Copper, Lead, and Nickel; whereas, children, from wealthier families, tend to be exposed to Cadmium, Arsenic, and inorganic Copper (Copper Sulfate). - Highlights: • Metals and Arsenic exposure in children (age 6–9) from Yucatan, Mexico • Quantification of As, Cd, Hg, Pb, Cr, Cu, Ni in Blood and Urine by AAS • Ethnographic research on sociocultural patterns and exposure pathways • Non-parametric statistical analysis • Variation in exposure based on geography, socioeconomic level, and lifestyles.

  3. Hydrochemistry of waters from five cenotes and evaluation of their suitability for drinking-water supplies, northeastern Yucatan, Mexico

    Science.gov (United States)

    Alcocer, Javier; Lugo, Alfonso; Marín, Luis E.; Escobar, Elva

    Waters from five cenotes that are currently being used for aquatic recreational activities and that lie along the Cancun-Tulum touristic corridor, Mexico, were evaluated hydrochemically to determine whether the cenotes may be considered as potential drinking-water sources. Several parameters exceed the Mexican Drinking Water Standards (MDWS), but since they do not pose a significant health threat, four of the five cenotes may be used as drinking-water sources. The common contaminants in the Yucatan Peninsula, fecal coliforms and nitrate, are in most cases below the MDWS (0-460 MPN/100ml and 0.31-1.18mg/L, respectively). Although these four cenotes meet the MDWS, a careful groundwater management policy needs to be developed to avoid contamination (fecal and nitrates) and salt-water intrusion. Résumé Les eaux de cinq cénotés, qui sont normalement utilisées pour des activités de plein air, dans la région touristique de Cancun-Tulum (Mexique), ont été soumises à analyses chimiques pour savoir si les cénotés peuvent être considérés comme des sources d'eau potable. Plusieurs paramètres dépassent les normes mexicaines en matière d'eau potable; mais comme ceux-ci ne posent pas de problème réel de santé, quatre des cinq cénotés peuvent être captés pour l'eau potable. Les contaminants habituels dans les eaux de la presqu'île du Yucatan, coliformes fécaux et concentrations élevées en nitrate, sont la plupart du temps au-dessous des normes (respectivement 0 à 460 germes/100ml et 0,31 à 1,18mg/l). Bien que ces quatre cénotés satisfassent aux normes, il est nécessaire de mettre en place des règles précises de l'utilisation de l'eau souterraine, afin d'éviter la contamination par les germes fécaux et par les nitrates, ainsi que l'intrusion marine. Resumen Se analizó hidroquímica y bacteriológicamente el agua de algunos cenotes localizados a lo largo del corredor turístico Cancun-Tulum, que actualmente se utilizan para diversas actividades

  4. 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.

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

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    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.

  6. Application of Artificial Neural Networks for Dengue Fever Outbreak Predictions in the Northwest Coast of Yucatan, Mexico and San Juan, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Abdiel E. Laureano-Rosario

    2018-01-01

    Full Text Available Modelling dengue fever in endemic areas is important to mitigate and improve vector-borne disease control to reduce outbreaks. This study applied artificial neural networks (ANNs to predict dengue fever outbreak occurrences in San Juan, Puerto Rico (USA, and in several coastal municipalities of the state of Yucatan, Mexico, based on specific thresholds. The models were trained with 19 years of dengue fever data for Puerto Rico and six years for Mexico. Environmental and demographic data included in the predictive models were sea surface temperature (SST, precipitation, air temperature (i.e., minimum, maximum, and average, humidity, previous dengue cases, and population size. Two models were applied for each study area. One predicted dengue incidence rates based on population at risk (i.e., numbers of people younger than 24 years, and the other on the size of the vulnerable population (i.e., number of people younger than five years and older than 65 years. The predictive power was above 70% for all four model runs. The ANNs were able to successfully model dengue fever outbreak occurrences in both study areas. The variables with the most influence on predicting dengue fever outbreak occurrences for San Juan, Puerto Rico, included population size, previous dengue cases, maximum air temperature, and date. In Yucatan, Mexico, the most important variables were population size, previous dengue cases, minimum air temperature, and date. These models have predictive skills and should help dengue fever mitigation and management to aid specific population segments in the Caribbean region and around the Gulf of Mexico.

  7. Methane and sulfate dynamics in sediments from mangrove-dominated tropical coastal lagoons, Yucatan, Mexico

    Science.gov (United States)

    Chuang, P. C.; Young, Megan B.; Dale, Andrew W.; Miller, Laurence G.; Herrera-Silveira, Jorge A.; Paytan, Adina

    2016-01-01

    Porewater profiles in sediment cores from mangrove-dominated coastal lagoons (Celestún and Chelem) on the Yucatán Peninsula, Mexico, reveal the widespread coexistence of dissolved methane and sulfate. This observation is interesting since dissolved methane in porewaters is typically oxidized anaerobically by sulfate. To explain the observations we used a numerical transport-reaction model that was constrained by the field observations. The model suggests that methane in the upper sediments is produced in the sulfate reduction zone at rates ranging between 0.012 and 31 mmol m−2 d−1, concurrent with sulfate reduction rates between 1.1 and 24 mmol SO42− m−2 d−1. These processes are supported by high organic matter content in the sediment and the use of non-competitive substrates by methanogenic microorganisms. Indeed sediment slurry incubation experiments show that non-competitive substrates such as trimethylamine (TMA) and methanol can be utilized for microbial methanogenesis at the study sites. The model also indicates that a significant fraction of methane is transported to the sulfate reduction zone from deeper zones within the sedimentary column by rising bubbles and gas dissolution. The shallow depths of methane production and the fast rising methane gas bubbles reduce the likelihood for oxidation, thereby allowing a large fraction of the methane formed in the sediments to escape to the overlying water column.

  8. Fishery of the Goliath grouper, Epinephelus itajara (Teleostei: Epinephelidae based on local ecological knowledge and fishery records in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Alfonso Aguilar-Perera

    2009-09-01

    Full Text Available The Goliath grouper, Epinephelus itajara, a large-bodied (~ 2.5 m TL, > 400 kg and critically endangered fish (Epinephelidae, is highly vulnerable to overfishing. Although protected from fishing in many countries, its exploitation in Mexico is unregulated; a situation that puts its populations at risk. Fishery records of E. itajara are scarce, which prevents determination of its fishery status. This work aimed to elucidate the E. itajara fishery in the northern Yucatan Peninsula by 1 analyzing available catch records and 2 interviewing veteran fishermen (local ecological knowledge from two traditional landing sites: Dzilam de Bravo and Puerto Progreso. Historic fishery records from two fishing cooperatives were analyzed in order to elucidate the current situation and offer viable alternatives for conservation and management. Catches have decreased severely. Local knowledge obtained from fishermen represented a very important source of information for reconstructing the fisheries history of this species. Conservation measures that incorporate regional and international regulations on critically endangered fish species are suggested. Rev. Biol. Trop. 57 (3: 557-566. Epub 2009 September 30.La cherna, Epinephelus itajara, un mero (Epinephelidae corpulento (~ 2.5 m TL, > 400 kg y amenazado, es altamente vulnerable a la sobrepesca. Si bien es protegido en varios países, en México su explotación no está regulada; situación que pone a su población en riesgo. Sus registros pesqueros son escasos, lo que impide determinar su condición pesquera. Este trabajo intentó ilustrar la pesquería en el norte de la Península de Yucatán usando procedimientos que involucraron analizar registros y entrevistar a pescadores veteranos (conocimiento ecológico tradicional de dos sitios de desembarque: Dzilam de Bravo y Puerto Progreso. Se analizaron registros pesqueros históricos de dos cooperativas pesqueras para determinar la situación actual y ofrecer

  9. Georadar Archaeological Prospection at the Historical Center of the Merida City, Yucatan, Mexico.

    Science.gov (United States)

    Barba, L.; Ortiz, A.; Blancas, J.; Ligorred, J.

    2007-05-01

    This paper shows the results of the georadar archaeological prospection carried out by the Laboratorio de Prospección Arqueologica from the Instituto de Investigaciones Antropologicas (IIA) of the Universidad Nacional Autonoma de Mexico (UNAM) verifing the archaeological and historical information recovered by the Departamento de Patrimonio Arqueologico y Natural del Municipio (DPANM) del Ayuntamiento de Merida en el Centro Histerico de la Ciudad de Merida under a joint project. The Historical Center of Merida has been classified as a "zone of high patrimonial value" after the topographic data and the historical documents recovered showed a long-term occupation, non interrupted since pre-Columbian times, when T Ho was the great capital of the northern region of the Maya area. For the rehabilitation program of the Historical Center of Merida has been a great priority to verify the existence of archaeological remains, pre-Columbian or colonial, under the present streets, gardens and plazas that could be damaged during the public infrastructure works. In order to prevent any damage to the patrimony a large georadar study was carried out pulling 200 and 400 MHz antennas of the GSSI SIR System 2 for 16500 m of the city streets, focusing in the areas where infrastructure works were imminent. After the analysis of the radar data it was possible to build up a map with the location of the most noticeable archaeological remains under the pavement of the streets that confirmed many of the topographic and documental proposed places. As a final result, by the first time a city government has available information to take present urban decisions, while preventing the damage to the archaeological patrimony of the same city.

  10. 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.

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

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    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. The Disruption of Subsistence Agricultural Systems in Rural Yucatan, Mexico may have Contributed to the Coexistence of Stunting in Children with Adult Overweight and Obesity.

    Science.gov (United States)

    Gurri, Francisco D

    2015-12-01

    This paper attempts to link last century's disruption of local agricultural systems to today's presence of childhood under nutrition and adult overweight and obesity in the Yucatan Peninsula. It first compares Height for Age (H/A), Weight for Age (W/A) and Body Mass Index (BMI) of children from three rural populations in Yucatan and Campeche, Mexico whose subsistence strategy had been altered to different degrees since 1970. It then compares BMI in adults, in the same regions, born before and after the alteration of their environment in the 1970's. Children in the least disrupted zone were taller and had lower BMI than children in the other two, but were not heavier than children from the richest disrupted zone. Children in the poorest disrupted zone were shorter and lighter than the rest. BMI in adult men was higher in the two most disrupted zones only in those cohorts that grew up after the traditional agricultural regime was altered. It is concluded that disruptions of staple-based subsistence agriculture promoted a stockier phenotype in children and a tendency to accumulate body fat. Persistence of these conditions in the twenty first century has favored the coexistence of stunting during childhood with adults who easily become overweight.

  13. 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

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    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.

  14. Lead from hunting activities and its potential environmental threat to wildlife in a protected wetland in Yucatan, Mexico.

    Science.gov (United States)

    Arcega-Cabrera, Flor; Noreña-Barroso, Elsa; Oceguera-Vargas, Ismael

    2014-02-01

    This study provides insights into the status of lead in the protected wetland of El Palmar, located on the northwestern littoral of the Yucatan Peninsula. This reserve is ecologically and economically important because it provides feeding and breeding habitats for many species, as well as being an ecotourism destination (especially for bird watching). Although it is a protected area, duck species are heavily hunted within the reserve during the winter. As a result, animals feeding or living in sediments could be exposed to anthropogenic lead. Total lead and its geochemical fractionated forms were measured in sediment cores from six selected sites in "El Palmar" wetland, during pre- and post-hunting seasons, to approximate the potential environmental threat (especially for benthonic living/feeding organisms). Anthropogenic lead concentrations detected in soil cores ranged from below the minimum infaunal community effect level (30.24 μg g(-1)) during the pre-hunting season, to bordering the probable infaunal community effect level (112.18 μg g(-1)) during the post-hunting season, according to SquiiRTs NOAA guidelines. Yet, these results were lower than expected based on the intensity of hunting. Consequently, this article explores the possibility that the lower than expected lead concentration in sediments results from (1) degradation of shot and transformation to soluble or particulate forms; or (2) ingestion of lead shot by benthic and other lacustrine species living in the protected area. Geochemical fractionation of lead demonstrated that in the top 6 cm of the soil column at heavily active hunting sites (EP5 and EP6), lead was associated with the lithogenic fraction (average 45 percent) and with the organic fraction (average 20 percent). Bioavailable lead (sum of lead adsorbed to the carbonates, Fe/Mn oxyhydroxides and organic fractions) in sediments was lower than 50 percent for the heavily active hunting areas and higher for the rest of the sites

  15. A new genus of speleophriid copepod (Copepoda: Misophrioida) from a cenote in the Yucatan, Mexico with a phylogenetic analysis at the species level.

    Science.gov (United States)

    Boxshall, Geoff A; Zylinski, Sarah; Jaume, Damià; Iliffe, Thomas M; Suárez-Morales, Eduardo

    2014-06-23

    A new genus and species of speleophriid copepod, Mexicophria cenoticola gen. et sp. nov., is described based on material collected from a cenote in the Yucatan Peninsula of Mexico. It is characterised by relatively reduced fifth legs that are located adjacent to the ventral midline in both sexes, by the possession of a bulbous swelling on the first antennulary segment in both sexes, and by the reduced setation of the swimming legs. The presence of just one inner margin seta on the second endopodal segment of legs 2 to 4 is a unique feature for the family. A phylogenetic analysis places the new genus on a basal lineage of the family together with its sister taxon, Boxshallia Huys, 1988, from Lanzarote in the Canary Islands, and recovers the existing genera as monophyletic units. The zoogeography is discussed at local, regional, ocean basin  and global scales.

  16. Frequency of Varroa destructor, Nosema spp and Acarapis woodi in commercial colonies of bees (Apis mellifera in Yucatan, Mexico

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    Martínez-Puc Jesús Froylán

    2015-10-01

    Full Text Available Today it has been observed that diseases affecting bees (Apis mellifera have caused significant economic losses in the European continent and in parts of the United States due to high mortality in honey bee colonies without a cause apparent, which is known as the syndrome of depopulation of hives. It is noteworthy that this mortality is not yet presented in Yucatan. In order to determine the frequency and levels of infestation Acarapis woodi and Varroa destructor, and the frequency and levels of infection Nosema spp. commercial colonies of bees (A. mellifera in Yucatan, was collected from June to December 2006, a total of 165 samples distributed in 13 towns of Yucatan. V. destructor frequency was 63.6%, with an average level of infestation of 2.85 ± 0.79 (mites / 100 bees. The frequency of Nosema spp. was 81.8%, with an average infection level = 1'234000 ± 118000 (spores / bee, the presence of A. woodi in the samples analyzed was detected. The existence of an association between V. destructor and Nosema spp was observed. (X2 = 6.53, df = 1, p = 0.01.

  17. A new species of predaceous midge of the genus Monohelea Kieffer from Mexico (Diptera: Ceratopogonidae).

    Science.gov (United States)

    Felippe-Bauer, M L; Huerta, H; Bernal, S I

    2000-01-01

    A description and illustrations of Monohelea maya, new species, based on male and female characteristics are provided. The specimens were collected in the special biosphere Reserves of Ria Lagartos and Ria Celestun, Yucatan State, Mexico.

  18. A new species of predaceous midge of the genus Monohelea Kieffer from Mexico (Diptera: Ceratopogonidae

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    Maria Luiza Felippe-Bauer

    2000-12-01

    Full Text Available A description and illustrations of Monohelea maya, new species, based on male and female characteristics are provided. The specimens were collected in the special biosphere Reserves of Ria Lagartos and Ria Celestun, Yucatan State, Mexico.

  19. Occurrence of Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodríguez-Canul, 1994 (Monogenea: Dactylogyridae) in the Cichlid Cichlasoma urophthalmus from a flooded quarry in Yucatan, Mexico

    OpenAIRE

    Mendoza-Franco,E. F.; Vidal-Martínez,V.; Simá-Álvarez,R.; Rodríguez-Canul,R.; Vivas-Rodríguez,C.; Scholz,T.

    1995-01-01

    Cichlids, Cichlasoma urophthalmus, collected in a flooded quarry in the Yucatan Peninsula, Mexico, from January through June 1992, had high levels of infection with the ancyrocephaline Sciadicleithrum mexicanum (Monogena: Dactylogyridade) in all montlhly samples. Neither occurrence nor maturation of the worms eshibited any pronounced monthly fluctuation. The infection rate was found to be sizedependent, greater in longer fish. The worms occurred on primary lamellae of gill filaments of all ar...

  20. Impacts of geochemical and environmental factors on seasonal variation of heavy metals in a coastal lagoon Yucatan, Mexico.

    Science.gov (United States)

    Arcega-Cabrera, F; Garza-Pérez, R; Noreña-Barroso, E; Oceguera-Vargas, I

    2015-01-01

    This study investigated the influence of geochemical and environmental factors on seasonal variation in metals in Yucatan's Chelem lagoon. Anthropogenic activities discharge non-treated wastewater directly into it with detrimental environmental consequences. Accordingly, this study established the spatial and temporal patterns of fine grain sediments and concentrations of heavy metals. Multivariate analyses showed fine grain facies deposition, transition sites dominated by fine grain transport, and fine grain erosion sites. Spatial and temporal variations of heavy metals concentration were significant for Cd, Cu, Cr, and Pb. As, Cd, and Sn were as much as 12 times higher than SQuiRTs standards (Buchman 2008). The results indicate that aquifer water is bringing metals from relatively far inland and releasing them into the lagoon. Thus, it appears that the contamination of this lagoon is highly complex and must take into account systemic connections with inland anthropogenic activates and pollution, as well as local factors.

  1. 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

    The Terminal Cretaceous Chicxulub Impact Crater had a strong control on the depositional and diagenetic history of the northern Yucatan Platform during most of the Cenozoic Era. The Chicxulub Sedimentary Basin (henceforth Basin), which approximately coincides with the impact crater, is circumscribed by a concentration of karstic sinkholes known as the Ring of Cenotes. Santa Elena Depression (henceforth Depression) is the name proposed for the bowl-shaped buried feature, first contoured by geophysical studies, immediately south of the Basin, in the area where the Ticul 1 and UNAM 5 wells were drilled. Lithologic, petrographic, and biostratigraphic data on PEMEX, UNAM, and ICDP cores show that: 1) Cenozoic deposits are much thicker inside the Basin than inside the Depression, 2) in general, the Cenozoic formations from inside the Depression are the thickest among those outside the Basin, 3) variably dolomitized pelagic or outer-platform wackestone or mudstone occur both inside the Basin and Depression, 4) the age of the deeper-water sedimentary carbonate rocks is Paleocene-Eocene inside the Basin and Paleocene?-Early Eocene inside the Depression, 5) the oldest formations that crop out are of Middle Eocene age at the edge of the Basin and Early-Middle Eocene age inside the Depression, 6) saline lake deposits, that consist chiefly of anhydrite, gypsum, and fine carbonate, and also contain quartz, chert, clay, zeolite, potassium feldspar, pyrite, and fragments of wood, are present in the Cenozoic section of the UNAM 5 core between 282 and 198 m below the present land surface, 7) the dolomite, subaerial exposure features (subaerial crusts, vugs, karst, dedolomite), and vug-filling cement from the Eocene formations are more abundant inside the Depression than inside the Basin. The depositional environments that are proposed for explaining the Cenozoic facies succession within the Santa Elena Depression are: 1) deeper marine water (Paleocene?-Early Eocene), 2) relatively

  2. Characterization of constitutive materials and technology of the mural painting of the acropolis of the archaeological zone of Ek Balam, Yucatan, Mexico

    International Nuclear Information System (INIS)

    Alonso O, A.; Vazquez N, J.; Ruiz M, C.; Mendoza A, D.; Espinosa P, M.; Ruvalcaba, J.L.; Vandenabeele, P.

    2005-01-01

    The conservation project of Ek'Balam is one of the few experiences of systematic conservation applied in an archaeological Maya site at the Yucatan Peninsula in Mexico. The project started in the year 2001 when important stone, stucco and painting decorations were discovered during archaeological excavations. Being a recently discovered site, the conservation program includes a research program based on particular conservation issues detected as potential risk of archaeological data losses. One of the research topics is based on deter- mining the ancient painting technology used in mural and stucco decorations through the characterization of building and decorative composite materials. Archaeometric techniques have been used to fulfil the proposed goal. Raman, X-ray Fluorescence, Light and Electron Microscopy were practiced on a set of 35 wall painting samples. Preliminary results obtained on pigments characterization have partially revealed general features of wall painting technique at Ek'Balam during the late Classic period. Some particular pigments, not reported ever for mural paintings, have been identified in Ek'Balam samples. (Author)

  3. 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.

  4. 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

  5. Use of enzyme linked immunosorbent assay (ELISA) for the diagnosis of brucellosis in cattle in Yucatan, Mexico

    International Nuclear Information System (INIS)

    Dajer, A.; Gutierrez, E.; Zapata, D.

    1998-01-01

    Sera (247) from non-vaccinated brucellosis negative herds, 328 negative sera from Brucella abortus strain 19 vaccinated herds (brucellosis free), and 95 sera positive to the Rose Bengal test (RBT) and Complement Fixation test (CFT) from Brucella abortus-infected herds, were used to determine the relative sensitivity and specificity of a FAO/IAEA I-ELISA kit and the Rivanol Agglutination Test (RAT), using the CFT as a 'gold standard'. A threshold value for the I-ELISA was determined to be 37 PP using the mean plus 3 standard deviations of the negative sera from vaccinated animals. The I-ELISA showed a high relative sensitivity (100%) and a good relative specificity (92.5%), using the threshold determined for local conditions. The RAT gave a lower sensitivity value than the CFT (97.8%) and good specificity (99.3%). The I-ELISA could be used as a screening test under Yucatan conditions or as a confirmatory test in places where vaccination is not carried out. The RAT lacks sensitivity and is therefore not recommended for use in final stages of eradication programs but could be used in control programmes or early stages of eradication campaigns as a confirmatory test. (author)

  6. 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

  7. 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.

  8. Infection by Trypanosoma cruzi in mammals in Yucatan, Mexico: a serological and parasitological study Infecção pelo Trypanosoma cruzi em mamíferos em Yucatan, México: estudo sorológico e parasitológico

    Directory of Open Access Journals (Sweden)

    J Zavala-Velázquez

    1996-08-01

    Full Text Available In order to determine Trypanosoma cruzi infection among mammals in Yucatan, Mexico, 372 animals, both wild and synanthropic including carnivores, marsupials and rodents were studied. Serological studies by indirect haemagglutination (IHA were carried out to detect antibodies to T. cruzi and a parasitological study was also performed (blood smear and histopathology. Of all the animals tested 18.54% were serologically positive, with a significantly higher frequency among the wild ones (33.33% compared to the synanthropic ones (17.79%. To determine T. cruzi in positive animals, blood was inoculated into a white mouse (webster type to prove myocardium colonization. The serological and parasitological positivity of these animals, as well as their behavior in the environment, taken together with the socioeconomic and cultural characteristics of the population, suggest that in Yucatan, Mexico, Canis familiaris, Didelphis marsupialis and Rattus rattus act as a link with the wild cycle.Para determinar a infecção pelo Trypanosoma cruzi em mamíferos em Yucatan, México, foram estudados 372 animais selvagens e sinantrópicos incluindo carnívoros, marsupiais e roedores. Estudos sorológicos pela hemaglutinação indireta (IHA foram realizados para detectar anticorpos contra o T. cruzi e estudos parasitológicos (esfregaços de sangue e histopatologia. De todos os animais testados 18,54% foram sorologicamente positivos com freqüência significativamente maior entre os silvestres (33,3% em comparação com os sinantrópicos (11,79%. Para determinação do T. cruzi nos animais positivos, o sangue foi inoculado em camundongos brancos (tipo Webster para provar a colonização miocárdica. Através da sua positividade sorológica e parasitológica, bem como seu comportamento no meio ambiente acompanhado pelas características sociais, econômicas e culturais da população, deduz-se que em Yucatan, México, Canis familiaris, Didelphis marsupialis e Rattus

  9. Characterization of constitutive materials and technology of the mural painting of the acropolis of the archaeological zone of Ek Balam, Yucatan, Mexico; Caracterizacion de materiales constitutivos y tecnologia de la pintura mural de la acropolis de la zona arquelogica de Ek Balam, Yucatan, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Alonso O, A.; Vazquez N, J.; Ruiz M, C. [INAH, 11000 Mexico D.F. (Mexico); Mendoza A, D.; Espinosa P, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Ruvalcaba, J.L. [IFUNAM, 04510 Mexico D.F. (Mexico); Vandenabeele, P. [Universidad de Ghent, Belgica (Belgium)]. e-mail: alealonsolvera@yahoo.com

    2005-07-01

    The conservation project of Ek'Balam is one of the few experiences of systematic conservation applied in an archaeological Maya site at the Yucatan Peninsula in Mexico. The project started in the year 2001 when important stone, stucco and painting decorations were discovered during archaeological excavations. Being a recently discovered site, the conservation program includes a research program based on particular conservation issues detected as potential risk of archaeological data losses. One of the research topics is based on deter- mining the ancient painting technology used in mural and stucco decorations through the characterization of building and decorative composite materials. Archaeometric techniques have been used to fulfil the proposed goal. Raman, X-ray Fluorescence, Light and Electron Microscopy were practiced on a set of 35 wall painting samples. Preliminary results obtained on pigments characterization have partially revealed general features of wall painting technique at Ek'Balam during the late Classic period. Some particular pigments, not reported ever for mural paintings, have been identified in Ek'Balam samples. (Author)

  10. 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.

  11. Occurrence of Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodríguez-Canul, 1994 (Monogenea: Dactylogyridae in the Cichlid Cichlasoma urophthalmus from a flooded quarry in Yucatan, Mexico

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    E. F. Mendoza-Franco

    1995-06-01

    Full Text Available Cichlids, Cichlasoma urophthalmus, collected in a flooded quarry in the Yucatan Peninsula, Mexico, from January through June 1992, had high levels of infection with the ancyrocephaline Sciadicleithrum mexicanum (Monogena: Dactylogyridade in all montlhly samples. Neither occurrence nor maturation of the worms eshibited any pronounced monthly fluctuation. The infection rate was found to be sizedependent, greater in longer fish. The worms occurred on primary lamellae of gill filaments of all arches, with lower numbers of parasites attached to the fourth gill arch. Otherwise, there was no significant site preference of worms. Only minor histopathological changes were found at the sites of attachment, and these were restricted to the epithelial cells of the primary lamellae of thegill filaments. The lack of seasonal periodicity in this tropical monogenean is compared to seasonal cycles typical of temperate species.

  12. Entomopathogenic fungi from 'El Eden' Ecological Reserve, Quintana Roo, Mexico.

    Science.gov (United States)

    Torres-Barragán; Anaya, Ana Luisa; Alatorre, Raquel; Toriello, Conchita

    2004-07-01

    Entomopathogenic fungi were isolated and identified from insects collected from the tropical forest and an agricultural area at El Eden Ecological Reserve, Quintana Roo, Mexico. These fungi were studied to determine their potential as biological control agents of greenhouse Trialeurodes vaporariorum (Homoptera: Aleyrodidae), and to contribute to the knowledge of biodiversity of this area. No pest insects were observed in the tropical forest. In contrast, all insects collected in the agricultural area were considered important pests by the local farmers, with the whitefly, as the most relevant, plentiful in Cucurbitaceae plants. From approximately 3400 collected insects in three different surveys, different anamorphic Ascomycetes were recovered. One isolate of Aspergillus sp., two of Penicillium sp., three of Paecilomyces marquandii, and three of Verticillium sp. out of 308 insects (2.9%) from three insect orders, Hymenoptera, Diptera and Isoptera in the tropical forest. In contrast, a higher number of fungal isolates were recovered from the agricultural area: three isolates from Aspergillus parasiticus, 100 of Fusarium moniliforme, one of Aschersonia sp., and 246 of Fusarium oxysporum out of 3100 insects (11.3%) from three insect orders, Homoptera, Coleoptera and Lepidoptera. The results of this study show Fusarium moniliforme and F oxysporum as highly virulent to infected insects in the agricultural area, with 100 and 246 isolates respectively, out of 350 infected insects of 3100 studied specimens. Laboratory whitefly nymph bioassays with isolates Ed29a of F. moniliforme, Ed322 of F. oxysporum, and Ed22 of P marquandii showed 96 to 97.5% insect mortality with no significant differences (P < 0.05) among them. F. oxysporum Ed322 produced no mortality when inoculated on tomato, bean, squash and maize seedlings (with and without injuries) compared to the 100% mortality caused by phytopathogenic strains, F. oxysporum f. sp. lycopersici and F. oxysporum f. sp. radicis

  13. Meat production perspective in Yucatan

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    Victor M. Toledo-Lopez

    2011-12-01

    Full Text Available The evolution of meat production in Mexico during the last decade is the result of the complex interaction between different areas of livestock production and consumers’ preferences, being the former widely influenced by new tendencies and purchasing capacity. In Yucatan, there are two meat product processing plants. Yucatan’s research projects are basically focused to production, handling and genetics. This research is developed in Research Centers like Universidad Autonoma Yucatan’s Ciencias Biologicas Agropecuarias Campus, INIFAP Mococha, Instituto Tecnologico Conkal and Instituto Tecnologoco Merida. Many projects are inter-institutional and others by Cuerpos Academicos inside the institutions. Grants are provided by state, national or international dependencies. In the Instituto Tecnologico Merida research projects are on different animals’ meat quality and novel meat products.

  14. Changes in stature, weight, and nutritional status with tourism-based economic development in the Yucatan.

    Science.gov (United States)

    Leatherman, Thomas L; Goodman, Alan H; Stillman, Tobias

    2010-07-01

    Over the past 40 years, tourism-based economic development has transformed social and economic conditions in the Yucatan Peninsula, Mexico. We address how these changes have influenced anthropometric indicators of growth and nutritional status in Yalcoba, a Mayan farming community involved in the circular migration of labor in the tourist economy. Data are presented on stature and weight for children measured in 1938 in the Yucatan Peninsula and from 1987 to 1998 in the Mayan community of Yalcoba. In addition, stature, weight and BMI are presented for adults in Yalcoba based on clinic records. Childhood stature varied little between 1938 and 1987. Between 1987 and 1998 average male child statures increased by 2.6cm and female child statures increased by 2.7cm. Yet, 65% of children were short for their ages. Between 1987 and 1998, average child weight increased by 1.8kg. Child BMIs were similar to US reference values and 13% were considered to be above average for weight. Forty percent of adult males and 64% of females were overweight or obese. The anthropometric data from Yalcoba suggest a pattern of stunted children growing into overweight adults. This pattern is found elsewhere in the Yucatan and in much of the developing world where populations have experienced a nutrition transition toward western diets and reduced physical activity levels. 2010 Elsevier B.V. All rights reserved.

  15. Prevalencia y factores de riesgo en Yucatán, México, para litiasis urinaria Urolithiasis prevalence and risk factors in Yucatan, Mexico

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    Martha Medina-Escobedo

    2002-11-01

    Full Text Available Objetivo. Determinar la prevalencia de urolitiasis en el estado de Yucatán, México, y una posible asociación de ésta con antecedentes familiares de la enfermedad y la dureza del agua. Material y métodos. Durante 1996 se efectuó una encuesta transversal en población abierta mayor de un año de edad, del estado de Yucatán. Los sujetos se clasificaron como litiasis definitiva (LD, litiasis probable (LP y sin litiasis (SL. Se determinó dureza total, dureza de calcio y dureza de magnesio a las muestras de agua empleadas para el consumo humano. Se emplearon ji cuadrada y t de student para comparación de medias de muestras independientes en el análisis. Resultados. De un total de 5 832 encuestas, 323 sujetos (5.5% se catalogaron como LD, y 282 (4.8% como LP. La prevalencia de litiasis se incrementó con la edad, partiendo de 1% en población de 18 años o menor, hasta 11.3% en los mayores de 50. El 44% del grupo LD y 34% del LP tuvieron antecedente familiar de urolitiasis, comparado con 28% del grupo SL (pObjective. To measure the prevalence of urolithiasis in Yucatan, and to establish a possible association of the disease with family history and water hardness. Material and Methods. During 1996, a survey was conducted on the population over one year of age in the State of Yucatan. Subjects were classified as having definite lithiasis (DL, probable lithiasis (PL, or no lithiasis (NL. Total hardness, calcium hardness, and magnesium hardness, were determined in drinking water samples. Results. From a total of 5 832 questionnaires, 323 subjects (5.5% were found to have DL, and 282 (4.8% PL. The prevalence of lithiasis increased sharply with age, ranging from 1% in the population 18 years or younger, to 11.3% in those over 50 years. A family history of urolithiasis was positive in 44% of subjects with DL and in 34 % of those with PL, compared to 28% of those with NL (OR=2.8, 95% CI=2.2-3.4, p<0.0001, and OR=1.8, 95% CI=1.4-2.4, p<0

  16. Environmental Exposure of Children to Toxic Trace Elements (Hg, Cr, As) in an Urban Area of Yucatan, Mexico: Water, Blood, and Urine Levels.

    Science.gov (United States)

    Arcega-Cabrera, F; Fargher, L; Quesadas-Rojas, M; Moo-Puc, R; Oceguera-Vargas, I; Noreña-Barroso, E; Yáñez-Estrada, L; Alvarado, J; González, L; Pérez-Herrera, N; Pérez-Medina, S

    2018-05-01

    Merida is the largest urban center in the Mexican State of Yucatan. Here domestic sewage is deposited in poorly built septic tanks and is not adequately treated. Because of contamination from such waste, water from the top 20 m of the aquifer is unsuitable for human consumption. Given this situation and because children are highly vulnerable to environmental pollution, including exposure to toxic trace elements, this study focused on evaluating the exposure of children to arsenic (As), chromium (Cr), and mercury (Hg) in water. It also evaluated the relationship between the levels of these elements in water and their concentrations in urine and blood. Among the 33 children monitored in the study, arsenic surpassed WHO limits for blood in 37% of the cases, which could result from the ingestion of poultry contaminated with organoarsenic compounds. In the case of WHO limits for Mercury, 65% of the water samples analyzed, 28% of urine samples, and 12% of blood samples exceeded them. Mercury exposure was correlated with biological sex, some lifestyle factors, and the zone in Merida in which children live. These data suggest that the levels of some toxic metals in children may be affected by water source, socioeconomic factors, and individual behavior.

  17. [G894T (NOS3) and G1958A (MTHFD1) gene polymorphisms and risk of ischemic heart disease in Yucatan, Mexico].

    Science.gov (United States)

    García-González, Igrid; Solís-Cárdenas, Alberto de Jesús; Flores-Ocampo, Jorge A; Alejos-Mex, Ricardo; Herrera-Sánchez, Luis Fernando; González-Herrera, Lizbeth Josefina

    2015-01-01

    Cardiovascular medicine is focused on the search for genetic risk markers with predictive and/or prognostic value. Among the genetic variants of interest are G894T endothelial nitric oxide synthase and G1958A methylenetetrahydrofolate dehydrogenase1 gene polymorphisms. The aim of this study was to determine the possible association between these polymorphisms and ischemic heart disease in patients from Southern of Mexico (Yucatán). Case-control study matched by age, sex and origin was designed. We studied 98 patients with coronary disease and 101 controls. Participants were evaluated for the usual risk factors. The polymorphisms were identified using the polymerase chain reaction/restriction fragment length polymorphism analysis. Informed consent was obtained from all participants. The G894T and G1958A polymorphisms were not associated with ischemic heart disease, however, the TT genotype (G894T) was associated with the angina (OR=10.2; 95%CI, 1.51-68.8; p=0.025). The genotype GT (G894T) was the most frequent in patients with family history of coronary artery disease. Multiple logistic regression analysis identified smoking (OR=5.21; 95%CI, 2.1-12.9; p=0.000), hypertension (OR=3.54; 95%CI, 1.47-8.56; p=0.005) and obesity (OR=1.16; 95%CI, 1.1-1.27; p=0.001) as risk factors predicting the ischemic heart disease. The G894T and G1958A polymorphisms showed not association with ischemic heart disease. However, homozygosis for the 894T allele (NOS3) confers at risk to develop angina on Yucatán. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  18. Cactus Nurseries and Conservation in a Biosphere Reserve in Mexico

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    María T. Pulido

    2013-09-01

    Full Text Available Documenting how socio-ecosystem conservation knowledge and practice arise and are modified are issues of ethnobiological interest. In the Barranca de Metztitlán Biosphere Reserve (RBBM, plant nurseries, some of which were created as Environmental Management Units (UMAs, have been established to grow and conserve cacti. This paper describes these nurseries, their role in cactus conservation, and the benefits and limitations for the people managing them. The nurseries have helped decrease illegal traffic in cacti and have enabled ex situ conservation of 22 cacti species. Cactus management has changed from extraction to cultivation, as a result of the knowledge and actions of multiple actors. The main limitation is marketing, a recurring problem for non-timber forest products (NTFP. Greater coordination among stakeholders is recommended, such as involvement by non-governmental organizations to improve their probability of success, as well as learning from the experience of other cactus UMAs. Improving the market for cacti is an issue that needs an immediate solution; otherwise conservation efforts could relapse.

  19. Blood Feeding Status, Gonotrophic Cycle and Survivorship of Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) Caught in Churches from Merida, Yucatan, Mexico.

    Science.gov (United States)

    Baak-Baak, C M; Ulloa-Garcia, A; Cigarroa-Toledo, N; Tzuc Dzul, J C; Machain-Williams, C; Torres-Chable, O M; Navarro, J C; Garcia-Rejon, J E

    2017-12-01

    Blood-feeding status, gonotrophic cycle, and survival rates of Aedes (Stegmyia) aegypti (L.) was investigated in catholic churches from Merida, Yucatan. Female Ae. aegypti were caught using backpack aspirator during 25 consecutive days in rainy (2015) and dry season (2016). Blood-feeding status was determined by external examination of the abdomen and classified as unfed, fed, and gravid. Daily changes in the parous-nulliparous ratio were recorded, and the gonotrophic cycle length was estimated by a time series analysis. Also, was observed the vitellogenesis to monitoring egg maturity. In total, 408 females Ae. aegypti were caught, and there was a significant difference in the number of females collected per season (Z = -6.729, P ≤ 0.05). A great number was caught in the rainy season (n = 329). In the dry season, 79 females were caught, which the fed females were twice greatest than the unfed. The length of gonotrophic cycle was estimated on the base of a high correlation coefficient value appearing every 4 days in rainy at 26.7 ± 1.22°C, and 3 days in dry season at 29.8 ± 1.47°C. The daily survival rate of the Ae. aegypti population was higher in both seasons, 0.94 and 0.93 for the rainy and dry season, respectively. The minimum time estimated for developing mature eggs after blood feeding was similar in both seasons (3.5 days in rainy versus 3.25 days in dry). The measurement of the vectorial capacity of Ae. aegypti in catholic churches could help to understand the dynamics of transmission of arboviruses in sites with high human aggregation.

  20. Conservation priorities for mammals in megadiverse Mexico: the efficiency of reserve networks.

    Science.gov (United States)

    Ceballos, Gerardo

    2007-03-01

    A major goal of conservation biologists is to identify critical areas for the conservation of biological diversity and then strategically include them in an efficient system of reserves. In general, however, reserve networks have been selected for different objectives, and most countries lack an evaluation of their reserves' ability to represent a percentage of the national diversity. This paper evaluates the effectiveness of a network of reserves to represent the species of mammals in Mexico. The focus of the analyses is on species and site level, evaluating the representation of all terrestrial mammals in the 30 most important reserves. The representation of all species, endemic species, endangered species, and species with restricted distributions in the reserves was assessed and compared. Endemic or endangered species with restricted distributions were expected to be less represented in reserves than were widespread species. The most important reserves for the conservation of mammals were determined with the use of complementarity analyses. Priority sites for the representation of all the species currently absent from the reserve network were then selected. The results have broad applications for conservation. First, 82% of the mammal species from Mexico were represented in the reserve network, which covers a small portion (3.8%) of the country. Second, this percentage is certainly larger as several reserves were not evaluated due to a lack of data. A priority for a national conservation strategy could be to conduct biological surveys in those reserves lacking inventories to evaluate their contribution to conservation. Third, in spite of its demonstrated value, Mexico's reserve network can be improved by designating complementary areas. Additional priority sites, where reserves are required to represent most gap species in the network, were identified. Finally, it is clear that this reserve network has limitations for maintaining biodiversity and ecosystem

  1. Spatial and temporal variability in fire occurrence within the Las Bayas Forestry Reserve, Durango, Mexico

    Science.gov (United States)

    S. A. Drury; T. T. Veblen

    2008-01-01

    Patterns of fire occurrence within the Las Bayas Forestry Reserve, Mexico are analyzed in relation to variability in climate, topography, and human land-use. Significantly more fires with shorter fire return intervals occurred from 1900 to 1950 than from 1950 to 2001. However, the frequency of widespread fire years (25% filter) was unchanged over time, as widespread...

  2. Surf Zone Sediment Size Variation, Morphodynamics, and Hydrodynamics During Sea/Land Breeze and El-Norte Storm in Sisal, Yucatan, Mexico

    Science.gov (United States)

    Alrushaid, T.; Figlus, J.; Torres-Freyermuth, A.; Puleo, J. A.; Dellapenna, T. M.

    2016-02-01

    Coastlines around the world are under ever-increasing pressure due to population trends, commerce, and geophysical processes like tropical storms and erosion. This multi-institutional field campaign was conducted to improve our understanding of complex nearshore processes under varying forcing conditions on a microtidal, sandy beach located in Sisal, Yucatan from 3/27 to 4/12/2014. Hydrodynamics, morphodynamics, and textural variability were investigated during: (1) a cold front event (referred to as El-Norte); (2) land breeze (LB); and (3) sea breeze (SB). The instrumentation layout included three surf/swash zone cross-shore transects where water elevation, suspended sediment concentration, bed load, and current velocities were measured, as well as several offshore ADCP for hydrodynamic measurements. TKE, τb, ɛ and were estimated using the data obtained from surf zone ADV. In addition, Hs and Tsin the surf zone were computed using measurements from ADV pressure sensors, while a separate pressure transducer was used to obtain water free-surface elevation within the swash zone. During SB cycles the study area experienced wind velocities reaching up to 12ms-1, and 15ms-1 during El-Norte. Elevated wind stress during El-Norte resulted in Hs of 1.5m and 0.6m in water depths of 10m and 0.4m, respectively. Surface sediment grab samples during SB/LB cycles showed that the swash zone had a moderately well sorted distribution with a mean grain size of 0.5mm, while poor sorting and a mean grain size of 0.7mm were found during El-Norte. Additionally, measured bathymetry data showed evidence for offshore sandbar migration during strong offshore currents (0.4ms-1) during El-Norte, while onshore sandbar migration was evident during SB/LB periods (0.3ms-1 and 0.1ms-1, respectively). This study highlights how different weather forcing conditions affect hydrodynamics, morphodynamics, and textural variability on a sandy beach. Aside from furthering our knowledge on these complex

  3. Assessing biodiversity in Nuevo Leon, Mexico: Are nature reserves the answer?

    Science.gov (United States)

    Cantu, C.; Wright, R.G.; Scott, J.M.; Strand, Espen

    2004-01-01

    The Mexican state of Nuevo Leon, located in the northeastern portion of the country, currently has 26 state and three federal nature reserves covering approximately 4.5% of its land area. These reserves were established for a variety of reasons not necessarily related to conservation purposes. In 2000 in response to a growing concern about the lack of organized conservation reserve planning to protect the important biological and physical features of Mexico, the Mexican Commission for Knowledge and Use of Biodiversity proposed 12 new terrestrial reserves for Nuevo Leon. The new reserves, if established, would increase the proportion of protected lands in the state to almost 24% of the state's land area. We compiled a Geographic Information System (GIS) analysis using digital thematic maps of physical and ecological features to examine how well the existing and proposed reserves incorporated the major biological and physical features of the state. The existing reserves are located primarily in regions with elevations > 1,000-1,500 m, on less productive soils, and are dominated by pine and oak forest cover types. As a result, the state's dominant biotic region - low elevation coastal plain with xeric scrub vegetation - is disproportionately under represented in the current reserve system. The new reserves would expand the protection of biophysical resources throughout the state. However, the inclusion of important resources in the low elevation coastal lands would still be limited.

  4. An optical laser device for mapping 3D geometry of underwater karst structures: first tests in the Ox BelHa system, Yucatan, Mexico; Un dispositivo laser optico para la cartografia 3D de la geometria de estructuras karsticas submarinas: primeros resultados en el sistema de Ox BelHa, Yucatan, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Schiller, A.; Renard, P.

    2016-07-01

    In the course of extended hydrological studies in the coastal Karst plain of Yucatan, near the town of Tulum amongst others, a novel laser scanning device was developed and applied for the acquisition of the 3d-geometry of ground water conduits. The method is derived from similar industrial systems and for the first time adapted to the specific measurement conditions in underwater cave systems. The device projects a laser line over the whole perimeter at a certain position. This line represents the intersection of a plane with the cave walls. The line is imaged with a wide angle camera system. Through proper design and calibration of the device it is possible to derive the true scale geometry of the perimeter via special image processing techniques. By acquiring regularly spaced images it is possible to reconstruct the true scale and 3 d-shape of a tunnel through the incorporation of location and attitude data. In a first test in the Ox Bel Ha under-water cave system, about 800 metres of tunnels have been scanned down to water depths of 20 metres. The raw data is further interpolated using the ODSIM-algorithm in order to delineate the 3D geometry of the cave system. The method provides easy, operable acquisition of the 3-D geometry of caves in clear water with superior resolution and speed and significantly facilitates the measurement in underwater tunnels as well as in dry tunnels. The data gathered represents crucial input to the study of the state, dynamics and genesis of the complex karst water regime. (Author)

  5. 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.

  6. 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.

  7. [Historical presence of invasive fish in the biosphere reserve sierra de Huautla, Mexico].

    Science.gov (United States)

    Mejía-Mojica, Humberto; de Rodríguez-Romero, Felipe Jesús; Díaz-Pardo, Edmundo

    2012-06-01

    The effects of invasive species on native ecosystems are varied, and these have been linked to the disappearance or decline of native fauna, changes in community structure, modification of ecosystems and as vectors of new diseases and parasites. Besides, the development of trade in species for ornamental use has contributed significantly to the import and introduction of invasive fish in some important areas for biodiversity conservation in Mexico, but the presence of these species is poorly documented. In this study we analyzed the fish community in the Biosphere Reserve Sierra de Huautla by looking at diversity changes in the last 100 years. For this, we used databases of historical records and recent collections for five sites in the Amacuzac river, along the Biosphere Reserve area. We compared the values of similarity (Jaccard index) between five times series (1898-1901, 1945-1953, 1971-1980, 1994-1995 and 2008-2009), and we obtained values of similarity (Bray-Curtis) between the five sites analyzed. In our results we recognized a total of 19 species for the area, nine non-native and ten native, three of which were eliminated for the area. Similarity values between the early days and current records were very low (.27); the major changes in the composition of the fauna occurred in the past 20 years. The values of abundance, diversity and similarity among the sampling sites, indicate the dominance of non-native species. We discuss the role of the ornamental fish trade in the region as the leading cause of invasive introduction in the ecosystem and the possible negative effects that at least four non-native species have had on native fauna and the ecosystem (Oreochromis mossambicus, Amatitlania nigrofasciata, Pterygoplichthys disjunctivus and P pardalis). There is an urgent need of programs for registration, control and eradication of invasive species in the Sierra de Huautla Biosphere Reserve and biodiversity protection areas in Mexico.

  8. Rural aquaculture as a sustainable alternative for forest conservation in the Monarch Butterfly Biosphere Reserve, Mexico.

    Science.gov (United States)

    López-García, José; Manzo-Delgado, Lilia L; Alcántara-Ayala, Irasema

    2014-06-01

    Forest conservation plays a significant role in environmental sustainability. In Mexico only 8.48 million ha of forest are used for conservation of biodiversity. Payment for Environmental Services in the Monarch Butterfly Biosphere Reserve, one of the most important national protected areas, contributes to the conservation of these forests. In the Reserve, production of rainbow trout has been important for the rural communities who need to conserve the forest cover in order to maintain the hibernation cycle of the butterfly. Aquaculture is a highly productive activity for these protected areas, since it harnesses the existing water resources. In this study, changes from 1999 to 2012 in vegetation and land-use cover in the El Lindero basin within the Reserve were evaluated in order to determine the conservation status and to consider the feasibility of aquaculture as a means of sustainable development at community level. Evaluation involved stereoscopic interpretation of digital aerial photographs from 1999 to 2012 at 1:10,000 scale, comparative analysis by orthocorrected mosaics and restitution on the mosaics. Between 1999 and 2012, forested land recovered by 28.57 ha (2.70%) at the expense of non-forested areas, although forest degradation was 3.59%. Forest density increased by 16.87%. In the 46 ha outside the Reserve, deforestation spread by 0.26%, and land use change was 0.11%. The trend towards change in forest cover is closely related to conservation programmes, particularly payment for not extracting timber, reforestation campaigns and surveillance, whose effects have been exploited for the development of rural aquaculture; this is a new way to improve the socio-economic status of the population, to avoid logging and to achieve environmental sustainability in the Reserve. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. [The jaguar Panthera onca (Carnivora: Felidae) in “El Cielo” Biosphere Reserve, Tamaulipas, Mexico].

    Science.gov (United States)

    Carrera-Treviño, Rogelio; Lira-Torres, Iván; Martínez-García, Luis; López-Hernández, Martha

    2016-12-01

    Information on the ecology of jaguars (Panthera onca) in “El Cielo” Biosphere Reserve in Tamaulipas, Mexico is scant and limited to anecdotic records in a handful of publications. The objectives of our study were to: a) determine population density and structure of jaguars, b) compare their activity patterns with that of pumas (Puma concolor), c) ascertain potential prey relative abundance, and d) evaluate local resident’s perception on loss of domestic animals due to jaguar predation. Between April 2013 and April 2014 we conducted camera trapping in Gomez Farias Township with a total sampling effort of 8 580 camera trap days. Besides, we completed 136 semi-structured interviews among local residents of Gomez Farias and Llera Townships to gather information on domestic animal losses attributed to jaguars and other carnivores. We identified eight different jaguar individuals during a complete year of camera-trapping, composed of four adult females, one juvenile female, two adult males and one juvenile male. We estimated a jaguar density of 5.9 ± 1.3 jaguars/100 km². Activity patterns for jaguars and pumas were similar as both were nocturnal and crepuscular in nature. The most abundant potential prey species for jaguars in the study site were Crax rubra, Cuniculus paca, Mazama temama, Odocoileus virginianus and Didelphis virginiana; while the rarest were Mephitis macroura and Procyon lotor. Interview results suggested that chickens, dogs, and house cats were the most consumed domestic animals from all reported losses by local residents (n= 107). This study represents the first attempt to describe jaguar ecology in “El Cielo” Biosphere Reserve; however, there is a need of additional monitoring efforts to determine the current status of jaguars in a larger area in order to establish conservation strategies. Finally, this jaguar population may have an important role in maintaining the species in the Sierra Madre Oriental biological corridor connecting

  10. Uranium exploration, mining and milling proposal, Navajo Indian Reservation, New Mexico

    International Nuclear Information System (INIS)

    Babby, W.D.

    1974-01-01

    The Secretary of the Interior has been requested to approve an exploration permit and mining lease which are part of a uranium exploration, mining, and milling Agreement, negotiated between the Navajo Tribe and the Exxon Corporation. The exploration area is a 400,000 acre tract located on the Navajo Reservation in San Juan County, New Mexico. If uranium ore in sufficient quantities to warrant development is discovered, Exxon is authorized to take a total of 51,200 acres to lease for mining, of which only 5,120 surface acres may be used for mining and milling purposes. While all exploration and predevelopment costs prior to mining must be borne by Exxon, the Navajo Tribe has reserved the right to participate in the venture on either a royalty basis or as a partner holding up to a 40 percent working interest. Impacts resulting from exploration will include disturbance of soils and vegetation and air quality degradation resulting from the vehicular movement and the operation of drilling equipment. If mining and milling takes place significant environmental impacts include: sub-surface water depletion, soils and vegetation disturbance, air quality degradation, interruption of the wildlife habitat, population increases, increased demands on community services and facilities, and disruption of established lifestyles and social patterns. Low levels of radioactive emissions will be found at mine and mill sites. Income and employment opportunities from the project to the Navajo Tribe, Navajo people, and the entire San Juan County community will be significant

  11. Never judge an iguana by its spines: Systematics of the Yucatan spiny tailed iguana, Ctenosaura defensor (Cope, 1866).

    Science.gov (United States)

    Malone, Catherine L; Reynoso, Víctor Hugo; Buckley, Larry

    2017-10-01

    Spiny tailed iguanas are highly diverse clade of lizards in Mesoamerica, ranging from northern Mexico through Panama. Utilizing 2 regions of mitochondrial DNA (1948bp) and 4 nuclear loci (2232bp) we explored the relationships between these species and the phylogeographic history of the major clades. We discovered that the lineage endemic to the Yucatan Peninsula renders the genus Ctenosaura paraphyletic. To resolve this non-monophyly, we resurrect the taxon Cachryx Cope, 1866, and provide a new diagnosis for the genus. We also find that small body-size and highly spinose tails in the species previously referred to the subgenus Enyaliosaurus, have evolved independently 3 times. Cachryx were recovered as sister to the lineage of iguanines endemic to the Galapagos Islands, and we discuss biogeographic scenarios to explain this relationship as well as those among the primary clades of Ctenosaura in Mesoamerica. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Territorialisation, Conservation, and Neoliberalism in the Tehuacán-Cuicatlán Biosphere Reserve, Mexico

    Directory of Open Access Journals (Sweden)

    Alison Elizabeth Lee

    2014-01-01

    Full Text Available The territorialisation of a botanical garden and the Tehuacán-Cuicatlán Biosphere Reserve (TCBR in southern Mexico is examined from the perspective of local residents of one rural town and the biologists whose professional careers involved extensive research in the region. While there were brief periods of conflict between residents and outsiders over the use of local lands for conservation, the cumulative effects demonstrate a general acceptance of the conservation paradigm. Local residents re-appropriated an older discourse linking their land rights to indigenous ancestors in order to mobilise collective support to ensure local control of the botanical garden. The discourse was subsequently incorporated into a local ecotourism project providing cultural substance complementary to the biological and visual aspects of the landscape. Contradictions between conservation and livelihoods were minimal due to neoliberal policies that encouraged migration to the United States of America and wage work in regional maquiladoras. Consequently, the territorialisation of conservation spaces was not disruptive to the increasingly proletarianised, non-agricultural livelihoods of local residents.

  13. Spatial and temporal land cover changes in Terminos Lagoon Reserve, Mexico.

    Science.gov (United States)

    Soto-Galera, Ernesto; Piera, Jaume; López, Pilar

    2010-06-01

    Terminos Lagoon ecosystem is the largest fluvial-lagoon estuarine system in the country and one of the most important reserves of coastal flora and fauna in Mexico. Since the seventies, part of the main infrastructure for country's oil extraction is located in this area. Its high biodiversity has motivated different type of studies including deforestation processes and land use planning. In this work we used satellite image analysis to determine land cover changes in the area from 1974 to 2001. Our results indicate that tropical forest and mangroves presented the most extensive losses in its coverage. In contrast, urban areas and induced grassland increased considerably. In 2001 more than half of the ecosystem area showed changes from its original land cover, and a third part of it was deteriorated. The main causes of deforestation were both the increase in grassland and the growth of urban areas. However, deforestation was attenuated by natural reforestation and plant canopy recovery. We conclude that the introduction of cattle and urban development were the main causes for the land cover changes; however, the oil industry activity located in the ecosystem, has promoted indirectly to urban growth and rancher boom.

  14. CHANGES IN FOREST COVERAGE IN THE NATURAL RESERVE AGUA SELVA, MEXICO

    Directory of Open Access Journals (Sweden)

    Camerino Alejandro Montiel

    2010-03-01

    Full Text Available The impact of ecotourism on the Natural Reserve Agua Selva, Mexico, was assessed. Changes of land use in the forest were evaluated.  An analysis of some socio-economic and cultural changes in the community since ecotourism was introduced was carried out. The perception of villagers towards ecotourism is also presented. The analysis was made with satellite images landsat type (sensor MSS and TM obtained in 1976 and 2000. Cartography and farm plots were also used for the analysis of land use changes. Socio-economic changes were analyzed based on questionnaires and semi-structured interviews. The introduction of ecotourism in the area of study had both positive and negative effects. Although ecotourism did not reverse the deforestation processes, the general deforestation rate was 0.49%. This is smaller to reports in literature for other zones in Tabasco with similar characteristics in the same period of time.  It was found that there was a positive change of Villager’s attitudes towards ecotourism in the last 15 years. This is mainly because this activity is a source of income and has become progressively more important compared to other rural economic activities. It was found that the community participation is scarce and thus has caused problems in the management of specific projects. The results of this research suggest that the success of ecotourism in Agua Selva depends on the integration of ecotourism with the other agricultural and social programs implemented in the area. Implementing agricultural development programs not linked to ecotourism activities can lead to deforestation which is the reserve’s main attraction.

  15. 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.

  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. Assessment of current and proposed nature reserves of Mexico based on their capacity to protect geophysical features and biodiversity

    Science.gov (United States)

    Cantu, C.; Wright, R.G.; Scott, J.M.; Strand, Espen

    2004-01-01

    Mexico currently has 144 nature reserves covering approximately 9.1% of its land area. These reserves were established for a variety of reasons - often unrelated to the protection of biodiversity. In 2000 in response to a growing concern about the lack of organized conservation reserve planning to protect the important threatened biological and physical features of Mexico, the Mexican Commission for Knowledge and Use of Biodiversity (CONABIO) proposed the establishment of 151 new reserves for Mexico covering 51,429,500 ha. We compiled a GIS analysis using digital thematic maps of physical and biological features to examine how the existing and proposed reserves serve to protect the biodiversity and physical features of the country. Using a conservation target of placing a minimum of 12% of the land area of each important biophysical feature in nature reserves, we found that the 144 existing nature reserves covering 18 million ha (9% of the country) only meet that target for elevation ranges >3000 m and areas with poor soils. These mountainous areas represent less than 1% of the country. The gaps in the existing nature reserves network occur mainly at lower and intermediate elevations (<3000 m) areas with xeric, tropical, and temperate ecosystems, and high productivity soils. The areas proposed by CONABIO increase the proportion of protected lands in the country to over 27% and most of the conservation targets for geophysical features, and land cover, categories are met. Whether this area would be sufficient to maintain viable populations and ecological integrity of species and ecosystems is unknown. Even with the new reserves, low elevation coastal lands would be below the conservation target in the nature reserves. To include a representative sample of these lands would be difficult as these are the same areas where the majority of people live. ?? 2003 Elsevier Ltd. All rights reserved.

  18. Soil Survey Geographic (SSURGO) database for Fort Bliss Military Reservation, New Mexico and Texas

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

  19. Frecuencia de anticuerpos contra el virus C de la hepatitis en pacientes con cirrosis hepática en Yucatán, México Frequency of antibodies against the hepatitis C virus in patients with hepatic cirrhosis in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Renán A Góngora-Biachi

    2003-10-01

    Full Text Available OBJETIVO: En este estudio reportamos la prevalencia de anticuerpos contra el virus C de la hepatitis (Ac-VCH en un grupo de pacientes con cirrosis hepática (CH. MATERIAL Y MÉTODOS: Se hizo un estudio prospectivo, transversal y descriptivo, de marzo de 1998 a mayo de 1999. Se estudiaron a 153 pacientes (117 (76% hombres y 36 (24% mujeres con diagnóstico de CH, que eran atendidos en el Hospital General Agustín O' Horan y en el Centro de Investigaciones Regionales Doctor Hideyo Noguchi, en la ciudad de Mérida, Yucatán, México. Se aplicó un cuestionario con datos clínico-epidemiológicos y se determinó la presencia de Ac-VCH (ELISA de 2ª generación y RIBA-2 para confirmar el diagnóstico a cada paciente. Se determinó también el antígeno de superficie de la hepatitis B (AgsHB y anticuerpos contra el antígeno central de la hepatitis B (Anti-HBc mediante el método de ELISA. La presencia de Ac-VCH fue relacionada con las variables epidemiológicas de los sujetos. La prevalencia de anti-HCV y la frecuencia de características se compararon entre los pacientes positivos y negativos con las pruebas de c² y exacta de Fisher. RESULTADOS: El 32% de los pacientes con CH (35/117 (30% hombres y 14/36 (39% mujeres fueron positivos para los Ac-VCH. El alcoholismo estuvo presente en todos los hombres serorreactivos y en ninguna de las mujeres positivas (pOBJECTIVE: To report the prevalence of antibodies against the hepatitis C virus (anti-HCV in a group of patients with hepatic cirrhosis (HC. MATERIAL AND METHODS: A prospective transversal and descriptive study was carried out from March 1998 to May 1999. Study subjects were 153 patients; 117 (76% male and 36 (24% female, diagnosed with HC. They were attended at the General Hospital Agustín O' Horan and at Regional Research Center Doctor Hideyo Noguchi, in Merida, Yucatan, Mexico. A clinical-epidemiologic questionnaire completed by interview was used for data collection. Anti-HCV were detected

  20. Recovery of Biomass Following Shifting Cultivation in Dry Tropical Forests of the Yucatan

    OpenAIRE

    Read, L; Lawrence, Deborah; Foster, David Russell

    2003-01-01

    Land-use change in the tropics is creating secondary forest at an unprecedented rate. In the tropical Americas, mature dry tropical forest is rapidly being converted to secondary forest during the fallow period of shifting cultivation. This study addresses changes in forest biomass during forest recovery following shifting cultivation of maize (corn) in the Southern Yucatan Peninsular Region (SYPR), Mexico. We sampled stems .1 cm diameter at breast height at 36 study sites in t...

  1. Ecological aspects of nesting in Caiman crocodilus chiapasius (Bocourt 1876) in La Encrucijada Biosphere Reserve, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Desales, G.A.; Monroy-Vilchis, O.; Charruau, P.; Zarco-Gonzalez, M.M.

    2016-07-01

    Studies on caiman, Caiman crocodilus chiapasius, in Mexico are scarce. The present study was conducted to evaluate the key characteristics regarding the reproductive ecology of caiman in Mexico. We conducted nest searches from April to September 2014. We observed that nests were built in June and that hatching occurred in September and October. The phase of the moon had an effect on nesting events. The height of the nest, the distance to the nearest tree, and the distance from the top of the nest to the first egg were related to hatching success and incubation temperature. (Author)

  2. Structure and Variability of the Loop Current along the Yucatan Slope and Shelf Break.

    Science.gov (United States)

    Sheinbaum, J.; Athie, G.; Candela, J.; Ochoa, J.; Romero, A.

    2016-02-01

    Yucatan Current and Loop Current variability is investigated using data from an array of moorings that was deployed during 2006-2011 at the western Yucatan Channel and two other strategic cross-sections further north over the Campeche Bank, where the core and western edge of the currents are usually located. Measurements show the cores of the Yucatan Current and Loop Current have a more offshore (onshore) position in summer (winter-spring) suggesting seasonality and a relation to transport variations. Some eastward displacements of the currents are associated with periods of positive horizontal shear (cyclonic vorticity anomalies) propagating northward from the Caribbean coast of Mexico into the Gulf. Ten of the thirteen Loop Current eddies released between 2006 and 2011 were found to be clearly related to these propagating cyclonic anomalies that after crossing the Yucatan Channel produce intense pulses of eddy kinetic energy in the mooring sections downstream. Current structure and variability above and below 1000 m depth have very different characteristics. Diffferences are also found between western and eastern mooring measurements at similar depths. Wind forcing, coastally trapped waves and small scale frontal eddies appear to be the source of this east-west asymmetry.

  3. Mechanisms of the 40-70 Day Variability in the Yucatan Channel Volume Transport

    Science.gov (United States)

    van Westen, René M.; Dijkstra, Henk A.; Klees, Roland; Riva, Riccardo E. M.; Slobbe, D. Cornelis; van der Boog, Carine G.; Katsman, Caroline A.; Candy, Adam S.; Pietrzak, Julie D.; Zijlema, Marcel; James, Rebecca K.; Bouma, Tjeerd J.

    2018-02-01

    The Yucatan Channel connects the Caribbean Sea with the Gulf of Mexico and is the main outflow region of the Caribbean Sea. Moorings in the Yucatan Channel show high-frequent variability in kinetic energy (50-100 days) and transport (20-40 days), but the physical mechanisms controlling this variability are poorly understood. In this study, we show that the short-term variability in the Yucatan Channel transport has an upstream origin and arises from processes in the North Brazil Current. To establish this connection, we use data from altimetry and model output from several high resolution global models. A significant 40-70 day variability is found in the sea surface height in the North Brazil Current retroflection region with a propagation toward the Lesser Antilles. The frequency of variability is generated by intrinsic processes associated with the shedding of eddies, rather than by atmospheric forcing. This sea surface height variability is able to pass the Lesser Antilles, it propagates westward with the background ocean flow in the Caribbean Sea and finally affects the variability in the Yucatan Channel volume transport.

  4. Environmental flow calculation for the maintenance of the water reserve of the Piaxtla River, Sinaloa, Mexico

    Directory of Open Access Journals (Sweden)

    Guadalupe de la Lanza Espino

    2014-03-01

    Full Text Available The calculation of river flows necessary to maintain the environmental services of the diverse river basins in Mexico has been an element to be considered in complying with the Mexican Norm and in allowing an adequate administration of water resources. Several methods have been proposed for this calculation, among which a very simple one is a hydrological method that requires a data base on runoff to determine the volume of water that ecosystem functions need. Hydrological methodology proposed by the NMX cited above, provides guidelines for establishing a regime as a percentage of average annual runoff and it is assumed maintain biological attributes at certain levels of conservation. It also analyzes the regime of seasonal normal flow for wet hydrological conditions, socks, dry and very dry, and the system of avenues (considered as the sudden increase in the volume and speed of the current in a river due to runoff resulting from rain cyclical or extraordinary, it is also known as flooding, considering at least three categories of avenues (intra-annual, annual and interannual low magnitude of average size with corresponding attributes of magnitude, duration, frequency, time of occurrence and rate exchange. For greater certainty calculation it will always be necessary to have records in the three levels of a basin. This level of analysis is to determine the final volume of ecological flow, considering the benchmark to achieve the previously defined environmental objective. For ecological calculation referred by the NMX, some fundamental aspects were considered, such as: ecology importance (which ranks among very high, high, medium and low based on the concepts of the rule itself ; use pressures (determined as the ratio percentage of the volume allocated over the concession between the annual average availability basin or aquifer, determined as high ≥ 80%, ≥ 40% high, medium and low ≥ 11% ≤ 10% ; the environmental objective (ecological

  5. Spatial and temporal land cover changes in Terminos Lagoon Reserve, Mexico

    Directory of Open Access Journals (Sweden)

    Ernesto Soto-Galera

    2010-06-01

    Full Text Available El ecosistema de Laguna de Términos es el más grande sistema fluvio lagunar estuarino del país y una de las reservas más importantes de flora y fauna costera en México. Desde la década de los setentas, parte de la infraestructura necesaria para la explotación del petróleo en el país se encuentra localizada en esta área. Su importante biodiversidad ha motivado diferentes estudios en el área que incluyen procesos de deforestación y ordenamiento del territorio. Se realizó un análisis de imágenes de satélite para determinar los cambios de uso del suelo y vegetación en el área entre 1974 y 2001. Los resultados indican que la selva tropical y el mangle presentan las mayores pérdidas de cobertura. En contraste, las áreas urbanas y los pastos inducidos han incrementado considerablemente su extensión. En el año 2001 más de la mitad del área ocupada por el ecosistema mostró cambios en sus coberturas originales y una tercera parte estaba deteriorada. La deforestación fue causada principalmente por el incremento de los pastizales y el crecimiento de las áreas urbanas. Sin embargo, estas pérdidas fueron atenuadas por la regeneración natural. Se concluye que la introducción de pasto para la ganadería y el desarrollo urbano fueron las principales causas de los cambios de uso de suelo, sin embargo, la industria petrolera asentada en el ecosistema ha fomentado indirectamente el crecimiento urbano y el auge ganadero.Terminos Lagoon ecosystem is the largest fluvial-lagoon estuarine system in the country and one of the most important reserves of coastal flora and fauna in Mexico. Since the seventies, part of the main infrastructure for country’s oil extraction is located in this area. Its high biodiversity has motivated different type of studies including deforestation processes and land use planning. In this work we used satellite image analysis to determine land cover changes in the area from 1974 to 2001. Our results indicate

  6. 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.)

  7. Jackpile-Paguate Uranium Mine Reclamation Project, Laguna Indian Reservation, Cibola County, New Mexico

    International Nuclear Information System (INIS)

    1986-10-01

    The final version of environmental impact statement, EPA No. 860443F, relates to a proposed reclamation plan for the Jackpile-Paguate uranium mine in New Mexico. The statement describes backfilling of disturbed areas, the reduction of waste dump slopes, steam stabilization, and revegetation plans. Positive impacts include the restoration of the site to productive land use, the reduction of hazards, and aesthetic improvements. Negative impacts include a one-time loss of water and assignment of labor. The Surface Mining Control and Reclamation Act of 1977 provides a legal mandate for the statement. The summary includes a reference to the draft statement

  8. Trends in deforestation and forest degradation after a decade of monitoring in the Monarch Butterfly Biosphere Reserve in Mexico.

    Science.gov (United States)

    Vidal, Omar; López-García, José; Rendón-Salinas, Eduardo

    2014-02-01

    We used aerial photographs, satellite images, and field surveys to monitor forest cover in the core zones of the Monarch Butterfly Biosphere Reserve in Mexico from 2001 to 2012. We used our data to assess the effectiveness of conservation actions that involved local, state, and federal authorities and community members (e.g., local landowners and private and civil organizations) in one of the world's most iconic protected areas. From 2001 through 2012, 1254 ha were deforested (i.e., cleared areas had <10% canopy cover), 925 ha were degraded (i.e., areas for which canopy forest decreased), and 122 ha were affected by climatic conditions. Of the total 2179 ha of affected area, 2057 ha were affected by illegal logging: 1503 ha by large-scale logging and 554 ha by small-scale logging. Mexican authorities effectively enforced efforts to protect the monarch reserve, particularly from 2007 to 2012. Those efforts, together with the decade-long financial support from Mexican and international philanthropists and businesses to create local alternative-income generation and employment, resulted in the decrease of large-scale illegal logging from 731 ha affected in 2005-2007 to none affected in 2012, although small-scale logging is of growing concern. However, dire regional social and economic problems remain, and they must be addressed to ensure the reserve's long-term conservation. The monarch butterfly (Danaus plexippus) overwintering colonies in Mexico-which engage in one of the longest known insect migrations-are threatened by deforestation, and a multistakeholder, regional, sustainable-development strategy is needed to protect the reserve. © 2013 Society for Conservation Biology.

  9. A Regional-Scale Groundwater Model Supporting Management of the Sian Ka'an Biosphere Reserve and its Catchment, Quintana Roo, Mexico

    Science.gov (United States)

    Neuman, B. R.; Merediz Alonso, G.; Rebolledo Vieyra, M.; Marin, L.; Supper, R.; Bauer-Gottwein, P.

    2007-05-01

    The Caribbean Coast of the Yucatan Peninsula is a rapidly developing area featuring a booming tourism industry. The number of hotel rooms in the Riviera Maya has increased from 2600 in 1996 to 26,000 in 2005, while the total population in the Mexican federal state of Quintana Roo has grown from 500,000 in 1990 to 1,115,000 in 2005. This explosive growth threatens the region's water resources, which primarily consist of a less than 50m thick freshwater lens residing in the regional karst aquifer underlying the entire Yucatan Peninsula. The Sian Ka'an Biosphere Reserve, a 6400 km2 combined marine/terrestrial nature protection area is situated south of Tulum (approx. 87.3° - 88° W, 19° - 20° N). The site is listed as a UNESCO world heritage site and is protected under the Ramsar Convention. It includes extensive freshwater wetlands, saline/brackish mangrove swamps, tropical rainforests and parts of the world's second largest coral reef. The freshwater supply to the system occurs primarily via subsurface inflow. Large freshwater springs emerge through vertical sinkholes (cenotes) in the lagoons of Sian Ka'an. Management of this unique ecosystem in view of the rapid development and urbanization of the surrounding areas requires detailed knowledge on the groundwater flow paths in and around the reserve. Moreover, mapping and delineation of its groundwater catchment zone and groundwater traveling time zones is essential. To this end, a regional-scale steady-state groundwater flow model of the Sian Ka'an Biosphere reserve and its catchment was developed. The model is implemented in MIKE SHE with a finite-difference cell size of 1 km2 and is driven with temporally averaged climate forcings. The karst aquifer is treated as an equivalent porous medium. Darcy's law is assumed to be valid over regional scales and the main structural elements of the karst aquifer are included in the model as zones of varying hydraulic conductivity. High conductivity zones in the Sian Ka

  10. Factors affecting ethnobotanical knowledge in a mestizo community of the Sierra de Huautla Biosphere Reserve, Mexico.

    Science.gov (United States)

    Beltrán-Rodríguez, Leonardo; Ortiz-Sánchez, Amanda; Mariano, Nestor A; Maldonado-Almanza, Belinda; Reyes-García, Victoria

    2014-01-27

    Worldwide, mestizo communities' ethnobotanical knowledge has been poorly studied. Based on a mestizo group in Mexico, this study assesses a) the use value (UV) of the local flora, b) gendered differences in plant species, and c) the association between socio-economic variables and ethnobotanical knowledge. To assess the degree of knowledge of plant resources, we conducted 41 interviews collecting information on knowledge of local plant resources and the socio-economic situation of the informant. We also collected free listings of useful plants by category of use to identify the UV of each species. With the support of key informants, we photographed and collected the plant material recorded during the interviews and free listings on five different habitats. Paired t-tests and a Wilcoxon signed rank test were used to determine differences in the number of species known by men and women. Differences in distribution were analyzed by means of the Shapiro-Wilk's W normality tests. To determine the association of socio-economic factors and ethnobotanical knowledge, we used a non-metric multidimensional scaling analysis (NMDS). Informants listed 185 species. Medicinal plants constituted the most diverse group (90 species). Tropical deciduous forest is the habitat that concentrates the highest proportion of plant resources (80 species). The use-values were classified into three groups: A (4-6 UV; three species), B (0.35-1.37 UV; 39 species) and C (0-0.29 UV; 143 species). High-quality wood species and those associated to religious ceremonies had the highest UV. Women's and men's knowledge of plant species showed statistically significant differences at the interspecific and the intracategorical levels (Student's test, T15 = 4.8, p economic activities associated with the intracultural distribution of ethnobotanical knowledge among mestizo Mexican communities. It also provides information on plant resources and habitats and how local peasants value them. This information

  11. The malleability of infant motor development: cautions based on studies of child-rearing practices in Yucatan.

    Science.gov (United States)

    Solomons, H C

    1978-11-01

    Tests with the Bayley Motor Scale were given to 288 infants, equally divided by sex, in Yucatan, Mexico. These were 2 to 54 weeks in age and came from three sociocultural levels. In comparison to USA infants, early acceleration of motor development was followed by a marked downward trend. This phenomenon, if observed in a single child, may indicate progressive neurologic disease. Child-rearing practices would appear to account for the difference in pattern of test performance.

  12. Outcrop Analysis of the Cretaceous Mesaverde Group: Jicarilla Apache Reservation, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ridgley, Jennie; Dunbar, Robin Wright

    2001-04-24

    Field work for this project was conducted during July and April 1998, at which time fourteen measured sections were described and correlated on or adjacent to Jicarilla Apache Reservation lands. A fifteenth section, described east of the main field area, is included in this report, although its distant location precluded use in the correlations and cross sections presented herein. Ground-based photo mosaics were shot for much of the exposed Mesaverde outcrop belt and were used to assist in correlation. Outcrop gamma-ray surveys at six of the fifteen measured sections using a GAD-6 scintillometer was conducted. The raw gamma-ray data are included in this report, however, analysis of those data is part of the ongoing Phase Two of this project.

  13. Emissions from Biomass Burning in the Yucatan

    Science.gov (United States)

    Yokelson, R.; Crounse, J. D.; DeCarlo, P. F.; Karl, T.; Urbanski, S.; Atlas, E.; Campos, T.; Shinozuka, Y.; Kapustin, V.; Clarke, A. D.; hide

    2009-01-01

    In March 2006 two instrumented aircraft made the first detailed field measurements of biomass burning (BB) emissions in the Northern Hemisphere tropics as part of the MILAGRO project. The aircraft were the National Center for Atmospheric Research C-130 and a University of Montana/US Forest Service Twin Otter. The initial emissions of up to 49 trace gas or particle species were measured from 20 deforestation and crop residue fires on the Yucatan peninsula. This included two trace gases useful as indicaters of BB (HCN and acetonitrile) and several rarely, or never before, measured species: OH, peroxyacetic acid, propanoic acid, hydrogen peroxide, methane sulfonic acid, and sulfuric acid. Crop residue fires emitted more organic acids and ammonia than deforestation fires, but the emissions from the main fire types were otherwise fairly similar. The Yucatan fires emitted unusually amounts of SO2 and particle chloride, likely due to a strong marine influence on the peninsula.

  14. The role of feral mammals on wildlife infectious disease prevalence in two nature reserves within Mexico City limits.

    Science.gov (United States)

    Suzán, Gerardo; Ceballos, Gerardo

    2005-09-01

    Wild and feral medium-sized mammals were live trapped at two natural protected areas within the Mexico City limits to determine antibody prevalence for the most common infectious diseases (rabies, toxoplasmosis, and canine parvovirus) in dogs and cats. Mammals were trapped during the dry (March-April) and rainy seasons (July-August) of 1996 and 1997. A total of 68 individuals were captured, representing 8 species: opossums (Didelphis virginiana), ringtails (Bassariscus astutus), spotted skunks (Spilogale gracilis), weasels (Mustela frenata), rock squirrels (Spermophilus variegatus), Mexican gray squirrels (Sciurus aureogaster), feral cats (Felis catus), and feral dogs (Canis familiaris). There was marked seroprevalence for parvovirus (86.6%) and lower seroprevalences for both toxoplasma (23.9%) and rabies (17.9%). There were no significant prevalence differences among mammals in both protected areas, which were of contrasting size and isolation (i.e., small and isolated versus large and nonisolated). We suggest that high seroprevalence of these three infectious agents in wild mammals is a result of the high densities of feral dogs and cats in the two areas sampled. Feral dogs are able to maintain the infectious agents in these localities regardless of the protected area size and isolation. However, the native mammals of the small and isolated reserve are more vulnerable to infectious diseases because of small population size and genetic bottlenecks. Our results indicate that natural areas in and around Mexico City are a refugium for latent infectious agents, several of which are zoonotic. These findings suggest that conservation measures, such as eradication of feral mammals and vaccination programs, in the protected areas and surrounding areas could be beneficial.

  15. Aquatic food webs in mangrove and seagrass habitats of Centla Wetland, a Biosphere Reserve in Southeastern Mexico

    Directory of Open Access Journals (Sweden)

    Manuel Mendoza-Carranza

    Full Text Available Mangrove and seagrass habitats are important components of tropical coastal zones worldwide, and are conspicuous habitats of Centla Wetland Biosphere Reserve (CWBR in Tabasco, Mexico. In this study, we examine food webs in mangrove- and seagrass-dominated habitats of CWBR using stable isotope ratios of carbon and nitrogen. Our objective was to identify the importance of carbon derived from mangroves and seagrasses to secondary production of aquatic consumers in this poorly studied conservation area. Carbon and nitrogen isotope ratios of basal sources and aquatic consumers indicated that the species-rich food webs of both habitats are dependent on riparian production sources. The abundant Red mangrove Rhizophora mangle appears to be a primary source of carbon for the mangrove creek food web. Even though dense seagrass beds were ubiquitous, most consumers in the lagoon food web appeared to rely on carbon derived from riparian vegetation (e.g. Phragmites australis. The introduced Amazon sailfin catfish Pterygoplichthys pardalis had isotope signatures overlapping with native species (including high-value fisheries species, suggesting potential competition for resources. Future research should examine the role played by terrestrial insects in linking riparian and aquatic food webs, and impacts of the expanding P. pardalis population on ecosystem function and fisheries in CWBR. Our findings can be used as a baseline to reinforce the conservation and management of this important reserve in the face of diverse external and internal human impacts.

  16. 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

  17. Role of forest conservation in lessening land degradation in a temperate region: the Monarch Butterfly Biosphere Reserve, Mexico.

    Science.gov (United States)

    Manzo-Delgado, Lilia; López-García, José; Alcántara-Ayala, Irasema

    2014-06-01

    With international concern about the rates of deforestation worldwide, particular attention has been paid to Latin America. Forest conservation programmes in Mexico include Payment for Environmental Services (PES), a scheme that has been successfully introduced in the Monarch Butterfly Biosphere Reserve. To seek further evidence of the role of PES in lessening land degradation processes in a temperate region, the conservation state of the Cerro Prieto ejido within the Reserve was assessed by an analysis of changes in vegetation cover and land-use between 1971 and 2013. There were no changes in the total forest surface area, but the relative proportions of the different classes of cover density had changed. In 1971, closed and semi-closed forest occupied 247.81 ha and 5.38 ha, 82.33% and 1.79% of the total area of the ejido, respectively. By 2013, closed forest had decreased to 230.38 ha (76.54% of the ejido), and semi-closed cover was 17.23 ha (5.72% of the ejido), suggesting that some semi-closed forest had achieved closed status. The final balance between forest losses and recovery was: 29.63 ha were lost, whereas 13.72 ha were recovered. Losses were mainly linked to a sanitation harvest programme to control the bark beetle Scolytus mundus. Ecotourism associated with forest conservation in the Cerro Prieto ejido has been considered by inhabitants as a focal alternative for economic development. Consequently, it is essential to develop a well-planned and solidly structured approach based on social cohesion to foster a community-led sustainable development at local level. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Building ties: social capital network analysis of a forest community in a biosphere reserve in Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Luis Rico García-Amado

    2012-09-01

    Full Text Available Governance of the commons depends on the capacity to generate collective action. Networks and rules that foster that collective action have been defined as social capital. However, their causal link is still not fully understood. We use social network analysis to assess social capital, decision-making, and collective action in a forest-based common pool resource management in La Sepultura Biosphere Reserve (Chiapas, Mexico. Our research analyzes the productive networks and the evolution of coffee groups in one community. The network shows some centrality, with richer landholders tending to occupy core positions and poorer landless peasants occupying peripheral ones. This has fostered the community's environmentally oriented development but has also caused internal conflicts. Market requirements have shaped different but complementary productive networks, where organic coffee commercialization is the main source of bridging ties, which has resulted in more connectivity and resilience. Conservation attitudes, along with the institutional setting of the community, have promoted collective action. The unresolved conflicts, however, still leave some concerns about governance in the future.

  19. Peasant coffee in the Los Tuxtlas Biosphere Reserve, Mexico: A critical evaluation of sustainable intensification and market integration potential

    Directory of Open Access Journals (Sweden)

    Anne Cristina de la Vega-Leinert

    2016-12-01

    Full Text Available Abstract Production of low-input, shaded coffee in the Los Tuxtlas UNESCO Biosphere Reserve (LTBR, Veracruz, Mexico, an economically marginalized but ecologically rich region, was strongly affected by the collapse in international prices and the reconfiguration of the Mexican coffee sector in the 1990s. This place-based study used qualitative methods to investigate local strategies to reactivate coffee cultivation and improve market integration. Ninety-five producers, processors and cooperative representatives were interviewed to: 1 characterize the different actors in the local coffee commodity chain; 2 explore how producers, organized or not, shape and are constrained by the local coffee sector, and 3 evaluate whether producers land use strategies may be compatible with conservation in the LTBR. We combine the Land Sparing and Sharing framework with the UNESCO Biosphere Reserve zonation system to conceptualize how coffee plantations can be spatially integrated in protected areas and facilitate synergies between local livelihoods and conservation. Our empirical study illustrates the complexity and dynamism of the LTBR coffee sector. It highlights the resourcefulness of producers in adapting their cultivation systems, but also the narrow maneuvering room farmers have to exploit textbook synergies between conservation and fair trade and / or certified organic markets. In principle, coffee cultivation can be expanded and intensified without affecting remaining primary forest (Land Sparing and contribute to maintain a diverse landscape matrix in productive agroforestry systems (Land Sharing. However, few producers have the means required to successfully achieve profitable and long-term market integration. Future research on sustainable land use management in, and around, protected areas needs to explicitly address local, sectoral and market dynamics as drivers of land use at the local level. Although these dynamics may create windows of opportunity

  20. Hydrogeology of the south-eastern Yucatan Peninsula: New insights from water level measurements, geochemistry, geophysics and remote sensing

    DEFF Research Database (Denmark)

    Gondwe, Bibi Ruth Neuman; Lerer, Sara Maria; Stisen, S.

    2010-01-01

    The Yucatan Peninsula is one of the world’s largest karstic aquifer systems. It is the sole freshwater source for human users and ecosystems. The region hosts internationally important groundwater-dependent ecosystems (GDEs) in the 5280km2 Sian Ka’an Biosphere Reserve. The GDEs are threatened by ...

  1. 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.

  2. Chicxulub Impact Crater and Yucatan Carbonate Platform - Stratigraphy and Petrography of PEMEX Borehole Cores

    Science.gov (United States)

    Gutierrez-Cirlos, A. G.; Perez-Drago, G.; Perez-Cruz, L.; Urrutia-Fucugauchi, J.

    2008-12-01

    Chicxulub impact crater is the best preserved of the three large multi-ring structures documented in the terrestrial record. Chicxulub, formed 65 Ma ago, is associated with the Cretaceous/Tertiary (K/T) boundary layer and the impact related to the organism extinctions and events marking the boundary. The crater is buried under Tertiary sediments in the Yucatan carbonate platform in the southern Gulf of Mexico. The structure was initially recognized from gravity and magnetic anomalies in the PEMEX exploration surveys of the northwestern Yucatan peninsula. The exploration program included eight deep boreholes completed from 1952 through the 1970s. The investigations showing Chicxulub as a large complex impact crater formed at the K/T boundary have relayed on the PEMEX decades-long exploration program. However, despite frequent use of PEMEX information and core samples, significant parts of the database and cores remain to be evaluated, analyzed and incorporated with results from recent efforts. Access to PEMEX Core Repository has permitted to study the cores and collect new samples from some of the boreholes. We analyzed cores from Yucatan-6, Chicxulub-1, Sacapuc-1, Ticul-1, Yucatan-1 and Yucatan-4 boreholes to make new detailed stratigraphic correlations and petrographic characterization, using information from PEMEX database and the recent studies. In C-1 cores, breccias show 4-8 cm clasts of fine grained altered melt dispersed in a medium to coarse grained matrix composed of pyroxene and feldspar with little macroscopic alteration. Clasts contain 0.2 to 0.1 cm fragments of silicate material (basement) that show variable degrees of digestion. Melt samples from C-1 N10 comes from interval 1,393-1,394 m, and show a fine-to-medium grained coherent microcrystalline groundmass. Melt and breccias in Y-6 extend from about 1,100 m to more than 1,400 m. Sequence is well sorted, with an apparent gradation in both the lithic and melt clasts. In this presentation we report on

  3. The evaluation, certification and approbation of oil and gas reserves in Mexico; facts and performance; Sistema de estimacion, certificacion y aprobacion de reservas de hidrocarburos en Mexico; analisis de desempeno

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Padilla, Victor [Universidad Nacional Autonoma de Mexico (Mexico)]. E-mail: energia123@hotmail.com

    2013-07-15

    The evaluation, certification, approval and disclosure system of reserves applied in Mexico since 2010 aims to replicate the best practices of the international oil industry. It has gained rigor, simplicity, truthfulness and transparency, however its performance has been unequal: it has achieved to provide more certitude over the proved reserves but it has failed to dissipate the uncertainty over the probable and possible reserves. [Spanish] El sistema de evaluacion, certificacion y aprobacion de reservas aplicado en Mexico desde 2010 busca reproducir las mejores practicas de la industria petrolera internacional. Ha ganado en rigor, sencillez, veracidad y transparencia, sin embargo, su desempeno ha sido desigual, pues ha logrado brindar mayor certeza sobre las reservas probadas, pero no ha podido disipar la incertidumbre sobre las reservas probables y posibles.

  4. Beekeeping, environment and modernity in localities in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Enrique Rodríguez Balam

    2015-09-01

    Full Text Available In this paper, we reflect on the local knowledge about the European honey bee Apis mellifera scutellata, namely its biology, behavior, social structure, communication, and the relationships that these organisms maintain with the environment and their natural enemies. We also discuss the impacts that land use has on this economic activity. The empirical knowledge of beekeepers converges quite well with the scientific knowledge concerning this group of organisms.

  5. Beekeeping, environment and modernity in localities in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Enrique Rodríguez Balam

    2015-05-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n3p143 In this paper, we reflect on the local knowledge about the European honey bee  Apis mellifera scutellata, namely its biology, behavior, social structure, communication, and the relationships that these organisms maintain with the environment and their natural enemies. We also discuss the impacts that land use has on this economic activity. The empirical knowledge of beekeepers converges quite well with the scientific knowledge concerning this group of organisms.

  6. 1 Sunday November 30, 2008 Merida, Yucatan, Mexico Fiesta ...

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

    Jayne Bergeron

    2008-11-30

    Nov 30, 2008 ... Higher Education and Scientific Research in Rwanda. He then became the ...... availability of protective clothing and masks and alter- ...... count on collection services for used pesticide containers, bags and packaging. Fair.

  7. Social-ecological dynamics of change and restoration attempts in the Chihuahuan Desert grasslands of Janos Biosphere Reserve, Mexico

    Science.gov (United States)

    Shrub encroachment and grassland loss are widespread throughout the US-Mexico borderlands with negative consequences for production of livestock and ecosystem services. In this paper we detail the complex social and ecological phenomena associated with this pattern of degradation in a large area in ...

  8. 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.

  9. Storm-generated bedforms and relict dissolution pits and channels on the Yucatan carbonate platform

    Science.gov (United States)

    Gulick, S. P.; Goff, J. A.; Stewart, H. A.; Perez-Cruz, L. L.; Davis, M. B.; Duncan, D.; Saustrup, S.; Sanford, J. C.; Fucugauchi, J. U.

    2013-12-01

    The Yucatan 2013 (cruise number 2013/4_ECORD) geophysical and geotechnical hazard site survey took place aboard the R/V Justo Sierra in April 2013. Our study was conducted within the Chicxulub impact crater, encompassing three potential IODP drilling sites. The survey was located ~32 km northwest of Progreso, Mexico; data acquired included ~15.6 km2 of complete multibeam bathymetry coverage, ~435 line km of side scan sonar and CHIRP data, 204 line kilometers of magnetometer data, and 194 line kilometers of surface tow boomer profiles. Based on these data, this portion of the Yucatan Shelf consists of flat-lying, hard limestone rock overlain by isolated ribbons of carbonate sand limestone bedrock. This reflector is flat-lying and undisturbed throughout the survey area. Therefore, none of these dissolution pits appear to be underlain by a cenote or sink hole. The NW sector of the survey area exhibits a more complex morphology than the alternating ribbon/bare rock morphology elsewhere, including linear scarps (up to ~1 m relief), deeper pitting (up to ~1 m relief), and sinuous, dendritic channeling (up to ~2 m relief). The geologic origin of these features will require further investigation. Sand drifts are present in this region, but are thinner and cover less area. These observations show the dominant modern sediment formation and transport processes on this starved platform are from large storms and hurricanes that place large regions of the platform at wave base. Remaining observed features were generated during times of lower sea level.

  10. 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.

  11. Nature of the Yucatan Block Basement as Derived From Study of Granitic Clasts in the Impact Breccias of Chicxulub Crater

    Science.gov (United States)

    Vera-Sanchez, P.; Rebolledo-Vieyra, M.; Perez-Cruz, L.; Urrutia-Fucugauchi, J.

    2008-05-01

    The tectonic and petrologic nature of the basement of the Yucatan Block is studied from analyses of basement clasts present in the impact suevitic breccias of Chicxulub crater. The impact breccias have been sampled as part of the drilling projects conducted in the Yucatan peninsula by Petroleos Mexicanos, the National University of Mexico and the Chicxulub Scientific Drilling Project. Samples analyzed come mainly from the Yaxcopoil-1, Tekax, and Santa Elena boreholes, and partly from Pemex boreholes. In this study we concentrate on clasts of the granites, granodiorites and quartzmonzonites in the impact breccias. We report major and trace element geochemical and petrological data, which are compared with data from the granitic and volcanic rocks from the Maya Mountains in Belize and from the Swannee terrane in Florida. Basement granitic clasts analyzed present intermediate to acidic sub-alkaline compositions. Plots of major oxides (e.g., Al2O3, Fe2O3, TiO2 and CaO) and trace elements (e.g., Th, Y, Hf, Nb and Zr) versus silica allow separation of samples into two major groups, which can be compared to units in the Maya Mountains and in Florida basement. The impact suevitic breccia samples have been affected by alteration likely related to the hydrothermal processes associated with the crater melt sheet. Cloritization, seritization and fenitization alterations are recognized, due to the long term hydrothermalism. Krogh et al. (1993) reported U-Pb dates on zircons from the suevitic breccias, which gave dates of 545 +/- 5 Ma and 418 +/- 6 Ma, which were interpreted in terms of the deep granitic metamorphic Yucatan basement. The younger date correlates with the age for the Osceola Granite and the St. Lucie metamorphic complex of the Swannee terrane in the Florida peninsula. The intrusive rocks in the Yucatan basement may be related to approx. 418 Ma ago collisional event in the Late Silurian.

  12. Determination of 137Cs and 60Co pollution in the area of the Laguna Verde Nuclear Power Plant, Mexico.

    Science.gov (United States)

    Salas Mar, Bernardo

    2015-11-01

    The project 'Radiological Analysis of Environmental Samples in the Gulf of Mexico and the coast of Quintana Roo', had the aim of identifying and quantifying anthropogenic radionuclides in environmental samples consisting of silt, sand and sea water. This paper presents the results of the radiological analysis of these samples, which was made in the multichannel system for gamma spectrometry with hyperpure germanium detector in the Laboratory of Radiological Analysis of Environmental Samples, located at the Physics Department, Faculty of Sciences, of the Autonomous National University of Mexico (UNAM). The sampled points are along the coast of the contiguous states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo. This paper presents the qualitative and quantitative concentrations of the main identified anthropogenic radionuclides (60)Co and (137)Cs. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Trace elements and heavy metals in the Grand Bay National Estuarine Reserve in the northern Gulf of Mexico

    Science.gov (United States)

    The Grand Bay National Estuarine Research Reserve has the highest biotic diversity of habitats and offer a reserve of food resources and commercially significant species. Rapid human civilization has led to accumulation of heavy metals and trace elements in estuaries. The Grand Bay National Estuarin...

  14. Tidal currents in the Yucatan Channel

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo Gonzalez, Fatima [Centro Universitario de la Costa, Universidad de Guadalajara, Guadalajara, Jalisco (Mexico); Ochoa, Jose; Candela, Julio; Badan, Antonio; Sheinbaum; Gonzalez Navarro, Juan Ignacio [Departamento de Oceanografia Fisica, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Ensenada, Baja California (Mexico)

    2007-07-15

    Currents data from a ten-month period at 197 measuring points covering all Yucatan Channel were processed by harmonic analysis to estimate tidal parameters for the O{sub 1}, K{sub 1}, M{sub 2} and S{sub 2} components. The highly detailed coverage confirms the known dominance for the O{sub 1} and K{sub 1} diurnal components, but also showed, for the first time, their intensification in the deep eastern margin of the channel where maximum amplitudes in main axis are 17 and 19 cm.s{sup -}1. The data also confirms weak semi-diurnal components, of which the most intense, M{sub 2} and S{sub 2}, have amplitudes only up to 2 cm.s{sup -}1. The tidal ellipses were elongated (i.e. with eccentricities close to one) in the NNW direction. The O{sub 1}, K{sub 1}, M{sub 2} and S{sub 2} contributions in transport variability through the channel have amplitudes of 11.7, 12.5, 1.2 and 1.0 Sv, all well determined above noise. [Spanish] Se presentan, a detalle sin precedente, las caracteristicas de las corrientes de marea O{sub 1}, K{sub 1}, M{sub 2} y S{sub 2} en el canal de Yucatan. Mapas de los parametros que definen las elipses, como son las amplitudes en los ejes principales, la orientacion, la fase y la razon-senal-ruido se obtienen, por el clasico analisis armonico en mediciones de 10 meses en duracion, en 197 puntos que cubren ampliamente un plano vertical del canal. En acuerdo con reportes anteriores, las senales diurnas O{sub 1} y K{sub 1} dominan, demostrandose aqui que sus amplitudes alcanzan, en la parte profunda y Este, 17 y 19 cm.s{sup -}1. El analisis tambien revela senales semidiurnas M{sub 2} y S{sub 2} muy debiles con amplitudes maximas de 2 y 1cm.s{sup -}1. Las elipses son muy alargadas (i.e. con excentricidad cercana a uno) y orientadas al nornoroeste. Los valores de la razon senal a ruido indican que los parametros de las dos constituyentes diurnas se encuentran bien determinados, mientras que las semidiurnas quedan muy contaminadas por el ruido. El rasgo mas

  15. 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…

  16. ISVEE 14 Yucatan 2015 14th Symposium of the International Society for Veterinary Epidemiology and Economics.

    Science.gov (United States)

    de Anda, Jorge Hernández

    2017-02-01

    The 14th Symposium of the International Society for Veterinary Epidemiology and Economics (ISVEE 14) was held in Merida, Yucatan, Mexico during 3-7 November. 2015. The purpose of ISVEE 14 Yucatan 2015 was to provide a global forum for graduate students, postdoctoral fellows, junior and senior investigators, as well as health policymakers to exchange information that can advance the fields of veterinary epidemiology and economics, and other disciplines in the health and social sciences. The main theme of ISVEE 14 was Planning Our Future. Human population growth is predicted to increase nearly 50% to 11 billion by 2050, and climate change and changing land use can have an impact on local and global food systems, interactions among humans, wildlife and domestic animals, as well as local, regional, and global public health alerts. How can we help our systems of education, research, and public policy adapt? Are new veterinary graduates and epidemiology practitioners prepared to become active protagonists in the solution of health issues that affect humans and animal populations in a changing environment? What innovative research is needed to understand and enhance the food systems of the future? What are the expected roles or contributions of veterinarians or epidemiology practitioners on future climate change, food systems, and health? Is our profession or discipline leading One Health initiatives? Are there current or new models that make national veterinary services more efficacious and efficient for disease control and eradication? To help us answer these questions, the organizing committee of ISVEE 14 invited five distinguished keynote speakers to share their vision and innovative ideas on education, technological developments, research, and public policy of our future with a concentration in the following five areas: (i) One Health (Jonna Mazet), (ii) climate change (Bernard Bett), (iii) animal health economics (Jonathan Rushton), (iv) national veterinary services

  17. 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.

  18. Diversidad de mamíferos de la Reserva Natural Sierra Nanchititla, México Diversity of mammals in the Natural Reserve Sierra Nanchititla, Mexico

    Directory of Open Access Journals (Sweden)

    Octavio Monroy-Vilchis

    2011-03-01

    Full Text Available La Reserva Natural Sierra Nanchititla (RNSN, por su extensión, es la segunda área natural protegida del Estado de México; sin embargo, se desconoce gran parte de su biodiversidad. El objetivo de este trabajo fue estimar su diversidad mastofaunística. Se utilizó el trampeo directo para la colecta de mamíferos pequeños y trampas-cámara para el estudio de los mamíferos medianos y grandes. Se calculó la diversidad a partir del índice de Margalef, y se evaluaron la dominancia y la equidad mediante los índices de Simpson y Shannon-Wiener, respectivamente. Se registraron 53 especies de mamíferos; 3 de ellas son el primer registro estatal, 10 son endémicas de México y 4 las considera en alguna categoría de vulnerabilidad el gobierno mexicano. En la zona habitan 5 de las 6 especies de felinos de México. La composición mastofaunística de la RNSN fue comparada con la de la sierra Purépecha, Michoacán, con la que comparte el 38% de las especies. De acuerdo con el índice de Jaccard, la similitud entre ambas es baja. Considerando los resultados, la importancia de la RNSN con respecto a su diversidad mastofaunística es evidente, así como la necesidad de delinear estrategias para su conservación.The Sierra Nanchititla Natural Reserve (SNNR is the second largest natural protected area in the State of Mexico, however its biodiversity is largely unknown. The aim of this research was to estimate its mammalian diversity. Direct trapping was used to capture small mammals and camera-trapping for the study of medium and large mammals. Diversity was calculated from Margalef's index, dominance and equity were evaluated through Simpson's and Shannon-Wiener indexes, respectively. Fifty three species were registered, 3 of them are the first record for the State of Mexico, 10 are endemic to Mexico and 4 are considered in some category of vulnerability by the Mexican government. The area is inhabited by 5 of the 6 Mexican felid species. The

  19. Subsurface Analysis of the Mesaverde Group on and near the Jicarilla Apache Indian Reservation, New Mexico-its implication on Sites of Oil and Gas Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Ridgley, Jennie

    2001-08-21

    The purpose of the phase 2 Mesaverde study part of the Department of Energy funded project ''Analysis of oil-bearing Cretaceous Sandstone Hydrocarbon Reservoirs, exclusive of the Dakota Sandstone, on the Jicarilla Apache Indian Reservation, New Mexico'' was to define the facies of the oil-producing units within the subsurface units of the Mesaverde Group and integrate these results with outcrop studies that defined the depositional environments of these facies within a sequence stratigraphic context. The focus of this report will center on (1) integration of subsurface correlations with outcrop correlations of components of the Mesaverde, (2) application of the sequence stratigraphic model determined in the phase one study to these correlations, (3) determination of the facies distribution of the Mesaverde Group and their relationship to sites of oil and gas accumulation, (4) evaluation of the thermal maturity and potential source rocks for oil and gas in the Mesaverde Group, and (5) evaluation of the structural features on the Reservation as they may control sites of oil accumulation.

  20. Analysis of oil-bearing Cretaceous sandstone hydrocarbon reservoirs, exclusive of the Dakota Sandstone, on the Jicarilla Apache Indian Reservation, New Mexico; TOPICAL

    International Nuclear Information System (INIS)

    Ridgley, Jennie; Wright Dunbar, Robyn

    2000-01-01

    This is the Phase One contract report to the United States Department of Energy, United State Geological Survey and the Jicarilla Apache Indian Tribe on the project entitled''Outcrop Analysis of the Cretaceous Mesaverde Group: Jicarilla Apache Reservation, New Mexico.'' Field work for this project was conducted during July and August 1998, at which time fourteen measured sections were described and correlated on or adjacent to Jicarilla Apache Reservation lands. A fifteen section, described east of the main field area, is included in this report, although its distant location precluded use in the correlation's and cross-sections presented herein. Ground-based photo mosaics were shot for much of the exposed Mesaverde outcrop belt and were used to assist in correlation. Outcrop gamma-ray surveys at six of the fifteen measured sections using a GAD-6 scintillometer was conducted. The raw gamma-ray data are included in this report, however, analysis of those data is part of the ongoing Phase Two of this project

  1. A dataset on the species composition of amphipods (Crustacea) in a Mexican marine national park: Alacranes Reef, Yucatan.

    Science.gov (United States)

    Paz-Ríos, Carlos E; Simões, Nuno; Pech, Daniel

    2018-01-01

    Alacranes Reef was declared as a National Marine Park in 1994. Since then, many efforts have been made to inventory its biodiversity. However, groups such as amphipods have been underestimated or not considered when benthic invertebrates were inventoried. Here we present a dataset that contributes to the knowledge of benthic amphipods (Crustacea, Peracarida) from the inner lagoon habitats from the Alacranes Reef National Park, the largest coral reef ecosystem in the Gulf of Mexico. The dataset contains information on records collected from 2009 to 2011. Data are available through Global Biodiversity Information Facility (GBIF). A total of 110 amphipod species distributed in 93 nominal species and 17 generic species, belonging to 71 genera, 33 families and three suborders are presented here. This information represents the first online dataset of amphipods from the Alacranes Reef National Park. The biological material is currently deposited in the crustacean collection from the regional unit of the National Autonomous University of Mexico located at Sisal, Yucatan, Mexico (UAS-Sisal). The biological material includes 588 data records with a total abundance of 6,551 organisms. The species inventory represents, until now, the richest fauna of benthic amphipods registered from any discrete coral reef ecosystem in Mexico.

  2. Public Opinion and Repression in Yucatan: 1808-1816

    Directory of Open Access Journals (Sweden)

    Laura Machuca Gallegos

    2017-04-01

    Full Text Available Across the Hispanic world, the first two decades of the 19th Century were characterized by the development of a new political force called public opinion. The objective of this article is to analyze its appearance in Merida, Yucatan: though far from the great centers of power, this city actively participated in the same political, social and cultural processes as the rest of ibero-America in the period starting in 1808. The author centers their attention on the Sanjuanistas, a group active during this time whose goal was to defend the Constitution of Cadiz. Yucatan, far from representing  a local case, instead reveals the ins and outs of new forms of sociability, above all in the field of political practices, and their embrace by society.

  3. The Orphans of Cholera Morbus in Yucatan, 1833

    OpenAIRE

    Elsa Malvido; Paola Peniche Moreno

    2013-01-01

    This essay discusses the phenomenon of orphanhood which affected a large number of children after the cholera epidemic that struck Yucatan in July 1833. Moreover, it inquires into the fate of children whose parents died of cholera, the role played by kinship networks to provide them with shelter, and the influence of the Church and the State on the situation. Based on first hand sources, the author suggests that the orphanhood produced by cholera served as a pretext for economically and socia...

  4. Explaining variations in the diversity of parasitoid assemblages in a biosphere reserve of Mexico: evidence from vegetation, land management and seasonality.

    Science.gov (United States)

    González-Moreno, A; Bordera, S; Leirana-Alcocer, J; Delfín-González, H; Ballina-Gómez, H S

    2017-11-23

    Insect fauna biodiversity in natural protected areas has not been thoroughly studied. Therefore, the aim of this work was to assess whether and how vegetation types, land management and seasonality influence the diversity of Ichneumonidae (Hymenoptera) in the Ría Lagartos Biosphere Reserve (Mexico). A sampling programme was conducted using Malaise traps from 2008 to 2009 in three vegetation types, each with two conservation zones (core and buffer zones). Three seasons were considered: rainy, dry and north-winds (isolated storms from November to February). A total of 336 species were identified. Rarefaction and Generalized Linear Model indicated higher species richness and abundance, respectively, in the buffer zone of the dry forest; possible explanations for this finding include the intermediate disturbance hypothesis, wherein diversity can be higher in sites where disturbance is not very frequent or very intense, and the 'enemies hypothesis', wherein structural complexity and high plant diversity favour increased predators or, in this case, parasitoids. Diversity was higher during the rainy season, which may have been due to the higher availability of resources. Vegetation and management had a positive impact on the Coc (attack cocoons and pupae) and Myc (attack concealed larvae living in the fruiting bodies of mushrooms) parasitoid guilds. Members of the Coc guild are generalist parasitoids, which may be favoured in complex vegetation with a high richness of potential hosts and non-hosts. The Myc guild requires certain environmental conditions that promote fungal growth, such as humidity, that is absent in the other vegetation types of savannah and coastal dune scrubland.

  5. Representación gráfica del riesgo de mortalidad neonatal en un centro perinatal regional en Mérida, Yucatán, México The graphical display of neonatal mortality risk at a regional perinatal center in Merida, Yucatan, Mexico: The joint effect of birth weight and gestational age

    Directory of Open Access Journals (Sweden)

    Lorenzo Osorno-Covarrubias

    2002-07-01

    Full Text Available Objetivo. Determinar el riesgo de mortalidad neonatal por edad gestacional y el peso al nacer. Material y métodos. Se estudió una cohorte de 19 668 neonatos que egresaron entre el 1 de enero de 1995 y el 31 de octubre de 1999 del Centro Médico Nacional Ignacio García Téllez, del tercer nivel de atención perinatal del Instituto Mexicano del Seguro Social de la Península de Yucatán. Se registraron el peso al nacer, edad gestacional y condición de egreso. Se calculó el riesgo absoluto (RA de mortalidad para cada semana de edad gestacional y grupo de peso. Resultados. El RA de mortalidad observado en neonatos de entre 34 a 44 semanas y peso mayor o igual a 2 250 g fue de 0.4%, de 15% para aquellos de entre 26 a 32 semanas con peso mayor o igual a 1000 g, y de 73% para los de entre las 26 a las 34 semanas, con peso al nacimiento de entre 750 y 1 000 g. Conclusione. El RA de mortalidad neonatal aumentó a menor. edad gestacional y peso. Los datos pueden ser utilizados como valores de referencia para nuestro hospital y para comparación con otros hospitales.Objective. To determine the neonatal mortality risk according to gestational age and birth weight. Material and Methods. The cohort consisted of 19 668 newborns of Centro Médico Nacional (National Medical Center Ignacio García Téllez, a tertiary level healthcare institution of the Instituto Mexicano del Seguro Social (Mexican Institute of Social Security, IMSS of the Yucatan Peninsula. All new-borns discharged from the hospital between January 1 st , 1995 and October 31 st , 1999 were included in the study. Birth weight, gestational age, and conditions upon discharge were recorded. Absolute risk (AR of mortality was calculated for each week-of-gestation- and birth group. Results. Observed AR in newborns 34 to 44 weeks of gestational age and weighing at least 2 250 g was 0.4, while that for those 26 to 32 weeks of gestational age and weighing between 1000 g was 15%. Conclusions. AR of

  6. 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

  7. The Orphans of Cholera Morbus in Yucatan, 1833

    Directory of Open Access Journals (Sweden)

    Elsa Malvido

    2013-07-01

    Full Text Available This essay discusses the phenomenon of orphanhood which affected a large number of children after the cholera epidemic that struck Yucatan in July 1833. Moreover, it inquires into the fate of children whose parents died of cholera, the role played by kinship networks to provide them with shelter, and the influence of the Church and the State on the situation. Based on first hand sources, the author suggests that the orphanhood produced by cholera served as a pretext for economically and socially privileged groups to get hold of free labor force both for domestic service and hacienda work.

  8. 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

  9. 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)

  10. 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

  11. Five new species of the genera Heerz Marsh, Lissopsius Marsh and Ondigus Braet, Barbalho and van Achterberg (Braconidae, Doryctinae) from the Chamela-Cuixmala biosphere reserve in Jalisco, Mexico

    Science.gov (United States)

    Zaldívar-Riverón, Alejandro; Martínez, Juan José; Ceccarelli, Fadia Sara; Shaw, Scott R.

    2012-01-01

    Abstract Five new species belonging to the poorly known Neotropical doryctine parasitoid wasps genera Heerz Marsh (Heerz ecmahla sp. n. and Heerz macrophthalma sp. n.), Lissopsius Marsh (Lissopsius pacificus sp. n. and Lissopsius jalisciensis sp. n.) and Ondigus Braet, Barbalho & van Achterberg (Ondigus cuixmalensis sp. n.) are described from the Chamela-Cuixmala Biosphere reserve in Jalisco, Mexico. Keys to the described species of the above three genera are provided. The phylogenetic placement of the examined taxa is investigated based on mitochondrial (COI) and nuclear (28S, 2nd and 3rd domain regions) DNA sequence data. PMID:22328849

  12. [Population estimates and conservation of felids (Carnivora: Felidae) in Northern Quintana Roo, Mexico].

    Science.gov (United States)

    Ávila-Nájera, Dulce María; Chávez, Cuauhtémoc; Lazcano-Barrero, Marco A; Pérez-Elizalde, Sergio; Alcántara-Carbajal, José Luis

    2015-09-01

    Wildlife density estimates provide an idea of the current state of populations, and in some cases, reflect the conservation status of ecosystems, essential aspects for effective management actions. In Mexico, several regions have been identified as high priority areas for the conservation of species that have some level of risk, like the Yucatan Peninsula (YP), where the country has the largest population of jaguars. However, little is known about the current status of threatened and endangered felids, which coexist in the Northeastern portion of the Peninsula. Our objective was to estimate the wild cats' density population over time at El Eden Ecological Reserve (EEER) and its surrounding areas. Camera trap surveys over four years (2008, 2010, 2011 and 2012) were conducted, and data were obtained with the use of capture-recapture models for closed populations (CAPTURE + MMDM or 1/2 MMDM), and the spatially explicit capture-recapture model (SPACECAP). The species studied were jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus pardalis), jaguarundi (Puma yaguaroundi) and margay (Leopardus wiedii). Capture frequency was obtained for all five species and the density for three (individuals/100km2). The density estimated with The Mean Maximum Distance Moved (MMDM), CAPTURE, ranged from 1.2 to 2.6 for jaguars, from 1.7 to 4.3 for pumas and from 1.4 to 13.8 for ocelots. The density estimates in SPACECAP ranged from 0.7 to 3.6 for jaguars, from 1.8 to 5.2 for pumas and 2.1 to 5.1 for ocelots. Spatially explicit capture recapture (SECR) methods in SPACECAP were less likely to overestimate densities, making it a useful tool in the planning and decision making process for the conservation of these species. The Northeastern portion of the Yucatan Peninsula maintains high populations of cats, the EEER and its surrounding areas are valuable sites for the conservation of this group of predators. Rev. Biol.

  13. 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

  14. 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)

  15. Sequence Stratigraphic Analysis and Facies Architecture of the Cretaceous Mancos Shale on and Near the Jicarilla Apache Indian Reservation, New Mexico-their relation to Sites of Oil Accumulation; FINAL

    International Nuclear Information System (INIS)

    Ridgley, Jennie

    2001-01-01

    The purpose of phase 1 and phase 2 of the Department of Energy funded project Analysis of oil- bearing Cretaceous Sandstone Hydrocarbon Reservoirs, exclusive of the Dakota Sandstone, on the Jicarilla Apache Indian Reservation, New Mexico was to define the facies of the oil producing units within the Mancos Shale and interpret the depositional environments of these facies within a sequence stratigraphic context. The focus of this report will center on (1) redefinition of the area and vertical extent of the ''Gallup sandstone'' or El Vado Sandstone Member of the Mancos Shale, (2) determination of the facies distribution within the ''Gallup sandstone'' and other oil-producing sandstones within the lower Mancos, placing these facies within the overall depositional history of the San Juan Basin, (3) application of the principals of sequence stratigraphy to the depositional units that comprise the Mancos Shale, and (4) evaluation of the structural features on the Reservation as they may control sites of oil accumulation

  16. 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

  17. Measuring the Wavelength of a Diode Laser and the Birefringence of Mica: The Experimental Examination of the IPHO 40 Held in Mexico

    Science.gov (United States)

    Moran-Lopez, J. L.; Ortiz, M. E.; Rodriguez, L. F.; Romero-Rochin, V.

    2010-01-01

    The experimental examination applied in the 40th International Physics Olympiad held in Merida, Yucatan, Mexico, is presented. The examination consisted of two parts: (1) based on the measurements of a diffraction pattern produced by a diode laser impinging on a sharp edge of a razor blade, the students were asked to estimate the wavelength of the…

  18. The Africanization of honeybees (Apis mellifera L.) of the Yucatan: a study of a massive hybridization event across time.

    Science.gov (United States)

    Clarke, Kylea E; Rinderer, Thomas E; Franck, Pierre; Quezada-Euán, Javier G; Oldroyd, Benjamin P

    2002-07-01

    Until recently, African and European subspecies of the honeybee (Apis mellifera L.) had been geographically separated for around 10,000 years. However, human-assisted introductions have caused the mixing of large populations of African and European subspecies in South and Central America, permitting an unprecedented opportunity to study a large-scale hybridization event using molecular analyses. We obtained reference populations from Europe, Africa, and South America and used these to provide baseline information for a microsatellite and mitochondrial analysis of the process of Africanization of the bees of the Yucatan Peninsula, Mexico. The genetic structure of the Yucatecan population has changed dramatically over time. The pre-Africanized Yucatecan population (1985) comprised bees that were most similar to samples from southeastern Europe and northern and western Europe. Three years after the arrival of Africanized bees (1989), substantial paternal gene flow had occurred from feral Africanized drones into the resident European population, but maternal gene flow from the invading Africanized population into the local population was negligible. However by 1998, there was a radical shift with both African nuclear alleles (65%) and African-derived mitochondria (61%) dominating the genomes of domestic colonies. We suggest that although European mitochondria may eventually be driven to extinction in the feral population, stable introgression of European nuclear alleles has occurred.

  19. PREVALENCE AND RISK FACTORS ASSOCIATED WITH THE PRRS VIRUS IN SEMEN OF BOARS IN PIG FARMS OF YUCATAN

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    Aremi Jordan-Craviotto

    2009-07-01

    Full Text Available The objectives of the present study were to estimate the prevalence of and to determine the risk factors associated with the porcine reproductive and respiratory syndrome virus (PRRSV, American strain in semen of boars in pig herds of Yucatan, Mexico. Ninety two boars from 26 herds were ejaculated once. Semen samples were processed by the RT-nPCR test using the ORF7 primer to detect the PRRS virus. The true prevalence estimated was 10.1% (95% CI = 4.1-16.1%. Significance of risk factors was determined by Fisher-exact test. The odds of detecting genetic material of the PRRSV was greater (OR = 9.2 in semen of boars used under natural mating than those used in artificial insemination. In herds where boar’s acclimatization was not practiced the odds of a positive boar was 4.3. Another risk factor (P < 0.05 was the origin of the animals. In conclusion, the prevalence of the PRRSV in boar semen was smaller to the notified in the literature and determinate in blood serum. Management practices, such as the use of the artificial insemination and acclimatization of the boar, could be useful in reducing the prevalence of the PRRS virus in the pig farms.

  20. Chicxulub Impact Crater and Yucatan Carbonate Platform - PEMEX Oil Exploratory Wells Revisited

    Science.gov (United States)

    Pérez-Drago, G.; Gutierrez-Cirlos, A. G.; Pérez-Cruz, L.; Urrutia-Fucugauchi, J.

    2008-12-01

    Geophysical oil exploration surveys carried out by PEMEX in the 1940's revealed occurrence of an anomalous pattern of semi-circular concentric gravity anomalies. The Bouguer gravity anomalies covered an extensive area over the flat carbonate platform in the northwestern Yucatan Peninsula; strong density contrasts were suggestive of a buried igneous complex or basement uplift beneath the carbonates, which was referred as the Chicxulub structure. The exploration program carried out afterwards included a drilling program, starting with Chicxulub-1 well in 1952 and comprising eight deep boreholes through the 1970s. An aeromagnetic survey in late 1970's showed high amplitude anomalies in the gravity anomaly central sector. Thus, research showing Chicxulub as a large complex impact crater formed at the K/T boundary was built on the PEMEX decades-long exploration program. Despite frequent reference to PEMEX information and samples, original data and cores have not been openly available for detailed evaluation and integration with results from recent investigations. Core samples largely remain to be analyzed and interpreted in the context of recent marine, aerial and terrestrial geophysical surveys and the drilling/coring projects of UNAM and ICDP. In this presentation we report on the stratigraphy and paleontological data for PEMEX wells: Chicxulub- 1 (1582m), Sacapuc-1 (1530m), Yucatan-6 (1631m), Ticul-1 (3575m) Yucatan-4 (2398m), Yucatan-2 (3474m), Yucatan-5A (3003m) and Yucatan-1 (3221m). These wells remain the deepest drilled in Chicxulub, providing samples of impact lithologies, carbonate sequences and basement, which give information on post- and pre-impact stratigraphy and crystalline basement. We concentrate on stratigraphic columns, lateral correlations and integration with UNAM and ICDP borehole data. Current plans for deep drilling in Chicxulub crater target the peak ring and central sector, with offshore and onshore boreholes proposed to the IODP and ICDP

  1. A New ′Conservation Space′? Protected Areas, Environmental Economic Activities and Discourses in Two Yucatán Biosphere Reserves in Mexico

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    Sabrina Doyon

    2014-01-01

    Full Text Available This article examines some of the local socioeconomic repercussions of two biosphere reserves on the Yucatán Peninsula-Ría Celestún and Ría Lagartos. We analyse aspects of the relationship that the residents of the six villages located within the two reserves have with their environment, by examining both the ′environmental economic activities′ residents are involved in and their discourses on, and interpretations of, the notion of environment and the conservation precepts put forward by the biosphere reserves. Our research explores how the objectives of the United Nations Educational, Scientific and Cultural Organization′s Man and Biosphere Programme, disseminated by biosphere reserves, are put into practice on the ground. In particular, we look at how environmental economic activities are experienced and practised without necessarily being accompanied by the integration, acceptance, and internalisation of conservation principles-and how these activities contribute, or fail to contribute, to the crystallisation of a new ′conservation space′.

  2. Geochemical variability of the Yucatan basement: Constraints from crystalline clasts in Chicxulub impactites

    Science.gov (United States)

    Kettrup, B.; Deutsch, A.

    2003-07-01

    The 65 Ma old Chicxulub impact structure with a diameter of about 180 km is again in the focus of the geosciences because of the recently commenced drilling of the scientific well Yaxcopoil- 1. Chicxulub is buried beneath thick post-impact sediments, yet samples of basement lithologies in the drill cores provide a unique insight into age and composition of the crust beneath Yucatan. This study presents major element, Sr, and Nd isotope data for Chicxulub impact melt lithologies and clasts of basement lithologies in impact breccias from the PEMEX drill cores C-1 and Y-6, as well as data for ejecta material from the K/T boundaries at La Lajilla, Mexico, and Furlo, Italy. The impact melt lithologies have an andesitic composition with significantly varying contents of Al, Ca, and alkali elements. Their present day 87Sr/86Sr ratios cluster at about 0.7085, and 143Nd/144Nd ratios range from 0.5123 to 0.5125. Compared to the melt lithologies that stayed inside the crater, data for ejecta material show larger variations. The 87Sr/86Sr ratios range from 0.7081 for chloritized spherules from La Lajilla to 0.7151 for sanidine spherules from Furlo. The 143Nd/144Nd ratio is 0.5126 for La Lajilla and 0.5120 for the Furlo spherules. In an tCHUR(Nd)-tUR(Sr) diagram, the melt lithologies plot in a field delimited by Cretaceous platform sediments, various felsic lithic clasts and a newly found mafic fragment from a suevite. Granite, gneiss, and amphibolite have been identified among the fragments from crystalline basement gneiss. Their 87Sr/86Sr ratios range from 0.7084 to 0.7141, and their 143Nd/144Nd ratios range from 0.5121 to 0.5126. The TNdDM model ages vary from 0.7 to 1.4 Ga, pointing to different source terranes for these rocks. This leads us to believe that the geological evolution and the lithological composition of the Yucatàn basement is probably more complex than generally assumed, and Gondwanan as well as Laurentian crust may be present in the Yucatàn basement.

  3. Hongos tremeloides (Heterobasidiomycetes de la Reserva de la Biosfera de Calakmul, Campeche, México Tremelloid fungi (Heterobasidiomycetes from Calakmul Biosphere Reserve, Campeche, Mexico

    Directory of Open Access Journals (Sweden)

    Sigfrido Sierra

    2012-03-01

    Full Text Available Se registran 7 especies de hongos tremeloides de la Reserva de la Biosfera de Calakmul: Auricularia cornea Ehrenb., A. delicata (Fr. Henn., A. mesenterica (Dicks. Pers., Dacryopinax elegans (Berk. et M.A. Curtis G.W. Martin, D. spathularia (Schwein. G.W. Martin, Tremella wrightii Berk. et M.A. Curtis y Tremelloscypha gelatinosa (Murrill Oberw. et K. Wells. Todas son registros nuevos para la reserva. Auricularia cornea y T. gelatinosa son nuevos registros para el estado de Campeche.Seven species of tremelloid fungi are recorded from Calakmul Biosphere Reserve: Auricularia cornea Ehrenb., A. delicata (Fr. Henn., A. mesenterica (Dicks. Pers., Dacryopinax elegans (Berk. et M.A. Curtis G.W. Martin, D. spathularia (Schwein. G.W. Martin, Tremella wrightii Berk. et M.A. Curtis and Tremelloscypha gelatinosa (Murrill Oberw. et K. Wells. All are new records for the reserve. Auricularia cornea and T. gelatinosa are new records for Campeche state.

  4. 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...

  5. [Infective endocarditis. 5-years experience in a third-level reference center in Yucatan, Mexico].

    Science.gov (United States)

    Vega-Sánchez, Angel Emmanuel; Santaularia-Tomas, Miguel; Pérez-Román, Diana Isabel; Cortés-Telles, Arturo

    2016-01-01

    Infective endocarditis is a disease with high morbidity and mortality. The clinical characteristics differ among populations. Therefore it is important to know the characteristics of the disease in our region. This is an observational study that included all patients diagnosed with infective endocarditis from 1 January 2009 until 31 December 2014. The data are showed as frequencies and percentages altogether with medians with interquartile range. 10 cases were included. The median age was 34 years (IQR 26-41). Several risk factors were identified and included: previous valvular heart disease, patients with chronic kidney disease who have had a vascular access and previous history of immunological disease. The native mitral valve was the most affected. The size of vegetations had a median length of 14 mm (IQR 9.3-16). Streptococcus alpha hemolytic was the most common organism. In-hospital mortality rate was 10 %. The behavior of the disease is similar to other national series. We identify risk factors that could be related to the type of morbidities in the region.

  6. 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.

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

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    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.

  8. 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.

  9. Metazoan parasites of fishes from the Celestun coastal lagoon, Yucatan, Mexico.

    Science.gov (United States)

    Sosa-Medina, Trinidad; Vidal-Martínez, Víctor M; Aguirre-Macedo, M Leopoldina

    2015-08-31

    The aims of this study were to produce a checklist of the metazoan parasites of fishes from the Celestun coastal lagoon and to determine the degree of faunal similarity among the fishes based on the metazoan parasites they share. A checklist was prepared including all available records (1996-2014) of parasites of marine, brackish water and freshwater fishes of the area. All of these data were included in a presence/absence database and used to determine similarity via Jaccard's index. The results indicate the presence of 62 metazoan parasite species infecting 22 fish species. The number of metazoan parasite species found in the fishes from the Celestún lagoon is apparently the highest reported worldwide for a tropical coastal lagoon. The parasites included 12 species of adult digeneans, 27 digeneans in the metacercarial stage, 6 monogeneans, 3 metacestodes, 9 nematodes, 2 acanthocephalans, 2 crustaceans and 1 annelid. Forty parasite species were autogenic and 23 were allogenic and 1 unknown. The overall similarity among all of the species of fish with respect to the metazoan parasites they share was low (0.08 ± 0.12), with few similarity values above 0.4 being obtained. This low similarity was due primarily to the presence of suites of parasites exclusive to specific species of fish. The autogenic component of the parasite fauna (40 species) dominated the allogenic component (21 species). The most likely explanation for the large number of fish parasites found at Celestún is the good environmental condition of the lagoon, which allows the completion of parasite life cycles and free circulation of euryhaline fishes from the marine environment bringing marine parasites into the lagoon.

  10. Dietetic characteristics of a sample of Mayan dual burden households in Merida, Yucatan, Mexico

    OpenAIRE

    Azcorra, Hugo; Wilson, Hannah; Bogin, Barry; Varela-Silva, Maria Inês; Vázquez-Vázquez, Adriana; Dickinson, Federico

    2013-01-01

    The Maya are the most populous and shortest in stature Native American ethnic group. The Maya provide us a good opportunity to study the dietetic characteristics of a group who experience nutritional dual burden (the combination of under and overnutrition) at the individual, mother-child dyad and population level. The aim of this study is to describe general dietetic patterns of a sample of Maya mothers and children who experienced nutritional dual burden and were living in the city of Merida...

  11. Connectivity among sinkholes and complex networks: The case of Ring of Cenotes in northwest Yucatan, Mexico

    Science.gov (United States)

    Gomez-Nicolas, Mariana; Rebolledo-Vieyra, Mario; Huerta-Quintanilla, Rodrigo; Canto-Lugo, Efrain

    2014-05-01

    A 180-km-diameter semicircular alignment of abundant karst sinkholes (locally known as cenotes) in northwestern Yucatán, México, coincides approximately with a concentric ring of the buried Chicxulub structure, a circular feature manifested in Cretaceous and older rocks, that has been identified as the product of the impact of a meteorite. The secondary permeability generated by the fracturing and faulting of the sedimentary sequence in the Chicxulub impact, has favored the karstification process and hence the development of genuine underground rivers that carry water from the continent to the sea. The study of the structure and morphology of the crater has allowed researchers to understand the key role of the crater in the Yucatán hydrogeology. It is generally accepted that the Ring of Cenotes, produced by the gravitational deformation of the Tertiary sedimentary sequence within the crater, controls the groundwater in northern Yucatán. However, today there is not solid evidence about the connectivity among cenotes, which is important because if established, public policies could be designed to manage sanitary infrastructure, septic control, regulation of agricultural and industrial activities and the protection of water that has not been compromised by anthropogenic pollution. All these directly affect more than half a million people whose main source of drinking water lies in the aquifer. In this contribution we investigated a set of 16 cenotes located in the vicinity of a gravimetric anomaly of Chicxulub crater ring, using complex networks to model the interconnectivity among them. Data from a geoelectrical tomography survey, collected with SuperSting R1/IP equipment, with multi-electrodes (72 electrodes), in a dipole-dipole configuration was used as input of our model. Since the total number of cenotes on the ring structure amounts to about 2000, the application of graph theoretic algorithms and Monte Carlo simulation to efficiently investigate network properties is proposed. We created a digital network model representing the observation network topology.

  12. The Influence of Water Access in Subjective Well-Being: Some Evidence in Yucatan, Mexico

    Science.gov (United States)

    Guardiola, Jorge; Gonzalez-Gomez, Francisco; Grajales, Angel Lendechy

    2013-01-01

    The literature on happiness or subjective well-being has explored the determinants of happiness without taking into consideration the role that water plays. In this paper we attempt to draw attention to water in subjective well-being studies. Approximately one hundred million people do not have access to water. A lack of clean water causes…

  13. First assessment of low- to medium-temperature geothermal reserves in 20 Mexican states; Primera estimacion de las reservas geotermicas de temperatura intermedia a baja en veinte estados de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Eduardo R.; Torres, Rodolfo J. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: iglesias@iie.org.mx

    2009-07-15

    A first, partial, assessment is included of the low- to medium-temperature geothermal reserves in 20 Mexican States and their aggregate value. The assessment covers about 29.16% of the identified geothermal-surface manifestations in the public database. For reserve assessments, we use the volumetric method, supplemented with Montecarlo simulations and statistics, to quantify inherent uncertainties. Our estimations are presented on a state-by-state basis. We estimate the aggregated reserves of the 20 states as between 7.7 x 1016 and 8.6 x 1016 kJ, with 90% confidence. The most likely reservoir temperatures range between 60-180 degrees Celsius, with a mean of 111 degrees Celsius. Such massive amounts of recoverable energy-and the associated temperatures-are potentially important for the economic development of nearby localities and the nation. [Spanish] En este trabajo se hace una primera estimacion, parcial, de las reservas geotermicas de temperatura intermedia a baja de Mexico. La estimacion incluye 29.16% de las manifestaciones geotermicas identificadas en la base de datos publica utilizada. Para estimar las reservas se utilizo el metodo de volumen, suplementado con simulaciones por el metodo de Montecarlo, con el fin de cuantificar las incertidumbres inherentes. Las estimaciones se presentan estado por estado. Estos resultados indican que las reservas agregadas de los 20 estados considerados estan entre 7.7 x 1016 y 8.6 x 1016 kJ, con 90% de confianza. La distribucion de las temperaturas de yacimiento mas probables varia entre aproximadamente 60 y 180 grados centigrados, con un valor medio de 111 grados centigrados. La enorme magnitud de estas reservas, y sus temperaturas asociadas, son potencialmente importantes para el desarrollo economico de las poblaciones ubicadas en su cercania.

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

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    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.

  15. Molecular characterization of atypical antigenic variants of canine rabies virus reveals its reintroduction by wildlife vectors in southeastern Mexico.

    Science.gov (United States)

    Garcés-Ayala, Fabiola; Aréchiga-Ceballos, Nidia; Ortiz-Alcántara, Joanna M; González-Durán, Elizabeth; Pérez-Agüeros, Sandra I; Méndez-Tenorio, Alfonso; Torres-Longoria, Belem; López-Martínez, Irma; Hernández-Rivas, Lucía; Díaz-Quiñonez, José Alberto; Ramírez-González, José Ernesto

    2017-12-01

    Rabies is an infectious viral disease that is practically always fatal following the onset of clinical signs. In Mexico, the last case of human rabies transmitted by dogs was reported in 2006 and canine rabies has declined significantly due to vaccination campaigns implemented in the country. Here we report on the molecular characterization of six rabies virus strains found in Yucatan and Chiapas, remarkably, four of them showed an atypical reaction pattern when antigenic characterization with a reduced panel of eight monoclonal antibodies was performed. Phylogenetic analyses on the RNA sequences unveiled that the three atypical strains from Yucatan are associated with skunks. Analysis using the virus entire genome showed that they belong to a different lineage distinct from the variants described for this animal species in Mexico. The Chiapas atypical strain was grouped in a lineage that was considered extinct, while the others are clustered within classic dog variants.

  16. 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

  17. FINANCIAL MANAGEMENT IN THE FAMILY AND NON-FAMILY SME´S IN THE TEXTILE INDUSTRY IN MEXICO

    OpenAIRE

    Martha Isabel Bojorquez Zapata; Antonio Emmanuel Perez Brito; Jorge Humberto Basulto Triay

    2014-01-01

    In this paper, we analyze differences in financial management practices between family and non-family Small and Medium Enterprises (SMEs) in the textile industry. We hypothesize that family SMEs use different sources of funding for new investments, tend to have less debt, are more profitable and use less financial and accounting information for decision making than non-family SMEs. We survey 24 textile SMEs located in Yucatan, Mexico. The results show that family SMEs rely more heavily on int...

  18. [Obesity, body morphology, and blood pressure in urban and rural population groups of Yucatan].

    Science.gov (United States)

    Arroyo, Pedro; Fernández, Victoria; Loría, Alvar; Pardío, Jeannette; Laviada, Hugo; Vargas-Ancona, Lizardo; Ward, Ryk

    2007-01-01

    To characterize body morphology and blood pressure of adults of the Mexican state of Yucatan. Rural-urban differences in weight, height, waist, and hip circumferences, and blood pressure were analyzed in 313 urban and 271 rural subjects. No rural-urban differences in prevalence of obesity and overweight were found. Hypertension was marginally higher in urban subjects. Rural abnormal waist circumference was higher in young men and young women. Comparison with two national surveys and a survey in the aboriginal population (rural mixtecos) showed similar prevalence of obesity as ENSA-2000 and higher than mixtecos and ENEC-1993. Abnormal waist circumference was intermediate between ENSANUT-2006 and mixtecos and hypertension was intermediate between ENEC and mixtecos. The Maya and mestizo population of Yucatan showed a high prevalence of obesity and abnormal waist circumference not accompanied by a comparable higher hypertension frequency. This finding requires further confirmation.

  19. Differences in coastal and oceanic SST trends north of Yucatan Peninsula

    Science.gov (United States)

    Varela, R.; Costoya, X.; Enriquez, C.; Santos, F.; Gómez-Gesteira, M.

    2018-06-01

    The coastal area north of Yucatan has experienced a cooling SST trend from 1982 to 2015 during the upwelling season (May-September) that contrasts with the warming observed at the adjacent ocean area. Different drivers were analyzed to identify the possible causes of that unusual coastal cooling. Changes in coastal upwelling and in sea-atmosphere heat fluxes are not consistent with the observed coastal cooling. The eastward shift of the Yucatan Current observed over the last decades is hypothesized as the most probable cause of coastal cooling. This shift enhances the vertical transport of cold deeper water to the continental shelf from where it is pumped to the surface by upwelling favorable westerly winds.

  20. The Securing of a Precarious Commerce: Exchanges between Seville and Yucatan (1590- 1600

    Directory of Open Access Journals (Sweden)

    Manuela Cristina García Bernal

    2000-10-01

    Full Text Available This work underlines the importance of Yucatan's commercial relations across the Atlantic Ocean, as opposed to the traditional belief  that  these exchanges were small and  infrequent. Due to the margination and poverty of the province, in 1590 the Span­ish Crown granted Yucatan a license  to send two small  ships each year, with the necessary products. This license  allowed the securing of a trade that until  then had  been quite  precarious. This is why the quantitative and qualitative analyses of the move­ments of ships and merchandise between 1590 and 1600 lets us understand why, despite being considered secondary, this re­gion's commerce occupied, as seen from Seville, a considerable position among the  great amount of Atlantic trade. These analy­ses also reveal  why  during the  seventeenth  century Yucatan would come  to be  the  most  favored of the smaller posts along the Spain-Indies trading route.

  1. Recurrencia histórica de peces invasores en la Reserva de la Biósfera Sierra de Huautla, México Historical presence of invasive fish in the Biosphere Reserve Sierra de Huautla, Mexico

    Directory of Open Access Journals (Sweden)

    Humberto Mejía-Mojica

    2012-06-01

    registro, control y erradicación de especies invasoras en la reserva de Biosfera Sierra de Huautla y áreas de protecciónde la biodiversidad en MéxicoHistorical presence of invasive fish in the Biosphere Reserve Sierra de Huautla, Mexico. The effects of invasive species on native ecosystems are varied, and these have been linked to the disappearance or decline of native fauna, changes in community structure, modification of ecosystems and as vectors of new diseases and parasites. Besides, the development of trade in species for ornamental use has contributed significantly to the import and introduction of invasive fish in some important areas for biodiversity conservation in Mexico, but the presence of these species is poorly documented. In this study we analyzed the fish community in the Biosphere Reserve Sierra de Huautla by looking at diversity changes in the last 100 years. For this, we used databases of historical records and recent collections for five sites in the Amacuzac river, along the Biosphere Reserve area. We compared the values of similarity (Jaccard index between five times series (1898-1901, 1945-1953, 1971-1980, 1994-1995 and 2008-2009, and we obtained values of similarity (Bray-Curtis between the five sites analyzed. In our results we recognized a total of 19 species for the area, nine non-native and ten native, three of which were eliminated for the area. Similarity values between the early days and current records were very low (.27; the major changes in the composition of the fauna occurred in the past 20 years. The values of abundance, diversity and similarity among the sampling sites, indicate the dominance of non-native species. We discuss the role of the ornamental fish trade in the region as the leading cause of invasive introduction in the ecosystem and the possible negative effects that at least four non-native species have had on native fauna and the ecosystem (Oreochromis mossambicus, Amatitlania nigrofasciata, Pterygoplichthys

  2. Effect of alcohol on skin permeation and metabolism of an ester-type prodrug in Yucatan micropig skin.

    Science.gov (United States)

    Fujii, Makiko; Ohara, Rieko; Matsumi, Azusa; Ohura, Kayoko; Koizumi, Naoya; Imai, Teruko; Watanabe, Yoshiteru

    2017-11-15

    We studied the effect that three alcohols, ethanol (EA), propanol (PA), and isopropanol (IPA), have on the skin permeation of p-hydroxy benzoic acid methyl ester (HBM), a model ester-type prodrug. HBM was applied to Yucatan micropig skin in a saturated phosphate buffered solution with or without 10% alcohol, and HBM and related materials in receptor fluid and skin were determined with HPLC. In the absence of alcohol, p-hydroxy benzoic acid (HBA), a metabolite of HBM, permeated the skin the most. The three alcohols enhanced the penetration of HBM at almost the same extent. The addition of 10% EA or PA to the HBM solution led to trans-esterification into the ethyl ester or propyl ester of HBA, and these esters permeated skin as well as HBA and HBM did. In contrast, the addition of 10% IPA promoted very little trans-esterification. Both hydrolysis and trans-esterification in the skin S9 fraction were inhibited by BNPP, an inhibitor of carboxylesterase (CES). Western blot and native PAGE showed the abundant expression of CES in micropig skin. Both hydrolysis and trans-esterification was simultaneously catalyzed by CES during skin permeation. Our data indicate that the alcohol used in dermal drug preparations should be selected not only for its ability to enhance the solubility and permeation of the drug, but also for the effect on metabolism of the drug in the skin. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. [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.

  4. Avifauna de la Reserva de la Biosfera Barranca de Metztitlán, Hidalgo, México Birds of the Biosphere Reserve Barranca de Metztitlán, Hidalgo, Mexico

    Directory of Open Access Journals (Sweden)

    Raúl Ortiz-Pulido

    2010-08-01

    Full Text Available El manejo y conservación de un área natural protegida depende en gran parte del conocimiento biológico que se tenga sobre ella. En este estudio se presenta el listado de las aves de la Reserva de la Biosfera Barranca de Metztitlán, Hidalgo, México realizado durante 7 años de trabajo de campo y que incluye 271 especies. Las familias más ricas fueron Tyrannidae y Parulidae (24 especies cada una, Emberizidae (19, Icteridae (13 y Trochilidae (12. Se registran 117 especies como residentes, 88 migratorias, 34 ocasionales, 6 con poblaciones residentes-migratorias y 26 sin estacionalidad clara. Se observaron 16 especies abundantes, 67 comunes, 153 raras y 35 sin abundancia relativa clara. Los tipos de vegetación más utilizados por las aves son: matorral submontano (113 especies, bosque tropical caducifolio (97, bosque de tascate (96 y matorral crasicaule con dominancia de S. dumortieri (91. Los gremios alimenticios mejor representados fueron: insectívoro (235 especies, frugívoro (88 y granívoro (85. Con base en la normatividad mexicana, se registraron 17 especies bajo alguna categoría de riesgo y 32 con algún grado de endemismo. En la zona habitan cerca del 60% de las aves de Hidalgo y 27% de las de México, razón por la cual se sugiere que esta zona sea declarada Área Importante para la Conservación de las Aves (AICA en México.Management and conservation of natural protected areas depends critically on their biological knowledge. Herein we report a check-list of the Barranca de Metztitlán Biosphere Reserve, Hidalgo, Mexico. We registered 271 species. The families that include more species were Tyrannidae and Parulidae (24 species each one, Emberizidae (19, Icteridae (13 and Trochilidae (12. We recorded 117 resident species, 88 migratory, 34 transient, 6 with resident-migratory populations and 26 with status not clear. We registered 16 abundant species, 67 common, 153 rare, and 35 with undetermined abundance. The richest vegetation

  5. 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.)

  6. 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

  7. 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...

  8. Diversidad de anfibios y reptiles de la Reserva de la Biosfera Barranca de Metztitlán, Hidalgo, México Diversity of amphibians and reptiles from the Barranca de Metztitlán Biosphera Reserve in Hidalgo, Mexico

    Directory of Open Access Journals (Sweden)

    Victor D. Vite-Silva

    2010-08-01

    Full Text Available La Reserva de la Biosfera Barranca de Metztitlán (RBBM es una extensa área protegida (96 042.94 ha de la zona centro del estado de Hidalgo, México. La reserva es bien conocida por su flora endémica, pero existe poca información disponible sobre su herpetofauna. En este estudio se examina la biodiversidad de la comunidad de anfibios y reptiles que habitan en cada uno de los 4 tipos de vegetación de la reserva: bosque de pino-encino, bosque tropical caducifolio, matorral submontano y matorral xerófilo. El trabajo de campo se llevó a cabo entre junio de 2006 y agosto de 2007, periodo de estación de lluvias y secas. En total, se registran 7 especies de anfibios y 31 de reptiles para la RBBM, distribuidas en 14 familias y 29 géneros. En todos los tipos de vegetación, la riqueza de especies de reptiles fue mayor en la estación de lluvias, mientras que la de especies de anfibios fue mayor en la de secas. Entre los tipos de vegetación, el bosque tropical caducifolio exhibió la diversidad y riqueza de especies más grande de anfibios y reptiles. El bosque de pino-encino presentó la mayor equidad y diversidad de especies que los otros tipos de vegetación. El matorral xerófilo y matorral submontano fueron los más similares entre sí en diversidad de especies. Este trabajo representa una aportación significativa al conocimiento de la herpetofauna de la RBBM, y una base para estudios futuros sobre historia natural de los anfibios y reptiles de esta reserva.The Barranca de Metztitlán Biosphere Reserve (BMBR is an extensive protected area (96 042.94 ha in Hidalgo state of central Mexico. The reserve is well known for its globally significant endemic flora, but relatively little information is available regarding its herpetofauna. We examined reptile and amphibian community biodiversity occurring in each of 4 vegetation types characteristic of the reserve: pine-oak forest, tropical deciduous forest, sub-montane shrubland, and arid tropical

  9. Amphibians and reptiles of the Calakmul Biosphere Reserve, México, with new records

    OpenAIRE

    Colston, Timothy; Barão-Nóbrega, José António; Manders, Ryan; Lett, Alice; Wilmott, Jamie; Cameron, Gavin; Hunter, Sidony; Radage, Adam; Littlefair, Etienne; Williams, Robert; Lopez Cen, Antonio; Slater, Kathy

    2015-01-01

    We provide a list of amphibians and reptiles of the Calakmul Biosphere Reserve in the southern half of the Mexican Yucatan, in the state of Campeche. The study area was sampled through opportunistic, transect and pitfall trap surveys conducted for three successive years. These surveys resulted in a total of 2,359 amphibian and reptile encounters, belonging to 20 amphibian and 69 reptile species from 24 total families. We present herein the records for one snake, one chelonian and two salamand...

  10. Preliminary Geochemical and Rock Magnetic Study of a Stalagmite From Quintana Roo, Northeastern Yucatan Peninsula

    Science.gov (United States)

    Urrutia-Fucugauchi, J.; Perez-Cruz, L.; Zhao, X.; Rebolledo-Vieyra, M.; Rodriguez, A.

    2012-04-01

    We present the preliminary results of geochemical, stable isotopes and rock magnetic studies of a stalagmite from a cave in eastern Quintana Roo, northern Yucatan peninsula. In the past years, there has been increased interest in understanding the paleoclimatic and paleoenvironmental evolution of the Yucatan peninsula and northern Central America, investigating the relationships between climate variations and the development of the Maya civilization. In particular, the variations in regional precipitation and occurrence of several drought periods, which might have been related to the collapse of the Classic Maya period. Stable isotope data on speleothems from different sites in Yucatan and Central America have provided evidence on changes in precipitation, which have affected the Maya region. The stalagmite is ~47 cm long and about 4-5 cm wide at its base. It was collected from the Hilariós Well cave in Tulum, Quintana Roo. Magnetic susceptibility and geochemical analyses have been completed as part of the initial characterization of the stalagmite, with measurements taken every centimeter. Geochemical analyses have been carried out for x-ray fluorescence, with a Niton XRF analyzer. Magnetic susceptibility was determined with a Bartington MS2 instrument using the high resolution surface probe. Additional rock magnetic analyses include magnetic hysteresis loops and isothermal remanent magnetization (IRM) acquisition, and saturation IRM demagnetization, which have been measured with a MicroMag instrument. Hysteresis loops are diamagnetic, with small varying low-coercivity ferromagnetic components. The elemental compositions of major oxides and trace elements vary with depth. Calcium is the major element and displays a pattern of small amplitude fluctuations with a trend to lower values at the bottom, which are also shown in other elements such as barium. Silica and elements such as titanium and strontium are positively correlated and show an apparent cyclic pattern

  11. Preliminary study of the offshore wind and temperature profiles at the North of the Yucatan Peninsula

    International Nuclear Information System (INIS)

    Soler-Bientz, Rolando; Watson, Simon; Infield, David; Ricalde-Cab, Lifter

    2011-01-01

    Highlights: → This is the first study that reports the properties of the vertical wind resources for the offshore conditions of the North coast of the Yucatan Peninsula. → A significant and detailed analysis of the thermal patterns has revealed a complex structure of the atmospheric boundary layer close to the shore. → The structure of the diurnal wind patterns was assessed to produce an important reference for the wind resource availability in the study region. → It was identified that the sea breeze blows in directions almost parallel to the shoreline of the North of the Yucatan Peninsula during the majority of the 24 h cycle. → The analysis of the offshore data revealed a persistent non-uniform surface boundary layer developed as result of the advection of a warn air over a cold sea. - Abstract: The stability conditions in the atmospheric boundary layer, the intensity of the wind speeds and consequently the energy potential available in offshore conditions are highly influenced by the distance from the coastline and the differences between the air and sea temperatures. This paper presents a preliminary research undertook to study the offshore wind and temperature vertical profiles at the North-West of the Yucatan Peninsula coast. Ten minute averages were recorded over approximately 2 years from sensors installed at two different heights on a communication tower located at 6.65 km from the coastline. The results have shown that the offshore wind is thermally driven by differential heating of land and sea producing breeze patterns which veer to blow parallel to the coast under the action of the Coriolis force. To investigate further, a dataset of hourly sea surface temperatures derived from GEOS Satellite thermal maps was combined with the onsite measured data to study its effect on the vertical temperature profile. The results suggested largely unstable conditions and the potentially development of a shallow Stable Internal Boundary Layer which occurs

  12. Are the London Declaration's 2020 goals sufficient to control Chagas disease?: Modeling scenarios for the Yucatan Peninsula.

    Science.gov (United States)

    Lee, Bruce Y; Bartsch, Sarah M; Skrip, Laura; Hertenstein, Daniel L; Avelis, Cameron M; Ndeffo-Mbah, Martial; Tilchin, Carla; Dumonteil, Eric O; Galvani, Alison

    2018-03-01

    The 2020 Sustainable Development goals call for 100% certified interruption or control of the three main forms of Chagas disease transmission in Latin America. However, how much will achieving these goals to varying degrees control Chagas disease; what is the potential impact of missing these goals and if they are achieved, what may be left? We developed a compartmental simulation model that represents the triatomine, human host, and non-human host populations and vector-borne, congenital, and transfusional T. cruzi transmission between them in the domestic and peridomestic settings to evaluate the impact of limiting transmission in a 2,000 person virtual village in Yucatan, Mexico. Interruption of domestic vectorial transmission had the largest impact on T. cruzi transmission and prevalence in all populations. Most of the gains were achieved within the first few years. Controlling vectorial transmission resulted in a 46.1-83.0% relative reduction in the number of new acute Chagas cases for a 50-100% interruption in domestic vector-host contact. Only controlling congenital transmission led to a 2.4-8.1% (30-100% interruption) relative reduction in the total number of new acute cases and reducing only transfusional transmission led to a 0.1-0.3% (30-100% reduction). Stopping all three forms of transmission resulted in 0.5 total transmission events over five years (compared to 5.0 with no interruption); interrupting all forms by 30% resulted in 3.4 events over five years per 2,000 persons. While reducing domestic vectorial, congenital, and transfusional transmission can successfully reduce transmission to humans (up to 82% in one year), achieving the 2020 goals would still result in 0.5 new acute cases per 2,000 over five years. Even if the goals are missed, major gains can be achieved within the first few years. Interrupting transmission should be combined with other efforts such as a vaccine or improved access to care, especially for the population of already

  13. Are the London Declaration’s 2020 goals sufficient to control Chagas disease?: Modeling scenarios for the Yucatan Peninsula

    Science.gov (United States)

    Bartsch, Sarah M.; Skrip, Laura; Hertenstein, Daniel L.; Ndeffo-Mbah, Martial; Dumonteil, Eric O.; Galvani, Alison

    2018-01-01

    Background The 2020 Sustainable Development goals call for 100% certified interruption or control of the three main forms of Chagas disease transmission in Latin America. However, how much will achieving these goals to varying degrees control Chagas disease; what is the potential impact of missing these goals and if they are achieved, what may be left? Methods We developed a compartmental simulation model that represents the triatomine, human host, and non-human host populations and vector-borne, congenital, and transfusional T. cruzi transmission between them in the domestic and peridomestic settings to evaluate the impact of limiting transmission in a 2,000 person virtual village in Yucatan, Mexico. Results Interruption of domestic vectorial transmission had the largest impact on T. cruzi transmission and prevalence in all populations. Most of the gains were achieved within the first few years. Controlling vectorial transmission resulted in a 46.1–83.0% relative reduction in the number of new acute Chagas cases for a 50–100% interruption in domestic vector-host contact. Only controlling congenital transmission led to a 2.4–8.1% (30–100% interruption) relative reduction in the total number of new acute cases and reducing only transfusional transmission led to a 0.1–0.3% (30–100% reduction). Stopping all three forms of transmission resulted in 0.5 total transmission events over five years (compared to 5.0 with no interruption); interrupting all forms by 30% resulted in 3.4 events over five years per 2,000 persons. Conclusions While reducing domestic vectorial, congenital, and transfusional transmission can successfully reduce transmission to humans (up to 82% in one year), achieving the 2020 goals would still result in 0.5 new acute cases per 2,000 over five years. Even if the goals are missed, major gains can be achieved within the first few years. Interrupting transmission should be combined with other efforts such as a vaccine or improved access to

  14. Representations of eating and of a nutrition program among female caregivers of children under 5 years old in Tizimin, Yucatan, Mexico Representaciones sobre la alimentación y el programa de nutrición entre mujeres responsables de niños mexicanos menores de 5 años Representação da alimentação e de programa alimentar entre mulheres responsáveis por crianças mexicanas menores de 5 anos

    Directory of Open Access Journals (Sweden)

    Gloria de los Ángeles Uicab-Pool

    2009-12-01

    Full Text Available This study was carried out between January and April 2008 with 14 caregivers of children younger than 5 years residing in Tizimín city, Mexico. It aimed to understand the social representations of eating and the Programa Oportunidades [Opportunity Program] held by caregivers taking into account their social and cultural context. This qualitative investigation with an ethnographic approach was based on participant observation and semi-structured interviews. Two empirical categories emerged: 1 feeding and 2 an aid. The first refers to the caregivers' representation of eating patterns of children younger than 5 years and the second reveals that the program is considered an aid, which favors and helps caregivers to meet part of their needs. The study achieved the proposed objectives since it enabled us to understand caregivers in the complex task of feeding these children and also to propose strategies in several spheres to improve infant nutrition.El estudio fue realizado con 14 responsables del cuidado del menor de 5 años en Tizimín, México, durante el período de enero la abril de 2008. Se buscó comprender las representaciones sociales de estas personas en relación a la alimentación y la los componentes de nutrición del Programa Oportunidades, considerando el contexto social y cultural. La investigación cualitativa con abordaje antropológico, tipo etnográfico tuvo como base la observación participante y las entrevistas semiestructuradas, dirigidas a las responsables. De los resultados emergieron dos categorías empíricas: 1 dar de comer y 2 una ayuda. La primera se refiere a cómo las responsables representan la alimentación del menor de 5 años y la segunda reveló que el Programa es considerado una ayuda y que las apoya a solucionar, en parte, sus necesidades. Se alcanzaron los objetivos al comprender a las responsables en esa tarea compleja que realizan de alimentar a los niños y así proponer estrategias, en varias esferas

  15. The stress response and exploratory behaviour in Yucatan minipigs (Sus scrofa): Relations to sex and social rank.

    Science.gov (United States)

    Adcock, Sarah J J; Martin, Gerard M; Walsh, Carolyn J

    2015-12-01

    According to the coping styles hypothesis, an individual demonstrates an integrated behavioural and physiological response to environmental challenge that is consistent over time and across situations. Individual consistency in behavioural responses to challenge has been documented across the animal kingdom. Comparatively few studies, however, have examined inter-individual variation in the physiological response, namely glucocorticoid and catecholamine levels, the stress hormones secreted by the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, respectively. Variation in coping styles between individuals may be explained in part by differences in social rank and sex. Using 20 Yucatan minipigs (Sus scrofa) we: (1) investigated the existence of consistent inter-individual variation in exploratory behaviour and the hormonal stress response, and tested for correlations as predicted by the coping styles hypothesis; and (2) evaluated whether inter-individual behavioural and hormonal variation is related to social rank and sex. Salivary stress biomarkers (cortisol, alpha-amylase, chromogranin A) were assessed in the presence and absence of a stressor consisting of social isolation in a crate for 10 min. Principal components analysis on a set of behavioural variables revealed two traits, which we labelled exploratory tendency and neophobia. Neither exploratory tendency nor neophobia predicted the physiological stress response. Subordinate pigs exhibited higher catecholamine levels compared to dominant conspecifics. We observed sex differences in the repeatability of salivary stress markers and reactivity of the stress systems. The results do not provide support for the existence of behavioural-physiological coping styles in pigs. Sex is an important determinant of the physiological stress response and warrants consideration in research addressing behavioural and hormonal variation. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. [Analysis of the impact of mortality due to suicides in Mexico, 2000-2012].

    Science.gov (United States)

    Dávila Cervantes, Claudio Alberto; Ochoa Torres, María del Pilar; Casique Rodríguez, Irene

    2015-12-01

    The objective of this study was to analyze the burden of disease due to suicide in Mexico using years of life lost (YLL) between 2000 and 2012 by sex, age group (for those under 85 years of age) and jurisdiction. Vital statistics on mortality and population estimates were used to calculate standardized mortality rates and years of life lost due to suicide. Between 2000 and 2012 a sustained increase in the suicide mortality rate was observed in Mexico. The age group with the highest rate was 85 years of age or older for men, and 15-19 years of age for women. The highest impact in life expectancy due to suicide occurred at 20 to 24 years of age in men and 15 to 19 years of age in women. The states with the highest mortality due to suicide were located in the Yucatan Peninsula (Yucatan, Quintana Roo and Campeche). Mortality due to suicide in Mexico has increased continually. As suicides are preventable, the implementation of health public policies through timely identification, integral prevention strategies and the detailed study of associated risk factors is imperative.

  17. Mesozoic Continental Sediment-dispersal Systems of Mexico Linked to Development of the Gulf of Mexico

    Science.gov (United States)

    Lawton, T. F.; Molina-Garza, R. S.; Barboza-Gudiño, R.; Rogers, R. D.

    2013-05-01

    continental-margin arc blocked westward drainage and detritus was captured in rift basins. Latest Middle Jurassic fluvial systems formed as the Yucatan block rotated counterclockwise and the Gulf of Mexico began to open. Sediment dispersal, partly equivalent to salt deposition in the Gulf, was largely southward in southern Oaxaquia, but large-volume braided river systems on the Maya (Yucatan) block, represented by the Todos Santos Formation in Chiapas, evidently flowed northward along graben axes toward the western part of the Gulf of Mexico Basin. River systems of nuclear Mexico, or Oaxaquia, occupied a broad sedimentary basin west and south of a divide formed adjacent to the translating Maya block. Despite their big-river characteristics, these deposits contain mainly Grenville and Permo-Triassic grains derived from Oaxaquia basement and subordinate Early and Middle Jurassic grains derived from volcanic rocks and plutons of the arc. Early Late Jurassic (Oxfordian) marine flooding of the entire Gulf rim and nuclear Mexico, evidently resulting in part from marginal subsidence adjoining newly-formed oceanic crust, terminated fluvial deposition adjacent to the young Gulf of Mexico.

  18. It takes two to tango: self incompatibility in the bromeliad Tillandsia streptophylla (Bromeliaceae) in Mexico.

    Science.gov (United States)

    Ramírez Morillo, Ivón M; Chi May, Francisco; Carnevali, Germán; May Pat, Filogonio

    2009-09-01

    Floral phenology and breeding system of Tillandsia streptophylla (Bromeliaceae) were studied in a low inundated forest in Yucatan, Mexico. During the flowering season, from March to August, terminal scapose 1-branched, paniculate inflorescences are produced with one flower per branch opening per day, over a period of 11-29 days. Flowers are tubular, light violet, with the stigma placed below the anthers, both protruding above the corolla. Flowers are protandrous, with anthers releasing pollen from 0500 hours and stigma becoming receptive around 0900 hours. Controlled experimental crosses suggest that Tillandsia streptophylla is self incompatible and therefore, pollinator-dependent.

  19. Fat, weather, and date affect migratory songbirds' departure decisions, routes, and time it takes to cross the Gulf of Mexico.

    Science.gov (United States)

    Deppe, Jill L; Ward, Michael P; Bolus, Rachel T; Diehl, Robert H; Celis-Murillo, Antonio; Zenzal, Theodore J; Moore, Frank R; Benson, Thomas J; Smolinsky, Jaclyn A; Schofield, Lynn N; Enstrom, David A; Paxton, Eben H; Bohrer, Gil; Beveroth, Tara A; Raim, Arlo; Obringer, Renee L; Delaney, David; Cochran, William W

    2015-11-17

    Approximately two thirds of migratory songbirds in eastern North America negotiate the Gulf of Mexico (GOM), where inclement weather coupled with no refueling or resting opportunities can be lethal. However, decisions made when navigating such features and their consequences remain largely unknown due to technological limitations of tracking small animals over large areas. We used automated radio telemetry to track three songbird species (Red-eyed Vireo, Swainson's Thrush, Wood Thrush) from coastal Alabama to the northern Yucatan Peninsula (YP) during fall migration. Detecting songbirds after crossing ∼1,000 km of open water allowed us to examine intrinsic (age, wing length, fat) and extrinsic (weather, date) variables shaping departure decisions, arrival at the YP, and crossing times. Large fat reserves and low humidity, indicative of beneficial synoptic weather patterns, favored southward departure across the Gulf. Individuals detected in the YP departed with large fat reserves and later in the fall with profitable winds, and flight durations (mean = 22.4 h) were positively related to wind profit. Age was not related to departure behavior, arrival, or travel time. However, vireos negotiated the GOM differently than thrushes, including different departure decisions, lower probability of detection in the YP, and longer crossing times. Defense of winter territories by thrushes but not vireos and species-specific foraging habits may explain the divergent migratory behaviors. Fat reserves appear extremely important to departure decisions and arrival in the YP. As habitat along the GOM is degraded, birds may be limited in their ability to acquire fat to cross the Gulf.

  20. Fat, weather, and date affect migratory songbirds’ departure decisions, routes, and time it takes to cross the Gulf of Mexico

    Science.gov (United States)

    Deppe, Jill L.; Ward, Michael P.; Bolus, Rachel T.; Diehl, Robert H.; Celis-Murillo, A.; Zenzal, Theodore J.; Moore, Frank R.; Benson, Thomas J.; Smolinsky, Jaclyn A.; Schofield, Lynn N.; Enstrom, David A.; Paxton, Eben H.; Bohrer, Gil; Beveroth, Tara A.; Raim, Arlo; Obringer, Renee L.; Delaney, David; Cochran, William W.

    2015-01-01

    Approximately two thirds of migratory songbirds in eastern North America negotiate the Gulf of Mexico (GOM), where inclement weather coupled with no refueling or resting opportunities can be lethal. However, decisions made when navigating such features and their consequences remain largely unknown due to technological limitations of tracking small animals over large areas. We used automated radio telemetry to track three songbird species (Red-eyed Vireo, Swainson’s Thrush, Wood Thrush) from coastal Alabama to the northern Yucatan Peninsula (YP) during fall migration. Detecting songbirds after crossing ∼1,000 km of open water allowed us to examine intrinsic (age, wing length, fat) and extrinsic (weather, date) variables shaping departure decisions, arrival at the YP, and crossing times. Large fat reserves and low humidity, indicative of beneficial synoptic weather patterns, favored southward departure across the Gulf. Individuals detected in the YP departed with large fat reserves and later in the fall with profitable winds, and flight durations (mean = 22.4 h) were positively related to wind profit. Age was not related to departure behavior, arrival, or travel time. However, vireos negotiated the GOM differently than thrushes, including different departure decisions, lower probability of detection in the YP, and longer crossing times. Defense of winter territories by thrushes but not vireos and species-specific foraging habits may explain the divergent migratory behaviors. Fat reserves appear extremely important to departure decisions and arrival in the YP. As habitat along the GOM is degraded, birds may be limited in their ability to acquire fat to cross the Gulf.

  1. Registro del águila elegante (Spizaetus ornatus en la Reserva de la Biosfera sierra de Manantlán, Jalisco-Colima, México A new record for the Ornate Hawk-Eagle (Spizaetus ornatus in the Sierra Manantlán Biosphere Reserve, Jalisco-Colima, Mexico

    Directory of Open Access Journals (Sweden)

    Marcelo Aranda

    2009-04-01

    Full Text Available Se presenta un registro del águila elegante (Spizaetus ornatus en un bosque de encino-pino de la Reserva de la Biosfera Sierra de Manantlán, Jalisco-Colima, correspondiente a un individuo de 2 a 3 años de edad. Este registro es significativo ante la escasez de registros de esta especie en el occidente de México, los cuales corresponden a localidades en los estados de Nayarit (1 Colima (3, Jalisco (1 y Guerrero (1. Se considera que el águila elegante está en peligro de extinción en México (NOM-059-ECOL-2001; su presencia en esta área natural protegida da aliento para su conservación.An immature Ornate Hawk-Eagle (Spizaetus ornatus was observed and photographed while perched in pine-oak forest in the Sierra de Manantlán Biosphere Reserve, Jalisco-Colima, Mexico. From plumage characteristics we believe the eagle to be 2-3 years old. This record is significant due to the paucity of records for this species in Western Mexico: Nayarit (1 Colima (3, Jalisco (1 and Guerrero (1. The Ornate Hawk-Eagle is considered as a threatened species in Mexico, and this record from a natural protected area brings hope for its conservation.

  2. 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).

  3. MaritimeMaya2011: The Costa Escondida Project: Exploring the Hidden World of the Maritime Maya on the Yucatan Peninsula between 20110509 and 20110531

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The northeast tip of the Yucatan Peninsula is a largely unexplored coastline where ancient Maya traders traveled in massive dugout canoes filled with goods from...

  4. Evaluation of the health status of a coastal ecosystem in southeast Mexico: Assessment of water quality, phytoplankton and submerged aquatic vegetation.

    Science.gov (United States)

    Herrera-Silveira, Jorge A; Morales-Ojeda, Sara M

    2009-01-01

    The coastal environment of the Yucatan Peninsula (SE, Mexico) includes a wide variety of ecosystems ranging from mangroves to coral reefs, resulting in a heterogeneous landscape. Specifically, the marine system is characterized by environmental differences which respond to regional and local forcing functions such as marine currents and groundwater discharges (GD). Such functional characteristics were used here to define four subregions across the Yucatan coast and diagnose the health status of this coastal marine ecosystem. To achieve this goal, we conducted an analysis and integration of water quality variables, an eutrophic assessment, evaluated changes in submerged aquatic vegetation (SAV), and analyzed the community structure and distribution of harmful phytoplankton. The first step was to determine the reference values for each subregion based on data previously collected from 2002 to 2006 along the coast of Yucatan, 200m offshore. The trophic index (TRIX) and Canadian index for aquatic life (CCMEWQI) were used to diagnose each subregion and then the ASSETS approach was conducted for Dzilam and Progreso, sampling localities on each end of the health status continuum (those with the best and worst conditions). Overall, results indicated that the marine coastal ecosystem of Yucatan is in good condition; however, differences were observed between subregions that can be attributed to local forcing functions and human impacts. Specifically, the central region (zone HZII, Progreso-Telchac) showed symptoms of initial eutrophication due to nutrient inputs from human activities. The eastern region (zone HZ III, Dzilam-Las Bocas) showed a meso-eutrophic condition linked to natural groundwater discharges, while the other two subregions western (zone HZI Celestun-Palmar) and caribbean (zone HZ IV Ria Lagartos-El Cuyo) exhibited symptoms of oligo-mesotrophic condition. These findings may be considered baseline information for coastal ecosystem monitoring programs in

  5. Reconstruction of precipitation variability in the Strait of Yucatan associated with latitudinal shifts in the position of the Intertropical Convergence Zone since the Last Glacial Maximum

    Science.gov (United States)

    Staines-Urías, Francisca; Seidenkrantz, Marit-Solveig; Fischel, Andrea; Kuijpers, Antoon

    2017-04-01

    The elemental composition of sediments from gravity core HOLOVAR11-03 provides a ca. 40 ka record of past climate variability in the Strait of Yucatan, between the Caribbean Sea and the Gulf of Mexico, a region where precipitation variability is determined by the seasonal position of the Intertropical Convergence Zone (ITCZ). Within this region, sea level pressure decreases and rainfall increases as the ITCZ moves north of the equator in response to increased solar insolation in the Northern Hemisphere during boreal summer. In contrast, as the ITCZ retracts southward towards the equator during boreal winter, rainfall diminishes and the regional sea level pressure gradient strengthens. On interannual, multidecadal and millennial timescales, fluctuations in the average latitudinal position of the ITCZ in response to insolation forcing modulate the intensity and duration of the seasonal regimens, determining average regional precipitation and, ultimately, the elemental composition of the marine sedimentary record. Regionally, higher titanium and iron content in marine sediments reflect greater terrigenous input from inland runoff, indicating greater precipitation, hence a more northerly position of the ITCZ. Correspondingly, Ti and Fe concentration data were used to reconstruct regional rainfall variability since the Last Glacial Maxima (LGM ˜24 cal ka BP). HOLOVAR11-03 age model (based on 4 AMS 14C dates obtained from multi-specific samples of planktic foraminifera) shows stable sedimentation rates in the area throughout the cored period. Nonetheless, higher terrestrial mineral input is observed since the LGM and all through the last glacial termination (24 to 12 cal ka BP), indicating a period of increased precipitation. In contrast, lower Ti and Fe values are typical for the period between 12 and 8 cal ka BP, indicating reduced precipitation. A positive trend characterizes the following interval, showing a return to wetter conditions lasting until 5 cal ka BP

  6. Bostonians, Yucatan, and the First Paths of American Archaeology in the Americas, 1875-1894

    Directory of Open Access Journals (Sweden)

    Guillermo Palacios

    2012-07-01

    Full Text Available This work discusses the relevance pre-Hispanic archaeological areas in the Yucatan peninsula had for the creation of American archaeology, especially of its original centers in Bostonand New York, which held periodical and sometimes conflicting relations with Chicago. The author claims that the “discovering” of what during the 1920's became known as the “Mayan Area” offered New England antique dealers their own and exclusive area, which was gradually “cleansed” of European agents and put under the control of a close-knit group of Bostonians and their allies, thanks, among other things, to the control of the consulate in Merida. The process of conceptually and institutionally construing the Mayan Area, which began in the 1880's, was essential for professionalizing American archaeology, consolidating its most important museums, and positioning the United States, in an exercise of scientific and cultural State building, at the same level as the European archaeological and anthropological communities.

  7. Chemical and biological tracers to determine groundwater flow in karstic aquifer, Yucatan Peninsula

    Science.gov (United States)

    Lenczewski, M.; Leal-Bautista, R. M.; McLain, J. E.

    2013-05-01

    Little is known about the extent of pollution in groundwater in the Yucatan Peninsula; however current population growth, both from international tourism and Mexican nationals increases the potential for wastewater release of a vast array of contaminants including personal care products, pharmaceuticals (Rx), and pathogenic microorganisms. Pathogens and Rx in groundwater can persist and can be particularly acute in this region where high permeability of the karst bedrock and the lack of top soil permit the rapid transport of contaminants into groundwater aquifers. The objective of this research is to develop and utilize novel biological and chemical source tracking methods to distinguish between different sources of anthropogenic pollution in degraded groundwater. Although several methods have been used successfully to track fecal contamination sources in small scale studies, little is known about their spatial limitations, as source tracking studies rarely include sample collection over a wide geographical area and with different sources of water. In addition, although source tracking methods to distinguish human from animal fecal contamination are widely available, this work has developed source tracking distinguish between separate human populations is highly unique. To achieve this objective, we collected water samples from a series of drinking wells, cenotes (sinkholes), wastewater treatment plants, and injection wells across the Yucatan Peninsula and examine potential source tracers within the collected water samples. The result suggests that groundwater sources impacted by tourist vs. local populations contain different chemical stressors. This work has developed a more detailed understanding of the presence and persistence of personal care products, pharmaceuticals, and fecal indicators in a karstic system; such understanding will be a vital component for the protection Mexican groundwater and human health. Quantification of different pollution sources

  8. A new anchialine Stephos Scott from the Yucatan Peninsula with notes on the biogeography and diversity of the genus (Copepoda, Calanoida, Stephidae

    Directory of Open Access Journals (Sweden)

    Eduardo Suárez-Morales

    2017-04-01

    Full Text Available Surveys of the anchialine crustacean fauna of the Yucatan Peninsula (YP, Mexico, have revealed the occurrence of calanoid copepods. The genus Stephos Scott, 1892, belonging to the family Stephidae is among the most frequent and widely distributed groups in anchialine caves but has not been hitherto recorded from the YP. Recent collections from an anchialine cave in an island off the northern coast of the YP yielded many specimens of a new species of Stephos. The new taxon, S. fernandoi sp. n., is described here based on male and female specimens. The new species is clearly distinguished from its congeners by the following characters: male left fifth leg with three terminal lamellae plus subdistal process, right leg with distal row of peg-like elements; female fifth leg with single long, acute apical process; genital double-somite with two rows each of 4 long spinules adjacent to operculum; legs 2-4 with articulated setae. The diversity of the genus shows regional differences; the Australia-Western Pacific region is the most diverse (eleven species, followed by the Mediterranean (seven species and the Northeastern Atlantic (six species; only four species are known from the Northwestern Tropical Atlantic (NWTA. The morphology of the female fifth leg was examined to explore possible biogeographic trends in the genus; patterns suggest multiple colonization events in the highly diverse regions and a relatively recent radiation in the NWTA, characterized by anchialine forms. The introduction of stephid copepods in the region may be a relatively recent event derived from colonization of benthopelagic ancestral forms and subsequent invasion onto cave habitats. The new species appears to be linked to the strictly anchialine Miostephos.

  9. SEROPOSITIVITY TO LEPTOSPIROSIS IN DOMESTIC RESERVOIRS AND DETECTION OF Leptospira spp. IN WATER SOURCES, IN FARMS OF YUCATAN, MEXICO.

    Directory of Open Access Journals (Sweden)

    Maria Fidelia Cardenas-Marrufo

    2010-11-01

    Full Text Available Leptospirosis is a zoonotic infectious disease with a worldwide distribution. WHO classifies this disease as reemergent and it represents risk to human health with economical repercussion to animal reproduction. Leptospirosis occurs with higher frequency in countries with tropical weather. A transversal study was conducted to determine the frequency of infection of L. interrogans in 476 reservoir animals -212 bovines, 203 pigs, and 61 dogs in 34 animal production units. Positivity frequency the reservoirs was 30.5%. 31 out of 34 animal units had positive reservoirs. The most frequent serovars were tarassovi (53.6%, and hardjo (31.6% in cattle; bratislava (66% and icterohaemorragiae (18.7% in pigs; and canicola (79.8% and icterohaemorragiae (9.8% in dogs. 68 pools of water samples from water tanks were analyzed by DNA amplification of a 16S rRNA fragment for L. interrogans detection using Lepat1-Lepat2 primers. It is recommended to use preventive measures such as vaccination to domestic animals to reduce the risk of transmission to the human population.

  10. Senescence of Manilkara zapota trees and implications for large frugivorous birds in the Southern Yucatan Peninsula, Mexico

    NARCIS (Netherlands)

    Antonius Weterings, Martinus Jacobus; Weterings-Schonck, Suzanne Maria; Vester, Henricus Franciscus Maria; Calme, Sophie

    2008-01-01

    It has long been established that mature forests are mosaics of patches in different development phases but it has seldom explicitly been taken into account in ecological studies. We demonstrate here that these development phases, which are related to the population dynamics of trees, play an

  11. Regional reduction in paleogroundwater discharge and rainfall in the Late Holocene Yucatan Peninsula reconstructed from trace metals in benthic foraminifera

    Science.gov (United States)

    Broach, K. H.; Chapman, B. L.; Paytan, A.; Street, J.

    2017-12-01

    As climate change progresses, droughts are predicted to become more common in regions dominated by seasonal precipitation, a problem compounded where precipitation provides significant freshwater resources. The Yucatan Peninsula relies on rain-recharged groundwater for potable water, and regional development due to tourism will further strain supply. Historical and geochemical evidence suggest extensive droughts harmed Mayan Civilization and may again impact the Yucatan in the near future, but proxies around the Yucatan and Caribbean region are complicated by variability and even opposing interpretations. An integrated rainfall signal is needed to smooth variability and separate local aberrations from long-term regional trends that can be used for risk assessment. Here we present a 5,000 year record of rainfall sourced from a broad swath of the peninsula and recorded as trace metal ratios in the foram Ammonia parkinsoniana. Rainwater percolation across the western peninsula forms a groundwater lens that discharges as brackish springs in our field site Celestun Lagoon resulting in trace metal gradients (Li, B, Sr, Ba, Nd) along the lagoon that oscillate with discharge. Sr/Ca and Ba/Ca ratios in the forams suggest a long-term decrease in spring water discharge for the western Yucatan during the last 2,500 years with notable drops coinciding with known droughts (e.g. 800-950 CE) and more variability on a regional scale to 5,000 years. B/Ca ratios appear to depend on proximity to springs and may respond to low-pH discharge water while Nd/Ca ratios suggest sporadic incursions of seawater into the lagoon, possibly related to severely reduced spring water discharge or large hurricane events. We interpret these results to mean that periods of decreased rainfall broadly affect the western peninsula which may pose problems for large population centers like Merida. Future work will focus on periodicity of such rainfall changes and impact on the ecological environment of

  12. A case for archaeological reconnaissance of the Cabo Catoche-Porvenir region of the northeastern Yucatan Peninsula

    Science.gov (United States)

    Duller, Charles E.

    1990-01-01

    Satellite remote sensing technology is a tool with which archaeologists can, with relative ease, survey a region that is otherwise inaccessible. The northeast corner of the Yucatan Peninsula is such an area: it is isolated and sparsely inhabited, with dense forest and extensive swamps. From Cabo Catoche inland to Cancun, this remote corner of the ancient Maya world is virtually unexplored. Recent satellite images disclose evidence of past human activity in this unexplored region and offer a compelling argument for an archaeological reconnaissance.

  13. Uranium resources in New Mexico

    International Nuclear Information System (INIS)

    McLemore, V.T.; Chenoweth, W.L.

    1989-01-01

    For nearly three decades (1951-1980), the Grants uranium district in northwestern New Mexico produced more uranium than any other district in the world. The most important host rocks containing economic uranium deposits in New Mexico are sandstones within the Jurassic Morrison Formation. Approximately 334,506,000 lb of U 3 O 8 were produced from this unit from 1948 through 1987, accounting for 38% of the total uranium production from the US. All of the economic reserves and most of the resources in New Mexico occur in the Morrison Formation. Uranium deposits also occur in sandstones of Paleozoic, Triassic, Cretaceous, Tertiary, and Quaternary formations; however, only 468,680 lb of U 3 O 8 or 0.14% of the total production from New Mexico have been produced from these deposits. Some of these deposits may have a high resource potential. In contrast, almost 6.7 million lb of U 3 O 8 have been produced from uranium deposits in the Todilto Limestone of the Wanakah Formation (Jurassic), but potential for finding additional economic uranium deposits in the near future is low. Other uranium deposits in New Mexico include those in other sedimentary rocks, vein-type uranium deposits, and disseminated magmatic, pegmatitic, and contact metasomatic uranium deposits in igneous and metamorphic rocks. Production from these deposits have been insignificant (less than 0.08% of the total production from New Mexico), but there could be potential for medium to high-grade, medium-sized uranium deposits in some areas. Total uranium production from New Mexico from 1948 to 1987 amounts to approximately 341,808,000 lb of U 3 O 8 . New Mexico has significant uranium reserves and resources. Future development of these deposits will depend upon an increase in price for uranium and lowering of production costs, perhaps by in-situ leaching techniques

  14. Experimental infection of Contracaecum multipapillatum (Nematoda: Anisakinae) from Mexico in the domestic cat.

    Science.gov (United States)

    Vidal-Martínez, V M; Osorio-Sarabia, D; Overstreet, R M

    1994-08-01

    Juveniles of Contracaecum multipapillatum infected the Mayan cichlid (Cichlasoma urophthalmus) and adults infected the olivaceous cormorant (Phalacrocorax olivaceus) and the great egret (Casmerodius albus) in the coastal lagoon at Celestun, State of Yucatan, Mexico. All are new host records, and, even though the geographic locality record of Mexico for the species has not been published, unidentified but presumably conspecific specimens have been reported from there. When juveniles of C. multipapillatum were fed to a kitten, but not rats, ducks, or chickens, they developed into adults. Measurements and morphological data are provided on the specimens from the kitten. Development of an avian ascaridoid in the intestine of a mammal increases the potential of this widespread species to infect other mammals, including humans.

  15. Nueva contribución al conocimiento de los macromicetos de la Reserva Ecológica del Pedregal de San Ángel, D.F., México New contribution to the knowledge of the macromycetes of the Ecological Reserve of the Pedregal of San Ángel, D.F., Mexico

    Directory of Open Access Journals (Sweden)

    Teófilo Herrera

    2006-06-01

    Full Text Available Se citan 8 especies de macromicetos recolectados en el área poniente de la Reserva Ecológica del Pedregal de San Ángel, D.F., México, de las cuales 5 son lignícolas y 3 humícolas, Se desarrollan a la sombra y entre hojarasca de plantas superiores. Entre los agaricales la familia Agaricaceae es la mejor representada. Se citan por primera vez en la micobiota del Pedregal de San Ángel: Gymnopus confluens, Agrocybe pediades, Agaricus arvensis y A. silvaticus, Setchelliogaster rheophyllus y Coprinus truncorumse citan por primera vez para México.Eight species of macromycetes were collected from the Ecological Reserve of the Pedregal de San Angel D.F. Mexico. Five of them are lignicolous, and 3 are humicolous developing under the shade of trees and among the litter of vascular plants. In the Agaricales the family Agaricaceae is the best represented. Gymnopus confluens, Agrocybe pediades, Agaricus arvensis and A. silvaticus, are first records in the mycobiota of the Pedregal de San Ángel. Setchelliogaster rheophyllus and Coprinus truncorum first records for Mexico are presented in this paper.

  16. Advanced data processing of airborne electromagnetic data for imaging hidden conduit networks in the coastal karst plain of Tulum (Mexico)

    International Nuclear Information System (INIS)

    Schiller, A.; Schattauer, I.; Ottowitz, D.

    2016-01-01

    This study is part of a series of international research cooperations which commenced in 2007 and are still ongoing. The study area is located on the east coast of the Yucatan Peninsula, Mexico, and comprises the northern most part of the Sian Kaan biosphere reserve, a coastal wetland of international importance, as well as the city of Tulum in the state of Quintana Roo, and part of the second largest barrier reef in the world some 300 metres to one kilometre off shore. Two airborne surveys, conducted in 2007 and 2008 by the Geological Survey of Austria, covered an area of some 200 square kilometres, including the well-known Ox Bel Ha cave system, already mapped by exploration divers. In order to get additional ground truth data and input for the hydrological model, extended ground geophysical campaigns have been conducted an - nually. The first processing of the airborne electromagnetic (AEM) data revealed not only a clear signature from known caves but also the image of a vast, unexplored, hidden conduit network. However, lateral and depth resolution was limited due to measurement drift and noise as well the specific behaviour of the ap - plied inversion technique. Newly developed algorithms for processing AEM data and inversion results have improved the signal-to-noise ratio significantly and enabled the imaging of well defined structures in the underground. Therefore, the AEM method is now capable of quickly deliver crucial structural information of karst-water regimes in difficult accessible areas with unique depth information compared to previous studies. (Author)

  17. Cytotoxic diterpenes from roots of Crossopetalum gaumeri, a Celastraceae species from Yucatan Peninsula.

    Science.gov (United States)

    Miron-Lopez, Gumersindo; Bazzocchi, Isabel L; Jimenez-Diaz, Ignacio A; Moujir, Laila M; Quijano-Quiñones, Ramiro; Quijano, Leovigildo; Mena-Rejon, Gonzalo J

    2014-05-01

    Four new diterpenes, crossogumerins A-D (1-4) along with six known ones (5-10) were isolated from the root bark of Crossopetalum gaumeri, an endemic medicinal plant from the Yucatan Peninsula. Their structures were elucidated on the basis of 1D and 2D NMR techniques, including HMQC, HMBC, and ROESY experiments. Compounds 1-5, 8-10 were evaluated for cytotoxicity against HeLa (carcinoma of the cervix) and Hep-2 (lung carcinoma) human tumor cells lines and against normal Vero cells (African green monkey kidney) in lag and log phase of growth. Podocarpane diterpenes, crossogumerin B (2) and nimbiol (10), exhibited the highest activity against HeLa cells (IC50 values of 3.1 and 8.1 μM, respectively), but also selectivity on Vero cells (SI 22.6 and 7.5, respectively). The preliminary SAR studies suggest that an epoxy moiety in ring B and a hydrogen bond-donor group strategically positioned in the diterpene core are important requirements for cytotoxicity and selectivity. Copyright © 2014. Published by Elsevier Ltd.

  18. An Index of Biotic Integrity for shallow streams of the Hondo River basin, Yucatan Peninsula.

    Science.gov (United States)

    Schmitter-Soto, Juan J; Ruiz-Cauich, Lissie E; Herrera, Roberto L; González-Solís, David

    2011-01-15

    An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. SEQUENCE STRATIGRAPHIC ANALYSIS AND FACIES ARCHITECTURE OF THE CRETACEOUS MANCOS SHALE ON AND NEAR THE JICARILLA APACHE INDIAN RESERVATION, NEW MEXICO-THEIR RELATION TO SITES OF OIL ACCUMULATION

    International Nuclear Information System (INIS)

    Jennie Ridgley

    2000-01-01

    Oil distribution in the lower part of the Mancos Shale seems to be mainly controlled by fractures and by sandier facies that are dolomite-cemented. Structure in the area of the Jicarilla Apache Indian Reservation consists of the broad northwest- to southeast-trending Chaco slope, the deep central basin, and the monocline that forms the eastern boundary of the San Juan Basin. Superimposed on the regional structure are broad low-amplitude folds. Fractures seem best developed in the areas of these folds. Using sequence stratigraphic principals, the lower part of the Mancos Shale has been subdivided into four main regressive and transgressive components. These include facies that are the basinal time equivalents to the Gallup Sandstone, an overlying interbedded sandstone and shale sequence time equivalent to the transgressive Mulatto Tongue of the Mancos Shale, the El Vado Sandstone Member which is time equivalent to part of the Dalton Sandstone, and an unnamed interbedded sandstone and shale succession time equivalent to the regressive Dalton Sandstone and transgressive Hosta Tongue of the Mesaverde Group. Facies time equivalent to the Gallup Sandstone underlie an unconformity of regional extent. These facies are gradually truncated from south to north across the Reservation. The best potential for additional oil resources in these facies is in the southern part of the Reservation where the top sandier part of these facies is preserved. The overlying unnamed wedge of transgressive rocks produces some oil but is underexplored, except for sandstones equivalent to the Tocito Sandstone. This wedge of rocks is divided into from two to five units. The highest sand content in this wedge occurs where each of the four subdivisions above the Tocito terminates to the south and is overstepped by the next youngest unit. These terminal areas should offer the best targets for future oil exploration. The El Vado Sandstone Member overlies the transgressive wedge. It produces most of

  20. Nuclear industry in a country with a substantial oil reserve

    International Nuclear Information System (INIS)

    Alvarez, R.; Castillo, H.; Costa, D.; Galan, I.; Martinez, M.

    1981-01-01

    The importance of the development of a nuclear industry in a country like Mexico, with a substantial oil reserve is analyzed, taking into account the technical, economical, political, ecological and social aspects of the problem. (author)

  1. A serological survey for avian infectious bronchitis virus and Newcastle disease virus antibodies in backyard (free-range) village chickens in Mexico.

    Science.gov (United States)

    Gutierrez-Ruiz, E J; Ramirez-Cruz, G T; Camara Gamboa, E I; Alexander, D J; Gough, R E

    2000-12-01

    The commercial flocks in Yucatan, Mexico are free of Newcastle disease virus (NDV) in its velogenic viscerotropic form, but little is known about the disease status of backyard poultry. A seroprevalence survey in 30 villages using haemagglutination inhibition (HI) tests for infectious bronchitis virus (IBV) and NDV antibodies was carried out from December 1997 to June 1998. The seroprevalences were 56.5% (95% CI 50-63%) for IBV and 2.2% (95% CI 0.5-3.8%) for NDV. All the villages had chickens that were positive for antibodies to IBV and nine of the villages had chickens that were positive for antibodies to NDV. This suggests that IBV may be responsible for a large proportion of the respiratory disease observed in backyard chickens in Yucatan. The implications of these findings are discussed, including the highly susceptible status of the backyard chickens in Yucatan to NDV and the possibility of this virus being one cause of the syndrome known as mortandad by the local people.

  2. Nano particles as the primary cause for long-term sunlight suppression at high southern latitudes following the Chicxulub impact - evidence from ejecta deposits in Belize and Mexico

    DEFF Research Database (Denmark)

    Vajda, Vivi; Ocampo, Adriana; Ferrow, Embaie

    2015-01-01

    deposits occur in Belize and southern Mexico where the so called Albion island spheroid bed is superimposed on the target rock (the Barton Creek Formation). We analysed the spheroid bed via Mössbauer spectroscopy, petrology, XRD, and palynology at several sites ~ 350-500 km distance from the crater centre....... Our results show that the relative concentrations of Fe in nano-phase goethite (α-FeOOH) are very high in the spheroid bed samples from Albion Island (Belize) and from Ramonal South (Mexico), but are low to absent in the spheroid bed at Ramonal North, and in the Cretaceous target rock. Moreover, our......Life on Earth was sharply disrupted 66 Ma ago as an asteroid hit the sea-floor in what is today Yucatan Peninsula, Mexico. Approximately 600 km3 of sedimentary rock were vapourized, ejected into the atmosphere and subsequently deposited globally as an ejecta apron and fallout layer. Proximal ejecta...

  3. 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....

  4. Uranium - raw material reserves for coming generations

    International Nuclear Information System (INIS)

    Keutner, H.

    1981-01-01

    Large uranium occurences have been discovered in the South of Mexico. The deposits are situated in the Sierra Mixteca. Reserves of 9.400 tons had been at Mexico's disposal even before these new discoveries. The quantitiy discovered recentyl amounts to 20.000 tons. The uranium reserves available apart from those in centrally controlled economic systems are presently estimated at five million tons. Meanwhile American scientists have found out that all the rivers of the world transport about 16.000 tons of uranium from the continents into the oceans per annum. The energy value of this washed out amount of uranium corresponds to the 25-fold world power demand of today. US scientists have discovered that the oceans can provide uranium for about seven million years of the present world energy demand. While the petroleum reserves decrease worldwide it seems that the exploration of uranium has just been started. (orig.) [de

  5. Spatial and temporal characterization of fish assemblages in a tropical coastal system influenced by freshwater inputs: northwestern Yucatan peninsula

    Directory of Open Access Journals (Sweden)

    Daniel Arceo-Carranza

    2009-06-01

    Full Text Available Coastal lagoons are important systems for freshwater, estuarine and marine organisms; they are considered important zones of reproduction, nursery and feeding for many fish species. The present study investigates the fish assemblages of the natural reserve of Dzilam and their relationship with the hydrologic variables. A total of 6 474 individuals (81 species were collected, contributing with more than 50% considering the Importance Value Index (IVI, Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon. Differences in species composition were found between seasons the highest during the cold fronts. Spatially, differences were related with the presence of freshwater seeps, the highest in the ecological characterized eastern part and the lowest with higher difference in specific composition located in the western part of the internal zone, due to a higher abundance and dominance of L. rhomboides. Salinity and temperature were the variables that presented a higher influence in the distribution of some pelagic species such as A. mitchilli and A. hepsetus. Because of the abundant freshwater seeps characteristic of the coastal lagoons of Yucatan Peninsula their community structure and fish assemblage display spatial and temporal differences in specific composition. Rev. Biol. Trop. 57 (1-2: 89-103. Epub 2009 June 30.Las lagunas costeras son sistemas importantes para muchas especies de organismos dulceacuícolas, estuarinos y marinos, ya que son consideradas zonas de reproducción, refugio y alimentación de muchas especies de peces. El presente estudio analizó los ensamblajes de la comunidad íctica de la reserva de Dzilam y su relación con las variables hidrológicas. Se capturaron un total de 6 474 individuos (81 especies, en donde Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon contribuyeron con m

  6. Natural gas in Mexico

    International Nuclear Information System (INIS)

    Ramirez, M.

    1999-01-01

    A series of overhead viewgraphs accompanied this presentation which focused on various aspects of the natural gas industry in Mexico. Some of the viewgraphs depicted statistics from 1998 regarding natural gas throughput from various companies in North America, natural gas reserves around the world, and natural gas reserves in Mexico. Other viewgraphs depicted associated and non-associated natural gas production from 1988 to 1998 in million cubic feet per day. The Burgos Basin and the Cantarell Basin gas production from 1997 to 2004 was also depicted. Other viewgraphs were entitled: (1) gas processing infrastructure for 1999, (2) cryogenic plant at Cd. PEMEX, (3) average annual growth of dry natural gas production for 1997-2004 is estimated at 5.2 per cent, (4) gas flows for December 1998, (5) PGPB- interconnect points, (6) U.S. Mexico gas trade for 1994-1998, (7) PGPB's interconnect projects with U.S., and (8) natural gas storage areas. Technological innovations in the industry include more efficient gas turbines which allow for cogeneration, heat recovery steam generators which reduce pollutant emissions by 21 per cent, cold boxes which increase heat transfer efficiency, and lateral reboilers which reduce energy consumption and total costs. A pie chart depicting natural gas demand by sector shows that natural gas for power generation will increase from 16 per cent in 1997 to 31 per cent in 2004. The opportunities for cogeneration projects were also reviewed. The Comision Federal de Electricidad and independent power producers represent the largest opportunity. The 1997-2001 investment program proposes an 85 per cent sulphur dioxide emission reduction compared to 1997 levels. This presentation also noted that during the 1998-2001 period, total ethane production will grow by 58 tbd. 31 figs

  7. Mexico: Imports or exports?

    International Nuclear Information System (INIS)

    Estrada, J.

    2002-01-01

    This presentation provides an overview of Mexico's energy sector. Proven oil reserves place Mexico in ninth position in the world and fourth largest in natural gas reserves. Energy is one of the most important economic activities of the country, representing 3 per cent of Gross Domestic Product (GDP). Oil exports represent 8.4 per cent of total exports. Approximately 40 per cent of total public investment is earmarked for energy projects. The author discusses energy resources and energy sector limitations. The energy sector plan for the period 2001-2006 is discussed. Its goals are to ensure energy supply, to develop the energy sector, to stimulate participation of Mexican enterprises, to promote renewable energy sources, and to strengthen international energy cooperation. The regulatory framework is being adapted to increase private investment. Some graphs are presented, displaying the primary energy production and primary energy consumption. Energy sector reforms are reviewed, as are electricity and natural gas reforms. The energy sector demand for 2000-2010 and investment requirements are reviewed, as well as fuel consumption for power generation. The author discusses the National Pipeline System (SNG) and the bottlenecks caused by pressure efficiency in the northeast, flow restriction on several pipeline segments, variability of the Petroleos Mexicanos (PEMEX) own use, and pressure drop on central regions. The entire prospect for natural gas in the country is reviewed, along with the Strategic Gas Program (PEG) consisting of 20 projects, including 4 non-associated natural gas, 9 exploration and 7 optimization. A section dealing with multiple service contracts is included in the presentation. The authors conclude by stating that the priority is a national energy policy to address Mexico's energy security requirements, to increase natural gas production while promoting the diversification of imports, and a regulatory framework to be updated in light of current

  8. Determination of 137Cs and 60Co pollution in the area of the Laguna Verde Nuclear Power Plant, Mexico

    International Nuclear Information System (INIS)

    Salas Mar, Bernardo

    2015-01-01

    The project 'Radiological Analysis of Environmental Samples in the Gulf of Mexico and the coast of Quintana Roo', had the aim of identifying and quantifying anthropogenic radionuclides in environmental samples consisting of silt, sand and sea water. This paper presents the results of the radiological analysis of these samples, which was made in the multichannel system for gamma spectrometry with hyper-pure germanium detector in the Laboratory of Radiological Analysis of Environmental Samples, located at the Physics Department, Faculty of Sciences, of the Autonomous National University of Mexico (UNAM). The sampled points are along the coast of the contiguous states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo. This paper presents the qualitative and quantitative concentrations of the main identified anthropogenic radionuclides 60 Co and 137 Cs. (authors)

  9. Ocupación y abundancia de aves rapaces nocturnas (Strigidae en la Reserva de la Biosfera Selva El Ocote, Chiapas, México Occupancy and abundance of nocturnal raptors (Strigidae in the Selva El Ocote Biosphere Reserve, Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Emerenciano Rivera-Rivera

    2012-09-01

    Full Text Available Evaluar la proporción de sitios ocupados explica la distribución espacial de los individuos dentro de una comunidad y es importante para desarrollar estrategias de conservación. En este estudio se evalúan los patrones de ocupación y abundancia de 5 especies de aves rapaces nocturnas en 2 sitios con diferentes niveles de heterogeneidad (estructura y composición del paisaje en la Reserva de la Biosfera Selva El Ocote. Se utilizaron puntos de conteo y provocación auditiva para estimar índices de ocupación y abundancia y modelos lineales generalizados para determinar las posibles relaciones entre los índices estimados y los atributos estructurales del hábitat. La variación espacial de los patrones de ocupación y abundancia se explica por la estructura del hábitat (i.e., altura de árboles, área basal, distancia con asentamientos humanos y áreas abiertas a escala local, y por la heterogeneidad (2 o más tipos de coberturas en el paisaje. Dado que se encontraron relaciones especie-específicas con los atributos del bosque tropical perennifolio, es recomendable promover el manejo diversificado y sustentable del paisaje que favorezca la presencia de áreas extensas con cobertura forestal y por lo tanto la persistencia de especies amenazadas asociadas al interior del bosque.Evaluation of occupancy explains the spatial distribution of species in the community and is important to develop conservation strategies. We evaluated occupancy and abundance patterns of nocturnal raptors in 2 sites with different level of heterogeneity (landscape structure and composition in the Selva El Ocote Biosphere Reserve. Through point counts and owl playback callings we estimate occupancy and abundance patterns. We explored possible relationships between patterns of recorded species and structural habitat attributes using generalized linear models. Occupancy and abundance spatial variation was explained by structural habitat characteristics (i.e., tree height

  10. A maternal Western diet during gestation and lactation modifies offspring’s microbiota activity, blood lipid levels, cognitive responses, and hippocampal neurogenesis in Yucatan pigs

    NARCIS (Netherlands)

    Val-Laillet, David; Besson, M.; Guérin, S.; Coquery, N.; Randuineau, G.; Kanzari, A.; Quesnel, H.; Bonhomme, N.; Bolhuis, J.E.; Kemp, B.; Blat, S.; Huërou-Luron, Le I.; Clouard, C.M.

    2017-01-01

    A suboptimal early nutritional environment (i.e., excess of energy, sugar, and fat intake) can increase susceptibility to diseases and neurocognitive disorders. The purpose of this study was to investigate in nonobese Yucatan minipigs (Sus scrofa) the impact of maternal diet [standard (SD) vs.

  11. In vitro culture and characterization of putative porcine embryonic germ cells derived from domestic breeds and yucatan mini pig embryos at days 20-24 of gestation

    DEFF Research Database (Denmark)

    Petkov, Stoyan Gueorguiev; Marks, Hendrik; Klein, Tino

    2011-01-01

    Embryonic germ cells (EGC) are cultured pluripotent cells derived from primordial germ cells (PGC). This study explored the possibility of establishing porcine EGC from domestic breeds and Yucatan mini pigs using embryos at Days 17-24 of gestation. In vitro culture of PGC from both pooled...

  12. Building the gas sector in Mexico

    International Nuclear Information System (INIS)

    Navarrete, J.E.

    1996-01-01

    Hydrocarbon reserves in Mexico, ranked 8th in the world, were discussed. On January 1, 1996, Mexico's hydrocarbon proven reserves were 62.1 billion barrels ( a decline of some 10 billion barrels since 1984). Of this 48.8 billion corresponded to crude oil and 13.3 billion to natural gas. Mexico's natural gas pipeline network includes 10,280 kilometres in transmission and 2,211 kilometres in distribution, concentrated along the Gulf of Mexico and in the central and northern regions of the country. A new regulatory framework for natural gas, passed in Congress in 1995, was outlined. The new amendments were designed to strengthen the natural gas industry through private investment in the storage, transportation and distribution of natural gas. Stages for third party access were identified. Increased North American regional integration by interconnections between Mexican, American and Canadian pipeline networks, and the effects of such integration on investments, were examined. figs

  13. Horizontal movements of Atlantic blue marlin (Makaira nigricans) in the Gulf of Mexico

    Science.gov (United States)

    Kraus, R.T.; Wells, R.J.D.; Rooker, J.R.

    2011-01-01

    We examined movements of Atlantic blue marlin (Makaira nigricans) from the Gulf of Mexico based upon 42 pop-up archival transmitting (PAT) tags. Long deployments (including one 334-day track) revealed diverse movement patterns within the Gulf of Mexico. North-south seasonal changes in blue marlin distribution showed strong correspondence with established seasonal patterns of sea surface temperature and primary production. During the summer spawning season, blue marlin utilized outer shelf and shelf edge waters in the northern Gulf of Mexico, and longer duration tracks indicated overwintering habitats in the Bay of Campeche. Egress occurred throughout the year and was difficult to determine because some tracks ended in the Straits of Florida (n = 3) while other tracks recorded movement through it or the Yucatan Channel (n = 4). Our results indicate that Atlantic blue marlin have a more restricted geographic range of habitats than previously recognized and that the Gulf of Mexico provides spatially dynamic suitable habitat that is utilized year-round through seasonal movements. ?? 2011 Springer-Verlag.

  14. Advanced data processing of airborne electromagnetic data for imaging hidden conduit networks in the coastal karst plain of Tulum (Mexico); Tecnicas avanzadas de analisis de datos electromagneticos aerotransportados para cartografia de redes de conductos karsticos de la planicie costera de Tulum (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Schiller, A.; Schattauer, I.; Ottowitz, D.

    2016-07-01

    This study is part of a series of international research cooperations which commenced in 2007 and are still ongoing. The study area is located on the east coast of the Yucatan Peninsula, Mexico, and comprises the northern most part of the Sian Kaan biosphere reserve, a coastal wetland of international importance, as well as the city of Tulum in the state of Quintana Roo, and part of the second largest barrier reef in the world some 300 metres to one kilometre off shore. Two airborne surveys, conducted in 2007 and 2008 by the Geological Survey of Austria, covered an area of some 200 square kilometres, including the well-known Ox Bel Ha cave system, already mapped by exploration divers. In order to get additional ground truth data and input for the hydrological model, extended ground geophysical campaigns have been conducted an - nually. The first processing of the airborne electromagnetic (AEM) data revealed not only a clear signature from known caves but also the image of a vast, unexplored, hidden conduit network. However, lateral and depth resolution was limited due to measurement drift and noise as well the specific behaviour of the ap - plied inversion technique. Newly developed algorithms for processing AEM data and inversion results have improved the signal-to-noise ratio significantly and enabled the imaging of well defined structures in the underground. Therefore, the AEM method is now capable of quickly deliver crucial structural information of karst-water regimes in difficult accessible areas with unique depth information compared to previous studies. (Author)

  15. New records of ectoparasitic Acari (Arachnida) and Streblidae (Diptera) from bats in Jalisco, Mexico.

    Science.gov (United States)

    Martínez, Maria M Ramírez; Lopez, M Pilar Ibarra; Iñiguez-Dávalos, Luis Ignacio; Yuill, Thomas; Orlova, Maria V; Reeves, Will K

    2016-12-01

    Ectoparasites of bats in the Neotropics are diverse and play numerous ecological roles as vectors of microbial pathogens and endoparasites and as food sources for other cave fauna living both on their hosts and in bat roosts. The ectoparasites of bats in Jalisco State of western Mexico have not been as well described as those of other states with recent checklists that have focused primarily on the Yucatan Peninsula. We captured bats from 2011-2015 on the south coast and Sierra de Amula, Jalisco using mist nets, and we removed ectoparasites by hand. We identified 24 species of streblid bat flies and six ectoparasitic mites from bats caught in mist nets. There were an additional eight possibly undescribed species of Streblidae. Our collections extend the known range of species into Jalisco. © 2016 The Society for Vector Ecology.

  16. Replacing reserve requirements

    OpenAIRE

    Edward J. Stevens

    1993-01-01

    An examination of the fading significance of the Federal Reserve System's reserve requirements and the recent flowering of required clearing balances, a rapidly growing feature of Reserve Bank operations.

  17. 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...

  18. 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...

  19. 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...

  20. Mexico: swapping crude for atoms

    International Nuclear Information System (INIS)

    Navarro, B.

    1982-01-01

    Mexico, considered the Saudi Arabia of the Western Hemisphere because of its proven and potential petroleum reserves, has surprised the world: it has embarked on the biggest nuclear-electric program in the Third World, only to postpone it days before scheduled approval of an international bidding (on which the atomic energy industry had pinned its hopes). A graph shows Mexican supplies of electricity by source with official projections to 1990. The point of entrance of the first nuclear reactor, originally scheduled for 1982, won't come onstream until 1983; and how nuclear-generated electricity grows close to 5% of the total in 1990. The big question is, will the future President of Mexico give the green light to the atomic megaproject. And if he does, how will Mexico deal with the serious logistics problems and grave ecological implications confronting the industry worldwide. In this issue, the author and Energy Detente touch on these questions and review the nuclear power status of Mexico, as well as addressing some of its global problems. Also presented in this issue is an update of the fuel price/tax series for the Western Hemisphere countries

  1. Reef demise and back-stepping during the last interglacial, northeast Yucatan

    Science.gov (United States)

    Blanchon, Paul

    2010-06-01

    The elevation of reefs and coastal deposits during the last Interglaciation (MIS-5e) indicates that sea level reached a highstand of as much as 6 m above the present, but it is uncertain how rapidly this level was attained and how it impacted reef development. To investigate this problem, I made a detailed sedimentological analysis of a well-dated reef from the northeast coast of the stable Yucatan Peninsula. Two linear reef tracts were delineated which are offset and at different elevations. The lower reef tract crops out along northern shore for 575 m and extends from below present mean sea level to +3 m. The reef crest facies consists of large Acropora palmata colonies dispersed within a coral boulder-gravel and is flanked by an A. cervicornis-dominated reef-front and a large area of lagoonal framework formed by coalesced patches of A. cervicornis and Montastraea spp. Constituents in the upper centimetre of the lower tract are heavily encrusted by a cap of crustose corallines and, in places, are levelled by a discontinuous marine-erosion surface. The upper reef tract crops out ~150 m inland up to an elevation of +5.8 m and parallels the southern section of shore for ~400 m. It also consist of an A. palmata-dominated crest facies flanked by reef-front, back-reef and lagoonal frameworks. In this case, however, lagoonal frameworks are dominated by a sediment-tolerant assemblage of branching coralline algae. Also different is the lack of encrustation by corallines, and the infiltration of upper tract facies by beach-derived shell-gravels from regressive shoreface deposits above. These results indicate that the lower reef tract and lagoonal patch-reefs formed at a sea level of +3 m. Final capping by crustose corallines and discontinuous marine erosion indicates that the lower tract was terminated by the complete demise of corals on the crest but only patchy demise in the lagoon. Areas of continuous framework accretion between the lagoonal patch reefs and the upper

  2. INTERVENCIÓN ARQUEOMAGNÉTICA DEL HORNO DE LA HACIENDA SAN PEDRO CHOLUL (MÉRIDA, YUCATÁN (Archaeomagnetic Dating of a Kiln from the San Pedro Cholul Hacienda (Merida, Yucatan

    Directory of Open Access Journals (Sweden)

    Héctor Hernández Álvarez

    2017-12-01

    Full Text Available En el presente trabajo se reportan los resultados de un estudio arqueomagnético realizado en un horno para la quema de cal encontrado en la hacienda henequenera de San Pedro Cholul, localizada al noroeste de la ciudad de Mérida en el estado de Yucatán, México. La finalidad del estudio es establecer una cronología confiable y analizar las posibles consecuencias sociales, económicas y ambientales de este asentamiento, el cual existió posiblemente desde mediados del siglo XIX hasta los años sesenta del siglo pasado. Para la determinación de la cronología, se utilizó el método de datación arqueomagnética a estructuras pirotecnológicas de estas características. Las muestras estudiadas provienen de rocas y ladrillos del horno y arrojan una edad entre 1835 y 1896, la cual concuerda con la información histórica disponible y se interpreta como el periodo de producción más importante de la región. ENGLISH: This paper presents the results of an archaeomagnetic study carried out on a lime burning kiln at the henequen hacienda of San Pedro Cholul (northwest of the city of Merida in the state of Yucatan, Mexico. The purpose of the study is to establish a reliable chronology and to estimate the possible social, economic and environmental implications of this settlement, which may have existed from the middle of the nineteenth century until the 1960s. Archaeomagnetic dating was carried out on samples obtained from rocks and bricks from the kiln and give an age between 1835 and 1896. This date range agrees with available historical information and is interpreted as the most important production period of the region.

  3. Benthic amphipods (Amphipoda: Gammaridea and Corophiidea) from the Mexican southeast sector of the Gulf of Mexico: checklist, new records and zoogeographic comments.

    Science.gov (United States)

    Paz-Ríos, Carlos E; Ardisson, Pedro-Luis

    2013-01-01

    The southeast region of the Gulf of Mexico is considered to be biologically important, because it is a connection and transition zone between the Caribbean and the Gulf of Mexico, harboring great marine biodiversity. Nevertheless, benthic amphipods have been poorly studied in the Mexican southeast sector of the Gulf of Mexico with few studies listing species. The aim of this study is to provide an update checklist of species for the Mexican southeast sector (based on literature review and records from the present study) as well as a brief zoogeographical analysis for the Gulf of Mexico amphipod fauna, putting them in context with the fauna on the tropical western Atlantic. Fifty-five species were listed for the Mexican southeast sector; 36 of them showed a geographical extension to the Yucatan continental shelf representing 23 new records for the Mexican southeast sector, nine for the southeast region and four for the Gulf of Mexico. Based on the zoogeographical analysis, there is support of the application of Carolinian and Caribbean zoogeographic provinces to amphipods in the Gulf of Mexico.

  4. Radiological analysis of environmental samples in some points of the coast of the Gulf of Mexico and Coast of Quintana Roo, Mexico

    International Nuclear Information System (INIS)

    Salas Mar, Bernardo; Martinez Negrete, Marco Antonio; Ruiz Chavarria, Gerardo; Abarca Munguia, Jose

    2008-01-01

    Full text: We describe in this paper the results obtained by the project 'Radiological analysis of environmental samples in some points of the coast of the Gulf of Mexico and coast of Quintana Roo, Mexico'. The purpose of the study is to identify and quantify the natural and anthropogenic radionuclides present from sediments, sand and seawater from several sites located along the coast of the Gulf of Mexico and the Caribean Sea. The samples are analysed in a Canberra Multichannel analyzer system for gamma spectrometry, equipped with a detector of hyper pure germanium and a Genie 2000 software, in the 'Laboratory of Radiological Analysis of Environmental Samples', belonging to the Physics Department, Faculty of Sciences, National Autonomous University of Mexico (UNAM). The geographic sites were samples were taken include the states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo. The results of this studies will be published at the end of the project and we hope they will be useful for the national health and industrial sectors. Until now we have identified and measured the presence of natural radionuclides such as Potassium-40 (K-40), Bismuth 212 (Bi-212), Lead-212 (Pb-212), Bismuth-214 (Bi-214), Lead-214 (Pb-214), Radium-226 (Ra-226), Actinium 228 (Ac-228), Uranium-235 (U-235), as well as some anthropogenic radionuclides found near the Laguna Verde Nuclear Power Plant. The project is scheduled to last for three years, finishing in 2009. At its ending we shall be able to present conclusions and identify some tendencies, in connection with the background and possible radioactive contamination of the studied zones. This project takes place under the auspice of the 'Program of Support to Projects of Research and Technological Innovation' of the National Autonomous University of Mexico. (author)

  5. 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…

  6. 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…

  7. Mexico: 'oil mentality' at last accepts a role for gas

    International Nuclear Information System (INIS)

    Higgs, R.

    1992-01-01

    The history of Mexico's policy of concentrating on oil and treating natural gas as a nuisance is traced. The current redefinition of natural gas policies by PEMEX, Mexico's giant oil and gas state monopoly, and the expanding petrochemical industry are discussed. Proven reserves of natural gas, imports of gas from the US, and the growing demand for gas products are considered. (UK)

  8. The Economic Impact of Coal Mining in New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Peach, James; Starbuck, C.

    2009-06-01

    The economic impact of coal mining in New Mexico is examined in this report. The analysis is based on economic multipliers derived from an input-output model of the New Mexico economy. The direct, indirect, and induced impacts of coal mining in New Mexico are presented in terms of output, value added, employment, and labor income for calendar year 2007. Tax, rental, and royalty income to the State of New Mexico are also presented. Historical coal production, reserves, and price data are also presented and discussed. The impacts of coal-fired electricity generation will be examined in a separate report.

  9. Unveiling the face of diversity: interlegality and legal pluralism in the Mayan area of the Yucatan Peninsula

    NARCIS (Netherlands)

    Herrera, J.I.

    2011-01-01

    José Israel Herrera bestudeerde het eigen recht en de eigen rechtstoepassing door Maya-gemeenschappen in Mexico. Worden deze eigen normen in het officiële Mexicaanse recht serieus genomen? Geeft Mexico gevolg aan de internationale verplichting om de eigen cultuur en leefwijzen van inheemse volken

  10. Estimation of gas reserves in North America

    International Nuclear Information System (INIS)

    Laherrere, J.

    2001-01-01

    If the oil market is global, the gas market is divided into three zones: North America, Europe and Asia. The official forecast of the future demand of North America gas is optimist as it is based on estimates of resources which are ten times those of the proved reserves. The poor practice (SEC rules) of proved reserves (when the rest of the world uses proven+probable) leads to a constant revision and a growth of the past discoveries, showing well a wrong evaluation. The official databases are then very poor, even those of the US federal domain, which have to be public. The study of the technical data of reserves of US, Canada and Mexico leads to a more pessimistic estimation of the ultimate reserves and then to the future local supply. In the Gulf of Mexico (the main hope), the production of natural gas in shallow water decline and the discoveries in the deep-water are mainly oil. The non-conventional gas seems to level. But the future demand is also too optimistic, based on cheap price and on a steady growth. However the local gas supply will be likely insufficient, and the demand will need imported liquefied natural gas. (author)

  11. Effect of an axially-symmetric cyclonic vortex on the sea surface temperature in the Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, E.E.; Mendoza, V.M.; Adem, J. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: eevu@atmosfera.unam.mx

    2006-04-15

    A model for the mixed layer of the Gulf of Mexico has been used to determine the effect that an idealized cyclonic vortex has in the sea surface temperature. The model consists of the equations of conservation of thermal energy and this of balance between mechanical energy and thermal energy, last based on the Kraus-Turner theory; both equations are vertically integrated in the mixed layer. As atmospheric forcing, we prescribe the surface wind associated with an axially-symmetric cyclonic vortex characterized by two parameters: the maximum tangential velocity and the radius at which that velocity is reached. The values of these two parameters, which depend on the position of the vortex, correspond to two cases: hurricane Hilda, which crossed the central part of the Gulf of Mexico between September 29 and October 3, 1964 and hurricane Gilbert whose trajectory between 11 and 17 September, 1988 crossed the Caribbean Sea, the Yucatan Peninsula and the southwest Gulf of Mexico. The results show that a cyclonic vortex with such characteristics, produce during its passage by the sea vertical turbulent water transport through the thermocline (entrainment) that is able to cool down the mixed layer in several degrees and increases the thermocline depth in several meters, in agreement with the observations. [Spanish] Se aplica un modelo de capa de mezcla para el Golfo de Mexico con el objeto de determinar el efecto de un vortice ciclonico idealizado sobre la temperatura de la superficie del mar. El modelo consiste basicamente de dos ecuaciones, la de conservacion de energia termica y la de balance entre energia mecanica y energia termica, esta ultima derivada de la teoria de Kraus-Turner; ambas ecuaciones son verticalmente integradas y acopladas en la capa de mezcla. Como forzamiento atmosferico sobre la superficie del mar se prescribe el viento asociado a un vortice ciclonico axialmente simetrico caracterizado por dos parametros: la velocidad tangencial maxima y el radio al

  12. Hummingbirds and the plants they visit in the Tehuacán-Cuicatlán Biosphere Reserve, Mexico Colibríes y las plantas que visitan en la Reseva de la Biosfera Tehuacán-Cuicatlán, México

    Directory of Open Access Journals (Sweden)

    Raúl Ortiz-Pulido

    2012-03-01

    Full Text Available We describe the relative abundance, plant species visited, and plant communities used by hummingbird species inhabiting the Tehuacán-Cuicatlán Biosphere Reserve, a semiarid area in South-central Mexico. We recorded 14 hummingbird species and 35 plant species distributed in 4 plant communities during our study. We found 86 different hummingbird-plant interactions. Amazilia violiceps and Cynanthus latirostris were the most common hummingbirds, while C. latirostris, A. violiceps, and Cynanthus sordidus were the hummingbirds that visited more plant species. Hummingbirds were distributed differentially between plant communities inside the reserve, with 12 species being present in the arboreal plant community of the lowlands, 11 both in cactus forest and perennial spine shrub plants, and 6 in perennial unarmed shrub plants. Cercidium praecox (Fabaceae was the plant species with the highest number of visiting hummingbird species (10 species. Cactus forest and perennial spine shrub plants were the plant communities with largest number of possible interactions (57 and 51, respectively. The mean connectance value of the interaction matrix was similar between plant communities (near to 22%, but lower than those reported previously in other places. In the Tehuacán-Cuicatlán Biosphere Reserve the hummingbird-plant interaction system will be preserved if the hummingbirds C. latirostris, A. violiceps, C. sordidus, and L. clemenciae, and the plants C. praecox, I. arborescens, E. chiotilla, and N. glauca, are protected.Describimos la abundancia relativa, especies de plantas visitadas y tipos de vegetación utilizados por los colibríes de la Reserva de la Biosfera Tehuacán-Cuicatlán, México. Durante nuestro de estudio registramos 14 especies de colibríes y 35 especies de plantas utilizadas por ellos dentro de cuatro tipos de vegetación, representando 86 diferentes interacciones colibrí-planta. Amazilia violiceps y Cynanthus latirostris fueron los

  13. Early radioisotope uses in Mexico

    International Nuclear Information System (INIS)

    Segovia, N.; Tejera, A.; Bulbulian, S.; Palma, F.

    1991-10-01

    Mexico is traditionally a mining country and the first information about the presence of uranium is related to mine exploitation. Around 1945 when uranium became economically important, a rumor had spread that large amounts of black ceramics from Oaxaca were being purchased and sent abroad because of its assumed high uranium content. It was only in 1949 when minerals containing thorium and uranium were declared by law as 'National Reserves'. In those years a radium emanation plant was installed at the 'Hospital General' in Mexico City with the main purpose of carrying out radon seed implantation in tumors. In the fifties a radium dial painting facility was operating in the city of Toluca some 70 km from Mexico City. In 1955, when the National Commission of Nuclear Energy (CNEN) was founded by a government decree, two main activities were in sight: a training program on 'Radioisotope Techniques and Nuclear Instrumentation' and the creation of specialized laboratories. In this paper a general description of these events and undertakings spanning the decades 1940 to 1970 is given. (Author)

  14. Early radioisotope uses in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N; Tejera, A; Bulbulian, S; Palma, F

    1991-10-15

    Mexico is traditionally a mining country and the first information about the presence of uranium is related to mine exploitation. Around 1945 when uranium became economically important, a rumor had spread that large amounts of black ceramics from Oaxaca were being purchased and sent abroad because of its assumed high uranium content. It was only in 1949 when minerals containing thorium and uranium were declared by law as 'National Reserves'. In those years a radium emanation plant was installed at the 'Hospital General' in Mexico City with the main purpose of carrying out radon seed implantation in tumors. In the fifties a radium dial painting facility was operating in the city of Toluca some 70 km from Mexico City. In 1955, when the National Commission of Nuclear Energy (CNEN) was founded by a government decree, two main activities were in sight: a training program on 'Radioisotope Techniques and Nuclear Instrumentation' and the creation of specialized laboratories. In this paper a general description of these events and undertakings spanning the decades 1940 to 1970 is given. (Author)

  15. Using Landsat 5 TM Data to Identify and Map Areas of Mangrove in Tulum, Quintana Roo, Mexico

    Science.gov (United States)

    Meachum, Samuel Standish

    Mangroves are recognized worldwide as a major ecosystem that provides significant ecosystem services. They are threatened due to rising pressures from human overpopulation and economic development. The Caribbean Coast of Mexico's Yucatan Peninsula contains mangrove habitat that have been negatively impacted by the development of the region's tourist industry. However, little research has been done to map and quantify the extent of mangrove in the region. This study used remote sensing techniques to identify mangrove in the Municipality of Tulum located in Quintana Roo, and to produce an accurate vector based thematic map that inventories these areas. Anatomical differences were analyzed and related to high-resolution field spectral data for each mangrove species. A vector map of mangrove habitat, including areas of inland mangrove, was produced with an overall accuracy of 88%. The 19,262 ha. of mangrove identified by this study represents a 140% increase in area over previous studies.

  16. Hydrodynamics of the groundwater-fed Sian Ka'an Wetlands, Mexico, From InSAR and SAR Data

    DEFF Research Database (Denmark)

    Gondwe, Bibi Ruth Neuman; Hong, S.; Wdowinski, S.

    2008-01-01

    The 5300 km2 pristine Sian Ka'an wetland in Mexico is fed entirely by groundwater from the karst aquifer of the Yucatan Peninsula. The area is undeveloped and hence difficult to access. The inflow through underground rivers and karst structures is hard to observe resulting in difficulties......-changes of the backscattered radar signal, which can be related to the water level changes in vegetated wetlands. SAR data reveals information of surface properties such as the degree of flooding through the amplitude of the backscattered signal. We used RADARSAT-1 InSAR and SAR data to form 36 interferograms and 13 flooding...... maps with 24 to 48 day intervals covering the time span of October 2006 to March 2008. The dataset has a high spatial resolution of ca. 20 to 60 m. Sian Ka'an consists of a mosaic of freshwater sloughs, canals, floodplains and brackish tidally-influenced areas. Throughout most of the year, water level...

  17. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

    Venezuela is an important player in the energy world, because of its hydrocarbons reserves. The process for calculating oil and associated gas reserves is described bearing in mind that 90% of the gas reserves of Venezuela are associated to oil. Likewise, an analysis is made of the oil reserves figures from 1975 to 2003. Reference is also made to inconsistencies found by international experts and the explanations offered in this respect by the Ministry of Energy and Petroleum (MENPET) and Petroleos de Venezuela (PDVSA) regarding the changes that took place in the 1980s. In turn, Hubbert's Law is explained to determine peak production of conventional oil that a reservoir or field will reach, as well as its relationship with remaining reserves. Emphasis is placed on the interest of the United Nations on this topic. The reserves of associated gas are presented along with their relationship with the different crude oils that are produced and with injected gas, as well as with respect to the possible changes that would take place in the latter if oil reserves are revised. Some recommendations are submitted so that the MENPET starts preparing the pertinent policies ruling reserves. (auth)

  18. Reproductive biology of Hechtia schottii, a dioecious Bromeliaceae, in Mexico

    Directory of Open Access Journals (Sweden)

    Ivón M Ramírez Morillo

    2008-03-01

    Full Text Available Hechtia schottii is a terrestrial, rosetofilous, dioecious, polycarpic succulent herb, that grows mainly in shrubby associations, and less frequently, in secondary low caducifolious forests, both on calcareous soils or limestone outcrops in Yucatan and Campeche States, Mexico. We studied phenology, floral and pollination biology, and breeding system at Calcehtok, Yucatan, during two flowering seasons. Plants bloom mainly during the dry season (November-April and disperse seeds during the rainy season (May-October. Both floral morphs have diurnal anthesis; pollen is removed ca. 1 h after anthesis starts and both floral morphs are visited by several insect species, especially bees, but results suggest that the introduced honey bee, Apis mellifera, is the pollinator. Controlled crossings show that the species is functionally dioecious and requires to be serviced by pollinators based on fruit setting only in unassisted cross pollination crosses. Rev. Biol. Trop. 56 (1: 279-289. Epub 2008 March 31.Hechtia schottii es una hierba terrestre, suculenta, rosetófila, dioica y policárpica, que crece en asociaciones arbustivas y selva baja caducifolia secundaria, ambos en suelos calcáreos o limosos. Estudiamos la fenología, la biología floral, reproductiva y de la polinización en una población en Calcehtok, Yucatán, México, durante dos estaciones de floración. Las plantas florecen principalmente en la época de secas (noviembre-abril y la dispersión de semillas es durante la estación de lluvias (mayo-octubre. Ambas formas (morphs florales tienen antesis diurna; el polen es removido ca. 1 h después del comienzo de la antesis y ambas formas florales son visitadas por varias especies de insectos, especialmente abejas, pero los resultados sugieren que la abeja introducida, Apis mellifera, es el polinizador. Cruces controlados muestran que la especie es funcionalmente dioica y que requiere de un polinizador, ya que solo produce frutos por polinizaci

  19. Development and Calibration of a Model for the Determination of Hurricane Wind Speed Field at the Peninsula of Yucatan

    Directory of Open Access Journals (Sweden)

    L.E. Fernández–Baqueiro

    2009-01-01

    Full Text Available In this work a model to calculate the wind speed field produced by hurricanes that hit the Yucatan Peninsula is developed. The model variables are calculated using equations recently developed, that include new advances in meteorology. The steps in the model are described and implemented in a computer program to systematize and facilitate the use of this model. The model and the program are calibrated using two data bases; the first one includes trajectories and maximum wind velocities of hurricanes; the second one includes records of wind velocities obtained from the Automatic Meteorology Stations of the National Meteorology Service. The hurricane wind velocity field is calculated using the model and information of the first data base. The model results are compared with field data from the second data base. The model is calibrated adjusting the Holland's pressure radial profile parameter B; this is carried out for three hurricane records: Isidore, Emily and Wilma. It is concluded that a value of B of 1.3 adjusts globally the three hurricane records and that the developed model is capable of reproducing satisfactorily the wind velocity records.

  20. Tektite-bearing, deep-water clastic unit at the Cretaceous-Tertiary boundary in northeastern Mexico

    Science.gov (United States)

    Smit, J.; Montanari, A.; Swinburne, N. H.; Alvarez, W.; Hildebrand, A. R.; Margolis, S. V.; Claeys, P.; Lowrie, W.; Asaro, F.

    1992-01-01

    The hypothesis of Cretaceous-Tertiary (K-T) boundary impact on Yucatan, Mexico, predicts that nearby sites should show evidence of proximal impact ejecta and disturbance by giant waves. An outcrop along the Arroyo el Mimbral in northeastern Mexico contains a layered clastic unit up to 3 m thick that interrupts a biostratigraphically complete pelagic-marl sequence deposited at more than 400 m water depth. The marls were found to be unsuitable for determining magnetostratigraphy, but foraminiferal biostratigraphy places the clastic unit precisely at the K-T boundary. We interpret this clastic unit as the deposit of a megawave or tsunami produced by an extraterrestrial impact. The clastic unit comprises three main subunits. (1) The basal "spherule bed" contains glass in the form of tektites and microtektites, glass spherules replaced by chlorite-smectite and calcite, and quartz grains showing probable shock features. This bed is interpreted as a channelized deposit of proximal ejecta. (2) A set of lenticular, massive, graded "laminated beds" contains intraclasts and abundant plant debris, and may be the result of megawave backwash that carried coarse debris from shallow parts of the continental margin into deeper water. (3) At the top, several thin "ripple beds" composed of fine sand are separated by clay drapes; they are interpreted as deposits of oscillating currents, perhaps a seiche. An iridium anomaly (921 +/- 23 pg/g) is observed at the top of the ripple beds. Our observations at the Mimbral locality support the hypothesis of a K-T impact on nearby Yucatan.

  1. An Index of Biotic Integrity for shallow streams of the Hondo River basin, Yucatan Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Schmitter-Soto, Juan J., E-mail: jschmitt@ecosur.mx; Ruiz-Cauich, Lissie E.; Herrera, Roberto L.; Gonzalez-Solis, David

    2011-01-15

    An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. - Research Highlights: {yields} An Index of Biotic Integrity based on fishes is proposed for streams of the Hondo River basin. {yields

  2. Skyline Reservation System

    Data.gov (United States)

    US Agency for International Development — Flight reservation application used for in-country flights by USAID and DoS staff in Afghanistan. The application is managed and maintained by the vendor and USAID...

  3. [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.

  4. GNIS: Parks and Reserves (2013)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The Geographic Names Information System (GNIS) is the Federal standard for geographic nomenclature. The U.S. Geological Survey developed the GNIS for the U.S. Board...

  5. Enhancing Diversity In The Geosciences; Intensive Field Experience In USA And Mexico For Middle And High School Teachers Serving Large Hispanic Populations.

    Science.gov (United States)

    Leal-Bautista, R. M.; Kitts, K. B.; Velazquez Oliman, G.; Perry, E. C.

    2008-12-01

    To encourage Hispanic participation and enrolment in the geosciences and ultimately enhance diversity within the discipline, we recruited ten middle and high school science teachers serving large Hispanic populations (60-97%) for a paid three-week field experience supported by an NSF Opportunities for Enhancing Diversity in the Geosciences grant. In 2006, the field experiences focused on volcanic events and the water problems of the Central part of Mexico. In 2008, the field experiences focused on karstic and hydrogeological conditions of the Yucatan Peninsula. In addition to the geological aspects of the fieldwork experience, the trip to Mexico exposed the teachers to a social environment outside of their community where they interacted with a diverse group of scientists from the Universidad National Autonoma de Mexico (UNAM), Centro de Investigacion Cientifica de Yucatan (CICY) and Centro Nacional de Desastres (CENAPRED). A key part of this project was the encounter between American and Mexican teachers that included a day of presentations, panel discussion and some class-room activities. Direct interaction between the cooperating teachers and the American and Mexican geoscientists provided actual scientific research experiences to educate and to help dispel misconceptions the teachers themselves may have had about who geoscientists really are and what they do. Teachers of the 2006 group produced educational materials from their field experiences and presented these materials at professional conferences. We measured the efficacy of these activities quantitatively via pre- and post-tests assessing confidence levels, preconceptions and biases, NIU staff observations of participants in their home institutions, and evaluations of participants' field books and pedagogical materials. We present these data here and identify specific activities that are both effective and efficient in changing teacher behaviours and attitudes enabling them to better connect with their

  6. Microbial diversity and biomarker analysis of modern freshwater microbialites from Laguna Bacalar, Mexico.

    Science.gov (United States)

    Johnson, D B; Beddows, P A; Flynn, T M; Osburn, M R

    2018-05-01

    Laguna Bacalar is a sulfate-rich freshwater lake on the Yucatan Peninsula that hosts large microbialites. High sulfate concentrations distinguish Laguna Bacalar from other freshwater microbialite sites such as Pavilion Lake and Alchichica, Mexico, as well as from other aqueous features on the Yucatan Peninsula. While cyanobacterial populations have been described here previously, this study offers a more complete characterization of the microbial populations and corresponding biogeochemical cycling using a three-pronged geobiological approach of microscopy, high-throughput DNA sequencing, and lipid biomarker analyses. We identify and compare diverse microbial communities of Alphaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria that vary with location along a bank-to-bank transect across the lake, within microbialites, and within a neighboring mangrove root agglomeration. In particular, sulfate-reducing bacteria are extremely common and diverse, constituting 7%-19% of phylogenetic diversity within the microbialites, and are hypothesized to significantly influence carbonate precipitation. In contrast, Cyanobacteria account for less than 1% of phylogenetic diversity. The distribution of lipid biomarkers reflects these changes in microbial ecology, providing meaningful biosignatures for the microbes in this system. Polysaturated short-chain fatty acids characteristic of cyanobacteria account for Bacalar microbialites. By contrast, even short-chain and monounsaturated short-chain fatty acids attributable to both Cyanobacteria and many other organisms including types of Alphaproteobacteria and Gammaproteobacteria constitute 43%-69% and 17%-25%, respectively, of total abundance in microbialites. While cyanobacteria are the largest and most visible microbes within these microbialites and dominate the mangrove root agglomeration, it is clear that their smaller, metabolically diverse associates are responsible for significant biogeochemical cycling in this

  7. The Quaternary Environmental Change in the Northeast of Quintana Roo, Mexico:The Paleopedological Proxies

    Science.gov (United States)

    Cabadas Báez, H. V.; Sedov, S.; Solleiro Rebolledo, E.

    2010-03-01

    The Yucatán Peninsula, located in the southeast part of Mexico, is characterized to be an extended and low altitude platform constituted by calcareous rocks. These rocks are mainly limestones formed since Cretaceous under a marine shelf environment. In the northeast coast, the youngest sediments are found, as products of Quaternary sea level changes. We studied various profiles in quarries, following north-south transect in the Yucatan coast, near Cancún. In such profiles a sequence consisting of different kind of calcareous sediments and a soil in the surface were analyzed. The base of the sequence is constituted by a petrocalcic horizon (calcrete) that was formed during the last interglacial, 125,000 yrs. ago. Under the calcrete, a transgressive sequence appears with calcareous sediments of lagoon and reef facies. The uppermost part consists of dune-like sediments with crossed stratification overlied by another petrocalcic horizon, maybe formed during the Pleistocene-Holocene transition. Soils of the Yucatan Peninsula are very thin, rich in organic matter, neutral and well structured, and their image do not correspond to that found in tropical soils (deep, strongly weathered, leached). They are directly associated with the dune sediment dissolution because are infilling the "space" generated by rock dissolution. Calcrete is always in the uppermost part, but is broken and crossed by soil. This sequence reveals some aspects of the environmental dynamic during Late Pleistocene-Holocene. First, a dryer environment is assumed due to the presence of the calcrete in the base. During the glacial period, a transgressive environment prevailed and marine calcareous sedimentation started. During Last Glacial Maximum a regression occurred, the climate was drier and the formation of dune sediments and another calcrete occurred. In the Holocene climate changed shifting toward more humid conditions that produced the modern soil cover, under tropical conditions.

  8. Reconstructing water level in Hoyo Negro, Quintana Roo, Mexico, implications for early Paleoamerican and faunal access

    Science.gov (United States)

    Collins, S. V.; Reinhardt, E. G.; Rissolo, D.; Chatters, J. C.; Nava Blank, A.; Luna Erreguerena, P.

    2015-09-01

    The skeletal remains of a Paleoamerican (Naia; HN5/48) and extinct megafauna were found at -40 to -43 mbsl in a submerged dissolution chamber named Hoyo Negro (HN) in the Sac Actun Cave System, Yucatan Peninsula, Mexico. The human remains were dated to between 12 and 13 Ka, making these remains the oldest securely dated in the Yucatan. Twelve sediment cores were used to reconstruct the Holocene flooding history of the now phreatic cave passages and cenotes (Ich Balam, Oasis) that connect to HN. Four facies were found: 1. bat guano and Seed (SF), 2. lime Mud (MF), 3. Calcite Rafts (CRF) and 4. Organic Matter/Calcite Rafts (OM/CRF) which were defined by their lithologic characteristics and ostracod, foraminifera and testate amoebae content. Basal radiocarbon ages (AMS) of aquatic sediments (SF) combined with cave bottom and ceiling height profiles determined the history of flooding in HN and when access was restricted for human and animal entry. Our results show that the bottom of HN was flooded at least by 9850 cal yr BP but likely earlier. We also found, that the pit became inaccessible for human and animal entry at ≈8100 cal yr BP, when water reaching the cave ceiling effectively prevented entry. Water level continued to rise between ≈6000 and 8100 cal yr BP, filling the cave passages and entry points to HN (Cenotes Ich Balam and Oasis). Analysis of cave facies revealed that both Holocene sea-level rise and cave ceiling height determined the configuration of airways and the deposition of floating and bat derived OM (guano and seeds). Calcite rafts, which form on the water surface, are also dependent on the presence of airways but can also form in isolated air domes in the cave ceiling that affect their loci of deposition on the cave bottom. These results indicated that aquatic cave sedimentation is transient in time and space, necessitating extraction of multiple cores to determine a limit after which flooding occurred.

  9. Selling the SPR [Strategic Petroleum Reserve

    International Nuclear Information System (INIS)

    Gurney, J.

    1997-01-01

    The Strategic Petroleum Reserve (SPR) in the USA was created in 1975, in conjunction with the wider reserve programme of the International Energy Agency, following the 1973/74 Arab oil embargo. The only source of funding for the SPR has been annual appropriations bills from Congress. In 1994, however, Congress, seeking ways to balance the nation's budget and given the perception by many free market economists that the danger of serious oils supply disruption has passed, refused to allocate funds for SPR oil purchases. No crude oil stocks have been added to the reserve since then. In 1996, congress took the further step of requiring sales of oil from the reserve in order to pay for the programme's running costs and to meet the costs of maintaining the reserve's storage facilities. The reserve oil is stored in caverns under salt domes in the coastal regions of the Gulf of Mexico and some of these are beginning to fracture to the extent that they are having to be decommissioned. The SPR has been investigating ways of raising money in order to lessen its dependence on Congress. These include leasing pipelines and a marine terminal, and allowing the storage of foreign owned oil in underused caverns. (author)

  10. US uranium reserves

    International Nuclear Information System (INIS)

    Hansen, M.V.

    1981-01-01

    The current low level of demand, compounded by rapidly rising costs and low prices, has caused a significant reduction in drilling for uranium in the United States, and the trend is likely to continue for a few more years. The effect on uranium reserves will be fewer additions to reserves because less exploration is being done. Further reductions will occur, especially in low-cost reserves, because of increasing costs, continuing depletion through production, and erosion through the high grading of deposits to fulfill previous contractual commitments. During the past several years, it has been necessary to increase the upper reserve cost level twice to compensate for rising costs. Rising costs are reducing the $15 reserves, the cost category corresponding most closely to the present market price, to an insignificant level. An encouraging factor related to US uranium reserves is that the US position internationally, as far as quantity is concerned, is not bad for the longer term. Also, there is a general opinion that US consumers would rather contract for domestic uranium than for foreign because of greater assurance of supply. Still another factor, nearly impossible to assess, is what effect rising costs in other countries will have on their uranium reserves. The annual conferences between the Grand Junction Area Office staff and major uranium companies provide a broad overview of the industry's perception of the future. It is not optimistic for the short term. Many companies are reducing their exploration and mining programs; some are switching to other more marketable mineral commodities, and a few are investing more heavily in foreign ventures. However, there is general optimism for the long term, and many predict a growth in demand in the mid-1980s. If the industry can survive the few lean years ahead, rising prices may restore its viability to former levels

  11. Prevalence of clinically important species of the genus Vibrio in catered seafood of city and port of Progreso de Castro, Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    José Franco Monsreal

    2015-06-01

    Full Text Available INTRODUCCIÓN Las especies del género Vibrio son bacilos gramnegativos de entre 2 y 3 µm de largo, de forma algo curva, dotados de un único flagelo polar que les permite una elevada movilidad. Soportan bien los medios alcalinos, así como las concentraciones salinas. No forman esporas, son oxidasa positiva y anaerobios facultativos. El objetivo del presente estudio fue estimar las prevalencias de las especies de importancia clínica del género Vibrio en alimentos marinos de origen animal crudos, marinados sin calor, parcialmente cocidos con calor y completamente cocidos con calor. MÉTODOS Se trata de un estudio con enfoque cuantitativo. Se obtuvo un listado de 38 establecimientos especializados en la venta de alimentos marinos de origen animal para consumo humano. El número de alimentos marinos de origen animal en dichos establecimientos fue 790. Para la homogeneización y el enriquecimiento de las muestras, así como para el aislamiento y la identificación de las especies, se procedió según la metodología descrita en el Bacteriological Analytical Manual. Se obtuviero intervalos de de confianza de 95% para los porcentajes de incidencia. RESULTADOS Las prevalencias obtenidas en alimentos marinos crudos, marinados sin calor, parcialmente cocidos con calor y completamente cocidos con calor fueron 44,30% (276/623, 32,00% (8/25, 30,53% (29/95 y 17,02% (8/47, respectivamente. CONCLUSIONES Se considera conveniente tener presentes estos resultados con el objeto de prevenir problemas sanitarios que pudieran en algún momento repercutir en la salud de la población consumidora de la ciudad y puerto de Progreso de Castro, Yucatán, México.

  12. Exploration, modelling and management of groundwater-dependent ecosystems in karst – the Sian Ka'an case study, Yucatan, Mexico

    DEFF Research Database (Denmark)

    Gondwe, Bibi Ruth Neuman

    . Således har projektets resultater en direkte indvirkning på forvaltningen og beskyttelsen af dette verdensberømte naturområde, der tiltrækker tusindvis af turister hvert år. Projektet har brugt en multi-disciplinær metode til at undersøge problemstillingen. Et væld af feltundersøgelser er blevet...

  13. Photoprotection related to xanthophyll cycle pigments in epiphytic orchids acclimated at different light microenvironments in two tropical dry forests of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    de la Rosa-Manzano, Edilia; Andrade, José Luis; García-Mendoza, Ernesto; Zotz, Gerhard; Reyes-García, Casandra

    2015-12-01

    Epiphytic orchids from dry forests of Yucatán show considerable photoprotective plasticity during the dry season, which depends on leaf morphology and host tree deciduousness. Nocturnal retention of antheraxanthin and zeaxanthin was detected for the first time in epiphytic orchids. In tropical dry forests, epiphytes experience dramatic changes in light intensity: photosynthetic photon flux density may be up to an order of magnitude higher in the dry season compared to the wet season. To address the seasonal changes of xanthophyll cycle (XC) pigments and photosynthesis that occur throughout the year, leaves of five epiphytic orchid species were studied during the early dry, dry and wet seasons in a deciduous and a semi-deciduous tropical forests at two vertical strata on the host trees (3.5 and 1.5 m height). Differences in XC pigment concentrations and photosynthesis (maximum quantum efficiency of photosystem II; F v/F m) were larger among seasons than between vertical strata in both forests. Antheraxanthin and zeaxanthin retention reflected the stressful conditions of the epiphytic microhabitat, and it is described here in epiphytes for the first time. During the dry season, both XC pigment concentrations and photosystem II heat dissipation of absorbed energy increased in orchids in the deciduous forest, while F v/F m and nocturnal acidification (ΔH(+)) decreased, clearly as a response to excessive light and drought. Concentrations of XC pigments were higher than those in orchids with similar leaf shape in semi-deciduous forest. There, only Encyclia nematocaulon and Lophiaris oerstedii showed somewhat reduced F v/F m. No changes in ΔH(+) and F v/F m were detected in Cohniella ascendens throughout the year. This species, which commonly grows in forests with less open canopies, showed leaf tilting that diminished light interception. Light conditions in the uppermost parts of the canopy probably limit the distribution of epiphytic orchids and the retention of zeaxanthin can help to cope with light and drought stress in these forests during the dry season.

  14. Plasma cholinesterase inhibition in the clay-colored robin (Turdus grayi) exposed to diazinon in maradol papaya crops in Yucatan, Mexico

    Science.gov (United States)

    Cobos, V.M.; Mora, M.A.; Escalona, G.

    2006-01-01

    The use of organophosphorous pesticides in agriculture can result in intoxication of birds foraging in sprayed crops. Effects on birds resulting from pesticide intoxication are varied and include behavioral and reproductive effects, including death. One widely used insecticide in Maradol papaya crops is diazinon which has been associated with various incidents of intoxication and death of wild birds. The objective of this study was to evaluate the impact of diazinon application to papaya crops on plasma cholinesterase activity of the clay-colored robin (Turdus grayi). We captured clay-colored robins foraging in a papaya crop the following day after the field had been sprayed with diazinon at a dose of 1.5 kg/ha during March and May, respectively. We took a blood sample from the brachialis vein of the birds captured and measured plasma enzymatic activity. The plasma samples from birds used as controls were taken during the same time period and were analyzed in a similar way. Enzymatic activity of males was greater than that of females (53,52%) and mean cholinesterase inhibition was 49.43%. Cholinesterase inhibition was greater during May than in March probably due to more continuous exposure and ingestion of the insecticide through food and possible absorption through the skin. This degree of enzymatic inhibition is possibly affecting the behavior of the clay-colored robin and could result in death in severe cases.

  15. Dynamics and contaminants in the coastal lagoon system of Nichupte-Bojórquez located in the Peninsula of Yucatan, Mexico

    Science.gov (United States)

    Carbajal, N.; Gaviño, J.; Galicia, M. A.

    2007-05-01

    Measurements of hydrographic parameters like temperature, salinity, pH, turbidity, dissolved oxygen and determination of concentrations of contaminants like ammonia, surfactants, phosphate, nitrite and nitrate give a picture about the degradation of the lagoon system of Nichupté-Bojórquez. Numerical experiments reveal that the tidal circulation is not intense enough to induce an efficient exchange of water. Tidal currents are small and limited to regions near the two mouths which connect the lagoon system with the Caribbean Sea. The circulation induced by wind forcing is more effective in generating strong currents in the different lagoons of the system. The wind induced circulation reduces the residence time of water. To explain the observed distribution of contaminants, we also simulate numerically the dispersion of contaminants. We present a general picture of the environmental problems of this beautiful lagoon system.

  16. An Index of Biotic Integrity for shallow streams of the Hondo River basin, Yucatan Peninsula

    International Nuclear Information System (INIS)

    Schmitter-Soto, Juan J.; Ruiz-Cauich, Lissie E.; Herrera, Roberto L.; Gonzalez-Solis, David

    2011-01-01

    An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. - Research Highlights: → An Index of Biotic Integrity based on fishes is proposed for streams of the Hondo River basin. → Twelve variables were

  17. Handbook on loss reserving

    CERN Document Server

    Schmidt, Klaus; Schnaus, Anja

    2016-01-01

    This handbook presents the basic aspects of actuarial loss reserving. Besides the traditional methods, it also includes a description of more recent ones and a discussion of certain problems occurring in actuarial practice, like inflation, scarce data, large claims, slow loss development, the use of market statistics, the need for simulation techniques and the task of calculating best estimates and ranges of future losses. In property and casualty insurance the provisions for payment obligations from losses that have occurred but have not yet been settled usually constitute the largest item on the liabilities side of an insurer's balance sheet. For this reason, the determination and evaluation of these loss reserves is of considerable economic importance for every property and casualty insurer. Actuarial students, academics as well as practicing actuaries will benefit from this overview of the most important actuarial methods of loss reserving by developing an understanding of the underlying stochastic models...

  18. Multifocal epithelial hyperplasia in a community in the Mayan area of Mexico.

    Science.gov (United States)

    González-Losa, Maria R; Suarez-Allén, Rosa E; Canul-Canche, Jaqueline; Conde-Ferráez, Laura; Eljure-Lopez, Nixma

    2011-03-01

    Multifocal epithelial hyperplasia is a pathology of the oral mucosa which has been reported in diverse ethnic groups. Human papillomavirus (HPV) types 13 and 32 DNA has been detected in these lesions. The aims of this paper are to describe the epidemiological and clinical characteristics of an outbreak in a rural community in the Mayan area of Mexico and to identify a possible route of transmission through saliva. A cross-sectional study was conducted in Chemax (Yucatan, Mexico). Clinical and epidemiological data were obtained through direct interviews. Samples of oral cells and saliva were taken. HPV 13 and 32 were identified by polymerase chain reaction using specific primers. A total of 57 patients were studied, of whom 79.1% were aged jugal mucosa, and more frequently, the tongue. HPV 13 was found in all the patients and HPV 32 in none. A total of 42 saliva samples were positive for HPV 13. Human papillomavirus type 13 is involved in multifocal epithelial hyperplasia among the Mexican Mayan population. The presence of HPV 13 in cells from saliva, combined with poor hygiene behaviors, may explain the familial distribution of the pathology. © 2011 The International Society of Dermatology.

  19. BOVINE RESPIRATORY SYNCYTIAL VIRUS EPIDEMIOLOGY AND RISK FACTORS ON CATTLE HERDS OF CAMPECHE STATE, MEXICO

    Directory of Open Access Journals (Sweden)

    Lisandro Alberto Encalada Mena

    2016-12-01

    Full Text Available High seroprevalence in Yucatan and proximity to the state of Campeche make it necessary to determine the seroprevalence and risk factors of bovine respiratory syncytial virus (VRSB in the state of Campeche, Mexico. Thus the objective of the present work was to determine the seroprevalence and risk factors bovine respiratory syncytial virus (BRSV of the state of Campeche, Mexico. The sampled of 36 cattle herds (842 sera were analyzed by indirect ELISA kit, in the 11 municipalities of Campeche. A survey to obtain risk factors (sex, age of animals, number of animals grazing density, management system, presence of sheep on the farm and access to the roadside was applied and calculated X2 for each variable considered. Of the total number of samples analyzed (842, 273 were positive (32.47%. The prevalence ranges found ranged from 0% to 84%, so in 9 of the herds there were no positive samples, indicating a 75% (27/36 of dispersion of this virus. X2 analysis indicated that all variables were significant and are risk factors regarding with respect to the variable seroprevalence of BRSV. The results indicate a wide circulation of BRSV and we suggest implement recommendations that will enable a lower spread of this virus in the cattle population.

  20. Genetic diversity and structure in semiwild and domesticated chiles (Capsicum annuum; Solanaceae) from Mexico.

    Science.gov (United States)

    Aguilar-Meléndez, Araceli; Morrell, Peter L; Roose, Mikeal L; Kim, Seung-Chul

    2009-06-01

    The chile of Mesoamerica, Capsicum annuum, is one of five domesticated chiles in the Americas. Among the chiles, it varies the most in size, form, and color of its fruits. Together with maize, C. annuum is one of the principal elements of the neotropical diets of Mesoamerican civilizations. Despite the great economic and cultural importance of C. annuum both worldwide and in Mexico, however, very little is known about its geographic origin and number of domestications. Here we sampled a total of 80 accessions from Mexico (58 semiwild and 22 domesticated) and examined nucleotide sequence diversity at three single- or low-copy nuclear loci, Dhn, G3pdh, and Waxy. Across the three loci, we found an average reduction of ca. 10% in the diversity of domesticates relative to semiwild chiles and geographic structure within Mexican populations. The Yucatan Peninsula contained a large number of haplotypes, many of which were unique, suggesting an important region of chile domestication and center of diversity. The present sampling of loci did not conclusively resolve the number and location of domestications, but several lines of evidence suggest multiple independent domestications from widely distributed progenitor populations.

  1. [Trend analysis of acquired syphilis in Mexico from 2003 to 2013].

    Science.gov (United States)

    Herrera-Ortiz, Antonia; Uribe-Salas, Felipe J; Olamendi-Portugal, Ma Leonidez; García-Cisneros, Santa; Conde-Glez, Carlos Jesús; Sánchez-Alemán, Miguel A

    2015-01-01

    To identify the population group in which syphilis increase was concentrated. The information was collected from the Mexico health statistical yearbooks. The information disaggregated by sex, age group and state during the period 2003 to 2013 was used to form different databases. Linear regression analysis with confidence interval at 95% was used to evaluate changes over time in different population groups. An increase of 0.67 cases per 100,000 population (95%CI 0.30-1.04) in men was detected from 2010. The increase was concentrated in each group of 20-24 and 25-44. The highest incidence of acquired syphilis was reported in the last two years: 2012 and 2013. The last year reported a 1.85 times higher incidence than reported in 2003. Aguascalientes, Distrito Federal, Durango, Mexico, Oaxaca, Puebla, Quintana Roo, Yucatan and Zacatecas reported that syphilis increased during the study period. Acquired syphilis may be reemerging in our country among young men; this increase is not uniform across the country, it is necessary to focus intervention measures for this sexually transmitted infection.

  2. Cubic Satellites, Vanguard Technology Integration, an Educational Opportunity of Modernization in Mexico

    Science.gov (United States)

    Moreno-Franco, Olmo A.; Muñoz-Ubando, L. A.; Moreno-Moreno, Prudenciano; Vargas-Méndez, Eduardo E.

    This paper provides a theoretical approach on the CubeSat standard making a cost-benefit analysis in the use of pico-satellites at the education and technology integration model for educational modernization. With the CubeSat format is planned to develop an orbit LEO pico-satellite as part of a multidisciplinary project led by the Robotics Institute of Yucatan (TRIY), assisted with previous experience in Mexico and Colombia, to build a satellite capable of stabilizing through a robotic device, which will be a training model for human resources in Mexico. The CubeSat initiative represents a technological development of more than 10 years who is still alive and growing, attracting new participants from different educational institutions and global business, which has proven to be a project that would be made and successful results with a significant low budget compared to other space missions, and finally is an opportunity to bring students and teachers to the aerospace industry, through a convergence of technology, and academic discipline.

  3. New meaning from old collections- figurines from the Museo de Jonuta, Chapas Mexico

    International Nuclear Information System (INIS)

    Sears, Erin L.

    2001-01-01

    Old collections of archaeological ceramics, often with diverse histories can be a rich source of new information when they are linked with new excavation materials through instrumental neutron activation analysis or other comparable analytical technique. INAA has been applied to study of Maya ceramics from southern Mexico for more than forty years, specially in the modern states of Tabasco, Chapas, Campeche and Yucatan and the Guatemala region of El Peten, More than 1.100 analyzes of fine paste orange and gray pottery provides an extensive compositional background against which to view the chemical variation of a recently analyzed collection of Maya figurines from the Museo de Jonuta, Tabasco Mexico. These figurines constitute an important assemblage of archaeological pottery as they reveal stylistic patterns of continuity in artistic traditions and aspects of stylistics change at and immediately before the time of the so called a Maya Collapse. Since the town of Jonuta is located in hypothesized home of non Maya invaders who are thought to be factors in the Maya collapse. INAA data on the figurines sources of production and related patterns of representational style, provide new data to address the social changes that took place in the lowland Maya regions at the end of the 8 th Century

  4. Presence of Toxoplasma gondii in Drinking Water from an Endemic Region in Southern Mexico.

    Science.gov (United States)

    Hernandez-Cortazar, Ivonne B; Acosta-Viana, Karla Y; Guzman-Marin, Eugenia; Ortega-Pacheco, Antonio; Segura-Correa, Jose C; Jimenez-Coello, Matilde

    2017-05-01

    Toxoplasmosis can be acquired through the ingestion of contaminated drinking water with oocysts of Toxoplasma gondii, highly resistant to the routinely disinfection processes; based on chlorination commonly used in the water supply industry. The aim of this study was to determine the presence of T. gondii DNA in samples of public drinking water from an endemic region of southern Mexico. In total 74 samples of water (5 L each) were collected from the three well fields (I, II, and III) and 71 independent wells, distributing public drinking water to the city of Merida Yucatan, after passing through the chlorination process. Water samples were filtered and concentrated by a sucrose solution, then DNA was extracted and evaluated through a nested-PCR (nPCR) specific for T. gondii. Positive samples were detected in 5.4% (4/74) of the water samples. This is the first report of the presence of T. gondii DNA in public drinking water from a large city in southern Mexico, where their consumption without any postpurification treatment could pose a risk for acquiring the infection in the urban population.

  5. Lithium reserves and resources

    International Nuclear Information System (INIS)

    Evans, R.K.

    1978-01-01

    As a result of accelerating research efforts in the fields of secondary batteries and thermonuclear power generation, concern has been expressed in certain quarters regarding the availability, in sufficient quantities, of lithium. As part of a recent study by the National Research Council on behalf of the Energy Research and Development Administration, a subpanel was formed to consider the outlook for lithium. Principal areas of concern were reserves, resources and the 'surplus' available for energy applications after allowing for the growth in current lithium applications. Reserves and resources were categorized into four classes ranging from fully proved reserves to resources which are probably dependent upon the marketing of co-products to become economically attractive. Because of the proprietary nature of data on beneficiation and processing recoveries, the tonnages of available lithium are expressed in terms of plant feed. However, highly conservative assumptions have been made concerning mining recoveries and these go a considerable way to accounting for total losses. Western World reserves and resources of all classes are estimated at 10.6 million tonnes Li of which 3.5 million tonnes Li are located in the United States. Current United States capacity, virtually equivalent to Western World capacity, is 4700 tonnes Li and production in 1976 approximated to 3500 tonnes Li. Production for current applications is expected to grow to approx. 10,000 tonnes in year 2000 and 13,000 tonnes a decade later. The massive excess of reserves and resources over that necessary to support conventional requirements has limited the amount of justifiable exploration expenditures; on the last occasion, there was a a major increase in demand (by the USAEA) reserves and capacity were increased rapidly. There are no foreseeable reasons why this shouldn't happen again when the need is clear. (author)

  6. Brazilian uranium reserves

    International Nuclear Information System (INIS)

    Marques, J.P.M.

    1981-01-01

    Due to a growing demand of electric power to support Brasil's development, the use of nuclear energy will be indispensable. The nuclear fuel cycle for the production of energy, starts with the uranium exploration. The work performed in this field led to the discovery of several deposits in the country, which to-date totalize a reserve of 236,300t of U 308 , ranking Brazil in the 6th place among the nations of the western world holding uranium reserves. (Author) [pt

  7. Mammalian diversity in climatic domains for Tehuacán-Cuicatlán Biosphere Reserve, Mexico Diversidad de mamíferos en los dominios climáticos de la Reserva de la Biosfera Tehuacán-Cuicatlán, México

    Directory of Open Access Journals (Sweden)

    Oswaldo Téllez Valdés

    2010-12-01

    Full Text Available The Tehuacán-Cuicatlán biosphere reserve (BRTC is rich in mammalian diversity, but geographical distribution information is absent or insufficient for most species. Consequently, previous efforts to model the ecological niche and potential distribution of mammals have been hampered. The main purpose of this study was to examine the patterns of mammalian diversity in BRTC using a climatic domains classification. Biological datasets composed of geographically referenced localities commonly are raw input during analyses of geographical distributions of species, but in countries like Mexico datasets frequently are incomplete and biased. The recent availability of interpolators and geographic information systems make possible the enhancement of environmental datasets and open the possibility to use climatic parameters to explain biological patterns. In this study we generated a climatic domain classification for the Tehuacán-Cuicatlán valley and its surrounding areas of influence. With this approach, climatic domains were used as biodiversity surrogates, and we justified the overlapping of environmental data with the biological dataset (species, longitude, latitude, and elevation to evaluate and complement the available mammal diversity information within BRTC.La reserva de la biosfera Tehuacán-Cuicatlán (BRTC posee gran diversidad de mamíferos, pero la información sobre distribución geográfica es incompleta para la mayoría de las especies. Esto ha representado una dificultad en esfuerzos previos para modelar el nicho ecológico y la distribución potencial de mamíferos en la BRTC. Nuestro objetivo fue comparar los patrones de diversidad de mamíferos en la BRTC usando una clasificación de dominios climáticos. Las bases de datos biológicas compuestas de localidades georeferenciadas generalmente son usadas como datos crudos en análisis de distribución geográfica de especies, pero en países como México frecuentemente est

  8. Comparison of small mammal prevalence of Leishmania (Leishmania) mexicana in five foci of cutaneous leishmaniasis in the State of Campeche, Mexico.

    Science.gov (United States)

    Van Wynsberghe, N R; Canto-Lara, S B; Sosa-Bibiano, E I; Rivero-Cárdenas, N A; Andrade-Narváez, F J

    2009-01-01

    In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.

  9. 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.

  10. Session 7: Reserve

    International Nuclear Information System (INIS)

    Bailey, R.; Crockford, G.

    2001-01-01

    The reserve session was devoted to some issues that came up through the workshop, which were grouped into three main areas: The Global Accelerator Network, Problems of stress and how to get organized to minimize them, What should an operations group be responsible for? This paper summarizes the discussions that took place. (author)

  11. SUIKERBOSRAND NATURE RESERVE

    African Journals Online (AJOL)

    reserve, the total length being 66 km with six overnight huts. There are also the BokmakiePie. Nature Troil. and the Cheetah Interpretive Troil. which can be used by day visitors. The former has two loops, one of 10 km and another of 17 km. The. Cheetah Troil. is much shorter and various points of interest are interpreted en ...

  12. School Shootings Stun Reservation

    Science.gov (United States)

    Borja, Rhea R.; Cavanagh, Sean

    2005-01-01

    This article deals with the impact brought by the school shootings at Red Lake Indian Reservation in Minnesota to the school community. A deeply troubled 16-year-old student shot and killed seven other people and himself at a high school. The nation's deadliest school attack since the 1999 slayings at Colorado's suburban Columbine High School took…

  13. Uranium reserves fall: AAEC

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Figures released by the AAEC show that Australia's reasonably assured resources of uranium recoverable at US$80 a kg fell by 5,000 tonnes during 1980-81. Reserves at 30 June 1981 totalled 294,000 tonnes. This represented 17 per cent of the Western World's low cost reasonably assured resources

  14. Carious lesions and maize consumption among the Prehispanic Maya: an analysis of a coastal community in northern Yucatan.

    Science.gov (United States)

    Cucina, Andrea; Cantillo, Cristina Perera; Sosa, Thelma Sierra; Tiesler, Vera

    2011-08-01

    Patterns of carious lesions were analyzed in the Classic period coastal Maya population of Xcambó, a salt production and administration center in northern Yucatan. To this end, the study investigated caries in the permanent dentitions of 163 adult skeletons, 23 from the Early Classic (AD 250-550) and 140 from the Late Classic period (AD 550-750), equally distributed between sexes. The archaeological and bioarchaeological evidence indicates a wealthy and socially homogeneous population dedicated to salt production and administration in the Early Classic that switched to pure administrative functions in the Late Classic. The results indicate an increase in caries from 7.4% and 21.2% (males and females respectively) from the Early Classic to 14.0% in males and 27.4% in females from the Late Classic period. The rate of caries in the Early and in the Late Classic phases of continuous occupation is not consistent with a simple interpretation of a heavier reliance on maize during the latter phase, characterized by a sedentary lifestyle, particularly for the male segment of the society now dedicated completely to the administration of the salt mines. Rather, the increase in caries rates in both sexes is best explained within a broader context of overall food habits, new cariogenic foods for both sexes, and the changes in lifestyle imposed by the increased socioeconomic role of the site. Our conclusions stress the limitations imposed by interpreting carious lesions solely in terms of single dietary components, such as maize consumption, without taking into account broader aspects of cultural and socioeconomic relevance. Copyright © 2011 Wiley-Liss, Inc.

  15. 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)

  16. 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.

  17. 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...

  18. 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...

  19. 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....

  20. 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...

  1. 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 ...

  2. 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.

  3. 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.

  4. Fractional Reserve Banking

    OpenAIRE

    Andreasen, Niels; Bjerregaard, Mads; Lund, Jonas; Olsen, Ove Bitsch; Rasmussen, Andreas Dalgas

    2012-01-01

    Projektet er bygget op omkring kritisk realisme, som er det gennemgående videnskabelige fundament til undersøgelsen af hvilke strukturelle grunde der er til finansiel ustabilitet i Danmark. Projektet går i dybden med Fractional Reserve Banking og incitamentsstrukturen i banksystemet. Vi bevæger os både på det makro- og mikroøkonomiske niveau i analysen. På makro niveau bruger vi den østrigske skole om konjunktur teori (The Positive Theory of the Cycle). På mikro niveau arbejder vi med princip...

  5. [Prevalence of high blood pressure and their association with body mass index in children between 5 and 11 years of Nahbalam, Yucatan].

    Science.gov (United States)

    Saury-Paredes, Leonel Alejandro

    To determine the prevalence of high blood pressure in children aged between 5-11 years in the community of Nahbalam, Yucatan, and its association with the body mass index. A transversal study with children of the primary school "Lazaro Cardenas del Rio" was performed, measuring blood pressure, height, and weight of 259 girls and boys; systolic and/or diastolic blood pressure equal or greater than percentile 95 for gender, age, and height at three measures was considered as hypertension; prehypertension was considered as blood pressure equal or greater than percentile 90 but lower than percentile 95. A prevalence of 11.9% prehypertension and 6.1% hypertension was found. There is an association between hypertension and overweight and obesity (p ≤ 0.001). The prevalence of high blood pressure in children of the community of Nahbalam, Yucatan, is 18%. The children with overweight and obesity have an almost tenfold greater risk of hypertension than the eutrophic children (OR: 9.896; 95% CI: 2.738-35.764).

  6. Geophysical Data Define Boundaries and Sub-Regions of the Northern Gulf of Mexico Basin: Structural Histories and Causes are Hypothesized.

    Science.gov (United States)

    Kinsland, G. L.

    2017-12-01

    Within the last several years new types of geophysical data of the southern margin of the North American Craton and the Northern Gulf of Mexico Basin (NGoMB) have become available, e.g., results from the USArray experiment, high resolution satellite gravity data of the GoM itself and new heat flow data. These data when combined with previously existing geophysical data (gravity, magnetic and seismic) and shallow structural data offer new insights into the boundaries and sub-regions of the NGoMB. I offer hypotheses for the development of the structures of the buried crust and upper mantle which cause these features. Of particular interest might be my suggestion that the NGoMB might have extended in a southeasterly direction prior to the counter-clockwise rotation of the Yucatan Peninsula which ultimately resulted in the GoM.

  7. Emerging deforestation trends in tropical dry forests ecoregions of Mexico and Central America

    Science.gov (United States)

    Portillo, C. A.; Cao, G.; Smith, V.

    2015-12-01

    Neotropical dry forests (TDF) have experienced an unprecedented deforestation that is leading to the loss of tropical biodiversity at a rapid pace, but information on deforestation dynamics in TDF is scarce. In this study, we present a sub-continental and national level assessment of TDF loss patterns in Mexico and Central America at high spatial and temporal resolution using remote sensing and GIS technologies. We used the Global Forest Change (GFC) dataset published by Hansen et al. (2013) which shows results from time-series analysis of Landsat images in characterizing global forest extent and change from 2000 through 2013. We analyzed forest loss within and around mapped TDF cover mapped by Portillo-Quintero et al. 2010. In order to minimize errors in source data, we overlaid a 25 x 25 km grid on top of the regional dataset and conducted a cell by cell and country by country inspection at multiple scales using high resolution ancillary data. We identified trends in the clustering of space-time TDF deforestation data using ArcGIS, categorizing trends in: new, consecutive, intensifying, persistent, diminishing, sporadic, oscillating and historical hotspots (high frequency of deforestation events) and cold spots (low frequency of deforestation). In general, the region is experiencing less frequent deforestation events with a higher number of intensifying and new cold spots across TDF landscapes. However, an important number of intensifying and persistent hotspots exist so no general trend in forest loss was detected for the period 2001-2013, except for El Salvador which shows a significant decreasing trend in forest loss. Mexico, Nicaragua, Honduras and Guatemala are the major sources of intensifying, persistent and new deforestation hot spots. These were identified in the southern pacific coast and the Yucatan Peninsula in Mexico, northwestern Guatemala, both western and eastern Honduras and around Lake Nicaragua in Nicaragua.

  8. The impact of biogenic carbon emissions on aerosol absorption inMexico City

    Energy Technology Data Exchange (ETDEWEB)

    Marley, N; Gaffney, J; Tackett, M J; Sturchio, N; Hearty, L; Martinez, N; Hardy, K D; Machany-Rivera, A; Guilderson, T P; MacMillan, A; Steelman, K

    2009-02-24

    In order to determine the wavelength dependence of atmospheric aerosol absorption in the Mexico City area, the absorption angstrom exponents (AAEs) were calculated from aerosol absorption measurements at seven wavelengths obtained with a seven-channel aethalometer during two field campaigns, the Mexico City Metropolitan Area study in April 2003 (MCMA 2003) and the Megacity Initiative: Local and Global Research Observations in March 2006 (MILAGRO). The AAEs varied from 0.76 to 1.56 in 2003 and from 0.54 to 1.52 in 2006. The AAE values determined in the afternoon were consistently higher than the corresponding morning values, suggesting the photochemical formation of absorbing secondary organic aerosols (SOA) in the afternoon. The AAE values were compared to stable and radiocarbon isotopic measurements of aerosol samples collected at the same time to determine the sources of the aerosol carbon. The fraction of modern carbon (fM) in the aerosol samples, as determined from {sup 14}C analysis, showed that 70% of the carbonaceous aerosols in Mexico City were from modern sources, indicating a significant impact from biomass burning during both field campaigns. The {sup 13}C/{sup 12}C ratios of the aerosol samples illustrate the significant impact of Yucatan forest fires (C-3 plants) in 2003 and local grass fires (C-4 plants) at site T1 in 2006. A direct comparison of the fM values, stable carbon isotope ratios, and calculated aerosol AAEs suggested that the wavelength dependence of the aerosol absorption was controlled by the biogenically derived aerosol components.

  9. Petroleum exploration and development opportunities in Mexico

    International Nuclear Information System (INIS)

    Jensen, R.; Daschle, R.

    2002-01-01

    This paper presents a historical overview of the energy sector in Mexico, an important player in the world energy market, whose trade and market policies support economic development and foreign investment. Trade, commerce and investment between Canada and Mexico has been increasing steadily ever since the North American Free Trade Agreement (NAFTA) came into effect in January 1994. TransAlta Corporation and Westcoast Energy Inc. are two very active investors in the energy sector. Westcoast has invested in increasing natural gas and oil production from the Cantarell field in the Gulf of Mexico through the Campeche Natural Gas Compression Service Project and the Cantarell Nitrogen Plant. TransAlta has invested in two natural gas fired power plants which are both expected to be in service for the second quarter of 2003. These include the 252 MW Campeche facility and the 259 MW Chihuahua facility. Mexico has proven crude oil reserves of 27 billion barrels, proven natural gas reserves of 30 tcf, and in 2000 had a crude oil production of 3.4 mmbl/d, of which half was exported. The energy sector in Mexico may need about $120 billion of investment by 2010, of which half will be used for crude oil exploration and production, transportation and refining and the other half for natural gas exploration and production, transportation and distribution and power generation. Recently, the Mexican government embarked on two initiatives. The first to increase the productivity and profitability of PEMEX, the largest corporation in Mexico and one of the largest in the world, and to allow a form of private investment in the development of non-associated natural gas fields. This paper discussed the significance of the Multiple Service Contracts (MSC) program which involves domestic and international petroleum exploration and development. It also discussed forms of business organizations, taxation and structuring, financial issues, employment and the North American Free Trade Agreement

  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. Are uranium reserves adequate?

    International Nuclear Information System (INIS)

    Anon.

    2006-01-01

    Against a backdrop of growing concerns about global warming and geopolitical pressures on fossil energies, especially natural gas and oil, interest in nuclear power has revived considerably. Conscious of its addiction to oil and reeling from a series of gigantic blackouts, the United States, in the words of its president, must 'aggressively move forward with the construction of nuclear power plants'. Some European countries have approved new power plant construction (Finland and France), while the more reserved ones (Belgium, Germany and Sweden) have begun to show a change in attitude. Asia, meanwhile, is host to the planet's largest number of potential nuclear construction projects in this first half of the 21. century. All these signs point to a sharp rise in uranium consumption, the basic fuel for these plants. But are there enough resources to support a nuclear revival on a planetary scale? The publication of the Red Book on uranium in late May 2006 was an opportunity for Thierry Dujardin, Deputy Director of Science and Development at the OECD's Nuclear Energy Agency, to take stock of resources. He gives his opinion in this paper

  14. Diffuse Lepromatous Leprosy Due to Mycobacterium lepromatosis in Quintana Roo, Mexico.

    Science.gov (United States)

    Han, Xiang Y; Quintanilla, Marco

    2015-11-01

    A 43-year-old woman of Mayan origin from Quintana Roo, Mexico, was diagnosed with diffuse lepromatous leprosy. The etiologic bacillus was determined to be Mycobacterium lepromatosis instead of Mycobacterium leprae. This case likely represents the first report of this leprosy form and its agent in the southeastern tip of Mexico. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Genetic Resources in the “Calabaza Pipiana” Squash (Cucurbita argyrosperma) in Mexico: Genetic Diversity, Genetic Differentiation and Distribution Models

    Science.gov (United States)

    Sánchez-de la Vega, Guillermo; Castellanos-Morales, Gabriela; Gámez, Niza; Hernández-Rosales, Helena S.; Vázquez-Lobo, Alejandra; Aguirre-Planter, Erika; Jaramillo-Correa, Juan P.; Montes-Hernández, Salvador; Lira-Saade, Rafael; Eguiarte, Luis E.

    2018-01-01

    Analyses of genetic variation allow understanding the origin, diversification and genetic resources of cultivated plants. Domesticated taxa and their wild relatives are ideal systems for studying genetic processes of plant domestication and their joint is important to evaluate the distribution of their genetic resources. Such is the case of the domesticated subspecies C. argyrosperma ssp. argyrosperma, known in Mexico as calabaza pipiana, and its wild relative C. argyrosperma ssp. sororia. The main aim of this study was to use molecular data (microsatellites) to assess the levels of genetic variation and genetic differentiation within and among populations of domesticated argyrosperma across its distribution in Mexico in comparison to its wild relative, sororia, and to identify environmental suitability in previously proposed centers of domestication. We analyzed nine unlinked nuclear microsatellite loci to assess levels of diversity and distribution of genetic variation within and among populations in 440 individuals from 19 populations of cultivated landraces of argyrosperma and from six wild populations of sororia, in order to conduct a first systematic analysis of their genetic resources. We also used species distribution models (SDMs) for sororia to identify changes in this wild subspecies’ distribution from the Holocene (∼6,000 years ago) to the present, and to assess the presence of suitable environmental conditions in previously proposed domestication sites. Genetic variation was similar among subspecies (HE = 0.428 in sororia, and HE = 0.410 in argyrosperma). Nine argyrosperma populations showed significant levels of inbreeding. Both subspecies are well differentiated, and genetic differentiation (FST) among populations within each subspecies ranged from 0.152 to 0.652. Within argyrosperma we found three genetic groups (Northern Mexico, Yucatan Peninsula, including Michoacan and Veracruz, and Pacific coast plus Durango). We detected low levels of gene

  16. Genetic Resources in the “Calabaza Pipiana” Squash (Cucurbita argyrosperma in Mexico: Genetic Diversity, Genetic Differentiation and Distribution Models

    Directory of Open Access Journals (Sweden)

    Guillermo Sánchez-de la Vega

    2018-03-01

    Full Text Available Analyses of genetic variation allow understanding the origin, diversification and genetic resources of cultivated plants. Domesticated taxa and their wild relatives are ideal systems for studying genetic processes of plant domestication and their joint is important to evaluate the distribution of their genetic resources. Such is the case of the domesticated subspecies C. argyrosperma ssp. argyrosperma, known in Mexico as calabaza pipiana, and its wild relative C. argyrosperma ssp. sororia. The main aim of this study was to use molecular data (microsatellites to assess the levels of genetic variation and genetic differentiation within and among populations of domesticated argyrosperma across its distribution in Mexico in comparison to its wild relative, sororia, and to identify environmental suitability in previously proposed centers of domestication. We analyzed nine unlinked nuclear microsatellite loci to assess levels of diversity and distribution of genetic variation within and among populations in 440 individuals from 19 populations of cultivated landraces of argyrosperma and from six wild populations of sororia, in order to conduct a first systematic analysis of their genetic resources. We also used species distribution models (SDMs for sororia to identify changes in this wild subspecies’ distribution from the Holocene (∼6,000 years ago to the present, and to assess the presence of suitable environmental conditions in previously proposed domestication sites. Genetic variation was similar among subspecies (HE = 0.428 in sororia, and HE = 0.410 in argyrosperma. Nine argyrosperma populations showed significant levels of inbreeding. Both subspecies are well differentiated, and genetic differentiation (FST among populations within each subspecies ranged from 0.152 to 0.652. Within argyrosperma we found three genetic groups (Northern Mexico, Yucatan Peninsula, including Michoacan and Veracruz, and Pacific coast plus Durango. We detected low

  17. Renewable energy research progress in Mexico: A review

    OpenAIRE

    ALEMÁN-NAVA Gibrán S. Alemán-Nava; CASIANO-FLORES Victor H.; CARDENAS-CHAVEZ Diana L.; DÍAZ-CHAVEZ Rocío; SCARLAT NICOLAE; MAHLKNECHT Jürgen; DALLEMAND Jean-Francois; PARRA Roberto

    2013-01-01

    Mexico ranks 9th in the world in crude oil reserves, 4th in natural gas reserves in America and it is also highly rich in renewable energy sources (solar, wind, biomasss, hydropower and geothermal). However, the potential of this type of energy has not been fully exploited. Hydropower is the renewable energy source with the highest installed capacity within the country (11,603 MW), while geothermal power capacity (958 MW) makes Mexico to be ranked 4th in the use of this energy worldwide. Wind...

  18. 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.

  19. 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)

  20. Horizontal movements, migration patterns, and population structure of whale sharks in the Gulf of Mexico and northwestern Caribbean sea.

    Science.gov (United States)

    Hueter, Robert E; Tyminski, John P; de la Parra, Rafael

    2013-01-01

    Whale sharks, Rhincodon typus, aggregate by the hundreds in a summer feeding area off the northeastern Yucatan Peninsula, Mexico, where the Gulf of Mexico meets the Caribbean Sea. The aggregation remains in the nutrient-rich waters off Isla Holbox, Isla Contoy and Isla Mujeres, Quintana Roo for several months in the summer and then dissipates between August and October. Little has been known about where these sharks come from or migrate to after they disperse. From 2003-2012, we used conventional visual tags, photo-identification, and satellite tags to characterize the basic population structure and large-scale horizontal movements of whale sharks that come to this feeding area off Mexico. The aggregation comprised sharks ranging 2.5-10.0 m in total length and included juveniles, subadults, and adults of both sexes, with a male-biased sex ratio (72%). Individual sharks remained in the area for an estimated mean duration of 24-33 days with maximum residency up to about 6 months as determined by photo-identification. After leaving the feeding area the sharks showed horizontal movements in multiple directions throughout the Gulf of Mexico basin, the northwestern Caribbean Sea, and the Straits of Florida. Returns of individual sharks to the Quintana Roo feeding area in subsequent years were common, with some animals returning for six consecutive years. One female shark with an estimated total length of 7.5 m moved at least 7,213 km in 150 days, traveling through the northern Caribbean Sea and across the equator to the South Atlantic Ocean where her satellite tag popped up near the Mid-Atlantic Ridge. We hypothesize this journey to the open waters of the Mid-Atlantic was for reproductive purposes but alternative explanations are considered. The broad movements of whale sharks across multiple political boundaries corroborates genetics data supporting gene flow between geographically distinct areas and underscores the need for management and conservation strategies for

  1. A New Species of Ligophorus (Monogenea: Dactylogyridae) from the gills of the Flathead Mullet Mugil cephalus (Teleostei: Mugilidae) from Mexico.

    Science.gov (United States)

    Rodríguez-González, Abril; Míguez-Lozano, Raúl; Llopis-Belenguer, Cristina; Balbuena, Juan Antonio

    2015-12-01

    A new monogenean species, Ligophorus yucatanensis n. sp. from the gills of the flathead mullet Mugil cephalus from the Yucatan Peninsula, Mexico, is described. The new species can be differentiated from all other species of Ligophorus by the morphology of the accessory piece of the copulatory organ. Its main lobe is cylindrical, tunnelled expanded distally, slightly bowed with a characteristic membranous opening at level of medial bifurcation of the accessory piece, forming a thick-walled bulbshaped expansion that ends in a round labium. The secondary lobe is spatulate, straight, and shorter than the main lobe. In addition, the new species can be distinguished from other species by the morphology of the haptoral ventral bar, and the distal end of the vaginal duct. Furthermore the ventral anchors are shorter than those of all other species of Ligophorus reported in the Gulf of Mexico and Caribbean Sea. In addition, the zoogeographical records of Ligophorus spp. on the M. cephalus species complex are briefly reviewed and updated.

  2. 77 FR 21846 - Reserve Requirements of Depository Institutions: Reserves Simplification

    Science.gov (United States)

    2012-04-12

    ... Requirements of Depository Institutions: Reserves Simplification AGENCY: Board of Governors of the Federal Reserve System. ACTION: Final rule. SUMMARY: The Board is amending Regulation D, Reserve Requirements of Depository Institutions, to simplify the administration of reserve requirements. The final rule creates a...

  3. 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.

  4. 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…

  5. [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.

  6. 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…

  7. Apicultura y organizaciones de apicultores entre los mayas de Yucatán Beekeeping and Apicultural Organizations Among the Mayas of Yucatan

    Directory of Open Access Journals (Sweden)

    Margarita Rosales González

    2010-01-01

    Full Text Available En las comunidades mayas la apicultura continúa siendo una actividad relevante pero complementaria, cuya lógica y condiciones de producción se contraponen a las nuevas normas del mercado internacional. La integración de organizaciones apícolas se considera una estrategia para la "modernización" de la apicultura y la comercialización de la miel en mejores condiciones. Este trabajo se refiere al sentido que tanto la apicultura como estas organizaciones tienen para sus integrantes, a sus expectativas, intereses, aprendizajes y a la forma en que se relacionan con instituciones y agentes externos. El escrito se basa en entrevistas y observaciones realizadas en 12 organizaciones apícolas durante 2005 y 2006 en el marco del proyecto de investigación del centro INAH Yucatán "Organizaciones indígenas y procesos de desarrollo en comunidades mayas del sur de Yucatán".In Mayan communities, beekeeping continues to be an important but complementary activity, whose logic and conditions of production are opposed to the new norms of the international market. The integration of apicultural organizations is considered as a strategy for the "modernization" of beekeeping and the commercialization of the honey in better quality. The present research deals with the meaning that beekeeping has for the members of such organizations, and it explores the expectations, interests and training processes of the members, analyzing finally how are the relationships between these organizations and external agents and institutions. The research is based on interviews and observations made in 12 apicultural organizations between 2005 and 2006, as part of the research project of the INAH Regional Center Yucatan, entitled "Indigenous Organizations and Processes of Development in Mayan Communities in Southern Yucatan".

  8. Mexico's energy dilemmas in an interdependent world

    International Nuclear Information System (INIS)

    Bauer, M.

    2008-01-01

    Mexico's energy system is overwhelmingly dependent on hydrocarbons. Although a significant producer of oil and gas, and a considerable exporter of crude oil, it is increasingly dependent on imports of oil products and natural gas for its internal energy demand. In a World where free trade is increasing the interdependence of the industrialized economies, Mexico's energy policy dilemma is basically between maintaining as much as possible its self sufficiency; or relying on imports, while generating oil revenues through exports to invest in developing a diversified economy. Energy demand projections to 2030 are carried out that exhibit the limitations of present available oil and gas proved reserves under past policies. Alternative energy policy scenarios are then examined. (authors)

  9. Migrant songbirds, habitat change, and conservation prospects in northern Peten, Guatemala: some initial results

    Science.gov (United States)

    David F. Whitacre; Julio Madrid M.; Ciriaco Marroquín; Mark Schulze; Laurin Jones; Jason Sutter; Aaron J. Baker

    1993-01-01

    A recently-created complex of reserves spanning the Guatemala, Mexico, Belize borders in the southern Yucatan Peninsula constitutes 5.5 million acres of contiguous, protected lowland forest. Information is needed on compatibility of various land-uses and biodiversity protection in multiple-use zones of these reserves. To address these and other needs related to...

  10. New Mexico Math Pathways Taskforce Report

    Science.gov (United States)

    New Mexico Higher Education Department, 2016

    2016-01-01

    In April 2015 New Mexico faculty, Dana Center staff, and New Mexico Higher Education (NMHED) co-presented the need for better math pathways statewide. Faculty from 6 institutions (New Mexico State University, New Mexico Highlands University, Dine College, Eastern New Mexico University, El Paso Community College, and San Juan College) participated…

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

    Directory of Open Access Journals (Sweden)

    Daniel Arceo-Carranza

    2015-09-01

    Full Text Available 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 analysis we determined the trophic differences among Caranx latus, Oligoplites saurus, Trachinotus falcatus, Synodus foetens, Lutjanus griseus, and Strongylura notata. C. latus, O. saurus, S. foetens, and S. notate, which are ichthyophagous species (>80% by number. L. griseus feeds mainly on crustaceans (>55% and fish (35%, while T. falcatus feeds on mollusks (>50% bivalves, >35% gastropods. The analysis of similarities (ANOSIM showed differences in the diet of all species. Cluster analysis, based on the Bray-Curtis similarity matrix revealed three groups; one characterized by the ichthyophagous guild (S. notata, S. foetens, C. latus, and O. saurus, other group formed by the crustacean consumers (L. griseus, and the third, composed by the mollusk feeder (T. falcatus. Species of the ichthyophagous guild showed overlap in their diets, which under conditions of low prey abundance may trigger competition, hence affecting juvenile stages of these marine species that use coastal lagoons to feed and grow.

  12. Evolution and hydrocarbon potential of offshore Pinar Del Rio area, Southern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tenreyro-Perez, R.; Lopez-Rivera, J.G.; Fernandez-Carmona, J.; Lopez-Quintero, J.O.

    1996-09-01

    The evolution of Southeast Gulf of Mexico comprises three main periods: pre-orogenic, syn-orogenic and post-orogenic. During pre-orogenic time, from Lower Jurassic to Campanian, the stages are the rift of Pangaea and the thermal subsidence (or drift). In drift stage two domains interacted in the space; the carbonate platforms (Bahamas, Yucatan, Organos and others), and the deepwater basins. These fluctuations were dictated by the differential subsidence and horizontal displacements of basement blocks as well as by the eustatic movements of the ocean. The Organos platform, for example, was entirely drowned since Upper Jurassic and the sedimentation continued in deepwater environment. The collision between Great Antilles Volcanic Arc and the continental margins since Upper Cretaceous modeled the Cuban orogen. Here, the southern facies thrusted over the northern section with simultaneous strike-slip movements. The interaction suddenly ceased in Eocene. The source rock levels are considerably more frequent in the deepwater domain than in the platforms. The Lower and Upper Jurassic as well as Lower and Middle Cretaceous horizons contain very high levels of organic matter. The offshore seismic shows the transition from the thrusted belt to the foreland basin with a typical triangle zone configuration. Reservoirs are expected in the Cretaceous section covered by seals conformed by early foreland basin sediments of Upper Cretaceous-Paleocene age. Foothill structures has a great potential for hydrocarbon exploration.

  13. Parasitic Zoonoses in Humans and Their Dogs from a Rural Community of Tropical Mexico

    Directory of Open Access Journals (Sweden)

    Antonio Ortega-Pacheco

    2015-01-01

    Full Text Available A cross-sectional study was made on 89 inhabitants and their dogs from a rural community of Yucatan, Mexico, to determine the serological prevalence of some zoonotic parasitic agents. Samples were taken to monitor the presence and intensity of infection with gastrointestinal parasites in dogs. In humans, the serological prevalence of T. canis, T. gondii, and T. spiralis was 29.2%, 91.0%, and 6.7%, respectively. No associations were found between positive cases and studied variables. From the total of blood samples taken from dogs, 87 (97.6% were seropositive to T. gondii; only 52 viable fecal samples were collected from dogs of which 46.2% had the presence of gastrointestinal parasites with low to moderate intensity; from those, 12% had the presence of T. canis. This study demonstrates the presence of the studied zoonotic agents in the area particularly T. gondii which suggest a common source of infection in dogs and humans and a high number of oocyts present in the environment. Preventive measures must be designed towards good prophylactic practices in domestic and backyard animals (T. canis and T. spiralis. Contaminated sources with T. gondii (food and water should be further investigated in order to design effective control measures.

  14. Microstructural study of pre hispanic and colonial pigments of diverse sites of Mexico

    International Nuclear Information System (INIS)

    Arenas A, J.; Espinosa P, M.; Fernandez, M.E.; Mondragon G, G.; Perez H, R.; Mendoza A, D.; Rodriguez L, V.; Martinez, G.

    2004-01-01

    The aim of this work is to show some studies about the pre hispanic paintings, blue paint, green and red colors found in several archaeological sites located in the southeast and center of Mexico, also were analyzed clays samples from Sacalum mine localized in Yucatan state. The samples were analyzed by X Ray Diffraction (XRD), Scanning Electron Microscopy (Sem) and Transmission Electron Microscopy both equipped with a microprobe for chemical elemental analysis by Energy Dispersive Spectroscopy (EDS). The results obtained by Sem showed that all the pre hispanic paintings are made of fiber-like structures of micrometers order. In other zones of the samples were identified irregular morphologies in which the fibers are supported. The EDS analysis identified the elements C, O, Na, Mg, Al, Si, Ca and Fe. The XRD and High Resolution Transmission Electron Microscopy (HREM) results showed fiber crystalline structures at nanoscopic level corresponding to paligorskite clay. Other particles were identified as calcite phase. In the red pigments were identified paligorskite fibers in some of them and another sample was identified cinnabar phase. In these last sample no was identify the paligorskite. (Author) 14 refs., 13 figs

  15. Biology of Crassicutis cichlasomae, a parasite of cichlid fishes in Mexico and Central America.

    Science.gov (United States)

    Scholz, T; Pech-Ek, M C; Rodriguez-Canul, R

    1995-03-01

    Field study on the biology of Crassicutis cichlasomae Manter, 1936 (Digenea: Homalometridae) was carried out in a small swamp in a limestone factory near Mérida, Yucatán, Mexico. Aquatic snails, Littorina (Littoridinopis) angulifera, harbouring C. cichlasomae rediae, cercariae and metacercariae, served both as the first and second intermediate hosts. Feeding experiments confirmed the conspecificity of metacercariae from naturally infected snails with adults from naturally infected fish. Gravid C. cichlasomae worms were obtained from experimentally infected fish 19 days post exposure at 22-24 degrees C. Examination of fish from the swamp in Mitza and other localities in the Yucatan Peninsula showed that the cichlids Cichlasoma urophthalmus and C. meeki were definitive hosts of C. cichlasomae. There was no pronounced preference of C. cichlasomae adults for the site of their location in the intestine of the definitive host; a slightly higher proportion (41%) of worms was only found in the anterior third of the gut. The time of miracidium development varied from 18.5 to 27.5 days; different temperature (20.1-35.7 degrees C) or light/darkness regimes influenced only slightly the rate of embryonic development, with shorter development times at higher temperature (34.8-35.7 degrees C) and constant darkness and/or light. With the exception of the sporocyst, all developmental stages are described and figured.

  16. Characterization of agroecosystems with sheep production in the eastern side of Yucatán, Mexico.

    Directory of Open Access Journals (Sweden)

    Bernardino Candelaria-Martínez

    2015-06-01

    Full Text Available The aim of this study was to characterize and group agroecosystems with sheep production in the eastearn side of Yucatan, Mexico. This study was held from August 2012 to April 2013. A semi-structured questionnaire was applied while interviewing 93% of producers from seven municipalities that have sheep within their agroecosystems. Random sampling, cluster analysis, ANOVA using GLM and comparison of means by Tukey (P>0.05 were performed. Four different groups of agroecosystems with sheep production were obtained: GA (elderly people in charge, middle schooling, and high amount of land, large herds or more years practicing sheep farming, GB middle age people in charge, higher schooling, intermediate amount of land, and intermediate herd size, GC (elderly people in charge, less schooling, low amount of land and reduced herd size, and GD (younger people in charge, high schooling, low amount of land, small herd size and less time performing the activity. Sheep farming was the first, second, and third productive option for 12%, 75% and 11,8% of producers. In some cases, sheep production in the region has been practiced for over 15 years; however it is the economic priority only of a small group of producers. Access to resources determined their level of development and lack of organization among sheep producers is evident.

  17. Jatropha in Mexico: Environmental and Social Impacts of an Incipient Biofuel Program

    Directory of Open Access Journals (Sweden)

    Margaret Skutsch

    2011-12-01

    Full Text Available Three case studies from Mexico are presented in which the impacts of the recent introduction of jatropha cultivation for biodiesel production are examined. In Chiapas and Michoacan, local social and environmental impacts were assessed using interviews with key informants and questionnaires directed at three groups of stakeholders: jatropha cultivators, farmers in the same areas who are not cultivating jatropha, and laborers on jatropha farms. Results show that the farmers are primarily motivated to participate by the subsidies offered in a government program in the first 2 years, rather than any proven economic benefit. Our farm budget study indicated that profits would be marginal for these farmers. However, no cases of land alienation were involved, and impacts on food security and deforestation are currently not significant. Employment opportunities for landless laborers have increased in areas where jatropha is now grown. The program is only in its third year currently, so these outcomes would need to be reexamined as it develops. In Yucatan, production is mainly in the hands of commercial companies, using estates formerly under low-intensity grazing and secondary forest. A carbon balance analysis indicated that there may be a significant loss of carbon stocks associated with jatropha plantation establishment on these estates. Depending on the maturity of the forest regrowth and the intensity of jatropha production, the carbon payback period varies from 2 to 14 years, although, in some scenarios, the carbon debt may never be recovered.

  18. Status of fossil fuel reserves

    International Nuclear Information System (INIS)

    Laherrere, J.

    2005-01-01

    Reserves represent the sum of past and future productions up to the end of production. In most countries the reserve data of fields are confidential. Therefore, fossil fuel reserves are badly known because the published data are more political than technical and many countries make a confusion between resources and reserves. The cumulated production of fossil fuels represents only between a third and a fifth of the ultimate reserves. The production peak will take place between 2020 and 2050. In the ultimate reserves, which extrapolate the past, the fossil fuels represent three thirds of the overall energy. This document analyses the uncertainties linked with fossil fuel reserves: reliability of published data, modeling of future production, comparison with other energy sources, energy consumption forecasts, reserves/production ratio, exploitation of non-conventional hydrocarbons (tar sands, extra-heavy oils, bituminous shales, coal gas, gas shales, methane in overpressure aquifers, methane hydrates), technology impacts, prices impact, and reserves growth. (J.S.)

  19. 77 FR 66361 - Reserve Requirements of Depository Institutions: Reserves Simplification

    Science.gov (United States)

    2012-11-05

    ... Requirements of Depository Institutions: Reserves Simplification AGENCY: Board of Governors of the Federal... (Reserve Requirements of Depository Institutions) published in the Federal Register on April 12, 2012. The... simplifications related to the administration of reserve requirements: 1. Create a common two-week maintenance...

  20. Are Private Reserves Effective for Jaguar Conservation?

    Directory of Open Access Journals (Sweden)

    Carmina E Gutiérrez-González

    Full Text Available We present the first study of density and apparent survival for a jaguar (Panthera onca population in northern Mexico using 13 years of camera trap data from 2000 to 2012. We used the Barker robust design model which combines data from closed sampling periods and resight data between these periods to estimate apparent survival and abundance. We identified 467 jaguar pictures that corresponded to 48 jaguar individuals. We included camera type and field technician as covariates for detection probabilities. We used three covariates to evaluate the effect of reserve on jaguar apparent survival: i private reserve creation ii later reserve expansions, and iii cattle ranches' conservation activities. We found that the use of digital cameras in addition to film cameras increased detection probability by a factor of 6x compared with the use of only film cameras (p = 0.34 ± 0.05 and p = 0.05 ± 0.02 respectively in the closed period and more than three times in the open period (R = 0.91 ± 0.08 and R = 0.30 ± 0.13 mixed and film cameras respectively. Our availability estimates showed no temporary emigration and a fidelity probability of 1. Despite an increase of apparent survival probability from 0.47 ± 0.15 to 0.56 ± 0.11 after 2007, no single covariate explained the change in these point estimates. Mean jaguar density was 1.87 ± 0.47 jaguars/100 km2. We found that 13 years of jaguar population monitoring with our sampling size were not enough for detecting changes in survival or density. Our results provide a baseline for studies evaluating the effectiveness of protected areas and the inclusion of ranch owners in jaguar conservation programs and long-term population viability.

  1. Henequén'ın Dönüşü, Bir Yeşil Lif İle Yucatan'da Karmaşık Bir Tarih

    OpenAIRE

    ANAYA, Yosi

    2014-01-01

    Meksika Mayaları ve Orta Amerika'nın önde gelen liflerinden birisi, sisal olarak bilinen Henequéndir. Sömürgecilik döneminin üretim merkezlerinden birisi olan Yucatan'ınadını alan Henequén, yüzyıllarca Yucatan Yarımadasının “Yeşil Altın”ı olarak bilindi. Yucatek ekonomisi, 20. yüzyıl boyunca ihtiyaç duyulan her türlü ip, halı,çuval ve kaba kumaşları sağlayan henequén tarlaları etrafında gelişti, yerleşti ve serpildi. 20. yüzyılda henequén lifi, daha ucuz fiyatlarla Madagaskar ve Ken...

  2. Industry sector analysis, Mexico: Annual petroleum report. Export Trade Information

    International Nuclear Information System (INIS)

    1992-01-01

    The comprehensive appraisal of the Mexican Petroleum industry was completed in July 1991. Some of the topics concerning the Mexican petroleum industry covered in the Annual Petroleum Report include: exploration efforts, oil reserves, pipelines, refining, finances, transportation, alternative energy sources, and others. The report also contains lists of petrochemicals produced in Mexico and extensive statistics on oil production and export prices

  3. Radon availability in New Mexico

    International Nuclear Information System (INIS)

    McLemore, V.T.

    1995-01-01

    The New Mexico Bureau of Mines and Mineral Resources (NMBMMR) in cooperation with the Radiation Licensing and Registration Section of the New Mexico Environment Department (NMED) and the US Environmental Protection Agency (EPA) have been evaluating geologic and soil conditions that may contribute to elevated levels of indoor radon throughout New Mexico. Various data have been integrated and interpreted in order to determine areas of high radon availability. The purpose of this paper is to summarize some of these data for New Mexico and to discuss geologic controls on the distribution of radon. Areas in New Mexico have been identified from these data as having a high radon availability. It is not the intent of this report to alarm the public, but to provide data on the distribution of radon throughout New Mexico

  4. U.S.-Mexico energy

    International Nuclear Information System (INIS)

    1991-05-01

    This paper reports that while Mexico's petrochemical industry has grown rapidly, it now faces shortages both in investment funds and in supplies of basic petrochemicals due to a financial crisis in the 1980s. Mexico has undertaken a series of policy reforms aimed at encouraging foreign and private investment, but these efforts have generally failed to entice U.S. investment in Mexico. U.S. petrochemical companies have cited unfavorable market conditions, insufficient basic petrochemical capacity in Mexico, concern about the reversibility of Mexican reforms, inadequate Mexican protection of intellectual property rights, and lack of investment protection for U.S. businesses as impediments to investment in Mexico. Cooperation between the two nations in overcoming these obstacles could help U.S. petrochemical companies maintain their positions in a competitive global market, while at the same time provide Mexico with much needed capital investment and technological expertise

  5. ALARA development in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, M.A.M. [Instituto Nacional de Investigaciones Nucleares, Col Lomas de Barrilaco (Mexico)

    1995-03-01

    Even though the ALARA philosophy was formally implemented in the early 1980`s, to some extent, ALARA considerations already had been incorporated into the design of most commercial equipment and facilities based on experience and engineering development. In Mexico, the design of medical and industrial facilities were based on international recommendations containing those considerations. With the construction of Laguna Verde Nuclear Power Station, formal ALARA groups were created to review some parts of its design, and to prepare the ALARA Program and related procedures necessary for its commercial operation. This paper begins with a brief historical description of ALARA development in Mexico, and then goes on to discuss our regulatory frame in Radiation Protection, some aspects of the ALARA Program, efforts in controlling and reducing of sources of radiation, and finally, future perspectives in the ALARA field.

  6. Neuropsychology in Mexico.

    Science.gov (United States)

    Ostrosky Shejet, Feggy; Velez Garcia, Alicia

    2016-11-01

    This invited paper explores the diverse pathways that have led to the development of neuropsychology in Mexico. The authors conducted a review of the literature and their own experiences to describe the seminal events and people relevant to the development of this area of research and practice. The master's degree is the usual level of educational attainment for those who wish to practice clinical neuropsychology. As of now, there is not a board certification process in neuropsychology, although there is one in clinical psychology. Neuropsychology and other mental health disciplines in Mexico and Latin America have historically been poorly funded, and have lacked optimal means of communication as to research findings and clinical initiatives and standards. However, there is reason to think that this will be improved upon in coming years.

  7. Dust storm, northern Mexico

    Science.gov (United States)

    1983-01-01

    This large dust storm along the left side of the photo, covers a large portion of the state of Coahuila, Mexico (27.5N, 102.0E). The look angle of this oblique photo is from the south to the north. In the foreground is the Sierra Madre Oriental in the states Coahuila and Nuevo Leon with the Rio Grande River, Amistad Reservoir and Texas in the background.

  8. 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. 

  9. Mexico and the CTBT

    International Nuclear Information System (INIS)

    Aguirre G, J.; Martinez L, J.; Ruiz E, L. J.; Aragon M, I. B.

    2013-10-01

    The Comprehensive Nuclear Test-Ban-Treaty (CTBT) is a treaty that prohibits all the nuclear explosions by anybody and in any place, either on the terrestrial surface, in the atmosphere, under the sea or underground. From the adoption of this Treaty by the United Nations, Mexico has had interest for its entrance in vigor, as integral part to assure the international peace. For this reason, our country signed the Treaty since it was open in September 24, 1996 and three years later ratified it, due to Mexico is part of the group of necessary countries for their entrance in vigor. During 13 years, the country has been committed and helped to the installation of monitoring stations, actions that allow the strengthening of the International System of Surveillance. The purpose of this work is to divulge the Treaty,its technologies and benefits; and also to diffuse the works realized by Mexico regarding the radionuclides monitoring station and noble gases both certified ones for the CTBT. Besides the radionuclides technology, Mexico has taken charge of the installation and operation of the seismic stations and hydro-acoustics that have been certified too. The radionuclides station Rn-44 located in Guerrero Negro, BCS has two technologies, an automated sampler of suspended particles in air brand Cinderella/ARAME and a noble gases system Sauna used for the particles detection of radioactive material gamma emitting and Xenon radioisotopes product of nuclear assays. Both technologies are transmitting data in real time to the International Center of Data. These technologies are shown in this work. (Author)

  10. Fractional Reserve in Banking System

    OpenAIRE

    Valkonen, Maria

    2016-01-01

    This thesis is aimed to provide understanding of the role of the fractional reserve in the mod-ern banking system worldwide and particularly in Finland. The fractional reserve banking is used worldwide, but the benefits of this system are very disputable. On the one hand, experts say that the fractional reserve is a necessary instrument for the normal business and profit making. On the other hand, sceptics openly criticize the fractional reserve system and blame it for fiat money (money n...

  11. [Obesity in Mexico].

    Science.gov (United States)

    Dávila-Torres, Javier; González-Izquierdo, José Jesús; Barrera-Cruz, Antonio

    2015-01-01

    Excess body weight (overweight and obesity) is currently recognized as one of the most important challenges of public health in the world, given its size, speed of growth and the negative effect it has on the health of the population that suffers. Overweight and obesity significantly increases the risk of chronic no communicable diseases, premature mortality and the social cost of health. An estimated 90 % of cases of type 2 diabetes mellitus attributable to overweight and obesity. Today, Mexico is second global prevalence of obesity in the adult population, which is ten times higher than that of countries like Japan and Korea. With regard to children, Mexico ranks fourth worldwide obesity prevalence, behind Greece, USA and Italy. In our country, over 70 % of the adult population, between 30 and 60 years are overweight. The prevalence of overweight is higher in men than females, while the prevalence of obesity is higher in women than men. Until 2012, 26 million Mexican adults are overweight and 22 million obese, which represents a major challenge for the health sector in terms of promoting healthy lifestyles in the population and development of public policies to reverse this scenario epidemiology. Mexico needs to plan and implement strategies and action cost effective for the prevention and control of obesity of children, adolescents and adults. Global experience shows that proper care of obesity and overweight, required to formulate and coordinate multisectoral strategies and efficient for enhancing protective factors to health, particularly to modify individual behavior, family and community.

  12. Mobile exhibition in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1960-04-15

    Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

  13. Mobile exhibition in Mexico

    International Nuclear Information System (INIS)

    1960-01-01

    Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

  14. Youth programmes in Mexico.

    Science.gov (United States)

    Rodriguez De Macias, G

    1990-12-01

    Research indicates that in-school adolescents in Mexico have their first sexual contact at the average age of 15.5 years. In 50% of cases, such contact is with a boyfriend or girlfriend, 28.1% with a fiance, and 18.3% with a prostitute. First sexual intercourse occurs with a spouse in only 1.3% of cases. Since only one in six young people in Mexico use a form of contraception, many unwanted pregnancies outside of marriage result. 450,000 births in 1989 were to mothers below 20 years old, with 15% of births annually being among teenage mothers. An estimated three million abortions occur annually in Mexico, and abortions are the fifth major cause of death at the national level. Teen pregnancy is decisively linked with poor living conditions and life expectancy, a relatively lower level of education, and rural residence. As for psychological and anthropological variables, most teens who become pregnant belong to large, unstable families with poor family communication, and are characterized as submissive, highly dependent, and of low self-esteem. Targeting students, workers, and other youths, the MEXFAM Youth Program selects and trains program coordinators over age 21 and volunteer promoters of both sexes aged 16-20 in urban/marginal communities. Promoters offer information to their peers and other youths in their local communities, distribute barrier contraceptives, and channel medical, psychological, and legal services to young people in need. Program procedure is described.

  15. New Mexico Clean Energy Initiatives

    Science.gov (United States)

    This presentation addresses New Mexico oil and gas development, brownfields, mining development, renewable energy development, renewable resources, renewable standards, solar opportunities, climate change, and energy efficiency.

  16. Family structure and child anemia in Mexico.

    Science.gov (United States)

    Schmeer, Kammi K

    2013-10-01

    Utilizing longitudinal data from the nationally-representative Mexico Family Life Survey, this study assesses the association between family structure and iron-deficient anemia among children ages 3-12 in Mexico. The longitudinal models (n = 4649), which control for baseline anemia status and allow for consideration of family structure transitions, suggest that children living in stable-cohabiting and single-mother families and those who have recently experienced a parental union dissolution have higher odds of anemia than those in stable-married, father-present family structures. Interaction effects indicate that unmarried family contexts have stronger associations with anemia in older children (over age five); and, that the negative effects of parental union dissolution are exacerbated in poorer households. Resident maternal grandparents have a significant beneficial effect on child anemia independent of parental family structure. These results highlight the importance of family structure for child micronutrient deficiencies and suggest that understanding social processes within households may be critical to preventing child anemia in Mexico. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Mexico: Rasgos de Su Historia. (Mexico: Highlights of Its History).

    Science.gov (United States)

    Orozco, Cecilio

    Intended for both teachers and students, this publication, written in Spanish, briefly traces Mexico's history from its Conquest in 1519 to the overthrow of Porfirio Diaz in 1910. The following are briefly discussed: Mexico's Conquest in 1519; events immediately after the fall of Tenochtitlan; the War for Independence; Texas' separation from…

  18. Financing options in Mexico`s energy industry

    Energy Technology Data Exchange (ETDEWEB)

    McKenna, J.J. [PricewaterhouseCoopers Securities, Houston, TX (United States)

    1999-10-01

    A series of brief notes accompanied this presentation which was divided into seven sections entitled: (1) capital markets update, (2) Mexican financial market update, (3) financing options in the energy industry, (4) the Venezuelan experience at La Apertura, (5) private and strategic equity alternatives, (6) Pricewaterhouse Coopers Securities, and (7) Mexico energy 2005 prediction. The paper focused on how the financial crisis and merger activity in Latin America will impact electricity reform in Mexico. It was noted that under Mexico`s Policy Proposal for Electricity Reform of the Mexican Electricity Industry, the financial community will seek to back companies in power generation, transportation and distribution. The difficulty of financing government businesses undergoing privatization was also discussed with particular emphasis on the challenge of accepting political and regulatory risks. The Latin private equity market and Canadian investment in Mexico was also reviewed. Since NAFTA (North American Free Trade Agreement) went into affect in 1994, Canadian investment in Mexico has more than tripled. Canadian companies have invested more than C$1.7 billion in Mexico since NAFTA. Pricewaterhouse Coopers Securities is a global investment bank which sees large opportunities in the Mexican energy market. They predict that in five years, Mexico will experience a gradual liberalization of the oil and gas sector, and a full liberalization of the gas pipeline and distribution business and the power generation, transmission and distribution business. 3 figs.

  19. Using Food Flow Data to Assess Sustainability: Land Use Displacement and Regional Decoupling in Quintana Roo, Mexico

    Directory of Open Access Journals (Sweden)

    Marco Millones

    2016-11-01

    Full Text Available Food flow data provide unique insights into the debates surrounding the sustainability of land based production and consumption at multiple scales. Trade flows disguise the spatial correspondence of production and consumption and make their connection to land difficult. Two key components of this spatial disjuncture are land use displacement and economic regional decoupling. By displacing the environmental impact associated with food production from one region to another, environmental trajectories can falsely appear to be sustainable at a particular site or scale. When regional coupling is strong, peripheral areas where land based production occurs are strongly linked and proximate to consumption centers, and the environmental impact of production activities is visible. When food flows occur over longer distances, regional coupling weakens, and environmental impact is frequently overlooked. In this study, we present an analysis of a locally collected food flow dataset containing agricultural and livestock products transported to and from counties in Quintana Roo (QRoo. QRoo is an extensively forested border state in southeast Mexico, which was fully colonized by the state and non-native settlers only in the last century and now is home to some of the major tourist destinations. To approximate land displacement and regional decoupling, we decompose flows to and from QRoo by (1 direction; (2 product types and; (3 scale. Results indicate that QRoo is predominantly a consumer state: incoming flows outnumber outgoing flows by a factor of six, while exports are few, specialized, and with varied geographic reach (Yucatan, south and central Mexico, USA. Imports come predominantly from central Mexico. Local production in QRoo accounts for a small portion of its total consumption. In combining both subsets of agricultural and livestock products, we found that in most years, land consumption requirements were above 100% of the available land not under

  20. Effect of climate change on wind waves generated by anticyclonic cold front intrusions in the Gulf of Mexico

    Science.gov (United States)

    Appendini, Christian M.; Hernández-Lasheras, Jaime; Meza-Padilla, Rafael; Kurczyn, Jorge A.

    2018-01-01

    Anticyclonic cold surges entering the Gulf of Mexico (Nortes) generate ocean waves that disrupt maritime activities. Norte derived waves are less energetic than the devastating waves from tropical cyclones, but more frequent ( 22 events/year) and with larger spatial influence. Despite their importance, few studies characterize Nortes derived waves and assess the effects of climate change on their occurrence. This study presents a method to identify and characterize Nortes with relation to their derived waves in the Gulf of Mexico. We based the identification of Nortes on synoptic measurements of pressure differences between Yucatan and Texas and wind speed at different buoy locations in the Gulf of Mexico. Subsequently, we identified the events in the CFSR reanalysis (present climate) and the CNRM-M5 model for the present climate and the RCP 8.5 scenario. We then forced a wave model to characterize the wave power generated by each event, followed by a principal component analysis and classification by k-means clustering analysis. Five different Nortes types were identified, each one representing a characteristic intensity and area of influence of the Norte driven waves. Finally, we estimated the occurrence of each Norte type for the present and future climates, where the CNRM-M5 results indicate that the high-intensity events will be less frequent in a warming climate, while mild events will become more frequent. The consequences of such changes may provide relief for maritime and coastal operations because of reduced downtimes. This result is particularly relevant for the operational design of coastal and marine facilities.

  1. Diversidad y datos reproductivos de mamíferos medianos y grandes en el bosque mesófilo de montaña de la Reserva de la Biosfera Sierra de Manantlán, Jalisco-Colima, México Medium and large mammal diversity and reproductive data in the cloud forest, Biosphere Reserve of Sierra Manantlán, Jalisco-Colima, Mexico

    Directory of Open Access Journals (Sweden)

    Marcelo Aranda

    2012-09-01

    Full Text Available El bosque mesófilo de montaña (BMM es uno de los ecosistemas con menor extensión territorial y de los más amenazados en México. Este trabajo presenta datos sobre la riqueza, abundancia relativa, actividad y datos reproductivos de especies de mamíferos medianos y grandes en el BMM ubicado en la Reserva de la Biosfera Sierra de Manantlán. Entre febrero de 2008 y agosto de 2009, mediante la utilización de fototrampas, se obtuvieron 372 registros independientes que corresponden a 17 especies. Esta información respalda la elección adecuada de método y sitios de monitoreo. Los resultados indican que el ecosistema se encuentra en buen estado de conservación, lo que coincide con lo que en fecha reciente registró la Comisión Nacional para el Conocimiento y Uso de la Biodiversidad. Es recomendable establecer acciones de monitoreo a mediano y largo plazo en múltiples sitios, para complementar la evaluación que se ha realizado de este ecosistema en el país.The cloud forest (CF is one of the ecosystems with less surface and the most threatened in Mexico. This paper presents information on the richness, relative abundance, activity and reproductive data of medium and large mammals in the CF located in the Sierra de Manantlán Biosphere Reserve. Between February 2008 and August 2009, we used camera-traps with which we obtained 372 independent records, corresponding to 17 species. We believe this data supports an appropriate choice of method and monitoring sites; but also data on richness, abundance and reproduction of the species indicate that the ecosystem is properly preserved in the area, which is consistent with recently reported Conabio. Therefore we recommend establishing monitoring activities in the medium and long term in multiple sites, which could complement the assessment that has been undertaken at national level in this ecosystem.

  2. Biosphere reserves: Attributes for success.

    Science.gov (United States)

    Van Cuong, Chu; Dart, Peter; Hockings, Marc

    2017-03-01

    Biosphere reserves established under the UNESCO Man and the Biosphere Program aim to harmonise biodiversity conservation and sustainable development. Concerns over the extent to which the reserve network was living up to this ideal led to the development of a new strategy in 1995 (the Seville Strategy) to enhance the operation of the network of reserves. An evaluation of effectiveness of management of the biosphere reserve network was called for as part of this strategy. Expert opinion was assembled through a Delphi Process to identify successful and less successful reserves and investigate common factors influencing success or failure. Ninety biosphere reserves including sixty successful and thirty less successful reserves in 42 countries across all five Man and the Biosphere Program regions were identified. Most successful sites are the post-Seville generation while the majority of unsuccessful sites are pre-Seville that are managed as national parks and have not been amended to conform to the characteristics that are meant to define a biosphere reserve. Stakeholder participation and collaboration, governance, finance and resources, management, and awareness and communication are the most influential factors in the success or failure of the biosphere reserves. For success, the biosphere reserve concept needs to be clearly understood and applied through landscape zoning. Designated reserves then need a management system with inclusive good governance, strong participation and collaboration, adequate finance and human resource allocation and stable and responsible management and implementation. All rather obvious but it is difficult to achieve without commitment to the biosphere reserve concept by the governance authorities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Reserves Represented by Random Walks

    International Nuclear Information System (INIS)

    Filipe, J A; Ferreira, M A M; Andrade, M

    2012-01-01

    The reserves problem is studied through models based on Random Walks. Random walks are a classical particular case in the analysis of stochastic processes. They do not appear only to study reserves evolution models. They are also used to build more complex systems and as analysis instruments, in a theoretical feature, of other kind of systems. In this work by studying the reserves, the main objective is to see and guarantee that pensions funds get sustainable. Being the use of these models considering this goal a classical approach in the study of pensions funds, this work concluded about the problematic of reserves. A concrete example is presented.

  4. Gulf of Mexico development

    International Nuclear Information System (INIS)

    Krenz, D.

    1998-01-01

    In recent years, the Gulf of Mexico (GOM) has seen significant deepwater growth. An overview of the GOM deepwater leaseholds by Shell and developments by competing companies is presented. Deepwater GOM developments, total production from the shelf and from deepwater wells, new offshore pipeline capacity and ownership, and processing plant capacity are also discussed. Significant deepwater growth in the Gulf is anticipated. Despite significant economic and technological challenges, the area is judged to be the prime exploration and production opportunity in the lower 48 states of the USA. tabs., figs

  5. Reservation wages and starting wages

    NARCIS (Netherlands)

    van Ophem, H.; Hartog, J.; Berkhout, P.

    2011-01-01

    We analyse a unique data set that combines reservation wage and actually paid wage for a large sample of Dutch recent higher education graduates. On average, accepted wages are almost 8% higher than reservation wages, but there is no fixed proportionality. We find that the difference between

  6. Can Creativity Predict Cognitive Reserve?

    Science.gov (United States)

    Palmiero, Massimiliano; Di Giacomo, Dina; Passafiume, Domenico

    2016-01-01

    Cognitive reserve relies on the ability to effectively cope with aging and brain damage by using alternate processes to approach tasks when standard approaches are no longer available. In this study, the issue if creativity can predict cognitive reserve has been explored. Forty participants (mean age: 61 years) filled out: the Cognitive Reserve…

  7. 21 CFR 808.81 - New Mexico.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false New Mexico. 808.81 Section 808.81 Food and Drugs... and Local Exemptions § 808.81 New Mexico. The following New Mexico medical device requirement is... from preemption under section 521(b) of the act: New Mexico Statutes Annotated, section 67-36-16(F...

  8. Relationship between organochlorine pesticides and stress indicators in hawksbill sea turtle (Eretmochelys imbricata) nesting at Punta Xen (Campeche), Southern Gulf of Mexico.

    Science.gov (United States)

    Tremblay, Nelly; Ortíz Arana, Alejandro; González Jáuregui, Mauricio; Rendón-von Osten, Jaime

    2017-03-01

    Data on the impact of environmental pollution on the homeostasis of sea turtles remains scarce, particularly in the Southern Gulf of Mexico. As many municipalities along the coastline of the Yucatan Peninsula do not rely on a waste treatment plant, these organisms could be particularly vulnerable. We searched for relationships between the presence of organochlorine pesticides (OCP) and the level of several oxidative and pollutant stress indicators of the hawksbill sea turtle (Eretmochelys imbricata) during the 2010 nesting season at Punta Xen (Campeche, Mexico). Of the 30 sampled sea turtles, endosulfans, aldrin related (aldrin, endrin, dieldrin, endrin ketone, endrin aldehyde) and dichlorodiphenyldichloroethylene (DDT) families were detected in 17, 21 and 26, respectively. Significant correlation existed between the size of sea turtles with the concentration of methoxychlor, cholinesterase activity in plasma and heptachlors family, and catalase activity and hexachlorohexane family. Cholinesterase activity in washed erythrocytes and lipid peroxidation were positively correlated with glutathione reductase activity. Antioxidant enzyme actions seem adequate as no lipids damages were correlated with any OCPs. Future studies are necessary to evaluate the effect of OCPs on males of the area due to the significant detection of methoxychlor, which target endocrine functioning and increases its concentration with sea turtles size.

  9. Begomovirus diversity in tomato crops and weeds in Ecuador and the detection of a recombinant isolate of rhynchosia golden mosaic Yucatan virus infecting tomato.

    Science.gov (United States)

    Paz-Carrasco, Lenin C; Castillo-Urquiza, Gloria P; Lima, Alison T M; Xavier, Cesar A D; Vivas-Vivas, Leticia M; Mizubuti, Eduardo S G; Zerbini, F Murilo

    2014-08-01

    Viral diseases caused by begomoviruses are of economic importance due to their adverse effects on the production of tropical and subtropical crops. In Ecuador, despite reports of significant infestations of Bemisia tabaci in the late 1990s, only very recently has a begomovirus, tomato leaf deformation virus (ToLDeV, also present in Peru), been reported in tomato. ToLDeV is the first monopartite begomovirus discovered that originated in the Americas, and its presence in Ecuador highlights the need for a wider survey of tomato-infecting begomoviruses in this country. Tomato and weed samples were collected in 2010 and 2011 in six provinces of Ecuador, and begomovirus genomes were cloned and sequenced using a rolling-circle-amplification-based approach. Most tomato samples from the provinces of Guayas, Loja, Manabi and Santa Elena were infected with tomato leaf deformation virus (ToLDeV). One sample from Manabi had a triple infection with ToLDeV, rhynchosia golden mosaic Yucatan virus (RhGMYuV) and an isolate that was a recombinant between the two. A new begomovirus was detected in another tomato sample from Manabi. Samples of Rhynchosia sp. from the provinces of Guayas and Manabi were infected by RhGMYuV. These results indicate not only the prevalence of ToLDeV in tomato in Ecuador but also the presence of other viruses, albeit at a much lower frequency.

  10. The Role of Transforms in Gulf of Mexico Opening

    Science.gov (United States)

    Lundin, E.; Doré, A. G.

    2017-12-01

    The curious pie-shaped Gulf of Mexico (GoM) may be considered a high-angle back-arc basin to the Pacific Ocean. Opening was strongly facilitated by transforms, including a terminal transform on its Pacific side. GoM also formed synchronously with the nearby Central Atlantic when Gondwanaland pulled away from Laurasia in the Jurassic. Notably, GoM's oceanic crust never connected with that of the Atlantic, and the isolated nature of this small ocean led to periodically confined conditions that influenced the petroleum system. Of particular importance are the deposition of Callovian age salt and Tithonian age source rocks. The central part of GoM is generally accepted as underlain by oceanic crust, but the position of the continent-ocean boundaries (COB) is debated, as well as the nature of intervening crust. We favor an interpretation of the COBs marked by the regional scale, large-amplitude Houston, Florida, and Campeche magnetic anomalies, in turn probably reflecting seaward dipping reflectors of magma-rich margins. GoM's unusual shape may indirectly represent utilization of pre-existing transforms during the break-up of Pangea. Transforms represent long, linear weaknesses where the crust and lithosphere is already broken. Transforms seem to have governed the break-up of several oceanic segments in the North Atlantic and Arctic. The Suwanne suture of the Rheic Ocean is a pronounced magnetic anomaly that crosses Georgia-Florida and becomes aligned with the Houston magnetic anomaly, which here is interpreted as the northern COB to GoM. The Suwanne suture is oriented at high angle to the rest of the Rheic suture along the Appalachians and probably experienced lateral motion during the transpressional closure of the Rheic Ocean. This transform arguably represents a weak element in the Ouachita-Marathon orogen that allowed the Yucatan microcontinent to easily be plucked from the North American margin during the dispersal of Pangea, forming the GoM in the process. This

  11. Securities issues in reserves reporting

    International Nuclear Information System (INIS)

    Legg, M.B.

    1997-01-01

    Securities issues in oil and gas reserves reporting were discussed. Alberta requires specific information regarding important oil and gas properties, plants, facilities and installations. When preparing the reserves report, the following elements are important to consider: (1) the author of the report must be a registered professional engineer or registered professional geologist, (2) the report itself must be an engineering document, (3) the content of the report must be extensive, (4) it should be prepared in accordance with petroleum engineering and evaluation practices, and must include a summary of estimated net reserves

  12. Mexico Wind Resource Assessment Project

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, M.N.; Elliott, D.L.

    1995-05-01

    A preliminary wind energy resource assessment of Mexico that produced wind resource maps for both utility-scale and rural applications was undertaken as part of the Mexico-U.S. Renewable Energy Cooperation Program. This activity has provided valuable information needed to facilitate the commercialization of small wind turbines and windfarms in Mexico and to lay the groundwork for subsequent wind resource activities. A surface meteorological data set of hourly data in digital form was utilized to prepare a more detailed and accurate wind resource assessment of Mexico than otherwise would have been possible. Software was developed to perform the first ever detailed analysis of the wind characteristics data for over 150 stations in Mexico. The hourly data set was augmented with information from weather balloons (upper-air data), ship wind data from coastal areas, and summarized wind data from sources in Mexico. The various data were carefully evaluated for their usefulness in preparing the wind resource assessment. The preliminary assessment has identified many areas of good-to-excellent wind resource potential and shows that the wind resource in Mexico is considerably greater than shown in previous surveys.

  13. Estimating Foreign Exchange Reserve Adequacy

    Directory of Open Access Journals (Sweden)

    Abdul Hakim

    2013-04-01

    Full Text Available Accumulating foreign exchange reserves, despite their cost and their impacts on other macroeconomics variables, provides some benefits. This paper models such foreign exchange reserves. To measure the adequacy of foreign exchange reserves for import, it uses total reserves-to-import ratio (TRM. The chosen independent variables are gross domestic product growth, exchange rates, opportunity cost, and a dummy variable separating the pre and post 1997 Asian financial crisis. To estimate the risky TRM value, this paper uses conditional Value-at-Risk (VaR, with the help of Glosten-Jagannathan-Runkle (GJR model to estimate the conditional volatility. The results suggest that all independent variables significantly influence TRM. They also suggest that the short and long run volatilities are evident, with the additional evidence of asymmetric effects of negative and positive past shocks. The VaR, which are calculated assuming both normal and t distributions, provide similar results, namely violations in 2005 and 2008.

  14. Shell trips over its reserves

    International Nuclear Information System (INIS)

    Jemain, A.

    2004-01-01

    Some mistakes in the evaluation of the proven reserves of Royal Dutch Shell group, the second world petroleum leader, will oblige the other oil and gas companies to be more transparent and vigilant in the future. The proven reserves ('P90' in petroleum professionals' language) are the most important indicators of the mining patrimony of companies. These strategic data are reported each year in the annual reports of the companies and are examined by the security exchange commission. The evaluation of reserves is perfectly codified by the US energy policy and conservation act and its accountable translation using the FAS 69 standard allows to establish long-term cash-flow forecasts. The revision announced by Shell on January 9 leads to a 20% reduction of its proven reserves. Short paper. (J.S.)

  15. Cognitive Reserve Scale and ageing

    Directory of Open Access Journals (Sweden)

    Irene León

    2016-01-01

    Full Text Available The construct of cognitive reserve attempts to explain why some individuals with brain impairment, and some people during normal ageing, can solve cognitive tasks better than expected. This study aimed to estimate cognitive reserve in a healthy sample of people aged 65 years and over, with special attention to its influence on cognitive performance. For this purpose, it used the Cognitive Reserve Scale (CRS and a neuropsychological battery that included tests of attention and memory. The results revealed that women obtained higher total CRS raw scores than men. Moreover, the CRS predicted the learning curve, short-term and long-term memory, but not attentional and working memory performance. Thus, the CRS offers a new proxy of cognitive reserve based on cognitively stimulating activities performed by healthy elderly people. Following an active lifestyle throughout life was associated with better intellectual performance and positive effects on relevant aspects of quality of life.

  16. Professionalizing the Estonian Reserve Component

    National Research Council Canada - National Science Library

    Everett, William

    1998-01-01

    .... In particular, citizen-soldier reserves can allow nations that do not face immediate external threats, such as Estonia, to meet their security requirements for less money than required by standing forces...

  17. Fractional Reserve Banking: Some Quibbles

    OpenAIRE

    Bagus, Philipp; Howden, David

    2010-01-01

    We explore several unaddressed issues in George Selgin’s (1988) claim that the best monetary system to maintain monetary equilibrium is a fractional reserve free banking one. The claim that adverse clearing balances would limit credit expansion in a fractional reserve free banking system is more troublesome than previously reckoned. Both lengthened clearing periods and interbank agreements render credit expansion unrestrained. “The theory of free banking” confuses increases in money held with...

  18. Reserve Special Flood Hazard Areas (SFHA)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This vector dataset depicts the 1% annual flood boundary (otherwise known as special flood hazard area or 100 year flood boundary) for its specified area. The data...

  19. Indian Reservation & Trust Land Boundaries (TIGER 2000)

    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...

  20. Texas-Mexico multimodal transportation: developments in Mexico

    Science.gov (United States)

    Boske, Leigh B.

    1994-03-01

    This presentation highlights the results of a recently completed study that examines the Texas- Mexico multimodal transport system already in place, current plans for improvements or expansion, and opportunities and constraints faced by each transport mode -- motor carriage, rail, maritime, and air. Particular emphasis is given to findings regarding transportation developments in Mexico. The study concludes that in Mexico, all modes are working at establishing new services and strategic alliances, intermodal arrangements are on the rise, and private-sector participation in infrastructure improvements is growing daily at Mexican seaports and airports as well as within that nation's highway and rail systems. This presentation looks at developments that concern privatization, deregulation, infrastructure improvements, financing arrangements, and new services in Mexico.

  1. Measuring the importance of oil-related revenues in total fiscal income for Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Loya, Manuel Lorenzo; Blanco, Lorenzo [Facultad de Economia, Universidad Autonoma de Nuevo Leon, Loma Redonda 1515 Pte., Col. Loma Larga, C.P. 64710, Monterrey, Nuevo Leon (Mexico)

    2008-09-15

    Revenues from oil exports are an important part of government budgets in Mexico. A time-series analysis is conducted using monthly data from 1990 to 2005 examining three different specifications to determine how international oil price fluctuations and government income generated from oil exports influence fiscal policy in Mexico. The behavior of government spending and taxation is consistent with the spend-tax hypothesis. The results show that there is an inverse relationship between oil-related revenues and tax revenue from non-oil sources. Fiscal policy reform is urgently needed in order to improve tax collection as oil reserves in Mexico become more and more depleted. (author)

  2. Measuring the importance of oil-related revenues in total fiscal income for Mexico

    International Nuclear Information System (INIS)

    Reyes-Loya, Manuel Lorenzo; Blanco, Lorenzo

    2008-01-01

    Revenues from oil exports are an important part of government budgets in Mexico. A time-series analysis is conducted using monthly data from 1990 to 2005 examining three different specifications to determine how international oil price fluctuations and government income generated from oil exports influence fiscal policy in Mexico. The behavior of government spending and taxation is consistent with the spend-tax hypothesis. The results show that there is an inverse relationship between oil-related revenues and tax revenue from non-oil sources. Fiscal policy reform is urgently needed in order to improve tax collection as oil reserves in Mexico become more and more depleted. (author)

  3. Rapid effects of marine reserves via larval dispersal.

    Directory of Open Access Journals (Sweden)

    Richard Cudney-Bueno

    Full Text Available Marine reserves have been advocated worldwide as conservation and fishery management tools. It is argued that they can protect ecosystems and also benefit fisheries via density-dependent spillover of adults and enhanced larval dispersal into fishing areas. However, while evidence has shown that marine reserves can meet conservation targets, their effects on fisheries are less understood. In particular, the basic question of if and over what temporal and spatial scales reserves can benefit fished populations via larval dispersal remains unanswered. We tested predictions of a larval transport model for a marine reserve network in the Gulf of California, Mexico, via field oceanography and repeated density counts of recently settled juvenile commercial mollusks before and after reserve establishment. We show that local retention of larvae within a reserve network can take place with enhanced, but spatially-explicit, recruitment to local fisheries. Enhancement occurred rapidly (2 yrs, with up to a three-fold increase in density of juveniles found in fished areas at the downstream edge of the reserve network, but other fishing areas within the network were unaffected. These findings were consistent with our model predictions. Our findings underscore the potential benefits of protecting larval sources and show that enhancement in recruitment can be manifested rapidly. However, benefits can be markedly variable within a local seascape. Hence, effects of marine reserve networks, positive or negative, may be overlooked when only focusing on overall responses and not considering finer spatially-explicit responses within a reserve network and its adjacent fishing grounds. Our results therefore call for future research on marine reserves that addresses this variability in order to help frame appropriate scenarios for the spatial management scales of interest.

  4. Evidence That Marine Reserves Enhance Resilience to Climatic Impacts

    Science.gov (United States)

    Micheli, Fiorenza; Saenz-Arroyo, Andrea; Greenley, Ashley; Vazquez, Leonardo; Espinoza Montes, Jose Antonio; Rossetto, Marisa; De Leo, Giulio A.

    2012-01-01

    Establishment of marine protected areas, including fully protected marine reserves, is one of the few management tools available for local communities to combat the deleterious effect of large scale environmental impacts, including global climate change, on ocean ecosystems. Despite the common hope that reserves play this role, empirical evidence of the effectiveness of local protection against global problems is lacking. Here we show that marine reserves increase the resilience of marine populations to a mass mortality event possibly caused by climate-driven hypoxia. Despite high and widespread adult mortality of benthic invertebrates in Baja California, Mexico, that affected populations both within and outside marine reserves, juvenile replenishment of the species that supports local economies, the pink abalone Haliotis corrugata, remained stable within reserves because of large body size and high egg production of the protected adults. Thus, local protection provided resilience through greater resistance and faster recovery of protected populations. Moreover, this benefit extended to adjacent unprotected areas through larval spillover across the edges of the reserves. While climate change mitigation is being debated, coastal communities have few tools to slow down negative impacts of global environmental shifts. These results show that marine protected areas can provide such protection. PMID:22855690

  5. Evidence that marine reserves enhance resilience to climatic impacts.

    Directory of Open Access Journals (Sweden)

    Fiorenza Micheli

    Full Text Available Establishment of marine protected areas, including fully protected marine reserves, is one of the few management tools available for local communities to combat the deleterious effect of large scale environmental impacts, including global climate change, on ocean ecosystems. Despite the common hope that reserves play this role, empirical evidence of the effectiveness of local protection against global problems is lacking. Here we show that marine reserves increase the resilience of marine populations to a mass mortality event possibly caused by climate-driven hypoxia. Despite high and widespread adult mortality of benthic invertebrates in Baja California, Mexico, that affected populations both within and outside marine reserves, juvenile replenishment of the species that supports local economies, the pink abalone Haliotis corrugata, remained stable within reserves because of large body size and high egg production of the protected adults. Thus, local protection provided resilience through greater resistance and faster recovery of protected populations. Moreover, this benefit extended to adjacent unprotected areas through larval spillover across the edges of the reserves. While climate change mitigation is being debated, coastal communities have few tools to slow down negative impacts of global environmental shifts. These results show that marine protected areas can provide such protection.

  6. Demand as frequency controlled reserve

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Togeby, M.; OEstergaard, J.

    2008-09-15

    Using demand as frequency controlled reserve (DFR) is an emerging technology which allow demand to participate actively in maintaining the system operation without reducing the energy service delivered to the customer and without need of user interaction. The basic premise is that traditional frequency controlled reserves from power plants and interconnections with neighbouring systems can be costly, slow and not fulfil the need for future power grids with a high share of wind power and fewer central power plants, and an intention to perform flexible operation such as is landing. Electricity demands, on the other hand, have advantages as frequency reserve including fast activation speed, smooth linear activation, low expected costs, and well-dispersed in the distribution grid. The main challenge of DFR is new methods for monitoring the available capacity. This project has investigated the technology of using electricity demands for providing frequency reserve to power systems. Within the project the potential and economy of DFR compatible loads in Denmark has been investigated, control logic has been designed, power system impact has been investigated, potential business models has been evaluated and an implementation strategy has been suggested. The tasks and goals of the project have been successfully accomplished based on which the conclusion and future recommendation are made. This project has developed the DFR technology that enables electricity demands to autonomously disconnect or reconnect to the grid in response to system frequency variations. The developed DFR technology is proved to be a promising technology from several perspectives. Technically, using DFR is feasible to provide reserves and enhance power system frequency control, while fulfilling technical requirements such as linear activation (or reconnection) according to frequency (or time). Environmentally, the DFR technology is pollution free in contrast to traditional reserves from generation

  7. Mexico City aerosol study

    International Nuclear Information System (INIS)

    Falcon, Y.I.; Ramirez, C.R.

    1987-01-01

    A major task in the field of air pollution monitoring is the development of devices for determining the mass and composition of airborne particulate matter as a function of size - and time. The sample collection device must be designed giving consideration to the nature of the aerosol and to the effects of the aerosol on human health. It has been established that particles smaller than 3.5 μm in diameter can penetrate deeply into the human respiratory system, and that larger particles are trapped in the upper respiratory passages. For these reasons, it is desirable to use a dichotomous sampler to collect particles in two size ranges, rather than to collect total particulates on a single filter. The authors discuss a study in Mexico City using a dichotomous sampler

  8. Mexico introduces pentavalent vaccine.

    Science.gov (United States)

    1999-08-01

    Combination vaccines have been introduced in Mexico. The national immunization program has incorporated the measles-mumps-rubella (MMR) vaccines in 1998, and the pentavalent vaccine in 1999. The two categories of antigen composition in combination vaccines are: 1) multiple different antigenic types of a single pathogen, such as the 23 valent pneumococcal polysaccharide vaccine, and 2) antigens from different pathogens causing different diseases, such as the DPT and MMR vaccines. Pentavalent vaccines are included in the second category. The vaccine protects against diphtheria, tetanus, pertussis, hepatitis B, and other diseases produced by Haemophilus influenzae type b (Hib). Combined diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenza type b (DTP-HB/Hib) vaccine has been distributed to 87% of Mexican children under 1 year of age. Over 800,000 doses of pentavalent vaccine have been administered.

  9. Improved Effectiveness of Reserve Forces During Reserve Duty Training.

    Science.gov (United States)

    Treadaway, Harry H.

    The problem areas of motivation, job enrichment, recruiting, and retention are addressed from the viewpoint of the behavioral scientist. Special attention is given to relating job enrichment and motivation techniques, as successfully demonstrated in industry, to the United State Army Reserve. Research method utilized was a literature review…

  10. Student-Centred Teaching Strategies by Gender, Grade Level, and Teacher’s Self-Concept in Mexico

    Directory of Open Access Journals (Sweden)

    PEDRO SÁNCHEZ-ESCOBEDO

    2018-05-01

    Full Text Available This study examined the student-centred teaching strategies of Mexican teachers by gender, grade level, and self-concept as an instructor. A conventional sample of 573 teachers from diverse school settings in the state of Yucatan in Mexico responded to a paper and pencil questionnaire. Results indicated, in general, that teachers prioritized classroom management and independent learning activities, in contrast with teaching strategies emphasized by policies and teacher´s training programs in the country, such as cooperative learning, differentiation, or promoting critical thinking. There were some gender and grade level differences. In general, female teachers promoted more independent activities than males. As expected, primary school teachers were more concerned with using differentiation teaching strategies than secondary education teachers, considering the greatest variance in younger students. Teachers self-concept had differential effects. Whilst self-efficacy feelings had no influence in the use of specific student-centred teaching strategies, high self-esteem teachers used more student-centred teaching strategies. The importance of asking teachers what they did, and how they felt as teachers was argued in light of results. Future research avenues regarding self-concept and teaching strategies are posited.

  11. Assessing the importance of four sandfly species (Diptera: Psychodidae) as vectors of Leishmania mexicana in Campeche, Mexico.

    Science.gov (United States)

    Pech-May, A; Peraza-Herrera, G; Moo-Llanes, D A; Escobedo-Ortegón, J; Berzunza-Cruz, M; Becker-Fauser, I; Montes DE Oca-Aguilar, A C; Rebollar-Téllez, E A

    2016-09-01

    Localized cutaneous leishmaniasis represents a public health problem in many areas of Mexico, especially in the Yucatan Peninsula. An understanding of vector ecology and bionomics is of great importance in evaluations of the transmission dynamics of Leishmania parasites. A field study was conducted in the county of Calakmul, state of Campeche, during the period from November 2006 to March 2007. Phlebotomine sandfly vectors were sampled using Centers for Disease Control light traps, baited Disney traps and Shannon traps. A total of 3374 specimens were captured in the two villages of Once de Mayo (93.8%) and Arroyo Negro (6.1%). In Once de Mayo, the most abundant species were Psathyromyia shannoni, Lutzomyia cruciata, Bichromomyia olmeca olmeca and Psychodopygus panamensis (all: Diptera: Psychodidae). The Shannon trap was by far the most efficient method of collection. The infection rate, as determined by Leishmania mexicana-specific polymerase chain reaction, was 0.3% in Once de Mayo and infected sandflies included Psy. panamensis, B. o. olmeca and Psa. shannoni. There were significant differences in human biting rates across sandfly species and month of sampling. Ecological niche modelling analyses showed an overall overlap of 39.1% for the four species in the whole state of Campeche. In addition, the finding of nine vector-reservoir pairs indicates a potential interaction. The roles of the various sandfly vectors in Calakmul are discussed. © 2016 The Royal Entomological Society.

  12. Use of multiplex polymerase chain reaction-based assay to conduct epidemiological studies on bovine hemoparasites in Mexico.

    Science.gov (United States)

    Figueroa, J V; Alvarez, J A; Ramos, J A; Vega, C A; Buening, G M

    1993-01-01

    A study was conducted to test the applicability of a Polymerase Chain Reaction (PCR)-based approach for the simultaneous detection of the bovine hemoparasites Babesia bigemina, B. bovis and Anaplasma marginale. Bovine blood samples from cattle ranches of a previously determined enzootic zone in the Yucatan Peninsula of Mexico, were collected from peripheral blood and processed for PCR analysis. Blood samples were subjected to DNA amplification by placing an aliquot in a reaction tube containing oligonucleotide primers specific for DNA of each hemoparasite species. The PCR products were detected by Dot-Blot nucleic acid hybridization utilizing nonradioactive, species-specific, digoxigenin PCR-labeled DNA probes. Four hundred twenty one field samples analyzed by the multiplex PCR-DNA probe assay showed 66.7%, 60.1% and 59.6% prevalence rates for B. bigemina, B. bovis and A. marginale, respectively. The multiplex PCR analysis showed that animals with single, double or triple infection could be detected with the parasite specific DNA probes. The procedure is proposed as a valuable tool for the epidemiological analysis in regions where the hemoparasite species are concurrently infecting cattle.

  13. Spatial and temporal structure of fish assemblages in a hyperhaline coastal system: Ría Lagartos, Mexico

    Directory of Open Access Journals (Sweden)

    Miguel Angel Peralta-Meixueiro

    Full Text Available The spatial and temporal fish species assemblages were analyzed throughout two annual cycles (2004-2005 and 2007-2008 in the Ría Lagartos Lagoon system, Mexico, via non-parametric multivariate analyses. We compared density and biomass of fish species among five habitat types defined by combinations of structure and environmental characteristics (hyperhaline, rocky, seagrass, channel, and marine, and three climatic seasons (dry, rainy, and northerlies. A total of 11,187 individuals distributed in 32 families and 63 species were collected. The most numerically abundant species were Floridichthys polyommus and Cyprinodon artifrons, while Sphoeroides testudineus contributed to the greatest biomass. Species composition consisted mainly of estuarine and euryhaline marine species. Spatially, a saline gradient was observed with marine conditions in the mouth, and increasing to over 100 in the inner zone of the system. Species richness, diversity and biomass declined from the mouth to the inner zone, while density showed an inverse tendency, with the highest values in the inner zone. Thus the salinity was the variable that best explained the spatial fish assemblages" structure. The ichthyofauna composition did not change over time, but the dominant species varied with the years. The abundance of juvenile specimens, suggest that the different habitats are used as feeding and breeding zones; hence it is proposed that protection strategies be pursued not only for the lagoon system but also for the northern zone of the Yucatan Peninsula.

  14. Extractive reserves in Brazilian Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Fearnside, P.M (National Institute for Research in the Amazon, Manaus-Amazonas (Brazil))

    1989-06-01

    In 1985 an opportunity arose for maintaining tracts of Amazonian forest under sustainable use. Brazil's National Council of Rubber Tappers and the Rural Worker's Union proposed the creation of a set of reserves of a new type, called extractive reserves. The first six are being established in one of the Brazilian states most threatened by deforestatation. The creation of extractive reserves grants legal protection to forest land traditionally used by rubber tappers, Brazil-nut gatherers, and other extractivists. The term extrativismo (extractivism) in Brazil refers to removing nontimber forest products, such as latex, resins, and nuts, without felling the trees. Approximately 30 products are collected for commercial sale. Many more types of forest materials are gathered, for example as food and medicines, for the extractivists' own use. The reserve proposal is attractive for several reasons related to social problems. It allows the rubber tappers to continue their livelihood rather than be expelled by deforestation. However, it is unlikely that sufficient land will be set aside as extractive reserves to employ all the tappers. Displaced rubber tappers already swell the ranks of urban slum dwellers in Brazil's Amazonian cities, and they have become refugees to continue their profession in the forests of neighboring countries, such as Bolivia.

  15. New Mexico, 2010 Census Place

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The TIGER/Line Files are shapefiles and related database files (.dbf) that are an extract of selected geographic and cartographic information from the U.S. Census...

  16. New Mexico, 2010 Congressional Districts

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The TIGER/Line Files are shapefiles and related database files (.dbf) that are an extract of selected geographic and cartographic information from the U.S. Census...

  17. New Mexico Urban Areas - Current

    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...

  18. August 1973 Veracruz, Mexico Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — South of Veracruz, southeastern Mexico. Damage: Severe. The earthquake caused heavy damage in the states of Morelos, Puebla, and Veracruz. Thousands were left...

  19. United States Strategy for Mexico

    National Research Council Canada - National Science Library

    Centner, Robert C

    2005-01-01

    The security and stability of Mexico is of national interest to the United States, and a strong, effective alliance between the two countries is pivotal to our national defense strategy and economic prosperity...

  20. Distribución y abundancia de la comunidad de peces en la porción litoral de la Reserva de la Biósfera Los Petenes, Campeche, México Distribution and abundance of fish community in the littoral area of "Los Petenes" Biosphere Reserve, Campeche, Mexico

    Directory of Open Access Journals (Sweden)

    Sandra Muñoz-Rojas

    2013-03-01

    Full Text Available La Reserva de la Biósfera Los Petenes constituye un hábitat crítico para una gran diversidad de especies de peces, la zona de pastos marinos es utilizada con fines de alimentación, protección, crianza y refugio temporal. El objetivo es analizar la estructura espacio-temporal de la comunidad de peces y su relación con la variabilidad ambiental e identificar las especies dominantes. Se realizaron 12 muestreos mensuales en 24 sitios a partir de mayo 2009 hasta abril 2010. Se realizaron 288 arrastres, se capturó un total de 21 795 organismos con un peso total de 279.5 kg. Se identificaron 46 especies de peces (34 géneros y 23 familias. Los intervalos de variación espacial de la abundancia fueron: 0.018-0.094ind./m²; 0.249-1.072g/m² y 9.75-19.32g/ind. Los índices de diversidad fueron: Hn=1.46-2.15bits/ind., J=0.45-0.71 y D=2.08-3.92. La variación temporal de la abundancia y diversidad fue de 0.026-0.066ind./m²; 0.342-0.764g/m² y 6.49-22.98g/ind. Hn=1.76-2.08; J=0.52-0.64 y D=3.07-4.18. Se identificaron 11 especies dominantes, que representan el 94.39% en número de individuos y 89.66% en peso de la captura total. El análisis cluster permite identificar cuatro grupos de especies que se asocian a las distintas condiciones de hábitat de la reserva. El análisis de correspondencia canónica destaca la asociación de H. plumierii con la salinidad y los sólidos disueltos. La RBLP cuenta con una alta diversidad de hábitats y la comunidad de peces ha desarrollado estrategias para aprovechar todas las condiciones espaciales y temporales y así satisfacer sus necesidades en el desarrollo de sus ciclos de vida.“Los Petenes” Biosphere Reserve (RBLP is a critical habitat for many aquatic and terrestrial species. It has the biggest and better conserved seagrass beds, and it represents an important habitat for food, protection and breeding of aquatic organisms, and a temporal refuge for migratory species. The objective of this study was to

  1. Transportation energy use in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum, C.; Meyers, S.; Sathaye, J.

    1994-07-01

    This report presents data on passenger travel and freight transport and analysis of the consequent energy use in Mexico during the 1970--1971 period. We describe changes in modal shares for passenger travel and freight transport, and analyze trends in the energy intensity of different modes. We look in more detail at transportation patterns, energy use, and the related environmental problems in the Mexico City Metropolitan Area, and also discuss policies that have been implemented there to reduce emissions from vehicles.

  2. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

  3. Hydrocarbon Reserves: Abundance or Scarcity

    International Nuclear Information System (INIS)

    2005-01-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

  4. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may

  5. 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

  6. Demand as Frequency Controlled Reserve

    DEFF Research Database (Denmark)

    Xu, Zhao; Østergaard, Jacob; Togeby, Mikael

    2011-01-01

    Relying on generation side alone is deemed insufficient to fulfill the system balancing needs for future Danish power system, where a 50% wind penetration is outlined by the government for year 2025. This paper investigates using the electricity demand as frequency controlled reserve (DFR) as a new...... balancing measure, which has a high potential and can provide many advantages. Firstly, the background of the research is reviewed, including conventional power system reserves and the electricity demand side potentials. Subsequently, the control logics and corresponding design considerations for the DFR...

  7. Demand as Frequency Controlled Reserve

    DEFF Research Database (Denmark)

    Xu, Zhao; Togeby, Mikael; Østergaard, Jacob

    This report summaries the research outcomes of the project ‘Demand as Frequency Controlled Reserve (DFR)’, which has received the support from Energinet.dk’s PSO program, Grant no. 2005-2-6380. The objective of this project is to investigate the technology of using electricity demands for providing...

  8. Yucatan Subsurface Stratigraphy from Geophysical Data, Well Logs and Core Analyses in the Chicxulub Impact Crater and Implications for Target Heterogeneities

    Science.gov (United States)

    Canales, I.; Fucugauchi, J. U.; Perez-Cruz, L. L.; Camargo, A. Z.; Perez-Cruz, G.

    2011-12-01

    Asymmetries in the geophysical signature of Chicxulub crater are being evaluated to investigate on effects of impact angle and trajectory and pre-existing target structural controls for final crater form. Early studies interpreted asymmetries in the gravity anomaly in the offshore sector to propose oblique either northwest- and northeast-directed trajectories. An oblique impact was correlated to the global ejecta distribution and enhanced environmental disturbance. In contrast, recent studies using marine seismic data and computer modeling have shown that crater asymmetries correlate with pre-existing undulations of the Cretaceous continental shelf, suggesting a structural control of target heterogeneities. Documentation of Yucatan subsurface stratigraphy has been limited by lack of outcrops of pre-Paleogene rocks. The extensive cover of platform carbonate rocks has not been affected by faulting or deformation and with no rivers cutting the carbonates, information comes mainly from the drilling programs and geophysical surveys. Here we revisit the subsurface stratigraphy in the crater area from the well log data and cores retrieved in the drilling projects and marine seismic reflection profiles. Other source of information being exploited comes from the impact breccias, which contain a sampling of disrupted target sequences, including crystalline basement and Mesozoic sediments. We analyze gravity and seismic data from the various exploration surveys, including multiple Pemex profiles in the platform and the Chicxulub experiments. Analyses of well log data and seismic profiles identify contacts for Lower Cretaceous, Cretaceous/Jurassic and K/Pg boundaries. Results show that the Cretaceous continental shelf was shallower on the south and southwest than on the east, with emerged areas in Quintana Roo and Belize. Mesozoic and upper Paleozoic sediments show variable thickness, possibly reflecting the crystalline basement regional structure. Paleozoic and Precambrian

  9. Interannual variability in the extent and intensity of tropical dry forest deciduousness in the Mexican Yucatan (2000-2016): Drivers and Links to Regional Atmospheric Conditions

    Science.gov (United States)

    Cuba, Nicholas Joseph

    The dry topical forests of the southern Yucatan Peninsula experience multiple natural and anthropogenic disturbances, as well as substantial interannual climate variability that can result in stark interannual differences in vegetation phenology. Dry season deciduousness is a typical response to limit tree water loss during prolonged periods of hot and dry conditions, and this behavior has both direct implications for ecosystem functioning, and the potential to indicate climate conditions when observed using remotely-sensed data. The first research paper of this dissertation advances methods to assess the accuracy of remotely-sensed measurements of canopy conditions using in-situ observations. Linear regression models show the highest correlation (R2 = 0.751) between in-situ canopy gap fraction and Landsat NDWISWIR2. MODIS time series NDWISWIR2 are created for the period March 2000-February 2011, and exhibit stronger correlation with time series of TRMM precipitation data than do MODIS EVI time series (R2= 0.48 vs. R2 = 0.43 in deciduous forest areas). The second paper examines differences between the deciduous phenology of young forest stands and older forest stands. Land-cover maps are overlaid to determine whether forested areas are greater than or less than 22 years old in 2010, and metrics related to deciduous phenology are derived from MODIS EVI2 time series in three years, 2008 to 2011. Statistical tests that compare matched pairs of young (12-22 years) and older (>22 years) forest stand age class samples are used to detect significant differences in metrics related to the intensity and timing of deciduousness. In all three years, younger forests exhibit significantly more intense deciduousness, measured as total seasonal change of EVI2 normalized by annual maximum EVI2 (pmediating environmental factors that drive the spatial and temporal variability in the intensity of deciduousness, and point toward analyzing deciduousness to reveal information about other

  10. On the phylogenetic position of Pseudophilomedinae within Sarsielloidea (Ostracoda, Myodocopida), with a description of one new Harbansus from Ningaloo Reef and redescription of H. paucichelatus from Yucatan

    Science.gov (United States)

    Karanovic, Ivana; Orduña-Martínez, Lorena; Ardisson, Pedro-Luis

    2015-03-01

    Previous studies have suggested incongruence between current systematics and molecular phylogenies of Sarsielloidea, with a possible polyphyly of the family Philomedidae. Here, we provide molecular phylogenetic analyses based on 18S rDNA and 28S rDNA. The former includes five new sequences and 12 from the GenBank, and the latter two new and six sequences from the GenBank. We use three methods, maximum likelihood, maximum parsimony, and neighbor joining, and all reconstructed phylogenies support previously suggested polyphyly, indicating a closer relationship of the subfamily Pseudophilomedinae with one subfamily of Sarsiellidae than with the nominotypical subfamily of Philomedidae. Morphological characters that may be key indicators of the phylogenetic relationships between three Sarsielloidea families are discussed. We also describe the 21st representative of the Pseudophilomedinae genus, Harbansus Kornicker, (Smith Contrib Zool 260:75, 1978), Harbansus ningalooi n. sp., from the Ningaloo Reef, Western Australia. This is the first Harbansus reported from the Australian west coast and the second from the Australian coral reef systems. It differs from all other congeners by peculiar claw-like processes on the posterior infold. Most Harbansus species have relatively restricted distributions, except Harbansus paucichelatus (Kornicker, in Inst Mar Sci 5:195-300, 1958), which has also been postulated to represent a species complex. We present a detailed morphological redescription of this species, based on the freshly collected material from the Yucatan Peninsula, as well as four mitochondrial COI sequences. These become the first COI sequences of the entire superfamily Sarsielloidea available on the GenBank. To facilitate future identification, we include a key to species of Harbansus.

  11. Tax revenue and innovations in natural gas supply: New Mexico

    International Nuclear Information System (INIS)

    Ulibarri, C.A.; Marsh, T.L.

    1994-10-01

    This paper develops an econometric model of natural gas supply at the state-level using New Mexico as a case study. The supply model is estimated using annual time series observations on production levels, delivered prices, proved reserves, existing wells, and extraction costs. The authors validate the model against historical data and then use it to consider the fiscal impacts on state tax revenue from innovations in extraction technologies

  12. Reproductive traits of tropical deep-water pandalid shrimps ( Heterocarpus ensifer) from the SW Gulf of Mexico

    Science.gov (United States)

    Briones-Fourzán, Patricia; Barradas-Ortíz, Cecilia; Negrete-Soto, Fernando; Lozano-Álvarez, Enrique

    2010-08-01

    Heterocarpus ensifer is a tropical deep-water pandalid shrimp whose reproductive features are poorly known. We examined reproductive traits of a population of H. ensifer inhabiting the continental slope (311-715 m in depth) off the Yucatan Peninsula, Mexico (SW Gulf of Mexico). Size range of the total sample ( n=816) was 10.4-38.9 mm carapace length. Females grow larger than males, but both sexes mature at 57% of their maximum theoretical size and at ˜30% of their total lifespan. Among adult females, the proportion of ovigerous females was high in all seasons, indicating year-round reproduction. Most females carrying embryos in advanced stages of development had ovaries in advanced stages of maturation, indicating production of successive spawns. In the autumn, however, the proportion of ovigerous females and the condition index of these females were lower compared to other seasons. This pattern potentially reflects a reduction in food resources following the summer minimum in particulate organic carbon flux to the deep benthos, as reported in previous studies. Spawns consisting of large numbers (16024±5644, mean±SD) of small eggs (0.045±0.009 mm 3) are consistent with extended planktotrophic larval development, an uncommon feature in deep-water carideans. Egg number increased as a power function of female size but with substantial variability, and egg size varied widely within and between females. There was no apparent trade-off between egg number and egg size and neither of these two variables was influenced by female condition. These results indicate iteroparity and a high and variable reproductive effort, reflecting a reproductive strategy developed to compensate for high larval mortality. The present study provides a baseline to compare reproductive traits between Atlantic populations of this tropical deep-water pandalid.

  13. Dengue Virus in Bats from Southeastern Mexico

    Science.gov (United States)

    Sotomayor-Bonilla, Jesús; Chaves, Andrea; Rico-Chávez, Oscar; Rostal, Melinda K.; Ojeda-Flores, Rafael; Salas-Rojas, Mónica; Aguilar-Setien, Álvaro; Ibáñez-Bernal, Sergio; Barbachano-Guerrero, Arturo; Gutiérrez-Espeleta, Gustavo; Aguilar-Faisal, J. Leopoldo; Aguirre, A. Alonso; Daszak, Peter; Suzán, Gerardo

    2014-01-01

    To identify the relationship between landscape use and dengue virus (DENV) occurrence in bats, we investigated the presence of DENV from anthropogenically changed and unaltered landscapes in two Biosphere Reserves: Calakmul (Campeche) and Montes Azules (Chiapas) in southern Mexico. Spleen samples of 146 bats, belonging to 16 species, were tested for four DENV serotypes with standard reverse transcriptase polymerase chain reaction (RT-PCR) protocols. Six bats (4.1%) tested positive for DENV-2: four bats in Calakmul (two Glossophaga soricina, one Artibeus jamaicensis, and one A. lituratus) and two bats in Montes Azules (both A. lituratus). No effect of anthropogenic disturbance on the occurrence of DENV was detected; however, all three RT-PCR–positive bat species are considered abundant species in the Neotropics and well-adapted to disturbed habitats. To our knowledge, this study is the first study conducted in southeastern Mexico to identify DENV-2 in bats by a widely accepted RT-PCR protocol. The role that bats play on DENV's ecology remains undetermined. PMID:24752688

  14. Epidemiology of diabetes mellitus in Mexico.

    Science.gov (United States)

    Bello-Chavolla, Omar Y; Rojas-Martinez, Rosalba; Aguilar-Salinas, Carlos A; Hernández-Avila, Mauricio

    2017-01-01

    Type 2 diabetes is the main health problem in Mexico. The large and growing number of cases and the remarkable economic impact of the disease support this statement. The condition is expressed at an earlier age and at a lower body mass index in Mexican mestizos compared with the age and body mass index reported in Caucasians. In addition, Mexican mestizos have an increased susceptibility to developing diabetic nephropathy. The Mexican health system needs major adjustments in order to prevent and treat type 2 diabetes. Treatment is not currently based on the needs and expectations of the patient. As a result, it is insufficient, belated, and costly. Close to 20% of the preventable deaths in Mexico are caused by diabetes and related metabolic diseases. Even a small decrease in this rate could result in substantial savings for the Mexican healthcare system. © The Author(s) 2016. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Governability in Contemporary Mexico

    Directory of Open Access Journals (Sweden)

    Leonardo Curzio Gutiérrez

    1998-04-01

    Full Text Available Given the difficulties to establish a concept of governability and the frequent ideological usage of the term, it is much more operative to turn to the principle of governability, in the broad sense, which supports itself on five pillars: the political legitimacy of the government, the governmental efficiency to attend to the demands of society, the existence of shared social project, the agreement with the principle special interest groups, and international viability. The analysis of the structure and relevance of these five points during the long period of political transition that Mexico underwent between 1988 and 1997 shows how it was possible for this country to play off certain factors against each other in order to secure governability and safeguard against the consequences of any resultant imbalances. Between 1998-1993, the government of Salinas de Gotari based itself on the viability of a neoliberal project within an international context, and on this projectís attention to domestic demands as well as on the governmentís pact with elites. Institutional integration and legitimacy made up, then, for a process of discreet liberalization and the lack of democratic electoral commitment, which culminated in the PRI’s 1994 elections victory.The assassination of Colosia, though, and the appearance of the EZLN and the subsequent crisis surrounding the peso’s devaluation that accompanied Ernesto Zedilloís rise to power soon led to the collapse of those pillars of support. Crowning the process of the silenttransition were the elections of 1997, which makes it possible to say that in Mexico today there are now smooth elections, but that reform of the State is still unresolved —a subject that includes the reduction of the president’s competence. Seen in the short term, the most direct threats to Mexico’s governability will come as a result of the lack of attention to those demands of society’s underprivileged and the ill

  16. Consequences of Chixculub Impact for the Tectonic and Geodynamic Evolution of the Gulf of Mexico North Carribean Region

    Science.gov (United States)

    Rangin, C.; Crespy, A.; Martinez-Reyes, J.

    2013-05-01

    The debate for Pacific exotic origin versus in situ inter American plate Atlantic origin of the Caribbean plate is active in the scientific community since decades. Independently of the origin of this plate, its fast motion towards the east at a present rate of 2cm/yr is accepted to have been initiated during the early-most Cenozoic. The Paleocene is a key period in the global evolution of Central America mainly marked also by the Chicxulub multiring meteor impact in Yucatan. We question here the genetic relationship between this impact event and the incipient tectonic escape of the Caribbean plate. The mostly recent published models suggest this impact has affected the whole crust down to the Moho, the upper mantle being rapidly and considerably uplifted. The crust was then fragmented 600km at least from the point of impact, and large circular depressions were rapidly filled by clastic sediments from Cantarell to Western Cuba via Chiapas and Belize. North of the impact, the whole Gulf of Mexico was affected by mass gravity sliding, initiated also during the Paleocene in Texas, remaining active in this basin up to present time. South of the impact, in the Caribbean plate, the Yucatan basin was rapidly opened, indicating a fast escape of the crustal material towards the unique free boundary, the paleo-Antilles subduction zone. Shear waves velocity data below the Caribbean plate suggest this crustal tectonic escape was enhanced by the fast eastward flowing mantle supporting a fragmented and stretched crust. The proposed model suggests Chicxulub impact (but also the hypothetic Beata impact) have fragmented brittle crust, then easily drifted towards the east. This could explain the Paleogene evolution of the Caribbean plate largely stretched during its early evolution. Geologically, this evolution could explain the absence of evident Paleogene oblique subduction along the Caribbean plate northern and southern margins, marked only by Mid Cretaceous dragged volcanic

  17. Demand Response Spinning Reserve Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H.; Nelson-Hoffman, Janine; Torres, Carlos; Hirth,Scott; Yinger, Bob; Kueck, John; Kirby, Brendan; Bernier, Clark; Wright,Roger; Barat, A.; Watson, David S.

    2007-05-01

    The Demand Response Spinning Reserve project is a pioneeringdemonstration of how existing utility load-management assets can providean important electricity system reliability resource known as spinningreserve. Using aggregated demand-side resources to provide spinningreserve will give grid operators at the California Independent SystemOperator (CAISO) and Southern California Edison (SCE) a powerful, newtool to improve system reliability, prevent rolling blackouts, and lowersystem operating costs.

  18. Gas reserves, discoveries and production

    International Nuclear Information System (INIS)

    Saniere, A.

    2006-01-01

    Between 2000 and 2004, new discoveries, located mostly in the Asia/Pacific region, permitted a 71% produced reserve replacement rate. The Middle East and the offshore sector represent a growing proportion of world gas production Non-conventional gas resources are substantial but are not exploited to any significant extent, except in the United States, where they account for 30% of U.S. gas production. (author)

  19. Uranium reserves and exploration activity

    International Nuclear Information System (INIS)

    Meehan, R.J.

    1975-01-01

    The strategy that ERDA plans to employ regarding resource appraisal is outlined. All types of uranium occurrences will be evaluated as sources of domestic ore reserves. Industry's exploration efforts will be compiled. These data will include information on land acquisition and costs, footage drilled and costs, estimates of exploration activities and expenditures, exploration for non-sandstone deposits, exploration in non-established areas, and foreign exploration plans and costs. Typical data in each of these areas are given

  20. Federal reservation of geothermal resources

    Energy Technology Data Exchange (ETDEWEB)

    Silver, R.M.

    1978-01-01

    Union Oil had developed or was seeking to develop wells on the land in Sonoma County, California in order to produce geothermal steam for generating electricity. The US Attorney General brought a quiet title action pursuant to 21(b) of the Geothermal Steam Act of 1970 to determine whether geothermal resources are included in the mineral reservation under the Homestead Act. The US District Court granted Union Oil's motion to dismiss for failure to state a claim upon which relief may be granted. On appeal, the Ninth Circuit reversed and remanded. In summary, the court concluded on the basis of the legislative history of the Stock-Raising Homestead Act that sources of energy are intended to remain in the government's possession, and the purposes of the Act will be best served by including geothermal resources in the reservation of mineral interests. Noting the strictly agricultural purpose of the Act, the subsurface estate reservation was broadly interpreted, even though title passed to all rights that were not expressly reserved. The court left open on remand the question of estoppel of the government from interfering with private lessees by developing subsurface resources compensation.This is a unique and intriguing decision, as it opens wide the definition of ''mineral interest,'' construing it in the timely terms of a valuable natural resource that may be in great demand for future energy needs. The decision is being appealed to the United States Supreme Court, and it will be interesting to observe whether this liberal interpretation of mineral interests will be upheld.

  1. Ultrasound in evaluating ovarian reserve

    Directory of Open Access Journals (Sweden)

    Eman Ahmaed Shawky Sabek

    2015-12-01

    Full Text Available The objective of this study was to compare the diagnostic accuracy of transvaginal ultrasound (TVS, as a less invasive technique instead of hormonal assay to evaluate the ovarian reserve. This study included fifty-five females with breast cancer and we compared the ovarian reserve for these patients by hormonal assay through measuring the serum AntiMullerian Hormone (AMH level and follicular stimulating hormone (FSH level before and after chemotherapy, and by transvaginal ultrasound through the ovarian volume (OV calculation and counting the Antral follicles (AFC before and after chemotherapy treatment. There was decline in the AntiMullerian Hormone level after chemotherapy by 27 ± 11.19% and decrease in the Antral follicle counts by 21 ± 13.43%. In conclusion there was strong relation between AMH level and AFC which makes the use of transvaginal ultrasound is a reliable alternative method to the hormonal assay to detect the ovarian reserve.

  2. 75 FR 28555 - Executive Green ICT & Energy Efficiency Trade Mission to Mexico City, Mexico

    Science.gov (United States)

    2010-05-21

    ... Trade Mission to Mexico City, Mexico AGENCY: International Trade Administration, Department of Commerce... Trade Mission to Mexico City from September 27-29, 2010. This Executive led mission will focus on... & Energy Efficiency conference will take place at the World Trade Center in Mexico City. Relevant issues on...

  3. The genus Clathria from the Gulf of Mexico and Mexican Caribbean, with redescription and resurrection of Clathria carteri (Poecilosclerida: Microcionidae).

    Science.gov (United States)

    Gómez, Patricia

    2014-04-16

    The present study deals with the morphologic variability of eight Clathria species from the southern Gulf of Mexico and Mexican Caribbean. Clathria (Clathria) foliacea, C. (C.) carteri, C. (Microciona) calla, C. (M.) echinata, C. (M.) spinosa, C. (Thalysias.) venosa, and C. (T.) virgultosa were collected by scuba diving and dredging from the southern Gulf of Mexico (Veracruz, Campeche Bank, Yucatan) to the Caribbean coast (Quintana Roo) from shoreline to 120 m depth. The population of Clathria seems to be neither abundant nor diverse in the studied area. However, the seven species considered here are presumed to have a slight morphologic variability, and the interspecific relationships had not been fully resolved. The present study focuses on their differentiation through comparison of external morphology, skeletal architecture, spiculation and measurements of characters as well as scanning electronic microscopy.    Comparisons were made among intra- and interspecific material and with the available type material. In particular, C. carteri Topsent (1889), previously synonymized with C. foliacea, is resurrected by establishing a neotype from material from the type locality, Campeche Bank; this has not been studied since its original description and is here redescribed for the first time. Another neotype is assigned for C. foliacea from Campeche also, since the original material is no longer available, and this species is redescribed also. Significant differences in spiculation between C. foliacea and C. carteri were found by one-way ANOVA. Although C. (T.) venosa resembles C. (T.) raraechelae in spiculation, these two species differ in measurements and skeletal organization. C. (T.) virgultosa is typified by a peculiar acanthostyle that is markedly spined on distal parts of the shaft, and by two types of tiny microscleres. This study has extended the known geographic distribution of each of these Clathria spp. within the lower Gulf of Mexico.

  4. Mexico's critical choices

    International Nuclear Information System (INIS)

    Marcos, E.

    1990-01-01

    In Mexico, the 1982 fall in international oil prices shook the national conscience and pushed the Mexican people in search of a new national image and toward the choices they must make to attain that image. But, according to the author of this paper, the country as a whole has already made critical choices for overall strategy and there are reasons for optimism. In the current economic environment of growing domestic demand and enhanced international competitiveness, the author sees PEMEX (the Mexican national oil company) facing not only the challenge of responding to the rapid changes taking place in the Mexican economy, but also making a significant contribution toward the solid and stable growth of the country. The relevant question is how PEMEX will live up to these expectations. This paper describes several steps PEMEX has taken already or is preparing to take in order to meet this challenge, including: investment in the domestic petrochemical industry; entry into the Eurobond market; development of new methods of project financing

  5. It takes two to tango: self incompatibility in the bromeliad Tillandsia streptophylla (Bromeliaceae in Mexico

    Directory of Open Access Journals (Sweden)

    Ivón M Ramírez Morillo

    2009-09-01

    Full Text Available Floral phenology and breeding system of Tillandsia streptophylla (Bromeliaceae were studied in a low inundated forest in Yucatan, Mexico. During the flowering season, from March to August, terminal scapose 1-branched, paniculate inflorescences are produced with one flower per branch opening per day, over a period of 11-29 days. Flowers are tubular, light violet, with the stigma placed below the anthers, both protruding above the corolla. Flowers are protandrous, with anthers releasing pollen from 0500 hours and stigma becoming receptive around 0900 hours. Controlled experimental crosses suggest that Tillandsia streptophylla is self incompatible and therefore, pollinator-dependent. Rev. Biol. Trop. 57 (3: 761-770. Epub 2009 September 30.Estudiamos la fenología floral y el sistema de cruzamiento de la bromelia Tillandsia streptophylla (Bromeliaceae en una selva baja inundable en Yucatán, México. Durante la estación de floración (marzo a agosto, las plantas producen una inflorescencia terminal, escaposa, paniculada, 1-dividida, con una flor abriendo por rama por día para un período de floración de 11-29 días por inflorescencia. Las flores son tubulares, de corola violeta claro, con el estigma y anteras exertos, pero las anteras más largas que el estigma en antesis. Las flores son protandras, con las anteras liberando el polen desde las 0500 horas y la receptividad del estigma comenzando a las 0900 horas. Los cruces experimentales controlados sugieren que Tillansdia streptophylla es auto incompatible y por ende, dependiente de los polinizadores.

  6. A recent perspective of the Circulation in the Gulf of Mexico

    Science.gov (United States)

    Candela, J.; Ochoa-de-La-Torre, J. L.; Sheinbaum, J.; Perez-Brunius, P.; Pallas-Sanz, E.; Kolodziejczyk, N.

    2013-05-01

    The flow through the Gulf of Mexico is an integral part of the North Atlantic Ocean Subtropical Gyre Circulation, known to be forced by the wind over the North Atlantic and by an equivalent contribution from the inter-hemispheric Meridional Overturning Cell. To the North Atlantic Circulation, the Gulf represents an important energy and vorticity sink through the particular behavior of the Loop Current within. Comprehending the structure and dynamics of the Loop Current System (which includes the Yucatan Current (YC), Loop Current (LC), the shedding of anticyclonic Loop Current Eddies (LCE) and peripheral cyclonic gyres) is fundamental for understanding the circulation in the entire Gulf. Within the Gulf, the eastern Loop Current and the western Campeche Bay (CB) regions are characterized by persistent eddy structures, with less structured eddy fields in between. Of these later ones, the northwestern Gulf is a geostrophic turbulence area, constantly perturbed by LCE, which represents, at the same time, an important dissipation and circulation forcing region for the Western Gulf. Important processes recently investigated that will be discussed: 1) The generation and maintenance of the Geostrophic Turbulence field in the north western Gulf. 2) The circulation in deep water induced by the surface geostrophic turbulence field. 3) The generation of intensive jets at depth by interaction of +/- gyres. 4) The generation of coastal trap waves by the interaction of LCEs with the western shelf. 5) The generation of deep topographic Roosby waves by topographic interactions of the LCEs with topography. 5) The characteristics of the Bay of Campeche Circulation, The Campeche Gyre and its interaction with LCEs. 6) The Gulf's response to the passage of hurricanes. 7) The trapping of inertial waves by the LCEs and the related enhanced mixing.

  7. Payments for Environmental Services in a Policymix: Spatial and Temporal Articulation in Mexico.

    Science.gov (United States)

    Ezzine-de-Blas, Driss; Dutilly, Céline; Lara-Pulido, José-Alberto; Le Velly, Gwenolé; Guevara-Sanginés, Alejando

    2016-01-01

    Government based Payments for Ecosystem Services (PES) have been criticized for not maximizing environmental effectiveness through appropriate targeting, while instead prioritizing social side-objectives. In Mexico, existing literature on how the Payments for Ecosystem Services-Hydrological program (PSA-H) has targeted deforestation and forest degradation shows that both the process of identifying the eligible areas and the choice of the selection criteria for enrolling forest parcels have been under the influence of competing agendas. In the present paper we study the influence of the PSA-H multi-level governance on the environmental effectiveness of the program-the degree to which forest at high risk of deforestation is enrolled- building from a "policyscape" framework. In particular, we combine governance analysis with two distinct applications of the policyscape framework: First, at national level we assess the functional overlap between the PSA-H and other environmental and rural programs with regard to the risk of deforestation. Second, at regional level in the states of Chiapas and Yucatan, we describe the changing policy agenda and the role of technical intermediaries in defining the temporal spatialization of the PSA-H eligible and enrolled areas with regard to key socio-economic criteria. We find that, although at national level the PSA-H program has been described as coping with both social and environmental indicators thanks to successful adaptive management, our analysis show that PSA-H is mainly found in communities where deforestation risk is low and in combination with other environmental programs (protected areas and forest management programs). Such inertia is reinforced at regional level as a result of the eligible areas' characteristics and the behaviour of technical intermediaries, which seek to minimise transaction costs and sources of uncertainty. Our project-specific analysis shows the importance of integrating the governance of a program in

  8. New Mexico HUC-10 Boundaries - 2013

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set is a complete digital hydrologic unit boundary layer to the watershed (10-digit) 10th level for the State of New Mexico. This data set consists of...

  9. New Mexico Museums and Cultural Centers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of museums and cultural centers in New Mexico, in point form, with limited attributes, compiled using...

  10. Mexico Terrain Corrected Free Air Anomalies (97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' gravity anomaly grid for Mexico, North-Central America and the Western Caribbean Sea is NOT the input data set used in the development of the MEXICO97 model....

  11. New Mexico HUC-8 Boundaries - 2013

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set is a complete digital hydrologic unit boundary layer to the Subbasin (8-digit) 8th level for the State of New Mexico. This data set consists of...

  12. HSIP Fire Stations in New Mexico

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Fire Stations in New Mexico Any location where fire fighters are stationed or based out of, or where equipment that such personnel use in carrying out their jobs is...

  13. Chikungunya fever: current status in Mexico.

    Science.gov (United States)

    Nava-Frías, Margarita; Searcy-Pavía, Ricardo Efrén; Juárez-Contreras, Carina Aurora; Valencia-Bautista, Anayeli

    Chikungunya fever is a tropical vector-borne disease that has been spreading rapidly around the world during the last 10 years, and which has been usually misdiagnosed as dengue. Nowadays, this disease is increasing in Mexico, mainly in the southern and central zones of the country, being significantly more common in women, children and young adults (28% in<20 years of age). The classical presentation includes fever, arthralgia, polyarthritis, back-pain, and skin rashes. Although symptoms and treatment are similar to those for dengue, there are key clinical features to differentiate these two diseases. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  14. Foreign Exchange Reserves: Bangladesh Perspective

    Directory of Open Access Journals (Sweden)

    Md Zahangir Alam

    2013-10-01

    Full Text Available This study is about foreign exchangereserves of Bangladesh. The mainpurpose of this study is to the influence of exchange rates on foreign exchangereserves to the Bangladesh context.  Both the primary and secondary data has been used inthis study. The primary data has been collected through a structuredquestionnaire from 50 respondents. The secondary data, namely Bangladeshforeign exchange reserves (FER, Bangladesh current account balance (CAB,Bangladesh capital andfinancial account balance (CFAB, and BDT/USD exchange rates (ER.  This study covers yearly data from July 01,1996 to June 30, 2005 and quarterly data from July 01, 2005 to June 30, 2012. Findingsof this study shows that out of the selected 16 factors affecting foreignexchange reserves, exchange rates occupy the first position, weighted averagescore (WAS being 4.56. Foreign exchange reserves (FER and current accountbalance (CAB have increased by 502.9087% and 1451.218%,whereas capital and financial account (CFAB has decreased by -649.024% on June30, 2012 compared to June 30, 1997. The influence of other factors heldconstant, as ER changes by 285.6894 units due to one unit change in FER, onaverage in the same direction which represents that ER has positive effect on theFER and this relationship is statistically significant.  62.1526 percentof the variation in FER is explained by ER. The outcomes of Breusch-Godfrey test (LM test, ARCHtest, and the Normality test are that there is a serial correlation among residuals, the variance of residuals is notconstant, and the residuals are not normally distributed.

  15. Naval Reserve Annual Operating Costs

    Science.gov (United States)

    1975-10-29

    C. c ) CPi i 0 0 00 0 le C C.C~r In 1]1 In 00 It .- I to C-38 ’U2 WIX ’W~ - m u. -C-LC m4 C v , v ul FA ?w % -D 1 o r cl jc j, II t %c oK W)i Ir of... platform programs, while Program 11 contains 26 sub-programs each having a separate Reserve program sponsor. The distribution of Program 11 resources is...a mix of specific skills required to bring an active Navy oper-Iating platform to organizational manning. Each SRU is tailored to a specific ship

  16. Subsistence fisheries in the Sierra Manantlán Biosphere Reserve (Jalisco/Colima, Mexico

    Directory of Open Access Journals (Sweden)

    Norman Mercado-Silva

    2011-01-01

    Full Text Available Las reservas de la biósfera enfrentan el doble objetivo de proteger ecosistemas ejemplares y proveer a las comunidades locales con oportunidades de desarrollo. Las pesquerías de subsistencia están presentes en muchas áreas protegidas en México, pero son poco conocidas. Los pescadores de subsistencia tienen pocas oportunidades para expresar sus opiniones acerca de la calidad de los ecosistemas de los cuales dependen para sobrevivir. Utilizamos encuestas para describir las pesquerías de subsistencia del Río Ayuquila, (Jalisco, Colima, México y documentar las perspectivas que los pescadores tienen de la calidad ambiental del río y el manejo que se le da al mismo. La pesquería de subsistencia en el Ayuquila tiene gran importancia para las comunidades rurales de la Reserva de la Biósfera Sierra de Manantlán, pero está poco organizada, y es secundaria en importancia a actividades agropecuarias en la región. La pesquería ha sido afectada por la contaminación y la sobreexplotación, pero esfuerzos realizados por la dirección de la reserva y los gobiernos locales han resultado en mejoras a lo largo del tiempo. Estas mejoras se ven reflejadas en las opiniones que los pescadores tienen acerca de la situación ambiental actual del río, y de las instituciones que se encargan de darle manejo. Describimos cómo procesos regionales han afectado al manejo que se da al río e identificamos áreas donde es posible mejorar su situación. El empoderamiento de los pescadores de subsistencia es posible a través de su participación en encuestas como las que aquí presentamos y que pueden ser utilizadas por instituciones regionales para mejorar las condiciones de vida de los pobladores y las estrategias de conservación de recursos naturales.

  17. An Evaluation of Mexico’s Declining Oil Production and Waning Petroleum Reserves

    Science.gov (United States)

    2011-03-01

    en México: Pozo de Pasiones . El Debate sobre la Propuesta de Reforma Energética” (paper presented at the Woodrow Wilson International Center for...87 Graefe, “The Policy Implications of Peak Oil,” 9. 88 Rossana Fuentes Berain, “Petreóleo en México: Pozo de Pasiones ...Petreóleo en México: Pozo de Pasiones . El Debate sobre la Propuesta de Reforma Energética,” 19. 112 Ibid., 14. 113 Lourdes Melgar, “Energy Transition

  18. Outcrop Gamma-ray Analysis of the Cretaceous mesaverde Group: Jicarilla Apache Indian Reservation, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ridgley, Jennie; Dunbar, Robyn Wright

    2001-04-25

    This report presents the results of an outcrop gamma-ray survey of six selected measured sections included in the original report. The primary objective of this second study is to provide a baseline to correlate from the outcrop and reservoir model into Mesaverde strata in the San Juan Basin subsurface. Outcrop logs were generated using a GAD-6 gamma-ray spectrometer that simultaneously recorded total counts, potassium, uranium, and thorium data.

  19. Using basal area to estimate aboveground carbon stocks in forests: La Primavera Biosphere's Reserve, Mexico

    NARCIS (Netherlands)

    Balderas Torres, Arturo; Lovett, Jonathan Cranidge

    2012-01-01

    Increasing use of woody plants for greenhouse gas mitigation has led to demand for rapid, cost-effective estimation of forest carbon stocks. Bole diameter is readily measured and basal area can be correlated to biomass and carbon through application of allometric equations. We explore different

  20. Working without a Union in New Mexico

    Science.gov (United States)

    Adele, Niame; Rack, Christine

    2008-01-01

    In this article, the authors provide a description of the academic climate in New Mexico. Like many other places in the world today, New Mexico is trying to find an identity in an environment that the authors label "increasingly privatized, corporatized, and militarized." New Mexico's higher education salaries are lower than those in…

  1. New Mexico Charter Schools Annual Report

    Science.gov (United States)

    New Mexico Public Education Department, 2013

    2013-01-01

    In 2011, the New Mexico legislature passed changes to the Charter School Act that provided more accountability for both charters and authorizers in New Mexico. As part of that law, the Public Education Department (PED) is asked to submit an annual report on the status of charter schools in New Mexico. This is the first report submitted under that…

  2. 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

  3. Digital Geologic Map of New Mexico - Formations

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The geologic map was created in GSMAP at Socorro, New Mexico by Orin Anderson and Glen Jones and published as the Geologic Map of New Mexico 1:500,000 in GSMAP...

  4. CERN servers go to Mexico

    CERN Multimedia

    Stefania Pandolfi

    2015-01-01

    On Wednesday, 26 August, 384 servers from the CERN Computing Centre were donated to the Faculty of Science in Physics and Mathematics (FCFM) and the Mesoamerican Centre for Theoretical Physics (MCTP) at the University of Chiapas, Mexico.   CERN’s Director-General, Rolf Heuer, met the Mexican representatives in an official ceremony in Building 133, where the servers were prepared for shipment. From left to right: Frédéric Hemmer, CERN IT Department Head; Raúl Heredia Acosta, Deputy Permanent Representative of Mexico to the United Nations and International Organizations in Geneva; Jorge Castro-Valle Kuehne, Ambassador of Mexico to the Swiss Confederation and the Principality of Liechtenstein; Rolf Heuer, CERN Director-General; Luis Roberto Flores Castillo, President of the Swiss Chapter of the Global Network of Qualified Mexicans Abroad; Virginia Romero Tellez, Coordinator of Institutional Relations of the Swiss Chapter of the Global Network of Qualified Me...

  5. Health technology assessment in Mexico.

    Science.gov (United States)

    Gómez-Dantés, Octavio; Frenk, Julio

    2009-07-01

    The history of health technology assessment (HTA) in Mexico is examined, starting with the efforts to incorporate this topic into the policy agenda and culminating with the recent creation of a specialized public agency. Information was gathered through a bibliographic search and interviews with actors involved in HTA in Mexico. HTA efforts were developed in Mexico since the mid-1980s with the participation both of academics and of policy makers, a relationship that eventually led to the creation of the Center for Technological Excellence within the Ministry of Health. Institutionalization of HTA in resource-constrained settings requires the development of a critical mass of researchers involved in this field, the implementation of information efforts, and the establishment of strong relationships between HTA experts and policy makers.

  6. Country watch: Mexico.

    Science.gov (United States)

    San Miguel Aguirre, E

    1997-01-01

    This article describes the program activities of the Mexican National Commission on Human Rights (CNDH), which in 1994 created a program to address human rights issues of HIV-infected victims. The aim was to answer complaints of discrimination against HIV-infected persons and to modify confrontational attitudes of groups that feel infringed upon by the rights of HIV-infected persons. CNDH formed a task force of HIV/AIDS medical experts, which recommended actions for three types of discriminatory practices. Persons with HIV/AIDS (PWHA) who were confined in prison filed complaints about the lack of necessary medications or medical attention. The Official Mexican Norm for the Prevention and Control of HIV stipulates, in its Manual for the Attention of Complaints Regarding HIV/AIDS, protocols for treatment of PWHA. This manual was distributed to 31 State Human Rights Commissions in Mexico. CNDH implemented an outreach program to educate the public about HIV/AIDS, to offer training courses, and to publish written materials about discrimination against PWHA. The CNDH conducted conferences and training sessions for workers in the health services, where most violations of human rights take place. CNDH works closely with the National Board for the Prevention and Control of AIDS to assess clinical records, train staff handling complaints, and channel complaints that require CNDH intervention. CNDH conducts training workshops for nongovernmental organizations. CNDH is constrained by bureaucratic procedures that slow the process of resolving complaints and by the small CNDH staff responsible for handling the more complex cases. However, CNDH has successfully resolved a number of complaints and improved the prison conditions of PWHA.

  7. Designing Distributed Generation in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Linvill, Carl [Regulatory Assistance Project, Montepelier, VT (United States); Brutkoski, Donna [Regulatory Assistance Project, Montepelier, VT (United States)

    2017-05-15

    Mexico's energy reform will have far-reaching effects on how people produce and consume electricity in the country. Market liberalization will open the door to an increasing number of options for Mexican residential, commercial, and industrial consumers, and distributed generation (DG), which for Mexico includes generators of less than 500 kilowatts (kW) of capacity connected to the distribution network. Distributed generation is an option for consumers who want to produce their own electricity and provide electricity services to others. This report seeks to provide guidance to Mexican officials on designing DG economic and regulatory policies.

  8. New Mexico Geothermal Data Base

    International Nuclear Information System (INIS)

    Witcher, J.C.; Whittier, J.; Morgan, R.

    1990-01-01

    This paper reports on the New Mexico Geothermal Data Base (NMGDB) which is a comprehensive public-domain data base of low-temperature geothermal resource information for New Mexico that is designed to assist researchers and developers. A broad range of geoscience, engineering, climatic, economic, and land status information are complied in the dBASE III PLUS data base management system for use on an IBM or IBM-compatible personal computer. A user friendly menu format with on-screen prompts allows easy and convenient use

  9. A Century in Reserve and Beyond

    National Research Council Canada - National Science Library

    Monagle, James P

    2008-01-01

    ... Reserve, this Strategy Research Project (SRP) describes the role of the Army Reserve from its beginning as a reserve corps of medical doctors to that of a strategic reserve force, and then to its current operational role...

  10. Environmental Assessment Reserve Military Operations Area

    Science.gov (United States)

    1989-12-01

    Control of Vibrations Caused by Blasting. Laboratorio National De Engenharia Civil, Lisboa, Portugal. Memoria 498. 11 p. Federal Air Quality Control...and FHP- 42-1(102) in Largo Creek Valley, Catron County, New Mexico, Gila National Forest. Laboratory of Anthropology Notes No. 144. Museum of New

  11. Las Tierras de Nuevo Mexico. [The Lands of New Mexico.

    Science.gov (United States)

    Swadesh, Frances Leon; And Others

    New Mexico was inhabited thousands of years ago. Each group of settlers saw the land in distinct ways. For some, its beauty consisted of its quality, the abundance of water, and the hope of a good harvest. For others, its beautiful sites were of more importance. Thus, each group established its own manner of living on the land and of using it.…

  12. Opportunity for America: Mexico`s coal future

    Energy Technology Data Exchange (ETDEWEB)

    Loose, V.W.

    1993-09-01

    This study examines the history, current status and future prospects for increased coal use in Mexico. Environmental implications of the power-generation capacity expansion plans are examined in general terms. Mexican environmental law and regulations are briefly reviewed along with the new sense of urgency in the cleanup of existing environmental problems and avoidance of new problems as clearly mandated in recent Mexican government policy initiatives. It is expected that new capital facilities will need to incorporate the latest in process and technology to comply with existing environmental regulation. Technology developments which address these issues are identified. What opportunities have new initiatives caused by the recent diversification of Mexico`s energy economy offered US firms? This report looks at the potential future use of coal in the Mexican energy economy, examining this issue with an eye toward identifying markets that might be available to US coal producers and the best way to approach them. Market opportunities are identified by examining new developments in the Mexican economy generally and the energy economy particularly. These developments are examined in light of the current situation and the history which brought Mexico to its present status.

  13. Deep-water northern Gulf of Mexico hydrocarbon plays

    International Nuclear Information System (INIS)

    Peterson, R.H.; Cooke, D.W.

    1995-01-01

    The geologic setting in the deep-water (depths greater than 1,500 feet) Gulf of Mexico is very favorable for the existence of large, commercial hydrocarbon accumulations. These areas have active salt tectonics that create abundant traps, underlying mature Mesozoic source rocks that can be observed expelling oil and gas to the ocean surface, and good quality reservoirs provided by turbidite sand deposits. Despite the limited amount of drilling in the deep-water Gulf of Mexico, 11 deep-water accumulations have been discovered which, when developed, will rank in the top 100 largest fields in the Gulf of Mexico. Proved field discoveries (those with announced development plans) have added over 1 billion barrels of oil equivalent to Gulf of Mexico reserves, and unproved field discoveries may add to additional billion barrels of oil equivalent. The Minerals Management Service, United States Department of the Interior, has completed a gulf-wide review of over 1,086 oil and gas fields and placed every pay sand in each field into a hydrocarbon play (plays are defined by chronostratigraphy, lithostratigraph, structure, and production). Seven productive hydrocarbon plays were identified in the deep-water northern Gulf of Mexico. Regional maps illustrate the productive limits of each play. In addition, field data, dry holes, and wells with sub-economic pay were added to define the facies and structural limits for each play. Areas for exploration potential are identified for each hydrocarbon play. A type field for each play is chosen to demonstrate the play's characteristics

  14. Emerging patterns of crack use in Mexico City.

    Science.gov (United States)

    Valdez, Avelardo; Kaplan, Charles; Nowotny, Kathryn M; Natera-Rey, Guillermina; Cepeda, Alice

    2015-08-01

    Recent studies in Mexico have documented a significant increase in crack cocaine use, indicating the potential for an emerging drug epidemic. Ethnographic observations and interviews were used describe the profiles and patterns of use among street-recruited crack users in Mexico City. The data came from an international research collaboration funded by the National Institutes of Health. A polythetic typology was developed based on five dimensions central to categorizing patterns of crack use behavior: frequency of use, duration of use, context, social networks, and social contracts. Four types of users were discovered applying these dimensions: dabblers, stable users, crack heads, and old heads. Although several similarities were documented between patterns of crack use in Mexico and those in the United States and Western Europe, several key aspects distinguished crack users in this population: (1) self-regulated use; (2) non-linear progression of crack; and (3) the influence of the dimensions pertaining to setting, social networks, and social contract as contributing to understanding of the previous two. Further, we provide a discussion of how specific contextual factors in Mexico may be giving rise to these emerging patterns. Compared to the U.S. and Europe, this study finds that the majority of crack users were able to self-regulate their use without major disruption to daily social functioning. As crack use spreads in Mexico and other Latin American countries, we need to recognize the importance of social context in developing more tailored health and social responses that are specific to these developing countries. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Use of medicinal plants by health professionals in Mexico.

    Science.gov (United States)

    Alonso-Castro, Angel Josabad; Domínguez, Fabiola; Maldonado-Miranda, Juan José; Castillo-Pérez, Luis Jesús; Carranza-Álvarez, Candy; Solano, Eloy; Isiordia-Espinoza, Mario Alberto; Del Carmen Juárez-Vázquez, María; Zapata-Morales, Juan Ramón; Argueta-Fuertes, Marco Antonio; Ruiz-Padilla, Alan Joel; Solorio-Alvarado, César Rogelio; Rangel-Velázquez, Joceline Estefanía; Ortiz-Andrade, Rolffy; González-Sánchez, Ignacio; Cruz-Jiménez, Gustavo; Orozco-Castellanos, Luis Manuel

    2017-02-23

    The use of medicinal plants in Mexico has been documented since pre-Hispanic times. Nevertheless, the level of use of medicinal plants by health professionals in Mexico remains to be explored. To evaluate the use, acceptance and prescription of medicinal plants by health professionals in 9 of the states of Mexico. Direct and indirect interviews, regarding the use and acceptance of medicinal plants, with health professionals (n=1614), including nurses, physicians, pharmacists, and odontologists from nine states in Mexico were performed from January 2015 to July 2016. The interviews were analyzed with the factor the informant consensus (FIC). The information obtained indicated that 46% of those interviewed feel patients should not use medicinal plants as an alternative therapy. Moreover, 54% of health professionals, and 49% of the physicians have used medicinal plants as an alternative therapy for several diseases. Twenty eight percent of health professionals, and 26% of the physicians, have recommended or prescribed medicinal plants to their patients, whereas 73% of health professionals were in agreement with receiving academic information regarding the use and prescription of medicinal plants. A total of 77 plant species used for medicinal purposes, belonging to 40 botanical families were reported by the interviewed. The results of the FIC showed that the categories of diseases of the digestive system (FIC=0.901) and diseases of the respiratory system (FIC=0.898) had the greatest agreement. This study shows that medicinal plants are used for primary health care in Mexico by health professionals. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  16. Time-course changes in circulating branched-chain amino acid levels and metabolism in obese Yucatan minipig.

    Science.gov (United States)

    Polakof, Sergio; Rémond, Didier; David, Jérémie; Dardevet, Dominique; Savary-Auzeloux, Isabelle

    2018-06-01

    High-fat high-sucrose diet (HFHS) overfeeding is one of the main factors responsible for the increased prevalence of metabolic disorders. Elevated levels of branched-chain amino acids (BCAAs) have been associated with metabolic dysfunctions, including insulin resistance (IR). The aim of this study was to elucidate whether elevated BCAA levels are the cause or the consequence of IR and to determine the mechanisms and tissues involved in such a phenotype. We performed a 2-mo follow-up on minipigs overfed an HFHS diet and focused on kinetics fasting and postprandial (PP) BCAA levels and BCAA catabolism in key tissues. The study of the fasting BCAA elevation reveals that BCAA accumulation in the plasma compartment is well correlated with IR markers and body weight. Furthermore, the PP excursion of BCAA levels after the last HFHS meal was exacerbated when compared with that of the first meal, suggesting a reduced amino acid oxidation potential. Although only minor changes in BCAA metabolism were observed in liver, muscle, and the visceral adipose tissue, the oxidative deamination potential of the subcutaneous adipose tissue was blunted after 60 d of HFHS feeding. To our knowledge, the present results demonstrated for the first time in a swine model of obesity and IR, the existence of a phenotype related to high-circulating BCAA levels and metabolic dysregulation. The oxidative BCAA capacity reduction specifically in the subcutaneous adipose tissue emerges, at least in the present swine model, as the more plausible metabolic explanation for the elevated blood BCAA phenotype. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Juvenile Justice in Mexico

    Directory of Open Access Journals (Sweden)

    Martha Frías Armenta

    2014-08-01

    Full Text Available The first tribunal in Mexico was established in the central state of San Luis Potosi in 1926. The Law Regarding Social Prevention and Juvenile Delinquency for the Federal District and Mexican territories was promulgated in 1928. In 2005, Article 18 of the Mexican Constitution was modified to establish a comprehensive system (“Sistema Integral de justicia” in Spanish of justice for juveniles between 12 and 18 years old who had committed a crime punishable under criminal law. Its objective was to guarantee juveniles all the due process rights established for adults, in addition to the special ones recognized for minors. The constitutional reform also provides a framework that includes special tribunals as well as alternative justice options for juveniles. With these reforms, institutionalization of minors was to be considered an extreme measure applicable only to felonies and to juveniles older than 14. In 2006, all states within the Mexican federation enacted the “Law of justice for adolescents”. This system, at both the federal and state levels, formalizes a new global paradigm with regard to the triangular relationship between children, the State and the Law. It recognizes that children are also bearers of the inherent human rights recognized for all individuals, instead of simply objects in need of protection. However, despite formally aligning Mexican juvenile justice law with the Convention on the Rights of the Child (CRC, issues of actual substantive rights remained and new ones have appeared. For example, juveniles younger than 14 who have not committed a felony are released from institutions without any rehabilitation or treatment options, and alternative forms of justice were included without evaluating their possibilities of application or their conditions for success. In addition, the economic status of most juvenile detainees continues to be one of the most important determining factors in the administration of justice

  18. Radioactive waste management in Mexico

    International Nuclear Information System (INIS)

    Paredes, L.; Reyes L, J.; Jimenez D, J.

    2000-01-01

    This paper describes the radioactive waste management in Mexico, particularly the activities that the National Institute of Nuclear Research (NINR) is undertaking in this field. Classification and annual generation of radioactive waste, together with practices and facilities relating to the management of radioactive waste are addressed. The respective national legal framework and policy are outlined. (author)

  19. Shell Trumpets from Western Mexico

    Directory of Open Access Journals (Sweden)

    Robert Novella

    1991-11-01

    Full Text Available Marine shells have been used as musical instruments in almost all parts of the world (Izikowitz 1935, including Mesoamerica, where large univalves, also called conch shells in the literature, had a utilitarian function as trumpets. Their use is well documented in most cultural areas of Mesoamerica, as in Western Mexico, through their various occurrences in archaeological contexts and museums collections.

  20. Pemex and Mexico's mixed emotions

    International Nuclear Information System (INIS)

    Dombey, D.

    1997-01-01

    Pemex, Mexico's state owned oil company, has long been a byword for overmanning, inefficiency, disregard for the environment and for having all the ills of state incorporation, with few of the benefits. Matters, however, are changing. Pemex wants to be normal. (author)